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<comments>
  <row Id="1" PostId="19" Text="Yeah, had old steppers going with the op-amp, but brushless seemed to give unreliable glitches compared to the stepper." CreationDate="2009-10-30T20:54:56.490" UserId="24" />
  <row Id="2" PostId="19" Text="You need to make sure you are connecting directly to the leads of the motor and have cut any and all the other circuitry out of the way. The motor I used had a number of hall effect sensors and such mounted internally. I opened it up and just unsoldered them before attaching the motor to the op-amp circuit." CreationDate="2009-10-30T21:18:38.370" UserId="12" />
  <row Id="3" PostId="46" Text="oh wow, I thought it was way more expensive than that.  Can you solder to it?" CreationDate="2009-10-31T00:43:32.450" UserId="24" />
  <row Id="4" PostId="46" Score="2" Text="Most conductive threads can not be soldered to. Instead connections are made by tying them to components. Instead you sew the thread around the components to make a connection. See this instructable for the general idea: http://www.instructables.com/id/STN40TRFMMCYRFD" CreationDate="2009-11-01T02:25:40.513" UserId="26" />
  <row Id="5" PostId="46" Score="1" Text="I just came across another method that claims to work really well, where you get metal beads (at a bead / craft store) and crimp them to the thread. Then solder the bead. Found here: http://www.kobakant.at/DIY/?p=1720" CreationDate="2009-11-01T03:32:25.220" UserId="26" />
  <row Id="6" PostId="92" Text="+1 - Excellent question" CreationDate="2009-11-01T04:30:52.943" UserId="106" />
  <row Id="7" PostId="121" Text="That sounds like it could be exactly what I'm after for the locking mechanism, thanks!" CreationDate="2009-11-02T00:45:44.530" UserId="117" />
  <row Id="8" PostId="120" Text="That's a pretty good idea, using and old CD drive. I think I have one or two of those laying around!" CreationDate="2009-11-02T00:46:57.270" UserId="117" />
  <row Id="9" PostId="120" Text="Not the first time a CD drive has been used as part of an access control system either, now that I think of it! http://thedailywtf.com/Articles/Open-Sesame.aspx" CreationDate="2009-11-02T04:51:03.160" UserId="117" />
  <row Id="10" PostId="120" Text="ya CD drives are really useful and easy to use all you need is a motor driver. Its a great way to get linear motion without building a gear system or by a linear actuator." CreationDate="2009-11-02T05:14:26.827" UserId="81" />
  <row Id="11" PostId="120" Text="Also you said something about and ID-2 with a custom antenna. Im using an id-12 and its range is only about 4 inches, but what if you used an ID-2 and ran its antenna around the outer perimeter of the door? That way as the animals will pass right through the antennae." CreationDate="2009-11-02T05:20:02.383" UserId="81" />
  <row Id="12" PostId="122" Text="Unfortunately if you look at the colours I listed above there are no Gold or Silver bands. Would red being the thickest band (most of the others are the same-ish size) signify it as the temperature band?" CreationDate="2009-11-02T09:25:41.357" UserId="103" />
  <row Id="13" PostId="123" Text="Cheers, I think I may print out this picture to keep next to my work area." CreationDate="2009-11-02T09:31:54.683" UserId="103" />
  <row Id="14" PostId="136" Text="I didn't outline a specific project because I wanted to get all types of suggestions. This is an interesting one I hadn't thought of, hacking a wifi router itself. However it's not quite what I want for my specific project, since it is much larger and uses more power than something designed for mobile applications. To be fair, a router itself has much more processing power than the two options I listed." CreationDate="2009-11-02T17:55:15.547" UserId="131" />
  <row Id="15" PostId="169" Text="thank you very much." CreationDate="2009-11-03T03:45:54.210" UserId="81" />
  <row Id="16" PostId="175" Score="1" Text="Unfortunately you need to be part of the &quot;Made for iPhone&quot; Program to use it!&#xA;&#xA;Cheers, &#xA;&#xA;Marcus" CreationDate="2009-11-03T10:45:12.007" UserId="3" />
  <row Id="17" PostId="140" Score="2" Text="Excellent points - and you are correct that I (incorrectly) assumed an Arduino in the mix. =)&#xA;&#xA;!c" CreationDate="2009-11-03T17:49:47.643" UserId="36" />
  <row Id="18" PostId="72" Text="Wow this is excellent! Nice write up, code, and breadboard layout in fritzing." CreationDate="2009-11-03T20:08:11.383" UserId="12" />
  <row Id="19" PostId="187" Text="Yep that's perfect!&#xA;&#xA;I also found this one which has a nice bit of explanation of what it all means  :) &#xA;&#xA;http://www.workhouse.dk/br/sobre/about-me/servo-size-calculator/" CreationDate="2009-11-03T22:43:21.957" UserId="21" />
  <row Id="20" PostId="182" Text="Not sure how ZigBee would work for this. Looking at http://en.wikipedia.org/wiki/ZigBee the range is 10m or more, which is probably a bit far away (really want a range more in the 1m mark), unless ZigBee transmitters can detect their range from each other?" CreationDate="2009-11-03T22:50:58.240" UserId="117" />
  <row Id="21" PostId="187" Text="There's some explanation here too (I think it may be the same) http://www.csd.net/~cgadd/eflight/calcs_servo.htm . What is Servo Torque anyway, something to do with flaps on Radio Controlled aircraft?" CreationDate="2009-11-03T22:53:15.080" UserId="103" />
  <row Id="22" PostId="151" Text="Also, the ATMega168 has a maximum current of 200mA through the Vcc and Gnd pins (each), so driving or sinking more than ten LEDs through an Arduino is also probably a bad idea (given the common current of 20mA used to light LEDs)." CreationDate="2009-11-04T21:12:23.557" UserId="11" />
  <row Id="23" PostId="194" Text="Looks interesting...what's the difference between Lantronix Matchport and WiPort?" CreationDate="2009-11-04T21:59:54.403" UserId="131" />
  <row Id="24" PostId="201" Text="Any joy with it?" CreationDate="2009-11-05T15:10:42.447" UserId="103" />
  <row Id="25" PostId="37" Score="1" Text="The upgrade went without a hitch!  I realized I had Arduino 12 installed, however, so I had to change things up a bit:&#xA;&#xA;-Upgraded Arduino software to version 17 (most recent).&#xA;-Set up software to work with the current chip (the 168).  Verified that communications were working.*&#xA;-Upgraded the Arduino hardware to an ATMega328p with the Arduino bootloader previously flashed (from Sparkfun).&#xA;-Verified the software and hardware still played together nicely.&#xA;&#xA;*The communication worked, but my software ran out of RAM.  I only wanted to verify communication, so I wasn't concerned by this." CreationDate="2009-11-06T14:55:30.600" UserId="11" />
  <row Id="26" PostId="256" Text="I would +1 vote this if I had the reputation.  I agree - the first place I thought of was a local university.  I'll give it a shot." CreationDate="2009-11-06T21:55:05.593" UserId="209" />
  <row Id="27" PostId="265" Text="It never occurred to me to run the circuit at the LED's forward voltage. Unfortunately, minimum forward voltage on this attiny2313 I'm using is 2.7V, so I can't get it low enough.  " CreationDate="2009-11-07T13:46:29.537" UserId="213" />
  <row Id="28" PostId="265" Text="So where do you expect to place the diodes, I assume connected to the leds in a common anode or a common cathode configuration - in which case you will be OK." CreationDate="2009-11-07T17:49:25.427" UserId="9" />
  <row Id="29" PostId="270" Text="Immediately reaches for the scissors, tape and sandpaper to add some to my soldering station." CreationDate="2009-11-07T22:20:21.927" UserId="103" />
  <row Id="30" PostId="271" Score="1" Text="Wow. Thank you for the time that you put into such an informative answer!" CreationDate="2009-11-08T04:48:02.597" UserId="216" />
  <row Id="31" PostId="274" Text="Thank you for the link. I will surely check it out once the 'training wheels' come off :)" CreationDate="2009-11-08T05:08:51.447" UserId="216" />
  <row Id="32" PostId="265" Text="Common cathode, which sounds safe, but for what icabrindus says about temperature dependence changing how things behave." CreationDate="2009-11-08T15:44:52.427" UserId="213" />
  <row Id="33" PostId="277" Text="Ooooh.  I hadn't thought about how temperature changes things.  I'd hope it'd be pretty stable for 50-90F, but these super cheap LEDs (ledshoppe.com) don't come with a lot of specs.  The attiny2313 doesn't seem to have any output protection resistors.  I may go back to resistors for safety.  Diodes sure were handy on the breadboard, though." CreationDate="2009-11-08T15:51:07.843" UserId="213" />
  <row Id="34" PostId="292" Text="Could you be a little more specific as to (1) the products you want compared, and (2) your needs?  Hint: add links, so we know which products you mean.&#xA;&#xA;It would also be nice if you created an account and used that account, instead of doing the unregistered user thang every time you have a question." CreationDate="2009-11-09T03:03:04.277" UserId="143" />
  <row Id="36" PostId="291" Text="I have Microsoft tool for free because of Dreamspark program :)" CreationDate="2009-11-09T09:00:14.720" UserId="224" />
  <row Id="37" PostId="291" Score="1" Text="Wherein you prove my point :(" CreationDate="2009-11-09T13:00:44.673" UserId="143" />
  <row Id="38" PostId="271" Score="2" Text="I'm glad to hear it.  After I wrote the answer, I thought to myself, &quot;I can't believe I just spent forty minutes answering a question on the internet!&quot;" CreationDate="2009-11-09T17:26:31.250" UserId="106" />
  <row Id="39" PostId="259" Score="1" Text="Thanks for the helpful answers everyone...I'd up-rank you, but new users have like a zillion restrictions on here." CreationDate="2009-11-09T19:26:52.520" UserId="131" />
  <row Id="40" PostId="291" Score="1" Text="If you limit yourself to Microsoft Robotics then you are restricted in the platform you can use it with, as it looks like it is tied to the .net languages. if you learn some form of Basic, C or even Assembler then with a few minor alterations you can use them on different platforms with relatively little difficulty." CreationDate="2009-11-09T21:49:20.720" UserId="103" />
  <row Id="41" PostId="305" Text="Yes - but the avr gcc compiler will program a register save/restore into the ISR won't it?" CreationDate="2009-11-10T08:35:23.950" UserId="9" />
  <row Id="42" PostId="315" Text="What an excellent overview. " CreationDate="2009-11-10T11:56:53.747" UserId="103" />
  <row Id="43" PostId="316" Text="Thanks for this info! The reason I didn't want to use a microcontroller is because I assumed it would be less power-efficient than a simpler circuit. But maybe if the amplification stage is the major power drain, the MCU would be a minor issue." CreationDate="2009-11-10T17:51:17.447" UserId="84" />
  <row Id="44" PostId="318" Text="Thanks for this info too. Wish I could accept more than one answer. The amplitude needs to be adjustable because 1) I don't know how much power I'll need and 2) conditions (e.g. temp) will probably affect the power level needed (though I could probably set it to &quot;high enough&quot; and be done). So it can be pretty coarse and maybe fixed, eventually." CreationDate="2009-11-10T17:56:40.017" UserId="84" />
  <row Id="45" PostId="311" Text="Thanks, Amos. Also helpful." CreationDate="2009-11-10T17:57:24.543" UserId="84" />
  <row Id="46" PostId="310" Score="3" Text="I'll add just a little more explanation, as requested by @Lou. My goal is to build an olive oil burner suitable for lightweight backpacking use. I don't know if this is going to work but it's an idea I want to try. This would turn olive oil into a multi-use item, burnable by me and my stove. It has higher energy content per oz than alcohol but its flash point is too low to burn as liquid at normal temps. So my idea is to vaporize it ultrasonically &amp; burn the vapor." CreationDate="2009-11-10T18:02:32.433" UserId="84" />
  <row Id="48" PostId="318" Text="@Grumdrig: This is where it's useful to answer the question yourself, mark your answer as a 'community wiki' answer, and then add in all of the good parts from the other answers.  By marking it as a community wiki answer, you let others improve the answer over time, while not taking credit for other's work." CreationDate="2009-11-10T18:37:46.300" UserId="143" />
  <row Id="49" PostId="319" Score="2" Text="Depending upon how much data you want to store, you may not need the SD card -- just store the data in the onboard EEPROM.  As an example, if you store time as minutes since start, you can span 45+ days with a 2-byte time value.  With 128 bytes of EEPROM, that's enough for 64 events.  Once you're done, just plug the device into your ISP connector and dump the EEPROM.  As for the enclosure, a simple Altoids tin works great, saving more money." CreationDate="2009-11-10T18:48:30.160" UserId="143" />
  <row Id="50" PostId="318" Score="1" Text="I agree with Craig. The thing about electronic projects like this is that the questions asked are usually not atomic, which makes it impossible to pick one answer.  Another nice feature of the community wiki is that the answer can evolve as the question evolves, and it makes it easier for people to follow the development of the project.&#xA;&#xA;If you are willing, would you post the results of your first shot with the circuit?  I'm really interested to see how well it atomizes with an ultrasonic solution, and I'm interested in the backpacking aspects.  I'll think of efficiencies while I wait." CreationDate="2009-11-10T19:17:19.667" UserId="11" />
  <row Id="51" PostId="326" Text="Wow, I think that qualifies as comprehensive." CreationDate="2009-11-10T19:20:38.050" UserId="103" />
  <row Id="52" PostId="306" Text="Paul's answer below suggests not." CreationDate="2009-11-10T19:49:17.183" UserId="103" />
  <row Id="53" PostId="318" Text="Thanks @Craig. Didn't know these meta-use subtleties; I'll accept my wikified answer in 36 hours(!) when chiphacker lets me." CreationDate="2009-11-10T20:45:02.013" UserId="84" />
  <row Id="54" PostId="318" Text="I've been playing with StackOverflow for over a year; you'll pick it up in time." CreationDate="2009-11-10T21:15:31.280" UserId="143" />
  <row Id="55" PostId="327" Text="Great. I'll be very interested to see how you get on, and videos/photos/details of your success (or catastrophic failure) will surely prove helpful." CreationDate="2009-11-10T21:24:29.060" UserId="103" />
  <row Id="56" PostId="305" Text="Maybe -- see what I added about register, stack, and RAM usage.  If you're really concerned, I'd suggest generating the assembly source (gcc -S foo.c) and examining it in detail." CreationDate="2009-11-10T21:45:27.583" UserId="143" />
  <row Id="57" PostId="331" Text="If they don't have a bootloader, what do you require to burn one in?" CreationDate="2009-11-10T23:06:58.480" UserId="103" />
  <row Id="58" PostId="326" Text="Hi Paul, I ordered and you shipped, now waiting ... (taps feet).&#xA;John." CreationDate="2009-11-10T23:12:13.080" UserId="9" />
  <row Id="59" PostId="331" Score="1" Text="You just need an AVR programmer. Either ISP (supports all AVR's) or JTAG (supports most). This could be as simple as a parallel port programmer -- build it yourself with a couple resistors and diodes...or you could order a fancy AVRISP MKII USB programmer." CreationDate="2009-11-10T23:18:12.267" UserId="131" />
  <row Id="60" PostId="314" Text="That's an odd product you're selling there...a breakout board for a breakout board?" CreationDate="2009-11-10T23:32:53.597" UserId="131" />
  <row Id="61" PostId="314" Text="Are you like a SparkFun redistributer or something? It seems like you're selling the same stuff as them but at a 20% higher price" CreationDate="2009-11-10T23:34:12.203" UserId="131" />
  <row Id="62" PostId="331" Text="Like the mega-isp?" CreationDate="2009-11-10T23:39:16.673" UserId="103" />
  <row Id="63" PostId="314" Text="Yes we are, prices are in Australian Dollars" CreationDate="2009-11-11T01:49:10.553" UserId="3" />
  <row Id="64" PostId="332" Text="This should be tagged 'electronics', which will require creating a new tag." CreationDate="2009-11-11T03:59:41.227" UserId="143" />
  <row Id="65" PostId="319" Text="THANKS for the advice." CreationDate="2009-11-11T04:28:52.620" />
  <row Id="66" PostId="332" Text="Aren't all of the questions on here technically about electronics?" CreationDate="2009-11-11T09:36:30.173" UserId="103" />
  <row Id="67" PostId="342" Text="Why not put the actual urls underneath, the main text in the style of footnotes?" CreationDate="2009-11-11T12:18:10.033" UserId="103" />
  <row Id="68" PostId="341" Text="I assume you can convert the hex to assembler though." CreationDate="2009-11-11T12:22:06.297" UserId="103" />
  <row Id="69" PostId="340" Text="You can recover the hex, and in theory you can disassemble the hex to assembly (I don't know of any toolkits that will do this for an AVR off-hand, but they probably exist).  Getting it back to the original sketch, of course, is pretty much impossible because of how compilers work.  You may be able to recover a functionally equivalent sketch, if you can find the tools to do so, but it would likely look VERY different from the original and there's no guarantee it would be able to recompile (size, memory limitations)." CreationDate="2009-11-11T14:16:58.990" UserId="11" />
  <row Id="70" PostId="341" Score="2" Text="AVRStudio includes a functional disassembler. Open the HEX file (file-&gt;open), select &quot;AVR Simulator&quot; and the correct chip, then open the disassembler (file-&gt;disassembler)." CreationDate="2009-11-11T14:36:22.203" UserId="243" />
  <row Id="71" PostId="331" Score="1" Text="mega isp is great is you already have an Ardunio with bootloader and want to load the bootloader into another chip. Also consider tinyusb (http://www.adafruit.com/index.php?main_page=product_info&amp;cPath=16&amp;products_id=46 ), connects to usb port and can program AVR chips from PC." CreationDate="2009-11-11T16:37:16.350" UserId="9" />
  <row Id="72" PostId="351" Text="Forgot to mention I run Mac. Edited the question accordingly." CreationDate="2009-11-11T19:49:58.070" UserId="94" />
  <row Id="73" PostId="351" Text="By 'PC' I mean all PC's, not just Windows-running PC's (since Apple seems to think their personal computers are not also PC's). Some of them in my list have mac software...but that's not something specifically I looked for, so it's not in the chart, sorry." CreationDate="2009-11-11T19:57:07.053" UserId="131" />
  <row Id="74" PostId="341" Text="Can you do this on non-AVR chips like Pics for instance?" CreationDate="2009-11-11T20:58:46.533" UserId="103" />
  <row Id="75" PostId="342" Text="@Amos, because the formatter does a good job of recognizing URLs in many formats, and the 'new user' filter hits on count(links) &gt; 1, regardless of their formatting.  I lost an extensive answer the first day for the same reason (I posted it and didn't see the error message)." CreationDate="2009-11-11T21:21:51.573" UserId="143" />
  <row Id="77" PostId="353" Text="Nice, that looks like it should be good. But why no Linux GUI the things written using Qt4!" CreationDate="2009-11-11T22:09:17.857" UserId="103" />
  <row Id="78" PostId="332" Text="@Amos, not really.  This question is low-level electronics ... really, how transistors work and are used.  Most of the questions here are higher level: how can put pieces together to solve a specific problem.  That's why I think it needs a specific tag." CreationDate="2009-11-11T23:51:57.213" UserId="143" />
  <row Id="79" PostId="342" Text="Right, I hadn't realised." CreationDate="2009-11-11T23:54:23.623" UserId="103" />
  <row Id="80" PostId="341" Text="Yes, MPlab includes a disassembler view in the memory window. Start a new project, import a hex file, then &quot;view-&gt;program memory&quot;, then choose &quot;symbolic&quot; or &quot;machine&quot; as the view type.&#xA;&#xA;It's also not perfect, but if you're an assembly programmer, it's usable." CreationDate="2009-11-12T00:20:04.267" UserId="243" />
  <row Id="82" PostId="365" Text="I agree (and agreed above), a one way hash would be useful and if you are programming the system then you could make the pin as long as you want eg 8 digits gives 100 000 000 combinations, which should take much longer." CreationDate="2009-11-12T11:46:15.420" UserId="103" />
  <row Id="83" PostId="358" Text="But if they have no access to your chip you don't need to encrypt the pin." CreationDate="2009-11-12T11:54:17.870" UserId="103" />
  <row Id="84" PostId="378" Text="Getting it to work inside the simulator was my initial hurdle until I worked out how to break the code apart into separate files and simply &quot;mock&quot; out some of the labels that I'd jump to in the real code. I'll post the whole thing once I'm done. Retrofitting the unit tests to the code is taking a while but it has been well worth it." CreationDate="2009-11-12T13:06:04.757" UserId="255" />
  <row Id="85" PostId="367" Score="1" Text="Using an AVR micro with a Microchip MAC/PHY?  What's next? Cats and dogs living together?  :)" CreationDate="2009-11-12T15:08:37.763" UserId="204" />
  <row Id="88" PostId="380" Text="I understand cryptography, read Bruce Schneier, and have programmed for over twenty years. I understand the real threat is just breaking the door down and walking past any sort of Arduino controller. I just can't in good conscience install it with clear text PINs in teh EEProm if it can be avoided.&#xA;Fly" CreationDate="2009-11-12T16:25:50.917" />
  <row Id="109" PostId="378" Text="Now that I've had a proper chance to look through your methodology, I think it's quite elegant. Maybe I'll have a look at avrs after Christmas, as there seems to be a lot more community based stuff around for them than for the Pics. Any ideas what a decent Linux IDE for AVR Assembler programming might be." CreationDate="2009-11-12T22:50:58.670" UserId="103" />
  <row Id="116" PostId="394" Text="all I want to do with it is to grab the info that displays on the lcd - so battery life, onboard sensor, speed...&#xA;&#xA;I guess ultimatly I would want to do some wireless controlling with it too....this may change my requirements a bit." CreationDate="2009-11-13T00:39:03.860" UserId="267" />
  <row Id="117" PostId="402" Score="1" Text="This isn't a very good way to go about it. Things like buffer chips are generally used for logic, and not for supplying power. I bet it would work, but probably not for more than something small like 50mA or whatever the limits of that particular chip." CreationDate="2009-11-13T04:41:41.557" UserId="131" />
  <row Id="122" PostId="414" Text="yes I want it to act like a normal keyboard." CreationDate="2009-11-13T05:49:26.257" UserId="245" />
  <row Id="123" PostId="378" Score="1" Text="There's a GNU tool chain that you can use in place of AVR Studio (which is Atmel's free toolset). It's probably possible to run that on Linux, but I haven't needed to." CreationDate="2009-11-13T09:44:19.790" UserId="255" />
  <row Id="124" PostId="424" Score="1" Text="I haven't really thought about testing the interaction between the interrupt code and the non interrupt code. It's a good point. I was planning on testing my PWM generation timer interrupt code outside of an interrupting situation in a similar way to the way I'm testing my main line serial code. I guess even once I have coverage for all of that I'm still missing the interaction.  I suppose that I could trigger interrupts from within the tests (it's easy with the timer interrupt but all interrupt code could be set to run on a timer interrupt within the test harness). Non trivial though." CreationDate="2009-11-13T09:49:12.743" UserId="255" />
  <row Id="126" PostId="423" Text="Thinking about it, a shmitt trigger is probably the piece I left out, by making sure that the trigger level is high enough I am sure you could accurately measure a delay. If the difference in delay would be enough, I am not sure." CreationDate="2009-11-13T10:39:48.757" UserId="230" />
  <row Id="127" PostId="424" Score="1" Text="I may misunderstand you, but I try to be quite careful of non-interrupt and interrupt code interactions. I probably should be more lax in my use of atomic operations, but it has never been shown to cause harm at the level I have our optimizer.&#xA;&#xA;The issues arise when one interrupt delays another, a common one I help students with would be interrupt driven PWM generation. If you need an extremly precise speed, for example using a Compare module in your chip, and another interrupt is busy spending time on something else and delays you by 50uS that could be world ending." CreationDate="2009-11-13T10:45:04.457" UserId="230" />
  <row Id="128" PostId="424" Score="1" Text="In some cases you can have priority, or you can even have an interrupt disable itself and re-enable global interrupts internally, platform dependent, but the easiest path for my own development is limiting time in interrupt to things absolutely necessary and have normal code do the rest of the work." CreationDate="2009-11-13T10:47:43.670" UserId="230" />
  <row Id="130" PostId="420" Text="Even at a smaller University you may be able to find students looking for experience who can do part of the job for you, we used to get offers of employment for both monetary and experiential rewards all the time, passed on by the head of the course (this was for programmers/web designers usually as that was the nature of my course)." CreationDate="2009-11-13T11:04:56.087" UserId="103" />
  <row Id="131" PostId="380" Text="There's any number of simple obfuscation methods that would be just as effective in this role if you want to avoid storing clear-text PINs.  The responders above were only trying to help you understand what cryptography does and does not do.&#xA;&#xA;Here's an AES library:&#xA;http://www.hoozi.com/Articles/AESEncryption.htm&#xA;&#xA;I'd also like to say that just because you've programmed for 20 years, it doesn't mean you &quot;understand&quot; cryptography. It is a totally different field. A 20-year auto mechanic is a skilled person, but I wouldn't expect him to design a CAN bus from scratch.  Check your attitude, please." CreationDate="2009-11-13T13:26:02.183" UserId="11" />
  <row Id="132" PostId="390" Score="1" Text="Upvoted -- A good resource, and this should be set as the answer to the question." CreationDate="2009-11-13T13:26:51.743" UserId="11" />
  <row Id="133" PostId="408" Text="These are interesting solutions, but I'm not sure  the differences will be enough (especially with resistance) to get an accurate measurement with common parts.  Inductance may work better with an filter to slow down the discharge of the field.  Longer delay = greater inductance, and you could adjust it to your measurement resolution." CreationDate="2009-11-13T13:36:15.703" UserId="11" />
  <row Id="134" PostId="424" Score="1" Text="My current design is explained on my blog, as is a proposed new design. Right now I have 64 channels of PWM generated by a timer interrupt and no other interrupts; serial is done by polling. This means the PWM is rock solid but the serial may have issues. My new design would use interrupts for UART as well as the timer for PWM generation and careful reenabling and blocking of interrupts to ensure glitch free PWM and glitch free UART processing... " CreationDate="2009-11-13T15:24:07.780" UserId="255" />
  <row Id="136" PostId="408" Text="Agreed, one would need to include additional components (opamp, constant current source, for one solution) to measure the small resistance changes.  The inductance method also requires additional circuitry to measure the inductance change, and can be significantly affected by other nearby objects (if the user is wearing a watch it may affect the measurement enough to believe it's on a different tap)" CreationDate="2009-11-13T16:05:36.913" UserId="161" />
  <row Id="140" PostId="412" Text="ah, unfortunately thats the route i went down and didn't work for me..." CreationDate="2009-11-13T17:58:15.537" />
  <row Id="141" PostId="412" Score="2" Text="What failed for you?" CreationDate="2009-11-13T18:18:25.450" UserId="143" />
  <row Id="143" PostId="412" Score="1" Text="This is a good suggestion, but it might be better if you explained how exactly the arduino board automatically selects power instead of just saying &quot;go look at their schematic&quot;. Their schematic isn't all that clear, and it may not be obvious what the functions of the different ICs do to someone who hasn't used them before (Specifically the LM358D and the MC33269D which appear to be involved in the power supply selection)" CreationDate="2009-11-13T22:09:20.893" UserId="131" />
  <row Id="147" PostId="378" Text="Just found this link to a Linux Journal article on developing for AVR under Linux: http://www.linuxjournal.com/article/7289" CreationDate="2009-11-14T16:49:26.073" UserId="255" />
  <row Id="148" PostId="424" Score="2" Text="I was using the PWM as an example, the system I have had this problem on has 3 SPI interfaces with 1 of the SPI connections having 3 chips we use on it. There are 4 different port interrupts informing of change in state of external chips and a few other things going on.&#xA;&#xA;The problem becomes worse the more interfaces you have." CreationDate="2009-11-14T19:40:10.423" UserId="230" />
  <row Id="149" PostId="424" Text="Understand. I haven't yet worked out how it might be possible to test such interactions. The main reason for the question was to find out if others had any better ideas :) " CreationDate="2009-11-14T22:39:38.243" UserId="255" />
  <row Id="150" PostId="229" Score="1" Text="Hi Jules, I fixed the link on the BlinkM project gallery page.  Let us know what you make with a BlinkM!" CreationDate="2009-11-15T04:14:03.920" UserId="215" />
  <row Id="151" PostId="424" Text="Yes, I understood your question, and considered it an excellent one. I could not add any to the answer, so why not expand the questions space." CreationDate="2009-11-15T08:15:38.523" UserId="230" />
  <row Id="152" PostId="420" Text="I would agree, if all you really want is a partner, talk to professors and find out if they can get you in contact with anyone. Please be cautious though, I have met a good share of incompetent students that professors like.&#xA;&#xA;Like all things, professional experience can mean alot." CreationDate="2009-11-15T09:43:19.643" UserId="230" />
  <row Id="153" PostId="452" Score="2" Text="Yes, I realise they're the same except for the output. I assumed that there was a reasonably easy way to wire the servo to the active low IC. The servos are simple Hitec HS-422s. If I were to run a wire from VCC, via, I assume, a resistor, to the active low output pin then I assume that nothing would flow unless the pin is pulled low?" CreationDate="2009-11-15T09:55:21.227" UserId="255" />
  <row Id="154" PostId="452" Score="1" Text="I am not completely sure I understand your question, you are correct, your device will not pull current from a pull-up resistor when its output is high. The gate of the servo will pull current though the resistor and/or from your high output, probably both. It is still going to be high for the exact opposite duty cycle.&#xA;&#xA;Before if you were doing a duty cycle of 5% and now a duty cycle of 95%. &#xA;&#xA;The data sheet at http://www.robotshop.us/PDF/Servomanual.pdf, or I should say product guide, gives great information. Your pulse time with a specific off time in important. " CreationDate="2009-11-15T10:40:16.630" UserId="230" />
  <row Id="155" PostId="452" Score="1" Text="Why do you need to change chips to Active Low?" CreationDate="2009-11-15T10:40:39.700" UserId="230" />
  <row Id="156" PostId="452" Score="2" Text="I don't, I just bought a tube of them by mistake and want to know if it's possible. I've seen a design for a similar design of servo controller that uses what (from the data sheet) seemed to be active low ICs and I was curious :)" CreationDate="2009-11-15T11:51:26.487" UserId="255" />
  <row Id="157" PostId="452" Score="1" Text="Ahh, I am sorry, I was trying to stop you from changing designs, do you have the other design? You really just need to put inverters in, if you do not mind the space, it can be done with a transistor and a resistor." CreationDate="2009-11-15T11:55:58.417" UserId="230" />
  <row Id="158" PostId="448" Score="1" Text="I have a First Class Honours Degree in Computing which included lots of programming (C++ mainly, a bit of VB6, some assembler). I also have a degree in Maths and teach Maths to Secondary School kids. I can and do program in a variety of languages (not C though) and am looking into various new things including playing with Microcontrollers." CreationDate="2009-11-15T14:27:12.263" UserId="103" />
  <row Id="159" PostId="448" Text="The 16f88 was one of the chips I was looking into." CreationDate="2009-11-15T14:27:53.120" UserId="103" />
  <row Id="160" PostId="263" Text="Just thought I'd update and note that everything seems to be working, though not as perfectly as I might like.  I'm actually hitting the current limit of my regulator when I have too many LEDs switched on at once, which causes them to dim a little." CreationDate="2009-11-15T15:05:27.903" UserId="213" />
  <row Id="162" PostId="448" Text="Just reread your answer and realised you specified the 16f688 not 16f88." CreationDate="2009-11-15T19:48:26.897" UserId="103" />
  <row Id="163" PostId="450" Text="its 4000 and 8000hz" CreationDate="2009-11-15T20:24:41.563" UserId="81" />
  <row Id="164" PostId="466" Text="(Someone with clout please add an [op-amp] or [amplifier] tag.)" CreationDate="2009-11-15T21:44:49.673" UserId="84" />
  <row Id="165" PostId="448" Score="1" Text="The 16F88 is a perfect choice. There are a million different PICs out there, and I think about 50,000 of them are good for starting. &#xA;&#xA;Programming Microcontrollers very often posses problems to people I have helped with a CS background because they did not take many classes about electricity, something I wish they would add to degree programs.&#xA;&#xA;I do not think the programming will be challenging at all though, but it would probably not be a bad choice to get your a development board. This would be affected by your price range.&#xA;&#xA;http://www.microchipdirect.com/ProductSearch.aspx?Keywords=DV164120" CreationDate="2009-11-15T21:58:20.473" UserId="230" />
  <row Id="166" PostId="448" Score="1" Text="I think that last link I posted might be a good choice, it will give you a board already wired up to work with for 50 dollars(-25% if you have a .edu email) and then you have a programmer you can use for any other chips you get.&#xA;&#xA;I look forward to hearing how your projects go." CreationDate="2009-11-15T21:59:17.023" UserId="230" />
  <row Id="167" PostId="450" Text="Schmitt trigger plus counting times between rising edges. One will be double the other. If the amplitude of your signal give trouble, just through it through an amp, if you need a design, I can toss you one." CreationDate="2009-11-15T22:01:56.677" UserId="230" />
  <row Id="168" PostId="450" Text="design help would be AWESOME amplitude is an issue and I was thinking about using an amp." CreationDate="2009-11-15T22:40:25.333" UserId="81" />
  <row Id="169" PostId="470" Text="That makes tons of sense. Thanks!" CreationDate="2009-11-15T23:54:25.850" UserId="84" />
  <row Id="170" PostId="466" Text="Clicking the diagram link gives me a Bad Request (Invalid URL) in Firefox 3.5 running on Debian Lenny. There's a discussion here: http://stackoverflow.com/questions/1623242/problem-with-dynamic-svg-image-generation about how to implement it, but I think that trying to do it in something like a tinymce(?) text area isn't going to work without being explicitly defined by the site admin because I'm guessing &lt; svg &gt;  tags are filtered out for a start." CreationDate="2009-11-15T23:59:00.033" UserId="103" />
  <row Id="171" PostId="466" Text="Actually that points to a different method of embedding svg in html. I'll have a look tomorrow and see if I can see what's up with this, as it's now long past my bed time." CreationDate="2009-11-16T00:25:00.493" UserId="103" />
  <row Id="172" PostId="472" Score="1" Text="Stu,  Chiphacker is just the place for this sort of question  :)" CreationDate="2009-11-16T01:32:33.433" UserId="21" />
  <row Id="173" PostId="470" Text="Glad to hear it!" CreationDate="2009-11-16T02:23:23.673" UserId="230" />
  <row Id="174" PostId="450" Text="What kind of information do you have about the amplitude, if it is wildly varying there are a lot of ways to approach it. the schmitt trigger approach really does better if both signals would have the same amplitude.&#xA;&#xA;If they will both have the same amplitude, but just need an amp, that is very easy to do, and I can honestly give you some very simple methods to do such." CreationDate="2009-11-16T03:54:39.560" UserId="230" />
  <row Id="175" PostId="472" Text="I am working on an answer, but how are you checking how &quot;bright&quot; your UV light is, a UV light should not be very bright to your eyes, but could easily hurt your eyes.&#xA;&#xA;The second thing is determining what power the material needs and determining your output power and the transparency of your material." CreationDate="2009-11-16T05:56:06.130" UserId="230" />
  <row Id="176" PostId="466" Text="In the link there, the stackexchange software seems to prefix the `data:image/svg+xml;base64,PD94b...` URL with `http://`. It doesn't recognise `data:` as valid in a URL." CreationDate="2009-11-16T07:36:00.640" UserId="84" />
  <row Id="177" PostId="475" Text="Well worded.&#xA;&#xA;Making sure your developer is good is very very important." CreationDate="2009-11-16T08:57:45.637" UserId="230" />
  <row Id="178" PostId="324" Text="Don't forget Zener Diodes!" CreationDate="2009-11-16T09:21:32.223" UserId="230" />
  <row Id="179" PostId="466" Text="I've just been to the svg-edit page, created a drawing (aka 2 lines) and got it to display in my browser, but when I view source, take the svg elements that describe the drawing and place them in a html file, before viewing them in a browser, I get nothing." CreationDate="2009-11-16T09:43:59.667" UserId="103" />
  <row Id="182" PostId="480" Text="I'm getting the feeling that if I were using these chips to expand I/O for a reason other than servo control then swapping the active high for active low would be less of an issue, since I'd just reverse the circuit that I was connecting to the pin. However, since I need to drive the servo control line with +VE I need the inverters to give that to me as I can't drive the control line from somewhere else and simply sink it into the IC." CreationDate="2009-11-16T10:03:26.320" UserId="255" />
  <row Id="183" PostId="480" Text="As an aside, the PWM servo control using the active high ICs is working nicely. I run 8 of the 1 of 8 decoder chips off of my microprocessor and then cycle through the address lines (changing them every 2.5ms) so that I can generate the required 50Hz refresh on all 64 channels. This allows me to generate the required 600us-2.4ms pulses on each channel. I assume the PCF8575C is easier to use because you just send it a command to turn the appropriate pin on/off and it stays that way rather than the 238's needing the corresponding pin on the microprocessor to be held high for the duration." CreationDate="2009-11-16T10:09:57.863" UserId="255" />
  <row Id="185" PostId="466" Text="I can get it to display by using it as the source in an embed tag, but obviously markdown strips embed tags." CreationDate="2009-11-16T10:55:11.270" UserId="103" />
  <row Id="186" PostId="448" Text="These were exactly the boards I was looking at last week. Although I think the 16f88 is 18 pin so would I need to get the board for 18 pin chips too, which is about £15 extra?" CreationDate="2009-11-16T11:06:03.993" UserId="103" />
  <row Id="187" PostId="448" Text="I am not sure what the question is, that sounds perfectly reasonable to me." CreationDate="2009-11-16T12:00:06.177" UserId="230" />
  <row Id="188" PostId="480" Score="1" Text="It really depends on application, I am glad to hear it is working. In many cases the chip you are hooked to is easy to deal with the change of active high to active low, but yours was not one of those." CreationDate="2009-11-16T12:10:42.520" UserId="230" />
  <row Id="189" PostId="483" Score="1" Text="Agreed. This is what we currently use to weatherproof our devices.&#xA;&#xA;The water vapour problem can still happen, but this would be more along the lines of common industry practice." CreationDate="2009-11-16T15:59:17.180" UserId="230" />
  <row Id="190" PostId="450" Text="I know the information is vague, if you are needing an amp that is simple to build, http://en.wikipedia.org/wiki/Common_emitter will get the job done. I love to build them, and often with only two resistors.&#xA;If you need more help getting it working, let me know, but often it is as simple as pretending the base emitter junction is .7 and picking voltages that work for you and matching them with resistors." CreationDate="2009-11-16T17:01:26.997" UserId="230" />
  <row Id="191" PostId="448" Text="The one you linked to (Pickit 2 starter Kit) comes with a board which is good for 8, 14 and 20 pin chips, I was just checking that I would need to also buy the DM164120-4 board too, in order to cope with an 18 pin chip which is what the 16f88 is. I was checking because at least one site I went to last week implied that the DM164120-1 board which comes with the kit would do for 18 pin PICs too." CreationDate="2009-11-16T17:12:41.647" UserId="103" />
  <row Id="192" PostId="466" Text="@Amos Yeah, same here. If svg-edit were modified to, perhaps, make an image and post it so some image hosting service and give you the URL, and also to include images for standard components, it might make a decent tool for making schematics." CreationDate="2009-11-16T17:24:02.677" UserId="84" />
  <row Id="193" PostId="487" Text="Looks like they're US based what do you mean by &quot;UK company&quot;?" CreationDate="2009-11-16T19:27:02.773" UserId="255" />
  <row Id="194" PostId="491" Text="Check out this other question that's related to yours: http://chiphacker.com/questions/317/low-voltage-motion-sensor&#xA; .&#xA;Oh wait...that's you again. Why did you post the same exact question twice?" CreationDate="2009-11-16T21:07:58.947" UserId="131" />
  <row Id="195" PostId="466" Score="1" Text="The problem with embedding base64 encoded svgs in your html appears to be that if you allow it, then you may leave your site open to xss exploits. It is possible to embed arbitrary code to be executed in a base 64 encoded svg so it's probably better for this site that they don't allow it. Back to the drawing board then (all puns fully intended)." CreationDate="2009-11-16T21:13:54.987" UserId="103" />
  <row Id="196" PostId="466" Text="Interesting. Did not know that. Time to give up that particular plan." CreationDate="2009-11-16T21:27:45.027" UserId="84" />
  <row Id="197" PostId="472" Text="Yeah, Kortuk.&#xA;I'm not really doing anything scientific like measuring brightnesses, gear to measure this would cost quite a bit I'm sure.&#xA;Indeed I haven't looked into the light, and I'm wearing some prescription sunglasses, very good at blocking all kinds of UV light, whilst exposing the boards. The purple glow emitted is surprisingly bright for a 4 watt bulb.  &#xA;Maplins dont report any sort of exposure time or power but mention you should be using their own UV box - of which, may I add - costs around £80 I think, so I wont be going for that!&#xA;Many thanks for your responses!&#xA;" CreationDate="2009-11-16T21:45:26.563" UserId="284" />
  <row Id="198" PostId="475" Text="Hi SiliconFarmer&#xA;I did indeed follow the instructions, except I didn't have a half a litre container, only some plastic cups, so I adapted the teaspoon measure by about 50% because I used about 1/4 litre water. &#xA;It didn't seem to make any change to the board at all!&#xA;I'm assuming thats because the exposure was all wrong but I cant be sure you see.&#xA;Thanks for the info, but I have access to a laser printer, work photocopier that dont mind me using it for personal reasons, AND my inkjet printer, so no need for print shop services.&#xA;However I will be trying laser Toner on xparency next. &#xA;Thx!" CreationDate="2009-11-16T21:50:23.690" UserId="284" />
  <row Id="199" PostId="472" Text="@mad_z.&#xA;Great, thanks! Except I noticed there are no pre-defined tags for these words-&quot;pcb&quot;,&quot;etch&quot;,&quot;presensitized&quot; etc etc etc, and it wouldn't let me submit until I put in one known tag.  &#xA;Perhaps when I earn enough kudos it'll let me add them... ;-)" CreationDate="2009-11-16T21:54:14.187" UserId="284" />
  <row Id="200" PostId="476" Text="Thank you so much Dago, there are some gems in there!  &#xA;It would have taken me ages to think up that stepped exposure trick, thats given me a great method to start working out exposure times!  &#xA;I'll try and find this 11W flurescent, I dont remember seeing any with a U shaped bulb though (I assume thats what you mean). My UV sterilizer does have a U shaped bulb and it seems to be giving me very quick results in relation to the incandescent I used.  &#xA;Again I thought glass would block a lot of the required UV light, even picture frame glass. Why not plastic or acrylic?  &#xA;Thanks again!&#xA;" CreationDate="2009-11-16T22:04:42.373" UserId="284" />
  <row Id="201" PostId="488" Text="Ahh thats you is it!? Cool, you know it was your Instructable that got me started doing this in the first place! Your fault! ;-)  &#xA;Anyway, I printed it out on some Staples transparency sheets here -&#xA;&lt;a href=&quot;http://www.staples.co.uk/presentation-equipment/transparencies/epson-canon-apple-inkjet-transparencies-20-pack&quot;&gt;Staples Inkjet Transparencies&lt;/a&gt;  &#xA;This stuff is well textured too, but if I print it out once, I hold it up to some halogen light bulbs and can see a purple glow thru the black opaque areas, if I double up I see a much darker purple glow.&#xA;Cant tell if UV light is blocked.&#xA;" CreationDate="2009-11-16T22:12:42.450" UserId="284" />
  <row Id="202" PostId="493" Text="Yeah, I've considered just buying an OhMiBod, but they're pricey! When you say &quot;measure voltage peaks&quot;, what do you mean exactly...just a comparator?" CreationDate="2009-11-16T22:14:20.873" UserId="207" />
  <row Id="203" PostId="488" Text="Sorry, linky screwed up, heres another try - &#xA;http://www.staples.co.uk/presentation-equipment/transparencies/epson-canon-apple-inkjet-transparencies-20-pack&#xA;" CreationDate="2009-11-16T22:17:57.483" UserId="284" />
  <row Id="204" PostId="476" Text="Happy to help :) Plastic and acrylic are bad because they are pretty much opaque to UV light. I Believe &quot;regular glass&quot; like one used in picture frames is not perfect either but it is pretty transparent at UV wavelengths. I think the optimal solution would be quartz glass which is basically transparent to UV light but quartz is rare, expensive and unnecessary in this application.&#xA;&#xA;The table lamp type I was talking about is this one: [img]http://www.servicelighting.com/catpics/philips/26109.jpg[/img]&#xA;&#xA;Commonly used in table lamps." CreationDate="2009-11-16T22:35:50.093" UserId="140" />
  <row Id="205" PostId="488" Text=":)   When I print, I set it for black and white (not even set to photo quality). When I hold it up to the light, I don't see purple, but I can see through the black a little bit. However, when I lay it down on the surface of the PCB its real dark looking and I haven't had any problems." CreationDate="2009-11-16T22:59:58.800" UserId="6" />
  <row Id="206" PostId="488" Text="I am using a 15W bulb, placed about 5 inches over top of my work. The PCB is laying on the workbench, pre-sensitized side up then one sheet of transparency with the design over top and a clear piece of acrylic over both to hold the transparency down and keep it from moving. I expose it for 14 minutes then place it in the developer which I have mixed as a 1 to 10 ratio (heated, and I jiggle it back and forth wearing a rubber glove). Within seconds my design appears and then I put the board in cold water to stop the developing process. Then move onto the etching process, etc." CreationDate="2009-11-16T23:00:03.033" UserId="6" />
  <row Id="207" PostId="498" Text="I'm assuming Mr. Noise is asking us to help with his homework assignment and he is not allowed to use the obvious solution." CreationDate="2009-11-17T00:57:58.840" UserId="286" />
  <row Id="208" PostId="488" Text="That's a nice instructable, but it is missing information on the inkjet printer.  Setting the printer to BW and not photo seems to be an important detail to get the print dark enough.  I also suggest, if available, setting the print density to the darkest setting (which I do on my Laserjet).  &#xA;&#xA;Could it be that some brands of ink just aren't as opaque to IR as others?  So knowing your make of printer might be useful, also.&#xA;&#xA;" CreationDate="2009-11-17T01:18:41.623" UserId="286" />
  <row Id="210" PostId="448" Score="1" Text="If you get the DM164120-1, I would suggest you use the PIC that comes with it. I am right in the middle of helping someone with a project that they need to teach class tomorrow or I would look more, but every place I find your board I cannot find it's schematic. I can tell you based on the pin-out of the PIC16F631 it is not compatible with a PIC16F88. The power and programming pins will not line up.&#xA;If you buy a dev board, just use the PIC that comes with it, you will be significantly happier." CreationDate="2009-11-17T02:00:11.930" UserId="230" />
  <row Id="211" PostId="498" Score="2" Text="Biggest reason is because I am trying to learn something about electronics.  I've already done it in code which I can fall back on if need be...and no it's not a homework assignment, just a modest circuit bend for my own entertainment and edification. Thanks for the answer, it gives me a direction to work towards." CreationDate="2009-11-17T02:38:59.553" UserId="290" />
  <row Id="212" PostId="404" Text="Thanks for the responses everyone.  As pointed out i'm partly trying to gauge how easy it would be to do with the coil or wether to just fake it.  Although feasible it sounds like it will be easier to fake it. " CreationDate="2009-11-17T03:14:09.727" />
  <row Id="213" PostId="486" Score="1" Text="I would have suggested you just edit my post with your extra information. You have a very good grasp of op-amp theory, something I rarely see in people anymore." CreationDate="2009-11-17T03:18:28.880" UserId="230" />
  <row Id="214" PostId="20" Score="1" Text="phooky is absolutely correct, but the internal WDT has limitations: it can't run for more than about 6 seconds (depends on CPU model) and there's no way to do a clean &quot;reboot&quot; purely from software. You can tell the CPU to jump to position 0 and restart the bootloader, but then you may be left with dodgy stuff in RAM and things like interrupt flags still set in the CPU. Asserting RESET in hardware ensures the Arduino will come up with a clean environment." CreationDate="2009-11-17T03:41:09.323" UserId="31" />
  <row Id="216" PostId="499" Text="Thanks Adam! I'll start looking into efficient ways of doing PWM (I'm guessing tiny AVR chips are going to work best). I'll be using this shaftless pager motor: http://www.solarbotics.com/products/vpm2/ possibly in conjunction with one of these: http://www.precisionmicrodrives.com/product_info.php?products_id=172 for extra impact." CreationDate="2009-11-17T04:14:37.513" UserId="207" />
  <row Id="218" PostId="494" Score="1" Text="50-100 is reasonable. Right now I don't think building my own is my first choice, but thanks for the link. The schools angle is one that I have been thinking of as a backup plan. I like the idea of trading knowledge for cutting time ;)" CreationDate="2009-11-17T07:44:39.440" UserId="255" />
  <row Id="219" PostId="502" Score="3" Text="Yeah, We did the same Motorola work. There is a big shift towards ACVR inside the tinker/educational community at many schools, but I think the PICs from Microchip are a better starting product personally. I think they have a broader range of applications, but I will admit in Low power apps I use MSP430s created by TI." CreationDate="2009-11-17T09:18:13.423" UserId="230" />
  <row Id="220" PostId="317" Text="Tom, when I read your question it seems that you are looking more for a location sensor, like GPS, so you can track the location of an object/animal/person. Is this correct, or do you just want to time stamp motion." CreationDate="2009-11-17T09:22:00.123" UserId="230" />
  <row Id="221" PostId="476" Text="The glass you normally have available will glow in UV light I believe as it absorbs and radiates the UV light. It has an absorption of 80-90% in the process, I believe." CreationDate="2009-11-17T09:32:18.137" UserId="230" />
  <row Id="223" PostId="503" Score="2" Text="Don't tell the &quot;everything should be done on a uC&quot; crowd, but I love the 555 and I just happen to have a pile of them, thanks!" CreationDate="2009-11-17T12:48:08.803" UserId="290" />
  <row Id="225" PostId="335" Score="1" Text="Digital pots are generally used to set the gain or attenuation of an external circuit in a few discrete steps (256).  To get a DC voltage out of it, you'd need to connect this to a voltage source, but it's really not the application these are meant for. A DAC, on the other hand, outputs a voltage directly, and will generally have many more steps and more accuracy. A DAC is what this poster is looking for." CreationDate="2009-11-17T17:24:14.770" UserId="142" />
  <row Id="226" PostId="342" Text="It's a digital-to-analog converter, not analog-to-digital." CreationDate="2009-11-17T17:25:12.367" UserId="142" />
  <row Id="227" PostId="342" Text="And you should be able to edit your post and add the links now that you have some reputation." CreationDate="2009-11-17T17:26:33.117" UserId="142" />
  <row Id="228" PostId="513" Text="Which virtual machine will allow the USB JTAGICE to run from the XP image?" CreationDate="2009-11-17T17:40:24.413" UserId="161" />
  <row Id="229" PostId="476" Text="Like I said, it might not be optimal but it's good enough :) I'm getting sub-2min exposure times with under 8W input to my UV-led panel (including power that is wasted in the resistors, most likely like a watt of actual light output) while using a couple mm thick picture frame glass (most likely regular soda-lime glass)." CreationDate="2009-11-17T17:58:08.450" UserId="140" />
  <row Id="230" PostId="513" Score="2" Text="I don't use a USB JTAGICE but VMWare Workstation supports every other USB device I've ever tried with it and I'd be surprised if it didn't work with that one; it's just a USB device after all..." CreationDate="2009-11-17T19:09:28.837" UserId="255" />
  <row Id="231" PostId="515" Score="4" Text="You could save yourself the diode bridge and rectification if you used a DC wall transformer instead of an AC wall transformer. You would still need a voltage regulator to get a stable 5V though, almost all wall transformers are NOT voltage regulated, and a '5V' wall transformer will more likely give you somewhere between 5V and 9V." CreationDate="2009-11-17T19:10:40.913" UserId="131" />
  <row Id="232" PostId="498" Text="That's reasonable, if you specify that in your questions in the future, people will understand better." CreationDate="2009-11-17T19:12:19.790" UserId="131" />
  <row Id="233" PostId="517" Text="Ok.  But which ones, specifically, and how much work is involved to get them to support it?" CreationDate="2009-11-17T19:34:00.707" UserId="142" />
  <row Id="234" PostId="516" Score="1" Text="The peak voltage seen at the output of the rectifier will be 2 diode drops (2.2 V total) less than the input peak voltage." CreationDate="2009-11-17T19:43:08.910" UserId="204" />
  <row Id="235" PostId="516" Score="6" Text="Endolith has an exceptional approach. I would like to note one thing, USE A HEAT SINK. If you are going to put 1 amp through a linear regulator, use a heat sink, it is a lot more power to dissipate than people realize." CreationDate="2009-11-17T20:15:25.983" UserId="230" />
  <row Id="236" PostId="476" Text="I had no idea plastics blocked UV light so much. Thanks for that.&#xA;I know glass blocks UV pretty well though, because its designed to prevent rooms from being bathed in dangerous UV on sunny days - thats why you're curtains dont end up bleached after a time.&#xA;I suppose you can say that about every kind of transparent sheet material available on the market as preventing dangerous exposure is a key requirement for most transparent materials.&#xA;I'd wager the 'saving grace' for picture frame glass is that its so thin in relation to window glass, makes it less absorbant.&#xA;Thanks all.&#xA; &#xA;" CreationDate="2009-11-17T20:21:09.957" UserId="284" />
  <row Id="238" PostId="516" Text="Oops. Including the diode drops changes the answer. Did I make any other mistakes?" CreationDate="2009-11-17T20:28:20.300" UserId="142" />
  <row Id="239" PostId="488" Text="Indeed SiliconFarmer, I'm using a Canon MP610, yes I think the inks aren't as good as they could be. They're brilliant for their normal task of producing good quality prints though.  &#xA;I also have an HP Laserjet 4000, I'll be printing to laserjet transparencies and trying again, I'm sure it will end up pretty much totally opaque, at least to the eye.  &#xA;Thanks for those proportions you give for the various chemicals, and the timings, ArduinoFun, but you use a dedicated developer dont you? I'm using Caustic Soda and they may be different, I also read somewhere you shouldn't heat up Caustic Soda" CreationDate="2009-11-17T20:28:57.953" UserId="284" />
  <row Id="240" PostId="518" Score="1" Text="Maybe you can elaborate on what exactly the project is that you want it to do?" CreationDate="2009-11-17T21:16:27.657" UserId="131" />
  <row Id="241" PostId="448" Score="1" Text="This page: http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&amp;nodeId=1406&amp;dDocName=en531769 shows boards that are compatible with the PicKit 2 and 3. In the second box down it states that the DM161420-1 &quot;Does not support PIC10F 8DIP or 18-Pin Devices.&quot; and then has the DM161420-4 which is 18 pin compatible. There don't appear to be any schematics lower down the page for the 18 pin, but there are for the other board in the users guide. So I'm guessing thats the way to go then if I do go for the 16F88 as a starter.Alternatively the 18 pin board comes with a PIC16F648A. " CreationDate="2009-11-17T21:57:37.533" UserId="103" />
  <row Id="242" PostId="445" Text="I've bookmarked Embedded Adventures for when I've got an hour or two to kill, and had a look at the Bitwacker for future reference. Cheers." CreationDate="2009-11-17T21:59:42.073" UserId="103" />
  <row Id="243" PostId="476" Text="Success! Of a sort.  &#xA;I have successfuly exposed, developed AND etched my PCB. Only trouble is the developed photoresist didn't end up the sharpest image of the mask, I think for some reason my glass sheet wasn't holding the mask down to the board fully. Unknown why, as it was pressing hard against it.&#xA;Just for the record, here are some findings for the community -  &#xA;-Certain inkjets, it seems, dont print out opaque enough no matter what settings you use - I switched to a laserjet to transparency.&#xA;-exposure with a UV sterilizer @ 4watts means 15+mins exposure.&#xA;Thanks all for your support!&#xA;" CreationDate="2009-11-18T01:20:12.193" UserId="284" />
  <row Id="244" PostId="517" Text="To find which ones specifically: Click on each of them, and read the page and see if it says &quot;HID&quot; anywhere on it. Then if you want to know how much work it would be: read the datasheet for the module and see how much you have to do to initialize it, send events, etc. Many of the modules you can communicate with via UART, which is usually pretty simple from a microcontroller, with &quot;AT&quot; commands, similar to how modems worked in the olden days. Again the datasheet should list the available commands." CreationDate="2009-11-18T01:32:42.433" UserId="131" />
  <row Id="245" PostId="520" Score="2" Text="This one is clever for using the minimum number of components, just a single capacitor and a relay. Downside is the relay is quite large, but the original asker might be able to find smaller or solid state ones that work the same way (may require addition of an extra resistor to slow the capacitor charge/discharge time)" CreationDate="2009-11-18T01:43:27.967" UserId="131" />
  <row Id="246" PostId="488" Text="Yeah I am using Positive Type Developer Concentrate. My printer is a Dell V305. I only set it to black and white to save on ink. If you have it set to color and photo it will just use up more ink but the print looks a little darker when I tested with it. I will have to add that into the instructable. You could go over areas with a black sharpie marker to darker things up." CreationDate="2009-11-18T03:58:18.193" UserId="6" />
  <row Id="247" PostId="448" Score="2" Text="Yes, you have done your research well. My help may have been a little misguided. If you want to get your feet wet, a development board is a way to avoid dealing with the hardware of building a PIC before you are ready. If you go this path, I would suggest using the PIC that comes with the board and determine your next choice of PIC after you are ready to build your own boards.&#xA;&#xA;If you want your own pic from the beginning, buy a programmer, the pic and anything you need to run the pic from the start. You can save money and use a breadboard." CreationDate="2009-11-18T04:31:07.223" UserId="230" />
  <row Id="248" PostId="528" Text="What is the voltage range, or load resistance range?" CreationDate="2009-11-18T04:49:25.200" UserId="161" />
  <row Id="249" PostId="518" Text="I think this forum is the right place for this, as a side note." CreationDate="2009-11-18T07:14:03.263" UserId="230" />
  <row Id="250" PostId="533" Text="Hi Amos, &#xA;&#xA;I'm looking for even longer than those. The pins on those are 10mm long - however the pins on the ethernet shield are 15 mm long." CreationDate="2009-11-18T09:56:42.903" UserId="298" />
  <row Id="251" PostId="534" Text="Hi JohnC,&#xA;&#xA;That's a good idea. I'll use that if I can't get longer headers." CreationDate="2009-11-18T09:57:47.647" UserId="298" />
  <row Id="252" PostId="476" Text="One reason why the photoresist might have ended up a bit &quot;fuzzy&quot; is that you need to print the mask to the transparency sheet so that the side which has the ink is pressed against the board. If the ink is on the other side of the transparency sheet there will be a &quot;gap&quot; (=the transparency sheet) between the board and the actual mask resulting in fuzzy edges." CreationDate="2009-11-18T10:42:17.920" UserId="140" />
  <row Id="253" PostId="448" Score="1" Text="I think that I'll go with the PicKit 2 Starter Kit then, and add new chips/boards as and when. This seems like a reasonably cheap option initially as I get can the kit direct from microchip for £31.24 which includes a development board and chip (16f690).&#xA;Cheers, now to find some decent tutorials/books." CreationDate="2009-11-18T10:49:35.373" UserId="103" />
  <row Id="254" PostId="448" Score="1" Text="Hey, if you order it with an account you registered using a .edu email you will receive a 25% discount." CreationDate="2009-11-18T13:21:57.950" UserId="230" />
  <row Id="255" PostId="448" Text="MicrochipDirect has a UK based section which may be different to the US one. My School account ends .co.uk, when they are registered specifically to schools here they tend to end .sch.uk, Universities tend to end .ac.uk. I might see if they do have any discounts anyway, even though it's for my benefit not the School's, they tend to be quite flexible like that." CreationDate="2009-11-18T14:25:25.200" UserId="103" />
  <row Id="256" PostId="76" Score="1" Text="You should probably specify the load. The best solution for 100 mA it's probably different than the one for 10A." CreationDate="2009-11-18T14:47:59.337" UserId="218" />
  <row Id="257" PostId="533" Text="littlebirdceo and mad_z work who are Site Admins here work for Little Bird Electronics in Sidney, which is where I got that link from, maybe they'll be able to find you some." CreationDate="2009-11-18T14:52:56.710" UserId="103" />
  <row Id="258" PostId="536" Text="Fritzing looks really cool, and appears to be useful for schematic diagrams as well." CreationDate="2009-11-18T19:07:55.927" UserId="106" />
  <row Id="259" PostId="448" Text="The discount has nothing to do with the school gaining benefit, it is about not charging a college(Uni) student as much. I would suggest trying your luck." CreationDate="2009-11-18T20:13:57.500" UserId="230" />
  <row Id="260" PostId="544" Text="Cheers, I'll have a look. Does JAL use a specific IDE, there one available for Linux?" CreationDate="2009-11-18T22:03:12.440" UserId="103" />
  <row Id="261" PostId="448" Text="I meant that as our Domain name ends .co.uk, School would have to verify my link to them probably. But they are quite good about such things even if the benefit to the School is not immediately apparent. Although if I'm not careful I'll end up teaching electronics to randomly selected students next year, as that seems to be the way of things at times, especially if the Tories get in." CreationDate="2009-11-18T22:10:02.920" UserId="103" />
  <row Id="262" PostId="495" Text="Between chiphacker and my @tcmaker buds I've got a bunch of potential solutions.  I've simmed a couple in SPICE and there's certainly some potential, I just need to see if they will mesh with my bend.  Thanks for the answers everyone!  I'll try to post up any updates on my progress." CreationDate="2009-11-18T22:44:16.163" UserId="290" />
  <row Id="263" PostId="546" Score="1" Text="Maybe you should give a schematic of what you are talking about, I find it very hard to understand your paragraph explaining what you connected to what." CreationDate="2009-11-18T22:45:34.823" UserId="131" />
  <row Id="265" PostId="537" Text="No it really isn't. Still very much worth using though. This tutorial should help you to get started: http://www.instructables.com/id/Draw-Electronic-Schematics-with-CadSoft-EAGLE/" CreationDate="2009-11-18T22:59:01.570" UserId="105" />
  <row Id="266" PostId="495" Text="Here's one solution written up by a friend of mine, very detailed explanation and includes an LTSpice schematic. http://uptownmaker.blogspot.com/2009/11/pulses-on-pushbutton.html" CreationDate="2009-11-18T23:00:17.987" UserId="290" />
  <row Id="267" PostId="544" Score="1" Text="Yes it has one called JAL Edit, it will keep you right on the coding side and has a the typical tools that you tend to find on IDE's &#xA;&#xA;http://jal.sunish.net/jaledit" CreationDate="2009-11-18T23:09:43.070" UserId="312" />
  <row Id="268" PostId="448" Text="Ohh, I understood, I have quite a few friends from the UK. I was just telling you that being a student is all they require, it can be a personal project." CreationDate="2009-11-19T00:18:39.390" UserId="230" />
  <row Id="269" PostId="544" Text="Unfortunately that's Windows only, there does appear to be one for Linux called PicShell, current Beta is at: http://linux.softpedia.com/get/Text-Editing-Processing/IDEs/Picshell-52408.shtml" CreationDate="2009-11-19T09:54:09.723" UserId="103" />
  <row Id="270" PostId="556" Text="No, I can't find one, I've found that one or a similar model but much more expensive." CreationDate="2009-11-19T11:30:48.460" UserId="103" />
  <row Id="271" PostId="552" Text="I had a &quot;2*&quot; to compensate for the full bridge." CreationDate="2009-11-19T16:20:48.213" UserId="204" />
  <row Id="272" PostId="552" Text="Do you have a web site that describes the choke method?" CreationDate="2009-11-19T16:22:17.643" UserId="204" />
  <row Id="273" PostId="551" Text="Good point about the limitations of that equation!" CreationDate="2009-11-19T16:23:34.617" UserId="204" />
  <row Id="274" PostId="546" Text="What are the two circuits you're trying to connect together?" CreationDate="2009-11-19T20:56:57.433" UserId="142" />
  <row Id="275" PostId="502" Text="For our third year group project, we built a wireless electrocardiogram rig based on a PIC chip for the data collection and RS-232 reporting to a computer running the host application. The one we used was a great little unit (can't remember spec now, it's been a while) and really gave me a proper appreciation for Micro's in small, complex logic devices. :D" CreationDate="2009-11-19T21:18:34.163" UserId="295" />
  <row Id="276" PostId="561" Text="Wow, that is cheap." CreationDate="2009-11-19T22:09:25.403" UserId="103" />
  <row Id="277" PostId="562" Text="Only 100 LEDs? That's only a 10x10 grid...you can show like 2 or 3 letters only, not a whole lot of info." CreationDate="2009-11-19T22:30:35.593" UserId="131" />
  <row Id="278" PostId="562" Text="It isnt going to need to show letters....just symbols  &#xA;&#xA;X  O   -&gt;   thats sort of thing.&#xA;&#xA;The major project is to do with traffic flow etc so this is just a cool little demo we want to set up" CreationDate="2009-11-19T23:54:19.750" UserId="267" />
  <row Id="279" PostId="562" Score="1" Text="From the two previous answers, I'm guessing the question is &quot;can anyone recommend a source for these LEDs&quot;, but it's usually a good idea to make that kind of thing explicit :)" CreationDate="2009-11-20T03:40:45.983" UserId="213" />
  <row Id="280" PostId="551" Score="1" Text="Here is a somewhat better equation for cases where Vripple is large.  This is less pessimistic than Vripple = I/(2fC), but it is still pessimistic for values of Vripple &lt; 1/2 * Vpeak.  &#xA;&#xA;Instead of assuming there is no rising sine wave at t=1/2*f, approximate the rectifier output with triangles instead of sine wave (to make the math easier).&#xA;&#xA;Solving the two equations to see when the capacitor's falling voltage intercepts the rising triangular wave, to get:&#xA;&#xA;Vt = Vp * (4fCVp/I -1) / (4fCVp/I +1)&#xA;f=60, C=1000, Vp=14.8, I=1&#xA;Vt = 8.3 volts&#xA;Which is nicely above 7805 dropout voltage of 5v + 1.5v ." CreationDate="2009-11-20T08:38:52.757" UserId="19" />
  <row Id="281" PostId="378" Text="My main concern with that article is that it's from 2005 and so may be out of date." CreationDate="2009-11-20T14:46:29.843" UserId="103" />
  <row Id="282" PostId="342" Text="Post edited to include some links -- corrected the minor errors too." CreationDate="2009-11-20T16:09:38.397" UserId="243" />
  <row Id="283" PostId="581" Text="What kind of range do you want?" CreationDate="2009-11-21T07:45:12.953" UserId="142" />
  <row Id="284" PostId="580" Score="1" Text="It would help to see what you have already tried, ie schematic." CreationDate="2009-11-21T08:08:24.880" UserId="230" />
  <row Id="285" PostId="593" Text="Overview: http://hyperphysics.phy-astr.gsu.edu/hbase/Electronic/opampcon.html" CreationDate="2009-11-21T23:37:42.180" UserId="142" />
  <row Id="287" PostId="589" Text="That looks interesting." CreationDate="2009-11-23T09:22:25.537" UserId="103" />
  <row Id="288" PostId="603" Text="Plus if you were looking at angles with an accuracy of 1 degree, you would only need 90ish values in the table. All the others can be derived from the angles in the first quadrant. If you do this for sine and cosine, you can derive the values for tangent from these as: tan(theta) = sin(theta)/cos(theta). Do you need to do arcsin, arccos and arctan too?" CreationDate="2009-11-23T09:35:03.623" UserId="103" />
  <row Id="289" PostId="603" Text="Agreed Amos, I like your solution also, but multiplication show be chosen based on the presence of hardware for it normally, not all PICs have hardware multipliers.&#xA;&#xA;In reality, you can use a look up table for the degrees and a simple linear approximation from there and never know the difference also if it is that important." CreationDate="2009-11-23T16:31:01.467" UserId="230" />
  <row Id="290" PostId="610" Score="1" Text="I am not sure how much you paid for your FPGA, but it is more. A dedicated IC plus a micro-controller will not break 20 dollars in single quantities.&#xA;&#xA;I do think that using the FPGA is a cool solution and +1 for learning one of the biggest emerging technologies around. I think FPGA development should be something well taught in Uni.&#xA;&#xA;Many embedded developers are switching to them because they are so flexible." CreationDate="2009-11-23T16:34:22.667" UserId="230" />
  <row Id="291" PostId="604" Text="Thanks for your answer. I did some testing and it is probably not the BRAKE pin but the S/S pin that needs voltage before the IC will let the motor spin. I'll do some more testing, but this might be the solution.&#xA;&#xA;" CreationDate="2009-11-23T17:58:29.417" UserId="323" />
  <row Id="292" PostId="612" Text="Yeah, my answer is geared towards future boards, the current one is probably easier to cut the traces yourself." CreationDate="2009-11-23T19:57:24.643" UserId="230" />
  <row Id="293" PostId="282" Text="What are the limitations you mention of using Arduino ide for developing with Teensy?" CreationDate="2009-11-23T20:30:12.883" UserId="94" />
  <row Id="294" PostId="614" Text="What are you trying to do with the ultrasound? What are you coupling the signal into? (air? water? steel?). These things do matter when deciding what to do with the signal." CreationDate="2009-11-23T23:45:26.273" UserId="259" />
  <row Id="295" PostId="625" Score="1" Text="thanks. summarization of the tutorial:&#xA;* __Inline Resistor__. Uni-directional. Step-down only. -- reduces current, IC's i/o clamping diodes can them limit max input.&#xA;* __Series Resistors__ Uni-directional. Step-down only, but granular.&#xA;* __Diode__ Uni-directional. Step-down. Safer. High from 5v blocks Diode; 3.3v side then ties to high. But, if you reverse diode configuration couldnt you also step-up?&#xA;* __Mosfet__ Bi-directional. Step-down or Step-up.&#xA;From comments:&#xA;* __Optical isolation__ example: 4N25. high current.&#xA;* __Zener diode__ example: 1N4728A&#xA;* __74HC244/125__ Uni-directional" CreationDate="2009-11-24T01:03:36.353" UserId="196" />
  <row Id="297" PostId="626" Text="Maxim totally slipped my mind.  In addition TI has a list of conversion IC's categorized by direction (uni/bi): http://focus.ti.com/logic/docs/translationselection.tsp?sectionId=458" CreationDate="2009-11-24T01:35:27.723" UserId="196" />
  <row Id="298" PostId="502" Score="1" Text="Sounds like a great project for senior design. I am getting ready to change up how my school teaches PIC. I got some professional development boards and will be teaching students how to handle multiple interfaces." CreationDate="2009-11-24T07:58:32.817" UserId="230" />
  <row Id="299" PostId="111" Score="2" Text="I have two major things to add to this. First, most 12V batteries do not die at 0V, but instead at something quite close, at least within 5 V, of your full charge voltage. A common technique to get higher resolution measurments in the operating range is to step down the voltage with a zener diode. A resistor in series with a zener and you measure across the resistor.&#xA;&#xA;Second, most people do not realize you need to draw current from a battery to get a good idea of the power left." CreationDate="2009-11-24T08:18:09.780" UserId="230" />
  <row Id="300" PostId="618" Text="It is out of date, but it is still the easiest way to look up how different tasks are accomplished in one location. In every field you can find a single book that represents the core material of the field, this book is just that, but for all of EE." CreationDate="2009-11-24T08:24:10.387" UserId="230" />
  <row Id="301" PostId="610" Text="I used a Pluto 3 board I already had at home (http://www.knjn.com/ShopBoards_RS232.html). The matrix driver used less than 10% of FPGA resources but a lot of I/O pins. With external demux to drive columns, the smallest board should be enough. Yes, I'm aware this is more expensive than the custom IC+ micro solution, but I think it's worth it: I learnt to use Quartus, and the satisfaction to &quot;draw&quot; a schematic on screen, and see the FPGA that &quot;execute&quot; that schematic in the real world is priceless :-)" CreationDate="2009-11-24T09:45:24.763" UserId="244" />
  <row Id="303" PostId="623" Score="1" Text="I think &quot;Trying to insert non-stranded into a breadboard is like trying to push string!&quot; should actually say stranded." CreationDate="2009-11-24T10:09:39.050" UserId="103" />
  <row Id="304" PostId="642" Text="Nice link, have enjoyed my first 10 minutes of reading." CreationDate="2009-11-24T12:11:51.037" UserId="230" />
  <row Id="305" PostId="623" Text="I am not sure what you mean, stranded is by far easier to solder in projects. There are certain situations where non-stranded is easier, but stranded gets better contact and better joints." CreationDate="2009-11-24T14:17:38.147" UserId="230" />
  <row Id="306" PostId="623" Text="The full paragraph says: &quot;Non-Stranded-Easy to solder, will fit into breadboard. Trying to insert non-stranded into a breadboard is like trying to push string!&quot; This is contradictory, either non-stranded is easy to fit into a breadboard or it's like pushing string. From experience I would say that stranded is more like pushing string than not, hence my comment." CreationDate="2009-11-24T14:55:38.390" UserId="103" />
  <row Id="307" PostId="635" Score="2" Text="Adafruit and Sparkfun have some excellent cables with the pins already on the end.  $7/100 is pretty darn cheap - I use them whenever I'm going between boards." CreationDate="2009-11-24T17:48:11.757" UserId="213" />
  <row Id="308" PostId="623" Score="1" Text="the wire in cat-5 cables is very small (maybe 22-24 gauge?). This is great if you are soldering, but if you stick it in a breadboard it pops out very easily." CreationDate="2009-11-24T18:09:34.693" UserId="12" />
  <row Id="309" PostId="639" Text="What sensor are you using, and what output does it give? (eg analog voltage from 0-5V, I2C, PWM, etc)" CreationDate="2009-11-24T20:50:31.500" UserId="131" />
  <row Id="310" PostId="626" Text="Yeah, other IC manufactures make similar chips too, Maxim is just the one I've actually used before." CreationDate="2009-11-24T20:51:38.390" UserId="131" />
  <row Id="311" PostId="625" Text="Ah, I didn't realize the mosfet works in both directions, from their page it looked like it only worked one way, especially the line about &quot;This circuit will not work the other direction (high voltage to low voltage)&quot;. But after reading the PDF from Phillips Semi, it's clear to me." CreationDate="2009-11-24T20:55:50.837" UserId="131" />
  <row Id="312" PostId="651" Text="I don't have a specific application right now. I'm just looking for a general overview so that I'm prepared. That said, wikipedia is always a good resource. But I'm hoping there's a resource that focused on hardware design." CreationDate="2009-11-24T22:27:45.530" UserId="327" />
  <row Id="313" PostId="623" Text="Corrected non-stranded comment, late night posting is never a reat idea!  &#xA;&#xA;I personally have found stranded cable more difficult to solder.  &#xA;&#xA;In terms of it popping out of breadboard, Again not in my experiance.   " CreationDate="2009-11-24T22:41:21.137" UserId="312" />
  <row Id="314" PostId="643" Score="1" Text="But why bother?  For that kind of work, non-stranded wire is cheap and somtimes the additional stiffness adds to the ease of use..." CreationDate="2009-11-24T22:43:41.490" UserId="312" />
  <row Id="315" PostId="633" Text="I agree, but we are talking a lot of bending... I can think of situations where this can be a problem, but  not so much at a the prototyping stage" CreationDate="2009-11-24T22:46:23.653" UserId="312" />
  <row Id="316" PostId="618" Score="3" Text="I think all books are out of date prety much as soon as the binding is glued into place!  &#xA;&#xA;I think though if you can absorb this book as your basic starting position (and I am still absorbing after 12 months!) other sources such as t'internet dont tend to throw up too much outside your newly aquired vocabularly..." CreationDate="2009-11-24T22:54:03.763" UserId="312" />
  <row Id="317" PostId="430" Text="Thanks guys, this gave me a good insite" CreationDate="2009-11-25T01:07:04.587" />
  <row Id="318" PostId="629" Text="Thanks very much! I actually found out about chiphacker through Little Bird: I've ordered a few Arduino bits through LBE before, so it's awesome to hear they're getting motors in stock." CreationDate="2009-11-25T02:45:23.127" UserId="295" />
  <row Id="319" PostId="631" Text="That shield is awesome! I'll have to keep it mind for some future projects I have in mind (hint: MAME cabinet :D)" CreationDate="2009-11-25T03:42:07.453" UserId="295" />
  <row Id="320" PostId="625" Text="Davr, MOSFETs can be used to create one direction or bi-direction. A single MOSFET is one direction. A few MOSFETs and you can create a circuit with an Vin for each side of the shifter and is fully bidirectional." CreationDate="2009-11-25T06:01:37.713" UserId="230" />
  <row Id="321" PostId="652" Text="Micron has some good app notes: http://www.micron.com/support/part_info/technotes. Any other good ones?" CreationDate="2009-11-25T07:02:10.837" UserId="327" />
  <row Id="322" PostId="653" Text="Good point.  While its not impossible to crimp onto solid core cable, even when extra care has been made to provide strain relief the termination can be fragile..." CreationDate="2009-11-25T07:35:08.183" UserId="312" />
  <row Id="324" PostId="640" Text="Someone downvoted me, if they could tell me why I could try to improve my posting style." CreationDate="2009-11-25T07:46:27.490" UserId="230" />
  <row Id="325" PostId="625" Text="davr. I read &quot;will not work the other direction&quot; as meaning that low voltage connection must be on the left of the MOSFET and high on the right and hence it is not directly related to the uni/bi-directionality of the schematic. After reading the Phillips PDF I assume that the single MOSFET layout at sparkfun is bi-directional, or Kortuk am I wrong? " CreationDate="2009-11-25T11:11:19.127" UserId="196" />
  <row Id="326" PostId="651" Text="You should spend time learning about the different protocol's in my opinion. I2C, SPI, UART are the biggest. They are followed by many other protocols that can be very specific to the type of memory you need. I would suggest reading about memory to find out what interests you, then research what interfaces are available." CreationDate="2009-11-25T12:32:02.870" UserId="230" />
  <row Id="327" PostId="660" Text="This is all PC memory, this does not give an accurate description of the different memory out there for the embedded world. If you had been more clear that computer(PC) memory like DRAM was what you were looking for you would have seen what you were looking for from answers." CreationDate="2009-11-25T12:33:37.933" UserId="230" />
  <row Id="328" PostId="644" Text="You can also take a twisted pair from cat 5 and rap foil around it and ground the foil at both ends. This will do decent shielding. The differential signal will make it significantly more noise resistant after that step. " CreationDate="2009-11-25T12:35:11.133" UserId="230" />
  <row Id="329" PostId="643" Text="I was referring to the remote sensor as a finished product.  Say I want to put a photodiode and op-amp on protoboard, but then plug that component into my breadboard as I build the bigger system.  I'd use stranded wire connected &quot;permanently&quot; to the protoboard, and tin the other end for use with the breadboard." CreationDate="2009-11-25T21:49:15.703" UserId="51" />
  <row Id="351" PostId="687" Text="Heh.....I'd be interested in this too!" CreationDate="2009-11-26T04:15:33.197" UserId="267" />
  <row Id="353" PostId="683" Text="Should probably keep the questions related to electronics" CreationDate="2009-11-26T04:36:26.430" UserId="245" />
  <row Id="354" PostId="684" Score="2" Text="welcome to the dark side of rapidly evolving technology :/" CreationDate="2009-11-26T05:50:36.450" UserId="330" />
  <row Id="355" PostId="528" Text="what kind of accuracy do you need?" CreationDate="2009-11-26T05:51:19.673" UserId="330" />
  <row Id="356" PostId="460" Text="Arduino, not Ardunio" CreationDate="2009-11-26T05:54:17.033" UserId="330" />
  <row Id="357" PostId="144" Text="??? these days DSPs and microcontrollers have not much different between them. they're optimized for high-performance DSP processing, yes, but no reason you can't do general-purpose stuff, unless you need to deal with a LOT of memory, and even then you just have to find a DSP with an external data/address bus." CreationDate="2009-11-26T05:59:51.610" UserId="330" />
  <row Id="360" PostId="643" Text="Yes that would be a pretty sensible thing to do under the circumstances" CreationDate="2009-11-26T06:59:36.250" UserId="312" />
  <row Id="362" PostId="683" Text="I guess I'm just looking to find some like minded people to hack these guys with.   I believe there is a hackerspace set up in sydney...so failing finding a Football League I could head there to hack." CreationDate="2009-11-26T08:36:02.970" UserId="267" />
  <row Id="365" PostId="696" Text="By monitor I mean determine the number of cycles used by code. something like (note, formatting of code will probably be flattened by comment engine): clocks = startCountingAtmegaClocks(); for ... { for ... { digitalRead ... }} Serial.print(&quot;num of used cycles :&quot;); Serial.print(currentCountingAtmegaClocks() - clocks, DEC);" CreationDate="2009-11-26T11:18:52.847" UserId="196" />
  <row Id="366" PostId="696" Text="But yeah, your response is what I've assumed my options are. I guess, I assume if I can calculate the clock cycles the assembler would take by hand that someone has perhaps already written some nice code to do this programatically" CreationDate="2009-11-26T11:23:57.493" UserId="196" />
  <row Id="374" PostId="699" Text="Thanks. Yes, I can see this is probably the most accurate solution.  I'm still chucking away at code that would give me at least even general cycle use analysis inside the code. I'm going to be using this to build some testing tools and it would be nice to set my upper bounds for parameters such as max allowed run time based on how efficiently the code + everything related to it is running on the current Atmel CPU in use" CreationDate="2009-11-26T22:11:53.853" UserId="196" />
  <row Id="381" PostId="705" Text="Actually we do, but I agree my original post does sound a bit amateurish. I am a mechanical engineer who mainly works in the energy industry (although in IT these days) and my steam engineer colleague is VERY experienced and knows what he is doing. Can't say too much at the moment (NDAs). However, it is the R &amp; D data measurement and monitoring that we are trying to do as cost efficiently as possible. Also using wireless is because we don't want to be too close during the R &amp; D phase." CreationDate="2009-11-27T09:58:58.550" UserId="297" />
  <row Id="385" PostId="664" Score="1" Text="Didn't realize that - thanks!" CreationDate="2009-11-27T17:35:49.893" UserId="84" />
  <row Id="388" PostId="712" Text="Avoiding right angles --- do you mean literally making rounded corners on traces?  (Unless it can be a straight line I guess.)" CreationDate="2009-11-27T22:29:07.273" UserId="344" />
  <row Id="391" PostId="710" Score="1" Text="Are you sure you need that much processing speed? 10 kHz doesn't sound too fast. Perhaps something like an ARM7 or dsPic will be sufficient." CreationDate="2009-11-27T22:57:36.677" UserId="328" />
  <row Id="393" PostId="712" Text="I think he means that you can have angles just not at 90 degrees. I haven't seen any rounded corners, well, in a long time. But if you look at the motherboard in your PC youll also see all corners are much less than &lt;90 degrees. If the line needs to go 90 then it will often be split into, well, maybe a few 30 deg angles " CreationDate="2009-11-28T00:02:48.087" UserId="196" />
  <row Id="394" PostId="712" Score="3" Text="Two 45 deg angle corners is typical. But using transmission line tracks and proper termination is more important than corner style. If you don't have terminated transmission lines, then different corner styles won't make any difference." CreationDate="2009-11-28T00:22:41.780" UserId="328" />
  <row Id="395" PostId="664" Text="The LM358 is a dual op-amp, not a comparator." CreationDate="2009-11-28T03:28:05.947" UserId="328" />
  <row Id="396" PostId="664" Text="gack! you're right, I had a brain cramp, I was thinking of an LM393." CreationDate="2009-11-28T03:47:39.290" UserId="330" />
  <row Id="397" PostId="710" Text="depends on the control loop's details and requirements: phase margin is impacted by the latency from input to output of the control algorithm. If the signal processing is complicated, that will take more cycles than if it's simple. If the phase margin requirements are stringent, you will have less time available. Better to design a board with a bit of a surplus of CPU power, than to design a board with a bit of a deficit, as you can always make things slower." CreationDate="2009-11-28T04:59:47.200" UserId="330" />
  <row Id="398" PostId="712" Text="two 45degree angles is very common as in a trace they have excellent matching properties, I will find a guide later that explains what design considerations to take into account to do this properly." CreationDate="2009-11-28T14:20:14.530" UserId="230" />
  <row Id="399" PostId="719" Text="Very well said, I would like to add there are many buck converters that operate well at .8 V so you can easily use two solar panels in series." CreationDate="2009-11-28T14:22:05.217" UserId="230" />
  <row Id="400" PostId="719" Text="@Kortuk: boost converters? (not buck converters)" CreationDate="2009-11-28T15:39:39.203" UserId="330" />
  <row Id="401" PostId="721" Text="That's a pretty neat device. I'll have to order one and try it out." CreationDate="2009-11-28T16:32:58.850" UserId="238" />
  <row Id="403" PostId="633" Score="1" Text="I had a broken wire in a digital circuit I did that drove me crazy. I took apart and rewired the whole thing three times and the problem kept moving." CreationDate="2009-11-28T16:56:08.313" UserId="238" />
  <row Id="405" PostId="719" Text="Sorry, my mind was not with me. I have no idea why I typed buck. Your voltage must not have been low enough." CreationDate="2009-11-28T18:49:59.037" UserId="230" />
  <row Id="406" PostId="740" Score="1" Text="[MyHDL](http://www.myhdl.org/doku.php) tries to fix some of those problems." CreationDate="2009-11-28T19:02:21.820" UserId="238" />
  <row Id="408" PostId="719" Text="Definitely a good point." CreationDate="2009-11-28T23:30:23.313" UserId="238" />
  <row Id="409" PostId="684" Text="jotasa, I know you are probably losing hope, but I should be able to read all of their documents this thursday evening and get you an answer." CreationDate="2009-11-29T18:42:04.613" UserId="230" />
  <row Id="412" PostId="751" Text="I'm looking for more of the physics of it. For instance, if I wanted to manually create a record, how would I do it?  Would I create a voltage across a section of the tape? How much voltage?&#xA;" CreationDate="2009-11-29T22:28:43.190" UserId="107" />
  <row Id="413" PostId="755" Text="We can have the controller some distance away. We have had trouble with thermocouple stability, and were looking at platinum wire sensors that use a precision resistance bridge with resisters that are fine tolerance over a wide temperature range. The pressure side seems still to be more difficult." CreationDate="2009-11-29T22:49:27.503" UserId="297" />
  <row Id="414" PostId="709" Text="We will be dealing with superheated steam, and we will need to log over considerable periods of time. I still think that we will need the pressure measurements." CreationDate="2009-11-29T22:50:40.823" UserId="297" />
  <row Id="415" PostId="751" Score="1" Text="A coil is positioned very near the tape, to write a 1, the coil is energized and it magnetizes that spot on the tape.  Reading is conducted similarly, the magnetized place on the tape induces a small current in the read head." CreationDate="2009-11-29T23:02:40.157" UserId="331" />
  <row Id="416" PostId="736" Text="I totally give this a go.  I'm at UNSW and uni is highly regarded in the robot dog soccer league...so I might look into that too!" CreationDate="2009-11-29T23:16:38.350" UserId="267" />
  <row Id="417" PostId="756" Score="1" Text="current mirrors are not more efficient than resistors. Any linear circuit, which a given amount of current passes through, and which drops a given amount of voltage, has the same energy usage. Doesn't matter whether it is a resistor or a diode or a transistor or something else. Current sources have value in this situation, but that value is being able to control the LED current, and not anything to do with efficiency." CreationDate="2009-11-29T23:25:54.507" UserId="330" />
  <row Id="418" PostId="751" Text="Could the magstripe be &quot;simulated&quot; by having metal strips with a small amount of voltage applied to them for the duration that they're read?  Each strip would represent a &quot;bit&quot; for instance." CreationDate="2009-11-29T23:30:33.953" UserId="107" />
  <row Id="419" PostId="751" Score="2" Text="@wackyvorlon: where are you getting your information? I'm pretty sure (but cannot find references online) that bits are encoded on magnetic strips using Manchester encoding, and NOT static levels, so that it is possible to use clock recovery techniques. I am also pretty sure that there are not several tracks and a strobe, but rather a single track. In any case it's useless to hypothesize unless someone can find a reputable source of information." CreationDate="2009-11-29T23:31:13.203" UserId="330" />
  <row Id="420" PostId="751" Score="2" Text="hmm... found this: it appears you may be correct. http://www.epanorama.net/documents/smartcard/magcard.html" CreationDate="2009-11-29T23:33:17.280" UserId="330" />
  <row Id="421" PostId="758" Text="Oops - it's the ATMega168 version." CreationDate="2009-11-30T03:05:22.183" UserId="295" />
  <row Id="422" PostId="691" Text="I understand your point here, but properly designed, you can use one zener diode in place of 5 or 10 resistors. They hold the same voltage over an extremely wide range of currents. the resistance of your wires and a semi-stable power source work perfectly. This is not the most intelligent system when compared to a switching system, but it gets the job done.&#xA;&#xA;You can cheaply overdo the voltage on an LED and PWM it on and off and it will accomplish the same task, but in far less controllable way." CreationDate="2009-11-30T03:10:17.920" UserId="230" />
  <row Id="423" PostId="758" Score="3" Text="@Sketchy you can edit you question if you need to, rather than adding detail in a comment." CreationDate="2009-11-30T03:38:10.407" UserId="328" />
  <row Id="424" PostId="721" Text="I would stand behind TI support any day, nice device." CreationDate="2009-11-30T04:09:05.583" UserId="230" />
  <row Id="425" PostId="759" Text="Brilliant - that answers my question handily. I didn't think the 168 would be capable of full human audio spectrum sampling, but if I can get a sample rate of at least 660 Hz I should be able to identify the high e string with no aliasing. I'll bump that up a bit for safety and sensibility though.&#xA;&#xA;Thanks!" CreationDate="2009-11-30T04:26:44.063" UserId="295" />
  <row Id="426" PostId="762" Text="Excellent, thanks for the info :)" CreationDate="2009-11-30T07:56:17.343" UserId="356" />
  <row Id="427" PostId="767" Text="seems very prone to error, ambient light, sloshing, etc." CreationDate="2009-11-30T12:54:06.380" UserId="330" />
  <row Id="428" PostId="642" Text="Make that the first few days of reading. Excellent writer and engineer." CreationDate="2009-11-30T12:55:47.687" UserId="230" />
  <row Id="429" PostId="516" Score="2" Text="Quick point: 2 diode drops isn't necessarily 2.2v.  The voltage drop of a PN junction is very much dependant on it's construction and the type of semiconductors involved.  They will even vary among devices of the same type.&#xA;&#xA;Mind, as well, that the 7805 is fine as long as it's got more than two or three volts of head room to regulate in.  The higher the input, however, the more power it has to dissipate.  Switching regulators, while somewhat more complex, are enormously more efficient." CreationDate="2009-11-30T15:13:31.957" UserId="331" />
  <row Id="430" PostId="552" Text="Look up things like high pass filters, they take advantage of the fact that inductive reactance increases with frequency, while capacitive reactance decreases.  " CreationDate="2009-11-30T15:16:12.313" UserId="331" />
  <row Id="431" PostId="755" Text="How precise/accurate do your measurements need to be?  I know the plants around here generally use thermocouples in control for the 1,000PSI+ boiler control systems.  &#xA;&#xA;McMaster-Carr has some pressure transducers that are rated for 1500 psi and up:&#xA;&#xA;http://www.mcmaster.com/#pressure-transducers/=4q8sr6&#xA;&#xA;Pretty cheap, too.  The NIST traceable ones are more money, but if that's what you want, it's available.  Are you working on this with an instrumentation engineer, or a vendor for process automation stuff?" CreationDate="2009-11-30T15:24:26.397" UserId="331" />
  <row Id="432" PostId="751" Text="It's pretty old-school technology." CreationDate="2009-11-30T15:29:18.830" UserId="331" />
  <row Id="433" PostId="770" Text="Mind, it depends a lot on the dialectric constant of the fluid.  Unless I'm mistaken, capacitive sensing is used more for detection of presence/absence than level.  It seems just about every method I've run into is dependant on specific gravity, though.  Tanks holding fluids of variable composition are tough to regulate." CreationDate="2009-11-30T15:31:37.940" UserId="331" />
  <row Id="434" PostId="763" Score="1" Text="My concern, I think, is that you really need to run an FFT to pick out the fundamental.  Guitars produce all kinds of frequencies when a string is plucked, and counting the zero crossings only gives you enough information to construct a square wave, making an FFT pretty thoroughly useless." CreationDate="2009-11-30T15:35:54.707" UserId="331" />
  <row Id="436" PostId="378" Text="I do AVR-GCC on Linux all the time. It works like a champ.  (and if you've used Arduino on Linux, you've used it too)" CreationDate="2009-11-30T18:56:07.997" UserId="215" />
  <row Id="437" PostId="710" Text="thanks, it's true, timing is critical in this application.  i didn't want to get into it, but actually the output should be computed within the time of one sample, so latency is key." CreationDate="2009-11-30T21:05:56.887" UserId="344" />
  <row Id="438" PostId="763" Text="Single-note guitar output (especially electric) is a close approximation of a sine wave, once you get past the initial transient.  No weird harmonics anywhere near the amplitude of the fundamental. All cheapie digital guitar tuners just do zero-crossing timing and don't do anything in the frequency domain.  Here's one example of the technique on an AVR 2323 (close relative to Arduino) http://www.myplace.nu/avr/gtuner/index.htm  and here's another using the Arduino with MIDI out http://www.youtube.com/watch?v=oGKE1vmAWCA" CreationDate="2009-11-30T21:57:31.500" UserId="215" />
  <row Id="439" PostId="516" Score="1" Text="1N4004 datasheet lists 1.1 V drop for 1 A of current and KBP005 bridge rectifier lists 1.0 V for 1.0 A, so it's a typical value." CreationDate="2009-11-30T22:25:09.957" UserId="142" />
  <row Id="440" PostId="765" Text="This isnt worthy of as an answer but a friend of mine did this for an art project a couple years ago.  Anyone interested I'd be happy to introduce you and I'm sure he would be happy to explain how he did it.  His project is over here: http://unixarts.com/sealevel.html  This combined both pumps and the sensors and required enough accuracy to loop up and down without too much skew" CreationDate="2009-11-30T23:25:03.267" UserId="196" />
  <row Id="441" PostId="602" Text="Taylor series are great for pure math but not particularly good for practical computations." CreationDate="2009-12-01T00:12:16.823" UserId="330" />
  <row Id="442" PostId="751" Text="Yes, but is there a way to replicate a magstripe using a PCB (and either coils in PCB wire to represent 1's or 0's when they are on or off?)" CreationDate="2009-12-01T00:39:34.240" UserId="107" />
  <row Id="443" PostId="763" Text="Great comments, thanks guys!" CreationDate="2009-12-01T02:35:53.833" UserId="295" />
  <row Id="444" PostId="771" Score="1" Text="Thanks very much! That's gonna be a bit more than I need to get a simple tuner going, but that chip looks perfect for some of my future projects. I'd eventually like to get a simple inline DSP deck going to experiment with effects processing.&#xA;&#xA;Thanks!" CreationDate="2009-12-01T02:43:29.273" UserId="295" />
  <row Id="445" PostId="781" Text="this may help too, this is a setup using an arduino and a mag reader.  part lists and schematics may help with your PIC project! http://hackmiami.org/2008/12/21/magnetic-stripe-card-reader/" CreationDate="2009-12-01T07:32:17.293" UserId="368" />
  <row Id="446" PostId="781" Text="these links may help as well... &#xA;http://www.instructables.com/id/Magnetic_stripe_card_spoofer/   &#xA;http://www.instructables.com/id/SMBGT71FJBYZ4QP/" CreationDate="2009-12-01T07:35:54.483" UserId="368" />
  <row Id="447" PostId="783" Text="there's a bug in your comment...instead of making a link, you made a broken image" CreationDate="2009-12-01T16:07:41.807" UserId="131" />
  <row Id="448" PostId="783" Text="fixed the link - great site thanks JT" CreationDate="2009-12-01T20:48:18.870" UserId="21" />
  <row Id="449" PostId="726" Text="That's classified. Are you cleared for GAME ANDES REDSHIFT?&#xA;&#xA;(Hint: Read The Atrocity Archives by Charles Stross for why I think this is so funny.)" CreationDate="2009-12-01T20:56:30.723" UserId="105" />
  <row Id="451" PostId="799" Text="They look like a brilliant supplier, but postage to Australia may be a bit pricy. Great suggestion, thanks!" CreationDate="2009-12-01T23:58:36.350" UserId="295" />
  <row Id="452" PostId="800" Score="2" Text="Could you provide some more info? Where do you want to get the info too? Those processes have lots of interfaces; Ethernet, CAN, UART, SPI, GPIO. JTAG could be used if it's only for development. You could use any of these." CreationDate="2009-12-02T00:39:57.220" UserId="328" />
  <row Id="453" PostId="801" Text="That's some weird power options...by far the most common ARM voltage I've seen is 3.3V." CreationDate="2009-12-02T01:18:14.943" UserId="131" />
  <row Id="454" PostId="802" Text="I've tried it with the power connected and unconnected to the target board (Olimex SAM7-P256) with no luck." CreationDate="2009-12-02T02:05:56.317" UserId="378" />
  <row Id="455" PostId="801" Text="The arm process on the board is at 3.3volts (and I'd expect the JTAG connector to adapt to this voltage too), the 5-9-12V supply is to power a board. " CreationDate="2009-12-02T02:07:20.040" UserId="378" />
  <row Id="456" PostId="712" Text="Today I ran across some auto route software that does infact use curves. http://www.eremex.com/products/topor/competitiveadvantages/uniquefeatures.html" CreationDate="2009-12-02T14:03:55.087" UserId="196" />
  <row Id="457" PostId="814" Text="This sounds great, I would just like to add that you need to load (pull current from) a battery to get a realistic measurement of the remaining battery life. You are much better off with a higher current divider with an off switch." CreationDate="2009-12-02T14:39:42.817" UserId="230" />
  <row Id="458" PostId="813" Text="Yeah, I will get you links to the ones I know of that work well tomorrow night. If you can use 3V then you should just use a Buck, If you need 5, you will need a buck boost." CreationDate="2009-12-02T14:42:33.667" UserId="230" />
  <row Id="459" PostId="814" Text="I just posted a similar response, and voted to delete it.  Apparently I had an old version of the page cached.  I voted this up, it's the way to go." CreationDate="2009-12-02T19:29:50.113" UserId="11" />
  <row Id="460" PostId="814" Text="+1 for switching the voltage divider. A very useful trick." CreationDate="2009-12-02T20:15:38.623" UserId="328" />
  <row Id="461" PostId="693" Text="That'll teach me to not read the question properly. Deleted my answer as it merely referred to the same sheet mentioned by todbot as: &quot;The Atmel appnotes on mega88-&gt;mega88P migration&quot;." CreationDate="2009-12-02T20:42:19.297" UserId="103" />
  <row Id="462" PostId="813" Text="Hmm OK I'll consider driving the uC on straight 3v3. The application drives some power MOSFETs so I will test to see if 3v3 logic level is sufficient to drive the MOSFETs otherwise I'll need some sort of voltage level translator (more parts, eep!). But it's all good :)" CreationDate="2009-12-02T20:48:09.827" />
  <row Id="464" PostId="831" Text="Thank you a ton, I will look into it within the week, I will leave the question open for other answers, but you are a great help!" CreationDate="2009-12-03T00:30:28.347" UserId="230" />
  <row Id="465" PostId="832" Score="2" Text="I use them for the drivers, which is why I make my choice, if a single client has a problem, it makes all of the cost saved go out the window." CreationDate="2009-12-03T01:42:49.387" UserId="230" />
  <row Id="466" PostId="830" Text="You will be there soon." CreationDate="2009-12-03T01:43:05.133" UserId="230" />
  <row Id="467" PostId="824" Score="2" Text="I am confused as to what this received a down-vote for. If the voter could give me feedback I will try to avoid such an action in the future." CreationDate="2009-12-03T01:56:14.343" UserId="230" />
  <row Id="468" PostId="826" Text="One note: The FIFOs on these chips tend to be pretty deep (as in 512 or 1024 characters deep!). That's good for most uses (obviously it keeps the data moving better), but if you want to receive single bytes with low latency, it can be a problem. I don't know how to adjust this for Windows, but if you need help with Linux, search the linux-serial mailing list for my name (Kohne) and you should find my relevant hacks." CreationDate="2009-12-03T02:55:28.140" UserId="259" />
  <row Id="469" PostId="826" Text="Yes, the other issue here is people forget often that USB is not like serial, it is not a dedicated connection with instant bus arbitration. If you are using USB, you must accept that there is a latency involved with it. We end up with a 20-100mS latency normally, a real serial port would be preferable, but what customer will have one." CreationDate="2009-12-03T03:00:13.850" UserId="230" />
  <row Id="470" PostId="175" Text="well that sucks. do you have an official infopage for that? Maybe another reason to give android a try. there's an andrpid arduino project:&#xA;http://web.media.mit.edu/~bonifaz/amarino/" CreationDate="2009-12-03T03:37:00.323" />
  <row Id="471" PostId="834" Score="1" Text="You can edit your post." CreationDate="2009-12-03T03:59:30.600" UserId="230" />
  <row Id="472" PostId="822" Score="3" Text="+1 for pointing out the importance of perspective. I would add, if it's 1% of your power budget, it's not worth worrying about (unless you have a bunch of voltage dividers!) -- if it's 5-10% of your power budget, it may be worth worrying about; if it's 20% or more it is. (just my 2c)" CreationDate="2009-12-03T04:44:59.243" UserId="330" />
  <row Id="473" PostId="814" Text="@Kortuk: you have a very good point, but I'd decouple the voltage divider from the battery load. It's really easy to drive an N-channel FET directly from a microcontroller (well... there should be a small resistor between micro output + FET gate, I usually use 10-100 ohms) and have a resistor from FET drain to power supply. Much easier than trying to combine these two functions and finagle a switchable voltage divider. Besides, there are lots of times when you want to measure a battery voltage at no-load or near no load. Actually if I had to pick one or the other, I'd measure it at no-load." CreationDate="2009-12-03T04:49:42.060" UserId="330" />
  <row Id="474" PostId="824" Score="1" Text="ditto. It's a great question...." CreationDate="2009-12-03T04:51:32.110" UserId="330" />
  <row Id="475" PostId="834" Text="yeah except I did it anonymously and had a cookie fail :/" CreationDate="2009-12-03T05:04:05.647" UserId="386" />
  <row Id="476" PostId="826" Score="1" Text="+1 -- I was going to say the same things. I've used FTDI chips successfully with 921.6 Kbaud and yet have rarely run into any buffer overruns on my PC, so they've done a good job with both the hardware and Windows drivers." CreationDate="2009-12-03T05:14:38.903" UserId="330" />
  <row Id="477" PostId="826" Score="1" Text="@Michael K: FIFOs won't affect your latency unless they're badly designed. The latency with any USB &lt;-&gt; RS232 converter is primarily due to the inherent USB timeslot restrictions, as Kortuk points out." CreationDate="2009-12-03T05:16:10.210" UserId="330" />
  <row Id="478" PostId="802" Text="I can't think of anything else obvious to try. Maybe it is toast :(." CreationDate="2009-12-03T05:31:16.960" UserId="328" />
  <row Id="479" PostId="833" Text="Keyspan's OK, we have those at work and they're one of the few non-FTDI devices that has worked well for me. it didn't go up to the baud rate I had hoped though." CreationDate="2009-12-03T13:50:54.603" UserId="330" />
  <row Id="480" PostId="840" Text="I frequently catch myself trying to recite Ohm's law and rewrite it  for the value I'm solving for.  I can do it pretty quickly in my head, but it would be nice to have a cheat sheet with the simple stuff worked out.  Anything really complex I do on my laptop or in my notebook anyway, which isn't limited to my workbench.  This is a great list to pick from." CreationDate="2009-12-03T14:03:27.923" UserId="11" />
  <row Id="481" PostId="842" Text="I finally got a link that didn't require subscription to the iWrap documentation.  Have you tried the SLEEP command? (s5.42, http://www.rfsolutions.co.uk/acatalog/WT11-iWRAP_UserGuide.pdf)" CreationDate="2009-12-03T14:27:31.627" UserId="11" />
  <row Id="482" PostId="811" Score="1" Text="Are you thinking thermal or NIR?  Thermal would be a bit expensive for the project and subject to a whole host of other problems.  I don't think an NIR camera would provide much more useful information than any gray scale image you could get from any other sensor, and frankly a filter to pick your desired band would be cheaper." CreationDate="2009-12-03T14:41:06.050" UserId="11" />
  <row Id="483" PostId="844" Text="What about WHAT inductor?  It would probably be best to provide details for the network in question.&#xA;&#xA;Also, if you have access to a lab I suggest trying it out.  Seeing it really helps you grasp what's going on." CreationDate="2009-12-03T14:57:36.197" UserId="11" />
  <row Id="486" PostId="412" Text="the arduino circuit is designed to switch between an external voltage &gt;7V and 5V from the usb.  it depends on the incoming voltage being higher, whereas i was trying to switch between 5V and 5V.&#xA;&#xA;i ended up just using a switch... heh." CreationDate="2009-12-03T15:43:36.620" />
  <row Id="487" PostId="844" Score="1" Text="Yeah, please give us the full text of the homework problem if you want us to solve it for you" CreationDate="2009-12-03T15:59:56.853" UserId="131" />
  <row Id="488" PostId="844" Score="2" Text="someone *please* add a homework tag" CreationDate="2009-12-03T17:40:45.637" UserId="330" />
  <row Id="490" PostId="839" Text="equations are not useful without an explanation of what they refer to" CreationDate="2009-12-03T17:43:48.957" UserId="330" />
  <row Id="491" PostId="811" Text="Was thinking about thermal - but I didn't have any idea how much they were." CreationDate="2009-12-03T18:07:15.203" UserId="238" />
  <row Id="492" PostId="822" Text="Sounds like a good rule of thumb to me. The other important point, is that we can measure and calculate these things. And doing so it more helpful than guessing :)" CreationDate="2009-12-03T20:39:47.107" UserId="328" />
  <row Id="493" PostId="822" Text="Good point Jason. A bit more about the application: it is a lighting system that will be sitting unused for long periods of time, and then when powered on, draws about 3A from the supply with a constant current circuit. So in operation, the power draw for voltage monitoring is an insignificant part of total power draw. However in the standby mode, I'd like for the battery capacity to not be unnecessarily drained as much as possible, or rather I'd like any unavoidable parasitic drain to be minimised in standby mode. " CreationDate="2009-12-03T21:32:52.447" />
  <row Id="494" PostId="822" Text="@Kheng: Is it possible to have everything except the microcontroller on a separate power supply? They switch the peripherals on all at once with one relay or fet under the control of the uC. It should then be easy to control the standby current of of the uC and you don't have to worry about minimising the power in individule circuits." CreationDate="2009-12-03T21:57:28.093" UserId="328" />
  <row Id="495" PostId="837" Text="I work at a startup company where the most experienced embedded systems guys are just out of college(ie. Myself and the other guy that has been working with me for about 2 years). I spend a very large portion of time teaching myself about industry practice during my work week. As I have been reading I have been informed for all but our lowest cost system an RTOS would be a large improvment." CreationDate="2009-12-03T22:13:46.093" UserId="230" />
  <row Id="496" PostId="837" Text="There seem to be very low resource RTOS system for things like PICs and MSP430s that can help create a deterministic system out of a very complicated one, also greatly cleaning up our management of keeping modules separated. I have been part of a two man team that effectively built an in field data collection and routing system. Now that I look at RTOS I see it is perfect for what we designed." CreationDate="2009-12-03T22:22:14.390" UserId="230" />
  <row Id="497" PostId="837" Text="Sorry for using three post slots, your answer is very helpful, I am looking for a very low resource solution, but this information is valuable to have, thank you for the help." CreationDate="2009-12-03T22:23:24.607" UserId="230" />
  <row Id="498" PostId="837" Text="don't worry about the comment count (IMHO one thing that the StackExchange framework is lacking is support for discussions... the Q / A format covers most things but not some)... sounds like you have a pretty good handle on what you're looking for. I haven't looked at the FreeRTOS that Steve has mentioned but if it has been ported to low-end microcontrollers perhaps it will do the scheduling management you need." CreationDate="2009-12-04T00:10:12.887" UserId="330" />
  <row Id="499" PostId="837" Text="It seems to save the state of each thread though the stack(something like 50 push/pull statements) and can handle timed interrupts. My system would normally use a port interrupt for thread switching, but the task looks doable. I do wish this site type handled discussion in a better format." CreationDate="2009-12-04T00:46:37.690" UserId="230" />
  <row Id="500" PostId="826" Text="Yes, we have also implemented very very high baud-rates, it has been excellent so far." CreationDate="2009-12-04T01:04:21.617" UserId="230" />
  <row Id="501" PostId="684" Score="2" Text="I am not going to make this an answer, as it is not one, I do not see more information about it easily, but the datasheet is all I need to reverse engineer it. You should be able to do everything this chip does with a 3 dollar PIC. If you could figure out what this chip is connected to(Pin numbers are important) I can help post an answer about how to approach a reverse engineering job. You really need a working one for a full reverse engineer, or see if the system engineers will give you more information since it is out of production." CreationDate="2009-12-04T01:15:57.867" UserId="230" />
  <row Id="502" PostId="813" Text="I did a very fast search on the range you specified on TIs site. The link shows you the result and allows you to revise the search conditions. The chip it returned will supply 1A continuous. I am sorry the link is so long, I hope it still of help. They have some development boards that do not require a layout and I would suggest a development board that is low cost. The link is in my next post." CreationDate="2009-12-04T01:28:45.143" UserId="230" />
  <row Id="503" PostId="813" Text="It still does not fit. The search options are on the right of this page. http://focus.ti.com/analog/docs/powerhome.tsp?familyId=64&amp;contentType=4&amp;DCMP=TIHeaderTracking&amp;HQS=Other+OT+hdr_p_power. Part number is TPIC74100-Q1." CreationDate="2009-12-04T01:30:05.747" UserId="230" />
  <row Id="504" PostId="849" Text="I forgot to submit my response, so I will add a comment to avoid clutter. jkopel is correct here, you are better off with sensor-&gt;uC-&gt;USB, but the environment is key. If you need more pins you can get external ADC modules and interface to them through SPI or I2C protocol rather easily." CreationDate="2009-12-04T07:17:39.547" UserId="230" />
  <row Id="505" PostId="850" Text="Agreed, if you have an application with range on sensors, you should probably find a more intelligent way of data transfer." CreationDate="2009-12-04T07:23:50.167" UserId="230" />
  <row Id="507" PostId="851" Text="Tags are absurd because I wasn't able to create new ones." CreationDate="2009-12-04T10:32:52.230" UserId="198" />
  <row Id="508" PostId="851" Score="2" Text="Tags are based on reputation...you couldn't have just anyone logging in an creating / changing them...all you would get would be profanity and off topic conversation." CreationDate="2009-12-04T10:56:20.190" UserId="21" />
  <row Id="509" PostId="851" Text="I know, I was just absolving myself :) Thanks." CreationDate="2009-12-04T11:27:31.767" UserId="198" />
  <row Id="510" PostId="851" Score="2" Text="ppvi: I sympathize. I posted a feature request about this on stackexchange's website. In the meantime, just post a request for someone else to add them in a comment." CreationDate="2009-12-04T14:08:37.100" UserId="330" />
  <row Id="511" PostId="854" Score="1" Text="I'd like to stress that using UL-listed wall transformers are a great way to sidestep some of the certification issues, but make sure you understand what you're using.  You probably still need to do some power regulation/filtering in your product as well.  Good answer!" CreationDate="2009-12-04T14:59:47.460" UserId="11" />
  <row Id="512" PostId="852" Text="or wireless in that situation." CreationDate="2009-12-04T17:10:40.927" UserId="230" />
  <row Id="514" PostId="851" Score="3" Text="I can create a new account and ask a question (which has a large bold title) with profanity and off topic conversation, but I can't create my own tags (which are much smaller than the title)? Seems a little misguided, especially for bootstrapping new communities who don't have a whole lot of high ranking users or tons of tags already created." CreationDate="2009-12-04T18:25:56.353" UserId="131" />
  <row Id="515" PostId="851" Text="Note: I was forced to add tags. But only existing ones." CreationDate="2009-12-04T18:41:00.680" UserId="198" />
  <row Id="516" PostId="861" Score="1" Text="What programmer are you using to write to the chip?" CreationDate="2009-12-04T22:21:40.347" UserId="11" />
  <row Id="517" PostId="861" Text="According the the avrdude command line it was a usbtiny." CreationDate="2009-12-04T22:39:51.930" UserId="9" />
  <row Id="518" PostId="498" Score="2" Text="It's also not unreasonable to avoid a microcontroller because of the code creation/maintenance/testing costs. That's something that went over my head as a junior engineer, but which I have come to understand very well as I have gained experience. The &quot;oh, we can just do it in software&quot; mentality can get you into trouble sometimes when you have to prove something is going to work." CreationDate="2009-12-05T00:19:46.457" UserId="330" />
  <row Id="520" PostId="877" Score="1" Text="I thought I had seen RGB diodes where they managed to let you avoid this design constraint, although I will admit I normally use an intelligent driver if I have RGB diodes." CreationDate="2009-12-05T11:05:54.030" UserId="230" />
  <row Id="521" PostId="877" Text="Intelligent drivers handle current in a different way, and some of them don't need resistors at all (TCL5940, IIRC)" CreationDate="2009-12-05T11:13:52.227" UserId="244" />
  <row Id="522" PostId="881" Text="It's good to hear that someone else has seem something like it.  What was your filtering algorithm?" CreationDate="2009-12-05T18:43:16.917" UserId="213" />
  <row Id="523" PostId="751" Text="I'm not certain there is.  It's hard to figure the behavior of a coil on the PCB, and whether it would produce enough magnetic flux.  On the normal device, the coil is wrapped around a laminated iron core that has a split where it contacts the magnetic strip.  This creates much more flux than just the wire itself, and allows the flux to be better focused.  I wouldn't hold out high hopes for a PCB with circular tracings producing enough flux." CreationDate="2009-12-05T20:16:33.050" UserId="331" />
  <row Id="524" PostId="883" Score="1" Text="I'm a big advocate of buying components in bulk.  They have near infinite shelf life(except for electrolytics), and in bulk the price can halve.  When I buy transistors I tend to buy 75 or 100 at a time.  When I do that, I pay less than half per transistor, and I spread the shipping across more components." CreationDate="2009-12-05T20:18:49.660" UserId="331" />
  <row Id="525" PostId="887" Score="3" Text="I don't think you understand exactly the use of the forward voltage drop.  It refers to minimum forward bias for the junction to conduct.  It's important when connecting LEDs in serial, if the sum of the voltage drops is greater than the supply voltage, it will not behave properly.&#xA;&#xA;What is important for resistor sizing is supply voltage and maximum current.  The chart you link to gives luminosity/current graphs.  One must pick the requisite current, 50mA seems to be the peak they recommend.  Then use ohm's law with the current and supply voltage to specify the resistor.&#xA;" CreationDate="2009-12-05T20:37:13.773" UserId="331" />
  <row Id="526" PostId="888" Text="Auto reset is a feature of the electronics of the board itself, not the bootloader.&#xA;" CreationDate="2009-12-05T20:41:56.307" UserId="9" />
  <row Id="527" PostId="877" Text="I understand that, I was qualifying my knowledge by adding I normally do not use a resistor for my LEDs. When I am not using an intelligent LED driver, I normally make my own with a severe over current for short bursts." CreationDate="2009-12-05T20:55:08.167" UserId="230" />
  <row Id="528" PostId="887" Score="4" Text="I think both of you are saying the same thing in different words. Todbot calculates the resistor value the way I would, and it works. You are calculating the same thing, but you are being more specific what light amount you want. I have seen many datasheets where the voltage they specify is the voltage they will be if at max-light output(with DC current). You are taking a curve and picking the amount you want, neither approach is wrong." CreationDate="2009-12-05T20:58:12.373" UserId="230" />
  <row Id="529" PostId="887" Score="3" Text="wackyvorlon, for a given power supply voltage (5V say) and a given desired current through the LED (20mA usually), you need to know the forward voltage of the LED to calculate the value of the current limiting resistor." CreationDate="2009-12-05T21:11:05.903" UserId="215" />
  <row Id="530" PostId="881" Text="I would suggest you did what you said, take 3 reading, 5 would be better, 7 better than that, but if there is an error of something around 1/1000 then you just need 3. Take the median. Problem will be solved. if you take 5 it will take a freak occurrence to have a problem." CreationDate="2009-12-05T22:08:25.197" UserId="230" />
  <row Id="531" PostId="882" Score="1" Text="I think, given the question, it is safe to assume that mad_z would need more information then telling him to read the datasheet to help him." CreationDate="2009-12-06T00:23:59.400" UserId="12" />
  <row Id="532" PostId="891" Score="3" Text="I would like to note, there are op-amps designed for many different things, I had friends build something like this and it was not working because their op-amp offset was around 100mV and it was not a rail-rail op-amp. Otherwise, excellent design. I never consciously think about how to connect the sense lines, but I have always connected them to the resistor pads, dumb luck or something someone told me long ago, who knows." CreationDate="2009-12-06T00:43:43.157" UserId="230" />
  <row Id="533" PostId="887" Text="@todbot, I think he understood it, I just think he is saying it in a different way." CreationDate="2009-12-06T00:58:40.967" UserId="230" />
  <row Id="534" PostId="883" Text="I always buy in bulk from mouser/digikey(normally mouser) for parts, our school also does a weekly order that I can place parts on and have them free of shipping." CreationDate="2009-12-06T01:00:48.343" UserId="230" />
  <row Id="535" PostId="873" Text="I will admit, at work I have one cheap o-scope, at school I can get a hold of some nice equipment, but rarely need it. The most important thing for me at school is use of a current-limited power supply. At work we use batteries in our devices, so stuff blows up when we mess up. Nothing like shorting a car battery." CreationDate="2009-12-06T01:02:20.183" UserId="230" />
  <row Id="536" PostId="887" Text="agreed, now that I re-read it." CreationDate="2009-12-06T04:36:33.780" UserId="215" />
  <row Id="537" PostId="894" Text="Thanks for your help.  I did get it working without the additional transistor (though it runs backwards from what my switch readings say -- I think that makes sense).  I don't completely understand what you mean by the &quot;current limiting resistor&quot;, though.  That sounds like it'd be in parallel with the pull-up resistor?  I have pull-up power for the DS2406 and pull-up power for the transistor base." CreationDate="2009-12-06T06:19:35.790" UserId="347" />
  <row Id="538" PostId="894" Text="In [the diagram you linked](http://www.kpsec.freeuk.com/images/diopro.gif) there's a resistor connected between the input on the left and the base of the transistor.  Usually the value of this resistor is about 1k when using the transistor as a switch." CreationDate="2009-12-06T06:49:55.243" UserId="215" />
  <row Id="539" PostId="894" Text="Ah.  I didn't read that as a resistor (really new at electronics). This is the circuit that is working, but I'd appreciate someone warning warn me of risks of explosion.  Nothing smells funny.  :/ http://skitch.com/dlsspy/nkmma/ds2406-controlled-relay" CreationDate="2009-12-06T07:06:20.790" UserId="347" />
  <row Id="540" PostId="877" Text="Me too :-) &#xA;I think this is the only way to get rated light output in multiplexed led arrays. " CreationDate="2009-12-06T11:28:19.243" UserId="244" />
  <row Id="541" PostId="891" Score="1" Text="Kelvin connection layout: http://imgur.com/gVrH1 .&#xA;Source: http://focus.ti.com/lit/ml/slua366/slua366.pdf" CreationDate="2009-12-06T19:16:38.787" UserId="327" />
  <row Id="542" PostId="881" Text="I'm doing 5 now.  I tried just taking the higher of 2, but an error still crept in last night (I've got 3 sensors reading every minute, so I get thousands of datapoints a day)." CreationDate="2009-12-06T19:50:17.640" UserId="213" />
  <row Id="543" PostId="876" Score="2" Text="OK, I've tried this and it works OK (with a simple test with my multimeter) and is simple to do and doesn't take much in the way of additional components or board space which is good. My plan is to route the current sensor signal from each of the servos into one of the CD74HCT138E active low muxes and read them during the 50Hz PWM refresh cycle; so I read the feedback about the current draw for the servo as I generate the PWM for it...    " CreationDate="2009-12-06T21:46:46.467" UserId="255" />
  <row Id="544" PostId="891" Text="I think this is probably a little more complex (and I expect accurate) than I need. Since I have a minimum of 18 servos that I want to measure I guess the component count and cost will be prohibitive..." CreationDate="2009-12-06T21:48:19.197" UserId="255" />
  <row Id="545" PostId="891" Score="2" Text="I believe jason is giving an industry acceptable answer, until you want to sell the device, you are probably more than fine. I would suggest understanding his approach though, as the knowledge of what he was doing is far more valuable than the implementation. " CreationDate="2009-12-06T22:54:45.223" UserId="230" />
  <row Id="546" PostId="876" Score="3" Text="Please remember that multimeters have a built in lowpass. You may find that your microcontroller receives less valuable numbers without implementation of a simple lowpass RC filter." CreationDate="2009-12-06T22:55:57.560" UserId="230" />
  <row Id="547" PostId="887" Score="1" Text="&quot;Then use ohm's law with the current and supply voltage to specify the resistor.&quot;  That's wrong.  You need to use the supply voltage minus the voltage drop of the LED." CreationDate="2009-12-07T01:22:40.480" UserId="142" />
  <row Id="548" PostId="791" Text="For a Canon, just use CHDK.  http://chdk.wikia.com/wiki/CHDK" CreationDate="2009-12-07T01:25:42.657" UserId="142" />
  <row Id="549" PostId="891" Text="do you need to measure each one's current? anyway some of those zetex parts were around 50c each, i think" CreationDate="2009-12-07T01:37:33.820" UserId="330" />
  <row Id="550" PostId="595" Text="I will add my vote.  It can be found on abebooks as well.  Excellent book, covers how to do all manner of analog math with op-amps.  Linearization, converting linear to logarithmic, etc." CreationDate="2009-12-07T01:38:41.320" UserId="331" />
  <row Id="551" PostId="891" Score="1" Text="Speaking as someone who works with many tinkerers, it is a size issue normally and not a cost one. Complexity and size go up, bugs go up exponentially, especially bread-boarded." CreationDate="2009-12-07T04:14:18.310" UserId="230" />
  <row Id="552" PostId="887" Text="yes. viz. the LED calculator I linked to." CreationDate="2009-12-07T07:01:21.897" UserId="215" />
  <row Id="553" PostId="876" Text="That's good to know. " CreationDate="2009-12-07T07:39:48.567" UserId="255" />
  <row Id="554" PostId="891" Text="Kortuk, thanks, yes, I may well go this route if the other way doesn't work out for me." CreationDate="2009-12-07T07:42:33.310" UserId="255" />
  <row Id="555" PostId="891" Text="Jason, yes, I'm using the current measurement to tell me how much stress the servo is under. The idea being that I can use this as a simple feedback mechanism. I saw that the Zetex parts were pretty cheap, it was when I looked for something similar in a DIP package that I might have a chance of soldering that the prices went up. That said, if they came packaged in 8s in a single DIP then that might work better. I may end up playing with both approaches. Thanks for the info.  " CreationDate="2009-12-07T07:45:42.120" UserId="255" />
  <row Id="556" PostId="911" Text="Actually, I think I do need 64KHz. The PWM frequency is about 500Hz, which divides into periods of 2 milliseconds. At the lowest level (before turning off) it's on for 1/256 of that time, or 8 ms bursts. That works out to be 128KHz (I accidental used 128 levels in my original estimate)." CreationDate="2009-12-07T12:33:24.737" UserId="356" />
  <row Id="557" PostId="906" Score="1" Text="Do you really need to modulate at 64 kHz? If you are just trying to control the visible brightness that's faster than required. Some more details as the voltage range you expect from the battery and the operating current and voltage of the LED would help provide a better answer." CreationDate="2009-12-07T12:37:46.707" UserId="328" />
  <row Id="558" PostId="861" Text="That doesn't necessarily mean it was a usbtiny, it could be a clone." CreationDate="2009-12-07T13:42:38.873" UserId="11" />
  <row Id="559" PostId="910" Text="Hmm. Maybe I should only power them up when I'm about to do a reading." CreationDate="2009-12-07T13:59:57.803" UserId="213" />
  <row Id="560" PostId="891" Text="Digikey does sell those SMT adapters (little circuit boards with SIP pins), if you're worried about quick prototyping. If you're laying out a circuit board I wouldn't worry about SOT23's; I'm pretty clumsy and I can deal with them fine. (TSSOPs and 0402 components are another matter...) " CreationDate="2009-12-07T16:06:52.733" UserId="330" />
  <row Id="561" PostId="919" Text="Thanks for the response, wasn't trying to be confusing.  I wrote the above question using as much as I understood about the problem, so after reading your response, it sounds like I really don't know about what I'm talking about and I have a lot more to learn." CreationDate="2009-12-07T18:25:37.087" UserId="374" />
  <row Id="562" PostId="809" Text="I've been searching and I can't find any links joining haartraining and arduino, so you may be out of luck." CreationDate="2009-12-07T18:57:26.607" UserId="103" />
  <row Id="563" PostId="919" Score="1" Text="@sheepsimulator, I have run into a problem like this, as I only have a moment, look into schmitt trigger chips to buffer. The major thing to remember is a slew rate is often affected by the load on the device, if you want to drive 1A you will find the slew rate is going to be quite different than 1uA of current." CreationDate="2009-12-07T19:14:30.617" UserId="230" />
  <row Id="564" PostId="902" Score="1" Text="I've wondered about this, too.  Can you make a display of an array of LEDs and then detect touch by using the same LEDs to sense reflected light from a finger?" CreationDate="2009-12-07T20:26:33.947" UserId="142" />
  <row Id="565" PostId="919" Text="yeah, load capacitance (cables, MOSFET gates, etc.) really mattters." CreationDate="2009-12-07T20:37:58.197" UserId="330" />
  <row Id="566" PostId="919" Text="(&amp;Delta;v/&amp;Delta;t = I / C)" CreationDate="2009-12-07T20:38:38.790" UserId="330" />
  <row Id="567" PostId="891" Text="Ok, that's good to know. " CreationDate="2009-12-07T22:25:40.780" UserId="255" />
  <row Id="568" PostId="924" Score="1" Text="I went for a more basic description, your description is very astute though." CreationDate="2009-12-07T22:29:42.870" UserId="230" />
  <row Id="570" PostId="906" Text="I am wanting to control the physical brightness, and colour, of an RGB LED. I'm pretty sure that I'm looking at current figures of 200mA for each colour of the LED.&#xA;&#xA;The battery voltage should be 3.5-4.5v, and the voltage of the LEDs vary between 2.5-3.2v." CreationDate="2009-12-08T00:25:43.307" UserId="356" />
  <row Id="571" PostId="912" Text="Thanks for the info :)" CreationDate="2009-12-08T00:26:28.470" UserId="356" />
  <row Id="572" PostId="926" Score="1" Text="Firmata can also be used to control and Arduino from other software as well all you need to do is open up a serial port(though processing is probably the easiest)" CreationDate="2009-12-08T01:18:09.317" UserId="81" />
  <row Id="574" PostId="919" Text="@sheepsimulator, one more thing, if you are just trying to at a simple level make sure everything will work, compare your uC slew rate to your buffer slew rate. if the uC slew rate is slower, you will not notice a difference." CreationDate="2009-12-08T02:31:06.047" UserId="230" />
  <row Id="575" PostId="97" Score="1" Text="Mind, the charging sequence for the battery is highly dependant on it's chemistry.  LiPos require a special process." CreationDate="2009-12-08T05:41:48.067" UserId="331" />
  <row Id="576" PostId="886" Text="I've got one of the digitally controlled soldering irons like they sell at Sparkfun (Aoyue, I think).  Best tool purchase I've made." CreationDate="2009-12-08T19:56:17.443" UserId="213" />
  <row Id="577" PostId="886" Text="I've just bought a ZD-916 temperature controlled soldering iron from Maplin and the difference between that and my cheapo pencil iron is amazing. Suddenly I can almost solder properly :)" CreationDate="2009-12-08T22:36:01.123" UserId="255" />
  <row Id="578" PostId="886" Score="3" Text="Add a power supply to that list and you're golden." CreationDate="2009-12-09T02:16:51.617" UserId="238" />
  <row Id="579" PostId="928" Text="Hi Amos,&#xA;&#xA;Thanks for your comments. When I started debugging this problem I ignored the trailer as I thought that it was not relevant, but when I cleared the ARP cache on my computer and took a new copy of the packets moving across the network I realized that the trailer was the only thing that I could imagine being relevant that was different between the 2 packets.&#xA;&#xA;I've updated the question with a copy of each packet and a visual diff.&#xA;&#xA;thanks&#xA;&#xA;Hamish" CreationDate="2009-12-09T04:35:58.647" UserId="298" />
  <row Id="580" PostId="938" Score="2" Text="Yes, but if you strip the jacket and lightly scrape off the cladding on one side with a razor blade, the amount of light that gets through will vary as you bend the fiber. A nice feature is that you get a bi-directional signal. If you bend away from the scoring, less light gets through, if you bend toward it, more light gets through. You would have to use two traditional bend sensors to get that. They also look cool." CreationDate="2009-12-09T06:29:32.420" UserId="207" />
  <row Id="581" PostId="874" Text="I'm looking for something that allows me put several together in a daisy chain, much like the MAX6969 from Maxim whereby when I click on on Cin, 16 clock cycles later it shows up at Dout. So to have two of the same chips next to each other I can send out 32 bits of data, and both chips will now contain data." CreationDate="2009-12-09T08:41:47.490" UserId="373" />
  <row Id="582" PostId="913" Text="Cool but is there any project in Python ?" CreationDate="2009-12-09T08:53:21.613" UserId="199" />
  <row Id="583" PostId="928" Text="According to a thread here: http://www.edaboard.com/ftopic317401.html a user with a similar problem to yours traced it to the following: &quot;And I found the problem!!!&#xA;It seems that the MAC address is more than just an address. It actually contains information about the device and type of broadcasts. Seems that the switch didnt like multicast messages&quot;&#xA;I don't know if that helps at all." CreationDate="2009-12-09T10:28:07.173" UserId="103" />
  <row Id="584" PostId="930" Text="Interesting. You wouldn't be the same Wim who's also one of the Dwengo Team would you?" CreationDate="2009-12-09T11:16:59.567" UserId="103" />
  <row Id="585" PostId="928" Text="Does your ethernet shield come with a mac address or do you have to create one yourself for it?" CreationDate="2009-12-09T12:27:27.927" UserId="103" />
  <row Id="587" PostId="936" Text="Unfortunately the signals an ECG handles are considerably stronger than the signals handled by an EEG, thanks anyway but I'd imagine they would be way too weak to pick up a signal through the skull.   " CreationDate="2009-12-09T12:39:03.507" UserId="399" />
  <row Id="588" PostId="935" Text="Cheers dude, they sound like the perfect little amp, is there an equivalent IC that can handle multiple channels? I'd like to make a 16  Channel EEG, but I don't want to have 16 separate IC's for the job." CreationDate="2009-12-09T13:10:34.977" UserId="399" />
  <row Id="590" PostId="934" Text="I've looked it's ok, but it's quite a basic setup, low bit depth and limited channels, it's also quite a large piece of hardware. I want a much more compact and comprehensive system. A channel with a bit depth of 10 is like a bare minimum for getting a decent representation of a brain signal, I'll definitely want more than that" CreationDate="2009-12-09T15:31:18.833" UserId="399" />
  <row Id="591" PostId="811" Score="1" Text="Yeah, they're pretty neat but very expensive.  They're a drop in the bucket for, say, a weapons platform, but for a hobbyist they're a bit out of reach." CreationDate="2009-12-09T17:27:47.283" UserId="11" />
  <row Id="594" PostId="930" Text="Yep, same one ;-)" CreationDate="2009-12-09T18:09:15.920" UserId="401" />
  <row Id="595" PostId="935" Text="I've just been looking at my electrodes, they are single connection 1pin mini DIN. If I use an instrumentation amp with + and - inputs, does that mean it will output the differential between two electrodes? I'm a tad confused as to how the electrodes wire up. I have been researching an electrode array called a montreal 10/20, where the input of all the electrodes is summed and used to cancel out noise, how would this fit in with the instrumentation amp circuit?&#xA;&#xA;Cheers again Todbot" CreationDate="2009-12-09T18:28:12.613" UserId="399" />
  <row Id="596" PostId="935" Text="Yeah no clue.  I've not played with instrumentation amps in 15 years, and have never done EEG stuff.  I'd pour over OpenEEG.  It looks like there's multiple different electrode systems described there, maybe you can find some circuit bits that do what you want." CreationDate="2009-12-09T20:02:21.380" UserId="215" />
  <row Id="597" PostId="941" Text="Why community wiki?" CreationDate="2009-12-09T20:38:31.847" UserId="374" />
  <row Id="600" PostId="936" Score="1" Text="Actually Jim, the hardware Cyphunk has suggested should be just about right for your purposes. The skin potentials an ECG picks up are comparable to those of an EEG (both measure nerve impulse). The AD620, AD624 or AD625 should suit your purposes admirably, depending on what functionality and circuit setup features you prefer." CreationDate="2009-12-10T00:29:51.227" UserId="295" />
  <row Id="601" PostId="964" Score="1" Text="Horowitz and Hill not Howe" CreationDate="2009-12-10T02:07:35.083" UserId="238" />
  <row Id="602" PostId="935" Text="Cheers for the help todbot" CreationDate="2009-12-10T02:08:58.220" UserId="399" />
  <row Id="603" PostId="936" Text="Cheers Sketchy, I was hoping to make something with 16 channels, so I've been looking for a chip that has multiple instrumentation amplifiers. Do you know of any, you can recommend?" CreationDate="2009-12-10T02:19:19.073" UserId="399" />
  <row Id="604" PostId="967" Text="Thanks Kortuk. This certainly does help. Question on the caps: electrolytic or ceramic? On the BJTs, op-amps, regulators any specific part numbers I should look out for?" CreationDate="2009-12-10T07:29:40.830" UserId="245" />
  <row Id="605" PostId="962" Text="Far too ambitious for me at the moment given time constraints, but thanks for the suggestion. I'm excited to dive further into analog signal conditioning for future prototypes. " CreationDate="2009-12-10T08:37:14.283" UserId="207" />
  <row Id="606" PostId="967" Text="@Kortuk: Can you explain what you mean by using a BJT over an op-amp in your first paragraph a little further?" CreationDate="2009-12-10T10:40:20.617" UserId="328" />
  <row Id="607" PostId="928" Text="The ethernet shield does not come with a MAC - I use a microchip 24AA02E48 to obtain a unique MAC and initialize the networking code with that value. I have collected the MAC addresses from a couple of computers on my local network and tried setting the MAC to those values (after turning the computers off to ensure that there were no collisions) I am still getting the same problem." CreationDate="2009-12-10T11:27:16.863" UserId="298" />
  <row Id="608" PostId="971" Text="To me that implies that the trailers are not the problem." CreationDate="2009-12-10T11:47:02.327" UserId="103" />
  <row Id="609" PostId="971" Text="As surely unless you have some bizarre setup for your gateway, lots of other people would be having this problem." CreationDate="2009-12-10T11:48:47.800" UserId="103" />
  <row Id="610" PostId="971" Text="Right. Rather than trying to pin down whether there is an error in your setup or code, I suggest that you find an example of using an ethernet shield with an Arduino from the internet and see if that will work. There's one which uses the Twitter library from the arduino website: http://www.arduino.cc/playground/Code/TwitterLibrary Or there's one from the arduino forums here: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1234028200/1 although you may need to read the whole thread to get it working. Other than that, find someone who'll let you try connecting your kit to their network." CreationDate="2009-12-10T12:26:49.247" UserId="103" />
  <row Id="611" PostId="971" Text="If it works then we know it's your code, if it doesn't then we know it's your setup. If you can get it to work on someone elses network then we know that it's your network, etc." CreationDate="2009-12-10T12:56:47.380" UserId="103" />
  <row Id="612" PostId="964" Text="Ah, thank you Shawn. Right you are." CreationDate="2009-12-10T14:29:42.540" UserId="404" />
  <row Id="613" PostId="967" Score="1" Text="@jadiaz, I think having both electrolytic and ceramic are important. I like to keep alot of ceramics around in the smaller values(1uF and less) and I like to have all of my big caps be electrolytic, as they are being used as a power supply for the chip, but are not good at absorbing high frequency power.&#xA;&#xA;@Clint, I will edit in an example a little later when I have a chance." CreationDate="2009-12-10T17:53:26.750" UserId="230" />
  <row Id="614" PostId="974" Score="1" Text="I completely forgot Zener Diodes. I forgot Diodes all together, but they are used regularly. I love a zener, and 5.1V zener diodes are almost completely temperature independent." CreationDate="2009-12-10T19:18:05.830" UserId="230" />
  <row Id="615" PostId="961" Text="The app note tells you exactly what you can select, then you need to make sure your microcontroller can do the same baud rate with less than 10% error." CreationDate="2009-12-10T20:42:10.890" UserId="230" />
  <row Id="616" PostId="982" Text="Fireflies! Wow! I think I'm going to need a large number of chips and an equal number of ping-pong balls. (If you don't know what I'm talking about follow the link and look at the videos of synchronising 64 Fireflies)" CreationDate="2009-12-10T20:47:45.073" UserId="103" />
  <row Id="617" PostId="968" Score="1" Text="yeah, we have a general rule of no potentiometers in production circuits." CreationDate="2009-12-10T22:28:53.887" UserId="330" />
  <row Id="618" PostId="975" Score="1" Text="22ga is best for breadboarding. 20ga is too large, and 24ga you may find coming loose too easily." CreationDate="2009-12-10T22:29:33.527" UserId="330" />
  <row Id="619" PostId="985" Text="I knew I would forget a few, Analog multiplexers are an example. I never have enough, having to order 20 or so every couple months." CreationDate="2009-12-11T01:12:19.323" UserId="230" />
  <row Id="620" PostId="975" Text="Thanks for clarifying!  It's one of those things I never committed to memory and only notice when on the spot like this.  FWIW, I have successfully used 24-ga (In fact, I believe that's what the boxes of precut breadboard wires are) and haven't noticed any problems." CreationDate="2009-12-11T13:24:52.863" UserId="11" />
  <row Id="621" PostId="995" Score="1" Text="high accuracy resistors aren't really an issue anymore; you can get 0.1% resistors for under 10c in moderate quantities (take a look at mouser or digikey). But you have  point about ADCs and op-amps." CreationDate="2009-12-11T23:34:57.117" UserId="330" />
  <row Id="622" PostId="995" Score="1" Text="True, but drift can be an issue as well. Those are a little more pricey. What I really meant were the highest quality resistors that are used for those designs. They might have come down in cost but use enough of them and they are are significant adder to the BOM. Maybe I'm wrong though." CreationDate="2009-12-12T03:26:34.073" UserId="404" />
  <row Id="623" PostId="982" Text="Yeah, some kind lately soldered up 64 of them. Don't know if he is already finished ;)" CreationDate="2009-12-12T14:27:24.293" UserId="407" />
  <row Id="624" PostId="961" Text="10%? 10% error is way too high for good UART communications... usually it's something like +/- 3%." CreationDate="2009-12-12T15:07:39.813" UserId="330" />
  <row Id="625" PostId="970" Score="4" Text="I'd downgrade the resistors - I'm quite happy with 1/4 Watt resistors.  Also, I'd look at replacing the LM7805 with something more power efficient.  7805's will drain batteries all on their own :(" CreationDate="2009-12-12T16:38:03.563" UserId="213" />
  <row Id="626" PostId="999" Score="1" Text="This, normally a band-gap reference, is one of the most dependable references. They are very stable over a wide temperature range." CreationDate="2009-12-12T22:30:24.743" UserId="230" />
  <row Id="627" PostId="995" Text="1/f noise is the problem that most people catch, it is the same reason it is so hard to explain to someone why they need a chopper amp." CreationDate="2009-12-12T22:35:28.967" UserId="230" />
  <row Id="628" PostId="998" Text="this is the best answer -- you really need a hardware solution that is a comparator + pulse generator. Measuring voltage with an ADC will not protect you against fast glitches where the supply voltage drops faster than the ADC can measure it." CreationDate="2009-12-13T00:30:09.343" UserId="330" />
  <row Id="629" PostId="970" Text="Well... I guess I don't use batteries that much." CreationDate="2009-12-13T04:26:45.373" UserId="328" />
  <row Id="630" PostId="1003" Score="1" Text="Eh, depends. Digital stuff, yes, it's separate because you're usually working in software that will be translated to hardware through a programming language or in a micro. Analog signals, specifically analog control loops, are almost always implemented directly in hardware if I'm not mistaken. I think specializing in both would be difficult but knowledge of one while specializing on the other is important (i.e. learn how signals interact so you understand them in an electronic system)." CreationDate="2009-12-13T15:36:24.767" UserId="404" />
  <row Id="631" PostId="999" Text="I'm accepting this one because:  a) it would allow me to measure the voltage over time and b) might be doable with parts I already have on hand." CreationDate="2009-12-13T16:02:38.033" UserId="213" />
  <row Id="632" PostId="998" Text="Are those likely to happen when running on battery?" CreationDate="2009-12-13T16:03:14.710" UserId="213" />
  <row Id="633" PostId="1003" Text="Try telling that to an avionics or mechanical engineer who is developing an analog control system with hydraulics or pneumatics, or a mechanical system where the actuators are treated as a black box (e.g. buy an off the shelf servomotor + controller, + design the control loop)." CreationDate="2009-12-13T16:16:24.237" UserId="330" />
  <row Id="634" PostId="998" Text="If you have a high-current load, perhaps." CreationDate="2009-12-13T16:17:28.913" UserId="330" />
  <row Id="635" PostId="998" Text="Or if the 3.3V regulator fails!" CreationDate="2009-12-13T16:17:59.543" UserId="330" />
  <row Id="636" PostId="1004" Score="1" Text="Thanks, Mark, that's a perfect example of what I was looking for: a Make-based project for an 18fx550 with actual USB code. (I've found lots of simple projects with SDCC but none that exercise some of the more esoteric parts of the chips. thank you)" CreationDate="2009-12-13T16:38:53.950" UserId="215" />
  <row Id="637" PostId="1003" Text="Touche. I sometimes wrap myself up in the analog world :-)" CreationDate="2009-12-14T00:13:43.020" UserId="404" />
  <row Id="638" PostId="1003" Score="1" Text="Try telling that to a mechanical engineer at all. As a mechatronic engineer, I am perpetually dismayed by the reaction of my mechanical colleagues to anything electronic. *sigh*&#xA;&#xA;On a more relevant note, I think it's still very important to know the basics and even some of the more advanced elements of electrical engineering to support DSP. Too many times throughout signal classes at uni I'd pick up on problems with the sampling hardware that masquerade as DSP issues. Having end to end knowledge is important here given the number of potential error sources." CreationDate="2009-12-14T00:30:34.950" UserId="295" />
  <row Id="639" PostId="1003" Text="I would like to add, there are still universities that offer masters degrees in Controls engineering and in signal processing. My mate who got his masters in controls was a cross between chemical/electrical/mechanical when it came to his knowledge. I do think the larger the company, the more they care about the title." CreationDate="2009-12-14T00:31:22.407" UserId="230" />
  <row Id="640" PostId="1006" Text="IAR is a company specializing in compilers as far as I can tell. I use them at work and they have some perks, and a few disadvantages. I find their support is pretty excellent though, we use the MSP430, but they seem to cover every processor I look up." CreationDate="2009-12-14T00:36:27.970" UserId="230" />
  <row Id="641" PostId="1003" Text="One controls engineering course I took was a joint class between the electrical engineering and aerospace engineering departments. The aero's all had more trouble with electrical-ish concepts (big surprise!), but on the flip side in their world were all sorts of crazy yaw/roll/pitch coordinate system problems that those of us used to current/voltage looked at with bewilderment." CreationDate="2009-12-14T00:39:42.463" UserId="330" />
  <row Id="642" PostId="1009" Score="3" Text="+1 for mentioning QP statecharts." CreationDate="2009-12-14T03:45:46.377" UserId="330" />
  <row Id="643" PostId="1008" Score="1" Text="I love it when professors are ensuring we are mature enough. They occasionally forget it is our money paying for the class. I took a signals class with a new professor at my university and the DSP professor still taught for what the last professor taught. It was the largest waste of my time, he moved to discrete time and taught the exact same things my signal analysis professor had. " CreationDate="2009-12-14T05:43:58.340" UserId="230" />
  <row Id="644" PostId="941" Score="1" Text="Many people just add community wiki to allow others to improve the post. Many others just enable it to have it as such. You are allowing others to modify your statement, almost telling people you believe what you wrote but you accept others may know more." CreationDate="2009-12-14T09:42:23.503" UserId="230" />
  <row Id="645" PostId="1009" Text="+1 on Jason S's comment about giving +1 for mentioning QP state chars. Oh, also Star and +1 one the topic... cause it sounds groovy and i look forward to answers :P (sorry for the spam, just in a funny mood today ;) )" CreationDate="2009-12-14T12:27:24.093" UserId="196" />
  <row Id="647" PostId="1012" Score="1" Text="p.s. that doesn't mean i'm a 9-to-5-er... work time tends to bulge outwards a bit." CreationDate="2009-12-14T23:04:22.563" UserId="330" />
  <row Id="648" PostId="1012" Text="Agreed on that, I hate 80 hour weeks. I cannot wait to work at a real firm." CreationDate="2009-12-14T23:09:47.870" UserId="230" />
  <row Id="649" PostId="1007" Text="Thanks Hristos! That worked. " CreationDate="2009-12-15T01:40:48.970" UserId="6" />
  <row Id="650" PostId="1007" Text="I'm on XP but it worked." CreationDate="2009-12-15T01:43:23.330" UserId="6" />
  <row Id="651" PostId="1023" Score="1" Text="&quot;0x&quot; usually means that the following numbers or characters are Hex based. Otherwise the compiler will be way confused." CreationDate="2009-12-15T03:57:02.487" UserId="404" />
  <row Id="652" PostId="1023" Text="Thank you Chris!" CreationDate="2009-12-15T04:57:37.593" UserId="6" />
  <row Id="653" PostId="1033" Score="1" Text="I think tuupola is referring to the book called &quot;Getting Started with Arduino&quot; rather than saying that he thinks the Arduino is a waste of time. Welcome to chiphacker.com." CreationDate="2009-12-15T11:54:14.080" UserId="103" />
  <row Id="654" PostId="1031" Text="this is a great idea; I just picked up a 16x16 controllerless matrix and a controller would be great. neat video!" CreationDate="2009-12-15T12:14:24.983" UserId="417" />
  <row Id="655" PostId="1033" Text="oh a pebkac :D. Thanks Amos!" CreationDate="2009-12-15T12:42:45.053" UserId="419" />
  <row Id="656" PostId="1034" Text="Cheers, that sounds like the best approach, I think I'll probably look at designing and arduino clone that has a built in instrumentation amps and a hefty Atmel chip. If I power the unit via USB would I really need to use opto isolators? I thought the protective circuits on most peoples USB would be more than sufficient  " CreationDate="2009-12-15T13:13:32.810" UserId="399" />
  <row Id="657" PostId="1034" Text="I'm looking at using this Atmel chip -&gt; http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=AT32UC3B0256-A2UT-ND &#xA;Not totally sure, but I think it will do the job, and it looks like it wont need a separate chip to communicate with USB" CreationDate="2009-12-15T14:36:31.163" UserId="399" />
  <row Id="658" PostId="1027" Text="Eagle is a good idea too as long as you have the libraries all set up. Plus if you plan to make a board eventually, this would be a good start so you can later get a board layout going." CreationDate="2009-12-15T14:56:25.293" UserId="404" />
  <row Id="659" PostId="1041" Text="+1, very complete.  I hope someone writes a post for where to go outside of the US, perhaps in the UK." CreationDate="2009-12-15T16:20:46.460" UserId="374" />
  <row Id="660" PostId="1041" Text="Yeah, me too.  Any localizations that can chime in would be really helpful.  I tried to use general terms where possible, but I'm simply not familiar with retail establishments outside of my national borders so I couldn't really do it justice.  It might also help if @blalor would let us know where to target, though to be fair the question was originally only about online purchasing." CreationDate="2009-12-15T16:42:14.347" UserId="11" />
  <row Id="661" PostId="1022" Score="1" Text="If you have any programming background with any programmig language Getting Started with Arduino is IMO waste of money. It seems to be meant for people without any technical background. Better go straight to books like Making Things Talk." CreationDate="2009-12-15T18:07:32.540" UserId="94" />
  <row Id="662" PostId="1033" Text="Amos is correct. I ment the book not Arduino itself." CreationDate="2009-12-15T18:08:07.797" UserId="94" />
  <row Id="663" PostId="1026" Score="1" Text="Yeah, I was hoping for something like google docs of schematics, as I have never heard of any thing that nice, I thought I would just ask if anyone knew something about it." CreationDate="2009-12-15T18:25:52.590" UserId="230" />
  <row Id="664" PostId="1027" Text="I am not planning to make a board, I have programs for doing real schematics and layouts, the problem is that they have a large overhead in my time when it comes to me answering something on this board and require a dongle, which means I do not have them at home." CreationDate="2009-12-15T18:27:18.467" UserId="230" />
  <row Id="665" PostId="1038" Text="Thanks for the info, I will take a look at it." CreationDate="2009-12-15T20:28:42.777" UserId="230" />
  <row Id="666" PostId="933" Score="1" Text="What's wrong with the OpenEEG?  It's open source and it does all this stuff." CreationDate="2009-12-15T20:29:18.893" UserId="142" />
  <row Id="667" PostId="964" Text="So edit it!  :)" CreationDate="2009-12-15T20:31:35.850" UserId="142" />
  <row Id="668" PostId="935" Text="Yes, it does the difference between two electrodes, with common-mode signals cancelled out by the DRL amplifier." CreationDate="2009-12-15T20:40:37.870" UserId="142" />
  <row Id="669" PostId="1034" Score="1" Text="There are no &quot;protective circuits&quot; on USB ports.  When you touch a USB port, you're touching Earth ground.  There's zero isolation.  The only time it's ok to run without isolation in the EEG circuit is if it's floating (if you're connected to a laptop and the laptop is not plugged into anything else).  Just build in some real isolation so you don't have to worry about it." CreationDate="2009-12-15T20:42:42.750" UserId="142" />
  <row Id="670" PostId="1041" Score="1" Text="Your link to Mouser didn't come up as a link; try this instead &lt;http://www.mouser.com/Wire-Cable/Wire-Single-Conductor/_/N-5ggs?Keyword=stranded+hookup+wire&gt;" CreationDate="2009-12-15T20:56:48.353" UserId="143" />
  <row Id="671" PostId="1025" Text="I agree with you, but the sentence &quot;that I will be expected to work more and more from home possibly&quot; made my day. So you possibly think it will happen. Otherwise, I agree with you, possibly." CreationDate="2009-12-15T21:08:50.217" UserId="230" />
  <row Id="672" PostId="1041" Text="@W.CraigTrader Thanks!  I dashed it all out and didn't check the actual copy.  It looked good in the preview window, but I didn't actually mark it up so it parsed all weird in the post.  I just marked what I had up correctly and checked, it should show properly now." CreationDate="2009-12-15T21:30:08.363" UserId="11" />
  <row Id="673" PostId="964" Text="Ah, thank you endolith. Right you are." CreationDate="2009-12-15T23:46:25.227" UserId="404" />
  <row Id="675" PostId="1022" Text="I meant to add Making Things Talk also... another great book. Jon Oxer has a book coming out soon also. http://jon.oxer.com.au/" CreationDate="2009-12-16T02:32:21.927" UserId="6" />
  <row Id="676" PostId="1065" Text="non-toxic should probably be combined into one tag" CreationDate="2009-12-16T03:04:38.363" UserId="245" />
  <row Id="678" PostId="1066" Text="That's brilliant thanks!" CreationDate="2009-12-16T04:46:06.840" UserId="21" />
  <row Id="681" PostId="1071" Score="2" Text="I've always wanted to run a microcontroller's clock line with a pushbutton.  Let the human be the clock. :)  On a serious note, a really nice things about these static designs is their power consumption is linear with clock speed: slow down the clock and use less power.  This can be really handy." CreationDate="2009-12-16T06:27:47.190" UserId="215" />
  <row Id="682" PostId="1071" Score="2" Text="Yes, but I do like to note, power consumption is a linear function with an offset, even without a clock they still consume power, especially with any outputs being driven. We just got new interns at my work, I will suggest we use a pushbutton and see what happens." CreationDate="2009-12-16T06:39:05.733" UserId="230" />
  <row Id="683" PostId="1029" Text="I know how to do schematics/simulations/layouts and I am not finding this to be the issue. The problem I have had is having one that is very fast to use for when I want to give more detailed answers on chiphacker. I have some time for chiphacker, but not enough to be doing full simulations for questions regularly." CreationDate="2009-12-16T06:43:22.183" UserId="230" />
  <row Id="684" PostId="1069" Score="9" Text="I would like to add, this is an excellent question. Most senior EEs do not take the time to actually read and think about datasheets, which is either a complement for you or an insult to them, I would like to imply both." CreationDate="2009-12-16T06:44:50.277" UserId="230" />
  <row Id="685" PostId="1071" Score="5" Text="@todbot Nice idea. :-) But make sure to debounce the pushbutton." CreationDate="2009-12-16T08:49:59.420" UserId="339" />
  <row Id="686" PostId="1071" Score="3" Text="Try with a &quot;grind crank&quot; (as in the Jargon meaning: http://www.jargon.net/jargonfile/g/grindcrank.html ) :-))&#xA;(and yes, many years ago I built one to step thru code when I was using Turbo Pascal at school :-)" CreationDate="2009-12-16T09:19:26.897" UserId="244" />
  <row Id="687" PostId="1070" Score="1" Text="do you have an example of a micro that allows this?" CreationDate="2009-12-16T10:21:47.707" UserId="86" />
  <row Id="688" PostId="1029" Score="2" Text="The simple/intuitive nature of Fritzing will lend itself to your goals I think.  I encourage you to take a look." CreationDate="2009-12-16T10:24:00.713" UserId="86" />
  <row Id="689" PostId="1058" Text="Interesting boards you're making(?), you might want to add dollar symbols to your web shop or a statement that all prices are in dollars as nowhere does it seem to mention what currency you are using." CreationDate="2009-12-16T10:53:17.863" UserId="103" />
  <row Id="690" PostId="1025" Text="Chris, it was actually your last blog post that prompted this question. You were talking about how much easier it would be to just take a couple of classes. I just finished school. For me, work was non-stop; I went to classes on campus and came home to study - I had only a couple of hours a day on average when I was not working. I have been looking forward to having a job where work and home will be separated a little better." CreationDate="2009-12-16T13:07:51.053" UserId="238" />
  <row Id="691" PostId="1070" Score="2" Text="Microcontrollers which contain on-chip flash may specify a minimum (and maximum) flash clock speed when writing to flash. However, when reading from flash, this doesn't apply." CreationDate="2009-12-16T13:22:03.020" UserId="387" />
  <row Id="692" PostId="1071" Text="@todbot It's not really far-fetched or difficult, if you can accept a rough abstraction.  There are several examples of people using such gadgets to teach how computers work.  Myke Predko has a really good book, and it even comes with PCBs (though not for the computer project): http://www.amazon.com/Digital-Electronics-Guidebook-Michael-Predko/dp/0071377816/ref=sr_1_1?ie=UTF8&amp;qid=1260970753&amp;sr=8-1  " CreationDate="2009-12-16T13:41:14.270" UserId="11" />
  <row Id="693" PostId="1063" Score="3" Text="I will note that many FPGAs are large enough to contain multiple CPU cores, thus allowing the FPGA to be an entire computer unto itself." CreationDate="2009-12-16T15:03:31.467" UserId="143" />
  <row Id="694" PostId="1075" Score="2" Text="I keep a field notebook around for that.  It comes gridded, with ruled pages opposite for notes.  It's also water-resistant, so if it comes with you everywhere and you live in a rainy climate there's an extra level of protection." CreationDate="2009-12-16T16:52:39.163" UserId="11" />
  <row Id="695" PostId="1058" Text="Thanks. Yes those are my boards. &#xA;&#xA;I will update all the pages with the units of currency (dollars) today. Thanks for the report.&#xA;&#xA;(* jcl *)" CreationDate="2009-12-16T17:33:49.097" UserId="424" />
  <row Id="697" PostId="1070" Score="4" Text="MrEvil, the Atmel AVR ATtiny series mentioned in the question is fully static, as I think most all Atmel AVR chips.  And I think most all of Microchip's PIC microcontrollers." CreationDate="2009-12-16T17:56:14.290" UserId="215" />
  <row Id="698" PostId="1058" Text="Nice site, there's some great hardware on it!" CreationDate="2009-12-16T18:03:31.127" UserId="399" />
  <row Id="699" PostId="1071" Text="@everyone, I am 99% sure todbot knew that it would work and intended it as a joke since most RISC processors need so many clock ticks that it would be a long time.@starblue, As I was typing earlier I thought about joking about forgetting to debounce to get a higher clock rate per push." CreationDate="2009-12-16T18:10:02.170" UserId="230" />
  <row Id="700" PostId="1070" Text="I would like to add MSP430s to todbot's list. Most modern microcontrollers do, the dynamic kind are a headache to design for, so most do not." CreationDate="2009-12-16T18:11:12.623" UserId="230" />
  <row Id="701" PostId="1075" Text="I have design journals around that look the same, but I doubt my boss would enjoy me jotting down things for chiphacker in them." CreationDate="2009-12-16T18:13:48.157" UserId="230" />
  <row Id="702" PostId="1016" Text="Thanks!  I'll put that on the Christmas wish list." CreationDate="2009-12-16T21:41:09.010" UserId="267" />
  <row Id="703" PostId="1075" Text="Point taken on the picture, I wish I always had paper with me. I also wish my handwriting was readable." CreationDate="2009-12-16T23:03:11.200" UserId="230" />
  <row Id="706" PostId="1038" Text="WOW have never heard about geda, did an apt-get and checking it out now.  Really cool, thanks for sharing!" CreationDate="2009-12-17T03:01:24.313" UserId="368" />
  <row Id="707" PostId="1063" Score="2" Text="As a note, I think lower clock speeds can be misleading. compared to a PC, yes. Compared to a pic16, they can be faster, but it depends on the cost. Most of the cheaper ones I have had my hands on run at 40MHz, but again, product to product variation." CreationDate="2009-12-17T04:41:01.467" UserId="230" />
  <row Id="708" PostId="1073" Text="I know many Practicing EEs with many years of experience that will often just through an FPGA into the design instead of a uC where you used to see uC. I really think they are great for interface handling." CreationDate="2009-12-17T04:50:00.990" UserId="230" />
  <row Id="709" PostId="1081" Text="Those tutorials are great!" CreationDate="2009-12-17T06:42:19.180" UserId="207" />
  <row Id="711" PostId="1070" Score="2" Text="Actually, I think the ADC in the ATTiny13A doesn't work at low frequencies, maybe because of the sample-and-hold capacitor decaying?  &quot;By default, the successive approximation circuitry requires an input clock frequency between 50&#xA;kHz and 200 kHz to get maximum resolution. ... The ADC module contains a prescaler, which generates an acceptable ADC clock frequency from any CPU frequency above 100 kHz.&quot;" CreationDate="2009-12-17T15:26:20.377" UserId="142" />
  <row Id="712" PostId="1066" Text="That's for handling during industrial assembly, though, isn't it?  Not for wearing on a daily basis." CreationDate="2009-12-17T15:33:19.677" UserId="142" />
  <row Id="714" PostId="1041" Text="Thanks for the thorough answer and alternative suggestions, @Lou.  @morgellon nailed the answer that I was really looking for, tho: a specific wire that I can use to refine my search for others.  I live near Boston, MA (USA), but am primarily looking for online retailers.  The local place, You-Do-It Electronics, has hookup wire, but it stays thoroughly curled." CreationDate="2009-12-17T15:43:52.633" UserId="51" />
  <row Id="715" PostId="1083" Text="Thanks! That looks like exactly what I'm looking for.  Yay for additional vendors! :-) " CreationDate="2009-12-17T15:46:42.753" UserId="51" />
  <row Id="716" PostId="1083" Text="Based on this wire, it appears that the rubber insulation is what makes it flexible.  Further Googling shows that the 65/36 stranding (many fine strands) is suitable for wire which is constantly flexing." CreationDate="2009-12-17T16:06:03.510" UserId="51" />
  <row Id="717" PostId="1041" Text="I understand, and @morgellon deserves the accepted answer.  Just glad to be helpful." CreationDate="2009-12-17T17:02:23.477" UserId="11" />
  <row Id="720" PostId="962" Text="Why do you need a DAC?  You're just generating a DC offset with it?  That seems rather overkill." CreationDate="2009-12-17T17:21:46.807" UserId="142" />
  <row Id="721" PostId="937" Text="Would you be so kind as to show a schematic of your receiver?  Are you supplying the bias voltage of 1.9 V?" CreationDate="2009-12-17T17:22:27.147" UserId="142" />
  <row Id="722" PostId="959" Text="You don't need an instrumentation amp. A simple diff amp will do. You need a constant 1.9 V supply to use as your reference, though. I'm guessing something like this already exists in the circuit as the bias for the sensor. It would help to have a schematic. Also, after removing the bias, you need to re-add another bias to get it between the 0 and 5 V range of the ADC." CreationDate="2009-12-17T17:23:12.967" UserId="142" />
  <row Id="723" PostId="836" Text="Yeah, couldn't you just detect shadows on the screen instead?" CreationDate="2009-12-17T17:24:59.157" UserId="142" />
  <row Id="724" PostId="962" Text="Yeah. The DAC was predicated on the assumption of having to change the DC offset over a wide range. If you have a system with voltage spanning only a narrow range, (assuming you've done your tolerance analysis right) then a resistor divider and a reference may be adequate to produce an offset voltage. Or for a little more complexity, a resistor network + multiplexers (which is what some DACs are). A DAC isn't really that complicated or expensive a device, if you don't need ultra-high speed or ultra-fine resolution." CreationDate="2009-12-17T18:38:46.507" UserId="330" />
  <row Id="725" PostId="1088" Text="Looks interesting." CreationDate="2009-12-17T18:51:20.167" UserId="230" />
  <row Id="726" PostId="1087" Text="gEDA is looking nicer, I think I may install it on my personal laptop soon." CreationDate="2009-12-17T18:52:41.533" UserId="230" />
  <row Id="727" PostId="1089" Score="1" Text="Haha, I enjoyed your very functional description. They are absolutely amazing at parallel processing." CreationDate="2009-12-17T18:54:20.970" UserId="230" />
  <row Id="728" PostId="959" Score="1" Text="I agree that you don't NEED one, but it's a good idea. An instrumentation amp is just a diff amp with buffers before it (sometimes with added resistors for gain). If you just use a diff amp, you're at the mercy of the resistors in your diff amp; sometimes as low as 1K. If he's trying to measure something, that high impedance (from the buffers of an iAmp) can really help (i.e. no current flow into the measurement device)." CreationDate="2009-12-17T19:08:56.010" UserId="404" />
  <row Id="729" PostId="1066" Score="1" Text="according to the MSDS: &quot;Skin contact is expected to be the primary route of occupational exposure to SHIELDEX® silver coated non- woven/or/woven nylon fabric and yarns. Occupational exposure to this material has not been reported to cause significant adverse health effects&quot; - I haven't used the thread to be able to give a definitive but you can always consult with the company before using" CreationDate="2009-12-17T19:16:50.107" UserId="245" />
  <row Id="730" PostId="1091" Score="1" Text="i am trying the trial version and i think that it will be my choice.&#xA;it's complete well documented and not very expensive (personal licence for 150 $)" CreationDate="2009-12-17T19:59:11.840" UserId="199" />
  <row Id="731" PostId="1075" Text="This is what I do at work, too.  I just scribble something down, take a picture of it, and email it to the factory.  :)" CreationDate="2009-12-17T21:31:02.483" UserId="142" />
  <row Id="732" PostId="971" Text="You were right - trailers are not the problem. The problem was there there was a bug in my code which meant I was connecting to the wrong port and that I didn't realize that my computer was not receiving all of the packets on the network. (Probably because i'm using a router not a hub) I'll try to verify this by putting my computer and the arduino onto a hub together and making sure that wireshark can see all of the packets. Sorry for the mistake - I try to debug problems as much as possible before posting but I misunderstood what wireshark was showing m in this case. Hamish" CreationDate="2009-12-17T21:44:52.533" UserId="298" />
  <row Id="733" PostId="345" Text="I finally found our kitchen scale, and it looks workable.  Didn't notice your edit until just now.  Thanks for the idea." CreationDate="2009-12-18T00:38:36.707" UserId="106" />
  <row Id="734" PostId="1090" Text="Good stuff, Leon. Thanks!" CreationDate="2009-12-18T01:31:56.227" UserId="51" />
  <row Id="735" PostId="1096" Text="8-bit is the dominant microprocessor, but it is far from the most common, I thought I read earlier this year that they no longer make up more than 50% of market share." CreationDate="2009-12-18T01:39:54.993" UserId="230" />
  <row Id="736" PostId="1096" Score="2" Text="Actually, I would like to say that I do not agree with a large amount of the microcontrollers list. Most of the cheap ones they put in systems do not cost a dollar, many, dependent on brand, cannot provide the current to power an LED. There are also a very large group that break 20MHz, but in general do meet that spec. i think they are also great for hobyist." CreationDate="2009-12-18T02:34:50.333" UserId="230" />
  <row Id="737" PostId="1095" Text="Where can I find more about these &quot;microconverters&quot;?  The closest thing I've found is the TAS3202." CreationDate="2009-12-18T02:59:14.897" UserId="142" />
  <row Id="738" PostId="861" Text="Aren't Tiny13s like 80 cents?" CreationDate="2009-12-18T03:10:01.287" UserId="142" />
  <row Id="739" PostId="999" Text="Instructions: http://code.google.com/p/tinkerit/wiki/SecretVoltmeter" CreationDate="2009-12-18T03:15:51.357" UserId="142" />
  <row Id="740" PostId="1095" Text="they may have stopped calling them that. http://www.analog.com/en/analog-microcontrollers/analog-microcontrollers/products/index.html I've never been impressed much with ADI's microprocessors, their analog stuff is good, and their DSPs are supposed to be good but I don't have experience w/ them." CreationDate="2009-12-18T04:45:12.613" UserId="330" />
  <row Id="742" PostId="1098" Score="2" Text="I would like to add, sparkfun is rich, this is because there is a sudden emergence of &quot;tinkerers&quot; and they are easy to work with!" CreationDate="2009-12-18T07:07:56.693" UserId="230" />
  <row Id="743" PostId="1104" Score="2" Text="I might add that if you want to make money without working for someone else then go find a service you can provide that people are willing to pay you for. This is a pretty tried and true method which many people (myself included) use. Are you good at designing circuits? Then offer you services to others who want circuits designed. If nothing else it may keep you busy (and eating) while you are pursuing your own projects." CreationDate="2009-12-18T07:17:17.830" UserId="12" />
  <row Id="744" PostId="1104" Score="1" Text="Do you mean consulting?" CreationDate="2009-12-18T07:48:08.940" UserId="230" />
  <row Id="747" PostId="1104" Score="1" Text="Disagree about the suing of someone when they rip you off. It is SO expensive to do that and such a long process that you'll likely bankrupt yourself trying to do so. If you invent something under the flag of a company and have the company lawyers behind you, then you have a chance (usually against another company). Otherwise, I would not suggest thinking this will ever net you any money.&#xA;&#xA;I like your idea about how you &quot;just nee to do it&quot;. Time to market is much more important than the patents behind it (which definitely slows time to market). " CreationDate="2009-12-18T13:23:13.607" UserId="404" />
  <row Id="748" PostId="1096" Text="I've incorporated some revisions and made my answer a community wiki -- help me make it right!" CreationDate="2009-12-18T15:49:14.703" UserId="106" />
  <row Id="749" PostId="1110" Score="4" Text="Thanks for the useful comment, but the 8 lines of 'signature' is a little extreme, these stackoverflow-based sites tend to look down on advertising your own sites in your answers." CreationDate="2009-12-18T16:33:36.530" UserId="131" />
  <row Id="750" PostId="1110" Score="4" Text="@jluciani, if you want to advertise your other websites, put the links in your profile, not in your answers.  After all, your blog is not the answer to *this* question..." CreationDate="2009-12-18T16:54:40.437" UserId="143" />
  <row Id="751" PostId="1104" Score="2" Text="@kortuk I avoid the word consulting out of personal prejudice. Too often self declared &quot;consultants&quot; don't actually do anything. But, yeah that is another way to make money. Personally, I do freelance web development to make ends meet. I write software for people who need software. I realize there may not be a direct equivalent in the hardware business, but I am sure there is work to be had.&#xA;&#xA;@Chris that was sort of a joke.The is an entire industry around software patents that has small outfits with lots of vague patents attempting to strong arm any one they can into paying up." CreationDate="2009-12-18T17:15:43.880" UserId="12" />
  <row Id="752" PostId="1100" Text="Isn't getting someone else to witness the ideas a form of public disclosure?" CreationDate="2009-12-18T17:22:51.750" UserId="142" />
  <row Id="753" PostId="1104" Score="1" Text="&quot;The chances of getting rich either way are pretty damn small.&quot;  I'm not sure that's even true.  Sparkfun, Ladyada, and Makerbot are all relatively small open source operations, and although I'm not a very business-oriented person, I get the impression they all make a nice amount of money.  Sparkfun's giving away $100,000 of free stuff!  Could a company do that if they were struggling?" CreationDate="2009-12-18T17:26:12.887" UserId="142" />
  <row Id="754" PostId="1104" Text="And yes, the company I work for doesn't bother to patent anything, if it's even patentable.  We just try to beat our competitors to market.  They rip off our products and we rip off theirs." CreationDate="2009-12-18T17:29:03.103" UserId="142" />
  <row Id="755" PostId="1100" Score="4" Text="No. (well, it should be someone you trust!) The point is that if there's a legal challenge for invention date, someone else can state in court that he/she witnessed that you recorded your invention on such-and-such a date. Public disclosure, on the other hand, can include sale of an item that implements an idea -- so even if you don't reveal how you made a Whizamajig, if you sell it and it contains some of your ideas, that may be considered disclosure. (note: I Am Not A Lawyer)" CreationDate="2009-12-18T18:59:14.443" UserId="330" />
  <row Id="756" PostId="818" Text="Assuming they have what you need, and assuming you can figure out how to use them without documentation.  That's primarily what's kept me from AS&amp;S." CreationDate="2009-12-18T19:27:44.063" UserId="374" />
  <row Id="757" PostId="1018" Score="2" Text="How much iron do the sheep need in their diet to make steel wool?" CreationDate="2009-12-18T21:23:39.160" UserId="142" />
  <row Id="758" PostId="270" Score="2" Text="I'd just use tip cleaner or a soft scraper to get rid of plastic.  Sandpaper is guaranteed to ruin the soldering iron if you use it too much." CreationDate="2009-12-18T21:26:56.627" UserId="142" />
  <row Id="759" PostId="1034" Score="5" Text="Hello Jim,&#xA;As endolith has commented, USB has no protection.  The earth it is referenced to might be the local &quot;ground&quot; potential, or it might not.  If your laptop is plugged in to a 2-pin adapter, then ground for the laptop will be around 120VAC (in Australia), giving you at least a lot of common mode noise to contend with, the likely possibility of your patient getting &quot;tingles&quot; from your leads connected to his head (!) or in the worst case (of a fault in the power supply), a dead body and a manslaughter charge.&#xA;" CreationDate="2009-12-19T00:56:14.977" UserId="420" />
  <row Id="760" PostId="1034" Text="For your instrumentation amp, an INA129 from Burr Brown (Texas) might be good.  They are available in surface mount (SMT, small, SOIC) as well as through hole (TH, big, DIL).  You might end up just putting 16 of them down on the board to contend with local polarisation around your electrodes (which will give you your biggest DC offsets to deal with).  16 amps allows each amp to settle and you can then acquire through a multiplexer and A/D. Your A/D might be an AD7940 which Farnell sell for just 12 bucks-does 100kSPS at 14 bit, single ended 0-5V.  Nice.&#xA;" CreationDate="2009-12-19T01:16:04.570" UserId="420" />
  <row Id="762" PostId="1119" Text="I know the Mega is a bit overkill for a simple data acquisition task, but I don't want to be limited if I do get the wild hair to use tons of sensors.  A couple years ago I bought the PICAXE setup to build my first robot, but now I wish I would have done more research to get something more full-featured to support the inevitable addiction.  I suppose a more appropriate question might have been &quot;What Arduino board has the most functions/features?&quot; but I don't know if that question is unanswerable due to application-specific setups." CreationDate="2009-12-19T06:36:57.923" UserId="429" />
  <row Id="763" PostId="937" Text="If you mean the schematic for the receiver itself, I linked to the datasheet above. Here it is again: http://i-fiberoptics.com/pdf/IFD91.pdf If you mean how I have it hooked up, you can see in the photograph. The receiver is the black one. I'm giving it 2.2V (though, in the photo it's an li-ion battery) through the red wire to the side of the receiver with the orange dot, and I'm measuring the voltage across the resistor that goes to ground on the other side. " CreationDate="2009-12-19T07:55:32.477" UserId="207" />
  <row Id="764" PostId="971" Text="Don't worry about it, sometimes you have to step back from the problem or get a fresh pair of eyes on it to spot what would otherwise be obvious. I've been there too many times myself. So with the port issue fixed is everything working?" CreationDate="2009-12-19T10:26:33.273" UserId="103" />
  <row Id="767" PostId="1114" Score="1" Text="I had a hunch those were related.  Thanks, Adam!  Furthermore, that's the first actual description of the X/Y stranding designator that I've seen; even Wikipedia doesn't seem to lay it out like that!" CreationDate="2009-12-19T13:29:37.577" UserId="51" />
  <row Id="768" PostId="1128" Text="Hopefully this doesn't turn into flamebait.  That wasn't my intention." CreationDate="2009-12-19T19:02:50.587" UserId="213" />
  <row Id="769" PostId="1119" Text="You could say that the Mega has more features, but your tight it does depend on your setup. If all of your sensors are I2C then there is no difference they can all be controlled via a single I2C bus, which all arduinos have, serial on the other hand is a different story." CreationDate="2009-12-19T21:33:21.420" UserId="81" />
  <row Id="770" PostId="1095" Text="Maximum sampling rate 8 kHz, so not useful for audio. :/" CreationDate="2009-12-19T22:16:07.787" UserId="142" />
  <row Id="771" PostId="1128" Score="1" Text="It seems like a reasonable question to myself." CreationDate="2009-12-19T22:18:53.603" UserId="230" />
  <row Id="773" PostId="949" Text="Wow this forum really hates Max MSP code! It's all over the place. " CreationDate="2009-12-20T14:48:46.343" UserId="399" />
  <row Id="774" PostId="1132" Text="Why is the first freelance job more difficult?  Is there a way to build up a reputation from previous jobs that makes subsequent ones easier?" CreationDate="2009-12-20T15:07:13.567" UserId="142" />
  <row Id="775" PostId="1136" Score="3" Text="I think ceramics have the best lifetime actually. Tantalums are electrolytic, they're just a different material than aluminum electrolytic caps, and they do have better lifetimes than aluminum. see wikipedia: http://en.wikipedia.org/wiki/Tantalum_capacitor" CreationDate="2009-12-20T15:14:56.413" UserId="330" />
  <row Id="776" PostId="1135" Score="8" Text="Heating a transistor isn't the worst thing (as long as you run it cooler than its rated temp, + keep lots of margin so Arrhenius' equation gives you more lifetime). It's thermal cycling that's the killer." CreationDate="2009-12-20T15:16:47.253" UserId="330" />
  <row Id="777" PostId="1075" Text="I use a scanner (better quality for line drawings than camera) + paper/pencil. Looks great!" CreationDate="2009-12-20T15:18:17.813" UserId="330" />
  <row Id="778" PostId="1137" Text="just curious: what drawing program did you use for the annotations?" CreationDate="2009-12-20T15:19:04.160" UserId="330" />
  <row Id="779" PostId="1132" Text="Yes, it seems so. Also, you write the jobs you did into a CV/profile, and headhunters search for keywords. More keywords -&gt; more job offers." CreationDate="2009-12-20T15:22:39.217" UserId="339" />
  <row Id="780" PostId="1130" Text="GPL doesn't prevent people from using something commercially.  http://www.gnu.org/philosophy/selling.html" CreationDate="2009-12-20T17:08:37.830" UserId="142" />
  <row Id="781" PostId="1128" Text="This fits into my other question about patents, too.  How do people using open source licenses make money?  They just buy the parts in bulk and sell kits, and make money because the price is lower for the buyer than if they bought the parts in single quantities?  http://chiphacker.com/questions/1098/how-to-make-money-without-working-for-someone-else-patents" CreationDate="2009-12-20T17:11:44.260" UserId="142" />
  <row Id="782" PostId="1104" Score="1" Text="@endolith - SparkFun's prices are simply ridiculous - things that cost $10 elsewhere (electronic component retailers) cost anywhere from $50 to $100 at SparkFun. So $100,000 of free stuff is probably worth $10,000." CreationDate="2009-12-20T19:48:55.410" UserId="333" />
  <row Id="783" PostId="1137" Text="It looks like an effective way to communicate to non-engineers, I normally only communicate with engineers, but point taken for non-engineers." CreationDate="2009-12-20T21:16:59.977" UserId="230" />
  <row Id="784" PostId="1138" Text="Looks interesting." CreationDate="2009-12-20T21:20:41.100" UserId="230" />
  <row Id="785" PostId="1130" Text="It doesn't stop you from selling it or using it for commercial purposes! Just other people, at least not without your permission " CreationDate="2009-12-20T21:24:28.357" UserId="399" />
  <row Id="786" PostId="1141" Text="Maybe we should treat components and chips like words, and circuits as poems or stories. I feel it can be creative, some of the coolest circuits out there are a re-appropriation of a component for a use it was not originally intended. I'm sure when  Hans R. Camenzind designed the 555 timer, he did not imagine it being used as a squarewave oscillator.  " CreationDate="2009-12-20T21:30:37.317" UserId="399" />
  <row Id="787" PostId="1141" Text="Lest we forget, there is such a thing as aesthetics in the world of electronics and technology.&#xA;&#xA;Well I hope so!" CreationDate="2009-12-20T21:32:32.870" UserId="399" />
  <row Id="788" PostId="1137" Text="I used adobe illustrator CS4, but I'm sure any old drawing program would do the trick." CreationDate="2009-12-20T21:41:16.460" UserId="399" />
  <row Id="789" PostId="1088" Score="4" Text="You forgot to mention that you can use it as an IDE too for programming the chips you design into your circuit." CreationDate="2009-12-20T22:19:35.400" UserId="103" />
  <row Id="790" PostId="1137" Score="9" Text="But that's a parts placement diagram, not a schematic.  The schematic is for explaining a circuit's operation, the parts diagram is for building a physical copy." CreationDate="2009-12-21T02:26:47.960" UserId="411" />
  <row Id="791" PostId="1154" Score="4" Text="How about using gear?" CreationDate="2009-12-21T07:38:54.127" UserId="422" />
  <row Id="792" PostId="1043" Text="Thank You for all answers (and comments) :)" CreationDate="2009-12-21T07:42:04.090" UserId="422" />
  <row Id="793" PostId="1073" Text="Yes I think this is nice example: http://www.armadeus.com/english/index.html. Specially interesting for me is servo control example: http://marwww.in2p3.fr/~duval/wiki_html_dump/articles/m/o/t/MotionSystem_05a0.html" CreationDate="2009-12-21T08:07:33.027" UserId="422" />
  <row Id="794" PostId="1137" Text="That's partly true, a schematic however still does not explain how a circuit operates, merely how it fits together and what value the components are. I'm merely suggesting the use of annotated photographs as it's a quick way to share circuits. Do we have to use abstract symbols in a world where high quality images are so easy to produce??" CreationDate="2009-12-21T10:47:54.667" UserId="399" />
  <row Id="795" PostId="1161" Score="2" Text="Tin snips I think" CreationDate="2009-12-21T10:53:09.120" UserId="399" />
  <row Id="796" PostId="1046" Text="I want to make a multi purpose board, that can be reprogrammed to work with various audio and sensor inputs. It's kinda like an Arduino but for people who want to do more serious DSP. Cheers for the help" CreationDate="2009-12-21T11:05:36.990" UserId="399" />
  <row Id="797" PostId="1046" Text="I've gone and bought some of those texas instrument instrumentation amps. They look like the business, I'm just trying to work out a way to do multi channel. It would be good if all the signals could pass through the MCU ADCs and I could cross reference them afterward with the computer. I was thinking it would be good if the user could just select (in the software user interface) an arbitrary channel that the computer would then treat as the common mode, for example     " CreationDate="2009-12-21T11:15:00.910" UserId="399" />
  <row Id="798" PostId="1046" Text="The software end should be easy enough for me to work out, it'll probably take much longer for me to work out how the hardware will go! " CreationDate="2009-12-21T11:19:43.700" UserId="399" />
  <row Id="799" PostId="1164" Text="Gross or net? I prefer to use gross/year so there is no doubt when having more than 12 payments/year." CreationDate="2009-12-21T11:30:28.573" UserId="198" />
  <row Id="800" PostId="1171" Text="By the way, on paper I make about £1,300 sterling a month after tax, I work for myself and live in the the north east of england. At this stage my personal income is money invested by a fellowship scheme, rather than profit generated by sales. " CreationDate="2009-12-21T11:59:52.947" UserId="399" />
  <row Id="801" PostId="1156" Score="3" Text="gearmotors are a must for slow speeds!" CreationDate="2009-12-21T12:42:34.017" UserId="330" />
  <row Id="802" PostId="1163" Text="all very good points!" CreationDate="2009-12-21T12:43:32.000" UserId="330" />
  <row Id="803" PostId="1164" Text="please change to community wiki" CreationDate="2009-12-21T12:44:13.777" UserId="330" />
  <row Id="804" PostId="1155" Score="1" Text="I've got an Aoyue Int2901, using the included tip.  I got it 6 months ago and it's been great ever since.  Mine actually came from Fry's Electronics (outpost.com)." CreationDate="2009-12-21T13:57:59.727" UserId="213" />
  <row Id="805" PostId="1088" Text="I've never used that part.  :)" CreationDate="2009-12-21T15:36:55.450" UserId="142" />
  <row Id="806" PostId="1137" Score="2" Text="But how do you connect the parts to each other?  This isn't anything like a schematic." CreationDate="2009-12-21T15:40:02.177" UserId="142" />
  <row Id="807" PostId="1132" Text="But I already have a resume with &quot;real jobs&quot; on it.  :)" CreationDate="2009-12-21T15:45:31.963" UserId="142" />
  <row Id="808" PostId="1141" Text="Yes, it's &quot;creative&quot;, and yes, there are aesthetics involved, but the design is motivated almost entirely by the functionality.  In most cases, you move components and ground traces around because it makes the circuit work better, not because of how it looks, or because you're trying to express some criticism of society's treatment of the poor." CreationDate="2009-12-21T15:47:13.057" UserId="142" />
  <row Id="809" PostId="1130" Text="If you release something under the GPL, anyone can use it for commercial purposes without your permission." CreationDate="2009-12-21T15:49:50.543" UserId="142" />
  <row Id="810" PostId="1171" Text="Yes, working for the military is a great way to make lots of money, but it's too morally ambiguous for me.  I design consumer products, so, unlike the military, when I do my job well, no one dies.  Unlike medical equipment, if I screw up, no one dies." CreationDate="2009-12-21T16:00:25.663" UserId="142" />
  <row Id="811" PostId="1155" Text="That is good to know. Being able to return/exchange without having to ship it is a great option." CreationDate="2009-12-21T16:47:08.760" UserId="432" />
  <row Id="812" PostId="1164" Text="This also greatly depends on location. Even in the same country, people in different cities can earn much more or less, due to cost of living and other factors." CreationDate="2009-12-21T16:50:18.243" UserId="131" />
  <row Id="813" PostId="1179" Text="This is basically the same thing as a &quot;guillotine&quot; he mentioned." CreationDate="2009-12-21T16:54:52.647" UserId="131" />
  <row Id="814" PostId="1149" Score="3" Text="There's basically two options I see: get one of those super long range radio modules, like XBee that's rated for 1 mile distance, or get a cellphone module and communicate over the internet using the cellular network." CreationDate="2009-12-21T16:57:14.497" UserId="131" />
  <row Id="816" PostId="1173" Text="Here are some links for sheers that I had bookmarked.&#xA;   http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90757&#xA;   http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=5907&#xA;&#xA;http://www.grizzly.com/products/Sheet-Metal-Machine-12-/G6089&#xA;&#xA;(* jcl *)" CreationDate="2009-12-21T18:29:22.480" UserId="424" />
  <row Id="817" PostId="1192" Score="1" Text="I'm also interested in solutions for this, particularly open source/cross-platform. For quick, one off graphs to help me visualize the data I tend to use gnuplot. But these graphs are quite ugly and as far as I know, gnuplot doesn't support real-time.&#xA;&#xA;You'll likely end up having to use some libraries to build your own. For example: http://eli.thegreenplace.net/2008/08/01/matplotlib-with-wxpython-guis/" CreationDate="2009-12-21T19:42:08.923" UserId="403" />
  <row Id="819" PostId="1188" Score="2" Text="Agree with the etching of thin brass for the stencil. Also, it makes it convenient to adjust hole sizes to get the right amount of solder paste down.&#xA;&#xA;For solder paste, look east: dealextreme.com/details.dx/sku.7952 One caution about lead alloy solder paste. It is very sticky and you could easily ingest it if you aren't careful. Latex gloves are a good idea.&#xA;" CreationDate="2009-12-21T21:13:47.640" UserId="411" />
  <row Id="821" PostId="774" Score="2" Text="VHDL is actually based on Ada!&#xA;&#xA;Leon" CreationDate="2009-12-21T23:02:14.073" UserId="305" />
  <row Id="824" PostId="1155" Text="I also have Aoyue 968 for few months. I like it very much especially smoke absorber. How ever I haven't done any SMD project yet so I haven't tested hot air rework tool. " CreationDate="2009-12-22T00:01:50.900" UserId="422" />
  <row Id="825" PostId="1199" Text="I'm starting off with a few answers, please fee free to add your own! or edit existing families to add in your wisdom. Special thanks to Jason S for all the TI MCU/DSP wisdom. http://chiphacker.com/users/330/jason-s" CreationDate="2009-12-22T00:06:20.217" UserId="333" />
  <row Id="826" PostId="1202" Text="Blackfin doesn't have a MIPS core!" CreationDate="2009-12-22T01:27:36.503" UserId="305" />
  <row Id="827" PostId="1207" Score="5" Text="This is a circuit simulator, but I don't think it has anything to do with SPICE." CreationDate="2009-12-22T02:13:09.803" UserId="131" />
  <row Id="828" PostId="1206" Score="2" Text="As long as you're doing the whole 'ask common questions and answer them' thing, might be good to put some info in here about what a SPICE simulator exactly is (even if it's just a cut and paste from wikipedia)" CreationDate="2009-12-22T02:15:32.487" UserId="131" />
  <row Id="829" PostId="1212" Score="2" Text="If you have any wisdom to share I suggest editing the community-wiki answers instead. All of your points have already been mentioned in the 18F answer." CreationDate="2009-12-22T03:08:41.713" UserId="333" />
  <row Id="830" PostId="1206" Text="Oh well, I confused circuit / board-level simulation with SPICE simulation." CreationDate="2009-12-22T03:11:19.647" UserId="333" />
  <row Id="831" PostId="1225" Score="2" Text="There are excellent tutorials for it at sparkfun.com." CreationDate="2009-12-22T03:43:17.273" UserId="213" />
  <row Id="832" PostId="1191" Score="2" Text="Interesting reaction. This approach seems to be fairly common even with those reselling kits.&#xA;&#xA;For example:&#xA;http://www.adafruit.com/blog/2006/08/01/duel-nature-time-to-bake-the-pcbs/&#xA;http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=59&amp;page=&#xA;&#xA;It is interesting what can be done." CreationDate="2009-12-22T06:18:20.613" UserId="432" />
  <row Id="833" PostId="1218" Text="Why wouldn't you bother with the hot air stuff?" CreationDate="2009-12-22T06:22:09.730" UserId="432" />
  <row Id="834" PostId="1208" Text="This answer is the polite version of http://lmgtfy.com/?q=Arduino" CreationDate="2009-12-22T10:58:52.427" UserId="198" />
  <row Id="835" PostId="1130" Text="Right you are, I'll start chewing the rim of my hat now!&#xA;Am I right in thinking that, if someone wants to sell your LGP Licensed product they too would have to release it under the same type of License? So in other words they couldn't take your product and just patent it?" CreationDate="2009-12-22T13:03:40.193" UserId="399" />
  <row Id="836" PostId="1130" Text="This is the reason I use the LGPLv3 in combination with the creative commons license -&gt; http://creativecommons.org/licenses/by-nc-sa/3.0/&#xA;I think it's this one that protects against use of your work in a commercial capacity. " CreationDate="2009-12-22T13:06:31.267" UserId="399" />
  <row Id="837" PostId="1191" Score="5" Text="I'd like to know more.  This answer, while not really UNhelpful, isn't helpful, either.  Why are you so against this approach?  Knowing more might help @cymen make an educated decision.  To make this answer more helpful I would also have linked to any of a vast collection of SMT hand-soldering videos on the Internet, or the tutorials at SparkFun (for example).  Certainly, a reflow skillet or oven are not necessary by any stretch of the imagination, and you've got quite a rep, so I would expect your reasons are well-considered and it would benefit us all to hear them." CreationDate="2009-12-22T13:07:32.263" UserId="11" />
  <row Id="838" PostId="1171" Text="cool - it sounds like a good job, plus the added benefit of living in France, I heard the medical health service was fantastic.&#xA;" CreationDate="2009-12-22T13:12:55.223" UserId="399" />
  <row Id="839" PostId="1137" Score="3" Text="I normally have a photo of the tracks too, unless it's single side surface mount. And No, you're right it's nothing like a schematic.&#xA;&quot;Thought it may be of interest to people checking out this thread&#xA;&quot; I just thought it was interesting when looking at sharing circuit designs, it's so easy to take a hi res image nowadays, and sometimes this can share a greater amount of detail for less effort.  " CreationDate="2009-12-22T13:24:40.470" UserId="399" />
  <row Id="840" PostId="1196" Text="why the -1? could anyone comment about the downvote? I vaguely remember this being asked before, in which case it should be closed as a duplicate." CreationDate="2009-12-22T13:38:16.053" UserId="330" />
  <row Id="841" PostId="1196" Text="hmm, not a duplicate on this site, although it was asked on electronics exchange: http://electronics.stackexchange.com/questions/147/what-is-the-arduino" CreationDate="2009-12-22T13:40:34.987" UserId="330" />
  <row Id="842" PostId="1180" Text="seems like the right answer to me!" CreationDate="2009-12-22T13:42:12.317" UserId="330" />
  <row Id="843" PostId="1232" Text="that's great Lou, it should do the job perfectly. cheers" CreationDate="2009-12-22T15:46:31.190" UserId="399" />
  <row Id="844" PostId="1232" Text="Glad to hear it!  It looks like you'll need to do some playing with the resistor values to get what you want, now that I look at the doc more closely, but once you figure out the resistances you can probably fix all that down with precision resistors.  I wouldn't mind seeing the final values for future reference, this would be a great reference for battery-powered applications." CreationDate="2009-12-22T15:49:24.310" UserId="11" />
  <row Id="845" PostId="1231" Score="1" Text="Why do you need 9V DC? I hope it's not to feed it into another power regulator which then regulates it down to 5V" CreationDate="2009-12-22T16:24:55.353" UserId="131" />
  <row Id="846" PostId="1232" Text="Hmmm. I'm suspicious. I like TI but the datasheet looks really weird for a switching regulator (where's the description of timing = either specified as a switching frequency, or via hysteretic control?), and it also looks like you need a VSERIES_IN1 that is at least 4.5V." CreationDate="2009-12-22T16:40:56.417" UserId="330" />
  <row Id="847" PostId="1231" Score="3" Text="how much current do you need? 10mA? 1A? what's your input range? (1.5V +/- ____ ?)" CreationDate="2009-12-22T16:42:03.077" UserId="330" />
  <row Id="848" PostId="1232" Score="1" Text="I did a quick web search of &quot;TL499A 1.5v to 9v&quot; and came up with this AVRFreaks article which deals with using a TL499A to get 9V from a AAA battery: http://www.avrfreaks.net/index.php?name=PNphpBB2&amp;file=printview&amp;t=61722&amp;start=0   Apparently it works, but the posters were getting better results with two batteries (3v)." CreationDate="2009-12-22T17:04:19.550" UserId="11" />
  <row Id="849" PostId="1232" Score="1" Text="yah, agreed -- efficiency in switching regulators always goes down when you deal with lower voltages in/out, or if you have a larger ratio between in/out voltages w/o a transformer (e.g. if the switching duty cycle is close to 0 or 1.)." CreationDate="2009-12-22T17:26:50.117" UserId="330" />
  <row Id="851" PostId="1228" Score="2" Text="In case it goes bad in the future, that tinyurl resolves to http://wiblocks.luciani.org/remix/index.html" CreationDate="2009-12-22T18:39:14.230" UserId="259" />
  <row Id="852" PostId="1235" Text="Good point. On another note: LED replacement bulbs then have the voltage regulator and load resister built in to the housing?" CreationDate="2009-12-22T19:37:27.433" UserId="245" />
  <row Id="853" PostId="1235" Text="Edited original question to include more info." CreationDate="2009-12-22T19:47:41.407" UserId="245" />
  <row Id="854" PostId="1197" Text="Edward, why have you copy and pasted my answer from Electronics Exchange without attributing it to me? Plus if you are going to copy questions and answers across surely you should be making them Community Wiki. If you are planning on closing down Electronics Exchange is it not possible to copy over users/questions/answers/votes wholesale? Or could you copy them all over as either closed questions or Community Wiki? " CreationDate="2009-12-22T20:06:27.437" UserId="103" />
  <row Id="855" PostId="1235" Text="Yes - led mains voltage bulbs need a rectifier and voltage regulator, they are contained in the bulb package." CreationDate="2009-12-22T20:34:45.133" UserId="9" />
  <row Id="856" PostId="1191" Text="With fine pitch QFP chips I'd have thought that manual soldering would produce better results, if the right equipment is used. Drag-soldering is very fast, and the whole job will take about the same amount of time.&#xA;&#xA;Leon" CreationDate="2009-12-22T21:34:12.500" UserId="305" />
  <row Id="861" PostId="1233" Text="Thanks for all the extra info! I'm just trying to power a 555 timer with a AAA battery, the timer is hooked up to a piezoelectric buzzer less than a centimeter wide, it's a little square wave buzzer type thing. I'm just trying to keep it small so I can mount it in a badge, it's a project I'm doing with my little brother. " CreationDate="2009-12-22T23:10:45.817" UserId="399" />
  <row Id="862" PostId="1034" Text="Cool y'all thanks for all the help, I took your advice and got some INA129s to experiment with. By the looks of things I'll be using an opto-isolator, I don't want to be frying peoples brains! " CreationDate="2009-12-22T23:17:47.130" UserId="399" />
  <row Id="864" PostId="1241" Text="I think solution suggested by me would be cheaper. But maybe Your is more solid, compact and easier to build. And You dad hardware already." CreationDate="2009-12-22T23:36:43.183" UserId="422" />
  <row Id="865" PostId="1233" Text="oh! In that case, you might want to consider looking at a different version of the 555 + a buzzer, something that would work on a single AAA battery. It would save you the efficiency hit of a switching converter." CreationDate="2009-12-22T23:53:07.227" UserId="330" />
  <row Id="866" PostId="1233" Text="...e.g. TLC555 works off of 2V (http://focus.ti.com/docs/prod/folders/print/tlc555.html), not quite but almost there." CreationDate="2009-12-22T23:54:03.653" UserId="330" />
  <row Id="867" PostId="1219" Text="I have this same one and have been happy with it." CreationDate="2009-12-23T02:28:23.503" UserId="6" />
  <row Id="868" PostId="1241" Text="We considered both, but the module we found was expensive and overseas. Given I had an Arduino and an ethernet shield already, this became a little simpler :-) &#xA;&#xA;Thanks so much for your suggestion!" CreationDate="2009-12-23T03:24:17.427" UserId="431" />
  <row Id="869" PostId="1146" Text="This is a great idea, and I even found a breakout board with this on it to make integration even easier. My only reservations were with power requirements and size. &#xA;&#xA;Thanks for your suggestion! I will definitely remember this for future projects :-)" CreationDate="2009-12-23T03:25:44.883" UserId="431" />
  <row Id="870" PostId="1160" Text="Thanks for the info. Helped to clear up some questions I had :)" CreationDate="2009-12-23T03:26:37.293" UserId="431" />
  <row Id="871" PostId="1251" Score="1" Text="so, where are you located?" CreationDate="2009-12-23T05:01:49.607" UserId="411" />
  <row Id="874" PostId="1233" Text="Cool I'll probably look for both, I'll go to my local electronics store today and see what's available. The 551 sounds good, but I'd also like to try the voltage controller method also, I don't need the battery to last that long." CreationDate="2009-12-23T10:25:57.487" UserId="399" />
  <row Id="875" PostId="1201" Text="I guess @zklapow mean &quot;Python&quot; not &quot;hon&quot;." CreationDate="2009-12-23T10:45:26.243" UserId="94" />
  <row Id="877" PostId="1260" Score="2" Text="This is what I've done and it works quite well.  You need to be careful with your ATX power supply choice, however, as not all of them have the voltages you reference. Mine's missing −5V, which is an optional (now obsolete?) part of the spec." CreationDate="2009-12-23T10:57:38.573" UserId="51" />
  <row Id="879" PostId="1034" Text="AD7940, wow that looks the biz, how does it send the digital data? is it serial? would I need to use something like an FTDI chip to hook it up with USB? Also would this ADC chip be in place of using an MCU?&#xA;Thanks in advance. " CreationDate="2009-12-23T11:51:54.643" UserId="399" />
  <row Id="880" PostId="947" Text="Forgot to mention, the joy of a 555 timer is that it will not require amplification to drive a small speaker or piezoelectric buzzer, however most other oscillators will require amplification with an extra IC or a couple of Transistors." CreationDate="2009-12-23T11:58:29.580" UserId="399" />
  <row Id="881" PostId="1262" Score="3" Text="Be careful, it is easy to disable ISP and lock yourself out by setting the wrong fuses." CreationDate="2009-12-23T12:05:58.610" UserId="339" />
  <row Id="888" PostId="1266" Text="PS. Piezoelectric buzzers/pickups are only about £1 sterling, or 2 Aussie dollars " CreationDate="2009-12-23T13:32:28.577" UserId="399" />
  <row Id="890" PostId="1260" Text="I didn't know that ATX had 3.3v in it. Thanks!" CreationDate="2009-12-23T13:38:00.023" UserId="417" />
  <row Id="891" PostId="1268" Text="Even a few millimeters of metal seems doubtful to me. If you can put an accelerometer inside to sense jostling that might work. you'd need a circuit connection from inside the box to earth ground outside the box, though, to provide a voltage reference relative to the box. Otherwise, even with a few millimeters thick piece of metal, you have a Faraday shield with near-uniform electric potential, and no way to tell whether that potential is affected by anything outside it." CreationDate="2009-12-23T13:41:28.867" UserId="333" />
  <row Id="892" PostId="1268" Text="&#xA;But iPhones don't have a connection to ground, and they're able to use capacitance sensing. You can sense the capacitance of a human being touching a conductive object without anything connected to ground. Faraday cage only stops electrostatic fields, not AC." CreationDate="2009-12-23T13:42:11.313" UserId="333" />
  <row Id="894" PostId="1263" Text="sorry to butt in, but I was wondering if there are physical fuses inside the ATmega or are they like a software emulation of a fuse? Oh, and what happens if you blow a fuse? &#xA;Am I even thinking of the same kind of fuse?   " CreationDate="2009-12-23T14:05:09.907" UserId="399" />
  <row Id="895" PostId="1271" Text="I think for sending notes, you would be able to implement a simple MIDI program on the MCU which it could output messages directly then just hook up to a regular MIDI module or computer. As for sending audio down I2C, I'm not sure if the data rate would be good enough, I'll have to have a look into that. Maybe it could be a kind of synth/sampler box that uses MIDI over I2C?   " CreationDate="2009-12-23T14:49:58.417" UserId="399" />
  <row Id="896" PostId="1271" Text="would you want this device to have on board memory for audio file storage? " CreationDate="2009-12-23T14:59:01.530" UserId="399" />
  <row Id="897" PostId="1263" Score="3" Text="no, they are not at all like that kind of fuse. they are basically just a few bits of flash or eeprom memory, separate from the rest, that are used as configuration paramaters." CreationDate="2009-12-23T16:39:38.290" UserId="131" />
  <row Id="898" PostId="1268" Text="You can use a t-network to sense capacitance through a conductive barrier like a metal project case.  They've been used in soil moisture sensors for that reason." CreationDate="2009-12-23T17:01:48.723" UserId="86" />
  <row Id="902" PostId="1268" Text="@MrEvil: interesting... could you post a link?" CreationDate="2009-12-23T19:03:23.143" UserId="330" />
  <row Id="903" PostId="1193" Text="I like the processing idea, not exactly turn-key though." CreationDate="2009-12-23T21:40:25.417" UserId="86" />
  <row Id="904" PostId="1158" Score="2" Text="Yep for straight edges this is the quickest, most accurate and more importantly the safest (no fibreglass dust)&#xA;&#xA;I find that a few scores then use a square edge and bang the ob is done." CreationDate="2009-12-23T22:26:48.400" UserId="312" />
  <row Id="905" PostId="1225" Score="6" Text="Eagle is not free but there is a light freeware version with board area limited to 100 x 80 mm (4 x 3.2 inches)&#xA;It's excellent but necissate some time to learn and once it's done you'll get perfect result" CreationDate="2009-12-23T23:25:50.400" UserId="199" />
  <row Id="906" PostId="1279" Text="cool, I'll keep you posted" CreationDate="2009-12-24T02:36:16.460" UserId="399" />
  <row Id="907" PostId="1193" Text="http://www.glacialwanderer.com/hobbyrobotics/?p=261" CreationDate="2009-12-24T04:29:33.503" UserId="86" />
  <row Id="908" PostId="1263" Text="I see, thanks for the info" CreationDate="2009-12-24T13:23:21.707" UserId="399" />
  <row Id="909" PostId="1279" Text="I've got a meeting with an Electrical Engineer in January, he's acting as mentor on the biofeedback project and will be helping with the technical specification. Hopefully by the end of January I will have the final proposal for the circuit design. I'll post further details on Chiphacker then." CreationDate="2009-12-24T13:32:49.233" UserId="399" />
  <row Id="910" PostId="1281" Text="I was actually thinking of the Theremin when I wrote that." CreationDate="2009-12-24T16:50:40.070" UserId="305" />
  <row Id="911" PostId="1169" Text="That video was incredibly helpful!  Gives me an idea of what to expect with responsiveness and insight to what may or may not be realistic with applications.  Thank you very much for that! " CreationDate="2009-12-24T19:25:46.137" UserId="429" />
  <row Id="912" PostId="1120" Text="Awesome, so maybe in a couple years we can expect to see high-speed/precision actuators on the market.  I suppose the contraction does not increase [significantly] with the increase in temperature?  I'll still have to get some and piddle around to see what its characteristics really are for hobbyist potential.  Perhaps I'll log the data I collect to post on the net for others with the same curiosity to read." CreationDate="2009-12-24T19:28:56.163" UserId="429" />
  <row Id="913" PostId="1127" Text="Awesome answer -- I was planning to buy the ATMega which was identified as the biggest, but you hold a very very good point with the multiple cheaper boards and adding inputs if necessary using multiplexers.  I think this is the route that I will go.  The virtual limitation of pre-built inputs would be greatly made up for by the additional capabilities of having multiple boards.&#xA;&#xA;I will be using USB of course until I build something better (bluetooth is in the future, but merely as a serial bridge so not philosophically different than serial-&gt;usb)." CreationDate="2009-12-24T19:43:45.197" UserId="429" />
  <row Id="915" PostId="1120" Text="If you end up buying some, please do post your results -- I would be curious to see." CreationDate="2009-12-26T06:07:57.260" UserId="207" />
  <row Id="918" PostId="1211" Score="2" Text="Latency, latency, latency." CreationDate="2009-12-26T06:12:55.787" UserId="207" />
  <row Id="919" PostId="1289" Text="Do you have any recommendations for good solid state relays to handle A/C and capable of many many cycles?  Also, what good heating element should I use?  Thoughts?" CreationDate="2009-12-26T21:41:51.553" UserId="107" />
  <row Id="920" PostId="1271" Text="As my goal would be to play back sound samples (or perhaps do some rudimentary wavetable synthesis), some on-board audio storage would help.  That might help with the data-rate, too -- I could upload sound samples and then play them back on demand." CreationDate="2009-12-26T23:46:26.967" UserId="106" />
  <row Id="921" PostId="1293" Text="HEHE, so simple. I was unnecessarily daunted by this approach. Until it was explained so simply I didn't know how to go about constructing the makefile. Thanks for the direction :)" CreationDate="2009-12-27T03:01:23.367" UserId="443" />
  <row Id="922" PostId="1293" Text="This is what I do too. EMACS and a Makefile. You can also compile Arduino stuff this way too. &#xA;&#xA;(* jcl *)" CreationDate="2009-12-27T04:06:46.733" UserId="424" />
  <row Id="923" PostId="1293" Text="You can also use Eclipse as the IDE/editor and use the makefile for compile and download. With OpenOCD and ARM it is even possible to debug via JTAG (I don't know whether this works with AVR)." CreationDate="2009-12-27T11:49:15.460" UserId="339" />
  <row Id="924" PostId="1271" Text="That sounds viable, you could send MIDI messages over I2C which could then trigger samples stored on the module, maybe on an SD card or something. I had a look into it, and the chances of sending audio down I2C looks slim, it's just not capable of the data rates needed.&#xA;" CreationDate="2009-12-27T15:25:01.547" UserId="399" />
  <row Id="925" PostId="1290" Text="The clickatell.com seems to be primarily for internet SMS gateway.  I need to be able to send/receive messages only using SMS (not internet) from my application." CreationDate="2009-12-27T15:34:19.333" UserId="107" />
  <row Id="926" PostId="1271" Text="I'd say, 'let me send the data in parallel, then', but the microcontrollers I want to use probably aren't fast enough to really make it worthwhile." CreationDate="2009-12-27T15:46:45.100" UserId="106" />
  <row Id="927" PostId="1298" Text="That would be quite a simple kit, I think it would work well, It could be a kind of reprogrammable VU meter, for cool visual effects. Humm....I'll get back to you on that one, it's a definite possibility " CreationDate="2009-12-27T16:29:22.297" UserId="399" />
  <row Id="928" PostId="1303" Text="you have to watch out w/ I2C with multiconductor cables, the capacitance can cause the bus to slow down significantly." CreationDate="2009-12-27T23:49:59.633" UserId="330" />
  <row Id="930" PostId="1297" Text="Yes, I have tried to get KontrollerLab working before but my PC recently crashed very badly and I have only just been setting everything up again. It looks to be from the same crew that made Ktechlab which I have found to be a very useful for schematic and circuit design. Thanks for the input." CreationDate="2009-12-28T00:40:03.210" UserId="443" />
  <row Id="931" PostId="1301" Text="Cheers for the lead, but as you don't sound all that convinced I wont trouble myself too much :)" CreationDate="2009-12-28T00:41:24.847" UserId="443" />
  <row Id="932" PostId="1301" Text="I would just like to add that I have to use eclipse at work (not for avrs though) and i do not reccommend it. For microcontrollers you can do without all that bloat." CreationDate="2009-12-28T01:37:35.360" UserId="417" />
  <row Id="935" PostId="1310" Text="Thank you for the help. My current need is less than 3 amps. I would prefer something like a TO-92 package, because I am hoping to fit several on an arduino shield with some other components." CreationDate="2009-12-28T03:24:49.447" UserId="451" />
  <row Id="936" PostId="1306" Text="RS485 is definitely a good way to go for such a thing. " CreationDate="2009-12-28T03:42:03.913" UserId="72" />
  <row Id="937" PostId="1218" Score="2" Text="I just haven't seen an application where they really beat Braid and a desolder gun. I guess maybe they are good for mounting high pin count chips and/or BGA?  I have one but I never use it so I guess I might have an unfair bias." CreationDate="2009-12-28T03:44:32.180" UserId="72" />
  <row Id="938" PostId="1310" Score="2" Text="That may be difficult to find in that small a package. TO-92 has a thermal resistance that is three times that of the TO-220. Higher &#xA;thermal resistance package and a smaller die size makes cooling&#xA;difficult (which decreases your current specification).&#xA;&#xA;I would use the Digikey search and select TO-92 package, 12V (and higher) breakdown and see what the results are. At the On-Semi site&#xA;the highest current was 500mA for an N-channel FET in a TO-92 package.&#xA;&#xA;(* jcl *)&#xA;&#xA;" CreationDate="2009-12-28T04:51:12.783" UserId="424" />
  <row Id="939" PostId="1310" Text="Thank you!  That explanation helps a lot.  Can you elaborate on the gate drive level and what Rds(on) is?" CreationDate="2009-12-28T06:07:06.910" UserId="451" />
  <row Id="940" PostId="1314" Score="2" Text="ditto etch your own PCB" CreationDate="2009-12-28T08:48:14.353" UserId="81" />
  <row Id="941" PostId="1317" Score="1" Text="Basically OK, but you need another resistor in series with LED and transistor to set the current for the bright state, otherwise your LED will die." CreationDate="2009-12-28T12:12:49.017" UserId="339" />
  <row Id="942" PostId="1317" Text="yes this is true. I figured it was implied but I should have mentioned it anyway." CreationDate="2009-12-28T12:16:59.463" UserId="417" />
  <row Id="943" PostId="1310" Score="2" Text="Gate drive is the voltage between the gate and the source (Vgs). The Vgs turns the FET on and off. To get the lowest resistance between the drain and source (Rds(on)) you typically need to drive the FETs at a Vgs of 10V. Driving a FET at a lower Vgs increases&#xA;Rds(on). For most applications driving the FET at 3V or 5V &#xA;produces an Rds(on) that is acceptable but you need to review&#xA;the datasheet.&#xA;&#xA;The Rds(on) determines the amount of power the FET dissipates and &#xA;your cooling requirements. A low Vgs (and corresponding high Rds(on)) plus a high thermal resistance package (TO92) may be a problem.&#xA;" CreationDate="2009-12-28T13:19:58.430" UserId="424" />
  <row Id="944" PostId="1319" Score="2" Text="simplifies transmitter, but complicates the receiver" CreationDate="2009-12-28T13:26:17.653" UserId="330" />
  <row Id="945" PostId="1323" Score="1" Text="Cool, it sounds like a reprogrammable audio visualizer kit is the order of the day. Do you want this as a kit that can be used along side other audio equipment for a gig? &#xA;&#xA;Would you like this device to work standalone, in conjunction with a computer or both?&#xA;&#xA;Thanks for the input." CreationDate="2009-12-28T14:49:01.870" UserId="399" />
  <row Id="946" PostId="1319" Text="If he's tracking loads of points, he's probably not going to be using an Arduino or any other microcontroller." CreationDate="2009-12-28T15:18:02.030" UserId="103" />
  <row Id="947" PostId="1323" Score="1" Text="I would expect to take an audio output from a sound board (or a cheap computer mic) into a 1/8 inch jack on the device. It would be ideal if it can be programmed then used without a computer." CreationDate="2009-12-28T15:56:44.980" UserId="238" />
  <row Id="948" PostId="1320" Score="1" Text="I think you meant to link here:  &#xA;http://www.luciani.org/getting-it-done/assembly-hints/assembly-hints-index.html#breadboard-hints" CreationDate="2009-12-28T19:01:18.773" UserId="131" />
  <row Id="949" PostId="1320" Text="Yeah. I was lazy and just linked to the top page in my ee-notes section ;)" CreationDate="2009-12-28T20:13:04.987" UserId="424" />
  <row Id="950" PostId="1318" Text="It sounds like either one will work.  I'm mainly thinking of these two particular protocols because most of the AVRs support them natively, without adding extra components.  Otherwise, RS485 or CAN would be a good choice." CreationDate="2009-12-28T20:17:03.737" UserId="213" />
  <row Id="951" PostId="1319" Text="..for the receiver that is, plus it's not the programming that's the problem it's the circuits so the simpler the circuit the better." CreationDate="2009-12-28T23:58:10.100" UserId="103" />
  <row Id="952" PostId="1324" Text="tough question! -- i'll ask around at work when I get a chance -- there's some Japanese company that makes some pressure sensors that are low cost.... although it could be that they are just low cost in high volumes." CreationDate="2009-12-29T01:02:50.377" UserId="330" />
  <row Id="953" PostId="1330" Score="1" Text="I2C is much slower than SPI... it could also have been in how your project managed arbitration in case of collisions... or the capacitance may have been high enough with all those nodes that you just had to use a slow clock rate." CreationDate="2009-12-29T01:04:57.143" UserId="330" />
  <row Id="954" PostId="1306" Text="keep in mind that RS485 has two aspects different than RS232 that are somewhat independent: the physical differential logic levels, and the multimaster aspect. You can pick + choose these, we've used both LVDS and RS485 translators with UART (RS232) for point-to-point w/o getting into the multidrop parts of RS485. " CreationDate="2009-12-29T01:07:27.713" UserId="330" />
  <row Id="955" PostId="1329" Text="That would be good, I've been thinking about a more extensive synth for a while now. What kind of controls would you like the synth to have? Potentiometers, sliders, jog wheels or LDRs? I'd love to hear you opinion." CreationDate="2009-12-29T11:34:03.970" UserId="399" />
  <row Id="957" PostId="1324" Text="Thanks, additional options would be useful." CreationDate="2009-12-29T17:07:05.363" UserId="354" />
  <row Id="958" PostId="1334" Score="1" Text="Thanks for complete answer. I will again consider using LED matrix driver.&#xA;&#xA;You're right, that I worry about wiring, but I think Your idea about crating pcb for this is nice.&#xA;&#xA;However I'm not sure if I understand correctly Your suggestion about ribbon cable. I think I need 4 wires for each group of 3 LEDs, so I think double pair telephony cable could be better. I also think about using telephony sockets (RJ11) for connecting my LEDs groups to PCB.&#xA;&#xA;    " CreationDate="2009-12-29T18:45:29.850" UserId="422" />
  <row Id="959" PostId="1334" Score="1" Text="One more question about drivers. Waiting time in Mouser for TLC5951 is quiet long. Is it any alternative for TLC5951? On TI website I found tlc5952 (http://focus.ti.com/docs/prod/folders/print/tlc5952.html) but it seems like it doesn't have per LED brightness control." CreationDate="2009-12-29T18:46:17.883" UserId="422" />
  <row Id="960" PostId="1333" Text="Thanks, I will check that." CreationDate="2009-12-29T18:57:12.727" UserId="422" />
  <row Id="961" PostId="1336" Text="Thanks for the comments, that's a really good point, the kit could be much more expansive, with more options. &#xA;More hackable! " CreationDate="2009-12-29T19:54:42.287" UserId="399" />
  <row Id="962" PostId="1335" Text="I think that these functions could be generated using the re programmable analogue/digital synth kit suggested by msutherl. This is good help with deciding functionality, cheers." CreationDate="2009-12-29T19:57:12.667" UserId="399" />
  <row Id="963" PostId="1337" Score="2" Text="could you please clarify what your question is?" CreationDate="2009-12-29T22:38:50.390" UserId="330" />
  <row Id="964" PostId="1334" Score="1" Text="Telephone cable could work. I just suggested ribbon cable (flat cable) because it's fairly common in electronics. Whatever gets the job done would work (obviously :).&#xA;&#xA;That is quite a long lead time from Mouser. You might try Digikey.com or just an equivalent LED driver from Mouser (http://www.mouser.com/Optoelectronics/Drivers/LED-Drivers/_/N-6hpc2/). The tlc5952, as you said, doesn't offer the individual LED brightness control. But, there's lots of other options.&#xA;&#xA;I tried looking on the TME website for something that could work, but their website isn't the most user friendly so I gave up." CreationDate="2009-12-29T22:49:43.533" UserId="403" />
  <row Id="965" PostId="1338" Score="1" Text="most hardware PWM peripherals let you select frequency; if you keep duty cycle constant then PWM can still give you variable-frequency control" CreationDate="2009-12-29T23:29:40.600" UserId="330" />
  <row Id="966" PostId="1338" Score="1" Text="Changing the pulse width doesn't change the fundamental frequency but it does change the harmonics. " CreationDate="2009-12-29T23:40:08.597" UserId="424" />
  <row Id="967" PostId="1329" Text="For me, ideally, it wouldn't come with any interface components to keep the base price low (perhaps you could have a set of recommended components for those who want them). I would be interested in strictly computer control (using OSC and with the option to use MIDI). I should be able to plug it into a computer and have a standard way to access every parameter. Alternatively I should be able to control every parameter with MIDI commands sent to the microcontroller or from within a sequencer application within the microcontroller itself. This could turn into a big project!" CreationDate="2009-12-29T23:42:04.703" UserId="207" />
  <row Id="968" PostId="1329" Text="But, if the price was low, I know a lot of people would be interested. People always want to do sound synthesis with micro-controllers and run into problems. Either it's a bitch to program or you use the Wave Shield: http://www.ladyada.net/make/waveshield/ Alternatively, you could make a digital synth, or hybrid analog/digital (say, digital oscillators and analog filters). " CreationDate="2009-12-29T23:44:41.080" UserId="207" />
  <row Id="971" PostId="1329" Text="I did a four channel numerically controlled oscillator application note. The hardware is my NB1A kit which has an ATmega168/328 + DAC + RTC. I loaded the wavetable with a sinewave but other waveforms are possible. The app-note is at http://tinyurl.com/ydmz2su &#xA;I also have prototyped a MIDI interface + quad 2-pole filter for the NB1A. My plan is to filter the NCO and add MIDI with this peripheral.&#xA;&#xA;A couple of other synth things at prototype -- a white noise board (1&quot;x2&quot;) based on the Moog/Arp avalanche designs and a four-pole&#xA;VCF based on the ARP4075 design.&#xA;&#xA;" CreationDate="2009-12-30T02:22:07.307" UserId="424" />
  <row Id="972" PostId="1279" Text="Sounds great! look forward to it!" CreationDate="2009-12-30T02:23:36.680" />
  <row Id="973" PostId="1337" Text="I am not sure how interesting they will be but it is easy to try and you get to judge. As the pulse narrows the amplitudes of the harmonics increases. Keep narrowing the pulse and you get white noise. &#xA;&#xA;I think you would have more interesting options doing a numerically controlled oscillator. You can change the waveforms loaded into the&#xA;wavetable.&#xA;&#xA;" CreationDate="2009-12-30T02:57:27.437" UserId="424" />
  <row Id="977" PostId="1334" Text="Thank You again.&#xA;&#xA;I found only large ribbon cables. Probably I can divide them into narrower parts, but I wasn't sure if my wiring idea is correct. In this situation I will probably use twisted pair cable.&#xA;&#xA;Thank You for info about Digikey.com, it looks like nice store and they have TLC5951DAP in stock. However shipping costs would be USD 60 :/ . So i think I will use MAX7219.&#xA;&#xA;I was trying to found in mouser.com something like TLC5951DAP but it hard for me to fund something with individual LED brightness control." CreationDate="2009-12-30T13:02:16.923" UserId="422" />
  <row Id="978" PostId="1334" Text="Yes TME website isn't user friendly. This is direct link to LED drivers (choice is not too large): http://www.tme.eu/en/katalog/index.phtml#cleanParameters%3D1%26search%3DLED%26id_category%3D100221%26bf_szukaj%3D+  I would be very grateful if you could look at it if You have time.&#xA;&#xA;I also thinking about ordering samples from TI have you any experiences with this?" CreationDate="2009-12-30T13:15:21.950" UserId="422" />
  <row Id="979" PostId="1342" Text="Where did you read that in the data sheet? I can't find it." CreationDate="2009-12-30T15:49:53.637" UserId="339" />
  <row Id="982" PostId="1342" Score="1" Text="I found it, @starblue.  Page 29, Port B: &quot;All port pins have individually selectable pull-up resistors. The Port B output buffers can sink 20 mA and thus drive LED displays directly.&quot;  @joeforker, are you sure you have your circuit wired correctly and the code properly set up for this use?  Would you mind posting a schematic and your code for review?" CreationDate="2009-12-30T16:10:22.513" UserId="11" />
  <row Id="983" PostId="1343" Score="3" Text="I suppose it means &quot;don't do that&quot; rather than &quot;the chip will make sure no more than 40 mA passes through an I/O pin&quot;." CreationDate="2009-12-30T16:11:01.203" UserId="1363" />
  <row Id="984" PostId="1343" Score="4" Text="Those are Absolute Maximum Ratings, not current-limiting functions of the chip. From the datasheet, &quot;Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.&quot; I'm pretty sure those pins will allow you to pull as much current as inherent resistances will allow and it will not stop at 40 mA. Actually, on review of the datasheet, I DID find a reference to current-regulating behavior (Page 29, Port B).  Still, I don't think a pin not configured this way will stop at 40mA.  Either way, though, I think I'd just use the resistor." CreationDate="2009-12-30T16:12:04.263" UserId="11" />
  <row Id="985" PostId="1343" Score="1" Text="Further reading reveals a 100mA limit for a single port." CreationDate="2009-12-30T16:16:55.140" UserId="1363" />
  <row Id="986" PostId="1334" Text="OK. I ordered few MAX7219.s and STC2026.s, so I will test both solutions. Maybe I will use TLC5951DAP in future projects. Thank You again for help." CreationDate="2009-12-30T17:57:39.360" UserId="422" />
  <row Id="987" PostId="1343" Score="2" Text="As Lou mentioned there is no current limiting function. Also Note 3 on page 49 states that &quot;Pins are not guaranteed to sink more than the listed test condition.&quot; The listed test conditions for IOL are 20mA for Vcc of 5V and 10mA for Vcc or 3V." CreationDate="2009-12-30T18:37:52.693" UserId="424" />
  <row Id="988" PostId="1342" Score="8" Text="The statement on Page 29 doesn't imply current regulating behavior. &#xA;It states that there is sufficient sink current to drive an LED meaning an external buffer is not required for currents of 20mA or less. You still need to limit currents if your design is capable of sinking currents higher than 20mA." CreationDate="2009-12-30T19:02:32.393" UserId="424" />
  <row Id="989" PostId="1155" Text="I received my Kada 952D and it works! The package was a little under $140 shipped and it was shipped on a Friday and was out for delivery on a Monday. Included were extra ceramic elements for the iron and the hot air component and extra tips.&#xA;&#xA;I tried removing some SMD and through the hole compenents from an cheap networking card with the hot air and managed to make the PCB smoke and pucker on the highest heat setting. So it is certainly powerful enough. The iron seems to be fine. I'll mention downsides in next comment..." CreationDate="2009-12-30T22:00:39.037" UserId="432" />
  <row Id="990" PostId="1155" Score="1" Text="I've noticed two downsides: the minor one is that the soldering iron stand is plastic and really light. Replacing it with a metal one won't be expensive. The more major downside is the issue already mentioned by another poster: there is no switch that definitely turns the power off. Turning off the two switches means that the air pump stays on while the heating element of the hot air side cools down. So leaving it plugged in all the time is something I'm not comfortable doing. One final issue is that the hot air pump is a little noisy. Having separate iron and hot air would be nice." CreationDate="2009-12-30T22:03:16.287" UserId="432" />
  <row Id="991" PostId="1218" Text="Fair enough. I don't have any experience with it so I was curious. Apparently, the SparkFun people like the hot air station but it doesn't go into why. I posted some details above my main comment above but if I was to &quot;do over&quot;, I'd go with a stand alone iron (probably Weller or Hakko) and consider a stand alone hot air station later on down the road." CreationDate="2009-12-30T22:05:02.773" UserId="432" />
  <row Id="992" PostId="1191" Text="My impression is that the benefit of using a reflow approach is that it can be faster when assembling many of the same PCBs as in a kit. For one or two, it is not needed. However, when the hand starts to cramp up and there is more work to do... I'm curious though just as a hobbyist so I picked up a used toaster oven at the resale shop today and I'm going to try it." CreationDate="2009-12-30T22:09:09.767" UserId="432" />
  <row Id="993" PostId="1218" Text="Actually, this goes into why SparkFun likes hot air for SMD: http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=102" CreationDate="2009-12-30T22:26:08.500" UserId="432" />
  <row Id="994" PostId="1191" Text="Hmm, I suppose it could be faster to use a reflow approach... i'm still kind of skeptical. But I'm not a soldering expert, just know what works well + am reluctant to trade increased speed for increased risk. Good luck!" CreationDate="2009-12-31T00:28:41.283" UserId="330" />
  <row Id="995" PostId="1341" Text="I believe there's a large community for this kind of stuff: http://lmgtfy.com/?q=diy+stomp+box+kits" CreationDate="2009-12-31T04:48:49.307" UserId="207" />
  <row Id="997" PostId="1344" Text="yes, and note that these are current limits on their *specification*, not necessarily or usually current limits built into the part, so if you go outside the limits they make no claims as to the survival or function of the part." CreationDate="2009-12-31T13:17:39.347" UserId="330" />
  <row Id="999" PostId="1341" Text="Wow, thanks for the help! I guess I had in mind something more minimal for the knob twiddling set (e.g. Drone Lab, but you know, effects)" CreationDate="2009-12-31T14:00:10.300" UserId="290" />
  <row Id="1000" PostId="1340" Text="I pretty sure I'll be able to implement a record feature on the kit, I'm hoping once the kit is done people will reprogram it for various applications " CreationDate="2009-12-31T14:47:49.400" UserId="399" />
  <row Id="1001" PostId="1341" Text="it's true, there are loads of kits out there for making effects pedals. I've recently designed a simple distortion unit, i'll be putting a bare bones version on my shop in the new year. " CreationDate="2009-12-31T14:50:28.307" UserId="399" />
  <row Id="1002" PostId="1328" Text="I love it, maybe I could use an LDR and another contrasting control method, just to mix it up a bit! " CreationDate="2009-12-31T14:52:33.540" UserId="399" />
  <row Id="1003" PostId="1353" Text="Um, no they don't. They make microcontrollers. All the other objects shown on that page are things you have to add. The OP has a microcontroller already, he's just looking for something to interface with or include power devices." CreationDate="2009-12-31T17:36:48.450" UserId="330" />
  <row Id="1004" PostId="1353" Score="1" Text="Microchip PWM modules can generate trapezoidal waveforms directly." CreationDate="2009-12-31T17:54:41.703" UserId="305" />
  <row Id="1005" PostId="1273" Text="How did you get RRDtool installed?  Did you compile RRDtool and its dependencies from source, use fink/homebrew/etc, or find pre-compiled binaries?" CreationDate="2010-01-01T15:07:43.920" UserId="106" />
  <row Id="1006" PostId="1359" Text="Stupid decimal point. :-) Thanks, John!  I'd missed that I need to be looking at the voltage &lt;i&gt;drop&lt;/i&gt;, not Vss." CreationDate="2010-01-03T03:26:08.443" UserId="51" />
  <row Id="1007" PostId="1361" Text="Is there a place to buy these from? From the site it looks like they are still putting together kits???" CreationDate="2010-01-03T22:59:47.430" UserId="21" />
  <row Id="1008" PostId="1362" Text="There's an RGB 8x8 LED Matrix kit called the Meggy or something, looked pretty neat. In the form factor of a gameboy or something, so you can battery power it and write simple games." CreationDate="2010-01-04T04:54:13.080" UserId="131" />
  <row Id="1009" PostId="1355" Text="Wow, very difficult. You may as well have a proper audio DAC for this. You could do it with an arduino audio shield, but it's not easy to sound convincing! Basically the hardware is already out there but the software would take a long time to develop. It's a great idea tho." CreationDate="2010-01-04T13:10:59.483" UserId="399" />
  <row Id="1010" PostId="1362" Text="There's loads of different LED matrix solutions, I'm not really interested in creating another. You can find all the info on the arduino website, they even show how to do 8x8 without shift registers http://www.arduino.cc/playground/Main/DirectDriveLEDMatrix" CreationDate="2010-01-04T13:42:59.560" UserId="399" />
  <row Id="1012" PostId="1318" Text="If you're not restricted to through-hole packages, then ST has their cost-effective and powerful STM32 and STM8 microcontrollers with CAN, NXP have a range of LPC17xx microcontroller and there are a few others out there as well. CAN is becoming increasingly common (and affordable) on a lot of microcontrollers." CreationDate="2010-01-04T14:48:44.077" UserId="201" />
  <row Id="1013" PostId="1361" Text="It looks like they've been putting together the kits for about 18 months. But the schematics etc are available for free." CreationDate="2010-01-04T16:49:01.580" UserId="103" />
  <row Id="1014" PostId="954" Text="Be aware that David swears in many of his video blogs, so it may not be suitable for children, or even at work (without headphones)." CreationDate="2010-01-04T18:35:51.083" UserId="161" />
  <row Id="1017" PostId="1371" Text="Do you happen to have a copy of this article? I found a copy here[1], but it doesn't have the diagrams. The inspiration for that project is AN-265[2], which is probably sufficient...&#xA;&#xA;[1] http://www.accessmylibrary.com/coms2/summary_0286-9127919_ITM&#xA;[2] http://www.national.com/an/AN/AN-265.pdf&#xA;" CreationDate="2010-01-05T15:32:08.007" UserId="51" />
  <row Id="1018" PostId="1371" Text="It's on my bookshelf. The article is based on the AN-265 but the AN-265 circuit is discrete and the Poptronics design uses ICs.&#xA;The Poptronics design uses an AD633 multiplier to get V*I, an LTC1062 filter (on the AD633 output) and an opamp preamp for the current transformer." CreationDate="2010-01-05T16:46:43.457" UserId="424" />
  <row Id="1019" PostId="1371" Text="Would a transformer be necessary for low current situations like this (expanded the question some)?" CreationDate="2010-01-05T17:21:35.070" UserId="347" />
  <row Id="1020" PostId="1370" Text="I'm not sure.  For this vibration sensor, I think it'd probably be fine to know &quot;vibrating&quot; vs. &quot;not vibrating&quot;.  There's specifically some kind of op-amp thing in the related products on sparkfun, so that may be right." CreationDate="2010-01-05T17:24:16.377" UserId="347" />
  <row Id="1022" PostId="1371" Text="&#xA;I missed the sentence where you mentioned the piezo and when I saw 90V&#xA;and AC I was thinking line voltage :( Since the voltage the sensor&#xA;outputs is isolated from the line a simple attenuation (or buffer)&#xA;like davr suggested is fine. On page 41,42 of the technical manual&#xA;they show low voltage op-amp circuits interfaced directly to the&#xA;sensor. Where does the 90V come from? Sorry about the&#xA;confusion." CreationDate="2010-01-05T17:53:42.930" UserId="424" />
  <row Id="1023" PostId="1318" Score="1" Text="There are indeed some AVR's with CAN receivers built in, but just like the other vendors, it's only in a limited subset of their chips." CreationDate="2010-01-05T18:55:11.917" UserId="131" />
  <row Id="1025" PostId="1361" Text="Plus right on cue they've just shown up on the Makezine Blog - http://blog.makezine.com/archive/2010/01/open_source_swarm_robot_project.html" CreationDate="2010-01-05T23:47:58.680" UserId="103" />
  <row Id="1026" PostId="1371" Text="That was entirely my fault.  I'm still new enough to know what all details are important." CreationDate="2010-01-06T08:23:56.693" UserId="347" />
  <row Id="1027" PostId="1374" Score="2" Text="What do you mean?  The best OS to do Arduino development on, or the best OS to run on your Arduino (a la FreeRTOS)?" CreationDate="2010-01-06T13:36:37.363" UserId="51" />
  <row Id="1028" PostId="1371" Text="No problem. I am assuming you found the wide range of circuits on the four or five pages starting at 41. With those circuits you will not be generating high-voltage and you should have no problems with an Arduino interface. That app-note is an excellent reference." CreationDate="2010-01-06T14:31:43.497" UserId="424" />
  <row Id="1029" PostId="1374" Score="3" Text="In addition, it might be worthwhile to ask &quot;best for what?&quot;  That is, each OS (arduino or computer) would have different advantages given different problem spaces.  That would be helpful in answering your question." CreationDate="2010-01-06T14:58:05.267" UserId="36" />
  <row Id="1030" PostId="1381" Text="I usually program my boards from the command line. You can compile Arduino sketches or C/C++ using a makefile or shell script. I use EMACS to edit and make to compile. It is very quick. " CreationDate="2010-01-06T16:36:03.797" UserId="424" />
  <row Id="1032" PostId="1381" Text="Is it just a C/C++ Mode or is there a separate Arduino Sketch Mode?" CreationDate="2010-01-06T20:48:13.180" UserId="103" />
  <row Id="1033" PostId="1390" Score="5" Text="Do you get a nickel every time you mention Metcal or something?" CreationDate="2010-01-07T00:03:20.853" UserId="131" />
  <row Id="1034" PostId="1390" Text="Metcal is an excellent iron. I use an SP-200 with a 20mil bent tip for SMD soldering. The quality of the tips and the heating response time works extremely well. There are a wide variety of tips and tools. " CreationDate="2010-01-07T00:10:50.687" UserId="424" />
  <row Id="1035" PostId="834" Text="Thanks for posting the code and the link. Just an hour ago I got my NB1 board to pair with my android using the WT12A. I was looking for some more detailed examples of the iWRAP commands and just found your post ;) Sweet! I would press the up-arrow a couple of times but it looks like it is one to a customer ;)" CreationDate="2010-01-07T02:00:00.273" UserId="424" />
  <row Id="1036" PostId="1381" Score="1" Text=" The Arduino team wrapped the Java based editor for the &quot;Processing&quot; programming environment  (from which the whole &quot;sketch&quot; thing originated) together with AVR-GCC (a freely available version of the GNU C/C++ compiler for AVR microcontrollers) and written an easy to use library on top of that. So it's all just C/C++ but instead of writing : PORTB |= (1&lt;&lt;PB2) you write: digitalWrite(10,HIGH) which is somewhat easier to understand. You can still use the &quot;hardcore&quot; AVR syntax in the sketch if you want. An Arduino &quot;sketch&quot; is a C++ program that is to be wrapped into a library before compilation." CreationDate="2010-01-07T07:32:18.247" UserId="10" />
  <row Id="1037" PostId="1397" Text="I retagged your question as it's relevant for any microcontroller or sensitive IC." CreationDate="2010-01-07T12:49:42.280" UserId="330" />
  <row Id="1038" PostId="1390" Text="ditto here. Metcals are great!" CreationDate="2010-01-07T12:56:32.047" UserId="330" />
  <row Id="1039" PostId="1396" Score="3" Text="If you are soldering TQFP one pin at a time, you are doing it wrong.&#xA;&#xA;Search YouTube for &quot;drag soldering&quot;.&#xA;&#xA;Myself, I prefer a 1.8mm chisel tip.  I've soldered TQFP, TSSOP, DFN with it.  The super-tiny tips just make a mess.  They don't transfer enough heat to the joint and it's easy to lift a trace when the solder freezes to the tip." CreationDate="2010-01-07T15:05:50.367" UserId="411" />
  <row Id="1040" PostId="1406" Score="2" Text="Thanks. I want to have a wireless connection directly to a phone so I believe that BT is the only option that is standard on most phones. For other applications I am using a CC2500 design which has a total parts cost of around $2-$3.  " CreationDate="2010-01-07T18:04:08.363" UserId="424" />
  <row Id="1042" PostId="1381" Text="I was actually referring to EMACS, does it have a separate Arduino Sketch mode or is jluciani just using the existing modes for C/C++?" CreationDate="2010-01-07T23:04:03.127" UserId="103" />
  <row Id="1043" PostId="1377" Text="Thanks, this is excellent as well. Nice breakout board." CreationDate="2010-01-08T02:53:30.440" UserId="354" />
  <row Id="1044" PostId="1377" Text="I still have some - so if anybody is interested - hit the contact button on my site ;)" CreationDate="2010-01-08T07:42:13.477" UserId="407" />
  <row Id="1045" PostId="1414" Text="If you're having trouble etching i've made a video explaining a simple method for making PCBs at home -&gt; http://www.youtube.com/watch?v=frsDN7usyCs" CreationDate="2010-01-08T08:45:50.357" UserId="399" />
  <row Id="1046" PostId="1399" Text="So, like this?&#xA;http://i.imgur.com/mdK0b.png&#xA;I'm pretty sure I need to add a resistor in there somewhere but I'm not sure where...?&#xA;Also do you know where to buy one of these optimized &quot;ESD clamping diodes&quot;?  Maybe I'm not searching for the right thing." CreationDate="2010-01-08T10:50:47.480" />
  <row Id="1047" PostId="1390" Text="I use a second-hand STSS power unit with an MX-500 handpiece and cartridges, costing about the same as a new Weller. It's much better than the Weller, of course." CreationDate="2010-01-08T11:20:03.117" UserId="305" />
  <row Id="1048" PostId="1417" Text="He just wanted to know where those numbers came from. I doubt you bothered to comment the source of those constants (since they are right in the user manual!)" CreationDate="2010-01-08T14:08:20.433" UserId="259" />
  <row Id="1049" PostId="1396" Score="3" Text="First, you can drag solder with a tiny tip - it's never frozen up for me (are you sure you're using the right iron and tip if your tip is freezing?  Sounds to me like a bad tool, or poor skill.), secondly, soldering it one pin at a time is certainly not 'wrong' - in fact I'm scratching my head at why you would think so. It's a different technique, certainly, and can be more time consuming, but it doesn't damage the chip, pin, or PCB, and results in a good solder joint. The man whose only tool is a hammer tends to see everything as a nail. I find it useful to have and use several techniques." CreationDate="2010-01-08T14:41:23.860" UserId="161" />
  <row Id="1050" PostId="1416" Score="1" Text="A hot glue gun is invaluable for this sort of thing.  It will melt quite quickly near soldering irons, so glue after things are in place, but that property means you can fix your fixes if need be without a huge headache." CreationDate="2010-01-08T16:34:21.393" UserId="11" />
  <row Id="1051" PostId="1416" Score="2" Text="Buss wire too. I use tweezers to hold it in place while the solder cools. " CreationDate="2010-01-08T19:25:14.193" UserId="424" />
  <row Id="1052" PostId="1399" Score="1" Text="they're called TVS (transient voltage suppressors) -- I had a brain blank when writing the above stuff. will fix, thanks." CreationDate="2010-01-08T21:18:08.033" UserId="330" />
  <row Id="1053" PostId="1399" Score="1" Text="in your sketch, put a resistor between the switch and the TVS." CreationDate="2010-01-08T21:23:40.153" UserId="330" />
  <row Id="1054" PostId="1279" Text="I had my first meeting with the projects technical mentor and we are now finalizing the components for the first prototype. If you want to keep track of progress on the biofeedback development board please follow this thread -&gt; http://forum.sonodrome.co.uk/projects-f2/rnd-on-an-eeg-t20.htm#124 thanks." CreationDate="2010-01-09T02:23:15.703" UserId="399" />
  <row Id="1055" PostId="1270" Text="Thanks for everyones comments, advice and ideas, it seems there are a few reoccurring themes, i'll definitely be considering implementing a few of them. Thanks again Chiphakers!  " CreationDate="2010-01-09T02:27:32.573" UserId="399" />
  <row Id="1056" PostId="1420" Text="http://focus.ti.com/docs/toolsw/folders/print/ez430-chronos.html" CreationDate="2010-01-09T10:55:02.660" UserId="339" />
  <row Id="1057" PostId="1424" Score="2" Text="By the way, don't use a synthetic sponge, they melt!" CreationDate="2010-01-09T15:07:50.733" UserId="399" />
  <row Id="1058" PostId="1415" Score="2" Text="Yes, this does work; I'm using this in one of my robots and it works beautifully. Get a high-turn 10k potentiometer, and you can find the value you need pretty easily." CreationDate="2010-01-10T13:31:27.303" UserId="238" />
  <row Id="1059" PostId="1422" Score="2" Text="It doesn't look like the MRF24J40MA does Bluetooth." CreationDate="2010-01-10T15:30:47.237" UserId="424" />
  <row Id="1060" PostId="1404" Score="1" Text="Also similar: http://electronics.stackexchange.com/q/514/142" CreationDate="2010-01-10T19:47:02.540" UserId="142" />
  <row Id="1061" PostId="1429" Text="That's a great idea! Would you be thinking of coaxial or optical s/pdif? Cheers&#xA; " CreationDate="2010-01-11T07:34:43.717" UserId="399" />
  <row Id="1062" PostId="1415" Text="That's cool, you could get a stereo potentiometer, then you could adjust the top speed of both the motors with one knob, then you could change the speed for different applications/demonstrations. " CreationDate="2010-01-11T07:44:49.707" UserId="399" />
  <row Id="1064" PostId="1408" Text="I helped my mate make a couple of these for a university project, wow those things are crazy! I just remember having loads of hassle trying to glue a lever onto a micro switch at the front (so it turns around when it hits a wall). I think he'd bought the basic kit, so we were building them into old computer mouses. I think they're a fantastic starter robot kit!" CreationDate="2010-01-11T07:51:27.227" UserId="399" />
  <row Id="1065" PostId="1408" Text="It would be groovy to design an evasive robot with a bright light on for the mousebot to chase after! " CreationDate="2010-01-11T07:59:30.970" UserId="399" />
  <row Id="1066" PostId="1416" Text="yes, wire-wrap wire is perfect for these kinds of &quot;edits&quot;.  And if you use wire with the same color conductor as your soldermask (green wire over green board), it's very hard to see the edits! :)" CreationDate="2010-01-12T00:06:44.913" UserId="215" />
  <row Id="1067" PostId="1416" Text="(oops, I means same color insulation)" CreationDate="2010-01-12T00:07:28.653" UserId="215" />
  <row Id="1068" PostId="1436" Text="To be honest, I did not see the links right away, so went hunting for a local distributor. The 2x4 IDC connectors I could not find anywhere, and could only find ugly rainbow ribbon cable to pull apart.&#xA;&#xA;I have now found your links and will order from OS!&#xA;&#xA;Thanks so much!" CreationDate="2010-01-12T01:07:29.173" UserId="431" />
  <row Id="1069" PostId="1279" Text="This is very interesting indeed! I'm interested in recording sleep signals etc, so I'd be eagerly watching the development of this project and hoping to contribute in some way. Looking forward to buy a kit.!" CreationDate="2010-01-12T01:11:48.383" />
  <row Id="1070" PostId="1436" Text="PS By 'Local' i meant Australia ;-)" CreationDate="2010-01-12T01:21:14.043" UserId="431" />
  <row Id="1071" PostId="1436" Text="Tod I'm also interested! &#xA;&#xA;Cheers, &#xA;&#xA;Marcus" CreationDate="2010-01-12T01:34:09.947" UserId="3" />
  <row Id="1072" PostId="1440" Text="I would make one correction to your code, when you set DDRB you should use DDRB |=(1&lt;&lt;6) so as not to affect an other bits." CreationDate="2010-01-12T05:56:47.610" UserId="81" />
  <row Id="1073" PostId="1440" Text="Also there is a delay_ms() function available. But in general, in more complex programs, you usually do not want to be hard coding delays into your app." CreationDate="2010-01-12T15:44:25.293" UserId="131" />
  <row Id="1074" PostId="1446" Text="I'm looking at them as the new ones have twelve 14bit ADCs. I don't know of any other chips (atmel/microchip or otherwise) that offer that many or with that resolution.  " CreationDate="2010-01-12T20:00:25.760" UserId="399" />
  <row Id="1075" PostId="1452" Text="I need ethernet/wireless, but I don't really need graphics or video out is my issue with the beagleboard." CreationDate="2010-01-13T07:03:22.780" UserId="81" />
  <row Id="1076" PostId="1452" Text="Depends how much processing power you need, you can't really beat the beagleboard. And like I said, people have reported success using it with a USB ethernet/wireless adapter. I think there actually may be some beagleboard clones with on-board ethernet." CreationDate="2010-01-13T16:45:15.050" UserId="131" />
  <row Id="1077" PostId="1456" Score="2" Text="I'd avoid the $140 USB Oscilloscope...it only samples at a max rate of 1MHz. And at $250, the PropScope still only does 25MHz. Decent, but the MSO-19 does much faster it looks like." CreationDate="2010-01-13T17:04:56.080" UserId="131" />
  <row Id="1078" PostId="1442" Score="1" Text="The GCC port supports the 430X variant in the cvs version.  Regular msp430 support is more mature, of course." CreationDate="2010-01-13T18:23:09.207" UserId="411" />
  <row Id="1079" PostId="1442" Text="I am not an MSPGCC user so I can only go from what I pick up from the chatter on the yahoo MSP group.  From a quick look at the sourceforge user forum for MSPGCC there are still issues with the large memory devices.  It is not as seamless as the IAR and Rowley offerings." CreationDate="2010-01-13T21:39:14.503" UserId="400" />
  <row Id="1080" PostId="1420" Text="In the comments section of the Make:Blog link there's reference to geting it working using XP in VirtualBox under Ubuntu." CreationDate="2010-01-13T21:50:47.563" UserId="103" />
  <row Id="1081" PostId="1455" Score="3" Text="Since people appear to be interested, here are some of the features: 2 channel with external trigger, math functions (addition, fft, etc), tons of measurement functions(freq, vrms, vpeak, etc) colour LCD, USB host to dump waveforms/screen captures on a USB drive, USB slave for computer control (windows only but works in vmware on my mac), multiframe recording, single trigger mode (this is why I bought it; freeze scope on trigger for analysis or storage) and a lot more that I can't remember off the top of my head!" CreationDate="2010-01-14T03:06:45.513" UserId="417" />
  <row Id="1082" PostId="1462" Score="1" Text="A whole synthesizer may be a bit much, perhaps a voltage controlled function generator whould be a start towards it, with a useful device at the end.  You could then go on to a full synthesizer." CreationDate="2010-01-14T14:43:54.430" UserId="1498" />
  <row Id="1083" PostId="1462" Score="1" Text="A voltage controlled function generator would be an excellent project by itself. Great bench instrument. " CreationDate="2010-01-14T17:15:23.867" UserId="424" />
  <row Id="1084" PostId="1466" Text="I'm not too sure about how much power the solenoids draw, the datasheet says they are 12v 1.5W? I suppose the Arduino will depend on  what parts of the board are in use, I looked at the Arduino website and it says it draws in the region of mA and at a max of 1A if your using all the ports. So I'm guessing I need an amp for each solenoid and an amp for the Arduino (assuming thats not over kill) So it's 7Amps could I use the nearest value PSU? if I give it 6A will it struggle? or would 9A cook it?    " CreationDate="2010-01-14T21:11:27.150" UserId="399" />
  <row Id="1085" PostId="1467" Text="I'm planning on using some npn transistors on the Arduinos outputs and protective diodes over the solenoids. Is that the kinda thing you mean?" CreationDate="2010-01-14T21:13:39.637" UserId="399" />
  <row Id="1086" PostId="1466" Text="sorry dude, I should say thanks for the response first! " CreationDate="2010-01-14T21:15:29.750" UserId="399" />
  <row Id="1087" PostId="1466" Text="hang on, I think I see what you mean now. so if they're 12v 1.5w they draw 0.125A so 6 solenoids is 0.75 amp plus the 1 amp for the Arduino. So do I need around 12v 2Amp DC power supply?  " CreationDate="2010-01-14T21:54:51.160" UserId="399" />
  <row Id="1088" PostId="1467" Text="There is a lot more to it than that. The solenoids will take a lot of current - you need to look into power and ground distribution to ensure that it doesn't affect the MCU." CreationDate="2010-01-14T22:16:43.133" UserId="305" />
  <row Id="1089" PostId="1467" Text="thanks, I may yet end up posting the circuit once i've got it on the breadboard. I don't want to knacker the MCU" CreationDate="2010-01-14T23:17:08.723" UserId="399" />
  <row Id="1090" PostId="1472" Score="1" Text="If you use supply voltage as the ADC reference then the ADC is ratiometric as well, so everything should continue to work the same (more noise perhaps) as the voltage goes down.  Somewhere below the published minimum rating the circuit will cease to work of course. " CreationDate="2010-01-14T23:34:52.013" UserId="411" />
  <row Id="1091" PostId="1031" Text="Pretty video! And that schematic editor is there to be used." CreationDate="2010-01-15T05:43:53.223" UserId="227" />
  <row Id="1092" PostId="1455" Text="I have a Rigol DS1052E and bought it because of the review at the eevblog. I haven't used it that much until now but what I've seen, it's seem to be really good value for the money." CreationDate="2010-01-15T08:03:08.707" UserId="409" />
  <row Id="1093" PostId="1462" Score="2" Text="Have a look at http://www.musicfromouterspace.com/ if you want schematics etc for full analog synths, etc." CreationDate="2010-01-15T09:50:36.400" UserId="103" />
  <row Id="1094" PostId="1474" Text="Thanks, what i'm trying to find is an MCU with at least 12 ACDs and I want them to have at least a 14 bit resolution, as far as I know PSoc is the only chips that will provide it. I want to use Atmel, because of their popularity and ease of use, but the just don't cut the mustard!  " CreationDate="2010-01-15T09:57:52.423" UserId="399" />
  <row Id="1095" PostId="1474" Text="I was wondering if there are separate ADC chips that are compatible with an Atmel MCU?" CreationDate="2010-01-15T09:59:36.173" UserId="399" />
  <row Id="1096" PostId="1472" Text="Well, your noise probably won't scale down as your readings will, so your signal to noise ratio will probably decrease.  In effect, you will be reading more noise and less signal, making your readings less accurate.  If the IC is rated for those voltages (iirc it is) then yes, all of the calculations will scale down but the maximum range should remain +/-250g (check the data sheet to be sure).  Running it at the highest voltage possible usually increases your SNR and gives you better results." CreationDate="2010-01-15T13:14:15.210" UserId="11" />
  <row Id="1097" PostId="1453" Text="Cool, hadn't seen these devices before, seem pretty reasonably priced." CreationDate="2010-01-15T17:31:49.223" UserId="131" />
  <row Id="1099" PostId="1399" Text="Okay, so I mentioned my project on IRC and someone gave me the following advice: &quot;&lt;HTT-Bird&gt; yeah, a switch line, use 1n4148s to GND and VCC with a 100nF cap bypassing the rails, a series resistor in the line too helps &lt;HTT-Bird&gt; like 10ohm or something &lt;HTT-Bird&gt; keep the diodes from getting completely shot&quot; - Is this equivalent, or does it behave differently? Also I'm having trouble finding a 3.3v TVS that I can mount on my ProtoShield, do those exist? Thanks for your help!" CreationDate="2010-01-16T04:39:16.027" />
  <row Id="1100" PostId="1479" Text="close enough for estimation purposes. The 51 uA is from the 3.3V which would get boosted up from 2.6-3V. The 25uA Iq is from the 2.6-3V battery. You're missing the increase in current (maybe 15-20%) due to step-up effects. But this brings it really close to 100uA, so you're pretty much spot on." CreationDate="2010-01-16T22:22:36.177" UserId="330" />
  <row Id="1101" PostId="1399" Score="1" Text="not quite the same. what httbird is talking about is clamping the voltage to the power rails. That's ok, but I'd use Schottky diodes rather than 1N4148s: they are faster and have lower on-state voltage. The bypass cap helps prevent voltage spikes on the power rails; if you care about it, add a 4V zener or something across the power rails. Should be a high enough voltage so leakage current is minimal at the high end of your power supply spec, but not much higher than that." CreationDate="2010-01-16T22:25:37.957" UserId="330" />
  <row Id="1102" PostId="1084" Text="Hi, Justin. If by the &quot;cat's tag&quot; you mean the one inserted under the skin by the vet, no reader is going to be able to read it at a range of more than a couple of centimetres. They're purely for identification and not designed for proximity detection at all.  Most existing cat doors I've seen that use this chip involve a tunnel that forces the cat to come close enough to the sensor. No good for my various sized animals." CreationDate="2010-01-17T09:50:27.223" UserId="117" />
  <row Id="1103" PostId="1482" Score="4" Text="Your title should be &quot;DIY USB Mass storage tutorial&quot; because you are specifically asking for a tutorial on how make your own flash drive. A question about making your own USB gadgets has been asked a while ago." CreationDate="2010-01-17T14:11:00.527" UserId="10" />
  <row Id="1104" PostId="1474" Text="You may want to start a separate question about a different MCU with 12 ADC's and 14 bit resolution rather than adding it to this one.&#xA;" CreationDate="2010-01-18T00:59:17.327" UserId="107" />
  <row Id="1105" PostId="1486" Text="Do not count on reaching either the dark current and light current unless you actually reach light and dark, a fan blade will probably not reach these levels, but they are a good place to start.  Plan to have more gain in your pocket." CreationDate="2010-01-18T01:17:18.320" UserId="1498" />
  <row Id="1106" PostId="1490" Text="If you give me a better idea about what result you're after, bearing in mind how complicated you wanna go, I could point you in the direction of something more specific. Peace" CreationDate="2010-01-18T12:34:15.463" UserId="399" />
  <row Id="1107" PostId="1489" Score="1" Text="good question, but I don't think any of us chiphacker users would know any of the TI motives beyond what is in the datasheet or on wikipedia http://en.wikipedia.org/wiki/74181" CreationDate="2010-01-18T12:45:55.557" UserId="330" />
  <row Id="1108" PostId="1479" Text="My concern is that your calculations don't include the number of batteries.  There has to be a reason to put another battery in the product. " CreationDate="2010-01-18T13:24:48.960" UserId="204" />
  <row Id="1109" PostId="1489" Text="@Jason:thanks for your comment.then where is the good place to this question?" CreationDate="2010-01-18T14:09:20.893" UserId="493" />
  <row Id="1110" PostId="1493" Text="You may need to make a cover/lid for the top, so it limits the overall light going into the box, but that depends on what kind of sound you want." CreationDate="2010-01-18T14:18:16.400" UserId="399" />
  <row Id="1111" PostId="1492" Score="1" Text="It's real easy to fine tune the circuit, you can put a resistor in series with the photocell, or you can change the value of the ceramic capacitor (the smaller the value of your cap, the higher the pitch and brightness of your oscillator). For instance - A 0.1uf cap will take the 555 timer to the limits of the human hearing range when you shine a bright light into the photocell, but when you cover the cell the pitch should be lower than the human hearing range and will be audible as pulses not tones." CreationDate="2010-01-18T14:27:47.317" UserId="399" />
  <row Id="1112" PostId="1492" Score="2" Text="You can also use a similar trick to listen to the discreet frequencies found in the laser of an optical mouse. Just hold the laser on the photocell of said circuit, and listen to the crazy noises! " CreationDate="2010-01-18T14:36:09.360" UserId="399" />
  <row Id="1114" PostId="1492" Score="1" Text="To be exact, it's making a square wave oscillator to create a tone, then your using the fan to modulate the pitch of that tone. It's not a sine wave by any means, but you won't get that from a PC fan! I'm positive it would make a pretty great sounding oscillator tho" CreationDate="2010-01-18T14:49:06.260" UserId="399" />
  <row Id="1115" PostId="1493" Text="If you do make this project, I wanna hear it! (jim@sonodrome.co.uk)&#xA;Cheers." CreationDate="2010-01-18T14:59:14.773" UserId="399" />
  <row Id="1116" PostId="1479" Score="2" Text="With batteries in series, they'll both drain at the same rate and provide the same amount of current.  You've got a 3V 2700mAh battery instead of two 1.5V 2700mAh cells." CreationDate="2010-01-18T17:52:16.847" UserId="213" />
  <row Id="1117" PostId="1496" Text="Cool, they look really good, I'll definitely look into them, cheers" CreationDate="2010-01-18T19:19:10.077" UserId="399" />
  <row Id="1118" PostId="1495" Text="thanks for the heads up" CreationDate="2010-01-18T21:22:26.740" UserId="399" />
  <row Id="1119" PostId="1486" Text="Yes, good point, i'll take some measurements with the components in-situ to get an idea of the dynamic range of the photodiode in normal conditions." CreationDate="2010-01-18T21:36:12.270" UserId="178" />
  <row Id="1120" PostId="1493" Text="Wow, thanks for your detailed help Jim. I'll read up about the 555. Lots of work to do!" CreationDate="2010-01-18T21:52:41.913" UserId="178" />
  <row Id="1121" PostId="1491" Text="I like the use of the ping-pong balls to make the glowing orbs and self organising systems are fascinating in the patterns that emerge." CreationDate="2010-01-18T22:39:27.130" UserId="178" />
  <row Id="1122" PostId="1485" Score="1" Text="Gijs Gieskes's work provided inspiration for this project. Check out his site and the videos - some amazing creative stuff.&#xA;&#xA;http://gieskes.nl/&#xA;http://vimeo.com/gijs" CreationDate="2010-01-18T22:43:28.500" UserId="178" />
  <row Id="1123" PostId="1496" Text="also: note that audio codecs are generally cheaper/simpler than &quot;regular&quot; DC-accurate ADCs, since audio doesn't need to handle frequencies correctly if they're below human hearing, so you don't have to pay for DC-accurate conversion. I don't have enough experience to advise you on a good audio codec, though." CreationDate="2010-01-18T22:54:38.490" UserId="330" />
  <row Id="1124" PostId="1489" Text="not sure... check with a TI sales rep? perhaps they could put you in touch w/ one of the old-timers who worked on the 74181 back in the 1970's." CreationDate="2010-01-18T22:55:35.147" UserId="330" />
  <row Id="1125" PostId="1493" Text="Hi Jim, i've documented some testing results here and some questions:&#xA;http://mintmedia.co.nz/Fan_oscillator" CreationDate="2010-01-19T01:26:39.277" UserId="178" />
  <row Id="1126" PostId="1493" Text="Dude! you're totally right, the photodiode is different to the photocell, my bad. It won't work in the same way. The photocell is acting as a variable resistor. Sorry, I'm not too hot on photodiodes " CreationDate="2010-01-19T07:42:12.577" UserId="399" />
  <row Id="1127" PostId="1493" Text="Also the ground is supposed to be the negative terminal of the battery! I've used them before with an ACDC power adapter, and I didn't bother limiting the current, they were fine. " CreationDate="2010-01-19T07:49:37.627" UserId="399" />
  <row Id="1128" PostId="1493" Text="If you want more channels you just have to make a mixer and you can add as many as you want, just ask if you want the circuit diagram they're not difficult." CreationDate="2010-01-19T07:52:18.667" UserId="399" />
  <row Id="1129" PostId="1493" Text="If you put in a 1KΩ pot between +9v and the photocell, you should have more than enough adjustment of the pitch, bearing in mind the light in the room will play the biggest part in controlling the pitch. If you just pop it on a breadboard first you can have a good mess about with the values, the 555 timer is so robust it's nigh on impossible to break, so don't be scared to just get stuck in." CreationDate="2010-01-19T08:05:08.560" UserId="399" />
  <row Id="1130" PostId="1495" Text="+1: Excellent answer." CreationDate="2010-01-19T09:30:29.330" UserId="201" />
  <row Id="1131" PostId="1491" Text="Me too, I thought they were fantastic." CreationDate="2010-01-19T11:01:19.593" UserId="103" />
  <row Id="1132" PostId="1077" Text="Thanks for that list, John!" CreationDate="2010-01-19T15:14:15.837" UserId="51" />
  <row Id="1133" PostId="1490" Text="@Jim, It would be good if you could point me to board layout." CreationDate="2010-01-19T15:59:32.047" UserId="231" />
  <row Id="1134" PostId="1490" Text="No board layouts spring to mind, but there are loads of circuit diagrams for simple LED VU meters, for instance there's one in the data sheet for the LB1403N. Unfortunately you would have to modify the circuit in order for it to work with Light bulbs. &#xA;I'll keep an eye out for something more suitable, tho." CreationDate="2010-01-19T17:30:50.473" UserId="399" />
  <row Id="1135" PostId="1490" Text="If you want a convincing disco light you will probably need to delve into using a programmable chip. This example -&gt; http://electronics.rory.co.nz/projects/lighting/disco_lights.php&#xA;Shows a basic DIY implementation of a sound activated disco light using a cheap picaxe micro controller " CreationDate="2010-01-19T17:39:32.530" UserId="399" />
  <row Id="1136" PostId="1077" Text="You're welcome." CreationDate="2010-01-20T00:06:22.897" UserId="424" />
  <row Id="1137" PostId="1504" Score="1" Text="What resolution? What do you consider low-cost?" CreationDate="2010-01-21T03:01:32.357" UserId="424" />
  <row Id="1138" PostId="1504" Text="Don't have a specific resolution needs, I'd like to know some options. As for low cost, the cheaper the better...but I'd say the range is $20-$50." CreationDate="2010-01-21T06:38:18.490" UserId="131" />
  <row Id="1139" PostId="1505" Text="Which have you used from Newhaven, their color TFT displays? They look interesting, though it might require a good number of I/O pins, but still usable (8-bit paralell + a few more for control signals)" CreationDate="2010-01-21T17:20:15.957" UserId="131" />
  <row Id="1140" PostId="1505" Text="I've used the NHD-2.4-240320YF-CTX#-T-1-ND and the NHD-C128128BZ-FSW-GBW-ND.  Unfortunately they both require 16 bit interfaces (the data sheets, unfortunately, are misleading) so they won't be easy to drive directly from the arduino, but a serial in parallel out chip could be used.  They don't require high speed updates, and they are reasonably nice displays." CreationDate="2010-01-22T03:03:47.827" UserId="161" />
  <row Id="1141" PostId="1508" Text="It sounds (no pun intended) like you are looking for some sort of shock sensor (accelerometer) to detect the impact of the kick.  The problem that I see here is how do you limit the impact detection to just the kick event and not detect the impact of the foot/boot on the ground?" CreationDate="2010-01-22T10:08:11.550" UserId="400" />
  <row Id="1142" PostId="1509" Text="I'd agree this is definitely the most economic method. The Piezoelectric buzzers are also fantastically sensitive, but would not react to airborne sound. However beware of handling the bare piezoelectric disk as they are very delicate. You won't want to use a sealed Piezoelectric disk in a plastic case, you will need to snap off the case, or buy one without a case. When using the Piezo as a pickup you want to attach the bare element directly to the surface you wanna detect vibration in. I'd use hot glue if it's permanent, you need a good solid contact..." CreationDate="2010-01-22T11:28:02.457" UserId="399" />
  <row Id="1143" PostId="1509" Text="...Try not to snap the wire connections on the piezo disk, as trying to re solder them ruins the ceramic layer and the disk wont work anymore. A small amount of hot glue on the wires leading to the piezo will stop them from moving about and snapping off. " CreationDate="2010-01-22T11:32:40.637" UserId="399" />
  <row Id="1144" PostId="1509" Text="Those MSI sensors aren't disks, they are a flexible film, and quite robust." CreationDate="2010-01-22T13:03:29.127" UserId="305" />
  <row Id="1145" PostId="1507" Text="My robot is a cannibalized RC car, servo on the front and a dc motor on the back the trouble is DC motor requires 7v to start and i think vin supplies 5v no? So if i disconnect vin connection to the arduino from ardumoto and connect it to the power directry i will be able to drive the motors?" CreationDate="2010-01-22T13:25:16.867" UserId="496" />
  <row Id="1146" PostId="1512" Text="Vin can also be used to supply power to the Arduino.  It comes in, as expected, before the voltage regulator (That's why it can be used to tie in directly to the external power supply and why it has no potential when the board is powered over USB)." CreationDate="2010-01-22T16:49:05.790" UserId="11" />
  <row Id="1147" PostId="1512" Text="So does that mean, if i use a 9V 2amp adapter connected to the power plug on the arduino do i get 9v 2amp on the vin pin?" CreationDate="2010-01-22T17:48:43.797" UserId="496" />
  <row Id="1149" PostId="1512" Text="You should consider editing the question above to add this. I'm a bit confused as to what you mean. Is the connector rated at 9V, 2A, or is your connector hooked up to a power supply that can yield 9V at 2A? If it's the former, no: Whatever you are using (say, a battery) will determine your specs, and if you go over the adapter's limits you risk causing permanent damage. If it's the latter, possibly, but remember the Arduino will need current to run as well. It sounds like you have a project in mind. Perhaps if you told us more about the project, we could give more helpful answers." CreationDate="2010-01-22T17:54:50.280" UserId="11" />
  <row Id="1150" PostId="1512" Text="i have edited the question to include information about what i am trying to do." CreationDate="2010-01-22T18:29:30.127" UserId="496" />
  <row Id="1151" PostId="1511" Text="According to the spec sheet, which I got from a link from the SparkFun Ardumoto site, the device can take 46V up to 2A per channel, 4A total, for close to 100W per channel or roughly 1/8 HP (.13).  At 2A, 9V, you're looking at 18W or 1/40 hp, which might be too low.  I've added a comment to post the motors you have used on the other question, and if you would be so kind, post the power supply, code, and any other customizations you have made as well.  It sounds like you may need more power, but if you post this info we can certainly help you troubleshoot and make sure nothing else is going on." CreationDate="2010-01-22T19:33:54.943" UserId="11" />
  <row Id="1153" PostId="1506" Text="Could you post links to the motors you have used, and if you would, the power supply, code, and any other customizations you have made as well, please? Also, it'd be good to know what RC car you are basing this off of. That will help us to help you" CreationDate="2010-01-22T19:36:09.973" UserId="11" />
  <row Id="1154" PostId="1511" Text="Lou thanks, my power source is a generic adapter which provides 9v 2 amps as for the motors they don't have any make or model on them i'll check with the shop i bought them for the specs tomorrow it's 10pm here." CreationDate="2010-01-22T20:09:37.230" UserId="496" />
  <row Id="1155" PostId="1511" Text="No problem!  We're here to help!  You'll probably have a slew of stuff come in over your night as the Americas get off of work (just a few hours...)." CreationDate="2010-01-22T20:19:04.380" UserId="11" />
  <row Id="1156" PostId="1503" Text="Hi again - my terminology brain kicked in and I remembered that we called these things &quot;color organs&quot;. Discovercircuits (http://www.discovercircuits.com/C/color-org.htm) has a couple of schematics that might get you what you're looking for. The one by Randy Linscott looks pretty close to my recollection of what I built a million years ago. Good luck." CreationDate="2010-01-22T22:46:06.487" UserId="425" />
  <row Id="1157" PostId="1218" Text="I saw that vid. that is why I got a hot air.  The problem is in actual application the air is usually blocked by other components." CreationDate="2010-01-23T14:42:31.500" UserId="72" />
  <row Id="1158" PostId="1517" Text="The supply is unregulated. 5V and 350mA from 230V AC. MY trigger was the only load." CreationDate="2010-01-24T09:33:50.047" UserId="491" />
  <row Id="1159" PostId="1517" Score="2" Text="You should lookup the specification on the supply. I would be very surprised if you have enough load on the supply for specified performance. Once you find the minimum load requirement add a resistor to draw the minimum current. " CreationDate="2010-01-24T14:21:56.240" UserId="424" />
  <row Id="1160" PostId="1523" Text="Brilliant, thanks for this, I've just Bookmarked it." CreationDate="2010-01-24T20:22:08.590" UserId="103" />
  <row Id="1161" PostId="1513" Score="1" Text="I agree that a switch in the front of the shoe is a much simpler and more robust solution.  " CreationDate="2010-01-24T22:44:38.437" UserId="142" />
  <row Id="1162" PostId="1519" Text="Nice blog.  But most of it is over my head.  When I do end up doing the disco lights, it's probably going to be a &quot;paint by colors&quot; type of project." CreationDate="2010-01-25T07:42:15.587" UserId="231" />
  <row Id="1163" PostId="1210" Text="+1 for TINA-TI." CreationDate="2010-01-25T21:00:00.363" UserId="142" />
  <row Id="1164" PostId="1527" Text="How are you going to power this?  If it's off of batteries, how long would you want it to last?" CreationDate="2010-01-26T13:19:08.550" UserId="11" />
  <row Id="1165" PostId="1525" Text="My first attempts to implement didn't do anything to crank up the volts and therefore failed, but I haven't done anything about it yet - thanks for the info - I'll check this out." CreationDate="2010-01-26T18:09:01.787" UserId="84" />
  <row Id="1166" PostId="1530" Score="9" Text="Typically signatures are not allowed - your user page is a more appropriate place for such things." CreationDate="2010-01-26T18:16:30.843" UserId="161" />
  <row Id="1167" PostId="1532" Text="Yup, this looks pretty much spot on, thanks!  I thought JST was a connector style, not a manufacturer, as I'd only seen them referred to in the context of the 0.1&quot; pitch connectors used for things like servo cabling." CreationDate="2010-01-26T21:02:42.620" UserId="215" />
  <row Id="1168" PostId="1534" Text="Good comments. Thanks. &#xA;&#xA;SOT23-5 is one of my favorites. Pin pitch is large and you &#xA;can't reverse it. Lots of parts are available in SOT23.&#xA;&#xA;For power diodes I go with SMB or SMC. For the signal diodes&#xA;I have been using SOD123 (rather than the much smaller SOD323).&#xA;&#xA;I also avoid the cylindrical packages but did not have any problems with a tilt sensor I had to use. " CreationDate="2010-01-27T00:16:33.240" UserId="424" />
  <row Id="1171" PostId="1532" Text="You're welcome. You asked the right question at the right time. I just finished two Li-ion charger boards that use the JST connectors ;) Pics at http://tinyurl.com/yfs3ws3" CreationDate="2010-01-27T00:23:16.457" UserId="424" />
  <row Id="1172" PostId="1538" Text="sensors.getTempCByIndex returns a value of XX.xx in degreesC&#xA;&#xA;You lost me on the the rest - still trying to get my head around &quot;cast&quot; &quot;Float&quot; and all these other unfamiliar terms (i'm from a BASIC background - sorry!)" CreationDate="2010-01-27T11:20:14.463" UserId="503" />
  <row Id="1173" PostId="1538" Text="so if what i am getting returned is a &quot;float&quot; (floating point number????) is there some way I can convert it into a string??&#xA;I tried putting the (sensor.getTempCByIndex) command into the client.sendto() without any luck - i just got errors about &quot;cast&quot; that i simple dont understand yet :-(" CreationDate="2010-01-27T11:22:06.693" UserId="503" />
  <row Id="1174" PostId="1537" Text="libraries used are HOPERF &amp; DallasTemperature" CreationDate="2010-01-27T11:34:02.830" UserId="503" />
  <row Id="1176" PostId="1539" Text="I've been trying to learn on PC - brain too stuck in the world of Basic! I've actually learnt more about &quot;C - like&quot; programming in a week of Arduino than months trying to work it our on the PC. I'm just weird sorry :P&#xA;Thanks for the link - I'll have a look anyway" CreationDate="2010-01-27T20:35:57.373" UserId="503" />
  <row Id="1177" PostId="1540" Text="Thanks - that looks like it should work. Its sort of what i expected it to be but as I'm still getting my head around the program structures (being ex BASIC) i just couldn't work it out. I'll give it bash this morning and see what results i get - thank you! :-)" CreationDate="2010-01-27T20:38:02.627" UserId="503" />
  <row Id="1178" PostId="1538" Text="Thank you for the extra description - some of this is starting to make sense now :-)" CreationDate="2010-01-27T20:38:48.383" UserId="503" />
  <row Id="1179" PostId="1539" Text="A thoroughly good book, it starts off looking at C then moves onto C++." CreationDate="2010-01-27T20:57:22.680" UserId="103" />
  <row Id="1180" PostId="1540" Text="YAY - many thanks! With a little bit of adjustment I got that to work properly. I now have my temp to 2 decimal places being sent over the RF and displayed in the serial monitor window.&#xA;I'm also using SoftwareSerial to display data on an LCD. using LCD.print(tempC) gives an error even though serial.print(tempC) works fine. I had a read of the SoftwareSerial library page and changed the line to LCD.print(tempC, DEC) which works but only gives me the whole part of the temp whereas the serial.print gives me the whole plus decimal. I'll keep reading to see if I can sort it out :-)&#xA;Many thanks!" CreationDate="2010-01-28T01:45:53.377" UserId="503" />
  <row Id="1181" PostId="1540" Text="Working! Codes not pretty but it works :-)&#xA;Thanks again!" CreationDate="2010-01-28T04:12:04.660" UserId="503" />
  <row Id="1182" PostId="1539" Text="Downloaded..........." CreationDate="2010-01-28T05:54:02.287" UserId="503" />
  <row Id="1183" PostId="1540" Text=".....and after a tidy-up saved over 700bytes to boot :-)" CreationDate="2010-01-28T05:55:03.550" UserId="503" />
  <row Id="1184" PostId="1540" Text="Nice!  Congrats!" CreationDate="2010-01-28T13:23:31.227" UserId="51" />
  <row Id="1185" PostId="1545" Score="1" Text="I spoke to someone at Arrow Electronics in Perth.  They are listed on the Vishay web site as a local distributor.&#xA;&#xA;I haven't been able to find an email address of anyone at Vishay who looks like they'd be able to help.  I guess they don't do that by mistake." CreationDate="2010-01-28T14:48:44.867" UserId="505" />
  <row Id="1186" PostId="1546" Text="When I read the OP I thought he was saying that he wanted a timer, with selectable food stuffs/weights which could be stuck on the oven, not that he wanted to automate the oven controls. In other words just a timer (with a buzzer etc) stuck on the outside. But I could be wrong." CreationDate="2010-01-28T22:05:23.650" UserId="103" />
  <row Id="1187" PostId="1546" Text="Amos is correct and I understand that you could move the electronics but I figured it would be an interesting question to get some answers to. Thanks. " CreationDate="2010-01-29T07:20:35.167" UserId="417" />
  <row Id="1188" PostId="1546" Text="I guess the proper question then is what temperatures are you expecting to see at the electronics? Maybe some testing with a cooking thermometer in the location you plan to place the electronics is in order. That way we know what our target ambient rating needs to be." CreationDate="2010-01-29T14:56:56.743" UserId="498" />
  <row Id="1189" PostId="1550" Text="4 ways: radiation, conduction, convection, and phase change (evaporation/condensation/boiling/freezing/melting/sublimation/etc... I guess this may be a subcase of conduction since usually it's not the thing being affected that is undergoing the phase change, but rather something next to it)" CreationDate="2010-01-29T17:41:15.690" UserId="330" />
  <row Id="1190" PostId="1550" Text="You're right.  I didn't include it because it seems like any heat contribution from a phase change would be in the noise or make all other issues irrelevant. :-) " CreationDate="2010-01-29T19:43:01.387" UserId="483" />
  <row Id="1191" PostId="1532" Text="The price for the crimping tool is laugh-out-loud hilarious. I'm sure you can just use a regular crimping tool or needle-nose pliers and save yourself $430 or so. :-)" CreationDate="2010-01-29T22:38:55.540" UserId="51" />
  <row Id="1192" PostId="1555" Text="So can i use the same servo library thats included with the arduino to also control a speed controller?" CreationDate="2010-01-30T00:45:50.633" UserId="496" />
  <row Id="1193" PostId="1555" Text="Yes, I am assuming you are using a standard esc." CreationDate="2010-01-30T03:21:52.920" UserId="1498" />
  <row Id="1194" PostId="1532" Text="The prices are high for hobbyists but those are professional tools. The design cost, documentation cost, manufacturing cost is spread over very small production runs. The weak dollar does not help.&#xA;&#xA;I do a fair number of header crimps so I bought the Tyco (formerly&#xA;Amp) tool when it was on sale at Newark for around $250. Ratcheting&#xA;mechanism insures that all crimps are the same. The two piece die crimps the wire and strain-relief in the same pass. &#xA;&#xA;For terminals I do not use often I would use needle-nose plies and solder the crimp. &#xA;" CreationDate="2010-01-30T14:04:32.087" UserId="424" />
  <row Id="1195" PostId="1554" Text="One more option for playing with msp430 is Chronos watch: http://wiki.msp430.com/index.php/EZ430-Chronos," CreationDate="2010-01-30T15:41:42.013" UserId="422" />
  <row Id="1197" PostId="1547" Text="I think he wants to put the electronics in the oven.  For that, you'd probably need an asbestos potholder." CreationDate="2010-02-02T15:45:36.277" UserId="374" />
  <row Id="1198" PostId="1000" Text="If I may ask, why?" CreationDate="2010-02-02T16:15:49.087" UserId="374" />
  <row Id="1199" PostId="1556" Score="1" Text="You can easily beat that with the Goodfet ($10 parts, board free from Travis), or the ez430 stick ($20).&#xA;&#xA;I believe the Goodfet is a better design.  The ez430/430UIF uses TI's 3410 USB-&gt;serial chip, but the Goodfet uses an FTDI chip with much better driver support." CreationDate="2010-02-02T17:10:02.067" UserId="411" />
  <row Id="1200" PostId="1566" Text="We checked on Rabbit's website and it does not seem they sell it. The sockets are in parallel with the molex slots so they are one and the same. " CreationDate="2010-02-04T13:36:41.090" UserId="514" />
  <row Id="1201" PostId="1562" Text="Now that is interesting.  I happen to have some Shapelock, and I really haven't done much with it.  (At the moment, I'm just trying to build a simple robot, as a practice before trying to build a rather larger robot.  If I actually get anywhere with this, and remember, I'd be happy to post some details.)" CreationDate="2010-02-04T17:37:02.383" UserId="106" />
  <row Id="1202" PostId="1568" Text="An excellent idea.  Thank you." CreationDate="2010-02-04T17:38:19.837" UserId="106" />
  <row Id="1203" PostId="1566" Text="Are the sockets bottom entry or just top entry? If they are bottom entry and there are no obstructions underneath a single interface  board with screw terminals around the periphery should be fairly easy to create. You should see if Rabbit has a dimensioned print. &#xA;&#xA;From the top you could do individual boards with a right angle header and a screw-terminal (which I believe was your original idea ;)" CreationDate="2010-02-04T20:08:42.797" UserId="424" />
  <row Id="1204" PostId="1566" Text="Yes, you can do top or bottom. I wouldn't even know where to create such a prototype board (I am a Embedded Software Engineer not Electrical / Hardware Engineer).. I imagine you can buy these boards somewhere? Do you have a link? " CreationDate="2010-02-05T00:39:35.730" UserId="514" />
  <row Id="1205" PostId="1566" Text="I am an Embedded Hardware Engineer so I would just make my own ;) &#xA;If Rabbit doesn't sell something I am not sure. For my embedded boards I have been making a little screw terminal board. Scroll down to the bottom picture at http://wiblocks.luciani.org/NB2/index.html&#xA;If you changed the bottom connector to pins and scaled it properly something like that should work." CreationDate="2010-02-05T01:13:40.100" UserId="424" />
  <row Id="1206" PostId="1566" Text="Yea I am really looking for something built already with screw terminals. Unless there is a prototype board already that has the terminals and you just have to solder the pins." CreationDate="2010-02-05T22:02:05.017" UserId="514" />
  <row Id="1207" PostId="1000" Score="3" Text="Because you use them for everything.  :)  Pull-up resistors on digital chips, gain resistors on op-amps, etc.  It's always the value we run out of first." CreationDate="2010-02-05T22:24:16.117" UserId="142" />
  <row Id="1208" PostId="1572" Text="+1. bulb brightness is neither a consistent nor a linear function of voltage." CreationDate="2010-02-06T14:11:10.443" UserId="330" />
  <row Id="1209" PostId="1562" Text="Hmm. Thanks for the link to shapelock (sounds neat!), but I would not recommend using it for any motor that is going to heat up. Motors can easily exceed 150F = 65 C." CreationDate="2010-02-06T14:14:06.477" UserId="330" />
  <row Id="1210" PostId="1562" Text="Jason you are correct that if the motor heats up above 150 this is not a good solution, however for a small robot I don't think his hobby motor will get that hot but I could be wrong, I find quite often I am :)" CreationDate="2010-02-06T20:01:36.437" UserId="498" />
  <row Id="1211" PostId="1576" Text="Thanks... I guess dremmel it is then." CreationDate="2010-02-09T12:04:02.753" UserId="329" />
  <row Id="1214" PostId="1580" Text="Can you give us identifying information on what kind of 16x2 LCD you are trying to hook up?" CreationDate="2010-02-09T19:31:05.087" UserId="11" />
  <row Id="1215" PostId="1582" Text="If you have the back light working then the pin identification should be easy, as the back light is always controlled from pins 14 (anode - 5V) and 15 (cathode - ground). Note can take high current so if you want to control from Arduino then use a transistor." CreationDate="2010-02-09T19:58:10.883" UserId="9" />
  <row Id="1216" PostId="1584" Text="LUFA is very good.  And the AVR USB chips are getting better and better.  If you prefer to develop on Linux or OSX, LUFA on an AVR is a good choice.  If you're Windows, then look at the PIC development environment. The low-end PIC USB chips have more features and are easier to use than the low-end AVR USB chips, but you really can only develop for them on Windows." CreationDate="2010-02-10T17:32:29.930" UserId="215" />
  <row Id="1217" PostId="1588" Text="Hey thanks! I hope you are right. But there is no regulated PSU in the vehicle AFAIK. It's just a feed from the battery.&#xA;&#xA;Does that make a difference?" CreationDate="2010-02-11T14:49:58.110" UserId="527" />
  <row Id="1218" PostId="1588" Text="It seems like your device doesn't need a regulated PSU, if it accepts between 10V and 30V. Your car battery should always be above 10V I think (except maybe during the few seconds when starting your car)" CreationDate="2010-02-11T15:38:22.600" UserId="131" />
  <row Id="1219" PostId="1588" Score="2" Text="I wanted to add that everything connected to a car battery should have a fuse. I recommend something like http://www.sunlightauto.co.nz/pe/media/p430690ed8648a.jpg " CreationDate="2010-02-11T18:14:04.220" UserId="198" />
  <row Id="1220" PostId="1590" Text="Ok.  Do you know the exact avr-objcopy incantation to do that splitting?  I've figured out quite a bit of the avrdude part, I think, but not what the right way of splitting the ELF files is." CreationDate="2010-02-12T02:42:14.623" UserId="526" />
  <row Id="1221" PostId="1590" Text="Did some random googling, above is what I found" CreationDate="2010-02-12T06:45:34.323" UserId="131" />
  <row Id="1222" PostId="1591" Text="It definitely says 12W &quot;maximum&quot;. That's what is troubling me." CreationDate="2010-02-12T06:48:16.967" UserId="527" />
  <row Id="1223" PostId="1589" Text="I am checking with the manufacturer already, but timezone differences and mis-communications are taking time. I will update the status of the question once I get more info. Thnx!" CreationDate="2010-02-12T06:50:05.953" UserId="527" />
  <row Id="1224" PostId="1590" Text="Thanks, that got me most of the way.  For the record, you also have to extract the eeprom section from the elf files, and of course set the fuses right." CreationDate="2010-02-12T08:22:42.037" UserId="526" />
  <row Id="1225" PostId="1590" Text="Ah ok, I haven't programmed eeprom from the PC before (I've always had my software program its own eeprom), so I didn't think of that." CreationDate="2010-02-12T19:16:59.297" UserId="131" />
  <row Id="1226" PostId="1591" Text="It's speaking of the maximum the unit will draw then. You are still good to go with out the need for a current limiting circuit. The only time you ever need a current limiting circuit is with something like Laser diodes that will consume enough power to burn up if they aren't regulated. I am sure there may be a few other odd devices as well but your device is definately not one of them. " CreationDate="2010-02-13T03:59:27.533" UserId="498" />
  <row Id="1227" PostId="1595" Text="The problem with that one is that it you cannot see the waveforms for different things and it does not allow me to make circuits graphically" CreationDate="2010-02-13T19:06:45.050" UserId="1200" />
  <row Id="1228" PostId="1595" Text="Also there is no tutorial" CreationDate="2010-02-13T19:07:54.987" UserId="1200" />
  <row Id="1229" PostId="1595" Score="3" Text="You CAN see the waveforms for different things, you CAN make circuits graphically, and there IS a tutorial.  http://www.falstad.com/circuit/directions.html" CreationDate="2010-02-13T20:18:38.627" UserId="142" />
  <row Id="1230" PostId="1595" Text="My bad, seems I didn't really look well enough" CreationDate="2010-02-14T16:27:46.800" UserId="1200" />
  <row Id="1231" PostId="1596" Text="well seems solid but alas I am not on windows, I am a long time linux user. Well does it work with wine?" CreationDate="2010-02-14T16:30:02.830" UserId="1200" />
  <row Id="1232" PostId="1596" Score="2" Text="I believe it does. Although Linear Tech does not support Linux I believe the fellow who develops the software tries to maintain compatibility. &#xA;&#xA;On Linux (which is all I use) there is gnucap and ngspice. I would not consider either of these beginner packages. Installation of the different packages and downloading the various device models can be &#xA;a hassle. &#xA;&#xA;I hope to put a tutorial up on my website -- Simulation using gnucap, ngspice and Mathematica. " CreationDate="2010-02-14T19:06:58.313" UserId="424" />
  <row Id="1233" PostId="1595" Score="1" Text="Yeah this one is my favorite for simple and medium complexity circuits. Plus the fact that it's cross-platform, and runs from a browser requiring no installs." CreationDate="2010-02-15T18:01:27.557" UserId="131" />
  <row Id="1234" PostId="1598" Text="A car battery is 50 AH?  Good heavens.  " CreationDate="2010-02-15T19:47:08.313" UserId="106" />
  <row Id="1235" PostId="1604" Score="1" Text="Remember that voltages of a supply and load need to match, while the current capability of a supply just needs to be *larger* than the draw of the load.&#xA;&#xA;In other words, it's not like a 2 amp supply is going to shove the full 2 amps down the poor little Arduino's throat.  It's going to supply a voltage, and the Arduino will only draw as much as it wants." CreationDate="2010-02-15T21:59:20.953" UserId="142" />
  <row Id="1236" PostId="1608" Score="1" Text="+1 for mentioning MOSFETs rather than darlington PNPs" CreationDate="2010-02-15T23:25:23.220" UserId="330" />
  <row Id="1237" PostId="1609" Score="1" Text="You need to specify if you want to control one or multiple leds.&#xA;&#xA;Also, I would add &quot;avoiding serial control and additional ICs&quot;. The answer tends to infinite if refresh rate or hardware parts are not constraints." CreationDate="2010-02-16T14:11:05.990" UserId="198" />
  <row Id="1238" PostId="1613" Text="I like this suggestion but I think it represents a &quot;plan B&quot;. I would rather figure out the actual specs (or as close as possible)." CreationDate="2010-02-17T03:09:19.663" UserId="12" />
  <row Id="1239" PostId="1617" Score="1" Text="I second that.&#xA;I've played with the RFM12B modules to build a wireless accelerometer. http://tinkerlog.com/2010/02/07/remote-accelerometer/&#xA;The modules are cheap and easy to program. The Arduino lib provided by JeeLabs works great. " CreationDate="2010-02-17T07:59:29.873" UserId="409" />
  <row Id="1240" PostId="1617" Score="1" Text="And the modules are available at Sparkfun as well: http://www.sparkfun.com/commerce/product_info.php?products_id=9582" CreationDate="2010-02-17T13:02:51.160" UserId="409" />
  <row Id="1241" PostId="627" Text="Try Oatley electronics; they've got heaps plus i/f hardware &amp; controllers 2." CreationDate="2010-02-17T21:47:31.583" UserId="515" />
  <row Id="1242" PostId="1622" Text="Buy parts to fix the laptops on eBay. :)" CreationDate="2010-02-17T22:28:18.863" UserId="142" />
  <row Id="1243" PostId="1613" Text="I understand. I was going to do this anyway so I set up a test and posted a video on my blog. This is actually done very often in industrial applications. However if you don't use a stepper driver with chopper features then all bets are off. As for the driver needing to be oversized, I think you can see the little EasyDriver that is rated at 750MA is not straining at all and for $15 you can't beat it. Good luck with your project." CreationDate="2010-02-18T03:46:16.563" UserId="498" />
  <row Id="1244" PostId="1613" Text="I forgot to mention that I am betting your steppers are much larger and you would most likely need a larger driver than this but maybe not." CreationDate="2010-02-18T03:53:09.800" UserId="498" />
  <row Id="1250" PostId="1634" Score="2" Text="It's $110 for 155 square inches, not square cm. A huge difference in size! (100 sq cm == 15 sq in)" CreationDate="2010-02-18T16:50:07.390" UserId="131" />
  <row Id="1254" PostId="1636" Score="5" Text="Even if the microcontroller itself (eg a PIC) runs at 40MHz, most likely the signals it is interfacing with the world will be nowhere near that speed. IIRC for PICs the fastest thing you could do is SPI, and that's at 1/4th the clock speed, so 10MHz in that case. Still much too fast for a 1MHz or even a 10MHz scope of course though, so your main point still stands." CreationDate="2010-02-18T17:58:56.810" UserId="131" />
  <row Id="1255" PostId="1634" Score="1" Text="My mistake, I dropped a zero in my mind!" CreationDate="2010-02-18T19:35:06.873" UserId="11" />
  <row Id="1257" PostId="1636" Text="Thank you for the comment, I was considering buying some software like the SignalScope but I'll stick with the DSO Nano as my first oscilloscope." CreationDate="2010-02-19T08:51:34.390" UserId="545" />
  <row Id="1258" PostId="1621" Text="Note that while the FPGA article goes through the basics of interfacing a very simple LCD graphics display, the laptop display in the 9300 is significantly more complex, and a completely different electrical interface is required than the one used in the referenced article." CreationDate="2010-02-19T21:14:05.203" UserId="161" />
  <row Id="1259" PostId="1621" Text="Yeah, I added that link to demonstrate just how hard it can be to roll your own solution.  I hope nobody thought I was proposing it as a complete answer!" CreationDate="2010-02-19T21:31:38.570" UserId="11" />
  <row Id="1260" PostId="1637" Text="At the moment I'm just looking for a place that can do it.  I'll probably start out with something the size of an Arduino shield, although I do have a plastic case I'd like to use that will take a 188.5mm by 110mm (7.42&quot; by 4.33&quot;) PCB.  I'd only need one of each design.  The links you've posted are very helpful though - thanks!" CreationDate="2010-02-20T09:30:56.010" UserId="548" />
  <row Id="1261" PostId="1634" Text="What do you mean by 'multiple designs'?  Do you mean the same design repeated or entirely different designs? (I doubt I'm going to be that prolific!)" CreationDate="2010-02-20T09:32:48.253" UserId="548" />
  <row Id="1262" PostId="1646" Score="1" Text="Wow, thanks for the advice... I'm looking at the LM2575 because it seemed like a simple enough switching regulator.  If you have a better suggestion for a more efficient 12 -&gt; 5v 1A switching regulator I'd love to hear it." CreationDate="2010-02-21T00:18:14.913" UserId="551" />
  <row Id="1263" PostId="1646" Score="1" Text="The issue is what kind of parts to you want to solder? TI has a nice TH module PTN78000W 7V-36V Adjustable output voltage 1.5A which is around $12. All you need is a couple of caps and a resistor. A couple of ICs you could check are the TI TPS54232D, LT1936, LT1767. I would do a search at TI and at Linear Technology." CreationDate="2010-02-21T02:20:39.103" UserId="424" />
  <row Id="1264" PostId="1646" Text="Excellent, I've gone for the PTH08080W... similar projects to mine seem to be using it, and it gives me lots to play with. Thanks!" CreationDate="2010-02-21T05:55:21.867" UserId="551" />
  <row Id="1265" PostId="1613" Text="Nice post Mark, and thanks! My steppers are quite a bit larger then the ones you are using, but I am going to get one of the EasyDriver boards and give it a try." CreationDate="2010-02-21T18:19:00.603" UserId="12" />
  <row Id="1266" PostId="1658" Text="You will need to be careful with pulling power from USB. When you first plug a device into a USB port you are granted 100mA at 5v = 0.5W. Your device can then request for additional power and get 500mA at 5v = 2.5W.&#xA;&#xA;You will also need to insure that your device wont have a large pull when you first plug it in.&#xA;&#xA;Wikipedia talks a bit about USB power in the 'Power' section at http://en.wikipedia.org/wiki/Universal_Serial_Bus#Power" CreationDate="2010-02-22T03:46:50.127" UserId="319" />
  <row Id="1267" PostId="1656" Text="Thanks for that - 1-Wire looks like it's fairly popular and well suited for low power sensor networks." CreationDate="2010-02-22T04:51:39.770" UserId="554" />
  <row Id="1268" PostId="1657" Text="Thanks - it's good to hear of potential problems I may run into down the track. I've tried to clarify my needs a little in the above post." CreationDate="2010-02-22T04:55:08.000" UserId="554" />
  <row Id="1269" PostId="1659" Text="I've considered trying to modulate RS232 with a hi freq signal coupled to a 12V supply - I'm guessing it would be important to isolate the PSU capacitance so that it doesn't try to smooth out the ripples?" CreationDate="2010-02-22T04:59:56.383" UserId="554" />
  <row Id="1270" PostId="1634" Text="As I recall, that's for entirely different designs.  The same design, repeated, would not cause the extra fee.  However, I'd get in touch with them and see what's up.  I'm sure all of that is flexible." CreationDate="2010-02-22T15:56:43.367" UserId="11" />
  <row Id="1271" PostId="1658" Text="Kellenjb, enumeration is not exactly the same as requesting more power, I like to think of it as verifying you are an intelligent device. Most people also forget if they are giving their device to someone else it may be plugged into an un-powered hub, resulting in maximum pull of 100mA no matter the situation." CreationDate="2010-02-22T18:20:41.247" UserId="230" />
  <row Id="1272" PostId="1660" Text="Axeman, I do not have anything to say but that you have impressed me sir/ma'am. That solution makes me giggle." CreationDate="2010-02-22T18:25:11.930" UserId="230" />
  <row Id="1273" PostId="1661" Text="I agree with adam here except that I believe all communication should be done FM and you can build some really nice filters to get your signal back almost perfectly. He has mentioned this, but I thought I would add a note to clarify that a noisy signal can be beautiful again with the right filter and FM modulation." CreationDate="2010-02-22T18:30:03.647" UserId="230" />
  <row Id="1274" PostId="1656" Score="1" Text="Hi Peter, since you specifically asked for UART. I managed to find a maxim app notes for using UART as a 1-wire bus master. (see http://www.maxim-ic.com/app-notes/index.mvp/id/214 ).&#xA;" CreationDate="2010-02-22T20:05:30.080" UserId="555" />
  <row Id="1275" PostId="1661" Text="FM is significantly better than AM or many other simple modulation schemes, but it does exact a slightly higher cost in terms of hardware and/or software, and if the signal quality is good it may be overkill." CreationDate="2010-02-22T21:11:50.590" UserId="161" />
  <row Id="1276" PostId="1662" Text="Do you have any online references for this?  Is this done in the audio codec or the driver?" CreationDate="2010-02-22T21:40:40.517" UserId="374" />
  <row Id="1277" PostId="1656" Text="Thanks again Terry - I'll take a look" CreationDate="2010-02-22T22:20:54.273" UserId="554" />
  <row Id="1278" PostId="1662" Score="1" Text="Hi sheepsimulator, IDT's AC'97 codec (STAC9752A) implements this impedance-based jack sensing. Unfortunately, it is some proprietary current sensing techniques that IDT's calling Universal Jack(tm). ADI also has a AC'97 codec (AD1888) with yet another proprietary jack sensing mechanism.&#xA;&#xA;Nonetheless, it is definitely done in the audio codec chip. Hope this helps..." CreationDate="2010-02-23T00:01:25.520" UserId="555" />
  <row Id="1279" PostId="1660" Text="Kortuk, I hope that you &quot;giggling&quot; means &quot;thumbs up&quot; (I'm italian and not very strong in english, as you can see :-) )&#xA;Anyway, years before my &quot;invention&quot; (but I discovered it after my project was completed) model railroad factories designed,standardized and implemented (in the same way) DCC: Digital Command Control, for the same purpose: &#xA;http://en.wikipedia.org/wiki/Digital_Command_Control" CreationDate="2010-02-23T14:24:13.887" UserId="244" />
  <row Id="1280" PostId="1073" Score="1" Text="Also of note is that there are more and more &quot;C to VHDL&quot; or &quot;C to Verilog&quot; converters. They aren't the most efficient things yet but you can convert already written code into hardware that can be utilized for a speed improvement. Pretty cool if you ask me (and if you have the dough for it)." CreationDate="2010-02-23T16:40:18.983" UserId="404" />
  <row Id="1281" PostId="1667" Text="$50?  Where?  The only ones I've seen were twice that... I'm guessing this isn't a SheevaPlug." CreationDate="2010-02-23T17:59:44.160" UserId="213" />
  <row Id="1283" PostId="1667" Text="@parsenome: There's an outfit in India that makes one. See here: http://embedded-computing.com/news/id?16226 and here: http://www.e-consystems.com/esom270.asp" CreationDate="2010-02-23T18:39:51.760" UserId="544" />
  <row Id="1284" PostId="1668" Score="1" Text="I've wanted to see something of this nature, particularly for this site.  If you have an interest in heading up such a coding project, I would definitely contribute.  I think it would be useful and I could use another sample for reference." CreationDate="2010-02-23T18:41:45.620" UserId="11" />
  <row Id="1285" PostId="1671" Text="We probably could trust them, but we probably won't. Even if the software costs 10k that's cheaper than someone from China stealing your stuff and cutting your legs out from under you (although they're often good enough at it to do something like that without the actual schematic)." CreationDate="2010-02-23T19:25:20.060" UserId="404" />
  <row Id="1286" PostId="1667" Score="1" Text="In quantity the sheevaplug is expected to be at or under $50, but if you check our their webpage they're already looking at the next generation.  Chances are that they'll be increasing the power/utility of the device rather than doing a cost optimization though." CreationDate="2010-02-23T20:04:44.643" UserId="161" />
  <row Id="1287" PostId="1668" Text="I've wanted something like this for a long time." CreationDate="2010-02-24T01:33:47.167" UserId="142" />
  <row Id="1288" PostId="1115" Text="http://en.wikipedia.org/wiki/Atmel_AVR" CreationDate="2010-02-24T05:00:37.357" UserId="544" />
  <row Id="1289" PostId="1678" Text="I kind of like the image annotator, though I'm not so certain about keeping a separate image for every schematic page on a wiki. That could be a bit cumbersome, though it would fit with our current wiki usage." CreationDate="2010-02-24T15:40:40.340" UserId="404" />
  <row Id="1290" PostId="1679" Text="I'm sleeping them when not used - the XBee gets woken up once a minute when I want to transmit a reading.  I'll see what happens if I bring the batteries in and warm them up." CreationDate="2010-02-24T19:27:51.507" UserId="213" />
  <row Id="1292" PostId="1685" Score="1" Text="I'm assuming that &quot;power supply wires&quot; mean low voltage wires.  If they are AC supply wires then yes, most of the other answers are unsuitable without taking this into account." CreationDate="2010-02-24T22:27:37.277" UserId="161" />
  <row Id="1293" PostId="1679" Text="Another idea for batteries may be the Li-ion rechargeables from A123 Systems. I happened to be looking at the ANR26650 for a different project. The operating temperature range is -30degC to 60degC. These are 3.3V cells (26mm diameter, 65mm tall). The voltage is specified at apx 2.5V at 75% capacity at -20degC." CreationDate="2010-02-25T01:13:17.363" UserId="424" />
  <row Id="1294" PostId="1685" Score="1" Text="X10 assumes by design an AC power line and needs specific tuned transformer. Don't think it fits to the &quot;The simple the better&quot; part of the question :-)" CreationDate="2010-02-25T10:19:11.443" UserId="244" />
  <row Id="1295" PostId="1686" Text="We do this at work, too.  I'll also take screenshots and draw on schematics in the GIMP and just attach the images to emails.  I suppose emails are a sort of version control.  :)" CreationDate="2010-02-25T15:03:11.670" UserId="142" />
  <row Id="1296" PostId="1671" Text="If it's good, they're just going to buy one and reverse-engineer it anyway.  :)" CreationDate="2010-02-25T15:04:41.577" UserId="142" />
  <row Id="1297" PostId="1693" Text="The differential signalling is nonsense." CreationDate="2010-02-25T19:53:38.660" UserId="339" />
  <row Id="1298" PostId="1695" Text="Which devices do you use?" CreationDate="2010-02-26T00:06:33.437" UserId="544" />
  <row Id="1299" PostId="1696" Text="I want one, too." CreationDate="2010-02-26T03:18:12.177" UserId="142" />
  <row Id="1300" PostId="1699" Text="Whoa, NXP already have a Cortex-M0 uC?! I couldn't seem to find it on NXP's website. Can you tell me what the Part # is for that CortexM0 uC that you are using? I am only familiar w/ their ARM7 and CortexM3 processor. Thanks." CreationDate="2010-02-26T13:56:54.907" UserId="555" />
  <row Id="1302" PostId="1702" Text="1.5&quot; is pretty tiny, but it might be good for some things, and it looks pretty cheap. Thanks for the suggestion." CreationDate="2010-02-26T22:51:22.867" UserId="131" />
  <row Id="1304" PostId="1699" Text="The LPC1111, etc. The LPC1111 is used on the LPCXpresso." CreationDate="2010-02-27T19:11:27.020" UserId="305" />
  <row Id="1305" PostId="1706" Score="1" Text="LOL! ` ` ` ` ` `" CreationDate="2010-02-28T00:49:48.950" UserId="161" />
  <row Id="1306" PostId="1706" Score="2" Text="Because you're too lazy to implement them? ;-)" CreationDate="2010-02-28T01:51:34.660" UserId="561" />
  <row Id="1307" PostId="1699" Text="Leon, Thanks! I see it now. Apparently, it is brand new series of part just recently released last Quarter (there is a lot of embedded processor recently...). This new processor looks good! $2 single quantity @ 50Mh, wow. Gotta get my hands on some now XD." CreationDate="2010-02-28T21:20:53.807" UserId="555" />
  <row Id="1308" PostId="1712" Text="Chiphacker also offers a form of documentation on who had the idea. This makes IP lawsuits much easier.&#xA;&#xA;I would suggest against anything beyond small scale selling of a project someone shared the idea of without a contract involving IP with the original person." CreationDate="2010-03-01T10:46:02.217" UserId="230" />
  <row Id="1309" PostId="1695" Score="1" Text="RS232 can go significantly faster than 115k. I have run RS232 at MBAUD before, it is just a distance thing and clock error." CreationDate="2010-03-01T11:02:35.383" UserId="230" />
  <row Id="1310" PostId="1715" Text="+1, highly informative!" CreationDate="2010-03-01T15:57:44.977" UserId="444" />
  <row Id="1311" PostId="1702" Text="I have a 2.0&quot; screen as well, but not nearly as much documentation to work with. Resolution is 240x320 (QVGA) with 16.8M Colors I believe. It is on our website at: http://www.continuumtech.ca/detail.asp?control=1024026 (there are a few other LCD's as well)&#xA;If someone can figure this out." CreationDate="2010-03-01T16:37:08.370" />
  <row Id="1312" PostId="1717" Text="Thank you.  I am aware of this fact.  There are no microcontrollers rated to run anywhere near this temperature so we have to do lots of in-house testing.  It turns out that many parts run just fine above their rated temperature." CreationDate="2010-03-01T18:16:01.517" UserId="529" />
  <row Id="1313" PostId="1716" Score="3" Text="Wow, what are you doing that requires the microcontrollers to be so hot? Can't you just put the mcu outside of the hot area, maybe running wires to some sensors inside?" CreationDate="2010-03-01T18:23:56.227" UserId="131" />
  <row Id="1314" PostId="1719" Text="Thank you Leon.  Unfortunately, I have to stay in the ARM family." CreationDate="2010-03-01T20:52:42.660" UserId="529" />
  <row Id="1315" PostId="1729" Text="The resistors are fairly high value (last band is orange, if I'm not mistaken...), the capacitors are largish (ie, at least 1uF, more likely 4.7uF or higher), and he's using an LED and seems to indicate that it blinks (ie, not just dim 50% PWM) so I'm guessing it's under 10Hz - and most small relays can handle 10Hz anyway." CreationDate="2010-03-02T22:04:39.663" UserId="161" />
  <row Id="1316" PostId="1731" Text="For more ideas - have a look at the products I have on my website (I'm probably the worst judge if they're any good tho). Anyway, they're all simple audio/sound related kits - http://www.sonodrome.co.uk/shop.html  " CreationDate="2010-03-03T03:35:28.150" UserId="399" />
  <row Id="1317" PostId="1731" Text="P.s I need a good open source FM radio receiver, preferably a compact one, if you fancy designing that! " CreationDate="2010-03-03T03:37:29.313" UserId="399" />
  <row Id="1318" PostId="1731" Text="Thanks Jim, these are the kind of answers I'm looking for...I'll leave this question &quot;unanswered&quot; for a bit to allow more responses to come in in.  Nice one." CreationDate="2010-03-03T11:15:21.397" UserId="561" />
  <row Id="1319" PostId="1729" Score="1" Text="Actually @Adam, it says in the question &quot;the circuit works just fine with 100uf capacitors.&quot;" CreationDate="2010-03-03T15:44:47.513" UserId="1301" />
  <row Id="1320" PostId="1734" Score="1" Text="Wow!  Thanks Terry.  Although I can't make use of an 8051 right now, hopefully someone else will benefit from this post.  Another interesting note - it looks like the HT83C51 only comes in a DIP package which may be an issue for some applications." CreationDate="2010-03-03T17:57:10.063" UserId="529" />
  <row Id="1321" PostId="1736" Text="So, how many transistors have you already killed this way?" CreationDate="2010-03-03T20:48:03.153" UserId="339" />
  <row Id="1322" PostId="1736" Text="@starblue I haven't had to replace a single transistor. I used a relatively small relay, so there isn't a lot of inductive feedback." CreationDate="2010-03-03T23:21:47.727" UserId="1301" />
  <row Id="1323" PostId="1736" Score="2" Text="I see that a diode appeared in the right place. :-) And, you normally don't need the resistor in series with the relay if the relay coil is rated for the supply voltage." CreationDate="2010-03-04T06:21:23.843" UserId="339" />
  <row Id="1324" PostId="1740" Score="4" Text="I absolutely agree. But, I *want* to make one :-)" CreationDate="2010-03-05T00:10:51.957" UserId="566" />
  <row Id="1325" PostId="1740" Score="1" Text="+1 for having the ambition for such an undertaking.  Best of luck." CreationDate="2010-03-05T00:56:33.597" UserId="529" />
  <row Id="1327" PostId="1742" Text="Why don't you use transistors to drive the main solenoid?" CreationDate="2010-03-05T07:43:16.653" UserId="339" />
  <row Id="1328" PostId="1745" Text="Thanks, that looks a lot like the LinuxStamp - http://opencircuits.com/Linuxstamp. The AT91RM9200 looks promising." CreationDate="2010-03-05T10:36:21.653" UserId="566" />
  <row Id="1329" PostId="1742" Text="because i had suitable relays and not suitable transistors :-)&#xA;The original cct i am using drove a 2 wire dc motor operated valve which only needed power in one polarity or the other for 1-2 seconds to change state. The solenoid is similar in that it only needs a short pulse of one polarity or the other to change state.&#xA;It was deemed quicker to adapt the current cct that wait for parts to do something differnt." CreationDate="2010-03-05T10:46:45.270" UserId="503" />
  <row Id="1330" PostId="1744" Text="Cheers - i think i have some suitable zeners on hand - will look in the morning. Thanks" CreationDate="2010-03-05T10:47:29.667" UserId="503" />
  <row Id="1331" PostId="1744" Text="So to clarify your &quot;back to back - series connected&quot; comment: does that mean both cathodes together with anodes to each solenoid terminal? OR 2 zeners in parallel A to K and one junction to each solenoid terminal?" CreationDate="2010-03-05T10:49:19.220" UserId="503" />
  <row Id="1332" PostId="1746" Score="3" Text="Mini servos are really cheap... http://tinyurl.com/y8v4ahm" CreationDate="2010-03-05T12:16:05.697" UserId="566" />
  <row Id="1333" PostId="1744" Text="Yes, both cathodes together with the anodes to the solenoid terminal is right. I've tried to clarify the answer a little. " CreationDate="2010-03-05T12:37:21.043" UserId="328" />
  <row Id="1334" PostId="1746" Text="Another source of cheap servos ($4.90 [USD]) http://www.dealextreme.com/details.dx/sku.20087" CreationDate="2010-03-05T12:43:52.427" UserId="161" />
  <row Id="1335" PostId="1751" Text="I was wondering how the circuit achive that 3600 number, what components come into play for that? As regards the diodes I'm a bit skeptical about them being used for just PIC protection... could you elaborate why do you think they are PIC pin protection diodes?" CreationDate="2010-03-05T14:53:29.433" UserId="444" />
  <row Id="1336" PostId="1751" Score="1" Text="See my corrected text.&#xA;&#xA;I think that you will find details of micro-stepping and PWM on the Microchip web site - look at the motor control pages." CreationDate="2010-03-05T14:57:25.017" UserId="305" />
  <row Id="1337" PostId="1743" Text="This is a good solution. With sufficient bypass capacitance (the voltage supply will most likely have enough, add more if you're worried), you'll be fine. You just need to make sure the energy in the solenoid's inductance can return to the power supply w/o raising the voltage to the point of causing damage." CreationDate="2010-03-05T17:43:49.887" UserId="330" />
  <row Id="1339" PostId="1741" Text="That EVK1100 is a lot more complicated than is strictly necessary.  Those kinds of eval boards usually have a lot of extra peripherals - things like LCDs, buttons and such that are there to give you a leg up on getting output from the chip.  Making your own board you'll only include the things you care about and usually end up with a much simpler design." CreationDate="2010-03-05T17:58:00.230" UserId="213" />
  <row Id="1340" PostId="1752" Text="Nice idea!  Could require more I/O to implement..." CreationDate="2010-03-05T18:03:07.743" UserId="161" />
  <row Id="1341" PostId="1749" Text="Near duplicate: http://chiphacker.com/questions/1222/what-are-low-cost-circuit-and-pcb-design-software/1226#1226" CreationDate="2010-03-05T19:42:33.750" UserId="339" />
  <row Id="1342" PostId="1741" Text="Most eval boards, definitely.  The EVK1100 looks a bit better than many in by separating out those parts that are core and those that are peripherals.  At least it seems like that from the pics, I don't have one. :)" CreationDate="2010-03-06T08:56:59.337" UserId="215" />
  <row Id="1343" PostId="1753" Text="The full version does up-to 16 layers." CreationDate="2010-03-06T15:09:00.073" UserId="1301" />
  <row Id="1344" PostId="1761" Text="Thank you.  I wonder if there's a way to change the endian setting in MARS...?" CreationDate="2010-03-06T16:48:18.790" />
  <row Id="1345" PostId="1772" Score="1" Text="It helps that the Propeller chip has circuitry specially designed for this type of operation." CreationDate="2010-03-07T15:13:05.943" UserId="1301" />
  <row Id="1346" PostId="112" Score="2" Text="Hardware is great but the dev tools from Microchip are AWFUL." CreationDate="2010-03-07T16:44:09.053" UserId="330" />
  <row Id="1347" PostId="168" Text="Hardware is great but the dev tools from Microchip are AWFUL." CreationDate="2010-03-07T16:44:26.663" UserId="330" />
  <row Id="1348" PostId="1794" Text="Thanks I wasn't sure as I only use Linux." CreationDate="2010-03-08T21:58:27.047" UserId="103" />
  <row Id="1349" PostId="1764" Score="1" Text="I like their blog too: http://blog.makezine.com/" CreationDate="2010-03-08T22:52:11.720" UserId="103" />
  <row Id="1350" PostId="1796" Text="Good suggestions Clint.&#xA;&#xA;Sending small analogue signals over any sort of distance is never easy.  Could you provide amplification or conversion to a balanced or even current loop interface at the sensor end to reduce the sensitivity of the interface to noise pickup." CreationDate="2010-03-09T11:18:26.513" UserId="400" />
  <row Id="1351" PostId="1800" Text="While everything you write is correct, I can't see how it addresses the question. The circuit works fine in one environment, but not another. If your suggestion was the culprit I would expect to see the problem on the bench as well." CreationDate="2010-03-09T20:40:22.010" UserId="328" />
  <row Id="1352" PostId="1796" Text="You're right about amplifying near the sensor before transmission, but I'd guess that would be over kill in this situation. We're only trying to measure 10's of mV, not uV. Without more info on the circuit mjh2007 is using, all of this is becoming wild speculation." CreationDate="2010-03-09T20:46:09.423" UserId="328" />
  <row Id="1353" PostId="1173" Score="2" Text="Tin snips work great for short cuts, but they sometimes seem to add a little flex to the board while they're working.  I wouldn't trust them for anything &gt; 1-2 inches, and preferably not when I cared about the boards on both sides." CreationDate="2010-03-09T23:15:24.707" UserId="213" />
  <row Id="1354" PostId="1793" Text="Thanks for the help! I've been wanting to play with microcontrollers for a while, but the Arduino seems too &quot;ready-made&quot; for my tastes. The PICs, and especially the dsPIC (I'm into DSP), seem like just the ticket." CreationDate="2010-03-10T00:59:33.187" />
  <row Id="1355" PostId="1104" Text="Can you give some examples of things that cost $10 elsewhere (in low quantities) and cost $50+ on Sparkfun?" CreationDate="2010-03-10T03:04:11.010" UserId="142" />
  <row Id="1356" PostId="1809" Text="I had no idea there were hardware categories.  http://www.rentacoder.com/RentACoder/misc/BidRequests/ShowBidRequests.asp?lngBidRequestListType=3&amp;txtMaxNumberOfEntriesPerPage=10&amp;lngBidRequestCategoryId=96&amp;optSortTitle=2&amp;optBidRequestPhase=2&amp;lngSortColumn=-6&amp;blnModeVerbose=True&amp;optBiddingExpiration=1" CreationDate="2010-03-10T06:52:38.840" UserId="142" />
  <row Id="1357" PostId="1785" Text="Thanks for the info James, I had visited that page earlier and although the explanation is very lucid, I couldn't get the hang of it, I will try again though..." CreationDate="2010-03-10T11:28:46.510" UserId="444" />
  <row Id="1358" PostId="1792" Text="Just to give everyone an update. It looks like the problem was with the voltage regulator. The filter capacitors at the outputs were not large enough. We used 1uF datasheet recommended 10uF. Looking at the voltage rail with the oscilloscope showed ~200 mV of ripple going into the voltage divider. I though I had checked that before, but apparently not. Checking a power supply with just a multi-meter is really not enough I guess." CreationDate="2010-03-10T14:08:15.400" UserId="588" />
  <row Id="1359" PostId="1798" Text="It's a little late to make another hardware change to the board so we can't switch to a better current source, however you were right to point me in the direction of the power supply. I had checked it with a multi-meter and it looked ok, but when I looked at it with the oscilloscope the problem became clear. Thanks!" CreationDate="2010-03-10T14:10:45.040" UserId="588" />
  <row Id="1360" PostId="1181" Text="You can get bi-metal blades, they tend to last longer." CreationDate="2010-03-10T15:06:38.113" UserId="1301" />
  <row Id="1361" PostId="1815" Text="It's hard to imagine a place on earth where it would be cheaper to make your own PCB instead of ordering an Arduino on eBay. But, hey, more fun - that's a sure thing :-) !" CreationDate="2010-03-10T18:17:11.737" UserId="560" />
  <row Id="1362" PostId="1821" Text="Thanks ! I was not sure it was a stand: I fear that it will become too hot for my table when holding the iron. As for the iron itself, it is branded &quot;Antex&quot;, but it seems that Maplin/Antex sells the same products anyway." CreationDate="2010-03-10T21:02:46.100" UserId="595" />
  <row Id="1363" PostId="1821" Text="If you prop the plastic part on the soldering iron handle on the stand then it will not get hot." CreationDate="2010-03-10T22:08:53.823" UserId="9" />
  <row Id="1364" PostId="1822" Text="I think the holes are just strain relief but as you say they can be used to fasten the stand to a bench." CreationDate="2010-03-10T22:10:43.133" UserId="9" />
  <row Id="1365" PostId="1823" Text="How's that for a coincidence, both of us linking to the same review within a minute of each other." CreationDate="2010-03-10T23:07:20.277" UserId="103" />
  <row Id="1366" PostId="1173" Score="1" Text="I agree with that. Typically I use them to trim corners if I need to round a corner. Saves a lot of filing ;) " CreationDate="2010-03-11T01:18:21.757" UserId="424" />
  <row Id="1367" PostId="1819" Text="I really liked the paperduino idea, its just perfect for my purposes (if i could get it to work)" CreationDate="2010-03-11T05:53:27.040" UserId="1200" />
  <row Id="1368" PostId="1815" Text="actually I don't know the price to get a PCB constructed in the market here, but I was talking about the toner transfer method to try at home" CreationDate="2010-03-11T05:55:10.157" UserId="1200" />
  <row Id="1370" PostId="1811" Text="I realize that there will be a high initial cost, as long as there is a low per unit cost its OK. Freelancer website seems to be what I am looking for, thanks. Now I just need to think of an appropriate price tag. " CreationDate="2010-03-11T18:05:34.380" UserId="592" />
  <row Id="1371" PostId="1800" Text="ah, I missed that detail from the original post." CreationDate="2010-03-11T21:18:47.063" UserId="330" />
  <row Id="1372" PostId="1833" Text="This is exactly what I needed." CreationDate="2010-03-11T21:39:41.337" UserId="374" />
  <row Id="1373" PostId="1838" Score="1" Text="For cryptography, I'd steer clear of MD5 altogther..." CreationDate="2010-03-11T22:10:41.793" UserId="566" />
  <row Id="1374" PostId="1800" Text="Good suggestion. The PGA that I’m using has a built in analog multiplexer so the 8 analog channels are fed to a multiplexer then the PGA then to a single microprocessor analog port. I though it could be one channel interfering with the other channels, but the frequency I'm switching channels and sampling at is very low (20Hz)." CreationDate="2010-03-11T22:24:27.243" UserId="588" />
  <row Id="1376" PostId="1842" Score="1" Text="Just FYI boiling water will generally always be 100 C, so a temperature sensor wouldn't tell you too much :P" CreationDate="2010-03-12T19:25:30.497" UserId="131" />
  <row Id="1377" PostId="1842" Score="1" Text="With a really accurate sensor he should be able to determine altitude and level of solubles. " CreationDate="2010-03-12T19:43:30.810" UserId="230" />
  <row Id="1378" PostId="1842" Score="1" Text="&quot;the ability to be submersed into boiling water&quot; &#xA;&#xA;Presumably, the water will also be at other temperatures besides boiling..." CreationDate="2010-03-12T19:52:02.743" UserId="142" />
  <row Id="1379" PostId="1839" Score="1" Text="+1 for Wireshark! I just downloaded it and I’ve started to check out the packets to see if I can find any hints as to what could be wrong." CreationDate="2010-03-12T19:53:46.577" UserId="588" />
  <row Id="1380" PostId="1842" Text="I got that also endolith, I was just kidding around and I think Davr was just attempting to save smoore some time. No one gets hurt when you warn one too many times, it is a problem when you do not warn enough times." CreationDate="2010-03-12T22:51:30.290" UserId="230" />
  <row Id="1381" PostId="1843" Text="This sounds great, I would like to add that the more material you put in the thermal path between the solution you are measuring and your sensor the larger the delay between solution temperature change and your temperature changing." CreationDate="2010-03-12T22:52:41.520" UserId="230" />
  <row Id="1382" PostId="1839" Text="I love packet sniffers. It is my favorite form of robot porn. Second is schematics." CreationDate="2010-03-12T23:22:50.760" UserId="230" />
  <row Id="1383" PostId="1191" Score="1" Text="Jason, my company just modded an over like discussed here for rapid prototyping. we still order large sets done by a professional company, but when we want 100 or even 1 prototype, we oven it. It works great and I never have coldjoint problems, but i don't when we have hand soldered, in general, either." CreationDate="2010-03-13T10:37:03.100" UserId="230" />
  <row Id="1384" PostId="1823" Text="I have used the PK3 and love it. I think it is the only way to go. The full USB makes programming large hex files fast!" CreationDate="2010-03-13T10:41:46.820" UserId="230" />
  <row Id="1386" PostId="1826" Text="I've just discovered this app. It's great !" CreationDate="2010-03-13T18:55:16.867" UserId="595" />
  <row Id="1387" PostId="1829" Text="Thanks to all. &#xA;Using my Borders coupons I bought hardcopies of &#xA;&quot;Getting Started with Arduino&quot; by M. Banzi&#xA;&quot;Making Things Talk&quot; by T Igoe (very nice)&#xA;&#xA;I downloaded the ASK manual as well several well written tutorials including todbot's excellent PDF series!" CreationDate="2010-03-14T03:34:58.230" UserId="591" />
  <row Id="1388" PostId="1860" Text="Thanks for the tip. I think I'll just go with the PK3 and get on with the fun stuff." CreationDate="2010-03-14T03:42:54.487" />
  <row Id="1389" PostId="1863" Score="1" Text="This is totally true.  Even in the best case of davr's graph, the voltage drop vs capacity stays fairly constant (just a few tenths of a volt), until the big drop off.  I've been bitten many times by AAs I thought were good until *wham* they go dead.  So you can do a &quot;this is definitely bad&quot; test, but it's hard to say &quot;this battery is probably good for a while&quot;." CreationDate="2010-03-14T18:39:17.420" UserId="215" />
  <row Id="1391" PostId="1871" Text="&lt;img src=&quot;http://www.themountainfold.com/test/IMG_1119.png&quot;&gt;" CreationDate="2010-03-14T21:09:01.263" UserId="605" />
  <row Id="1392" PostId="1870" Text="What company is doing the re-issue? Where are they being sold? Thanks." CreationDate="2010-03-14T21:28:00.433" UserId="424" />
  <row Id="1393" PostId="1871" Text="weird.  that's like a 0.064&quot; pin spacing?  wacky.  If I had that chip, I'd probably make my own socket out of a cut up machined wire-wrap socket.  The longer wire-wrap pins would let you bend the socket holes around to match the oddball pin spacing. Once you get all the socket holes aligned, fix the spacing with hot glue.  Pretty hacky though." CreationDate="2010-03-14T21:33:17.360" UserId="215" />
  <row Id="1394" PostId="1871" Text="14 pins per inch, so 1/14&quot; pin spacing. Yuck" CreationDate="2010-03-14T21:36:11.567" UserId="566" />
  <row Id="1395" PostId="1874" Text="I tried soldering to the pins themself and that was a loosing process, I didn't want to spend 3 hours working on it. Thanks" CreationDate="2010-03-14T21:44:53.807" UserId="605" />
  <row Id="1396" PostId="1838" Score="1" Text="@Joby: appreciate the thought, but MD5 has aspects of it that are just fine for cryptography. You just have to know its strengths and weaknesses.&#xA;" CreationDate="2010-03-15T00:41:58.060" UserId="330" />
  <row Id="1397" PostId="1846" Score="1" Text="Don't completely rule out MD5: your statement of &quot;It shouldn't be used for cryptographic purposes as it is too insecure&quot; is too overgeneralized." CreationDate="2010-03-15T00:44:27.413" UserId="330" />
  <row Id="1398" PostId="1846" Score="1" Text="Also don't use the fact that a hash algorithm has or doesn't have rainbow tables as a consideration to use it or not. If SHA doesn't have many rainbow tables now, it will. Append a secret &quot;salt&quot; to a message to get around that problem." CreationDate="2010-03-15T00:47:58.267" UserId="330" />
  <row Id="1399" PostId="1859" Text="ok i have this doubt, I have an old computer which actually has a serial port. Now is it necessary that I add the usb converter? Will that make any difference to the software?" CreationDate="2010-03-15T07:07:25.490" UserId="1200" />
  <row Id="1400" PostId="1842" Text="Doesn't meet the &quot;cheap as possible&quot; but here is the link to the Analog Devices probe --&#xA;http://www.analog.com/en/other-products/ios-subsystems/ac2626/products/product.html" CreationDate="2010-03-15T12:23:42.363" UserId="424" />
  <row Id="1401" PostId="1843" Text="@Kortuk-Good point. I'll try to keep the added material to a minimum. Do you have any recommendations for sealing the tube? Would it be best to just weld the aluminum shut at one end? To fix the sensor in the tube would I be best off using something like a CPU adhesive (http://www.arcticsilver.com/arctic_silver_thermal_adhesive.htm) to conduct heat?" CreationDate="2010-03-15T12:29:15.643" UserId="602" />
  <row Id="1402" PostId="1842" Text="sounds like maple sugaring equipment... I want one too. :-)" CreationDate="2010-03-15T12:33:43.377" UserId="330" />
  <row Id="1403" PostId="1842" Text="Caramelizing and beer brewing is the plan, but maple sugaring sounds interesting as well...the more uses I can find the better!" CreationDate="2010-03-15T12:41:17.507" UserId="602" />
  <row Id="1404" PostId="1845" Text="Your hunch is right in that I have not used thermocouples much.  In fact, I would consider myself a novice when it comes to sensors, but I'm trying to get into it more. Would you say the other temp sensor I linked to  to be a better starting point for a beginner?" CreationDate="2010-03-15T12:49:52.577" UserId="602" />
  <row Id="1405" PostId="1885" Text="Unfortunately a WiFi adapter itself is going to run you at least $50. Also WiFi is not a good choice for temperature sensors, due to its high complexity and power requirements. You want something that is very low power, so that you can run your sensor for months off a single battery." CreationDate="2010-03-15T16:16:28.457" UserId="131" />
  <row Id="1406" PostId="1888" Text="You might want to ask three separate questions, since they aren't really related, instead of stuffing them all in one post." CreationDate="2010-03-15T19:43:21.400" UserId="131" />
  <row Id="1407" PostId="1887" Score="1" Text="Is your problem that you don't know how to use your mbed to send signals, or that you don't know what signals to send? Or both? :)" CreationDate="2010-03-15T19:44:58.307" UserId="131" />
  <row Id="1408" PostId="1895" Text="I agree, making it myself is not the best option. I guess I'd need to move to a country where things are made! - in order to buy things that are more local and less wasteful. thanks for the comments" CreationDate="2010-03-15T20:28:26.597" UserId="399" />
  <row Id="1409" PostId="1897" Text="I've just checked out PCB cart - the ordering system looks really convenient, Cheers. " CreationDate="2010-03-15T20:36:30.873" UserId="399" />
  <row Id="1410" PostId="1868" Text="Interesting, but that's like 0.0001 MHz sample rate. Might be useful for a few things, but for many things it's not." CreationDate="2010-03-15T20:44:28.160" UserId="131" />
  <row Id="1411" PostId="1889" Text="Maybe it's just me, but mbed seems overpriced. The board is $100, but the actual microcontroller can be bought for $10. I didn't look at it much, maybe their software is really good &amp; that makes up for the cost? " CreationDate="2010-03-15T20:48:15.560" UserId="131" />
  <row Id="1412" PostId="1902" Text="I didn't say it had to use transistors." CreationDate="2010-03-16T00:44:38.570" UserId="142" />
  <row Id="1413" PostId="1889" Text="+1 for the interesting suggestions." CreationDate="2010-03-16T01:54:08.500" UserId="329" />
  <row Id="1414" PostId="1900" Text="+1 for the interesting links!" CreationDate="2010-03-16T01:59:26.773" UserId="329" />
  <row Id="1415" PostId="1890" Text="Looks like a proprietary protocol... is it?" CreationDate="2010-03-16T02:01:36.567" UserId="329" />
  <row Id="1416" PostId="1911" Score="4" Text="If you haven't read it yet, check out the [Wikipedia][1] article; it's pretty great.&#xA;&#xA;&#xA;  [1]: http://en.wikipedia.org/wiki/Microcode" CreationDate="2010-03-16T02:31:15.890" UserId="238" />
  <row Id="1418" PostId="1902" Score="4" Text="Maybe not, but you did mention them and tagged the question CMOS. So it seemed like a reasonable assumption." CreationDate="2010-03-16T02:47:02.037" UserId="328" />
  <row Id="1419" PostId="1911" Score="4" Text="Microcode is probably not what you're talking about. Unless you are designing your own CPU, you probably wont be interested in microcode. You might be confusing the 'micro' in 'microcode' with 'microcontroller', but they're not the same thing." CreationDate="2010-03-16T03:01:28.797" UserId="131" />
  <row Id="1420" PostId="1845" Text="Start with this&#xA;http://www.sparkfun.com/commerce/product_info.php?products_id=250 &#xA;and check this tutorial out&#xA;http://www.arduino.cc/playground/ComponentLib/Thermistor" CreationDate="2010-03-16T03:07:00.443" UserId="498" />
  <row Id="1421" PostId="1903" Text="thanks for the links&#xA;" CreationDate="2010-03-16T03:13:11.947" UserId="399" />
  <row Id="1422" PostId="1910" Text="ohh, Feynman I should read that too!" CreationDate="2010-03-16T03:27:32.853" UserId="605" />
  <row Id="1423" PostId="1910" Score="1" Text="I may have read that a long time ago.  Is that the essay that talks about reversible computation?" CreationDate="2010-03-16T03:32:15.793" UserId="142" />
  <row Id="1424" PostId="1910" Score="2" Text="That's the one." CreationDate="2010-03-16T04:47:23.020" UserId="424" />
  <row Id="1425" PostId="1890" Text="The RFM12B module does FSK on a configurable frequency, yes. But the JeeNode comms protocol is open source." CreationDate="2010-03-16T06:58:02.910" UserId="566" />
  <row Id="1426" PostId="1889" Text="Its $100?! Wow, I bought mine for £30 over here—which is easily comparable with the cost of a programmer and a chip or two. Yeah, $100 is a bit steep!" CreationDate="2010-03-16T10:26:56.490" UserId="617" />
  <row Id="1427" PostId="1888" Text="Good point :P Thanks" CreationDate="2010-03-16T10:27:53.807" UserId="617" />
  <row Id="1428" PostId="1891" Text="Excellent idea, though for ~150 LEDs that'll be at least 10 of the 16 bit ones, would I be able to carry that many instructions over I2C? There's no need for speed (the LEDs are acting as individually accessible lamps)" CreationDate="2010-03-16T10:29:47.610" UserId="617" />
  <row Id="1429" PostId="1887" Text="The second, I'm happy sending whatever I need to from mbed, but I'm not sure what pulses to send! I do need to work on the phrasing of these questions a bit :P" CreationDate="2010-03-16T10:38:19.070" UserId="617" />
  <row Id="1430" PostId="1911" Score="1" Text="No, I'm taking about microcode.  I'm studying CPU internals and trying to understand the lowest layers like microcode." CreationDate="2010-03-16T15:06:40.880" />
  <row Id="1431" PostId="1891" Text="I don't know.  You'd have to read the datasheet.  That page says you can only use 8 8-bit chips per I2C bus, so you'd need three I2C buses available.&#xA;&#xA;Can you put up with lamps flickering so fast they aren't visible?  That would allow a much simpler circuit.  Even if you need them to be continuously on, if they don't need to switch states very often you can uses latches for a simpler circuit." CreationDate="2010-03-16T15:27:04.230" UserId="142" />
  <row Id="1434" PostId="1914" Text="by 'true-op', i mean instructions that are NOT synthetic or pseudo assembly language instructions.&#xA;&#xA;for the 2nd question, i meant to ask whether microcode instructions map to assembly language true-op instructions." CreationDate="2010-03-16T20:21:51.777" />
  <row Id="1435" PostId="1900" Text="Glad you liked my site. Thanks." CreationDate="2010-03-16T20:27:29.987" UserId="424" />
  <row Id="1436" PostId="1900" Text="Non-pro XBees are rated at ~1mW at their lowest power setting, which will give you near 100% packet transmission within ~10 feet (line of sight) in my experience, an XBee Pro has a max power consumption of ~300mA during transmission but is rated for 1+ mile line of sight. The non pros can do something like 100ft with their max power consumption (about 1/10 of the pro I believe)." CreationDate="2010-03-16T21:57:15.457" UserId="536" />
  <row Id="1437" PostId="1915" Text="cheers muchly Todbot&#xA;" CreationDate="2010-03-16T22:17:43.463" UserId="399" />
  <row Id="1438" PostId="1916" Text="What operating system do you use? Windows or Mac?" CreationDate="2010-03-16T23:05:15.927" UserId="566" />
  <row Id="1439" PostId="1914" Text="@Louis - In general there is no published assembly code that is a 1:1 translation to the microcode.  Intel and AMD (and others) keep their microcode proprietary, as it gives very strong insight into the internal architecture of the processor.  I've heard that for some specialized purposes they are willing to provide information on it to, for instance, researchers so they can get that last 1% of performance out of the machine for certain applications, but for the most part the published spec only includes the machine code and general architecture description." CreationDate="2010-03-17T01:45:49.430" UserId="161" />
  <row Id="1440" PostId="1913" Text="+1 for the useful link. I am looking for something with an API i.e. I want to interface the sensor to a computer." CreationDate="2010-03-17T10:52:57.213" UserId="329" />
  <row Id="1441" PostId="1922" Text="I think what @Adam Davis is saying, though, is that if you use a bootloader (even one you wrote) then you can't program lock bit protected areas.  So, if you did write your own encrypted bootloader, you couldn't prevent the chip from being read (issue 1).  That seems to be what I'm getting from the link and the datasheet, anyway." CreationDate="2010-03-17T12:23:33.047" UserId="11" />
  <row Id="1442" PostId="1900" Text="The numbers that I listed in the writeup are from the XBee literature sited at the bottom of the page. For a whip antenna they state a performance increase of 5:1 (pro:std). For the chip antenna the range is around 3.5:1. These values are all outdoors, line-of-sight. Indoors the difference is only around 2:1 and the ranges are 140ft:80ft. " CreationDate="2010-03-17T12:25:41.627" UserId="424" />
  <row Id="1443" PostId="1922" Text="if the bootloader and the code is encrypted it would solve the second problem, the first problem is almost solved if he uses a secure enough encryption. (the speed of uC may be a bottle neck)." CreationDate="2010-03-17T15:14:35.690" UserId="1200" />
  <row Id="1444" PostId="1922" Text="True.  @Adam Davis suggested an encrypted token language above." CreationDate="2010-03-17T15:32:39.210" UserId="11" />
  <row Id="1445" PostId="1215" Text="I use XMOS; I am happy with their products." CreationDate="2010-03-17T18:57:13.743" />
  <row Id="1446" PostId="964" Text="I also agree.Art of Electronics is fantastic." CreationDate="2010-03-17T19:37:01.217" UserId="626" />
  <row Id="1447" PostId="1926" Text="As a note: for manual build of arm-elf-gcc, I am using a modified version of the instructions at http://www.hermann-uwe.de/blog/building-an-arm-cross-toolchain-with-binutils-gcc-newlib-and-gdb-from-source" CreationDate="2010-03-17T19:39:33.383" UserId="626" />
  <row Id="1449" PostId="1927" Text="I dunno, I'd much rather have someone else go through all the trouble of figuring out how to compile &amp; package GCC than having to learn that myself. My goal is to write programs, not to maintain toolchains, so learning how to do that is not that useful to me." CreationDate="2010-03-17T21:26:25.337" UserId="131" />
  <row Id="1450" PostId="1930" Text="Agreed, I would suggest contacting Weller. Companies can be very helpful in this capacity." CreationDate="2010-03-17T22:38:01.143" UserId="230" />
  <row Id="1451" PostId="1919" Text="Thanks very much to chemicaloliver, todbot and Joby Taffey for your responses.  &#xA;&#xA;Strange.....works fine on one laptop but not the other.  Mystery???&#xA;&#xA;Thanks to everyone.&#xA;John" CreationDate="2010-03-18T02:13:08.980" />
  <row Id="1452" PostId="1936" Text="That's really quite awesome." CreationDate="2010-03-18T22:51:33.380" UserId="566" />
  <row Id="1453" PostId="1936" Score="3" Text="The ATtiny5 isn't available anywhere. The similar PIC10 chips are widely available." CreationDate="2010-03-18T23:26:58.743" UserId="305" />
  <row Id="1454" PostId="1938" Text="Sounds like it could be done with a 555 timer also" CreationDate="2010-03-19T00:14:56.363" UserId="566" />
  <row Id="1455" PostId="1936" Text="Maybe it's too new...the ATtiny10 seems to be in stock at a few places. It's the same size, and mostly same features, just appears to have a bit more memory." CreationDate="2010-03-19T14:37:01.410" UserId="131" />
  <row Id="1456" PostId="1936" Score="1" Text="$1.05 for one, or $0.66 each if you buy 25: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=ATTINY10-TSHRCT-ND" CreationDate="2010-03-19T14:45:24.057" UserId="131" />
  <row Id="1457" PostId="1872" Score="1" Text="What are your requirements?" CreationDate="2010-03-19T17:37:59.080" UserId="588" />
  <row Id="1458" PostId="1945" Score="5" Text="For this type of application I would suggest pretending to be a HID. Drivers already written, you just emulate a mouse or a similar device." CreationDate="2010-03-19T18:04:58.200" UserId="230" />
  <row Id="1459" PostId="1927" Text="Yes, but as far as I know those packages don't exist. (For AVR I use avr-gcc.)" CreationDate="2010-03-19T20:12:47.043" UserId="339" />
  <row Id="1460" PostId="1950" Text="Not character capable, unfortunately." CreationDate="2010-03-20T14:23:32.077" UserId="161" />
  <row Id="1461" PostId="1949" Score="2" Text="Can you give additional information, such as how many characters and lines you want to display in that area, and what the ballpark range is for &quot;on the cheap side&quot;?" CreationDate="2010-03-20T14:24:34.743" UserId="161" />
  <row Id="1462" PostId="1949" Score="1" Text="Did you mean LED rather than LCD?" CreationDate="2010-03-20T20:45:43.697" UserId="328" />
  <row Id="1463" PostId="1951" Text="Oh wow, if an LCD TV is the cheapest option, I should give up now!" CreationDate="2010-03-20T22:29:01.097" UserId="601" />
  <row Id="1464" PostId="1951" Text="A large LED display will probably cost more than a TV!" CreationDate="2010-03-21T04:23:06.647" UserId="305" />
  <row Id="1465" PostId="1952" Text="Yes this would become a rather easy solution when using I2C or SPI to talk to the LCDs, so that might be a feature the TS would want to look out for." CreationDate="2010-03-21T22:01:51.737" UserId="348" />
  <row Id="1466" PostId="1821" Text="As the iron will be resting on the edge of the metal stand, there will not be enough surface area to conduct the heat from the iron to cause a scorch mark on the table top. Personally, I found that the sand to be too light but it's a freebie really." CreationDate="2010-03-22T01:08:51.637" UserId="640" />
  <row Id="1467" PostId="1962" Text="Thanks for the quick reply.&#xA;Yeah that's exactly what I wanted and I could easily program it but I don't want to do it with a MCU! I cannot find any circuits that do something like this automatically." CreationDate="2010-03-22T08:53:24.130" UserId="641" />
  <row Id="1468" PostId="1853" Text="While will not knocking someone's attempt to rediscover lost arts or replicating the experiments done in the past, it's unlikely you'd be as successful as a modern led. " CreationDate="2010-03-22T09:41:54.100" UserId="640" />
  <row Id="1469" PostId="1961" Text="Some more details would help. The min and max frequency, how fast you want it to ramp, once it speeds up does it just stay at the max, do you just need a square wave output, how accurate/stable/linear does it need to be..." CreationDate="2010-03-22T10:15:25.943" UserId="328" />
  <row Id="1471" PostId="1961" Text="Linear or logarithmic ramp?" CreationDate="2010-03-22T14:59:25.453" UserId="142" />
  <row Id="1472" PostId="1902" Score="1" Text="I mentioned it as an example of a new technology that greatly reduced current usage.  I'm wondering if there's theoretically something better." CreationDate="2010-03-22T16:37:36.487" UserId="142" />
  <row Id="1475" PostId="1967" Score="2" Text="Best according to what criteria? Fastest? Cheapest? Most storage?" CreationDate="2010-03-22T17:59:49.930" UserId="305" />
  <row Id="1476" PostId="1970" Score="2" Text="The electrons will *never* appear at the other end, since it's AC and they're only moving back and forth." CreationDate="2010-03-22T19:13:28.423" UserId="142" />
  <row Id="1477" PostId="1970" Score="3" Text="And a stopwatch isn't really necessary.  &quot;For example, for a copper wire of radius 1 mm carrying a steady current of 10 amps, the drift velocity is only about 0.024 cm/sec&quot;.  So it would take about an hour for an electron to travel one meter." CreationDate="2010-03-22T19:25:03.670" UserId="142" />
  <row Id="1478" PostId="1853" Score="1" Text="I could be wrong but I was reading this as &quot;I would like to fab some custom LED assemblies&quot;. " CreationDate="2010-03-22T19:44:48.083" UserId="424" />
  <row Id="1479" PostId="770" Text="The capacitance based liquid level sensors work best at detecting presence or absence of fluid. In order to read the water level charge/discharge the plates using a fixed resistor and measure the time. As mentioned above adding contaminates to the water (like salt) can cause a drastic change in capacitance and therefore your reading for a fixed liquid level. If the liquid you are measuring is homogeneous this is much less of a problem." CreationDate="2010-03-22T19:49:58.427" UserId="588" />
  <row Id="1480" PostId="1970" Text="@endolith - I thought it was very slow, I just couldn't recall from classes so long ago.  In this case it's AC, so for even short wires it won't appear, but in tiny silicon amplifiers in might." CreationDate="2010-03-22T20:43:12.183" UserId="161" />
  <row Id="1481" PostId="1976" Text="the marvell guruplug is out now, has all sorts of extra goodies like esata and gigabit (the plus model has dual gigabit!). http://www.globalscaletechnologies.com/c-4-guruplugs.aspx" CreationDate="2010-03-22T20:56:39.290" UserId="417" />
  <row Id="1482" PostId="1973" Text="+1, that article made me think more clearly about this subject." CreationDate="2010-03-22T22:09:24.433" UserId="374" />
  <row Id="1483" PostId="1982" Score="1" Text="So you would suggest 600 or 700°F? Or going straight up to 850°F (which seems like it might be excessive and risk damaging the parts from even short exposure)." CreationDate="2010-03-23T00:35:12.793" UserId="647" />
  <row Id="1484" PostId="1982" Score="1" Text="My iron is as on max at 800°F (I use lead free solder). It's important to have a light touch when working with surface mount parts. For through hole, attach a crocodile clip or heatsink to the legs of sensitive components." CreationDate="2010-03-23T00:45:12.137" UserId="566" />
  <row Id="1485" PostId="1985" Text="Re: voltage vs PWM - indeed. Question updated. Thanks." CreationDate="2010-03-23T01:01:33.820" UserId="566" />
  <row Id="1488" PostId="1988" Text="It sounds like I was erring a bit on the side of conservatism. I'll try 700°F or so and see if that gives me improved results." CreationDate="2010-03-23T03:25:24.570" UserId="647" />
  <row Id="1489" PostId="1963" Text="Thanks Clint. The VCO is something that I will most likely use!" CreationDate="2010-03-23T06:52:18.450" UserId="641" />
  <row Id="1490" PostId="1992" Text="Cheers, thanks for the tips" CreationDate="2010-03-23T11:38:33.767" UserId="399" />
  <row Id="1491" PostId="1897" Score="1" Text="Much more expensive than Golden Phoenix, though.  I've seen a bunch of GP stuff and it was quite nice." CreationDate="2010-03-23T16:37:10.277" UserId="213" />
  <row Id="1492" PostId="1999" Text="Some of the converter tools done like to deal with secure pdfs.&#xA;&#xA;Along the lines of your suggestion, Gimp works well." CreationDate="2010-03-23T22:24:41.353" UserId="550" />
  <row Id="1493" PostId="2015" Text="problem is its very hard to obtain an arduino where I live. I am planning to make one for my own but that too is not working out (read don't have time)." CreationDate="2010-03-24T08:13:14.937" UserId="1200" />
  <row Id="1494" PostId="2014" Score="1" Text="This is likely the easiest solution." CreationDate="2010-03-24T09:41:22.753" UserId="215" />
  <row Id="1495" PostId="2014" Text="This was the first solution that came to my mind.  It may not be as elegant, but the disc drive manufacturer has really done all the hard work for you (wrt opening the drive)." CreationDate="2010-03-24T12:16:03.823" UserId="11" />
  <row Id="1496" PostId="1979" Text="I would expect a moving coil cartridge to have a *higher* output than a moving magnet, given identical coils and magnets, since the coil has less mass." CreationDate="2010-03-24T13:55:25.250" UserId="142" />
  <row Id="1497" PostId="1128" Text="There was a meeting about this: http://scienceblogs.com/commonknowledge/2010/03/open_hardware.php" CreationDate="2010-03-24T14:12:29.513" UserId="142" />
  <row Id="1498" PostId="2014" Text="I had a friend in college that did this to one of his drives. It worked great." CreationDate="2010-03-24T14:42:22.007" UserId="588" />
  <row Id="1499" PostId="1979" Score="2" Text="From Wikipedia: &quot;A disadvantage however is that moving-coil cartridges generate an even lower voltage signal than a moving-magnet type cartridge. This is because the moving coil cannot be large enough (it would be too heavy) to generate equivalent voltage levels. The resulting signal is only a few hundred microvolts, and thus more easily swamped by noise, induced hum, etc.&quot;" CreationDate="2010-03-24T14:47:07.457" UserId="544" />
  <row Id="1503" PostId="2007" Text="Touch sensor idea makes me think of Christmas tree worms snapping shut when you touch them. http://youtube.com/watch?v=UW3vDVrs4OQ  " CreationDate="2010-03-24T16:31:37.143" UserId="142" />
  <row Id="1504" PostId="2010" Text="Can you explain in more detail what you're trying to do?  An FET can pass AC, as used in transmission gates. http://en.wikipedia.org/wiki/Transmission_gate" CreationDate="2010-03-24T16:33:14.293" UserId="142" />
  <row Id="1505" PostId="2026" Text="Wow!  I'm going to have to look into that some more.  " CreationDate="2010-03-24T17:49:42.097" UserId="106" />
  <row Id="1506" PostId="2010" Text="Sorry, I didn't provide much detail. I know a triac would b the 'correct' item for this, but I'm wanting to know if a transistor could do it also. My problem is that if a transistor passes the AC, the voltage will vary over time; If the voltage at the base is constant, I would have to make sure the this difference never exceeds the max base-collector voltage; But if this voltage also varied, at the same frequency, I cold use higher AC voltages without  worrying about the base-collector max." CreationDate="2010-03-24T19:06:45.807" />
  <row Id="1507" PostId="2011" Text="In regard to the diode, I mean putting it in parallel with the transistor in order to protect it from reverse voltage, which I expect to exceed the transistors maximum; This also means it only handles the positive part of the AC sine wave." CreationDate="2010-03-24T19:10:59.610" />
  <row Id="1508" PostId="2033" Score="1" Text="That's a good point...if you don't plan to make money off your idea, why are you so against someone else attempting to?" CreationDate="2010-03-24T21:11:50.190" UserId="131" />
  <row Id="1510" PostId="2010" Score="1" Text="The problem, as I see it, is going to be power dissipation. When the transistor is swinging through its conduction area, it is required to drop a significant amount of voltage. This is not true if the transistor is switched completely on or off, like it is in DC switching applications. Essentially, what you would have is a half-wave amplifier. 100 watts is a lot of power for a speaker, but not so much for a toaster." CreationDate="2010-03-24T21:17:05.203" UserId="544" />
  <row Id="1511" PostId="2010" Text="Actually, I do want to use the transistor for switching, not amplification; Just I can't see how I can use DC switch AC." CreationDate="2010-03-24T22:29:32.687" />
  <row Id="1512" PostId="2034" Text="That's a nice little bot." CreationDate="2010-03-24T23:23:26.543" UserId="106" />
  <row Id="1513" PostId="2033" Score="2" Text="It's his choice.  Under a NC-only license, people can still make money off it - they just have to talk to you first.  Maybe you want to be involved in the making and selling stage, or know that even a small cut of the profits will be a huge amount for you.   I don't know why everyone's so deadset against people making money off their designs." CreationDate="2010-03-25T00:08:54.487" UserId="142" />
  <row Id="1514" PostId="2038" Text="I haven't seen real RS232 in years, thankfully.&#xA;&#xA;The API idea appeals" CreationDate="2010-03-25T00:47:21.303" UserId="566" />
  <row Id="1515" PostId="2037" Text="The OLS appeals. To self-build though, it looks so complex I'd probably need another one to debug it :)" CreationDate="2010-03-25T00:51:09.457" UserId="566" />
  <row Id="1516" PostId="2037" Score="2" Text="@Joby - probably.  But it's only $50 assembled, so it's not that big a hit." CreationDate="2010-03-25T03:15:57.100" UserId="161" />
  <row Id="1517" PostId="2006" Text="It turns out that gimp read my secured PDF directly. I was surprised, but it worked.&#xA;&#xA;As for taping a small piece on a regular sheet of paper, that's a good idea. Will have to try that." CreationDate="2010-03-25T05:25:30.613" UserId="550" />
  <row Id="1518" PostId="2006" Text="I use Pulsar's toner-transfer paper with the cut-and-tape method.  It works pretty well. :-)" CreationDate="2010-03-25T11:59:12.563" UserId="51" />
  <row Id="1519" PostId="2041" Text="Forward/backward/brake/coast?  PWM could do variable speed forward and backward from a single pin." CreationDate="2010-03-25T15:34:17.863" UserId="142" />
  <row Id="1520" PostId="2041" Text="@endolith Really?  I'd never heard of doing that.  I can see that it could be done if you had a chip on the other end to decode the signal and re-encode it on two pins (foward/backward and a new PWM signal) sent on to an H-Bridge." CreationDate="2010-03-25T16:14:32.867" UserId="106" />
  <row Id="1521" PostId="2010" Text="Still don't understand what you're trying to do.  Of course you can &quot;use a transistor with AC&quot;, but that could mean all kinds of different things.  Are you trying to use low-voltage to switch a high-voltage device on and off?  Are you trying to make a dimmer control for light bulbs?  Are you trying to power a transistor directly from an AC line, during only the positive cycles?  Are you trying to amplify an AC signal like a loudspeaker amplifier?" CreationDate="2010-03-25T19:18:34.423" UserId="142" />
  <row Id="1523" PostId="2041" Text="Well you're not running the motor directly from the PWM pins, so you can offset it and amplify it. You can use 0% duty cycle to mean full reverse, 50% duty cycle to mean off, and 100% duty cycle to mean full forward, for instance.  But what are brake and coast?" CreationDate="2010-03-25T19:21:15.473" UserId="142" />
  <row Id="1524" PostId="2041" Text="@endolith The chart on http://www.ikalogic.com/H_bridge_1.php shows the four modes of operation of an H-Bridge -- the motor turns forward/clockwise, the motor turns in reverse/counter-clockwise, the motor has active braking applied to it, or the motor is freewheeling or coasting." CreationDate="2010-03-25T20:33:50.420" UserId="106" />
  <row Id="1525" PostId="2010" Score="1" Text="I am trying to us LV to switch HV, but using a transitor (not triac or relay). I am not making a dimmer control. The transistor need only operate on positive cycles, I would put a diode in parallel with it so it doesn't block negative ones (and to protect it from reverse current). I am wanting to use it as a switch, not to amplify anything." CreationDate="2010-03-26T00:22:22.780" />
  <row Id="1526" PostId="2050" Score="1" Text="How bizarre, I went to do an apt-get install, only to discover that I'd already installed it at some other point. I think I'll have a play." CreationDate="2010-03-26T10:53:53.823" UserId="103" />
  <row Id="1527" PostId="1141" Text="Of course, there are exceptions.  http://gieskes.nl/instruments/files/hard-soft-synth-1/version1/HSS-top-verson1.jpg http://gieskes.nl/undefined/x/files/3trins/3trins-front-angle.jpg  http://www.flickr.com/photos/joesmooth/3526918573/" CreationDate="2010-03-26T14:30:46.350" UserId="142" />
  <row Id="1528" PostId="2026" Text="There also mention of Dave Mellis doing some work with Scratch&#xA;for Arduino -- See http://web.media.mit.edu/~mellis/" CreationDate="2010-03-26T16:24:25.933" UserId="424" />
  <row Id="1529" PostId="1720" Score="1" Text="Don't forget the licensing fees for QP if your code is proprietary." CreationDate="2010-03-26T17:31:53.510" UserId="588" />
  <row Id="1530" PostId="367" Text="I have one of these - it works well. Comes as a kit with all the surface mount parts pre-soldered. uIP sources and ethernet driver come with it." CreationDate="2010-03-27T00:23:54.240" UserId="566" />
  <row Id="1531" PostId="2057" Text="Hey can this thing emit human language? I mean like words? " CreationDate="2010-03-27T05:43:49.347" UserId="1200" />
  <row Id="1532" PostId="1923" Text="Thanks for the info.  I still don't quite understand why, but I've gotten it working now.  You're right that the CTRL pins put the device in power down mode, they just don't seem to behave the way the datasheet indicates.  The datasheet also fails to mention that you can *either* write to the device or update the values over I2C - it doesn't seem to be possible to have the device generating a signal while it's accessible over the I2C bus.  Well at any rate, I've heard stories about badly written datasheets, I guess I've come across my first one :-)" CreationDate="2010-03-27T07:41:33.913" UserId="548" />
  <row Id="1533" PostId="2057" Score="1" Text="Have a look at Cantarino - http://code.google.com/p/tinkerit/wiki/Cantarino" CreationDate="2010-03-27T07:50:03.213" UserId="566" />
  <row Id="1534" PostId="2023" Text="I've just been working with an IC that does this, now I understand why!  But how do you &quot;undo&quot; the bias at the other end to move the signal back to +V/-V?" CreationDate="2010-03-27T08:09:55.650" UserId="548" />
  <row Id="1535" PostId="1991" Score="1" Text="I have managed to converse with Ann at futurlec a few times, if they are really busy they have trouble saying no (they don't like to lose &quot;face&quot;) so instead they will blabber on about other things. plus they take so bloody long. I'm about to try pcbwing.com next month, seems ok. " CreationDate="2010-03-27T09:42:07.913" UserId="1307" />
  <row Id="1536" PostId="2057" Text="@Joby the resource you gave was great but I saw the demo, it is not actually saying anything audible.Any other you know of?" CreationDate="2010-03-27T12:23:34.267" UserId="1200" />
  <row Id="1538" PostId="2066" Score="2" Text="You can use a filter before the speaker to smooth out the PWM, regardless of how fast the speaker itself moves." CreationDate="2010-03-27T12:51:16.200" UserId="142" />
  <row Id="1539" PostId="2023" Text="Use a coupling capacitor with a bias resistor to ground.  :)" CreationDate="2010-03-27T12:53:52.923" UserId="142" />
  <row Id="1540" PostId="2063" Text="I like the Fox Hunt game idea!" CreationDate="2010-03-27T14:09:28.547" UserId="625" />
  <row Id="1541" PostId="2057" Text="Not without a DAC, no." CreationDate="2010-03-27T15:11:48.433" UserId="566" />
  <row Id="1542" PostId="2063" Text="if  you do try it out please mail be the feedback. I would like to know if the concept works with crystal radio." CreationDate="2010-03-27T16:56:01.637" UserId="1200" />
  <row Id="1543" PostId="2057" Text="@Joby what do you have with a DAC?" CreationDate="2010-03-27T17:24:29.950" UserId="1200" />
  <row Id="1544" PostId="2057" Text="Mixing audio samples on an GBA/ARM7 - http://www.hackpadsoftware.com/projects/gbaboal.html" CreationDate="2010-03-27T19:40:58.893" UserId="566" />
  <row Id="1546" PostId="1098" Text="This seems relevant: http://www.tinaja.com/patnt01.asp" CreationDate="2010-03-27T23:49:45.470" UserId="142" />
  <row Id="1549" PostId="2077" Score="1" Text="It's based on the sump.org design I mentioned earlier." CreationDate="2010-03-28T13:02:51.690" UserId="305" />
  <row Id="1550" PostId="2073" Score="3" Text="This seems like a class problem." CreationDate="2010-03-28T21:16:40.133" UserId="230" />
  <row Id="1551" PostId="2079" Text="I can still hear the tune in my head" CreationDate="2010-03-29T06:36:43.447" UserId="566" />
  <row Id="1552" PostId="2048" Text="I've used solder paste with a few QFN chips and had pretty good results, but you do need to be careful to not put down too much solder paste.  With the proper use of a stencil and a lot of care, I imagine one could get decent results with BGA.  I'd be ready to expect a high failure rate, especially when you start off." CreationDate="2010-03-29T12:38:15.760" UserId="11" />
  <row Id="1553" PostId="2086" Text="I haven't seen the LBE code, does it give any more information about why it won't initialize?  Also, is the hardware list up there complete, or are there any other sensors/whatnot connected?" CreationDate="2010-03-29T12:49:53.683" UserId="11" />
  <row Id="1554" PostId="2087" Text="I have designed a few boards with SD cards (not micro, but electronically I believe the SPI is the same).  I would definitely start with looking at the voltage levels, because I was only able to get reliable results at 3v3.  5v is asking for trouble." CreationDate="2010-03-29T12:50:20.423" UserId="11" />
  <row Id="1555" PostId="2071" Text="Thanks for all the really great ideas and tips from your experience!" CreationDate="2010-03-29T13:10:13.183" UserId="625" />
  <row Id="1557" PostId="2071" Text="@DoxaLogos - I'm glad I could share.  I can't wait to here what you and others come up with." CreationDate="2010-03-29T14:12:29.793" UserId="106" />
  <row Id="1558" PostId="2095" Score="1" Text="That's the ticket! I actually had another ss device here and had already determined it wouldn't work for that very reason. Doh!" CreationDate="2010-03-29T18:02:10.717" UserId="238" />
  <row Id="1559" PostId="2088" Text="I have used resistor dividers to bring a 5v signal down to 3v3 without problem on SD devices over SPI and haven't had problems.  From what I've seen on the scope, it's not a significant issue at slower speeds.  Good thing to point out for anyone running a card at higher speeds!" CreationDate="2010-03-29T18:25:46.540" UserId="11" />
  <row Id="1560" PostId="2088" Text="Also, I was going to suggest trying a smaller card earlier but I got busy at work.  I have not found a card that hasn't worked, but I've heard that if you keep cards to 2GB and lower, your luck is better.  For reference, all my SD cards that I've used in projects are leftovers/salvage which are years old.  I think the newest one I've tried is around a year old." CreationDate="2010-03-29T18:28:46.903" UserId="11" />
  <row Id="1561" PostId="2037" Score="2" Text="Oh, man, that's cool.  I didn't even know I needed one until now!  And it works as an AVR programmer, too." CreationDate="2010-03-29T18:31:33.997" UserId="106" />
  <row Id="1562" PostId="1872" Score="1" Text="That's a pretty rich feature set.  I prefer my power supply and test equipment outboard; the rest of the features can be added to the breadboard as needed.  Given the availability of items like $50 logic analyzers (http://dangerousprototypes.com/open-logic-sniffer/) and $89 digital storage oscilloscopes (http://www.seeedstudio.com/depot/micro-digital-storage-oscilloscopedso-nano-p-512.html) I'm not sure the all-in-one approach is practical if you want to go cheap." CreationDate="2010-03-29T18:42:44.603" UserId="544" />
  <row Id="1563" PostId="2088" Text="This must be opposite day. I haven't found a card that works ;) If you have any info on the cards that do work (mfg/mfg pn) that would be great. Also what hardware/software are you using? Thanks." CreationDate="2010-03-29T19:21:35.427" UserId="424" />
  <row Id="1564" PostId="2097" Score="1" Text="You might want to define &quot;better&quot; - is the lower voltage the problem?  The switching noise?  The current draw?  Cost?  Power consumption?  For the problem specs, what is the minimum requirements you have for a supply that meets your needs?" CreationDate="2010-03-29T20:45:20.563" UserId="161" />
  <row Id="1565" PostId="2096" Text="cheers dude - I got an promo email last week from TI and this chip was on the front page - crazy!" CreationDate="2010-03-30T10:58:44.250" UserId="399" />
  <row Id="1567" PostId="618" Score="3" Text="Many of the foundational principles are timeless." CreationDate="2010-03-30T22:52:32.773" UserId="544" />
  <row Id="1568" PostId="2096" Text="I can't get this chip yet - darn, they said it would be available some time from May to mid summer! - talk about drumming up interest" CreationDate="2010-03-31T08:29:49.493" UserId="399" />
  <row Id="1569" PostId="2105" Text="i don't think that a PCB is in any way &quot;quick&quot;. I takes at least an hours to make it and that does not compare with the breadboard option." CreationDate="2010-03-31T13:24:15.320" UserId="1200" />
  <row Id="1570" PostId="2111" Text="That's interesting.  Interesting indeed." CreationDate="2010-03-31T19:16:50.047" UserId="106" />
  <row Id="1571" PostId="2105" Text="I can make a PCB in under 30 minutes." CreationDate="2010-03-31T20:47:59.397" UserId="305" />
  <row Id="1572" PostId="2111" Text="Scratch will communicate with other programs via sockets!  That's amazing!" CreationDate="2010-03-31T21:36:26.973" UserId="106" />
  <row Id="1573" PostId="2114" Text="It's definitely far more expensive than a straight analog solution in the short term, but I'm thinking it might buy me time in the long run. And it just looks fun." CreationDate="2010-03-31T22:08:07.193" UserId="207" />
  <row Id="1574" PostId="2113" Text="Interesting.  Unfortunately, it does not look like something I can leverage for my purposes." CreationDate="2010-03-31T23:12:34.750" UserId="106" />
  <row Id="1575" PostId="2114" Text="@msutherl - Yeah, they do look like fun.  I have a dev kit around here somewhere that I was excited to get, that I never had time to play with." CreationDate="2010-04-01T00:59:10.697" UserId="161" />
  <row Id="1576" PostId="2116" Text="thanks jcl – take a look at my edits to the main question (&quot;I'm not looking for the best solution for my current project, I'm curious as to whether you think PSoC is a good investment for general prototyping.&quot;)" CreationDate="2010-04-01T01:14:48.970" UserId="207" />
  <row Id="1578" PostId="2116" Text="As for this particular application, I'm making a sensor glove with conductive lycra. I'm planning to do signal processing on the hand, possible before A/D with an XBee. " CreationDate="2010-04-01T01:26:08.677" UserId="207" />
  <row Id="1579" PostId="2114" Text="Also, I was assuming I would need amplification and filtering before the A/D to get cleaner data into the computer as per recommendations in this thread: chiphacker.com/questions/937/… (I'm anticipating that I will be dealing with similarly weak/noisy signals). I'm a student, so I've got time to play around with these things! The idea is to overdo it for the sake of learning." CreationDate="2010-04-01T01:27:14.753" UserId="207" />
  <row Id="1580" PostId="2116" Text="I usually just use a small prototyping board (solder type) and then go to a PCB layout. &#xA;&#xA;I am not sure the learning curve on the PSoC. If it is not too steep then try it on a project or two. Any analog design you learn with PSoC should apply to a discrete solution too. &#xA;&#xA;It is not difficult to come up with a few preferred parts for a &quot;bag of tricks&quot;. A couple of rail-to-rail opamps, an instrument amp, a reference, some precision resistors. &#xA;&#xA;" CreationDate="2010-04-01T02:03:48.667" UserId="424" />
  <row Id="1581" PostId="2115" Score="1" Text="Knowing the frequency of interest would go a long way in getting a relevant answer. Some things that work great at HF and below ( &lt; 30MHz ) don't work well at UHF and microwave ranges ( &gt; 300 MHz ). " CreationDate="2010-04-01T03:06:45.357" UserId="638" />
  <row Id="1582" PostId="2118" Text="I meant two identical antennas oriented differently so one would be better suited to certain polarizations." CreationDate="2010-04-01T06:00:47.193" UserId="582" />
  <row Id="1583" PostId="2121" Score="2" Text="...or the 741 op-amps..." CreationDate="2010-04-01T08:56:43.173" UserId="611" />
  <row Id="1584" PostId="618" Score="4" Text="This is definately the best general electronics book I ever came accross. I never understood op-amps at a very fundemental level until I read the section on op-amps in this book. Worth the price for that moment of clarity alone. If you're ever teaching electronics and trying to explain virtual ground this is where to start. It always confused students to see their signal 'dissapear' at the input pin of the op-amp." CreationDate="2010-04-01T09:06:08.400" UserId="611" />
  <row Id="1585" PostId="2122" Score="1" Text="http://home4film.com/questions/44/what-is-mains-conditioning" CreationDate="2010-04-01T14:28:30.960" UserId="1301" />
  <row Id="1586" PostId="2105" Score="3" Text="please tell me how do you do that? that really fast by any standards" CreationDate="2010-04-01T14:34:49.467" UserId="1200" />
  <row Id="1587" PostId="2123" Text="You're right - that's a big problem too - but it's normally quite cheap to just go over the circuit and make sure it's grounded properly. Is there a particular type of capacitor you would recommend for using with a filter?&#xA;" CreationDate="2010-04-01T14:55:06.363" UserId="399" />
  <row Id="1588" PostId="2110" Text="I will see if i can get one i think there a bit rare now" CreationDate="2010-04-01T19:55:38.010" UserId="665" />
  <row Id="1589" PostId="2123" Text="@Jim: See my edit." CreationDate="2010-04-01T20:33:23.137" UserId="544" />
  <row Id="1590" PostId="2123" Text="Thanks for the schematic - could this be added post ac/dc PSU, on say a regular wall-wart power supply? (they're all plastic moulded &amp; I can't pull them apart) I've been making simple IC based amps that are powered by a 9v battery and I'd like to include the option of plugging them in with a store bought PSU - thanks for the help" CreationDate="2010-04-01T21:03:45.803" UserId="399" />
  <row Id="1591" PostId="2123" Text="@Jim: Yes, some additional filtering caps, and possibly a voltage regulator in-line, should do the trick.  Make sure you respect the current capabilities of the wall-wart; if you are pulling current at the limits of the wall-wart's capability, that could be a big reason you're getting hum." CreationDate="2010-04-01T22:51:27.593" UserId="544" />
  <row Id="1592" PostId="1466" Text="you should not consider the arduino to be the whole 1A even if you are using every pin. That will all depend on the loads of arduino. The rating given on the site is considering the loads and I think the loads are your solenoids. The boards itself just draws 0.2mA I think" CreationDate="2010-04-02T03:21:59.590" UserId="1200" />
  <row Id="1593" PostId="2125" Text="That would be 20 / 80 and would mean about 250mA of current, right?" CreationDate="2010-04-02T03:22:31.850" UserId="444" />
  <row Id="1594" PostId="2125" Score="2" Text="Yep, I've added a bit more to the answer that should help explain it." CreationDate="2010-04-02T03:57:00.247" UserId="328" />
  <row Id="1595" PostId="2125" Text="Actually I was trying to test out a constant current source however I found that my assumptions were not supported by the practical readings that I later took." CreationDate="2010-04-02T04:21:52.693" UserId="444" />
  <row Id="1596" PostId="2128" Text="I'm sure - I have a load of battery operated audio equipment and I'd like to covert them to accept a regular wall wart PSU - I just need a filter to go between the two. They currently don't have a ad/dc input just a 9v battery " CreationDate="2010-04-02T21:11:50.187" UserId="399" />
  <row Id="1597" PostId="2123" Text="Cool I'll give the V reg and caps a go&#xA;&#xA;Thanks for your help" CreationDate="2010-04-02T21:13:23.243" UserId="399" />
  <row Id="1598" PostId="2078" Text="To get the Arduino to play the notes asynchronously you would need to use a system similar to MIDI - with separate commands for note on and note off etc, the built in tone library does this but does not do polyphony - but the latest version looks like it does - http://code.google.com/p/rogue-code/wiki/ToneLibraryDocumentation" CreationDate="2010-04-05T18:59:38.597" UserId="399" />
  <row Id="1599" PostId="2059" Score="2" Text="I remember looking at an NES emulator a long time ago and I believe they used three waveforms each with a programmable frequency. Two square waves and one triangle wave." CreationDate="2010-04-05T19:28:57.373" UserId="588" />
  <row Id="1600" PostId="2141" Text="probably should also mention that the order page is here: http://www.globalscaletechnologies.com/c-4-guruplugs.aspx" CreationDate="2010-04-06T11:18:03.367" UserId="417" />
  <row Id="1601" PostId="2145" Text="I need to use that disclaimer more often.  :D" CreationDate="2010-04-07T14:50:18.793" UserId="142" />
  <row Id="1602" PostId="2062" Score="1" Text="If you're using PWM (switching at a much higher frequency than the desired signal), then you can already mix multiple signals together using only the one output pin." CreationDate="2010-04-07T14:53:34.187" UserId="142" />
  <row Id="1603" PostId="2059" Text="...and one noise source, apparently.  http://en.wikipedia.org/wiki/NES_Sound_Format" CreationDate="2010-04-07T14:54:42.623" UserId="142" />
  <row Id="1604" PostId="2145" Text="How small is a small run? As mentioned by Ian, there are usually huge fixed startup costs to get custom things designed, even if the individual parts are fairly cheap. " CreationDate="2010-04-07T18:23:01.487" UserId="131" />
  <row Id="1605" PostId="2150" Text="the SPDT RF switch seems to be what I am looking for.&#xA;Here is a great app note I found:&#xA;AVR2021: AT86RF231 Antenna Diversity&#xA;www.atmel.com/dyn/resources/prod_documents/doc8158.pdf" CreationDate="2010-04-08T05:56:44.307" UserId="582" />
  <row Id="1606" PostId="2154" Text="Hi Leon.  Just to be a little pedantic, that would be inversely proportional ;-)" CreationDate="2010-04-08T13:18:39.643" UserId="400" />
  <row Id="1607" PostId="2146" Text="Thanks for the link!" CreationDate="2010-04-08T13:55:24.593" UserId="329" />
  <row Id="1608" PostId="2154" Text="Leon, [this page][1] suggests the opposite: higher frequency crystals are only available in larger packages. What do you think ?&#xA;&#xA;  [1]: http://www.icmfg.com/thruhole_crystals.html" CreationDate="2010-04-08T15:56:21.760" UserId="595" />
  <row Id="1609" PostId="2151" Score="1" Text="Technically - the height influences the frequency, I doubt that the frequency influences the height (much) :-)" CreationDate="2010-04-08T15:56:46.687" UserId="566" />
  <row Id="1610" PostId="2154" Score="2" Text="@Jonathan - The higher frequency crystals - above 25MHz - are often driven at harmonic frequencies above the fundamental frequency.  Further, larger crystals also can be driven at higher power so the harmonic frequencies can be more easily selected for.  What this means is that *sometimes* for *some uses* a higher frequency crystal is actually larger than a lower frequency crystal driven at its fundamental frequency.  Note the operational mode and max ESRW in this table as the frequency goes up: http://www.icmfg.com/crystal_hc49u.html" CreationDate="2010-04-08T18:30:01.330" UserId="161" />
  <row Id="1611" PostId="2151" Score="1" Text="These are crystals, not crystal oscillators." CreationDate="2010-04-08T18:33:33.697" UserId="339" />
  <row Id="1612" PostId="2154" Text="Ian is correct, of course. I should have said inversely proportional" CreationDate="2010-04-08T19:27:01.960" UserId="305" />
  <row Id="1613" PostId="2151" Text="@starblue: thanks for pointing this out... edited questiong accordingly." CreationDate="2010-04-08T20:02:51.763" UserId="595" />
  <row Id="1614" PostId="2154" Text="@Adam: thanks for that informative comment!" CreationDate="2010-04-08T20:03:35.403" UserId="595" />
  <row Id="1615" PostId="2169" Text="Can you draw a schematic?" CreationDate="2010-04-09T17:30:03.587" UserId="142" />
  <row Id="1616" PostId="739" Score="3" Text="It would help a lot to know what kind of algorithms you need to implement. Chances are that you don't need an FPGA at all, which will save you a lot of development time ;-)" CreationDate="2010-04-09T18:39:28.710" UserId="672" />
  <row Id="1617" PostId="1754" Score="1" Text="Here's a great blog from a guy trying to create a tiny CPU for a CPLD http://www.stevechamberlin.com/cpu/" CreationDate="2010-04-09T19:03:08.900" UserId="566" />
  <row Id="1619" PostId="2174" Text="There are many devices that exist that have niche use. PLLs are extremely common and it would blow your mind how often you have varicaps in something.!" CreationDate="2010-04-10T09:46:30.787" UserId="230" />
  <row Id="1620" PostId="1992" Text="If you used pcbwing.com, may change your view, they better quality, lower prices." CreationDate="2010-04-10T16:08:39.803" />
  <row Id="1621" PostId="471" Score="1" Text="The problem with the Beagleboard is that you don't get access to digital audio I/O. They D/A converters are wired in. Russ White at Twisted Pear Audio has hacked it to work with the Buffalo D/A's, but I'm told it's not so easy. " CreationDate="2010-04-10T18:42:01.490" UserId="207" />
  <row Id="1622" PostId="2179" Text="Thats precisely the idea. I endeavour to enable the bot to determine its remaining charge, and to navigate its way back to the charging base then it needs a top up. Having an inductive charging method means that could be as simple as parking atop an inductive charging pad.&#xA;&#xA;Thanks for the suggestions there, I'll take a look at those controllers. Will be interesting to see if anyone can help me with the inductive side." CreationDate="2010-04-11T03:40:38.613" />
  <row Id="1623" PostId="2182" Score="1" Text="In reference to rule three, this can be true but as you tweek resistor and cap values you tweek your cutoff frequency. If you go to a lower cutoff frequency, it takes longer to charge, higher frequency charges faster but has greater ripple." CreationDate="2010-04-11T22:16:18.280" UserId="230" />
  <row Id="1624" PostId="2162" Text="Now that iPad is out, you can get a good deal on a Kindle DX on ebay." CreationDate="2010-04-12T01:17:46.437" UserId="625" />
  <row Id="1625" PostId="1307" Text="Don't forget that avr-gcc also includes a perfectly good assembler. It has a slightly different syntax to AVRA and Atmel's assembler, but it works just as well." CreationDate="2010-04-12T07:47:21.390" UserId="504" />
  <row Id="1626" PostId="2190" Score="4" Text="Providing the example circuit, even it lacks values, might help." CreationDate="2010-04-12T13:29:59.010" UserId="206" />
  <row Id="1627" PostId="2193" Text="It is also good design to have a gate resistor to limit the current to the gate." CreationDate="2010-04-12T13:51:56.247" />
  <row Id="1628" PostId="2179" Text="I've marked your response as correct tronixstuff. Thanks for reponding :) I might see what else I can fond in inductive tech with a few more google searches." CreationDate="2010-04-12T13:59:53.960" />
  <row Id="1629" PostId="2194" Text="Can you show an example circuit?" CreationDate="2010-04-12T15:09:26.707" UserId="142" />
  <row Id="1630" PostId="2192" Text="Would gutting a Wii nun chuck and using that be too expensive? The major issue may be that it isn't sensitive enough. " CreationDate="2010-04-12T15:49:12.580" UserId="638" />
  <row Id="1632" PostId="76" Score="1" Text="Did you mean &quot;relay diode&quot;" CreationDate="2010-04-12T16:15:28.667" UserId="206" />
  <row Id="1633" PostId="2193" Text="Not usually. Limiting the current to the gate slows the charging of the input capacitance (Ciss). This increases the switching losses since the FET now takes longer to switch. The higher the voltage you have to switch the worse the losses are. Also the higher your switching frequency is the worse your losses are since you are switching more per unit time." CreationDate="2010-04-12T16:35:52.440" UserId="424" />
  <row Id="1635" PostId="2193" Text="The application doesn't seem to have high speed needs, only an on/off feature to save battery.  I would recommend the series resistor, especially if it is driven directly by the processor.  Additionally, once you etch the board it is much easier to put a low value resistor if there are speed issues than trying to add one if the current spike is causing other problems (disturbances to analog circuitry, unexpected resets, etc.)." CreationDate="2010-04-12T18:10:03.040" UserId="688" />
  <row Id="1637" PostId="2207" Score="1" Text="For capacitors and inductors, it's impedance not resistance that change with frequency." CreationDate="2010-04-12T20:22:19.737" UserId="305" />
  <row Id="1638" PostId="2207" Text="Correct. I used resistance in the first paragraph and impedance in the second. Thanks. " CreationDate="2010-04-12T20:42:21.310" UserId="424" />
  <row Id="1639" PostId="2202" Text="Mea Culpa. I was thinking about the problem incorrectly. I have deleted the original comment where I incorrectly stated a problem about capacitive coupling. Thank you for pointing this out." CreationDate="2010-04-12T20:52:08.550" UserId="638" />
  <row Id="1641" PostId="2179" Text="Cheers mate, looking forward to hearing how you go!" CreationDate="2010-04-12T23:42:46.133" UserId="1307" />
  <row Id="1642" PostId="2162" Text="How is the Kindle for any type of .pdf? Can you zoom in and out of a page? Thinking it would be very useful for all those .pdf books floating around the internet. Thanks. " CreationDate="2010-04-12T23:44:25.873" UserId="1307" />
  <row Id="1643" PostId="2162" Text="Let me start off by saying that the way I want to view pages is portrait mode. The &quot;zoom&quot; functionality is achieved by switching the screen to landscape, and letting the PDF reader fit the width of the document. It works, but that's not the way you want to read your PDF since the scrolling isn't very fluid. PDF books are usually OK, but if they have large margins, or dense text, you may need to make some adjustments. The ideal PDF for the Kindle has no margins. Hence the part about using a PDF printer to print the original PDF into a &quot;cropped&quot; format." CreationDate="2010-04-13T00:09:13.867" UserId="638" />
  <row Id="1644" PostId="2187" Text="I should have been more clear. The reason for wanting a device designed to drive a 7-seg is due to maintenance. I am going to be putting this project together for a professor and they whatever student he can get his hands on is going to have to maintain and add features. I have a feeling they may not do maintenance well or properly and having a simpler chip would be better in my eyes." CreationDate="2010-04-13T01:50:32.880" UserId="230" />
  <row Id="1645" PostId="2187" Text="Well, any digital output and a resistor can drive a LED. I'm assuming you have a microcontroller driving your display. You didn't give any ballpark figure on number of digits. The &quot;hard&quot; part is making a uC function to change a number into a byte signalling on/off LED's. The chips are very simple and easy to understand. Expansion is easy, and there's no multiplexing to worry about. The chips are fairly cheap too.&#xA;" CreationDate="2010-04-13T04:55:57.777" UserId="638" />
  <row Id="1646" PostId="2206" Score="1" Text="They're both lowpass filters, but LC is second-order." CreationDate="2010-04-13T05:03:53.487" UserId="142" />
  <row Id="1647" PostId="2214" Text="Thanks: great to know I'm not barking up the wrong tree! The voltage seemed a bit high (closer to 5v than 3v), but it's difficult for me to say exactly what the voltages are in this circuit due to my crazy idea of using PWM to step the voltage down. When briefly subjected to a similar voltage outside of this circuit, however, the motor didn't sputter.  Maybe the load is causing the AVR to reset, or the PWM signal needs to be explicitly filtered..  Anyway, thanks again." CreationDate="2010-04-13T05:25:20.897" UserId="504" />
  <row Id="1648" PostId="2216" Text="Thanks Dave. That's good advice. It's nice to know I'm not totally out in the woods." CreationDate="2010-04-13T05:46:34.573" UserId="647" />
  <row Id="1649" PostId="2166" Text="The UsbKey has a special cable that is marked with usb otg, so I think it can... (but I never tried it)" CreationDate="2010-04-13T11:30:44.453" UserId="689" />
  <row Id="1650" PostId="2214" Text="I've just tried it with the PWM replaced by a solid HIGH and the sputter persists. It must be due to the drooping of the 9V under the load, as you suggested." CreationDate="2010-04-13T13:41:17.203" UserId="504" />
  <row Id="1651" PostId="2196" Text="Thanks, I will try this. If it does not work, I will try purpose-built piezoelectric (Tim's post)." CreationDate="2010-04-13T13:56:48.267" UserId="323" />
  <row Id="1652" PostId="2219" Score="1" Text="Great example of when it is NOT ok to use a breadboard!" CreationDate="2010-04-13T14:10:54.333" UserId="588" />
  <row Id="1653" PostId="2218" Text="interesting - cheers dude, it looks like good value" CreationDate="2010-04-13T17:39:42.640" UserId="399" />
  <row Id="1654" PostId="2214" Text="How is it a crazy idea to step down with PWM?  That's what any switching amplifier or regulator does.  You can easily figure out if it's droop of the 9 V by just measuring the input terminals of the regulator with a multimeter, with and without the motor running.  If it's the switching of the output that's causing the problem, then filter it out or increase the PWM frequency." CreationDate="2010-04-13T19:29:11.953" UserId="142" />
  <row Id="1655" PostId="2214" Text="What's the voltage across the motor itself?  Is the transistor not able to source enough current even when fully closed?" CreationDate="2010-04-13T19:35:04.787" UserId="142" />
  <row Id="1656" PostId="2222" Text="Wire wrap wire is perfect for this kind of thing. It is sometimes marketed as 'Kynar' wire. I can recommend it." CreationDate="2010-04-13T21:49:42.040" UserId="307" />
  <row Id="1657" PostId="2226" Score="4" Text="A little more detail on what you're looking for as far as cost/size. Eg, for some people $200 is cheap, for others $200 is expensive. And do you need it to fit into a 2 inch space or if it's 2 feet is that ok? Just some rough requirements will help." CreationDate="2010-04-14T00:03:19.377" UserId="131" />
  <row Id="1660" PostId="2226" Text="Some further questions: Would the presence of Ethernet and/or WiFi eliminate the need for a modem? Are you comfortable hooking up level shifters to turn a simple UART into a RS232 compliant port? How many modules are you needing to make (would a more expensive, easier to use system make sense over a bare-bones kit? What really is your cost constraint (this is very important!)? " CreationDate="2010-04-14T02:41:33.663" UserId="638" />
  <row Id="1663" PostId="2214" Text="It works!  Actually, and this is rather embarrassing, the solution had nothing to do with the schematic above: the breadboard had a faulty track that was periodically breaking the circuit due to vibrations from the motor. :-/ (Should I remove this question do you think?)" CreationDate="2010-04-14T08:24:23.587" UserId="504" />
  <row Id="1665" PostId="2225" Text="The first cabling is outstanding :-) " CreationDate="2010-04-14T17:39:07.970" UserId="244" />
  <row Id="1666" PostId="2216" Text="Your sentence about solder bridges made me laugh :-)&#xA;Yes. IT IS FUN to make solder bridges... after some practice, you learn the correct timing, the correct temperature, the magic of a little blow on a bridge segment... it's an art :-)&#xA;Some of my first prototypes also had DRAWINGS made with solder tracks. &#xA;BTW: I can easily etch my own double sided PCB, but I like to build prototypes in this way also if I've already designed the PCB. " CreationDate="2010-04-14T18:07:28.923" UserId="244" />
  <row Id="1669" PostId="2237" Text="I actually have and haven't got any response. I'm hoping someone here can help me out, though. http://forum.sparkfun.com/viewtopic.php?f=13&amp;t=19693" CreationDate="2010-04-14T19:37:52.887" UserId="693" />
  <row Id="1671" PostId="2237" Text="There have been several posts there in the past. Try searching for them." CreationDate="2010-04-14T22:01:25.177" UserId="305" />
  <row Id="1673" PostId="2241" Text="I was testing on my laptop (Dell Inspiron 1501) with the device plugged in to the USB port on the side of the laptop, but that's not a bad thought! I'll try on my desktop, both in the motherboard USB and a powered hub." CreationDate="2010-04-15T00:30:21.647" UserId="693" />
  <row Id="1676" PostId="2239" Text="I think i can explain this, but it will take me writing a little, i will try to fill out an answer tomorrow." CreationDate="2010-04-15T05:44:39.567" UserId="230" />
  <row Id="1677" PostId="77" Score="1" Text="Which microcontroller?" CreationDate="2010-04-15T14:35:03.497" UserId="206" />
  <row Id="1680" PostId="725" Text="What's your platform? FPGA or microcontroller?" CreationDate="2010-04-15T16:05:07.653" UserId="672" />
  <row Id="1681" PostId="2241" Text="You were right! I guess the port I was using wasn't giving it enough power - I hooked it up to a USB hub, and it started working right away - thanks!" CreationDate="2010-04-15T22:29:19.360" UserId="693" />
  <row Id="1682" PostId="2247" Text="Your very first link (ZB1 Boards) has an extra slash at the end, breaking the URL." CreationDate="2010-04-15T22:38:14.880" UserId="693" />
  <row Id="1683" PostId="2247" Text="I just fixed it. Thank you. " CreationDate="2010-04-15T22:58:50.243" UserId="424" />
  <row Id="1684" PostId="2244" Text="I believe the ZeroG is the radio only - you still have to run the TCP/IP stack on your own processor." CreationDate="2010-04-16T01:30:17.757" UserId="696" />
  <row Id="1685" PostId="2252" Text="thanks a lot, i really apreciate your answer, i think once we have running one board, this is the best and cheaper solution!" CreationDate="2010-04-16T05:31:53.907" UserId="699" />
  <row Id="1686" PostId="2248" Score="1" Text="thanks for the information, probably i will go with this solution.&#xA;anyway i have 2 questions about:&#xA;- what exactly is XBee? (it´s just commercial name?)&#xA;- http://www.digi.com/pdf/ds_idigi_pro_kit_zb.pdf what do you think about this one? maybe using this IP/Zigbee gateway make me the dev easier.&#xA;&#xA;thanks " CreationDate="2010-04-16T05:33:30.550" UserId="699" />
  <row Id="1687" PostId="2253" Text="I have one of these. It's great for getting low level access to the 802.15.4 radio, but it doesn't make anything easy. Also, you need an AVR JTAG ICE system to program it ( unless you hack it - http://ossmann.blogspot.com/2010/01/killerbee-on-budget.html )" CreationDate="2010-04-16T08:07:52.217" UserId="566" />
  <row Id="1688" PostId="2253" Text="A $50 AVR Dragon could be used for debugging and programming." CreationDate="2010-04-16T11:26:21.333" UserId="305" />
  <row Id="1689" PostId="2248" Score="2" Text="XBee is the tradename that MaxStream uses for their ZigBee modules." CreationDate="2010-04-16T11:34:37.597" UserId="424" />
  <row Id="1690" PostId="2248" Text="@donperignon I've not had any experience with it, but the ConnectPort X4 gateway they include looks pretty cool! My guess would be it makes the monitoring of the XBee network easier, rather than having to have a receiver connected to your server." CreationDate="2010-04-16T13:21:21.003" UserId="693" />
  <row Id="1691" PostId="2244" Text="That is correct, but Microchip supplies the TCP/IP stack." CreationDate="2010-04-16T14:30:52.303" UserId="588" />
  <row Id="1692" PostId="2244" Text="Ok, so this is a good solution only if you are using PICs then. If you are using some other mcu, probably not a good solution?" CreationDate="2010-04-16T18:20:08.050" UserId="131" />
  <row Id="1693" PostId="2249" Text="Yeah the RN-131 is the same as the WiFly GSX. The Redpine modules also look interesting." CreationDate="2010-04-16T18:21:21.807" UserId="131" />
  <row Id="1695" PostId="2244" Text="Yes you are right. I think the license for their stack stays you must run it on a Microchip microprocessor. The question was tagged PIC so I thought that might be an option." CreationDate="2010-04-16T20:44:08.387" UserId="588" />
  <row Id="1696" PostId="2258" Text="I just swapped the amp out a few times and rebuilt the circuit and now the output is pinned at 4.4V. Not sure what's going on, going to keep trying!" CreationDate="2010-04-17T01:41:41.487" UserId="207" />
  <row Id="1697" PostId="2260" Text="Thanks Mark. Are you suggesting that I keep using the INA126, or substitute it for a general purpose op-amp?" CreationDate="2010-04-17T01:54:51.727" UserId="207" />
  <row Id="1698" PostId="2259" Score="1" Text="Does &quot;single-supply mode&quot; mean that it can be operated with a single power supply? What about this line on page 8: &quot;The INA126/2126 can be operated from a single power supply with careful attention to input common-mode range, output voltage swing of both op amps and the voltage applied to the Ref terminal.&quot;?" CreationDate="2010-04-17T02:06:33.040" UserId="207" />
  <row Id="1699" PostId="2260" Text="I don't see any reason not to use that IC.  You may also look into a wheatstone bridge as opposed to what i posted, it may work better in your application." CreationDate="2010-04-17T02:09:48.243" UserId="703" />
  <row Id="1700" PostId="2259" Text="Replacing V+ and V- with 5V from a separate power supply changed things up a bit. Now my output range is 0.26-0.92! Changing the gain resistor has no effect on the output range." CreationDate="2010-04-17T02:11:06.300" UserId="207" />
  <row Id="1701" PostId="2259" Text="&quot;Single Supply Mode&quot; means one supply voltage. For most applications V+ would be connected to a positive voltage and V- to GND. After I wrote the answer I saw that note (and the circuit on page 9). I didn't go through the spec in detail but applying a reference voltage to Vref could work. You may want to see if there is an app notes that gives the equations otherwise you could derive the equations yourself. All of the component values are shown in the internal schematic. " CreationDate="2010-04-17T02:18:42.090" UserId="424" />
  <row Id="1702" PostId="2259" Text="you were correct on being careful with the common mode range, you'll notice in the application note on the single supply setup that they biased the input terminals to 2.5V and a low differential range presumably keeping it under the 2.65V saturation point.  If you use a wheatstone bridge you do need to apply a voltage to Vref as the difference could now be negative depending on what you choose the balance point to be in the bridge." CreationDate="2010-04-17T02:31:30.333" UserId="703" />
  <row Id="1703" PostId="2259" Text="This is becoming more complicated than I was expecting. What do you think would be the simplest solution?" CreationDate="2010-04-17T02:42:55.007" UserId="207" />
  <row Id="1704" PostId="2259" Text="I have some OP27's that I can use instead...do you think I could get away with a simple differential amplifier setup?" CreationDate="2010-04-17T02:49:03.293" UserId="207" />
  <row Id="1705" PostId="2259" Text="The AD623 ;) See http://tinyurl.com/y3sj6kz" CreationDate="2010-04-17T02:50:20.270" UserId="424" />
  <row Id="1706" PostId="2259" Text="Maybe. It depends on the accuracy you require, how much noise, etc. You will be much better off with an instrument amplifier. An IA was designed to do the exact function you require." CreationDate="2010-04-17T02:54:11.653" UserId="424" />
  <row Id="1707" PostId="2259" Text="If only Digikey shipped on Saturdays!" CreationDate="2010-04-17T02:59:46.737" UserId="207" />
  <row Id="1708" PostId="2259" Text="I can't seem to get the INA126 to work even with the DC power supply, so I'm trying an OP27 in a differential configuration. " CreationDate="2010-04-17T04:30:35.820" UserId="207" />
  <row Id="1709" PostId="2260" Text="I'll second the wheatstone bridge. It will give you a nice, easy to use differential voltage to measure, which should make the amplifier circuit easy to design." CreationDate="2010-04-17T09:26:14.857" UserId="638" />
  <row Id="1710" PostId="2259" Text="Did you try biasing the reference pin to 2.1V? " CreationDate="2010-04-17T12:07:55.177" UserId="424" />
  <row Id="1711" PostId="2266" Score="1" Text="You need to be more specific. Which make/model of barcode scanner? Are you using a development board for the AT90USB1287, or your own?" CreationDate="2010-04-17T12:22:48.560" UserId="566" />
  <row Id="1712" PostId="2260" Text="Ok, thanks for the suggestion. I'll give it a try. Are precision resistors a must?" CreationDate="2010-04-17T16:02:19.310" UserId="207" />
  <row Id="1713" PostId="2260" Text="Ideally you would want matched resistors but as your going to have to empirically match an amount of fabric folding to a voltage value and create that relationship in the uC and being at the balance point often is unlikely i don't think it would be critical.  I always use 1% resistors anyway except on very slow values where they are expensive." CreationDate="2010-04-17T20:30:37.537" UserId="703" />
  <row Id="1714" PostId="2259" Text="Yes, I did. I tried just about every configuration that I could think of and the result was always a smaller range. " CreationDate="2010-04-17T22:35:02.263" UserId="207" />
  <row Id="1715" PostId="929" Text="stereo input into your speaker? Now that's making due with the bare essentials! lol" CreationDate="2010-04-18T07:29:18.020" UserId="708" />
  <row Id="1716" PostId="1730" Score="1" Text="s/EMACS/vi/  :)" CreationDate="2010-04-18T07:41:43.423" UserId="708" />
  <row Id="1718" PostId="2278" Score="1" Text="Here is an interesting rule-of-thumb that I found from a document that TI wrote (its in the order of: TYPE  then MAX FREQUENCY) Aluminum Electrolytic, 100 kHz;&#xA; Tantalum Electrolytic, 1 MHz;&#xA; Mica, 500 MHz;&#xA; Ceramic, 1 GHz" CreationDate="2010-04-18T13:45:08.343" UserId="319" />
  <row Id="1719" PostId="2258" Text="Sounds like you are saturating your amp. If you only have 5v on the V+ pin then (according to the datasheet) your output voltage can only be (V+)–0.75, meaning 5-.75=4.25V with a 25kohm load. Since you are seeing your output pinned at 4.4V (above the 4.25 mentioned above) you have most likely saturated the opamps." CreationDate="2010-04-18T13:56:19.277" UserId="319" />
  <row Id="1720" PostId="2259" Text="One more comment to this very long chain. Have you tried giving it a positive and negative voltage? This is much easier to do then to bias the amps. So V+ would be 5V and V- would be -5V with pin 5 (ref) being 0V in relation to your V+ and V-." CreationDate="2010-04-18T14:01:18.433" UserId="319" />
  <row Id="1721" PostId="618" Score="1" Text="I second the suggestion.&#xA;&#xA;You should get going by reading only the first (analog) part of the book. The digital part is a little out of date and IMHO was not so great in the first place." CreationDate="2010-04-18T15:07:11.373" UserId="659" />
  <row Id="1722" PostId="2259" Text="he needs to bias the output anyway.  The ADC he's using will only accept 0-5Vish." CreationDate="2010-04-18T23:02:17.877" UserId="703" />
  <row Id="1723" PostId="2274" Text="Thanks for this answer. It conveyed a lot of useful information at a basic enough level that I could understand it." CreationDate="2010-04-19T01:07:25.740" UserId="647" />
  <row Id="1724" PostId="2277" Text="If pin C0 floats HIGH and C1 is connected to AREF which is also HIGH, then there shouldn't be any change.  Did you try connecting C1 to ground to get zero when you run select_wire(1)?" CreationDate="2010-04-19T03:31:10.220" />
  <row Id="1725" PostId="2286" Text="By ground you mean a pull-down resistor so the input will default to being grounded and flip to 5V when the switch is pressed?" CreationDate="2010-04-19T06:38:06.643" UserId="647" />
  <row Id="1726" PostId="2286" Score="2" Text="Yes, that is what he means. Often people use a ground plane but not a power plane in hobbyist projects. this leads to ground being a much lower impedance path. My issue with this is simple, i would rather have the switch connect to a very low impedance path and the resistor to the higher impedance path as this will lead to smother transitions when buttons are pressed and less transients imposed on nearby devices using power." CreationDate="2010-04-19T09:45:51.223" UserId="230" />
  <row Id="1727" PostId="2286" Score="4" Text="To expand on this, decoupling capacitors should be on your board, a nearby decoupling capacitor will act as a power source for the surrounding area to higher frequency transients, the allowing the switch to see the same impedance regardless of the net it is connected to." CreationDate="2010-04-19T09:46:38.710" UserId="230" />
  <row Id="1728" PostId="2284" Score="1" Text="I normally favor a pull up as older devices and some very very low power devices will have a state they favor for power saving. This is often the high state." CreationDate="2010-04-19T09:47:17.010" UserId="230" />
  <row Id="1730" PostId="2150" Text="I would not use a mechanical switch, but I do suggest the SPDT RF switch, I have used them before, they are easy to have running in very little time. Like all things, match your impedance." CreationDate="2010-04-19T09:50:38.203" UserId="230" />
  <row Id="1731" PostId="2286" Text="@Kortuk thanks for the clarification." CreationDate="2010-04-19T11:07:20.687" UserId="689" />
  <row Id="1732" PostId="2280" Text="+1 Looks nice :)" CreationDate="2010-04-19T11:08:10.560" UserId="689" />
  <row Id="1733" PostId="2272" Score="2" Text="Tey are referred to as decoupling caps (not smoothing caps) in the industry." CreationDate="2010-04-19T13:53:22.863" UserId="206" />
  <row Id="1734" PostId="2278" Score="1" Text="+1 For &quot;bypass cap&quot; and noise... " CreationDate="2010-04-19T14:50:14.700" UserId="689" />
  <row Id="1735" PostId="2291" Text="Yes, it does support CDC." CreationDate="2010-04-19T18:04:15.997" UserId="305" />
  <row Id="1736" PostId="2277" Text="@rzr oh wait... yea, you may be right. I got confused and thought AREF was ground(and thus, 0)... yea I'll look into this tonight.. Also, you should've just made your comment an answer :)" CreationDate="2010-04-19T18:55:40.567" UserId="708" />
  <row Id="1737" PostId="2239" Text="&gt;100 views and no answers?  :/" CreationDate="2010-04-19T21:31:05.503" UserId="142" />
  <row Id="1738" PostId="2287" Text="The major thing is impedance matching, just because the wire is longer does not mean that it will not match. You are correct that most antenna's are very selective in frequency, but many are not. " CreationDate="2010-04-19T22:07:59.433" UserId="230" />
  <row Id="1739" PostId="2277" Text="Didn't seem good enough for an actual answer :)" CreationDate="2010-04-20T02:39:27.140" />
  <row Id="1740" PostId="2272" Text="@Brian Thanks for the clarification. I modified the title to make it easier for future users to find (but left the reference in the body to make it searchable via smoothing capacitor)." CreationDate="2010-04-20T05:20:54.100" UserId="647" />
  <row Id="1741" PostId="2281" Score="4" Text="Most voltage spikes are visible even on a 100MHz oscilloscope since their frequency is related to your clock. An ATmega running at 8MHz will show a spike every 1/8MHz = 125ns." CreationDate="2010-04-20T09:09:48.723" UserId="659" />
  <row Id="1742" PostId="2297" Text="Yep, I'd recommend a regulator..." CreationDate="2010-04-21T00:30:39.347" UserId="708" />
  <row Id="1743" PostId="2192" Score="2" Text="You can get accelerometers for less than 10 dollars that are quite nice." CreationDate="2010-04-21T10:58:36.917" UserId="230" />
  <row Id="1744" PostId="2278" Text="You match my definition of bypass and decoupling cap. Glad to hear one more soul has read just too much." CreationDate="2010-04-21T13:09:04.343" UserId="230" />
  <row Id="1745" PostId="2306" Text="Ah, series inductor-- a good thought." CreationDate="2010-04-21T14:12:35.833" UserId="712" />
  <row Id="1746" PostId="2306" Text="Cool, thanks for the help - I've got the ICL7660SPCA (I assume this is an S version), i've used electrolytic caps and the synths current draw is around 20mA or less" CreationDate="2010-04-21T15:03:04.833" UserId="399" />
  <row Id="1747" PostId="2305" Text="Cheers, that's loads of help. I had a sneaking suspicion that another capacitor was in order - just didn't know where to stick it.  " CreationDate="2010-04-21T15:07:26.343" UserId="399" />
  <row Id="1748" PostId="2305" Text="Excellent. Glad to be of service." CreationDate="2010-04-21T15:17:05.820" UserId="712" />
  <row Id="1749" PostId="2306" Score="1" Text="You really what those to be ceramic. The ESR in the capacitors could be part of your problem. In my LCD interface I use the TDK FK26X5R1A106M 10uF X7R capacitor (TH on 200mil spacing) for a voltage doubler. Not too expensive. " CreationDate="2010-04-21T15:47:22.897" UserId="424" />
  <row Id="1750" PostId="2306" Text="thanks again - I'll be looking into getting some better caps then" CreationDate="2010-04-21T17:18:07.020" UserId="399" />
  <row Id="1751" PostId="2023" Score="1" Text="To expand on endolith's comment, capacitors block DC and pass AC.  So if you put a capacitor in series with the output, it will block the DC bias.  In combination with a resistor to ground (on the non-biased side of the capacitor!), it will set the corner frequency of the filter, adjusting how much AC will pass.  A higher resistance will lower the corner frequency, allowing more AC to pass.  The formula for corner frequency is 1/2piRC." CreationDate="2010-04-21T19:12:13.543" UserId="1278" />
  <row Id="1752" PostId="2306" Text="You're welcome." CreationDate="2010-04-21T20:29:49.947" UserId="424" />
  <row Id="1753" PostId="2192" Score="1" Text="@Kortuk&#xA;You might want to say where?" CreationDate="2010-04-21T21:13:40.390" UserId="323" />
  <row Id="1755" PostId="2313" Score="1" Text="Yes - to be specific the cross section of the hole is trapezoidal (ie the hole is larger at the bottom face). This allows the paste to release from the stencil more easily." CreationDate="2010-04-22T03:56:30.510" UserId="554" />
  <row Id="1756" PostId="2318" Text="Are you sure you even need it?" CreationDate="2010-04-22T03:57:39.510" UserId="142" />
  <row Id="1758" PostId="2328" Score="1" Text="I've come across a few professionally.  I suspect that the hobbyist market as a whole is a drop in their bucket." CreationDate="2010-04-22T11:34:06.693" UserId="484" />
  <row Id="1759" PostId="2328" Score="1" Text="I agree with that. I do not believe that a microcontroller (or probably most semiconductor companies) would survive long if their primary market has hobbyist. There wouldn't be enough volume. The hobbyist market may be a drop in the Atmel bucket but it does seem like a small bucket ;) Maybe there should be a follow-up question -- What companies and types of OEM applications use Atmel microcontrollers?" CreationDate="2010-04-22T11:46:22.000" UserId="424" />
  <row Id="1760" PostId="2328" Text="I use AVR32 in professional products.  It knocks spots off the ARM cortex-M3 devices (in my application).  I have looked at AVR8 but they never quite made it.  MSP430 beat them soundly." CreationDate="2010-04-22T12:20:05.280" UserId="400" />
  <row Id="1761" PostId="2324" Text="Moderators: This should be a Community Wiki question." CreationDate="2010-04-22T12:29:23.707" UserId="330" />
  <row Id="1762" PostId="2319" Text="Gack! Don't use the shielding as the ground wire." CreationDate="2010-04-22T12:33:47.513" UserId="330" />
  <row Id="1763" PostId="2282" Text="+1 for mentioning the 10nF caps. 0.1uF is good for default, but the 10nF or even 1nF caps will have lower impedances at high frequencies because they have lower parasitic inductances." CreationDate="2010-04-22T12:39:30.490" UserId="330" />
  <row Id="1764" PostId="2328" Score="2" Text="@Ian What types of products?" CreationDate="2010-04-22T14:08:13.060" UserId="424" />
  <row Id="1765" PostId="2319" Text="I'm not saying it's a *good* idea, but for a sensor where the current will be a few mA, isn't the impedance of most shielding low enough?" CreationDate="2010-04-22T14:12:52.630" UserId="712" />
  <row Id="1766" PostId="2324" Text="And are they as popular in industry as they are in the hobbyist world?" CreationDate="2010-04-22T14:12:59.887" UserId="142" />
  <row Id="1767" PostId="2312" Text="Actually, we're hand-placing the components, but then running them through a proper SMT reflow oven.  We've noticed that some components with a fine pitch are prone to bridging, so I'm curious as to whether the reduced pad size would also reduce bridging." CreationDate="2010-04-22T15:09:23.433" UserId="1278" />
  <row Id="1768" PostId="2325" Text="Before I got into microcontrollers and electronics, I had heard of &quot;PIC&quot; and I had not heard of &quot;AVR&quot; (though I had heard of Arduino). " CreationDate="2010-04-22T15:15:44.063" UserId="207" />
  <row Id="1769" PostId="2332" Text="Do you need 802.11a/b/g/n?" CreationDate="2010-04-22T15:54:01.687" UserId="712" />
  <row Id="1770" PostId="2333" Score="1" Text="MAX232-- definitely an excellent addition." CreationDate="2010-04-22T17:02:59.503" UserId="712" />
  <row Id="1771" PostId="2325" Text="'PIC' seems to have become a generic term for an MCU in some ways, like 'Hoover' for a vacuum cleaner." CreationDate="2010-04-22T18:53:21.437" UserId="305" />
  <row Id="1772" PostId="2335" Text="Florescents aren't 60 Hz (well, maybe some are).  Ballasts are used to ramp that 60 Hz up to 20 kHz or so." CreationDate="2010-04-22T19:13:01.547" UserId="1278" />
  <row Id="1773" PostId="2339" Text="Specifically, I know lead-acid batteries require a constant current source (or current-limited source, depending on your perspective) to charge them up to a certain voltage, after which they use a constant voltage charge.  http://www.batteryuniversity.com/partone-13.htm" CreationDate="2010-04-22T19:28:20.763" UserId="142" />
  <row Id="1774" PostId="2332" Text="Do you plan to implement the TCP/IP stack on your own uC or do you want the module/chipset to provide that too?" CreationDate="2010-04-22T19:29:54.383" UserId="696" />
  <row Id="1775" PostId="2326" Score="2" Text="+1 gcc FTW!  We've been trying to use a couple of Microchip C compilers, and their interpretation of the C-spec has caused invective to emanate from a coworkers cube.  He wishes he had gcc." CreationDate="2010-04-22T20:53:01.213" UserId="374" />
  <row Id="1776" PostId="2288" Text="I had my own non-stackable headers already on hand, so that's what I was using.&#xA;&#xA;I'm just going to solder onto the nubs of the header pins where they stick through the shield.  Not going for Underwriters Lab certification or anything like that so I think it will do.  Thanks!" CreationDate="2010-04-22T21:04:08.857" UserId="707" />
  <row Id="1777" PostId="2340" Text="If solar cell voltage remains constant how can the current change? You must be thinking about some kind of smart switching-mode load since this would not be possible with normal resistive loads." CreationDate="2010-04-22T21:36:28.460" UserId="659" />
  <row Id="1778" PostId="2315" Text="switcher circuit design can be difficult, if your not careful with controlling the switching current loops you can induce noise throughout your design not to mention generate large about of EMI.  Also keep in mind that the output of the switcher will have a much higher ripple voltage than the output of LDOs.  If you have anything noise sensitive you will need to plan for at least an LC filter on the output." CreationDate="2010-04-23T00:50:55.623" UserId="703" />
  <row Id="1779" PostId="2348" Text="They aren't common for fairly good reasons.  Is there a particular reason you need such a supply?" CreationDate="2010-04-23T01:27:08.803" UserId="703" />
  <row Id="1782" PostId="2349" Text="But how thick does the metal need to be? and Would the roof tape be adequate? I was just gonna use screws to ground the foil, and to make connecting across corners. I'm just surprised this kind of this isn't on the net already (while the mineral-oil fish-tank PC is), So I was afraid there was a good reason that I'd missed; come to think of it, what RF protection does the fish-tank PC get?" CreationDate="2010-04-23T01:45:51.033" />
  <row Id="1783" PostId="2349" Text="In regard to earthing, I meant if there was an exposed contact or something; If you push a screwdriver in there it would probably short with the earthed case first. " CreationDate="2010-04-23T01:46:08.020" />
  <row Id="1784" PostId="2348" Text="I am looking for a substitute for a Theremin power supply. This particular design works a lot better with an earth grounded supply. The design could be changed but I was hoping to use the original circuit." CreationDate="2010-04-23T03:32:20.863" UserId="424" />
  <row Id="1785" PostId="2342" Score="2" Text="Analog IC design uses a LOT of current references. Both bipolar transistors as well as CMOS transistors are very current dependent. Current references, as well as current mirrors are extremely common because so many things are current dependent. With bias current through an amplifier or other circuit you can control power consumption, bandwidth, slew rate, and much more. This is not the case in digital circuits, as the fine control over a transistor that a current reference offers is not necessary. " CreationDate="2010-04-23T04:25:46.407" UserId="638" />
  <row Id="1786" PostId="2318" Text="What kind of sensor are you using? What kind of protocol (if it's a complex sensor) does it use? Where are you seeing the noise - in the digital output or the analog front-end of the sensor?" CreationDate="2010-04-23T04:31:52.883" UserId="638" />
  <row Id="1787" PostId="2318" Text="We are having trouble with sites using a particular fluro ballast, other sites are fine. The sites are remote so diagnosis is hard. The sensors (hall effect) are in a light box with the fluros." CreationDate="2010-04-23T05:27:51.063" UserId="554" />
  <row Id="1788" PostId="1862" Text="You could mix in some graphite... :)" CreationDate="2010-04-23T05:33:38.437" UserId="554" />
  <row Id="1789" PostId="2330" Text="Can a ground loop be a problem if the other circuit (sensor) is isolated from the ground?" CreationDate="2010-04-23T06:28:33.930" UserId="659" />
  <row Id="1790" PostId="2349" Text="I updated my answer, but as you'll see I don't really know the answers to your additional points.  And I know nothing about the fish-tank :)" CreationDate="2010-04-23T06:33:00.123" UserId="696" />
  <row Id="1791" PostId="2327" Text="Too bad it seem to costs a little more than an ATmega48 which could be used for the same purpose (the downside being the need to write a second program)." CreationDate="2010-04-23T06:46:11.193" UserId="659" />
  <row Id="1792" PostId="2315" Text="The cheapest switchers I know of are the old (but still in production) MC34063. Just be sure to use use very fast diodes (preferably Schottky)." CreationDate="2010-04-23T06:50:46.417" UserId="659" />
  <row Id="1793" PostId="2330" Text="Ott is definitely the reference to have for this." CreationDate="2010-04-23T08:32:18.223" UserId="328" />
  <row Id="1794" PostId="2330" Score="1" Text="@jpc: yes. The shield is not intended to carry current, so that it is of uniform potential. So you need to use another conductor to carry the return current at ground. But if you tie the shield to the ground conductor at both ends, then you have a loop." CreationDate="2010-04-23T11:36:27.373" UserId="330" />
  <row Id="1795" PostId="2319" Score="1" Text="it's less that, than the idea that the shielding is not supposed to supply current to/from a circuit. Otherwise it can act as an antenna and radiate noise. You hide the circuit currents from the external world inside the shield." CreationDate="2010-04-23T11:39:03.690" UserId="330" />
  <row Id="1796" PostId="2304" Text="so i've got 10uƒ tantalum capacitors now - instead of the 2 electrolytic caps and i've also tried one from the positive rail to the ground, but i've got no change in the audio problems? " CreationDate="2010-04-23T13:21:37.967" UserId="399" />
  <row Id="1797" PostId="2306" Text="couldn't get any joy with the caps - you mentioned using an induction coil, I'm not familiar with them, any suggestions about where to start with using a coil " CreationDate="2010-04-23T13:23:55.643" UserId="399" />
  <row Id="1798" PostId="2355" Text="Could you please clarify:&#xA;1. Are the keys broken and you want to fix them.&#xA;2. Do you want to use them in some other project.&#xA;3. Do you have a working keyboard?&#xA;" CreationDate="2010-04-23T19:08:37.383" UserId="659" />
  <row Id="1799" PostId="2304" Text="Ahh!! got it, it wasn't a problem with the capacitor - I've just got a shoddy old breadboard! It's working now" CreationDate="2010-04-23T21:19:45.520" UserId="399" />
  <row Id="1800" PostId="2332" Text="@pingswept - g and n would be nice, but b is fine.  @mtrw - I can go either way." CreationDate="2010-04-23T23:41:56.133" UserId="161" />
  <row Id="1801" PostId="2341" Text="Sadly, not wifi.  They are nice chips though." CreationDate="2010-04-23T23:46:36.767" UserId="161" />
  <row Id="1803" PostId="2355" Text="The keys all still work, to the best of my knowledge.  The full keyboard is a subassembly of a fried Silent 700, and is connected by a pin header with about forty contacts.  I'm trying to convert this to a USB keyboard.&#xA;&#xA;We used to have a working Silent 700 as well, but it was donated to another hackerspace some time ago." CreationDate="2010-04-24T02:35:53.840" UserId="70" />
  <row Id="1804" PostId="2360" Text="The home automation and alarm industry is an area I had never thought of looking at for this type of supply. Thanks for the answer. " CreationDate="2010-04-24T02:58:48.630" UserId="424" />
  <row Id="1805" PostId="2360" Text="@ jluciani I haven't been involved in that industry in 6 or 7 years but commercial fire alarms used to run at 24V and code required earth grounded enclosures so you'll probably want to focus the hunt for an ideal unit in that particular area." CreationDate="2010-04-24T03:58:00.803" UserId="703" />
  <row Id="1806" PostId="954" Score="1" Text="ok I must break it to his fan base but my 6 year old neighbor girl could act much better than him. He seems so he is amazed by...I dont know...he is alive or whatever. But I could never take that guy seriously. Granted his material may be good (I would never know as he is unbearable) but hell he IS UNBEARABLE." CreationDate="2010-04-24T05:30:09.450" UserId="1200" />
  <row Id="1807" PostId="2364" Score="2" Text="I am not anti-reddit but that is not exactly what I want. Just look at the first page, if I wanted Q&amp;A I would just tune in to chiphacker. I want a site which gathers links to interesting posts and intelligent(?) discussion goes on there. " CreationDate="2010-04-24T07:46:12.380" UserId="1200" />
  <row Id="1808" PostId="2362" Text="start one ? I'd certainly visit it :D" CreationDate="2010-04-24T09:31:37.407" UserId="417" />
  <row Id="1810" PostId="2259" Text="With respect to other instrumentation amps to try out, I am a big fan of the TI INA333 for single supply applications at or below 5V. I use them a lot in my job, and they have never given me these kinds of headaches." CreationDate="2010-04-24T14:38:23.613" UserId="631" />
  <row Id="1811" PostId="2340" Text="You are correct-- solar panels generally feed into a power tracking circuit that varies its impedance with a switching element to maximize the power extracted from the panel." CreationDate="2010-04-24T15:25:25.657" UserId="712" />
  <row Id="1812" PostId="2315" Text="Yeah, the National simple switchers aren't cheap, but they're pretty hard to screw up. The reason that they're expensive is that they have some of the passives integrated into the chip package. I think it's a worthwhile tradeoff if you're just trying to get something working. They'd be a bad choice in a production design." CreationDate="2010-04-24T16:20:34.527" UserId="712" />
  <row Id="1813" PostId="2368" Score="8" Text="There is a big difference between being pro FOSS and pro-piracy. I have never gotten the impression that Hack-a-Day is the later. Some of their posts may push the limits of the EULA included with some software (e.g. loading OSX on a non-Apple machine) but that hardly constitutes software piracy. &#xA;&#xA;I must say that I am kind of offended that you would insinuate that the good folks at hack-a-day promote steeling outright. They have by far been on of my favorite blogs regarding DIY projects, hardware hacking, and trends in machine-user interaction for the better part of a decade." CreationDate="2010-04-24T16:20:45.027" UserId="631" />
  <row Id="1814" PostId="2138" Text="I've used the Technologic Systems boards before-- they're good stuff." CreationDate="2010-04-24T20:22:23.693" UserId="712" />
  <row Id="1815" PostId="2372" Text="Thanks for the recommendation." CreationDate="2010-04-24T20:57:13.650" UserId="712" />
  <row Id="1816" PostId="2371" Text="Thanks for the info.&#xA;&#xA;You mentioned &quot;a very minimal loader&quot; as an alternative. Are you suggesting I write my own, or are there simpler bootloaders than RedBoot and uBoot? Also, any preference between the two? (I'm kind of leaning toward uBoot, as I have a little more experience with it.)&#xA;&#xA;I'd also be interested in any experience you have with OpenEmbedded or Buildroot. I've used Buildroot with an older Gumstix board. That they switched to OpenEmbedded suggests that might be better." CreationDate="2010-04-24T21:00:09.853" UserId="712" />
  <row Id="1817" PostId="2370" Text="Nice answer, thanks, although what are the frequencies that is based on? I wonder if there is any way to test this?" CreationDate="2010-04-24T22:03:32.483" />
  <row Id="1818" PostId="2374" Text="Would an answer depend on what temperature the metal might reach at that current, and its corresponding resistance?" CreationDate="2010-04-24T22:26:31.840" />
  <row Id="1819" PostId="2370" Text="You can calculate skin depth here: http://www.microwaves101.com/encyclopedia/calsdepth.cfm&#xA;&#xA;The depth decreases as frequency goes up. One implication of this, if I understand it correctly, is that low-frequency noise, like 60 Hz hum, is difficult to block." CreationDate="2010-04-24T22:30:45.950" UserId="712" />
  <row Id="1820" PostId="2374" Text="OK for 6A: not true; it's rated for AC, the OP is using it at DC." CreationDate="2010-04-25T00:57:58.323" UserId="330" />
  <row Id="1821" PostId="2370" Text="So according to that calculator, to block 60hz a single sheet of aluminum baking foil isn't thick enough correct? " CreationDate="2010-04-25T02:09:24.907" UserId="708" />
  <row Id="1822" PostId="861" Text="@endo more like $1.95 when not buying in bulk T_T" CreationDate="2010-04-25T02:14:50.487" UserId="708" />
  <row Id="1823" PostId="1199" Text="@Edward, This site is in bootstrap mode so everyone can edit CW posts" CreationDate="2010-04-25T02:27:05.920" UserId="708" />
  <row Id="1824" PostId="1214" Text="Please elaborate on the hardware tools and delivery problems. I've been using AVR chips for a while and they were very nice and easy to get into the world of physical computing. " CreationDate="2010-04-25T02:28:32.893" UserId="708" />
  <row Id="1825" PostId="2378" Text="`avr-gcc  -std=c99 -Wall -Os -mmcu=attiny13 -o hello.out helloworld.c` is the relevant line in my makefile(self created). and I use almost identical code except for to flip the LED I use `PORTB &amp;= ~(1 &lt;&lt; LED);` and such" CreationDate="2010-04-25T04:42:27.457" UserId="708" />
  <row Id="1826" PostId="2378" Text="And yea, the size is constant, but even 46 bytes seems kinda heavy if all it has to do is setup a stackframe" CreationDate="2010-04-25T04:43:44.697" UserId="708" />
  <row Id="1827" PostId="2362" Text="would you fund me?" CreationDate="2010-04-25T06:20:35.173" UserId="1200" />
  <row Id="1828" PostId="2377" Text="As a little side note, some people would call that a &quot;Blinky&quot;-program. " CreationDate="2010-04-25T06:44:47.813" UserId="689" />
  <row Id="1829" PostId="2371" Score="1" Text="By minimal loader - yes, I meant writing one, here's an overview - http://www.simtec.co.uk/products/SWLINUX/files/booting_article.html&#xA;&#xA;OpenEmbedded seems better for building packages which can be installed at runtime, Buildroot is good for targetting static embedded systems. Though, I haven't used either for a couple of years..." CreationDate="2010-04-25T07:21:56.430" UserId="566" />
  <row Id="1830" PostId="2374" Text="See jluciani's answer. It's the correct rating in the absence of any other data.&#xA;&#xA;The calculation would depend on the contact resistance, the mass of the metal, and so on, which would determine the temperature." CreationDate="2010-04-25T10:52:17.493" UserId="305" />
  <row Id="1831" PostId="1214" Text="Have a look at the AVR Freaks forum - people are always complaining about the Dragon and other tools, and the non-availability of many chips. They also complain about the lack of support from Atmel." CreationDate="2010-04-25T10:56:22.507" UserId="305" />
  <row Id="1832" PostId="2368" Score="1" Text="one persons pirate hacker is another persons tech liberator - it depends on your perspective. But I do agree with the FOSS collective - something has to be done to allow people to share, learn, develop and enhance ideas without the huge monetary cost or risk of being labeled a criminal. I'm sick of huge corporations having their cake and eating it - without thinking about how technology and ideas have developed and proliferated since the dawn of mankind  " CreationDate="2010-04-25T12:13:46.580" UserId="399" />
  <row Id="1833" PostId="2380" Score="1" Text="clarification: I haven't placed any of the wrong parts, so I just have to add the right ones which will come in a few days. " CreationDate="2010-04-25T12:38:43.587" UserId="471" />
  <row Id="1834" PostId="2383" Text="thanks a bunch!" CreationDate="2010-04-25T12:42:27.130" UserId="417" />
  <row Id="1835" PostId="2380" Score="2" Text="I'd definitely reflow it now, in that case." CreationDate="2010-04-25T13:17:46.297" UserId="305" />
  <row Id="1836" PostId="2348" Text="Every Dell laptop power brick that I've come across has had a ground pin on the input side, and presumably has a negative ground." CreationDate="2010-04-25T15:05:01.303" UserId="1301" />
  <row Id="1837" PostId="2368" Score="1" Text="I'm not talking about hacking different hardware devices to do things they didn't intend, but the fact that they have had posts that only talk about music or software piracy sites, and in a very sympathetic way to said pirates." CreationDate="2010-04-25T16:34:35.723" UserId="131" />
  <row Id="1838" PostId="2368" Text="Sure it's easy, sure the chances of getting caught are very low, but downloading software, music, movies and using/enjoying them without compensating their creator is ethically wrong. If I write some awesome tool that's useful for hobbyists, and sell it for $20, I'd be pretty annoyed if hackaday posts a way to get it for free without paying me." CreationDate="2010-04-25T16:38:27.607" UserId="131" />
  <row Id="1839" PostId="2368" Text="@aReddishGreen: For example: http://hackaday.com/2008/05/30/oink-arrests/ http://hackaday.com/2008/12/03/firefox-add-on-makes-pirating-easier/ especially this one: http://hackaday.com/2008/07/17/should-you-get-a-seedbox-for-your-bittorrent-needs/ " CreationDate="2010-04-25T16:44:09.117" UserId="131" />
  <row Id="1840" PostId="2382" Text="I can't seem to find the crt0 source, but in crt1 there is what seems to be an interrupt vector table. Maybe that is it" CreationDate="2010-04-25T20:11:32.823" UserId="708" />
  <row Id="1841" PostId="2377" Score="1" Text="@Johan well I wasn't sure how to spell &quot;blinkenlights&quot; " CreationDate="2010-04-25T21:10:16.043" UserId="708" />
  <row Id="1842" PostId="2382" Text="I can't find it on my system either :( I compiled all the tools from source so I thought it would be there. If you google for &quot;crt0.S atmel&quot; a couple of Atmel app-notes about startup, crt0 and gcc optimization come up. Maybe there are some hints in those docs." CreationDate="2010-04-25T21:58:01.960" UserId="424" />
  <row Id="1843" PostId="2388" Text="Do you mean that the enclosures are made up of 5-6 pieces of plastic, or that they hold pieces of plastic? Also, can part of the enclosures be powder-coated sheet-metal? (If so, I recommend frontpanelexpress.com.)" CreationDate="2010-04-25T23:34:44.000" UserId="712" />
  <row Id="1844" PostId="2388" Text="@pingswept: thanks for the comment: I've re-worded the question for clarity." CreationDate="2010-04-25T23:52:18.087" UserId="729" />
  <row Id="1845" PostId="2389" Text="I realize that and this is why I'm asking here, hoping that somebody can suggest something cheaper than creating injection molds.  @mtrw suggested using Selective Laser Sintering in this question: http://chiphacker.com/questions/2145/plastic-enclosure-for-small-product, but I'm not sure it can produce smooth enough surface" CreationDate="2010-04-26T00:47:45.763" UserId="729" />
  <row Id="1846" PostId="2382" Text="@jlu I'm trying to figure out the difference between the two but haven't gotten any thing good on Stack Overflow yet: http://stackoverflow.com/questions/2709998/crt0-o-and-crt1-o-whats-the-difference" CreationDate="2010-04-26T01:09:30.127" UserId="708" />
  <row Id="1847" PostId="2382" Score="1" Text="avr-libc has a different CRT for each type of AVR chip, and the standard avr-libc distros only include the .o version of the file.  The one for the ATtiny13 is located at [avr-libc-path]/avr-3/lib/crttn13.o&#xA;" CreationDate="2010-04-26T01:37:04.597" UserId="215" />
  <row Id="1848" PostId="2389" Text="I guess it depends on your budget, but for something thats a couple of inches big, various rapid prototyping 3d printing methods will run you in the range of $20 per piece, versus maybe $2 each if you had thousands of them manufacturered" CreationDate="2010-04-26T02:46:35.317" UserId="131" />
  <row Id="1849" PostId="2382" Text="@todbot hmm. Ah, ok yea I have it in `/avr-libc-1.6.7/avr/lib/avr2/attiny13/crttn13.S`" CreationDate="2010-04-26T03:12:22.143" UserId="708" />
  <row Id="1850" PostId="2382" Text="It looks like the crt code is gcrt1.S and is in avr-libc/crt1 I believe that the Makefile (in the same directory) compiles the object files for the various devices." CreationDate="2010-04-26T03:14:17.320" UserId="424" />
  <row Id="1851" PostId="2390" Text="The price for SLA you quoted seems about right.  Also, SLA is fragile - if you drop it it'll probably fracture." CreationDate="2010-04-26T06:41:36.837" UserId="696" />
  <row Id="1852" PostId="2389" Text="@Rom - you're right about SLS.  It's no good for polished surfaces." CreationDate="2010-04-26T06:43:15.947" UserId="696" />
  <row Id="1853" PostId="2328" Text="@jluciani Very small, low power satellite data modems.  The low power modes of the MSP and AVR32 are excellent with RAM data retention.  The ARM low power modes (except for the new energy micro parts) do not allow usart operation in the low power state and often do not keep RAM contents." CreationDate="2010-04-26T13:36:58.407" UserId="400" />
  <row Id="1855" PostId="2370" Text="Another good question, what kind of frequencies do we need to block?&#xA;&#xA;That is, What kind of radiation might there be externally that may be harmful to the computer, and what frequencies will the computer itself generate that need to be prevented from escaping?&#xA;" CreationDate="2010-04-26T15:22:28.253" />
  <row Id="1856" PostId="2370" Text="	Using the values 280.2 uΩ*cm for resistivity and 1.00002 for rel. permeability (for Aluminium) with the calculator posted above, I get: 1Hz -&gt; 0.843 m, 60Hz -&gt; 10.876 cm, 20KHz -&gt; 5.957 mm, 1MHz -&gt; 0.843 mm, 1Ghz -&gt; 26.64 um, 2.4GHz -&gt; 17.2 um, 5.8GHz -&gt; 11.06 um, 10GHz -&gt; 8.42 um. Although, someone please check my working, I can't be sure of any of the above. – CH 2 mins ago" CreationDate="2010-04-26T15:23:43.360" />
  <row Id="1857" PostId="2371" Text="Excellent link. Thanks." CreationDate="2010-04-26T16:55:29.460" UserId="712" />
  <row Id="1858" PostId="2391" Text="Thank you for the answer!  Yes, I've seen your comment before asking my question, but unfortunately I need a very specific enclosure and I'm pretty sure none of the existing ones would do.  Thanks for providing the ballpark costs for tooling, that helps a lot!" CreationDate="2010-04-26T18:51:17.370" UserId="729" />
  <row Id="1859" PostId="2395" Text="I can do it for some, but not all of the parts.  I think that's a good option for keeping the costs down.  Thank you for suggestion!" CreationDate="2010-04-26T18:53:03.747" UserId="729" />
  <row Id="1860" PostId="2390" Text="Thank you for the comment!  I will check them out.  Fragility is a factor for me, unfortunately." CreationDate="2010-04-26T18:56:59.277" UserId="729" />
  <row Id="1861" PostId="2232" Text="The Protomold guys look really great, thanks." CreationDate="2010-04-26T23:23:14.967" UserId="659" />
  <row Id="1862" PostId="2397" Text="Datasheet comes up very easily on a google search. That invalidates the main reason behind your answer." CreationDate="2010-04-26T23:53:49.483" UserId="131" />
  <row Id="1863" PostId="2397" Text="Ah, that does indeed suggest that I am wrong." CreationDate="2010-04-27T00:13:39.437" UserId="712" />
  <row Id="1864" PostId="2397" Text="Answer amended." CreationDate="2010-04-27T00:19:45.217" UserId="712" />
  <row Id="1867" PostId="2325" Text="And I thought that &quot;PIC&quot; was a &quot;four letter word&quot; !!!" CreationDate="2010-04-27T10:31:09.937" UserId="400" />
  <row Id="1871" PostId="2326" Score="1" Text="I've started to like the Microchip C18 compiler now that I’ve gotten use to it. Learning how to use #pragma and the interrupt vectors was probably the hardest part. The C libraries they provide can save a lot of development time." CreationDate="2010-04-27T17:14:56.217" UserId="588" />
  <row Id="1872" PostId="2397" Text="Do I get any rep for that?" CreationDate="2010-04-27T19:58:14.967" UserId="588" />
  <row Id="1873" PostId="2397" Text="Sorry, mjh2007, I didn't even notice your answer when I amended mine. I was just responding to davr's comment above. But I'll upvote you all the same." CreationDate="2010-04-27T20:31:17.333" UserId="712" />
  <row Id="1875" PostId="2370" Text="Ignore the &quot;– CH 2 mins ago&quot; above :-/&#xA;&#xA;" CreationDate="2010-04-27T20:52:18.010" UserId="733" />
  <row Id="1877" PostId="763" Text="I don't think guitar tuners count zero crossings, and this certainly isn't a good method. It ain't even close to a sine wave, and there can be many zero crossings per cycle:  http://flic.kr/p/7ns9nu" CreationDate="2010-04-27T21:12:45.470" UserId="142" />
  <row Id="1878" PostId="758" Score="1" Text="For guitar tuners, there are a number of questions on stackoverflow about frequency estimation.  http://stackoverflow.com/questions/65268/music-how-do-you-analyse-the-fundamental-frequency-of-a-pcm-or-wac-sample/ I've answered a bunch of them and posted sample code for some methods here: http://gist.github.com/255291" CreationDate="2010-04-27T21:15:09.617" UserId="142" />
  <row Id="1879" PostId="2370" Text="Hi CH. I think your resistivity is off. It should be 2.802 uΩ*cm. I suspect you misread uΩ*m as uΩ*cm.&#xA;&#xA;I get 104.89 um for 1 GHz using 2.802 uΩ*cm and 1.00002 for permeability. Does that seem right to you?" CreationDate="2010-04-27T21:30:20.427" UserId="712" />
  <row Id="1880" PostId="2370" Text="Ah, wait, my answer should have been 104.89 uinches, not um. In um, it's 2.66 um, which makes more sense-- exactly 10x off from your answer, and the resistivity is square-rooted in the calculator." CreationDate="2010-04-27T21:32:59.800" UserId="712" />
  <row Id="1881" PostId="2409" Text="I've looked at CT's and hall effect sensors but I wanted to look into this method more. " CreationDate="2010-04-27T23:46:52.167" UserId="245" />
  <row Id="1882" PostId="2408" Text="The problem with using a 0.01 Ohm resistor is that you will get only 9mV for a 100W load. This may be quite difficult to measure without some good amplifier in front of the ADC (or a nice sigma-delta ADC with low reference voltage)." CreationDate="2010-04-27T23:56:26.780" UserId="659" />
  <row Id="1883" PostId="2408" Text="That's a good point. I'd assume that you need an instrumentation amplifier across the shunt resistor." CreationDate="2010-04-28T01:58:50.530" UserId="712" />
  <row Id="1884" PostId="763" Text="The tuners I've seen had a low-pass filter to turn the input signal as much into a sine wave as possible." CreationDate="2010-04-28T04:21:38.510" UserId="215" />
  <row Id="1885" PostId="2244" Score="2" Text="The WiShield and related products from AsyncLabs uses the ZeroG chipset to give WiFi to Arduino-compatible boards." CreationDate="2010-04-28T07:05:59.850" UserId="215" />
  <row Id="1886" PostId="793" Text="Do you have any good links?" CreationDate="2010-04-28T13:52:39.537" UserId="689" />
  <row Id="1887" PostId="793" Text="@Johan - From my answer, you can tell I don't know a whole lot about it.  At work we have a book on CANOpen that we use from http://www.canopenbook.com/.  The wikipedia pages don't look too bad.  If your'e primarily writing higher-level software, the important thing is to realize a message has an 11-bit ID, and a 8-byte data segment.  I'll be working on a CANOpen project in the upcoming days/months, perhaps I can give more links later." CreationDate="2010-04-28T15:28:47.290" UserId="374" />
  <row Id="1888" PostId="1889" Text="I never seen it sold for $100. $60 rather. It has a USB programmer, Flash memory and an Ethernet PHY on board. Not to mention you don't have to solder a TQFP100." CreationDate="2010-04-28T15:43:00.503" UserId="659" />
  <row Id="1889" PostId="2411" Text="To clarify-- do you mean you want to build the case the iPad sits in, or do you want to build the entire system, including the display?" CreationDate="2010-04-28T16:17:56.367" UserId="712" />
  <row Id="1890" PostId="2370" Text="Wikipedia lists the Electrical Resistivity of Aluminium at 20DegC as '28.2 nΩ·m' which is 28.2 (0.001)uΩ.(100)cm = 28.2 (0.1)uΩ.cm = 282 uΩ.m amirite? :&gt;&#xA;&#xA;so my value was off by 1.8" CreationDate="2010-04-28T20:54:52.277" />
  <row Id="1891" PostId="2368" Text="'very-pro-software-piracy' on the strength of posts like this (which are themselves two years old)? first, seedboxes can seed more than pirated wares. second, they mention RIAA and MPAA, i.e. music and movies, nothing about software. third, the oink (a music sharing site) raid was a travesty of justice, nothing to do with HADs views on piracy.&#xA;&#xA;It's preposterous to even *mention* these considering HAD hardly ever mentions software piracy; it seem to me you've harbored some sort of grudge." CreationDate="2010-04-28T21:04:42.533" />
  <row Id="1892" PostId="2368" Text="Yeah, I admit, the site may have changed since back then. Maybe it was just one editor posting all those things and he's changed or gone now. I just got annoyed when it seemed like there were a bunch of posts in a row (back in 2008 as you saw). There's no point to &quot;seedboxes&quot; besides piracy. If it's legit torrents like linux ISO's, then just download it directly, no need to hide it. If you run a linux project and want to distribute it via torrent, just distribute it from your official server, no need to rent a server from some shady 3rd party." CreationDate="2010-04-28T21:49:57.017" UserId="131" />
  <row Id="1893" PostId="2368" Text="Oink was a music piracy site, that was its whole purpose. Maybe they people shouldn't have been arrested, I don't know. Either way, it had no place on hackaday, a site about hacks, DIY, etc. I suppose I kind of lump music/movie/software piracy all into one bucket, but maybe I shouldn't. Maybe the people who are ok with enjoying audio and video works without paying the creators are not ok with enjoying software works without paying the creators. I dunno." CreationDate="2010-04-28T21:52:04.910" UserId="131" />
  <row Id="1894" PostId="432" Score="1" Text="+1 MATLAB suggestion.  It's much better to make it work in MATLAB before porting it to an actual DSP." CreationDate="2010-04-28T21:58:44.567" UserId="1278" />
  <row Id="1895" PostId="2417" Text="Is this similar to the infamous Write Only memory? ;-)" CreationDate="2010-04-29T05:11:11.900" UserId="625" />
  <row Id="1896" PostId="2362" Text="if i had any money" CreationDate="2010-04-29T05:43:10.213" UserId="417" />
  <row Id="1897" PostId="2429" Text="Oh wow, excellent. Thank you for that great answer. John." CreationDate="2010-04-29T08:32:44.503" UserId="1307" />
  <row Id="1899" PostId="2440" Score="2" Text="This is probably the best forum to ask this question, to my knowledge.  Welcome to CH!" CreationDate="2010-04-29T15:56:31.100" UserId="374" />
  <row Id="1900" PostId="2441" Text="If there's a voltage on one battery relative to the other, then they have different static electric charges, which will be equalized after you connect them together." CreationDate="2010-04-29T17:51:38.063" UserId="142" />
  <row Id="1901" PostId="2441" Text="@endolith - True... so that means my answer is incorrect, isn't it?  What could be said to correct my answer?" CreationDate="2010-04-29T18:28:53.137" UserId="374" />
  <row Id="1902" PostId="2444" Score="1" Text="Yes, that explanation makes sense.  Thanks!" CreationDate="2010-04-29T19:36:19.397" UserId="374" />
  <row Id="1903" PostId="2444" Text="Excellent. Glad to be of service." CreationDate="2010-04-29T19:52:41.663" UserId="712" />
  <row Id="1904" PostId="2449" Text="I suspect you're not going to have much luck getting that question answered here.&#xA;&#xA;(On the other hand, who knows what wisdom is lurking amongst the populace?)" CreationDate="2010-04-29T19:59:14.853" UserId="712" />
  <row Id="1905" PostId="144" Text="The only thing a DSP has that a uC doesn't these days is circular addressing modes.  Other than that, they're basically the same thing.  Maybe a typical uC has more I/O and DMA channels, but the Analog Devices Blackfin family makes that a pretty outdated assumption too." CreationDate="2010-04-29T20:16:40.080" UserId="696" />
  <row Id="1906" PostId="2449" Text="Any other places where this question would be more appropriate?" CreationDate="2010-04-29T20:23:28.787" />
  <row Id="1907" PostId="2446" Text="Related: http://chiphacker.com/questions/1092/whats-the-difference-between-a-microcontroller-and-a-microprocessor" CreationDate="2010-04-29T21:08:43.857" UserId="142" />
  <row Id="1908" PostId="1710" Text="Yeah, that definitely looks like a 2-1 multiplexer.  It passes A or C to the output, depending on the value of B." CreationDate="2010-04-29T21:25:46.553" UserId="1278" />
  <row Id="1909" PostId="2433" Score="2" Text="+1 that's my experience, too.  Common mode choke will degrade the signal.  As pingswept mentions, you should include the footprint for the choke (and ESD protection too!); you can always just not populate those components during assembly if they are not needed." CreationDate="2010-04-29T21:31:52.797" UserId="1278" />
  <row Id="1910" PostId="2441" Text="In his example it all stops at the setup since there is no return path for the current so no current will ever flow which is actually stated in the first line of the article you linked &quot;As was previously mentioned, we need more than just a continuous path (circuit) before a continuous flow of electrons will occur&quot; and covered in more depth in the previous section." CreationDate="2010-04-29T22:13:17.577" UserId="703" />
  <row Id="1911" PostId="2397" Text="@mjh2007: Hey, how about this-- since you came up with the Google result before me, why don't you take the last two paragraphs of my answer and add it to yours, and I'll delete mine." CreationDate="2010-04-29T22:25:59.330" UserId="712" />
  <row Id="1912" PostId="2449" Text="Sorry, Fred-- your guess is as good, or perhaps better, than mine." CreationDate="2010-04-29T22:38:41.900" UserId="712" />
  <row Id="1913" PostId="2440" Text="@mike: Could you edit the title of this question to be more descriptive? Maybe something like &quot;Current flow in batteries?&quot;" CreationDate="2010-04-29T22:54:52.867" UserId="712" />
  <row Id="1914" PostId="2440" Text="Thanks for the edit." CreationDate="2010-04-30T00:32:51.607" UserId="712" />
  <row Id="1915" PostId="2449" Text="Do you know any of your classmates? Maybe ask one of them? :)" CreationDate="2010-04-30T05:04:03.073" UserId="131" />
  <row Id="1917" PostId="1181" Text="You can get carbide scribing tools from eBay pretty cheap, use with a ruler of something to start a straight score mark. Also, score both sides. If you can them use a press to hold one, or both sides (with wood or something to prevent bare metal press scratching board) then that can reduce the 'splintering' either side of the score mark." CreationDate="2010-04-30T14:16:40.193" UserId="733" />
  <row Id="1923" PostId="2458" Score="1" Text="ajs410, i have no idea why someone down voted you. Your answer is by far my favorite, electricity can be simplified, but a solid understanding of what you are explaining is required for a professional to grow." CreationDate="2010-04-30T20:57:39.480" UserId="230" />
  <row Id="1924" PostId="2465" Score="4" Text="the cable is almost always using twisted pair in this situation. The returns are referencing which other wire they are twisted with. This is for EMI and a set input impedance." CreationDate="2010-04-30T20:59:18.030" UserId="230" />
  <row Id="1925" PostId="2425" Score="1" Text="Quite rarely do datasheets or even application notes actually give you all the information to use a part successfully in regards to EMI emissions and noise generation in the rest of the system.  Classic examples that should hardly ever be followed are that a single 0.1uF cap is sufficient power supply decoupling for a power pin and that you should have separate analog and digital ground planes (doing this one especially almost always results in EMI disasters).  Another tip as you found is to be liberal with ferrite beads and common mode chokes on any signal that leaves or enters the board." CreationDate="2010-04-30T22:09:53.440" UserId="703" />
  <row Id="1928" PostId="2239" Score="2" Text="i think it might actually be negative feedback; as the drain voltage rises, the current into the base of the BJT increases, this increases the current from the emitter, which increases the voltage drop across the output resistor, so the voltage at the drain is driven downward, opposite to the starting assumption." CreationDate="2010-05-01T01:22:18.727" UserId="740" />
  <row Id="1929" PostId="2469" Text="@JustJeff: Any particular areas of depth for those vendors?" CreationDate="2010-05-01T01:43:06.033" UserId="712" />
  <row Id="1930" PostId="2468" Text="@jluciani: Excellent!" CreationDate="2010-05-01T01:44:27.033" UserId="712" />
  <row Id="1931" PostId="2469" Text="@pingswept: i think of them as 'surplus' houses, though that may be dated, as they've both grown a lot over recent years. Used to sell cannibalized chunks of surplus hardware, dirt cheap. You could get weird assemblies with logic/motors/optics, etc., as well as traditional parts. They may not have every last component by every manufacturer, but they do have a good assortment of stuff for hobby projects, esp. robotics related ones." CreationDate="2010-05-01T03:57:26.517" UserId="740" />
  <row Id="1932" PostId="2472" Text="I'd take heed of W5VO's answer too - Point number 1 is a really important, you don't want to blow the thing up with 220V!" CreationDate="2010-05-01T11:03:59.090" UserId="399" />
  <row Id="1933" PostId="2449" Text="Maybe StackOverflow would be a good place?" CreationDate="2010-05-01T11:08:34.167" UserId="659" />
  <row Id="1934" PostId="1096" Score="1" Text="AT91SAM7S256 is definitely a microcontroller nor a microprocessor." CreationDate="2010-05-01T11:22:19.817" UserId="659" />
  <row Id="1935" PostId="2465" Score="1" Text="It has very little to do with resistance, it's all about EMI and impedance." CreationDate="2010-05-01T14:13:14.933" UserId="339" />
  <row Id="1936" PostId="2474" Text="+1 for pointing out the difference between Cortex-A and Cortex-M series..." CreationDate="2010-05-01T16:55:06.180" UserId="689" />
  <row Id="1937" PostId="2469" Text="Thanks for the details." CreationDate="2010-05-01T19:12:21.777" UserId="712" />
  <row Id="1938" PostId="2467" Score="3" Text="I would like to point out that shipping cost and time should be strongly considered when thinking about who you want to buy from. If you keep having to buy little things over and over again your shipping cost and prototyping time gets very long. I would much rather spend a few extra cents on the part its self and save weeks of delay on a project. All depends on what you are doing though." CreationDate="2010-05-01T21:55:50.090" UserId="319" />
  <row Id="1939" PostId="2474" Score="1" Text="microcontroller has embedded flash and ram. Microprocessors have their memory externally." CreationDate="2010-05-02T00:09:24.360" UserId="230" />
  <row Id="1940" PostId="2459" Text="'Cruch' connector, ok. I agree, and a crimp connector would be preferable to the punch connector." CreationDate="2010-05-02T06:02:26.983" UserId="207" />
  <row Id="1941" PostId="2484" Text="often arm based systems use arm Microprocessors, not microcontrollers." CreationDate="2010-05-02T07:39:48.147" UserId="230" />
  <row Id="1942" PostId="2447" Score="1" Text="This is a microprocessor, not a microcontroller, as JPC notes below" CreationDate="2010-05-02T07:40:20.890" UserId="230" />
  <row Id="1943" PostId="2011" Text="Triac for low current applications. When I think low current I think 500 mA or less, a TRIAC can go much much higher than this. " CreationDate="2010-05-02T07:42:13.607" UserId="230" />
  <row Id="1944" PostId="2483" Score="1" Text="You can even make it look like fake USB - many keyboards I have seen are dual-mode USB and PS/2. You could have a USB connector wired up like the &quot;USB to PS/2&quot; adapter and just interface using PS/2. Don't know if the requirement is USB or just a keyboard with a USB connector. " CreationDate="2010-05-02T07:59:18.190" UserId="638" />
  <row Id="1947" PostId="2483" Score="2" Text="IIRC most of these keyboard and mouse adapters did not contain any logic and required the mice/keyboards to have true USB signals on the PS/2 connector (which has 2 unused pins)." CreationDate="2010-05-02T16:26:31.977" UserId="659" />
  <row Id="1948" PostId="2483" Text="Actually I'm looking for a way to work with a real USB keyboard, but in case that will get complicated, I'll sure go with the PS/2 option. &#xA;Thanks for the advice!&#xA;" CreationDate="2010-05-02T23:32:04.363" UserId="752" />
  <row Id="1949" PostId="2340" Text="solar cell voltage is related to the band-gap in the semiconductor material the cell is made of. photons at or above the band gap energy cause electron-hole pairs to form in the junction, and the field from the lattice drives these in opposite directions, supplying the current. so the voltage is related to the material, relatively constant, and the current depends on the number of suitably energetic photons striking the cell, so the available current is related to the amount of illumination. fwiw, i'd say this makes a solar cell a more of a voltage source, not a current source." CreationDate="2010-05-03T00:18:07.840" UserId="740" />
  <row Id="1951" PostId="2494" Text="It's all in the USB spec.  The normal bits are differential, but the &quot;end of packet&quot; signal is both lines pulled low, so you need to look at both, really." CreationDate="2010-05-03T02:31:39.470" UserId="142" />
  <row Id="1952" PostId="2496" Score="1" Text="I think jcl has the right idea. You might also google &quot;pogo pin.&quot;" CreationDate="2010-05-03T02:36:54.990" UserId="712" />
  <row Id="1953" PostId="2494" Score="1" Text="Here's a decent summary of the packets used: http://www.beyondlogic.org/usbnutshell/usb3.htm" CreationDate="2010-05-03T02:38:38.627" UserId="712" />
  <row Id="1954" PostId="2496" Text="I'm sold with the Mill-max idea! Thanks a bunch!&#xA;I'm calling my local distributor tomorrow." CreationDate="2010-05-03T04:16:30.300" UserId="1267" />
  <row Id="1955" PostId="2496" Text="You're welcome. Mill-max is good with samples. You could probably get a couple pieces to verify the parts will work in your application." CreationDate="2010-05-03T10:38:28.550" UserId="424" />
  <row Id="1956" PostId="2501" Score="1" Text="At my job some rosin flux was the problem behind a TX antenna mismatching, we now use water based flux. to clean it we give the board a good rinse and then dry it with compressed air." CreationDate="2010-05-03T18:17:44.697" UserId="230" />
  <row Id="1957" PostId="2458" Score="1" Text="They probably voted me down because it looked like I was saying 1.5 + 1.5 = 3.  What I wanted to stress, though, was how each terminal is *relative* to the others along the Y axis.  B- and A+ are the same potential because they're hooked up by a wire.  With no potential difference, there is no current flow." CreationDate="2010-05-03T18:27:30.767" UserId="1278" />
  <row Id="1958" PostId="2494" Text="Don't forget about bit stuffing!" CreationDate="2010-05-03T18:29:15.213" UserId="1278" />
  <row Id="1959" PostId="2465" Text="That is what I said in the comment previous starblue. Read the last sentence." CreationDate="2010-05-03T21:10:52.280" UserId="230" />
  <row Id="1960" PostId="2219" Score="2" Text="I'm pretty sure the same thing would have happened if she'd been wearing a PCB." CreationDate="2010-05-04T00:01:57.147" UserId="222" />
  <row Id="1961" PostId="2505" Score="1" Text="Where I'm getting confused is here &quot;unlike the multi cycle cpu, the pipelined datapath requires that every instruction use all five stages of execution.&quot;(1)  This implies that the multicycle and pipelined datapaths are two different things.  So if someone says &quot; The MIPS 5-stage pipeline system uses the multi-cycle datapath&quot;, based on my initial understanding, the answer would be true.  But based on the quote, the answer would be false.  Can someone clarify?&#xA;&#xA;(1) http://cseweb.ucsd.edu/~j2lau/cs141/week6.html" CreationDate="2010-05-04T02:57:54.260" />
  <row Id="1963" PostId="2433" Score="1" Text="The document you attached is very helpful. I think I have finally read through all of it. Thank you very much for pointing me to it." CreationDate="2010-05-04T06:13:28.717" UserId="319" />
  <row Id="1964" PostId="2505" Score="1" Text=" 	I see what you are trying to learn here, but this is the second time I have seen a question that is clearly for a class. I think just asking a class question here does get a quick answer but this is a disservice to you and to the people answering. You learn a very large amount about devices and systems through the process of researching a question. People on here spend time doing your homework. You are shorting yourself of education and members of this forum of their time." CreationDate="2010-05-04T06:46:24.723" UserId="230" />
  <row Id="1965" PostId="2507" Text="are you sure it is not an 0606 component(ie. Measurements of the device)?" CreationDate="2010-05-04T07:05:03.280" UserId="230" />
  <row Id="1966" PostId="2507" Text="I know for sure it's a rectifier. All it says is 06 and then 06 again perpendicular to the first 06." CreationDate="2010-05-04T07:51:46.667" UserId="756" />
  <row Id="1967" PostId="2507" Text="As Kortuk said, 0606 is the measurement of the device, as in physical dimensions of the chip. 0606 means the chip is 6 mils wide by 6mils long (0.006in x 0.006in). Is your rectifier through hole or surface mount? 0606 would refer to surface mount." CreationDate="2010-05-04T08:04:22.267" UserId="319" />
  <row Id="1968" PostId="2507" Text="Definitely through hole." CreationDate="2010-05-04T08:10:31.050" UserId="756" />
  <row Id="1969" PostId="2507" Text="I'll step back and let others take a shot since I am not sure :-)" CreationDate="2010-05-04T08:21:39.420" UserId="319" />
  <row Id="1970" PostId="2507" Text="can you expand on where you got the device from, any links to a vendors page?" CreationDate="2010-05-04T08:27:03.677" UserId="230" />
  <row Id="1971" PostId="2508" Text="most processors/controllers today still have instructions that take more than one clock cycle, even in a pipeline. " CreationDate="2010-05-04T10:57:06.367" UserId="230" />
  <row Id="1972" PostId="2508" Text="OK, I understand that multicycle doesn't imply pipelining but does pipelining imply multicycle?  In general, pipelining uses multiple cycles so there's a lot of similarity but from the link above, the pipelined datapath and the multicycle datapath are very different.  This is what I was trying to confirm." CreationDate="2010-05-04T11:57:18.657" />
  <row Id="1973" PostId="2510" Text="I've updated question with a picture." CreationDate="2010-05-04T20:06:19.830" UserId="756" />
  <row Id="1974" PostId="2507" Text="I got it in an assortment of diodes from eBay." CreationDate="2010-05-04T20:10:03.933" UserId="756" />
  <row Id="1975" PostId="2512" Score="1" Text="Are you pressing the reset button on the Arduino immediately before you download?" CreationDate="2010-05-04T21:08:07.083" UserId="424" />
  <row Id="1976" PostId="2507" Text="Since it is an assortment from eBAY it may not be a mfg pn. It could be some sort of OEM number." CreationDate="2010-05-04T21:12:49.553" UserId="424" />
  <row Id="1977" PostId="2508" Text="@Henley: my take on it is that pipelining does imply multi-cycle instructions, otherwise, how can you pipeline?" CreationDate="2010-05-04T21:30:27.437" UserId="740" />
  <row Id="1978" PostId="2508" Text="@Kortuk: I didn't mean to imply modern CPUs don't have multi-cycle instructions, it was a hasty bit of writing I've edited a little, hopefully makes more sense now." CreationDate="2010-05-04T21:31:52.490" UserId="740" />
  <row Id="1979" PostId="2508" Text="I had a feeling you knew that, JustJeff, but others may not." CreationDate="2010-05-04T23:27:44.107" UserId="230" />
  <row Id="1980" PostId="2517" Text="In fact there's a project to make a GPS to SD Card logger here, which might have some useful bits about using an SD card: http://www.gedanken.demon.co.uk/gps-sd-logger/" CreationDate="2010-05-05T08:43:15.953" UserId="103" />
  <row Id="1982" PostId="2509" Text="Pretty close! I guess you used my breadboard as a reference :) Any ideas what it could be?" CreationDate="2010-05-05T08:57:50.777" UserId="756" />
  <row Id="1983" PostId="2445" Text="Thanks, useful app note...." CreationDate="2010-05-05T09:26:52.027" UserId="611" />
  <row Id="1984" PostId="2444" Text="Not actually the correct answer, see below..." CreationDate="2010-05-05T09:40:02.767" UserId="611" />
  <row Id="1985" PostId="2485" Text="Please make this a community wiki." CreationDate="2010-05-05T13:43:12.107" UserId="330" />
  <row Id="1986" PostId="2518" Text="Do you know of a case where someone has used that parallel port for an ATA/IDE interface?" CreationDate="2010-05-05T14:36:22.770" UserId="588" />
  <row Id="1987" PostId="2444" Score="1" Text="@Tim Ring: I think your answer is correct, but I'm not sure where you think I've gone wrong. I understand that &quot;tristate&quot; refers to the ability of a pin to be configurable into three states-- high, low, or high impedance. But in colloquial terms, when someone says &quot;Tristate a pin,&quot; they mean to put it into high impedance state." CreationDate="2010-05-05T14:38:51.253" UserId="712" />
  <row Id="1988" PostId="2522" Text="What logic test are you using to detect (unsuccessfully) pin 6 going low? Also, can you detect the pin going low with a multimeter or scope? Might it need a pull-down resistor?" CreationDate="2010-05-05T14:42:59.287" UserId="712" />
  <row Id="1989" PostId="2526" Score="2" Text="Just about what I was going to say. Do make sure you don't end up switching any power to ground with out a resistor inline, I have seen this happen when people play with relays." CreationDate="2010-05-05T15:11:45.400" UserId="319" />
  <row Id="1990" PostId="2522" Text="For logic testing I just used ~  .  &#xA;&#xA;So,&#xA;&#xA;if (PORTA.IN &amp; ~(1&lt;&lt;6))&#xA;&#xA;Pulldown mode = 010  I have tried this but perhaps my ~(1&lt;&lt;6) is the wrong way to read this.&#xA;&#xA;I have not tested this on a multi-meter.  I will when I get home.  Does that help?" CreationDate="2010-05-05T15:13:25.790" UserId="29" />
  <row Id="1991" PostId="2526" Score="1" Text="Also, you might want to check out this page (it is the opposite of what you want but might help you out): http://www.instructables.com/answers/How-can-I-change-a-normally-open-switch-to-a-norma/" CreationDate="2010-05-05T15:14:18.087" UserId="319" />
  <row Id="1992" PostId="2522" Text="My initial instinct was like pingswept said, check to see if you need a pull-down resistor." CreationDate="2010-05-05T15:17:37.163" UserId="319" />
  <row Id="1993" PostId="2518" Text="@mjh2007 Theres a library from Microchip for the PIC32 to interface to compact flash cards using the PMP thats beta: http://www.microchip.com/forums/tm.aspx?m=364311  CF cards normally operate in IDE mode so you could probably tweak it to work." CreationDate="2010-05-05T16:58:01.437" UserId="703" />
  <row Id="1994" PostId="2528" Text="Thanks! How about if I didn't know it required 12 VDC? How would I be able to figure out the minimal power requirements for a board then?" CreationDate="2010-05-05T17:01:18.417" />
  <row Id="1995" PostId="2528" Text="Contact the manufacturer, but the voltage requirements should be written right on the part itself. One other way though I don't recommend it is to check some of the IC components that are tied directly to the power supply rails on the board. The component with the lowest voltage rating is the board supply voltage." CreationDate="2010-05-05T17:09:14.397" UserId="588" />
  <row Id="1996" PostId="2526" Text="he needs to invert the sensor signal not the power signal to the valves.  " CreationDate="2010-05-05T17:13:57.873" UserId="703" />
  <row Id="1997" PostId="2530" Score="1" Text="That's really good. Thanks!" CreationDate="2010-05-05T18:08:29.393" />
  <row Id="1998" PostId="2527" Score="1" Text="Why don't you ask the seller?" CreationDate="2010-05-05T19:53:00.810" UserId="339" />
  <row Id="1999" PostId="2526" Text="This is more along the line of what I was thinking about.&#xA;&#xA;A quick note: It appears to be 24V AC ( not DC ). Max output amps is .83. &#xA;&#xA;On the controller box, I have two Common terminals, and then the two Sensor terminals ( along with the 9 valve terminals ). &#xA;&#xA;I think I can use the box's common to power this: http://www.radioshack.com/graphics/uc/rsk/Support/ProductManuals/2750249_DS_EN.pdf And hook up the NO side of that relay to the Sensor terminals ( the extra set to my own LED showing 'rain mode' as on ).  &#xA;&#xA;Do I need to mess with Diodes/Resistors for this? It all seems in 'range' to me.&#xA;" CreationDate="2010-05-05T19:53:06.577" />
  <row Id="2000" PostId="2522" Text="@ril3y - you do not want to use (PORTA.IN &amp; ~(1 &lt;&lt; 6)). That would be like (PORTA.IN &amp; 0xBF), which will be true if any pin *except* pin 7 is high.  I believe what you meant to try is !(PORTA.IN &amp; (1 &lt;&lt; 6))" CreationDate="2010-05-05T20:39:54.857" UserId="1278" />
  <row Id="2001" PostId="2525" Text="And interesting idea. I am more of a programmer and this is enticing. The extra bells and whistles I could add would be cool. I think for now, i'll work on just using an old school DPDT relay. Then maybe later integrate it with this, or PIC, or something, and tie the watering system to other data ( like output from my PC )." CreationDate="2010-05-05T20:51:29.037" />
  <row Id="2002" PostId="2525" Text="You might also take a look at the Garduino: http://www.instructables.com/id/Garduino-Gardening-Arduino/&#xA;&#xA;But I do think a relay is a decent choice. There's a lot to be said for simplicity." CreationDate="2010-05-05T20:54:08.707" UserId="712" />
  <row Id="2003" PostId="2525" Text="Better link: http://garduino.dirtnail.com/" CreationDate="2010-05-05T20:55:04.227" UserId="712" />
  <row Id="2005" PostId="2526" Score="1" Text="Assuming you can get access to DC somewhere you can do this with a single MOSFET transistor." CreationDate="2010-05-05T22:19:00.623" UserId="703" />
  <row Id="2006" PostId="1098" Score="2" Text="Open source hardware companies make quite a bit of money, it would seem: http://www.sparkfun.com/commerce/news.php?id=358" CreationDate="2010-05-05T22:43:16.370" UserId="142" />
  <row Id="2007" PostId="1902" Text="In other words, is it possible to measure the voltage on a wire without drawing any current from it in the process?  Is it theoretically possible to make a switching device that has *no* input capacitance?  Is it possible to measure the pressure in a pipe without letting any water out?" CreationDate="2010-05-05T22:51:35.437" UserId="142" />
  <row Id="2008" PostId="2536" Score="1" Text="i thought that it must have been banned for burning holes in the ozone, but it's nice to see 'CFC free' on those." CreationDate="2010-05-06T03:57:47.863" UserId="740" />
  <row Id="2009" PostId="2537" Score="2" Text="I have to admit, that is quite fun." CreationDate="2010-05-06T11:56:12.900" UserId="230" />
  <row Id="2010" PostId="1075" Text="That takes me back - similar to all those old Radio Shack books by Forrest Mims III..." CreationDate="2010-05-06T12:02:09.077" UserId="1307" />
  <row Id="2011" PostId="2541" Score="1" Text="I will see if I can get a desk copy, the reviews seem good!" CreationDate="2010-05-06T12:52:37.060" UserId="230" />
  <row Id="2012" PostId="2516" Text="I gave my best answer without reading his text. It seems I was taught something different." CreationDate="2010-05-06T13:37:46.417" UserId="230" />
  <row Id="2013" PostId="2542" Score="1" Text="Actually I used DeoxIT on my scope and it didn't &quot;last&quot;, either.  I seem to remember it working well after I used it, but it's back to being intermittent now.  Hmmmm" CreationDate="2010-05-06T13:54:33.970" UserId="142" />
  <row Id="2014" PostId="2537" Text="This is a cool idea since you can't upload files to this site... So a small ascii-art can probably help showing some simple things :)" CreationDate="2010-05-06T14:15:03.273" UserId="689" />
  <row Id="2015" PostId="2537" Score="1" Text="It seems to work with wine under Ubuntu as well." CreationDate="2010-05-06T20:13:26.693" UserId="689" />
  <row Id="2016" PostId="2543" Text="I am certain that these transmitters do not use any encoding mechanisms and I am not able to modify the transmitter, hence my problem." CreationDate="2010-05-06T20:16:40.080" UserId="417" />
  <row Id="2018" PostId="2543" Text="You need to add encoding, then, if NRZ is required." CreationDate="2010-05-06T20:30:50.233" UserId="305" />
  <row Id="2019" PostId="2123" Text="+1 ground loop, that's my first guess when people are hearing mains in audio equipment" CreationDate="2010-05-06T21:14:01.947" UserId="1278" />
  <row Id="2020" PostId="2516" Text="I think you got multi-cycle *instructions* confused with a multi-cycle *datapath*." CreationDate="2010-05-06T21:23:02.117" UserId="1278" />
  <row Id="2021" PostId="2539" Score="1" Text="When you say 'TTL level noise', do you mean that the signal is staying well out of the TTL forbidden zone, that it's just toggling unexpectedly? If so, is it isolated spikes, or like switch bounce? Or is the signal spending time wandering around between 0.8 and 2.4? The solution will depend on the kind of noise." CreationDate="2010-05-06T22:28:08.087" UserId="740" />
  <row Id="2022" PostId="2050" Score="1" Text="Despite it's UI, Kicad is really quite powerful for the price (free) - 16 layer boards, Gerber export and no limit on board size." CreationDate="2010-05-07T02:09:37.580" UserId="554" />
  <row Id="2023" PostId="2543" Score="2" Text="unfortunately I cannot add or change anything on the transmit end so there is no way to add encoding" CreationDate="2010-05-07T08:42:12.463" UserId="417" />
  <row Id="2024" PostId="2539" Text="I am talking about isolated spikes from 0-5V and back that occur randomly but potentially quite often (up to 25% of the signal)" CreationDate="2010-05-07T08:43:54.333" UserId="417" />
  <row Id="2025" PostId="1902" Score="1" Text="&gt; Is it possible to measure the pressure in a pipe without letting any water out?&#xA;&#xA;Yes. Just install rubber membranes on both ends. But you cannot do this without moving any water and moving water loses energy to the tubing. :)" CreationDate="2010-05-07T11:23:06.853" UserId="659" />
  <row Id="2026" PostId="2546" Text="It does run proprietary firmware but there is an option of adding and downloading your own firmware. If I am lucky (read smart enough) I can reverser engineer the source by downloading the proprietary ones. " CreationDate="2010-05-07T12:31:03.810" UserId="1200" />
  <row Id="2028" PostId="2543" Text="You encode the data before it is input to the transmitter." CreationDate="2010-05-07T12:33:59.830" UserId="305" />
  <row Id="2029" PostId="2551" Text="Are you trying to minimize the material cost, or just beat the commercial version's price? How much do the commercial ones cost, roughly?" CreationDate="2010-05-07T12:46:55.663" UserId="712" />
  <row Id="2030" PostId="2546" Score="1" Text="Ah, that's interesting. Just being able to transfer new firmware is a huge step. If you're new to this sort of thing, take a look at Reversing by Eldad Eilam. You'll also need a disassembler-- I believe the standard tool is IDA Pro: http://www.hex-rays.com/idapro/ (though I haven't used it in years)." CreationDate="2010-05-07T14:04:55.887" UserId="712" />
  <row Id="2031" PostId="2444" Score="1" Text="I'm not disputing that the three states are high/low/highZ, I'm saying the bit where you say &quot;if a pin is in high impedance state, it can be pulled to high or low by an external device without much current flow&quot; This is really not the reason, you trisate a device, you deselect it to dis-connect it from the bus (by putting it in a hi-z state other devices can communcate with each other).&#xA;" CreationDate="2010-05-07T14:43:02.543" UserId="611" />
  <row Id="2032" PostId="2444" Text="Ah, OK, I think I see what you mean.&#xA;&#xA;I agree that in the multidrop bus situation you describe, the point of the hi-Z state is not limiting current flow, but to allow another device to control the pin state, like you say. But there are times, other than the bus situation, where you might use a pin as an output some of the time, but use it as a high impedance input the rest of the time." CreationDate="2010-05-07T16:05:57.200" UserId="712" />
  <row Id="2033" PostId="2556" Text="That's a *very* good idea." CreationDate="2010-05-07T16:06:47.300" UserId="712" />
  <row Id="2034" PostId="2554" Score="2" Text="4kV in your pocket, what could possibly go wrong..." CreationDate="2010-05-07T16:29:56.563" UserId="566" />
  <row Id="2035" PostId="712" Text="re: Xilinx, I think you mean xapp623.  http://www.xilinx.com/support/documentation/application_notes/xapp623.pdf" CreationDate="2010-05-07T16:38:40.447" UserId="1278" />
  <row Id="2036" PostId="715" Text="I have gotten this book, it is absolutely fantastic. I am only on chapter 3, but the first three chapters have both taught me new material and made me think of material I know in different ways." CreationDate="2010-05-08T07:55:38.477" UserId="230" />
  <row Id="2037" PostId="2539" Text="So you're expecting a pure square wave, but there are also glitches in the signal that are much shorter in duration than the expected period of the square wave?" CreationDate="2010-05-08T16:38:28.600" UserId="142" />
  <row Id="2040" PostId="2571" Text="I knew about BEAM robotics. But as you say its overly simple and to make something cool out of such a technology is very hard (see the irony here).Also beam robotics is not as active now. There is no new work done on such a technology.&#xA;But I think Vehicles is something that may get me started good" CreationDate="2010-05-08T20:43:30.710" UserId="1200" />
  <row Id="2041" PostId="2541" Text="Not very relevant to the original question IMHO.&#xA;&#xA;OTOH you may want to try http://dspguide.com/ . It is available as a free PDF download but I proudly own a copy. It is really great for learning DSP." CreationDate="2010-05-08T21:50:51.203" UserId="659" />
  <row Id="2042" PostId="710" Text="Steve: It is quite difficult not to compute the output in time of one sample since this means you are not real-time anymore and won't be able to control anything." CreationDate="2010-05-08T21:55:55.757" UserId="659" />
  <row Id="2043" PostId="2536" Text="In fact, I just got my own bottles of DeoxIT at Radio Shack.  :)" CreationDate="2010-05-08T22:51:05.013" UserId="142" />
  <row Id="2044" PostId="2575" Text="Yeah...just spend the $0.50 and buy one..." CreationDate="2010-05-09T15:28:09.727" UserId="131" />
  <row Id="2045" PostId="2539" Text="that is correct" CreationDate="2010-05-09T20:26:03.187" UserId="417" />
  <row Id="2046" PostId="2575" Score="1" Text="In all fairness to the OP, they may not be in the position to purchase or locate one without great distance or expense. I live in Brisbane CBD, 3rd largest city in Australia... and usually have to have everything delivered. " CreationDate="2010-05-10T02:01:32.953" UserId="1307" />
  <row Id="2047" PostId="730" Text="I think a dsPIC can easily work on a two layer board, it just requires a very careful layout. Your answer was clear and concise though." CreationDate="2010-05-10T04:34:07.283" UserId="230" />
  <row Id="2048" PostId="2565" Score="1" Text="TI TPL9202 is a very interesting looking part. The power supply voltage could be as high as 24VDC for our application and it looks like the recommended maximum supply voltage for the TPL9202 is only 18V. I'll keep it in mind for other projects. I'll probably go with the Darlingtons for this project." CreationDate="2010-05-10T12:44:56.547" UserId="588" />
  <row Id="2049" PostId="2580" Score="2" Text="Could you give us the first 200 bytes in raw hex?" CreationDate="2010-05-10T14:37:05.667" UserId="712" />
  <row Id="2052" PostId="2582" Text="Tried that. GNU file says it is &quot;data&quot;." CreationDate="2010-05-10T16:41:53.827" UserId="752" />
  <row Id="2053" PostId="2582" Score="1" Text="Could you post some of it? Tried searching for ASCII in it with &quot;strings&quot;?" CreationDate="2010-05-10T16:44:02.780" UserId="566" />
  <row Id="2054" PostId="2579" Text="Yes, try this. A pot is just an adjustable voltage divider, and you can approximate that with two resistors with values chosen to make a &quot;fixed&quot; pot.  By using two 4.7k resistors like Axeman says, it's like having a pot stuck at the midpoint." CreationDate="2010-05-10T19:48:08.590" UserId="215" />
  <row Id="2056" PostId="2592" Text="I was originally using a 10K ohm. I've just switched it to a 440 ohm, and now I'm seeing 4.83V at the V+ pin, while my 5v is actually 4.88v (measured at the Vcc side of the resister.&#xA;&#xA;" CreationDate="2010-05-12T00:15:15.847" UserId="776" />
  <row Id="2057" PostId="2593" Score="1" Text="That does it! I had it in backwards. Now I'm getting 3.02v, but when I hold onto the sensor to warm it up, it gets higher, and when I let go, it cools down.&#xA;&#xA;" CreationDate="2010-05-12T00:45:13.120" UserId="776" />
  <row Id="2058" PostId="2593" Text="Nice deductive work there, jluciani!" CreationDate="2010-05-12T01:31:28.823" UserId="712" />
  <row Id="2059" PostId="2593" Text="Thankss (* jcl *)" CreationDate="2010-05-12T02:13:31.673" UserId="424" />
  <row Id="2060" PostId="2596" Text="what linux did you use on that?" CreationDate="2010-05-12T02:29:01.883" UserId="740" />
  <row Id="2061" PostId="2596" Text="That looks like a really cool board. Though, for that price I can get a mini2440 with a 3.5&quot; touchscreen to boot. Truth be told, I don't really need a fancy color display, so I'll probably get a cheap-o serial 20x2 character LCD somewhere. I was hoping to find something that was in the sub-$50 category. By the way, nice idea with the thermostat and cool blog in general!" CreationDate="2010-05-12T03:00:13.023" />
  <row Id="2062" PostId="2597" Text="(@endolith: Thanks for the spelling help.)" CreationDate="2010-05-12T03:06:29.480" UserId="712" />
  <row Id="2063" PostId="2596" Text="@JustJeff: The board comes with a small distribution called TSLinux, but they also provide a downloadable Debian image, which you can boot from an SD card. I used Debian so I could get Apache, Python, and Django without having to configure everything myself." CreationDate="2010-05-12T03:11:00.897" UserId="712" />
  <row Id="2064" PostId="2596" Score="1" Text="@jfl207: Thanks. The thermostat code is on Github if you're interested: http://github.com/pingswept/thermopyla/tree/master/thermo/&#xA;and you can see the one public page that the thermostat serves here: http://thermo.pingswept.org:8080/thermolog/&#xA;&#xA;I hadn't seen the mini2440 before; it looks like a pretty good choice. They don't appear to have any distributors in the US, but I assume that's just my problem." CreationDate="2010-05-12T03:22:55.960" UserId="712" />
  <row Id="2065" PostId="2597" Text="That approach assumes that the button is connected directly to a pin somewhere in the phone.  If the button is part of a scanned grid (like many keyboards), tying the line high or low could give you some pretty crazy results.  A mosfet would make more sense in that situation." CreationDate="2010-05-12T03:41:40.007" UserId="70" />
  <row Id="2067" PostId="2600" Text="When the boot lock bits are set to prevent app code reading from bootloader section - can app code jump to the bootloader, or can you only get there by forcing a reset?" CreationDate="2010-05-12T09:34:29.913" UserId="566" />
  <row Id="2068" PostId="2596" Text="@pingswet: There are a few stores in the US that carry the mini SBCs. One example is http://andahammer.com. I'll also edit my original post to reflect a cheap board that I found. Would love to hear your thoughts on it." CreationDate="2010-05-12T12:17:16.463" />
  <row Id="2069" PostId="2596" Score="1" Text="@jfl207: That board looks great. Getting a serial port to work with that will be straightforward, and USB will probably not be too bad. Ethernet might be harder-- it looks like there is no Ethernet PHY on the board. (The PHY is the chip that translates from the Linux MII driver, which is a 4 wire, 25 MHz bus, to Ethernet, which is 2 differential pairs, 125 MHz, MLT-3 encoded, blah, blah, blah.) The other question is how you will connect to the board. It's not clear to me that it will plug into a breadboard, as it looks like it has double-row headers. That would mean you have to make a PCB." CreationDate="2010-05-12T12:37:16.097" UserId="712" />
  <row Id="2070" PostId="2596" Score="1" Text="(Ran out of characters in that last comment.) The point is: you're probably better off paying the additional $30 for the SDK, unless you want to lay out a PCB yourself. That's certainly a viable route, but only do that if you want to. You say this is your &quot;first project&quot;; I think it might be ill-advised to try a PCB with Ethernet on your first go." CreationDate="2010-05-12T12:41:18.073" UserId="712" />
  <row Id="2071" PostId="2602" Score="1" Text="I think Ian nailed this one. If you're looking for an easier, but less accurate hack, you could use a current shunt. This is a very low, very precise resistor (say, 0.1 ohms) that you put in series with your battery. You could then use the Arduino to measure the battery voltage and the voltage difference across the shunt. Sample those at 10 Hz, and you can calculate the instantaneous power. Track that over time, and I bet you could get within 10% of the true value if your load and temperature are pretty constant." CreationDate="2010-05-12T12:48:27.697" UserId="712" />
  <row Id="2072" PostId="2604" Text="So you are saying that if I have a atmega8 chip with a bootloader burned in it I can remove all the circuitry for the ISP and just connect the proper pins from the serial to the arduino? Also can you tell me how will I connect the serial with the atmega8" CreationDate="2010-05-12T12:51:42.953" UserId="1200" />
  <row Id="2073" PostId="2596" Text="Yeah, I think you're right. It'll probably be too hard for me because I'm a beginner. I guess I'll get something that has ethernet and USB on board. Any other SBC suggestions are welcome." CreationDate="2010-05-12T12:52:55.667" />
  <row Id="2074" PostId="2597" Text="@phooky: Right-- the scanned grid is a likely implementation, and a MOSFET is the right tool for the job. I'll add more detail if jason11 comes back with some answers, or you can. Know a good N-channel / P-channel MOSFET pair?" CreationDate="2010-05-12T12:54:05.730" UserId="712" />
  <row Id="2075" PostId="2604" Score="2" Text="Once you have the bootloader, here's a very minimal Arduino circuit. Connect your PC (via a TTL level converter) to the TX/RX/GND pins.&#xA;&#xA;http://profmason.com/wp-content/uploads/2008/09/arduinopins.jpg&#xA;&#xA;See this question for some more details:&#xA;http://chiphacker.com/questions/2512/ftdi-basic-breakout-5v/" CreationDate="2010-05-12T12:55:24.030" UserId="566" />
  <row Id="2076" PostId="2596" Score="2" Text="Take a look at Gumstix, the Beagleboard, and the Hawkboard. The Hawkboard was just released recently, and it's quite cheap." CreationDate="2010-05-12T12:58:27.457" UserId="712" />
  <row Id="2077" PostId="2596" Text="Fantastic. Thanks!" CreationDate="2010-05-12T13:00:18.067" />
  <row Id="2078" PostId="2596" Text="(Well, $89 cheap. Cheap for a Linux board covered in peripherals.)" CreationDate="2010-05-12T13:00:29.143" UserId="712" />
  <row Id="2079" PostId="2596" Text="Yeah, the fact that it has VGA out on board is quite awesome for the price." CreationDate="2010-05-12T13:05:23.913" />
  <row Id="2081" PostId="2602" Score="1" Text="This suggestion is effectively rolling your own version of a coulomb counter.  The problem is that you will have to add analogue signal level shifting and amplification to the shunt resistor voltage so that the analogue signal is within the ADC input voltage range and covers a reasonable span of that range." CreationDate="2010-05-12T13:13:44.330" UserId="400" />
  <row Id="2082" PostId="2604" Text="I just checked out the schematics again, but they include something like max232 or a circuit with transistors, diodes and caps. Why is that? (I am talking about the serial circuit)." CreationDate="2010-05-12T13:16:59.913" UserId="1200" />
  <row Id="2084" PostId="2604" Score="1" Text="The max232 converts RS232 level serial (as comes from the 9-pin connector on a PC) to TTL level (5v) signals suitable for talking to the Arduino/AVR. The max232 circuit can be replaced by an FTDI USB to TTL serial chip to connect to a PC." CreationDate="2010-05-12T13:21:12.187" UserId="566" />
  <row Id="2085" PostId="2604" Score="2" Text="A little note here: The Arduino bootloader only listens on the serial port for new code for a very short while at startup. Older Arduino bootloaders wait for a few seconds before the start executing code. Newer bootloaders start very quickly and have to be reset by the DTR line from an FT232. If you plan on using a max232, upload the older bootloader. Also check Sparkfun (http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=104) for some great AVR tutorials." CreationDate="2010-05-12T13:33:39.283" UserId="10" />
  <row Id="2088" PostId="2604" Score="2" Text="It's actual AVR object code. The Arduino beats some rival platforms (eg. Basic Stamp) in that it runs compiled object code not an interpreter." CreationDate="2010-05-12T14:14:19.420" UserId="566" />
  <row Id="2089" PostId="2604" Text=" @Joby Taffey - This is a tangential question: The code that is loaded via the Arduino IDE into the Arduno - is it actual AVR microcode, or a special microcode to be interpreted by an interpreter in the bootloader firmware (ala the BASIC Stamp)?" CreationDate="2010-05-12T14:14:44.987" UserId="374" />
  <row Id="2090" PostId="2578" Text="thanks for that link..." CreationDate="2010-05-12T14:46:13.973" UserId="591" />
  <row Id="2091" PostId="2602" Text="@Ian: True facts. Probably need some noise filtering too." CreationDate="2010-05-12T14:55:36.217" UserId="712" />
  <row Id="2092" PostId="2604" Text="if we require the max232 levels to be converted then does that not mean &quot;external circuitry&quot; which the arduino claims to avoid?" CreationDate="2010-05-12T15:56:01.720" UserId="1200" />
  <row Id="2093" PostId="2604" Text="An RS232/TTL level converter is considered &quot;standard&quot;, it's easy to come by unlike an AVR ISP" CreationDate="2010-05-12T16:03:01.157" UserId="566" />
  <row Id="2094" PostId="2607" Score="1" Text="I would rather reduce my own silicon and hand etch my own transistors than go to Radio Shack. That place is emblematic of the tinkering recession brought about by consumer electronics in the last 20 years. With the arrival of Make Magazine, Sparkfun, and the like, we might be through the tinkering recession, but the place still makes me want to gouge my eyes out." CreationDate="2010-05-12T16:10:49.847" UserId="712" />
  <row Id="2095" PostId="2607" Text="(Just to be clear-- nothing personal against you, tcrosley. I just have a vendetta against Radio Shack for leaving me stranded without components in the late 90s.)" CreationDate="2010-05-12T16:11:55.103" UserId="712" />
  <row Id="2096" PostId="2604" Text="So thats all? I thought there was more to it. Thats quite disappointing. " CreationDate="2010-05-12T16:29:53.183" UserId="1200" />
  <row Id="2099" PostId="2607" Text="The inflated (and continually inflating) prices on RS components+cables have caused some electronics geeks to call it the &quot;RadioShack tax.&quot;" CreationDate="2010-05-12T17:12:57.093" UserId="374" />
  <row Id="2100" PostId="2605" Text="I just ordered 4 today  (from ZA site though)  :)" CreationDate="2010-05-12T17:20:38.237" UserId="781" />
  <row Id="2101" PostId="2604" Text="@Rick_2047 - Trying to do RS-232 comms without a RS232/TTL level converter doesn't work very well.  When I was 12 and learning about tech, I picked up a MV1200 Basic interpreter chip from a company in back of circuit cellar that said you didn't need to use one, and it worked very poorly until I hooked an RS232/TTL converter up with an inverter inbetween." CreationDate="2010-05-12T20:45:50.917" UserId="374" />
  <row Id="2102" PostId="2612" Score="3" Text="You might find more Q/A for this on stackoverflow.com." CreationDate="2010-05-12T22:44:04.877" UserId="374" />
  <row Id="2103" PostId="2591" Text="USB modem?  I would bet you could find a top-notch RS-232 modem on the used market from US Robotics for a great price.  Their modems implemented virtually all the AT commands and would certainly do the trick." CreationDate="2010-05-13T00:09:22.123" UserId="374" />
  <row Id="2104" PostId="2591" Text="What OS does the board need to run?" CreationDate="2010-05-13T00:11:19.243" UserId="374" />
  <row Id="2107" PostId="2591" Text="Re: OS -- I don't care about the underlying OS, really. Though, I suppose I'd prefer some flavor of Linux as a learning platform." CreationDate="2010-05-13T03:15:40.963" />
  <row Id="2108" PostId="2591" Text="Re: Modem -- Would I be able to use an RS-232 modem to implement something like an answering machine? Any limitations on the telephony APIs I can use in general with such a modem?" CreationDate="2010-05-13T03:15:47.640" />
  <row Id="2109" PostId="2612" Text="First of all, you have to be the author of the open source project. Generally if you're just a user, you can't do much. You may be, it just wasn't clear to me from the wording in your question." CreationDate="2010-05-13T04:25:34.517" UserId="131" />
  <row Id="2110" PostId="2612" Text="What country is this? since the laws differ quite a lot." CreationDate="2010-05-13T08:41:07.873" UserId="689" />
  <row Id="2111" PostId="2617" Text="I can get access to an smd reflow heat gun but I am not sure of which parameters to use ie nozzle diameter, temp, etc. While I have been tinkering for a long time, I have never done anything like this before." CreationDate="2010-05-13T12:05:43.967" UserId="417" />
  <row Id="2112" PostId="2617" Text="s/reflow/rework/" CreationDate="2010-05-13T12:28:17.380" UserId="417" />
  <row Id="2113" PostId="2617" Score="2" Text="Use a light touch, don't force the chip off. Experiment with some junk boards first" CreationDate="2010-05-13T12:32:25.647" UserId="566" />
  <row Id="2115" PostId="2603" Score="1" Text="no external circuitry is a preposterous claim... to talk to a computer over a serial port you at least need an RS232 transciever, like a MAX232 of some sort; or as the arduino does, you can talk TTL UART directly to a USB interface chip like FTDIs." CreationDate="2010-05-13T18:30:56.603" UserId="771" />
  <row Id="2116" PostId="2585" Score="1" Text="@Joby Taffey - have you tested any of the below?" CreationDate="2010-05-13T19:07:05.537" UserId="374" />
  <row Id="2118" PostId="2402" Text="2.4Ghz is the frequency 802.11(wifi) operates over.  Not all 2.4ghz modules are wifi." CreationDate="2010-05-13T21:00:33.727" UserId="582" />
  <row Id="2119" PostId="2628" Text="I removed the high-voltage tag since 15V did not seem very high to me. :)" CreationDate="2010-05-14T00:29:13.090" UserId="659" />
  <row Id="2120" PostId="2619" Score="1" Text="I strongly recommend this method (paradoxically lots of solder is good for desoldering ;). You may also try using two soldering guns (transformer type are my favorite) to compliment the lots-of-solder but you should make it with only one.&#xA;&#xA;In this particular case you don't need the traces under the chip so don't worry if you destroy them a little in the process (just make sure there are no shorts after you are done)." CreationDate="2010-05-14T00:37:02.040" UserId="659" />
  <row Id="2122" PostId="2630" Text="There are nice high-current relays that are thru-hole mounted on PCBs.&#xA;&#xA;In either case (MOSFET or relay) the PCB traces would require reinforcement with some copper wire to handle 60A without overheating." CreationDate="2010-05-14T01:03:22.993" UserId="659" />
  <row Id="2123" PostId="2630" Score="2" Text="If you are using a PCB, which I don't recommend, I suggest a trace width calculator, for example [1]. Sixty amps is a serious current. Using a service like BatchPCB, which uses 1oz copper, means a very wide trace. &#xA;&#xA;&#xA;&#xA;&#xA;[1] http://home.comcast.net/~pcb.george/trace.html" CreationDate="2010-05-14T12:29:43.703" UserId="1402" />
  <row Id="2124" PostId="2630" Score="1" Text="60A is serious current, but if it's limited to a particular duration (e.g. 1msec) then it's not quite as much of an issue. But you have a point." CreationDate="2010-05-14T13:39:29.943" UserId="330" />
  <row Id="2125" PostId="2634" Score="1" Text="Seconded, be humble, rarely is there a part released that does not work. Unless you are buying the part from one of the educational supplies that intentionally buys the defected parts, you are probably to blame." CreationDate="2010-05-14T14:12:31.583" UserId="230" />
  <row Id="2126" PostId="2628" Score="2" Text="Everything below ~48V is considered **low** voltage." CreationDate="2010-05-14T15:08:09.710" UserId="1301" />
  <row Id="2129" PostId="2642" Score="1" Text="From a quick look online, a microblaze core would use about half of the logic cells in a XC3S400A. In addition, the Cortex A8 would run at 600MHz - 800MHz, whereas microblaze on the FPGA would run at 200MHz - 300MHz." CreationDate="2010-05-14T18:03:56.370" UserId="131" />
  <row Id="2130" PostId="2643" Text="I understand that I won't find an FPGA that beats a micro on cost and performance, but it seems like there might exist an FPGA that beats the cost of micro + FPGA, while providing similar performance, all in one chip. Does that make sense?" CreationDate="2010-05-14T18:55:43.097" UserId="712" />
  <row Id="2131" PostId="2642" Text="So it would be ~3x slower (assuming your system is processor-bound), but comparable cost, while leaving excess gates for something else." CreationDate="2010-05-14T18:56:58.340" UserId="712" />
  <row Id="2132" PostId="2644" Score="2" Text="*Very* interesting." CreationDate="2010-05-14T18:57:15.970" UserId="712" />
  <row Id="2134" PostId="2640" Score="1" Text="If your'e solo, try to find a guru/EE to consult.  Next best thing is ChipHacker, I suppose." CreationDate="2010-05-14T19:49:12.783" UserId="374" />
  <row Id="2135" PostId="2543" Text="He specified that he could not change how the transmission was done, I think that implies Penjuin cannot change the data being sent to it. " CreationDate="2010-05-14T21:00:37.733" UserId="230" />
  <row Id="2136" PostId="2645" Text="Could you give a few more details? What Labjack are you using? The U12? What basic package? Is it the LabView driver, a Windows DLL, or something else?" CreationDate="2010-05-14T21:36:52.803" UserId="712" />
  <row Id="2137" PostId="2642" Score="1" Text="That's just comparing frequency, the most basic way of comparing actual processing speed. I don't have enough knowledge about it, but it's possible for example that at the same clock speed, an ARM is twice as fast as a Microblaze" CreationDate="2010-05-14T22:00:37.363" UserId="131" />
  <row Id="2138" PostId="2642" Score="1" Text="Yeah, fair enough. A first approximation, I guess." CreationDate="2010-05-14T22:38:51.790" UserId="712" />
  <row Id="2139" PostId="2638" Text="Pinning mistakes are in my experience the most common problems." CreationDate="2010-05-15T06:33:47.627" UserId="659" />
  <row Id="2140" PostId="2628" Text="yeah no worries I was initially going to make it much higher but changed my requirements" CreationDate="2010-05-15T06:42:23.993" UserId="582" />
  <row Id="2141" PostId="2634" Text="Thirded... excellent advice above. Especially when you're tired, and something isn't working. " CreationDate="2010-05-15T13:34:15.300" UserId="1307" />
  <row Id="2142" PostId="2652" Text="Simply, my goal is to learn about receiver design. So I want to start with something as simple as possible, that I can build with discrete components and that I can measure on and understand the workings of.&#xA;&#xA;Wikipedia provides a naive circuit, that will probably not work. The second link just uses some IC that does the work.&#xA;&#xA;The last link looks promising. Although it is focused on receiving AM stations which as far as I remember is in the 150-250 kHz spectrum. Will this also work as low as 77.5kHz?" CreationDate="2010-05-15T14:52:22.627" UserId="718" />
  <row Id="2143" PostId="2655" Text="I searched for a local Ham radio club but couldn't find any. Actually most of the Ham radio clubs are concentrated at south india and I am in west India(Gujarat) and specifically in my own city I couldn't find anyone who can help." CreationDate="2010-05-15T17:14:17.767" UserId="1200" />
  <row Id="2145" PostId="2653" Text="Don't want to make a stir, but... is this question off-topic?  It is related to electronics, and I personally have a license and think it's a good thing to learn.  But it's a very different angle than most of the other posters take on this board." CreationDate="2010-05-15T17:26:59.577" UserId="374" />
  <row Id="2146" PostId="2638" Score="1" Text="I wish I could mark them all up, but this was obviously my particular problem. " CreationDate="2010-05-15T17:50:59.040" UserId="776" />
  <row Id="2148" PostId="2653" Text="I thought it was relevant because I specifically asked for resources to understand the electronics of this field. If I would have asked for where to buy the equipment and how to setup antennas then that would have been off topic :) ." CreationDate="2010-05-15T18:24:46.223" UserId="1200" />
  <row Id="2151" PostId="2646" Text="The power levels involved don't look too terribly large, but the 115V input is kind of heavy-duty for battery based applications. You might want to check out golf cart or wheel chair systems for examples, though I suspect these are probably more in the neighborhood of 24V" CreationDate="2010-05-15T20:14:25.277" UserId="740" />
  <row Id="2152" PostId="2646" Text="or i should have asked, does this have to be a battery based system, or would you consider using 'the grid'?" CreationDate="2010-05-15T20:15:43.683" UserId="740" />
  <row Id="2153" PostId="2653" Text="It's a question about getting started in an area of electronics. There are broad scope questions already on the board about other topics, like robotics, Arduinos,  and microcontrollers. The question itself (second paragraph) doesn't even mention amateur radio. The mention of amateur radio sets the context of the question. You could reword the question, swap out &quot;amateur radio&quot; with specifics - multi-band two-way voice/CW/digital communication in the MF/HF/VHF/UHF frequencies, and my answer probably wouldn't change." CreationDate="2010-05-15T23:36:28.840" UserId="638" />
  <row Id="2154" PostId="2647" Text="Sorry, I answered the question before it was edited." CreationDate="2010-05-16T05:48:05.023" UserId="230" />
  <row Id="2155" PostId="2653" Score="1" Text="This is a perfect question for the forum Rick. These are the types of questions I prefer to see, too often someone asks a question here because they are too lazy to ready a simple wikipedia article." CreationDate="2010-05-16T05:51:44.330" UserId="230" />
  <row Id="2156" PostId="2655" Text="The issue is that each country has it's own specific set of rules, I will ask my friend who is Tamil and does RF what he would do in india." CreationDate="2010-05-16T05:53:16.817" UserId="230" />
  <row Id="2157" PostId="2461" Text="Well written, I would like to note, something with a high turn on voltage is normally visible when the on AC wave only lightly passes it as it spends a significant amount of time off at 60Hz and your eye will see it. " CreationDate="2010-05-16T05:56:32.870" UserId="230" />
  <row Id="2159" PostId="2655" Text="If you go to qrz.com and type your city name you will find the names and addresses of many local radio amateurs (I just tried it). I'm sure that if you contact one them he will be able to help you and will probably let you operate his station. You might find that there is a local club." CreationDate="2010-05-16T06:16:53.633" UserId="305" />
  <row Id="2160" PostId="2655" Text="The problem with qrz is that they provide only mail addresses. I cannot go knocking at the door of a ham you know. That would be kinda embarrassing." CreationDate="2010-05-16T06:48:19.920" UserId="1200" />
  <row Id="2161" PostId="2655" Text="You should be able to find email addresses, in some cases, or phone nunbers." CreationDate="2010-05-16T20:14:17.043" UserId="305" />
  <row Id="2163" PostId="2662" Text="I have quite a few comments, but only one I have time to type right now. When I say frequency of the signal I am referring to the frequency components of my signal. This is determined completely by the rise/fall time of a digital signal." CreationDate="2010-05-17T00:10:28.383" UserId="230" />
  <row Id="2164" PostId="2655" Text="start emailing people until you find someone to help you get involved." CreationDate="2010-05-17T00:11:34.967" UserId="230" />
  <row Id="2165" PostId="2666" Text="Thanks for the input. Maybe I should just start with an ordinary AM broadcast receiver. I'm just a lot more interested in something where I can receive some data. :)" CreationDate="2010-05-17T05:38:03.117" UserId="718" />
  <row Id="2166" PostId="2649" Text="Thank you to everyone for your responses, especially Mark and justjeff. I don't have a real oscilloscope to do some measurements, so I will buy some wire tomorrow and just see what happens. " CreationDate="2010-05-17T05:55:44.190" UserId="1307" />
  <row Id="2167" PostId="2666" Score="1" Text="You may start with an AM receiver and then try to convert it to a 77.5kHz receiver with digital output. For some more links on the DCF77 you may check my Delicious links: http://delicious.com/jpcl/Projects%2Fdcf77" CreationDate="2010-05-17T09:32:23.590" UserId="659" />
  <row Id="2168" PostId="2607" Score="1" Text="Radio Shack are expensive, but they can also be convenient on a Sunday when you need just one part to test something out. " CreationDate="2010-05-17T14:01:31.373" UserId="1402" />
  <row Id="2169" PostId="2672" Text="http://electricalwhat.com/diodes/junction/" CreationDate="2010-05-17T14:11:27.380" UserId="142" />
  <row Id="2170" PostId="2669" Score="2" Text="Just to clarify, this is really two symbols." CreationDate="2010-05-17T14:14:35.097" UserId="638" />
  <row Id="2171" PostId="2669" Score="1" Text="Updated the question; thank you!" CreationDate="2010-05-17T14:30:40.337" UserId="51" />
  <row Id="2172" PostId="2652" Text="Yeah it should work fine for 77 kHz, but either the pots or the capacitors connected to them will need to be higher value.  The op-amp is just configured as a bandpass filter.  If you're aiming for a specific frequency, you don't really need the pots.  Use a simulator or find a calculator to get the right values for your frequency." CreationDate="2010-05-17T14:33:15.063" UserId="142" />
  <row Id="2174" PostId="2669" Score="1" Text="Thanks, everyone!" CreationDate="2010-05-17T14:40:32.740" UserId="51" />
  <row Id="2175" PostId="2666" Score="1" Text="Build that op-amp circuit and tune into a strong AM broadcast first, then adjust the values and move to 77.5 kHz when you've got it working." CreationDate="2010-05-17T14:41:05.943" UserId="142" />
  <row Id="2177" PostId="2669" Text="seems to me like this question would have better been served at electronics.stackexchange.com..." CreationDate="2010-05-17T16:17:21.340" UserId="771" />
  <row Id="2178" PostId="2676" Text="Thanks! This makes sense." CreationDate="2010-05-17T17:05:36.530" UserId="793" />
  <row Id="2179" PostId="2676" Text="Glad to hear it, I really suggest you spend some time on battery university." CreationDate="2010-05-17T17:29:19.333" UserId="230" />
  <row Id="2180" PostId="2653" Text="Personally, I think this is a good question (although I am a bit biased - I do have a license).  I just wanted to get others opinions.  I would have posted this in a meta-chiphacker, if there was one." CreationDate="2010-05-17T18:37:44.617" UserId="374" />
  <row Id="2181" PostId="2668" Text="reinstall the application is the best suggestion I have." CreationDate="2010-05-17T18:45:39.890" UserId="230" />
  <row Id="2182" PostId="2662" Text="I assume a digital signal for my entire post and when i say the &quot;frequency&quot; of a digital signal i'm referring to the max switching frequency of the signal.  whiles its common to discuss the content of analog signals in the frequency domain its generally not as useful to discuss digital signals in that domain. " CreationDate="2010-05-17T21:50:30.903" UserId="703" />
  <row Id="2183" PostId="2669" Text="@vicatcu: Not that site again...I wish everything would stay on one site, and not be split across two. A bigger community is better for everyone (askers and answerers). This site already has at least five times the questions and three times the users of that other one." CreationDate="2010-05-17T22:00:15.557" UserId="131" />
  <row Id="2184" PostId="2683" Score="1" Text="Blender: $0 - can export STL files, but the UI can a steep learning curve" CreationDate="2010-05-18T00:11:28.900" UserId="554" />
  <row Id="2185" PostId="2683" Text="Excellent-- I'll add that to the list. Have you ever made a case from an STL file generated by Blender?" CreationDate="2010-05-18T00:23:01.123" UserId="712" />
  <row Id="2186" PostId="2668" Text="reinstalling was no help in this case." CreationDate="2010-05-18T05:28:10.587" UserId="791" />
  <row Id="2187" PostId="2655" Text="@Kortuk, I did exactly that. I have emailed like 24 people and got two phone calls. Didn't talk long but maybe this will get somewhere" CreationDate="2010-05-18T07:00:39.563" UserId="1200" />
  <row Id="2188" PostId="2685" Text="Another comment from Eric was that the 2.5 series is not necessarily the most modern and up-to-date in the XBee family. Any one with more detail on this please let me know." CreationDate="2010-05-18T07:45:48.647" UserId="791" />
  <row Id="2189" PostId="2325" Text="(generic word) No it hasn't." CreationDate="2010-05-18T08:07:16.910" UserId="796" />
  <row Id="2190" PostId="2214" Score="2" Text="If you remove it, nobody can benefit from it!" CreationDate="2010-05-18T08:21:48.637" UserId="796" />
  <row Id="2191" PostId="861" Text="Also, what good is another tiny if it just dies the same way?&#xA;&#xA;*If you didn't fix it, it isn't fixed.*" CreationDate="2010-05-18T08:47:04.163" UserId="796" />
  <row Id="2193" PostId="1318" Text="Microchip has a few PICs with CAN. http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010302.  I will admit though, they are a bit &quot;funky&quot; to program, especially in Microchip's C18/C30 libraries.  In code review, we've observed some library code that was very difficult to read due to particulars of implementation - a transmit buffer that's used as a receive buffer, flag names that are actually the opposite of what they represent.  Certainly not something I'd recommend for someone new to microcontroller development." CreationDate="2010-05-18T12:42:10.250" UserId="374" />
  <row Id="2194" PostId="2193" Score="1" Text="@Henrik, @jluciani: gate resistor is not for limiting current to the gate, per se (which you don't want to do). It's for several other reasons: controlling the turnon/turnoff time (resistor in parallel w/ diode allows turnoff to be faster), preventing ultrahigh-frequency oscillations due to device gain and device lead inductance, and isolating faults from propagating to the circuit that drives it (esp. if directly from a microcontroller pin)." CreationDate="2010-05-18T12:43:21.577" UserId="330" />
  <row Id="2195" PostId="2193" Text="A 50-200 ohm resistor usually suffices, you don't want one that is significantly larger." CreationDate="2010-05-18T12:44:11.133" UserId="330" />
  <row Id="2196" PostId="2694" Score="1" Text="What voltage does your PIC need to function?" CreationDate="2010-05-18T14:39:42.523" UserId="230" />
  <row Id="2197" PostId="2693" Text="Thanks for answering Jason, I meant to and when I saw the question today realized I forgot." CreationDate="2010-05-18T14:41:43.630" UserId="230" />
  <row Id="2198" PostId="2696" Score="1" Text="using a charge monitoring IC is really only required when using systems that have recharge and discharge with very large capacities. I have used the voltage monitoring method with a 10 bit ADC and it has worked very well. The important part of the system is loading the Battery." CreationDate="2010-05-18T14:54:24.577" UserId="230" />
  <row Id="2199" PostId="2695" Text="extra information specific to AA has been added." CreationDate="2010-05-18T14:55:37.973" UserId="230" />
  <row Id="2200" PostId="2696" Score="1" Text="the timer method is not a good long term solution, the age and temperature conditions of a battery greatly affect the charge. We recently bought 2k batteries from an American supplier and they had clearly bought from the chinese supplier a year earlier, as they worked significantly worse than our 3 year old temperature controlled batters, and neither compare to new batteries." CreationDate="2010-05-18T14:59:31.260" UserId="230" />
  <row Id="2201" PostId="2695" Text="If you are only interested in specifically seeing failure start you can watch for that last discharge change in voltage in the end and the moment it starts use a warning." CreationDate="2010-05-18T15:01:52.957" UserId="230" />
  <row Id="2202" PostId="2689" Text="Wouldn't that require a constant current into the base?  Not a connection from the signal to the base.  http://ecee.colorado.edu/~mathys/ecen2250/labs/lab07/pnp01.png" CreationDate="2010-05-18T15:05:00.737" UserId="142" />
  <row Id="2204" PostId="2693" Text="&quot;at high frequencies&quot; meaning &quot;at signal frequencies&quot;? Wouldn't constant current out of the BJT require constant current into the base? &quot;BJE emitter resistor&quot; should be &quot;BJT emitter resistor&quot;? If the BJT is just acting as a buffer, what's the benefit over a circuit like this? imgur.com/qeEZw.png  The physical resistor can't be made as high as the &quot;virtual resistance&quot; provided by the current source?  Better linearity?" CreationDate="2010-05-18T15:34:00.923" UserId="142" />
  <row Id="2205" PostId="2694" Score="1" Text="What do you consider plenty of time." CreationDate="2010-05-18T15:55:38.510" UserId="230" />
  <row Id="2206" PostId="2696" Text="That picture is at a 100mA Discharge, if you increase the discharge, the voltage follows a more linear curve. you also see the final drop earlier and can turn on notification and stop testing the battery to extend life." CreationDate="2010-05-18T16:05:55.410" UserId="230" />
  <row Id="2207" PostId="2239" Text="I hope to understand this question someday... we have some gifted EEs on this site..." CreationDate="2010-05-18T17:19:15.883" UserId="374" />
  <row Id="2208" PostId="2694" Text="How much current does it draw?" CreationDate="2010-05-18T17:22:12.837" UserId="142" />
  <row Id="2209" PostId="2668" Text="Yeah, i see the first answer. I have had a problem like this before and reinstalling helped alot." CreationDate="2010-05-18T21:18:25.737" UserId="230" />
  <row Id="2210" PostId="2693" Text="&quot;what's the benefit over a circuit like this&quot;: Good question. Gain looks about the same (dominated by BJT base resistor Rb... in your posted circuit it's the two bias resistors in parallel) in both cases. Output impedance looks about the same... when I first saw the circuit on this page I thought the capacitor was a battery, and I thought: &quot;oh, of course, they're making the BJT into a constant current source, why wouldn't you just use a zener...&quot; in which case you truly could use a constant current source w/r/t the BJT -- the advantage of this deals with parasitics in the BJT..." CreationDate="2010-05-19T01:13:27.350" UserId="330" />
  <row Id="2211" PostId="2709" Score="1" Text="Yep - not latching the door shut. By &quot;latching&quot; I mean that the switch stays in some state until reset. I know that it is possible to have the MCU listen continuously, but would rather only do that once every few minutes. (I'm really trying to conserve power, so mcu will hopefully spend most of its time asleep)" CreationDate="2010-05-19T02:20:14.470" UserId="1402" />
  <row Id="2212" PostId="2693" Text="In general, whenever you have a capacitor in series with a signal path, &quot;low&quot; frequency and DC signals are blocked, while &quot;high&quot; frequencies are passed. The capacitor creates a high-pass filter. What constitutes &quot;high&quot; and &quot;low&quot; depends on the circuit resistance and the capacitor value. " CreationDate="2010-05-19T03:00:49.053" UserId="638" />
  <row Id="2213" PostId="1728" Score="1" Text="Yes, the Atmel SAM3S allows you to use external regulators for both 3.3 volt I/O and 1.8 volt core supplies.  Be careful with any flash MCU operated above its maximum rated temperature.  Higher temp means charge leaks off the flash floating gates faster, reducing the data retention time.  You can probably work around if you re-write the flash (and refreshing the gate charges) often.  If a typical part has 20 year data retention at 85 degrees C, you may see much shorter retention at 125 degrees C.  So be safe and re-write the flash every 6 to 12 months.  You will still be on your own." CreationDate="2010-05-19T03:21:30.533" UserId="797" />
  <row Id="2214" PostId="2708" Text="So do you have an idea about how you want to sense when the door is open or closed, or is that part of the question?&#xA;Also, would you say that you are primarily interested in when the door opens and closes, not in a &quot;latch&quot;? " CreationDate="2010-05-19T03:22:18.210" UserId="638" />
  <row Id="2215" PostId="2702" Text="Is there any difference in behavior if you were to display &quot;11&quot; or &quot;88&quot;? " CreationDate="2010-05-19T03:57:31.093" UserId="638" />
  <row Id="2216" PostId="2713" Text="ah figured out what it was, but that coded aperture is pretty interesting, glad you posted that." CreationDate="2010-05-19T05:35:56.627" UserId="582" />
  <row Id="2217" PostId="2714" Score="2" Text="Which one matches the image you supplied?" CreationDate="2010-05-19T07:34:31.797" UserId="638" />
  <row Id="2218" PostId="2708" Text="Good point. That is part of the question :) &#xA;I don't mind when the door opens and closes, just that it has done so. " CreationDate="2010-05-19T11:03:57.500" UserId="1402" />
  <row Id="2219" PostId="2702" Text="how much current is your power supply rated for? what are you using?" CreationDate="2010-05-19T15:24:41.483" UserId="771" />
  <row Id="2220" PostId="2709" Text="This is kind of a cool idea, so you'd mount this sensor on the frame and mount a piece of card on the door that breaks the beam when the door is closed? The drawback of this approach is that this type of sensor is always on, and looking at the datasheet it draws between 50-100 mA." CreationDate="2010-05-19T15:55:45.293" UserId="771" />
  <row Id="2221" PostId="2702" Text="@W5VO: if I sequentially (and cumulatively) light segments a through g, it works up to c on both LEDs. Then, when I add the d segment into the mix, LED2 goes blank and LED1 displays a to d. If I unplug the ground lead at this point, and then plug it in, LED2 lights up correctly for a brief moment then goes out again." CreationDate="2010-05-19T17:43:09.770" UserId="770" />
  <row Id="2222" PostId="2705" Text="Thanks for the link. The tutorials give me hope that what I'm trying to achieve is possible." CreationDate="2010-05-19T18:07:52.527" UserId="770" />
  <row Id="2223" PostId="2709" Text="I bet you could solve that mechanically. Maybe the cardboard could actually be a scrap of plastic that's bent so it fits into the slot sensor. When the door opens, it pulls out of the slot and un-bends, but when the door closes, it doesn't fit back into the slot. (It would need to be reset by hand, but from the question, I think that's OK.) Then you could turn the sensor off almost all the time." CreationDate="2010-05-19T19:22:24.583" UserId="712" />
  <row Id="2224" PostId="2714" Score="1" Text="Agree with W5VO... most of the pictures on that page look like sheets of dots, not the pixelated creature in your post." CreationDate="2010-05-19T20:17:37.877" UserId="374" />
  <row Id="2225" PostId="2703" Text="Your answer got me thinking about my next steps, which include using the Arduino as a digital switch for other self-powered devices. For instance, controlling a RC vehicle with its own LiPo battery. For now though, I will sit down and try do the math to see how a separate supply might help." CreationDate="2010-05-19T20:41:30.880" UserId="770" />
  <row Id="2226" PostId="2705" Score="2" Text="It's working! I removed the resistors and dropped the supply voltage to 3.3V and although they're quite bright, I got 3 of the LEDs consistently counting up to 999. Now I just need to buy another 3 and finish the project." CreationDate="2010-05-19T20:43:43.780" UserId="770" />
  <row Id="2228" PostId="2714" Text="Yeah, Google Image Search just finds regular patterns of dots or checkerboards: http://google.com/images?q=camera+calibration+pattern  It's probably a fiducial marker." CreationDate="2010-05-19T21:30:37.813" UserId="142" />
  <row Id="2229" PostId="516" Score="1" Text="you sometimes also see a diode across the 7805, anode to the input, so as to clamp the output from going (much) higher than the input - how necessary/unnecessary would that be?" CreationDate="2010-05-19T22:46:02.887" UserId="740" />
  <row Id="2230" PostId="2705" Text="Is that all you did? Nothing was hooked up incorrectly?" CreationDate="2010-05-19T22:53:44.503" UserId="638" />
  <row Id="2231" PostId="2702" Text="yea you clearly are current limiting your voltage supply based on the previous comment..." CreationDate="2010-05-20T01:07:07.170" UserId="771" />
  <row Id="2232" PostId="552" Text="A inductor does resist changes in current, but keep in mind that your circuit may want to change current rapidly. When you change the current needed for the circuit the inductor will have to dump the current somewhere. " CreationDate="2010-05-20T01:39:51.903" UserId="319" />
  <row Id="2233" PostId="2705" Text="I rebuilt the circuit from scratch, so I cannot exclude the possibility I inadvertently fixed some silly wiring mistake. " CreationDate="2010-05-20T06:46:23.310" UserId="770" />
  <row Id="2234" PostId="2702" Text="@vicatcu: I will have to look at the numbers; presumably it would mean measuring the current through every input and output to the circuit (3.3V, GND and also the 3 digital input pins used to drive the ICs' data/clock/latch) " CreationDate="2010-05-20T07:11:29.400" UserId="770" />
  <row Id="2235" PostId="2705" Text="Congratulations on getting it working - you are right, sometimes it pays just to pull something apart and start over again. " CreationDate="2010-05-20T10:57:45.400" UserId="1307" />
  <row Id="2236" PostId="2720" Score="1" Text="very cool. I do like the idea of just using an SD card rather than dealing with file transfers." CreationDate="2010-05-20T12:37:12.883" UserId="1235" />
  <row Id="2237" PostId="294" Text="typical max current varies heavily by manufacturer and design. I know many uC that cannot pass 4mA or less." CreationDate="2010-05-20T14:48:47.593" UserId="230" />
  <row Id="2238" PostId="2516" Text="No worries, I upvoted you, but it seems no-one else has." CreationDate="2010-05-20T15:27:24.353" UserId="230" />
  <row Id="2239" PostId="2721" Text="That's too bad that it is discontinued. " CreationDate="2010-05-20T17:38:06.330" UserId="1235" />
  <row Id="2240" PostId="2720" Text="What would you suggest if I want a little higher quality or color video?" CreationDate="2010-05-20T18:32:45.617" UserId="1235" />
  <row Id="2241" PostId="2719" Text="That is very similar to what I want to do but I can't use someone elses product." CreationDate="2010-05-20T18:35:07.797" UserId="1235" />
  <row Id="2242" PostId="2724" Text="Good point about assembly. For learning assembly, the Toolstick sounds great." CreationDate="2010-05-20T21:06:07.350" UserId="712" />
  <row Id="2243" PostId="2721" Text="@Jordan, yea but did you see the C6810 and C6820 on the COMedia website? I would contact them and see if they have any distributors in your neck of the woods? Those things seem like they are exactly what you are looking for... Let us know what they cost and if they're available in the USA, will ya?" CreationDate="2010-05-20T21:16:14.620" UserId="771" />
  <row Id="2244" PostId="2721" Text="@Jordan - there are some for sale options here as well http://www.electronics123.com/s.nl/sc.8/category.241/.f" CreationDate="2010-05-20T21:18:37.957" UserId="771" />
  <row Id="2245" PostId="2723" Text="I'd like to stick with low-level development.&#xA;&#xA;This SiLabs board http://www.silabs.com/products/mcu/Pages/C8051F120DK.aspx has been recommended; it looks excellent in terms of development and debugging tools. However, it just doesn't seem very beginner friendly. I suppose I'd like to have my hand held in the beginning. &#xA;&#xA;Something like this http://cgi.ebay.com/8051-MCU-development-board-studying-KIT-stepper-motor-/110534052706?cmd=ViewItem&amp;pt=LH_DefaultDomain_0&amp;hash=item19bc57cb62 has lots of things to toy with. Obviously, the support would be bad though; I'd like to combine both of the above." CreationDate="2010-05-20T21:48:26.590" UserId="800" />
  <row Id="2246" PostId="2726" Text="After skimming through that document I am wondering what you would see if you applied no voltage to either pin. So, connect ground to ground and then use your Oscope to probe the pins. " CreationDate="2010-05-21T13:38:58.113" UserId="319" />
  <row Id="2247" PostId="2726" Text="Yeah, that's a good idea. I bet the magnets induce a current in some sort of loop, which you are expected to feed to an amplifier/comparator." CreationDate="2010-05-21T14:37:02.580" UserId="712" />
  <row Id="2248" PostId="516" Text="See pg 11 of http://www.national.com/ds/LM/LM340.pdf and pg 38 of http://www.st.com/stonline/books/pdf/docs/2143.pdf  Read the datasheets! :)  I also see reversed diodes across the output to prevent it from going below ground." CreationDate="2010-05-21T14:50:31.903" UserId="142" />
  <row Id="2249" PostId="2726" Text="After drawing it out I think I have a better idea of what is going on. I bet pin 1 and pin 3 are connected to the inductor. The resistant that is being read is most likely the internal resistance of the reader head. Pin 2 is most likely just a shielding ground and not connected to the reader head itself." CreationDate="2010-05-21T15:10:14.763" UserId="319" />
  <row Id="2250" PostId="737" Score="1" Text="This answer was accepted?" CreationDate="2010-05-21T16:13:02.107" UserId="230" />
  <row Id="2251" PostId="2726" Text="I thought the same thing, but doesn't 65 ohms seem high for an inductor? I'd expect less than 1 ohm at DC. Maybe the ohmmeter is doing something funny?" CreationDate="2010-05-21T16:17:13.337" UserId="712" />
  <row Id="2252" PostId="737" Score="1" Text="Looks like a tyre kicker" CreationDate="2010-05-21T16:38:05.943" UserId="566" />
  <row Id="2253" PostId="2729" Score="1" Text="What does TTY mean?  Do you mean TTL?" CreationDate="2010-05-21T16:40:11.043" UserId="374" />
  <row Id="2254" PostId="2729" Score="1" Text="I was thinking unix for some reason, the serial output to the alarm mumpad is what I was thinking of." CreationDate="2010-05-21T16:44:13.277" />
  <row Id="2255" PostId="2729" Text="The problem your'e mentioning is a _hardware problem_ (mismatched logic levels), and not a software problem.  So I wouldn't refer to the system as a TTY in the case." CreationDate="2010-05-21T16:46:59.577" UserId="374" />
  <row Id="2256" PostId="2655" Text="Good luck Rick! Let me know if I can be of any help." CreationDate="2010-05-21T16:58:15.487" UserId="230" />
  <row Id="2257" PostId="2730" Text="Im not really sure, I'm fairly new to hardware electronics so this project might be over my head. Thanks anyway" CreationDate="2010-05-21T17:01:28.693" />
  <row Id="2258" PostId="2730" Text="@Aaron - Since the DSC-1555 is a home security/automation device, you might find some more tips/help on a DIY home security or home automation site, as they might know more about how the DSC-1555 works.  The folks here are primarily into electronics and embedded stuff, but not specifics like that." CreationDate="2010-05-21T18:28:47.867" UserId="374" />
  <row Id="2259" PostId="2730" Text="@Aaron - Another thought - try wiring up the numpad to a PC serial port, and using a terminal emulator running on that port with different options (baud rate, bits, parity, flow control, etc) to see if you can get any data out.  You may need to use a null-modem to connect the two together, as the TX/RX lines may need to be swapped." CreationDate="2010-05-21T18:32:38.000" UserId="374" />
  <row Id="2260" PostId="2730" Text="If it's RS232 then use a MAX232 as a level converter." CreationDate="2010-05-21T19:02:13.637" UserId="339" />
  <row Id="2261" PostId="2729" Score="2" Text="A TTY is a teletype. I think here it means RS232 aka serial port, 12V is the standard voltage for that." CreationDate="2010-05-21T19:08:03.777" UserId="339" />
  <row Id="2262" PostId="2726" Text="I have seen inductors with significantly higher resistance. you can get very high inductance inductors by using very very thin wire with a very high resistance/foot plus a lot of coils. I have used uH inductors that break 500 Ohms because size and inductance were a large factor while the resistance was not." CreationDate="2010-05-21T21:03:46.240" UserId="230" />
  <row Id="2263" PostId="1318" Text="CAN and RS-485 are really apples and oranges.  CAN defines the bit level protocol as well as the physical electrical layer (PHY).  RS-485 is just a physical layer specification, it specifies nothing about the protocol.  It would be completely up to you to find or implement an actual protocol on top of the RS-485 PHY.  CAN was designed for high noise environments, its mostly used in the automobile and manufacturing industries.  Its protocol is a rather complex message passing system and has very high overhead (low actual data rate) but has high data integrity." CreationDate="2010-05-21T22:20:57.987" UserId="703" />
  <row Id="2264" PostId="1455" Text="I have one of these as well, as so far it's proved quite useful for my needs. It does what it says on the box, and seems to do it well." CreationDate="2010-05-21T22:30:15.163" UserId="647" />
  <row Id="2265" PostId="2734" Score="1" Text="By the way, are you sure you need +/- 9V? I thought the 741 went down to +/- 5, which you can almost do by splitting the 9 V supply." CreationDate="2010-05-22T22:17:44.810" UserId="712" />
  <row Id="2266" PostId="2726" Text="Interesting. I didn't know that." CreationDate="2010-05-22T22:18:32.750" UserId="712" />
  <row Id="2267" PostId="2732" Text="Sweet! Might we see a blog post with the results?" CreationDate="2010-05-22T22:19:49.100" UserId="712" />
  <row Id="2268" PostId="2737" Score="3" Text="TI makes a 'rail splitter' just for this application: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=296-6548-5-ND&#xA;&#xA;if you choose to use a generic op amp, be careful of stability issues if your using decent sized bypass capacitors on your +/- supply lines, adding a resistor to the output of the op amp will increase stability but increase resistance to ground which can have negative effects on audio circuits (increased cross talk in a multichannel system for instance)" CreationDate="2010-05-22T22:31:26.570" UserId="703" />
  <row Id="2269" PostId="2695" Text="Thanks for this and the other answers, it's given me enough to read about :)" CreationDate="2010-05-23T09:15:13.647" UserId="710" />
  <row Id="2270" PostId="2696" Text="Thanks, it looks like I might be able to use this " CreationDate="2010-05-23T09:15:38.620" UserId="710" />
  <row Id="2271" PostId="2486" Text="I can recommend Little Bird Electronics and Jaycar too, both are excellent." CreationDate="2010-05-23T10:01:18.333" UserId="25" />
  <row Id="2272" PostId="2723" Score="1" Text="@pingswept Oh man. I hate to be the pedantic guy again, but the Arduino is not programmed with Java. It's programmed with C/C++ and the code is compiled with AVR-GCC.&#xA;&#xA;I don't know where this 'Arduino is programmed with Java' meme started, but it's wrong. It's probably due to the fact that Arduino uses the same IDE as Processing, which is, in fact, Java code. Or maybe it's because the IDE runs in Java." CreationDate="2010-05-23T14:15:46.633" UserId="746" />
  <row Id="2273" PostId="2723" Text="Hey, no problem. That's not pedantic at all. I think you're right that I was thinking of the Processing IDE-- I've used that a fair bit, and I haven't used an Arduino in the last year or so. I'll correct my post." CreationDate="2010-05-23T14:50:04.783" UserId="712" />
  <row Id="2274" PostId="2695" Text="If you are willing to accept error in the time to replace batteries you should be able to use a timer and just recalibrate for new batteries every few months." CreationDate="2010-05-23T15:36:30.690" UserId="230" />
  <row Id="2275" PostId="2655" Text="Make sure you determine your legal levels in India, US legal radiation limits will differ and you can get yourself in big big shit in India if you radiate too much power and they think you are a terrorist or spy." CreationDate="2010-05-23T16:31:39.283" UserId="230" />
  <row Id="2276" PostId="1137" Text="I think it was nice to add to this thread and I applaud you for it. I could see this helping give others ideas, and that is what I wanted this thread for." CreationDate="2010-05-23T17:18:39.003" UserId="230" />
  <row Id="2277" PostId="516" Score="1" Text="@rdeml: You can buy voltage rectifiers that have a total of 0.5v drop, unfortunately my box of parts is all packed up ready for a move or I could get you a part number." CreationDate="2010-05-24T02:41:13.720" UserId="373" />
  <row Id="2278" PostId="2738" Score="1" Text="Right, there are lots of pin campatible amps that are much better.  If you are really cheap and have the 741 you can use it." CreationDate="2010-05-24T14:43:13.453" UserId="1498" />
  <row Id="2279" PostId="2718" Text="Jordan, I would suggest you created a new question from the ADDED section and accepted someones information for your original question. That was you reward someone for their hard work and allow someone to be rewarded for helping you with the next step." CreationDate="2010-05-24T14:52:10.070" UserId="230" />
  <row Id="2280" PostId="2718" Text="When you create the new question could you link me to your datasheets you found for the new cameras, I am used to doing that type of interface but I would like to look at the datasheet to confirm my knowledge first." CreationDate="2010-05-24T14:52:51.770" UserId="230" />
  <row Id="2286" PostId="2750" Text="And so there should be a linear connection, thus it will equivalent stall with a 0.4kg weight hanging from a 2cm long arm?" CreationDate="2010-05-25T15:38:35.883" UserId="718" />
  <row Id="2287" PostId="2750" Text="That's correct, assuming you're on Earth." CreationDate="2010-05-25T16:05:36.067" UserId="712" />
  <row Id="2289" PostId="2750" Text="Poor assumption." CreationDate="2010-05-25T16:55:40.350" UserId="230" />
  <row Id="2291" PostId="2750" Text="@Kortuk - Designing rovers for other planets, are we?  :)" CreationDate="2010-05-25T17:05:05.883" UserId="374" />
  <row Id="2293" PostId="2750" Score="1" Text="IMHO is &quot;Assuming a planet that has same gravity as Earth&quot; :-)" CreationDate="2010-05-25T17:51:35.250" UserId="244" />
  <row Id="2294" PostId="2751" Text="that table is in Kg * cm, or N*m, not in Kg/cm." CreationDate="2010-05-25T18:35:52.407" UserId="230" />
  <row Id="2296" PostId="2751" Text="Unfortunately use of &quot;/&quot; instead of &quot;*&quot; (or nothing) for some measure units is common in non-scientific environment (like kW/h versus kWh, or mph versus m/h)&#xA;" CreationDate="2010-05-25T20:27:08.673" UserId="244" />
  <row Id="2297" PostId="2748" Text="I'm in the USA - socal" CreationDate="2010-05-25T21:05:51.353" UserId="1267" />
  <row Id="2298" PostId="2750" Text="Which is why the proper SI unit has dimensions of *force* times distance, not *mass* times distance! =P" CreationDate="2010-05-25T22:15:04.773" UserId="740" />
  <row Id="2299" PostId="2751" Text="Yeah, I know that can happen, but I am not sure that it is that case." CreationDate="2010-05-26T02:12:46.300" UserId="230" />
  <row Id="2300" PostId="2751" Score="1" Text="@Kortuk, it is :-)&#xA;I've used enough RC servos to tell you that that unit is really kg*cm, written almost always as kg/cm. And that, on this planet, a 3kg/cm servo will stall with a 3kg weight hung from a 1cm shaft. &#xA;Talking about kg versus N as a force unit, well, &quot;Kilogram-force&quot; IS a (non SI) force unit: is defined as the force exerted on one kilogram of mass by a ~9.806 m/s2  gravitational field ~= 9.806N" CreationDate="2010-05-26T09:02:13.750" UserId="244" />
  <row Id="2301" PostId="2755" Text="Looks like some great ideas Jeff! I'll buy a few chips and hopefully start to see what method works best. " CreationDate="2010-05-26T16:32:33.827" />
  <row Id="2302" PostId="2756" Text="please make this a community wiki question" CreationDate="2010-05-27T00:55:55.440" UserId="330" />
  <row Id="2303" PostId="2760" Text="The pins are not reversed parity. I have checked all silly connections." CreationDate="2010-05-27T11:31:07.510" UserId="811" />
  <row Id="2304" PostId="2761" Text="I am thinking you are right, the UPS does not like the high frequency square wave. I am really wishing that I had looked at the generators output on a scope... but its since be brought back." CreationDate="2010-05-27T11:34:09.850" UserId="811" />
  <row Id="2305" PostId="1610" Text="learned something new today; you have my upvote :-)" CreationDate="2010-05-27T14:06:47.437" UserId="595" />
  <row Id="2306" PostId="2111" Text="It is easier to use Catenary with Build Your Own Blocks.  See http://robotclub.ab.ca/blog/27/code-blocks-electronic-bricks-and-lego-beams" CreationDate="2010-05-27T20:11:36.607" UserId="106" />
  <row Id="2307" PostId="2768" Text="Those are likely &quot;epoxy-paper&quot; boards. I did not clamp the board while populating it." CreationDate="2010-05-27T20:37:49.130" UserId="595" />
  <row Id="2308" PostId="2768" Text="They kind of look like epoxy-paper. If you can hold the board flat&#xA;with a vice or clamp while you solder it may bend less when the clamp&#xA;is removed. " CreationDate="2010-05-27T22:14:16.127" UserId="424" />
  <row Id="2309" PostId="2772" Text="good answer! (says a motor guru)" CreationDate="2010-05-27T22:32:25.280" UserId="330" />
  <row Id="2310" PostId="2041" Text="brake &amp; coast are modes where the controller doesn't supply any power, and the mechanical load back-drives the motor, so it acts as a generator. If you turn off all 4 drive transistors, the motor free-wheels or coasts; if you turn on either both the high-sides, or both the low-sides, you form a low impedance electrical load to the motor, which causes it to act like a brake." CreationDate="2010-05-27T22:37:03.057" UserId="740" />
  <row Id="2311" PostId="2778" Text="Actually a ZIF connector is irrelevant if it's been done on another bus, this is just a physical layer." CreationDate="2010-05-28T00:44:49.553" />
  <row Id="2312" PostId="2778" Text="Do I understand correctly that you're trying to make two displays show the same thing at the same time?&#xA;&#xA;Do you have a part number for the display?" CreationDate="2010-05-28T00:59:48.747" UserId="712" />
  <row Id="2313" PostId="2778" Text="Yes I am trying to display on two displays at the same time, I do not have the LCD part number. It's a black box at the moment. The driver chip is potted." CreationDate="2010-05-28T01:42:11.963" />
  <row Id="2314" PostId="2780" Text="I'll definitely try that, thanks!&#xA;" CreationDate="2010-05-28T03:48:21.320" />
  <row Id="2315" PostId="2783" Score="3" Text="Are you doing this just one time? " CreationDate="2010-05-28T13:26:37.227" UserId="1402" />
  <row Id="2316" PostId="2784" Score="1" Text="eBay is also a great place to get ZIF sockets and similar paraphernalia." CreationDate="2010-05-28T13:27:19.020" UserId="1402" />
  <row Id="2317" PostId="2786" Score="1" Text="If the board is dense you could also turn existing vias into programming points. You need to remove the soldermask and possibly&#xA;change the pad and hole size. A row of pads could be a lot easier if it fits." CreationDate="2010-05-28T17:07:51.327" UserId="424" />
  <row Id="2318" PostId="2786" Text="what the heck are pogopins... are you talking about a 2x3 ISP header (see my answer below)" CreationDate="2010-05-28T18:11:53.903" UserId="771" />
  <row Id="2319" PostId="2786" Score="1" Text="Pogo pins are metal rods with spring-loaded tips. They're often used in test fixtures when you need to make a temporary connection to a circuit." CreationDate="2010-05-28T18:16:47.843" UserId="712" />
  <row Id="2320" PostId="2786" Text="Picture of pogo pins: http://www.flickr.com/photos/pingswept/2280832792/" CreationDate="2010-05-28T18:17:33.770" UserId="712" />
  <row Id="2321" PostId="2792" Text="Sounds ideal!  I have a few CR2032s hanging about; I'll give them a whirl." CreationDate="2010-05-28T21:13:39.937" UserId="70" />
  <row Id="2322" PostId="2792" Text="Just watch their voltage, and remember to always measure a batteries voltage under load to check how much life is left." CreationDate="2010-05-28T21:25:22.003" UserId="230" />
  <row Id="2323" PostId="2783" Text="I will be doing it for a whole batch (&gt;1)" CreationDate="2010-05-28T21:58:24.170" UserId="417" />
  <row Id="2324" PostId="2794" Text="ok - I don't see anything about BGAs? Am I missing something obvious?" CreationDate="2010-05-29T01:23:55.940" UserId="399" />
  <row Id="2325" PostId="2794" Text="There are links to places that sell adaptor boards. Perhaps one of the sites sells the adaptor you need." CreationDate="2010-05-29T01:57:57.697" UserId="712" />
  <row Id="2326" PostId="2794" Text="Actually, as I looked through those sites just now, I didn't see any BGA adapters. Sorry about that." CreationDate="2010-05-29T02:05:55.963" UserId="712" />
  <row Id="2327" PostId="2794" Text="Could you get the part in its TQFP-64 package instead?" CreationDate="2010-05-29T02:06:35.260" UserId="712" />
  <row Id="2328" PostId="2782" Text="Thrust on full-size manned aircraft is controlled by varying the propeller pitch or the articulated rotor pitch, keeping the petrol-powered engine running at a constant speed.&#xA;&#xA;Thrust on model quadcopters and other model multi-rotor helicopters and many model rigid-wing aircraft is controlled by varying the electric motor speed. Each drive motor is connected to a rigid propeller.&#xA;Such helicopters don't have a swash plate.&#xA;Inverted hovering requires changing the direction of the motor.&#xA;http://spectrum.ieee.org/automaton/robotics/robotics-software/quadcopter-hexacopter-octocopter-uavs&#xA;" CreationDate="2010-05-29T06:11:18.480" UserId="813" />
  <row Id="2329" PostId="2774" Text="Excellent. My understanding is that both pusher props and tractor props are designed so they apply force directly through the center of gravity, precisely for the reasons you've mentioned here.&#xA;I'm assuming that the line of force doesn't change when you reverse direction -- does that sound reasonable?&#xA;If the airplane is stable when you go from cruising down to the runway and you suddenly kill the power to the motor on touchdown, then I'm guessing that a little bit of reverse thrust is going to be just as stable." CreationDate="2010-05-29T06:16:49.950" UserId="813" />
  <row Id="2330" PostId="2776" Text="I have to handle dead time properly in order to avoid shoot-through even in the normal forward-running case. I'm glad you reminded me to check this, though -- it's quite possible that covering the full range from fast-forward to fast-reverse may require tweaking the dead time." CreationDate="2010-05-29T06:36:17.197" UserId="813" />
  <row Id="2331" PostId="2785" Text="I see lots of boards that have a place for such a header (either rows of through-holes or rows of SMT pads) to be soldered to the board, but the header itself is missing.&#xA;I assume that the manufacturer uses the pogo-pins mentioned by Joby to temporarily touch the programmer to those pads on the board." CreationDate="2010-05-29T06:44:45.590" UserId="813" />
  <row Id="2332" PostId="2782" Text="True for every single point you've cited. But the original question was about model RC planes (so thrust -&gt; motor speed) and model RC heli and inverted hovering (so thrust -&gt; pitch). Coaxial multi-rotor heli AFAIK can't do inverted hovering. Quadcopters are another matter, and I've yet to see a quad that can REALLY go upside-down during flight..." CreationDate="2010-05-29T11:43:02.373" UserId="244" />
  <row Id="2333" PostId="2794" Text="sorry it's currently only available as a proto BGA " CreationDate="2010-05-29T12:19:28.220" UserId="399" />
  <row Id="2334" PostId="2795" Text="cheers - unfortunately it's the wrong layout, it's the right pitch tho so it's a start!" CreationDate="2010-05-29T12:20:42.400" UserId="399" />
  <row Id="2335" PostId="2796" Text="it's just not currently available in QFP as the chip is only available as a prototype BGA right now.....thanks for all the help tho!" CreationDate="2010-05-29T12:22:42.730" UserId="399" />
  <row Id="2336" PostId="2794" Text="@ Pingswept - Cheers for havin' a look tho " CreationDate="2010-05-29T12:28:30.100" UserId="399" />
  <row Id="2337" PostId="2796" Score="1" Text="It actually shouldn't be too hard to solder that BGA with a hot air soldering gun, i'd probably also pre heat the PCB.  If your near a university with a decent EE department they may let you use their lab for a few minutes.  " CreationDate="2010-05-29T19:39:48.990" UserId="703" />
  <row Id="2338" PostId="2796" Text="I was hoping to do it in that fashion cuz i've got a heat gun, just need to find a suitable PCB - not sure if it would be cheaper to get one made up?  " CreationDate="2010-05-29T20:10:20.330" UserId="399" />
  <row Id="2339" PostId="2797" Text="Are you saying you have tried to build it and it didn't work? Make sure you aren't trying to pull too much current from your microcontroller." CreationDate="2010-05-29T21:01:37.937" UserId="319" />
  <row Id="2340" PostId="2796" Score="3" Text="your going to have a hard time doing it with a heat gun.  You need control over the air flow and temperature and theres a decent chance you'll kill the chip in the process.  What you really want to do is look up the reflow temperature profile for the IC and use a IR temperature gauge to follow it as closely as possible." CreationDate="2010-05-29T23:39:09.240" UserId="703" />
  <row Id="2341" PostId="2796" Text="did find these guys: http://www.emulation.com/catalog/off-the-shelf_solutions/prototyping_adapters/bga_csp/bga_csp.cfm&#xA;&#xA;But for $115 each i'd probably just design the PCB for the entire circuit and be done with it." CreationDate="2010-05-29T23:51:31.587" UserId="703" />
  <row Id="2342" PostId="2802" Text="Why would I use a 7447? It uses 7 pins to drive one display." CreationDate="2010-05-30T06:17:23.370" UserId="1200" />
  <row Id="2343" PostId="2797" Text="I had already seen all the mentioned links. What I really wanted was a way to wire charlieplexing on the breadboard. The way I see it, it will require too much of wires. There has to be a better way. As soon as I get my computer working I would post a picture of how I had done it." CreationDate="2010-05-30T06:19:07.423" UserId="1200" />
  <row Id="2344" PostId="2797" Text="You don't need to go directly from a µC pin to all LED pins, instead you can use chains of wires." CreationDate="2010-05-30T07:15:11.010" UserId="339" />
  <row Id="2345" PostId="2797" Text="@starblue can you elaborate a little" CreationDate="2010-05-30T07:33:29.770" UserId="1200" />
  <row Id="2346" PostId="2802" Text="A 7447 uses 4 pins to convert from binary to the 7 segments. Then all you need to do is to enable the correct display to display it. " CreationDate="2010-05-30T10:44:04.437" UserId="776" />
  <row Id="2347" PostId="2797" Score="1" Text="@Rick_2047: 4 seven segment displays will indeed require a lot of space/wires on the breadboard. It may be easier to solder wires directly on the displays instead: http://www.instructables.com/files/deriv/F6I/LTSP/F4WY1KXJ/F6ILTSPF4WY1KXJ.MEDIUM.jpg" CreationDate="2010-05-30T11:18:05.713" UserId="595" />
  <row Id="2348" PostId="2808" Text="As erik said, LM7806 and a couple of caps will do the job: http://www.bibrand.de/GPS/dc-wire.gif" CreationDate="2010-05-30T11:23:56.763" UserId="595" />
  <row Id="2349" PostId="2807" Score="3" Text="Is this a signal or a power supply?" CreationDate="2010-05-30T11:50:19.647" UserId="142" />
  <row Id="2352" PostId="2797" Text="When you say &quot;port&quot; in your question, are you thinking 1 single pin, or like a 8 bit parallel output port? If you are referring to 1 pin then you probably have a misunderstanding of how charlie-plexing works." CreationDate="2010-05-30T12:22:34.963" UserId="319" />
  <row Id="2353" PostId="2797" Text="@kellenjb:I mean a whole 8 Bit port, like PORTB PORTC and PORTD.&#xA;" CreationDate="2010-05-30T13:32:50.030" UserId="1200" />
  <row Id="2354" PostId="2797" Text="@JonathnD can you tell me from which instructable did you pic that picture up?" CreationDate="2010-05-30T14:03:22.060" UserId="1200" />
  <row Id="2355" PostId="2812" Score="2" Text="I think I must of had brain freeze.. the simplest solution I think is just to increment an variable of type long int every time a rising edge is detected. Read that value once every second and then reset it to zero." CreationDate="2010-05-30T16:12:13.907" UserId="819" />
  <row Id="2356" PostId="2812" Score="2" Text="Actually I will need to read the value every 4 seconds to measure down to 0.25Hz" CreationDate="2010-05-30T16:25:49.530" UserId="819" />
  <row Id="2357" PostId="2814" Text="Yes your probably right -it will be too slow for 1MHz but Id imagine a 20MIPS RISC processor could do better than 50KHz. Anyway I was also considering clocking an 8bit binary counter with the signal and connecting the carry out of the counter to the external interrupt pin of the MCU, then reading frequency of the signal as the sum of the carry bit interrupts plus the o/p count value of the counter every n seconds, Im guessing that is what you were getting at when you said a combination of hardware and software counters. " CreationDate="2010-05-30T19:32:55.570" UserId="819" />
  <row Id="2358" PostId="2796" Text="Thanks for the help" CreationDate="2010-05-30T20:24:09.593" UserId="399" />
  <row Id="2359" PostId="2815" Text="Yes I mentioned that in the update  to my question (earlier)that I would have to count to 4 seconds for... and I yes I *would like* to be able to differentiate between say 500,000.00Hz and 500,000.25Hz. I had thought of using different ranges, I could easily tie this in with the rest of the hardware as the signal has 6 selectable ranges so I could probably design a simple 6 to 3 encoder to indicate which range... but I'm not sure if would be necessary if I use a hardware counter coupled with 4 second update time, this should take  care of the problems at either end of the spectrum" CreationDate="2010-05-30T20:40:34.417" UserId="819" />
  <row Id="2360" PostId="2817" Score="1" Text="Excellent timororr, that will do I exactly what I want without cost of  extra IC's which is always good, I think I was too quick to dismiss the possibility of solving the problem in software. Thanks" CreationDate="2010-05-31T07:24:04.850" UserId="819" />
  <row Id="2361" PostId="2797" Text="@Rick_2047: the same instructable that I linked in my answer: http://www.instructables.com/id/Charlieplexing-7-segment-displays/" CreationDate="2010-05-31T11:13:15.693" UserId="595" />
  <row Id="2362" PostId="2811" Text="There is a relatively easy way to do this using a capture interrupt on a PIC and Timer 1 running at a very high speed. If you are still interested in other methods let me know and I can outline it in an answer." CreationDate="2010-05-31T19:51:16.720" UserId="230" />
  <row Id="2363" PostId="2814" Text="I think the OP was referring to the built-in hardware counter. They all have overflow interrupts that can be used for improving the counting range." CreationDate="2010-05-31T20:59:15.507" UserId="659" />
  <row Id="2364" PostId="2716" Text="I agree. It's simplest to have the hardware only sense &quot;door closed&quot; or &quot;door open&quot;, and have the software keep track of whether the door has ever been opened, how long the door has been open, how long the door has been closed, etc.&#xA;&#xA;The above &quot;2 pieces of metal&quot; is fine for prototyping.&#xA;Later you may want to switch to some other door sensor less vulnerable to static charge. -- a magnet and a hall effect sensor, a spot painted white and an optical reflective sensor, etc.&#xA;Anything that gives you a &quot;0&quot; when the door is open and a &quot;1&quot; when the door is closed.&#xA;" CreationDate="2010-05-31T23:34:03.543" UserId="813" />
  <row Id="2365" PostId="2784" Score="1" Text="Not necessary -- it's generally much easier to do in-circuit programming on the board after the part is in place." CreationDate="2010-05-31T23:47:35.203" UserId="330" />
  <row Id="2366" PostId="2811" Text="I haven't started work on this yet so yes Im still interested." CreationDate="2010-06-01T10:07:13.607" UserId="819" />
  <row Id="2367" PostId="2807" Text="this is a technicality, but what I think you're actually asking for here is a DC-DC converter. A level-shifter doesn't &quot;scale&quot; a voltage level, it merely &quot;offsets&quot; it." CreationDate="2010-06-01T16:26:42.890" UserId="771" />
  <row Id="2368" PostId="2817" Text="@timrorr, i'm interested in your thoughts on my answer below if you feel like reading it" CreationDate="2010-06-01T18:40:53.213" UserId="771" />
  <row Id="2369" PostId="2821" Text="I don't have more than one crystal on one chip. The arduino one's have there own 16MHz clock while the normal chips use the internal clock." CreationDate="2010-06-02T03:45:52.837" UserId="1200" />
  <row Id="2370" PostId="2832" Text="most of the systems I work with are in the 50k lines of code range." CreationDate="2010-06-02T16:35:51.097" UserId="230" />
  <row Id="2371" PostId="250" Score="1" Text="I've traced it for better contrast &#xA;http://i49.tinypic.com/10i9ouc.png&#xA;" CreationDate="2010-06-02T18:11:05.430" UserId="582" />
  <row Id="2372" PostId="2837" Text="I read a I have to expect to spend up front time to get it to stop throwing false positives. What lint had you chosen to use at the time?" CreationDate="2010-06-02T19:30:10.963" UserId="230" />
  <row Id="2373" PostId="2814" Text="@starblue, is the code I wrote below what you had in mind with your answer?" CreationDate="2010-06-02T20:35:43.887" UserId="771" />
  <row Id="2375" PostId="2842" Text="Overall, looks quite good. The power supply looks to be the main drawback.. though I'm wondering, if it only pulls 5 watts, how tough could that be." CreationDate="2010-06-03T03:29:34.963" UserId="740" />
  <row Id="2376" PostId="2837" Text="At the time it was version 8.0." CreationDate="2010-06-03T04:52:01.413" UserId="625" />
  <row Id="2377" PostId="2841" Text="What does SBC stand for?" CreationDate="2010-06-03T07:54:54.173" UserId="689" />
  <row Id="2378" PostId="2841" Score="3" Text="Single Board Computer" CreationDate="2010-06-03T08:23:02.883" UserId="566" />
  <row Id="2379" PostId="2846" Text="I think the Gumstix boards are perfect when you need small size, but they're a little more expensive than the competition." CreationDate="2010-06-03T14:05:00.040" UserId="712" />
  <row Id="2380" PostId="2837" Text="Do you know what company made it, there are many different Lint programs out there. I was told it is named lint because of the little pieces of lint it finds that the compiler misses." CreationDate="2010-06-03T14:57:32.217" UserId="230" />
  <row Id="2381" PostId="2846" Text="They kill me in price. I like them, but I would much rather make my own 20 dollar solution then spend a couple hundred on that. I guess i do not value my time well enough." CreationDate="2010-06-03T15:50:00.723" UserId="230" />
  <row Id="2382" PostId="2847" Text="Accelerometers are designed for this actually, there is an entire section on how to do it. Accelerometers are very very low cost in many cases and sometimes cost is a larger issue then perfect functionality." CreationDate="2010-06-03T16:03:08.450" UserId="230" />
  <row Id="2383" PostId="2847" Score="2" Text="I always try to explain this to students, and I am going to add it here because I think it is an important concept. Engineering is not always about doing it the best way, it is about doing it in such a way that the user has cannot tell the difference in anything except the price tag." CreationDate="2010-06-03T16:04:17.200" UserId="230" />
  <row Id="2384" PostId="2847" Score="2" Text="There is something to be said for doing it first, and there is alot to be said for doing it better than the last guy." CreationDate="2010-06-03T16:04:41.177" UserId="230" />
  <row Id="2385" PostId="2849" Text="I do not think it will attenuate the signals, unless you are referring to the higher frequencies, which is the point of the cap. He needs to go to 50Hz or lower to match his data sampling device." CreationDate="2010-06-03T16:10:37.100" UserId="230" />
  <row Id="2386" PostId="2850" Score="1" Text="Just for the record, this answer is epic." CreationDate="2010-06-03T16:51:58.577" UserId="712" />
  <row Id="2387" PostId="2849" Score="1" Text="Ah, I hadn't thought about it from the aliasing perspective. I still think that large caps will attenuate high frequency signals, but that's actually a good thing in this case. So yes, setting the bandwidth around 50 Hz is good." CreationDate="2010-06-03T16:54:36.700" UserId="712" />
  <row Id="2388" PostId="2837" Score="1" Text="Sorry, Gimpel's PC-LINT.  What's nice is that they at least help you tame the output some with some predefined rule sets based on the compiler and editor you use.  They're available for download at their site: gimpel.com" CreationDate="2010-06-03T17:06:29.873" UserId="625" />
  <row Id="2389" PostId="2850" Score="1" Text="Dr. Kortuk, Ph.D in accelerometers! :-)" CreationDate="2010-06-03T17:08:12.287" UserId="625" />
  <row Id="2390" PostId="2829" Score="1" Text="It really depends on the specs and the quantities of your PCB. Can you let us know the approximate size of the PCB, the quantity you want, how many layers, and if there are any other unusual requirements?" CreationDate="2010-06-03T18:11:41.130" UserId="131" />
  <row Id="2391" PostId="2833" Text="Just tried E-Teknet - they are not bad pricewise for boards. The assembly price is high tho. " CreationDate="2010-06-03T19:40:02.090" UserId="1402" />
  <row Id="2392" PostId="2847" Text="I agree, but it depends on your motives (which troy has not stated); do you want it to work well, or do you want to learn ? They are not necessarily mutually exclusive, but you wouldn't write your own compiler just to blink an LED unless you specifically wanted to learn about compiler design." CreationDate="2010-06-03T20:33:00.313" UserId="417" />
  <row Id="2393" PostId="2847" Text="Yeah, I adding that to discuss your answer, in general if he needs to be able to tell a different orientation 30 times a second it is going to have gigantic accelerations on it, which in turn means you need a lot more than 100 samples a second." CreationDate="2010-06-03T20:42:17.717" UserId="230" />
  <row Id="2394" PostId="2847" Text="It does seem that the user has an accelerometer, and it being harder gives you a chance to learn more. The LED idea was just because there is a decent chance if you implement something cheap like that you will be using a cheap acceleration measurement device." CreationDate="2010-06-03T20:52:45.990" UserId="230" />
  <row Id="2395" PostId="2061" Text="I have purchased the &quot;Make: Electronics&quot; book, and all I can say is &quot;WOW&quot;." CreationDate="2010-06-03T21:15:16.937" UserId="625" />
  <row Id="2396" PostId="2850" Text="I wrote this answer because I kept thinking I had forgotten something, then I realized it was a bit long, and added the real quick how to do it answer, but it seems people prefer the long answer." CreationDate="2010-06-03T21:57:22.937" UserId="230" />
  <row Id="2398" PostId="2854" Score="1" Text="I am just starting to play with RTOS, and When I asked here I got great advice, but I had a feeling that most users here do not know what an RTOS is. I do not mean this in a bad way, I just think there may be value asking this in other forums also to increase your chance of receiving a good answer." CreationDate="2010-06-03T22:08:19.750" UserId="230" />
  <row Id="2399" PostId="2855" Text="Thank you for the input, looks like great information." CreationDate="2010-06-03T22:13:34.170" UserId="230" />
  <row Id="2400" PostId="824" Text="I accepted a question because, even thought this is open ended, I had a number of great responses and wanted to reward at least one writer for the effort." CreationDate="2010-06-03T22:14:47.240" UserId="230" />
  <row Id="2401" PostId="2841" Text="He is not the only one to wonder that." CreationDate="2010-06-03T22:26:29.883" UserId="230" />
  <row Id="2402" PostId="2842" Text="5 watts at 1.6 volts can be hard. Although I have no idea what voltage it takes and am just adding this comment as a side note." CreationDate="2010-06-03T22:29:12.390" UserId="230" />
  <row Id="2403" PostId="2856" Text="I actually tried this as my first. It is not an RTOS in any real meaning of the word. It is not preemptive in any way. It requires regular use of yield commands so that the RTOS can decide who runs next, you have to intentionally put them in constantly in case another program needs to take over." CreationDate="2010-06-04T03:41:33.000" UserId="230" />
  <row Id="2404" PostId="2824" Text="Measuring a frequency using the period works quite well with slow waveforms (you're relying on the internal timer being much quicker than the external signal) but quickly hits a limit as the input signal frequency increases.&#xA;&#xA;Basically, as you've found, the time spent inside the timer capture interrupt becomes dominant; there is no time left for any other parts of the code to run.&#xA;&#xA;While I'm not that familiar with the ATTiny a quick look at the datasheet shows that timer/counter1 does support external event counting so let the hardware handle the counting." CreationDate="2010-06-04T04:57:14.377" UserId="820" />
  <row Id="2405" PostId="2837" Text="Thanks for the info!" CreationDate="2010-06-04T05:29:01.800" UserId="230" />
  <row Id="2406" PostId="2061" Text="Glad you liked it. At the last Ignite I received a free copy. I have done a couple of the first projects with my seven year old." CreationDate="2010-06-04T13:57:00.767" UserId="424" />
  <row Id="2407" PostId="2854" Text="I have to try anyway:-)  You never know who lurks here:-)" CreationDate="2010-06-04T14:06:35.913" UserId="625" />
  <row Id="2408" PostId="2850" Text="On the vibration noise, I may have had a larger amount during operating time due to the presence of a Brushless DC(BLDC) Motor, but before it was turned on there were still significant vibration figures." CreationDate="2010-06-04T14:33:19.213" UserId="230" />
  <row Id="2409" PostId="2854" Text="Yeah, I asked the lint question here also. Never hurts to hope for a bite." CreationDate="2010-06-04T15:09:17.907" UserId="230" />
  <row Id="2410" PostId="2856" Score="1" Text="I think that it's still called an RTOS.  It just sounds like it has a cooperative scheduler instead of a fully preemptive scheduler." CreationDate="2010-06-04T18:16:35.393" UserId="625" />
  <row Id="2411" PostId="2824" Text="@timrorr, wow yes that is *way* smarter way of doing it :) I posted updated AVR-GCC code in a separate post. Care to take a look and see what you think?" CreationDate="2010-06-04T18:25:24.283" UserId="771" />
  <row Id="2412" PostId="2836" Text="I looked up the Metcal. $650 is a bit over my budget. Is it really worth it?" CreationDate="2010-06-04T18:32:43.393" UserId="1402" />
  <row Id="2413" PostId="2811" Text="For some reason it did not ever let me know you had commented on my comment." CreationDate="2010-06-04T19:21:28.580" UserId="230" />
  <row Id="2414" PostId="2811" Text="@Kortuk: The software only notifies you if I leave a comment to one of your answers or questions.  It might also notify you of this comment, because I put @Kortuk in front of it.  But that is a StackOverflow software change, and I don't know if it got trickled into the StackExchange codebase or not." CreationDate="2010-06-04T19:40:32.793" UserId="544" />
  <row Id="2416" PostId="2836" Score="1" Text="depends on your usage.  The problem with cheap soldering irons with temperature adjustment is that they need to be calibrated fairly often or you risk the chance of burning ICs.  More accurately they would have to be calibrated for every possible tip.  With Metcal(or similar) irons the temperature control is built into the tips which are ~$20 a piece.  At the end of the day its a matter of how much use the solder station sees and how much $ you lose if you burn an IC.  The first time you spend 3 days trying to debug a circuit as a result of a burnt IC you may sing praises of Metcal." CreationDate="2010-06-05T05:16:39.023" UserId="703" />
  <row Id="2418" PostId="2865" Text="A big blue resistor 1 ohm experiences 5V and 5A. It becomes very hot. No burning. Except heat, how to see something is wrong?" CreationDate="2010-06-05T16:59:30.000" UserId="834" />
  <row Id="2419" PostId="123" Text="The diagram appears to have moved to http://itll.colorado.edu/index.php/electronics_center/resistor_chart/" CreationDate="2010-06-05T18:48:04.000" UserId="103" />
  <row Id="2420" PostId="2865" Text="The power dissipation is 25 W. If that's below the manufacturer's rating, everything is OK. If you don't know the manufacturer's rating, and you can't estimate it by the package dimensions, you should monitor the current and voltage for a while to see if the resistance is staying constant-- if it changes, either it will start to burn, or your device will stop working. If the resistance is constant, the resistor is doing its job." CreationDate="2010-06-05T18:56:41.987" UserId="712" />
  <row Id="2422" PostId="2871" Score="1" Text="I usually test the resistor with small current and voltage let say 5V and 5A, depending on the voltage of course. Then, I calculate the resistance. Cannot trust thickness at all as guessed so many times wrong." CreationDate="2010-06-05T18:59:41.020" UserId="834" />
  <row Id="2423" PostId="2868" Score="2" Text="We need more information to answer your question. For starters, what voltage and frequency sine wave are you putting in, and what gain do you expect? (If you could show us a schematic, that would increase the chances of you getting an answer by at least 10x.)" CreationDate="2010-06-05T19:04:23.657" UserId="712" />
  <row Id="2424" PostId="2865" Text="would like know an experienced answer about &quot;can't estimate it by the package dimensions&quot;. Usually buying assorted sets, no packages, no manufacturer info. Do you mean by pkg &quot;to evaluate from the size-colour-material&quot;? I think such evaluation is speculative and better just measure with multi-meter." CreationDate="2010-06-05T22:04:59.087" UserId="834" />
  <row Id="2425" PostId="2871" Score="4" Text="5 A is a small current?  o_O" CreationDate="2010-06-05T22:19:43.917" UserId="142" />
  <row Id="2426" PostId="2865" Score="3" Text="Electrolytic capacitors explode, too.  I have a small scar to prove it.  :)" CreationDate="2010-06-05T22:21:48.797" UserId="142" />
  <row Id="2427" PostId="2865" Score="3" Text="When I mentioned estimating by package dimensions, I meant that even if a resistor comes from an unknown source, its ability to dissipate heat is going to be roughly proportional to surface area, so you can make a good guess. For example, if it's a small cylinder, 2 mm diameter and 5 mm long, it can probably handle around 0.25 W. If it's the size of a hot dog, it's up in the 100 W area." CreationDate="2010-06-05T22:35:05.177" UserId="712" />
  <row Id="2428" PostId="2873" Text="Thanks, here's the schematic I'm working from:&#xA;&#xA;http://www.musicfromouterspace.com/analogsynth/STATEVARVCFFEB2006/STATEVARVCFFEB2006.html&#xA;&#xA;I'm referring to U6, on the second page of the schematic. It looks like it is hooked up as an emitter follower. DC voltage at pin 7 is -36.7mV and at 8 is -252mV. Does that help at all? " CreationDate="2010-06-05T22:54:03.800" UserId="835" />
  <row Id="2429" PostId="2037" Text="Open source? Where can I find the schematic PCB?" CreationDate="2010-06-05T23:00:21.043" UserId="834" />
  <row Id="2430" PostId="2875" Score="7" Text="Do us a favor and fill out your profile. Specifically change your username to something other then the default for Google openid users." CreationDate="2010-06-05T23:20:24.340" UserId="319" />
  <row Id="2431" PostId="2877" Score="3" Text="That looks pretty cool. However, as a warning to the person who asked the question, computer power supplies are great at pumping out a lot of current, but not so great at being low noise. You will learn have to learn fast how to reduce noise on your power lines." CreationDate="2010-06-06T02:27:21.793" UserId="319" />
  <row Id="2432" PostId="2877" Text="Yes, absolutely. Hopefully the OP is productively studying and not just trying to 'explode' components :)" CreationDate="2010-06-06T03:30:28.917" UserId="1307" />
  <row Id="2433" PostId="2878" Score="1" Text="might want to give a bit more info on your application ?" CreationDate="2010-06-06T03:55:01.180" UserId="417" />
  <row Id="2434" PostId="2879" Text="Apparently, 7805CWs are not explosive. Got it dirty hot even with 6A and about 5V. Just connected the outermost legs to catode and anode in the DC power-supply. Where do I need the middle leg?" CreationDate="2010-06-06T13:54:05.723" UserId="834" />
  <row Id="2435" PostId="2879" Text="... time to finish my explosion chamber :)" CreationDate="2010-06-06T13:54:28.890" UserId="834" />
  <row Id="2436" PostId="2878" Score="2" Text="Mostly just curiosity. I know many of our students have had issues finding one that can get a lock inside a building. I know buildings are difficult to get locks in, but my Garmin GPS is able to get a lock in the same room. So, not looking for high accuracy or refresh rate, just something that can have reception that is about the same as commercial products." CreationDate="2010-06-06T17:41:50.687" UserId="319" />
  <row Id="2437" PostId="2879" Text="6A = Big heatsink... or spread the load over more than one power supply?" CreationDate="2010-06-06T17:43:53.097" UserId="689" />
  <row Id="2440" PostId="2871" Text="When your entire goal is something exploding, i guess so." CreationDate="2010-06-06T18:46:19.323" UserId="230" />
  <row Id="2441" PostId="2884" Text="That is an interesting approach, but does require external hardware, always a bad thing to deal with." CreationDate="2010-06-06T19:02:26.857" UserId="230" />
  <row Id="2442" PostId="2376" Text="I cannot believe this only got one upvote." CreationDate="2010-06-06T19:07:06.863" UserId="230" />
  <row Id="2443" PostId="2884" Text="What external hardware?  I meant the internal pullup resistor." CreationDate="2010-06-06T19:30:21.350" UserId="72" />
  <row Id="2444" PostId="2884" Text="The pin does need external hardware to pull it low by default? Or do the pins by definition float to a low voltage? To me you need a pull down of a value significantly greater than your internal pull up to make sure this pin floats low." CreationDate="2010-06-06T19:52:54.057" UserId="230" />
  <row Id="2445" PostId="2884" Text="I do not mean to say it is not a good answer, I was just adding my input. There is rarely a perfect method, I just mean to make sure any disadvantages are fleshed out. The advantage is a simple way to create a software generated interrupt. It does seem you need to enable that pull-up, then quickly disable it and hope it has floated low before you use it again." CreationDate="2010-06-06T19:55:22.070" UserId="230" />
  <row Id="2446" PostId="2856" Text="Yes, it is still technically an RTOS, but I had and still have very little value for it. I know it is a personal thing, but to me it needs to be preemptive to be valuable. I still +1 as it was a good answer and of value." CreationDate="2010-06-06T20:45:28.240" UserId="230" />
  <row Id="2447" PostId="2884" Text="Hmm... This is an interesting point.  The way I use it isn't by enabling and disabling the pull up... I enable the pull up and then write 1 or 0 to the pin. Leaving the pullup active in both cases.  I see what you are saying now though about it possibly having some indeterminancy.  This would be dependant on the way your MCU was structured.  Good talk!" CreationDate="2010-06-06T20:55:20.327" UserId="72" />
  <row Id="2449" PostId="2879" Text="Is 7805CW a type of 7805? I wasn't able to find anything on the CW on google. I find it hard to believe that you are getting 6A and 5V. First of all, the middle lead on 7805s is a ground lead. I wouldn't think you would get much output without connecting this lead. Also, most 7805's that I have worked with start to drop their voltage after going over 1-1.5amps." CreationDate="2010-06-07T01:02:12.853" UserId="319" />
  <row Id="2451" PostId="2884" Score="1" Text="The pin change interrupt works even when you configure the pin as an output - and I think that's what Scott's doing. Must also be using an open-drain output, and hence the need to enable the pull-up." CreationDate="2010-06-07T02:28:49.493" UserId="740" />
  <row Id="2453" PostId="2879" Score="1" Text="Personally I usually don't use 7805 (and the others) for bigger loads than 0.5A. But if you have a small design like a mcu that just needs 5V to run... " CreationDate="2010-06-07T06:09:12.543" UserId="689" />
  <row Id="2454" PostId="2886" Text="If they really were 4 ohms, that would give a current of 30/4 amps and therefore power of 225 watts which instantly destroy most components." CreationDate="2010-06-07T08:43:52.047" UserId="710" />
  <row Id="2455" PostId="2886" Text="I wasn't worried about you... just the component.  Not to sound unconcerned!" CreationDate="2010-06-07T11:07:34.130" UserId="72" />
  <row Id="2456" PostId="2885" Text="Thanks, you were right about looking at R57. Needed to change the value." CreationDate="2010-06-07T12:28:58.057" UserId="835" />
  <row Id="2457" PostId="2874" Score="1" Text="30V is too much for a thermistor unless the thermistor resistance is very large &gt; 10k Ohms. If the thermistor resistance is very large you will still experience a significant amount of self-heating with the thermistor. Instead of applying a fixed voltage and measuring current have you just tried measuring resistance directly at a known temperature?" CreationDate="2010-06-07T12:47:28.940" UserId="588" />
  <row Id="2458" PostId="2892" Score="1" Text="Glad to hear that you were able to get a lock inside your office. I am going to look into these. I actually use PICs and MSP430s. Around this community it seems as though many people use Arduinos." CreationDate="2010-06-07T14:51:44.650" UserId="319" />
  <row Id="2459" PostId="1764" Text="Amen to that bro!" CreationDate="2010-06-07T14:52:20.357" UserId="399" />
  <row Id="2462" PostId="2889" Text="first, normally if someone says 24VAC, they often mean RMS, which means if you measure it, it will be much higher. Second, 15V drop does not mean alot of power dissipation, I doubt the microcontroller pulls much current at all." CreationDate="2010-06-07T15:01:17.157" UserId="230" />
  <row Id="2464" PostId="1764" Text="plus you can get a digital subscription - much cheaper than the paper-based version" CreationDate="2010-06-07T15:32:42.387" UserId="1307" />
  <row Id="2466" PostId="2889" Text="The power dissipation of a linear regulator most certainly is directly proportional to the difference between Vin and Vout.  For the 7805 Pd = (Vin - Vout)IL + Vin*IG.  Even for low IL with Vin - Vout = 15 even if hes only draws 100mA for the uC and some LED's or whatever thats 1.5W + Vin*IG of power he needs to dissipate as heat.&#xA;&#xA;As for the rectifier, 24V RMS is ~34V peak to peak, using a half wave rectifier with decent smoothing, not voltage boost and silicon diodes we would except (17 - 0.7)/PI = 5.18V DC.  Using a full bridge rectifier we would expect (2 * 17 - 1.4)/PI = 10.37V DC.&#xA;" CreationDate="2010-06-07T16:21:37.277" UserId="703" />
  <row Id="2467" PostId="2889" Text="Now we would expect smoothing capacitors to raise the average DC level of the output but it will never reach 20V DC without a boost stage as the peak voltage level of a 24V RMS signal is ~+17V" CreationDate="2010-06-07T16:27:28.643" UserId="703" />
  <row Id="2470" PostId="2865" Text="@pingswept: so far right, thank you for sharing the tip. It is very useful actually." CreationDate="2010-06-07T20:04:52.743" UserId="834" />
  <row Id="2471" PostId="2865" Text="+1 for the last clarifying comment." CreationDate="2010-06-07T20:05:39.673" UserId="834" />
  <row Id="2474" PostId="2871" Text="@endolith: well actually I start from the smallest unit of the equipment, usually 0.1V. If I cannot find the upper bound for the component, I gradually increase to some easy number such as 1V. Calculate V-I to get P. Chose 5V just because it is nice number but it can be a bit too high for testing, do not start with it, start small and then increase slowly to let component react." CreationDate="2010-06-07T20:57:43.277" UserId="834" />
  <row Id="2475" PostId="2879" Text="+1 like reusing" CreationDate="2010-06-08T00:02:26.037" UserId="834" />
  <row Id="2476" PostId="2885" Text="Score! That is why this site rocks!  Need help find help, have help give help!  How does that synth sound btw?" CreationDate="2010-06-08T00:45:50.643" UserId="72" />
  <row Id="2477" PostId="2889" Score="1" Text="I will do this as 2 points. first, power dissipation, I am not saying you are incorrect that it is horribly inefficient, but most through hole linear regulators can easily dissipate 1.5 W without an overheat issue. On that note, a PIC microcontroller is pretty rare to push above 50mA unless you are driving I/O or using a high end 16 bit or 32 bit processor at a very high clock rate." CreationDate="2010-06-08T01:08:18.523" UserId="230" />
  <row Id="2478" PostId="2889" Text="I am not implying it is a pic micro, just an example." CreationDate="2010-06-08T01:08:50.177" UserId="230" />
  <row Id="2479" PostId="2889" Score="2" Text="Second, you have done the RMS conversion incorrectly. This is an error I will admit to having made a few times. 24V RMS is going to become 24 times square-root of 2, increasing in magnitude. it will be magnitude 33.9411255, peak to peak of double that, almost 68V. down the page at http://en.wikipedia.org/wiki/Root_mean_square they have an example where they point out peak to peak voltage in the US is around 340V, which is double 170, which is 120rms * root(2)." CreationDate="2010-06-08T01:14:54.957" UserId="230" />
  <row Id="2480" PostId="2092" Score="1" Text="Seconding &quot;Make: Electronics: Learning Through Discovery&quot; - helped a lot of things click for me. It's well illustrated and full of examples." CreationDate="2010-06-08T18:10:03.607" UserId="835" />
  <row Id="2481" PostId="2902" Score="1" Text="Could you please post real links!" CreationDate="2010-06-08T19:24:29.680" UserId="339" />
  <row Id="2482" PostId="2906" Score="1" Text="Awesome, very helpful answer." CreationDate="2010-06-08T23:17:05.340" UserId="835" />
  <row Id="2483" PostId="2879" Text="@Johan: could yo clarify how you get smooth DC? I have 7805reg, 12AC adaptor, 2 pieces of 100\muF caps, 1kOhms' resistors. Caps connected to the legs of reg, Rs connected to legs of caps. The voltage fluctuate, not greatly but still in range 4.81-4.86, the graph is more like sinusoidal. Do I need diodes to smooth it or sthing wrong?" CreationDate="2010-06-08T23:22:30.433" UserId="834" />
  <row Id="2484" PostId="2908" Text="Are you referring to voltage here? The wikipedia article's circuit assumes AC voltage, as this rectifier circuit 'converts' ac to dc voltage." CreationDate="2010-06-09T03:36:07.273" UserId="536" />
  <row Id="2485" PostId="2906" Score="1" Text="as a side note, if he does crazy stuff and causes odd ringing sounds to come out of it. Or if after there are sounds there are after effects he designed this system to use the inductance of the wiring to cause ringing to get extra noises." CreationDate="2010-06-09T04:17:13.960" UserId="230" />
  <row Id="2488" PostId="2877" Score="1" Text="+1 for suggesting reuse :)" CreationDate="2010-06-09T04:53:03.513" UserId="834" />
  <row Id="2489" PostId="2908" Text="pfyon: Thank you." CreationDate="2010-06-09T05:06:47.527" UserId="834" />
  <row Id="2490" PostId="123" Text="Thanks Amos! I've updated the link ;-)" CreationDate="2010-06-09T07:29:01.013" UserId="3" />
  <row Id="2491" PostId="2913" Score="1" Text="There is one thing that many people are not taking into account. A polarized cap, specifically the electrolytic cap, has a very very low leakage current and is one of the most idea capacitors when properly biased. In labs I have found when I could use them they made filter design significantly easier." CreationDate="2010-06-09T14:32:41.243" UserId="230" />
  <row Id="2492" PostId="2914" Text="These are the same numbers I found." CreationDate="2010-06-09T14:37:04.890" UserId="230" />
  <row Id="2493" PostId="2790" Text="Has this worked out for you? Let me know how things go!" CreationDate="2010-06-09T14:41:23.327" UserId="230" />
  <row Id="2495" PostId="2906" Text="Kortuk - that's interesting, can you be a bit more clear? It definitely sounds like that's a possibility. Is it some sort of resonance?" CreationDate="2010-06-09T15:14:01.880" UserId="835" />
  <row Id="2497" PostId="2914" Text="it is still open what does it mean and why is it chosen? -- cannot believe it is just a random identifier" CreationDate="2010-06-09T15:23:43.533" UserId="834" />
  <row Id="2498" PostId="2917" Text="TI does sell buck modules that are already made and you just solder Leads to. You should be able to find them at TI.com, if you need I can go find a link." CreationDate="2010-06-09T15:47:45.730" UserId="230" />
  <row Id="2501" PostId="2922" Score="1" Text="In a real circuit auto-route is the devil. if your circuit works in a breadboard auto-route will probably work, but if you circuit has any high speed signals it will be your end. It will end up taking ground traces on long walks through the woods. I have seen simple boards(less than 30 components) have half volt sin waves on ground pins because of auto-route." CreationDate="2010-06-09T16:02:07.700" UserId="230" />
  <row Id="2502" PostId="2922" Text="Auto-route however is very good for beginners to learn to do layouts." CreationDate="2010-06-09T16:02:20.990" UserId="230" />
  <row Id="2503" PostId="2921" Score="1" Text="yes, a part number is for book keeping. They are about finding parts in stock, they have no bearing on function of the device. a well design system has some connection between device and assigned part number, like the 78k might mean it is a diode, but that is it." CreationDate="2010-06-09T16:03:50.723" UserId="230" />
  <row Id="2504" PostId="2914" Text="the 78k probably is a number used for all diodes, but yes, it is a random identifier. It is based on some internal system, but it is random as far as you will ever know and does not correlate to device function." CreationDate="2010-06-09T16:04:49.143" UserId="230" />
  <row Id="2506" PostId="2914" Score="1" Text=" 	My name Kortuk identifies me, it does not let you know how awesome I am unless you have used a kortuk before and found out that, on the whole, people with the name kortuk are winners." CreationDate="2010-06-09T16:13:28.533" UserId="230" />
  <row Id="2507" PostId="2922" Score="1" Text="I have been able to make single sided boards in 5-10 minutes and then tried to run auto-route to compare and auto-route would fail and say it needed another layer." CreationDate="2010-06-09T16:13:44.523" UserId="319" />
  <row Id="2508" PostId="2922" Text="As a response to your edit: You just need to make sure that the ground and power traces are good. Auto-route is still the devil, the cause of early onset male-pattern baldness and global warming." CreationDate="2010-06-09T16:20:20.300" UserId="230" />
  <row Id="2510" PostId="2922" Text="To add on to Kortuk, I don't feel as though I have done much that I would consider high bandwidth digital I/O or RF design, but I have run into issues with auto-router. Even just connecting a microcontroller to a FTDI usb chip has caused me headaches when autorouter was used. I have been able to route a circuit with a microcontroller, RFID, USB, Canbus, IR, and XBee by hand with no issues." CreationDate="2010-06-09T16:26:56.883" UserId="319" />
  <row Id="2511" PostId="2923" Text="Are you saying you should run power and ground along the edge of the board?" CreationDate="2010-06-09T16:44:47.800" UserId="230" />
  <row Id="2512" PostId="2923" Text="I do agree that 90% is placement." CreationDate="2010-06-09T16:45:30.093" UserId="319" />
  <row Id="2513" PostId="2884" Text="this is the correct answer. the datasheet expressly states that the interrupt will fire even if the port pin is configured to an output. that's the whole point in fact :)" CreationDate="2010-06-09T17:15:19.527" UserId="771" />
  <row Id="2517" PostId="2923" Text="@Kortuk I ment to say that ground should be run around the edge, at least where single and double sided boards are concerned" CreationDate="2010-06-09T18:20:29.323" UserId="819" />
  <row Id="2518" PostId="2915" Score="2" Text="There are lights on the market that do this, here are 120v AC type http://store.sundancesolar.com/120voacledre.html  I am assuming you are wanting to have the fun of building this, and doing it for cheaper then those lights though, which is why this is just a comment and not an answer. " CreationDate="2010-06-09T18:27:39.213" UserId="319" />
  <row Id="2519" PostId="2923" Text="Volting, Ground should be as short of a connection as possible, should be as low of impedance as possible, and you should shoot for making a ground plane, even on one layer where it will not be very much. Running a trace near the edge greatly increases your emissions, and if you have anything running at higher speeds I can guarantee that you have EMI problems and the FCC will not like an product. I know I am railing on this, but people often do not realize how much of a science a layout is. You are doing it very well, and I agree in general, but you should take a look at my link." CreationDate="2010-06-09T18:29:09.573" UserId="230" />
  <row Id="2520" PostId="2923" Text="I think if you take a little time and read up how to do layouts you could go from doing decent ones to getting excellent ones." CreationDate="2010-06-09T18:29:31.600" UserId="230" />
  <row Id="2523" PostId="2913" Score="2" Text="Dear Kortuk: The Wikipedia &quot;capacitor&quot; article ( http://en.wikipedia.org/wiki/capacitor ) says you are wrong.&#xA;It claims that electrolytic capacitors and tantalum capacitors (and what other kind of polarized cap is there?) &quot;suffer from ... high leakage current&quot; compared to other capacitors (which are all nonpolarized, right?).&#xA;Do you have any kind of published source -- perhaps capacitor manufacturer datasheets -- that tells me how to &quot;properly bias&quot; these capacitors to get very low leakage?" CreationDate="2010-06-09T19:30:31.380" UserId="813" />
  <row Id="2524" PostId="2921" Text="cannot understand down-vote, have to label question as beginner. The thing &quot;78K2120&quot; is similar to smallCaps' markings such as &quot;104 K5K&quot;, &quot;154 C1K&quot;, &quot;104K X7R50&quot; and probably many other markings -- easy for beginners to overlook!" CreationDate="2010-06-09T19:30:34.623" UserId="834" />
  <row Id="2525" PostId="2912" Score="1" Text="as a side note, if they mean 5VAC rms, which often is the case, then the actual wave is going to be 5V*squareroot(2) in magnitude." CreationDate="2010-06-09T19:36:02.013" UserId="230" />
  <row Id="2526" PostId="2913" Text="Thank you, wiki magic workers, for fixing the highly confusing typos I originally posted in this answer!" CreationDate="2010-06-09T19:37:31.727" UserId="813" />
  <row Id="2527" PostId="1838" Text="+1 for linking to the C source code in the original RFC.&#xA;Even though I would probably go with the source code from Microchip, the same people that made the chip this is going to run on." CreationDate="2010-06-09T19:49:03.870" UserId="813" />
  <row Id="2528" PostId="2879" Text="You must send DC into the 7805, so you need to rectify your AC with 4 diods and another capacitor. " CreationDate="2010-06-09T20:01:36.883" UserId="689" />
  <row Id="2529" PostId="2879" Text="http://upload.wikimedia.org/wikipedia/en/a/a3/RC_Filter.png" CreationDate="2010-06-09T20:02:43.380" UserId="689" />
  <row Id="2530" PostId="2931" Score="1" Text="I need you to give me one very important spec. What are you buying it for? If you are tinkering with cheap electronics or if you are planning to use other commercial products to connect to it makes a big difference." CreationDate="2010-06-09T20:41:24.977" UserId="230" />
  <row Id="2531" PostId="2935" Text="are you building your FF's out of discrete gates?" CreationDate="2010-06-09T21:19:03.627" UserId="740" />
  <row Id="2532" PostId="2935" Text="No I am using just JK ICs." CreationDate="2010-06-09T21:37:44.150" UserId="92" />
  <row Id="2533" PostId="2923" Text="@Kortuk your quite right PCB is a science and yes grounds should be kept short and ground planes should be utilized when possible. I got the impression from the OP that he was primarily interested in untangling the rats nest and that was what my answer is aimed at... On small designs where EMI is not a major concern, running the ground around the edge of the board (not necessarily the whole way around) makes it easily accessible and can simplify placement &amp; routing. Of course if you have space for a ground plane then pour on the copper :) " CreationDate="2010-06-09T22:44:51.253" UserId="819" />
  <row Id="2534" PostId="2931" Text="I will be using the supply to power a PLC and a touch-screen HMI. Together they draw a max of 2A at 24V. Ideally *only* the PLC and HMI will be connected to the supply. Input power will (theoretically) be coming from a dedicated 120VAC line." CreationDate="2010-06-09T23:10:22.447" UserId="842" />
  <row Id="2535" PostId="2936" Text="So overload protection covers input spikes, and foldback protection covers short circuits/burnouts in the load?" CreationDate="2010-06-09T23:12:49.153" UserId="842" />
  <row Id="2536" PostId="2938" Text="Thanks! It looks like most people did not get the question, but it is still interesting." CreationDate="2010-06-10T00:24:55.687" UserId="230" />
  <row Id="2537" PostId="2936" Text="Yes. I believe that is what he means in one sentence. Well explained mark." CreationDate="2010-06-10T00:51:02.750" UserId="230" />
  <row Id="2538" PostId="2930" Text="mine is more of an approach to try to do it yourself. I agree with this one also. It is a different approach, but just as valid. I have done this before." CreationDate="2010-06-10T00:53:18.223" UserId="230" />
  <row Id="2539" PostId="2936" Text="yup, 1 additional note:  Foldback current protection is much more important for a linear supply than it is for a switching supply such as those you listed.  Linear supplies increase their power dissipation as the difference between Vin and Vout increases.  Because of this, when the current limit is hit and voltage begins to drop, power dissipation increases even if the current is held constant, this can cause the supply to exceed its thermal limits.  Switching supplies don't have this relationship so as long they have high side current protection they should be safe." CreationDate="2010-06-10T01:13:46.147" UserId="703" />
  <row Id="2540" PostId="2885" Text="Sounds great. I'll probably post some video soon." CreationDate="2010-06-10T02:06:32.997" UserId="835" />
  <row Id="2541" PostId="2935" Text="are you saying you want it to count from 2 to 10, and then roll over back to 2?" CreationDate="2010-06-10T02:43:04.163" UserId="771" />
  <row Id="2543" PostId="2844" Text="thanks to everyone for the comments.  very helpful&#xA;regards&#xA;TROY" CreationDate="2010-06-10T03:27:01.820" UserId="830" />
  <row Id="2544" PostId="2943" Score="1" Text="I think the only way you could test the voltage rating of a capacitor is by destroying it." CreationDate="2010-06-10T04:45:42.450" UserId="142" />
  <row Id="2545" PostId="2926" Text="volting: you misunderstood the link you gave is 15 times cheaper than my local store." CreationDate="2010-06-10T06:17:49.177" UserId="834" />
  <row Id="2546" PostId="2935" Text="Exactly Vicatcu" CreationDate="2010-06-10T10:39:35.840" UserId="92" />
  <row Id="2547" PostId="2936" Text="Thank you for this answer (which I'm accepting, because of its completeness), as well as for the explanation of linear vs. switching supplies! Is high-side current protection yet another type of protection?" CreationDate="2010-06-10T13:48:13.783" UserId="842" />
  <row Id="2548" PostId="2941" Text="Did you answer your own question?" CreationDate="2010-06-10T14:15:54.467" UserId="319" />
  <row Id="2549" PostId="2943" Text="If you set a low current limit and slowly step the voltage up you might be able to figure it out without damaging it. But there is still a 95% chance you will with nice equipment." CreationDate="2010-06-10T15:23:09.327" UserId="230" />
  <row Id="2550" PostId="2943" Text="This is not a case of not buying assorted sets, it is a case that you need to keep things organized and labeled. if you could tell everything by just looking at components there would not need to be nearly as strict of design flows as there are." CreationDate="2010-06-10T15:23:59.607" UserId="230" />
  <row Id="2551" PostId="2909" Text="Why did you not take the time to just comment on his. This is something you got because of his answer, he should be rewarded." CreationDate="2010-06-10T15:32:24.237" UserId="230" />
  <row Id="2552" PostId="2913" Text="@david, It seems I am wrong. I did it from memory from almost 4 years ago. There was a reason we would use them, it may have been due to Low ESR or low series inductance compared to the other caps available. When I said properly biased I meant that you kept voltage in correct polarization. Sorry if it sounded like there was a magic voltage that everything worked at better." CreationDate="2010-06-10T15:39:01.813" UserId="230" />
  <row Id="2553" PostId="2952" Text="If it's not safe to rely on that I imagine I could build a small protection circuit and feed my real board from that. Any suggestions on what i need to do this?" CreationDate="2010-06-10T15:44:51.123" UserId="710" />
  <row Id="2554" PostId="2947" Text="most things like microcontrollers sport diodes in the pins that allow ESD to discharge harmlessly. They are called ESD protection diodes normally." CreationDate="2010-06-10T15:48:42.350" UserId="230" />
  <row Id="2555" PostId="2955" Text="I am glad it gives me a notice that you posted this, because I was typing almost the same thing." CreationDate="2010-06-10T15:57:34.870" UserId="230" />
  <row Id="2556" PostId="2954" Score="2" Text="this is the case for most people. I still have never had a problem at work, and we are on carpet." CreationDate="2010-06-10T16:11:41.660" UserId="230" />
  <row Id="2557" PostId="2955" Score="2" Text="That sounds good. I might make a little board with such a fuse and a 3.3 and 5v regulator on that I can plus my power supply into one end and my experiment into the other just in case..." CreationDate="2010-06-10T16:24:57.627" UserId="710" />
  <row Id="2558" PostId="2936" Text="sorry i've been using high side current protection and 'standard' current protection rather interchangeably.  High side current sensing is detecting the current flow on the + side of the supply and implementing current limiting based on that level of current.  This is often done but sensing the the voltage across a small resistor to determine the current then feeding that voltage into a comparator that will trip the over current protection when needed.  Its also possible to do this on the low side, by having the sense resistor on the ground side of the circuit, but its not as common." CreationDate="2010-06-10T16:30:05.587" UserId="703" />
  <row Id="2559" PostId="2936" Text="this is what you almost always see as &quot;short circuit protection&quot; in a power supply if they don't define a specific type of protection.  There are also other ways to do this type of protection but what i listed is the more common way that i've seen.  In a linear supply the comparator is usually replaced with a single transistor that feeds back into the control transistor but the concept is the same." CreationDate="2010-06-10T16:34:07.397" UserId="703" />
  <row Id="2560" PostId="2949" Text="Thank you, after consulting with one of my coworkers on at my internship earlier today we discovered that there was a problem in Multisim which I had used to verify my answer. Which was the same approach as you describe." CreationDate="2010-06-10T16:56:24.803" UserId="348" />
  <row Id="2561" PostId="2955" Text="That is a good choice john." CreationDate="2010-06-10T17:14:03.400" UserId="230" />
  <row Id="2562" PostId="2941" Text="He answered his own question within an hour of asking with a very very basic answer..." CreationDate="2010-06-10T17:15:45.457" UserId="230" />
  <row Id="2563" PostId="2958" Text="Thanks, makes sense. After some thought, and the other answer to my question I think my best option is not to assume anything but build a small protected board that I plug my adaptor into that I can test completely and then plug *that* into my more experimental circuits." CreationDate="2010-06-10T17:48:50.670" UserId="710" />
  <row Id="2564" PostId="2962" Score="2" Text="have a model number or preferably a link to the datasheet?" CreationDate="2010-06-10T19:36:49.283" UserId="703" />
  <row Id="2565" PostId="2947" Score="1" Text="They are a palliative that provide some protection but are often themselves damaged as they protect the main device.  On the second ESD event there is no protection left on the pin." CreationDate="2010-06-10T19:47:41.240" UserId="400" />
  <row Id="2566" PostId="2963" Score="1" Text="One datasheet I am looking at has a &quot;Maximum Peak output voltage swing&quot; of +/-13.5V.  This is in a table of Vcc of +/-15V.  So my drop-out is about 1.5V.  If I have the op-amp setup with 0V and +5V, I'll get an op-amp that goes from 1.5V to 3.5V.  I'll pick a different op-amp." CreationDate="2010-06-10T20:11:56.383" UserId="204" />
  <row Id="2567" PostId="2962" Score="1" Text="I was looking at the LF347 from TI.  But this question was more on how to decipher a datasheet to find the parameter that I want." CreationDate="2010-06-10T20:13:32.280" UserId="204" />
  <row Id="2570" PostId="2947" Text="I had never been told that, nor have i seen common failures were people do not use protection. I would like to know more about it. On that note Ian, do not take me wrong, I am a strong supporter of ESD protection, I just feel being honest with people about what protections already exist is worthwhile. You have said the same thing in your post, so no worries." CreationDate="2010-06-10T20:44:04.517" UserId="230" />
  <row Id="2571" PostId="2965" Text="not trying to pitch digikey specifically, insert whatever distributer you want (mouser, newark, allied).  Considering the nature of his question the last thing i would recommend is going and buying another freezer bag of unspecified parts.  The bag of ceramic discs on the site you linked only specifies &quot;at least 50v&quot; and if the image is correct, provides no information as to the tolerance, temperature range, ESR or even what values are included in the kit.  You get what you pay for." CreationDate="2010-06-10T20:56:05.247" UserId="703" />
  <row Id="2572" PostId="2953" Text="Side note, if you have tile floors and your building is very humid you have fewer risks as you discharge through the air at a higher rate." CreationDate="2010-06-10T21:07:24.780" UserId="230" />
  <row Id="2573" PostId="2963" Score="4" Text="If an op-amp is quoted as going &quot;rail to rail&quot; then it will be able to go very close to the rail voltages. There are many different parameters in an op-amp and every circuit has it's own needs." CreationDate="2010-06-10T21:10:07.990" UserId="230" />
  <row Id="2574" PostId="2967" Score="5" Text="what is &quot;op.F 2400\pm200 Hz&quot; and op.V  ? " CreationDate="2010-06-10T22:22:39.733" UserId="582" />
  <row Id="2575" PostId="2967" Score="1" Text="&quot;op.F&quot; is operating frequency of 2400+/-200 Hz. &quot;op.V&quot; is the operating voltage." CreationDate="2010-06-10T22:55:01.517" UserId="712" />
  <row Id="2577" PostId="2969" Score="1" Text="so that thing is basically a speaker, but with a frequency response you wouldn't want to use for anything but an annunciator?" CreationDate="2010-06-10T23:28:59.133" UserId="740" />
  <row Id="2578" PostId="2969" Score="1" Text="it would output speech OK by OK i mean it wouldn't sound good (it would actually probably be rather annoying to listen to) but the critical frequencies for understanding of speech based on the articulation index are from 1k to 4k so you could probably understand it even if you wanted to throw your shoes at the thing." CreationDate="2010-06-10T23:34:48.827" UserId="703" />
  <row Id="2579" PostId="2969" Score="1" Text="My impression was that it was for beeping. Perhaps our associate 0x2A31 can let us know what he finds out." CreationDate="2010-06-11T00:23:57.197" UserId="712" />
  <row Id="2580" PostId="2969" Text="yea i assume that it was the 'system speaker' on the motherboard for beep codes but who knows what he plans for it :)" CreationDate="2010-06-11T00:38:52.160" UserId="703" />
  <row Id="2581" PostId="2971" Text="+1 for using a oscilloscope, and not a multimeter. " CreationDate="2010-06-11T05:33:24.717" UserId="689" />
  <row Id="2582" PostId="2951" Text="Thanks for the feedback.  I have redone the schematic here the link http://dl.dropbox.com/u/5434831/Ipod/Schematic_v2.png  I may have a look at the LM317 as an alternative as it seems to be better suited to the higher currents.  Can you explain the Capacitors?  I dont really know what size to use, only thing I can work out is make sure that the are voltage rated and bigger uF is better in this situation???  I also dont understand the ground noise current? any links?" CreationDate="2010-06-11T05:50:26.977" />
  <row Id="2583" PostId="2957" Text="Hi Kortuk, thanks for the response. I have had a look at that and pin 21 is going to be hooked to a 1MOhm resistor so taht when I turn the car power off it will shut the iPod/iPhone off.  There is a bit up further on that page about Pin 11, if its put to ground then the audio will go out through pin 3 and 4.  Im hoping that this will work, if not I will keep fiddling.&#xA;&#xA;Thanks again. Ben" CreationDate="2010-06-11T06:02:11.843" />
  <row Id="2584" PostId="2957" Text="should work if it says so!" CreationDate="2010-06-11T12:52:39.190" UserId="230" />
  <row Id="2585" PostId="2965" Text="This should have been a comment, and i agree with mark here, he was not pitching digikey." CreationDate="2010-06-11T13:02:11.883" UserId="230" />
  <row Id="2586" PostId="2974" Text="not very magical, but when i use XBee at school it is the same." CreationDate="2010-06-11T13:02:46.720" UserId="230" />
  <row Id="2587" PostId="2976" Text="Seconded. The mat on the bench will do wonders." CreationDate="2010-06-11T13:54:38.530" UserId="230" />
  <row Id="2588" PostId="2951" Text="Ok, where did you get those iPod pinouts?  They're reversed from the manufacturer's pinouts.  http://ipodlinux.org/wiki/Dock_Connector  &#xA;&#xA;Otherwise that schematic looks good.  &#xA;&#xA;As for ground currents, I'll put that in my answer." CreationDate="2010-06-11T14:19:11.653" UserId="142" />
  <row Id="2589" PostId="2951" Text="if you read what is written in his link they say they have numbered the pins opposite of what it says if you open the iPod. They made a reference and then realized it was opposite of apple, but instead of updating their site just said, pay attention to pins be opposite." CreationDate="2010-06-11T14:51:17.377" UserId="230" />
  <row Id="2590" PostId="2976" Score="1" Text="Sorry, i meant to ask earlier, how the hell did you total an RS232 port?" CreationDate="2010-06-11T15:06:10.990" UserId="230" />
  <row Id="2591" PostId="2951" Text="Yeah, the capacitor rating just needs to be higher than the voltage they will see.  The alternator can supply up to 14 V, so the input cap needs to be at least 16 V rating.  The output cap just needs to be at least 6.3 V rating.  Anything higher will work, too.  " CreationDate="2010-06-11T15:08:13.467" UserId="142" />
  <row Id="2592" PostId="2973" Text="I actually intentionally work on a bench that has conductive paint. It is tied to ground properly and I always keep my forearms or elbows touching it as I work." CreationDate="2010-06-11T16:28:06.917" UserId="230" />
  <row Id="2593" PostId="2977" Text="Most devices are damaged at a level of static discharge far below what you can feel. On that note, I turned on an LED with static once and it still works." CreationDate="2010-06-11T16:29:03.843" UserId="230" />
  <row Id="2594" PostId="1654" Text="AC or DC power supply? What is the power supply voltage?" CreationDate="2010-06-11T17:17:01.300" UserId="588" />
  <row Id="2595" PostId="2979" Text="It helps if the radiator is properly grounded. If it is not, it could act as something to help you charge." CreationDate="2010-06-11T20:06:03.037" UserId="230" />
  <row Id="2596" PostId="2979" Score="1" Text="Tie it to ground with a wire, through a resistor of 100k or more and you will be fine." CreationDate="2010-06-11T20:06:20.617" UserId="230" />
  <row Id="2597" PostId="2977" Text="The board still works I should say, it was one part." CreationDate="2010-06-11T20:06:46.730" UserId="230" />
  <row Id="2598" PostId="2941" Text="It is not a case of know better. It is a problem that you posted before thinking about, immediately recognized, then posted the answer." CreationDate="2010-06-11T20:16:11.877" UserId="230" />
  <row Id="2599" PostId="2971" Text="tested it with oscilloscope, the point is a junction point with ACD and DCV characteristics. Adding a cap or a resistor to the point smooth the voltage. +1" CreationDate="2010-06-11T20:59:31.600" UserId="834" />
  <row Id="2600" PostId="2941" Text="Kortuk: very well but I sensed something missing as the accepted answer revelead" CreationDate="2010-06-11T21:01:29.583" UserId="834" />
  <row Id="2601" PostId="2909" Text="Kortuk: Yes and I am not taking credit of it, please, see the &quot;the source is --&quot;. I think it is better to consider each point separately well in an answer rather than tell everything you know on a one big answer. Anyway, it is not identical it evolved to a next question which I think is now much easier to read than reading jammed comments." CreationDate="2010-06-11T21:05:32.623" UserId="834" />
  <row Id="2602" PostId="2909" Text="Kortuk: cannot see a reason why you're pointing these things? There are still many points answered in 1-3. I will attack them soonish if there is no-one else to attack them. I call it self-learning and I think it is a good thing. Tronixstuff's article is just an introduction and did not cover all of points in the question." CreationDate="2010-06-11T21:07:51.247" UserId="834" />
  <row Id="2603" PostId="2973" Text="It is not that I think I will fry anything. It is that bugs take weeks to find already, if I spend weeks and it ends up something gets ESD'ed I may think it was a bug and lose a real one. Or actually waste weeks on ESD." CreationDate="2010-06-11T21:42:10.833" UserId="230" />
  <row Id="2605" PostId="2978" Score="2" Text="if this is with the 2 test pins attached to the sound card input you may want to look at each test pin individually with the other end of the sound card input hooked to a gnd point on the board.  1 Pin may be the clk and 1 the data line and what you recorded may be the difference of those 2 signals." CreationDate="2010-06-11T22:06:07.700" UserId="703" />
  <row Id="2606" PostId="2978" Text="seriously though, is there some way to actually see the waveform? it's hard to analyze with just ears." CreationDate="2010-06-11T22:06:41.680" UserId="740" />
  <row Id="2607" PostId="2979" Score="1" Text="If you walk across carpet from the radiator to PC, it does not help at all. If you walk around in clothes that generate static, it does not help." CreationDate="2010-06-11T22:14:20.237" UserId="230" />
  <row Id="2608" PostId="2965" Text="checked them well-labelled. Corrected reply to more attacking the question. Thanks for critical feedback." CreationDate="2010-06-11T22:43:33.170" UserId="834" />
  <row Id="2609" PostId="2965" Text="just use your schools caps and if they pop, so what, clearly they were free caps." CreationDate="2010-06-11T22:56:59.623" UserId="230" />
  <row Id="2610" PostId="2978" Score="1" Text="open it in an audio editor...audacity works fine" CreationDate="2010-06-11T23:02:00.460" UserId="703" />
  <row Id="2612" PostId="2943" Text="@Kortuk: even if you brought the voltage up slowly, the moment the dielectric failed, all the energy stored in the cap at the point of breakdown will dump through the defect. it seems like it will look fine right up to the nanosecond when it pops." CreationDate="2010-06-12T01:23:17.900" UserId="740" />
  <row Id="2613" PostId="2790" Text="I'm close to finding out-- most of the rest of the device is running, so I'll be testing this in a fridge soon.  I'll let you know!" CreationDate="2010-06-12T01:55:35.260" UserId="70" />
  <row Id="2614" PostId="2858" Text="Interesting. I am trying this: &#xA;void loop(){&#xA; digitalWrite(outPin, HIGH);&#xA; delay(3);&#xA; digitalWrite(outPin, LOW);&#xA; sensorValue = analogRead(inPin);&#xA;  Serial.println(sensorValue);&#xA;}&#xA;&#xA;and all I am receiving is 170, no matter what light it is in. If I unplug it it goes to about 227. There is no change if I adjust the delay time." CreationDate="2010-06-12T02:09:54.390" UserId="678" />
  <row Id="2615" PostId="2983" Text="the wave form actually makes sense if one line is the clk and one the data.  The section with &quot;10101010&quot; would be created if the data line was held low (or high) but the clock was running.  The section with &quot;01101001&quot; could be created by the actual data being transmitted combined with the clock still running.  It still looks like an odd standard as that would mean the clock is running when no data is being transmitted so its definitely not I2C, i guess it could be SPI but it would be a weird implementation." CreationDate="2010-06-12T02:53:42.470" UserId="703" />
  <row Id="2616" PostId="2983" Text="@Mark: i think i see what you mean, you think the clock is 50% duty cycle with a period of about 7msec, toggling constantly. what i'm thinking, though, is that the clock is that little glitchy thing you see about 0.25ms after every major level change. It's also there in between bit cells with adjacent 0's or adjacent 1's as well. But even if it's the 50% d.c. thing, you can XOR that out and it still isn't a very complex signal. I'm going to go squint at it some more, maybe there are occasional deviations from the pattern." CreationDate="2010-06-12T03:06:04.870" UserId="740" />
  <row Id="2617" PostId="2958" Score="1" Text="Remember, though, that not everything is UL listed." CreationDate="2010-06-12T03:09:33.067" UserId="836" />
  <row Id="2618" PostId="2985" Text="no on 2nd thought, i'd probably just use an inverter to get the complementary signals, and do away with the D-FF and the need to clock it." CreationDate="2010-06-12T03:45:17.230" UserId="740" />
  <row Id="2619" PostId="2983" Text="Thanks for the help. Recording the pins separate is good idea.&#xA;&#xA;There are sometimes different lengths of deviation. For example, @3,4 there is a 4 clock cycles high. Or @4,3 there is a 3 clock cycles high.&#xA;&#xA;I could also record again, but than from the start, so also the booting part will be recorded.&#xA;&#xA;Is there perhaps a program that I can feed this audio-file and I can try different data protocols?" CreationDate="2010-06-12T10:53:53.320" UserId="323" />
  <row Id="2622" PostId="2992" Score="2" Text="How fast does the DC offset change? Or better yet, how fast do you need to know if the dc offset has changed? If you use a really large cap you could measure a DC voltage, but it would change slow compared to the signal." CreationDate="2010-06-12T13:09:41.953" UserId="319" />
  <row Id="2623" PostId="2992" Text="I haven't done any calculations but It would be probably be sufficient to update the DC offset reading every 200-500ms" CreationDate="2010-06-12T13:58:11.467" UserId="819" />
  <row Id="2625" PostId="2993" Text="What about detecting the negative peak rather than the DC offset as this would not be complicated by frequency response issues. To rectify scale and level shift would TL072's be fast enough?" CreationDate="2010-06-12T14:04:06.293" UserId="819" />
  <row Id="2626" PostId="2943" Text="In my mind i was being hopeful he had a way, I did not think he did, and you confirmed it." CreationDate="2010-06-12T14:13:13.900" UserId="230" />
  <row Id="2627" PostId="2993" Score="1" Text="Negative peak detection might work just as well. I'd worry a little about the diode turn-on time-- at 1 MHz, a large diode will take several cycles to turn on. You should, of course, use a small diode, but I'm not sure how fast they get. If you can switch in the nanoseconds, which I think is likely for a low power signal, it should work fine." CreationDate="2010-06-12T14:24:52.687" UserId="712" />
  <row Id="2628" PostId="2993" Score="1" Text="Regarding TL072's speed, I think they'll be marginally fast enough. Their gain-bandwidth product (GBW) is listed at 3 MHz, which means that at 1 MHz, you can only get a gain of 3. You probably only need a gain of 2, so in theory, you're OK. If you can get some easily, I might try something faster, like an LT1056 (6.5 MHz GBW). But if this is just for fun, or school, or whatever, the TL072's should work." CreationDate="2010-06-12T14:28:57.270" UserId="712" />
  <row Id="2630" PostId="2995" Text="to get the specs on the hawkboard, you have to get the 'users manual' (pdf) from the hardware links, and look at section 1.1 - you'd think they'd put this on their page though." CreationDate="2010-06-12T15:01:28.660" UserId="740" />
  <row Id="2632" PostId="2983" Text="well, if you post the data from each pin we can probably tell you the protocol (i think its just SPI).  &#xA;&#xA;Thats really only the first 25% of the battle.  After you know that you need to look at what data its transmitting and figure out what it is/does/means.  The best way to do that is with a SPI to USB converter so you can monitor the bus on a PC and inject data into it.&#xA;&#xA;This can be done with a few different tools such as the bus pirate flyguy mentioned or several other units, http://www.diolan.com/i2c/u2c12.html is my favorite." CreationDate="2010-06-12T15:26:35.640" UserId="703" />
  <row Id="2633" PostId="2996" Text="+1 I read it a few months ago, its an excellent tutorial" CreationDate="2010-06-12T15:29:43.357" UserId="819" />
  <row Id="2636" PostId="2995" Text="I already have a couple of ts7800s lying around will use those. My only concern is the mass storage part. I will have to rebuild the kernel to enable USB Gadget so that the ts7800 can present itself as a mass storage device. But that is feasible right ? Or does the TS7552 provide all of this out of the box ?" CreationDate="2010-06-12T15:39:32.167" />
  <row Id="2637" PostId="2993" Text="I have a few different signal diodes so Ill do some tests with regard to speed. " CreationDate="2010-06-12T16:02:38.703" UserId="819" />
  <row Id="2638" PostId="2993" Text="The LT1056 seem hard to find and quite pricey, I think I have a few NE5534's (&quot;Typical&quot; GBW of 10MHz) that I may use if needed otherwise Ill probably just stick with the TL072's as the project isn't for production just fun." CreationDate="2010-06-12T16:09:51.297" UserId="819" />
  <row Id="2639" PostId="2923" Score="1" Text="I have found a ground plane in a two layer design greatly reduces complexity. Yes, I just find all too often people form bad layout habits and it carries over to problems with their circuits, and they often blame the circuits." CreationDate="2010-06-12T16:39:14.830" UserId="230" />
  <row Id="2640" PostId="2958" Text="Yeah, they are probably made to open-circuit is the problem." CreationDate="2010-06-12T16:39:55.290" UserId="230" />
  <row Id="2641" PostId="3000" Score="1" Text="sounds nice, the only reason i suggested building one was for efficiency, not for cost." CreationDate="2010-06-12T16:52:59.513" UserId="230" />
  <row Id="2642" PostId="3000" Score="2" Text="I agree. Or better, find one of the thousands of abandoned wall warts, strip off the device adapter and use that. Free!" CreationDate="2010-06-12T19:03:48.523" UserId="1402" />
  <row Id="2643" PostId="2918" Text="I'm interested in how the fabrication works out. Please keep us posted." CreationDate="2010-06-12T19:12:04.357" UserId="1402" />
  <row Id="2645" PostId="2995" Text="I suspect that a TS-7800 will do the job, but you're right that you'll have to do some work to make it appear as a USB storage device. I bet it's been done before, though." CreationDate="2010-06-12T20:12:56.497" UserId="712" />
  <row Id="2646" PostId="2993" Score="1" Text="I suspect that in practice, the TL072's will work fine. If you actually get the thing mostly working, you could upgrade the opamps to improve your performance at the high end." CreationDate="2010-06-12T20:14:47.753" UserId="712" />
  <row Id="2647" PostId="2993" Text="Exactly what I was thinking, I will be testing on the breadboard before I commit to anything so..." CreationDate="2010-06-12T23:23:58.593" UserId="819" />
  <row Id="2648" PostId="2916" Text="That sounds like a question, not an answer. ;)&#xA;&#xA;The fuse bytes are specifically bytes that cannot be changed by software. That's their chief distinction from other parts of the flash/EEPROM." CreationDate="2010-06-13T00:15:24.087" UserId="484" />
  <row Id="2649" PostId="2990" Score="1" Text="If you go for the intractable then beware that silicon vendor ratings are most commonly statistical so you still get 1 part out of 1000 that is more than 3 sigma from the mean. It may ruin your design or it may not. :)" CreationDate="2010-06-13T00:43:05.063" UserId="659" />
  <row Id="2650" PostId="2977" Text="To damage anything &quot;normal&quot; you must cause quite a current. To do this to modern, protected chips through standard human body resistance you need quite a voltage so I still think that if there are no sparks then you should be safe.&#xA;&#xA;In production we sometimes get returns from our customers but never any of this could be tracked down to a possible ESD issue. For an example of an issue you should worry about (albeit this one did not pass our Q&amp;A): we once had some eerie problems with one NAND gate which was left with floating inputs. It worked with a chip from one vendor and failed with another." CreationDate="2010-06-13T00:49:58.717" UserId="659" />
  <row Id="2651" PostId="2977" Text="SUMMARY: In prototyping, unless you got full-custom ASICs or a chip worth more than $50 (translate to you own currency and financial threshold), you should not worry about ESD too much. We find normal precautions, without straps, sufficient. There are multitudes of other very cool failure options you should fear! (like mistaking Vcc &amp; GND ;-)" CreationDate="2010-06-13T00:53:22.810" UserId="659" />
  <row Id="2652" PostId="2953" Text="Good tip about the ESD ratings. These should guide the decision about the amount of protection needed on a case by case basis." CreationDate="2010-06-13T00:56:49.090" UserId="659" />
  <row Id="2653" PostId="2953" Text="Yes, We have a device that is &lt;500V rated, which means almost nothing can destroy it, luckily it is soldered down in a professional facility and other devices lend it protection." CreationDate="2010-06-13T03:16:10.980" UserId="230" />
  <row Id="2654" PostId="2923" Text="@volting, As a side note. I was not trying to imply you were wrong. You seem quite apt, but I always try to add these notes so someone new is informed of the decisions they made. Bad layouts I have seen cause as many problems as poor soldering and more problems then poor design, since design review normally catches problems sooner." CreationDate="2010-06-13T04:22:17.757" UserId="230" />
  <row Id="2655" PostId="3000" Text="if cheap is your goal, I agree." CreationDate="2010-06-13T04:28:51.953" UserId="230" />
  <row Id="2656" PostId="2884" Text="interesting. I guess that is a way to do it, you do still lose an I/O over it, but 1 I/O pin is not that bad." CreationDate="2010-06-13T14:53:30.433" UserId="230" />
  <row Id="2657" PostId="3003" Text="I bought two, neither worked. Though, there's now a new firmware which uses SPI rather than rs232-ttl from the FPGA to PIC. But, the support from the forums is excellent. Not for the faint hearted!" CreationDate="2010-06-13T20:15:04.637" UserId="566" />
  <row Id="2659" PostId="2995" Score="1" Text="http://www.linux-usb.org/gadget/" CreationDate="2010-06-14T09:08:05.737" UserId="566" />
  <row Id="2660" PostId="2984" Text="Ok, if I accidentally destroy one then that's no problem. I only thought of using them because I have a cupboard full of old ones." CreationDate="2010-06-14T10:16:25.603" UserId="710" />
  <row Id="2661" PostId="3009" Text="13.56 MHz, are you working at High Frequency RFID?" CreationDate="2010-06-14T14:03:39.823" UserId="230" />
  <row Id="2662" PostId="2966" Text="It is not a guaranteed 2.5 V for 0G. since he will probably use a computer to do the math I doubt that the method he uses to do the math will mater." CreationDate="2010-06-14T14:51:50.933" UserId="230" />
  <row Id="2663" PostId="3007" Text="+1 for minimalistic spirit. This actually sounds like it would be a lot of fun to integrate. It would also come with a lot of bumps and bruises along the way, no doubt... " CreationDate="2010-06-14T16:05:44.430" UserId="771" />
  <row Id="2664" PostId="3011" Text="Teensy + WiShield.&#xA;Teensy'll run the LUFA mass-storage code." CreationDate="2010-06-14T16:12:05.763" UserId="566" />
  <row Id="2665" PostId="2986" Text="hm... this seems like a pretty cool little board, have you actually used it?" CreationDate="2010-06-14T16:29:26.153" UserId="771" />
  <row Id="2666" PostId="3010" Text="The capacitive coupling is likely to be a killer. We must minimize the ac current that can flow across the transformer so there is no ground loop.&#xA;&#xA;We have prototyped a solution with antennas and a 1cm air gap. This works well. Just need to miniaturize this into a PCM component.&#xA;&#xA;Selecting the actual component and identifying manufacturers is the problem.&#xA;&#xA;We are using unbalanced differential signals so noise isn't a real concern." CreationDate="2010-06-14T16:33:18.077" />
  <row Id="2667" PostId="3010" Text="At 1cm can you really call it an antenna? It is intentionally in the near field. The major thing it seems you need to me is to place a piece of metal between the two devices and ground it well. This will block capacitive coupling, but your inductive coupling of the transformer should work well." CreationDate="2010-06-14T16:40:17.703" UserId="230" />
  <row Id="2668" PostId="3010" Text="My lunch break starts now, but I will be back a bit later and will add more and look up a few components if that will help." CreationDate="2010-06-14T16:41:40.170" UserId="230" />
  <row Id="2669" PostId="3010" Text="The air gap is between the two antennas. Just two antennas inductively coupled.&#xA;&#xA;The devices have their grounds connected together, this is why it is important no current flows across transformer. If there is no current across the transformer there is no current that can flow this common ground between devices causing issues (there is no ground loop return path)." CreationDate="2010-06-14T16:47:12.977" />
  <row Id="2670" PostId="3010" Text="you could possibly use an opto-isolator as opposed to isolating with a transformer as well." CreationDate="2010-06-14T20:32:29.467" UserId="703" />
  <row Id="2671" PostId="3010" Text="Yes, there are systems that use opto-isolators to do this, and they are more designed for voltage isolation. They are often used in medical equipment where a surge in power cannot allow the device to surge it's output or electrocute the user." CreationDate="2010-06-14T20:56:31.910" UserId="230" />
  <row Id="2672" PostId="3012" Text="this is clearly a community wiki type of question right?" CreationDate="2010-06-14T21:58:20.867" UserId="771" />
  <row Id="2673" PostId="3012" Text="why don't you tell us a little bit more about what you already know?" CreationDate="2010-06-14T21:59:36.107" UserId="771" />
  <row Id="2674" PostId="3012" Text="Wish you were at my school, we could have you trained and doing microcontrollers in our design labs within that time." CreationDate="2010-06-14T22:14:41.613" UserId="230" />
  <row Id="2675" PostId="3010" Text="The issue is that your signal will couple through the LEDs. Make sure you put a really good shield around the first coil and tie it to ground on all sides." CreationDate="2010-06-14T22:15:50.033" UserId="230" />
  <row Id="2676" PostId="3016" Text="do you have a stencil for solder paste?" CreationDate="2010-06-14T23:22:00.277" UserId="230" />
  <row Id="2677" PostId="3016" Score="3" Text="Can you tell us a bit more about the PCB? Does it have solder mask? surface mount? through hole? &#xA;&#xA;How big/complex is the PCB? " CreationDate="2010-06-14T23:40:44.267" UserId="319" />
  <row Id="2679" PostId="3012" Score="2" Text="your in college man, get yourself a book of pick up lines, try them all out at least 5 times.  Record the results :)" CreationDate="2010-06-15T00:53:36.013" UserId="703" />
  <row Id="2681" PostId="3016" Text="I have to agree, can you tell us what kind of board, if it is all through hole, a stencil is worthless, but if it has all surface mount components then you will save years of your life.&#xA;&#xA;Are they 0603 footprint, or 1206, another big difference. And solder mask is always a big deal." CreationDate="2010-06-15T02:43:41.597" UserId="230" />
  <row Id="2682" PostId="3012" Text="Yes, get your priorities straight!  :)" CreationDate="2010-06-15T03:02:26.990" UserId="142" />
  <row Id="2683" PostId="3018" Text="I will probably not have time to discuss this till tomorrow afternoon, but this is a great project and a great question." CreationDate="2010-06-15T05:04:32.793" UserId="230" />
  <row Id="2685" PostId="125" Text="nitpick: According to Wikipedia ( http://en.wikipedia.org/wiki/brushless_DC_electric_motor ),&#xA;BLDC motors are optimized to work best when driven by switched DC: full positive, undriven, and full negative.&#xA;Permanent magnet AC motors are optimized to work best when driven by a sine wave; that's the only significant difference between them.&#xA;&#xA;I agree with your conclusion: it is probably worth it to use an off-the-shelf ESC rather than develop one yourself." CreationDate="2010-06-15T06:22:43.647" UserId="813" />
  <row Id="2686" PostId="3012" Text="I am getting my priorities straight. I joined up to learn, but I don't get much of that out of the classes and assignment and tutorials (we sleep through the former as most of the lecturers dont know much and copy the latter as they are just from the books and not very challenging). So I look up other ventures to take to expand my knowledge." CreationDate="2010-06-15T06:23:56.603" UserId="1200" />
  <row Id="2687" PostId="3013" Text="Umm... interesting you mentioned it. I had been planning to dabble into Nv Nets for a few weekends and see what comes out of it. I have already made some hoppers and a mousey." CreationDate="2010-06-15T06:25:37.153" UserId="1200" />
  <row Id="2688" PostId="3015" Text="I know some avr C so I think I can expand on that." CreationDate="2010-06-15T06:26:02.813" UserId="1200" />
  <row Id="2689" PostId="3020" Score="2" Text="I assume the downvotes were for the use of all caps?" CreationDate="2010-06-15T08:19:13.760" UserId="103" />
  <row Id="2691" PostId="3020" Score="2" Text="Guess so, I made it more readable." CreationDate="2010-06-15T08:25:59.620" UserId="566" />
  <row Id="2692" PostId="3015" Score="4" Text="C++ is not used as widely in embedded systems as C. Hopefully, it will stay that way." CreationDate="2010-06-15T08:42:06.860" UserId="566" />
  <row Id="2693" PostId="3021" Text="Joby&#xA;New to this type of forum. What is the best way to chat with you if this is permitted.&#xA;Greg" CreationDate="2010-06-15T09:28:00.690" />
  <row Id="2694" PostId="3021" Text="Post comments, then when we're done, we can fold changes into the question and answers." CreationDate="2010-06-15T10:00:21.223" UserId="566" />
  <row Id="2695" PostId="3021" Text="Joby&#xA;I have used the example code. First downloaded to the Arduino with Hilo off then replaced hilo and reset arduino but nothing happens. Not sure whats going on. There are no leds on the hilo to help with feedback.&#xA;" CreationDate="2010-06-15T10:52:39.163" />
  <row Id="2696" PostId="3021" Text="I'm afraid that I haven't a clue, but hopefully somebody else will..." CreationDate="2010-06-15T11:05:16.360" UserId="566" />
  <row Id="2697" PostId="3021" Text="Joby many thanks for your time. Much appreciated." CreationDate="2010-06-15T11:08:44.113" />
  <row Id="2698" PostId="3019" Text="Excellent information-- thanks." CreationDate="2010-06-15T12:57:14.037" UserId="712" />
  <row Id="2699" PostId="3018" Text="(I have a feeling that Kortuk is about to lay down the truth, like with that accelerometer question a couple weeks ago.)" CreationDate="2010-06-15T13:00:38.253" UserId="712" />
  <row Id="2700" PostId="3015" Text="@Joby, I agree with the anti-C++ sentiment in the context of microcontrollers, @Kortuk modified my original post and added the C++ rhetoric." CreationDate="2010-06-15T13:31:36.310" UserId="771" />
  <row Id="2701" PostId="3014" Text="Yea, if you have have an EE background, you should at least be able to get the &quot;Technician&quot; class by taking the exam cold. You might even be able to eek through the &quot;General&quot; class exam." CreationDate="2010-06-15T13:34:12.917" UserId="771" />
  <row Id="2702" PostId="3020" Text="Are you saying that you can't burn a sketch to the Arduino while the Libelium Hilo shield is attached? " CreationDate="2010-06-15T14:03:28.013" UserId="771" />
  <row Id="2703" PostId="3025" Text="I consider myself good with making boards out of General purpose PCBs. The types which look somewhat like a breadboard or have some other pattern on it. I once thought of learning the skill of making real PCBs but the problem is where I live getting a PCB manufactured is expensive as hell. So there is just no motivation." CreationDate="2010-06-15T14:29:35.363" UserId="1200" />
  <row Id="2704" PostId="3025" Text="FYI I have already assembled a shield ready Arduino on a General Purpose PCB." CreationDate="2010-06-15T14:30:05.877" UserId="1200" />
  <row Id="2705" PostId="3015" Text="@Joby - Why should C++ be avoided for embedded systems?" CreationDate="2010-06-15T14:56:50.760" UserId="374" />
  <row Id="2706" PostId="3018" Text="Thank you for the vote of faith pingswept, but I was hired as a consultant to my school when they had a project with accelerometers they could not get working. This has never happened for CC2420, so I do not know them as well." CreationDate="2010-06-15T15:23:27.633" UserId="230" />
  <row Id="2707" PostId="3025" Text="You can learn about PCB layout without getting boards professionally manufactured. Google for &quot;toner transfer&quot;, or you can just scribble on a copper clad board with an etch resist pen. It needn't be expensive." CreationDate="2010-06-15T15:27:01.887" UserId="566" />
  <row Id="2708" PostId="3015" Text="I've created a new question/wiki for this. http://chiphacker.com/questions/3027/is-c-suitable-for-embedded-systems" CreationDate="2010-06-15T15:56:30.557" UserId="566" />
  <row Id="2709" PostId="3024" Text="2% is significantly smaller then the least allowable error. In a system with 8 bits of data, with a start and stop bit, you have 10 bits to each packet. When a packet starts the receiver synchronizes to it. With an error of less than 10% difference in clock rate of the two sides is met you will find there is no error, as on each bit you will stay within the band of the proper reading." CreationDate="2010-06-15T15:57:02.147" UserId="230" />
  <row Id="2710" PostId="3024" Text="I hope that makes sense, often a computer is pretty spot on so you can have an error of almost 10% at your arduino without a problem." CreationDate="2010-06-15T15:57:33.220" UserId="230" />
  <row Id="2713" PostId="3027" Score="3" Text="Quick question:  when you say _embedded_, do you mean microcontroller?  microprocessor?  embedded x86 / embedded PC?" CreationDate="2010-06-15T16:07:28.530" UserId="374" />
  <row Id="2714" PostId="3027" Score="1" Text="I didn't intend to cause a holy war; the intent was to learn what your arguments were against it." CreationDate="2010-06-15T16:08:23.167" UserId="374" />
  <row Id="2715" PostId="3027" Score="2" Text="It's come up in several questions before, so I thought a central place would be good." CreationDate="2010-06-15T16:13:45.967" UserId="566" />
  <row Id="2717" PostId="3028" Text="I agree in reference to small systems, but I think we have different definitions of small systems. When you have 1kB of ROM and well written C code takes all but 1 byte of ROM, that is a small system." CreationDate="2010-06-15T16:20:40.880" UserId="230" />
  <row Id="2718" PostId="3028" Score="4" Text="I am not arguing that C cannot have a smaller footprint, but you could have used C++ still and obtained a very similar result for designing for what was just discussed. I think the issue is most OOP programmers are used to systems with dynamic memory and using very inefficient constructs, resulting in completely useless code for lower power systems. " CreationDate="2010-06-15T16:27:45.313" UserId="230" />
  <row Id="2719" PostId="3027" Score="3" Text="C++ vs embedded is a contentious topic. I have a strong opinion, but I didn't think it was fair to raise a question and play at scoring points. I hope that a community wiki will make for a more balanced discussion." CreationDate="2010-06-15T16:36:55.483" UserId="566" />
  <row Id="2720" PostId="3025" Text="@Rick_2047: If you don't mind me asking, what EE stuff do you have available? I would have guessed that PCBs are cheap in India, but it seems I would have guessed wrong. (Apologies for googling your country of origin-- figured it was fair game since it was on your blog.)" CreationDate="2010-06-15T16:37:19.083" UserId="712" />
  <row Id="2721" PostId="3025" Text="@Rick_2047: Also, if you've already assembled an Arduino, I'd focus on making it do something awesome. Maybe build an H-bridge for driving a small DC motor or stepper motor? That's the start of a robot." CreationDate="2010-06-15T16:39:15.727" UserId="712" />
  <row Id="2722" PostId="3025" Text="@pingswept no problem, I am not one of those privacy freaks. On another note what do you mean by &quot;EE stuff&quot;? I assembled an arduino but have decided not to take that path. I am comfortable with C so I have taken up avr-gcc. I made a robot control board using a atmega32 and l293d. Was working on interfacing some sensors but for some reason it seems boring.Thats why I posted this question." CreationDate="2010-06-15T16:45:21.997" UserId="1200" />
  <row Id="2723" PostId="3013" Text="I was just wondering if it is really alive right now. Except for the mailing list at yahoo groups there is not much activity I can find." CreationDate="2010-06-15T16:46:45.743" UserId="1200" />
  <row Id="2724" PostId="3027" Text="I understood why you did it, I base my opinions on what allows a job to be done well and fast, but Most people I know consider it a hot topic, and easily turn their faces red." CreationDate="2010-06-15T16:46:55.027" UserId="230" />
  <row Id="2726" PostId="2038" Score="1" Text="Do you mean the Saleae Logic Pod?  http://www.saleae.com/logic/" CreationDate="2010-06-15T17:54:17.557" />
  <row Id="2727" PostId="3028" Text="Thanks for posting your argument!" CreationDate="2010-06-15T17:55:40.423" UserId="374" />
  <row Id="2728" PostId="3028" Text="I've done mainly larger-scale x86 SBC development in C++, so I find it useful to hear experiences (positive or negative) in using C++ on platforms with less resources." CreationDate="2010-06-15T17:57:50.733" UserId="374" />
  <row Id="2729" PostId="3025" Text="@Rick_2047: I was sort of surprised that PCBs are out of the price range of students-- in the US, small PCBs cost about as much as 2 sandwiches or 1 book. I was wondering what else is available to students for embedded elctronics. For example, do you have access to oscilloscopes? Just multimeters? Can you buy ICs through the mail? I know that in some places, shipping electronics is unreliable, slow, and expensive. Just curious about what India's like for a young engineer." CreationDate="2010-06-15T18:16:16.063" UserId="712" />
  <row Id="2730" PostId="3025" Text="@pingswept, now that you have got me started listen, read rather, to the rant. PCBs cost about 500Rs that is around 25 McD burgers or two first hand or 5 second hand books. Forget about purchasing through the mail, its really slow and shipping is way up and over my usual order. But that does not deter me, I go regularly to a local electronics dealer. So much so that as soon as I reach there he goes &quot;Harshal (his servant),get two of his PCBs, one 28 pin socket, one 16 pin socket, 1 Meter roll of 10 color hookup wires&quot;. Then he asks what else I want. Oscillosocpes are expensive. I thought cont.." CreationDate="2010-06-15T18:30:15.200" UserId="1200" />
  <row Id="2731" PostId="3025" Text="of purchasing one from the local scrap dealer but thought that a little damage, will give me wrong readings so I didn't purchase it. ICs are not usually a problem. The local vendor gets me those in a few days or I go to the city market. Where most of everything is available. This is the senario in India. Now you may be wondering 500Rs is just 10$. But bear in mind that my allowance is non existant and my usual order costs me 120Rs or so." CreationDate="2010-06-15T18:33:44.357" UserId="1200" />
  <row Id="2732" PostId="3028" Text="I have done a very large amount of development on computers with C++, I have done almost none on embedded platforms. I have done a very very large amount of development on embedded platforms, and I mean in the range of MSP430s and PICs. This has all been done in C. No libraries or anything. I would like to use C++ on an embedded systems project, there are many good reasons, so far I have not heard reasons that cannot be resolved by using strict rules on what constructs of C++ that can be used." CreationDate="2010-06-15T18:43:17.380" UserId="230" />
  <row Id="2733" PostId="3030" Score="1" Text="We may differ, but I find that just opening any project I cannot tell what is going on immediately, but if I know something about what it is doing and I have something well coded in C and something well coded in C++ the C++ always seems more clear. You still need to implement encapsulation for good development in C, which C++ makes very easy to do. Proper use of classes can make it very clear where you interfaces are, and they can be completely handled through an object." CreationDate="2010-06-15T18:54:31.430" UserId="230" />
  <row Id="2734" PostId="3014" Text="i just took practice tests again. The Extra level was easier. The first practice test i took for technician had very few rules about FCC in it. The others gave me a 60% because I do not know the rules. The extra level seemed to mostly be technical, but I am also specialized in RF." CreationDate="2010-06-15T18:56:45.013" UserId="230" />
  <row Id="2736" PostId="3025" Text="If you do not mind me asking, What part of India are you in? I plan to visit Bengaluru(Bangalore) in the next two years, hopefully make it to the ESC. I know many students at my school whom are from India, but I think in most cases have very rich families. Thank you for the information about what happens there, I think the different cultures can be very very interesting. " CreationDate="2010-06-15T19:03:38.610" UserId="230" />
  <row Id="2737" PostId="3025" Text="I am in Ahmedabad, Gujarat. What do you mean by ESC? Also by previous posts I infer you are an academician, so by any chance you are visiting IISc Banglore? Just curious." CreationDate="2010-06-15T19:08:18.693" UserId="1200" />
  <row Id="2738" PostId="3030" Text="Totally agreed on encapsulation and classes. Operator overloading and inheritance, not so much." CreationDate="2010-06-15T19:26:03.373" UserId="712" />
  <row Id="2739" PostId="3030" Text="Haha, yes, operator overloading can be used to obfuscate the function of code. If someone is operator overloading it needs to be for clear reasons or not done at all. Inheritance should only be used in specific cases where you actually are doing something that is just like the parent with a few additions. I think I would not every use either function in OOP. I have used both, but in an embedded system cannot think of a case were I would. Just as I think a compiler with an 80 character limit on variable names should be immediately scrapped." CreationDate="2010-06-15T19:53:13.303" UserId="230" />
  <row Id="2740" PostId="3027" Text="I agree with @Joby, this is a 100% clear Community Wiki... " CreationDate="2010-06-15T20:11:57.837" UserId="771" />
  <row Id="2741" PostId="3030" Score="1" Text="I just threw up in my mouth a little at the thought of programming an MCU in Python..." CreationDate="2010-06-15T20:14:19.213" UserId="771" />
  <row Id="2742" PostId="3015" Text="@Rick_2047, for the love of God, when you say &quot;avr C&quot; I hope you mean that you are using the avr-gcc compiler (WinAVR toolchain), and eclipse-AVR as your development environment. At least you stand a chance of your C knowlege being portable in that case :)." CreationDate="2010-06-15T20:27:04.937" UserId="771" />
  <row Id="2743" PostId="3024" Text="@Kortuk, I'm just taking the datasheet at face value. A personal computer may very well be more tolerant than the AVR's UART to precision of your bit-timing." CreationDate="2010-06-15T20:28:41.063" UserId="771" />
  <row Id="2744" PostId="3015" Text="I find very few applications where an object oriented design paradigm is really a win in readability and maintainability.  Even less often do you find an application where object oriented design fits and was implemented in a way that it was at all an advantage over a functional design.  " CreationDate="2010-06-15T20:40:14.713" UserId="703" />
  <row Id="2745" PostId="3015" Text="I rolled back my changes. I did not mean to cause a fuss. I think C++ would be valuable, but it seems many here do not. I like C++, but the articles I read from some of the Guru's of embedded systems are what caused me to add this." CreationDate="2010-06-15T20:47:13.570" UserId="230" />
  <row Id="2746" PostId="3025" Text="http://www.esc-india.com/ is what I am interested in. I am still involved in academia, I am currently at okstate.edu. I am also working at a start-up company. My Girlfriend is raised in the USA, but her mother is born mumbai and raised in Bengaluru. Her grandmother still lives in Bengaluru, I would like to meet her, and I would like to see some of India." CreationDate="2010-06-15T20:53:52.870" UserId="230" />
  <row Id="2747" PostId="3027" Text="yeah, i missread something and thought someone else was the original poster. My bad, clearing my comments." CreationDate="2010-06-15T20:59:48.083" UserId="230" />
  <row Id="2748" PostId="3030" Text="You are not the only one, but if it works well and is efficient, I can forgive." CreationDate="2010-06-15T21:01:16.273" UserId="230" />
  <row Id="2749" PostId="3030" Text="python-on-a-chip http://code.google.com/p/python-on-a-chip/" CreationDate="2010-06-15T21:01:44.460" UserId="566" />
  <row Id="2750" PostId="3030" Text="I have a general rule, if it can do the task better and faster, then I will use it. in some cases one is more important than the other." CreationDate="2010-06-15T21:02:40.950" UserId="230" />
  <row Id="2751" PostId="3015" Text="@Kortuk, no worries I appreciate the dialogue" CreationDate="2010-06-15T21:04:17.513" UserId="771" />
  <row Id="2752" PostId="3025" Text="This is a fantastic answer" CreationDate="2010-06-15T21:05:36.810" UserId="771" />
  <row Id="2753" PostId="3031" Text="My issue here is simply, why do I want to know the complexity of the driver that was written to control USART1 if it has been fully developed to handle the interface." CreationDate="2010-06-15T21:19:47.640" UserId="230" />
  <row Id="2754" PostId="3025" Text="@Rick_2047: Interesting. In some ways, it sounds better than where I'm from (Boston, USA), because you can actually buy components locally. Because shipping is relatively cheap and fast in the US, virtually all of the hobby electronics shops have been destroyed by Digikey and such. Thanks for the perspective. Will you keep us posted on what you learn/build?" CreationDate="2010-06-15T22:34:02.700" UserId="712" />
  <row Id="2755" PostId="1070" Score="3" Text="endolith -- I agree, ADCs usually don't work at low frequencies.&#xA;As far as I can tell, everything else on practically all modern microcontrollers continue to work fine all the way down to &quot;0 Hz&quot;, aka &quot;pause indefinitely&quot;.&#xA;In particular, many microcontrollers have a &quot;low-power sleep&quot; mode that stops all clocks, until something -- typically a person pushing a button -- wakes it up and it resumes right where it left off.&#xA;http://en.wikipedia.org/wiki/Static_logic_(digital_logic)" CreationDate="2010-06-15T22:52:49.697" UserId="813" />
  <row Id="2757" PostId="3035" Score="1" Text="Inkscape outputs SVG images, which is a requirement:&#xA;3. It has to be able to export in SVG: the SVG is the format that was proposed by wikipedia for diagrams. It provides the best quality at the minimum space. &#xA;Most schematic capture programs have the same view you took - Graphics as such (other than PDF export) are useless. Wikipedia wants the prettiest, smallest graphics. What we want is different: The fastest, easiest way to create a schematic and its simulation." CreationDate="2010-06-16T02:14:07.420" UserId="857" />
  <row Id="2758" PostId="2038" Text="That's the one. Sorry about the misspelling. Since March I have used the pod quite a bit to debug a uSD library. The device is worth the money but the software interface is awkward. I am not sure if other devices in the price range are any better. If I used this tool a lot I would look into writing my own interface. " CreationDate="2010-06-16T02:30:26.147" UserId="424" />
  <row Id="2759" PostId="3020" Text="I can't burn to the arduino with the shield attached with the 2 links in the Arduino postion. If the links are removed then it will burn ok." CreationDate="2010-06-16T03:20:22.280" />
  <row Id="2760" PostId="3024" Text="Thanks for this information. I will try different rates and see if I can pick one that works." CreationDate="2010-06-16T03:22:16.303" />
  <row Id="2761" PostId="3023" Score="1" Text="You can get a stencil from stencilsunlimited.com or integratedideas.com.&#xA;&#xA;Of course, as Kellenjb pointed out, this works only if you have a limited set of conditions: soldermask, smt, and pitch are all important in making this work.&#xA;&#xA;If you only have to do 20-100, and they're only a couple inches square, you'll get it done by hand with a good iron long before the stencils come in the mail.  If you're doing this as a business, plan for stencils, or look into a cheap (relatively) pick-n-place for small jobs. (ex. http://www.manncorp.com/pick-and-place/mc384) " CreationDate="2010-06-16T03:58:39.050" UserId="857" />
  <row Id="2762" PostId="3028" Score="1" Text="so what your saying is you don't want to use C++, you want to use something between C and C++ (lets just call it C+?).  In that case i agree, theres a lot of crap in C++ people use just because its available, not because its optimal.  Almost any language is capable of producing good, fast code, its a matter of how its used.  Most holy wars over languages are not a result of the languages capabilities but an argument over how easy it is for an idiot to do idiotic things, which is an idiotic argument really :p" CreationDate="2010-06-16T04:00:54.693" UserId="703" />
  <row Id="2763" PostId="3038" Text="I have a few reservations about ARM. First of all, it is a real &quot;professional&quot; thing so it always seems hard at the very first glance. Yes I can program AVR very well (I give lectures on it) and have made several projects using the ATMega serise but do you think that this would be enough to get started with AVR? Also I never have enough money to buy the kits, I make my own, not a problem. But ARM schematics are hard to find. Can you recomend a cheap arm processor which I can use to get started?" CreationDate="2010-06-16T04:04:53.920" UserId="1200" />
  <row Id="2764" PostId="3015" Text="@vicatcu, Oh yes, I mean AVR-GCC + Vim. " CreationDate="2010-06-16T04:05:54.793" UserId="1200" />
  <row Id="2765" PostId="3025" Text="@pingswept, it may sound better than boston in case of availability of ICs and components (I can virtually buy any of the things used in industries somewhere in my city) but bear in mind that there is no market for hobby kits. I couldn't find any local suppliers for Arduinos or such." CreationDate="2010-06-16T04:23:48.853" UserId="1200" />
  <row Id="2766" PostId="3038" Text="I just looked at the website of one of the local vendors, they say all the ARM are in SMD. Is that so? That would make it really hard to make a board for myself" CreationDate="2010-06-16T04:43:49.703" UserId="1200" />
  <row Id="2767" PostId="3038" Text="If you have a steady hand, surface mount soldering really isn't too bad. If you don't have a PCB or adapter board, you can even glue your chip upside down then wirewrap the legs." CreationDate="2010-06-16T09:38:38.097" UserId="566" />
  <row Id="2768" PostId="3036" Text="This goes inline with what I have read from other embedded systems consultants. I have always been taught that with C, you cut your self in little ways constantly, but a bug in C++ is going to be more rare, but when you screw up you are going to lose a leg. Thank you for writing a clear response with some expertise that I do not have." CreationDate="2010-06-16T14:23:12.730" UserId="230" />
  <row Id="2769" PostId="3036" Text="I had been informed that you really need to spend time and get trained in proper techniques before charging headfirst into C++." CreationDate="2010-06-16T14:23:36.160" UserId="230" />
  <row Id="2770" PostId="3028" Score="1" Text="&quot;Most holy wars over languages are not a result of the languages capabilities but an argument over how easy it is for an idiot to do idiotic things, which is an idiotic argument really.&quot; Was a very enjoyable sentence. I need your last name so I can quote that one." CreationDate="2010-06-16T14:27:54.643" UserId="230" />
  <row Id="2771" PostId="1029" Text="Fritzing seems to have a lot of community potential. If it takes off in the same way as the Arduino project, it could be really great. Right now, it's lacking some essential components, but seems to be moving forward. " CreationDate="2010-06-16T14:27:55.543" UserId="835" />
  <row Id="2772" PostId="3028" Text="I try to argue over how powerful a language is for getting things done. I think C++ gives great leaps and bounds in power for getting things done. With proper design and implementation I see great improvements in how we develop systems, which is what I want, and if it can help others, but just requires a little more training, then I am interested." CreationDate="2010-06-16T14:30:38.337" UserId="230" />
  <row Id="2773" PostId="3028" Score="1" Text="I really do not use the dynamic memory in C either though. There is nowhere that I have to have it. In long term I have read that it can get very very segmented and start causing problems. I need to have very clearly designed cases for running out of memory, and I need to be able to monitor exactly how much is left." CreationDate="2010-06-16T14:34:56.090" UserId="230" />
  <row Id="2774" PostId="3036" Text="On the note of Computer Science majors going crazy in EE land. At my job the worst piece of code we have was written by a CS major. We spent forever trying to teach him what the hardware was. He made a structured system using UML and built the entire system based on it in java using proper inheritance and so forth. It worked, until anything changed, and then it was a bad patch job to add features, or a complete redesign. The code is almost not usable because of how thoroughly he obfuscated the whole thing with inheritance. " CreationDate="2010-06-16T14:36:55.570" UserId="230" />
  <row Id="2775" PostId="3040" Score="1" Text="I would like to comment on your second point, you say that it helps break up a complex problem into a lot of little pieces and that feature should be ignored. This is the exact reason that I am so pro-C++. A very large body of research into programming shows that a linear growth in program size gives an exponential growth in development time. this follows the opposite way, if you can properly split up a program then you can give an exponential decay in development time. This is by far the most important thing." CreationDate="2010-06-16T14:49:54.313" UserId="230" />
  <row Id="2776" PostId="3024" Text="Greg, I am sorry if I was not being clear, I was trying to make the point that unless you picked a horrible BAUD rate(one with more than 10% error on divide from system clock) then you should be fine." CreationDate="2010-06-16T14:52:37.897" UserId="230" />
  <row Id="2777" PostId="3024" Text="@vicatcu, The 2% i see in the linked section is not telling you what the tolerance of the baud rate is, it is telling you how much a resonator system may differ based on resonator tolerance. That affects your BAUD rate accuracy, but only in a minor way. If you have a 2% error, and divide the clock by 100 then you have a .02% error, negligible." CreationDate="2010-06-16T14:54:05.100" UserId="230" />
  <row Id="2778" PostId="3020" Text="I wish you lived in OK, I do not know arduino's well, but I can use an Oscope to find anything." CreationDate="2010-06-16T14:58:46.067" UserId="230" />
  <row Id="2779" PostId="2038" Text="I use it almost daily for working with half-duplex RS-485.  Personally, I like the interface compared to others in the price range.  A different scope I've used is the USBee line of devices, but they're pricier for similar functionality. FWIW, they've migrated to more of a Saleae interface recently.  " CreationDate="2010-06-16T15:06:20.443" />
  <row Id="2780" PostId="3035" Text="Still an interesting solution" CreationDate="2010-06-16T15:16:21.747" UserId="230" />
  <row Id="2781" PostId="3044" Score="1" Text="This solution is for a signal, if you want to power a system with it, i may have missunderstood you." CreationDate="2010-06-16T16:31:32.877" UserId="230" />
  <row Id="2783" PostId="3043" Score="2" Text="I am giving a +1, i am not sure if he wants something for power, or if it is a signal, you did power, i did signal." CreationDate="2010-06-16T16:36:21.967" UserId="230" />
  <row Id="2784" PostId="3043" Text="I've also had success with CMOS voltage converters (http://www.national.com/mpf/LM/LMC7660.html#Overview) they're easy to use but limited in their usefulness" CreationDate="2010-06-16T16:37:27.497" UserId="399" />
  <row Id="2785" PostId="3044" Text="Cheers for pointing that out, I missed that one - doh!" CreationDate="2010-06-16T16:38:29.070" UserId="399" />
  <row Id="2786" PostId="3044" Score="2" Text="Nice diagram - they look kinda retro!" CreationDate="2010-06-16T16:40:25.340" UserId="399" />
  <row Id="2787" PostId="3043" Text="Thanks guys, this gives me a lot to go with - I'll check it all out." CreationDate="2010-06-16T16:53:39.113" UserId="835" />
  <row Id="2788" PostId="3044" Score="1" Text="They are awesome, want links? http://chiphacker.com/questions/1024/uploading-schematics-for-chip-hacker/2537#2537" CreationDate="2010-06-16T16:58:41.010" UserId="230" />
  <row Id="2789" PostId="3044" Score="1" Text="That is how I learned about it, and I think I love it." CreationDate="2010-06-16T16:58:52.853" UserId="230" />
  <row Id="2790" PostId="3044" Text="I would have assumed he is looking for a way to convert a signal since he was talking about a voltage range." CreationDate="2010-06-16T16:59:35.923" UserId="588" />
  <row Id="2791" PostId="3036" Text="It's not just bugs that bite you, but unmaintainable code that will bite you too.  Sure, when you start that project out using those neat C++ features everything goes swimmingly, but after 2 or 3 years entropy kicks in if no serious effort is put into refactoring as you develop.  That's what I'm facing right now..the code rots faster over time in C++.  " CreationDate="2010-06-16T17:22:08.937" UserId="625" />
  <row Id="2792" PostId="3036" Text="UML and statemachines.  You really need to look into Miro Samek's stuff at http://www.state-machine.com. He's built an efficient system that's easy to refactor and change, but it does take some time to grok it." CreationDate="2010-06-16T17:24:36.763" UserId="625" />
  <row Id="2793" PostId="3044" Text="That was my assumption, but the beautiful part of this board is that multiple people respond and we covered the options." CreationDate="2010-06-16T17:56:02.663" UserId="230" />
  <row Id="2794" PostId="3045" Text="Not that I could find quickly, good luck to others!" CreationDate="2010-06-16T17:57:35.767" UserId="230" />
  <row Id="2795" PostId="2537" Text="I have now used it, and for just throwing a schematic together, awesome!" CreationDate="2010-06-16T18:01:54.233" UserId="230" />
  <row Id="2796" PostId="3045" Text="You could try asking for samples from places that sell them in bulk." CreationDate="2010-06-16T18:03:10.990" UserId="319" />
  <row Id="2797" PostId="3031" Text="I did not down vote you, but I would like to point out that C++ does not need to enforce OOP, just gives the tools to do it. Enforcing good coding standards is the job of the developer. It can help if the language makes it easier, but the language will never do it on it's own. C can be unreadable in some cases." CreationDate="2010-06-16T18:09:02.917" UserId="230" />
  <row Id="2798" PostId="3030" Text="My claim is that programmer time is often more expensive than hardware. Imagine trying to do network programming in C vs. Python, in order to save $50 on hardware. For small volume applications, high-level languages win, now that embedded hardware is as powerful as it is." CreationDate="2010-06-16T18:30:23.430" UserId="712" />
  <row Id="2799" PostId="3030" Text="I agree, I work at a company where we expect to sell many millions of devices, so the non-recurring expenses are rather low per unit, but the hardware matters. In a small project it makes sense. I meant by my earlier comment that better and faster are important. You just need faster though." CreationDate="2010-06-16T19:15:30.130" UserId="230" />
  <row Id="2800" PostId="3043" Text="So are you trying to make dual power supplies Greg?" CreationDate="2010-06-16T19:19:38.923" UserId="230" />
  <row Id="2801" PostId="3036" Text="That is what killed us in Java DoxaLogos. And for us, run time bugs are an issue and in most of our maintenance we have a chance of run time bugs because our system is running past the 95% load point." CreationDate="2010-06-16T21:43:52.980" UserId="230" />
  <row Id="2802" PostId="3036" Text="Thank you for the link, I always try to learn more!" CreationDate="2010-06-16T21:44:03.027" UserId="230" />
  <row Id="2803" PostId="3046" Text="If you give me a link to the associated docs, I should be able to take a look tomorrow and help out." CreationDate="2010-06-16T22:24:00.963" UserId="230" />
  <row Id="2804" PostId="3043" Text="No, doing some work with a DAC-based idea, where I'll need to scale the voltage output." CreationDate="2010-06-16T23:06:45.177" UserId="835" />
  <row Id="2805" PostId="3051" Text="+1, I enjoyed it, although a bit long. I only use C at work, but I am really trying to move to C++ because there are many bonuses. I have my biases, mostly because of what has gone wrong, or the fact that I have a boss who changes specs within 2 days of telling us what is needed. I am still learning, and I expect to feel that way for about another 4-5 years. I will still learn after that point, but my company does not have a style guide that is followed or an inspection process and I am trying to get both." CreationDate="2010-06-17T01:00:08.323" UserId="230" />
  <row Id="2806" PostId="3043" Text="I thought so, I was confused as to why you took an answer that was showing you how to get different power rails over one that scales the range. I think they are both right, but for different questions." CreationDate="2010-06-17T01:07:14.277" UserId="230" />
  <row Id="2807" PostId="3051" Text="I think you hit the nail on the head with your comment on bending the tool around the problem.  It reminds me of the saying, &quot;When all you have is a hammer, everything looks like nail!&quot; Was that a pun?;-)&#xA;&#xA;TDD is definitely flies in the face of up front thought, and I don't think I'll ever get comfortable with the idea of making tests to create the design...especially in embedded systems.  How in the world can you mock a hardware piece to unit-test a device driver without wasting a lot of time on the mock piece?!  " CreationDate="2010-06-17T01:08:47.407" UserId="625" />
  <row Id="2808" PostId="3051" Score="1" Text="Now, I'm not knocking unit tests on an application level (above driver) on certain embedded systems.  There is some value of the instant feedback of unit-testing and rooting out bugs early in the development phase, but the whole TDD paradigm to give birth to the design seems to me a little braindead.  I prefer to take some time to &quot;think&quot; about the problem and diagram it out either in my head, on paper, or on a whiteboard, before starting to code.  I also think TDD encourages the market to not do upfront research on requirements, because it's supposed to help with constant requirement change." CreationDate="2010-06-17T01:13:18.857" UserId="625" />
  <row Id="2809" PostId="3051" Text="And to put a final note on my super long comment..&#xA;&#xA;We don't need language experts to work the design.  We need expert designers who can work the language(s)." CreationDate="2010-06-17T01:21:29.723" UserId="625" />
  <row Id="2810" PostId="3051" Text="sorry for the epically long rant, i tend to get rather frantic when i see an issue debated heavily when i see it as a simple result of a deeper problem that i think should be the real topic of discussion." CreationDate="2010-06-17T01:52:30.797" UserId="703" />
  <row Id="2811" PostId="3001" Text="Was this helpful to you Jennifer?" CreationDate="2010-06-17T02:07:21.713" UserId="319" />
  <row Id="2812" PostId="3051" Text="@doxalogos The TDD point is a good one.  The one issue i had in my, admittedly limited, experience with companies that force these issues is that they require a TDD but are unwilling to produce a firm PRD. " CreationDate="2010-06-17T02:35:43.097" UserId="703" />
  <row Id="2813" PostId="3051" Text="@doxalogos err, sorry i've gone and confused TDD with TRD, too many TLA(Three Letter Acronyms) " CreationDate="2010-06-17T02:38:22.000" UserId="703" />
  <row Id="2814" PostId="3040" Text="on your second point as well:  Simply using an OOP design methodology doesn't produce more compartmentalized code.  Having a good base design does, how one expresses that design is left to the developer.  OOP does not define that you separate your code properly, it provides another option, and more over, the appearance that you did so, but, it certainly does not enforce good design, that is up to the developer." CreationDate="2010-06-17T02:58:19.853" UserId="703" />
  <row Id="2815" PostId="3046" Text="what do you mean by 'proper UART communication'? you don't need clock synchronization between the AVR and the other end of the UART to make it work.  I guess maybe if your bit banging the UART on the AVR end which i find unlikely." CreationDate="2010-06-17T03:12:21.980" UserId="703" />
  <row Id="2818" PostId="3051" Text="@mark, can you define PRD and TRD." CreationDate="2010-06-17T04:30:48.357" UserId="230" />
  <row Id="2819" PostId="3051" Text="PRD = product requirements document, MRD = marketing requirements document, TRD = technical requirements document. TDD = Test Driven Development." CreationDate="2010-06-17T04:34:37.897" UserId="625" />
  <row Id="2820" PostId="3051" Text="@doxalogos, The TDD(Test Driven Development) idea is interesting, but I think it is inherently flawed. I agree 100% with all that you say on it. On the note of unit tests, I have read stories of companies that when implementing a well developed software inspection process they could drop unit tests and save time to release." CreationDate="2010-06-17T04:40:35.933" UserId="230" />
  <row Id="2821" PostId="3051" Text="@DoxaLogos, Thanks for the definitions, my company is small, I knew TDD, but that was it." CreationDate="2010-06-17T04:41:14.217" UserId="230" />
  <row Id="2822" PostId="3040" Text="That is always true. I have never heard of a language that does enforce good design. I think we mostly imply that is the developers job and that C++ makes it easy to use and implement in an organized fashion." CreationDate="2010-06-17T04:43:12.590" UserId="230" />
  <row Id="2823" PostId="3041" Text="Kortuk&#xA;I received a reply Libelium and they say that you must take the shield off to load the Arduino. &#xA;This I have done but the shield still will not go. You can actually just remove one of the links and it will load with the shield on.&#xA;I watched the serial output from the arduino and all is coming out correctly although there seems to be 2 characters appear before the AT commands come through. I have replied to Libelium so will wait until I get an answer from them.&#xA;Thanks for your interest and suggestions." CreationDate="2010-06-17T05:47:25.170" />
  <row Id="2824" PostId="3041" Text="Kortuk&#xA;Point 2 above, Yes I think the Hilo is using the same pins for the serial bits. I don't know if there is any feedback from the Hilo as there are no led's or visual feedback. I did try to put more delays in the program so it has time to wait for the OK from the Hilo, but only guessing. I will copy the characters that appear and post this info, It may be a clue as to whats happening." CreationDate="2010-06-17T06:05:36.557" />
  <row Id="2825" PostId="3054" Text="Is this one of those miniature circular saws, with a lid over a reservoir, if so I have one of these and may have to give it a go?" CreationDate="2010-06-17T10:58:59.330" UserId="103" />
  <row Id="2827" PostId="3057" Score="4" Text="Input voltage range? Sample rate? Linearity? " CreationDate="2010-06-17T12:37:12.990" UserId="400" />
  <row Id="2829" PostId="3046" Text="@Mark I mean the TX clock of the AVR has to match the RX clock of the PC within a few % and vice versa, not guaranteed without an XTAL." CreationDate="2010-06-17T15:21:35.543" UserId="1363" />
  <row Id="2830" PostId="3049" Text="What should I look for in a solid-state relay? Is it possible to get a latching solid-state relay? " CreationDate="2010-06-17T16:21:44.430" UserId="327" />
  <row Id="2833" PostId="3040" Text=" 	@Mark - I agree. It has been a learning process for me. " CreationDate="2010-06-17T17:13:41.523" UserId="374" />
  <row Id="2834" PostId="3058" Text="Why is this an answer?" CreationDate="2010-06-17T17:29:07.773" UserId="230" />
  <row Id="2835" PostId="3051" Text="@Mark - I agree with your design-up-front sentiments, but only to a point.  I think heavy design-up-front works pays off if a) you're requirements are fairly stable/known, and b) the developers doing the design are _experienced_.  In a prev. job, I was tasked with doing a design and it was heavily timeboxed by my team lead, and I thought, &quot;What a dumb thing to do!  Design-up-front saves money (cf. Code Complete book)??&quot;  But in coding I discovered tons of things I didn't know to look for.  If I had done lots of  design and minimize code time, it would have been a waste. JME." CreationDate="2010-06-17T17:57:10.720" UserId="374" />
  <row Id="2836" PostId="3051" Text="@sheepsimulator I obviously agree on the second point, I assume the lead system architects are experienced developers.  On the first point i actually disagree.  I think the more you expect the requirements to change the more time you should spend in the design phase because you need to produce a good, easy to change, design.  I know some philosophies propose rapid development. In some cases this works well like lots of bad or inexperienced programmers on staff. All these design philosophies come down to is saying &quot;i have no prayer of designing a flexible system, so lets not waste time trying&quot;." CreationDate="2010-06-17T19:02:31.843" UserId="703" />
  <row Id="2837" PostId="3051" Text="Our requirements are changing on us all the time here, but the systems we spend the most time designing have the fastest coding and maintenance time. We spent a very large amount of time on one subsystem because we know how important it would be in the future and that it would need to change. It is the only subsystem that any changes have been less than a day worth of work on, and it has had many." CreationDate="2010-06-17T19:33:31.837" UserId="230" />
  <row Id="2838" PostId="3038" Text="Cheap, powerful, and simple never seem to go together very well.  If you think it's going to be hard to learn, you'll want the most mature and well-known processors.  Those are also the best supplied, which is good for price, but in the end you'll probably just want the easiest one to learn.&#xA;(Next post)" CreationDate="2010-06-17T19:50:49.320" UserId="857" />
  <row Id="2839" PostId="3038" Text="The variables are:&#xA;Manufacturer: Unlike the AVR, which is Atmel only, ARM doesn't make chips.  If Atmel goes bankrupt, and all your designs use AVR, you're sunk.  Not so with ARM-Minimal effort should be required to go between manufacturers.  I'd recommend sticking with Atmel, because they have good documentation, and you're familiar with them.&#xA;&#xA;Core:  There are lots of flavors: see &lt;http://en.wikipedia.org/wiki/ARM_architecture#ARM_cores&gt;.  I'd recommend an ARM7TDMI, ARM9TDMI, or CortexM3 (Atmel AT91SAM7, AT91SAM9, AT91SAM3)  Basically, you want not-to-new and no MMU (external memory mgr.)" CreationDate="2010-06-17T19:58:35.053" UserId="857" />
  <row Id="2840" PostId="3038" Text="From those, there are still lots of options. But, if I had to pick one, I'd say use the Atmel AT91SAM7S256, and try to set up something like this board:&#xA;http://www.olimex.com/dev/images/ARM/ATMEL/SAM7-Hxxx-sch-C1.gif&#xA;It's not nearly as bad (complex) as most boards, but it should be simple to add peripherials by referencing other SAM7 dev boards, like Atmel's AT91SAM7S-EK or Olimex's sam7-mt256, sam7-p256, sam7-ex256 (different proc))" CreationDate="2010-06-17T20:11:39.163" UserId="857" />
  <row Id="2841" PostId="3058" Text="I am using an ATtiny2313 which does not have e.g. a PCINTn on the RX pin. So I think the answer is to use use AVR054 and go ahead and solder RX to INT0." CreationDate="2010-06-17T20:19:09.123" UserId="1363" />
  <row Id="2842" PostId="3038" Text="The support isn't quite as good-there's no ARM-duino, no ARMfreaks, (http://www.at91.com/ and http://www.embeddedrelated.com/groups/AT91SAM/1.php exist, but aren't as good as AVRfreaks) and it is definitely more for professionals.   Don't despair! You can still use AVRfreaks a little, sparkfun.com sells and has support forums for the chip above, and of course there's chiphacker!&#xA;&#xA;As far as the SMT vs DIP goes, you can glue your LQFP upside down, solder 30-gauge wires onto the leads, and bring them out to .1&quot; headers on protoboard (hot-glue them down to keep them from breaking later.)" CreationDate="2010-06-17T20:38:28.467" UserId="857" />
  <row Id="2843" PostId="3054" Text="That's a great idea!  I've got a neighbor with a tile saw, I'll have to give it a try. What kind of blade do you use?" CreationDate="2010-06-17T20:47:05.387" UserId="857" />
  <row Id="2844" PostId="3065" Text="Where is the stripe on the diode?" CreationDate="2010-06-17T21:24:13.217" UserId="142" />
  <row Id="2845" PostId="3068" Text="Thanks for the detailed answer and history! " CreationDate="2010-06-17T22:08:14.333" UserId="857" />
  <row Id="2846" PostId="3069" Text="I saw an Accumulator on the DSP block diagram, but didn't know what it did.    Good to know!  &#xA;I understand that I2C and serial are not the same as processing waveforms when you're sending ASCII data, but some peripherials (Serial-access accelerometers, external A/D, GPS, etc. encode waveforms in their data streams.  It has to get into the DSP somehow!" CreationDate="2010-06-17T22:10:57.360" UserId="857" />
  <row Id="2847" PostId="3054" Text="@Amos - Cut away!  Any blade meant for ceramic/glass tile will work very well for fiberglass PCBs." CreationDate="2010-06-17T22:33:20.663" UserId="161" />
  <row Id="2848" PostId="3065" Score="2" Text="Your question would be much easier to answer if you supplied a schematic.  As is, we can only guess.  If you don't have a normal schematic editor, just tab over to gliffy.com, make a diagram of your three components, take a screenshot, and upload it to your favorite image host." CreationDate="2010-06-17T22:33:49.397" UserId="857" />
  <row Id="2849" PostId="3054" Text="@Reemrevnivek - I have a wet use blade suitable for ceramic tiles.  It's a simple diamond wet saw blade." CreationDate="2010-06-17T22:34:03.030" UserId="161" />
  <row Id="2850" PostId="3069" Score="2" Text="most signal processing is mathematically comprised of multiplying matrices and/or vectors together.  The process of doing this results in a lot of answer = a*b + c*d + e*f type calculations.  On a cpu without a MAC that takes a lot of instructions to do, with a MAC it can be many times faster." CreationDate="2010-06-17T22:35:45.637" UserId="703" />
  <row Id="2853" PostId="3072" Score="1" Text="Aha! This is it.  So the zener will be in the range of 5-10V, and we'll have one resistor (to limit the zener current) in series with a parallel combination of your zener and the series combination of a resistor and an LED." CreationDate="2010-06-17T22:50:10.757" UserId="857" />
  <row Id="2855" PostId="3030" Text="@pingswept I agree, programmer time is expensive. As Linus notes, in the case of open source volunteers, it's priceless. Commercially though, the cost of development vs. manufacture does have a big impact once you go into volume. My current role is porting an embedded linux+python+zigbee system to arm-cortex-m3 for the cost savings." CreationDate="2010-06-17T22:59:53.463" UserId="566" />
  <row Id="2856" PostId="3031" Score="1" Text="All languages are good for something. C++ is fast. OOP, if well done, makes it much easier for multiple developers to work in parallel and to code for the unknown. I think this is why it has so much traction in game development." CreationDate="2010-06-17T23:08:41.480" UserId="566" />
  <row Id="2857" PostId="3074" Score="1" Text="I think I understand the difference in intent (your second paragraph), but I'm just not sure why I would do that when micros don't have DSP-like math ability and DSPs have micro-like peripherial sets.     &#xA;&#xA;As I said in my OP, the dsPIC33 and PIC24 can have an almost identical feature set and an identical price.   &#xA;&#xA; Correct me if I'm wrong, but while the DSP has repetitive processing facilities, I don't think that the PIC24 (or any other micro that I've looked at) has any advantage over a DSP in mode changes, like a dual pipeline or faster FLASH. " CreationDate="2010-06-17T23:28:23.333" UserId="857" />
  <row Id="2858" PostId="3061" Text="I would normally do that, but the main device will be far away from the analog lines and I feel that if I run long wires it is just asking for noise" CreationDate="2010-06-17T23:50:51.157" UserId="417" />
  <row Id="2859" PostId="3057" Text="0-5V, 50ksps+ and I am not sure what linearity refers to but I will definitely look into it. Thanks." CreationDate="2010-06-17T23:51:54.543" UserId="417" />
  <row Id="2860" PostId="3074" Text="@reemrevnivek: so you're saying, why not always just choose a DSP? " CreationDate="2010-06-18T00:33:18.420" UserId="740" />
  <row Id="2861" PostId="3073" Score="1" Text="No, do not do this. It will act as a capacitor also, but once you pass a few volts it will blow out the insulator." CreationDate="2010-06-18T03:38:21.487" UserId="230" />
  <row Id="2862" PostId="3073" Text="http://en.wikipedia.org/wiki/Electrolytic_capacitor will explain it." CreationDate="2010-06-18T03:39:02.000" UserId="230" />
  <row Id="2863" PostId="3061" Score="2" Text="That is a good reason, another reason is when you need very high accuracy ADC a internal ADC cannot cut it. Unless the chip is designed specifically for it, which an AVR micro is not, most chips add a lot of noise going near them, which is the reason for high quality ADCs that give digital output." CreationDate="2010-06-18T03:46:05.167" UserId="230" />
  <row Id="2864" PostId="3058" Text="No, I think you are miss-understanding." CreationDate="2010-06-18T03:47:07.037" UserId="230" />
  <row Id="2865" PostId="3070" Text="depends on how big the zener is &lt;3" CreationDate="2010-06-18T05:44:52.947" UserId="230" />
  <row Id="2866" PostId="3065" Score="1" Text="One thing the extra resistors are used for is to fool the electronics into thinking it is looking at normal globes, otherwise the globe check system can give you false reports. Try it without the resistors and see what appears on the dash." CreationDate="2010-06-18T07:16:32.830" />
  <row Id="2867" PostId="1089" Text="A codebreaker project: http://www.copacobana.org/" CreationDate="2010-06-18T08:00:12.673" UserId="834" />
  <row Id="2868" PostId="3073" Text="@kortuk: i think it's crazy, because if one is always forward biased, one is also always reverse biased, but i tell you i have seen this sort of thing sold commercially - maybe something else was going on there. fwiw it was in an audio crossover circuit." CreationDate="2010-06-18T10:02:05.940" UserId="740" />
  <row Id="2870" PostId="3081" Text="d'oh! thanks, didn't spot that one. I have a tile cutter too, definitely worth a try." CreationDate="2010-06-18T10:51:06.077" UserId="566" />
  <row Id="2871" PostId="3082" Text="here's a nice example of our tin plating - http://forum.sonodrome.co.uk/general-discussion-f1/pcb-artwork-t43.htm" CreationDate="2010-06-18T11:44:59.230" UserId="399" />
  <row Id="2872" PostId="3060" Text="I'd agree, SPI is the way to go when using ADCs with MCUs.....they are much easier to use! " CreationDate="2010-06-18T11:49:02.067" UserId="399" />
  <row Id="2873" PostId="3058" Text="@Kortuk I would be very happy to get another answer, but my answer to my own question is 'go ahead and solder two pins together and use AVR054'." CreationDate="2010-06-18T12:55:46.653" UserId="1363" />
  <row Id="2874" PostId="3074" Text="@JustJeff: Yes, that's exactly what I'm saying." CreationDate="2010-06-18T12:57:28.293" UserId="857" />
  <row Id="2875" PostId="3070" Score="1" Text="No, I don't think that has anything to do with it.  A typical car alternator has 80-120 Amps of current with which it tries to reach 13.8V.  If the zener can sink that kind of current, it would dissipate 1,300W and make a nice little space heater.  If you have a source, I want one!" CreationDate="2010-06-18T13:01:58.227" UserId="857" />
  <row Id="2876" PostId="3082" Score="1" Text="I've been experimenting with these http://www.megauk.com/through_hole_rivets.php (without the fancy machine). They're quite low profile, but I haven't tried them under chips yet. Here's a pic from someone else's blog http://www.makestuff.eu/wordpress/?p=774" CreationDate="2010-06-18T13:40:14.543" UserId="566" />
  <row Id="2877" PostId="3082" Text="Nice - they look real professional, the rivets themselves aren't too bad a price either" CreationDate="2010-06-18T13:44:19.470" UserId="399" />
  <row Id="2879" PostId="3085" Text="Thanks for the reply. It looks like you are generating RGB signals though, not composite video? I tried connecting that pin both ways though and unfortunatly it made no difference. " CreationDate="2010-06-18T14:25:10.483" UserId="710" />
  <row Id="2881" PostId="3085" Text="Oops, I misread, updated." CreationDate="2010-06-18T14:28:21.180" UserId="566" />
  <row Id="2882" PostId="3085" Text="Good ideal I will try using one of the RGB signals. In fact now I look into it it would probably better if I just generated RGB data anyway as then I could use a colour display, assuming I can get it to work at all." CreationDate="2010-06-18T14:36:22.193" UserId="710" />
  <row Id="2883" PostId="3085" Text="Yeah, doing a PAL colourburst on a PIC would be a &quot;challenge&quot;" CreationDate="2010-06-18T14:37:32.310" UserId="566" />
  <row Id="2884" PostId="2039" Score="2" Text="Sump-spin-off: http://www.seeedstudio.com/depot/preorder-open-workbench-logic-sniffer-p-612.html?cPath=75 (~43USD)" CreationDate="2010-06-18T15:17:50.517" UserId="834" />
  <row Id="2885" PostId="3073" Text="You could do it if you used a diode in parallel with each cap. As long as the diode kept it below the blow through voltage. Still very risky." CreationDate="2010-06-18T15:42:27.543" UserId="230" />
  <row Id="2886" PostId="3073" Text="I would use schottky diode diodes to keep further from blow-through." CreationDate="2010-06-18T15:48:39.300" UserId="230" />
  <row Id="2887" PostId="3073" Text="Interesting addendum though." CreationDate="2010-06-18T15:49:20.640" UserId="230" />
  <row Id="2888" PostId="3081" Text="My only worry is, it might wreck the black plastic that's keeping light off of the board. We'll see." CreationDate="2010-06-18T16:04:54.980" UserId="566" />
  <row Id="2889" PostId="3023" Text="Are Stencils useful for single pcbs or are they only useful when you have multiple un-panelized pcbs?" CreationDate="2010-06-18T16:05:26.633" UserId="582" />
  <row Id="2890" PostId="3077" Text="conformal coating is quite nice." CreationDate="2010-06-18T16:26:42.530" UserId="230" />
  <row Id="2891" PostId="3083" Text="you got your +1 just for using the logic analyzer feature of the PICKIT2. I have never seen it used as everywhere I work we have O-Scopes everywhere. It looks sexy. the questions was great also." CreationDate="2010-06-18T16:48:18.220" UserId="230" />
  <row Id="2892" PostId="3069" Score="1" Text="This comment is flat out WRONG.  Not all, but many MCUs include hardware multipliers with MAC functions.  This has nothing to do with a DSP vs. MCU distinction.  Yes, DSPs are more likely to have a MAC than an MCU, but there are far more fundamental differences than this small feature." CreationDate="2010-06-18T16:53:08.747" />
  <row Id="2893" PostId="3083" Text="I'd love a proper oscilloscope then I could see the voltages on the &quot;mixed&quot; signals here. But I don't have one and they cost more than I can justify spending for a hobby project. The pickit2 logic analyzer seems to work very well indeed though for many digital signals. I'd almost buy one just for that!" CreationDate="2010-06-18T17:37:08.400" UserId="710" />
  <row Id="2894" PostId="3069" Text="If you turn the clock back 15 years, you see almost no MCU's with this feature.  If you take the MAC or equivalent feature out of the DSP, can you honestly say that you have a DSP? I certainly wouldn't want to buy one if didn't have it or something close too it. There architecture differences when you get into Harvard vs. von Neuman and memory access, but I was giving a simple answer without going into a long detailed explanation.  I think you're too harsh with your comment by saying &quot;Flat out WRONG&quot;.  You're welcome to post an answer discussing the depth you think needs to be covered." CreationDate="2010-06-18T17:43:34.810" UserId="625" />
  <row Id="2895" PostId="3083" Text="I've tried the suggestions below and no had success at all. Are my timings and resistors correct?&#xA;&#xA;I have a pic16something somewhere too. I think I'll build one of the projects I've seen around that use one of those then at least i won't be trying to debug my own hardware, my own software AND an unknown connection to the TV all at the same time. And when that works restart this project." CreationDate="2010-06-18T17:46:14.560" UserId="710" />
  <row Id="2896" PostId="2976" Text="Grabbed a cable connected to the port and somehow managed to shock to the rcv line instead of the shell. Shouldn't have killed it even so, but apparently I can build up one heck of a charge some days." CreationDate="2010-06-18T17:59:18.803" UserId="259" />
  <row Id="2897" PostId="3083" Text="I cannot say I know better than you do, but you have peaked my interest." CreationDate="2010-06-18T18:41:03.580" UserId="230" />
  <row Id="2898" PostId="3036" Text="@Kortuk - one more comment on &quot;charging headfirst into C++&quot;.  I agree that ideally that you want to spend time to first learn C++ before charging in headfirst, but sometimes it doesn't work out that way.  At my previous employer, we had a situation where we chose to us another division's code written in C++ for its features, but the whole floor was group of EE's that mostly knew C. I was one of the few that had some C++ training at the time, but not much.  You could imagine the chaos that ensued:-)" CreationDate="2010-06-18T20:17:59.427" UserId="625" />
  <row Id="2899" PostId="3036" Text="@Doxa, Yes I can. I have been buying books and trying to give myself as much training as possible before we start any new systems." CreationDate="2010-06-18T20:49:50.943" UserId="230" />
  <row Id="2900" PostId="3031" Score="1" Text="Yes, I agree. The reason I see it for the embedded world is because of the sheer amount of features and functions being added to alot of the different systems already in place and new systems being developed. Project get bigger and bigger. Either we take longer to develop them or we start applying and contorting what the CS world has already done on PCs." CreationDate="2010-06-18T20:51:27.523" UserId="230" />
  <row Id="2901" PostId="3087" Text="I had seen that PDF as well, but I was looking more on the hands on experience from people around. You've just provided that. Thanks!&#xA;I don't have the part in my hands yet, but I think I will be soldering  leads directly on the connector.&#xA;Thanks for the hint on the length, although it seems the controller is embedded in the package, so data is going through SPI, which I'd assume is less critical than raw VGA signals I'd assume." CreationDate="2010-06-18T21:20:00.397" UserId="1267" />
  <row Id="2902" PostId="3087" Text="If you've got steady hands, a fine tip, and a magnifier (for inspection at the very least), you should be able to solder to the connector.  " CreationDate="2010-06-18T21:59:02.953" UserId="857" />
  <row Id="2903" PostId="3087" Text="What kind of resolution/frame rate/color are you working with?  SPI seems like a strange way to send video data.  60(Hz refresh)*740(Horizontal pixels [1]) * 520(Vertical pixels [2]) *8 ((or 10 or 12) bit color)  = 180MHz, way more than SPI (or anything that's not differential and/or DC balanced) can handle.  If you're going over SPIa at a data rate that a microcontroller can handle, don't worry about length - Give yourself a comfortable amount of room.&#xA;[1][2] Data sent while frame valid and line valid are off" CreationDate="2010-06-18T21:59:06.543" UserId="857" />
  <row Id="2904" PostId="3073" Score="2" Text="&quot;Special capacitors designed for AC operation are available, usually referred to as &quot;non-polarized&quot; or &quot;NP&quot; types. In these, full-thickness oxide layers are formed on both the aluminum foil strips prior to assembly. On the alternate halves of the AC cycles, one or the other of the foil strips acts as a blocking diode, preventing reverse current from damaging the electrolyte of the other one. Essentially, a 10 microfarad AC capacitor behaves like two 20 microfarad DC capacitors in inverse series.&quot;" CreationDate="2010-06-18T22:10:01.823" UserId="142" />
  <row Id="2906" PostId="1203" Text="An interesting thing about these is that each individually numbered memory address holds a 16 bit word." CreationDate="2010-06-18T22:37:12.300" UserId="740" />
  <row Id="2907" PostId="1214" Score="1" Text="Not sure if you're supporting or voting against the AVR.  Can you post some of your own personal experiences? It's easy to find negative reviews from frustrated posters, but harder to find nice chips and a good support forum.   &#xA;    &#xA;I don't think there would be a community capable of generating 500,000 posts on 75,000 topics if the general consensus was negative." CreationDate="2010-06-18T22:46:22.230" UserId="857" />
  <row Id="2908" PostId="3089" Text="agreed and would add that having a separate IC and having to do SPI transfers (which are power hungry in themselves) is quite possibly not a power win over doing the encryption on the MSP430, assuming its fast enough to keep up with your data rate.  If its not, as others said, reconsider your platform choice.  I realize your going for very low power but if you need that level of encryption and only need a MSP430 for other operations then encryption needs to be a very high priority in your power budget." CreationDate="2010-06-18T23:25:58.347" UserId="703" />
  <row Id="2909" PostId="3036" Text="@Kortuk. I'm sure you can, and I'm glad you have the foresight to do it.  That's why I began learning it myself in college while my degree was EE.  My point was that sometimes it doesn't work out that way.  All those engineers now had to work in a C++ environment without any training because the continual &quot;time to market&quot;. The mistake was on the management side of course, and not their fault." CreationDate="2010-06-19T00:19:19.310" UserId="625" />
  <row Id="2910" PostId="3094" Text="What crimpers do you use with those?" CreationDate="2010-06-19T01:20:37.357" UserId="857" />
  <row Id="2911" PostId="3095" Score="1" Text="[quote]The one I use for prototyping is the Radio Shack 276-1595 that I've had forever.[/quote]  Yup, you can repurpose many crimpers to do other terminals.  Generally, one step wraps the insulation, and a smaller one wraps the wire itself.  Just be sure not to mash the box end of your terminal." CreationDate="2010-06-19T01:24:44.573" UserId="857" />
  <row Id="2912" PostId="3096" Text="Sorry, just realized you had linked all Mouser parts. They don't carry JST brand, but I'm sure that they have similar offerings.  Wasn't trying to convert you to Digikey or anything." CreationDate="2010-06-19T01:26:54.697" UserId="857" />
  <row Id="2913" PostId="3097" Text="That makes sense; Lua has sandboxing capabilities as well.  However, what do you do if they enter &quot;while true do --[[nothing]]-- end&quot;?  " CreationDate="2010-06-19T01:31:33.913" UserId="857" />
  <row Id="2914" PostId="3097" Text="What language are you using?  I'm not aware of many alternatives to eLua.  " CreationDate="2010-06-19T01:31:36.863" UserId="857" />
  <row Id="2915" PostId="1708" Text="I keep my spreadsheet private, and I'm going to need to move it to a database on a dedicated drive in a while...   Great points!  The problem is that your develop-transform-polish-ponder-implement-&gt;[repeat x99]-&gt;profit lifecycle is incompatible with my budget." CreationDate="2010-06-19T01:43:22.920" UserId="857" />
  <row Id="2916" PostId="1712" Text="Agreed! &quot;The motivation should not be things that sell, but rather for the sake of doing interesting projects&quot; is a great point, but don't forget that doing interesting projects is often more fun and more successful with a team!" CreationDate="2010-06-19T01:45:42.873" UserId="857" />
  <row Id="2917" PostId="3097" Score="1" Text="BTW, this is the kind of answer I'm looking for-I'm just going to wait a while longer for some more answers to filter in." CreationDate="2010-06-19T01:48:31.763" UserId="857" />
  <row Id="2918" PostId="3094" Text="I've found that the low-cost ones sold for use with Molex KK terminals work, with care. The Harwin tool is expensive, I think." CreationDate="2010-06-19T02:22:18.087" UserId="305" />
  <row Id="2919" PostId="3096" Text="Thanks for the response. I've bought from digikey too, so it's cool." CreationDate="2010-06-19T06:24:15.040" UserId="550" />
  <row Id="2920" PostId="3092" Text="I would be interested if someone pointed out a scripting language for 8-bit and 16-bit chips like the megaAVR or PICs." CreationDate="2010-06-19T08:19:11.283" UserId="1200" />
  <row Id="2921" PostId="3038" Text="@reemrevnivek y ou should have made a whole answere out of your comments.&#xA;&#xA;ARMs or AVR32 look a good venture. But I don't think I am ready for it. I will spend some more time with megaAVR and may be some PICs." CreationDate="2010-06-19T08:23:34.993" UserId="1200" />
  <row Id="2922" PostId="3097" Text="@reemrevnivek - **1)** I will be running them in an interrupt-able manner.  I haven't decided whether that means I'll be running a full pre-emptive multitasking OS, or simply running all my &quot;important&quot; code on interrupt timers (the latter is relatively easy anyway), or some other solution.  **2)** Many scripting languages are embeddable.  I asked this same question on SO a 18 months ago, and got lots of good answers: http://stackoverflow.com/questions/191222/what-is-a-good-embeddable-language-i-can-use-for-scripting-inside-my-software" CreationDate="2010-06-19T13:41:17.607" UserId="161" />
  <row Id="2923" PostId="1708" Text="@reemrevnivek - I do all that in my head ;-P  - I don't actually develop things physically until I've mentally gone through the whole process and brainstormed about a particular idea for quite some time." CreationDate="2010-06-19T13:46:19.233" UserId="161" />
  <row Id="2924" PostId="3089" Text="Physical security is always a big issue. I have been very impressed at what extent TPMs designers go to prevent people from figuring out what goes on inside. However, for many projects it can be assumed that if you have physical access, you can get anything you want. If you are just wanting to encrypt communications (wireless, internet, etc) then I could see a separate chip being ok." CreationDate="2010-06-19T18:07:41.507" UserId="319" />
  <row Id="2925" PostId="3101" Text="feel free to fiddle with the tags, guys, i couldn't find good matches and invented a couple of those" CreationDate="2010-06-19T23:38:24.537" UserId="740" />
  <row Id="2926" PostId="3102" Text="hmm.. so i'd still need to get from 10BaseT to 100BaseT, and I've not had great luck in the past trying to get commodity networking gear to work different speeds on different ports. Sounds like the best bet would be to stick an AUI 'enabled' NIC in a clunker PC that's already on my LAN, and try to jury rig some kind of AUI crossover cable." CreationDate="2010-06-20T02:09:20.520" UserId="740" />
  <row Id="2927" PostId="3102" Text="Yeah, you'd need an old managed switch to be able to force low speed on just one port. But I bet a 10BASE-T hub circa 1996 would do the trick. Probably keep your house warm too." CreationDate="2010-06-20T02:35:09.777" UserId="712" />
  <row Id="2929" PostId="3099" Text="Can you tell us about how many employees this company has?  I'm just curious about &quot;we have process improvement engineers and R&amp;D engineers who spend their entire careers working on and thinking up new ideas&quot;." CreationDate="2010-06-20T03:01:40.960" UserId="142" />
  <row Id="2930" PostId="3089" Text="Joby, your information is both astute and valuable, but our application is very specific, and if they can get within about 10 yards of our device the encryption has no value. Our RF signals travel miles, so they must be secure. I will add information to the question." CreationDate="2010-06-20T03:26:01.303" UserId="230" />
  <row Id="2931" PostId="3091" Text="If you can give me links to articles about the known attacks it would be valuable." CreationDate="2010-06-20T03:27:31.133" UserId="230" />
  <row Id="2933" PostId="3104" Text="Thanks very much, now working with a modified library." CreationDate="2010-06-20T09:54:54.727" />
  <row Id="2934" PostId="3106" Score="1" Text="This will require the IN terminal to sink a current of (5-Vin)/(2R), so you'll have to choose R large enough to not overwhelm the input with unwanted current. then, your ADC input will need to have at least an order of magnitude more input impedance than the R value, in order not to unduly load down the divider network. Which all may (or may not) be possible. To the data sheets! " CreationDate="2010-06-20T13:35:38.133" UserId="740" />
  <row Id="2935" PostId="3102" Text="@pingswept: thanks for the info, esp the book ref. looks like networking this thing could turn into a major time sink, not to mention a scavenger hunt for yet more obsolete hardware. probably better off trying to find a way to image the HD, rip the ROMs, and run it in an emulator." CreationDate="2010-06-20T14:06:35.353" UserId="740" />
  <row Id="2937" PostId="3110" Text="The webpack should be free for you also." CreationDate="2010-06-20T19:32:24.347" UserId="230" />
  <row Id="2938" PostId="3073" Text="That is awesome, but it is a process that a tinkerer cannot do, as JustJeff pointed out. I was just trying to point out a method that an at home user could do." CreationDate="2010-06-20T19:38:56.180" UserId="230" />
  <row Id="2939" PostId="3106" Score="2" Text="-1: you'd better use precision resistors and a precision reference for 5V." CreationDate="2010-06-20T19:39:58.630" UserId="330" />
  <row Id="2940" PostId="3036" Text="@doxa, Yeah, the guy before me was very apt and did a great job. His code is unusable because of ridiculous time to deployment and feature creep he had to do hack edits to keep his head above water. All I can do is fight and sometimes accept the consequences. " CreationDate="2010-06-20T19:40:44.033" UserId="230" />
  <row Id="2941" PostId="3109" Score="1" Text="+1 -- this is the proper way to do it if you don't have an ADC taking in negative inputs." CreationDate="2010-06-20T19:41:13.630" UserId="330" />
  <row Id="2942" PostId="3030" Text="Sounds like an awesome project Joby." CreationDate="2010-06-20T19:41:32.833" UserId="230" />
  <row Id="2943" PostId="3075" Text="Please make this a &quot;community wiki&quot; question: it is likely to have multiple answers." CreationDate="2010-06-20T19:55:18.037" UserId="330" />
  <row Id="2944" PostId="2852" Score="1" Text="We use Advanced Circuits heavily in our company and have had very good results with them." CreationDate="2010-06-20T19:56:44.947" UserId="330" />
  <row Id="2945" PostId="2852" Text="Have you used them for assembly or just PCB fab?" CreationDate="2010-06-20T20:33:04.713" UserId="424" />
  <row Id="2946" PostId="3112" Text="Thanks for the input. Interesting and very similar to what I have read." CreationDate="2010-06-20T20:38:05.630" UserId="230" />
  <row Id="2947" PostId="3075" Text="Good plan, will do" CreationDate="2010-06-20T20:40:45.980" UserId="566" />
  <row Id="2948" PostId="2433" Score="1" Text="@ajs410, I think adding the footprint and not populating increases the chance of a need as you will almost guarantee extra mismatch at the pad location." CreationDate="2010-06-20T21:26:33.780" UserId="230" />
  <row Id="2949" PostId="3113" Text="First, welcome to the site! I hope we can offer you a warm welcome, but your question might be a dupe.&#xA;These questions:&#xA;http://chiphacker.com/questions/700/using-a-16-mhz-crystal-on-a-atmega328p , &#xA;http://chiphacker.com/questions/717/troubleshooting-an-atmega328p-clock-setting , and &#xA;http://chiphacker.com/questions/861/recovering-an-attiny13 also refer to fuse settings on AVRs.  But, this is a different chip (slightly), different fuse settings, and a different programmer, so I say we let it stand (And I don't have the rep to flag it). &#xA;" CreationDate="2010-06-20T22:43:57.723" UserId="857" />
  <row Id="2950" PostId="3100" Score="3" Text="First, I may have exaggerated when I said they're pie-in-the-sky ideas.  They're legitimate, feasible projects, with an established need.  (&quot;Can we run our programs embedded on this device as a script instead of connecting the device to a PC?&quot; -&gt; My experience with eLua). Others I just want to explore further than we've already gone.  When I've talked to my boss about some of my ideas, he's been supportive and interested, but we've never actually gotten to the point of setting aside any time to work on them. That's the stage I'm at. " CreationDate="2010-06-20T22:56:54.233" UserId="857" />
  <row Id="2951" PostId="3114" Text="the lfuse was origally set to 0x64. Thanks for that fuse calculator link, a great resource indeed." CreationDate="2010-06-21T00:16:15.957" UserId="872" />
  <row Id="2952" PostId="3100" Text="I have some things to add, but it will be tuesday before I can." CreationDate="2010-06-21T04:20:11.537" UserId="230" />
  <row Id="2953" PostId="3109" Text="Wow!, this is fantastic!!, is there some datasheet gotcha, that the input should be only so much negative than the voltage level that powers the negative rail of the op-amp?" CreationDate="2010-06-21T06:22:08.030" UserId="444" />
  <row Id="2954" PostId="3105" Score="1" Text="the -1 to -3V that I'm measuring is the output of a LM337 that I want to monitor." CreationDate="2010-06-21T06:23:09.933" UserId="444" />
  <row Id="2955" PostId="3111" Text="Glad to be of service :-)" CreationDate="2010-06-21T08:13:35.317" UserId="566" />
  <row Id="2956" PostId="3118" Score="2" Text="Nice one and very interesting!!" CreationDate="2010-06-21T10:14:54.677" UserId="444" />
  <row Id="2957" PostId="3119" Score="1" Text="+1, Awesome!!, I had a look at the soldering tutorial and was totally floored!! " CreationDate="2010-06-21T12:51:05.823" UserId="444" />
  <row Id="2958" PostId="3109" Score="3" Text="No, the rails of the op-amp are the bounds for your output. Where a rail to rail op-amp will go very close to the bounds. You could, and many have, spent their life designing op-amps. There is no such thing as a perfect op-amp, but there is normally a perfect op-amp for a specific case." CreationDate="2010-06-21T14:03:12.117" UserId="230" />
  <row Id="2959" PostId="3109" Score="1" Text="On that note, in this configuration, if you surpass around -Vcc as your input your output will hit the Vcc rail. Some op-amps will not go within a volt or more of the rail, some op amps will go within 50mV. If you get a larger input signal, divide it by a larger amount, if you have a -1 to -10 V signal, divide by 2, problem solved. " CreationDate="2010-06-21T14:04:46.563" UserId="230" />
  <row Id="2960" PostId="3119" Score="1" Text="I would like to add, I went to the site and immediately read things that I would not agree with. On the note of soldering, the vapor released when you are using solder is bad, make sure not to breath it in, you are better off with a carbon filter of some sort sucking it away." CreationDate="2010-06-21T14:08:30.130" UserId="230" />
  <row Id="2961" PostId="3119" Text="Absolutely. I use one myself but neglected to discuss it. Fixed. " CreationDate="2010-06-21T14:23:58.063" UserId="1307" />
  <row Id="2963" PostId="3119" Score="1" Text="@Kortuk, could you be more specific in your criticism? I just read through a few articles, and it all looked correct to me, minus a few typos." CreationDate="2010-06-21T14:31:31.830" UserId="712" />
  <row Id="2964" PostId="3119" Text="Just try to avoid saying the smoke is non-toxic, flux is the leading cause of work-related asthma. I mean no offense, the site is quite nice, but I found things on it that I do not believe to be true." CreationDate="2010-06-21T14:31:59.893" UserId="230" />
  <row Id="2965" PostId="3119" Text="Sorry, my last post was almost at the same time as your Ping, let me grab one. I only read two sections before going about work. The other thing I looked at was http://tronixstuff.wordpress.com/2010/05/27/electronic-components-the-diode/" CreationDate="2010-06-21T14:34:31.293" UserId="230" />
  <row Id="2966" PostId="3119" Text="He has a diode that he uses like a zener, as he explains afterwards. It has peek repetitive reverse voltage of 50V, and is rated at 1A forward current. He designs a circuit to allow 1A to flow from a 200V source, and uses the diode to output 50V. This will not work. Regardless of everything, if the datasheet has exact values for every diode you get, you will find that this makes your diode release a funny colour smoke. This is designed for 50W of dissipation. " CreationDate="2010-06-21T14:37:08.050" UserId="230" />
  <row Id="2967" PostId="3119" Text="When I was first learning electronics it was application circuits I remembered the best, if I had read this I would have taken it as a method of doing that task, and probably would have set a few parts on fire." CreationDate="2010-06-21T14:38:15.327" UserId="230" />
  <row Id="2968" PostId="3119" Text="I think the site is good overall, I just want to put a disclaimer. " CreationDate="2010-06-21T14:38:37.120" UserId="230" />
  <row Id="2969" PostId="3119" Text="Hello everyone. Thank you for your constructive feedback. If you have any more, kindly comment on the blog or email me at john at tronixstuff dot com. Cheers. " CreationDate="2010-06-21T14:59:09.017" UserId="1307" />
  <row Id="2970" PostId="3119" Text="Completely missed the comment area. I can leave comments and try to read over them when I have time if it would be of help." CreationDate="2010-06-21T15:13:18.567" UserId="230" />
  <row Id="2971" PostId="3119" Score="1" Text="+1 to Kortuk and tronixstuff for civil discourse!" CreationDate="2010-06-21T16:10:05.377" UserId="712" />
  <row Id="2972" PostId="3100" Score="2" Text="If your boss is supportive and interested, and you really want to get stuff implemented, try implementing one or two on your own time-- maybe get to work an hour early and try something out. If you can get to a convincing proof of concept, your boss might go for it." CreationDate="2010-06-21T16:15:25.907" UserId="712" />
  <row Id="2973" PostId="3119" Text="The danger of solder fumes was discussed here, http://chiphacker.com/questions/1904/are-solder-fumes-bad-for-me" CreationDate="2010-06-21T16:30:44.630" UserId="566" />
  <row Id="2974" PostId="3111" Text="I laughed that I completely missed it. Sometimes I get to dumb check myself." CreationDate="2010-06-21T16:32:49.123" UserId="230" />
  <row Id="2975" PostId="3091" Text="As a side note, tables in ROM can be done by almost any micro, unless you mean it has a seperate addressable section of the tables. If you have room in rom you can load a table of constants." CreationDate="2010-06-21T16:33:32.040" UserId="230" />
  <row Id="2976" PostId="3098" Text="Thanks for the pictures. I haven't received my samples yet, but I'll post the results of my experience here as well." CreationDate="2010-06-21T17:13:03.720" UserId="1267" />
  <row Id="2977" PostId="3085" Text="Just do finish up this post - I tried using a different TV and it worked perfectly and yet I still can't get it to work on the original one. Clearly some difference there I need to investigate some time in the future," CreationDate="2010-06-21T18:08:45.573" UserId="710" />
  <row Id="2978" PostId="3091" Text="http://www.embedded.com/design/224900352 is an article on power attacks against FPGAs. Not specific for the listed AVR though, still a good read if you don't know how power attacks work." CreationDate="2010-06-22T00:26:58.173" UserId="536" />
  <row Id="2979" PostId="3126" Text="what kind of memory we talking about SRAM, SDRAM, DDR, DDR2, DDR3?" CreationDate="2010-06-22T02:09:49.870" UserId="625" />
  <row Id="2981" PostId="1013" Text="Is the set[1] good for a hobbiest/student? Have looked for the equipments you listed a long time. [1] http://www.elexp.com/ktc_lead.htm" CreationDate="2010-06-22T05:57:42.023" UserId="834" />
  <row Id="2982" PostId="3122" Score="2" Text="Cannot find international S&amp;H. I have used Futurlec with its &quot;Value Packs&quot;[1] and S&amp;H is transparent [2]. But have to try your tip:  particularly the testing set[3] interests me. Again just a satisfied customer. [1] http://www.futurlec.com/ValuePacks.shtml [2]http://www.futurlec.com/Delivery.shtml  [3] http://www.elexp.com/kit.htm" CreationDate="2010-06-22T06:06:16.820" UserId="834" />
  <row Id="2983" PostId="1013" Text="For pointy probes, I have used just 22AWG wire strapped with normal multimeter probes. Works well and needs just 1 set of probes." CreationDate="2010-06-22T06:50:38.527" UserId="834" />
  <row Id="2984" PostId="3123" Text="Good link, however most of the videos on the are highly technical and I could understand the LED and Photodiode out of those, I will seal it up for future use though.." CreationDate="2010-06-22T07:22:01.307" UserId="444" />
  <row Id="2985" PostId="3116" Text="Thanks, I will try that. Looks like the &quot;boundary scan&quot; feature is a fairly new feature in OpenOCD, but worth looking into. Says that it will work with the USB-Blaster as well.. thanks! btw, I signed up for XJTAGS 30 day evaluation (with a controller and everything), the package is on its way now.. " CreationDate="2010-06-22T08:11:30.740" />
  <row Id="2986" PostId="3120" Text="Is it possible to evaluate the tools in any way without buying it?" CreationDate="2010-06-22T08:12:49.943" />
  <row Id="2987" PostId="3129" Text="Thanks for the answer Mark. I was confused if an MMU was necessary or not. Looking at Sparkfun, they actually have an LPC 2294 on sale right now, which has an external memory bus. I think I'll go with that." CreationDate="2010-06-22T11:27:18.677" UserId="876" />
  <row Id="2988" PostId="3123" Text="Yes, you should be able to understand his discussion of education in the 21st century. You might gain some value from his functional decomposition lectures if you would like to know more about how to approach breaking down a problem." CreationDate="2010-06-22T14:41:05.770" UserId="230" />
  <row Id="2989" PostId="3118" Text="I have and always will love watching these simulations." CreationDate="2010-06-22T14:41:38.220" UserId="230" />
  <row Id="2990" PostId="3123" Text="He does teach optics and Lasers though.  I think that If I got you the order to watch the videos in, you could learn them without a problem, but out of order you will be missing concepts." CreationDate="2010-06-22T15:00:31.833" UserId="230" />
  <row Id="2991" PostId="3131" Text="I do not know the atmel series to write an answer, but often there is no replacement excluding the one they are working on. Makes sense why they are working on it now. " CreationDate="2010-06-22T15:24:14.540" UserId="230" />
  <row Id="2992" PostId="3129" Score="2" Text="an MMU is used to map a virtual address space to physical devices.  Its used by operating systems to isolate the memory of different processes, for paging, resolving memory fragmentation issues, memory mapping dynamic hardware devices, etc.  It virtualizes the memory sub suystem.  In most cases you would only need an MMU if you wanted to run a operating system with a full set of multiprocessing features.  For instance you would need an MMU to run the full linux kernel, although there is uClinux that has been modified to run without an MMU." CreationDate="2010-06-22T16:34:14.137" UserId="703" />
  <row Id="2993" PostId="3131" Text="I think you may be right. I've heard that the ATtiny2313 has an unusual pin arrangement for AVRs (I love the very convenient PORTB all on one side) perhaps shared with very obsolete old parts with no RAM..." CreationDate="2010-06-22T17:52:59.013" UserId="1363" />
  <row Id="2994" PostId="1950" Text="the link is bad." CreationDate="2010-06-23T02:30:23.207" UserId="790" />
  <row Id="2995" PostId="1217" Text="I have used LTspice for years and the Yahoo group is very active with help, support, demo files and expanding libary of models.&#xA;&#xA;http://tech.groups.yahoo.com/group/LTspice/" CreationDate="2010-06-23T07:40:29.853" />
  <row Id="2996" PostId="3135" Text="Yup, this is what I thought of as well.  A little small at 1.2&quot; square, but the rest of it specs out just right." CreationDate="2010-06-23T12:14:42.033" UserId="857" />
  <row Id="2997" PostId="2325" Score="3" Text="citation needed" CreationDate="2010-06-23T13:10:39.537" UserId="1363" />
  <row Id="2998" PostId="3137" Text="fantastic. thanks!" CreationDate="2010-06-23T13:33:53.990" UserId="417" />
  <row Id="2999" PostId="3134" Text="Yes, this tutorial is quite informative: http://www.ladyada.net/learn/lcd/st7565.html" CreationDate="2010-06-23T15:04:00.947" UserId="771" />
  <row Id="3000" PostId="3141" Score="7" Text="+1 on the TI MSP430s. I think they win the lowest power consumption contest." CreationDate="2010-06-23T15:25:11.343" UserId="712" />
  <row Id="3001" PostId="3141" Score="5" Text="I'm sure you could power one off a few potatoes :)&#xA;" CreationDate="2010-06-23T15:39:47.527" UserId="399" />
  <row Id="3002" PostId="3141" Text="@Jim, nah citrus fruit works way better!" CreationDate="2010-06-23T15:53:47.337" UserId="771" />
  <row Id="3003" PostId="3135" Text="This one doesn't look like it's easy to connect to. From what I see, you need a special connector (which SparkFun supplies), and then the leads on the connector are pitched at 0.5mm." CreationDate="2010-06-23T18:06:55.727" UserId="790" />
  <row Id="3004" PostId="3126" Text="No kind in particular. Something larger than 64k..." CreationDate="2010-06-23T18:29:40.583" UserId="876" />
  <row Id="3005" PostId="3140" Score="1" Text="You are correct, using a UV light source in this method will be dangerous. The darker the room, the better it works, the worse off your eye is for exposure." CreationDate="2010-06-23T19:33:48.653" UserId="230" />
  <row Id="3006" PostId="1216" Text="Should we merge this answer with the other 16-bit MSP430 answer?" CreationDate="2010-06-23T20:17:45.827" UserId="813" />
  <row Id="3007" PostId="3140" Text="heck, even IR lasers can be more dangerous in the dark, b/c your pupil is more dilated." CreationDate="2010-06-23T23:23:12.093" UserId="740" />
  <row Id="3008" PostId="3143" Score="1" Text="The oxygen in the air starts to attenuate strongly as you dip below 300nm, so range would be very limited at that wavelength. But that stuff is Extremely Dangerous anyway." CreationDate="2010-06-23T23:33:25.177" UserId="740" />
  <row Id="3009" PostId="1013" Text="If I had to pick one, I would buy the #6342 pogo tips in a heartbeat. They weren't that expensive, and the springyness is invaluable for making good contact. You just can't do that with non-compliant wires or probes, without having to sit there and press hard against the component in question." CreationDate="2010-06-23T23:47:31.507" UserId="330" />
  <row Id="3010" PostId="3147" Text="Actually there are plenty of conductive epoxies available - they are usually made with a high silver content and tend to be quite expensive. They are generally only used when soldering is no good for some other reason (such as the risk of heat damage to other components). " CreationDate="2010-06-24T00:45:20.850" UserId="259" />
  <row Id="3011" PostId="3147" Score="2" Text="Conductive epoxy is good for repairing lifted traces." CreationDate="2010-06-24T01:19:28.833" UserId="222" />
  <row Id="3012" PostId="1950" Text="Cheers updated link" CreationDate="2010-06-24T06:22:47.083" UserId="3" />
  <row Id="3013" PostId="3141" Score="2" Text="What do you mean by &quot;buffer&quot;? Normally you would use a diode, preferably a Schottky diode for its low voltage drop." CreationDate="2010-06-24T08:42:26.553" UserId="339" />
  <row Id="3014" PostId="3152" Text="Awesome. I thought it would be something like that." CreationDate="2010-06-24T14:01:42.753" UserId="1363" />
  <row Id="3015" PostId="3151" Text="I don't know about these AVRs but on every embedded system that I have ever worked on, and there have been plenty, you cannot/must not use printf or its equivalent from inside an interrupt function.  As a start, if the output device uses interrupts then this function, as it never returns, will probably block its operation." CreationDate="2010-06-24T14:58:09.877" UserId="400" />
  <row Id="3016" PostId="2644" Text="I think you're mistaken about the ARM cores only appearing in Virtex devices.  The press release doesn't say as much, and I don't think you can infer that from the fact that PPC cores only appear in V2P, V4FX, and V5FXT parts.  Xilinx's website mentions the devices being optimized for &quot;performance, cost, and power&quot; (see http://www.xilinx.com/technology/roadmap/processing-platform.htm); you'll notice cost is never an optimization vector for the Virtex series." CreationDate="2010-06-24T15:41:20.273" UserId="886" />
  <row Id="3017" PostId="2644" Text="Also, ARM is never mentioned in the 7-series FPGAs announcement (http://www.xilinx.com/technology/roadmap/7-series-fpgas.htm), and there's no V6 or V7 part with a PPC.  My take on all this is that they're moving away from embedded processors in the high-performance parts." CreationDate="2010-06-24T15:43:46.587" UserId="886" />
  <row Id="3018" PostId="3019" Text="There are open source Microblaze implementations (like aeMB -- http://opencores.org/project,aemb) that should port to other (non-Xilinx) FPGAs." CreationDate="2010-06-24T15:45:38.580" UserId="886" />
  <row Id="3019" PostId="1115" Text="Some dirt-cheap but meagre boards exist: $29 from Lattice (http://www.latticesemi.com/products/developmenthardware/developmentkits/xp2breviadevelopmentkit.cfm), $49 from Avnet (http://www.silica.com/index.php?id=1193), $49 to $64 from Gadget Factory (http://shop.gadgetfactory.net/index.php?main_page=index&amp;cPath=1&amp;zenid=4v1d54h7ftva0vaa6eeb0itkp1)" CreationDate="2010-06-24T15:55:23.007" UserId="886" />
  <row Id="3020" PostId="3140" Score="1" Text="All Lasers are more dangerous in the dark. I did not mean to imply anything different from that. High brightness IR LEDs are in general not a major concern. High Brightness UV light is. It does not need to be a laser to cause permanent eye damage. Just the one I have in the darkroom at school can make you rub your eyes for ours." CreationDate="2010-06-24T15:55:53.793" UserId="230" />
  <row Id="3021" PostId="3151" Text="I understand that it's bad style, but all I wanted to do was output where the code was.  A toggled LED, global string in a Big Loop, or any number of outputs could have been used, but printf is easy to read.  The point was to write a blocking interrupt (which is definitely bad practice in 99% of the cases I can imagine!)" CreationDate="2010-06-24T18:42:48.333" UserId="857" />
  <row Id="3022" PostId="3122" Text="Futurlec have improved their shipping times lately, my first orders took around a month, now they're down to around ten days. " CreationDate="2010-06-25T01:50:23.510" UserId="1307" />
  <row Id="3023" PostId="3148" Text="Dead right about the high price. Long looked for cheap wire wrapping tool but haven't found. Got recommend expensive products such as &quot;Slit-N-Wrap® Tools: P160-1B, P184-1 -- by Vector Electronics&quot; and Radio Shack's cheap wire wrap thing (only US). So had to do it myself with wooden stick having 22AWG-30AWG all way through, cheap and reusable :)" CreationDate="2010-06-25T10:26:49.140" UserId="834" />
  <row Id="3024" PostId="3122" Text="Contacted Electronix Express. Minimum order is 100USD for international shippings, not for me as above 50USDs' pkgs tend to go to customs -- sad and true." CreationDate="2010-06-25T10:49:59.793" UserId="834" />
  <row Id="3025" PostId="2500" Text="do not have isopropyl alcohol around so using paint-removal-spray for car-industry or acetone, to remove extra rosin. Spay rosin-blackened spot and then just rinse with water. Probably cheaper than electronics spays as bottles are bigger." CreationDate="2010-06-25T11:29:10.137" UserId="834" />
  <row Id="3026" PostId="2500" Text="Where do you get IPA?" CreationDate="2010-06-25T11:30:34.610" UserId="834" />
  <row Id="3027" PostId="3161" Score="5" Text="I bought a few ceramic caps about 10 years ago. I still have them. Imagine my surprise when I read the news &quot;fabulous new ceramic dielectric invented 8 years ago.&quot; Buy what you need right now, the smug feeling of &quot;I saved $0.005 on this cap&quot; every time you solder is going to be completely overwhelmed by &quot;why don't I have the much better ones invented right after I bought this obsolete reel&quot;." CreationDate="2010-06-25T12:42:57.740" UserId="1363" />
  <row Id="3028" PostId="3161" Text="joeforker: thanks not ordering caps. What about the other? No idea how long rosin will last in good ventilation." CreationDate="2010-06-25T12:56:56.713" UserId="834" />
  <row Id="3029" PostId="3162" Text="why not items with moving parts? I can see a problem if they are not held in good conditions but otherwise cannot see why-how would things such as pots stale or go unusable?" CreationDate="2010-06-25T13:09:59.357" UserId="834" />
  <row Id="3030" PostId="3162" Score="2" Text="Things like pots tend to seize up if never turned. Not all moving parts are problematic, but things like pots (which you basically can't lubricate) are going to be an issue." CreationDate="2010-06-25T13:58:49.977" UserId="259" />
  <row Id="3031" PostId="3110" Text="sorry but cannot really see what is the &quot;open source&quot; with it. Would rather slip coin with over half cheaper like: http://item.taobao.com/auction/item_detail.jhtml?item_id=9276311138962f69faea041ca986c196." CreationDate="2010-06-25T15:11:12.497" UserId="834" />
  <row Id="3032" PostId="3161" Score="2" Text="joeforker's  comment about obsolete components applies to other parts like semiconductors. The type of components you want depends on the types of projects you are doing. Lot's of systems in the past had a triple power supply (+5V, +-15V). Newer designs are going to single supplies. If you had a lot of dual supply op-amps (like the LM741) it may not meet your future needs. I would put the  LM741 on the NO list. &#xA;&#xA;I would add some ceramic caps to the list but not to many since&#xA;the recent improvements in dielectric have pushed the size and the&#xA;cost down. " CreationDate="2010-06-25T15:13:50.247" UserId="424" />
  <row Id="3033" PostId="3161" Score="1" Text="Hasn't the 741 been a relatively poor opamp by any day's standards for a long time now?" CreationDate="2010-06-25T16:16:08.343" UserId="883" />
  <row Id="3034" PostId="2852" Text="Just PCB fab.  Interesting fact; about half a block down the road from Advanced Circuits in Colorado is Advanced Assembly.  They aren't specifically affiliated with Advanced Circuits, but if you place an order at AC, then AA will go pick the order up to assemble it.  Saves on some shipping costs!" CreationDate="2010-06-25T17:22:22.097" UserId="1278" />
  <row Id="3035" PostId="3141" Score="1" Text="@starblue a buffer is an electrical component that typically is used increase drive strength and providing a low-impedence output while &quot;passing through&quot; the input signal. It has the effect of effectively isolating its input from its output, while making the output &quot;follow&quot; the input. There are many ways of implementing it (an op-amp is one way; two CMOS inverters in series is another way), but you can also find them as discrete components or ICs. " CreationDate="2010-06-25T17:47:46.753" UserId="771" />
  <row Id="3036" PostId="3066" Text="Hmmm, possibly, but aren't zeners usually glass/transparent? This one is just a black cylinder." CreationDate="2010-06-25T17:53:55.720" UserId="733" />
  <row Id="3037" PostId="3065" Text="everything's just in series.&#xA;" CreationDate="2010-06-25T17:55:03.527" UserId="733" />
  <row Id="3039" PostId="3141" Score="1" Text="@vicatcu I think starblue knows what a logic buffer is - Just a non-inverting amplifier. He might have been wondering if you were referring to something different. You're forgetting that the input bias current to a buffer is on the order of nano- or micro-amps, and that this current is shunted to ground rather than to your capacitor. A conventional buffer (like the CD4010) won't work without power and ground.  As your answer was selected, please edit it to reflect this fact." CreationDate="2010-06-25T19:24:14.877" UserId="857" />
  <row Id="3040" PostId="2790" Text="Just don't forget, if you have problems I may be able to give advice." CreationDate="2010-06-25T19:55:10.933" UserId="230" />
  <row Id="3041" PostId="3161" Text="The 741 was a poor op-amp by yesterday's standards." CreationDate="2010-06-25T19:58:48.030" UserId="142" />
  <row Id="3044" PostId="3141" Text="That was my issue also. A buffer will need a power source. 1wire communication with power is easy if you have power lines for the components on the board with your device." CreationDate="2010-06-25T20:56:16.000" UserId="230" />
  <row Id="3045" PostId="3166" Text="Already been posted: http://chiphacker.com/questions/1763/what-are-the-best-hardware-hacking-magazines/2894#2894" CreationDate="2010-06-25T21:10:49.607" UserId="790" />
  <row Id="3046" PostId="2248" Text="@donperignon I've used their ConnectPort X2. It's pretty well supported, runs much of the Zigbee stack in python, which can be modified for additional functionality. The IP interface uses XML RPC, so you can run the entire thing just be doing HTTP POSTs to the IP address. I believe the X4 is similar." CreationDate="2010-06-25T22:40:49.110" />
  <row Id="3047" PostId="3166" Text="Ah, that's odd. I'm sure I couldn't see it." CreationDate="2010-06-25T22:49:58.097" UserId="883" />
  <row Id="3048" PostId="3170" Text="Basically the airsoft gun circuit goes: battery -&gt;trigger -&gt; SPST switch -&gt; turns on motor -&gt; shoots. &#xA;&#xA;So all I have to do is replace that switch with this relay and use the digital pin to trigger it?&#xA;&#xA;Can I do sustained fire with this? (hold the trigger down)" CreationDate="2010-06-26T00:12:27.367" />
  <row Id="3049" PostId="3161" Score="1" Text="please make this question community wiki as it does not have a single answer" CreationDate="2010-06-26T00:25:36.327" UserId="330" />
  <row Id="3050" PostId="3170" Text="@ssfdr: Yes   ." CreationDate="2010-06-26T00:55:28.977" UserId="131" />
  <row Id="3051" PostId="3170" Score="2" Text="I'd go with a MOSFET because with a relay you would also need a transistor to switch the relay, also relays are kinda bulky compared to a MOSFET." CreationDate="2010-06-26T03:37:20.633" UserId="212" />
  <row Id="3052" PostId="469" Text="Very well put, I have seen many many students who are fluent with there theory of how a diode works but cannot identify one from a bunch of components" CreationDate="2010-06-26T04:57:20.253" UserId="1200" />
  <row Id="3053" PostId="3147" Text="thanks michael / jeanne, updated my answer to mention conductive epoxy." CreationDate="2010-06-26T19:47:49.917" UserId="703" />
  <row Id="3054" PostId="3170" Text="If it's a one-off, some of these &quot;expensive&quot; solenoids might be scavenged from old cassette decks, VCR's or the like. But if it's hitting and electronic switch, it's probably easier to interface there if invasive connection is ok. You may even be able to make a kind of OR circuit inside so either the trigger or your electronics can trigger it. So you'll have a gun with a socket for external trigger for example." CreationDate="2010-06-26T22:30:07.647" UserId="883" />
  <row Id="3055" PostId="2711" Text="If you have a controller, it probably makes sense to use it.&#xA;&#xA;It may also have power down modes that allow a timer or rtc to keep running so you can still keep time while the cpu sleeps. Alternatively, you could use an external RTC." CreationDate="2010-06-26T22:32:49.547" UserId="883" />
  <row Id="3056" PostId="2709" Text="If polling, the sensor only needs to be on when it's polled. Arrange it so the controller can switch it on/off." CreationDate="2010-06-26T22:34:09.467" UserId="883" />
  <row Id="3057" PostId="1200" Text="GCC is available.&#xA;http://mspgcc.sourceforge.net/ (old)&#xA;http://mspgcc4.sourceforge.net/ (new)&#xA;" CreationDate="2010-06-27T08:42:44.513" UserId="883" />
  <row Id="3058" PostId="1199" Text="I'd like to see/hear which ones are available from where and especially if any are available as samples." CreationDate="2010-06-27T08:43:46.617" UserId="883" />
  <row Id="3059" PostId="1205" Text="SDCC also supports PIC, I think." CreationDate="2010-06-27T08:44:09.220" UserId="883" />
  <row Id="3060" PostId="1216" Text="There's a more complete answer so I'd say yes." CreationDate="2010-06-27T08:45:19.610" UserId="883" />
  <row Id="3061" PostId="3090" Text="If you use Linux, you can probably have a fully working toolchain in under half a minute with &quot;sudo apt-get install gcc-avr avr-libc avrdude&quot;. Winavr is essentially fully compatible. I've been keeping shared codebase between the two without even a single change in a Makefile.&#xA;&#xA;If you have a hardware parallel or even serial port, complete ISP hardware consists of a few off the shelf connectors and a couple of passives (resistors). There's several USB options available and the $30 (shipped worldwide) Bus Pirate directly does AVR ISP  and so much more." CreationDate="2010-06-27T08:49:18.743" UserId="883" />
  <row Id="3062" PostId="3090" Text="AVR is also one of the very few chips your nearby electronics store may actually also have on the shelf." CreationDate="2010-06-27T08:50:28.333" UserId="883" />
  <row Id="3063" PostId="3177" Text="Thanks for your reply.  The camera datasheet they gave me says that it has transmission rates of &quot;100, 200, 400, 800 Mbit/s&quot;.  Do you think 100Mbit/s (~13 MHz?) would be okay, or is that still too high?&#xA;&#xA;&gt;You can probably find verilog blocks for such an interface freely available.&#xA;&#xA;That would be amazing.  Is there a specific site I would find them, or should they just be on TI's or Altera's sites?  Google searches just seem to be finding datasheets.&#xA;&#xA;If that doesn't work I'll suggest the LLC chip, though I'm not sure what our power limitations are.  Once again, thanks so much for your help!&#xA;" CreationDate="2010-06-27T09:02:38.003" />
  <row Id="3064" PostId="3177" Text="Oh wow sorry for the formatting on that, I didn't realize comments didn't have the normal formatting of regular posts." CreationDate="2010-06-27T09:03:29.173" />
  <row Id="3065" PostId="1200" Text="The problem with TI lately seems to be that their &quot;e-store&quot; simply doesn't work and the new kits are always sold out or otherwise not in stock. There would seem to be a lot of demand for Chronos and Launchpad as well as the EZ and EZ RF kits, but they are occasionally nearly unattainable unless you find a store that has some in stock.&#xA;&#xA;Hopefully this will clear up soon." CreationDate="2010-06-27T09:07:25.163" UserId="883" />
  <row Id="3066" PostId="1200" Text="TI also apparently offers samples of their chips." CreationDate="2010-06-27T09:07:53.620" UserId="883" />
  <row Id="3067" PostId="1200" Text="Elektor also offers a board that will extend the ez430 towards a more traditional devkit.&#xA;http://www.elektor.com/products/kits-modules/modules/080558-91-experimenting-with-the-msp430.925177.lynkx" CreationDate="2010-06-27T09:09:10.763" UserId="883" />
  <row Id="3068" PostId="3177" Text="No worries, the site does alot well, comments is not one of them." CreationDate="2010-06-27T15:22:56.657" UserId="230" />
  <row Id="3069" PostId="3058" Text="I was asking for links to your datasheet. I will write and answer when I confirm I am not misunderstanding. I do not think you need the cal feature at all." CreationDate="2010-06-27T15:24:20.010" UserId="230" />
  <row Id="3070" PostId="2734" Score="3" Text="There are a lot of single supply opamps available. 741 may not be the best candidate for audio to start with." CreationDate="2010-06-27T17:27:40.713" UserId="883" />
  <row Id="3071" PostId="2191" Text="What are the criteria for &quot;small&quot; here?" CreationDate="2010-06-27T17:36:57.447" UserId="883" />
  <row Id="3072" PostId="3177" Text="@psychomedic check my edit" CreationDate="2010-06-27T17:42:35.070" UserId="703" />
  <row Id="3073" PostId="1205" Text="Yes, SDCC works very well for PIC18 and upwards. Note that the syntax is slightly different from Microchip's C compilers though so you may have to do some porting if you want to reuse code." CreationDate="2010-06-27T19:13:33.907" UserId="401" />
  <row Id="3074" PostId="1220" Text="Merged into the PIC16F answer." CreationDate="2010-06-27T19:19:57.083" UserId="401" />
  <row Id="3075" PostId="3174" Text="I guess I'd better avoid the phrase &quot;1-wire&quot; then..." CreationDate="2010-06-27T19:22:12.730" UserId="566" />
  <row Id="3076" PostId="3177" Text="It's supposed to plug right into the header on the board, so hopefully we can get away with it or find some other solution.  I think it's supposed to turn on quite a while after it reaches proper altitude, but I'm not sure how the conditions will be up there for vibrations and whatnot.  I'll bring it up with them and see what they have to say.  Thanks so much for your help." CreationDate="2010-06-27T21:13:09.783" />
  <row Id="3078" PostId="1342" Text="Can &quot;drive LED displays directly&quot; means there's enough juice available to drive a led without a switch/transistor/buffer/driver. Enough to burn most types, too. Also, I think all AVR's have push-pull outputs that you can switch to weak pullups or completely open drain by fiddling with a couple of port registers. It does indeed need some setup and isn't related to LEDs (think I2C)." CreationDate="2010-06-28T00:19:34.530" UserId="883" />
  <row Id="3079" PostId="1205" Text="I've been reluctant to use sdcc as the documentation seems to describe the pic code generation as experimental. " CreationDate="2010-06-28T08:02:35.257" UserId="710" />
  <row Id="3080" PostId="2358" Text="Big vote for the pic24 series. You don't see nearly as much online for them as the 8 bit pics but they are faster, more powerful and easier to use and don't cost any more than the 8 bit ones of similar spec." CreationDate="2010-06-28T08:05:25.003" UserId="710" />
  <row Id="3081" PostId="3058" Text="@Kortuk the factory calibration was really close, but I didn't know until I wrote my own calibration routine! It probably would have worked fine without all the trouble." CreationDate="2010-06-28T12:49:51.147" UserId="1363" />
  <row Id="3082" PostId="690" Score="3" Text="As someone who currently spends half their time terrified about bricking his mega32, I'd appreciate it if you could elaborate on this. :P" CreationDate="2010-06-28T19:44:35.200" UserId="831" />
  <row Id="3083" PostId="3173" Text="What kind of things can you get free samples of? Any examples of parts you got from particular stores?" CreationDate="2010-06-28T19:51:01.963" UserId="831" />
  <row Id="3084" PostId="3189" Text="Since you probably don't have enough power from the serial port to drive the TPS61080, you may want to combine my answer with Erik's -- create V+ (24v) from your 3.3v supply using the TPS61080 (unless you have another source of 24v), and drive the transistor from the output of the serial port." CreationDate="2010-06-28T21:08:44.877" UserId="1322" />
  <row Id="3085" PostId="3173" Text="@Grey: Well I just got a free 2X40 character LCD from Purdy Electronics. I only recently discovered this whole sample thing. Here's a place that lists quite a few suppliers that have sample programs: http://www.instructables.com/id/Free_Electronic_Samples/" CreationDate="2010-06-29T00:41:16.147" UserId="790" />
  <row Id="3087" PostId="3192" Text="Spelling fixed!" CreationDate="2010-06-29T03:17:39.450" UserId="712" />
  <row Id="3088" PostId="3193" Text="I HAVE to have a transistor? What type?&#xA;" CreationDate="2010-06-29T03:28:00.163" />
  <row Id="3089" PostId="3193" Text="That is a DPDT relay, I am not sure how to hook up a spdt" CreationDate="2010-06-29T04:04:23.740" />
  <row Id="3090" PostId="3193" Text="Number of poles on the other side shouldn't make the switching any different. You'll just need to identify more pins if there's no data." CreationDate="2010-06-29T05:27:43.213" UserId="883" />
  <row Id="3091" PostId="3190" Text="Or a mosfet for even easier drive. Searching for relay driver and low-side switches should yield a lot of examples. Looking up open drain/collector may also be enlightening if the concept isn't familiar." CreationDate="2010-06-29T05:31:15.363" UserId="883" />
  <row Id="3092" PostId="894" Text="The base current for the NPN comes from the pullup, doesn't it. When the OD output closes, base is at ground and there's no current. I don't think you need further limiting or did I miss something?" CreationDate="2010-06-29T05:45:58.467" UserId="883" />
  <row Id="3093" PostId="3190" Text="I have no real experience with mosfets, and this solution is the one I implemented a few weeks ago (using TTL levels). But your answer is as good as any." CreationDate="2010-06-29T05:51:22.963" UserId="348" />
  <row Id="3094" PostId="635" Text="+1 for pin headers. Cables for them are also easy to come by if you have a source for junk PC's as they're full of them :)" CreationDate="2010-06-29T05:54:06.030" UserId="883" />
  <row Id="3095" PostId="2879" Text="I've been keeping an eye out for 5V and 12V (especially &gt;=1A) wall warts on flea markets and other random places for a long time. They can be very handy, just need a suitable set of plugs/adaptors so you can go to pin headers, breadboard and/or banana plugs." CreationDate="2010-06-29T06:37:33.527" UserId="883" />
  <row Id="3096" PostId="3085" Text="I found in the end that I had a badly wired scart lead with the ground wired to the wrong lead even though I checked it about 100 times! For some reason is worked on one TV but not another. I now have it working well on both." CreationDate="2010-06-29T07:05:12.913" UserId="710" />
  <row Id="3097" PostId="3187" Text="Many thanks, I'll try this approach." CreationDate="2010-06-29T07:06:22.067" />
  <row Id="3098" PostId="3198" Text="@Joby, Unfortunately, it is much more complicated than simply writing to the SCU_GPIOTYPE register.  There is also the SCU_GPIOOUT, SCU_GPIOIN, GPIO_DATA, GPIO_DIR, GPIO_SEL, SCU_PCGR1, and SCU_PRR1 registers.  There may even be more.  This is why I suggested using the firmware library from ST." CreationDate="2010-06-29T16:26:09.963" UserId="529" />
  <row Id="3099" PostId="3195" Score="1" Text="Unfortunately I am not in charge of choosing the components, or I would most certainly choose... pretty much anything else.  This is the camera we are using: http://www.ptgrey.com/products/grasshopper/index.asp  It has a general purpose IO but you can't get the pictures off the camera with it and it has volatile memory.  As for the onboard camera, I'm pretty sure ours doesn't have that, so I guess I may have used the wrong link, but all the other components are the same, sorry. " CreationDate="2010-06-29T21:23:31.983" />
  <row Id="3100" PostId="3200" Text="Do I need a diode? And lets say that the top two are A and B and the bottom two are C and D. and that one by itself is E. Can you edit your explanation because I am still un sure." CreationDate="2010-06-29T23:34:32.870" />
  <row Id="3101" PostId="3200" Text="Yes, you need the diode. Without it, when the relay shuts off, the energy stored in the coil will dissipate itself by burning out the transistor and possibly your arduino." CreationDate="2010-06-29T23:46:03.827" UserId="740" />
  <row Id="3102" PostId="3200" Text="Using your lettering scheme, the relay coil would be C and D." CreationDate="2010-06-29T23:47:33.060" UserId="740" />
  <row Id="3103" PostId="3200" Text="Those are all I have to use? the other 4 pins don't matter?" CreationDate="2010-06-29T23:49:30.563" />
  <row Id="3104" PostId="3200" Text="A,B, and E are the switching side of the relay, which in this case are equivalent to the SPDT switch you already have in the nerfgun. If you wire those in parallel with the existing switch, you should be able to use either the original switch or the arduino to fire the gun." CreationDate="2010-06-29T23:59:53.720" UserId="740" />
  <row Id="3105" PostId="3202" Text="thanks (+1) for throwing some pictures in for this" CreationDate="2010-06-30T00:00:44.890" UserId="740" />
  <row Id="3106" PostId="3204" Text="+1 A radio modem would be simple and fairly cheap. But, I already have a microcontroller so want to avoid adding another expensive chip if possible." CreationDate="2010-06-30T00:51:14.457" UserId="566" />
  <row Id="3107" PostId="3204" Text="How cheap counts as cheap? Say, less than £2? £3?" CreationDate="2010-06-30T00:54:28.263" UserId="712" />
  <row Id="3108" PostId="3204" Text="Less than £2. In volume, a Bluetooth transceiver is ~$1. The type of radios in car keyfobs must be pennies..." CreationDate="2010-06-30T01:02:04.037" UserId="566" />
  <row Id="3109" PostId="843" Score="1" Text="The condition is incorrect, it should read &quot;if (buf[0] == 'A')&quot;. Or perhaps ('A'==*buf) :-)" CreationDate="2010-06-30T01:30:26.537" UserId="566" />
  <row Id="3110" PostId="3192" Text="Dupe? http://chiphacker.com/questions/1043/controlling-high-voltage-device-with-arduino" CreationDate="2010-06-30T01:50:32.993" UserId="142" />
  <row Id="3111" PostId="3197" Text="Rowley includes a header file which should mostly work for my device, but the problem is that there is little to no documentation about the different ports. This library you linked to provides me with a lot more documentation.&#xA;&#xA;I am going to try to use it to get my chip working and will post back here if your answer fixes my problem.&#xA;&#xA;Thanks for the help." CreationDate="2010-06-30T07:15:56.767" UserId="909" />
  <row Id="3112" PostId="3204" Score="2" Text="I don't believe you will get the same price for hobby purposes that a car manufacturer is able to get. The cheapest option I know is the RF Transmitter/receivers from Sparkfun mentioned in the other answer." CreationDate="2010-06-30T07:46:35.283" UserId="909" />
  <row Id="3113" PostId="3201" Text="You might get more feedback if you can rework your query into a single question." CreationDate="2010-06-30T08:28:03.283" UserId="566" />
  <row Id="3114" PostId="3197" Text="This is tested and works fine. I used the default project generated startup options to configure the basics of the chip. This function called from main as a hardware init function. To enable and disable the port all I have to do is use GPIO_WriteBit from the library code referenced. - Thanks again for your answer." CreationDate="2010-06-30T09:27:06.813" UserId="909" />
  <row Id="3115" PostId="3198" Text="This is the first approach I tried, so I could stick with the simple header included in a Rowley project. Figuring out exactly what to write where was overwhelming. Perhaps this solution is more efficient if you really need high code density, but you would probably have to find a reference telling you exactly what to write to each register. Perhaps reverse engineer the library from ST? I am accepting the library solution as the answer to this question, but of course the approach of writing registers directly is possible as well." CreationDate="2010-06-30T09:30:17.930" UserId="909" />
  <row Id="3116" PostId="3207" Text="I concur. These are made by Wisher, and are very good. " CreationDate="2010-06-30T09:36:57.697" UserId="1307" />
  <row Id="3118" PostId="3068" Text="Another addition perhaps. In an application with quite about 80 I/O lines and 12 analog inputs we are now using a single microcontroller with a linked FPGA to handle the I/O streams. Solutions like this are becoming more common. We are using this system: http://www.embeddedarm.com/products/board-detail.php?product=ts-7800 to make the development quick for a short Time-to-Market and I must say it works very well (Of course the price of such a product may not be suited for applications with a lower selling price/expected value.) – Wouter Simons 33 secs ago" CreationDate="2010-06-30T09:52:26.060" UserId="909" />
  <row Id="3120" PostId="322" Text="A zener diode doesn't solve this! If you have a look at the U/I-curve of an LED, you'll see that -- in order to have the LED work at a certain current -- you need to control the voltage **very** precisely. Any deviation of the voltage over the LED results in a *huge* change in current. Therefore, you're much better of controlling the current directly." CreationDate="2010-06-30T12:37:47.560" UserId="401" />
  <row Id="3121" PostId="691" Score="1" Text="The zener doesn't change the fact that you'd be controlling voltage -- of which the LED current is depending, but with extreme sensitivity which makes the system inherently unstable." CreationDate="2010-06-30T12:41:50.023" UserId="401" />
  <row Id="3122" PostId="756" Text="I have to agree with Jason here. If you want more efficiency than a resistor (or some other circuit that just burns away the excess voltage, such as a current mirror or a current source using a FET), you'll need something like a DC-DC converter or switching power supply." CreationDate="2010-06-30T13:18:00.927" UserId="401" />
  <row Id="3123" PostId="3204" Text="Unless you manage to repurpose a keyfob.." CreationDate="2010-06-30T13:30:45.463" UserId="883" />
  <row Id="3124" PostId="3212" Score="2" Text="It may help us to actually see the opamp drawn out. Any easy way for you to show us what you are talking about is by drawing in this program: http://www.tech-chat.de/aacircuit.html It will convert your circuit to ascii so that you can just copy and paste it into your question." CreationDate="2010-06-30T13:36:43.893" UserId="319" />
  <row Id="3125" PostId="144" Score="1" Text="There may be some risks involved in adding random functions to the load on the dsp, but they should be quite capable of general purpose interfacing such as displays/buttons/communication lines." CreationDate="2010-06-30T13:44:48.197" UserId="883" />
  <row Id="3126" PostId="3223" Text="The problem with this is that the overhead of the running OS is going to kill almost any type of application. Power consumption is in no relation to what you would find using some form of DSP. In short, it will work, but the standalone PC option is very inefficient." CreationDate="2010-06-30T14:06:02.230" UserId="909" />
  <row Id="3127" PostId="1153" Text="Wonderful link! Bookmarked. I was not planning to work on a project like this, but I have to make it now I saw that little video :-)" CreationDate="2010-06-30T14:22:48.097" UserId="909" />
  <row Id="3128" PostId="3212" Text="When the buffer output changes, does the buffer input change? Answer that, and I bet you'll be closer to solving the problem. " CreationDate="2010-06-30T15:11:56.927" UserId="712" />
  <row Id="3129" PostId="3209" Text="Yeah, IR is annoying due to the line of sight issue. But it may be an option for some projects" CreationDate="2010-06-30T16:26:04.007" UserId="131" />
  <row Id="3130" PostId="3142" Text="Cool! Are you using a development board or did you make your own?" CreationDate="2010-06-30T16:56:48.293" UserId="876" />
  <row Id="3131" PostId="3231" Text="For the first version, I completed it using an ARM7TDMI-S processor. You mentioned SPI line integrity, this actually is important. What are some ways that I can secure the transmission? (That might be for a whole seperate question though)" CreationDate="2010-06-30T17:39:20.173" UserId="876" />
  <row Id="3132" PostId="3142" Text="My local STMicro rep gave me an &quot;IAR KickStart Kit for STM32&quot;&#xA;&#xA;http://www.iar.com/website1/1.0.1.0/658/1/?item=prod_prod-s1/225&#xA;&#xA;to play with; however the micro is only a 64-pin package so it doesn't have the FSMC pins, so I may end up getting the boards with the 144-pin package." CreationDate="2010-06-30T18:13:35.063" UserId="1322" />
  <row Id="3133" PostId="3222" Text="Thanks. That's what my co-worker told me." CreationDate="2010-06-30T19:52:19.233" UserId="854" />
  <row Id="3134" PostId="3231" Score="1" Text="well, i don't think there is anything thats perfect in terms of keeping people off those traces.  If the data on the line isn't encrypted your SOL.  You can use BGA chip packages and run the signal traces on internal layers in the PCB.  That would at least keep out those without real motivation.  But unless one of the IC's has them internally SPI need pull up resistors so there would still be surface access to the signal." CreationDate="2010-06-30T20:31:20.263" UserId="703" />
  <row Id="3135" PostId="3211" Text="This seems like a matter of crappy breadboards, not breadboards in general.  There's no reason why they couldn't be made to have a secure connection." CreationDate="2010-06-30T21:41:04.010" UserId="142" />
  <row Id="3136" PostId="3212" Text="The two summing nodes shouldn't affect each other.  Can you draw the circuit?" CreationDate="2010-06-30T21:51:37.430" UserId="142" />
  <row Id="3137" PostId="2453" Text="Thanks for all of these helpful comments! As I mentioned in an earlier comment, the problem was actually a faulty breadboard, but the advice you've given is great to know. The intent of the diode was as you described, but obviously I got that wrong.  I'll also add the decoupling capacitor in future." CreationDate="2010-06-30T23:45:40.950" UserId="504" />
  <row Id="3138" PostId="3239" Score="4" Text="This site isn't really a &quot;do it for me&quot; kind of site. It's more like you attempt to solve something on your own, and then when you have a specific problem where you get stuck, you post the details here and we help. If you want someone to do it for you, you can hire 3rd world people for pretty cheap from places like oDesk / eLance / rentacoder / etc." CreationDate="2010-07-01T03:55:41.140" UserId="131" />
  <row Id="3142" PostId="3214" Text="Tnxs for ur attention, im using 2k resistors on the lm358 and 1k resistors to gnd to assure cero voltage saturation&#xA;&#xA;this is my schematic: http://www.glowfoto.com/static_image/30-232532L/9652/png/06/2010/img4/glowfoto" CreationDate="2010-07-01T04:54:35.123" UserId="920" />
  <row Id="3143" PostId="3211" Score="1" Text="Perhaps you are right, I will never claim to be an expert. But for the limited price of using PCB in a commercial environment, even with duplicate components when making multiple setups, I still prefer it. I work on industrial systems and when we want to test something on the line, I feel secure knowing that everything is soldered on. I suppose for the hobbyist a breadboard is still the right choice in many cases." CreationDate="2010-07-01T06:51:24.023" UserId="909" />
  <row Id="3144" PostId="1534" Text="0603 is a problem for me because I am a bit too unstable even using expensive equipment (Weller soldering station for SMD, etc.) The problem I have is that my hand is just too unstable. Although I voted for your post and I do believe your answers are quite good, if you are making a kit I'd try to stay on the safe side (for people like me)." CreationDate="2010-07-01T07:13:42.180" UserId="909" />
  <row Id="3145" PostId="3234" Text="I have a composite input on the TV. Well, a composite input on the SCART connection anyway." CreationDate="2010-07-01T08:06:44.667" UserId="710" />
  <row Id="3147" PostId="3247" Text="But I was under the impression that the motor inside a servo is pretty similar to the DC motor above. Clearly the ardunio seems to be able to drive that." CreationDate="2010-07-01T13:30:40.803" UserId="905" />
  <row Id="3148" PostId="3247" Score="3" Text="With a servo, the motor is not powered by the Arduino. The Arduino is just providing a low power signal to tell it which way to turn." CreationDate="2010-07-01T13:38:18.243" UserId="566" />
  <row Id="3149" PostId="3248" Score="2" Text="Wow those articles actually do help... I'd never tried applying solder to the board, THEN the chip. Explains why my SMD stuff never works :-P" CreationDate="2010-07-01T13:53:41.083" UserId="876" />
  <row Id="3150" PostId="3248" Text="I found the sparkfun one after answering your question, have actually been studying the little youtube videos they did to learn a few more techniques. I burnt my fingers, but it works though! :D" CreationDate="2010-07-01T13:57:35.450" UserId="909" />
  <row Id="3151" PostId="3197" Text="Oh a PS, didn't realize until now. The text: GPIO_IPConnected needs to be GPIO_IPInputConnected in both instances." CreationDate="2010-07-01T13:59:26.617" UserId="909" />
  <row Id="3152" PostId="3247" Text="Hang on, when you say &quot;Arduino&quot; you mean the Atmel chip? Cause in the servo tutorial, there is no other power supply. The 5V and gnd are both coming from the arduino board. I take it you mean that the PWM output which is connected to the Atmel chip doesn't provide enough current?" CreationDate="2010-07-01T14:37:41.773" UserId="905" />
  <row Id="3153" PostId="3247" Text="Indeed, I do. You're right. The servo power line comes off the Arduino's power supply, the PWM signal comes from an AVR pin." CreationDate="2010-07-01T14:40:05.967" UserId="566" />
  <row Id="3154" PostId="3218" Text="Thanks! Now I see there is no easy (cheap) way to tweak varistor combining it with other things. Well, let it be :)" CreationDate="2010-07-01T14:51:40.363" UserId="914" />
  <row Id="3155" PostId="3225" Text="Yep, looks like I misused the term *Varistor*. I've meant linear potentiometer actually. Thanks for clarification." CreationDate="2010-07-01T14:55:41.250" UserId="914" />
  <row Id="3156" PostId="3141" Text="@reemrevnivek power the buffer from the positive terminal of the capacitor. As long as the bus is idle for a short period of time at startup, it should sustain itself." CreationDate="2010-07-01T16:48:23.290" UserId="771" />
  <row Id="3157" PostId="3239" Text="What made you decided to use 433MHz?" CreationDate="2010-07-01T17:04:34.397" UserId="319" />
  <row Id="3159" PostId="3231" Text="+1 for the BGA-internal-layer-trace suggestion, except that SPI does not require pull-up resistors to my knowledge because SPI is daisy-chained point-to-point instead of a shared bus topology." CreationDate="2010-07-01T20:08:13.627" UserId="1278" />
  <row Id="3160" PostId="3261" Text="I'm not really looking to build one, I'm just wondering how they do it.&#xA;&#xA;The block diagram you linked to is a good example, though.  Multiple caps of varying values in parallel" CreationDate="2010-07-01T20:40:50.267" UserId="1278" />
  <row Id="3161" PostId="3260" Text="What are you asking? Are you wanting an iPhone to control the value of a capacitor?" CreationDate="2010-07-01T20:46:48.747" UserId="319" />
  <row Id="3162" PostId="3231" Text="I shouldn't have said &quot;need&quot; but rather &quot;often requires&quot;.  SPI can be a shared bus, thats what chip select lines are for.  This has nothing to do with the presence of pull up resistors.  The need for pull up resistors is dependent on the nature of the I/O pins on the microcontroller (or other devices on the bus).  If they are open-collector,aka open-drain in mosfets they may have very weak (~100kohm) pull-ups the bus won't work at higher speeds so an external, lower resistance, pull up is needed.  They may also have no pull up at all in which case they are incapable of driving the line high.  " CreationDate="2010-07-01T23:38:33.110" UserId="703" />
  <row Id="3163" PostId="3260" Text="Can you provide a reference for this &quot;programmable capacitor&quot; used in the iPhone?" CreationDate="2010-07-02T00:42:48.937" UserId="142" />
  <row Id="3164" PostId="3278" Score="1" Text="The busbee looks like a electronic analyzer.  Does it allow you to communicate from PC-to-Device via I2C?" CreationDate="2010-07-02T13:36:03.143" UserId="923" />
  <row Id="3165" PostId="2204" Text="It's nice to see a site where they will list the prices like that, w/o forcing you to talk to sales staff!" CreationDate="2010-07-02T13:59:04.803" UserId="740" />
  <row Id="3166" PostId="3278" Text="Yep you're right. It does not allow communication from PC-to-Device." CreationDate="2010-07-02T14:39:06.533" UserId="588" />
  <row Id="3171" PostId="2105" Text="I'd also like to hear more details." CreationDate="2010-07-02T16:35:17.447" UserId="876" />
  <row Id="3172" PostId="3281" Text="I'd love to see more info about using an Arduino to program an AVR." CreationDate="2010-07-02T16:49:54.453" UserId="835" />
  <row Id="3175" PostId="3281" Text="http://news.jeelabs.org/2010/07/02/fixing-a-faulty-atmega-arduino/" CreationDate="2010-07-02T18:05:39.793" UserId="566" />
  <row Id="3176" PostId="991" Text="It's the compiler supplied with the LPCXpresso boards, and uses gcc with the Eclipse IDE. The Rowley CrossWorks tools are much better." CreationDate="2010-07-02T19:34:06.947" UserId="305" />
  <row Id="3178" PostId="1893" Score="2" Text="One disadvantage of getting boards from the other side of the globe: ideally, a board house will look over your design and, if they see anything odd or particularly difficult to manufacture,  call or email you to be sure that's what you really want. But if there is a language barrier or a timezone barrier, they might not bother." CreationDate="2010-07-03T03:04:36.983" UserId="222" />
  <row Id="3179" PostId="3211" Text="Agreed, I haven't seen a solderless breadboard in years." CreationDate="2010-07-03T03:23:48.160" UserId="222" />
  <row Id="3180" PostId="3290" Text="Can you be more specific?" CreationDate="2010-07-03T12:21:05.240" UserId="566" />
  <row Id="3181" PostId="3290" Text="im only new to arduino and this code is from a friend so i cant tell you why it is like that.. do you know what they error suggests that im getting?" CreationDate="2010-07-03T12:23:48.277" />
  <row Id="3182" PostId="3290" Text="Updated my reply" CreationDate="2010-07-03T12:29:11.060" UserId="566" />
  <row Id="3183" PostId="3290" Text="no difference same error" CreationDate="2010-07-03T12:32:03.423" />
  <row Id="3184" PostId="3286" Score="6" Text="This data is pretty much always in every datasheet. If you can't find it, look harder. In general for microcontrollers, you should expect to be able to drive or sink anywhere between 4 and 20mA. Many also have a separate limit per port, so don't try to pull the max off of every pin at once because you may over load the port." CreationDate="2010-07-03T12:38:30.183" UserId="319" />
  <row Id="3185" PostId="3290" Score="4" Text="Alex, in sites like chiphacker, you should post this as a comment. It is not a typical message board where you switch back and forth in a thread." CreationDate="2010-07-03T12:40:09.180" UserId="319" />
  <row Id="3186" PostId="3288" Text="In Arduinos, do you have to specify the product number in a pound define or is that a setting in the software?" CreationDate="2010-07-03T12:42:14.410" UserId="319" />
  <row Id="3187" PostId="3289" Text="This is a perfectly good attempt at an answer, but I do not understand why it was accepted as the correct answer if it did not fix his problem." CreationDate="2010-07-03T12:43:27.747" UserId="319" />
  <row Id="3188" PostId="3289" Text="I agree, please remove the &quot;correct answer&quot; tick until someone solves your problems." CreationDate="2010-07-03T12:45:17.157" UserId="566" />
  <row Id="3189" PostId="3284" Score="1" Text="Carl is correct, if you can't electrically tie two circuits together, it is best to use optics." CreationDate="2010-07-03T12:45:49.557" UserId="319" />
  <row Id="3190" PostId="3289" Text="As a note to Alex, If you accept someones answer, you are telling everyone that your question has been answered and that you don't really need any more responses." CreationDate="2010-07-03T12:48:21.207" UserId="319" />
  <row Id="3191" PostId="3287" Score="1" Text="The specs you want are 'Low-level output sink current' and 'High-level output source current'." CreationDate="2010-07-03T13:57:59.180" UserId="259" />
  <row Id="3192" PostId="3288" Text="is this code an exact paste from your arduino editor?" CreationDate="2010-07-03T14:37:01.300" UserId="740" />
  <row Id="3193" PostId="3285" Text="i have a small but reasonable amount of experience with smd passives and personally I wouldn't even bother to try and hand solder 0201 components (probably 0402 as well) unless it was absolutely necessary, and then I would definitely use a microscope. All of my smd boards use 0805s. great answer by the way!" CreationDate="2010-07-03T14:41:21.343" UserId="417" />
  <row Id="3194" PostId="3288" Text="@Kellenjb: the Arduino IDE has a menu setting (Tools;Board) for that, which doesn't seem to insert anything into the edit window." CreationDate="2010-07-03T15:24:14.830" UserId="740" />
  <row Id="3196" PostId="3286" Score="3" Text="Theres also usually a limit for the entire IC that you should make sure not to exceed." CreationDate="2010-07-03T17:49:18.177" UserId="703" />
  <row Id="3197" PostId="3285" Text="Agree. I haven't worked with anything smaller than 1206s without a microscope. The problem in my experience with 0805s isn't necessarily assembling them without a microscope, it's inspecting them after. 0201s are a whole other world though - you have to even learn how to not lose them on the bench! " CreationDate="2010-07-03T18:13:00.640" UserId="906" />
  <row Id="3198" PostId="1534" Score="4" Text="MELF = Most End up Lying on Floor." CreationDate="2010-07-03T18:17:45.320" UserId="906" />
  <row Id="3199" PostId="967" Text="Tough N (P if you get a good deal) MOSFETs make a good basic brute force switch for a lot of purposes from PWM switching to adjustable current sources." CreationDate="2010-07-03T22:56:52.250" UserId="883" />
  <row Id="3200" PostId="1162" Text="*only*&quot; 9.6kbps... I remember accessing the internet with my 2.4kbps modem back in the day..." CreationDate="2010-07-03T23:42:20.697" UserId="771" />
  <row Id="3201" PostId="3296" Text="You should be able to avoid the solder bridges on the last couple of pins by removing the tip in line with the pins, instead of continuing in the same direction. It should then remove the excess solder. That's what Metcal recommends when drag-soldering with their mini-hoof cartridge." CreationDate="2010-07-04T04:45:03.800" UserId="305" />
  <row Id="3202" PostId="3297" Text="Albeit infrared isn't very popular other than in remote controls. It may be dead fairly soon anyway from some articles I've read." CreationDate="2010-07-04T05:47:39.667" UserId="854" />
  <row Id="3204" PostId="3297" Score="2" Text="@stanigator: IR dying out? Where did you hear that?" CreationDate="2010-07-04T15:03:17.200" UserId="740" />
  <row Id="3205" PostId="1091" Text="The Rowley toolset is great and the support is excellent." CreationDate="2010-07-04T16:01:54.900" UserId="221" />
  <row Id="3206" PostId="3299" Text="@Jeff, sorry. Actually I the CS/CE circles this has become such a common book that I forgot that some of the people here may not know the book" CreationDate="2010-07-04T18:11:02.470" UserId="1200" />
  <row Id="3207" PostId="3303" Score="1" Text="These are good books, but this is not what I have been looking for. This is not a &quot;What are your favourite books&quot; question. I am looking for a single concise book which would enable me to get my basics right and get me started on how to think up my own electronic systems." CreationDate="2010-07-04T18:17:02.933" UserId="1200" />
  <row Id="3208" PostId="3294" Text="I would really like a book on the history of electronics engineering. I mean, I have read many on Computing and such but found nothing on electronics" CreationDate="2010-07-04T18:44:35.547" UserId="1200" />
  <row Id="3209" PostId="3299" Text="@Rick_2047 - no prob, i pulled my earlier comment since it was OBE." CreationDate="2010-07-04T19:09:07.930" UserId="740" />
  <row Id="3210" PostId="3303" Score="2" Text="@rick_2047 your going to have to be more specific, electrical engineering is much larger and more complex field than computer science.  &quot;thinking in electronics&quot; can mean many things depending on the realm in which your interested (analog, digital, RF, etc)" CreationDate="2010-07-04T19:59:17.230" UserId="703" />
  <row Id="3211" PostId="3303" Text="I voted for &quot;The Art of Electronics&quot; (hence my +1). I also added some other books on specific subjects that deserve an honorable mention." CreationDate="2010-07-04T20:06:58.220" UserId="721" />
  <row Id="3212" PostId="3275" Text="We ended up going an entirely different route, so we could get CU/CL approval stickers. " CreationDate="2010-07-04T21:16:54.773" UserId="592" />
  <row Id="3213" PostId="3297" Score="4" Text="@stanigator: Your question was about short range wireless protocols. IrDA is a short range wireless protocol. This is actually a pretty good answer considering IR is one of the earlier forms of wireless communication." CreationDate="2010-07-04T21:26:10.573" UserId="319" />
  <row Id="3214" PostId="3302" Score="1" Text="How big are your spikes relative to your &quot;signal&quot;. I would look into what is causing the spikes before you go trying to remove them. There is a possibility that in flight you actually have bumps. It is also possible that you have a programming error. Or even a hardware error. If you rule out all of those option, then a low pass filter can be used." CreationDate="2010-07-04T21:35:31.897" UserId="319" />
  <row Id="3215" PostId="3305" Text="According to Cambridge University Press, the 3rd edition is planned for December 2011: http://www.cambridge.org/uk/catalogue/catalogue.asp?isbn=9780521809269" CreationDate="2010-07-04T22:01:32.170" UserId="721" />
  <row Id="3216" PostId="1396" Score="1" Text="+1 for microscope soldering. If you do it correctly with good equipment, the ic doesn't even get warm. I often find that the hard part of smd is inspecting the soldering joints which is near impossible without a microscope anyway" CreationDate="2010-07-05T00:38:24.023" UserId="417" />
  <row Id="3217" PostId="3307" Score="1" Text="Although you have completely denied the possibility of existance of what I want, I think this was the best answer. As soon as I asked this question, I began to realize how utterly stupid and demanding it was (but I decided to post it anyway). Electronics is a very vast field and couldn't be covered in a book. But you described my phrase &quot;Thinking in Electronics&quot; exactly how I had it in my head. perhaps there is no skipping the 4 semesters of basic electronics engineering at college." CreationDate="2010-07-05T11:10:30.783" UserId="1200" />
  <row Id="3218" PostId="967" Text="Agreed. I use P if they are a good deal, but in general use N, just due to the deal." CreationDate="2010-07-05T19:39:51.477" UserId="230" />
  <row Id="3219" PostId="322" Text="I enjoy you saying I should control the current directly, as V or I can be controlled, But I know what you mean. My standard practice, as with many is an LED Driver or a resistor. Still, no reason not to play with a zener. Especially if your generator has the resistance and dissipation power rating you need." CreationDate="2010-07-05T19:44:55.217" UserId="230" />
  <row Id="3220" PostId="3286" Score="1" Text="To sum up what kellen and Mark said. Read the datasheet. Honestly, there is no good replacement for actually reading the datasheet. As you read them you will get faster and learn what you can skip. But on many important decision points at work. I read the entire thing. It is funny when someone decided to leave  major note that changes functionality 2/3 of the way through the document as a footer. " CreationDate="2010-07-05T19:48:22.170" UserId="230" />
  <row Id="3221" PostId="2790" Text="Thanks; I'm pretty close.  The xbees I'm using are having some severe reliability issues, but it's not temperature-related." CreationDate="2010-07-05T19:55:00.310" UserId="70" />
  <row Id="3224" PostId="1159" Text="If you swap the antenna there are requirements for wire loss to keep from violating FCC. You will get the same max range regardless of antenna. FCC gives a limit for your power radiated in the direction of maximum radiation. So omnidirectional will hit the same boundary as a directive antenna, unless I am mistaken." CreationDate="2010-07-06T00:34:42.390" UserId="230" />
  <row Id="3225" PostId="1162" Text="yeah, but did you access the internet from 15 miles away wirelessly with something near the power of bluetooth." CreationDate="2010-07-06T00:35:40.283" UserId="230" />
  <row Id="3226" PostId="3285" Text="An 0201 resistor can easily be mistaken for a breadcrumb. I realized this when I was trying to solder a breadcrumb to the board!&#xA;&#xA;Seriously though, how does anyone get those puny little things soldered down properly by hand?" CreationDate="2010-07-06T07:32:13.193" UserId="909" />
  <row Id="3227" PostId="3286" Text="+1 to what Kortuk said. And just to add a pinch more - don't even neglect the application notes. There are frequently nuggets of useful info to be found there, too." CreationDate="2010-07-06T10:47:20.337" UserId="740" />
  <row Id="3228" PostId="3314" Score="3" Text="Short answer, I use mil." CreationDate="2010-07-06T13:21:27.357" UserId="319" />
  <row Id="3229" PostId="3309" Text="While this is a nice resource, its just an information of a bunch of books in one place. Indeed I can use this as online reference but this isn't exactly different from most of the books I have in my possession." CreationDate="2010-07-06T13:40:48.690" UserId="1200" />
  <row Id="3230" PostId="1026" Text="National Webench does a lot, but it's more wizard oriented and doesn't let you lay out circuits. You get to play with parameters and simulation very much like spice, though." CreationDate="2010-07-06T14:57:44.293" UserId="883" />
  <row Id="3231" PostId="3309" Score="3" Text="Rick, no offense, but are you sure that you went past the home page? This is a complete book, divided in volumes, by a single author. I've read SICP and I believe that this is the closest thing you'll find in the field of electronics.&#xA;&#xA;The navigation is a bit confusing, though. Start from here:&#xA;http://www.allaboutcircuits.com/vol_1/chpt_1/1.html. At the end of each chapter you have to go back to the volume index. The title of each chapter in the index is linked to some sort of cover, so you have to click on the first indented link of each chapter to keep reading.&#xA;&#xA;Or have I misunderstood you?" CreationDate="2010-07-06T16:05:20.643" UserId="933" />
  <row Id="3232" PostId="3066" Score="2" Text="No, I've seen zeners that are black cylinders before." CreationDate="2010-07-06T16:09:20.703" UserId="712" />
  <row Id="3233" PostId="3302" Text="Don't have any idea what's causing the spikes. I've tried different methods of moving the board in a lab environment to minimize vibration and still see the spikes so it appears to be an inherent anomaly. I guess my solution is going to have to be a filtering algorithm of some sort. Thanks for the response! Joe B" CreationDate="2010-07-06T16:48:09.987" />
  <row Id="3234" PostId="3304" Text="Thanks JustJeff. I have a general idea of what you're talking about but am a little confused by &quot;bias&quot; acceleration. Is there any site you could suggest to get me a little less confused?&#xA;&#xA;Thanks,&#xA;&#xA;Joe B" CreationDate="2010-07-06T16:51:08.123" />
  <row Id="3235" PostId="3320" Score="3" Text="What is motivating you to do it at home? With the free edition of EAGLE and typically less than $20 at BatchPCB you can get your board fabricated professionally... worth every penny in my experience :)." CreationDate="2010-07-06T17:05:48.830" UserId="771" />
  <row Id="3236" PostId="991" Text="In what way are they better? I'm asking because I have the LPCXpresso board and the tools seem to work well so I'm wondering how the other tools are better?" CreationDate="2010-07-06T17:56:35.197" UserId="710" />
  <row Id="3237" PostId="3320" Score="3" Text="@vicatcu: The advantages for making PCBs at home: Much quicker. You can have it that same day, instead of waiting several weeks for BatchPCB. Much cheaper...a 4&quot; x 6&quot; copper clad board might be $5, the same PCB at BatchPCB would cost $70. Disadvantages: messy chemicals, quality wont be as great (eg, can't make quite as small traces), drilling lots of holes by hand is a pain. " CreationDate="2010-07-06T18:04:38.560" UserId="131" />
  <row Id="3238" PostId="3320" Score="2" Text="@davr, basically you're looking at about $2.50 per square inch + $10 shipping for a prototype. 4&quot; x 6&quot; is a preposterous size for a typical PCB. I recently had a 2.5&quot; x 3.5&quot; PCB made at BatchPCB and it cost me about $30 all said and done. My take is that if you are prototyping and your circuit is simple enough, do it on a breadboard; if your circuit is complex, its worth the saved time and frustration to have it fabbed at BatchPCB and wait 3 weeks to get it back." CreationDate="2010-07-06T20:38:07.187" UserId="771" />
  <row Id="3239" PostId="3304" Text="most of these accelerometers detect not only the obvious acceleration caused by visibly moving the sensor, but also the acceleration due to gravity. If you keep the sensor in a fixed position, with one axis exactly vertical, this will show up as a constant value on the vertical axis. In different orientations, the value due to gravity will map to each axis by the cosine of the angle of that axis with respect to vertical." CreationDate="2010-07-06T21:34:12.890" UserId="740" />
  <row Id="3240" PostId="3324" Text="how do you etch?" CreationDate="2010-07-06T21:34:49.673" UserId="740" />
  <row Id="3241" PostId="3324" Score="1" Text="Ferric chloride in a small plastic container, in an old washing up bowl with about 1&quot; of boiling water poured into it, to keep the etchant hot. With continuous agitation, etching takes about five minutes." CreationDate="2010-07-06T21:57:27.337" UserId="305" />
  <row Id="3242" PostId="3320" Score="3" Text="My experience as a hobbyist is that there is a very high chance of messing up your first attempt at any particular board. (Oops I forgot to supply power to 2 chips, and none of my switches fit the holes drilled for them...) Then it takes another 3 weeks to get a fixed board...." CreationDate="2010-07-06T23:29:19.663" UserId="710" />
  <row Id="3243" PostId="3320" Score="5" Text="I think making your own PCB is &quot;one of those things you just have to do yourself&quot;, once or twice. " CreationDate="2010-07-07T01:20:36.197" UserId="1307" />
  <row Id="3244" PostId="1396" Score="2" Text="+1 agree with markrages, i use a 2.5mm chisel tip for 95% of SMD assembly.  I never use a smaller tip to assemble finer pitch devices, only for rework or for devices that are closely spaced enough that i would damage nearby components with a large tip.  Small tips do not prevent you from damaging chips.  In fact using a wide tip to solder more pins at a time usually results in less time spent heating the part making it safer.  It is all but impossible to solder a GND pin with a close connection to a ground plane well with 0.015in tip without spending 5 minutes on a single pin." CreationDate="2010-07-07T04:59:29.803" UserId="703" />
  <row Id="3245" PostId="3313" Text="Perhaps I was not clear, sorry, but it is not a chip, it's an object from two metals and a white rubber where the 3 wires come out from.&#xA;&#xA;The scale works on 6V and putting this on the red and black and measuring the white (with black) on an oscilloscope shows no change when pressure is applied.&#xA;&#xA;Red - Black -&gt; resistance: 1k&#xA;White - Black -&gt; resistance: 2k" CreationDate="2010-07-07T09:39:38.603" UserId="323" />
  <row Id="3246" PostId="3313" Text="Pressure has no effect on the resistance, very strange." CreationDate="2010-07-07T09:40:48.893" UserId="323" />
  <row Id="3247" PostId="3313" Text="Oh and there are 4 of these metal objects (with each 3 wires) on each corner that come together on a separate circuit and than connect with 4 pins to the main circuit board." CreationDate="2010-07-07T09:58:13.600" UserId="323" />
  <row Id="3248" PostId="3313" Text="I suspect what you have is a resistive strain gauge. I know you said that pressure has no effect on the resistance, but maybe it's just relatively insensitive. If it's from a scale, you probably need a few pounds of pressure on the sensor to move the signal." CreationDate="2010-07-07T12:36:21.937" UserId="712" />
  <row Id="3249" PostId="3313" Text="Ah, here's another thought-- maybe it's a capacitive sensor. You'd feed it a square wave on one side of the capacitor and measure how much the corners roll off on the other side. That theory doesn't work so well with the relatively low resistances you measured earlier, but it sure would be a cheap way to make a sensor for a consumer-grade scale." CreationDate="2010-07-07T12:38:55.710" UserId="712" />
  <row Id="3250" PostId="3309" Text="I went through it (skimming the contents) and then wrote the comment. I think the wording of the comment was wrong. I mean to say, this site does not add anything else other than the summation of all the books by different authors I have in my possession. It doesn't matter if the author is same or different, what matters is the content is the same. For example, its section on digital systems does not add much to what I already have in my Digital Design, by M M Mano. Same is for the section of Semiconductors, I have my book by floyd and thats all I need right now." CreationDate="2010-07-07T14:18:27.717" UserId="1200" />
  <row Id="3251" PostId="3309" Text="(Also these books are incomplete for these subjects which I really want to learn deeply)." CreationDate="2010-07-07T14:18:35.550" UserId="1200" />
  <row Id="3252" PostId="3294" Text="@Rick_2047 - That sounds like a good question." CreationDate="2010-07-07T16:03:38.423" UserId="374" />
  <row Id="3253" PostId="3295" Text="One thing i would add is to be quite careful of op amp circuits on breadboards.  The stray capacitance, high contact inductance and resistance can turn your nice filter into a nice oscillator very fast.  I haven't used one of these boards in years but avoid op amps with high bandwidth and filter designs with poles near the given topologies instability region.  I have been bitten by this issue in the past several times and its why i no longer use solder-less boards." CreationDate="2010-07-07T17:28:21.533" UserId="703" />
  <row Id="3254" PostId="3307" Text="you can teach yourself online.  MIT actually offers quite a few online courses that would cover most of what you need to know, this only works for some people though, depends on what type of learner you are.  http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/         " CreationDate="2010-07-07T17:38:28.780" UserId="703" />
  <row Id="3255" PostId="3324" Text="I used to do it similarly but before inkjet printers, the transparencies were hand drawn" CreationDate="2010-07-07T18:51:41.833" UserId="936" />
  <row Id="3256" PostId="3328" Score="1" Text="One way to avoid problems at the edges is to use a slightly oversized board, worth the money of the extra board." CreationDate="2010-07-07T19:03:59.100" UserId="1498" />
  <row Id="3257" PostId="3313" Text="I found under the LCD also a LM324(D) chip. This would indicate that it is a strain gauge?&#xA;&#xA;I still find it strange that most information I find about measuring weight are with 4 wires (Wheatstone bridge?) but this one is with 3 wires." CreationDate="2010-07-07T20:50:54.810" UserId="323" />
  <row Id="3258" PostId="3324" Text="Do you have an opinion on that 'renewable' etchant?" CreationDate="2010-07-07T21:03:00.673" UserId="740" />
  <row Id="3259" PostId="3331" Text="I was getting ready to research solutions to do something like this. Thank you for asking." CreationDate="2010-07-07T22:19:03.197" UserId="230" />
  <row Id="3260" PostId="3334" Text="That is the extent of my knowledge." CreationDate="2010-07-07T22:41:20.843" UserId="230" />
  <row Id="3261" PostId="3324" Text="Cupric chloride? I've tried something like it by regenerating ferric chloride etchant using hydrochloric acid and hydrogen peroxide. Over time, the iron disappears into the rinse water and it becomes cupric chloride. I found I could keep using it indefinitely, but it was quite a lot slower than reasonably fresh ferric chloride." CreationDate="2010-07-07T23:22:04.787" UserId="305" />
  <row Id="3262" PostId="2200" Text="Leopard board has ethernet, similar to beagle board" CreationDate="2010-07-08T00:05:15.713" UserId="582" />
  <row Id="3263" PostId="2280" Text="Beagle board = $149&#xA;IGEPv2 w/wifi= $179 " CreationDate="2010-07-08T00:08:36.097" UserId="582" />
  <row Id="3264" PostId="2468" Text="+1 for http://www.findchips.com/ !" CreationDate="2010-07-08T00:45:33.773" UserId="857" />
  <row Id="3265" PostId="970" Text="I'd agree that 1/2W is more than you need, but I'd advocate using the money you save by going to 1/4W to upgrade from E12 (10% tolerance) to at least E24 (5%).  See http://bit.ly/cTVeGp for more options, like stocking the E48 (2%) set in 1%.  To do the math for you, there are 12 values/decade in E12, 24 in E24, etc, for a total of 49 values in 100-1M for E12, 97 in E24, 195 in E48, etc.   If you can find them at close to $.05 each, and you get 10 each, that gives you $24.50 for E12,  $46.50 for E24, or $97.50 for E48.  Probably easier to get a kit like:http://elexp.com/cmp_2501.htm ." CreationDate="2010-07-08T01:19:30.867" UserId="857" />
  <row Id="3266" PostId="2486" Text="don't forget RS! http://australia.rs-online.com/web/" CreationDate="2010-07-08T01:33:02.760" UserId="417" />
  <row Id="3267" PostId="2468" Text="@jluciani completely unrelated side question, as i live in boston also, have you found or are involved in any local engineering meet-up style groups that aren't targeted at the college crowd?" CreationDate="2010-07-08T02:12:57.640" UserId="703" />
  <row Id="3268" PostId="684" Text="I don´t think you can read any information at all from this chip, and even if you can, what´s for? You cannot buy it anymore. Spend your time writing code for a new MCU, forget about COP8!" CreationDate="2010-07-08T02:49:06.177" UserId="940" />
  <row Id="3269" PostId="2468" Text="I am one of the organizers of the local Arduino/Robotics group. All are welcome and I am trying to get more college students involved. We have been meeting monthly at Microsoft NERD which is a few blocks from MIT. Search for us on meetup.&#xA;&#xA;Sprout (Somerville) has some project nights and meet-ups. http://thesprouts.org&#xA;&#xA;&#xA;There is a Boston dorkbot as well. Since dorkbot is based on &quot;doing strange things with electricity&quot; sometimes it's engineering and sometimes art. There is a mailing list for dorkbot. The mailing list may be a good place to ask about other groups as well. " CreationDate="2010-07-08T11:44:04.110" UserId="424" />
  <row Id="3270" PostId="3336" Score="1" Text="From their [documentation page](http://octopart.com/api/documentation), it looks like you can filter on supplier (DigiKey, in this case), although I just searched for a handful of parts on DigiKey's website and Octopart didn't mention DigiKey in the results." CreationDate="2010-07-08T12:00:49.527" UserId="836" />
  <row Id="3271" PostId="3344" Score="5" Text="Of all the things I have learned, version control (I use subversion currently) is the most valuable thing to my productivity. We had sourcesafe by Microsoft when I started here, so I used a bad solution and then a good." CreationDate="2010-07-08T13:41:05.123" UserId="230" />
  <row Id="3272" PostId="1158" Text="I use this too, with a ruler. Not the best but works fine to me." CreationDate="2010-07-08T14:02:37.673" UserId="938" />
  <row Id="3273" PostId="3314" Score="3" Text="Short answer, I use mm." CreationDate="2010-07-08T14:03:16.140" UserId="883" />
  <row Id="3274" PostId="1596" Text="See this site: http://claymore.engineer.gvsu.edu/~steriana/Videos/ for tutorials on how to use LTspice." CreationDate="2010-07-08T14:09:30.293" UserId="857" />
  <row Id="3275" PostId="3350" Text="I think it's more expensive. At least here in Brazil and for hobby. But thanks anyway for the reply." CreationDate="2010-07-08T14:15:24.390" UserId="938" />
  <row Id="3276" PostId="2544" Text="CRC is available at many automotive supply stores (Advance, Napa), and is cheaper than the Radio Shack stuff." CreationDate="2010-07-08T14:22:07.400" UserId="857" />
  <row Id="3277" PostId="3344" Text="I cannot imagine my life without a source control system. I use SVN currently too. I don't know how things worked before I know SVN." CreationDate="2010-07-08T14:25:40.190" UserId="938" />
  <row Id="3278" PostId="3284" Text="Ground is a commom problem too." CreationDate="2010-07-08T14:30:09.017" UserId="938" />
  <row Id="3279" PostId="3350" Text="Ah, depends on the markets. I'd expect a more mass produced device would end up being cheaper (at least used). But you may be right. Both are very pricey." CreationDate="2010-07-08T14:57:33.783" UserId="883" />
  <row Id="3280" PostId="34" Score="1" Text="You have just RTFM ;-)" CreationDate="2010-07-08T17:08:35.527" UserId="938" />
  <row Id="3283" PostId="3345" Score="1" Text="Please let us know what your goals / requirements are, might help people know more what you're looking for." CreationDate="2010-07-08T17:40:37.710" UserId="131" />
  <row Id="3284" PostId="398" Text="Your first paragraph assumes OP connects a PC between the monitor and the VCR.  Should work, though." CreationDate="2010-07-08T19:11:24.670" UserId="374" />
  <row Id="3286" PostId="291" Text="Agreeing with Amos - Don't tie yourself down to .net; you need to learn C." CreationDate="2010-07-08T20:23:06.263" UserId="857" />
  <row Id="3287" PostId="2962" Text="This question have many answers. Until today I have not needed yet to use the negative power supply. But will depend on the application." CreationDate="2010-07-08T20:51:11.253" UserId="938" />
  <row Id="3288" PostId="83" Text="&#xA;&#xA;I don't understand what you need the ethernet for. If you're using the Mac Mini to receive the commands from the iPhone over wifi, you can just send them to the Arduino via USB.&#xA;" CreationDate="2010-07-08T22:58:10.007" UserId="933" />
  <row Id="3289" PostId="3344" Score="1" Text="+1 for &quot;The bug is usually in the thing you are assuming works&quot;" CreationDate="2010-07-08T23:45:31.577" UserId="740" />
  <row Id="3290" PostId="3342" Text="Hi, in addition to putting RN41 on Arduino board, I would be using a Bluetooth Dongel on my desktop to communicate with Arduino, right? So, do you mean that the dongel would communicate serially on a COM port with the computer?&#xA;Thanks" CreationDate="2010-07-09T05:28:27.903" UserId="913" />
  <row Id="3291" PostId="3365" Text="Ah! This is the gcc-option type of solution I was going for.  It doesn't look like what I wanted to do (cast my chars to long) is actually valid C, so this is what I'll have to do.  If I understand the other posts about this on the web correctly, though, this prevents some optimizations (at higher levels) from changing other stuff elsewhere in my code.  But I'm not doing a lot of goofy casting elsewhere in my code (Just this buffer), so this should work. " CreationDate="2010-07-09T12:44:33.343" UserId="857" />
  <row Id="3292" PostId="3349" Text="Thanks for the response. I had been intending to learn qucs for a while now. I like their documentation and looks just the interim level simulator I wanted." CreationDate="2010-07-09T14:24:37.117" UserId="1200" />
  <row Id="3294" PostId="3384" Score="1" Text="Don't forget spare tips for the iron!" CreationDate="2010-07-09T17:11:02.393" UserId="1307" />
  <row Id="3295" PostId="2107" Text="Particularly I'm almost not using more breadboard. It's rare." CreationDate="2010-07-09T17:12:05.087" UserId="938" />
  <row Id="3296" PostId="954" Score="3" Text="Dave is just enthusiastic, he loves electronics design at work and at home... and it comes through in his videos. I enjoy listening to them in the background whilst doing something else. " CreationDate="2010-07-09T17:12:36.227" UserId="1307" />
  <row Id="3297" PostId="3391" Text="Good idea. Although I can debug my code on the prototype board I have so hopefully it won't need any debugging :)&#xA;&#xA;I'm mostly worried I'll miss some pin that needs to be set high / low or something" CreationDate="2010-07-09T19:17:38.363" UserId="710" />
  <row Id="3298" PostId="3365" Text="just be aware - suppressing warnings has a way of coming back to haunt you, though, since once you have the suppression switch in your build, subsequent warnings about new situations tend to get smothered. " CreationDate="2010-07-09T20:50:08.023" UserId="740" />
  <row Id="3300" PostId="3361" Score="1" Text="@Adam: I love that book! Pragmatic Programmer! I can't believe I forgot it!" CreationDate="2010-07-09T23:25:23.187" UserId="625" />
  <row Id="3301" PostId="3365" Text="Yes, of course this could prevent some optimizations." CreationDate="2010-07-09T23:53:39.977" UserId="933" />
  <row Id="3302" PostId="3381" Text="USB or RS-232 are bad suggestions. Simplest would be one with a TTL serial connection. Eg this one: http://www.sparkfun.com/commerce/product_info.php?products_id=9913&#xA;&#xA;You can connect it directly to the UART pins on your microcontroller. &#xA;&#xA;RS-232 would require an interface chip, and USB would require a microcontroller with USB host, and lots and lots of complicated code to interface with it." CreationDate="2010-07-10T02:16:29.083" UserId="131" />
  <row Id="3303" PostId="1206" Score="2" Text="Are you asking for freeware or open source? " CreationDate="2010-07-10T09:24:38.713" UserId="689" />
  <row Id="3304" PostId="954" Score="1" Text="ok there is a difference between enthusiasm and plain old over acting. And his way of making the videos would put over actors to shame." CreationDate="2010-07-10T12:47:03.007" UserId="1200" />
  <row Id="3305" PostId="3376" Score="1" Text="Electronics Exchange will be merged into Chiphacker?" CreationDate="2010-07-10T13:02:29.470" UserId="938" />
  <row Id="3306" PostId="1088" Score="2" Text="Interesting! I really have never heard of it. Thanks." CreationDate="2010-07-10T13:14:15.737" UserId="938" />
  <row Id="3307" PostId="2050" Score="1" Text="One up vote for KiCAD. Very good tool." CreationDate="2010-07-10T13:16:04.723" UserId="938" />
  <row Id="3308" PostId="1095" Text="I don't agree that it is Mostly marketing. I agree with JohnC answer." CreationDate="2010-07-10T13:23:39.570" UserId="938" />
  <row Id="3309" PostId="642" Text="He has a great course too." CreationDate="2010-07-10T13:30:18.880" UserId="938" />
  <row Id="3310" PostId="3328" Text="That's true...cheers Russ" CreationDate="2010-07-10T14:45:02.993" UserId="399" />
  <row Id="3311" PostId="3377" Text="Yeah! Thanks guys both of these books look pretty good.  Any other suggestions are welcomed as well." CreationDate="2010-07-10T17:00:35.770" UserId="657" />
  <row Id="3312" PostId="3364" Text="The global effects were my concern with the compiler option.  Thanks for this better solution!  " CreationDate="2010-07-10T18:20:05.560" UserId="857" />
  <row Id="3313" PostId="3394" Text="What do you want that's not on the typical application circuit of page 4 of the datasheet? (see http://www.rovingnetworks.com/documents/RN-41.pdf )&#xA;" CreationDate="2010-07-11T02:09:23.477" UserId="857" />
  <row Id="3314" PostId="3376" Text="Did someone say that?" CreationDate="2010-07-11T02:51:27.370" UserId="142" />
  <row Id="3315" PostId="3374" Score="1" Text="SPICE, or at least XSPICE (the version I've used) supports incrementing the value of a component in the circuit by some value and over multiple simulations." CreationDate="2010-07-11T04:53:32.240" UserId="1374" />
  <row Id="3316" PostId="826" Text="Ditto. I use them everywhere. Also, they're quite robust - I've accidentally run the entire FT232 off 3.3v and it still works without an external oscillator, contrary to what their datasheet says." CreationDate="2010-07-11T04:56:59.337" UserId="1374" />
  <row Id="3317" PostId="923" Text="I always visualized buck/boost regulators as big flywheels that you load on one side and kick on the other side to keep the spin going at the right speed." CreationDate="2010-07-11T08:30:17.360" UserId="883" />
  <row Id="3318" PostId="2306" Text="You can also combine (parallel) different types and ratings of caps to combine their frequency responses." CreationDate="2010-07-11T08:33:41.290" UserId="883" />
  <row Id="3319" PostId="2444" Text="Yes, tri-state means three states (0, 1, HiZ) and HiZ means it's not asserting 0|1. Using one to mean the other is absolutely wrong.&#xA;&#xA;There are actually cases where you can &quot;tristate a pin&quot;. For example, an AVR gpio pin can be configured to work in various modes. Some operations will make it a tristate pin, some open drain and some push-pull 0|1.&#xA;" CreationDate="2010-07-11T08:37:30.710" UserId="883" />
  <row Id="3320" PostId="3395" Text="I've always seen Li-Ion batteries specced as 4.2-3.0v... I guess manufacturers vary." CreationDate="2010-07-11T10:04:16.207" UserId="1374" />
  <row Id="3321" PostId="3384" Text="@tronixstuff - Only if you have a budget iron. I've managed more than a year on my OKI-Metcal iron tips, and they get almost daily use." CreationDate="2010-07-11T10:05:16.970" UserId="1374" />
  <row Id="3322" PostId="3384" Score="7" Text="I want to point out that for a beginner, most of this stuff iw waaaaaaaay out of budget. Aside from the Fluke and Weller, go surplus or secondhand. CRT oscilloscopes are still completely usable, and they're much less expensive. Chinese-made PSes are the same." CreationDate="2010-07-11T10:07:12.930" UserId="1374" />
  <row Id="3323" PostId="193" Text="Use comments, don't add an answer. This is not a forum." CreationDate="2010-07-11T10:10:23.380" UserId="1374" />
  <row Id="3324" PostId="923" Text="not a bad way to think of it. There are a million ways to think of it, and multiple ways to implement it, so it is different from person to person." CreationDate="2010-07-11T13:32:50.990" UserId="230" />
  <row Id="3325" PostId="3384" Text="@Fake Name: I agree about the power supplies, and buying surplus or used equipment is certainly a great way to save money. I disagree about the oscilloscope. If you're new to electronics, an analog scope is much harder to use-- you have to understand triggering before you'll get anything on the screen.&#xA;&#xA;Also, I think it's a better strategy to buy good equipment for more money than it is to buy low quality equipment for half price. I think saving money on tools can cost you more in the long run-- an unreliable scope or DMM can drive you insane." CreationDate="2010-07-11T14:11:06.230" UserId="712" />
  <row Id="3326" PostId="2444" Text="@XTL: I think you're misunderstanding what I wrote. I understand that tri-state means three states. Unfortunately, people regularly use it to mean the HiZ state. As you say, it's absolutely wrong to do so, but I'm trying to explain what people mean when they say &quot;tristate a pin.&quot;" CreationDate="2010-07-11T14:15:19.400" UserId="712" />
  <row Id="3327" PostId="2512" Text="If you connect the DTR pin of the breakout board to the RESET pin on the atmega through a 100nF capacitor there's no need to press the reset button to upload sketches." CreationDate="2010-07-11T15:21:31.810" UserId="933" />
  <row Id="3328" PostId="2304" Text="glad to hear it." CreationDate="2010-07-11T19:48:45.860" UserId="230" />
  <row Id="3329" PostId="953" Score="3" Text="My first podcast: http://chrisgammell.com/2010/07/11/podcast-1-introduction-and-circuit-analysis/&#xA;&#xA;Late in the game but I thought I'd throw it in there." CreationDate="2010-07-11T23:17:14.080" UserId="404" />
  <row Id="3330" PostId="3410" Score="2" Text="Why do you prefer the square versus the round?" CreationDate="2010-07-11T23:34:16.270" UserId="424" />
  <row Id="3331" PostId="3413" Text="I've seen those Luxo's on Stanley Supply, and never understood the price.  What makes it worth $230 as opposed to the $23 for this one from Wal-mart?&#xA;http://www.walmart.com/ip/Studio-Designs-Magnifying-Lamp-in-Black/14660620&#xA;&#xA;Maybe this is why I can't stand the distortion on mine.  However, I know that the magnifier lamps we use at work and school are the professional quality ones; I just linked the Wal-mart one to highlight the extreme price difference." CreationDate="2010-07-11T23:45:50.540" UserId="857" />
  <row Id="3332" PostId="3412" Text="I like the idea of the eye loupes - kinda like the surgeon or jeweler look.  I don't, however, like the idea of sticking them in my eyes.  Ow.  Apparently, this is how they're supposed to be used, and if I see some, I'll try it, but doesn't sound comfy.  Besides, if they were at all out of alignment you'd have to go cross-eyed to compensate. No thanks. I do like the price and idea a lot, but any ideas on a pair of glasses or visor or something like that hold them? " CreationDate="2010-07-11T23:52:04.707" UserId="857" />
  <row Id="3333" PostId="3412" Text="Can you hold a pair in your eyes comfortably?" CreationDate="2010-07-11T23:52:20.743" UserId="857" />
  <row Id="3334" PostId="3410" Text="I like the square too, the field of view that has the same magnification is larger.  With the round ones, the middle inch and a half is in focus, and things taper off rapidly as they approach the edges.  With the square/rectangular ones, you've got a larger area that looks the same." CreationDate="2010-07-11T23:54:14.203" UserId="857" />
  <row Id="3335" PostId="3413" Text="The Luxo is well built and the optics are very good (and replaceable). it is a professional level tool. Until now I have never seen the ones at Walmart so I am not sure how they compare. MSC direct also sells some lower cost lamps (and IIRC Luxo). Their sales prices can be very good. Just as I was starting to do more SMD soldering I found the Luxo in a clearance bin at Charrette. IIRC it was around $120 or so. Well worth the money." CreationDate="2010-07-11T23:58:41.153" UserId="424" />
  <row Id="3336" PostId="3410" Text="Third hands are also great, and probably necessary to hold the work steady under the magnifier tool (so they are relevant to this Q/A), I personally prefer the actual vice style: http://www.panavise.com/index.html?pageID=1&amp;page=full&amp;--eqskudatarq=2. The jaws will get burned pretty fast, so order a pair of the p/n 344 grooved jaws so you can hold circuit boards.&#xA;I also use a helping hands: http://www.amazon.com/Dual-Helping-Hands-with-Magnifier/dp/B0002BBZ2Y for a lot of work (quicker than using the vice).  Similar to my struggles with the lamps, I've never found the magnifying glass usable." CreationDate="2010-07-12T00:34:28.723" UserId="857" />
  <row Id="3337" PostId="3408" Text="Sorry to take over your q/a - I'm thinking about getting one of these for my work area, and so I've been shopping around!" CreationDate="2010-07-12T00:34:59.923" UserId="857" />
  <row Id="3338" PostId="3412" Score="1" Text="I've always used loupes, even for fine PCBs, and with good lighting, they're more than sufficient.  Confession time: in the spirit of &quot;yer doin' it wrong&quot;, I've always held the piece to my eye, I had no eye-dea (sorry) that the damn thing was supposed to be &quot;stuck&quot; in your eye.  Ow.  I think I'll keep using the loupe incorrectly." CreationDate="2010-07-12T02:25:56.753" UserId="221" />
  <row Id="3339" PostId="3410" Text="@jluciani well, mostly because i find it better suited to working with generally square or rectangular PCBs.  Especially when working near the corner of a PCB.  Round lenses tend to have a more rounded focus region meaning that when working near corners i spend more time adjusting my head / lens positioning.  I imagine its very much a personal preference issue and probably deeply impacted by how an individuals eye tend to focus.  " CreationDate="2010-07-12T03:44:15.700" UserId="703" />
  <row Id="3340" PostId="1921" Score="2" Text="If fuses bit not perfect, what kind of attact can bypass it ?" CreationDate="2010-07-12T04:16:05.110" />
  <row Id="3342" PostId="3414" Text="I wouldn't call unattainable or money better spent elsewhere best or even good." CreationDate="2010-07-12T07:29:52.660" UserId="883" />
  <row Id="3343" PostId="3142" Text="Am I missing something? 26 bits can directly address 2^6 = 64 M locations. 512MB with that would mean 8-byte words. Should that be 512Mb?" CreationDate="2010-07-12T07:40:23.577" UserId="883" />
  <row Id="3344" PostId="3384" Score="1" Text="Learning is not a bad thing and understanding an analog scope helps a lot. The major problem with one is that you can't catch anything fast and transient, only things that are slow enough to see in one sweep or repeat enough to form a trace. An alternative to a big digiscope today might be one of those computer-attached scopes. That'll also do some spectrum analysis." CreationDate="2010-07-12T07:47:56.817" UserId="883" />
  <row Id="3345" PostId="3416" Text="recipes are good too, plum chutney..." CreationDate="2010-07-12T07:59:28.297" UserId="1307" />
  <row Id="3346" PostId="954" Score="3" Text="Absolutely, but at the end of the day Dave's an EE, not an actor. :) " CreationDate="2010-07-12T08:01:45.047" UserId="1307" />
  <row Id="3347" PostId="1314" Text="Being able to etch or otherwise make pcb's is handy. You won't be dependent on some company and long shipping times for every little bit. Otherwise it's time for dead-bug or Manhattan or some other improvised method." CreationDate="2010-07-12T08:04:29.367" UserId="883" />
  <row Id="3348" PostId="1877" Text="IDE can run at some very slow speeds. Looking at top UDMA mode may not be required. We didn't even have those before late nineties :)" CreationDate="2010-07-12T08:06:17.323" UserId="883" />
  <row Id="3349" PostId="1206" Score="4" Text="I think the answer to the original question is &quot;yes&quot;." CreationDate="2010-07-12T08:08:57.260" UserId="883" />
  <row Id="3351" PostId="3403" Text="Thanks for the comprehensive answer. After all this I've decided that I can't solder the chip so instead I'll buy something like this http://www.olimex.com/dev/lpc-p1343.html . Which frankly only costs about, or even less than what it would cost me to make my own board anyway." CreationDate="2010-07-12T08:36:20.883" UserId="710" />
  <row Id="3352" PostId="3421" Text="This is exactly what I did a few years ago on the LPC2148, worked like a charm." CreationDate="2010-07-12T13:41:14.653" UserId="221" />
  <row Id="3353" PostId="3421" Text="It might be possible to arrange some other kind of suicide reset with external logic, but if you already have a WD..&#xA;&#xA;Just make sure you know what way it behaves when it comes back out of WDR so you won't be in a reset loop or such." CreationDate="2010-07-12T14:50:30.857" UserId="883" />
  <row Id="3355" PostId="3412" Score="1" Text="It doesn't hurt. :) Just put it in front of your eye and squint to hold it in place.  It's really being held by your cheek and the bottom of your eyebrow.  I don't think you use two at once, usually, so no need to go cross eyed.  At least I don't.  There are stereo glasses versions for dentists.   I've never used one." CreationDate="2010-07-12T15:32:36.123" UserId="142" />
  <row Id="3356" PostId="3414" Text="I agree that the price of many of those models is an exorbitant price for for the hobbyist or even the casual professional who needs to work with fine pitch components every once in a while.  However, some of my coworkers are using those microscopes for several hours a day, all week long.  Elsewhere in the company, workers on the production line use them for the entirety of their shift, inspecting tiny components.  The comfort and clarity mean that their eyes won't be damaged as they would from squinting through diopter lens.  It is the best quality, just not the best value." CreationDate="2010-07-12T16:31:53.217" UserId="857" />
  <row Id="3357" PostId="3403" Text="Twenty bucks for that dev board!?!?!?  Yes, go with the dev board all the way!" CreationDate="2010-07-12T16:36:28.700" UserId="857" />
  <row Id="3358" PostId="3421" Text="Yes, the watchdog is how I did it with an LPC2148 application, as well." CreationDate="2010-07-12T16:42:20.607" UserId="305" />
  <row Id="3360" PostId="3415" Text="How would you make your own boom? I've heard of people using LCD monitor mounts like this one: http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=1243305&amp;cm_mmc_o=VRqCjC7BBTkwCjCECjCE" CreationDate="2010-07-12T16:51:40.487" UserId="857" />
  <row Id="3361" PostId="3142" Text="@XTL: good catch, I corrected my answer." CreationDate="2010-07-12T17:04:32.777" UserId="1322" />
  <row Id="3362" PostId="3412" Score="1" Text="At less than $10 on Amazon, I'll have to add one to my next order!" CreationDate="2010-07-12T18:38:20.480" UserId="857" />
  <row Id="3363" PostId="3415" Text="Something like the one on the boom version. I've got a small lathe and milling attachment." CreationDate="2010-07-12T20:50:05.610" UserId="305" />
  <row Id="3365" PostId="3412" Text="In fact, I guess I don't even squint.  I raise my eyebrow high, put it in, and then relax, and that holds it in place." CreationDate="2010-07-13T03:13:35.900" UserId="142" />
  <row Id="3366" PostId="3430" Score="1" Text="See http://chiphacker.com/questions/906/ardiono-pwm-controlling-high-power-led/911#911" CreationDate="2010-07-13T11:52:37.390" UserId="339" />
  <row Id="3367" PostId="3433" Score="3" Text="@jes5199 - I'm not quite sure how this question deserves a meta tag; can you comment on your rationale?" CreationDate="2010-07-13T11:57:48.413" UserId="374" />
  <row Id="3368" PostId="3427" Text="As you are using an x64 version Windows, make sure that you're using the x64 version of inpout32 (http://www.highrez.co.uk/Downloads/InpOut32/default.htm)." CreationDate="2010-07-13T13:45:21.860" UserId="820" />
  <row Id="3369" PostId="3452" Text="No. If you do this, you'll restore all bit flags and maybe modify some undesirable bit." CreationDate="2010-07-13T16:21:07.667" UserId="938" />
  <row Id="3370" PostId="3438" Text="good god how did that even occur?  never seen solder string out and bridge like that." CreationDate="2010-07-13T16:40:09.557" UserId="703" />
  <row Id="3371" PostId="3426" Text="Is the outsource company the PCB fabrication house?  Is it the drill sizes?  Is it the panel sizes?  Is the outsource company the assembly house?  Sorry for the list of questions." CreationDate="2010-07-13T18:55:39.493" UserId="204" />
  <row Id="3373" PostId="3456" Text="&#xA;	Depends of course on whether you need a microcontroller in the circuit anyhow. I recently had a project where I needed a DMTF decoder. The chips cost about dollar in quantity. The difference in price between a PIC24F or an equivalent dsPIC33F (which also has a DSP) was also about a dollar in quantity. The DTMF decoder DSP routines were free from Microchip. Plus I now have a DSP for other stuff." CreationDate="2010-07-13T20:00:52.127" UserId="1322" />
  <row Id="3374" PostId="3438" Text="That's not solder, or the Arduino wouldn't work.  :)  I don't know what it is, though.  Fibers of some sort.  " CreationDate="2010-07-13T21:18:25.943" UserId="142" />
  <row Id="3375" PostId="1038" Score="2" Text="Since 'me' resurrected this thread with the Webtronix program a few hours ago, I thought I'd add for future reference that gEDA does include the Icarus and GTKWave simulators.  These take more work than an LTSpice simulation (You either have to add simulation data to all the parts you use, or write up a Verilog simulation), but gEDA (Unlike most PCB design packages) definitely does have a simulator." CreationDate="2010-07-14T02:06:16.330" UserId="857" />
  <row Id="3376" PostId="3444" Text="USB latency is more like hundreds of microseconds, not milliseconds.  Hi-Speed USB microframes are 125 us each." CreationDate="2010-07-14T04:31:33.777" UserId="1278" />
  <row Id="3377" PostId="3426" Text="Yes, the PCB fab house uses mil for everything - traces, panel sizes, drill sizes, etc.  They are not the assembly house, though." CreationDate="2010-07-14T04:41:51.680" UserId="1278" />
  <row Id="3378" PostId="3433" Score="2" Text="my notion was that I wasn't asking a question about a specific problem, but about the entire field. That seemed a little meta to me." CreationDate="2010-07-14T05:34:01.187" UserId="955" />
  <row Id="3379" PostId="3414" Score="1" Text="Get a second-hand stereo microscope (Ebay?).&#xA;They're **awesome** for SMT work." CreationDate="2010-07-14T07:45:39.657" UserId="1374" />
  <row Id="3380" PostId="3438" Score="1" Text="It's from whatever method was used to clean and deflux the board after soldering. Probably toothbrush bristles." CreationDate="2010-07-14T07:47:15.377" UserId="1374" />
  <row Id="3381" PostId="3438" Score="2" Text="**Edit** It could also be airborne lint. You wouldn't believe the crap that floats about in the air. I have a professional macro lens, and I've noticed if you leave things out for a few hours, they get filthy just from stuff precipitating out of the air." CreationDate="2010-07-14T07:48:47.780" UserId="1374" />
  <row Id="3382" PostId="3430" Text="Do you need to control them independently? If not, string them all together and use a simple switching dc-dc led driver. Zetex makes some that are really easy to use." CreationDate="2010-07-14T07:50:48.370" UserId="1374" />
  <row Id="3383" PostId="2305" Text="Also, add some 0.1uF ceramics across each rail to kill the really high frequency stuff.&#xA;It's probably unnecessary, but 0.1uF ceramics are like $0.02 a pop, so it's cheap insurance." CreationDate="2010-07-14T07:55:02.433" UserId="1374" />
  <row Id="3384" PostId="3384" Text="@pingswept - I disagree. I'd say that 99% of the time, an analog scope is **way** better than a digital scope, and the other 1% of the time you should be using a logic analyzer anyways. If you want good equipment, pick up a Tektronix 7904A with plugins, and it'll last you forever." CreationDate="2010-07-14T07:57:42.430" UserId="1374" />
  <row Id="3385" PostId="3384" Text="@pingswept - Also, with a digital scope, if you don't have triggering set up properly, you won't get anything meaningful anyways, so it's a non issue. Plus, every cheap DSO I've used has been horrible from a UI perspective. Analog scopes are just easier, from a response time and human-interface perspective. Having a discrete knob for every function makes understanding what the scope is doing immediately apparent." CreationDate="2010-07-14T07:59:38.493" UserId="1374" />
  <row Id="3386" PostId="3414" Text="I understand what you mean by distortion... I wonder if anyone knows if the larger diameter lenses are better or worse for this.  Despite living in a city, I have not seen any shops carrying this type of equipment, so I have not had a chance to check for myself.&#xA;&#xA;My budget is around £20 - £90max (35$-150$ approx) which excludes the other equipment you suggest.  But in a perfect world I would go for something like that rather than just dreamin.&#xA;&#xA;" CreationDate="2010-07-14T08:41:23.927" UserId="312" />
  <row Id="3387" PostId="3412" Text="I like the cost, but I don't see myself using one in an eye for populating a full PCB.  I think I will try and get hold of a hand held loupe for inspection though" CreationDate="2010-07-14T08:43:01.693" UserId="312" />
  <row Id="3388" PostId="3410" Text="I already use helping hands (the type with the clips) with magnifier.  I dont find them to be particularly useful,  A non-slip foam on my workbench is better I find.. The type with the vice looks far more practical" CreationDate="2010-07-14T08:48:23.587" UserId="312" />
  <row Id="3389" PostId="3384" Score="1" Text="I was able to buy a 60MHz dual-trace Tektronix scope, in good condition on eBay for $100 with shipping. If budget is a concern, an analog scope will cover probably 95% of your o-scope needs. What it lacks in data recording and transient analysis is made up in availability. The quality analog scope you can afford is always better than the full-featured digital scope you can't afford (if price is a factor.) " CreationDate="2010-07-14T09:12:17.687" UserId="965" />
  <row Id="3390" PostId="3443" Text="I'm not sure what you mean by tapping the +5V line. If I were testing power supplies, I would first test each source separately, then have the maximum rated load (for each source) on each one at the same time if there were no faults identified during individual testing. " CreationDate="2010-07-14T12:27:11.867" UserId="965" />
  <row Id="3391" PostId="3462" Score="2" Text="It depends which peripherals you want to interoperate with, at what voltages, at what speeds and at what distance." CreationDate="2010-07-14T12:33:43.583" UserId="566" />
  <row Id="3392" PostId="3384" Score="1" Text="@jesse: I think you've got it about right. An analog scope is far better than no scope and will work in a lot of cases. For me, &quot;most&quot; is around 70%, not 95%, but maybe I do more digital comm stuff than you." CreationDate="2010-07-14T12:50:29.760" UserId="712" />
  <row Id="3393" PostId="640" Score="1" Text="+1 - I think you did a good job of talking about places that people tend to ignore due to Google-syndrome." CreationDate="2010-07-14T12:58:00.660" UserId="374" />
  <row Id="3394" PostId="3466" Score="1" Text="I think if you have a very simple controller and you need to use bit-banging (basically manually operating the clock) it is much easier to implement SPI on a 4 left over GPIO ports." CreationDate="2010-07-14T13:28:56.367" UserId="909" />
  <row Id="3395" PostId="3462" Score="1" Text="I added more details to the question" CreationDate="2010-07-14T13:37:40.387" UserId="536" />
  <row Id="3396" PostId="3466" Text="I think you're right about it being easier to bitbang SPI than I2C. I'm hoping it won't come down to bit banging though." CreationDate="2010-07-14T13:38:46.503" UserId="536" />
  <row Id="3397" PostId="3468" Text="now it works again!" CreationDate="2010-07-14T13:51:09.960" UserId="952" />
  <row Id="3398" PostId="3468" Text="it behaves completely random" CreationDate="2010-07-14T14:02:37.537" UserId="952" />
  <row Id="3399" PostId="3471" Score="2" Text="If this solves your problem, you should tick this as the accepted answer." CreationDate="2010-07-14T14:37:39.327" UserId="566" />
  <row Id="3400" PostId="3466" Score="2" Text="+1 for the fishy-ness of the 2 wire system marketed as &quot;1-wire&quot;." CreationDate="2010-07-14T15:14:19.910" UserId="529" />
  <row Id="3401" PostId="1088" Text="Wow - thanks for that" CreationDate="2010-07-14T18:02:35.550" UserId="1307" />
  <row Id="3402" PostId="3444" Text="Ok, not as bad as I thought, but the point still stands. What happens if you try to use USB the way you would a parallel port, and send one byte at a time? 1 byte * (1 second / 125 microseconds) = 8000 bytes per second. And it gets even worse if you're say trying to do SPI, bit by bit, instead of something that can handle a whole byte at once. To use USB effectively you need some logic on the other end that can handle sending blocks of data at once, and your logic on the PC side should be designed to not need a response after every byte (or bit)." CreationDate="2010-07-14T18:20:49.057" UserId="131" />
  <row Id="3403" PostId="642" Text="I have heard of his course, but my company has less than 10 employees and only three firmware guys, not feasible. My school is just tight with money without a large enough firmware department." CreationDate="2010-07-14T19:03:15.100" UserId="230" />
  <row Id="3404" PostId="3466" Text="And to make it worse, many chips which implement the 1-wire (+ground) system require a third pin - Vcc - because they can't operate off of parasitic power! When I think of a 1-wire bus, I'm imagining some capacitively coupled setup, with a current-limited bridge rectifier, and some self-clocking line code; not 2 or 3 wires.  " CreationDate="2010-07-14T19:15:42.700" UserId="857" />
  <row Id="3405" PostId="3478" Text="I've used the labjack, it really slows down your computer if you do anything more serious (higher sampling rate), but it is great for slow sample rate simple logic. The NI systems are wonderful, but the software package is too expensive for home use. (At least for my home use.)" CreationDate="2010-07-14T19:25:50.453" UserId="909" />
  <row Id="3406" PostId="3475" Score="1" Text="What data rate do you need?  " CreationDate="2010-07-14T19:58:49.403" UserId="857" />
  <row Id="3408" PostId="3475" Text="@reemrevnivek: I estimate i would need about a 10 Hz sampling rate for inputs and 1 kHz for outputs, very slow I/O." CreationDate="2010-07-14T20:22:26.290" UserId="942" />
  <row Id="3409" PostId="759" Text="The phone system samples at 8000 Hz." CreationDate="2010-07-14T21:34:36.733" UserId="1363" />
  <row Id="3410" PostId="3477" Score="1" Text="I'd second the Hamblen and Furman book. I designed my own little Altera Flex 10K10 board and was able to use most of the code in the book with it. It's a cookbook, but none the worse for that." CreationDate="2010-07-14T22:08:30.437" UserId="305" />
  <row Id="3412" PostId="3487" Text="Yup, we have twisted wire bundles all over the place at work....&#xA;&#xA;I think that article overestimated the necessity of having another person hold the wire.  With the drill in one hand, and the other end of the wire in the other, you can easily get 5 foot cables." CreationDate="2010-07-15T01:01:06.540" UserId="857" />
  <row Id="3413" PostId="2792" Text="Well, it turns out the lithium cell is fine for my instrumentation amplifier and microcontroller, but the xbee I'm using draws far too much current.  I'll see what else is out there." CreationDate="2010-07-15T01:34:13.177" UserId="70" />
  <row Id="3414" PostId="3485" Text="Oh. but they are pretty costly....like $100 to $150 for 16 channels." CreationDate="2010-07-15T02:07:59.100" UserId="857" />
  <row Id="3415" PostId="2790" Text="50 mA is not low power." CreationDate="2010-07-15T02:58:19.937" UserId="857" />
  <row Id="3416" PostId="2790" Text="How short are &quot;short&quot; bursts? if they're less than a second, use a big cap in parallel with the battery." CreationDate="2010-07-15T07:00:32.807" UserId="1374" />
  <row Id="3417" PostId="3487" Text="The solution here is a bench-mounted vice! Make arbitrarily long twisted cable bundles..." CreationDate="2010-07-15T07:03:10.257" UserId="1374" />
  <row Id="3418" PostId="3475" Text="In your case the project you have found will probably work quite well. It is a system already put together (no soldering needed is always nice) and seems to have very basic firmware to give you access to all the ports you need. Low sampling rates mean that the serial connection will work sufficiently well. 40$ will not bankrupt you, right? If so, just try it before you look at a more expensive solution." CreationDate="2010-07-15T07:15:25.163" UserId="909" />
  <row Id="3419" PostId="3485" Text="I have an intronix 34 port logic analyzer to test my software (i.e. connect the inputs to the outputs of the microcontroller controlled pins). It's about 500$ I think, but it is also not really digital I/O is it? It is not meant to program custom logic with, just to analyze channels. Mine can work at 500Mhz sampling rate, but I don't usually need that speed, unless the peripherials I want the microcontroller to controll support speeds up to 200Mhz or so (which they usually do not). -- Anyway, long story short. I believe that a logic analyzer is not what the person asking the question needs." CreationDate="2010-07-15T07:20:38.537" UserId="909" />
  <row Id="3420" PostId="3495" Text="Nice board, mr. Schmalz" CreationDate="2010-07-15T07:22:28.800" UserId="909" />
  <row Id="3421" PostId="3495" Text="Well this is defiantly comforting. Being a mechanical engineer to begin with and knowing little about programming and even less about electronics; a prebuilt platform that interfaces with C/C++ is exactly what i needed in order to doge the electronics and microcontroller programming aspect. Thanks for your help!" CreationDate="2010-07-15T07:44:33.293" UserId="942" />
  <row Id="3422" PostId="3497" Score="1" Text="Can you post the code for your parser?" CreationDate="2010-07-15T08:55:48.627" UserId="566" />
  <row Id="3423" PostId="3490" Text="What's the correct crimping tool?" CreationDate="2010-07-15T12:36:25.873" UserId="51" />
  <row Id="3424" PostId="3508" Score="1" Text="Good answer. But doesn't really quantify how much should I worry if I get a drop on me and wash it off quickly." CreationDate="2010-07-15T13:05:46.560" UserId="710" />
  <row Id="3425" PostId="55" Score="3" Text="&quot;Lead cannot propagate through the skin.&quot;&#xA;&#xA;Not quite true. Organic lead compounds can be absorbed through the skin (see http://is.gd/dsVou). Also, powdered lead can enter the body through the skin but it appears to be contained to sweat and saliva (see http://is.gd/dsVuJ). You can probably see that if you absorb some lead at work (despite washing your hands), head home and then swap saliva as you kiss your wife/husband this could be a problem. In fact, the increased concentration of lead can remain for days!&#xA;&#xA;Also, I think you mean aerosolised, not atomised.&#xA;&#xA;apologies for the paywall links." CreationDate="2010-07-15T13:08:23.857" UserId="417" />
  <row Id="3426" PostId="2792" Text="Haha. I am sorry, i had no idea you were using an X-Bee, I could have told you that would be too much. If you place about 10 of the coin cells in parallel it will be fine for a while..." CreationDate="2010-07-15T13:49:24.393" UserId="230" />
  <row Id="3427" PostId="3508" Text="True, it is somewhat limited. I would defer to some of the more experienced folks here for that situation. Personally, though, it's probably better to have protective gear and not need it, rather than the other way around!" CreationDate="2010-07-15T13:50:27.557" UserId="965" />
  <row Id="3428" PostId="12" Text="Everything evaporates a little bit, even solid objects.  The vapor pressure of lead at 327.6°C is 4.21E-07Pa, though, which seems pretty low.  Here's a chart: http://www.powerstream.com/z/vapor-press1-big.png" CreationDate="2010-07-15T14:19:13.257" UserId="142" />
  <row Id="3429" PostId="3493" Text="Because my board has .1&quot; holes of course." CreationDate="2010-07-15T14:24:58.853" UserId="1363" />
  <row Id="3430" PostId="55" Score="1" Text="It can certainly get into the body through cuts or other small injuries.  I know I've been punctured by through-hole components or solder spikes many times over the years.  :/" CreationDate="2010-07-15T14:25:11.543" UserId="142" />
  <row Id="3431" PostId="3490" Text="Please edit to change &quot;these pins&quot; to mention a specific series. Otherwise readers have to follow the links in question to figure out what they are." CreationDate="2010-07-15T14:41:54.517" UserId="330" />
  <row Id="3432" PostId="3493" Text="Because everything else that you work with uses industry standard connectors.   " CreationDate="2010-07-15T14:43:32.743" UserId="222" />
  <row Id="3434" PostId="3487" Text="sometimes the 'other person' can even be a re-purposed metal coat-hanger slung over a door knob." CreationDate="2010-07-15T14:57:51.693" UserId="740" />
  <row Id="3435" PostId="3515" Text="That certainly lines up with what I've seen in the past. In one shop I worked at in southern Arizona, the humidity was so low you would get powerful electrostatic shocks just walking 5 feet. Wrist straps and mats were an absolute must!" CreationDate="2010-07-15T15:07:10.760" UserId="965" />
  <row Id="3436" PostId="3502" Text="The LM317 comes in a number of different package styles, all the way from surface mount to TO-2, and the current it can supply varies accordingly." CreationDate="2010-07-15T15:35:14.280" UserId="740" />
  <row Id="3437" PostId="3515" Score="1" Text="We were always supposed to wear cotton in the lab. Fleece was prohibited." CreationDate="2010-07-15T15:36:19.240" UserId="875" />
  <row Id="3438" PostId="3490" Text="I like that style of 'square socket pin locks into housing' connector. Of course they are very common. With care the pins can be taken out and rearranged to reconfigure and recycle [a connecter that came from an old computer]." CreationDate="2010-07-15T15:36:23.457" UserId="1363" />
  <row Id="3439" PostId="3515" Text="Being in the Army, we were required to wear highly starched Battle Dress Uniforms (BDUs.) Their ESD characteristics left MUCH to be desired." CreationDate="2010-07-15T15:48:13.140" UserId="965" />
  <row Id="3440" PostId="3517" Text="I personally don't enjoy above 60% (see @Leon Heller's answer) but I also don't want to have problems from handling-related ESD. I suppose the best way to mitigate handling exposure is ESD bags, though..." CreationDate="2010-07-15T15:52:11.197" UserId="965" />
  <row Id="3441" PostId="3462" Score="1" Text="I can't believe UART hasn't been mentioned at all... I'm just saying." CreationDate="2010-07-15T15:52:29.073" UserId="771" />
  <row Id="3442" PostId="3520" Text="Yea, I'm not in a position to switch IDEs, but CCS costs more than that, I expected a lot more out of the box capability" CreationDate="2010-07-15T15:53:48.480" UserId="771" />
  <row Id="3443" PostId="3520" Text="there is a version that you can download for free, but the free version has a built-in limit on the size of the images it can produce." CreationDate="2010-07-15T16:34:40.820" UserId="740" />
  <row Id="3444" PostId="3515" Score="1" Text="The fleece problem happens when you have separate hardware and software departments, and a representative of the latter has to be invited to the lab when verification testing gets interesting." CreationDate="2010-07-15T16:43:04.170" UserId="740" />
  <row Id="3445" PostId="3521" Text="So those boards are shipping already ? My boards are backordered and the expected shipping date is early August :-(&#xA;&#xA;What's your first impression on the launchpad ?" CreationDate="2010-07-15T16:45:40.823" UserId="595" />
  <row Id="3446" PostId="3521" Text="@JonathanD: there was a mad scramble the day that hack-a-day provided the link to the TI eStore; it looked like their server went down from the traffic, so I tacked one on to an order I was making from digikey. But I see digikey is fresh out, now, too. Anyway, windows couldn't find a driver for the board until after I'd installed CCSv4." CreationDate="2010-07-15T17:35:30.963" UserId="740" />
  <row Id="3447" PostId="3493" Text="@Joeforker - Both of the connectors I listed have a .1&quot; pitch." CreationDate="2010-07-15T17:37:29.173" UserId="857" />
  <row Id="3448" PostId="3493" Text="@Jeanne - What industry do you work in?  Other than Arduino (Which is polarized due to the nature of the board, and can be made locking by connecting the daughter and motherboards with standoffs and machine screws), I don't see many uses of the connectors which joeforker was using.  .1&quot; headers are designed for soldering board-to-board, not for connecting cables." CreationDate="2010-07-15T17:39:52.837" UserId="857" />
  <row Id="3449" PostId="3492" Text="If your twisted wire bundle has integrity issues, then you're doing it wrong.  Twist together your differential and power lines separately, and then twist the whole bundle.  You can buy twisted unshielded pair (for good reason), or you can make it yourself!" CreationDate="2010-07-15T17:41:41.380" UserId="857" />
  <row Id="3450" PostId="3521" Text="Yea, I feel like I've been really spoiled by how excellent the documentation of avr-gcc is, and it's like another world with TI's compiler - like I find myself unable to find a delay_ms utility function or anything like that..." CreationDate="2010-07-15T17:43:34.997" UserId="771" />
  <row Id="3452" PostId="221" Score="1" Text="Make sure you don't use a steel wool based scouring pad, or you'll damage the tip of your soldering iron, and get rapid oxidization as well. Must be brass! See this one: http://www.elexp.com/sdr_3460.htm, which comes in a weighted metal container with a rubber bottom for $5.75, replacement cleaners for $2.95." CreationDate="2010-07-15T17:48:49.090" UserId="857" />
  <row Id="3453" PostId="270" Text="Agreeing with Endolith - Sandpaper will destroy your tip, there's just a thin electroplating of iron on the tip which covers the softer brass, but the brass gets dissolved and coroded by contact with solder (Your tip becomes pitted and hollow.)" CreationDate="2010-07-15T17:50:22.080" UserId="857" />
  <row Id="3454" PostId="2790" Text="@FakeName - He's having trouble with his XBee, so &quot;Short&quot; is not so short here.  You'd need 50mA * 1s = 50 millicoulombs, so you'd need 50 mC/3.3V = 15,000 uF of capacitance (which would decay rapidly.) 50mA is usually not a candidate for capacitive backup." CreationDate="2010-07-15T17:56:10.930" UserId="857" />
  <row Id="3455" PostId="3517" Score="1" Text="You need ESD Bags. You need ESD straps, and you have to check each component to make sure they are not sensitive to humidity(this can happen quite commonly)" CreationDate="2010-07-15T18:32:27.190" UserId="230" />
  <row Id="3456" PostId="3492" Text="@reemrevnivek what you've described is still not safe, twisting 2 wires together does not make it acceptable as a way to transmit any signal, diff or single ended.  The nature of the wire core, the insulation, space between cores and number of turns per unit length all effect the characteristic impedance of the line. My point in the answer was that if a line requires that you take transmission line effects into account (be concerned about signal integrity) you should completely avoid this type of connection. Even transmitting 400khz I2C through something like this can be unreliable." CreationDate="2010-07-15T19:09:41.127" UserId="703" />
  <row Id="3457" PostId="3493" Score="1" Text="@reemrevnivik 0.1&quot; headers are used constantly, in many industries, in many production products for cable attachment.  For instance there are about a dozen such headers sitting on the motherboard the computer i'm typing on for everything from thermal measurement, to fan control, to speaker output, buttons, leds, etc." CreationDate="2010-07-15T19:12:14.680" UserId="703" />
  <row Id="3458" PostId="3520" Text="However, the code size limit is greater than the maximum amount of storage on those chips you get from the kit so you're only going to run into problems if/when you get some higher end MSP430s" CreationDate="2010-07-15T19:54:16.757" UserId="536" />
  <row Id="3459" PostId="3500" Text="That works perfectly. &#xA;&#xA;Thanks for the explaintion as well. I now know it was acting before the whole serial message arrived. So much headache for something so simple" CreationDate="2010-07-15T20:37:12.950" UserId="665" />
  <row Id="3460" PostId="3387" Text="Just learned the union keyword in another piece of code - This is probably the best answer! (Am I allowed to change the selection after this much time has elapsed?)  The union keyword is little known and little used, but this is a perfect example." CreationDate="2010-07-15T22:05:19.377" UserId="857" />
  <row Id="3461" PostId="3524" Text="Can you use call functions to read and write pin data directly from C++ programs running on your CPU?" CreationDate="2010-07-15T23:53:20.853" UserId="942" />
  <row Id="3462" PostId="3528" Score="3" Text="you are absolutely correct, this completely slipped my mind. To help illustrate this effect further, I fed a 1khz square wave into my oscilloscope and took a screen dump of the resulting Fourier transform (x axis is frequency basically): http://i.imgur.com/lJvtD.png . The harmonics are the repeating peaks." CreationDate="2010-07-16T01:58:39.773" UserId="417" />
  <row Id="3463" PostId="3528" Score="1" Text="@penjuin perfect illustration.  Just to clarify my answer for the owen, the device penjuin recommended is likely very capable of dealing with an ardunio, as you will likely never need to deal with an interface running at &gt;2mhz with that class of device.  I just wanted to make sure he didn't take it as a rule of thumb and have it end up biting him if he moves on to higher speed devices/interfaces later on." CreationDate="2010-07-16T02:33:05.587" UserId="703" />
  <row Id="3464" PostId="3524" Text="I was going to suggest that NXP would have something ARM based with some I/O, and if you couldn't get enough of them to just slap on I2C IO expanders. You can't beat the price of that thing, and it's plug 'n play. Excellent work." CreationDate="2010-07-16T05:42:46.213" UserId="974" />
  <row Id="3465" PostId="3485" Text="It's definitely I, but not O. No, I would agree that the logic analyzer is not what the person needs, given the new information." CreationDate="2010-07-16T11:59:48.790" UserId="857" />
  <row Id="3466" PostId="3528" Score="1" Text="A logic analyzer with variable threshold configured properly usually provides sufficient resolution for analyzing logic at only a few factors higher than the signal frequency. The problem exists in that the controller receiving the signal will switch to logic zero for anything below 1.2V (for example) and the the logic 1 for anything above 2.2V (for example) while the logic analyzer might switch over at 1.7V making the timing less precise. In many cases a sample rate of about 2-3 times faster in a digital circuit is sufficient to understand what is going on. " CreationDate="2010-07-16T13:42:05.540" UserId="909" />
  <row Id="3467" PostId="3522" Text="Agreed, it is never a good idea to read in the if statement. Best to wait for a command to be available and read it into blocks so you can reuse them in further tests. Especially if you end up doing if (Serial.read() == 't') ... if (Serial.read() == 'x') .... where the second read would contain a number from the command and no longer the command character." CreationDate="2010-07-16T13:48:39.800" UserId="909" />
  <row Id="3468" PostId="3506" Text="Thanks for all the answers, +1 for them all :)&#xA;Was hard to know which one to accept, they were all good. but that one seemed popular and answered my question most directly I suppose." CreationDate="2010-07-16T14:49:12.550" UserId="710" />
  <row Id="3469" PostId="3524" Text="I have no idea. I just saw it on Sparkfun's new products post." CreationDate="2010-07-16T14:52:21.480" UserId="142" />
  <row Id="3470" PostId="3534" Text="No, that's not what I mean.  I could measure those things by hand, as I did for that graph, but what I really want is a software tool that will let me change things and conveniently plot the response vs travel.  I have some solutions already, I just want a more convenient one." CreationDate="2010-07-16T14:57:02.423" UserId="142" />
  <row Id="3471" PostId="3530" Text="I really hate Code Composer. Sorry you have to deal with it." CreationDate="2010-07-16T15:19:12.793" UserId="875" />
  <row Id="3472" PostId="2865" Text="I've had a TDA2030 explode (explode seems a bit generous for a little snapping sound) and threw shrapnel at my shirt. I've also seen some modems with split chips after a thunderstorm. I presume other IC's with hard shells can do the same if overloaded." CreationDate="2010-07-16T15:49:37.693" UserId="883" />
  <row Id="3474" PostId="3528" Text="@wouter simons careful not to confuse bandwidth and sampling rate (i actually cleaned up my word usage in the answer as well).  A sampling rate of 2x the frequency of your signal is the bare minimum to detect that signal.  In practices scopes and especially analyzers usually oversample a lot.  For instance my tek scope has a 100mhz bandwidth but samples at 2.5ghz." CreationDate="2010-07-16T16:03:23.863" UserId="703" />
  <row Id="3475" PostId="3482" Text="I was wondering if learning the so called &quot;Netlist&quot; languages would be beneficial or easier over learning Verilog or VHDL?" CreationDate="2010-07-16T16:24:05.873" UserId="1200" />
  <row Id="3477" PostId="3544" Text="Yes!! That is what I need. What did you look up to find that? All my searches came up with cables and such." CreationDate="2010-07-16T19:40:26.690" />
  <row Id="3478" PostId="3544" Text="@sadse: when looking for a part like that, I usually make the rounds at several vendor sites. Digikey usually has more options than Jameco, but that can make it more difficult to settle on a specific item, but OTOH options are sometimes indispensable." CreationDate="2010-07-16T19:50:18.500" UserId="740" />
  <row Id="3479" PostId="2037" Score="2" Text="  ----&gt;Description of the HW: http://dangerousprototypes.com/2010/02/25/prototype-open-logic-sniffer-logic-analyzer-2/&#xA;  ----&gt;Eagle files: http://www.gadgetfactory.net/gf/project/butterflylogic/frs/?action=FrsReleaseBrowse&amp;frs_package_id=10&#xA;  ----&gt;PNG Schematic: http://dangerousprototypes.com.php5-11.dfw1-1.websitetestlink.com/wp-content/media/2010/02/cct-med.png&#xA;  ----&gt;PNG Layout: http://dangerousprototypes.com.php5-11.dfw1-1.websitetestlink.com/wp-content/media/2010/02/brd-large.png" CreationDate="2010-07-16T20:17:36.193" UserId="857" />
  <row Id="3480" PostId="3444" Text="So I can control up to 8 I/O pins directly from software from the CPU? Would I be able to interface more than 1 of these chips from the same program as well, effectively expanding the number of I/O pins available?" CreationDate="2010-07-16T22:45:17.223" UserId="942" />
  <row Id="3482" PostId="3548" Score="1" Text="what are the port settings, and what have you connected it to so far? was this a PC you connected it to? is this the 921600 bps device in your other question?" CreationDate="2010-07-17T01:03:28.643" UserId="740" />
  <row Id="3485" PostId="3550" Text="no it does not, I can't think of any 8 bit micros that have a high enough clock speed to work with 921600" CreationDate="2010-07-17T01:14:04.040" UserId="417" />
  <row Id="3487" PostId="3550" Text="here is a much more powerful ARM7 board: http://www.sparkfun.com/commerce/product_info.php?products_id=8627&#xA;&#xA;Unfortunately the max baud rate is still 115200 without modification (even on a much faster chip). I would also imagine that at such a high speed you would need to use specialised crystals or your error rate will be through the roof. Depending on your application, it may be easier just writing straight to the SD card from your hardware as opposed to sending it via RS232." CreationDate="2010-07-17T01:21:31.360" UserId="417" />
  <row Id="3496" PostId="1862" Text="Uh... Wet clay **is** conductive. Do you mean *polymer* clay?" CreationDate="2010-07-17T02:17:30.640" UserId="1374" />
  <row Id="3499" PostId="1862" Score="1" Text="You want to put mud on a circuit board?" CreationDate="2010-07-17T03:22:08.760" UserId="142" />
  <row Id="3500" PostId="3550" Text="@penjuin: I think AVR at 20MHz can handle UART at (just under) 1MHz without too much trouble." CreationDate="2010-07-17T05:10:45.337" UserId="131" />
  <row Id="3501" PostId="3384" Text="Probably so. I'm generally troubleshooting RF and audio, and the greatest difference I noticed between the 5-figure-priced Agilent digital scope and the 4-figure-priced (when new) Tektronix analog scope was the measurement capabilities of the Agilent. It was great for frequency measurement, amplitude, and pulse width. Without it, I used a counter (more accurate, anyway,) a spectrum analyzer (again, more accurate) and good old fashioned math for pulse width (not as accurate, but beggars can't be choosers...) Of course, many hobbyists can't afford a good spec-an, either." CreationDate="2010-07-17T07:13:10.880" UserId="965" />
  <row Id="3502" PostId="3376" Text="There have been at least two mentions of it:&#xA;&#xA;http://chiphacker.com/questions/666/what-about-electronics-exchange-closed&#xA;&#xA;http://chiphacker.com/questions/1256/merging-electronics-exchange-with-chiphacker&#xA;&#xA;I don't know of anything definite, but @Edward in the second question seems to be going forward with it by himself (As of December 2009)" CreationDate="2010-07-17T07:27:30.147" UserId="965" />
  <row Id="3503" PostId="3548" Text="I have set the device and VCOM port to 115200, 8bit, no parity, 2 stopbits, no xonxoff, no rtscts, no dsrdtr.&#xA;&#xA;Yes, it is the device in my other question. For the moment I will be using a PC, but would like to put the whole system into a box later on." CreationDate="2010-07-17T07:35:16.430" UserId="978" />
  <row Id="3504" PostId="3552" Text="Yes, I have tried most of the baud rates available to me. I have tried all stopbit, bytesize, buadrate combinations.&#xA;&#xA;I am sending through about 44kB/s through the serial cable.&#xA;&#xA;However, as a trial, I have tried reducing the datarate from the device to 8.4kB/s, and the baudrate to 115200. With their USB-Serial, it all works, with the FTDI, I get the same gibberish as before.&#xA;&#xA;I can configure the device to a variety of baudrates, sample rates, etc, but I have not had any luck with the FTDI :(&#xA;&#xA;But thanks!" CreationDate="2010-07-17T07:56:21.437" UserId="978" />
  <row Id="3505" PostId="3548" Score="1" Text="VCC is not standard RS232." CreationDate="2010-07-17T08:42:29.567" UserId="339" />
  <row Id="3506" PostId="3548" Text="2 stop bits is uncommon, the default usually is one stop bit." CreationDate="2010-07-17T08:44:49.157" UserId="339" />
  <row Id="3507" PostId="3557" Score="1" Text="I would consider that too close for comfort." CreationDate="2010-07-17T08:56:27.127" UserId="339" />
  <row Id="3508" PostId="3548" Text="I accepts 5-30V as its VCC, and it does use 2 stop bits. I have tried both 1 and 2 stop bits though." CreationDate="2010-07-17T09:24:34.927" UserId="978" />
  <row Id="3509" PostId="3560" Text="I'll have another stab at it, but from reading the specs, the xsens will accept 5-30v!" CreationDate="2010-07-17T09:25:36.843" UserId="978" />
  <row Id="3510" PostId="3560" Text="Yes, but what does it *output*?" CreationDate="2010-07-17T10:18:04.547" UserId="1374" />
  <row Id="3511" PostId="216" Text="That sound like your iron isn't heating properly, not that you have a dirty tip." CreationDate="2010-07-17T10:20:56.677" UserId="1374" />
  <row Id="3512" PostId="270" Text="All the tips I've ever used are copper, not brass." CreationDate="2010-07-17T10:21:28.940" UserId="1374" />
  <row Id="3513" PostId="3493" Text="@reemrevnivek 0.1&quot; headers are used in all kinds of products. They are most often used with ribbon cable, but there are times when ribbon cables are impractical. Perhaps the most common example is between front panel USB jacks and the motherboard of any desktop computer, and as Mark says, individual connections in a computer. " CreationDate="2010-07-17T11:07:03.217" UserId="222" />
  <row Id="3515" PostId="3552" Text="I ran into a situation once where a USB/FTDI based port that was supposed to be capable of 115.2k wouldn't play at that speed with a certain device. In that case, the device worked fine when connected to a 'real' com port built into the computer, and the FTDI based port worked with other devices at 115.2; but FTDI and that one device was just a pathological combination of interface chips." CreationDate="2010-07-17T12:55:17.827" UserId="740" />
  <row Id="3518" PostId="3544" Text="Adding terms like 'through hole' (or 'smd') might help with the search results. " CreationDate="2010-07-17T13:22:25.650" UserId="554" />
  <row Id="3520" PostId="3492" Text="@Mark, it seems to me this is done all the time with CAT5 cable. There are 4 pairs of wires which are twisted at different rates, then bundled together in a sleeve. Being that the question doesn't say as much, I'm not sure that crosstalk and impedance mismatch are even issues. If there are problems with radiating, simply use a small-diameter coax for interconnecting the sensitive lines." CreationDate="2010-07-17T13:59:35.610" UserId="965" />
  <row Id="3521" PostId="3552" Text="JustJeff, I have a similar situation with a peripheral we embed in our products. It works fine with a computer's serial port, but not with a PIC. Turns out its baud rate is a bit off. Apparently 'real' serial ports are more forgiving than microcontrollers. Luckily the PIC can be run at non-standard baud rates. " CreationDate="2010-07-17T14:14:53.620" UserId="222" />
  <row Id="3525" PostId="3432" Text="Just saw this post[1] on the SparkFun blog about using an FT232R for bit-band I/O. This is probably the cheapest way to go for something that will interface via USB.&#xA;&#xA;[1] http://www.sparkfun.com/commerce//news.php?id=386" CreationDate="2010-07-17T15:08:47.387" UserId="746" />
  <row Id="3526" PostId="3552" Text="@Jeanne Pindar: yeah, i've had that happen too. You get one device that's a little slow, another that's a little fast, and most things play with most other things. But once in a while you find that even though A talks to B and B talks to C, you just can't get A and C to talk, and the O-scope comes out.." CreationDate="2010-07-17T15:11:20.913" UserId="740" />
  <row Id="3528" PostId="3376" Text="I don't think they're being merged by anyone, but I've only got two questions on there, so I copied them here.  I intend to use chiphacker exclusively from now on, simply because it's bigger and there shouldn't be more than one stackexchange per topic." CreationDate="2010-07-17T15:14:32.310" UserId="142" />
  <row Id="3529" PostId="3557" Score="1" Text="@starblue: What's too close for comfort? Both the UART and the SD write speed are more than double he needs? (UART = 2.2MBps theoretical vs 0.92Mbps needed, SD = 350 kb/sec theoretical vs 112 kb/sec needed).   &#xA;&#xA;@JustJeff: Since the AVR wont be doing much else, my idea is that you can use the internal memory of the AVR to have a larger buffer. Ideally you'd read a single byte from UART and write that byte to SPI, but I think there may be some delays inbetween each block when writing to SD, so you might need to buffer a few bytes inbetween?" CreationDate="2010-07-17T15:50:00.417" UserId="131" />
  <row Id="3530" PostId="3528" Text="Great answer.  I followed your post just fine and can probably still measure what I want with one of the cheaper devices out there.  I'll keep an eye out for limitations as I explore more complicated components." CreationDate="2010-07-17T16:51:19.347" UserId="971" />
  <row Id="3531" PostId="3526" Text="After a half-day of more research, I can say that Saleae Logic should help me out with 90% of the ideas I have, for now.  The software looks polished and intuitive for a hardware &quot;outsider&quot; such as myself.  I can see how an oscilloscope would be immensely helpful, but for the types of simple projects, a USB logic analyzer seems like a good tradeoff." CreationDate="2010-07-17T16:55:02.773" UserId="971" />
  <row Id="3532" PostId="3565" Text="Thanks for the info." CreationDate="2010-07-17T17:10:57.980" UserId="230" />
  <row Id="3533" PostId="3567" Text="clearly a quick way to get it done when you are setup. I use multiple computers, many of them in a computer lab. I also like a solution I can quickly have working without installing software. If i set something up on one computer I think this may be the ticket." CreationDate="2010-07-17T17:11:51.763" UserId="230" />
  <row Id="3534" PostId="3569" Text="I do not have time for a little to look this up, but I believe the reason they started their own C compiler support with the PIC18 is because they are the first pic to support indirect addressing and a number of other features that C likes to use." CreationDate="2010-07-17T17:13:59.667" UserId="230" />
  <row Id="3536" PostId="3560" Score="1" Text="Also note that polarity between RS232 and TTL is inverted." CreationDate="2010-07-17T18:21:05.177" UserId="339" />
  <row Id="3537" PostId="3557" Score="1" Text="Ah, I missed the factor of 2.5 in the clock frequency for writing the SD card." CreationDate="2010-07-17T18:29:58.750" UserId="339" />
  <row Id="3538" PostId="3571" Text="It was right there under my nose. Thank you" CreationDate="2010-07-17T19:21:51.553" UserId="550" />
  <row Id="3540" PostId="3492" Score="1" Text="@jesse the twisted pairs in a CAT5 cable are twisted at different rates on purpose.  The reason is to avoid the same conductors being next to each other too often.  Having the conductors next to each other often can introduce transients into one wire of a pair more than the other defeating some of the effectively of differential signals.  You'll also find that higher rated CAT cable, such as CAT 5e and CAT 6 have higher minimum twist rates as this one of the steps taken to increase their frequency rating.  I said in my answer this only needs to be addressed for signals with integrity issues." CreationDate="2010-07-18T03:44:40.557" UserId="703" />
  <row Id="3541" PostId="3577" Text="are you looking for an audio recording-type ic or full blown speech synthesis ?" CreationDate="2010-07-18T06:58:57.443" UserId="417" />
  <row Id="3542" PostId="3577" Text="Not exactly speech synthesis, recordings will do. You know those greeting cards which say &quot;Happy B'day to you&quot; when you open them. Something like that" CreationDate="2010-07-18T08:06:48.527" UserId="1200" />
  <row Id="3544" PostId="3579" Text="If that still proved too much of a problem I suppose you could get some small plastic bags and subdivide each drawer further." CreationDate="2010-07-18T08:55:02.973" UserId="103" />
  <row Id="3546" PostId="3580" Text="dram is actually a capacitor bank. S/He might me DRAM." CreationDate="2010-07-18T14:00:23.583" UserId="230" />
  <row Id="3547" PostId="2944" Text="haha thanks, fixed it. silly typo." CreationDate="2010-07-18T14:00:54.480" UserId="348" />
  <row Id="3548" PostId="3580" Text="he, and I mean DRAM-ish. SRAM is flipflop based if i remember correctly. " CreationDate="2010-07-18T14:04:35.797" UserId="417" />
  <row Id="3550" PostId="3578" Text="I got a kit of resistors so I wouldn't need to hunt through them anymore.  Each value was in a little unlabeled bag, so I still had to hunt through them and read the color codes.  &gt;:(" CreationDate="2010-07-18T14:57:29.140" UserId="142" />
  <row Id="3551" PostId="3580" Text="What are you two talking about?" CreationDate="2010-07-18T15:47:35.107" UserId="1200" />
  <row Id="3553" PostId="3472" Score="1" Text="Can you clarify what you do want out of your HDL?  Most HDLs are designed for use with FPGAs because that's what most people need an FPGA for.  In general, a simulator (working from a graphical schematic) is used for non-FPGA and non-ASIC circuit design.  Do you want to build: (1)Discrete digital circuits, i.e. 74XX components, (2) Analog circuits, i.e. switching regulators, RF antennas/transceivers, generic op-amp circuits, or (3) Analog mixed-signal circuits, i.e. Interfacing between both digital and analog signals.  " CreationDate="2010-07-18T18:16:30.017" UserId="857" />
  <row Id="3554" PostId="3566" Text="Microsoft Excel is neither a CAD program (It's a spreadsheet), nor a program for a poor man (It's $150, according to office.microsoft.com)  When drawing as you suggest in Excel, you cannot visualize edge transitions other than vertical lines, which is unacceptable for a professional timing diagram. " CreationDate="2010-07-18T18:58:30.347" UserId="857" />
  <row Id="3555" PostId="3584" Text="That SMD binder is awesome! I was just looking for something like that last week! I'll definitely be getting a few. Thank you!" CreationDate="2010-07-18T19:46:53.980" UserId="712" />
  <row Id="3556" PostId="3566" Score="2" Text="for 200$ a year you can have all of the microsoft products. In reality, most companies I have been too have excel available. When I was looking at UML tools to make better drawings, they were 5 or more grand a seat. For a few very simple timing diagrams I had to use excel." CreationDate="2010-07-18T19:52:39.430" UserId="230" />
  <row Id="3557" PostId="3482" Text="Hard to say.  It depends on what you want to do with your language.   Can we get a better idea of what you want to do and what kind of language you want to use before we delve into the how and where for every permutation of a half-dozen languages and a great many use cases?" CreationDate="2010-07-18T20:06:10.573" UserId="857" />
  <row Id="3558" PostId="3580" Text="They're talking about volatile memory.  They're right, DRAM stores bits in a capacitor circuit (and as such, must be Dynamically accessed so the capacitors don't discharge), while SRAM stores data in a flipflop (and is therefore Static).  Basically, you want non-volatile memory (aka NVM)  (pref. Flash, or you can go with EEPROM) which allows you to, say, change the battery without losing everything." CreationDate="2010-07-18T20:19:59.110" UserId="857" />
  <row Id="3559" PostId="3580" Text="i should probably add that to call it DRAM is not fully correct. DRAM is used to store ones and zeroes, whereas each capacitor in the bank on these ics stores an analog-type voltage. For it to be stored in DRAM the audio must be encoded." CreationDate="2010-07-18T20:55:31.340" UserId="417" />
  <row Id="3561" PostId="3592" Text="you can get away with a much lower sampling rate than 15khz.  At 15khz you can reproduce up to 7.5khz audio which is very high for just speech.  If all you want is intelligible speech you only need up to about 4khz dropping your required sampling rate almost in half to 8khz which is what is used in many telephone systems.  " CreationDate="2010-07-18T22:16:49.563" UserId="703" />
  <row Id="3562" PostId="3573" Score="1" Text="be careful when you discuss the bit resolution of an ADC on a uC.  They may list 8-10bit on the datasheet and in marketing documentation but read further, you will usually find that between the capabilities of the device and the achievable noise floor, not to mention avoiding maxing out the voltage swing of the input, your usable resolution is 1,2 or more bits lower." CreationDate="2010-07-18T22:27:10.840" UserId="703" />
  <row Id="3563" PostId="3592" Text="I understand that you don't need to sample that fast.  Read the app note for more info.  If you want signals under 3,000 Hz (Voice), put in a lowpass filter.  Then, by the Nyquist–Shannon sampling theorem, you need to sample at 6,000 Hz .  To get an analog output without a discrete DAC (Added component) or special micro with an onboard DAC (Limited options) you need to use a PWM.  To get a smooth output from the PWM, you need to run at a frequency at least 2x your sample rate.  The PWM frequency is limited by (clock)/2*resolution; ex. 8MHz/2*2^8 = 15,625, which I approximated to 15,000, sry." CreationDate="2010-07-18T23:30:49.177" UserId="857" />
  <row Id="3564" PostId="3578" Score="3" Text="Don't overestimate the size of the storage cabinet required.  Especially if you subdivide by depth, you can stock a lot of components. For example, if you're stocking 5% resistors, you only need 3 rows of 8 bins, divided into 5 categories (&lt;100, &lt; 1k, &lt;10k, &lt;100k, &lt;1M)  to stock every resistor from 1 ohm to 910k." CreationDate="2010-07-18T23:41:35.943" UserId="857" />
  <row Id="3566" PostId="3592" Text="you miss understood the datasheet or are implying the wrong thing.  &quot;You're going to have 15,625 8-bit samples for every second of sound, so you'll likely want the external flash ($2 for 8-32MB will get you a lot of talk time).&quot;  This implies you need to store 15,625 samples when you do not.  You only need to store data at your needed sampling rate, 8khz or whatever is closest to this that divides into the uC clock rate.  The PWM runs at twice this rate but you do not need to store data for every PWM cycle as each pair of cycles is cut in half based on the value of the sample." CreationDate="2010-07-19T02:15:49.083" UserId="703" />
  <row Id="3567" PostId="3563" Text="I think this sounds like what I'm doing wrong. &#xA;I would need one of those transceivers.&#xA;I think they chose the MAX3160, because it does up to 1Mbps.&#xA;Anyone know where I can get a single board that can do USB at one end, and &quot;true&quot; rs232/EIA-232 the other? And be capable of speeds up to 921600?" CreationDate="2010-07-19T05:25:39.840" UserId="978" />
  <row Id="3568" PostId="3592" Text="Ah, I see that you're correct.  Rereading, I understand that the PWM must run at twice the sample rate, because they're using a count up/count down PWM.  Therefore, maximum resolution is achieved with 7,812 samples/second, as limited by the PWM maximum frequency.  Is this correct?  If so, I'll edit my answer." CreationDate="2010-07-19T12:36:27.983" UserId="857" />
  <row Id="3569" PostId="3596" Text="Any links to such a thing? I haven't ever implemented such a thing and don't know where I would start." CreationDate="2010-07-19T13:04:40.953" UserId="982" />
  <row Id="3570" PostId="3462" Text="Correct me if I'm wrong, but I didn't think UART was a bus. I thought it was just serial communication between two devices." CreationDate="2010-07-19T13:10:17.600" UserId="536" />
  <row Id="3572" PostId="3472" Text="I think I want to learn HDL to describe hardware. That is 1, 2 and 3. Also in one I want it to be non FPGA specific because I don't have the access or the finances to obtain those. " CreationDate="2010-07-19T14:13:09.100" UserId="1200" />
  <row Id="3573" PostId="3472" Text="I think I want to learn HDL to describe hardware. That is 1, 2 and 3. Also in one I want it to be non FPGA specific because I don't have the access or the finances to obtain those. I think mainly I want to use the HDL to simulate what I think up. A major plan of mine this year is to make my own computer. I think I will be using 74xx for that. Thats why to test my theories and circuits the idea of HDL came up." CreationDate="2010-07-19T14:15:36.590" UserId="1200" />
  <row Id="3574" PostId="1862" Score="1" Text="Clay dries hard, and cracks. You don't want to throw it at anything.  Alternatively, a silicone RTV, potting compound, or soft epoxy will dry into a slightly flexible mass." CreationDate="2010-07-19T14:17:08.570" UserId="857" />
  <row Id="3575" PostId="3593" Text="This can work. So I can just add the RC filter and attach the out to a speaker and that will produce a close approximation of original sound? So in principle if i record me talking will output have something like my voice? At least the accent?" CreationDate="2010-07-19T14:20:17.237" UserId="1200" />
  <row Id="3576" PostId="3604" Text="Well written. I skimmed it, but I saw nothing that went against my understanding." CreationDate="2010-07-19T14:43:34.577" UserId="230" />
  <row Id="3577" PostId="3596" Score="1" Text="What compiler are you using? There is a good chance the compiler you are using will do software uart for you." CreationDate="2010-07-19T14:46:39.117" UserId="319" />
  <row Id="3578" PostId="3608" Text="I'm already using the PWM to control the volume of the sounds - to create envelopes. If I control the overall volume with software I'll loose the envelope resolution, so I'm trying to have a separate way to control the volume " CreationDate="2010-07-19T15:10:46.377" UserId="399" />
  <row Id="3579" PostId="3608" Text="I can cope with linear, I'll just add a fixed value parallel resistor to curve it - shouldn't be a problem " CreationDate="2010-07-19T15:13:56.403" UserId="399" />
  <row Id="3580" PostId="3605" Text="I was thinking about putting the sound output from the Arduino's PWM pin through the Opto-Isolator and out to the speaker, then using another PWM pin to vary the brightness of the Opto-Isolator's emitter - Should I just draw a circuit? (a theoretical one)  " CreationDate="2010-07-19T15:20:40.913" UserId="399" />
  <row Id="3581" PostId="3472" Text="I don't know what your status is in terms of access and finances, but there are two options that I think are better than using 74xx.  The first is to use a simulator, like the free (*nix) gEDA software with Icarus Verilog and GTKWave to do simulations.  You can also use gschem to interface with these tools, and get schematic views of what you're doing. This way, you're not forever plugging and unplugging (and zapping and miswiring) dozens of 74xx.  You can also use an FPGA simulator, and then implement the logic in 74xx. (Out of room)&#xA;" CreationDate="2010-07-19T15:34:02.763" UserId="857" />
  <row Id="3582" PostId="3608" Text="You'll &quot;lose the envelope resolution&quot;?  What does that mean?" CreationDate="2010-07-19T15:38:34.083" UserId="142" />
  <row Id="3584" PostId="3608" Text="I'm using analogWrite() to set the volume of tones/oscillations and there's 255 steps which i'm ramping up and down like an amplitude envelope - so I'm concerned about keeping the envelopes smooth " CreationDate="2010-07-19T15:49:15.600" UserId="399" />
  <row Id="3585" PostId="3608" Text=":( sorry I'm not that good at explaining things with words - normally have to show, point and draw a load of Pictonary like diagrams " CreationDate="2010-07-19T15:57:12.510" UserId="399" />
  <row Id="3587" PostId="3609" Text="Yeah I think so - I was just seeing if i could do it with an Opto-isolator instead - cuz it's available locally, I'd have to get the digital potentiometer delivered - may end up ordering one anyway" CreationDate="2010-07-19T17:37:25.803" UserId="399" />
  <row Id="3588" PostId="3593" Text="Yes, that's it. You need to record the speech as a WAV file and convert it with Roman's software." CreationDate="2010-07-19T18:39:23.727" UserId="305" />
  <row Id="3589" PostId="3592" Text="yup, you've got it." CreationDate="2010-07-19T19:54:58.833" UserId="703" />
  <row Id="3590" PostId="1862" Score="2" Text="Most dry clays do not transfer heat very well, its a thermal insulator.  Not exactly what you want to cover an IC that generates heat with.  You could greatly reduce your operational temperature range or even cause thermal breakdown at room temperature.  " CreationDate="2010-07-19T20:11:05.430" UserId="703" />
  <row Id="3591" PostId="3596" Score="1" Text="hitech c I believe, whichever the free version is, and in mplab at that." CreationDate="2010-07-19T20:35:07.987" UserId="982" />
  <row Id="3592" PostId="3607" Text="You know I have heard of bit banging, but never bothered to look it up, after seeing the wiki entry, it's an interesting concept, and suspect that may be a future project for myself to improve my skills, thank you for that!!!" CreationDate="2010-07-19T20:41:20.970" UserId="982" />
  <row Id="3593" PostId="3608" Text="@reemrevnivek Thanks for the link to the Vishay chip - It looks like a good place to start - might just pick one up and do some experimenting" CreationDate="2010-07-19T21:12:11.000" UserId="399" />
  <row Id="3594" PostId="1723" Text="There is visual programming, http://www.modk.it/" CreationDate="2010-07-19T22:15:21.230" UserId="566" />
  <row Id="3595" PostId="3618" Score="1" Text="What type of IR detector - photo-transistor or photo-diode?" CreationDate="2010-07-19T23:25:50.337" UserId="305" />
  <row Id="3596" PostId="3620" Text="not for coin op but for tv remote control like projects, there are different kinds some are just the sensor and some are modules and the modules are now as small as what the sensors used to be so you may need to look at the catalog yourself to see if you can figure it out" CreationDate="2010-07-19T23:50:35.317" UserId="985" />
  <row Id="3597" PostId="3617" Text="Props for coding in assembler.  Nonetheless, I wouldn't recommend it for a beginner.  Also, if you're trying to code in assembler so your code will fit on the Arduino, then you must be developing some HUGE apps.   I use C 99% of the time, and check/tweak the bottlenecks and ISRs in assembler." CreationDate="2010-07-19T23:59:58.400" UserId="857" />
  <row Id="3598" PostId="3608" Text="Ah, analogWrite().  I think that, given how essential your PWM generation is to this project, you'll want to remove the abstraction that this uses.  You'll have much better resolution and sound quality, as well as volume adjustment, if you use the 16-bit Timer/Counter1 PWM, and write the setup and interrupts in C.  Read Chapter 15 of www.atmel.com/dyn/resources/prod_documents/doc2545.pdf, and see if you can do better than analogWrite. " CreationDate="2010-07-20T00:33:50.740" UserId="857" />
  <row Id="3599" PostId="3617" Text="No, you are right, no huge apps. It is just not as compiler friendly of an instruction set compared to others like msp430 and arm.  I think my main problem is although there is an avr gcc, it is not as trivial to build as the arm or msp430 or some others and I would rather spend time fiddling with the chip than the tools.&#xA;This is definitely not the first assembler you want to learn.  The poster was asking for a how do you do it, what are the options, so I mentioned mine since it is off the beaten path, something different than what most are going to use.&#xA;" CreationDate="2010-07-20T00:39:34.263" UserId="985" />
  <row Id="3600" PostId="3609" Text="The simplest way of reducing the volume is to reduce the amplitude of the PWM, and not add any components." CreationDate="2010-07-20T00:49:25.490" UserId="857" />
  <row Id="3603" PostId="3270" Text="I also use the CodeSourcery tools in one of my classes, with the Stellaris LM-3s6965 dev kit.   Our wiki (link to toolchain) is here: http://claymore.engineer.gvsu.edu/egr326/LM3S6965#Toolchain:_Windows_and_Linux  (See the MacOS X install instructions below as well.) The kit comes with a time-limited demo of their GUI tools, but the command line tools are not limited." CreationDate="2010-07-20T01:42:53.643" UserId="857" />
  <row Id="3604" PostId="1112" Text="There is one, the Parallax Propeller. It has eight 32-bit CPUs on the chip, and comes in DIL, QFP and QFN packages." CreationDate="2010-07-20T01:53:14.183" UserId="305" />
  <row Id="3605" PostId="1112" Score="1" Text="This is spot-on.  AVR over PIC due to licensing, and AVR over ARM due to simplicity of software and toolchain and soldering ability.  For your own projects, this may not apply.  However, if you want to develop an ARM-duino, take a look at the other, similar projects.  They don't catch on like the AVR has.  This may also be due to the Arduino dev environment." CreationDate="2010-07-20T02:19:52.767" UserId="857" />
  <row Id="3606" PostId="3624" Text="Nothing can compete with ARM right now.  &lt;- In industry.  In the hobbyist world, AVR is still really, really strong, and will be for a long time." CreationDate="2010-07-20T02:22:17.837" UserId="857" />
  <row Id="3607" PostId="1107" Score="1" Text="Who is your market?  If you're trying to sell something big in industry, then you'll want an ARM, because if Atmel goes under, you've got nothing left if you're using the AVR. With ARM, there's lots of other vendors that offer near drop-in replacements. The increased complexity of the ARM is less of an issue with good engineers than with hobbyists who don't know basics.   If you're selling to hobbyists, the learning curve will be too steep, processor power won't get used, and SMT will be an imagined brick wall.  Who are you worried about-hobbyist customers or potential employers? Pls. clarify." CreationDate="2010-07-20T02:30:11.497" UserId="857" />
  <row Id="3609" PostId="3607" Text="It may look exciting but you will very quickly add it to your repertoire and move on. I do congratulate you taking the time to do it." CreationDate="2010-07-20T02:51:38.160" UserId="230" />
  <row Id="3610" PostId="3626" Score="1" Text="How are you rolling your device - do you know you're not giving it a pitch change of 2 degrees?  The mounting error due to soldering might be that small. If you're fairly certain the mounting is good, then a more precise fixture might be the ticket.  Also, what accelerometer are you using?  Many have a function by which they can be trimmed, or have a +/- 2 degree (or worse) error bound.  " CreationDate="2010-07-20T03:11:31.557" UserId="857" />
  <row Id="3611" PostId="3574" Text="Not sure if Chiphacker is going to be your best source for this kind of question.  Most people here will be better at the electronics side of things.  However, you might still get some answers. BTW, I see that you are interested in waterproofing.  Are you developing a robotic boat or submersible?  That would be awesome." CreationDate="2010-07-20T03:15:33.610" UserId="857" />
  <row Id="3612" PostId="3624" Text="Absolutely agree one world avr is crazy popular, another world which happens to be the one where the products we buy a touch and use are, where the money is, it is something else.  So for fun at home learn one, for your day job learn the other, and and get to play all day and all night." CreationDate="2010-07-20T03:49:21.477" UserId="985" />
  <row Id="3613" PostId="3619" Text="TINA lets you vary the pot position, but I'm not sure how to plot AC signal gain as a function of pot position." CreationDate="2010-07-20T03:54:55.967" UserId="142" />
  <row Id="3614" PostId="3604" Score="1" Text="Thank you, well answered." CreationDate="2010-07-20T05:31:27.967" UserId="927" />
  <row Id="3615" PostId="3615" Text="Looks interesting, I'll have a closer look at your stuff when I get a minute." CreationDate="2010-07-20T06:55:16.910" UserId="103" />
  <row Id="3616" PostId="1112" Text="Which AVR32 tools are you using - I use IAR  on both AVR32 and MSP and have found this environment highly capable.  The cost is not an issue in a professional environment - equivalent to less than the cost of employing an engineer for a week." CreationDate="2010-07-20T08:10:12.710" UserId="400" />
  <row Id="3617" PostId="3622" Text="Wow cheers for all the comments and help, I think I get what you mean now, I've probably over thought it! I'm only interested in basic synthesis &amp; tones so I hooked it up without filtering and it sounds fine, amplitude control with the analogWrite() sounds nice and smooth too (I've increased the hardware timer to make it faster and smoother)" CreationDate="2010-07-20T09:24:50.690" UserId="399" />
  <row Id="3618" PostId="3608" Text="Thanks for the code! - I think that's what I've done?...I'll post a bit anyway " CreationDate="2010-07-20T09:34:08.500" UserId="399" />
  <row Id="3619" PostId="3609" Text="I know - I'm just already using that function for making the tones fade in and out" CreationDate="2010-07-20T09:35:44.867" UserId="399" />
  <row Id="3620" PostId="3622" Text="The only reason I'm trying to use an Opto-Isolator is because i can buy them from the local electronics shop - whereas they don't have any digital potentiometer ICs.....you've probably got a much simpler suggestion tho (I'm just not sure what to use)" CreationDate="2010-07-20T09:53:52.183" UserId="399" />
  <row Id="3621" PostId="3622" Text="Just thought - is this something i could be doing with a transistor? If I put the sound output through the transistor to the speaker, then just use PWM to stimulate the base? (have I been over thinking it?)" CreationDate="2010-07-20T09:57:58.690" UserId="399" />
  <row Id="3622" PostId="3421" Text="The watchdog timer here is mislabeled.  ARM documentation as well as Atmel and TI/Stellaris implementations of the ARM7TDMI (for starters) all refer to this interrupt as Reset, not 'Watchdog' as NXP does.  Use it like you'd use a reset interrupt.  " CreationDate="2010-07-20T12:26:44.083" UserId="857" />
  <row Id="3623" PostId="3605" Score="1" Text="Gah! Not enough rep to edit.  Could you kindly use the 'code' button (square '0101'), or insert 4 spaces before every line in your code? (Does the same thing.)  That way, we'll get pretty colors, indenting, and correct line breaks. " CreationDate="2010-07-20T12:59:55.047" UserId="857" />
  <row Id="3624" PostId="3608" Text="Basically  - Mine assumes you wanted to run at the max PWM frequency, so that you can get something closer to real talking/music. Mine also ignores the issues of setup and synchronizing the PWM frequency with the update of sound_buffer, so don't expect it to work.  Yours uses delayMicroseconds to generate a rhythmic pattern of tones." CreationDate="2010-07-20T13:04:34.767" UserId="857" />
  <row Id="3625" PostId="3615" Text="I maybe just don't know where to look all the time, but feel like compared to avr and arduino there are practically no tutorials on PIC's and I would really like to change that...." CreationDate="2010-07-20T13:20:56.680" UserId="982" />
  <row Id="3626" PostId="3605" Text="Got it! couldn't work out the code thing - got confused when i couldn't see any tags, doh!" CreationDate="2010-07-20T13:57:14.183" UserId="399" />
  <row Id="3627" PostId="3628" Score="1" Text="Nice first post, and welcome to the site.  Yes, even the highly accurate Bosch BMA180 has a cross axis sensitivity of 1.75%. So, a 90 degree change in one axis might cause a 1.57 degree readout on the others, and this may change every time you move it. An additional factor is the **alignment error** - Again, the BMA180 is only specified to be within +/- 1 degree relative to the case, but this is a constant for every physical chip and can therefore be calibrated out in software by your tester." CreationDate="2010-07-20T14:07:07.173" UserId="857" />
  <row Id="3629" PostId="1107" Score="2" Text="I am not trying to be offensive, but the question begs to be asked. Atmel is more than 25 years old, having very successful market other than ARM, AVR in itself is a very very successful platform. What are the chances of such a company going down. This sounds like saying, &quot;Don't use windows, what if MicroSoft goes down?&quot;" CreationDate="2010-07-20T14:17:40.800" UserId="1200" />
  <row Id="3630" PostId="1107" Text="I do agree with your other two points, namely that if you have a hobbyist market, the chances are rare that the full power of ARM will be utilized and SMT being a brick wall. " CreationDate="2010-07-20T14:18:52.283" UserId="1200" />
  <row Id="3631" PostId="3622" Text="got some hi freq transistors, gunna try them instead of using an opto-isolator...makes more sense, cheers 4 the help " CreationDate="2010-07-20T14:50:09.023" UserId="399" />
  <row Id="3632" PostId="3578" Text="Plus colour codes are quick to read if you've stocked by magnitude. Say you want 47k, look at the 10k-100k box/bag for something with purple (7) and once you have a few, you can check if they're what you want." CreationDate="2010-07-20T15:00:39.500" UserId="883" />
  <row Id="3633" PostId="3620" Text="I usually shop and compare between digikey and mouser in general, shipping costs are excessive from both places, but between them a good selection of products." CreationDate="2010-07-20T15:20:32.173" UserId="985" />
  <row Id="3634" PostId="3627" Text="Thank you everyone. Thanks for the link to Mouser. I always have trouble finding things at both Mouser and Digikey.  Mouser has the Largest selection between 850nm-940nm, Should the TSOP348 or something just like should detect the 850m 880, 940nm emitters? Is there an inexpensive test instrument that can show me the wavelength of an IR LED?  Thanks again&#xA;Russ" CreationDate="2010-07-20T15:25:03.723" />
  <row Id="3635" PostId="3625" Text="+1 Thanks, Its not how I remember doing it but It should do the trick. I won't mark this approved just yet I like to see if anyone has any alternatives..(although it doesn't look likely...)" CreationDate="2010-07-20T15:29:23.390" UserId="819" />
  <row Id="3636" PostId="3626" Score="1" Text="I'm using a high precision 6DOF manipulator. It gives me 0.01 degrees accuracy in all axes.&#xA;Mounting is done by pick and place. The sensor is a freescaleMMA7361LC. " CreationDate="2010-07-20T16:07:04.213" UserId="1267" />
  <row Id="3637" PostId="3628" Score="1" Text="I've collected a bunch of points at several pitches and rolls. I've plotted several lines characterizing the x-axis sensitivity and I was going to try to compensate the readouts using these compensation equations... " CreationDate="2010-07-20T16:08:31.207" UserId="1267" />
  <row Id="3638" PostId="3627" Text="If you have the time and the parts, build one yourself. For testing what kind of transmitter you have, get one of each detector, and build a circuit which measures their responses relative to each other (microammeter or something...) For a transmitter, have a circuit with a switch to select each diode, and a rheostat and ammeter to test at which point you get a satisfactory response. Lowest current here wins." CreationDate="2010-07-20T16:23:28.687" UserId="965" />
  <row Id="3639" PostId="3625" Score="1" Text="There are plenty of alternatives - You could use a transistor with a known Rds characteristic, and change the gate voltage from 0 to saturation, or just put in a voltage or current source and ramp through the voltage or current range that you want to establish across your resistor.  The varistor, however, is the controllable resistor you asked for." CreationDate="2010-07-20T16:35:30.413" UserId="857" />
  <row Id="3641" PostId="3622" Score="1" Text=" 	@Jim : You can continue to use your optoisolator - If it's like the one in your schematic, you should be able to just connect the PWM output to Pin 6 instead of Pin 1 on the 4N35 for a quick test. Also, your PWM isn't really high frequency. It's pretty quick as far as outputs from an Arduino go, but not even close in the realm of analog circuits: save your money on this one. Just make sure you're not using a MOSFET with a high gate capacitance, and you'll be fine." CreationDate="2010-07-20T16:40:47.147" UserId="857" />
  <row Id="3642" PostId="2607" Score="1" Text="I remember when Radio Shack had parts for radios. Now, all you can get is a car charger for your cell phone. Every time I go in there, a little piece of me dies..." CreationDate="2010-07-20T16:58:10.210" UserId="965" />
  <row Id="3643" PostId="2536" Score="1" Text="I used to use deoxit when I used to work on some old Army radars from the 60s. They were man-portable, and so were always getting exposed to water, mud, diesel fuel, weapon cleaning oil, and whatever else was in the area. That stuff works like magic on internal and external connectors as well as pots!" CreationDate="2010-07-20T17:02:53.677" UserId="965" />
  <row Id="3644" PostId="3627" Text="@Jesse - No, the detectors are generally too broadband for that purpose.  In addition, you can't know which side of the detectors' peak value that the frequency lies.  You do need multiple detectors, and you need to filter them.  This is packaged as a *color sensor*.  You could build your own, but it would be tedious and hard to calibrate." CreationDate="2010-07-20T17:22:55.227" UserId="857" />
  <row Id="3645" PostId="3620" Text="A little off-topic, but I don't think Digikey or Mouser have excessive shipping costs. For Digikey, most of the small orders will be $2.41 for USPS first class, you can get 1lb for $5, or 10lbs for around $10.  Mouser doesn't have USPS first class, but $7 for 1lb, and $10 for 10 lbs isn't bad.  As long as you group your order into a large project or stocking shipment, it's an insignificant percentage of your order.  You might be thinking of Amazon, which just rolls the cost of their shipping into their products and only gives it back if you get super slower shipping." CreationDate="2010-07-20T17:48:08.113" UserId="857" />
  <row Id="3648" PostId="3566" Text="@Kortuk Yes, I understand that most companies have Office \*AND\* Internet Explorer 6 available.  Don't encourage the practice.  Also, not sure what you were looking at for UML tools, more than half of the tools listed at http://en.wikipedia.org/wiki/Comparison_of_Unified_Modeling_Language_tools are free and open source." CreationDate="2010-07-20T17:58:20.880" UserId="857" />
  <row Id="3650" PostId="3625" Text="Sure.. but if my memory serves me correctly(which it probably doesn't) it is possible to do it with a regular resistor + some simulation command, which would be more intuitive and straight forward. Anyway Thanks again for the suggestions" CreationDate="2010-07-20T18:19:50.213" UserId="819" />
  <row Id="3651" PostId="608" Text="HT1632 looks pretty handy...but couldn't find a place to buy them in a quick search." CreationDate="2010-07-20T18:52:04.560" UserId="131" />
  <row Id="3653" PostId="650" Text="It can control a 32x16 array of RGB leds, but it's not cheap ($150 for the board alone, $350 for the board + LEDs + misc cables)" CreationDate="2010-07-20T18:59:44.237" UserId="131" />
  <row Id="3654" PostId="613" Text="Each can control an 8x8 matrix of single color, 64 LEDs, so you'd need 3 of them to control an RGB matrix. I didn't look into it to make sure it can actually handle a 24x8 matrix (what an RGB matrix really is), or if it would only handle 3 separate 8x8 matrixes." CreationDate="2010-07-20T19:02:25.370" UserId="131" />
  <row Id="3655" PostId="3625" Text="Use the source, Luke!  Open up the varistor model definition and subcircuit, and figure out what it does - The SPICE commands should be in there somewhere.  This document: http://ltspice.linear.com/software/scad3.pdf should help you." CreationDate="2010-07-20T19:20:37.440" UserId="857" />
  <row Id="3656" PostId="3629" Score="1" Text="I hate that magic slip and flip.  " CreationDate="2010-07-20T20:09:10.753" UserId="857" />
  <row Id="3658" PostId="3625" Text="Point taken! It came to me... what I used before was a parametric sweep" CreationDate="2010-07-20T20:22:40.540" UserId="819" />
  <row Id="3659" PostId="3637" Text="Yeah, I'd assumed his header files were fine... #define FOO (*(volatile unsigned int *)0x12345678) should be how his register defines should look, or he will have all manner of strangeness, you're absolutely right." CreationDate="2010-07-20T20:56:21.933" UserId="974" />
  <row Id="3660" PostId="3639" Text="I'm not hell bent on using an Opto Isolator, more like looking for an alternative to a digital potentiometer....The transistor is the best option for sure - thanks to everyone for the help  " CreationDate="2010-07-20T22:22:28.083" UserId="399" />
  <row Id="3661" PostId="3640" Score="1" Text="Very nice!  Just one suggestion: You'll get a lot more volume if you put D11 into a transistor as well.  Right now, you're limited to the current capability of the PWM pin, about 20mA.  You also risk damaging the Arduino.  8ohms is almost a short circuit; is your micro getting hot?  This transistor must be a PNP, because the speaker and Q1 will cause the voltage at the positive terminal of the speaker to be V+ if your transistor turns on.  Note, though, that this means that your on/off pulses will be inverted (The PNP is off when you apply V+, and on when you pull it to ground.)" CreationDate="2010-07-20T22:49:24.387" UserId="857" />
  <row Id="3662" PostId="3640" Text="No it's not hot (thankfully!) If I've got enough volume as it is - do you think I could put a resistor between D11 and the speaker to protect the Arduino?" CreationDate="2010-07-20T23:06:45.250" UserId="399" />
  <row Id="3663" PostId="3642" Text="Neat, just what I was thinking of. Thanks for making the schematics and everything available too." CreationDate="2010-07-20T23:56:19.083" UserId="131" />
  <row Id="3664" PostId="3641" Text="What country are you shipping to?" CreationDate="2010-07-21T00:39:37.607" UserId="1402" />
  <row Id="3665" PostId="3640" Score="1" Text="This is close to what I suggested...  Instead of the speaker going to the PWM, the speaker should go to +V. then use the PWM that was going to the speaker to the resistor instead.  Only one PWM needed, and that is the PWM that you control both the waveform (type of noise) and amplitude of the waveform (volume).&#xA;&#xA;What you have done is probably simpler for your software, but if you're interested in &quot;upping your game&quot; there's the method." CreationDate="2010-07-21T00:41:35.943" UserId="974" />
  <row Id="3666" PostId="3648" Score="1" Text="Meggy's a really cool device (I built my own similar project from scratch in the past, using a 8x8 RG matrix), but for this particular question, I'm looking for things that are simpler/cheaper. Things that I can buy the components in bulk, and a single set would cost maybe $5-$10. The bristlebot for example was about $4 + bring your own toothbrush" CreationDate="2010-07-21T04:33:16.550" UserId="131" />
  <row Id="3667" PostId="3649" Text="Do you have access to a PICkit 2, the currently best supported PICkit - and does it work properly?" CreationDate="2010-07-21T05:02:05.947" UserId="857" />
  <row Id="3668" PostId="3647" Text="Great answer!  Triacs and SCRs have always been something of a mystery to me.  It appears that you've gotten your answers from your experience, but do you have any good resources (Besides this answer) for learning about SCRs and triacs?  They're not listed in most textbooks I've read." CreationDate="2010-07-21T05:05:03.603" UserId="857" />
  <row Id="3669" PostId="3641" Text="USA...but most likely I will be looking at the contest of the kits, and buying the parts myself in bulk. This is for a group of 10-20 people, so I can save a lot of money doing it that way (getting parts straight from digikey, cutting out the middlemen so to speak)" CreationDate="2010-07-21T05:13:36.770" UserId="131" />
  <row Id="3670" PostId="3650" Text="nice :) - the white pumpkin is groovy!" CreationDate="2010-07-21T06:53:06.107" UserId="399" />
  <row Id="3671" PostId="3642" Text="No prob - thanks for the image resize!" CreationDate="2010-07-21T06:54:56.200" UserId="399" />
  <row Id="3672" PostId="3644" Text="I'll second the mouse bot - I made a few for my mate while I was at uni, well fun and easy to do - just don't get your light emitters and detectors mixed up!" CreationDate="2010-07-21T07:12:14.503" UserId="399" />
  <row Id="3673" PostId="1410" Text="It took me a long time to find the &quot;user manual&quot; too for NXP parts. I looked at the datasheets before and just thought they were hugely lacking in detail. " CreationDate="2010-07-21T08:50:39.187" UserId="710" />
  <row Id="3674" PostId="3650" Text="Good on you, simple and fun. Kudos." CreationDate="2010-07-21T10:09:20.710" UserId="1307" />
  <row Id="3675" PostId="3647" Text="&quot;Getting Started in Electronics&quot; by Forrest M Mims III. That was my bible growing up. Beyond that book, I'd suggest google; &quot;Triac circuits&quot; returned a few good links for learning in the first few results.&#xA;&#xA;Both Forrest M. Mims III and Robert Grossblatt were two of my favourite authors for learning electronics. If I were you I think I would see if I could grab some of their books from the local library." CreationDate="2010-07-21T12:56:55.433" UserId="974" />
  <row Id="3676" PostId="3649" Text="Nope, only the pickit 1," CreationDate="2010-07-21T13:34:59.163" UserId="982" />
  <row Id="3677" PostId="3652" Text="I guess my problem is that Microchip says I can program chip x, but mplab says I can't so I have to do a workaround, had I known that PicKit 2 was better at the time I bought this I would have bought it, but i've already sunk the $35 on this programmer when I did, I have a friend who has a PicKit 2, and I've considered just buying the parts and building one, but havn't spec'd it out yet." CreationDate="2010-07-21T13:36:48.053" UserId="982" />
  <row Id="3679" PostId="3100" Text=" 	@Kortuk - Were you going to add your things? It's been a while. I was just investigating my newly reached 1k rep here: http://sof.modos.org/tracker/seupdate/chiphacker.com/230 (230 is Kortuk, everyone else replace with your user #), and noticed that I had forgotten to select an answer because I was waiting for yours. Pingswept's answer is something I'm more than willing to accept, if you've forgotten what you were going to add. " CreationDate="2010-07-21T14:00:26.217" UserId="857" />
  <row Id="3680" PostId="3649" Text="Do you have the latest version of MPLAB?" CreationDate="2010-07-21T15:29:11.073" UserId="588" />
  <row Id="3681" PostId="3652" Text="The PICkit 1 only supports a very small number of devices, IIRC. It's not really intended as a programmer, it's more of a little evaluation kit." CreationDate="2010-07-21T15:33:53.010" UserId="305" />
  <row Id="3682" PostId="3493" Text="Up until a couple years ago, PATA/IDE drives in everybody's desktop PC were connected with 40-pin 0.1&quot; connectors." CreationDate="2010-07-21T15:45:32.150" UserId="131" />
  <row Id="3683" PostId="3649" Text="pickit 3 treats me very very well. And the program time on large files is an order of magnitude faster." CreationDate="2010-07-21T16:29:51.350" UserId="230" />
  <row Id="3684" PostId="310" Text="Olive oil burns fine with a wick, but that generally doesn't produce much bulk heat. It'll be more like a small candle." CreationDate="2010-07-21T17:12:48.890" UserId="883" />
  <row Id="3685" PostId="3652" Text="@onaclov2000 - in my experience, buying the parts and building one is almost always a net loss in any project, either in time or money, even assuming you don't make mistakes.  The only exception to that is when learning things.  If your goal is to program chips, I'd get the PICKit2 or 3." CreationDate="2010-07-21T17:27:15.070" UserId="374" />
  <row Id="3687" PostId="3653" Text="psuedo random works for dice games. I think he wants cryptographically secure." CreationDate="2010-07-21T19:19:19.370" UserId="230" />
  <row Id="3688" PostId="3656" Score="4" Text="This may not be very secure against side channel attacks as they can break in by securing control of one device, but as with all cryptography, application determines feasibility." CreationDate="2010-07-21T19:20:24.173" UserId="230" />
  <row Id="3689" PostId="3659" Text="Yea I have to use the PicKit programmer listed above, I just don't understand why mplab won't support, but it sounds like even pickit2 has the same issue." CreationDate="2010-07-21T19:29:15.950" UserId="982" />
  <row Id="3690" PostId="3649" Text="At the time it was the latest mplab, I'm not sure what it is right now, I would have to check and I'm not at home. I haven't had large files just yet so fortunately time to program isn't a biggie." CreationDate="2010-07-21T19:30:45.620" UserId="982" />
  <row Id="3691" PostId="3659" Text="Ah right.. Well, I suspect microchip are the only people who'd know that." CreationDate="2010-07-21T20:17:41.057" UserId="710" />
  <row Id="3692" PostId="310" Text="Yeah I know. It's not really enough to cook anything and combustion isn't very complete. (Soot is produced.)" CreationDate="2010-07-21T21:04:00.477" UserId="84" />
  <row Id="3693" PostId="3654" Score="1" Text="Sampling things like the analog pins is close to random, but will not have an even distribution.  Run the seed through random a couple times, however, and it will." CreationDate="2010-07-22T03:34:27.620" UserId="857" />
  <row Id="3694" PostId="3653" Score="1" Text="Can you give a hint as to the application and/or the degree of randomness that you require?  &#xA;&#xA;If it's for cryptography, there are additional considerations besides just the seed quality.  Some of the suggestions already made-- like sampling environmental inputs of various types may or may not be appropriate based on your requirements." CreationDate="2010-07-22T06:08:45.777" UserId="484" />
  <row Id="3695" PostId="3663" Text="I'm talking about something similar to this: http://www.dealextreme.com/details.dx/sku.24489" CreationDate="2010-07-22T09:13:14.123" />
  <row Id="3696" PostId="3654" Text="....through a pseudo random number generator a couple...  &lt;- How did that go missing?  NTS: Engage brain first, then fingers." CreationDate="2010-07-22T10:06:10.010" UserId="857" />
  <row Id="3697" PostId="3654" Text="Exactly - It's also not the most secure if using it for encryption / protection etc, but it will give you a nice random number for something like generative music or dice games. It's good and easy to implement too :)" CreationDate="2010-07-22T10:17:21.547" UserId="399" />
  <row Id="3698" PostId="3664" Text="You didnt really answer the question now, did you ?" CreationDate="2010-07-22T11:18:09.067" />
  <row Id="3699" PostId="3663" Text="That shield will need an enclosure to keep fingers out..." CreationDate="2010-07-22T11:34:07.147" UserId="566" />
  <row Id="3701" PostId="3664" Text="He answered it, but the answer wasn't what you wanted to hear.  He gave a link to some principles of PLC, which is an answer to your first question, and said that it's probably not reasonable for most applications, which is an answer to your second question." CreationDate="2010-07-22T13:09:16.630" UserId="857" />
  <row Id="3702" PostId="3662" Score="2" Text="I currently use the TI FET430UIF. The issue is that we have to break the code running to get data from the device. An ICE should have the ability to run normally without interruption and also dump critical values to me." CreationDate="2010-07-22T14:04:22.277" UserId="230" />
  <row Id="3703" PostId="3662" Text="If you have any information on how to set up my hardware to allow the USB FET to be more valuable would be well received though." CreationDate="2010-07-22T14:06:42.283" UserId="230" />
  <row Id="3704" PostId="3667" Text="That's for common cathodes. I have common anodes." CreationDate="2010-07-22T14:17:09.797" UserId="1363" />
  <row Id="3705" PostId="3664" Text="I think Atrigen has made it clear he wants to take the time to DIY. He also wants to do Ethernet over power-lines, there is some info here, but if the question asker feels like his question was avoided, and it reads the same to me, I think he is right. I will not downvote, a good answer, just not what he was wanting." CreationDate="2010-07-22T14:21:55.427" UserId="230" />
  <row Id="3707" PostId="3662" Text="I believe that this capability is beyond the scope of the TI debug interface built into the chip.  The problem is that this sort of debug capability has a cost in silicon and power dissipation.  As Horst Diewald said at a presentation I attended around the launch of the f5X devices, TI's overriding concern with this processor family is power consumption.  This drove the chip design and the capabilities of the on chip diagnostics used for manufacturing verification. At least you can set breakpoints while the chip is running." CreationDate="2010-07-22T14:24:23.943" UserId="400" />
  <row Id="3708" PostId="3667" Text="Ah, sorry. Thought you were looking for current sourcing IC. " CreationDate="2010-07-22T14:55:59.903" UserId="1307" />
  <row Id="3709" PostId="3661" Text="Thatis awesome, I didn't realize the SecureAVR line existed, thanks for the pointer!" CreationDate="2010-07-22T15:12:29.480" UserId="771" />
  <row Id="3710" PostId="3661" Text="BTW: If you REALLY need security, the simple, effective, and fast LCG method I presented isn't what you want: Many LCGs can be broken; just get 2-3 values in a row, and plug them into an LCG generator with a set of known constants - this would include everything on the Wikipedia page.  A matching pattern will let the attacker predict what the next number will be.  It's possible (but harder) to figure out what the constants are from nothing, as well." CreationDate="2010-07-22T15:41:15.117" UserId="857" />
  <row Id="3711" PostId="3591" Text="Can you edit your post to explain what you have successfully used to implement waveform diagrams? It isn't clear which of your above recommendations you have and have not had experience with." CreationDate="2010-07-22T15:56:38.330" UserId="906" />
  <row Id="3712" PostId="3285" Text="@Wouter - I have no idea, but I think it has something to do with magic.  I recently had to do rework on a board that had been returned from the RF lab (Where they were trying to limit the emissions from a 500MHz video transceiver).  Someone had stacked, one on top of the other, 3 (and sometimes 4) 0402 capacitors in a half dozen locations around the board.  In two spots, they had made inverted pyramids: an 0805 on an 0603 on an 0402. They had hand soldered a couple 0201 resistors, but thankfully none of those needed rework.  It was madness.  I build my boards with 0603." CreationDate="2010-07-22T16:47:06.043" UserId="857" />
  <row Id="3713" PostId="3667" Text="Thanks anyway, that looks like a cool chip." CreationDate="2010-07-22T17:04:19.250" UserId="1363" />
  <row Id="3714" PostId="3668" Text="Thank you for your explanation. I will be sure to include the row driver voltage drop in my calculations the next time I choose resistors for my LEDs!" CreationDate="2010-07-22T17:15:38.107" UserId="1363" />
  <row Id="3715" PostId="3645" Score="2" Text="Where can I get an 8,753,342,552,124,401 in one kit?  I want it!" CreationDate="2010-07-22T17:38:03.480" UserId="857" />
  <row Id="3716" PostId="3669" Text="I'm having a little bit of difficulty understanding what your circuit's doing. I can see that you're creating a tiny power supply with R1 and D2, but I'm confused as to what Q1's doing.&#xA;" CreationDate="2010-07-22T17:48:07.687" UserId="974" />
  <row Id="3717" PostId="3669" Text="Note that I need 8 of them..." CreationDate="2010-07-22T18:47:11.337" UserId="1363" />
  <row Id="3718" PostId="1562" Text="Shapelock is PCL, isn't it?" CreationDate="2010-07-22T19:47:37.463" UserId="883" />
  <row Id="3719" PostId="2955" Text="Mind you, I believe PTC's are very very slow. It might work for protecting from overload but not spikes like from shorts." CreationDate="2010-07-22T20:35:25.603" UserId="883" />
  <row Id="3720" PostId="3574" Score="1" Text="What other source is better for this kind of question?" CreationDate="2010-07-22T21:03:16.257" UserId="813" />
  <row Id="3721" PostId="3636" Text="Excellent! Thank you." CreationDate="2010-07-22T21:04:10.483" UserId="813" />
  <row Id="3722" PostId="3573" Score="1" Text="Yes, the real resolution (ENOB) is never quite as good as the marketing resolution.&#xA;However, that's true for *both* microprocessors *and* ADCs.&#xA;I hope that someday we all switch to using ENOB rather than marketing bits, kind of like most smart people have switched to using VIS (viewable image size) rather than &quot;outer diagonal&quot;." CreationDate="2010-07-22T22:21:27.270" UserId="813" />
  <row Id="3723" PostId="3669" Text="R1 pulls the gate of M1 up to V+ to turn it on.  D2 clamps the voltage here below the diode voltage so that you don't exceed your maximum Vgs.  This may not be necessary if you're using 12V and durable MOSFETS.  When the MOSFET turns on, current flows and establishes a voltage across R2.  R2 is selected such that the desired current (750mA) produces a voltage just less than Vbe at the base of Q1 - About 1.5 ohms in this case; but 750mA is a lot of current." CreationDate="2010-07-22T23:08:21.197" UserId="857" />
  <row Id="3724" PostId="3669" Text="When too little current flows, Vbe fails to cause current to flow through Q1, and the gate goes high.  When more current flows, Vbe increases, Q1 turns on, and the gate voltage is lowered.  Works like a charm, and much cheaper and smaller than an opamp measuring the voltage over a current sensing resistor.  Note that a zener at the base of Q1 would allow you to make R2 share the power dissipation with the MOSFET." CreationDate="2010-07-22T23:12:14.653" UserId="857" />
  <row Id="3725" PostId="3669" Text="@joeforker - Just replicate the circuit (with the exclusion of V1, of course) 8 times.  Nothing in that is expensive or big, except for M1.  But, (without a buck regulator) you're going to need something to dissipate some power." CreationDate="2010-07-22T23:16:34.663" UserId="857" />
  <row Id="3726" PostId="3672" Text="This reads byte 0 every time.  What evidence do you have that this byte is random? If it is, this is a great technique!" CreationDate="2010-07-23T01:19:59.927" UserId="857" />
  <row Id="3728" PostId="3644" Score="1" Text="Are you more interested in kits as in projects (Herbie), or kits as in sets of components(Lilypad, sort of)? The question sounds biased towards the project side of things. &#xA;&lt;br&gt;" CreationDate="2010-07-23T01:27:10.173" UserId="857" />
  <row Id="3729" PostId="3644" Text="I personally value flexibility (not locked into the instruction manual), expandability( minimum copper pad test points for all signals, firmware source), novelty (learn something new from it) and result usability. " CreationDate="2010-07-23T01:28:41.077" UserId="857" />
  <row Id="3730" PostId="3673" Text="I was playing with some RGB LEDs and looking for some ideas, and came across something wrong on the internet (http://imgs.xkcd.com/comics/duty_calls.png). Had to fix it. Sorry to bump an old question." CreationDate="2010-07-23T01:53:58.820" UserId="857" />
  <row Id="3731" PostId="2696" Text="@Endolith - What is your source on that image?  Energizer's alkaline appnote: data.energizer.com/PDFs/alkaline_appman.pdf has a similar curve (Theirs is time vs. voltage, rather than charge vs. voltage, see fig 12 page 10), but the drop is much more gradual.  Especially if the device is powered by a linear regulator, the drop in voltage won't affect the device too much." CreationDate="2010-07-23T02:31:45.430" UserId="857" />
  <row Id="3732" PostId="3671" Text="That is definitely the most robust way.  The other system hardly has to work: Just set a pin high on the watched system, set an interrupt on the watcher, and go into deep sleep mode.  Then, when it changes, start beeping (or whatever the signal is) every 5..10..30..60 minutes, etc. " CreationDate="2010-07-23T02:40:45.833" UserId="857" />
  <row Id="3733" PostId="3591" Text="I've used OpenOffice and Inkscape, as well as a vendor-specific simulator much like GTKWave (but useless without their hardware, I didn't think it would be helpful.)  I've used LaTeX to import images created in Inkscape, but that's because I wasn't aware of the timing packages at the time.   As I said in my post, I hadn't used Drawtiming." CreationDate="2010-07-23T02:54:28.480" UserId="857" />
  <row Id="3734" PostId="872" Text="Wouldn't the voltage drop across the resistor change depending on how many LED segments were on? (Assume for the moment that they are controlled either on or off -- no dimming.)" CreationDate="2010-07-23T07:17:50.287" UserId="965" />
  <row Id="3735" PostId="3671" Text="That wouldn't really work for me, it would inform me once it was too late to change the battery in time, not before.&#xA;&#xA;" CreationDate="2010-07-23T10:38:47.743" UserId="710" />
  <row Id="3736" PostId="3674" Text="In the end I did a few different thing. I reprogrammed the software to properly put the microcontroller in sleep mode between samples which has hugely reduce the average power consumption. The batteries I used still have a measured voltage of more than 90% of their original after about 2 months. I've set a level of about 80% to signal low battery. I think they'll still have 50% or so left, but that will give me plenty of time to change them" CreationDate="2010-07-23T10:44:07.957" UserId="710" />
  <row Id="3737" PostId="3671" Text="So you'll probably have to monitor the battery." CreationDate="2010-07-23T10:50:10.927" UserId="883" />
  <row Id="3738" PostId="1633" Score="1" Text="Re: the MAX1555, this appnote is pretty nice:&#xA;http://www.maxim-ic.com/app-notes/index.mvp/id/3241" CreationDate="2010-07-23T11:08:55.780" UserId="883" />
  <row Id="3739" PostId="3674" Text="Oh!  I didn't realize you weren't doing this already - and yes, sleep mode is a great thing." CreationDate="2010-07-23T12:34:39.170" UserId="857" />
  <row Id="3740" PostId="3644" Text="Possible duplicate of http://chiphacker.com/questions/1270/electronics-kits-any-requests - I only realized this after looking in the sidebar." CreationDate="2010-07-23T18:33:32.087" UserId="857" />
  <row Id="3741" PostId="3672" Text="This word (byte 0 &amp; 1 in fact) will be random, because at each startup I initialise the random generator with it's content. THEN I upload it with a new rand(). So the next init will look random from the current one... and so on...&#xA;But if I reset randinit to ffff (or 0000?), I will have the same randinit sequence! So it's not perfect.&#xA;&#xA;I forgot a warning about the fuse who erase the eeprom when uploading the *.hex ;)&#xA;" CreationDate="2010-07-23T19:57:41.467" UserId="824" />
  <row Id="3742" PostId="2696" Text="What do you mean by &quot;more gradual&quot;?  Their graph looks a little more steep to me." CreationDate="2010-07-23T20:54:57.600" UserId="142" />
  <row Id="3743" PostId="872" Text="Yes, And I was thinking if you would only have one on a time." CreationDate="2010-07-23T21:01:40.680" UserId="230" />
  <row Id="3744" PostId="3662" Text="Yes, I am used to using the actual chips, sometimes people make an ICE to allow you to do far more advanced debugging with one very expensive and complicated device." CreationDate="2010-07-23T21:11:57.590" UserId="230" />
  <row Id="3745" PostId="3677" Text="I do this too. I will script the generation of these&#xA;types of documents using Perl + TeX + METAPOST (or other command line tools). When the data changes I type &quot;make&quot; and the changes propagate through. &#xA;" CreationDate="2010-07-23T21:40:27.420" UserId="424" />
  <row Id="3746" PostId="3673" Text="reemrevnivek, that's a clever approach. I like it.&#xA;&#xA;This approach requires the hardware guy to pick a tiny resistor sufficient to drive the blue LED to full brightness at 100% on time, and to *trust* the software guy not to accidentally turn on the red LED PWM to 100% (which would probably overheat and destroy that red LED).&#xA;&#xA;Alas, many hardware guys that *don't* trust the software guy that much, even when the hardware guy and the software guy are the same person.&#xA;They say it's worth adding a few extra resistors to guarantee that software bugs can't damage the hardware." CreationDate="2010-07-24T00:07:57.733" UserId="813" />
  <row Id="3747" PostId="3681" Score="1" Text="If you view the input power as a signal floating on a DC bias, then a voltage regulator is acting like a filter that attenuates (as opposed to amplifying) fluctuations in the power signal. A poor man's voltage regulator is a single zener diode: http://en.wikipedia.org/wiki/Zener_diode#Uses" CreationDate="2010-07-24T06:29:59.257" UserId="721" />
  <row Id="3748" PostId="3681" Score="1" Text="@eryksun: indeed, though I was just attempting to split the difference w/o going into all the possibilities. I didn't think describing a regulator as an amplifier with zero bandwidth would help a beginner (note tag) to get oriented." CreationDate="2010-07-24T12:52:46.300" UserId="740" />
  <row Id="3749" PostId="3682" Text="Do you really need to record the ultrasound waves?  Or do you need to record the times and amplitudes of reflected pulses?  That thing apparently makes pulses at 35 MHz, which you're going to have a hard time recording..." CreationDate="2010-07-24T18:52:46.253" UserId="142" />
  <row Id="3750" PostId="1202" Text="What about pricing?" CreationDate="2010-07-24T22:43:38.337" UserId="718" />
  <row Id="3751" PostId="2455" Text="So, then, what do you do when you have to prototype some interface to a microcontroller? Fabricate a PCB for a circuit that you have no idea is correct?" CreationDate="2010-07-24T22:57:42.530" UserId="718" />
  <row Id="3752" PostId="3682" Text="Yep, i shouldve specified i want to get the reflected pulse´s information.. ideas??" CreationDate="2010-07-24T23:17:58.440" UserId="920" />
  <row Id="3753" PostId="3679" Score="2" Text="Short answer would be: Almost everything :)" CreationDate="2010-07-25T09:23:14.467" UserId="883" />
  <row Id="3754" PostId="3693" Text="In my particular case, we're talking about low-current devices/microcontrollers.  I am well within the limits of the DC adapter." CreationDate="2010-07-25T22:53:28.873" UserId="971" />
  <row Id="3755" PostId="3684" Text="Thank you for the reply! Very helpful ideas. I'll mess with it tomorrow and report back if I manage to get things solved.&#xA;&#xA;The period and duty cycle registers on the dsPIC33 are 16-bit registers, so I'm not sure the 128 thing is an issue, but it's a great catch nonetheless. I'll double-check that the values in the table are sane.&#xA;&#xA;My suspicion is that the code in the first snippet was periodically setting the period register to a value BELOW the TMR2 register, and thus it didn't generate a rising edge again until TMR2 overflowed. ~65000 cycles at 16 MHz is roughly 4 ms. We'll see :)" CreationDate="2010-07-26T00:26:29.323" />
  <row Id="3756" PostId="3669" Text="Wouldn't more MOSFET current turn Q1 on more (higher Vbe, more Ib), causing the MOSFET to essentially &quot;lock&quot; on with the gate voltage at D2's Zener voltage once the initial low signal turns it on?" CreationDate="2010-07-26T02:36:39.100" UserId="974" />
  <row Id="3757" PostId="3694" Text="Any tips on where to find a reasonably priced, quality adapter?  ie. a switched mode power supply with reliable voltage and current ratings?  If I could find one on Amazon.com, I wouldn't have ordered from SparkFun." CreationDate="2010-07-26T02:56:34.157" UserId="971" />
  <row Id="3758" PostId="3684" Text="It would be interesting to check whether the rising edge at the end of the &quot;4 ms&quot; exactly corresponds with the rising edge on the other signal. From the scope shot above, it looks like they're about 100 us apart, which is a lot of clock cycles. " CreationDate="2010-07-26T03:04:53.667" UserId="712" />
  <row Id="3759" PostId="3684" Text="By the way, just out of curiosity, why does it say &quot;Microchip Tecnology Inc.&quot; [sic] on your screenshot?" CreationDate="2010-07-26T03:05:38.393" UserId="712" />
  <row Id="3760" PostId="3684" Text="You have a keen eye! I agree, the delay between the rising debug pin edge and the restart of PWM is interesting. I wonder if it has to do with my theory that the while loop can jigger PR2 at any point in TMR2's countup and thus the next rising edge can appear at a largely random interval. I will definitely focus on it tomorrow. As for the Microchip watermark, I cross-posted my question to Microchip's forums (which so far have been less than helpful) and recycled the image here. They watermarked it and, apparently, misspelled their own name :)&#xA;&#xA;BTW I really appreciate your collaboration." CreationDate="2010-07-26T03:54:55.097" />
  <row Id="3761" PostId="3687" Text="Uhhh, Did you miss the &quot;300 ma&quot; in both the title of the post and the body?&#xA;A joule thief will do a few ma only." CreationDate="2010-07-26T07:35:20.830" UserId="1374" />
  <row Id="3762" PostId="3680" Text="Their inefficiency is directly related to the voltage drop across the regulator. Therefore, the efficiency is **entirely** a function of application, and it not something you can make a blanket statement about. I regularly use linear regulators to regulate a noisy ~6v down to 5v.  That's a efficiency of ~80%, which is as good as a switcher generally gets." CreationDate="2010-07-26T07:40:06.450" UserId="1374" />
  <row Id="3764" PostId="3675" Score="3" Text="I like the tag &quot;magic-smoke&quot; :)" CreationDate="2010-07-26T09:05:50.427" UserId="718" />
  <row Id="3766" PostId="3702" Score="2" Text="...I have always wanted to play with those little things." CreationDate="2010-07-26T12:35:16.603" UserId="319" />
  <row Id="3767" PostId="3696" Text="Safety approvals may cost a lot, but they usually get done by companies that are selling a lot. The savings of manufacturing in bulk usually is pretty close to matching the cost of getting safety approval. With this said, you should be able to buy a certified adapter for about the same cost of a non-certified." CreationDate="2010-07-26T12:43:16.650" UserId="319" />
  <row Id="3769" PostId="3680" Score="3" Text="@Fake Name: You're right that with a low-dropout regulator, you can get higher efficiency performance. But I think that when you're answering a question about the difference between a MOSFET and voltage regulator, it's reasonable to say that regulators tend to be less efficient compared to switchers, without going into the details. I'll change &quot;half&quot; to &quot;some.&quot;" CreationDate="2010-07-26T14:07:00.460" UserId="712" />
  <row Id="3771" PostId="3669" Text="@Andrew No, the MOSFET won't lock on with the gate voltage at the zener voltage, because the zener only *limits* the voltage to protect the gate; it is not a voltage source.  Stop thinking of R1 and D2 as a shunt regulator, instead think of R1 and Q1 as a Vbe-adjusted voltage divider, and the zener just as protection for the gate of M1. " CreationDate="2010-07-26T14:13:13.033" UserId="857" />
  <row Id="3775" PostId="3694" Score="1" Text="I get all of my wall warts from CUI through Digikey. Their products work well, their customer support is excellent, and their prices are decent. They're also UL certified. I've found that their switching regulated power supplies (link http://bit.ly/aKc9kZex) do really give a +/-2% regulation even at no load and continue to do so all the way to their maximum current, after which they taper off without damaging themselves." CreationDate="2010-07-26T14:44:03.673" UserId="857" />
  <row Id="3776" PostId="1468" Text="+/- 250 G's?!? What are you measuring with this thing?  The only things that I could imagine would be to mount it on a model rocket or a potato gun.  " CreationDate="2010-07-26T14:46:37.693" UserId="857" />
  <row Id="3778" PostId="194" Text="According to this matrix: &lt;www.lantronix.com/pdf/misc/Embedded-Module-Matrix.pdf&gt;, it looks like there's very little difference." CreationDate="2010-07-26T15:23:13.237" UserId="857" />
  <row Id="3780" PostId="3666" Text="It appears the &quot;magic search word&quot; I was missing is the humble buffer IC, a chip that turns a logic signal of x volts from its input into y volts at its output. They cost 15 cents. Of course a buffer that can source 1A is another thing and probably better left to a PNP + open drain." CreationDate="2010-07-26T16:42:06.510" UserId="1363" />
  <row Id="3781" PostId="3696" Text="SparkFun is a reseller. Unless they actually make the adapter themselves, they won't be the one applying for UL. Like Kallenjb says, it's cheap enough for manufacturers selling in bulk. &#xA;&#xA;Personally, I would never use unlisted adapters even if the application well within it's spec. In the off chance, you get a bad part, you can't predict how it will fail." CreationDate="2010-07-26T17:07:43.950" UserId="327" />
  <row Id="3782" PostId="3694" Text="I would be surprised if you couldn't get one in any local electronics store. &#xA;&#xA;On Amazon - http://www.amazon.com/15-Watt-9V-1-7A-Power-Adapter/dp/B002QHIVGK/ref=sr_1_1?ie=UTF8&amp;s=electronics&amp;qid=1280164973&amp;sr=8-1 . " CreationDate="2010-07-26T17:25:38.590" UserId="327" />
  <row Id="3783" PostId="3713" Text="I would agree with all of these points, and so I won't make my own answer.  However, I would add to &quot;Do I only need to match package/voltage/current&quot; that Schottky's can also vary widely in reverse leakage current (from nanoamps to milliamps!), which may or may not be important. Also, you didn't answer the &quot;PS&quot; - Those are OK prices (for singles).  However, they're all the cheaper, lower-power, lower current axial package.  TO-220 will run about a buck for singles." CreationDate="2010-07-26T18:00:23.950" UserId="857" />
  <row Id="3784" PostId="3712" Text="Embedded server and OS is a bit overkill for many applications I think. So that could be a Pro in some cases." CreationDate="2010-07-26T18:06:17.200" UserId="131" />
  <row Id="3785" PostId="3713" Text="Oh, and in your discussion of Schottky vs. fast/ultra-fast vs. Si, some rule-of-thumb times might help: Schottky - &lt;100 pS, ultra-fast 1-10nS, fast 10-100nS, Si/rectifier &gt;500nS.  " CreationDate="2010-07-26T18:09:03.237" UserId="857" />
  <row Id="3786" PostId="3717" Score="1" Text="+1 for &quot;...his software seems  like it mostly works OK, except for stuff connected to that one pin.&quot;  Been there, done that!" CreationDate="2010-07-26T18:14:05.827" UserId="857" />
  <row Id="3787" PostId="3675" Text="I assume that you mean &quot;higher than the maximum recommended voltage&quot;, which is usually Vcc + 0.7 or something like that.  0.1V higher? Absolutely nothing." CreationDate="2010-07-26T18:25:56.740" UserId="857" />
  <row Id="3788" PostId="3721" Text="Do you still have any problems? According to your final output log, everything worked correctly." CreationDate="2010-07-26T20:20:50.490" UserId="131" />
  <row Id="3789" PostId="3703" Score="1" Text="I'm also interested in how one actually uses debugwire. I keep seeing it in the manuals for my chips, but haven't had occasion to use it yet." CreationDate="2010-07-26T20:22:21.907" UserId="771" />
  <row Id="3790" PostId="3675" Text="Now that the ESD protection diodes have been explained, I think I understand the +- V recommendations in datasheets; presumably you are advised not to exceed the typical 0.6V diode drop from those diodes." CreationDate="2010-07-26T20:39:25.937" UserId="1363" />
  <row Id="3791" PostId="3720" Text="Most keyboards are USB HID devices these days so it is just a case of putting the codes you want into the keyboard input report..." CreationDate="2010-07-26T20:39:55.640" UserId="710" />
  <row Id="3792" PostId="3720" Text="Well, I say &quot;just&quot;, it requires quite a lot of knowledge and software to make it all work" CreationDate="2010-07-26T20:40:42.847" UserId="710" />
  <row Id="3793" PostId="3723" Text="Here's a good debouncing tutorial http://www.ikalogic.com/debouncing.php" CreationDate="2010-07-26T21:15:29.213" UserId="566" />
  <row Id="3794" PostId="3694" Text="Thanks for the recommendation.  I guess it just never entered my head that any adapter from a prominent retailer would lack a UL certification.  My Amazon comment was just to say that the more consumer electronics stores (online and off) make it hard to determine if you're really getting a switched mode supply, current limitations, and other specs." CreationDate="2010-07-26T22:33:49.927" UserId="971" />
  <row Id="3795" PostId="3696" Text="That's what I suspected-- I essentially have an unknown black box.  Even if it is well engineered, I'll spend the $7 for a new one with the safety approval.  At least I know now to check for approvals along with all the other specs on the supply." CreationDate="2010-07-26T22:37:12.407" UserId="971" />
  <row Id="3796" PostId="3718" Text="You are right, it really seems that avarice does support both the AVR Dragon and debugWire debugging. There is however the drawback, that to enable debugging with the debugWire, the reset pin fuse has to be change do debugWire mode, which means that ISP is no longer possible, leaving only the option of reflashing the device using high voltage programming. :/" CreationDate="2010-07-26T22:40:45.150" UserId="718" />
  <row Id="3797" PostId="3726" Score="2" Text="It's also worth noting that newer versions of avrdude have the newer chip configurations included, so check for updates there too." CreationDate="2010-07-27T00:05:11.140" UserId="554" />
  <row Id="3799" PostId="3731" Text="Differential signalling reduces the amount of interference emitted *into* other things. Balanced lines with differential inputs reduce the amount of interference picked up *from* other things. They're usually combined, but they don't necessarily have to be." CreationDate="2010-07-27T01:18:22.433" UserId="142" />
  <row Id="3800" PostId="3510" Text="Good answer and I agree completely. The basic point in working with these chemicals is to prevent long exposure to them. Wash it off if spashed on skin and perhaps an eye shower is good to have around if you are particularly worried, but I find that a tap (as mentioned in the article) works fine (although I only had to use it once and that was with the particularly dangerous chemical substance called deoderant.)" CreationDate="2010-07-27T05:28:03.857" UserId="909" />
  <row Id="3802" PostId="3719" Text="I've looked through OpenOCD User's Guide. It seems concerning boundary-scan OpenOCD has only one feature -- it can execute test vectors by playing svf/xsvf files. OpenOCD cannot monitor or control pin states interactively via boundary-scan like TopJTAG Probe does." CreationDate="2010-07-27T11:45:56.813" UserId="997" />
  <row Id="3803" PostId="3692" Score="1" Text="Thank you, zg. TopJTAG Probe seems very good to do small PCB checks." CreationDate="2010-07-27T11:49:33.523" UserId="997" />
  <row Id="3804" PostId="3739" Text="@JustJeff - part of me was thinking you could do this by placing the LED in parallel with a series RC circuit.  But that would only work if you had a non-DC input signal.  Another way in which I realized you were right was by thinking about the solarengine circuit - some transistors are required in order to get the LED to blink." CreationDate="2010-07-27T13:40:54.187" UserId="374" />
  <row Id="3805" PostId="3731" Text="Well if you are on the receiving end of a differential pair, you are doing it for the noise immunity. If you're on the transmitting end, you are usually doing it for the emissions and/or noise immunity. I guess I did not make it clear enough." CreationDate="2010-07-27T13:57:11.253" UserId="974" />
  <row Id="3806" PostId="3738" Score="1" Text="That second link looks like the simplest solution." CreationDate="2010-07-27T14:58:47.040" UserId="712" />
  <row Id="3807" PostId="3739" Text="you could make it blink with a wien-bridge or a twin-T oscillator, both only use R's and C's.  There are lots of oscillator topologies that only use R,L,C's.  Getting it to blink twice every 2 seconds would be a pain though.  May be possible with multiple oscillator circuits and some interesting feedback, but theres really no point, much more easily done with a few active components." CreationDate="2010-07-27T15:06:15.950" UserId="703" />
  <row Id="3808" PostId="3739" Text="@mark: using a DC supply, and passive elements only, at best you can get a resonant circuit. &quot;Wien did not have a means of developing electronic gain so a workable oscillator could not be realized.&quot; (Wikipedia); Regarding the twin-T, &quot;if it is connected as a negative feedback to an amplifier, and x&gt;2, the amplified becomes an oscillator.&quot; (Wikipedia)" CreationDate="2010-07-27T15:41:13.380" UserId="740" />
  <row Id="3809" PostId="3734" Score="1" Text="Is it possible to create a perpetual motion machine?" CreationDate="2010-07-27T15:46:13.220" UserId="771" />
  <row Id="3810" PostId="3735" Text="agreed, just prevent the transmitter from sending if the button is not pressed." CreationDate="2010-07-27T15:53:47.027" UserId="771" />
  <row Id="3811" PostId="3442" Text="i think a better method than pasting your code directly in your post (when you have a lot of it) is to put it somewhere else and provide a link to it. I recommend pastebin, which also provides line numbers so people can refer to them in responses." CreationDate="2010-07-27T15:55:57.797" UserId="771" />
  <row Id="3812" PostId="3742" Score="1" Text="I heartily agree, but I don't think that's what's happening. I think the IL gets translated into machine specific code when it's deployed. Here's a link that undergirds that assumption: http://www.microsoft.com/downloads/details.aspx?displaylang=en&amp;FamilyID=16fa5d31-a583-4c0d-af74-f4d5e235d5bc&#xA;&#xA;I AM pretty happy with Arduino so far...I think the only thing possibly persuading me is that I have found a pretty impressive shield selection on tinyclr.com...I haven't seen that extensive a shield selection for Arduino." CreationDate="2010-07-27T17:41:11.843" UserId="989" />
  <row Id="3813" PostId="3742" Score="1" Text="The power-to-programmer effort tradeoff is also why our desktop PCs take just as long to boot and launch programs as the computers we used 5 or 10 years ago. " CreationDate="2010-07-27T17:43:37.890" UserId="857" />
  <row Id="3815" PostId="3742" Text="@Chris - The problem is not that it doesn't run machine code, it's that it runs it through a bunch of abstractions. Abstraction, objects, generic libraries, modularity, etc. are all good in that they simplify programming, but they take time and space. " CreationDate="2010-07-27T17:46:42.180" UserId="857" />
  <row Id="3816" PostId="3741" Text="See also this question (Related to C++): http://chiphacker.com/questions/3027/is-c-suitable-for-embedded-systems" CreationDate="2010-07-27T17:49:07.497" UserId="857" />
  <row Id="3821" PostId="3724" Text="&quot;Multimedia&quot; keys are part of the standard itself, IMO. If you check http://www.computer-engineering.org/ps2keyboard/scancodes2.html you can find that all the multimedia keys have a specific scan code assigned to them. And I'm talking about how to use non-standard scan codes (the ones that are not associated with any specific key in the standard). As per my understanding there are around 150 scan codes that are not getting used.&#xA;(Continued in next comment...)" CreationDate="2010-07-27T18:04:10.923" UserId="994" />
  <row Id="3822" PostId="3724" Text="Even if we consider there are around 30 odd values that are used as commands, still there are quite a few scan codes that are &quot;undefined&quot;. I want to utilize those. Say in the range of 85h - DFh.&#xA;Can we do that?" CreationDate="2010-07-27T18:06:03.917" UserId="994" />
  <row Id="3823" PostId="3745" Score="1" Text="Either that, or ask all the questions that need to be asked here (I think/hope we're getting close), and then mark subsequent questions as duplicates, but that feels mean." CreationDate="2010-07-27T18:06:08.580" UserId="857" />
  <row Id="3824" PostId="3745" Score="1" Text="I dont think this is a duplicate of those posts.&#xA;&#xA;I am looking for specific kits, not just lists of individual components that someone can put together themselves.&#xA;&#xA;i.e. kits such as the Electronix Express kit you linked." CreationDate="2010-07-27T18:33:46.357" UserId="1009" />
  <row Id="3825" PostId="3720" Text="I'm not able to find any good article that describes how USB HID keyboard works, how exactly it communicates with host/PC, etc (the way above 2 sites describe the PS/2 protocol). If you know any site can you please give me the URL?&#xA;" CreationDate="2010-07-27T18:40:45.623" UserId="994" />
  <row Id="3826" PostId="3712" Text="I totally agree that some applications don't need the embedded server, but the asker was looking for &quot;Built-in protocol stack -- I want it to handle the WiFi protocol, along with DHCP, TCP/IP, DNS, etc, so that all I have to do is tell it what IP/port to connect to, and then handle the data myself.&quot;  This says embedded server to me, and that a bare TCP/IP stack will be lacking." CreationDate="2010-07-27T20:01:01.287" UserId="857" />
  <row Id="3827" PostId="3747" Text="There's little point in buying them if each bag isn't individually labeled though.  &gt;:(" CreationDate="2010-07-27T20:39:38.170" UserId="142" />
  <row Id="3829" PostId="3742" Text="Yeah, but I think the abstraction layers exist only (or at least mostly only) on the development machine.&#xA;&#xA;But of course, this is just the kind of information I need." CreationDate="2010-07-27T21:57:23.740" UserId="989" />
  <row Id="3831" PostId="3740" Text="This should work. The zener would not be carrying current all the time because the cap will discharge below the zener breakdown voltage every once in a while. Another resistor in series with the zener and the LED might be helpful, though, because otherwise, a very exact calculation of the timing will be neccessary in order not to blow the LED or zener." CreationDate="2010-07-27T22:19:51.037" UserId="930" />
  <row Id="3832" PostId="3737" Text="a transistor is normally not considered a passive." CreationDate="2010-07-27T22:57:07.670" UserId="230" />
  <row Id="3833" PostId="3751" Text="Cool - thanks for the PDF....I'm having a good read through it now, it looks real extensive!&#xA;&#xA;I've been using the ASD1298 by Texas instruments (has 8 instrument amps) it looks like the best candidate for my project. &#xA;&#xA;Just so busy with other projects right now! Will have to get cracking with the EEG soon.&#xA;&#xA;Thanks for the info and help :) &#xA;" CreationDate="2010-07-28T11:24:03.723" UserId="399" />
  <row Id="3835" PostId="3745" Text="Oh, I should add that they also sell individual resistor/capacitor/inductor/potentiometer kits on the same site." CreationDate="2010-07-28T12:22:02.900" UserId="857" />
  <row Id="3836" PostId="3753" Score="1" Text="That system uses the .NET Micro framework.  It is precisely the kind of system that Chris was looking for opinions on." CreationDate="2010-07-28T12:34:42.323" UserId="857" />
  <row Id="3837" PostId="3755" Text="This is probably the best answer by far to the original question: A vendor neutral netlist format.  Sadly, though, it's poorly supported." CreationDate="2010-07-28T13:01:12.443" UserId="857" />
  <row Id="3838" PostId="3747" Text="To be fair, most of the ones on eBay that I've seen are labeled.  I just bought a boatload of SMD caps/resistors on eBay and they all came labeled." CreationDate="2010-07-28T13:01:26.757" UserId="836" />
  <row Id="3839" PostId="1674" Score="2" Text="While this thread is bumped, I'll mention gnetlist as a command-line utility to translate between about 30 different netlist formats." CreationDate="2010-07-28T13:02:22.553" UserId="857" />
  <row Id="3840" PostId="3747" Text="@endolith: In my above two links, the first one specifically says &quot;Individually packed and labeled&quot;, and the second doesn't specifically say it, but the pictures show a bunch of separate little baggies with values written on them. " CreationDate="2010-07-28T16:18:06.413" UserId="131" />
  <row Id="3841" PostId="3754" Text="I believe that starter kit is exactly the same as Sparkfun's &quot;Inventor kit&quot;, just that this distributor is for the UK." CreationDate="2010-07-28T16:19:42.447" UserId="131" />
  <row Id="3842" PostId="3720" Text="@Vivek: There probably wont be a site describing only USB HID, you need to understand USB itself, of which HID is a subset." CreationDate="2010-07-28T16:21:38.077" UserId="131" />
  <row Id="3843" PostId="3742" Score="2" Text="@Chris - The abstractions are propagated all the way down to the machine code.  In the end, the machine performs operations on addresses: Load, store, add, conditional branch, etc. Assembly is a one-to-one translation of machine code, and C maps comparatively closely to it. However, higher-level languages have a lot of work to do, because there's no, say, try/catch instruction in any processor's instruction set.  The machine code required to implement an exception handler is not trivial.  " CreationDate="2010-07-28T18:08:50.213" UserId="857" />
  <row Id="3845" PostId="3760" Score="2" Text="6-layer PCB - nothing fancy!" CreationDate="2010-07-28T21:19:18.273" UserId="566" />
  <row Id="3846" PostId="3761" Text="Don't bother with APCircuits for anything other than 2-layer; they farm out their multilayer stuff to various US houses." CreationDate="2010-07-28T23:12:24.767" UserId="974" />
  <row Id="3847" PostId="3766" Text="Thanks for your reply. I'm really clueless in this realm and I'm just trying to figure out how things go together before buying parts to tinker with. Does the ESC provide power to the motor or do both the ESC and the motor have independent connections to the LiPo? Will it be feasible to send instructions to the Arduino via XBee point-to-point, then have the Arduino relay the instructions to the ESC? I've heard mention of ESC calibration via RC radios like Spektrum DX7, is this required, or can I sufficiently control the ESC with XBee and Arduino? Thanks again!" CreationDate="2010-07-28T23:31:23.967" UserId="1016" />
  <row Id="3848" PostId="3768" Text="Thanks Joby. How would I calibrate the ESC?" CreationDate="2010-07-28T23:33:21.760" UserId="1016" />
  <row Id="3849" PostId="3766" Text="The battery feeds power to the ESC, which slices it into something resembling 3-phase AC for the motor. I.e., all the power for the motor comes through the ESC. Re control, as Joby Taffey points out, there's an existing Arduino library for servo control. Once you get the speed parameter into the Arduino, it should be a snap to control the ESC." CreationDate="2010-07-28T23:39:09.143" UserId="740" />
  <row Id="3850" PostId="3766" Text="Cool, thanks Jeff." CreationDate="2010-07-28T23:40:22.263" UserId="1016" />
  <row Id="3851" PostId="3767" Text="Could you elaborate a little more on this trick? It sounds good." CreationDate="2010-07-29T00:44:06.957" UserId="712" />
  <row Id="3852" PostId="3767" Text="You have a single 4x3 board, for example. Instead of ordering two of these boards, you use panelization software (I prefer the Python script called gerbmerge) to make a panel of these boards. Board houses do this anyway, and my experience is that making a 3x4 board is only marginally cheaper than making a 10x14 panel of the same boards.  (in my case it cost me $100 more to get 4x the boards out of my last order). When I do this also order the boards tab-routed so they're easy to cut apart." CreationDate="2010-07-29T01:34:33.087" UserId="974" />
  <row Id="3853" PostId="3725" Text="Sounds like a plausible analysis to me. Well done, sir!" CreationDate="2010-07-29T03:37:45.457" UserId="712" />
  <row Id="3854" PostId="3760" Text="I thought the same thing, but have been helping a lot of professors get board orders in recently, so I think I could almost quote what specs he means." CreationDate="2010-07-29T05:08:16.480" UserId="230" />
  <row Id="3855" PostId="3771" Score="1" Text="We normally see eye to eye kellenjb, but on this I will have to side with jason. Every answer I have seem him make is very sound quality EE advice. I have a feeling he needs 6 for a nice layout, and 4 is just cutting by." CreationDate="2010-07-29T05:10:59.450" UserId="230" />
  <row Id="3856" PostId="3743" Score="4" Text="I disagree that knowledge of assembler and C are essential. It is critical to **understand how microcontrollers work**. Learning assembler (c, less so) is certainly one route to this understanding, but its not the only one. " CreationDate="2010-07-29T07:11:34.967" UserId="1374" />
  <row Id="3857" PostId="3755" Text="And of course, no one uses it.&#xA;Welcome to the world of High-priced EDA packages..." CreationDate="2010-07-29T07:19:12.013" UserId="1374" />
  <row Id="3858" PostId="933" Text="@endolith - It's expensive" CreationDate="2010-07-29T07:20:21.157" UserId="1374" />
  <row Id="3859" PostId="1034" Text="@Jim - Sounds like you're in a bit over your head.&#xA;An ADC is typically connected to, and largely run by, a separate MCU. They don't work by themselves. Everything is in the datasheet.&#xA;There's no need to use such a tiny ADC either, something with differential inputs will give you much better noise rejection." CreationDate="2010-07-29T07:23:22.387" UserId="1374" />
  <row Id="3860" PostId="936" Text="There is a reason they only put one instrumentation amp in a package.&#xA;The electrical layout is much better with a single amp per package, and there is no interaction between the channels." CreationDate="2010-07-29T07:26:04.320" UserId="1374" />
  <row Id="3861" PostId="3770" Text="It's definitely analogue. I'm hoping to reuse it in a prototype to save some money. I'll see if I can power up the board and measure the output." CreationDate="2010-07-29T09:27:03.967" UserId="566" />
  <row Id="3862" PostId="3754" Text="Yeah - it's the same kit, it's originally by .:oomlout:. but you can buy them from Sparkfun, Solarbotics, Adafruit and floris. Was using one last weekend at a Howduino event.....they're a fantastic buy. " CreationDate="2010-07-29T10:34:52.920" UserId="399" />
  <row Id="3863" PostId="3743" Score="3" Text="@Fake Name: Sure, that's why I said &quot;at least some of each.&quot;  Following a simple program from C to assembly to hex, and understanding each step, will make you a far better programmer.  You can later let the magic do its thing if you want to, but you need to understand the capabilities of the machine you're working with." CreationDate="2010-07-29T12:13:38.587" UserId="857" />
  <row Id="3864" PostId="3770" Score="2" Text="@Joby: Most of the STMicro gyroscopes can be had for under $10.  Save yourself the time and effort, and just buy a new one. IMO, prototypes should be as similar to the final product as possible." CreationDate="2010-07-29T12:53:36.947" UserId="857" />
  <row Id="3865" PostId="3767" Text="&quot;You'll still be paying $700 but at least you'll have a lower per-board cost.&quot; The board houses already do that to some degree; the difference in total cost between 5 boards and 10 boards might be only $50-$100." CreationDate="2010-07-29T13:16:42.123" UserId="330" />
  <row Id="3866" PostId="3767" Text="I've found that by panelizing myself I save the most money. I also tend to try and queue up two or three designs at once, panelize them together and get multiple separate designs in one PCB order." CreationDate="2010-07-29T13:52:55.337" UserId="974" />
  <row Id="3867" PostId="3771" Score="1" Text="going to 6 layers to make routing easier isn't going to do much for your signal integrity. Going to 6 layers because a 4-layer routing cuts up your power planes and makes them ineffective as supply planes is something quite different." CreationDate="2010-07-29T13:54:11.500" UserId="974" />
  <row Id="3868" PostId="3778" Text="I have the same TuxGraphics programmer.&#xA;" CreationDate="2010-07-29T15:15:56.103" UserId="1020" />
  <row Id="3869" PostId="3777" Text="Arrow appears to be out of stock at the moment." CreationDate="2010-07-29T15:22:05.947" UserId="857" />
  <row Id="3871" PostId="3776" Text="Do you want the debugging functionality of the JTAGICE?  *That's* the source of your price difference, not the Atmel vs. clone question.  Also, the Olimex part you linked to is a clone of the programmer parts of the STK500, not the ICE." CreationDate="2010-07-29T15:26:26.030" UserId="857" />
  <row Id="3872" PostId="3776" Text="No I don't want the debugging functionality of JTAGICE. But if I purchase the Raven evaluation set I just want to know that I will be able to compile and load the binaries onto the modules (preferably using Linux)." CreationDate="2010-07-29T18:08:50.303" UserId="1020" />
  <row Id="3873" PostId="3778" Text="Is there a way to use the TuxGraphic programmer (6 pins) without changing the Raven board? Is there a pin adapter that will work? How about the other Raven boards apart from JackDaw?" CreationDate="2010-07-29T18:20:08.177" UserId="1020" />
  <row Id="3875" PostId="3778" Text="I only have the USB board, for that - there's no other way, the ISP pins aren't brought out" CreationDate="2010-07-29T18:44:38.550" UserId="566" />
  <row Id="3876" PostId="3385" Text="Very good blog! Congratulations! One up vote." CreationDate="2010-07-29T20:52:16.927" UserId="938" />
  <row Id="3877" PostId="3767" Score="1" Text="This works, unless your board house doesn't allow panelized boards, or charges extra for it (I'm looking at you, 4PCB)." CreationDate="2010-07-30T00:28:17.443" UserId="1374" />
  <row Id="3878" PostId="3779" Text="Ugh. KNJN. That place lost my respect after they refused to give out the schematic for their dev boards, so I could modify the one I bought. It's a dev board, you kind of need the schematic." CreationDate="2010-07-30T00:34:19.633" UserId="1374" />
  <row Id="3879" PostId="3781" Score="1" Text="+1 for &quot;not particularly savvy about copyright law.&quot; Ugh." CreationDate="2010-07-30T01:24:12.963" UserId="857" />
  <row Id="3880" PostId="3781" Score="2" Text="I have seen many reference designs, even reference firmware, that notes you only have rights to use it if your use their chipset." CreationDate="2010-07-30T01:46:54.853" UserId="230" />
  <row Id="3881" PostId="3771" Text="I actually didn't take into consideration who was asking the question. I based my answer off of past experience with evaluating other people's layouts." CreationDate="2010-07-30T01:48:27.613" UserId="319" />
  <row Id="3882" PostId="3781" Text="@Kortuk: A good point-- I wouldn't be so cavalier in ignoring copyright law if you were using a competitor's chipset. That seems like a straightforward violation that would be hard to defend (assuming we're talking about reusing the PCB layout, not just the schematic)." CreationDate="2010-07-30T02:58:56.053" UserId="712" />
  <row Id="3883" PostId="3725" Text="Just a few more quick notes on this: first, it's not necessary keep and test the flag that indicates that the target frequency has changed within the ISR; PR2 and the duty cycle register can be unconditionally modified.  This could save a few cycles in some circumstances.&#xA;&#xA;Second, you get more accurate initial frequency and duty generation if the line that turns PWM on is placed as close as possible to the line that enables timer 2.  The further apart they are, the more time elapses with the PWM pin held high before the timer starts counting towards the compare values." CreationDate="2010-07-30T03:19:02.893" />
  <row Id="3884" PostId="3779" Text="Yea, I'm not really that thrilled with the board overall..." CreationDate="2010-07-30T12:37:31.920" UserId="876" />
  <row Id="3888" PostId="3783" Score="1" Text="So basically you want to detect a liquid, and know exactly which object is wet with an Arduino placed in a dry location 4-8 inches away?" CreationDate="2010-07-30T13:54:55.473" UserId="1363" />
  <row Id="3891" PostId="3782" Text="Good answer.  To sum it up a different way: Eval designs are rarely copyable because your design will usually have many additional components that impose many more layout constraints than the eval board designer had to deal with.  Even the schematic tends to change, especially in regards to choosing number and size of decoupling caps based on PCB power/ground layout and needed total capacitance on the power signals to reduce EMI emissions. " CreationDate="2010-07-30T15:10:55.217" UserId="703" />
  <row Id="3892" PostId="3767" Score="1" Text="Board houses that try to play dirty poker by saying my panel is &quot;not a board&quot; or that it's several boards don't get my business, plain and simple.  I am asking them for some square footage of FR4 with copper layers, silkscreen and holes. Nothing more.&#xA;&#xA;(well electrical test and so on is good too, but the point is that if they want to charge by the board instead of by the panel, they should make it clear. I won't be doing business with them if they do, however.)" CreationDate="2010-07-30T16:37:29.117" UserId="974" />
  <row Id="3893" PostId="3782" Text="For a lot of circuits, the layout is critical, and I think it's best to start with their circuit and layout, and then modify it as minimally as possible to get the functionality you need." CreationDate="2010-07-30T16:46:56.980" UserId="142" />
  <row Id="3894" PostId="3784" Text="Do you have forced air?  Without it, this is only feasible with a finned extrusion, unless you want to have a hot plate with dimensions in feet. " CreationDate="2010-07-30T17:29:06.947" UserId="857" />
  <row Id="3895" PostId="3794" Text="Well done, sir!" CreationDate="2010-07-30T19:48:20.097" UserId="712" />
  <row Id="3897" PostId="3781" Text=" 	@Kortuk - Microchip's excellent MRF24J40 wireless transciever and ENC28J60 Ethernet controller are perfect examples of the problem. Huge header files - Just the addresses from the datasheet - with the restriction: *Microchip grants to You a ... license to ... use the Software, for the sole and limited purpose of integrating the Software into ... Microchip microcontroller products.* Header files that can only be used with Microchip products? All of the contents are copied from the datasheet! " CreationDate="2010-07-30T20:27:25.073" UserId="857" />
  <row Id="3898" PostId="3783" Score="1" Text="I've always liked the idea of passive, unpowered sensors.  Tangents: http://micah.navi.cx/2008/09/using-an-avr-as-an-rfid-tag/ (could be used for more complex responses than just on and off) http://www.spybusters.com/Great_Seal_Bug.html (unpowered passive wireless microphone)" CreationDate="2010-07-30T21:22:04.493" UserId="142" />
  <row Id="3899" PostId="3781" Score="3" Text="I've spoken with Microchip employees at ESC, and they said the company makes all its money on selling large quantities of its ICs, so  they really don't care about making a profit on dev boards or programmers. That's why they will replace a broken programmer even if you damaged it.  So I imagine the same concept applies to their designs, as long as you're going to use their ICs and not trying to compete with them." CreationDate="2010-07-30T22:55:52.607" UserId="222" />
  <row Id="3900" PostId="3783" Text="@joeforker basically yes. I'm not worried about &quot;which object&quot; is wet as compared to &quot;oh, this thing is wet now. time to clean up the spill.&quot; I want to do it in a cheap/disposable way which isn't bulky (eg, detecting moisture or sweat in clothing), thus my interest in RFID tags as opposed to a perfboard-type thing." CreationDate="2010-07-31T03:11:47.813" UserId="1021" />
  <row Id="3901" PostId="3781" Score="1" Text="Wait, if you're using a competitors part, wouldn't you use the competitors reference design? It not like these things are generic (well, 95% of the time)." CreationDate="2010-07-31T05:12:30.750" UserId="1374" />
  <row Id="3902" PostId="3803" Text="And you can buy those where?" CreationDate="2010-07-31T09:16:04.613" UserId="339" />
  <row Id="3903" PostId="3793" Text="Thanks for the great lengths you went to in your reply reemrevnivek, and for all the links. Appreciated. My project is a bicycle-mounted GPS logger/tracker that I could recharge in the sun each day between commutes. So I'm still looking for a shield that manages rechargeable cells and a charging method. I'll check out all your links. Thanks again." CreationDate="2010-07-31T10:12:41.913" />
  <row Id="3904" PostId="3803" Text="There you go. Added links." CreationDate="2010-07-31T11:15:53.387" UserId="1374" />
  <row Id="3905" PostId="3797" Text="How big &amp; how many? If you just want one or two small ones, you could cannibalize an old GameBoy Advance. " CreationDate="2010-07-31T12:17:45.797" UserId="259" />
  <row Id="3906" PostId="3801" Text="Yeah, if at anytime I plug the arduino back into the USB and power the board through USB, the motor spins both ways again. This leads me to believe that the transistors on the H-Bridge are fine. I will check the circuit for the other things you mentioned and update the post with my findings. " CreationDate="2010-07-31T13:34:40.830" UserId="619" />
  <row Id="3907" PostId="3806" Text="I wondered about supply sag too, but he didn't say the arduino freaked out, just that the motor didn't turn. It wouldn't be surprising, though, for that kind of motor to take more current to get started one direction than another." CreationDate="2010-07-31T15:49:06.377" UserId="740" />
  <row Id="3908" PostId="3799" Text="The [Stellaris dev kits](http://dkc1.digikey.com/us/en/ph/Luminary/kits.html) use grayscale OLEDs from [Ritek Display](http://www.ritdisplay.com/in_English/index_English.asp), and have driver source code available.  The complete LM3s6965 dev kit is available for less than $70." CreationDate="2010-07-31T16:17:49.600" UserId="857" />
  <row Id="3909" PostId="3799" Text="Blech.  Forgot that some comment markdown isn't available on SE 1.0 sites.  When do we go to 2.0?" CreationDate="2010-07-31T16:18:49.240" UserId="857" />
  <row Id="3910" PostId="3802" Text="Many of the standard character LCDs which lack backlights are reflective.  Newhaven Display also sells a number of reflective modules, just search for 'reflective'.  (As well as their more popular transflective and transmissive modules, see here: http://www.newhavendisplay.com/app_notes/LCD_Variations.pdf for a comparison.)" CreationDate="2010-07-31T16:25:16.970" UserId="857" />
  <row Id="3911" PostId="3801" Text="As Pingswept observed, little hobby motors like those sometimes take more current in one direction than the other. You could try setting it for the direction that doesn't work, and manually give the motor a tweak to see if it starts. If it does start, it's probably a current delivery situation." CreationDate="2010-07-31T16:36:40.090" UserId="740" />
  <row Id="3912" PostId="3793" Text="Sounds like an awesome project!  I'd recommend contacting your Linear Tech local sales office: http://www.linear.com/contact/  They've been really helpful to me in the past. Also, be warned that GPS units and active antennas can really suck down some current." CreationDate="2010-07-31T16:41:14.177" UserId="857" />
  <row Id="3913" PostId="3796" Text="o_O  - An MSP430 dev kit with wireless, LCD, accelerometer, pressure, temperature, and battery voltage sensor that's ALSO a waterproof watch for $50!!!?!  Why did no one tell me about this?  BUY BUY BUY: http://search.digikey.com/scripts/dksearch/dksus.dll?Detail?name=296-25344-ND" CreationDate="2010-07-31T16:47:11.400" UserId="857" />
  <row Id="3914" PostId="3797" Text="Yes, more details please. Do you require color, or is monochrome ok? What resolution? size? etc" CreationDate="2010-07-31T16:55:11.597" UserId="131" />
  <row Id="3915" PostId="3794" Text="Thank you very much!" CreationDate="2010-07-31T17:14:11.183" UserId="876" />
  <row Id="3916" PostId="3811" Score="1" Text="The solder and soldering iron should be applied to the joint simultaneously." CreationDate="2010-07-31T20:07:56.137" UserId="305" />
  <row Id="3917" PostId="3811" Score="1" Text="@Leon - That's one way of doing it, but this method also works, especially now with better solder compositions.  This method is, in my experience, superior for working on small stuff with thick solder, when you want to precisely control the amount of solder applied." CreationDate="2010-07-31T20:24:42.983" UserId="857" />
  <row Id="3918" PostId="3811" Text="@Hugo - I didn't think this would be a problem, given that the board in question was a protoboard.  If the problem was soldering to a ground or power plane, that would be different. " CreationDate="2010-07-31T20:26:32.650" UserId="857" />
  <row Id="3919" PostId="3811" Text="The flux will burn off, and a dry joint is likely to result." CreationDate="2010-07-31T20:26:45.133" UserId="305" />
  <row Id="3920" PostId="3812" Text="Two points - heat sensitivity is largely dependent on the type of part.  SMD LEDs in particular should not be heated up too much. I'd agree that the parts which traditionally go in sockets won't be damaged.  I disagree that the finger method is a good idea because your finger will get burned, and 'too hot for your finger' is much, much less than too hot for most any chip.  " CreationDate="2010-07-31T20:31:32.727" UserId="857" />
  <row Id="3921" PostId="3801" Text="See update #1 and #2 of my question. I hope this is what you mean by making separate runs. " CreationDate="2010-07-31T21:50:44.197" UserId="619" />
  <row Id="3922" PostId="3811" Text="The flux will burn off the blob if you leave it too long, but that doesn't really matter. You're only using the blob to get good heat transfer to the part. You then add *more* solder, which contains the flux." CreationDate="2010-07-31T22:05:18.100" UserId="1024" />
  <row Id="3923" PostId="3805" Text="Two questions: What are the characteristics of a Proxxon soldering bolt (Wattage, temperature control, tip - I've never heard of the brand before and Google isn't giving me much), and precisely what kind of solder are you using (Tin/lead ratio, lead free, no-clean, flux concentration and activation level)?" CreationDate="2010-07-31T22:10:30.163" UserId="857" />
  <row Id="3924" PostId="3811" Text="@Leon - not if there's flux on the board!" CreationDate="2010-07-31T22:11:11.060" UserId="857" />
  <row Id="3925" PostId="3439" Text="&gt; Discrete logic is still faster than most microcontrollers.&#xA;Unless you're using a Cypress PSoC3." CreationDate="2010-07-31T22:16:45.817" UserId="1024" />
  <row Id="3926" PostId="3248" Score="2" Text="first guide is fine as far as how you physically go about it but the &quot;flood and suck&quot; method, well, sucks.  just use some flux and you don't need to suck at all.  In fact the major point missing in that article is that flux is your friend.  Get some no-clean flux pens and you can solder pretty much anything with exposed pads very quickly with almost any sized tip." CreationDate="2010-07-31T23:02:06.183" UserId="703" />
  <row Id="3927" PostId="3812" Text="meh you build up a resistance after you burn your finger a few times and have a nice build up of excess skin." CreationDate="2010-07-31T23:03:47.420" UserId="703" />
  <row Id="3929" PostId="3813" Text="Neat, but I have to say I'm more impressed with the LaTeX datasheets.  Where did you get that class (or did you roll your own)?  About the board, I do like the Altoids form factor, and the inclusion of the ADC.  Most boards seem to assume that the onboard (Slow, low resolution) ADC of the mico will be sufficient.  " CreationDate="2010-08-01T00:52:22.717" UserId="857" />
  <row Id="3930" PostId="3813" Text="Oh, and you might want to add your Li-Ion charger (http://wiblocks.luciani.org/not-quite-ready/LI-ION-index.html) to this question: http://chiphacker.com/questions/3785/arduino-battery-shield about an Arduino battery shield." CreationDate="2010-08-01T00:53:25.617" UserId="857" />
  <row Id="3931" PostId="3813" Text="I use my own LaTeX macros for the style. I use METAPOST for some of the diagrams and pdfinclude to embed the shematics, datasheets, etc. The BOMs are done using Postgres.&#xA;&#xA;The chip I added is a 12bit DAC not an ADC. Future boards will add&#xA;higher resolution ADCs. &#xA;&#xA;I was thinking of adding the li-ion charger to that question but it seemed like that user was looking for an arduino shield." CreationDate="2010-08-01T01:37:28.707" UserId="424" />
  <row Id="3932" PostId="3811" Text="I have tried both solder on the iron 1st and also the what i call normal way of iron to joint add solder wait for join to heat then apply normal amount. I will have to get some flux. As I have used this iron a lot in the past and the solder i am using has been good in the past as well its 0.8 mm diameter 60% mix" CreationDate="2010-08-01T03:12:58.140" UserId="665" />
  <row Id="3933" PostId="3806" Text="This was exactly the case, from my measurements the difference was 10mA. " CreationDate="2010-08-01T03:13:18.333" UserId="619" />
  <row Id="3934" PostId="3805" Text="60% mix 0.8 mm solder the bolt i can't remember the spec's of it EL12 proxxon at 310C heat, has been good in the past think it is time for an upgrade though. I have a flat chisel type tip on it" CreationDate="2010-08-01T03:15:36.627" UserId="665" />
  <row Id="3935" PostId="3808" Text="I will get some flux i have been meaning to add it to my kit for a long time now, but no good electronic shops around me in Melbourne closet that would even sell flux is Jaycar and i am not a fan" CreationDate="2010-08-01T03:17:10.720" UserId="665" />
  <row Id="3936" PostId="3817" Text="Those look great. It doesn't look like they make UV LEDs, but for blue and green, they look perfect. Thanks, John." CreationDate="2010-08-01T03:56:03.253" UserId="712" />
  <row Id="3937" PostId="3819" Text="If one of your supplies is the USB cable from your computer, then it is referenced to ground." CreationDate="2010-08-01T04:07:41.550" UserId="857" />
  <row Id="3938" PostId="3819" Text="@reemrevnivek- If your computer supplying the USB cable happens to be a laptop, perhaps not so much." CreationDate="2010-08-01T04:22:51.820" UserId="740" />
  <row Id="3939" PostId="3819" Score="1" Text="@JustJeff: True, but then it's floating, so it's OK to connect." CreationDate="2010-08-01T04:32:26.043" UserId="712" />
  <row Id="3940" PostId="3808" Text="Sorry, I'm from the USA (It's 3:30am...), and I'm not familiar with Australian electronics shops, so I can't recommend anything.  However, littlebirdceo and mad_z, the site admins, are both from Sydney and have an online electronics store which sells flux pens!  (I know that's not real close to Melbourne)" CreationDate="2010-08-01T07:36:25.573" UserId="857" />
  <row Id="3941" PostId="3805" Text="Googled it....looks like that won't be a problem.  I didn't know what &quot;soldering bolt&quot; meant, and was concerned that you were using some 25W non-temp controlled firestick." CreationDate="2010-08-01T07:37:55.520" UserId="857" />
  <row Id="3942" PostId="3244" Score="1" Text="Solder faster... Seriously." CreationDate="2010-08-01T08:18:21.300" UserId="1374" />
  <row Id="3943" PostId="3795" Text="I'd like to point out that, while my answer is arguably the better solution *to the problem*, jluciani's answer, which calculates Rsa (Thermal resistance, sink-to-ambient) to be 1.05, and links to a source which supplies finned sinks with various thermal resistances, is arguably the better answer *to the question.*" CreationDate="2010-08-01T16:46:46.917" UserId="857" />
  <row Id="3945" PostId="3798" Text="The button is 0x10, 0x20, 0x30 added to the status byte in the reply. IIRC 0xff is &quot;no data&quot;, 0x00 is no response and 0x01 is valid data.&#xA;&#xA;The leaping sounds like you were treating the readings as unsigned." CreationDate="2010-08-01T20:03:54.463" UserId="883" />
  <row Id="3946" PostId="3796" Text="They seem to be available again. Or were. The demand greatly exceeds the supply. Surely you've also seen the Launchpad?" CreationDate="2010-08-01T20:04:43.830" UserId="883" />
  <row Id="3947" PostId="3796" Text="Also, the waterproof part is a flat out lie." CreationDate="2010-08-01T20:28:21.593" UserId="883" />
  <row Id="3948" PostId="3796" Text="@XTL - Yup, they're in at Digikey, Mouser, Newark, and Farnell; they filled the backstock on 7/30. Yes, I've seen the launchpad.  Concerning the waterproof part, according to the user manual, it's meant to resist occasional splashes or rain - Pressing the buttons when wet, or submerging it will damage it.  I hope you didn't learn this by experience!" CreationDate="2010-08-01T21:07:51.437" UserId="857" />
  <row Id="3949" PostId="3798" Text="A causa materialis for negative (&quot;substracted from 255&quot;) values would also be the deceleration if you go from motion to rest (again)." CreationDate="2010-08-02T07:36:53.177" UserId="883" />
  <row Id="3950" PostId="3825" Text="Actually, Openchronos may be an even easier way to see some of the source:&#xA;&#xA;http://github.com/poelzi/OpenChronos/blob/master/driver/vti_as.c&#xA;" CreationDate="2010-08-02T08:28:59.657" UserId="883" />
  <row Id="3951" PostId="3825" Text="http://github.com/poelzi/OpenChronos/blob/master/logic/acceleration.c" CreationDate="2010-08-02T08:31:34.473" UserId="883" />
  <row Id="3952" PostId="3820" Text="It's only cheaper if you don't already have an STK500 :-) Will probably pick up a Dragon though. Thanks." CreationDate="2010-08-02T11:45:07.347" UserId="1363" />
  <row Id="3953" PostId="3820" Text="I've got an STK500 and a Dragon. 8-)" CreationDate="2010-08-02T11:58:31.667" UserId="305" />
  <row Id="3954" PostId="3827" Text="Neat! As far as I can tell, it takes DVI-D or VGA video as an input (over a mini-HDMI cable?), so many systems should work with it." CreationDate="2010-08-02T14:21:15.620" UserId="857" />
  <row Id="3955" PostId="3822" Text="I think the LZ1-00xx05 series is the winner. The webcam suggestion is a good one too. Thanks." CreationDate="2010-08-02T14:34:35.370" UserId="712" />
  <row Id="3956" PostId="3808" Text="Flux is a magical substance, it's really incredible how much of a difference it makes. I recommend &quot;clean-free&quot; varieties that come in a pen-like dispenser so you can dab it on easily." CreationDate="2010-08-02T15:18:22.673" UserId="771" />
  <row Id="3957" PostId="3820" Text="Also, I think you need a &quot;daughter board&quot; for the STK600 that has a ZIF socket and appropriate routings for your particular flavor of XMEGA." CreationDate="2010-08-02T15:22:17.850" UserId="771" />
  <row Id="3958" PostId="3808" Score="1" Text="@vicatu - What no-clean flux do you recommend?  I've always preferred Kester's RMA flux pens (which are not no-clean).  Contrary to their name, no-clean fluxes do leave some residue (Less than RMA, but still present).  The no-clean seems to refer to the increased difficulty in cleaning it off!  I prefer to ignore the flux on my experiments and hacks and to clean presentation boards0 well, rather than making every board mostly clean and struggling with the ones that have to look good." CreationDate="2010-08-02T16:32:32.560" UserId="857" />
  <row Id="3959" PostId="3831" Text="Try the National LMD18200D, or a kit that lets you connect to one." CreationDate="2010-08-02T19:00:47.947" UserId="712" />
  <row Id="3960" PostId="3830" Score="2" Text="Relays won't get you anywhere close to 20kHz." CreationDate="2010-08-02T21:03:16.970" UserId="857" />
  <row Id="3961" PostId="3830" Score="1" Text="What are you doing with the magnet?" CreationDate="2010-08-02T21:55:26.520" UserId="339" />
  <row Id="3962" PostId="3785" Text="jluciani has a Lithium battery charger for his Altoids form-factor Arduino-compatible boards....you might be able to adapt it to your needs: http://wiblocks.luciani.org/not-quite-ready/LI-ION-index.html" CreationDate="2010-08-03T00:57:47.320" UserId="857" />
  <row Id="3963" PostId="3743" Text="Whoops, sorry. Missed the &quot;Some of&quot;." CreationDate="2010-08-03T01:35:20.490" UserId="1374" />
  <row Id="3964" PostId="3808" Text="@reemrevnivek, don't quote me on this, but I think this is the one I'm currently using http://www.newark.com/itw-chemtronics/cw8400/lead-free-flux/dp/29K6229. If you're worried about making your board shiny, you can always give it an alcohol bath." CreationDate="2010-08-03T01:49:31.427" UserId="771" />
  <row Id="3965" PostId="3831" Text="@pingswept: that's a nice part, roughly like the L298N, but diodes included." CreationDate="2010-08-03T02:36:39.757" UserId="740" />
  <row Id="3966" PostId="3803" Text="Cholerteric should be Cholesteric.  These are cool because they're really low power!&#xA;Also, I'm not sure if the PixelQi is suitable for embedded systems, it's more designed as a plug-in module, with a datasheet to help laptop makers create conforming products." CreationDate="2010-08-03T03:20:44.397" UserId="857" />
  <row Id="3967" PostId="3836" Text="My Chronos is coming on Friday!  Seriously, though, this is just a slightly more complex form of the PIC -&gt; FTDI setup." CreationDate="2010-08-03T10:57:25.213" UserId="857" />
  <row Id="3968" PostId="3837" Score="1" Text="+1 for number five" CreationDate="2010-08-03T14:02:52.440" UserId="836" />
  <row Id="3969" PostId="3840" Text="This was my thought as well.  See Figure 5 in the datasheet for the timing diagram.  It looks like it's using a Mode 0 SPI bus (SPI Chip select = MM5450 data enable, Clock = clock, MOSI = data, and MISO = NC), so you might try using an SPI peripheral to talk to it more easily." CreationDate="2010-08-03T14:18:40.177" UserId="857" />
  <row Id="3970" PostId="3820" Text="There are ZIF sockets for TQFP and QFN parts?" CreationDate="2010-08-03T15:00:57.970" UserId="1363" />
  <row Id="3971" PostId="3837" Text="You don't need a special BIOS to read the state of the power button. You should be able to do it from Linux without any kernel hacking or anything. I'm pretty sure you can configure what happens when the power button gets pressed." CreationDate="2010-08-03T15:19:44.047" UserId="131" />
  <row Id="3972" PostId="954" Text="Dave and I started a radio show together. We'll have a name for it soon! http://chrisgammell.com/2010/08/02/2nd-radio-show-with-dave-jones-of-eevblog/" CreationDate="2010-08-03T17:27:19.533" UserId="404" />
  <row Id="3973" PostId="3837" Score="2" Text="I think Arduino and Processing should be the best way to start." CreationDate="2010-08-03T18:27:16.180" UserId="1030" />
  <row Id="3974" PostId="3839" Text="That's a nice pointer. Thanks!&#xA;" CreationDate="2010-08-03T18:28:34.680" UserId="1030" />
  <row Id="3975" PostId="3842" Text="Oh boy, it's not as easy as I thought it would be. Thanks for this perspective." CreationDate="2010-08-03T18:32:28.253" UserId="1030" />
  <row Id="3976" PostId="793" Text="I'm actually slowly working on a project with the means of learning this....this would be very helpful (especially car projects)" CreationDate="2010-08-03T18:56:15.240" UserId="982" />
  <row Id="3977" PostId="3811" Text="I changed to a old cheap bolt and it worked properly so I will need to check the temp on my good bolt, its time for a new one anyways" CreationDate="2010-08-03T20:37:08.767" UserId="665" />
  <row Id="3978" PostId="3846" Text="Try using altdrag to move the window upwards to get to a button that is off the screen: http://code.google.com/p/altdrag/" CreationDate="2010-08-03T20:45:52.867" UserId="131" />
  <row Id="3979" PostId="3803" Text="Whoops, my spellchecker doesn't recognize either.&#xA;As for the PixelQi screens, a screen is a screen. It's true they are 10&quot; displays, but that's the display size on the i-pad. If it uses a 10&quot; lcd, it can probably use the PixelQi display (with modifications)." CreationDate="2010-08-03T22:27:34.300" UserId="1374" />
  <row Id="3980" PostId="3840" Text="I tried that. The problem is that when I connect DE to an output pin on my uc, it is being driven by the data line. For example, if I set DATA high, it doesn't matter if I set DE high or low, it will follow DATA. From the datasheet, it seems that DE is the rail of an internal opamp that has DATA as input? Am I going crazy?" CreationDate="2010-08-03T23:30:34.977" UserId="1267" />
  <row Id="3981" PostId="3840" Text="BTW, I tried the above with both a pullup and pulldown on my output pin." CreationDate="2010-08-03T23:31:22.503" UserId="1267" />
  <row Id="3982" PostId="3840" Score="1" Text="Though the symbol for an opamp is indeed a triangle, I would guess that the triangle in the datasheet represents an input buffer, and the line coming in the top represents a line that enables that buffer. Given that DE and DATA are both inputs on the MM5450, I would guess that your problem lies on the microcontroller side. I'd try to get two outputs working independently on the micro, and then verify that they still work independently when you connect them to the MM5450. You're probably close-- keep at it." CreationDate="2010-08-04T01:15:33.833" UserId="712" />
  <row Id="3983" PostId="3840" Text="By the way, what micro are you using?" CreationDate="2010-08-04T01:16:01.040" UserId="712" />
  <row Id="3984" PostId="3726" Text="Peter, looking at the latest source in SVN, I cannot find a definition for the m48pa chip (i.e. 0x1e 0x92 0x0A identifier)..." CreationDate="2010-08-04T01:27:11.443" UserId="1031" />
  <row Id="3985" PostId="3726" Text="As a follow-up, adding the new lines to the avrdude config file allowed me to successfully program my ATMEGA48PA (using -p m48pa) firmware and fuses. Thanks silviof!" CreationDate="2010-08-04T02:24:03.007" UserId="1031" />
  <row Id="3986" PostId="3850" Text="i too recall reading this in AVR docs" CreationDate="2010-08-04T02:34:53.267" UserId="740" />
  <row Id="3988" PostId="469" Text="Wow... they try to teach you basic electronics without letting you play with resistors and capacitors? Did they at least use the water analogy?" CreationDate="2010-08-04T06:30:49.143" UserId="974" />
  <row Id="3989" PostId="3843" Score="2" Text="I disagree with this quite strongly.&#xA;&#xA;Electronics is no more demoralizing than learning to knit or how to play a musical instrument. If you want something custom and haven't got the patience and frame of mind to LEARN instead of applying a cookie-cutter solution then yes, you're in for a bit of a rude awakening. Head over to SparkFun and grab some flasher modules if that's all you need, but be prepared to stay within the limits of what they provide. You can't have both. :-)&#xA;&#xA;It's like I tell my kids... most things that are worth learning are going to take practice and patience to master.&#xA;" CreationDate="2010-08-04T06:37:59.110" UserId="974" />
  <row Id="3990" PostId="3854" Score="1" Text="You can also use this technique to read a timer made up of a hardware timer and a software counter incremented in the overflow interrupt." CreationDate="2010-08-04T07:57:41.670" UserId="339" />
  <row Id="3991" PostId="3853" Text="Why would that be illegal? I am just receiving a signal and boosting it, essentially just repeating it with more power. How is that illegal?" CreationDate="2010-08-04T08:25:48.447" UserId="1200" />
  <row Id="3992" PostId="3853" Score="5" Text="You need a license to transmit a signal on the mobile phone band, which you won't get." CreationDate="2010-08-04T10:08:08.397" UserId="305" />
  <row Id="3993" PostId="3799" Text="I have used a product with an OLED display and would definitely not consider this usable outdoors on an averagely sunny day (UK).  Having to shade the screen to read anything is a real pain." CreationDate="2010-08-04T11:07:15.347" UserId="400" />
  <row Id="3995" PostId="3855" Score="1" Text="On the *other* other hand, the college authorities may be quite dismayed that there is no coverage over the campus, because it will make the college less attractive to incoming students, prevent emergency calls, and make it harder for students to connect.  " CreationDate="2010-08-04T12:37:26.063" UserId="857" />
  <row Id="3996" PostId="3853" Text="ok I should have guessed that. Was a bit sleepy while writing that comment" CreationDate="2010-08-04T12:47:49.173" UserId="1200" />
  <row Id="3997" PostId="3857" Text="I like the idea of attaching that antenna, I should look into that." CreationDate="2010-08-04T12:49:05.083" UserId="1200" />
  <row Id="3998" PostId="3855" Text="Well the college I am talking about is sort of a all-you-can do college. It allows for total freedom in doing you work and there are no lectures as such.(Also its the best of the brand)." CreationDate="2010-08-04T12:50:35.283" UserId="1200" />
  <row Id="3999" PostId="3857" Score="1" Text="How would you attach an antenna to a mobile if it does not have the RF extension port?" CreationDate="2010-08-04T12:57:43.017" UserId="1200" />
  <row Id="4000" PostId="3852" Text="When i saw the title of your question I thought of these:  http://www.boost.org/doc/libs/1_43_0/doc/html/signals.html ..." CreationDate="2010-08-04T13:30:08.977" UserId="374" />
  <row Id="4001" PostId="3850" Text="Of course I checked the datasheet, but it's actually not as gory as you might think.  Nothing in the text for timer1 (chapter 6) indicates that the high byte gets buffered.  The there's a subsection under the async counter (6.5.1) that says &quot;for writes, it is recommended that the user simply stop the timer and write the desired values&quot;.  Nothing is mentioned for reads.  That's why I came to the community" CreationDate="2010-08-04T15:15:45.697" UserId="1278" />
  <row Id="4002" PostId="3854" Text="Thanks, I actually like this technique better than stuttering the timer during a read." CreationDate="2010-08-04T15:18:01.807" UserId="1278" />
  <row Id="4003" PostId="3840" Text="It's a pic18f4550 on a development board made by mikroe" CreationDate="2010-08-04T15:44:49.337" UserId="1267" />
  <row Id="4004" PostId="3858" Text="In case it wasn't clear...these LEDs are controlled independently and will not be multi/charlieplexed." CreationDate="2010-08-04T16:11:29.323" UserId="989" />
  <row Id="4005" PostId="3854" Score="1" Text="Finally found a Microchip app note, &quot;PIC Micro Mid-range MCU family&quot;.  It looks to be old, but seems to describe the 16F series in greater detail than the datasheet.  The technique suggested for reading the 16-bit free-running timer matches quite well with your suggestion, so I'm marking it as the answer." CreationDate="2010-08-04T16:22:08.823" UserId="1278" />
  <row Id="4006" PostId="3858" Score="3" Text="Why don't you use multiplexing?" CreationDate="2010-08-04T16:24:57.900" UserId="339" />
  <row Id="4007" PostId="3860" Text="Yeah, I know it was async timer, but it's the closest the datasheet got to addressing the problem.  Although now it makes more sense why they would suggest stopping the clock as opposed to mentioning Andrew's solution (even though they don't even mention *that* in the datasheet, but some separate app-note)" CreationDate="2010-08-04T16:38:15.483" UserId="1278" />
  <row Id="4008" PostId="3857" Text="You can't, without a lot of work. You will need to know a lot about RF." CreationDate="2010-08-04T16:44:58.403" UserId="305" />
  <row Id="4009" PostId="3857" Score="1" Text="On the board there is usually a circular pad that looks like a target that is also the spot where you would connect your own antenna You could attach a small pigtail (see wrt54g pigtail) . On some devices, like my Motorola Droid there is a micro SMA connector. I'm not sure if it's for the phone or GPS receiver. I've seem similar sockets in many, if not all phones I've had in the past.  I leave that research up to the question asker :) &#xA;" CreationDate="2010-08-04T17:50:38.420" UserId="1033" />
  <row Id="4010" PostId="3857" Text="Another idea, something I wanted to build a while ago, is a parabolic dish and position the phone's antenna right at the focal point. It would require some hardware but if you use hands free, it could be pretty sweet :)" CreationDate="2010-08-04T17:51:54.223" UserId="1033" />
  <row Id="4011" PostId="3854" Text="In general, my answer would have been &quot;do what the compiler does&quot; - write something in C, and see and see what the assembly looks like. " CreationDate="2010-08-04T18:41:15.697" UserId="771" />
  <row Id="4013" PostId="3843" Text="No, electronics is quite different to knitting. Both of these subjects are hard because they require practice to get good at, but a wooly jumper never mysteriously stops working when you wave your hand near it. Electronics has a whole 'nother arena of 'fun' waiting for you, even if you're very experienced. I've been in the business for 17 years, and things still bite me." CreationDate="2010-08-04T19:27:49.513" UserId="1024" />
  <row Id="4014" PostId="3857" Text="@brad I like your idea, building the parabolic dish will be a pain, but that would really sweeten the deal with focus locationing to a desired point" CreationDate="2010-08-04T20:22:58.987" UserId="1200" />
  <row Id="4015" PostId="3783" Score="1" Text="@Rascher - Do you need to identify the object when it's wet or when it's dry?  Your question asks about shorting the chip to its antenna so you only get a signal when it's wet. The converse would be to short the antenna (or other parts of the circuit) so that it won't resonate when wet, which would likely be preferable from a usability standpoint (unless it's supposed to be wet).  My guess is that what you'd really like  to do is short some &quot;I'm wet!&quot; bit in the output so that you can scan for wet/dry status.  Is this correct?" CreationDate="2010-08-04T20:32:03.963" UserId="857" />
  <row Id="4016" PostId="3850" Text="It *does* make it much easier now that you've posted the actual chip that you're using.  ;)&#xA;&#xA;And... I'd call it pretty gory: it explicitly says that overflow can occur between the reads. Your solution, stopping the timer, is indeed inelegant but perhaps a *safe* one, depending on your application.&#xA;" CreationDate="2010-08-04T20:41:30.460" UserId="484" />
  <row Id="4017" PostId="3857" Text="Yeah I wouldn't want to build the dish from scratch. Maybe there's a surplus dish out there. How about a circular polarized Yagi? Check out &quot;wiFi shootouts&quot;. You might also just make a yagi or Helical antenna with your phone being installed into the focal point where the driver element would go..?" CreationDate="2010-08-04T22:06:47.883" UserId="1033" />
  <row Id="4018" PostId="3794" Text="Glad the info was helpful.  Finding the correct info, or any info at all for that matter, can be a challenge with NXP.  But their chips are (IMO) the best bang-for-the-buck when it comes to ARM7 &amp; Cortex M3/M0." CreationDate="2010-08-04T22:16:14.157" UserId="221" />
  <row Id="4019" PostId="3831" Text="I tried a H-bridge made by Cana Kit and it works like a charm! I'm still using the 556 timer in complimentary configuration mode and it works perfectly. Thank you very much for the advice Joeforker! " CreationDate="2010-08-04T22:21:11.037" />
  <row Id="4021" PostId="3870" Text="Beautiful! I will only need the data travelling in one direction so the single UART on the ATMega chip is just enough! The two chips communicate with +/-5V UART, which I think is the same as the ATMega. Wow, that should be it! Thanks!" CreationDate="2010-08-04T23:01:10.493" UserId="1033" />
  <row Id="4022" PostId="3871" Text="Right, great advice, thank you!" CreationDate="2010-08-05T01:19:31.280" UserId="1033" />
  <row Id="4023" PostId="481" Score="1" Text="+1 for the &quot;design classes before senior year&quot; - in retrospect, a project each year wouldn't have been a bad thing." CreationDate="2010-08-05T02:09:48.517" UserId="740" />
  <row Id="4024" PostId="3858" Text="Well,  I was trying to keep the complexity in the software,  where it's easy for me. But it's looking more and more like it's easiest to go with a multi to reduce the connections.  I'm just intimidated by it...looks like I need to get past it. " CreationDate="2010-08-05T03:15:56.617" UserId="989" />
  <row Id="4025" PostId="3854" Score="2" Text="O_Engenheiro The loop executes twice for the case where an overflow occurs, and once in all other circumstances.  If you are looping more than that then either your timer clock is WAY too fast or your CPU is WAY too slow." CreationDate="2010-08-05T05:36:23.730" UserId="974" />
  <row Id="4026" PostId="3862" Text="Also remember that if you're multiplexing that you have to lower your current limit resistors. If the LEDs are capable of passing 20mA continuously and you're only driving them 1/5 (20%) of the time, you will want to drive them with at least 70-100mA of current in order to get decent light output.&#xA;&#xA;Just make sure (in software, or with a hardware watchdog) that you can't leave the multiplexed outputs at a static level, or that particular LED will be dissipating much more current than it's rated to. LEDs tend to go very bright, then dim, then sort of bright, then permanently black. :-)" CreationDate="2010-08-05T06:06:53.290" UserId="974" />
  <row Id="4028" PostId="3742" Text="@reemrevnivek Ok, so Try/Catch is slow. This is only an issue if you're using a try/catch block in a speed-critical section of the code, in which case you shouldn't be using a VM based language anyways. On the other hand, probably 80%-90% of the time MCUs are used, it's NOT speed critical, so significantly less programming results in no perceived loss or processing speed (I.e. the MCU does what it's programmed to do without any waiting on the part of the user)" CreationDate="2010-08-05T10:41:49.277" UserId="1374" />
  <row Id="4029" PostId="3822" Text="I have one of their 10W Multi-color LEDs, and it's **ridiculously** bright. Like, &quot;Do not look into beam with remaining eye&quot; bright." CreationDate="2010-08-05T11:09:26.117" UserId="1374" />
  <row Id="4030" PostId="3872" Text="Intriguing. This is pushing the limits of my understandings, but it's great! One part I don't understand is how the sniffer's UART is connected to the target so that it can intercept both directions of communication? I have several I/O Pins available, so could I just use two I/O Pins using this method and effectively collect both directions of traffic?" CreationDate="2010-08-05T11:52:10.310" UserId="1033" />
  <row Id="4031" PostId="3854" Text="@Andrew Kohlsmith, I deleted my comment. Sorry, I made an incorrect analysis of the code. Thanks.&#xA;" CreationDate="2010-08-05T12:26:42.840" UserId="938" />
  <row Id="4038" PostId="3864" Text="you only get +/- 1% deviation if you run the atmel calibration script on the chip, I believe" CreationDate="2010-08-05T15:53:54.687" UserId="771" />
  <row Id="4040" PostId="3865" Text="Yup, that's the manual which confirmed that Andrew's template was the best compromise.  Although I modified his example to look more like the assembly; i.e. instead of do-while, I just used an if." CreationDate="2010-08-05T16:57:53.840" UserId="1278" />
  <row Id="4042" PostId="3880" Text="Well, all components behave differently from their idealized versions in certain conditions.  Real inductors have DC resistance while idealized inductors don't, for instance." CreationDate="2010-08-05T17:54:13.373" UserId="142" />
  <row Id="4043" PostId="3883" Score="2" Text="Unless this is a shared frequency band (such as ISM), I'm pretty sure this lies within a Ham band. In which case you have to take the test to transmit in the band. The test covers these questions. " CreationDate="2010-08-05T18:25:40.797" UserId="1033" />
  <row Id="4046" PostId="3872" Text="The sniffer UART RX line is connected to the output of the AND gate.  Device A's UART TX is connected to one input of the AND gate, and device B's UART TX is connected to the other input of the AND gate.  Since the idle (no traffic) condition of a UART is a logic '1', the AND gate effectively combines both transmit signals into one. The I/O line on the sniffer is used to detect device B's start bit so that it can take the byte it is receiving on its UART and put it in the appropriate buffer (device A traffic or device B traffic)." CreationDate="2010-08-05T19:06:40.163" UserId="974" />
  <row Id="4047" PostId="3872" Text="The code fragment and the wiring of the AND gate allow the sniffer to record both directions of traffic flow with a single UART. This ONLY works if the traffic is half-duplex. That means that when one device is talking, the other is listening. If both talk at the same time (full duplex) then this would not work at all." CreationDate="2010-08-05T19:07:42.797" UserId="974" />
  <row Id="4048" PostId="3889" Text="I think that has very little to do with the issue.  This is a problem even for electrolytics that have folded layers (See http://www.vishay.com/docs/28356/intro.pdf)" CreationDate="2010-08-05T19:13:45.050" UserId="857" />
  <row Id="4050" PostId="3880" Text="+1 for &quot;I don't really buy it.&quot; I thought this for about the first three months of my analog circuit design class.  Still do sometimes.  *&quot;Imaginary numbers?  Get real!&quot;*  I should point out that I used the frequency in radians, while you used 2pi*f for the same purpose." CreationDate="2010-08-05T19:19:09.717" UserId="857" />
  <row Id="4051" PostId="3887" Score="2" Text="&quot;Impedance can be thought of like resistance, just in the frequency domain.&quot;  More accurately, resistance is a subset of impedance.  Impedance is the combination of the resistance and reactance of a component or subcircuit.  Maybe we should have a &quot;What is impedance&quot; question.  :D" CreationDate="2010-08-05T19:26:27.707" UserId="142" />
  <row Id="4052" PostId="3889" Text="Everything has inductance, but coils have more inductance than folded layers, so the parasitic inductance will be larger, and the inductance of a coiled capacitor will take over at lower frequencies than one with folded layers?" CreationDate="2010-08-05T19:32:50.823" UserId="142" />
  <row Id="4053" PostId="3883" Score="2" Text="KC2QLW ;) 433.92Mhz is actually the center frequency of an ISM band, not part of the Ham spectrum, and is goverend by Part 18 of the FCC rules." CreationDate="2010-08-05T19:57:03.870" UserId="771" />
  <row Id="4054" PostId="3888" Score="1" Text="Exactly.  This can be generalized to the statement that the ratio of RMS voltage to current at any point on the antenna is 50, and the unit is, of course, ohms.  " CreationDate="2010-08-05T20:07:03.803" UserId="857" />
  <row Id="4055" PostId="3887" Text="@Endolith - I agree, but only after several semesters of electrical theory do I understand your statement.  While that would be the most pure route to an understanding of electricity, it's obscured by imaginary numbers and calculus." CreationDate="2010-08-05T20:16:29.307" UserId="857" />
  <row Id="4056" PostId="3888" Score="2" Text="So how do you build one for a target impedence? What's the design process?" CreationDate="2010-08-05T21:20:39.583" UserId="771" />
  <row Id="4057" PostId="3888" Score="2" Text="Also presumably imperfections come into play and you have to &quot;tune&quot; the circuit to the antenna (something like that), is there a clear approach to doing that?" CreationDate="2010-08-05T21:21:44.890" UserId="771" />
  <row Id="4058" PostId="3661" Text="@reemrevnivek FYI, Atmel is selling off their SecureAVR line... they recommend their ARM-based 32-bit processors if you want cryptographic stuff which is a whole different ballgame in terms of development environment from AVR. They do have a couple with True RNGs on them though, maybe I'll play with them some day." CreationDate="2010-08-05T21:24:34.317" UserId="771" />
  <row Id="4059" PostId="3883" Text="It's part of the UK 70 cms amateur band allocation. People have been unable to get into their cars after parking them close to a 70 cms amateur radio transmitter." CreationDate="2010-08-05T22:10:51.270" UserId="305" />
  <row Id="4060" PostId="3888" Text="Radio amateurs use VSWR meters to check and tune antennas." CreationDate="2010-08-05T22:58:30.557" UserId="305" />
  <row Id="4061" PostId="3783" Text="@reemrevnivek Oh, that's a good idea! I just want to detect when it becomes wet. So &quot;I have just stopped receiving a signal from the tag, it must have gotten wet!&quot; is a completely fine way to solve the problem. So the next question: how? Are existing RFID tags sensitive (&quot;fragile&quot;) enough that they'd stop resonating when doused?" CreationDate="2010-08-05T23:41:24.183" UserId="1021" />
  <row Id="4062" PostId="3868" Text="huh - that is interesting. I suppose what I'm trying to do, in a sense, is homebrew my own." CreationDate="2010-08-05T23:43:47.623" UserId="1021" />
  <row Id="4063" PostId="3887" Text="Calculus is fun!  But you really don't need to know that stuff to understand impedance." CreationDate="2010-08-06T00:25:29.467" UserId="142" />
  <row Id="4064" PostId="3888" Text="The antenna's impedance should match the connector's impedance should match the line's impedance should match the transmitter's impedance.  Then there's no reflections." CreationDate="2010-08-06T00:59:03.537" UserId="142" />
  <row Id="4065" PostId="3890" Text="This is very useful. I am not an electrical engineer, and therefore would am very interested in heuristics like this. Please add more if you know of any. " CreationDate="2010-08-06T01:12:13.593" UserId="1402" />
  <row Id="4066" PostId="3775" Text="This is an old question, but I was trying to spin the motor at a rate proportional to the volume of the sound at a sufficient rate that frequency information would be conveyed (like a speaker)." CreationDate="2010-08-06T03:18:07.507" UserId="207" />
  <row Id="4067" PostId="3890" Score="1" Text="It's not really a heuristic, it can be predicted from basic electromagnetic theory. Something similar is the impedance of a folded half-wave dipole - 300 ohms." CreationDate="2010-08-06T04:29:23.013" UserId="305" />
  <row Id="4068" PostId="3890" Score="1" Text="Another example is the 30 ohms impedance of a 1/4 wave vertical over a ground plane." CreationDate="2010-08-06T04:32:47.167" UserId="305" />
  <row Id="4069" PostId="3894" Score="1" Text="A very good solution. I ran the aviation maintenance shop for a UAV unit in the US Army for 3 years. We had over 500 different &quot;line items&quot; of stuff. This method was the only way to keep it all organized and restocked. I did eventually did go to an Access database, but everyone else was too scared of Access." CreationDate="2010-08-06T07:02:59.133" UserId="965" />
  <row Id="4070" PostId="3888" Score="2" Text="If you don't use some kind of antenna tuner (L-C network, usually,) it is almost always required to do some cut-and-try trimming. There are all sorts of rule-of-thumb equations out there, but the best advice is to cut your (I'm assuming prototype) antenna a bit too long and test it with a meter that can measure forward and reflected power. Trim, then test again. You want to trim for minimum reflected power, which will mean that your power is being radiated instead of reflected back into the amplifier finals and heating them up." CreationDate="2010-08-06T07:13:10.617" UserId="965" />
  <row Id="4071" PostId="3895" Score="2" Text="Could you post some sort of schematic or diagram? It's hard to know without more details. As a rough guess, I would not expect IGBTs being shorted to affect the board driving the IGBTs." CreationDate="2010-08-06T12:47:10.217" UserId="712" />
  <row Id="4072" PostId="3880" Text="@reemrevnivek, sure and for those who don't know  omega = 2*pi*f is a good conversion to know; where omega is the &quot;angular frequency&quot; specified in radians, and f is frequency measured in Hz." CreationDate="2010-08-06T14:10:05.690" UserId="771" />
  <row Id="4073" PostId="3887" Score="1" Text="epic response..." CreationDate="2010-08-06T14:10:32.723" UserId="771" />
  <row Id="4074" PostId="3864" Text="Maybe. I wrote my own calibration firmware only to find out the factory OSCCAL was only 1 off (not 1% off) from the perfect calibration. And the USART worked fine with or without the calibration." CreationDate="2010-08-06T14:17:38.693" UserId="1363" />
  <row Id="4075" PostId="3887" Text="@Vicatu - I started off thinking, I'll just go over the basic parasitics, derive the impedance of a series LC circuit, and demonstrate that it's frequency dependent in such a way that the inductance becomes dominant at high frequency.  Then, I started typing, and it just wouldn't finish itself." CreationDate="2010-08-06T14:34:11.470" UserId="857" />
  <row Id="4076" PostId="3890" Text="A microstrip line with standard FR4 PCB material will be about 0.1&quot; wide." CreationDate="2010-08-06T16:18:59.883" UserId="305" />
  <row Id="4077" PostId="3887" Score="1" Text="imaginary numbers are just a tool to avoid differential equations amd integrals; they sort of make calculus into algebra :)" CreationDate="2010-08-06T16:42:56.590" UserId="771" />
  <row Id="4078" PostId="3887" Text="...make calculus into **complex** algebra.  Out of the frying pan and into the fire." CreationDate="2010-08-06T16:55:50.347" UserId="857" />
  <row Id="4079" PostId="3883" Text="K 1 G T O =) @leon interesting. @vicatcu qsl! " CreationDate="2010-08-06T19:02:22.953" UserId="1033" />
  <row Id="4080" PostId="3901" Score="3" Text="The counterpoint to this argument is that the optimizer likely will make things smaller and/or faster, and if you've got timing or size constrained code then you may break something by disabling the optimization, and waste your time debugging a problem that doesn't really exist.  Of course, the debugger may make your code slower and larger as well." CreationDate="2010-08-06T19:14:46.047" UserId="857" />
  <row Id="4081" PostId="3901" Text="Where can I learn more about this?" CreationDate="2010-08-06T19:17:50.247" UserId="938" />
  <row Id="4082" PostId="3901" Text="I haven't worked with the C30 compiler but for the C18 compiler there was an app note/manual for the compiler that covered what optimizations it supported." CreationDate="2010-08-06T19:30:17.117" UserId="703" />
  <row Id="4083" PostId="3889" Text="@reemrevnivek Interesting document, though there are no hard numbers on ESL. They seem to use several tricks to reduce ESR and ESL, like connecting to all layers simultaneously on the side of the roll, or connecting to the middle of the roll, so that the magnetic fields cancel." CreationDate="2010-08-06T20:11:51.777" UserId="339" />
  <row Id="4084" PostId="3901" Text="@O Engenheiro: Check your compiler docs for what optimizations it supports. Optimization varies wildly depending on compiler, libraries, and target architecture. " CreationDate="2010-08-06T20:43:47.057" UserId="259" />
  <row Id="4085" PostId="3901" Text="Again, not for the C30 compiler, but gcc publishes a LONG list of the various optimizations which can be applied.  You can also use this list to get fine-grained optimization, in case you have a particular control structure you want to keep intact.  The list is here:&#xA;http://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html" CreationDate="2010-08-06T20:44:46.680" UserId="857" />
  <row Id="4086" PostId="3887" Text="i wouldn't say your dodging calculus or diffEQ at all, they are used in the derivation of the impedance of these components at sinusoidal frequencies as well as in the derivation of the tools required for the transforms.  I mean you could say that using a fourier transform is dodging integration by the same logic :)  Its really euler's formula that makes this type of analysis possible.  Its a pretty wacky relationship at first glance actually.  " CreationDate="2010-08-06T21:42:42.543" UserId="703" />
  <row Id="4087" PostId="3906" Text="If I were you, I'd get a dual or quad rail-to-rail opamp, and just add the two resistors to make the differential amplifier work.  The 741 is old technology.  How old?  **1968**.  It's time to get new opamps!" CreationDate="2010-08-06T22:04:09.873" UserId="857" />
  <row Id="4088" PostId="3911" Text="You could post questions about your project here to help clarify your design ideas..." CreationDate="2010-08-07T11:21:40.163" UserId="566" />
  <row Id="4089" PostId="3891" Text="Insufficient space in &quot;comments&quot;, so I have responded as an &quot;answer&quot;. Thanks for your interest." CreationDate="2010-08-07T13:55:50.310" />
  <row Id="4090" PostId="3911" Text="If I were to do an internet search for a company that does EE projects, what type of company would I be searching for?  I just don't understand if there is a category of comapanies that would help me locate the existing firms in my area....  anyone?" CreationDate="2010-08-07T14:18:58.657" UserId="1044" />
  <row Id="4091" PostId="3919" Text="I'll second that" CreationDate="2010-08-07T14:56:05.040" UserId="399" />
  <row Id="4093" PostId="3911" Text="The companies you're looking for are called embedded systems design firms, or maybe product engineering firms. You might Google with: &quot;embedded systems consultant&quot; new york" CreationDate="2010-08-07T15:04:06.740" UserId="712" />
  <row Id="4094" PostId="3916" Text="The standard method is to edit your question to include this additional information. If you do, you can then delete this answer (and this comment will disappear).  Don't have time ATM to look into this, but it looks like an interesting problem, and I'll give it a go tonight!" CreationDate="2010-08-07T15:55:04.453" UserId="857" />
  <row Id="4095" PostId="3896" Score="1" Text="How do you interface to your Postgres database?" CreationDate="2010-08-07T18:51:32.337" UserId="857" />
  <row Id="4096" PostId="3893" Score="1" Text="Related question here: http://chiphacker.com/questions/3578/ but that seems to be more about the physical problem of selecting drawers/bins/boxes/envelopes than about the database design." CreationDate="2010-08-07T18:54:20.647" UserId="857" />
  <row Id="4098" PostId="3932" Text="So when I hook a DMM up to the center pin and surrounding shield of an RCA cable, voltage floats all over the place.  Is the shield supposed to be grounded?" CreationDate="2010-08-07T22:18:16.090" UserId="971" />
  <row Id="4099" PostId="3931" Text="Thanks.  most random strangers on the Internet don't know the stuff you do... :) So let's say I decide to hook it up to an Arduino (which isn't the specific MCU I had in mind, but I have one lying around), I would ground the shield (outside) of the RCA connector and hook the center pin to one of the analog ports?" CreationDate="2010-08-07T22:18:17.447" UserId="971" />
  <row Id="4100" PostId="3932" Text="For some specific numbers, I just tried this again.  TV off: 0.8mV, TV on: Jumps up to 2.7V and slowly trickles down.  Turning the set off again makes the meter jump, but eventually it just settles back to the value it was on before I turned it off, then the voltage continues to slowly trickle down." CreationDate="2010-08-07T22:26:42.940" UserId="971" />
  <row Id="4101" PostId="3931" Text="So when I try to measure the difference in ground potential, as you described, I get about 100mV, but the meter floats around by about 10 - 20mV.  Even with the TV set off.  Why wouldn't it be more stable than that?" CreationDate="2010-08-07T22:44:29.853" UserId="971" />
  <row Id="4102" PostId="3925" Text="I realize that this may be a little much.  I intended to offer a bounty on this, but then found that Chiphacker doesn't let me do that.  &#xA;Should I split these up into separate questions?" CreationDate="2010-08-07T22:47:43.500" UserId="857" />
  <row Id="4103" PostId="3931" Text="The shield *is* grounded already.  The important thing is to make sure that the ground on your Arduino and the ground on the shield are the same.  If you're using a battery or an isolated power supply (Like most wall warts), this does mean connecting the grounds. If you're using USB, which is earth grounded through your computer (unless, you're using a battery-powered laptop) you need to be sure that the ground on the USB is the same as the ground you find at that shield.  If you can reduce your ground loop, you'll get better readings (i.e., not uC GND pin -&gt; USB -&gt; PC -&gt; Home wiring -&gt; TV)" CreationDate="2010-08-07T22:51:51.603" UserId="857" />
  <row Id="4104" PostId="3931" Text="You're good - That tiny difference is because the two cables you're measuring are connected through the TV's PSU, then your home wiring, then the computer's PSU, then the USB connector on the motherboard, then the USB cable shield.  If you simply connect the two, the variation induced by this long wiring (aka ground loop) will be reduced, and you'll get better readings.  " CreationDate="2010-08-07T22:54:39.780" UserId="857" />
  <row Id="4105" PostId="3931" Text="You always do need to be careful connecting grounds that are at different potentials together. For this situation, it is probably not necessary for them to be at the exact same level. Because of this can you put a small resistor in series when you connect the grounds together. This way, even if they are at separate voltages your resistor will be able to handle the difference." CreationDate="2010-08-07T23:15:42.447" UserId="319" />
  <row Id="4106" PostId="3931" Text="If you wanted to go &quot;All Out&quot; you could make a preamp circuit that measured the difference between the tip and ring on your yellow monitor connector. I don't think you will need to worry about this though." CreationDate="2010-08-07T23:16:41.820" UserId="319" />
  <row Id="4107" PostId="3932" Text=".8mV is practically ground and should be treated as such for this application. The &quot;trickling down&quot; that you see is probably some stray capacitance, this means that if you put a resistor across the output (say 10k) it should bring the voltage down much quicker. Do you have your DMM set to AC or DC? " CreationDate="2010-08-07T23:23:48.447" UserId="319" />
  <row Id="4108" PostId="3932" Text="The meter is set to DC." CreationDate="2010-08-07T23:29:04.163" UserId="971" />
  <row Id="4109" PostId="664" Text="of course, an op-amp with no feedback will behave somewhat like a comparator. true, it's not the same as an o.c. output, but you can make use of the rail-to-rail swings to do similar things." CreationDate="2010-08-08T01:21:40.773" UserId="740" />
  <row Id="4110" PostId="3933" Text="Regarding #2, I thought that parallel would be more in tune with what the user expected. As long as the relay is off, it's exactly like it's not there.  Plus, it saves a ton of money on wiring the place with 14-4 wire.  Regarding #3, you can read that free on NFPA.org (Registration required, stuck in ridiculous RealRead viewer)." CreationDate="2010-08-08T01:57:11.677" UserId="857" />
  <row Id="4111" PostId="3933" Text="More on #3 - The code (NFPA 70A, article 725.55 part D) states that remote control devices must not be placed such that their conductors are routed no closer than 6mm to electric light power cables.  Pretty generous.  Not sure what this means for actually connecting to those wires, though.  I'll have to ask a friend.  My concern is that the inspector will see my device, and say &quot;Is that thing UL listed?&quot; ... &quot;No, I made it myself.&quot; ... &quot;Take it out. I'll be back next week.  That will be $XXX&quot;" CreationDate="2010-08-08T02:02:44.460" UserId="857" />
  <row Id="4112" PostId="481" Text="yeah, it would have done me wonders. I learned more in one project then I did with any other class." CreationDate="2010-08-08T03:21:41.030" UserId="230" />
  <row Id="4113" PostId="3934" Score="1" Text="What frequency?" CreationDate="2010-08-08T04:50:47.840" UserId="305" />
  <row Id="4114" PostId="3934" Text="Audio frequencies, I guess" CreationDate="2010-08-08T22:45:39.280" UserId="142" />
  <row Id="4115" PostId="3857" Text="It could work, but the elements will be pretty close together. If you go for high gain, the beamwidth will be pretty narrow, too. You'll want a tripod at that point. Which would look ridiculous. And bulky. On the plus side, you'd get cell service where nobody else does..." CreationDate="2010-08-09T07:57:45.507" UserId="965" />
  <row Id="4116" PostId="3941" Score="1" Text="This didn't have to be community wiki, it's a good normal question. :)" CreationDate="2010-08-09T13:22:39.793" UserId="374" />
  <row Id="4117" PostId="3935" Score="3" Text="You should clarify that you need a dual element potentiometer to do this, and I'm not sure you can find those for much less than 1 US dollar.  The circuit requires that R=R1=R2 (And C=C1=C2).  Also, the gain needs to be controlled so that oscillation will continue, see this page for more details: http://www.ecircuitcenter.com/circuits/opwien/opwien.htm" CreationDate="2010-08-09T13:40:53.177" UserId="857" />
  <row Id="4118" PostId="3935" Text="A good point, Nivek. I might suggest a dual digital pot like the Maxim MAX5496 or the Analog Devices AD5235, but that definitely increases the cost by two or three dollars.&#xA;&#xA;I suspect that there is also a way that you could use a current mirror made from some BJTs to make one pot do double duty, but I'll leave that attempt to someone who really knows what they're doing with analog stuff." CreationDate="2010-08-09T14:07:30.290" UserId="712" />
  <row Id="4120" PostId="3896" Text="I use perl for various utility scripts. I use Perl + Mason for webpage&#xA;access." CreationDate="2010-08-09T14:31:17.493" UserId="424" />
  <row Id="4121" PostId="3949" Text="http://www.exar.com/Common/Content/ProductDetails.aspx?ID=XR2206 is only a few bucks: http://www.futureelectronics.com/en/technologies/production-products/test-measurement/function-generators/Pages/4075065-XR2206D-F.aspx  &quot;The XR-2206 is a monolithic function generator&#xA;integrated circuit capable of producing high quality sine,&#xA;square, triangle, ramp, and pulse waveforms of&#xA;high-stability and accuracy. The output waveforms can be&#xA;both amplitude and frequency modulated by an external&#xA;voltage.&quot;" CreationDate="2010-08-09T14:48:59.890" UserId="142" />
  <row Id="4122" PostId="3937" Text="If you're using a microcontroller, I would think PWM output would be simpler. Then you only need a simple fixed-frequency filter." CreationDate="2010-08-09T14:52:53.907" UserId="142" />
  <row Id="4124" PostId="3919" Text="Also try posting on NYC dorkbot." CreationDate="2010-08-09T14:56:06.180" UserId="424" />
  <row Id="4127" PostId="3950" Score="2" Text="The magnitude being the only part you care about is very application dependent. every person uses these methods for different reasons." CreationDate="2010-08-09T15:38:48.613" UserId="230" />
  <row Id="4128" PostId="3950" Text="I like EMF and EMC, phase matters, alot." CreationDate="2010-08-09T15:39:13.923" UserId="230" />
  <row Id="4129" PostId="3949" Text="Oh, I've forgotten about the XR entirely. I actually meant to see if I could find a couple to try some time ago." CreationDate="2010-08-09T17:20:28.307" UserId="883" />
  <row Id="4130" PostId="3934" Score="3" Text="easiest and cheapest are typically opposint parameters ;)" CreationDate="2010-08-09T17:33:01.400" UserId="771" />
  <row Id="4131" PostId="3946" Score="1" Text="I would definitely recommend the FTDI solution as a fast and cost-effective solution for any one-off project.  (It's not clear if your joystick is a one-off or slated for 10k units!)&#xA;&#xA;A particularly nice version is their &quot;USB-TTL cable&quot; (about $20) which looks like a USB cable on one end, with a header or bare wires on the other end, and contains the USB chip inside.  This cable is used as the USB solution for many popular boards including the Arduino Lilypad and Arduino Pro." CreationDate="2010-08-09T19:00:26.607" UserId="484" />
  <row Id="4132" PostId="3946" Score="1" Text="If you do go down this route, you may still want your joystick to appear as a proper joystick driver in linux. You can do this with inputattach http://wiki.archlinux.org/index.php/Attaching_serial_input_devices_to_the_kernel_input_system" CreationDate="2010-08-09T19:07:41.583" UserId="566" />
  <row Id="4133" PostId="3930" Score="1" Text="personally i would just use a power meter on the mains wire that provides some sort of way to see the current being drawn (analog or digital out).  I would bet that the monitor out RCA would only be active when standard def content is playing, as HD content wouldn't work on that type of connection, perhaps its down converting all the time but i doubt it, especially for hdmi inputs, thats a lot of processing work for the tv to be just randomly doing all the time." CreationDate="2010-08-09T19:37:19.690" UserId="703" />
  <row Id="4134" PostId="3941" Text="Possibly, but I want others to be able to easily edit the question if they see the need." CreationDate="2010-08-09T19:52:11.687" UserId="965" />
  <row Id="4135" PostId="3941" Text="Not really fair for people who provide good answers." CreationDate="2010-08-09T22:04:28.043" UserId="718" />
  <row Id="4136" PostId="3941" Text="I unfortunately didn't consider that. Next time..." CreationDate="2010-08-09T22:06:57.703" UserId="965" />
  <row Id="4137" PostId="3721" Text="No I don't have problems anymore ...&#xA;Thanks to all for helping." CreationDate="2010-08-09T22:11:06.403" UserId="1004" />
  <row Id="4138" PostId="3927" Text="I saw that in my recent items feed, and wondered what had happened to it.  That's a nice system, and does point out that I could use plug-in devices to switch lamps rather than trying to tie into the wiring system, which gets around the inspection issue.  " CreationDate="2010-08-09T22:18:16.240" UserId="857" />
  <row Id="4139" PostId="3925" Text="I think that would help, yes." CreationDate="2010-08-09T23:27:55.963" UserId="566" />
  <row Id="4141" PostId="3978" Text="Wow - awesome. Thanks for that. " CreationDate="2010-08-10T11:41:10.377" UserId="1307" />
  <row Id="4144" PostId="3974" Text="Yes, I'm going to use one of the parts with embedded USB. The ideal would be to use the MSC protocol, but that adds a lot of complexity to my project. I'll probably settle with the HID data transfer rates.&#xA;&#xA;I thought about SD cards but that adds extra complexities on the enclosure as it has to be water splash proof." CreationDate="2010-08-10T16:23:01.877" UserId="1267" />
  <row Id="4147" PostId="3979" Score="1" Text="I disagree. The smallest erasable section on the AT25D is a 4kB page, and few micros have that much spare RAM available. I've used the AT25FS series of chips, which have a small (256 byte) page erase, but they're less than 5MB. Going with the buffered system means you don't have to worry as much about RAM management. Of course, if you have no need to edit your logs, then the AT25 series will work fine." CreationDate="2010-08-10T18:08:57.700" UserId="857" />
  <row Id="4148" PostId="3974" Score="2" Text="I'd suggest this route, because SD cards will give you the most storage space.  You say 5MB now, but if you want more later, you're pushing the limits of serial flash (And you're well above the limits of EEPROM). If waterproofing is an issue (and you have an appropriate USB option, which seems to be the case) you can read your SD card out over USB, and put it inside the enclosure permanently.  I've seen some designs which soldered the SD card to the board (Note: This worked, but I do not recommend it)." CreationDate="2010-08-10T18:13:34.590" UserId="857" />
  <row Id="4149" PostId="3974" Text="Got it, makes sense. I'll consider that option. Thanks" CreationDate="2010-08-10T20:48:09.610" UserId="1267" />
  <row Id="4150" PostId="3195" Text="You have NO influence on the hardware at all? That's a pretty f**ked up project, since it seems that the capabilities of the firmware is largely determining the feasibility.&#xA;It might be a good time to basically take a little while to think through what you have to do, and decide if you think it's feasible based on what you know (and it sure sounds like it's not), and if you don't think so, go to the project manager and let them know that it won't work." CreationDate="2010-08-11T10:32:51.370" UserId="1374" />
  <row Id="4151" PostId="3982" Text="I agree with what you are saying, but you could just copy the data from the source flash page to the destination flash page while modifying the bytes you want to change prior to erasing the source." CreationDate="2010-08-11T12:31:13.053" UserId="588" />
  <row Id="4153" PostId="3982" Text="@mjh - What if your source and destination are the same, and/or you don't have a free page?  Also, this is slow: send read command, send an address, read a byte, change if necessary, erase, send write command, send an address, write a byte, repeat x256, x512, or x4k.  Your other option is to send a read command, send read address, clock for N cycles, modify the bytes you want to change, erase, send write command, send write address, clock for N cycles.  This takes about 1/3 of the time that the RAM buffer takes." CreationDate="2010-08-11T12:52:35.110" UserId="857" />
  <row Id="4154" PostId="2478" Text="Have you checked the newest GCC (gcc4) version to make sure it isn't done already? Have you mentioned your intentions on any (gcc) relevant forum?" CreationDate="2010-08-11T15:09:40.643" UserId="883" />
  <row Id="4155" PostId="3993" Text="Looks like it might be the ICSP pins bottoming out that are causing the rocking." CreationDate="2010-08-11T15:22:14.667" UserId="712" />
  <row Id="4156" PostId="3734" Text="I presume you aren't starting with an AC supply :)" CreationDate="2010-08-11T15:36:51.680" UserId="883" />
  <row Id="4158" PostId="3997" Text="Which avrdude version with which programmer? My earlier attempts had numerous issues with PDI on the AVR ISPmk2" CreationDate="2010-08-12T06:26:45.807" UserId="867" />
  <row Id="4159" PostId="3992" Text="Hi,&#xA;Thanks for your reply. Thanks for pointing out the different types of headers, I didn't even notice it. I can't push the shield pcb all the way down on one side of the arduino - it moves a bit, but not enough to go all the way down. It seems that if the shield pins did have the black plastic bits, then it would sit perfectly (the gap looks to be almost exactly the right size for them)." CreationDate="2010-08-12T06:50:05.940" UserId="1049" />
  <row Id="4160" PostId="3992" Text="I've tried pressing the shield on with a reasonable amount of pressure, but the icsp connection is not letting it go down any further (even if the icsp header did push all the way down, I think there might still be at least some sort of gap between the shield pins and the arduino)." CreationDate="2010-08-12T06:50:46.893" UserId="1049" />
  <row Id="4161" PostId="3992" Text="I've also tested my arduino with other shields (I don't have any with the stackable headers though), and they seem to work fine.&#xA;&#xA;I was offered a replacement by Maddy which I accepted, and in the meantime asked Marcus about the possibility of refunding it for store credit, which he accepted. The replacement must have already been posted though, because that arrived today.&#xA;&#xA;I had a look at the replacement they sent me, and it seems to be exactly the same with the stackable headers, so this one also has the gap between the shield and the arduino." CreationDate="2010-08-12T06:50:57.907" UserId="1049" />
  <row Id="4162" PostId="3993" Text="Yes that's what seems to be happening - I've tested with another shield that has an icsp header on it (although it has the regular pins on either side of the shield, not the stackable headers), and the icsp header on that appears to be able to be pushed down further than the one on the xbee shield." CreationDate="2010-08-12T06:55:08.943" UserId="1049" />
  <row Id="4163" PostId="3916" Text="Okay. I follow the standard method in future. Hope you can help with the problem." CreationDate="2010-08-12T10:29:09.203" />
  <row Id="4164" PostId="3979" Text="Yes, large erase pages are annoying when an application needs to write some byte, and then later change that byte.&#xA;But why would a data logger ever need to do that?&#xA;It seems to me that, for data logging applications application, it makes no difference if the smallest erasable section is 256 byte or 1 Megabyte.&#xA;" CreationDate="2010-08-12T13:14:32.327" UserId="813" />
  <row Id="4165" PostId="3982" Text="Why would a data logger ever need to edit the logs on the micro?" CreationDate="2010-08-12T13:17:09.060" UserId="813" />
  <row Id="4167" PostId="3992" Text="unknown - Looks like a new ICSP header is in order! Those female sockets are available in different heights and contact depths. For instance the Digikey part S7106-ND is 8.5mm tall, and has a contact depth of 6.38mm, while the A32934-ND is shorter at 8.13mm tall, but only has a contact depth of 3.77mm (take a look at the datasheet images and you'll see what's going on). See also the 609-3582-ND and 609-2267-ND. So, your options now are to trim the male pins on your ICSP header, or to get a female socket with deeper contacts. " CreationDate="2010-08-12T13:20:08.290" UserId="857" />
  <row Id="4168" PostId="3982" Text="@davidcary - If your data logger does nothing but record one long stream of bytes, you're right - you'll never need to make changes.  If it has several configurations or log files which might break across page/block boundaries, or if you wanted to make changes to a header on the file at the end, you'd need to edit the memory without wiping the existing data." CreationDate="2010-08-12T14:18:20.597" UserId="857" />
  <row Id="4169" PostId="4005" Text="I hope that by &quot;on paper&quot; you mean &quot;in schematic form&quot; rather than with a pencil and some shredded trees.  Using any electronic schematic capture program will aid you in editing and viewing your schematic.  The ability to highlight nets and move component groups around is a wonderful thing.  For this project, I'd probably choose to use a simulator, so you can make sure that you've got the wiring correct." CreationDate="2010-08-12T15:26:23.167" UserId="857" />
  <row Id="4170" PostId="4005" Text="Also, traditional Charlieplexing gives you control of n^2-n LEDs with n control wires.  So,  I don't see how the irregularity of an 8th line will help the wiring.  Why not make an 8x7 LED array?  Having 8 lines will simplify the programming and the hardware." CreationDate="2010-08-12T15:30:36.560" UserId="857" />
  <row Id="4171" PostId="3974" Text="Is there a specialized chip that takes care of the SD interface and implements the file system or would I still have to implement a file system and the MSC class using the MSP430?" CreationDate="2010-08-12T15:53:56.290" UserId="1267" />
  <row Id="4172" PostId="3982" Text="At this point, I just need to create several log files, no need to modify them, except when the user plugs the device to USB and downloads it, then I need to erase (or make that space available again) the old log." CreationDate="2010-08-12T15:55:38.600" UserId="1267" />
  <row Id="4174" PostId="3982" Text="@Padu - You'll probably be fine with any of the options in that case. I was answering your fairly generic question about &quot;what kind of memory can be used with the MSP430&quot; rather than a specific data logger application.  " CreationDate="2010-08-12T16:52:03.520" UserId="857" />
  <row Id="4175" PostId="4005" Text="Just because it's an 8x5 array. The reason that it's 8x5 is because it's part of a prop:&#xA;&#xA;http://www.artoo-detoo.net/tag/front-logic&#xA;&#xA;Otherwise, you're absolutely right." CreationDate="2010-08-12T16:56:23.407" UserId="989" />
  <row Id="4176" PostId="4005" Text="Well, I use ExpressSCH, but in this case, I really do mean pencil and paper. I think there's a lot of value in stepping away from the technology from time to time. Once I've reached a certain point in the p&amp;p I'll move it into the software." CreationDate="2010-08-12T16:57:47.960" UserId="989" />
  <row Id="4177" PostId="3974" Text="@Padu - I felt this needed a little more room and formatting than a comment, so I added my response as an answer.   " CreationDate="2010-08-12T17:15:43.893" UserId="857" />
  <row Id="4178" PostId="3974" Text="@Ian - I added an answer about the SD interface, feel free to incorporate it or its links into your response." CreationDate="2010-08-12T17:16:10.870" UserId="857" />
  <row Id="4179" PostId="3960" Text="+1 Well done..." CreationDate="2010-08-12T17:58:33.067" UserId="985" />
  <row Id="4180" PostId="4015" Text="Try pushing the volume up button on the side of your cell.  That seems to work for me :) " CreationDate="2010-08-12T18:25:40.540" UserId="857" />
  <row Id="4181" PostId="4008" Text="Is it the correct shape at the source?" CreationDate="2010-08-12T19:58:42.960" UserId="142" />
  <row Id="4182" PostId="4018" Text="&quot;Bear in mind that even with 1 rep you can always comment on your own posts, and any answers to your questions, as per the /faq link at the top of the page.&quot;  Is he lying?  http://meta.stackoverflow.com/questions/53647/50-reputation-for-making-comments-is-too-high" CreationDate="2010-08-12T20:03:20.477" UserId="142" />
  <row Id="4183" PostId="4018" Text="@lin check the edit on my answer&#xA;" CreationDate="2010-08-12T20:22:50.797" UserId="703" />
  <row Id="4185" PostId="4018" Score="1" Text="I = C dv/dt will give you an idea of the rise time to expect. Make sure you account for all current paths, limiting resistors and loads.&#xA;&#xA;An easy way to test is to remove loading from the ATE driver and measure the rise time. Add capacitors to the output of the driver and measure. This will show you the effect of capacitance without all of the other DUT interface circuit in place.&#xA;&#xA;" CreationDate="2010-08-13T01:43:44.670" UserId="424" />
  <row Id="4186" PostId="4017" Text="Certainly laptops *attempt* to monitor battery state via the coloumb counter and voltage.&#xA;I see that Apple and other manufacturers recommend re-calibrating the battery by allowing it to completely discharge &quot;every few months&quot; ( http://support.apple.com/kb/ht1490 ).&#xA;&#xA;That implies to me that, without this calibration, the the laptop's estimate of the battery state is apparently not as accurate as one might want." CreationDate="2010-08-13T05:05:28.310" UserId="813" />
  <row Id="4187" PostId="4012" Text="Some Psion PDA's like the Ericsson MC218 had 2xAA main batteries (easily Ni**) and a CR2032 backup IIRC. I would actually run on the backup but show a warning.&#xA;&#xA;At idle it wanted what, 8mA? Turning on the disply backlight doubled that.&#xA;&#xA;Many devices have &quot;memory backup&quot; batteries or such, but they're too feeble to run the device itself." CreationDate="2010-08-13T05:14:16.863" UserId="883" />
  <row Id="4188" PostId="3000" Text="You can also find switch mode wall warts these days. Hit the flea markets." CreationDate="2010-08-13T05:39:27.373" UserId="883" />
  <row Id="4189" PostId="2930" Text="Yes, there are hysteretic LED driver chips that use an inductor and make the current ramp up and down between a low/high mark. The end result is a roughly constant current that suits LEDs/chains well." CreationDate="2010-08-13T05:40:53.050" UserId="883" />
  <row Id="4190" PostId="2930" Text=".. I expect those to be the most efficient thing. That leaves the problem of stepping down from mains. I doubt that extremely efficient total things exist ready-made if at all." CreationDate="2010-08-13T05:42:05.513" UserId="883" />
  <row Id="4191" PostId="4017" Text="Correct. Basically the battery charge meter integrates the current into and our of the cell to try and guess the battery charge. Over time, this measurement will drift. A full cycle basically lets the electronics measure the absolute charge-state, and removes the drift from the measurement." CreationDate="2010-08-13T10:57:04.060" UserId="1374" />
  <row Id="4192" PostId="4016" Text="I want to point out that BatteryUniversity sells specialized battery chargers. Therefore, it is in their interest to promulgate information about the NiCad memory effect, which seems to directly contravene information from other sources." CreationDate="2010-08-13T11:00:43.403" UserId="1374" />
  <row Id="4193" PostId="2919" Text="If you have such parts, you can also switch used ports/gates etc on logic chips, drivers and the like so you end up with ins and outs on the most convenient pins. It might look funny in a schematic but will work more neatly on a board." CreationDate="2010-08-13T12:11:43.417" UserId="883" />
  <row Id="4194" PostId="4016" Text="Thanks for pointing that out.  There are interpretations on both sides, from groups which have interest and groups which do not.  It's up for debate.  I think that BatteryUniversity is an excellent introductory resource, even if they might be biased." CreationDate="2010-08-13T12:50:20.840" UserId="857" />
  <row Id="4196" PostId="415" Text="Excellent answer, Adam." CreationDate="2010-08-13T14:38:22.633" UserId="221" />
  <row Id="4197" PostId="4016" Text="Excellent response. Forgive me for going on a tangent about: &quot;Having two equal batteries doesn't make much sense&quot; Is that so?&#xA;Of all the devices I can think of that use an AA cell or an AAA cell or a C cell, many use two equal batteries and practically all some even number of equal batteries." CreationDate="2010-08-13T15:06:57.310" UserId="813" />
  <row Id="4199" PostId="4022" Text="Just out of curiosity, why is this community wiki?" CreationDate="2010-08-13T15:39:08.053" UserId="857" />
  <row Id="4200" PostId="4024" Text="Perfect. That's exactly what I wanted to know, and I like the way you pre-emptively answered what would have been my next question." CreationDate="2010-08-13T15:54:31.613" UserId="813" />
  <row Id="4202" PostId="2919" Text="I have actually been split on this approach. Part of me wants to have the control to see that pins should be moved and do it manually. The other part of me says that for any complex board I will do, I should take advantage of features like this." CreationDate="2010-08-13T16:25:06.467" UserId="319" />
  <row Id="4203" PostId="4022" Text="I understand what &quot;wiki&quot; means on other web sites -- it means other people can fix-up my all too frequent typos, making me look smart.&#xA;The chiphacker FAQ implies it means the same thing here.&#xA;If it means something different on Stack Exchange web sites, could you give me a link to the explanation?" CreationDate="2010-08-13T16:33:53.607" UserId="813" />
  <row Id="4204" PostId="4022" Text="Here, wiki means that nobody gets any points. It's used for questions that might have multiple correct answers or provoke discussion. This question probably shouldn't be a wiki." CreationDate="2010-08-13T16:35:48.760" UserId="566" />
  <row Id="4205" PostId="4016" Text="@davidcary - You're using two different words: 'cell' and 'battery'. These are not synonymous.  Having multiple cells in series or parallel - the definition of a battery - makes lots of sense, and that's why you see it everywhere." CreationDate="2010-08-13T18:49:39.730" UserId="857" />
  <row Id="4207" PostId="4020" Text="Wow so it really is about 5.5dB... that's quite a bit of loss!" CreationDate="2010-08-14T00:53:08.373" UserId="974" />
  <row Id="4208" PostId="4016" Text="@reemrevnivek: I know of several devices that have one string of multiple cells (a battery) and another equal string of multiple cells (another battery).&#xA;Such devices generally wire both batteries in parallel, and no one has an accurate estimate of how much useful energy is left in the cells.&#xA;I'm assuming that the people who make such devices have *some* reason for using two equal batteries." CreationDate="2010-08-14T15:40:41.877" UserId="813" />
  <row Id="4209" PostId="4016" Text="Ah, the TPS110 looks like the perfect chip to implement the above scheme. Thank you." CreationDate="2010-08-14T15:46:20.447" UserId="813" />
  <row Id="4211" PostId="4029" Text="Can you give a bit more information about what Arduino shields you're using and what you're trying to achieve?" CreationDate="2010-08-15T12:41:04.110" UserId="566" />
  <row Id="4212" PostId="4029" Text="How do conditions differ when it works, and what does it do?" CreationDate="2010-08-15T16:16:14.940" UserId="106" />
  <row Id="4213" PostId="4031" Text="cool i'm lookig into it as an option now&#xA;thank you" CreationDate="2010-08-16T00:02:40.503" />
  <row Id="4216" PostId="4034" Text="i have one on order now, must play, must play" CreationDate="2010-08-16T08:06:55.893" />
  <row Id="4217" PostId="4030" Text="That's *Arduino*, after king Arduin of of Italy: http://en.wikipedia.org/wiki/Arduin_of_Italy " CreationDate="2010-08-16T08:44:49.200" UserId="484" />
  <row Id="4221" PostId="4036" Text="great ideas everyone, thank you very much, when my board arrives i will be able to set it up as needed. you are appreciated." CreationDate="2010-08-16T14:42:39.773" />
  <row Id="4222" PostId="4041" Score="2" Text="The Arduino language is C++ with automated headers and footers. In C++ (and C99) declaring variables mid code block is valid." CreationDate="2010-08-16T16:05:17.203" UserId="566" />
  <row Id="4224" PostId="469" Text="They probably did let us play with electronic parts but not with the ones you buy but with the special &quot;educational&quot; versions. I remember working with an educational &quot;binary logic&quot; board. All the components were visible only as symbols with connectors for patch cables. The educational value of that was no more than a computer simulation. It would have been fun to have been able to play with real components and at least get the idea that all the stuff you learned had some real application somewhere. And that components are quite cheap and readily available instead of &quot;special and expensive&quot;." CreationDate="2010-08-16T17:35:38.063" UserId="10" />
  <row Id="4225" PostId="4042" Score="2" Text="there a particular type of oscillator your interested in?  The how is different for various types." CreationDate="2010-08-16T18:23:18.477" UserId="703" />
  <row Id="4227" PostId="3847" Text="I am in the process of reverting my machine to XP, and then hopefully taking advantage of my Windows 7 upgrade I paid for a while back but never used." CreationDate="2010-08-16T21:04:56.680" UserId="982" />
  <row Id="4229" PostId="3846" Text="I'll give it a try, the problem I seemed to have was that whenever I released (even if I grabbed the bottom of the titlebar area) it would snap back down. That's what I'm worried will happen here, but we'll see...thx for the tip!" CreationDate="2010-08-16T21:06:41.263" UserId="982" />
  <row Id="4230" PostId="3847" Text="I do have to add that I was more interested in the linux/ubuntu side of the install, as I've seen this screencast, and that's how I got to the point on my netbook where I found my resolution wouldn't work." CreationDate="2010-08-16T21:09:40.707" UserId="982" />
  <row Id="4231" PostId="3847" Text="Added some linux info I originally posted to the user forums" CreationDate="2010-08-16T21:34:26.450" UserId="566" />
  <row Id="4232" PostId="1217" Score="1" Text="LTspice is a windows app, but is designed to also run under WINE, so you can use it on Mac/Linux with an appropriate wine-based interface layer." CreationDate="2010-08-16T23:02:34.710" UserId="484" />
  <row Id="4236" PostId="3110" Score="1" Text="Although it relies on the proprietary Xilinx toolchain, the Butterfly One includes 1) an open-source board design, 2) an open-source &quot;programmer&quot; (bitstream-&gt;flash utility), and 3) lots of open-source IP as examples. Recommended!" CreationDate="2010-08-17T14:45:11.627" />
  <row Id="4237" PostId="3847" Text="Thank you for the updates, I'll try to give it a whirl at home, this update will deserve an upvote.... :)" CreationDate="2010-08-17T17:28:14.887" UserId="982" />
  <row Id="4238" PostId="1142" Text="Looks like they've jacked the price up to $50...  I was tempted, however I found a &quot;clone&quot; on ebay for 23.99, not sure if it's any good, ever heard much about it?" CreationDate="2010-08-17T17:37:08.300" UserId="982" />
  <row Id="4239" PostId="1906" Score="1" Text="If you don't count all the energy required from the human to reset the gates each time..." CreationDate="2010-08-17T18:54:06.200" UserId="131" />
  <row Id="4240" PostId="4046" Text="Do you want to just monitor the bus, or are you looking to inject data too?" CreationDate="2010-08-17T19:19:04.603" UserId="1033" />
  <row Id="4241" PostId="4050" Text="Have you tested your Arduino on a different, working, system? I'd do that, to rule out problems with the Arduino." CreationDate="2010-08-17T19:45:03.800" UserId="566" />
  <row Id="4242" PostId="4029" Text="@Joby @Clint sorry for delay.&#xA;ethernet is Wiznet module.  condition where it fails is such:&#xA;connection is established (serial port is closed on PC), serial port is opened on PC and written to.  however, telnet connection does not receive written bytes.  other combinations, first serial connection, then telnet connection work" CreationDate="2010-08-17T21:16:08.407" UserId="1060" />
  <row Id="4243" PostId="1142" Text="It will be a clone of the PK2. If you want to work with the newer chips you will need the PK3, there aren't any clones of that as the circuit details haven't been published. I'd pay the extra and get the real thing." CreationDate="2010-08-17T21:19:45.180" UserId="305" />
  <row Id="4244" PostId="4066" Text="Getting close! It's a nice part, but at 10x10mm, it leaves almost no room for other components and wire termination, especially considering the number of vias required for a 179 pin BGA." CreationDate="2010-08-17T21:49:55.497" UserId="1024" />
  <row Id="4245" PostId="4064" Score="1" Text="Please provide details: Are you looking for one processor to handle all five inputs, or a separate processor for each?  How much processing do you need to do to the data?  What ADC resolution do you need?" CreationDate="2010-08-17T22:32:32.793" UserId="484" />
  <row Id="4247" PostId="4064" Text="Aren't there dedicated ICs made specifically to interface with it?  You can't choose different sensors?" CreationDate="2010-08-17T23:25:13.010" UserId="142" />
  <row Id="4248" PostId="4056" Text="Adiabatic logic is pretty much what I was looking for.  Something to improve on/get around the imperfections of CMOS." CreationDate="2010-08-17T23:51:20.347" UserId="142" />
  <row Id="4249" PostId="4068" Text="That's my backup plan if it turns out to be impossible to integrate all this into the available space. EtherCAT node is a couple of inches away." CreationDate="2010-08-18T00:31:38.087" UserId="1024" />
  <row Id="4250" PostId="4062" Text="If I use this step up: http://www.sparkfun.com/commerce/product_info.php?products_id=8249  do you think I could power the 12 leds?" CreationDate="2010-08-18T01:59:34.137" />
  <row Id="4251" PostId="3326" Text="and in a flash of facepalm, I'll add that when the instructions refer to the lighter blue side, it means the side that's almost white.  I thought it had a white side and a blue side and couldn't for the life of me get the toner onto the copper.  Turns out the shiny side (white) is the side coated with Dextrin." CreationDate="2010-08-18T02:50:51.273" UserId="836" />
  <row Id="4253" PostId="1754" Score="1" Text="HDL ⊕ Readable, unfortunately." CreationDate="2010-08-18T03:22:41.503" UserId="1374" />
  <row Id="4254" PostId="4070" Text="So if I used the 5v battery back all I would need to do is drop the current from the battery pack with a resistor and don't use any resistors on the LED's?" CreationDate="2010-08-18T03:51:38.590" />
  <row Id="4255" PostId="4070" Score="1" Text="@davetheguy Using higher voltage than you need and then dropping the voltage is wasteful if you're trying to get the most efficient." CreationDate="2010-08-18T04:07:00.157" UserId="131" />
  <row Id="4256" PostId="4070" Text="Well I am really just trying to get this thing to run. Long life isn't needed honestly. " CreationDate="2010-08-18T04:32:16.807" />
  <row Id="4257" PostId="4061" Score="4" Text="Really needs a schmitt trigger buffer on the input from the button (or if the flip-flop has schmitt trigger inputs that would work too). Otherwise, the FF may oscillate momentarily when the clock input rises slowly when the button is released.&#xA;(This can be somewhat mitigated with careful selection of the debouncing cap and resistor, but never eliminated)" CreationDate="2010-08-18T04:55:28.073" UserId="1374" />
  <row Id="4258" PostId="4063" Text="$0.02...maybe if you buy 27,000 of them like here: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=MMBT4124-FDITR-ND" CreationDate="2010-08-18T05:21:27.127" UserId="131" />
  <row Id="4259" PostId="4050" Text="can you please clarify, when you plug in the arduino, does the power light on the arduino come on, and windows indicate that a device has been plugged into the computer (recognized or otherwise)?" CreationDate="2010-08-18T06:46:55.570" UserId="1325" />
  <row Id="4260" PostId="4062" Text="12 x 20mA &gt; 200mA, so no" CreationDate="2010-08-18T09:23:35.067" UserId="566" />
  <row Id="4261" PostId="4048" Text="I see, thanks!&#xA;How about instead of sitting in the middle and talking to both sides, just tap into the communication passively (without the intent to change the data), logic analyzer style. Can it work?&#xA;" CreationDate="2010-08-18T09:34:03.470" UserId="752" />
  <row Id="4262" PostId="4074" Score="1" Text="I know about switching regulators, but I'm not comfortable with using them in a design.  I'm also concerned about switching noise that such a part would introduce. I would much prefer to having a heat dissipation issue than have an issue with a switch mode regulator. " CreationDate="2010-08-18T12:07:56.157" UserId="638" />
  <row Id="4263" PostId="4071" Text="+1 - But I believe that part only comes in SMT though." CreationDate="2010-08-18T13:00:04.397" UserId="374" />
  <row Id="4264" PostId="4048" Text="This is definitely possible. The USBee DX claims to be able to do this, so I would imagine any logic analyzer could take a crack at it." CreationDate="2010-08-18T13:17:35.983" UserId="974" />
  <row Id="4265" PostId="4071" Text="Yeah but even the cheapest microcontroller is going to cost more than simple digital logic.  It's a pretty complex system to do a simple task, and you're opening yourself up to the world of software bugs.  Also, does it increase production costs to be programming every micro?" CreationDate="2010-08-18T13:19:09.287" UserId="142" />
  <row Id="4267" PostId="4063" Text="$0.03 is an awful lot like $0.02 in small quantities..." CreationDate="2010-08-18T13:24:05.480" UserId="1325" />
  <row Id="4268" PostId="4060" Text="I think the best answer to this depends on the asker and whether or not you are more comfortable with a hardware or a software solution." CreationDate="2010-08-18T13:24:24.463" UserId="374" />
  <row Id="4269" PostId="4070" Score="1" Text="You could also use brighter LEDs with less current. They tend to be more expensive, but that may be well worth it in this case." CreationDate="2010-08-18T13:24:39.407" UserId="339" />
  <row Id="4270" PostId="4048" Text="Can an AVR running on 12Khz oscillator function as a passive listener (slow usb, hid)?&#xA;&#xA;" CreationDate="2010-08-18T13:31:27.203" UserId="752" />
  <row Id="4271" PostId="4070" Text="@davetheguy: With a 5 V pack, you could use 6 strings of LED-LED-resistor. The LEDs in each string would drop 4 V, so you want to drop the remaining 1 V across the resistor. 1 V / 0.020 A = 50 ohms. Your efficiency would be around 80%, and you could estimate the battery life if you knew the battery capacity in Wh, or V * Ah.  " CreationDate="2010-08-18T13:32:14.770" UserId="712" />
  <row Id="4272" PostId="2889" Text="a bridge rectifier does not output the Peak to peak voltage of its input, it rather outputs the zero to peak voltage.  " CreationDate="2010-08-18T13:36:14.433" UserId="1325" />
  <row Id="4273" PostId="4071" Text="So you'd use the internal pull-up resistor on PB0 set up as a digital input and then ground it to trigger it, right?  You shouldn't need a resistor in series with the switch that way." CreationDate="2010-08-18T13:56:10.623" UserId="142" />
  <row Id="4274" PostId="4075" Text="Personally, I need a standalone solution, but the question is meant to be general." CreationDate="2010-08-18T13:57:47.580" UserId="142" />
  <row Id="4275" PostId="4063" Text="3904s for 1.4 cents: http://www.newark.com/on-semiconductor/mmbt3904lt1g/bipolar-transistor-npn-40v-sot/dp/83K0942  At high quantities, capacitors are like 1 cent, and resistors are like 1/10th of a cent." CreationDate="2010-08-18T14:02:06.760" UserId="142" />
  <row Id="4276" PostId="4061" Text="Could you not also use an RC filter in the feedback path to prevent bouncing?" CreationDate="2010-08-18T14:10:38.853" UserId="142" />
  <row Id="4277" PostId="4074" Text="You might look at better ways to even the power distribution then. Use multiple regulators, pre-regulate or find some other way to bring the input voltage down or use separate pass elements (probably shown in datasheet as &quot;increasing current capacity&quot; or such). Those should be easier to cool that single small hot chip." CreationDate="2010-08-18T15:14:59.130" UserId="883" />
  <row Id="4278" PostId="4060" Text="It also depends on where this output switch is and what voltages (states!) you have available." CreationDate="2010-08-18T15:17:10.267" UserId="883" />
  <row Id="4279" PostId="4070" Score="1" Text="If you find that the LED drive losses are significant, there are some switching (hysteretic) LED drivers that can probably do better. You can make the MCU run more efficiently by smart coding and controller selection (keep it in sleep mode as much as possible). Either way, the LEDs themselves will probably be the power hog. Unless you can switch to HE LEDS as said or some other display technology (I presume this is  display). Hard to say anything wihtout knowing the actual application." CreationDate="2010-08-18T15:49:33.383" UserId="883" />
  <row Id="4280" PostId="4080" Score="4" Text="Can you give some more information on your project?  External Flash and RAM are available if you just need more memory.   Also, what does &quot;hobbyist friendly&quot; mean to you?  Are you concerned about the physical package, toolchain, cost, program complexity, peripheral complexity, and/or something else?" CreationDate="2010-08-18T17:21:07.457" UserId="857" />
  <row Id="4281" PostId="4060" Text="Just two states, high and low, like any digital logic.  If you want to do multiple states that you're cycling through, I think that would require a microcontroller.  You'd probably have one in your circuit anyway for that." CreationDate="2010-08-18T17:54:55.103" UserId="142" />
  <row Id="4282" PostId="4078" Text="Couldn't find CUI's regulators, but the Recom part number is R-78XX-0.5 (R-783.3-0.5 in this case) - See http://bit.ly/dz0WGq, and TI makes a similar product, the PT78HT2XX (PT78HT233) - see  http://www.ti.com/lit/gpn/pt78ht205" CreationDate="2010-08-18T18:00:26.300" UserId="857" />
  <row Id="4283" PostId="3857" Text="@jesse well put. There's definitely something to be said for doing something totally ridiculous. " CreationDate="2010-08-18T19:02:52.377" UserId="1033" />
  <row Id="4284" PostId="2946" Text="I'm essentially in the same project at my place too. When I get it done I'll try to remember to let you know, and if you have some time, let me know too!!! (I am however hoping to read the CAN bus, and eventually find a way to control my iPod with my steering wheel controls, not sure how yet)" CreationDate="2010-08-18T19:27:43.447" UserId="982" />
  <row Id="4285" PostId="4087" Text="A fine answer, Nivek! +1 for pulling off the existing connector and soldering on wires. I hate those damn JST connectors." CreationDate="2010-08-18T19:58:58.720" UserId="712" />
  <row Id="4287" PostId="4087" Text="@Ping - I love JST connectors. I use them almost every day.  However, I have the crimp tool. PS My name is Kevin. " CreationDate="2010-08-18T20:02:34.617" UserId="857" />
  <row Id="4288" PostId="4088" Score="2" Text="I wouldn't consider gumstix hobbyiest friendly. tiny connectors and OE isn't exactly easy for people to use. :-)" CreationDate="2010-08-18T20:17:32.617" UserId="974" />
  <row Id="4289" PostId="4087" Text="Yeah, if I had the crimp tool, I'd probably feel differently. PS Sorry about misspelling your name. I had kind of guessed your name was Kevin, but I thought it was funnier to call you Nivek." CreationDate="2010-08-18T20:25:32.117" UserId="712" />
  <row Id="4290" PostId="4088" Text="The tiny connectors are definitely a pain, but with a breakout board, I think they're pretty good. Personally, I think I'd take the Beagleboard over a Gumstix." CreationDate="2010-08-18T21:06:06.790" UserId="712" />
  <row Id="4291" PostId="4088" Text="By the way, just out of curiosity, why is it so hard to find powerful boards that are easy to use? Is it just that as the power goes up, the complexity rises? Or are most hobbyists too poor to afford more expensive boards, so none of the vendors care about ease of use?" CreationDate="2010-08-18T21:08:00.080" UserId="712" />
  <row Id="4292" PostId="4088" Score="5" Text="@pingswept - I was considering the same question, and I came to the conclusion that more powerful micros are useless without complexity to exercise the functionality. It's like the &quot;If you give a mouse a cookie&quot; story: If you give a processor designer lots of memory, he's going to want lots of peripherals to go with it.  If you give him lots of peripherals, he's going to want an NVIC and DMA to go with them.  If you give him DMA and an NVIC, he's going to want lots of pins to exercise them.  If you give him lots of pins, he's going to want a fine pitch package.  " CreationDate="2010-08-18T21:28:11.257" UserId="857" />
  <row Id="4293" PostId="4088" Score="1" Text="Also, &quot;Powerful&quot; doesn't ever mean the same thing to everyone.  This question is about the availability of an 8-bit micro with gobs of memory.  Maybe the OP has a use for it, but a faster 32-bit micro with more complexity to go with that memory is useful to more people." CreationDate="2010-08-18T21:33:10.023" UserId="857" />
  <row Id="4294" PostId="1696" Text="Not merely a binary file editor that displays in hex, but an actual hex-record editor? that would be cool. Wants one." CreationDate="2010-08-18T22:14:10.483" UserId="740" />
  <row Id="4296" PostId="4057" Text="@Brad - Do you have any personal experience with the Beagle USB 12 Protocol Analyzer?" CreationDate="2010-08-18T22:28:17.120" UserId="529" />
  <row Id="4297" PostId="4091" Score="1" Text="+1, this was the solution i went to post. 56 ohms is a good choice, or you could stick a 47 ohm in to leave a little headroom in the &quot;about 14V&quot; supply." CreationDate="2010-08-18T23:24:52.557" UserId="740" />
  <row Id="4298" PostId="4071" Score="1" Text="@TokenMacGuy No current should flow from PB0 to GND, since PB0 would be an input, not an output. @endolith correct, using the internal pull-up means no need for external pull-up. (In addition, the pull-up is not in series with the switch, with either an internal or external pull-up). @sheepsimulator coming in SMT is only a problem for the hobbyist. In that case, an extra dollar or two wouldn't be a problem, and you can easily step up to the 8-pin DIP ATtiny25." CreationDate="2010-08-19T00:46:49.910" UserId="131" />
  <row Id="4299" PostId="4071" Text="@endolith It depends on the application I guess. There are always tradeoffs. Everything but the very most basic of device has some sort of logic in it. Saying you open yourself up to the world of software bugs isn't that big of a deal...without the mcu you open yourself up to hardware bugs, since you are constructing some sort of digital/analog circuit to perform logic." CreationDate="2010-08-19T00:50:01.543" UserId="131" />
  <row Id="4301" PostId="4087" Text="I've successfully crimped those connectors with a $8.95 jameco crimper( http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_99443_-1 ). It's a lot more labor-intensive, and the resulting crimp doesn't look very nice, but it is certainly sturdy enough to un-mate the connector out by gripping just the wires" CreationDate="2010-08-19T04:58:24.900" UserId="1374" />
  <row Id="4302" PostId="1703" Score="2" Text="This also works on windows. It's part of the KDE for windows package." CreationDate="2010-08-19T04:59:12.573" UserId="1374" />
  <row Id="4303" PostId="4088" Text="@reemrevnivek - I think it's more that the majority of the market for small micros does not require large amounts of processing power, so the economies of scale prevents a large variety of powerful MCUs from being available." CreationDate="2010-08-19T05:01:44.943" UserId="1374" />
  <row Id="4304" PostId="4094" Score="1" Text="Do I understand correctly that you're looking for some sort of electromechanical actuator, like a small robotic hand, that can flip switches and push buttons? I suspect you might need two items-- a solenoid of some sort for pushing buttons, maybe with an attachment for flipping switches." CreationDate="2010-08-19T12:26:25.053" UserId="712" />
  <row Id="4305" PostId="2758" Text="Fascinating site" CreationDate="2010-08-19T12:52:06.227" UserId="1033" />
  <row Id="4306" PostId="4095" Score="1" Text="With some AVRs you need certain minimum voltages for higher clock speeds, could be that?" CreationDate="2010-08-19T12:54:50.677" UserId="566" />
  <row Id="4307" PostId="4094" Text="Thanks! You understand correctly. However I'll be glad if you can give me references for all those items you mentioned, as I'm not educated with robotics at all, I'm not familiar with all the terms in your comment." CreationDate="2010-08-19T12:55:04.937" UserId="1076" />
  <row Id="4309" PostId="4094" Score="2" Text="http://oomlout.com/a/products/sesw/ is a servo that attaches to a standard North American light switch." CreationDate="2010-08-19T13:43:35.213" UserId="1363" />
  <row Id="4310" PostId="4088" Text="@Fake Name - I can't follow your logic. It's redundant to say that small micros need small amounts of processing power, and powerful micros need to be powerful, but this doesn't mean that there is no demand for big micros.  There is a *huge* market for powerful MCUs in cell phones and media players.  Maybe I'm not understanding your definition of &quot;small&quot;?" CreationDate="2010-08-19T16:50:37.467" UserId="857" />
  <row Id="4312" PostId="4081" Text="And use the built-in &quot;bc&quot; precision calculator =) And a USB keyboard for user input, and a USB LCD Display for the frame buffer. Hmm, the Slug has everything you need! " CreationDate="2010-08-19T17:27:27.400" UserId="1033" />
  <row Id="4313" PostId="4079" Score="1" Text="How would you &quot;un-latch&quot; it though? Bringing the magnet close to the sensor a second time wouldn't dis-engage it, would it?" CreationDate="2010-08-19T18:28:16.940" UserId="131" />
  <row Id="4314" PostId="4099" Score="1" Text="The schematic in the first link requires registration to view, could you upload the img somewhere else so people could more easily view it?" CreationDate="2010-08-19T18:30:32.170" UserId="131" />
  <row Id="4315" PostId="4093" Score="1" Text="listening to it now - it's great!&#xA;Love the banter, it's especially funny when Dave tries to get Chris to say solder properly! [sorry Dave - &quot;soder&quot; is definitely wrong :)] Dave's random swearing and outbursts are a refreshing change to the usual grey drabness found in tech land" CreationDate="2010-08-19T19:14:24.453" UserId="399" />
  <row Id="4316" PostId="954" Score="1" Text="@tronixstuff - Whether he is an EE or not doesn't do anything to mitigate the fact that his videos are just plain obnoxious." CreationDate="2010-08-20T02:30:55.063" UserId="1374" />
  <row Id="4317" PostId="4102" Score="1" Text="Also, testing the switch outputs may reveal that they're interfacing  TTL or CMOS logic, which could be directly connected to the output of your device." CreationDate="2010-08-20T04:08:23.073" UserId="857" />
  <row Id="4318" PostId="4099" Text="can you see it now?" CreationDate="2010-08-20T04:44:40.273" UserId="142" />
  <row Id="4319" PostId="4095" Text="It would help guessing if you could show what exactly doesn't work and how. Maybe make a minimal test program that works on slow clock but not on a fast one." CreationDate="2010-08-20T05:28:09.713" UserId="883" />
  <row Id="4320" PostId="3941" Text="A number of users with higher Rep can edit your question when you do not click community wiki." CreationDate="2010-08-20T13:07:15.340" UserId="230" />
  <row Id="4321" PostId="4086" Text="I guess I would feel ackward asking sparkfun to give me the P/N of a part they sell on another distributor. Which is why I asked over here instead." CreationDate="2010-08-20T13:59:21.830" UserId="982" />
  <row Id="4322" PostId="4087" Text="I haven't looked into just desoldering the connector, that might just be the right idea I'm looking for. Can't believe I didn't think of that. Thank you!" CreationDate="2010-08-20T14:00:20.143" UserId="982" />
  <row Id="4323" PostId="4079" Text="I believe you would have to reverse the polarity of the magnet to &quot;clear it&quot; I will haave to hook it up again at home to test it out to be sure though, however I'm looking into how long it takes to &quot;reset&quot; if you remove power. I might be able to use it for my project that I was going to, by killing power for the specified time (provided it's not too long)" CreationDate="2010-08-20T14:02:15.787" UserId="982" />
  <row Id="4324" PostId="3847" Text="I don't have internet at home atm, so I haven't messed with the linux side since I can't download anything, BUT I did restore my xp image to my old laptop and brought up the windows side I had already downloaded on my netbook and it looks like everything I needed it to is working (from what I can tell) so now to figure out if I can do it in linux is the real test. -- Thank you for all the help." CreationDate="2010-08-20T14:05:30.133" UserId="982" />
  <row Id="4325" PostId="3538" Text="I just bought this a month ago, since I was working with a netbook primarily, I had issues with the screen size of my computer to be able to click the &quot;capture&quot; button, but if you have a normal sized laptop or desktop computer you'll be fine. I haven't used it extensively, but I the little I have I like, and the price is nice too!" CreationDate="2010-08-20T14:10:57.083" UserId="982" />
  <row Id="4326" PostId="3941" Text="Good point. Maybe I should have read the FAQ a bit more closely." CreationDate="2010-08-20T15:52:49.890" UserId="965" />
  <row Id="4327" PostId="4109" Text="Can you give some specific places to buy ARM chips? I can't seem to find very many ARM processors outside of development boards. And yea I guess I need to work on my SMD soldering skills then :)" CreationDate="2010-08-20T20:57:29.380" UserId="708" />
  <row Id="4328" PostId="4109" Text="And also I think I'll take this project in stages. At first I'll just worry about the basics with AVR and such, eventually I think it'd be nice to expand to a more powerful system though utilizing ARM" CreationDate="2010-08-20T20:58:25.523" UserId="708" />
  <row Id="4329" PostId="4109" Text="@earlz re: your first comment - Any place which sells micros at all will sell ARM products - Digikey, Mouser, Newark, Arrow, Allied, Future, sparkfun... Just name your distributor.   It's important to understand that ARM doesn't manufacture any physical chips, they make IP, which they then sell to a chip manufacturer (Atmel, TI, etc.) who make an ARM-compliant microcontroller.   To select a chip, first choose your core (ARM7, ARM9, Cortex M3, etc.), then go to a distributor, and see what options the manufacturers have. " CreationDate="2010-08-20T23:10:04.383" UserId="857" />
  <row Id="4330" PostId="4109" Text="@earlz re: your second comment - This depends on your approach.  Your AVR -&gt; ARM proposal is a fine idea if you want to write pure C for your application code, and then just write a hardware abstraction layer for each processor.  You won't use the full capabilities of the ARM this way, but that's OK. However, the AVR and embedded Linux approaches are fundamentally different.  If you expect to go to embedded Linux, I'd suggest purchasing a dev kit with a screen and button pad interface (this could be an AVR daughter board or keyboard), and then the second stage would be to make your own board." CreationDate="2010-08-20T23:17:25.790" UserId="857" />
  <row Id="4331" PostId="4112" Text="Can you clarify &quot;similar to the iPhone or iPad&quot; do you mean glass capacitive on color TFT?  Each of these points adds cost and complexity.  Which are essential to you?  Favorite-ing this so I can find it later..." CreationDate="2010-08-20T23:27:45.800" UserId="857" />
  <row Id="4332" PostId="1024" Text="You can always change your mind later if things change :)" CreationDate="2010-08-21T06:43:30.003" UserId="689" />
  <row Id="4333" PostId="64" Text="Ti has also come up with some neat devkits again &#xA;http://processors.wiki.ti.com/index.php?title=Ezdsp&#xA;" CreationDate="2010-08-21T09:46:47.013" UserId="883" />
  <row Id="4334" PostId="4096" Text="Hi, I have tried these division factors: 128, 64, 32, 16.&#xA;in 6Mhz it works with every one of them, but in 12Mhz it has no effect at all.&#xA;I used ADCSRA=0x87 (for example) in my CodeVision initialization code.&#xA;thanks" CreationDate="2010-08-21T13:46:36.760" />
  <row Id="4336" PostId="1024" Text="I hope noone takes my selection personally. It is the only program here that I have actually used to generate schematics for chiphacker. It takes me less than 2 minutes to have something posted. I will update the answer if something else becomes available. AAcircuit is not good for more complicated circuits." CreationDate="2010-08-21T13:58:03.403" UserId="230" />
  <row Id="4337" PostId="4119" Text="i've used vim on hex files, too, and you know, if there was some way to make a vim macro/plug-in/something that could recalculate the checksum, that would be a 99% solution. " CreationDate="2010-08-21T20:12:09.577" UserId="740" />
  <row Id="4338" PostId="4096" Text="Are you using a bypass capacitor between Vcc and GND? Have you tried filtering the analog vcc / aref as recommended in the datasheet? Are you using a solderless breadboard that can't handle high frequencies instead of a PCB?" CreationDate="2010-08-22T01:38:06.603" UserId="1363" />
  <row Id="4339" PostId="4119" Text="JustJeff: That's an interesting idea. It should be easy, I will try looking into it. (will have to learn some vimscript for this, but I wished to learn it anyway)" CreationDate="2010-08-22T20:29:13.897" UserId="659" />
  <row Id="4340" PostId="4124" Text="Excellent answer. Really excellent." CreationDate="2010-08-23T04:26:03.470" UserId="712" />
  <row Id="4341" PostId="4124" Text="Don't forget to mention Thumb2, which is an even larger improvement for most applications." CreationDate="2010-08-23T05:20:26.457" UserId="867" />
  <row Id="4342" PostId="4124" Text="Very interesting read. I'm learning a lot just reading questions and answers on this site." CreationDate="2010-08-23T12:55:38.100" UserId="982" />
  <row Id="4343" PostId="4122" Text="@Mark - doesn't overclocking also affect your RAM with certain parameter changes?  I had a friend that overclocked his i5, and his slot0 on the motherboard became damaged and caused memtest errors.  He changed the BCLOCK." CreationDate="2010-08-23T13:37:59.947" UserId="374" />
  <row Id="4344" PostId="4102" Text="@TokenMacGuy, the reason that I oppose modifications to this devices is: (1) Many times those are light switches which are connected directly to the home electricity network. Not sure I want to deal with that. (2) Actuator is more &quot;portable&quot;, if a friend jumps over and brings his stereo system - I can use my button pusher. If I want to turn on the air condition using its remote control - I can do that with the same button-pusher." CreationDate="2010-08-23T17:15:16.147" UserId="1076" />
  <row Id="4345" PostId="4112" Score="2" Text="Yeah, you can get small resistive touchscreens for super cheap, but I haven't found any good source for capacitive touchscreens. See my related question at: http://chiphacker.com/questions/259/capacitive-touchscreen-for-diy-usage" CreationDate="2010-08-23T18:10:41.047" UserId="131" />
  <row Id="4346" PostId="3567" Text="I usually use alt-printscreen + mspaint + imageshack.us. Same effect as above, maybe slightly more steps to follow, but works on every version of windows without installing anything." CreationDate="2010-08-23T18:19:48.840" UserId="131" />
  <row Id="4347" PostId="4126" Text="I see, I misunderstood what gerber files were for. Thought we could use them only for the holes and drills layers. Thanks for the link, I'll check it out." CreationDate="2010-08-23T18:30:56.667" UserId="1081" />
  <row Id="4350" PostId="4128" Text="For what I've been reading Excellon is much simpler than gcode so I think we have a winner :)" CreationDate="2010-08-23T20:02:08.143" UserId="1081" />
  <row Id="4351" PostId="4122" Text="@sheepsimulator - nice name :) and check my edit.  In short, he could have wildly overclocked his ram if he just blindly cranked up BCLK without lowering the memory multiplier.  RAM generally doesn't have much, if any, thermal protection so you have to pay attention to your memory clocks." CreationDate="2010-08-23T20:13:48.110" UserId="703" />
  <row Id="4352" PostId="4130" Score="1" Text="You say you're running a logger.  Would you care to post the code which should be running while you're taking your logs?  I strongly suspect that you do have some sort of stack overflow/null pointer issue.  " CreationDate="2010-08-23T22:44:42.753" UserId="857" />
  <row Id="4354" PostId="4130" Score="1" Text="Also, *when* should the system does not reset?  There are lots of ways to reset the micro (or at least make it start from the beginning of your code). Do you want it to continue running when a certain error is triggered? When you switch your program counter to 0x00? When the watchdog timer is triggered? When the reset button is pressed? If you do want one or more of these conditions, what should it do instead if it thinks it's so badly broken that it needs to reset?" CreationDate="2010-08-23T22:49:44.337" UserId="857" />
  <row Id="4355" PostId="4016" Text="+1 TPS110 recommendation.  We actually went with the TPS2113.  It was a perfect fit, almost like someone designed this chip just for our application." CreationDate="2010-08-23T23:30:03.570" UserId="1278" />
  <row Id="4356" PostId="4124" Text="Thank you very much Andrew, excellent answer, it helped me a lot with my doubt :)" CreationDate="2010-08-24T05:42:11.420" UserId="170" />
  <row Id="4357" PostId="4130" Text="Is there a way to emulate the processor on a computer?" CreationDate="2010-08-24T13:58:32.500" UserId="142" />
  <row Id="4358" PostId="4122" Text="@Mark - Cool.  Thanks for the response." CreationDate="2010-08-24T14:21:51.300" UserId="374" />
  <row Id="4359" PostId="4138" Text="It's an IR receiver circuit (dangerousprototypes.com/docs/USB_Infrared_Toy_schematic_and_partlist). It has an IR receiver, an IR LED, and a 20MHz crystal. The heat comes from the PIC, near the USB connector." CreationDate="2010-08-24T14:34:41.143" UserId="1084" />
  <row Id="4360" PostId="4133" Score="3" Text="+1 for &quot;petting&quot; the watchdog lol" CreationDate="2010-08-24T17:00:54.107" UserId="771" />
  <row Id="4361" PostId="4133" Score="1" Text="+1 for mentioning the watchdog timer. As far as I remember you need to explicitly disable it during startup, if you do not want to use it." CreationDate="2010-08-24T18:23:59.027" UserId="718" />
  <row Id="4362" PostId="4133" Score="1" Text="Yes, that was the immediate association for me too. And like another answer said, check the reset vector for clues." CreationDate="2010-08-24T19:09:46.877" UserId="883" />
  <row Id="4363" PostId="4141" Text="The PIC18 has a number of power management modes including an idle mode which allows the timer (and interrupts) to continue running while the processor isn't executing.  Therefore, the RC circuit shouldn't be necessary.  I agree that managing power with sleep/idle/run states is a great idea, but it would be hard to put your proposed circuit on this board." CreationDate="2010-08-24T19:33:34.427" UserId="857" />
  <row Id="4364" PostId="4133" Text="From now on, instead of retriggering or restarting my watchdog timers, I will pet them.  Good answer, by the way." CreationDate="2010-08-24T19:36:52.937" UserId="857" />
  <row Id="4366" PostId="4142" Text="The problem is when the device is enclosed in a case, then the PIC gets warmer." CreationDate="2010-08-24T20:23:25.603" UserId="1084" />
  <row Id="4367" PostId="4056" Text="Though I'd still like to know the lowest possible amount of energy theoretically necessary to process information." CreationDate="2010-08-24T21:08:28.453" UserId="142" />
  <row Id="4368" PostId="56" Text="For the record, cats can hear up to about 65 kHz, vs 20 kHz for humans (so sayeth the Internet)" CreationDate="2010-08-24T21:24:52.060" UserId="142" />
  <row Id="4369" PostId="4140" Text="Is there any reference you could point me to which explains this issue in some detail? Thanks!" CreationDate="2010-08-25T04:42:16.447" UserId="1085" />
  <row Id="4370" PostId="4148" Text="RAM? Would it be ever possible to keep in RAM that pointer through the lifecycle of the system? " CreationDate="2010-08-25T06:45:58.490" />
  <row Id="4371" PostId="4140" Text="sure, how about http://en.wikipedia.org/wiki/Three-state_logic and &#xA;http://www.cs.umd.edu/class/spring2003/cmsc311/Notes/CompOrg/tristate.html" CreationDate="2010-08-25T16:14:10.320" UserId="771" />
  <row Id="4372" PostId="4155" Text="have you read the wikipedia article on the subject? http://en.wikipedia.org/wiki/Charlieplexing" CreationDate="2010-08-25T16:31:20.930" UserId="771" />
  <row Id="4374" PostId="4155" Text="	Yes, exhaustively, and reviewed UziMonkey's stuff (which was very helpful at the beginning), and reviewed the Arduino forum stuff. There may be an obvious answer, but I am a bear of very little brain :)" CreationDate="2010-08-25T17:10:11.680" UserId="989" />
  <row Id="4375" PostId="4152" Text="Actually ,the &quot;RS232 in --&gt;TTL out--&gt;TTL in--&gt;Rs232 out&quot; are all on the same MAX-232 chip as shown in the figure." CreationDate="2010-08-25T17:31:13.113" UserId="921" />
  <row Id="4376" PostId="4156" Text="The devices are already on rs232. I don't want to put a MCU in between; just wanted to keep it simple :)" CreationDate="2010-08-25T17:32:53.377" UserId="921" />
  <row Id="4377" PostId="4154" Text="I tried the configuration shown in my figure (with the max232 looped in) and without it (directly to my PC's com ports). Both work fine. Now is a MAX-232 really needed in between? Does it provide a buffering action at all?" CreationDate="2010-08-25T17:35:39.100" UserId="921" />
  <row Id="4378" PostId="4154" Text="I don't think you need the MAX-232 -- the input to your PC COM port is probably pretty similar to the one on the MAX-232 chip, so the load would be the same." CreationDate="2010-08-25T17:50:18.830" UserId="1322" />
  <row Id="4379" PostId="4157" Text="Yeah, I know they CAN cross, but I'm trying like the devil to avoid that." CreationDate="2010-08-25T17:58:04.480" UserId="989" />
  <row Id="4380" PostId="4140" Text="I meant more for a reference for why multiplexers are not used in RAM. While the cmu reference certainly implies it when it mentions the current issue with large fan-in/fan-outs, it would be great to have a reference that explicitly mentions this. " CreationDate="2010-08-25T18:25:11.630" UserId="1085" />
  <row Id="4381" PostId="4159" Text="Yeah, that's the conclusion I've reached, too. " CreationDate="2010-08-25T18:48:18.357" UserId="989" />
  <row Id="4382" PostId="4148" Text="That depends on what you're doing.  Many times, this is indeed possible.  Imagine a small, self-contained datalogger. It might operate for years on a main battery, plus have a backup battery to maintain power through battery changes.  &#xA;&#xA;Flash memory doesn't last forever-- typically 10k - 100k cycles per page.  Whether that lifetime is minutes or decades depends heavily on your application." CreationDate="2010-08-26T00:51:28.477" UserId="484" />
  <row Id="4383" PostId="4157" Score="1" Text="@Chris - It's far better to have a logically organized schematic than one which has no crossing lines, or one which mimics the layout too closely.  Usually, the goal is to have current flowing from left to right, with high voltages at the top and lower ones at the bottom.  I understand that this is next to impossible with a Charlieplexed circuit,  but jluciani's method isn't bad. See tc3.iec.ch/pdf_files/pdf_tc3/3_594.pdf " CreationDate="2010-08-26T02:09:08.143" UserId="857" />
  <row Id="4384" PostId="4160" Text="The basestation works quite easily, btw. I even wrote some application using mingw on Debian that ran in Wine that could be dropped to a windows host with no changes." CreationDate="2010-08-26T06:21:19.617" UserId="883" />
  <row Id="4388" PostId="4164" Score="2" Text="however, perhaps an image processing shield exists, or could be developed, so that the Arduino would merely be doing the job of reading information from shields and commanding the invocation of certain actions from other shields" CreationDate="2010-08-26T17:23:33.983" UserId="771" />
  <row Id="4389" PostId="4131" Text="Lots of good info here. However they shouldn't be that much harder to work with...just because I have a 1024x768 touch digitizer, doesn't mean I need a 1024x768 LCD behind it. They are two separate issues." CreationDate="2010-08-26T18:17:23.763" UserId="131" />
  <row Id="4390" PostId="2082" Text="Check out `pk2-la` if you're running linux + PICkit2" CreationDate="2010-08-26T19:41:41.193" UserId="814" />
  <row Id="4391" PostId="4168" Text="Datasheet at http://www.wolfsonmicro.com/documents/uploads/data_sheets/en/WM8761.pdf" CreationDate="2010-08-26T20:41:50.407" UserId="566" />
  <row Id="4392" PostId="4169" Text="They're everywhere on computer motherboards, because they use lots of high speed busses. Take a look!" CreationDate="2010-08-26T20:58:58.297" UserId="1374" />
  <row Id="4394" PostId="4169" Score="2" Text="20 ms is 50 hz. I think you mean 20ns." CreationDate="2010-08-27T05:15:34.437" UserId="1374" />
  <row Id="4395" PostId="3811" Score="1" Text="HEAT was the answer i connected a TEMP sensor to my old bolt was lucky to get 100 degrees out of it" CreationDate="2010-08-27T08:34:29.597" UserId="665" />
  <row Id="4396" PostId="4174" Score="2" Text="Actually it's not VGA at all. VGA is analog component RGB, while CGA is digital TTL RGBI." CreationDate="2010-08-27T10:23:05.777" UserId="1091" />
  <row Id="4397" PostId="4177" Text="Well, maybe... But I really want the 320x200 resolution, and maybe it doesn't..." CreationDate="2010-08-27T11:48:19.613" UserId="1091" />
  <row Id="4398" PostId="4177" Text="That code generates exactly the frequencies you mentioned which are the same as an NTSC signal. The original CGA has a composite video output and a monitor plug. It's rather likely the internal monitor on these things uses the composite signal according to deduction and cursory inspection of vintage hardware forae. Why would they even bother going to the trouble to send a full color signal to an amber screen?" CreationDate="2010-08-27T13:24:09.997" UserId="1363" />
  <row Id="4399" PostId="4169" Text="Apparently related terms: &quot;skew minimization&quot;, &quot;skew control&quot;, &quot;serpentine delay&quot;, and you can do a trombone shape instead?" CreationDate="2010-08-27T14:11:29.050" UserId="142" />
  <row Id="4400" PostId="4181" Text="I'm interested in doing some reverse engineering of the MSP430 launchpad dev board's usb communication under linux. Do you know where I could find some more information on the devices under /dev that I can directly communicate with?" CreationDate="2010-08-27T16:35:21.580" UserId="536" />
  <row Id="4401" PostId="4183" Text="Thanks! That chip looks useful. A little more expensive but with a more desirable (lower) high-level input voltage." CreationDate="2010-08-27T16:54:20.780" UserId="1363" />
  <row Id="4402" PostId="4169" Text="That trace doesn't look like it's part of a bus...so how would it be used for matching propagation delays?" CreationDate="2010-08-27T19:43:36.757" UserId="1278" />
  <row Id="4403" PostId="2425" Text="Also, what speed is the USB port?" CreationDate="2010-08-27T20:18:33.583" UserId="142" />
  <row Id="4404" PostId="4187" Score="1" Text="great post thanks." CreationDate="2010-08-28T04:52:14.957" UserId="1200" />
  <row Id="4405" PostId="4169" Text="@ajs410 - The other traces may be on the other side of the board, or on internal layers. Remember, in this context, &quot;Bus&quot; basically means any place with more than one high speed data signals. It can be as few as two traces (Data, clock)." CreationDate="2010-08-28T05:41:20.990" UserId="1374" />
  <row Id="4406" PostId="4169" Score="1" Text="@endolith, you can do other shapes, but you generally don't want the very beginning of the trace running too close to the very end, since they will couple together capacitively." CreationDate="2010-08-28T05:42:47.823" UserId="1374" />
  <row Id="4407" PostId="4175" Score="1" Text="&quot;Frontend&quot;, &quot;Backend&quot;? Never heard those particular terms. With Circuit board design, there is the schematic and PCB stage. With embedded logic/ASIC work, there is HDL, layout, and routing. Can you be more specific?" CreationDate="2010-08-28T05:45:17.167" UserId="1374" />
  <row Id="4408" PostId="2789" Score="1" Text="I have one, they're excellent. Also, they have hardware compression, so you can get ~30 sec of sampling on two data lines, if the bus is quiescent for a while between packets." CreationDate="2010-08-28T05:53:17.210" UserId="1374" />
  <row Id="4411" PostId="4185" Text="There is a third, which is modified Harvard. A pure Harvard wouldn't be able to use the same storage to keep both programs and data. Therefore almost every implementation of Harvard has been modified to allow instruction memory to be addressed as data." CreationDate="2010-08-28T12:46:34.743" UserId="776" />
  <row Id="4412" PostId="4169" Text="@ajs410: There are other DACs on the board, also with these, of different shapes." CreationDate="2010-08-28T16:00:30.533" UserId="142" />
  <row Id="4413" PostId="2425" Text="The FT2232H is Hi-Speed, so I would plan for the &quot;worst case&quot; where the computer is Hi-Speed also." CreationDate="2010-08-28T16:03:39.590" UserId="319" />
  <row Id="4415" PostId="4195" Text="How do I check the number if I have a register containing zero? Also I want to generate just one bit which is true or false depending upon if the bus of 16 bits is zero or not" CreationDate="2010-08-28T19:22:48.333" UserId="1200" />
  <row Id="4416" PostId="4184" Text="Well, thanks for that I always run them at 5 volt which gives me problems sometimes, I will run pack at 7v and tie into the Vin and the normal GND." CreationDate="2010-08-29T00:45:44.653" UserId="665" />
  <row Id="4418" PostId="4197" Score="1" Text="This is also typical of the 32-bit ARM chips, and may be typical of most architectures. For the ARM, the APSR (Application Program Status Register) holds N, Z, C, V and Q bits (Negative, Zero, Carry, oVerflow, saturateQ) bits to provide other functions in addition to the zero bit you're looking for. These may or may not be useful to your machine." CreationDate="2010-08-29T01:46:08.377" UserId="857" />
  <row Id="4419" PostId="4193" Score="2" Text="To clarify, edebill should be using BOD." CreationDate="2010-08-29T01:55:19.087" UserId="857" />
  <row Id="4421" PostId="4177" Text="An extension of joe's comment would be that it would probably be easiest to get a graphics card that has composite out already, and skip the arduino :(" CreationDate="2010-08-29T01:59:33.830" UserId="857" />
  <row Id="4422" PostId="4198" Text="For later readers, the &quot;35 pounds each&quot; is the cost, not the weight.  It's a little more than $60 US to get it to the States at the current exchange rate." CreationDate="2010-08-29T02:02:14.033" UserId="857" />
  <row Id="4423" PostId="4131" Text="@davr, I agree with your statement that LCD and touchscreen resolutions are unrelated, but that doesn't mean they're easy.  Quoting my post: &quot;During initialization, the touchscreen and host exchange packets of about 80K bytes which tends to rule out using a smaller microcontroller.&quot;  80K ~= 1024 * 768" CreationDate="2010-08-29T02:04:36.620" UserId="857" />
  <row Id="4424" PostId="4197" Text="I got the or solution alright, but it bugs me I have to use so much of logic to get just one bit. There has to be some elegant solution." CreationDate="2010-08-29T06:37:00.260" UserId="1200" />
  <row Id="4426" PostId="4197" Text="@Rick_2047 - you didn't mention what you're implementing this with, but I'm guessing an FPGA? It would bug me too, to have to tie up whatever number of logic blocks just to do a high fan-in gate. That's a good reason to only put in only one of them." CreationDate="2010-08-29T14:03:07.550" UserId="740" />
  <row Id="4427" PostId="4200" Score="1" Text="+1 K&amp;R is the definitive reference" CreationDate="2010-08-29T14:23:56.410" UserId="566" />
  <row Id="4428" PostId="4177" Text="You are all missing the point... I don't want to get some random monitor to display a composite signal... I want to generate a &quot;native&quot; CGA signal, and use it with a CGA monitor." CreationDate="2010-08-29T14:26:49.197" UserId="1091" />
  <row Id="4429" PostId="4190" Text="No I'm not set on an Arduino :)&#xA;And I'm not going to display fullmotion video. I want to use the display the same way you would an LCD for systems-info." CreationDate="2010-08-29T14:28:06.293" UserId="1091" />
  <row Id="4430" PostId="4200" Score="1" Text="Make sure to get the second edition, with the &quot;ANSI C&quot; box on the cover: http://www.amazon.com/Programming-Language-2nd-Brian-Kernighan/dp/0131103628  The original is for an older version of C (1978). The 2nd edition is for 1988 ANSI C, and you should be aware that it does not cover the C99 standard." CreationDate="2010-08-29T17:06:38.967" UserId="857" />
  <row Id="4432" PostId="4177" Score="2" Text="You think the internal monitor is CGA. I think you are very likely to be wrong. Come back when you get the equipment." CreationDate="2010-08-29T17:37:24.540" UserId="1363" />
  <row Id="4433" PostId="4168" Score="2" Text="just to be clear, the trace does not form any sort of loop, and therefore has negligible inductance relative to a straight path between the components." CreationDate="2010-08-29T18:58:34.423" UserId="1325" />
  <row Id="4434" PostId="4190" Score="1" Text="Well, the propeller has an internal raster character map in ROM for displaying text on screens, so it sounds like exactly what you want, then." CreationDate="2010-08-30T01:34:22.743" UserId="1374" />
  <row Id="4435" PostId="4113" Score="1" Text="Oxalic acid removes ferric chloride stains." CreationDate="2010-08-30T03:17:55.060" UserId="305" />
  <row Id="4437" PostId="4214" Text="Thanks, This looks to be a great place to start. Makes me happy because I have already ordered a pic32 starter kit to wit my feet  from microchip.... I have used pic18's in the past. I never knew they had an ethernet interface on board:D " CreationDate="2010-08-30T14:50:13.817" UserId="811" />
  <row Id="4438" PostId="4215" Text="Thanks, I like the idea of being able to use my existing code.. it is written in python which would obviously not work for a pic chip. The database will not be housed on the chip it self. I will have to access the database which will be housed on a server. " CreationDate="2010-08-30T14:59:57.830" UserId="811" />
  <row Id="4439" PostId="4215" Score="1" Text="The protocol to access your database may also affect your choice. If you need HTTPS or SSL/TLS, you'll have a hard time fitting that in an 8bit micro." CreationDate="2010-08-30T15:02:24.303" UserId="566" />
  <row Id="4440" PostId="4215" Text="HTTPS or SSL/TLS would not be needed. I would just need to connect to a mysql database... " CreationDate="2010-08-30T15:06:07.253" UserId="811" />
  <row Id="4441" PostId="4215" Text="ah the old hammer + walnut..." CreationDate="2010-08-30T16:16:48.833" UserId="771" />
  <row Id="4443" PostId="4195" Text="a comparator... which degenerates to a glorified NOR gate..." CreationDate="2010-08-30T16:24:12.860" UserId="771" />
  <row Id="4444" PostId="4194" Score="2" Text="it doesn't sound like you're stuck really - more like you're unsatisfied :)" CreationDate="2010-08-30T16:25:17.820" UserId="771" />
  <row Id="4445" PostId="4215" Text="dspic has a library for asymmetric encryption. i doubt you want to deal with it." CreationDate="2010-08-30T17:01:40.037" UserId="230" />
  <row Id="4446" PostId="4195" Text="He might gain something this way if the registers are cheap (they are in an SRAM block in an FPGA) and he needs a register compare instruction for other reasons anyway." CreationDate="2010-08-30T17:03:29.783" UserId="659" />
  <row Id="4447" PostId="4213" Score="1" Text="i agree, and remembering the A weighting is very important. if this is for safety you need to make sure you meet all safety standards." CreationDate="2010-08-30T17:09:47.677" UserId="230" />
  <row Id="4448" PostId="4187" Score="1" Text="if you like it, accept it." CreationDate="2010-08-30T17:13:33.337" UserId="230" />
  <row Id="4449" PostId="4216" Text="Also, you can get servers that include an SD card. This makes it possible to serve up images and complex web pages." CreationDate="2010-08-30T17:34:18.833" UserId="1402" />
  <row Id="4450" PostId="4194" Score="1" Text="a X input NOR _is_ the elegant solution. In order to determine if the register contains zero, every bit must be examined to see if it contains a logical 0. You specified that you need a single bit output. Therefore you need some function with X inputs, and one output, like a NOR." CreationDate="2010-08-30T20:20:52.900" UserId="638" />
  <row Id="4451" PostId="4195" Text="@vicatu - actually if you want to compare two N bit numbers, you'd need N 2-input XOR gates. The OR/NOR thing is only good for zero tests." CreationDate="2010-08-30T22:20:54.277" UserId="740" />
  <row Id="4452" PostId="4197" Text="not exactly an FPGA but an HDL and hardware simulator." CreationDate="2010-08-31T04:58:12.697" UserId="1200" />
  <row Id="4453" PostId="4195" Text="but ultimately i would need to use as many gates as I have input bits or at least as many transistors. " CreationDate="2010-08-31T05:43:33.930" UserId="1200" />
  <row Id="4454" PostId="4177" Text="Hmm... You might be right... When reading up on the Wikipedia article about it it says composite monitor... Every other source says CGA monitor... Well then..." CreationDate="2010-08-31T06:30:02.130" UserId="1091" />
  <row Id="4455" PostId="4222" Text="you might rather post this question on the Freescale forum(may be you already have)." CreationDate="2010-08-31T09:56:19.323" UserId="921" />
  <row Id="4456" PostId="4193" Text="Not using BoD.  I'll have to see about adding it.  So the scenario here would be that the chip just starts flailing around as the voltage gets too low and accidentally corrupts its own flash?" CreationDate="2010-08-31T13:04:31.100" UserId="213" />
  <row Id="4458" PostId="2537" Text="Looks awesome! But the web site is all in german!" CreationDate="2010-08-31T13:16:39.543" UserId="1033" />
  <row Id="4459" PostId="4216" Text="@Dirk, or perhaps an SD shield like (http://www.seeedstudio.com/depot/sd-card-shield-for-arduino-v21-p-492.html) - but maybe that's what you meant :) " CreationDate="2010-08-31T13:29:15.477" UserId="771" />
  <row Id="4460" PostId="4223" Text="Have you looked at Adafruit's MintyMP3 design (http://www.ladyada.net/make/minty/) for ideas?" CreationDate="2010-08-31T13:34:11.037" UserId="771" />
  <row Id="4461" PostId="4209" Text="link broken for me." CreationDate="2010-08-31T16:05:03.507" UserId="230" />
  <row Id="4463" PostId="3248" Text="I agree in hindsight that the flood and suck method is not the best way to go, have been experimenting with the solder wick approach explained in the second article and it works much better. Try that instead I would say." CreationDate="2010-09-01T06:56:45.983" UserId="909" />
  <row Id="4464" PostId="4224" Text="I hadn't thought of trying to use the phone as a whole unit. Good idea!" CreationDate="2010-09-01T08:50:32.087" UserId="1374" />
  <row Id="4468" PostId="4227" Text="I know some USB micros use 12 pF caps.  But you are correct, they say that the actual capacitance is more like 15 pF but pin/trace parasites give you the other 3 pF." CreationDate="2010-09-01T21:25:32.663" UserId="1278" />
  <row Id="4472" PostId="2433" Text="Would you really get that much extra EMI from a pad that has no solder mask, but otherwise makes no stub on the trace?" CreationDate="2010-09-01T21:39:35.757" UserId="1278" />
  <row Id="4475" PostId="4244" Score="5" Text="Common &quot;Tin Foil&quot; is actually aluminium foil. Also, no. Solder will not stick to aluminium." CreationDate="2010-09-02T08:28:26.050" UserId="1374" />
  <row Id="4476" PostId="4224" Text="So, good luck in your tests :)" CreationDate="2010-09-02T09:22:38.693" UserId="1079" />
  <row Id="4477" PostId="4244" Score="3" Text="You may be better off just taping a wire onto the foil" CreationDate="2010-09-02T10:26:46.823" UserId="566" />
  <row Id="4478" PostId="4238" Text="The composite part of that could probably be used. But I would really like to get something graphic going on..." CreationDate="2010-09-02T11:04:44.220" UserId="1091" />
  <row Id="4479" PostId="4238" Text="Does you original computer has also an ISA CGA adapter card? If so, you should try to interface the ATMega to it." CreationDate="2010-09-02T11:55:31.973" UserId="1108" />
  <row Id="4480" PostId="4209" Text="For me it's ok. Try this link for direct download: http://www.mindviewinc.com/ThinkingInC/Beta3Download.php.&#xA;Or you can try this link: http://www.mindviewinc.com&#xA;Thanks" CreationDate="2010-09-02T13:06:12.493" UserId="938" />
  <row Id="4481" PostId="4229" Text="yep I know the MSP430 has internal settings for this... I'm on an XMega though... so no such luck." CreationDate="2010-09-02T14:00:08.827" UserId="771" />
  <row Id="4482" PostId="4228" Text="I'm not sure, but the datasheet shows recommendations for explicit capacitors in schematics... " CreationDate="2010-09-02T14:01:25.217" UserId="771" />
  <row Id="4483" PostId="4175" Text="'Backend' usually refers to the synthesis, place &amp; route etc of the RTL for an ASIC. " CreationDate="2010-09-02T14:20:04.517" UserId="814" />
  <row Id="4484" PostId="4243" Text="Then how do you study it? What are the resources on &quot;backend design&quot; that will allow you to do &quot;real work&quot;?" CreationDate="2010-09-02T14:34:03.213" UserId="718" />
  <row Id="4487" PostId="4247" Text="This doesn't seem to be an answer to the original question-- Cheap, yes, but very little room for creativity in what goes where." CreationDate="2010-09-02T18:05:59.440" UserId="484" />
  <row Id="4492" PostId="4247" Text="You are right, and this is a problem with all intro material. Consistency brings a LOT of benefits, so I figured why not move the creativity out to the physical build, instead of the soldering. " CreationDate="2010-09-02T20:36:49.610" UserId="1402" />
  <row Id="4493" PostId="4252" Text="Sorry, I didn't include a site....I actually just used microchips site www.microchip.com , and their datasheets for the chip you're using!" CreationDate="2010-09-02T21:41:45.667" UserId="982" />
  <row Id="4494" PostId="4243" Text="I'm not too sure; I'm into software side of electronics myself.I would imagine having a look at the curriculum of graduate course on VLSI would be a good starting point.    " CreationDate="2010-09-03T03:55:53.797" UserId="921" />
  <row Id="4496" PostId="4228" Text="The schematic may be generic so that it will apply to different crystals. I happened to be looking at the ATmega328P datasheet yesterday (which I believe also shows capacitors) and the recommendation was no capacitors for a 6pF crystal since the combination of the pin capacitance and layout capacitance would be sufficient (for most applications)." CreationDate="2010-09-03T10:44:41.780" UserId="424" />
  <row Id="4505" PostId="4199" Text="Have you learned a programming language before?" CreationDate="2010-09-03T22:00:01.090" UserId="374" />
  <row Id="4506" PostId="4249" Text="I tried it on a windows xp computer and it does connect as a mass storage device and shows that the sd card is empty. I've formatted the sd card about 4 times and tried different allocation sizes but i havent gotten anywhere.&#xA;&#xA;I'll try a smaller sd card and see how it goes.&#xA;&#xA;Thanks heaps" CreationDate="2010-09-04T03:58:46.467" />
  <row Id="4507" PostId="4224" Text="Yes, my Nokia phone has those pins behind the battery. Thanks for the links!" CreationDate="2010-09-04T04:00:47.270" UserId="1030" />
  <row Id="4508" PostId="4233" Score="1" Text="Could be another possibility, of course. Depends on the output stage (transformer driver) of the PHY. Considering the similarity to other parts by the manufacturer in the question, my guessing goes towards a connection to the supply rail (3V3)." CreationDate="2010-09-04T13:36:55.663" UserId="930" />
  <row Id="4509" PostId="4233" Score="1" Text="@zebonaut - yeah, there are undoubtedly several different ways to build the output stage of the PHY. I think the simple cap to ground would probably only work if both sides of the TX differential have push-pull drivers. It definitely wouldn't work if the TX outputs were simple open collector type things, then you'd *have* to put the C.T. at +V." CreationDate="2010-09-04T14:44:55.733" UserId="740" />
  <row Id="4510" PostId="4258" Score="1" Text="I was hoping for something a bit more polished so it is possible to travel with it. I don't want to risk the hassles of having some sketchy looking homemade electronics when flying." CreationDate="2010-09-04T19:05:50.853" UserId="354" />
  <row Id="4512" PostId="4256" Text="Yes, the official Arduino website&#xA;http://www.arduino.cc/en/Hacking/BuildProcess&#xA;specifically mentions that it uses avr-gcc." CreationDate="2010-09-04T20:40:58.993" UserId="813" />
  <row Id="4513" PostId="4258" Score="1" Text="@SteveP I've flown many times with sketch home made electronics. As long as it doesn't look or smell like explosives, you should be fine. You might get &quot;randomly selected&quot; for the extra special screening a little more often though." CreationDate="2010-09-04T22:00:24.307" UserId="131" />
  <row Id="4514" PostId="4181" Score="1" Text="I was researching the Linux user-space USB interface some time ago. (I ended up only programming for Windows and OS X) The only information I could find about the /proc interface was in the libusb library (it uses the interface) and the kernel sources itself (I don't remember the link or the filename anymore)." CreationDate="2010-09-05T01:29:58.653" UserId="659" />
  <row Id="4515" PostId="4264" Text="+1, Very informative and upto-date answer!" CreationDate="2010-09-05T16:27:29.097" UserId="444" />
  <row Id="4516" PostId="4264" Text="@Kevin Boyd: Thank you, sir! I've recently built a small Linux board using an ARM processor, so I was trying to answer the same question.&#xA;&#xA;If anyone else knows of candidates that rival the Cavium Networks chips, I'd love to know about them. (I went with an Atmel BGA chip in the end, the AT91SAM9G20.)" CreationDate="2010-09-05T19:51:57.237" UserId="712" />
  <row Id="4517" PostId="4239" Text="Some experimentation with a soldering iron and the circuit in question has suggested that your answer is correct. I'm not 100% sure yet, but it's definitely sending and receiving packets. Thanks!" CreationDate="2010-09-06T00:15:21.410" UserId="712" />
  <row Id="4518" PostId="2417" Text="@DoxaLogos - No. Basically it's a SD PROM (Programmable Read Only Memory) memory card. You flash it once, and the written content is then read-only." CreationDate="2010-09-06T02:14:55.227" UserId="1374" />
  <row Id="4519" PostId="4258" Text="I ended up ordering this type of dummy AAA to AA converter off of ebay:&#xA;&#xA;http://www.sourcingmap.com/battery-holder-converter-adaptor-size-aaa-p-34409.html&#xA;&#xA;It doesn't have the bottom connector, but the sizing will be right and I can easily wire two together given the shell is empty. " CreationDate="2010-09-06T05:37:37.970" UserId="354" />
  <row Id="4520" PostId="4264" Text="Something to beware of - I think that the NXP M0s don't support JTAG, so you may need to invest in an SWD tool" CreationDate="2010-09-06T09:55:06.583" UserId="566" />
  <row Id="4521" PostId="4258" Text="@SteveP - you know, you're probably only going to need one wire into each fake battery; if the device takes two, it most likely wants 3V, and two of the contacts in the battery compartment will just be bridged, so you'll need to determine which ends the device takes the power from, and wire to the corresponding battery ends." CreationDate="2010-09-06T13:28:51.153" UserId="740" />
  <row Id="4522" PostId="4260" Score="2" Text="See also http://chiphacker.com/questions/2704/cheapest-arm-with-an-mmu (AT91, imx233)" CreationDate="2010-09-06T14:27:22.817" UserId="1082" />
  <row Id="4523" PostId="4272" Text="where does bootloader main code reside then..." CreationDate="2010-09-06T14:57:25.880" UserId="771" />
  <row Id="4526" PostId="4272" Text="See Table 26-6. It depends on the BOOTSZ fuses." CreationDate="2010-09-06T15:04:15.067" UserId="566" />
  <row Id="4527" PostId="4272" Score="1" Text="@Joby, ah ok... see update to my question - I'm interested in trying to port the bootloader to an Tiny AVR that doesn't have separate memory space for boot loader code." CreationDate="2010-09-06T15:07:37.390" UserId="771" />
  <row Id="4528" PostId="4272" Score="1" Text="@Joby, so the bootloader code relies on &quot;...the Boot Reset Fuse can be programmed so that the Reset Vector is pointing to the Boot Flash&#xA;start address after a reset. In this case, the Boot Loader is started after a reset.&quot;" CreationDate="2010-09-06T15:10:42.973" UserId="771" />
  <row Id="4529" PostId="4270" Text="Wow, shame on you for withholding that knowledge for so long AFTER I asked the question." CreationDate="2010-09-06T16:56:18.007" UserId="1200" />
  <row Id="4530" PostId="4274" Text="Here's a tutorial http://www.glacialwanderer.com/hobbyrobotics/?p=7" CreationDate="2010-09-06T23:14:08.997" UserId="566" />
  <row Id="4531" PostId="4276" Text="Excellent answer: I spent 13 years in power electronics (motor control) and you've hit the major points. Depending on the accuracy required and whether he needs real power or not, he may have to sample the voltage and current simultaneously in order to calculate the RMS power draw. Hall effect sensors are often referred to as &quot;LEMs&quot;, after one of the bigger companies that make them. Also, if he's measuring a switched current he may have to worry about the crest factor in his current sensing circuitry." CreationDate="2010-09-07T01:36:06.900" UserId="974" />
  <row Id="4532" PostId="4272" Score="2" Text="Did you specifically want the Arduino bootloader? It emulates a STK500 programmer and as such is somewhat bulky. There is an atmega8 version in the bootloaders dir that compiles to under 1K with gcc-3, but even that will leave you fairly short on available flash." CreationDate="2010-09-07T02:54:41.650" UserId="554" />
  <row Id="4533" PostId="4281" Text="We are using this type of RS323 sniffing for over 15 years now without any problems" CreationDate="2010-09-07T12:27:18.973" UserId="495" />
  <row Id="4537" PostId="4291" Text="It's funny...programming a similar chip to do the same things, but with more difficult means is exactly what I have in mind :).&#xA;&#xA;A little background - I'm a software architect with many years of experience. The software, the computation, file system...that's all the easy stuff for me. What I really need to bang my head against is the electronics.&#xA;&#xA;The reason why I'm looking to move beyond Arduino is simply that I want to be able to produce single purpose devices that don't have the physical (and price) overhead of an Arduino board.&#xA;&#xA;I think from what you've said, #2 is what I'm looking for." CreationDate="2010-09-07T20:02:32.220" UserId="989" />
  <row Id="4539" PostId="4291" Text="Wow...that comment sounded really egotistical. I didn't mean it that way...anyhow, I just meant that I want to get rid of the hardware training wheels that Arduino gives me.&#xA;&#xA;In particular, I'm working on an LED array, similar to the LOLShield, though I think I'm going to multiplex it instead. I can do it with Arduino, but without it, I need some direction.&#xA;&#xA;TIA." CreationDate="2010-09-07T20:29:11.080" UserId="989" />
  <row Id="4540" PostId="4045" Text="I needed a little more theory to understand your answer, but I can now see that it's a good one. Thanks muchly." CreationDate="2010-09-07T20:31:01.763" UserId="989" />
  <row Id="4541" PostId="4276" Text="@Andrew: Thanks, I've only been looking into motor control (mostly related to electric vehicles) for a few months now, I'm glad my understanding meets the approval of a real expert!" CreationDate="2010-09-07T21:08:03.513" UserId="1325" />
  <row Id="4543" PostId="4270" Score="1" Text="@Rick - It looks like that answer took a long time to compose.  Be grateful that davidcary took the time to answer your question!  Some people aren't operating on the same schedule you are." CreationDate="2010-09-07T22:58:30.237" UserId="857" />
  <row Id="4544" PostId="180" Text="You can get the best of both worlds.  ATMega8 components can be configured to provide access to the internal comparator.  With a suitable voltage reference (adjustable with say, a trimpot), you can have interrupts on rising (or falling or both) edge of the analog signal.  link to forum topic explaining just that :http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1163394545" CreationDate="2010-09-07T23:42:47.727" UserId="1325" />
  <row Id="4547" PostId="4258" Score="1" Text="@SteveP: Good thinking.  I like the writeup on that site: *When you need use AA battery, but actually you only got a piece of AAA battery, than how? You will not worry about this sort of question with this Battery Holder Converter. It features a piece AAA battery can be used as a AA battery. Easy and your life will become more convenient.*" CreationDate="2010-09-08T01:39:09.970" UserId="857" />
  <row Id="4548" PostId="4299" Text="i almost suggested just soldering the power leads to small metal disks, which could be pressed in place by an actual battery, with a piece of plastic stuck in on the other end. could use a dead battery, but then there's the risk of caustic ooze. but as you say, fresh will do. a fresh, ordinary carbon-zinc dry cell would be ultra cheap and very long lasting in this setup." CreationDate="2010-09-08T02:31:48.773" UserId="740" />
  <row Id="4549" PostId="4281" Text="@Tim, well if you look at my figure, that's exactly what I'm doing but with a max232 in between (which is not necessary as I found out and as others pointed)." CreationDate="2010-09-08T03:23:44.263" UserId="921" />
  <row Id="4550" PostId="180" Text="There are hall-effect devices with a schmitt-trigger thresholded output. They're quite common.&#xA;Also, with a reed switch, you're going to have to debounce the output anyways." CreationDate="2010-09-08T04:26:32.247" UserId="1374" />
  <row Id="4551" PostId="4298" Text="I've been getting the feeling that there aren't many people doing embedded DSP. At least not many who are able to publish their work. These links were very helpful to me though." CreationDate="2010-09-08T14:13:04.650" UserId="319" />
  <row Id="4552" PostId="4291" Text="Ah, more electronic-y things instead of software-y... stuff. Maybe you'd get some nice experience doing sensor interfacing/datalogging.  It's not glamorous but to interface the sensors to your board you'd need to learn a few more things about hardware.  The Arduino doesn't really have that many hardware training wheels - certainly not as many as software.  Maybe a robot that incorporates several different types of sensors - ultrasounds, IR distance, shaft encoder, etc.  Certainly possible just with the Arduino and lots more hardware." CreationDate="2010-09-08T15:12:42.617" UserId="249" />
  <row Id="4554" PostId="4305" Text="Well, I did a brief Googling too, but I didn't have the correct words to look for, now you gave me something to search! Many thanks! This project is to measure CO and CO2 concentration on combustion gases. Looks like this sensor (http://www.alphasense.com/alphasense_sensors/c_carbon_monoxide.html) can do the CO portion of the process!" CreationDate="2010-09-08T16:10:25.753" UserId="940" />
  <row Id="4555" PostId="4272" Score="2" Text="would you even really want a boot loader at all?  surely for an ATTiny it's more likely worth your effort to program the device using an ICSP programmer (such as the usbTinyISP)" CreationDate="2010-09-09T01:17:54.693" UserId="1325" />
  <row Id="4556" PostId="4308" Text="Good idea. I have a second USB UART adapter, so I'll connect both of them to each other and try and pass data between them. " CreationDate="2010-09-09T12:36:53.327" UserId="1033" />
  <row Id="4557" PostId="4309" Text="Wow I never thought of that, but it's entirely possible. I'm using a wide tip soldering iron to solder to surface mount size connections, and it's possible I blobbed between TX/RX. I'll check that with an ohmmeter when I'm back in the lab tonight. " CreationDate="2010-09-09T12:37:59.003" UserId="1033" />
  <row Id="4558" PostId="634" Text="In the future, when you recommend avoiding something X, please consider adding at least a brief mention of one alternative to X." CreationDate="2010-09-09T16:56:44.520" UserId="813" />
  <row Id="4559" PostId="4307" Text="Hi, but where can I get the touch screen itself from? That is what I am asking. Not asking where to find an IC to work with my touchscreen that I don't have yet." CreationDate="2010-09-09T17:55:54.123" UserId="131" />
  <row Id="4560" PostId="4319" Score="2" Text="What is the ADC?" CreationDate="2010-09-09T18:32:47.713" UserId="305" />
  <row Id="4562" PostId="4319" Text="@Leon - I'm trying to find an ADC that has several sources.  I haven't picked one because I want to find a chip that has 2 other vendors that I could replace it." CreationDate="2010-09-09T19:13:30.127" UserId="204" />
  <row Id="4564" PostId="4324" Score="2" Text="Actually - that's a pretty cool idea, it's certainly alternative thinking! It's like a cuckoo clock on steroids :)&#xA;&#xA;Thanks Bjarkef" CreationDate="2010-09-09T19:53:34.337" UserId="399" />
  <row Id="4565" PostId="4324" Score="1" Text="Yes, I was actually thinking of a cuckoo clock. Do take pictures if you decide to try it. :)" CreationDate="2010-09-09T19:55:22.053" UserId="718" />
  <row Id="4567" PostId="4324" Text="The genius is...the generator and rig could be quite portable, the weight could just be sourced on site, which would save a huge amount of energy...I think your suggestion is gunna be hard to beat! (If I do build it - I'll be certain to post a pic)" CreationDate="2010-09-09T20:12:07.117" UserId="399" />
  <row Id="4568" PostId="4324" Text="Might be safer to use the energy to pump water into an above-ground reservoir through and generate as it runs back down through a narrow channel.  If you leave the reservoir open you would even get a boost when it rains. :-)" CreationDate="2010-09-09T20:47:38.067" UserId="974" />
  <row Id="4570" PostId="4324" Score="1" Text="Interesting...it'll remove the possibility of being crushed accidentally by the load, but it would be harder to set up a reservoir - compared to finding the nearest heavy object to dangle." CreationDate="2010-09-09T20:55:12.503" UserId="399" />
  <row Id="4571" PostId="4325" Text="I'm after a portable system that could be setup in a variety of environments, the problem with a lot of the generation methods you suggest is the lack of portability or ease of setup, especially when trying to generate 110 AH..." CreationDate="2010-09-09T21:30:35.050" UserId="399" />
  <row Id="4573" PostId="4325" Score="1" Text=" 	I appreciate what your saying about how green / ungreen a battery may be, but batteries die far sooner than generators - as long as I'm not using dirty energy to hoist the weight, is it not just a question of the generator being around long enough? ...to generate enough power and outweigh the environmental cost - when compared to a batteries ratio between (environmental cost) : (total power output over full lifespan)" CreationDate="2010-09-09T21:32:39.703" UserId="399" />
  <row Id="4574" PostId="4324" Score="1" Text="It's hard to find a 55gal barrel or dozen? Add some PVC and a few valves and the bulk of it's completed. You can probably find a 12V pump somewhere relatively cheap and you've got the &quot;charging&quot; circuit. But now you have the fun part left: generator design. Or, use an impeller to turn the crank of the generator you were going to use in the cuckoo-clock-on-steroids design.&#xA;&#xA;This is a REALLY interesting question, I'm glad you asked it. Gets us all thinking!" CreationDate="2010-09-09T22:24:20.010" UserId="974" />
  <row Id="4575" PostId="4324" Text="what powers the winches?" CreationDate="2010-09-09T22:44:47.997" UserId="740" />
  <row Id="4577" PostId="4329" Score="1" Text="Sorry, that's the mathematician in me exposed. I said &quot;least upper bound&quot;-- of all the possible upper bounds to specific energy, 1166.4 is the smallest candidate. But &quot;a possible answer&quot; would be a more reasonable way to phrase it." CreationDate="2010-09-09T23:42:31.493" UserId="712" />
  <row Id="4578" PostId="4329" Text="woops! for whatever reason i failed to parse the 'least' part. never mind!" CreationDate="2010-09-09T23:46:24.263" UserId="740" />
  <row Id="4579" PostId="4324" Text="i'd imagine it could be done by hand using a hand crank, maybe some gears and a ratchet - I guess it's at this stage i'd need to do some math to see if it's possible, don't want to be winding the thing up constantly just to power a desk lamp for 5 mins :)&#xA;  " CreationDate="2010-09-10T00:20:07.603" UserId="399" />
  <row Id="4580" PostId="3941" Text="These were some great answers! I took a long time considering which answer to mark as accepted, only because they were all excellent. I accepted Windell Oskay's answer mainly because he addressed the point of impedance matching (critical in RF) and because of his great analogies. Again, thanks for the great responses!" CreationDate="2010-09-10T06:13:28.100" UserId="965" />
  <row Id="4582" PostId="4069" Text="Wow, that's pretty amazing." CreationDate="2010-09-10T09:55:34.957" UserId="813" />
  <row Id="4584" PostId="4056" Text="All computer architectures alternate between storing bits in one place, piping stored bits through some combinational logic such as an ALU, and then storing the result bits elsewhere.&#xA;Storing a bit requires a theoretical minimum of kT ln(2).&#xA;There seems to be a debate over whether the lower limit of the combinational logic is actually zero or merely small compared to kT ln(2) -- or in other words, over whether the theoretical maximum amount of combinational logic operations one can do with a given amount of energy is infinite or finite.&#xA;See http://www.cise.ufl.edu/research/revcomp/ .&#xA;" CreationDate="2010-09-10T10:49:13.200" UserId="813" />
  <row Id="4585" PostId="4309" Text="TX &amp; RX not shorted. It must be something else. " CreationDate="2010-09-10T10:54:23.010" UserId="1033" />
  <row Id="4587" PostId="4308" Text="Verified the UART adapter this morning, it's rock solid with other devices and with this device when its in pass-thru mode (as opposed to AT mode). I sent a message off to their engineers to see what they say. " CreationDate="2010-09-10T12:02:22.957" UserId="1033" />
  <row Id="4588" PostId="1859" Text="The software on the PC talks to a &quot;COM port&quot;.&#xA;It neither knows nor cares that the serial bits are being translated to USB packets by a PC device driver, sent down the USB cable, and translated back to serial bits by the FTDI chip.&#xA;The software would work exactly the same with a standard PC RS232 serial port connected to a serial cable with some sort of 12 V RS232 - to - RS232-TTL converter, such as the MAX232." CreationDate="2010-09-10T12:15:33.757" UserId="813" />
  <row Id="4589" PostId="1141" Text="@endolith: very cool.&#xA;I created a new question to discuss this further -- http://chiphacker.com/questions/4333/what-is-the-most-amazing-pcb-artwork-youve-ever-seen ." CreationDate="2010-09-10T12:34:42.370" UserId="813" />
  <row Id="4591" PostId="961" Text="If there is a perfect clock on one side, you may have up to 10% error on the other(using 8 bit data, 1 start, 1 stop) without an error. You add parity, you need to decrease that maximum error. However, normally both sides are not perfect, and you have to decrease that overhead as both have it." CreationDate="2010-09-10T14:11:08.670" UserId="230" />
  <row Id="4592" PostId="4335" Text="give us a link to the one you want." CreationDate="2010-09-10T14:11:40.527" UserId="230" />
  <row Id="4593" PostId="4336" Text="I want to do this from a circuit. Maybe like an arduino." CreationDate="2010-09-10T14:12:18.247" />
  <row Id="4594" PostId="4336" Text="Would it be easier to use a none usb meter than try to figure out where the data is processed and do it from there?" CreationDate="2010-09-10T14:25:01.940" />
  <row Id="4595" PostId="4336" Score="1" Text="Yes, a non-USB device would almost certainly be easier to interface to." CreationDate="2010-09-10T14:27:43.257" UserId="566" />
  <row Id="4596" PostId="4336" Text="Do you have any idea how I could interface to one? I wouldn't even know where to find that portion of the circuit that stores the data. " CreationDate="2010-09-10T14:29:23.993" />
  <row Id="4597" PostId="4336" Text="Tell us more about the device you have." CreationDate="2010-09-10T14:31:40.143" UserId="566" />
  <row Id="4598" PostId="4336" Text="I don't have one yet. I didn't know the usb route would be more challenging because I planned on just buying one of those. If you have any cheap suggestions of ones that would be easy to inface to tell me. " CreationDate="2010-09-10T14:32:51.473" />
  <row Id="4599" PostId="4330" Text="@endolith: Thanks for the edit." CreationDate="2010-09-10T15:46:04.273" UserId="965" />
  <row Id="4600" PostId="4337" Text="Her stained boards looks great! http://www.youtube.com/watch?v=gzqyEXBJOv8#t=1m30s" CreationDate="2010-09-10T15:57:54.237" UserId="595" />
  <row Id="4601" PostId="4344" Score="1" Text="Would still need batteries tho, especially when trying to get 1200w...would probably end up with enough panels to cover the roof of a family home! :) " CreationDate="2010-09-10T17:48:23.173" UserId="399" />
  <row Id="4602" PostId="4201" Score="2" Text="+1 The PIC is not a C friendly platform anyway, and the last place I would try to learn C." CreationDate="2010-09-11T02:24:05.167" UserId="985" />
  <row Id="4603" PostId="954" Text="Fair enough. However lately he seems to have toned it down a bit, and the blog #110 was excellent." CreationDate="2010-09-11T02:35:51.333" UserId="1307" />
  <row Id="4604" PostId="4353" Text="&quot;what good is a harvard platform where the processor cannot ... load the next program to run?&quot;&#xA;Many CPUs have a fixed program that cannot be changed by software running on that CPU.&#xA;One advantage to this arrangement is that it makes it impossible to &quot;brick&quot; the system with a bug that writes to random memory, or a bad software update, or even with a good software update and an ill-timed power fail.&#xA;It makes it more difficult to update the software -- but really, how many times have you changed the software in your microwave?" CreationDate="2010-09-11T05:24:12.563" UserId="813" />
  <row Id="4605" PostId="4356" Score="2" Text="you need to describe your circuit. the application sounds like the sort of thing usually accomplished with a resistor and an NPN BJT, which *would* go open-circuit in the absence of input. So, what type of transistor is it? What's the zener's voltage and how is it connected?" CreationDate="2010-09-11T13:03:32.313" UserId="740" />
  <row Id="4606" PostId="4323" Text="Does this need to be portable? A pumped storage scheme (essentially bjarkef's answer with water) is used commercially sometimes." CreationDate="2010-09-11T13:15:26.897" UserId="1402" />
  <row Id="4607" PostId="4270" Text="@reemrevnivek that was meant as a joke dude." CreationDate="2010-09-11T15:14:05.883" UserId="1200" />
  <row Id="4608" PostId="4355" Text="Alas, the only &quot;digital video port&quot; I know about has 100 pins, and so is impossible to directly connect to the processors I am familiar with (which generally have less than 100 pins).&#xA;Since you seem to think your DVP can directly connect to a 44 pin processor, perhaps your DVP is different?&#xA;I know several processors that have an efficient way to accept parallel data, with a &quot;sample&quot; signal separate from 8 data bits.&#xA;Does your module have such a &quot;sample&quot; signal?&#xA;Perhaps&#xA;http://chiphacker.com/questions/4363/what-is-a-digital-video-port&#xA;is a good place to go into more detail.&#xA;" CreationDate="2010-09-11T19:43:51.333" UserId="813" />
  <row Id="4609" PostId="4363" Score="1" Text="http://wiki.answers.com/Q/What_is_a_digital_video_port" CreationDate="2010-09-11T19:45:50.893" UserId="813" />
  <row Id="4610" PostId="4354" Score="1" Text="I've looked at Gumstix, and by the time I buy the expansion board, I could buy a used netbook." CreationDate="2010-09-11T20:32:53.743" UserId="1134" />
  <row Id="4611" PostId="4354" Score="1" Text="Or, about $250 USD." CreationDate="2010-09-11T20:49:13.237" UserId="1134" />
  <row Id="4613" PostId="4352" Text="Good idea, $110 is close enough, I will look into it." CreationDate="2010-09-11T21:11:04.277" UserId="1134" />
  <row Id="4615" PostId="4353" Score="1" Text="On the microwave none, but I spend a fair amount of my time coding for microcontrollers and reload software many times a day.  Being limited to small, bug free, rom based systems the bricking problem is easily solved using von neumann.  The systems you describe have little use for the performance gain of the separate busses, the other feature of harvard architecture.  So my point was, harvard architecture just doesnt scale well without a way to load programs, making it somewhat obsolete." CreationDate="2010-09-12T04:26:52.130" UserId="985" />
  <row Id="4616" PostId="4353" Text="Hmm, they call the cortex-m3 harvard when it really isnt, same with avr (well they call it a modified harvard).  I am sure there are some pure harvard architecture processors (the PIC), and used to be more pure von neumann, but most are modified harvard or modified von neumann (data and instruction accesses in parallel) making them more the same than different.  Which is where I was headed in my answer, the pure harvard and pure von neumann are both rapidly becoming obsolete.  The poster wants to know what else is out there, well almost everything out there.&#xA;" CreationDate="2010-09-12T04:33:20.150" UserId="985" />
  <row Id="4617" PostId="4350" Score="1" Text="I've moved your posted answer from below into the original question, as StackExchange sites don't really function as discussion forums (eg post a response to someone else's post) instead if you need to clarify something about the original post you need to add it to the original question. If you ask a question then later come back and post your own solution to it separately, then that's fine." CreationDate="2010-09-12T11:44:55.063" UserId="103" />
  <row Id="4619" PostId="4352" Text="$110? it says $152 when i click the link" CreationDate="2010-09-12T16:17:39.373" UserId="131" />
  <row Id="4620" PostId="4372" Text="I guess your right, tried the SPI sniffer macro and even then I cant get it to output anything. Thanks for your help " CreationDate="2010-09-12T19:45:34.563" />
  <row Id="4621" PostId="4324" Text="And just to take this entirely retro: the best way to pump water is with a windmill mechanically pumping it.  Done all the time back in the day on farms.  " CreationDate="2010-09-12T23:54:13.957" UserId="249" />
  <row Id="4622" PostId="4375" Text="These look good for dividing by constants as you say, but don't really apply to my problem. He uses techniques such as precalculate the inverse - multiply by it, then shift." CreationDate="2010-09-13T02:09:16.547" UserId="554" />
  <row Id="4623" PostId="2811" Text="no, it did not let me know you had responded, even with the @kortuk. No worries. It looks like an answer has been found." CreationDate="2010-09-13T03:14:01.967" UserId="230" />
  <row Id="4624" PostId="4358" Text="done :) see description above." CreationDate="2010-09-13T03:44:18.480" UserId="1135" />
  <row Id="4625" PostId="4356" Text="see description above. :)" CreationDate="2010-09-13T03:44:39.227" UserId="1135" />
  <row Id="4627" PostId="4359" Text="I have something similar to what you described here, expect i didn't use a 50k resistor at the emiter/base leads" CreationDate="2010-09-13T03:48:58.993" UserId="1135" />
  <row Id="4628" PostId="4355" Text="By DVP meant the camera's parallel port, typically a cam module would have a 8bit Y bus and a 8 bit UV bus. Higher mp camera modules would probably have a wider bus." CreationDate="2010-09-13T10:47:47.260" UserId="444" />
  <row Id="4629" PostId="4381" Text="The problem is I need a valve that is not an on/off valve, but one that can actually control the amount of water flow." CreationDate="2010-09-13T12:41:01.840" UserId="1140" />
  <row Id="4630" PostId="4383" Text="Often I find that FPGAs must run at a slower clock speed for the same MCU, or they will be significantly more expensive. In the more expensive case you can easily implement extra hardware between the controller and the external pins, often quite worth it." CreationDate="2010-09-13T13:59:05.850" UserId="230" />
  <row Id="4632" PostId="4381" Score="2" Text="You want a proportional solenoid valve. Aalborg makes them; I suspect other folks do as well. Here's one, but it's probably overkill for water: http://www.aalborg.com/index.php/main_page/product_overview/id_product_overview/27" CreationDate="2010-09-13T14:53:03.930" UserId="712" />
  <row Id="4633" PostId="4381" Text="You could consider connecting several valves passing 1, 2, 4, 8 units of flow in exactly the same way as a digital to analog converter." CreationDate="2010-09-13T16:24:24.263" UserId="1363" />
  <row Id="4634" PostId="4381" Score="2" Text="You could also consider adjusting the pump with PWM." CreationDate="2010-09-13T16:26:27.050" UserId="1363" />
  <row Id="4635" PostId="4384" Score="1" Text="How is it solar powered? Is one of the resistors actually a photoresistor? Or are Vcc and ground hooked to a solar cell?" CreationDate="2010-09-13T16:36:50.757" UserId="712" />
  <row Id="4636" PostId="4383" Text="If an FPGA is needed in the system anyway, the MCU is &quot;free&quot;." CreationDate="2010-09-13T18:28:03.090" UserId="305" />
  <row Id="4637" PostId="4374" Score="2" Text="Is v an integer or floating point?" CreationDate="2010-09-13T18:35:21.807" UserId="588" />
  <row Id="4639" PostId="4391" Text="Thanks a lot! It's a pity the other answer got removed, it was actually quite helpful, too." CreationDate="2010-09-13T19:42:21.103" UserId="1036" />
  <row Id="4640" PostId="4377" Score="3" Text="A schematic, code and/or scope plot would be useful to show us what's happening." CreationDate="2010-09-13T20:08:27.317" UserId="249" />
  <row Id="4641" PostId="4356" Text="the 1N4007 is not a zener, it's a basic power rectifier type." CreationDate="2010-09-13T22:20:15.717" UserId="740" />
  <row Id="4642" PostId="4380" Text="Yes thanks, the formula is wrong. The point is to get linear acceleration from the output of the stepper, by varying the target speed by a constant each time interval (speed++ say). This must be mapped to the period (frequency) that a +ve edge is sent to the stepper motor controller - hence the inverse relationship (p=1/v)." CreationDate="2010-09-13T23:25:45.823" UserId="554" />
  <row Id="4643" PostId="4386" Text="This is similar to the techniques in the links that timrorr supplied and works well for dividing by constants, but not when dividing by a value that is unknown at compile time." CreationDate="2010-09-13T23:28:39.453" UserId="554" />
  <row Id="4644" PostId="4395" Text="I tried something similar in summing the divisor until it equals or exceeds the dividend, but found it to be fairly slow. It looks like the LUT will be the way to go - using avr-gcc you need special macros in &lt;avr/progmem.h&gt; to store it in flash." CreationDate="2010-09-13T23:34:00.413" UserId="554" />
  <row Id="4645" PostId="4374" Text="An integer, but as it gives a period in us, integer division is accurate enough here." CreationDate="2010-09-13T23:36:02.233" UserId="554" />
  <row Id="4646" PostId="4380" Text="Do you mean constant acceleration, i.e. a linearly increasing velocity?" CreationDate="2010-09-13T23:43:00.943" UserId="712" />
  <row Id="4647" PostId="4401" Score="1" Text="Won't be low cost...at $1200, you got that right" CreationDate="2010-09-14T01:21:28.050" UserId="131" />
  <row Id="4648" PostId="4380" Text="Ah yes, constant acceleration, I mucked that up when originally writing the question and remember fixing it there too" CreationDate="2010-09-14T04:22:06.900" UserId="554" />
  <row Id="4649" PostId="4377" Text="Do you have another Arduino board to try it with, so you can isolate the problem a little further?" CreationDate="2010-09-14T05:39:04.857" UserId="1307" />
  <row Id="4650" PostId="4401" Text="Yes, I haven't mentioned, but should be understandable from the way question was put, that I'm on a tight hobby budget here, so I can't afford anything worth more than about 30 $." CreationDate="2010-09-14T08:23:38.453" UserId="1036" />
  <row Id="4651" PostId="4404" Text="Thanks a lot! This answers my main question." CreationDate="2010-09-14T08:24:27.860" UserId="1036" />
  <row Id="4652" PostId="499" Text="Many AVR chips have PWM modes in their counter(s) and so do many other controllers. It's a very efficient system." CreationDate="2010-09-14T08:59:34.167" UserId="883" />
  <row Id="4653" PostId="4384" Score="1" Text="The latter -- Vcc and ground are hooked to the solar cell." CreationDate="2010-09-14T10:17:42.777" />
  <row Id="4654" PostId="4369" Text="Still no luck on my end. Ideas, anyone?" CreationDate="2010-09-14T10:25:16.947" UserId="1027" />
  <row Id="4656" PostId="4366" Score="1" Text="Thanks for the answer! Sounds like an interesting board. Here is a link to the Si4735: http://www.silabs.com/products/audiovideo/amfmreceivers/Pages/Si473435.aspx" CreationDate="2010-09-14T11:53:38.127" UserId="1025" />
  <row Id="4657" PostId="4366" Text="Thanks for posting that link. I am tempted to have a go myself and make a simple radio. Will add it to the list of 'things to do'... :)" CreationDate="2010-09-14T12:23:03.513" UserId="1307" />
  <row Id="4658" PostId="4414" Score="2" Text="Just a bit to clarify pingswept. The pot is dividing the voltage. You need to look at power to get a better idea of how much the audio is cut. In addition, the dB scale is used to determine the perceived audio drop by a human." CreationDate="2010-09-14T16:01:54.303" UserId="319" />
  <row Id="4661" PostId="4397" Text="I don't think the question was referring to having a few grounds.  It read *scattered by the winds to all four points of the compass*.  Also, while programmers don't have to worry about it after they import the header, I think that the bigger problem would be in the layout of the PCB." CreationDate="2010-09-14T17:51:06.693" UserId="857" />
  <row Id="4664" PostId="4397" Text="The fact that you have to spread apart your grounds has an effect on the placement of all pins. There is also a lot to do with how the chip was designed at the gate level. When you look at chip designs like this http://vega.unitbv.ro/~nicula/vlsi/layout.html you might be able to begin to see how it could be hard to put pins in order by their port" CreationDate="2010-09-14T18:47:32.083" UserId="319" />
  <row Id="4665" PostId="4418" Text="I can understand this, but I could before, this needs a bit more detail of what you have done. I see two sources with 1ohm output resistance fed through a 25k resistance to the same line which has a load resistance of 101k." CreationDate="2010-09-14T19:41:34.227" UserId="230" />
  <row Id="4666" PostId="4397" Text="@reemrevnivek, Yes, I understand that they are scattered, but why does that affect your layout. There should be Digital I/O almost everywhere. If you have a D- and a D+ for USB on a chip they are normally close for impedance reasons. But if it is general I/O you should know you can swap one Digital I/O to almost any other Digital I/O. decent layout/schematic suites allow you to mark pins as swappable. That way the layout runs smoothly." CreationDate="2010-09-14T19:45:04.047" UserId="230" />
  <row Id="4667" PostId="4384" Text="This is taking voltage from the cell, the larger it is the slower the system switches states, this causes lower frequency. I will take a shot in a simulator and see if I can swap it up from you. I am mostly EM, so I have not played with BJTs in a while and have forgotten how to quickly hotswap without a simulation double check." CreationDate="2010-09-14T19:49:11.027" UserId="230" />
  <row Id="4668" PostId="4394" Text="I am thinking about the interesting and cheaptastic LPC1* ARM chips. They only put 3 or 4 bits max per port in a row." CreationDate="2010-09-14T20:00:41.783" UserId="1363" />
  <row Id="4669" PostId="4414" Text="The relationship between voltage, power, and the loudness perceived by a human ear is nontrivial.  I really like the chart on this page http://www.gcaudio.com/resources/howtos/voltageloudness.html because it highlights how 3dB = 2x power, 6dB = 2x voltage, and 10dB = 2x loudness" CreationDate="2010-09-14T21:14:02.843" UserId="1278" />
  <row Id="4670" PostId="4409" Text="It's illegal in some countries, but not all." CreationDate="2010-09-14T23:16:30.327" UserId="536" />
  <row Id="4671" PostId="3268" Text="Bus pirate is an excellent tool, +1" CreationDate="2010-09-15T04:21:15.050" UserId="1325" />
  <row Id="4672" PostId="4101" Text="Solenoids can be controlled with relative ease, in much the same way as most electromagnetic devices, by means of PWM or similar duty cycling." CreationDate="2010-09-15T04:34:04.187" UserId="1325" />
  <row Id="4673" PostId="296" Text="According to the linked site, it looks like the board can be programmed via Jtag.  " CreationDate="2010-09-15T04:43:17.690" UserId="1325" />
  <row Id="4674" PostId="4375" Text="That's an excellent book!" CreationDate="2010-09-15T06:53:34.423" UserId="484" />
  <row Id="4675" PostId="4422" Text="As I said in the question, I was wondering if there was another way" CreationDate="2010-09-15T12:37:24.253" UserId="554" />
  <row Id="4676" PostId="4415" Text="Interesting, I wonder how this compares to the other methods mentioned" CreationDate="2010-09-15T12:45:47.630" UserId="554" />
  <row Id="4677" PostId="4405" Text="The two potentiometers could be physically attached to one another so that they both turn at the same time." CreationDate="2010-09-15T13:58:02.023" UserId="1301" />
  <row Id="4678" PostId="4414" Text="be careful of this chart. It is based on a linear load. This is not always true, and thus directly measuring voltage may not allow you to determine power. The dB scale is probably one of the more important things you should learn. i would suggest you spend some time getting a feel for it." CreationDate="2010-09-15T14:00:40.610" UserId="230" />
  <row Id="4679" PostId="4416" Text="bah; I clicked the arrow by mistake and I can't &quot;clear&quot; it. Leaving it at -1 since the link doesn't really provide much in the way of answers and the links the link provides lead only to commercial solutions or dead links. (I was really hoping to see the 187kbps AVR code!)" CreationDate="2010-09-15T14:06:04.603" UserId="974" />
  <row Id="4680" PostId="4416" Text="nevermind, bumped to +1 since I was eventually able to find this link from it. http://www.mikrocontroller.net/topic/106174" CreationDate="2010-09-15T14:07:38.847" UserId="974" />
  <row Id="4681" PostId="4414" Text="Also, please remember that dB scale is relative. Audio is often dBA(http://en.wikipedia.org/wiki/Weighting_filter#Environmental_noise_measurement). Power is often dBm(power relative to 1mW). " CreationDate="2010-09-15T14:11:35.567" UserId="230" />
  <row Id="4682" PostId="4405" Text="Yes, that would make it a blend control instead of a mixer." CreationDate="2010-09-15T14:14:25.157" UserId="142" />
  <row Id="4683" PostId="4423" Text="If you surround text in &lt;pre&gt; tags, it won't attempt to syntax highlight it, but it (should) still be monospace." CreationDate="2010-09-15T14:22:01.583" UserId="857" />
  <row Id="4684" PostId="4424" Score="2" Text="That's exactly what I do... I don't really understand this question. :-)" CreationDate="2010-09-15T14:23:53.517" UserId="974" />
  <row Id="4685" PostId="4428" Score="1" Text="They probably use a high grade connector due to the speed of signals you can send from that micro. pic32s are pretty high end, and they can send screaming fast rising edges. Screaming fast rising edge can mean a screaming micro if you have bad mismatches all over the place." CreationDate="2010-09-15T15:13:50.823" UserId="230" />
  <row Id="4688" PostId="4431" Text="I bet that the connector that Digikey sells has 120 pins because it has 120 in the part number. Not sure what's actually on the board, but I guess the OP can count them." CreationDate="2010-09-15T15:53:06.440" UserId="712" />
  <row Id="4689" PostId="4431" Text="I counted 120 on the connector&#xA;" CreationDate="2010-09-15T16:20:59.097" UserId="811" />
  <row Id="4690" PostId="4431" Text="hmmm. your right, the schematic shows 132 connections for the connector while there is obviously only 120.... Arg. I will check with mirco chip and post the response " CreationDate="2010-09-15T16:38:44.437" UserId="811" />
  <row Id="4691" PostId="4434" Text="I got one of these boards today, I plugged in a 5V wall wart and it's fine." CreationDate="2010-09-15T21:24:46.383" UserId="566" />
  <row Id="4692" PostId="4426" Text="Or to text... which I think is what the OP is asking for." CreationDate="2010-09-15T21:48:29.240" UserId="374" />
  <row Id="4694" PostId="4424" Text="I also suggest that these are done by hand, like all proper AA. :)" CreationDate="2010-09-16T10:01:36.993" UserId="883" />
  <row Id="4695" PostId="4431" Text="It's likely that the additional pins are electrically-neutral pads on the PCB put there for mechanical support.&#xA;Most connectors like that have a few metal legs for handling the forces generated when unmating. They get soldered to big pads on the PCB." CreationDate="2010-09-16T10:52:49.143" UserId="1374" />
  <row Id="4696" PostId="4431" Text="Ok, yeah, It looks like there are 12 mechanical legs on the connector. 120 + 12 gives you your 132 pin connector." CreationDate="2010-09-16T10:54:33.733" UserId="1374" />
  <row Id="4697" PostId="4423" Score="10" Text="They are usually done by hand, seriously. :)" CreationDate="2010-09-16T16:25:07.930" UserId="718" />
  <row Id="4699" PostId="4432" Text="Huh, it comes up as $30.00 when I'm logged in from the USA.   If this solves your problem, feel free to mark it as the accepted answer." CreationDate="2010-09-16T21:04:13.283" UserId="857" />
  <row Id="4700" PostId="4439" Text="...So is pingswept incorrect that the sampling rate limits your ability to acquire signals?  The way I read this is that you can essentially get as high a resolution as your timer tick supports.  So, for a 20MHz AVR, which traditionally has a 66kHz (off the top of my head) ADC sampling frequency, you could pretend that it had closer to a 20MHz frequency by sampling at 10us, 10.001us, 10.002us etc. after your trigger?  Pretty cool!  I'll have to try this next time." CreationDate="2010-09-16T21:10:16.950" UserId="857" />
  <row Id="4701" PostId="4442" Text="I'm still working on finding the right numbers, but the fade-**away** effect on this one is just awesome.  I'm still getting an instant power on (with a low &quot;R&quot;) or the triple never turns on (with a high &quot;R&quot;).  Hopefully the fade-in is somewhere in between." CreationDate="2010-09-17T01:52:29.977" UserId="1271" />
  <row Id="4702" PostId="4442" Text="Awesome, found it!  Beautiful fade-in, beautiful fade-out." CreationDate="2010-09-17T01:54:21.910" UserId="1271" />
  <row Id="4703" PostId="4439" Text="I don't believe that pingswept said anything wrong; he said that you'd have trouble accurately reconstructing high frequency signals, and he's right. You need your waveform to &quot;stay still&quot; for quite some time (in computer timeframe) in order to sample it enough times to get a nice picture of it, and even then your uC needs to be pretty good and your ADC as well.  There's a reason good oscilloscopes are expensive. :-) " CreationDate="2010-09-17T02:14:41.357" UserId="974" />
  <row Id="4704" PostId="4442" Text="Nicely done, sir!" CreationDate="2010-09-17T02:43:14.577" UserId="712" />
  <row Id="4705" PostId="4393" Text="This is good info, thanks. I have heard of C/C++ to HDL compilers. Have you tried them at all?" CreationDate="2010-09-17T10:10:48.550" UserId="1143" />
  <row Id="4706" PostId="4382" Text="Addendum - Are there any good examples in the real world that use hybrid architectures, that is, combining fpga's with microcontrollers?" CreationDate="2010-09-17T10:12:47.753" UserId="1143" />
  <row Id="4707" PostId="4431" Text="you are right, Those 12 extra legs are actually just connected to ground" CreationDate="2010-09-17T11:38:48.503" UserId="811" />
  <row Id="4708" PostId="4436" Text="Upvote for the Ganssle reference. The amount time he spent in his book on contact bounce was pretty amazing to me. I guess it is still something most people in industry do not think about. " CreationDate="2010-09-17T14:58:43.120" UserId="230" />
  <row Id="4709" PostId="4443" Text="Thanks, this seems like a good way to adjust the fade-away rate.  Right now it is working perfectly without the transistors, but I assume the numbers will get harder to juggle the more LEDs are involved." CreationDate="2010-09-17T19:51:22.273" UserId="1271" />
  <row Id="4710" PostId="1137" Text="Also, this picture makes an awesome background for a phone." CreationDate="2010-09-18T14:03:17.477" UserId="230" />
  <row Id="4713" PostId="4457" Score="2" Text="High-impedance headphones (not the Walkman variety) or a crystal earpiece should work." CreationDate="2010-09-19T17:56:32.750" UserId="305" />
  <row Id="4715" PostId="4456" Text="You'll need a good antenna." CreationDate="2010-09-19T18:50:22.923" UserId="305" />
  <row Id="4716" PostId="2433" Score="1" Text="yes. Actually, the main issue, and the reason you need a common-mode choke is due to the ability of a USB cable to radiate. if the signal enters your board, collides with a mismatch, the reflected signal will traverse the cable again, radiating. whenever you have a long wire is when you want to do your best to minimize reflections entering the coil. The reason you add a common-mode choke is due to the large amount of EM generated by common-mode currents compared to differential mode. But, even though a common mode choke should not affect differential mode, there are imperfections." CreationDate="2010-09-19T20:42:55.370" UserId="230" />
  <row Id="4717" PostId="4458" Text="the yahoo answer is very very poor. Please forgive me if you know the writer." CreationDate="2010-09-19T22:17:06.107" UserId="230" />
  <row Id="4718" PostId="4460" Score="1" Text="often different stages in the microcontroller need to be out of phase due to logic delay. using a higher speed oscillator and dividing down and using the two different edges for different sets of logic can greatly reduce cost of the device. JustJeff is spot on with using an oscillator that is a multiple of standard clock rates. It can make high speed transfers very easy." CreationDate="2010-09-19T22:19:09.207" UserId="230" />
  <row Id="4721" PostId="4462" Text="What compiler are you using. It looks similar to the c18, which I work with, let me know and I may just compiler this for a PIC and test it myself." CreationDate="2010-09-19T23:30:13.293" UserId="230" />
  <row Id="4723" PostId="4462" Text="@Kortuk: I'm using MPLAB c18 Lite. If you would like to give it a whirl it's here: http://pastebin.com/ZYcZG0eW . " CreationDate="2010-09-20T00:38:55.117" />
  <row Id="4724" PostId="4462" Text="John, My next note when I loaded it up was going to be the use of volatile. If you are using something that will be modified both inside interrupts and outside, mark it volatile. This however should not be an issue as the c18 lite does not optimize, and without an optimizer the volatile means nothing. " CreationDate="2010-09-20T01:06:50.910" UserId="230" />
  <row Id="4725" PostId="4462" Text="It will be later in the week before I am in a lab with free time. My students have work due on thursday, I will try to load it up by then, it may be next week." CreationDate="2010-09-20T01:08:44.247" UserId="230" />
  <row Id="4726" PostId="4462" Text="We changed all variabled modified or read inside of the interrupts to volatile but it did not change anything as expected. If we resolve our issue before then I will post back here to let you know. I may end up rewriting a large portion of the code to see if that helps. What's in main right now is just initialization followed by test code at the moment, right now just adding some data to an array and then turning on the TX interrupt. Thanks for taking a look!" CreationDate="2010-09-20T01:13:23.627" />
  <row Id="4732" PostId="4458" Text="hmm, Just took Microprocessors this semester, so I have no idea how wrong that could have been. I guess I got the answer here...thank you." CreationDate="2010-09-20T16:50:46.103" UserId="1163" />
  <row Id="4733" PostId="4393" Text="They're...okay.  For a single logic block, it's not too bad.  But I wouldn't write a whole design through that kind of compiler.  They're not too efficient because the languages are so incredibly different...you have to use special conventions, they don't just take any old ANSI C code." CreationDate="2010-09-20T16:56:50.533" UserId="1278" />
  <row Id="4734" PostId="4465" Text="I was going to initialize the code and then run it to see if there was a change, and if there was, this is what type of error I was going to look for. Good catch" CreationDate="2010-09-20T17:02:29.457" UserId="230" />
  <row Id="4735" PostId="4460" Score="2" Text="Are you sure about the duty cycle statement?  I was under the impression that an instruction cycle may require multiple clock cycles (e.g. one instruction cycle composed of a fetch cycle and an execute cycle).  I'm pretty sure even modern-day PICs have a 4-stage instruction cycle, which is why there's all the Fosc/4 throughout the datasheet" CreationDate="2010-09-20T17:09:50.143" UserId="1278" />
  <row Id="4736" PostId="4466" Text="Yes, disable interrupts that are related to a data structure while it is being modified.  Otherwise you open yourself up to race conditions" CreationDate="2010-09-20T17:21:07.713" UserId="1278" />
  <row Id="4737" PostId="4460" Score="1" Text="@ajs410 - the 8085 would definitely take multiple clock cycles to complete an instruction; all the 8 bit micros from that time (that I am aware of) took at least two clocks to do anything. What I'm referring to here is purely internal to the chip. If you look at block diagrams for these old beasts, you can see they have some internal busses, temporary registers and so forth, and it's these that I speculate might be using both edges. Any external bus cycles would be run between edges of the same polarity." CreationDate="2010-09-20T21:58:12.513" UserId="740" />
  <row Id="4738" PostId="4468" Score="2" Text="I don't think the OP is asking why you'd spread an instruction across multiple clocks, but rather why the 8085 is designed to require you to feed it a 2X clock (which it then divides internally) as opposed to just taking the intended clock frequency directly." CreationDate="2010-09-20T22:03:07.643" UserId="740" />
  <row Id="4739" PostId="4468" Text="everything you said about instructions is on, though." CreationDate="2010-09-20T22:33:57.270" UserId="740" />
  <row Id="4741" PostId="4472" Score="2" Text="Just a couple of tips? I guess that's better than a half dozen, but I think he would still be unhappy with going through a couple tips a session. :-)" CreationDate="2010-09-20T23:44:44.707" UserId="974" />
  <row Id="4742" PostId="4469" Text="The pastebin code, which has all of it does zero the counter." CreationDate="2010-09-21T01:53:35.640" UserId="230" />
  <row Id="4744" PostId="218" Text="That link didn't work for me, but I presume it's meant to point to this: http://store.curiousinventor.com/guides/How_to_Solder&#xA;" CreationDate="2010-09-21T03:27:36.560" UserId="70" />
  <row Id="4745" PostId="3268" Text="I have heard a lot of good things about the Bus Pirate, including the place I'm doing my Senior Project at buys a bunch of them and uses them all over the place." CreationDate="2010-09-21T04:49:19.760" UserId="982" />
  <row Id="4746" PostId="4475" Score="2" Text="Wow, I do the exact opposite. I spend the great majority of my design time on placement." CreationDate="2010-09-21T08:28:24.660" UserId="1374" />
  <row Id="4747" PostId="4470" Score="4" Text="Are you cleaning the tip **before** putting it down? That an easy way to a damaged tip. Only clean the tip when you pick the iron up. When you're putting it down, make sure to leave plenty of solder on it." CreationDate="2010-09-21T08:30:40.273" UserId="1374" />
  <row Id="4748" PostId="4382" Text="Sushrut J Mair - Generally when you have a FPGA and need a Micro, the micro gets implemented *in* the FPGA." CreationDate="2010-09-21T08:31:24.703" UserId="1374" />
  <row Id="4749" PostId="4439" Text="Also, you need a Sample &amp; hold that can acquire very fast. Most ADCs readout value is the average of the input over some period of time. You need a circuit that will sample the input value for a *very* short period of time, and then preserve that value long enough for the ADC to convert on it (Generally done with capacitors. There are specialized devices. Google &quot;Sample and Hold&quot;)." CreationDate="2010-09-21T08:37:35.887" UserId="1374" />
  <row Id="4750" PostId="4469" Text="It does? Where?" CreationDate="2010-09-21T11:01:22.523" UserId="554" />
  <row Id="4751" PostId="4479" Score="2" Text="I've been using Altium for about 10 years. In my experience, their autorouting hasn't improved to the level that's worth using for complex boards, which is when it would be useful. The boards it generates usually have the traces that are routed early on along direct paths, but the last few traces it routes are insane-- long and changing layers a lot, which is bad for high speed signals." CreationDate="2010-09-21T12:31:04.860" UserId="712" />
  <row Id="4752" PostId="4475" Score="2" Text="I spend time on my placement also. The process allows me to find issues with what pins I am using. Many times I am able to switch some pins around on the micro-controller in order for the layout to be cleaner. I can really only see this by constantly looking back and forth between my schematic and layout." CreationDate="2010-09-21T13:37:46.643" UserId="319" />
  <row Id="4753" PostId="4439" Text="Absolutely correct, Fake Name. Every ADC I've used on a microcontroller has had its own sample and hold that effectively decouples the ADC from the input after it's sampling time. If your ADC has a slow S/H (and it probably will) you'll need an external one." CreationDate="2010-09-21T14:12:00.597" UserId="974" />
  <row Id="4754" PostId="4478" Text="I bought the 4-layer version of Electra. It takes a long time to play around with its settings but it does very well on a &quot;clean&quot; config file. It was able to route the vast majority of my board very well, and left me with a dozen traces that I spent about 16 hours on. It doesn't (yet) do balanced traces or length matching, but both are on the todo list." CreationDate="2010-09-21T14:14:12.153" UserId="974" />
  <row Id="4755" PostId="4478" Text="I don't use it much, but I find that it usually routes to completion, or close to it." CreationDate="2010-09-21T14:56:37.527" UserId="305" />
  <row Id="4756" PostId="4253" Text="I'm a little confused on the downvote, does it not answer the question, and it's one less gate per bit?" CreationDate="2010-09-21T15:28:09.400" UserId="982" />
  <row Id="4757" PostId="4469" Text="It's initialized to 0 at the top, but I did a ctrl-f for TXCurrentPos and I only found the initializer and the incrementer." CreationDate="2010-09-21T17:11:57.820" UserId="1278" />
  <row Id="4758" PostId="4479" Text="I think the trick is that you shouldn't just let the auto-router do all the work.  They have a Smart Wire that auto-routes a single trace pretty effectively.  Their auto-router can also do one bus at a time.  Let it do the grunt work, and then you can tweak the results.  Use Smart Wire for the last few traces." CreationDate="2010-09-21T17:41:50.877" UserId="1278" />
  <row Id="4759" PostId="4344" Text="Well I think that's still better than the amount of water he's going to need.&#xA;&#xA;http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity&#xA;&#xA;&quot;1000 kilograms of water (1 cubic meter) at the top of a 100 meter tower has a potential energy of about 0.272 kW·h&quot;" CreationDate="2010-09-21T18:06:10.143" UserId="588" />
  <row Id="4760" PostId="4241" Text="It's worth mentioning that all the ARMs come with peripherals that are very specific to particular vendors. Apart from that, recompiling C (gcc dialect) code even between 8-bit AVR and 32-bit ARM7 is already very simple (I did this without a problem).&#xA;&#xA;Unless you do not use the built-in peripherals much or want to buy a chip that has much more power than you need (so you don't bother with DMA and such stuff) you should go with a vendor that seems solid. (unfortunately this probably rules out Atmel with its recent problems; I would rather go with NXP or TI)" CreationDate="2010-09-21T19:01:14.740" UserId="659" />
  <row Id="4761" PostId="4477" Text="Other than the name &quot;Respironics&quot; There is nothing else on the card at all. No numbers or letters of any sort.  Can you recommend a smart card reader that &quot;Might&quot; read this card, or which card reader would you buy if you were trying to buy one that stands the most chance of reading a lot of different cards.  I guess I will just try that and look at as a learning experience.  If that stands a chance at working. Thank you very much.&#xA;Russ" CreationDate="2010-09-22T01:05:16.713" />
  <row Id="4762" PostId="4382" Text="Yes, Fake Name, agreed. However, I was looking to find any real world cases where both FPGA's and MCU's are used to design a system. The idea being that the FPGA part of the design is used to implement 'evolvable' h/w that responds and morphs as per changing inputs to the system while the core logical processing is done by the MCU." CreationDate="2010-09-22T02:39:26.520" UserId="1143" />
  <row Id="4763" PostId="4393" Text="Thanks, this is useful. I've ordered Lattice Semiconductor's XP2 Brevia dev kit. I intend to try out some HDL to C compilers once I am comfortable with basic FPGA designing concepts." CreationDate="2010-09-22T02:40:27.300" UserId="1143" />
  <row Id="4764" PostId="4393" Text="Just saw the answer to my addendum in the original query. Thanks - so are you saying that practically speaking (at least with today's technology), a hybrid architecture of a standard MCU + a FPGA has very little value add to be really usable in real world situations?" CreationDate="2010-09-22T04:00:35.750" UserId="1143" />
  <row Id="4766" PostId="4479" Text="Well, ostensibly they redesigned the autorouter at some point recently (I went from 6.0 to 9.0 in one leap). The old one did suck. I haven't had a chance to play with the situs one yet.&#xA;&#xA;" CreationDate="2010-09-22T09:18:30.443" UserId="1374" />
  <row Id="4772" PostId="4462" Text="volatile does not affect you. You are not using an optimizer. Did you look at the answer from peter gibson?" CreationDate="2010-09-22T14:01:34.237" UserId="230" />
  <row Id="4773" PostId="4469" Text="I thought I saw it, I do not have time to look now. Sorry if I am mistaken." CreationDate="2010-09-22T14:02:13.740" UserId="230" />
  <row Id="4774" PostId="4469" Text="Click edit on your answer ajs410. Just change something super minor for me." CreationDate="2010-09-22T14:02:39.957" UserId="230" />
  <row Id="4775" PostId="4466" Text="The interrupt he was using to send the buffer he enables after the buffer has been filled." CreationDate="2010-09-22T14:03:12.540" UserId="230" />
  <row Id="4778" PostId="4469" Text="Originally we were going to have the buffer be 256 bytes meaning we could count on overflow to zero the pointers, but we ran into compile errors because the size of the data banks is 256 bytes. I reduced the buffer size to 128, but forgot to modify the code to zero the pointers after 128 bytes. Either way, we were trying to put about 40 bytes into the buffer and were still running into this problem. The latest version of the code zeros the pointers appropriately and I will post that code soon." CreationDate="2010-09-22T22:23:58.260" />
  <row Id="4779" PostId="4465" Text="That mistake was a result of me changing that line to debug and trying to change it back from memory. It's since been corrected and the problem persists. It did throw us for a loop however because we were getting results, but we figured it out shortly after I posted the code here." CreationDate="2010-09-22T22:26:59.377" />
  <row Id="4780" PostId="3985" Text="Wow.  I really like this response.  It positively EXUDES experience and trustworthiness.  I sincerely hope I'm in a position to hire you someday." CreationDate="2010-09-23T01:15:35.957" UserId="249" />
  <row Id="4784" PostId="4498" Text="sounds complex... what if I just switched to a dc motor? Can I use a s.s. relay and PWM? What's the best route to control say a 24v DC pump?" CreationDate="2010-09-23T13:49:50.993" UserId="1140" />
  <row Id="4786" PostId="4498" Text="H-Bridge transistor configuration and PWM is the preferred way to control DC motors.  If you don't need it to run both directions you can get away with one big transistor and PWM controlling it." CreationDate="2010-09-23T14:55:55.623" UserId="249" />
  <row Id="4787" PostId="4504" Text="That's a fixed-gain 20 dB mic amp, not a unity-gain buffer, but yes, something like that with an internal switch might work." CreationDate="2010-09-23T18:53:59.613" UserId="142" />
  <row Id="4788" PostId="4504" Text="LMV341 looks promising, with a high output impedance in shutdown so that the DC bias will remain unchanged until you turn it back on, assuming it's only connected to a capacitor." CreationDate="2010-09-23T20:20:34.830" UserId="142" />
  <row Id="4789" PostId="4504" Score="2" Text="op amp with shutdown." CreationDate="2010-09-23T22:48:58.693" UserId="230" />
  <row Id="4790" PostId="4495" Text="6 layers at 8&quot;x9&quot; seems huge to me. See the question that yours duplicates, some info there indicating you may not need 6 layers." CreationDate="2010-09-23T23:01:30.533" UserId="131" />
  <row Id="4794" PostId="4393" Text="Awesome. Thanks ajs410. I hope to spend a few weeks booting up myself into fpga's before getting into the exciting hybrid arch possibilities!" CreationDate="2010-09-24T13:12:43.707" UserId="1143" />
  <row Id="4795" PostId="3985" Text="I understand your response, but like most electrical design rules, there are cases where they do not hold up. I think this works well in most cases, but there are also many cases where you need the separation." CreationDate="2010-09-24T14:12:22.017" UserId="230" />
  <row Id="4796" PostId="3771" Text="@Andrew, when i say making routing easier, I am including avoidance of embedded traces in ground/power planes and a number of EMC considerations." CreationDate="2010-09-24T14:35:55.100" UserId="230" />
  <row Id="4797" PostId="3767" Text="4pcb makes the best deals I have found for ordering boards as a student. if you buy their 33 dollar special and place multiple boards on it then they charge an extra 50. in the past we buy something around 15 different 2 layer boards on one 88$ order." CreationDate="2010-09-24T14:38:13.473" UserId="230" />
  <row Id="4798" PostId="3983" Text="Everyone seems to say this. Most links show a ground plane that has been split in half and then had traces routed between it. This is not true. If you have an entire layer for Agnd and all associated traces routed with it you do not have increased noise. This is miss-information, that makes sense, but not when you have completely isolated layers. Do not split a ground layer in half, honestly, I do not consider it a good idea, but having a AGND layer and a DGND layer, that is different." CreationDate="2010-09-24T14:46:51.720" UserId="230" />
  <row Id="4799" PostId="4509" Text="Also take a look at http://chiphacker.com/questions/1654/injecting-a-communication-signal-over-dc-power-supply-lines.  &#xA;I don't think that this is a duplicate of either question, though." CreationDate="2010-09-24T15:05:26.457" UserId="857" />
  <row Id="4800" PostId="4508" Text="The idea is pretty simple - Add an AC waveform to the DC, and filter out the DC on the other end.  However, this assumes that you have a clean signal, which should be the case for digital electronics, but may not be the case for your railway.  Can you post an oscilloscope trace of the power lines while the train is running?  It might be noisy due to the motors, or PWM from your controller.  (Also, you mean *model* railway *components*, right?)" CreationDate="2010-09-24T15:12:04.690" UserId="857" />
  <row Id="4801" PostId="3981" Text="I just emailed their sales department, because, while I don't have a board ready, I expect to require one soon, and I didn't want the promo to expire.  I received the following reply: *&quot;The promotion pricing does not end it is ongoing. Juts part of our pricing structure. Thank you and let us know when your ready.&quot;*  Looks like a different definition of &quot;promotion&quot;, but that's fine by me!" CreationDate="2010-09-24T16:12:57.520" UserId="857" />
  <row Id="4802" PostId="4509" Text="I let others decide duplicate. I was trying to be helpful. I think it is not a duplicate if he adds a bit more information." CreationDate="2010-09-24T17:06:57.453" UserId="230" />
  <row Id="4803" PostId="4513" Text="Oh the horror. It appears the &quot;newer&quot; technology is called CTM (cellular text modem) which is a 4-tone modulation that will survive GSM compression. In other news I really hope nobody bothers to hook up a typewriter to a cell phone anymore, instead of a computer or smartphone." CreationDate="2010-09-24T17:59:07.377" UserId="1363" />
  <row Id="4805" PostId="4515" Text="I've seen all three, in commercial products.  :/  Yes, put it in the schematic.  Why not?  :)" CreationDate="2010-09-24T21:49:01.283" UserId="142" />
  <row Id="4806" PostId="4516" Text="If you leave the device end of the shield floating, I'm pretty sure you just made a huge antenna." CreationDate="2010-09-24T21:51:23.607" UserId="1278" />
  <row Id="4807" PostId="4516" Text="Disagree with the effect (giant antenna) and the reasoning (you're not guaranteed that the motherboard manufacturer wouldn't have used the same logic: &quot;It is grounded at the device end, so we won't bother&quot;)" CreationDate="2010-09-24T23:18:47.470" UserId="857" />
  <row Id="4808" PostId="3983" Text="I agree that a single copper layer divided into two regions, as in the experiments reported in the articles I linked to, is different from two independent copper layers, each one more-or-less covering the entire board, as described by the original poster.&#xA;&#xA;I am curious -- has anyone ever done an experiment showing whether having completely isolated AGND and DGND layers is better, worse, or about the same as an identical board with a single GND layer?" CreationDate="2010-09-25T03:50:13.217" UserId="813" />
  <row Id="4809" PostId="498" Text="I'm a little confused as to how using a miniature computer and software to implement a simple logic function is &quot;the obvious solution&quot;." CreationDate="2010-09-25T04:06:47.147" UserId="142" />
  <row Id="4810" PostId="4402" Text="The link you gave is a nice overview that confirms that yes, MIPI is a specific standard.&#xA;Alas, it doesn't give any details -- such as, how many wires does this interface need? What kind of connector does it use? -- nor does it link to any other web pages that give this information.&#xA;&#xA;By &quot;just a parallel bus interface&quot;, are you claiming that *any* digital interface that carries video is a kind of DVP, or are you saying that DVP is some specific standardized interface?" CreationDate="2010-09-25T04:11:25.740" UserId="813" />
  <row Id="4811" PostId="4452" Text="While your comment is technically true, I fail to see how it answers any part of the original question. Did you perhaps mean to post this in response to some other question?" CreationDate="2010-09-25T04:12:36.333" UserId="813" />
  <row Id="4812" PostId="4472" Text="Ah, levity. We all need a bit now and then." CreationDate="2010-09-25T10:58:06.343" UserId="883" />
  <row Id="4813" PostId="4513" Text="They've updated the standard several times since 1994-that was edition 1, we're now on edition 4 (Published 2002).  See the full list of Series V standards on &quot;Data communication over the telephone network&quot;  here: http://www.itu.int/itu-t/recommendations/index.aspx?ser=V The most recent spec is here: http://www.itu.int/rec/dologin_pub.asp?lang=e&amp;id=T-REC-V.18-200011-I!!PDF-E&amp;type=items [pdf]" CreationDate="2010-09-25T15:40:56.563" UserId="857" />
  <row Id="4814" PostId="4520" Text="I'm considering both options: http://chiphacker.com/questions/4373/computer-controlled-water-valve&#xA;&#xA;I'm having a hard time finding a valve that can be easily controlled." CreationDate="2010-09-25T17:34:56.127" UserId="1140" />
  <row Id="4815" PostId="4498" Text="It's not all that complicated; look up AC light dimmer circuits or soldering iron heat controllers for the basic idea." CreationDate="2010-09-25T20:17:27.063" UserId="974" />
  <row Id="4816" PostId="4522" Text="wow you actually read all those?" CreationDate="2010-09-25T21:04:12.510" UserId="1200" />
  <row Id="4817" PostId="4522" Text="Yes. They're mostly low traffic." CreationDate="2010-09-25T22:09:24.960" UserId="566" />
  <row Id="4818" PostId="4522" Score="3" Text="I read a lot more than that. The challenge is to find the low traffic but extremely high quality blogs, and fill your reader with that. :) Thanks for the dump. :)" CreationDate="2010-09-26T08:44:27.277" UserId="718" />
  <row Id="4819" PostId="4526" Score="7" Text="From my own experiences as a contractor I deliver schematics, layout files, component libraries, prototypes, gerbers, bills of material and &quot;and any other design notes&quot; upon confirmation of receipt of final payment. In other words, once the final payment clears the bank. If it's someone I've done work for before and we have an amiable relationship then it's not quite so strict.  If I were you I would make sure that you don't just get &quot;AutoCAD&quot; copies of the schematics and layout files -- they're only useful for documentation. If you want to make changes, you'll need the real working files." CreationDate="2010-09-26T11:24:38.097" UserId="974" />
  <row Id="4820" PostId="4529" Text="I understood how it works. I want to know the possible hardware to do it. i.e : Is there something easiest than a microcontroller ?" CreationDate="2010-09-26T18:13:28.197" UserId="824" />
  <row Id="4821" PostId="4526" Text="Andrew, This is a good answer. It should have been made as an actual answer and not just a comment." CreationDate="2010-09-27T01:33:18.640" UserId="319" />
  <row Id="4822" PostId="3336" Text="Apparently Digikey has specifically asked them not to inlude them in their search." CreationDate="2010-09-27T05:36:06.707" UserId="688" />
  <row Id="4823" PostId="4498" Score="1" Text="Andrew Kohlsmith - Resistive loads (e.g. Lights, a soldering iron) are *very* different from inductive loads (e.g. a motor). There is no real commonality between what is needed to control them." CreationDate="2010-09-27T10:00:02.743" UserId="1374" />
  <row Id="4825" PostId="4253" Text="The answer is confusingly worded (run-on sentence with little clear structure), which probably explains the downvote. Also, in CMOS technology (the most common today), the fundamental gates are NOR and NAND, meaning you need *more* logic to not have the inversion" CreationDate="2010-09-27T11:49:10.380" UserId="1181" />
  <row Id="4826" PostId="2003" Score="1" Text="+1 for backwards" CreationDate="2010-09-27T13:27:06.010" UserId="554" />
  <row Id="4827" PostId="3981" Text="That could be my mistake as well. I may have have misread the original email. If you end up ordering boards from e-teknit please post about your experience (quality, service, etc)." CreationDate="2010-09-27T14:23:40.360" UserId="424" />
  <row Id="4828" PostId="4527" Text="+1 for making sure the engineer provides a source for each part." CreationDate="2010-09-27T15:28:36.903" UserId="529" />
  <row Id="4829" PostId="4516" Text="So you're telling me that what amounts to a six foot wire connected only to the PC isn't going to radiate all kinds of RF EMI?" CreationDate="2010-09-27T16:49:56.023" UserId="1278" />
  <row Id="4830" PostId="4527" Text="As the person/company manufacturing the device it's YOUR responsibility to sign off on any parts that might be hard to find. Part of my responsibility is to make you aware of any potentially strange parts and get the ok from you to use them. No ok from you means that it's up to me to find another way to achieve the function of the unusual part." CreationDate="2010-09-27T18:04:14.557" UserId="974" />
  <row Id="4831" PostId="4526" Text="Indeed; I was riffing off of pfyon's answer but realized later that my comment would have been better suited on its own instead of as a comment." CreationDate="2010-09-27T18:04:46.537" UserId="974" />
  <row Id="4832" PostId="4533" Text="Thanks!  The reference page made it clear that 4800 was too fast, so I dropped to 300 baud and things are &quot;better&quot;.  The pinMode doesn't affect transmit, but I added it anyways to make things clearer.  I'm now trying slowing changing the delay between bits until something is received.  Minicom is just showing ? marks right now.  Worst case, my 16mhz and 20mhz oscillators arrive Friday." CreationDate="2010-09-27T18:07:36.287" UserId="1271" />
  <row Id="4833" PostId="4533" Text="Do you think it could be the voltage problem?  Adjusting the timing still hasn't worked, and I'm getting a lot of question marks, so something is being transmitted.  Can I fix it just by lowering the Vcc to the tiny to 3V, that is, can I just hook it up to some batteries instead of USB?  Do I connect ground to both the USB ground and the battery ground?" CreationDate="2010-09-27T18:28:19.697" UserId="1271" />
  <row Id="4834" PostId="4533" Text="Oh, also thanks for pointing out the yellow wire is for my tiny to transmit on.  The orange wire seems to flicker a lot (hooked to a LED from the PC).  Is the PC transmitting, or does it stay &quot;on&quot; most of the time?" CreationDate="2010-09-27T18:31:49.163" UserId="1271" />
  <row Id="4835" PostId="1996" Text="I'm trying to figure out exactly what your formula is.  It's remarkably close to f(x)=x^2, but the curve isn't quite deep enough.  f(x)=x^3/13 gets me a lot closer." CreationDate="2010-09-27T19:30:54.407" UserId="1278" />
  <row Id="4836" PostId="4536" Text="This is something I would be much happier recieving than just schematic, PCB, and BOM information.  Working prototypes + documented design decisions = much more comfort in whatever I'm delivering.   EE work isn't just connect-the-dots." CreationDate="2010-09-27T19:46:55.503" UserId="857" />
  <row Id="4837" PostId="4525" Text="Since you say auto-cad in your question, it should be clear to you that a contract ME who gives you a  SolidWorks or ProE file might cause problems.  You probably want to make sure that you can access whatever they give you.  I'd personally advocate open source tools like gEDA for this purpose, but something with a free demo viewer/exporter or freeware license (note that this doesn't include Eagle!) might also be acceptable." CreationDate="2010-09-27T19:51:41.377" UserId="857" />
  <row Id="4838" PostId="4539" Text="I'm not going to - but I expect PSGroove for Arduino Uno to appear any day now" CreationDate="2010-09-27T21:40:46.767" UserId="566" />
  <row Id="4839" PostId="4541" Text="I was excited about it for a minute, but, after looking at the schematic, I agree.   Here's hoping that fixing this is part of their plan: (1) Sell boards with missing connections. (2) Profit. (3) Announce that boards with missing connections can't do X, Y, or Z. (4) Sell V2 boards with connections properly implemented.  (5) Profit again. " CreationDate="2010-09-27T22:32:20.117" UserId="857" />
  <row Id="4840" PostId="4541" Text="Cunning\0\0\0\0" CreationDate="2010-09-27T23:07:29.253" UserId="566" />
  <row Id="4841" PostId="4533" Text="Yes, should stay HI when idle and flicker when transmitting - I'm not sure if the FTDI is capable of supplying enough current to drive an LED. The AVR will be fine, but I'd remove the LED from the FTDI-TX line. Crystal should fix up the timing issues (but you need to set the fuses to switch over from the internal oscillator)." CreationDate="2010-09-27T23:18:23.453" UserId="554" />
  <row Id="4842" PostId="4541" Score="3" Text="Well, it's all open source.  You can always make a derivative board that makes all the connections you like.&#xA;&#xA;The main goal of Arduino is to be an easy, welcoming platform for folks new to hardware hacking, though.  JTAG, etc. doesn't really advance that goal.  If you're looking for more power or more involved USB hacking, you probably want to look at the Netduino or something similar." CreationDate="2010-09-27T23:28:42.187" UserId="70" />
  <row Id="4843" PostId="4542" Text="Are you trying to implement a bunch of variable gains for a mixer, or oscillator frequencies for a synth, or something else?  There might be a cheaper way to do it than digital pots." CreationDate="2010-09-27T23:51:44.603" UserId="142" />
  <row Id="4844" PostId="4541" Text="+1 Agreed, Arduino is for hardware hacking. On that basis, it's inexcusable to not bring out the lines. Even to vias!" CreationDate="2010-09-27T23:54:35.447" UserId="566" />
  <row Id="4846" PostId="4542" Score="1" Text="@endolith: A computer controlled analog EQ. And a cheaper way is exactly what I'm looking for." CreationDate="2010-09-28T01:08:17.460" UserId="1182" />
  <row Id="4847" PostId="4545" Score="1" Text="That's creative." CreationDate="2010-09-28T01:09:36.167" UserId="1322" />
  <row Id="4848" PostId="4544" Text="Other ways in what way? Avoid using a solid-state variable resistor? A totality different architecture? The first might work but what I'm looking for actually would need ~150 independent degrees of freedom so the second may change the demands on the component but not the quantity needed. Also given the number needed, I need something has low cost for all unshared aspects." CreationDate="2010-09-28T01:16:33.990" UserId="1182" />
  <row Id="4849" PostId="4545" Score="1" Text="In other words, an analog opto-isolator?" CreationDate="2010-09-28T02:06:47.260" UserId="1182" />
  <row Id="4850" PostId="4545" Text="Yep, but with a photoresistor instead of a phototransistor.  They're used in optical limiters or compressors, for instance." CreationDate="2010-09-28T02:14:35.503" UserId="142" />
  <row Id="4851" PostId="4545" Text="A DSP is not an option. The point of the project is that the signal processing is analog. As to that last link, nope, I hadn't seen that but it's very close to what I'm thinking of." CreationDate="2010-09-28T03:07:31.087" UserId="1182" />
  <row Id="4852" PostId="4545" Text="as for those 6-wides, ~$50 isn't that bad..." CreationDate="2010-09-28T03:10:49.383" UserId="1182" />
  <row Id="4853" PostId="4548" Text="That would do quite well. The +/- 20% doesn't look that nice though. (More related devices: http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=11026&amp;mid=11&amp;lang=en&amp;pageId=79)&#xA;" CreationDate="2010-09-28T14:42:08.223" UserId="1182" />
  <row Id="4854" PostId="4526" Text="That is a good point. To be fair, the only experience I have with contracting is what we're told to expect from school." CreationDate="2010-09-28T18:04:12.567" UserId="536" />
  <row Id="4855" PostId="4547" Text="Tronixstuff: I am going to have to call you a geek for deciding to build that yourself just because it looks fun. Not to say I don't do similar things." CreationDate="2010-09-28T18:10:54.903" UserId="319" />
  <row Id="4856" PostId="4533" Text="Still working on it, but I'm convinced it is a timing problem or a horrible Arduino-on-ATTiny software problem.  A few middle 2-3 bytes are being received (but not displayed) and the rest are garbled as 0x80.  I'm gonna write my own (trivial) AVR soft serial send function while I wait for the crystal.  Is there some easy/cheap way to see what is being sent? 300 baud is still pretty fast for my old eyes." CreationDate="2010-09-28T18:32:02.047" UserId="1271" />
  <row Id="4858" PostId="4544" Score="2" Text="Since you posted the appnote, I can elaborate on one simple way - Do it just the same way they did it!  Do you really need more finely grained control than what they've implemented in their design?  The 55k, 25k, 16k, 11k, 8k, and 3k network controlled by FET switches will give you, as stated in the datasheet, better than 0.1 dB accuracy over 12dB.  You can adjust these numbers and/or resistor counts to get better control or more steps." CreationDate="2010-09-28T18:41:10.200" UserId="857" />
  <row Id="4859" PostId="4544" Text="Building your own digital pots for each one?  :D  You could use an analog multiplexer instead of individual FETs.  The CD4051 is $0.15 in large quantities and acts as a SP8T switch, for instance." CreationDate="2010-09-28T19:03:21.200" UserId="142" />
  <row Id="4860" PostId="4544" Text="@reemrevnivek, I've considered that and even took a first pass at the numbers: to get 256 steps at the spacing and accuracy I want requires about 16 elements (1 element = 1R, 1C and 2FETs) from rdeml's answer I can get 256 (sadly linear) steps for $.25 and that really pushes the DIY pot for cost." CreationDate="2010-09-28T19:12:41.650" UserId="1182" />
  <row Id="4861" PostId="4547" Text="That's fine with me, I've been called worse!" CreationDate="2010-09-28T22:21:01.390" UserId="1307" />
  <row Id="4862" PostId="4533" Text="Here's the datasheet for your chip http://bit.ly/cZTpWV Have a read through the &quot;System Clock...&quot; section. If you think that the freq is out, set a slower flashing led and time it (2mins say). 300 baud is very slow - a good SWSerial routine should be able to handle 19.2K with no problems. This app note (http://bit.ly/9DWYYt) demonstrates S/W serial at 38K with a 1MHz crystal. A cheap logic analyser is handy for debugging digital timing issues, check out the Open Workbench Logic Sniffer." CreationDate="2010-09-29T07:57:27.983" UserId="554" />
  <row Id="4864" PostId="4453" Text="&quot;One of the requirements is to be able to change the water pressure via computer interface&quot;. Waterfall with this requirement needs variable water flow. Water can not run as fast as electrons do, so pulsing will be very visible in waterfall and therefore it is out of the question." CreationDate="2010-09-29T08:37:36.327" UserId="1129" />
  <row Id="4865" PostId="4556" Score="1" Text="Should that read &quot;a pedantic masochist suffering from NIH syndrome&quot; (NIH =  Not Invented Here)?" CreationDate="2010-09-29T09:36:39.277" UserId="103" />
  <row Id="4866" PostId="4555" Text="It depends, it's one thing making something with a 6 pin MCU and some LEDs - quite another to try and build your own graphics card. The choice depends on your skill level and aims." CreationDate="2010-09-29T10:08:24.530" UserId="566" />
  <row Id="4868" PostId="4556" Score="1" Text="No, I just like doing things the long way sometimes. " CreationDate="2010-09-29T10:39:55.720" UserId="1307" />
  <row Id="4873" PostId="4560" Score="2" Text="What kind of circuit?  Do you want to saturate the transistor (logic circuit, on/off), or use it as an amplifier?" CreationDate="2010-09-29T13:57:05.180" UserId="1322" />
  <row Id="4874" PostId="4555" Score="2" Text="Depends how complicated the circuit is, and whether you have more time or money." CreationDate="2010-09-29T14:08:36.237" UserId="142" />
  <row Id="4876" PostId="4563" Text="Everyone loves signal inversion." CreationDate="2010-09-29T14:54:36.937" UserId="230" />
  <row Id="4877" PostId="4556" Score="3" Text="Many of us create projects to learn as well as make money.  If we do it all ourselves we get to make money and learn at the same time. It's not always NIH syndrome." CreationDate="2010-09-29T15:24:02.293" UserId="249" />
  <row Id="4878" PostId="4554" Text="Nice list, I am interested in Embedded systems so I think Embedded Software Primer would be a good read. Where did you get the book in India? Any website where I can order it online with reasonable shipping?" CreationDate="2010-09-29T15:25:13.150" UserId="1200" />
  <row Id="4879" PostId="4569" Score="2" Text="For this application, the (7)555 timer has the important feature of costing 35 cents in quantities less than 10,000." CreationDate="2010-09-29T15:37:32.047" UserId="1363" />
  <row Id="4880" PostId="4561" Score="3" Text="I find when building circuits using .7 works a lot better." CreationDate="2010-09-29T15:48:14.953" UserId="230" />
  <row Id="4881" PostId="4561" Text="This is one thing that I can really teach well in person, the internet is hard." CreationDate="2010-09-29T15:48:32.473" UserId="230" />
  <row Id="4882" PostId="4569" Score="1" Text="Learn the 555 timer. One of the best chips I have ever used. It is very low cost and it can be used for crazy crazy things. You should really take a look at some of the application circuits." CreationDate="2010-09-29T15:54:03.567" UserId="230" />
  <row Id="4883" PostId="4569" Text="They are also quite noise tolerant because of their reference being relative." CreationDate="2010-09-29T15:54:28.137" UserId="230" />
  <row Id="4884" PostId="4569" Text="Another problem, there's a learn curve related to MCU products that &quot;maybe&quot; more complex than learn how to use a LM555!" CreationDate="2010-09-29T16:18:15.143" UserId="940" />
  <row Id="4885" PostId="4559" Score="1" Text="RF modules are one part where I might want to avoid own design." CreationDate="2010-09-29T16:29:43.507" UserId="883" />
  <row Id="4886" PostId="4569" Text="Curves depend entirely on where you come from. Neither is exactly complicated.&#xA;&#xA;Odds are, though, that the MCU will require fewer (if any) external components and can put itself to various sleep modes etc. It will almost certainly require a computer. AVR can be programmed with a few resistors and a real parallel port, though." CreationDate="2010-09-29T16:36:49.680" UserId="883" />
  <row Id="4887" PostId="4569" Text="I don't disagree that it's a good, cheap, useful chip.  I'm just saying that for many applications you'll find that you need a 555 AND some sort of microcontroller, so you might as well just get the microcontroller.  Even if you think you only need a 555 you might get other good ideas once you finish version 1 that require a complex uC." CreationDate="2010-09-29T16:50:10.880" UserId="249" />
  <row Id="4888" PostId="4575" Score="1" Text="The simplest oscillator is just an inverter connected back to itself, but that's too trivial to be an answer." CreationDate="2010-09-29T19:23:01.177" UserId="142" />
  <row Id="4889" PostId="4575" Text="I would like a nice square wave" CreationDate="2010-09-29T19:26:34.620" UserId="1203" />
  <row Id="4890" PostId="4575" Score="1" Text="@endolith: that would not work. An inverter connected to itself will usually not oscillate, but instead stabilise and waste power. Instead you will need at least 3 in a ring configuration." CreationDate="2010-09-29T19:43:21.207" UserId="1225" />
  <row Id="4891" PostId="4581" Score="1" Text="just one other note. Board house and assembly house prices drastically decrease with product volumes so it can be hard to afford them with low quantites." CreationDate="2010-09-29T19:44:37.183" UserId="1235" />
  <row Id="4892" PostId="4579" Score="1" Text="It's a bad idea to use diodes to drop 0.7V, because, well, they don't. If your micro is in standby, they will drop 0.4V-0.6V (so the supply will go from 4.2V to 3.8V - bye bye) and at moderate load they can drop as much as 1V leaving you with only 3V and a possible power reset." CreationDate="2010-09-29T19:45:38.573" UserId="1225" />
  <row Id="4893" PostId="4575" Score="1" Text="@Thomas: Ok, ok, a Schmitt-input inverter.  :D  http://www.electronics-tutorials.ws/logic/log16.gif" CreationDate="2010-09-29T19:45:48.587" UserId="142" />
  <row Id="4894" PostId="4582" Text="I'm using a PIC24FJ64GA002" CreationDate="2010-09-29T19:50:33.507" UserId="1235" />
  <row Id="4895" PostId="4581" Text="1) I am planning to sell more than 50 yearly but less than 200. &#xA;2) There are about 20x 0603 resistors, 10x 0603 caps, and various chips, regulators and a few electrolytics.&#xA;3) I don't really enjoy it too much." CreationDate="2010-09-29T19:51:03.810" UserId="1225" />
  <row Id="4896" PostId="4578" Text="Two things need clarification: (1) How many motors do you want to control?  That is a key limit of the Arduino for robotics - You only have 6 PWMs.  (2) Why do you need an object-oriented programming language?  Would a well-documented C library with lots of examples like avr-libc be good enough?" CreationDate="2010-09-29T19:52:35.597" UserId="857" />
  <row Id="4897" PostId="4582" Text="Two onboard comparators and a 10 channel ADC. Any of those modules can be used to check the supply voltage is OK. The comparator is better because it can trigger an ISR. I've actually dealt with the PIC24F/H/dsPIC30F/33F series of chips and the interrupts have priorities AFAIK so you can make power fail more important than say ADC conversion done." CreationDate="2010-09-29T19:54:34.863" UserId="1225" />
  <row Id="4898" PostId="4578" Text="_@reemrevnivek:_ __1.__ 3 - 5 motors, and perhaps a solenoid. I'll update the question. __2.__ Personal preference really. Having looked at the examples on the arduino site, it looks like it's semi- object-oriented (a cross between C and C++) anyway." CreationDate="2010-09-29T19:56:30.003" UserId="1217" />
  <row Id="4899" PostId="4582" Text="A Schmitt trigger can be built with just a few transistors, a full-blown comparator is not really necessary here.  " CreationDate="2010-09-29T19:56:30.250" UserId="857" />
  <row Id="4900" PostId="4582" Text="Why use a Schmitt trigger with several transistors which continuously wastes power and costs board space when you have integrated on-die comparators which can be switched off when not needed? (Hint: you could power up the comparator maybe a few hundred times a second to check the supply voltage is in bounds, and save power when not needed.)" CreationDate="2010-09-29T19:58:07.870" UserId="1225" />
  <row Id="4901" PostId="4569" Text="555 takes a few less components in general. No regulator. Runs great off of a 9v battery. I am not arguing that uC is good. I just want to suggest that learning a 555 is pretty cool." CreationDate="2010-09-29T19:58:09.130" UserId="230" />
  <row Id="4902" PostId="4582" Score="1" Text="Rather than using any sort of comparitor, I was just going to look at 5V_RAW on one of my digital inputs and interrupt on any high to low transition. As soon as the interrupt occurs I flush the buffer.   But how do I stop the MCU from flickering on an off or is that really a worry?" CreationDate="2010-09-29T20:02:52.670" UserId="1235" />
  <row Id="4903" PostId="4583" Text="Why would you build your own op-amp when something like an LM324 is less than 20 cents in quantity? Unless you mean an amplifier based around an op-amp ... or am I missing something?" CreationDate="2010-09-29T20:09:04.480" UserId="1225" />
  <row Id="4904" PostId="4582" Text="That will not work. The supply will drop below 3V before a logic transition occurs. Also, the logic inputs will draw current when operating at neither high nor low." CreationDate="2010-09-29T20:10:59.480" UserId="1225" />
  <row Id="4905" PostId="4583" Text="I have no idea what a LM324 is, I don't now where I could buy that, but most importantly I'd like to learn... :)" CreationDate="2010-09-29T20:13:31.817" UserId="1258" />
  <row Id="4906" PostId="4583" Score="1" Text="First result on Google: http://www.national.com/mpf/LM/LM324.html&#xA;Buy it from Newark: http://www.newark.com/jsp/search/browse.jsp?N=500003+1001829+5116838&amp;Ntk=gensearch_001&amp;Ntt=LM324&amp;Ntx=mode+matchallpartial&amp;No=0&amp;getResults=true&amp;appliedparametrics=true&amp;locale=en_US&amp;catalogId=&amp;prevNValues=500003+1001829&amp;filtersHidden=false&amp;appliedHidden=false" CreationDate="2010-09-29T20:16:31.247" UserId="1225" />
  <row Id="4908" PostId="4561" Text="0.65V is more commonly found on the 'net and is a compromise. " CreationDate="2010-09-29T20:19:32.227" UserId="1225" />
  <row Id="4909" PostId="4580" Text="How would a microcontroller keep a steady voltage on all of these JFETs gates, though?  Seems like you'd have to use analog transmission gates, anyway." CreationDate="2010-09-29T20:22:56.200" UserId="142" />
  <row Id="4911" PostId="4587" Text="hehe... yes... I really don't know much about electronics... You've spotted that :)" CreationDate="2010-09-29T20:24:02.777" UserId="1258" />
  <row Id="4912" PostId="1012" Text="@Peter - Please don't make mundane grammatical edits with your enhanced beta privileges, as it bumps questions to the top of the list without adding significant content." CreationDate="2010-09-29T20:24:40.680" UserId="857" />
  <row Id="4913" PostId="4584" Text="[SPIN](http://en.wikipedia.org/wiki/Parallax_Propeller#Example_program) doesn't look like a very nice language. I think I'd rather stick with the Arduino's C/C++. I'll look into the [DMC-1](http://web4robot.com/MotorCtrl.html) though. I haven't yet decided on motors." CreationDate="2010-09-29T20:25:52.083" UserId="1217" />
  <row Id="4914" PostId="4590" Text="thanks dude, much appreciated" CreationDate="2010-09-29T20:28:42.760" UserId="1258" />
  <row Id="4915" PostId="4590" Text="No problem, not been on that Beavis Audio website in a while - I forgot how good it was, not only is it hilariously witty, the instructions and diagrams are fantastically clear too...fantastisch!" CreationDate="2010-09-29T20:36:46.533" UserId="399" />
  <row Id="4916" PostId="4582" Text="Ok, I just found in the datasheet that the PIC will operate all the way down to 2.35V when running at 32MHz. " CreationDate="2010-09-29T20:36:46.533" UserId="1235" />
  <row Id="4918" PostId="4582" Text="Yeah - great - but the SD card won't work below 3.3V ±10%. " CreationDate="2010-09-29T20:39:37.227" UserId="1225" />
  <row Id="4919" PostId="4367" Text="why doesn't the website have any hardware specs?" CreationDate="2010-09-29T20:39:38.157" UserId="1279" />
  <row Id="4920" PostId="4594" Text="So do I just clip the negative side of the signal and then average the maxes as they are sampled, or do I process the signal further before the ADC step? I guess what I'm really looking for is treating the noise as an amplitude modulated signal and trying to extract the signal. Does that make sense?" CreationDate="2010-09-29T20:52:37.360" UserId="152" />
  <row Id="4921" PostId="4595" Text="This reminds me of a Maxim appnote.&#xA;&#xA;You can configure some PMOS's up as OR gates, so you can switch to a secondary power supply (e.g. capacitor) when the primary supply is unavailable." CreationDate="2010-09-29T20:53:44.050" UserId="1225" />
  <row Id="4922" PostId="4594" Text="It depends how much speed you need. If you directly sample the loudness signal, you can do fancy stuff like RMS calculations, FFT's and you have a higher signal bandwidth, so it can respond to changes quickly. If you filter the signal (such as detecting the peaks) you can use a smaller micro." CreationDate="2010-09-29T20:58:31.687" UserId="1225" />
  <row Id="4923" PostId="4574" Score="1" Text="I saw the question you referenced, but it was not clear to me which of the toolchains there where truly free in the sense of the freedom software foundation's definition." CreationDate="2010-09-29T21:11:23.133" UserId="936" />
  <row Id="4924" PostId="4593" Text="Can you post a screenshot (or drawing) of your scope trace? This is a very different question if you're working with near sinusoids or signals with high spikes. If it's just a sinusoid, simply amplify it and run it through a bridge rectifier, outputting to a small cap and a drain resistor to get a nearly DC signal." CreationDate="2010-09-29T21:14:22.013" UserId="857" />
  <row Id="4925" PostId="4588" Text="I think that produces a nice sawtooth wave, which might be good enough." CreationDate="2010-09-29T21:16:49.870" UserId="1203" />
  <row Id="4927" PostId="4598" Text="I think this should read &quot;strong AND pulsating magnetic fields&quot;.  A stationary magnet won't induce any voltages. A fast magnet (like a spinning motor), even if it has small magnets, can cause voltage spikes." CreationDate="2010-09-29T21:25:00.957" UserId="857" />
  <row Id="4928" PostId="4598" Text="A moving magnet can cause problems, as can an electromagnet switching on. The magnet need not switch off to cause damage." CreationDate="2010-09-29T21:30:11.207" UserId="1225" />
  <row Id="4929" PostId="4561" Text="The exact value varies depending on the part, the amount of current, and the temperature." CreationDate="2010-09-29T21:33:19.703" UserId="142" />
  <row Id="4931" PostId="4593" Text="Related: http://electronics.stackexchange.com/questions/4208/noise-detection-data-logger-wireless" CreationDate="2010-09-29T21:39:32.970" UserId="142" />
  <row Id="4932" PostId="4598" Text="A stationary magnet would induce voltages if the wires move relative to it.  A refrigerator door opening won't cause any problems, though." CreationDate="2010-09-29T21:42:34.657" UserId="142" />
  <row Id="4933" PostId="4601" Score="1" Text="Because the transistor is an imperfect switch." CreationDate="2010-09-29T21:48:24.840" UserId="1225" />
  <row Id="4934" PostId="4600" Text="Well ultimately I want digital output, so that might work. I was just concerned about the required sampling rate." CreationDate="2010-09-29T21:54:32.377" UserId="152" />
  <row Id="4935" PostId="4602" Text="Thanks for the reply. I'm using 5v relay. I have a protection diode across coil already. I've replaced the transistor with no change. Relay is quite small, 32VDC 30A. Needs 200ma at 5V to switch. If I manually switch ground though, i.e short ground to the collector, I can cause the relay to switch." CreationDate="2010-09-29T21:57:46.567" UserId="446" />
  <row Id="4936" PostId="4602" Text=":{  Hm.   That should be well within the range of a a transistor switch - even a low-beta transistor should saturate at more than 200mA when driven by a microcontroller.  Have you tried probing the base directly (well, almost directly - Through a resistor of, say, 250-500 ohms to generate an appropriate base current)? It could be an issue with your code or micro - That's really all that's left to by process of elimination." CreationDate="2010-09-29T22:10:54.453" UserId="857" />
  <row Id="4937" PostId="4602" Text="I've just tried that and can confirm that it does saturate. I attatched an LED from the collector to 5V and it lights up fine. Re-attatched to the micro and it does saturate in time with the micro.  (Using a 23n904 if that matters). I've swapped micro with no success." CreationDate="2010-09-29T22:22:16.450" UserId="446" />
  <row Id="4938" PostId="4602" Text="What resistance do you have between the micro and the transistor?  (I assume you mean 2N3904 above...)" CreationDate="2010-09-29T22:25:39.983" UserId="857" />
  <row Id="4939" PostId="4602" Text="I have 1k to the base and a 10k pull down." CreationDate="2010-09-29T22:28:19.827" UserId="446" />
  <row Id="4940" PostId="4602" Score="2" Text="Well, it looks like (1) your resistor to the base is too big, and (2) you transistor is too small.  Take a look at the &quot;On Characteristics&quot; table on p2 of the Fairchild datasheet - As Ic increasesfrom 10 to 100mA, hFE (Or beta, depending on how you learned it) gets smaller.  Also look at the &quot;Typical Pulsed Current Gain vs Collector Current&quot; graph - Notice the sharp knee at about 100mA? You've discovered the difference between the salespeople's &quot;absolute maximums&quot; and the real maximums.  The 2N3904 isn't meant to run at 200mA continuously, and the closer you get to this, the less gain you get." CreationDate="2010-09-29T22:43:40.050" UserId="857" />
  <row Id="4941" PostId="4602" Score="1" Text="If the gain was 30 at 200mA, you would need a current of 200/30=~6mA, which would imply a 5V-Vbe = 4V / 6mA = 600 ohms resistance.  I am surprised that your relay is being this stubborn, but it looks like it just needs some more current." CreationDate="2010-09-29T22:46:32.237" UserId="857" />
  <row Id="4942" PostId="4602" Text="That defenitely sounds right. I'm switching to a smaller relay (80ma at 5V) to see if that works." CreationDate="2010-09-29T22:50:00.923" UserId="446" />
  <row Id="4943" PostId="4350" Text="Who the hell tagged this 'probablyabadidea' ? Linux runs just fine off of batteries. Some care must be taken to ensure that your use the correct filesystem and so on, but battery powered linux is hardly &quot;probably a bad idea.&quot;" CreationDate="2010-09-29T22:50:43.627" UserId="974" />
  <row Id="4944" PostId="4602" Score="1" Text="I usually use a 1n4007 connected how you describe (cathode to +V, anode to the coil/collector junction. The Zener won't be doing anything, it's just acting as a (poor) diode. Having said that, if you connect the zener with the anode to +V, cathode to the 1N4007 cathode, and anode of the 1N4007 to the coil/transistor collector junction, you help the relay shut off more quickly. Not really necessary for this application, though." CreationDate="2010-09-29T22:53:07.317" UserId="974" />
  <row Id="4945" PostId="4602" Text="I switched the resistor to base to 330ohm(was handy) and to the smaller relay (80ma), still no luck. Would the next step to try a bigger transistor (possibly a mosfet)?" CreationDate="2010-09-29T22:55:06.687" UserId="446" />
  <row Id="4946" PostId="4580" Score="2" Text="Ditto endolith: the main reason I was looking at FETs was that they gave hight enough gate impedance that they a small capacitor will let them hold a given state for a reasonable length of time, ms at least. (OTOH it would work if I didn't have to drive so many. +1)" CreationDate="2010-09-29T22:55:14.563" UserId="1182" />
  <row Id="4947" PostId="4602" Text="Oops, meant 600ohms. I've put the LED indicator back in and it's still saturating fine. However, when I attatch the leads to the relay the LED ceases to glow. Does this mean anything?" CreationDate="2010-09-29T23:06:50.110" UserId="446" />
  <row Id="4948" PostId="4588" Text="You only need one Schmitt-input inverter, as I linked above, and it should produce a square wave, not a sawtooth.  The input of the inverter will be a sawtooth, but the output will be a square.  http://www.electro-tech-online.com/attachments/electronic-projects-design-ideas-reviews/18327d1206915388-twinkling-led-matrix-schematic-needed-cmos-schmitt-oscillator.png" CreationDate="2010-09-29T23:16:09.363" UserId="142" />
  <row Id="4949" PostId="4600" Text="If you sample at a lower rate, you'll only be capturing lower frequencies (from DC to half the sampling frequency).  If you just want to capture someone blowing into a mic, that's probably good enough, though." CreationDate="2010-09-29T23:19:17.427" UserId="142" />
  <row Id="4950" PostId="4598" Text="If you have problems with a moving magnet near (but not right next to) a circuit loop, you will almost certainly have general EMI problems from ambient magnetic fields. If you have a PCB with a ground plane this is almost certainly not an issue." CreationDate="2010-09-29T23:49:39.993" UserId="330" />
  <row Id="4951" PostId="4585" Score="1" Text="+1. Good op-amps are hard to design, and generally cheap to buy. I had to design a basic op-amp out of 2N3904 and 2N3906 transistors for a college class, and it was a pain! Not so much because of the linear region, but the nonlinear crap that happens near the supply rails." CreationDate="2010-09-29T23:51:29.390" UserId="330" />
  <row Id="4952" PostId="4604" Score="2" Text="See also: http://stackoverflow.com/questions/3207597/cool-hardware-devices-that-can-be-programmed-in-net" CreationDate="2010-09-30T01:12:08.403" UserId="1305" />
  <row Id="4953" PostId="4367" Text="It does, you just have to dig a bit." CreationDate="2010-09-30T02:58:49.357" UserId="131" />
  <row Id="4954" PostId="4608" Text="That chip looks like more than I need, I wonder if that have one with a few less gadgets (not that I couldn't ignore them). --- Re a CPLD, I'd think a more constrained device like a port expander would be cheaper. Something like this: http://www.spikenzielabs.com/Catalog/index.php?main_page=product_info&amp;products_id=17" CreationDate="2010-09-30T03:00:57.710" UserId="1182" />
  <row Id="4955" PostId="4605" Text="Interesting, thanks!" CreationDate="2010-09-30T03:39:26.757" UserId="152" />
  <row Id="4956" PostId="4533" Text="Thanks! Finally got it working.  I bumped it up to 9600 baud at 1Mhz and then the delays were only 104 cycles, much easier to code.  I'll accept your answer as soon as I can login to my old account!" CreationDate="2010-09-30T03:53:33.283" UserId="1271" />
  <row Id="4957" PostId="4475" Text="I agree that placement is the most important aspect of getting a good board. I've route that autorouting is a good way to evaluation the placement" CreationDate="2010-09-30T04:29:22.990" UserId="550" />
  <row Id="4959" PostId="4620" Score="1" Text="Not quite with the flashing lights, I'm trying to control 32 stepper motors on a prototype automated universal fixturing device, except I don't have any funding...or knowledge of electronics whatsoever. Maybe I dismissed the micro controller too quickly, got any good step by step resources on how to get up to speed from the ground up with practical examples? (and I do mean from the ground up, I have a rather strange knowledge base that is way too theoretical and not enough practical, you can assume I know absolutely nothing...feels like it most the time anyways, heh)" CreationDate="2010-09-30T07:21:07.597" UserId="1319" />
  <row Id="4960" PostId="4608" Text="Why do you think a CPLD is more expensive?  http://www.mouser.com/ProductDetail/Lattice/LC4032ZE-7MN64C/?qs=sGAEpiMZZMsyU/nwJUBByk%252bnURPiRuu9" CreationDate="2010-09-30T07:24:46.857" UserId="1325" />
  <row Id="4961" PostId="4620" Score="1" Text="Controlling stepper motors is going to require a bit of extra throught. You won't be able to drive them directly from microcontroller output pins. You'll need to use some electronics 'glue' in between the pin and the motor so you don't fry the micro. Like anything its best to start off small and work your way up to more advanced examples. One of the more avid enthusiasts I've seen around is http://tronixstuff.wordpress.com has some good step by step beginners stuff. I know the guy that runs it also frequents this stack exchange." CreationDate="2010-09-30T08:03:07.727" UserId="1304" />
  <row Id="4962" PostId="4597" Text="+1 I like the experiments... like to see those refined and see more results! Also, my brain was wrong - yay!" CreationDate="2010-09-30T08:14:29.277" UserId="623" />
  <row Id="4963" PostId="4576" Text="Nice project. Got any videos or pictures of the output?" CreationDate="2010-09-30T08:28:01.747" UserId="566" />
  <row Id="4964" PostId="4620" Score="1" Text="Yup, I found a very nice stepper motor driver to use in between the control signals and motor (just uses 2 inputs, step and direction). I'll look through that tutorial you linked, thanks. Btw, just to make sure, I want it to be my computer that sends the commands real time via a c++ program to the micro controller to move the motors. Is this possible or very easy to do with this micro controller?" CreationDate="2010-09-30T08:40:06.087" UserId="1319" />
  <row Id="4965" PostId="4620" Score="1" Text="Of course. The microcontroller acts as the buffer between computer and stepper motor driver board. It can interpret the commands that you send and act on them as well as provide feedback to the PC if required. The other benefit of using something a bit conventional is that you can get a lot of support/advice from the community, the chances are always good that someone has done something similar. So thats pretty handy in itself.  The micro just provides a really nice low cost interface between pc and your driver boards. " CreationDate="2010-09-30T09:56:08.320" UserId="1304" />
  <row Id="4966" PostId="4627" Score="1" Text="Low-voltage programmers like the AVRISP mkII[1] or USBtinyISP[2] can be used to set fuses with avrdude or other programmers, but they can't save an AVR chip that's been made un-bootable or had its reset line turned into a GPIO.  You do need an high-voltage programmer for that sort of thing.&#xA;&#xA;[1] http://www.mouser.com/search/ProductDetail.aspx?qs=2mdvTlUeTfBRoycsKqwYpg%3D%3D&#xA;[2] http://www.ladyada.net/make/usbtinyisp/&#xA;" CreationDate="2010-09-30T10:14:06.200" UserId="51" />
  <row Id="4967" PostId="4616" Score="3" Text="You mean that it will consume 60 watt-hours in one hour" CreationDate="2010-09-30T10:16:59.037" UserId="400" />
  <row Id="4968" PostId="4627" Text="@blalor  In light of this information, I'll edit my answer." CreationDate="2010-09-30T10:18:04.807" UserId="1240" />
  <row Id="4969" PostId="4554" Text="I got the Primer book from Gangaram's, Bangalore. However, it should be easily available in most bookshops. Or try flipkart.com online - they have free shipping to anyplace in India." CreationDate="2010-09-30T12:08:39.980" UserId="1143" />
  <row Id="4970" PostId="4576" Text="See here: http://www.youtube.com/watch?v=RE18gHRUR40 and here: http://www.youtube.com/watch?v=RE18gHRUR40, and here: http://www.youtube.com/watch?v=NrI9Z3c4_jw&amp;feature=related" CreationDate="2010-09-30T12:13:30.390" UserId="1225" />
  <row Id="4971" PostId="4603" Text="I have also considered making kits, and I will be selling PCBs with instructions and all components for less." CreationDate="2010-09-30T12:19:19.427" UserId="1225" />
  <row Id="4972" PostId="4624" Text="In the words of Dave L. Jones, &quot;don't even think about marketing.&quot; I am not going to be building 50-100 immediately, I will build them on a per-order basis only. My marketing comes from interested people on the 'net, such as this RCGroups thread: http://www.rcgroups.com/forums/showthread.php?t=1290963." CreationDate="2010-09-30T12:20:19.147" UserId="1225" />
  <row Id="4973" PostId="4612" Score="1" Text="+1. The media gets this wrong all the time." CreationDate="2010-09-30T12:24:40.700" UserId="330" />
  <row Id="4974" PostId="4529" Score="1" Text="A pair of wheels phased 90 degrees apart *is* a Gray code (not &quot;Grey&quot;). You will not often find gray code encoders with more than 2 bits, mainly because of the decode complexity/incompatibility. Their accuracy isn't any better than a 2-bit system, it's just that you get a larger range of &quot;absoluteness&quot;" CreationDate="2010-09-30T12:28:46.073" UserId="330" />
  <row Id="4975" PostId="1012" Text="@reemrevnivek: Restored, thanks for pointing it out. I don't like when people &quot;correct&quot; my intentional use of colloquial grammar." CreationDate="2010-09-30T12:31:39.947" UserId="330" />
  <row Id="4976" PostId="4612" Text="The media is a great place to learn how to do things correctly ;-)" CreationDate="2010-09-30T12:36:46.147" UserId="319" />
  <row Id="4977" PostId="4588" Text="For some reason in college we chained a few of them together. It might be that we didn't use the RC circuit to create a delay at the time and were instead relying on the propagation delay of each of the gates. I edited my answer." CreationDate="2010-09-30T12:46:21.620" UserId="588" />
  <row Id="4978" PostId="4625" Text="Any ideas why those are so much more complex?  The AVR way (Low voltage, standard protocol) seems so much more sensible than requiring a custom programmer (like this guy with an 8051/8052 programmer need - help wanted, rep available! http://electronics.stackexchange.com/questions/4104)  " CreationDate="2010-09-30T12:51:25.387" UserId="857" />
  <row Id="4979" PostId="4529" Text="I always considered the 90 degree detectors a &quot;quatrature encoder&quot; -- in industry we had many 16 bit gray code (I'm Canadian, grey/gray is one of those fuzzy points of spelling here) encoders and yes, for exactly that reason: you wanted absolute position information with a high degree of resolution." CreationDate="2010-09-30T12:52:40.517" UserId="974" />
  <row Id="4980" PostId="4529" Text="to answer jojo l'abricot's comment: You want to do dead reckoning for a robot without a microcontroller? Take one of the bits into the &quot;direction&quot; input of an up/down counter. Take the other bit into the clock input.  I don't think you can get too much simpler than that, although I also don't think you'll be able to do much with a count value if you haven't got something (i.e. a microcontroller) to understand it." CreationDate="2010-09-30T12:54:21.337" UserId="974" />
  <row Id="4981" PostId="4608" Text="@TokenMacGuy: I think I saw a 28 I/O chip for about the same or a little less. Even so, not having to muck with yest another programmable device is worth something." CreationDate="2010-09-30T12:58:07.727" UserId="1182" />
  <row Id="4982" PostId="4624" Text="Ahhh that explains why I am so wealthy and Dave L. Jones isn't (or may not be! heh). Because I do consider marketing. :-) hobby businesses can be very profitable if done properly. There is no harm at all in giving it a go, in the immortal words of Gordan Gekko.. Greed is Good. Please do keep us posted on your build. I am very interested in data loggers myself!" CreationDate="2010-09-30T13:02:26.940" UserId="1304" />
  <row Id="4983" PostId="4625" Score="1" Text="There really isn't anything special or expensive about PIC programmers; many designs are available online, and most new PICs can be low voltage programmed." CreationDate="2010-09-30T13:06:46.403" UserId="974" />
  <row Id="4984" PostId="4582" Text="hmm yeah I forgot about that. Ok, I think I am going to use a 3.3V regulator, and also see if I can get 12volts from the main board as well as 5V so I can charge up the cap to a much higher voltage. A MCP1702 regulator can take inputs voltages all the way up to 13 volts." CreationDate="2010-09-30T13:12:58.830" UserId="1235" />
  <row Id="4985" PostId="4581" Text="Sounds like you should outsource the assembly. Make a lot of phone calls and you can find assembly houses that work much better with small-quantity folks than the usual assembly house which is only interested in very high quantities. Look for the smaller shops. Also, ask the bigger shops if they know of other shops that work will smaller quantities. I have had good luck with that." CreationDate="2010-09-30T13:19:32.577" UserId="1235" />
  <row Id="4987" PostId="1705" Text="-1 Waaaay too general, vague and unanswerable a question. (See also: http://meta.electronics.stackexchange.com/questions/32 )" CreationDate="2010-09-30T13:45:04.513" UserId="1329" />
  <row Id="4989" PostId="4625" Score="1" Text="IC manufacturers don't really care about how complex something is for hobbyists to use.  As long as it can be used in large quantity production, it's otherwise all about cost." CreationDate="2010-09-30T14:00:37.603" UserId="142" />
  <row Id="4990" PostId="4582" Text="What's the voltage of your .5F cap? 99% of the time it's less than 6 volts. Careful not to overvolt it; use two in series with some 1 megohm resistors in parallel (to balance the caps.)" CreationDate="2010-09-30T14:09:56.647" UserId="1225" />
  <row Id="4991" PostId="4640" Text="http://en.wikipedia.org/wiki/Motor_capacitor   http://www.electro-tech-online.com/electronic-projects-design-ideas-reviews/21305-value-capacitor-parallel-dc-motor.html" CreationDate="2010-09-30T14:14:41.660" UserId="142" />
  <row Id="4992" PostId="4619" Score="1" Text="Somewhat related: http://electronics.stackexchange.com/questions/3475/what-microcontroller-should-i-use" CreationDate="2010-09-30T14:16:11.957" UserId="142" />
  <row Id="4993" PostId="4643" Score="1" Text="Does this imply that a brushless motor would have no need of a cap?" CreationDate="2010-09-30T14:16:55.130" UserId="1308" />
  <row Id="4995" PostId="4643" Score="3" Text="brushless motors are actually three-phase AC motors with complex control circuitry. The motors themselves don't generate much EMI/RFI, but the choppers on the control circuit's drive section can sing, which is why you will often see filter circuitry around them." CreationDate="2010-09-30T14:27:51.643" UserId="974" />
  <row Id="4997" PostId="4647" Text="I second this. I have also seen that with such an arrangement the life of the motor itself gets extended. Any ideas why?" CreationDate="2010-09-30T14:34:44.223" UserId="1143" />
  <row Id="4998" PostId="4647" Score="1" Text="It is as close as possible to minimize the length of wire that can radiate. It is also as close as possible to minimize inductance. Inductance will stop a capacitor from doing its job." CreationDate="2010-09-30T14:42:06.363" UserId="230" />
  <row Id="4999" PostId="4612" Text="When the media does a report on something like terahertz, it kills me inside." CreationDate="2010-09-30T14:47:53.250" UserId="230" />
  <row Id="5001" PostId="4649" Text="A 60 W bulb would really be noticed?  What circuit do you use to harvest the energy from the radio tower?" CreationDate="2010-09-30T15:13:20.063" UserId="142" />
  <row Id="5002" PostId="567" Text="The servo controllers you are recommending are out of date. The new Maestro family of servo controllers is better in every way. http://www.pololu.com/catalog/category/12" CreationDate="2010-09-30T15:19:56.490" UserId="1256" />
  <row Id="5004" PostId="4612" Text="You mean terahertz imaging in airports?" CreationDate="2010-09-30T15:41:12.710" UserId="142" />
  <row Id="5005" PostId="4654" Score="1" Text="You have to be careful even with the Fluke &quot;True RMS&quot; reading meters. My 87-III is a &quot;true RMS&quot; meter but if you look at the specs you will see that their accuracy is affected by crest factor. The AC waveform you're measuring has to have a crest factor under 3.0 at full-scale to meet their accuracy specs.  This is fine for almost all general applications, but if you're trying to do some measurement of fast-rising waveforms you may need to defer that measurement to a 'scope." CreationDate="2010-09-30T16:13:08.863" UserId="974" />
  <row Id="5006" PostId="4649" Score="1" Text="It's not the power YOU get from it, but the power you block going to everyone else that gets noticed.  It's not the most efficient way of receiving power, so there's a noticeable loss in power in a very specific direction.  The closer you are to the tower, the larger the area of lower power, the easier it is to find you.  I found an article about it a while ago, I'll see if I can find it again." CreationDate="2010-09-30T16:16:37.917" UserId="249" />
  <row Id="5007" PostId="4654" Text="@Andrew, Good Point. An oscilloscope is a must have tool, can be a bit pricey for a general hobbyist though  " CreationDate="2010-09-30T16:32:05.907" UserId="1337" />
  <row Id="5008" PostId="4654" Score="1" Text="I've also heard something about True RMS AC+DC. Most TRMS meters only do AC coupled True RMS. I already have a 100 MHz DSO I bought for £150 (HP 54501A.) It does True RMS, both AC and DC, but its vertical accuracy is only ±1.5% and its ADC is limited to 8 bits. " CreationDate="2010-09-30T16:32:54.917" UserId="1225" />
  <row Id="5009" PostId="4566" Text="Are you referring to the original Netduino or the recently-announced Netduino Plus?" CreationDate="2010-09-30T16:44:06.530" UserId="1355" />
  <row Id="5010" PostId="4656" Text="Was that the same Fluke?  I'm a student, so I'll probably need a DMM for 20 years, but I don't want to need an upgrade in 5 years because my DMM is obsolete.  In my closet, I have an old analog multimeter - it's probably 20 years old, but I don't consider it adequate.  " CreationDate="2010-09-30T18:02:23.143" UserId="857" />
  <row Id="5011" PostId="4647" Text="Motor windings are inductors and if you were using PWM to control the speed you have a high-current, fast-rising repetitive pulse waveform. With the &quot;right&quot; lead length you could see reflections of the edge of the wave constructively interfere and ring up a voltage high enough to cause the (very thin) insulation at the first few turns of the winding to fail. A small cap across the leads would also block that.&#xA;&#xA;I don't think I've seen that on small DC motors, but it's a problem with large AC motors being driven with variable-frequency drives (VFDs or inverters as they're commonly called.)" CreationDate="2010-09-30T18:05:31.037" UserId="974" />
  <row Id="5012" PostId="4625" Score="1" Text="High-voltage programming was there first, it was the way to program UV-erasable EPROMs in the eighties (and microcontrollers containing such EPROMs)." CreationDate="2010-09-30T18:36:07.973" UserId="339" />
  <row Id="5013" PostId="4651" Text="As a note to add on to what everyone has said. Fluke makes very high quality equipment. The thing I love is that it is very hard to break one. This is especially critical if you think you might ever drop one or accidentally hook it up wrong. It may be worth it to just keep buying cheap ones every time one breaks. That's more of a personal opinion though." CreationDate="2010-09-30T18:44:52.387" UserId="319" />
  <row Id="5014" PostId="4653" Text="is it required to pass through arduino to do this ?" CreationDate="2010-09-30T19:09:01.230" UserId="1272" />
  <row Id="5016" PostId="4656" Score="2" Text="The same Fluke 8060A. Sorry about that. If I were to buy a new meter today I would probably get one with a USB port so that some bench tests could be automated. I would certainly look at Fluke but I would also look at Agilent. " CreationDate="2010-09-30T19:12:38.603" UserId="424" />
  <row Id="5017" PostId="4653" Text="Yes, the shield provides the electronics to drive the motors. The control logic and USB interface is on the Arduino." CreationDate="2010-09-30T19:19:16.923" UserId="566" />
  <row Id="5018" PostId="4649" Text="Added networking and environment clarification to my OP." CreationDate="2010-09-30T19:37:46.537" UserId="1329" />
  <row Id="5019" PostId="4645" Text="Added networking and environment clarification to my OP." CreationDate="2010-09-30T19:38:06.130" UserId="1329" />
  <row Id="5020" PostId="4645" Score="1" Text="Also, only being picky because this site is young, but is the picture really needed? It doesn't add anything useful... Useful link though :)" CreationDate="2010-09-30T19:40:34.713" UserId="1329" />
  <row Id="5021" PostId="4659" Text="I really love that thing, however, it does not really tell me a lot on how to connect the things together, nor how they behave. Clearly, it's an invaluable tool to do experiments though. It's really a lot of fun." CreationDate="2010-09-30T19:53:17.717" UserId="1272" />
  <row Id="5022" PostId="4645" Score="1" Text="@Jon: It does. I'm learning and seeing things is invaluable." CreationDate="2010-09-30T19:56:04.627" UserId="1272" />
  <row Id="5023" PostId="4645" Score="2" Text="It shows the size of the solar cell and PCB (which was part of the question), the number of components, etc." CreationDate="2010-09-30T20:17:20.033" UserId="142" />
  <row Id="5024" PostId="4663" Text="Not likely. I was just curious and I'm looking forward to seeing what people come up with. The last radio I built was a crystal radio kit when I was a pre-teen, I think. There's no prize involved, just a put your heads together and see if you can create something to help out." CreationDate="2010-09-30T20:29:27.447" UserId="152" />
  <row Id="5025" PostId="4649" Text="http://electronics.stackexchange.com/questions/4664/stealing-energy-from-radio-towers-or-power-lines" CreationDate="2010-09-30T20:56:06.210" UserId="142" />
  <row Id="5026" PostId="4658" Text="Do you want to also learn microcontroller programming?  There's only so much that can be done in hardware.  " CreationDate="2010-09-30T21:25:34.247" UserId="857" />
  <row Id="5027" PostId="4665" Text="+1, for the pulling things apart. One of my kids really likes to pull (old) things apart. Luckily he sometimes needs help from his dad ;-)." CreationDate="2010-09-30T21:25:39.470" UserId="1237" />
  <row Id="5029" PostId="4665" Score="2" Text="National Program of Technology Enhanced Learning (nptel) is a very good resource, and a better site would be there official website at nptel.iitm.ac.in.It can work for any thing you want, getting marks or personal learning. And it has some pretty heavy dose of basic theory. Look at Basic Electronics by Prof. Chitralekha Mahanta its in electronics and communication section. Complete this and you will get an equivalent of semester and a half of theory classes. " CreationDate="2010-09-30T21:34:08.183" UserId="1200" />
  <row Id="5030" PostId="4639" Score="1" Text="How much power are you looking for?  That's really going to be a major factor in selecting a source.  Consider that some systems, like the TI CC430 (note: wireless SOC, but not Wi-Fi), can operate on 1uA or less.  With currents like that, a coin cell will power it for years." CreationDate="2010-09-30T22:06:54.867" UserId="857" />
  <row Id="5031" PostId="4649" Score="2" Text="What about harvesting power from the 60Hz AC in the walls?  I don't think you'd take enough to be noticed there... http://www.interactivearchitecture.org/richard-box.html " CreationDate="2010-09-30T22:17:13.273" UserId="857" />
  <row Id="5032" PostId="4614" Text="+1 for 1's being more aerodynamic :) The FTDI TTL232R outputs logic level uart signals (0-5V), if you were interfacing directly with a standard serial port, you'd need an interface IC such as the MAX232, which converts the voltage levels both ways." CreationDate="2010-09-30T23:24:44.393" UserId="554" />
  <row Id="5033" PostId="4533" Text="Good to hear it's working now" CreationDate="2010-09-30T23:25:45.187" UserId="554" />
  <row Id="5034" PostId="4657" Text="There, one vote for you, though you should be able to vote. Could you kindly mention the brand name/model of the really nice but power hungry one?  Finding cheap ones of decent quality is hit-or-miss." CreationDate="2010-09-30T23:27:28.083" UserId="857" />
  <row Id="5035" PostId="4662" Text="*Note that it is tagged community wiki.*  Noted.  Now I'm wondering why this is community wiki.  Can you explain?" CreationDate="2010-09-30T23:28:57.940" UserId="857" />
  <row Id="5036" PostId="4656" Text="I think it depends on the Extech.  I got one from Radioshack in the US that had similar specs to a Fluke 87-V for about $50, and it was *extremely slow* in doing readings of any sort, and in general felt rather unreliable." CreationDate="2010-10-01T00:16:44.430" UserId="374" />
  <row Id="5037" PostId="4656" Score="2" Text="reemrevnivek - I doubt *any* DMM will go obsolete, unless science discovers new electrical attributes to measure, or if we need better performing instruments in the future." CreationDate="2010-10-01T00:18:00.823" UserId="374" />
  <row Id="5038" PostId="4664" Score="3" Text="As far as &quot;can be harvested&quot;, I would like to know both meanings, &quot;how much is legal&quot; and &quot;how much is practically possible&quot;.  I remember hearing the phone company would get mad if you used too much from the phone line, but &quot;rumors and anecdotes&quot; aren't very useful except for spreading more rumors and anecdotes." CreationDate="2010-10-01T00:26:39.420" UserId="1271" />
  <row Id="5039" PostId="4625" Text="Fixed the SCK claim.  I like the idea that only SPI is needed, but since computers don't have an SPI port (and heck the FTDI cable already has a **$4** chip in it!!) we might as well splurge on a $2 microcontroller.  The JTAG upload-and-debug argument has sold me on the benefits of a development board in general, and I think endolith has a good point that nobody cares what I spend my $20 on; manufacturers care what real engineers (and their employers) are going to spend their budget on." CreationDate="2010-10-01T00:46:50.163" UserId="1271" />
  <row Id="5040" PostId="4627" Text="I did see some instructions on making a high voltage programmer (and the datasheet for the chip seems to have pretty detailed instructions on designing one), but I'm waiting until I brick one of my chips until I try it.  My oscillators get here tomorrow, so I'll be burning fuses and tempting the brick fairy soon enough!" CreationDate="2010-10-01T00:49:25.957" UserId="1271" />
  <row Id="5041" PostId="4645" Text="Is there a reasonably cheap USB dongle to hold an XBee?  The XBee itself was like $20 if I remember correctly, and the PCB and USB microcontroller should be $5 ish?  I recall having a hard time figuring out how to get wifi for under $50 (other than used or refurbished parts).  XBee might be cheaper, lower cost, and just as easy for the end-user (once the USB-xbee is included)?  I have a project with wifi needs, but I have settled for using XBees to transmit to a master node with real internet (probably wired).  I am a beginner hobbyist, so I might be missing something important. :)" CreationDate="2010-10-01T01:20:35.073" UserId="1271" />
  <row Id="5042" PostId="4671" Score="1" Text="Thanks for your answer, but it didn't answer my question. The question isn't about what happens with the software (e.g. data loss), but how the hardware parts are affected." CreationDate="2010-10-01T01:34:07.673" UserId="1330" />
  <row Id="5043" PostId="4656" Text="Going back to obsolescence, sometimes the old analog meters are better than the digital ones. While you can find low-impedance digitals (or just put a resistor across the leads) and you can get digitals with averaging functions, an analog meter is perfect for those applications. I know of a few technicians who routinely use analog meters for certain functions. When they need accuracy, they go for the digital, but when the question is &quot;Is this 12VDC supply putting out anything?&quot; they usually just hit it with the analog that's been on their bench for decades." CreationDate="2010-10-01T02:18:14.533" UserId="965" />
  <row Id="5044" PostId="4630" Text="Thanks, that should give me a good start.   " CreationDate="2010-10-01T02:39:08.597" UserId="1295" />
  <row Id="5045" PostId="4666" Text="I love that magic-smoke smell when I'm at school - It means I've learned something.  When I'm at home, it means I burned something in the process, so the joy is (slightly) dulled. " CreationDate="2010-10-01T02:51:31.920" UserId="857" />
  <row Id="5046" PostId="4672" Score="2" Text="A power conditioner is more properly called a Power Distribution Unit, or PDU.  ADC is a major distributor, and they sell many of these in rackmount profiles." CreationDate="2010-10-01T03:16:14.403" UserId="857" />
  <row Id="5047" PostId="4629" Score="1" Text="You only mention a UPS.  The UPS protects the data from loss when the power cuts out quickly.  It's a PDU (Power Distribution Unit), which may be integrated into some UPSes, which regulates the output and provides the protection for the electronics.  A surge protector is another component which shouldn't be ignored.  Its function should be obvious, unless you're this guy: http://www.youtube.com/watch?v=dMriTkE3igY" CreationDate="2010-10-01T03:18:57.380" UserId="857" />
  <row Id="5048" PostId="4658" Score="1" Text="Wrong! You can conceivably do anything in raw hardware, it just becomes prohibitive to maintain eventually." CreationDate="2010-10-01T03:45:35.717" UserId="1374" />
  <row Id="5049" PostId="4608" Text="@BCS: That's a much better reason than the dollar or two cost." CreationDate="2010-10-01T04:08:03.107" UserId="1325" />
  <row Id="5051" PostId="4531" Score="2" Text="+1 for a good detailed query" CreationDate="2010-10-01T04:23:27.557" UserId="1376" />
  <row Id="5052" PostId="4664" Text="&quot;what is actually possible&quot; is interesting thing. and does it means if we don't harvest , it get wasted in heating air ?" CreationDate="2010-10-01T05:21:36.447" UserId="1312" />
  <row Id="5053" PostId="4681" Text="does using isolation transformer induce any lag ?" CreationDate="2010-10-01T06:43:41.463" UserId="1312" />
  <row Id="5054" PostId="4682" Text="what properties should I look in to motor if it has to run over a wide range ? i.e. from ~10 RPM to 7000 RPM" CreationDate="2010-10-01T06:49:38.500" UserId="1312" />
  <row Id="5056" PostId="4674" Text="I've rarely found the battery to be an issue. The cheapy &quot;Golden Power&quot; batteries they come with don't last, but put a new 9V battery in them and they work for years. (My el-cheapo multimeter has an auto power off function.)" CreationDate="2010-10-01T06:57:05.147" UserId="1225" />
  <row Id="5057" PostId="4355" Text="@Kevin, What is the exact part number of the 5MP CMOS camera module you are trying to interface with?" CreationDate="2010-10-01T07:47:41.233" UserId="1322" />
  <row Id="5058" PostId="4629" Text="@reemrevnivek: Thanks for the clarification." CreationDate="2010-10-01T07:56:18.713" UserId="1330" />
  <row Id="5059" PostId="4674" Text="Huh. I have a bunch of various fry's DMMs floating about, and they all die all the time. I guess there's a lot of variation." CreationDate="2010-10-01T08:36:35.807" UserId="1374" />
  <row Id="5060" PostId="4682" Text="A gear reducer with a clutch. If you want any torque at the low-end, anyways." CreationDate="2010-10-01T08:55:24.083" UserId="1374" />
  <row Id="5061" PostId="4681" Text="No. (fifteen characters)" CreationDate="2010-10-01T08:56:08.590" UserId="1374" />
  <row Id="5063" PostId="4682" Text="You may want to go for a brushless DC Motor, probably with sensors if you want to go for low RPM. You then could also use a RC driver. At least that is the way I would go if I needed a wide range drive." CreationDate="2010-10-01T09:31:19.873" UserId="1381" />
  <row Id="5065" PostId="4355" Text="I haven't got the module part number but the image sensor is omnivision, OV5642." CreationDate="2010-10-01T11:38:03.063" UserId="444" />
  <row Id="5066" PostId="4685" Text="+1 Nice! What make microscope do you use? Have you found it very useful vis a vis a single eye piece.  Never heard of RF heated soldering stations before, will try to do some webbing for these." CreationDate="2010-10-01T11:39:43.607" UserId="444" />
  <row Id="5067" PostId="4687" Text="+1, Good thoughts! What about soldering BGA etc. ever tried those? Nice idea about the blu-tack. What solder station do you prefer?" CreationDate="2010-10-01T11:44:11.777" UserId="444" />
  <row Id="5068" PostId="4355" Score="1" Text="OMAP35x does not solve your problem?" CreationDate="2010-10-01T11:54:13.283" UserId="938" />
  <row Id="5069" PostId="4689" Score="1" Text="You've talked about Netduino on your question." CreationDate="2010-10-01T12:02:09.710" UserId="938" />
  <row Id="5070" PostId="4687" Text="My iron at home is junk. I do like the Metcal at work though. BGAs are impossible for hobbyists as far as I can tell." CreationDate="2010-10-01T12:39:14.557" UserId="566" />
  <row Id="5072" PostId="4681" Score="3" Text="If you're going to compare to a voltage, compare to a few % of full line, not zero. It moves you out of the way of most of the noise you'll encounter, and the phase shift is fixed and thus easy to account for." CreationDate="2010-10-01T12:43:30.983" UserId="974" />
  <row Id="5073" PostId="4681" Text="good call Andrew :-)" CreationDate="2010-10-01T13:16:41.073" UserId="1376" />
  <row Id="5074" PostId="4697" Score="1" Text="Brilliant answer, thank you very much Andrew - my head is quite a bit less fuzzy now that you've cleared that up." CreationDate="2010-10-01T13:31:33.000" UserId="1333" />
  <row Id="5075" PostId="4355" Text="@ O Engenheiro --&gt; It would I guess and I and that you have pointed out TI I found some  DA Vinci processors that have hardware video ports!" CreationDate="2010-10-01T13:36:16.540" UserId="444" />
  <row Id="5076" PostId="4693" Text="+1 Good leads, I haven't looked into Gumstix, I think Beagleboard doesn't have access to the camera interface you can only connect a camera via USB(correct me if I'm wrong here).  OMAP35xx yes! good one it fits the bill, even the i.Mx series would. The Atmel ones I think does not have support over 3MP or so. Features, I want to capture the images to external ram and then do lots of image processing on them, so the more suited the processor and more hardware support the better for. What's your opinion?" CreationDate="2010-10-01T13:42:00.407" UserId="444" />
  <row Id="5077" PostId="4699" Text="I just got these two options." CreationDate="2010-10-01T13:52:04.490" UserId="938" />
  <row Id="5078" PostId="4700" Score="1" Text="Thanks very much for your answer, it has further clarified this to me. I think what I didn't get was that the voltage across components in parallel is the same and that the circuit only drains the maximum amount of current it can at any one time. Previously, I had thought of current/voltage less like a bucket of water and more like a power-hose with a fixed current. In clarifying these points for me, you have both allowed me to fully appreciate the basics of how current and voltage works - something 2 starter electronics books failed to do." CreationDate="2010-10-01T13:55:24.480" UserId="1333" />
  <row Id="5080" PostId="4701" Score="1" Text="Thanks for the extra info on output impedance." CreationDate="2010-10-01T14:05:57.307" UserId="1333" />
  <row Id="5081" PostId="3331" Text="Any special reasons for the ENCX24J600?  The ENC28J60 is much more popular." CreationDate="2010-10-01T14:09:10.313" UserId="857" />
  <row Id="5082" PostId="4693" Score="1" Text="I was about to offer up the Gumstix. There are several articles that explain how to use a camera with the Gumstix. I personally have not used them, but I have used the Gumstix with a USB camera and was able to do RTDSP on it." CreationDate="2010-10-01T14:12:16.187" UserId="319" />
  <row Id="5083" PostId="4664" Text="It doesn't get wasted in heating air, since air doesn't absorb the energy.  Except maybe a little, but we transmit on certain frequencies specifically because the air doesn't absorb them.  http://en.wikipedia.org/wiki/Absorption_%28electromagnetic_radiation%29" CreationDate="2010-10-01T14:13:18.737" UserId="142" />
  <row Id="5084" PostId="4693" Text="OMAP sounds like it'd work; just make sure that the amount of memory and memory technology (SDR, DDR, etc.) match what you are expecting. I also know that you have some advantage with OMAP in the sense that there *is* a DSP core there you can do some work with as well, although I have not personally used it." CreationDate="2010-10-01T14:18:58.123" UserId="974" />
  <row Id="5085" PostId="3331" Text="@reemrevnivek I need to communicate at 100 Mbps." CreationDate="2010-10-01T14:20:23.843" UserId="938" />
  <row Id="5086" PostId="4697" Score="2" Text="Although I'm sure I used to live in a house (not for very long) where plugging a radio into a wall socket which already had a lamp attached did make the lamp grow dimmer (though not for the reasons listed here)." CreationDate="2010-10-01T14:20:40.043" UserId="103" />
  <row Id="5087" PostId="4702" Text="+very informative!" CreationDate="2010-10-01T14:21:59.007" UserId="444" />
  <row Id="5088" PostId="4692" Text="upvote!, Haven't used any of the Metcal's before, what are the pros of these over other soldering irons or stations?" CreationDate="2010-10-01T14:24:55.320" UserId="444" />
  <row Id="5089" PostId="4683" Text="+1 for tea being an essential item on your desk... College student here, and I have a similar situation in my dorm, especially comparing to my labs at school or work (both with nearly limitless space). Low quantity will make space less of an issue, and good organization can make it work." CreationDate="2010-10-01T14:31:35.830" UserId="857" />
  <row Id="5090" PostId="4668" Text="I bought myself a second-hand scope about a year ago. It is an invaluable tool. I paid £150 for it, about $200 US. It has a 100 MHz analog bandwidth and is digitising (HP 54501A.) It only has 10 MS/s single shot speed though - which is the only disappointing thing." CreationDate="2010-10-01T14:40:57.240" UserId="1225" />
  <row Id="5091" PostId="4709" Text="The only problem that could be with this is that SCART doesn't always provide RGB. Sometimes it's just composite, sometimes it's even Y/Cb/Cr. But an ambilight with VGA would be pretty easy - just sample at each VSYNC change. With composite you'd need to sync to the colorburst then decode the amplitude and phase of the signal (encoding the two colour components.)" CreationDate="2010-10-01T14:54:17.367" UserId="1225" />
  <row Id="5092" PostId="4703" Text="One thing to note, the PIC18F97J60 only seems to be guaranteed for 100 flash write cycles, so may be a problem to develop for. http://ww1.microchip.com/downloads/en/DeviceDoc/39762e.pdf (pg 429)" CreationDate="2010-10-01T15:01:14.797" UserId="566" />
  <row Id="5093" PostId="4703" Text="The minimum number of write cycles is 100. Typical is 1k. I've never had a problem." CreationDate="2010-10-01T15:07:48.643" UserId="588" />
  <row Id="5095" PostId="4672" Score="2" Text="@reemrevnivek - What I was thinking of was more like http://www.apc.com/products/apcav/products/index.cfm?action=model&amp;id=310" CreationDate="2010-10-01T15:11:59.073" UserId="374" />
  <row Id="5096" PostId="4665" Text="Your right Rick_2047, nptel has helped me out loads in the past, I'm lovin' it!" CreationDate="2010-10-01T15:12:00.370" UserId="399" />
  <row Id="5099" PostId="4714" Text="Wi-Fi routers transmit using milliwatts.  Radio towers transmit using kilowatts." CreationDate="2010-10-01T16:03:46.633" UserId="142" />
  <row Id="5100" PostId="4714" Score="1" Text="Indeed, so the maths should scale up..." CreationDate="2010-10-01T16:14:10.120" UserId="566" />
  <row Id="5101" PostId="4574" Text="GCC based toolchains are guaranteed by the GPL to be free as per the GNU definition. However, toolchain vendors don't stay in business because of their giving nature: They sell support, IDEs, GUI debuggers, etc., and distribute working GCC implementations freely (except for Microchip-grr.) CodeSourcery G++ Lite is a free, unsupported command-line version of Sourcery G++ sponsored by CodeSourcery's hardware partners [that] .... contains command-line tools, including the GNU C and C++ compilers, the GNU assembler and linker, C and C++ runtime libraries, and the GNU debugger. " CreationDate="2010-10-01T17:16:10.643" UserId="857" />
  <row Id="5102" PostId="4714" Text="They're also different frequencies.  12 cm wavelength for Wi-Fi vs 560 m for AM." CreationDate="2010-10-01T17:45:58.453" UserId="142" />
  <row Id="5104" PostId="4694" Text="i used timer for measuring frequency ( in case of lag , and excel and lookup tables )...but i think i will go with low pass and opto coupler. thnks for answer." CreationDate="2010-10-01T18:01:08.367" UserId="1312" />
  <row Id="5105" PostId="4690" Text="thnks. a chip is always welcome instead of resistors and caps." CreationDate="2010-10-01T18:01:58.507" UserId="1312" />
  <row Id="5106" PostId="4681" Text="@andrew , :D nice idea!!" CreationDate="2010-10-01T18:04:30.390" UserId="1312" />
  <row Id="5107" PostId="3035" Text="ktechlab does have (experimental) svg export." CreationDate="2010-10-01T18:11:33.367" UserId="1181" />
  <row Id="5108" PostId="4714" Text="what frequency transmit power best for wireless ? higher or lower ?" CreationDate="2010-10-01T18:21:17.563" UserId="1312" />
  <row Id="5109" PostId="4723" Text="The book talks about an implementation of CANopen called MicroCANopen. What implementation of CANopen do you use?" CreationDate="2010-10-01T18:31:14.157" UserId="588" />
  <row Id="5111" PostId="4724" Score="2" Text="possible duplicate of [How do I learn HDL](http://electronics.stackexchange.com/questions/3472/how-do-i-learn-hdl)" CreationDate="2010-10-01T18:47:07.313" UserId="857" />
  <row Id="5112" PostId="4726" Text="Are you advocating a reading-only learning path, like this question: http://electronics.stackexchange.com/questions/4658 ?  When would you advise with hardware?" CreationDate="2010-10-01T18:48:38.980" UserId="857" />
  <row Id="5113" PostId="4726" Score="2" Text="No, not at all. Sorry if it came off that way. Experimentation is vital, and my own first test board was actually not even a premade kit but a CPLD basically hooked up to the parallel port. Hardware tends to be a matter more limited by your wallet. " CreationDate="2010-10-01T19:23:12.350" UserId="1181" />
  <row Id="5114" PostId="4728" Text="humble +1, Speechless!!" CreationDate="2010-10-01T19:28:02.287" UserId="444" />
  <row Id="5115" PostId="4692" Text="Very rapid heating when switched on, excellent temperature control, large range range of cartridges, and massive heat capacity." CreationDate="2010-10-01T19:49:37.220" UserId="305" />
  <row Id="5116" PostId="4730" Score="3" Text="OSD = Open Source Design? Object Storage Device? or Other Strange Definition?" CreationDate="2010-10-01T19:54:07.070" UserId="857" />
  <row Id="5117" PostId="4714" Score="5" Text="Distances also scale up...usually you are feet away from wifi and miles away from radio towers" CreationDate="2010-10-01T19:55:58.850" UserId="131" />
  <row Id="5118" PostId="3794" Text="NXP indeed has a very annoying site." CreationDate="2010-10-01T20:24:40.173" UserId="883" />
  <row Id="5119" PostId="4730" Score="1" Text="On Screen Display, which is also an Open Source Design. :)" CreationDate="2010-10-01T20:29:09.527" UserId="1225" />
  <row Id="5120" PostId="4732" Text="Will this work with AC? (line level ±2V max.)" CreationDate="2010-10-01T20:31:43.690" UserId="1225" />
  <row Id="5121" PostId="4732" Text="Yes, but you need to get the biasing right.  The analog input needs to be between the power rails of the IC, so 4 Vpp would fit if you use +5 V supply.  Typically you use DC-blocking and bias the signal up to half of the supply as it passes through the IC, then back down to 0 on the other end.  Alternately, you can use negative supplies, or switch the summing junction of an inverting amplifier so the voltage is always 0 and it's just current flowing through the switch." CreationDate="2010-10-01T20:40:31.627" UserId="142" />
  <row Id="5122" PostId="4732" Text="I could use an oscillator and a charge pump to generate a negative supply, but I'd rather not... (that is, size is a problem.)" CreationDate="2010-10-01T21:31:04.167" UserId="1225" />
  <row Id="5123" PostId="4732" Text="But your signal is +-2 V?  It's generated by some other circuit?  Or is it already biased?" CreationDate="2010-10-01T21:43:14.997" UserId="142" />
  <row Id="5124" PostId="4732" Text="I'm using a common battery ground. I am taking the output from a video camera with an audio channel. I haven't checked, but I suspect the output is ac coupled, so will have a ±2V or so swing." CreationDate="2010-10-01T21:49:21.357" UserId="1225" />
  <row Id="5125" PostId="4723" Score="1" Text="@mjh2007 - We rolled our own, since it needed to be used in conjunction with another protocol." CreationDate="2010-10-01T21:58:35.727" UserId="374" />
  <row Id="5126" PostId="4734" Text="sine to square: http://www.redcircuits.com/Page17.htm" CreationDate="2010-10-01T22:00:34.507" UserId="1400" />
  <row Id="5127" PostId="4734" Text="good Nixie data: http://www.tube-tester.com/sites/nixie/74141-NDT/74141-NDT.htm" CreationDate="2010-10-01T22:01:49.950" UserId="1400" />
  <row Id="5128" PostId="4721" Text="Yes -- they read just fine." CreationDate="2010-10-01T22:07:19.837" UserId="1236" />
  <row Id="5129" PostId="2865" Text="I've had an NPN explode (sending shrapnel flying - not good!!), as well as a small IC. Oh, and the occasional electrolytic." CreationDate="2010-10-01T22:27:37.427" UserId="1225" />
  <row Id="5131" PostId="4696" Text="@Nat Ryall: it is not clear from the description, is the &quot;1 + 4&quot; circuit as illustrated in the following image? http://i.imgur.com/wLDrk.png" CreationDate="2010-10-01T22:56:51.860" UserId="804" />
  <row Id="5132" PostId="4649" Text="How much you get will depend on how much current is being pulled through the wires.  I know for sure of one robot prototype that was successfully powered by the EM fields from high voltage lines, but keep in mind that the wiring in any given house is going to be limited to 15 or 20 amps and will only really be pulling that if you've got a vacuum or space heater hooked up to it." CreationDate="2010-10-01T23:52:42.063" UserId="249" />
  <row Id="5133" PostId="4645" Text="@Jack - Was this where you wanted to post this?  Unless there was a recent question about XBees that I'm not recalling, you should probably post this as a question.  As an answer, no, I don't know of any $5 dongle. An FTDI chip probably won't have the power to do it by itself, so you'd basically need PC -&gt; USB -&gt; Microcontroller (w/ USB) -&gt; XBee, which might be reduced to the $5 to $10 region for certain values of [Microcontroller (w/ USB)]" CreationDate="2010-10-02T00:57:42.047" UserId="857" />
  <row Id="5134" PostId="4685" Text="Metcal, and now Oki-Metcal soldering irons heat the soldering iron tip inductively using rf. Basically the iron has a ceramic covered wire coil in the handle, and it induces eddy currents in the actual tip which resistively heat it. It has a very large instantaneous heat capacity, which means that you can solder large components using a small tip, and your dwell-time on each component lead can be less, which reduces the chance of damaging something." CreationDate="2010-10-02T02:10:28.343" UserId="1374" />
  <row Id="5135" PostId="4685" Text="As for the microscope, I never use it monocularly. Having depth perception is tremendously useful. Brand-wise, it's a cheapo chinese thing." CreationDate="2010-10-02T02:11:26.317" UserId="1374" />
  <row Id="5136" PostId="4734" Score="1" Text="+1 just cause Nixie tubes are cool" CreationDate="2010-10-02T02:16:05.583" UserId="330" />
  <row Id="5137" PostId="4713" Score="4" Text="there's an OpenCAN as well as CANOpen? aiggh! horrid naming." CreationDate="2010-10-02T02:17:06.297" UserId="330" />
  <row Id="5138" PostId="4712" Score="1" Text="+1, good question." CreationDate="2010-10-02T02:17:55.343" UserId="330" />
  <row Id="5139" PostId="4697" Score="1" Text="current through each LED is not 5/330, it's (5 - Vf)/330 where Vf is the forward drop of the LED, usually 1.2-1.5V." CreationDate="2010-10-02T02:21:05.053" UserId="330" />
  <row Id="5141" PostId="1852" Text="Typically I would imagine the bus to be idle (de-asserted) the vast majority of the time, so for a battery application there are more important issues to deal with than trying to optimize I2C pullups just so :P" CreationDate="2010-10-02T03:02:27.240" UserId="1407" />
  <row Id="5142" PostId="4697" Score="1" Text="Yes, but he also doesn't have an LED with a resistance of 330 ohms. I was leaving the details out in order not to muddy the spirit of the question with pedantic details. :-)" CreationDate="2010-10-02T03:33:33.897" UserId="974" />
  <row Id="5143" PostId="4742" Text="So for your stereo player, you'll just mix music/whatever onto (arbitrarily) the left channel and have the right just be a series of loud sine pulses?" CreationDate="2010-10-02T04:14:55.470" UserId="1407" />
  <row Id="5144" PostId="4666" Text="Yes indeed - Forrest Mims' books got me started when I was a young lad, and I still have scans of them to this day." CreationDate="2010-10-02T06:46:10.370" UserId="1307" />
  <row Id="5145" PostId="4627" Text="It's notable that avrdude double-checks your fuse bits to prevent this problem. A slightly more common problem is setting the chip to external clock." CreationDate="2010-10-02T08:50:13.457" UserId="1181" />
  <row Id="5147" PostId="4705" Score="1" Text="@Richard: this is correct, except for the numbers. The voltage drop for a normal Si diode is 0.7 V, but for LEDs it is in range 1.6 V to 2.4 V, depending on the type. For the red standard LEDs it is 1.6 V at the standard operating current." CreationDate="2010-10-02T10:22:49.427" UserId="804" />
  <row Id="5148" PostId="4696" Text="@Nat Ryall: what type of LED are you using? For instance, red/greeen/yellow/blue, normal brightness/high brightness?" CreationDate="2010-10-02T10:36:03.193" UserId="804" />
  <row Id="5149" PostId="4696" Score="1" Text="@Nat Ryall: In &quot;decided to connect 4 more in parallel&quot;, what are each of the 4? Is it resistor+LED, LED or resistor? In other words, which of the following component counts is it? 5 resistors + 5 LEDs / 5 resistors + 1 LED / 1 resistor + 5 LEDs ?" CreationDate="2010-10-02T10:41:09.620" UserId="804" />
  <row Id="5152" PostId="1996" Text="It's no formula (not intentionally)... I've trown in the linearizer initial values just guessing:-). I've then powered the array, driving led columns in brightness order, and tweaked the values to get an even ramp. It's really easy with only 16 levels." CreationDate="2010-10-02T10:58:36.643" UserId="244" />
  <row Id="5153" PostId="4682" Text="@posipiet , given my little knowledge in power ac electronics, and my power requirement in lower range, i think i will go with BLDC. thanks for the answer." CreationDate="2010-10-02T11:03:17.993" UserId="1312" />
  <row Id="5154" PostId="4714" Text="Yeah, the near-field is about 1 wavelength, so distance varies a lot between the two." CreationDate="2010-10-02T11:08:27.593" UserId="142" />
  <row Id="5155" PostId="4705" Text="@Richard: LEDs are not Si devices. For instance the standard red LEDs are typically gallium arsenide phosphide (GaAsP) or Aluminium gallium arsenide (AlGaAs). Overview: http://en.wikipedia.org/wiki/Light-emitting_diode#Colors_and_materials " CreationDate="2010-10-02T11:14:28.707" UserId="804" />
  <row Id="5156" PostId="4751" Text="Thanks! I will use a P-ch fet then - sounds great. Through hole/surface mount is not an issue." CreationDate="2010-10-02T13:30:49.210" UserId="1225" />
  <row Id="5157" PostId="4742" Text="Yes exactly right." CreationDate="2010-10-02T13:44:59.273" UserId="1406" />
  <row Id="5158" PostId="4753" Text="Thanks. I guess I'm more interested in what's a reasonable value - .1 mfd, 10 mfd, 100mfd?  If it helps, the audio pulses will be fairly quick, like maybe around 250ms" CreationDate="2010-10-02T13:51:58.783" UserId="1406" />
  <row Id="5159" PostId="4758" Score="1" Text="SD cards have checksums for some parts of the protocol, but they're usually ignored in SPI mode.  Only the first command (which puts the card in SPI mode) must have a valid checksum. " CreationDate="2010-10-02T14:13:44.927" UserId="857" />
  <row Id="5160" PostId="4758" Text="@reemrevnivek, you're right. I'm looking for a protocol that allows me to perform large and small transactions with the FPGA and be confident they are error free. (which makes me think I would need a way for the master to know that the slave failed its check. The overhead is going to add up if I need a final slave acknowledge... Hmmm....)" CreationDate="2010-10-02T14:31:33.670" UserId="1411" />
  <row Id="5161" PostId="4713" Text="@Jason, I blame microsoft. " CreationDate="2010-10-02T14:35:01.543" UserId="230" />
  <row Id="5162" PostId="4753" Text="To be honest I wouldn't like to guess, I've not used any relays before and I just don't know enough about your circuit, there'll be an equation for it somewhere I'm sure...hopefully someone else will have the answer for ya, we'll just have to shout louder.......CHIPHACKERS!!!!! oops forgot...it's not Chiphacker anymore...what are we called now?" CreationDate="2010-10-02T15:05:12.867" UserId="399" />
  <row Id="5163" PostId="4742" Text="Hey Pete - could you give us an idea about the kind and size of motor or actuator you intend to use? also could you comment a little on the mechanics - maybe just mention how you'd like the resulting thing to move? - I just thought it might help people answer your question fully. " CreationDate="2010-10-02T15:14:52.137" UserId="399" />
  <row Id="5164" PostId="4732" Text="A &quot;common battery ground&quot;?  I mentioned the negative supply because the coupling caps take up space on the board and it wouldn't require them with a split supply, but if you're interfacing with an AC coupled signal from outside the device, you'll probably need coupling caps anyway." CreationDate="2010-10-02T15:29:25.963" UserId="142" />
  <row Id="5165" PostId="4742" Score="1" Text="You probably have to find the value of C1 experimentally.  It probably depends on the output impedance of your MP3 player.  Look at that point on a scope if you can." CreationDate="2010-10-02T15:38:25.307" UserId="142" />
  <row Id="5166" PostId="4754" Score="1" Text="TINA-TI is a free SPICE that works pretty well. http://focus.ti.com/docs/toolsw/folders/print/tina-ti.html" CreationDate="2010-10-02T15:41:41.283" UserId="142" />
  <row Id="5167" PostId="4746" Text="Are you 100% sure it's the same binary? How exactly do you copy the file under Ubuntu? Have you tried different ways of copying?" CreationDate="2010-10-02T15:42:33.407" UserId="1082" />
  <row Id="5168" PostId="2865" Text="I've once exploded a bunch of dead transistors and ICs -- and a few capacitors and resistors, just to compare -- with a 1 millifarade 300V capacitor battery. Well, this way everything explodes:) As an useful comment, I'd say that electrolytic capacitors are probably most dangerous because of acid, and small plastic cases of transistors tend to fly out with very high speed." CreationDate="2010-10-02T16:21:05.480" UserId="1311" />
  <row Id="5169" PostId="4737" Text="I think that using &quot;the highest resistor you can find&quot; won't work in some cases, particularly when that would be a 10MOhm resistor. I'd suggest using 20K ones, as that's only 1mA of current (and 20mW of power dissipated) even at 20V, which is probably the maximum voltage you would like to have zener diodes for." CreationDate="2010-10-02T16:24:28.347" UserId="1311" />
  <row Id="5170" PostId="4687" Score="1" Text="I personally use an old Pace station. Temp control helps tremendously." CreationDate="2010-10-02T16:28:53.217" UserId="965" />
  <row Id="5171" PostId="4759" Text="As a side note, multisim is more than able to let you do this kind of simulation." CreationDate="2010-10-02T17:23:54.633" UserId="230" />
  <row Id="5172" PostId="4741" Text="Some useful stuff in there thanks, hadn't heard of bridging. " CreationDate="2010-10-02T17:55:18.807" UserId="1329" />
  <row Id="5173" PostId="4341" Score="2" Text="Wow. Those are crazy. But in a good way." CreationDate="2010-10-02T19:08:11.477" UserId="814" />
  <row Id="5174" PostId="4764" Text="A suoercap has a significant self-discharge that is in the same order of magnitude as your load." CreationDate="2010-10-02T19:30:57.170" UserId="1322" />
  <row Id="5175" PostId="4764" Text="So any idea how long it will go even with that discharge? If it went for a few weeks it would probably be okay. Otherwise, I may need a supply monitor IC and a coin cell." CreationDate="2010-10-02T19:33:45.823" UserId="1225" />
  <row Id="5176" PostId="4762" Text="I am familiar with those protocols. SPI doesn't share the same characteristics as RS485/RS232 etc.. SPI is syncronous and is restricted to being master / slave.... the slave has no control over how many bytes the master sends or attempts to receive. Additionally, this protocol needs to be lightweight, chip to chip. Modbus and HDLC are device to device." CreationDate="2010-10-02T19:35:03.543" UserId="1411" />
  <row Id="5177" PostId="4764" Score="2" Text="I would use a coin cell." CreationDate="2010-10-02T19:37:47.047" UserId="1322" />
  <row Id="5178" PostId="4768" Text="Hmm, looks like I'm going to have to use a coin cell instead. :( I could use a 1F cap, but they get bigger and bigger..." CreationDate="2010-10-02T19:38:06.593" UserId="1225" />
  <row Id="5179" PostId="4740" Text="My transisters are extras left over from my nixie clock.  IT had a 33k resister on the signal wire and thats it.  Thanks" CreationDate="2010-10-02T19:48:18.050" UserId="1400" />
  <row Id="5180" PostId="4734" Text="Just got sending unit hooked up at 70 ish i was turning 180 hurtz and about 4.2 v ac.  I figure this should be able to handle at least 6 volts whitch i should never exceed.  " CreationDate="2010-10-02T19:49:19.223" UserId="1400" />
  <row Id="5182" PostId="4769" Score="1" Text="http://www.rachelselectronics.com/2010/09/sol_arduino-v1/" CreationDate="2010-10-02T21:03:21.873" UserId="1084" />
  <row Id="5183" PostId="4769" Text="Bluetooth TTL Transceiver Module w/ Breakout (http://www.mdfly.com/index.php?main_page=product_info&amp;cPath=8&amp;products_id=428)" CreationDate="2010-10-02T22:04:12.877" UserId="1084" />
  <row Id="5184" PostId="4750" Text="Can't find anything about having one schematic pin that counts as two symbol pins, or perhaps a pad that is more than one polygon? Maybe this feature does not exist in Eagle..." CreationDate="2010-10-02T22:16:47.707" UserId="1363" />
  <row Id="5185" PostId="4750" Text="@joeforker -- just add extra pins to the device, e.g. make thermalpad a pin both in the schematic and the device, and ground it on the schematic." CreationDate="2010-10-02T22:38:46.313" UserId="1322" />
  <row Id="5186" PostId="4762" Text="Thanks, I am currently using the same technique without the len and chgecksum. It is basicaly very similar to most of the other uses I've seen of SPI." CreationDate="2010-10-03T00:02:33.360" UserId="1411" />
  <row Id="5187" PostId="4632" Text="I bought the Hawkboard from IDA.Was delivered in  a week's time." CreationDate="2010-10-03T01:25:55.847" UserId="921" />
  <row Id="5188" PostId="4645" Text="@reemrevnivek: thanks.  Maybe it should have been a comment on the question, rather than this answer.  The OP wanted wifi for *convenience* to the end-user.  I was suggesting that not only would other kinds of radio (xbee/zigbee) be cheaper, but actually they could still be convenient." CreationDate="2010-10-03T03:17:49.070" UserId="1271" />
  <row Id="5189" PostId="3694" Text="-1, UL listed means *so much more* than being double insulated." CreationDate="2010-10-03T04:01:29.820" UserId="1407" />
  <row Id="5190" PostId="4743" Text="+1, Good thoughts for soldering leadless components!" CreationDate="2010-10-03T06:40:54.087" UserId="444" />
  <row Id="5191" PostId="4714" Score="4" Text="For an (arbitrarily decided) FM station on 101 (ish) MHz, you're looking at (very roughly) 72 dB of path loss for 1 km. For a 300 Watt station, that means a received power of something like 30 uW. This could be plus or minus 50 times, but it still wouldn't matter. On the optimistic side of 50 times, it's still only 1.5 mW." CreationDate="2010-10-03T08:20:08.193" UserId="965" />
  <row Id="5192" PostId="4778" Text="Ya I've tried that yesterday. But It Turns A Off when I Push B to On." CreationDate="2010-10-03T09:49:49.167" UserId="1424" />
  <row Id="5193" PostId="4287" Text="Not getting anything to do ? Come and Help me solving my Problem http://electronics.stackexchange.com/questions/4777/led-quiz-buzzer-circuit-with-logic-gates" CreationDate="2010-10-03T10:00:48.710" UserId="1424" />
  <row Id="5194" PostId="4693" Text="@Andrew Kohlsmith: OMAP vs DaVinci what would be more suitable for image processing? Another name that I have recently come across is Analog Devices' Blackfin family. I also see that all these are in Bga, so I wonder how to start prototyping? Is a starterkit /EDK only way out." CreationDate="2010-10-03T10:04:50.800" UserId="444" />
  <row Id="5195" PostId="4691" Text="I was looking more for a processor that can serve for image processing rather than a camera technology. However +1 for introducing something new." CreationDate="2010-10-03T10:06:15.757" UserId="444" />
  <row Id="5198" PostId="4737" Text="Point taken. The highest resistor you can find &quot;within reason&quot; would be a better answer." CreationDate="2010-10-03T18:48:44.583" UserId="1293" />
  <row Id="5199" PostId="4777" Score="2" Text="Capacitors are always advisable in logic circuits to filter power supply transients.  You should use (at least) one per logic IC, between the supply and ground as close to the IC's supply pin as possible." CreationDate="2010-10-03T19:09:43.597" UserId="1407" />
  <row Id="5200" PostId="4777" Text="Why Use Capacitor If I can go without it." CreationDate="2010-10-03T19:30:37.253" UserId="1424" />
  <row Id="5201" PostId="4777" Score="4" Text="Additionally, logic gates that have floating inputs (like all the inverters on your diagram) are almost always wrong." CreationDate="2010-10-03T19:30:37.963" UserId="1407" />
  <row Id="5202" PostId="4777" Score="2" Text="You could not use capacitors, but you may experience bizarre problems that are almost impossible to trace.  Get some 0.1 µF ceramic caps; they're way cheaper than any logic chips." CreationDate="2010-10-03T19:32:53.587" UserId="1407" />
  <row Id="5203" PostId="4785" Score="2" Text="I was almost done when yours was posted, and since I took a lightly different direction I still posted it. We said the same thing in different ways, +1 for you." CreationDate="2010-10-03T19:56:47.880" UserId="230" />
  <row Id="5204" PostId="4785" Score="2" Text="And for you sir!" CreationDate="2010-10-03T20:09:32.763" UserId="712" />
  <row Id="5206" PostId="4783" Text="Thanks joeforker.  So are you saying I could for example, build an oscillator into the device which is capable of producing the IR signal of 32-56K and then have the iPhone app; (a) tell the oscillator what frequency in the IR band to use and also the oscillating frequency?  (b) to tell the device the frequency in the IR band and then just control the oscillation by turning the beam on and off via a signal from the headphone jack?" CreationDate="2010-10-03T20:27:02.360" UserId="1415" />
  <row Id="5207" PostId="4778" Text="With the *outputs* of the AND gates fed into the 4-input NORs?  Turning A on should put a low on the second inputs of all the other AND gates, so then B should never be able to turn on until A turns off.  Since B can't turn on, the line from B to the 4-input NOR on A won't change." CreationDate="2010-10-03T23:11:07.077" UserId="1425" />
  <row Id="5208" PostId="4777" Text="Good advice, but I assumed from the question that he has been trying in a digital logic simulator, not on real hardware yet.  i.e. transients aren't an issue." CreationDate="2010-10-03T23:14:52.000" UserId="1425" />
  <row Id="5209" PostId="4790" Score="1" Text="They also have a gigantic Q." CreationDate="2010-10-03T23:43:17.020" UserId="230" />
  <row Id="5210" PostId="4787" Text="This is a major major reason to use caps, but from a new guy to circuits whom does digital I was betting they were all decoupling caps." CreationDate="2010-10-03T23:52:37.047" UserId="230" />
  <row Id="5211" PostId="4764" Text="seconded. A coin cell just gets the job done." CreationDate="2010-10-04T00:01:44.140" UserId="230" />
  <row Id="5212" PostId="4787" Text="Thst's why I started with &quot;Capacitors are *also* widely used...&quot;  If he is just starting out in electronics, he is going to run into them again." CreationDate="2010-10-04T00:46:41.837" UserId="1322" />
  <row Id="5213" PostId="4719" Text="thanks for pointing this out!" CreationDate="2010-10-04T01:23:35.790" UserId="1390" />
  <row Id="5214" PostId="4567" Text="+1 for Little Bird." CreationDate="2010-10-04T01:28:19.337" UserId="1437" />
  <row Id="5215" PostId="1778" Text="*Who better to get your answers from?* The Electronics and Robotics Stackexchange site?  Just kidding, a link to the creator of the device is just about as good as it gets." CreationDate="2010-10-04T01:54:23.660" UserId="857" />
  <row Id="5216" PostId="1852" Text="only thing i would add is a buffer above the summed capacitance of the devices on the bus.  The trace itself as well as the solder joints from pads to pins will also have some impedance.  On longer buses the capacitance of the trace/wire can be larger than the pin capacitance of the devices.  When designing production boards i don't usually determine the final pull up value till i have a prototype in hand and can scope the bus with various values." CreationDate="2010-10-04T02:01:05.977" UserId="1438" />
  <row Id="5217" PostId="4746" Text="Yes I am sure. I found the problem. It seems to be the way linux deals with vfat. It seems to prefix 0s before sending the file which are ignored by a lot of usb devices, but still is incompatible to the standard." CreationDate="2010-10-04T04:23:12.993" UserId="936" />
  <row Id="5218" PostId="4786" Text="In your second paragraph, do you mean you want the capacitor physically (geometrically) close to the high frequency component in order for it to get power?  What happens if its not there? Noise or sag? (Context: I want to use some radio in next month's hobbyist project, and I'm trying to get up to speed on what is involved.  I'm hoping to use a microcontroller with built in radio to do some low power transmission, maybe RFID style, basically just a few kilobytes every hour.  Do I need to know about this use of capacitors?)" CreationDate="2010-10-04T04:25:12.897" UserId="1271" />
  <row Id="5219" PostId="4784" Score="6" Text="Two words:  [time travel](http://en.wikipedia.org/wiki/Flux_capacitor#Flux_capacitor)." CreationDate="2010-10-04T04:52:52.290" UserId="1441" />
  <row Id="5220" PostId="4764" Text="As a side note, Super-caps are actually starting to be used on computer motherboards and GPSs. In any typical motherboard you wont loose power for too long and it doesn't take much power to keep a realtime clock. GPSs uses it to keep the last known gps position to get a faster lock on turn on." CreationDate="2010-10-04T05:15:26.377" UserId="319" />
  <row Id="5221" PostId="4786" Score="2" Text="i mean electrically close. This means that the ruler distance between parts may be short, but if the wire is a bent underneath 6 inch wire you have a problem. This will cause both noise and sag. the chip with a capacitor at a distance will have sag issues(possibly minor, look at the datasheet) but you will cause noise on the wire between them with it acting as an antenna." CreationDate="2010-10-04T05:22:16.457" UserId="230" />
  <row Id="5222" PostId="4786" Text="This is currently my specialization in my masters research, if you would like to discuss it in more detail you can ask another question, or I can edit more into my answer tomorrow." CreationDate="2010-10-04T05:22:55.333" UserId="230" />
  <row Id="5223" PostId="4787" Text="I did not mean to imply you were wrong, I was just giving a comment, something for others to read, and to note that I more than agree with your answer." CreationDate="2010-10-04T05:23:39.217" UserId="230" />
  <row Id="5224" PostId="4784" Text="If you can lay your hands on a couple, let me know. " CreationDate="2010-10-04T05:50:07.160" UserId="1307" />
  <row Id="5225" PostId="4778" Text="Did you mean something like this http://c.imagehost.org/0953/snap4.png ? " CreationDate="2010-10-04T05:53:00.310" UserId="1424" />
  <row Id="5226" PostId="4784" Text="Ya sure. I ordered an Arduino Board. they are delaying untill they get Uno Board in their Stock. I am waiting." CreationDate="2010-10-04T05:59:03.680" UserId="1424" />
  <row Id="5227" PostId="4795" Text="A good question, but it should be a community wiki question..." CreationDate="2010-10-04T06:42:17.523" UserId="689" />
  <row Id="5228" PostId="4784" Text="Oh not Unos, flux capacitors. " CreationDate="2010-10-04T08:05:34.710" UserId="1307" />
  <row Id="5229" PostId="4791" Text="If I'm not mistaken are you by any chance Mr. Roman Black, the inventor of the LiniStepper? " CreationDate="2010-10-04T08:46:22.480" UserId="444" />
  <row Id="5230" PostId="4791" Text="I'm sorry but I still don't understand what you mean by alternating fast between 2 microsteps, like AAA or AAB." CreationDate="2010-10-04T08:53:05.300" UserId="444" />
  <row Id="5231" PostId="2326" Text="I don't like the PIC18/PIC16's compilers, but I do like the 24F and dsPIC30F/33F compilers, which are based on GCC. " CreationDate="2010-10-04T09:28:32.833" UserId="1225" />
  <row Id="5232" PostId="4804" Text="@Thomas O I added a link to picture of the potentiometer (sorry for the quality, my camera is very broken!). The scale shown is in centimeters and it looks like the distance between left-most connector and right-most connector is about 2 cm." CreationDate="2010-10-04T10:17:37.497" UserId="1240" />
  <row Id="5233" PostId="4804" Text="Probably not much more than 1/2W then. 1W max. " CreationDate="2010-10-04T10:20:37.117" UserId="1225" />
  <row Id="5234" PostId="4804" Score="1" Text="A side note, if the potentiometer is 1k and is rated for 1/2W, then you should have no more than ~20V across it. " CreationDate="2010-10-04T10:26:43.953" UserId="1225" />
  <row Id="5235" PostId="4804" Score="1" Text="Thanks a lot! It's quite unfortunate that introductory electrical engineering courses on my university don't teach students how to actually use real circuit components." CreationDate="2010-10-04T10:34:23.707" UserId="1240" />
  <row Id="5236" PostId="4693" Text="I've done work with Blackfin as well, but never in a video capture capacity. They do come in TQFP packages which would be more accessible to someone doing the soldering themselves. I don't know much about DaVinci, sorry." CreationDate="2010-10-04T10:56:10.097" UserId="974" />
  <row Id="5237" PostId="4795" Score="2" Text="possible duplicate of [Basic Electronics Book](http://electronics.stackexchange.com/questions/616/basic-electronics-book)" CreationDate="2010-10-04T12:11:32.757" UserId="330" />
  <row Id="5238" PostId="4809" Score="6" Text="The other side of the compromise is that the resistor values are kept &quot;reasonably&quot; high so that the current and hence power dissipated through the resistor chain is kept small.  They could all be made 1R in value but this would waste 1.4 watts compared to the 0.14mW in the chain above." CreationDate="2010-10-04T12:13:14.063" UserId="400" />
  <row Id="5239" PostId="4763" Text="Actually I use Microchip so that's very helpful. Thanks!" CreationDate="2010-10-04T12:29:05.600" UserId="588" />
  <row Id="5240" PostId="4804" Score="4" Text="AndrejaKo: This is an issue at many universities. We got a grant a few years back from the NSF to restructure many of our engineering courses. Now even non-electrical engineers have to take a course where they spend half of the semester in the theoretical world and the other half is spent with a breadboard doing projects." CreationDate="2010-10-04T13:08:50.623" UserId="319" />
  <row Id="5243" PostId="4808" Text="Possible duplicate: http://electronics.stackexchange.com/questions/1849/is-there-a-correct-resistance-value-for-pull-up-resistors" CreationDate="2010-10-04T13:54:25.983" UserId="142" />
  <row Id="5244" PostId="4815" Text="Brilliant site - I didn't know about it. Had a look at http://extremeelectronics.co.in/avr-tutorials/interfacing-temperature-sensor-lm35/ and the pdf available for download: wow! I hope the rest of tutorials are of that standard." CreationDate="2010-10-04T13:54:27.260" UserId="1443" />
  <row Id="5245" PostId="4645" Text="Is there a zigbee to Wi-Fi &quot;repeater&quot;? :)  Then you could have lots of low-power sensors, with the convenience of data being automatically available over the home network." CreationDate="2010-10-04T14:01:25.013" UserId="142" />
  <row Id="5246" PostId="4763" Score="1" Text="Those are all for the pic18. It seems with CANopen you have a master that modifies settings on the others, for most of what my use of canbus includes, this fits perfectly." CreationDate="2010-10-04T14:13:50.377" UserId="230" />
  <row Id="5247" PostId="4809" Text="that 1M should pull you to 5V. If you have too large a leakage current for your ADC, which is common, then it can still be pulled somewhere other than 5V. it is for power reasons that it is 1M. Justjeff, I do not know what you mean by antenna, I am 90% sure that the resistance has nothing to do with it being an antenna." CreationDate="2010-10-04T14:19:51.070" UserId="230" />
  <row Id="5248" PostId="4793" Text="the art of electronics is not the easiest read." CreationDate="2010-10-04T14:20:45.553" UserId="230" />
  <row Id="5249" PostId="4784" Score="2" Text="Hope we were of help, I would suggest that you change your username to an actual name instead of an auto-generated one." CreationDate="2010-10-04T14:21:49.477" UserId="230" />
  <row Id="5250" PostId="4784" Score="1" Text="Capacitors on power supply lines as you describe are called &quot;bypass capacitors&quot; or &quot;decoupling capacitors&quot;.  http://en.wikipedia.org/wiki/Decoupling_capacitor  There are many other uses of capacitors in circuits." CreationDate="2010-10-04T14:28:43.493" UserId="142" />
  <row Id="5251" PostId="4819" Text="Do you know if LaunchPads are shipping?  For $5 it seems worth while, but I think mouser is a few months behind.  TI direct seems willing to sell me it, but they don't seem willing to tell me when it will ship.  Order now for Christmas?" CreationDate="2010-10-04T14:35:53.040" UserId="1271" />
  <row Id="5252" PostId="4812" Text="what size supercap did you use?" CreationDate="2010-10-04T14:35:56.520" UserId="230" />
  <row Id="5253" PostId="4820" Text="that link to the high-low tech wiki is exactly what i needed, thanks very much!" CreationDate="2010-10-04T14:41:51.430" UserId="623" />
  <row Id="5254" PostId="4819" Text="I ordered 12 from digikey, they arrived within 48 hours. People have reported problems with TI's eStore though." CreationDate="2010-10-04T14:42:00.587" UserId="566" />
  <row Id="5255" PostId="4812" Text="I used a 0.47F super-cap." CreationDate="2010-10-04T14:51:30.110" UserId="588" />
  <row Id="5256" PostId="4764" Text="36 Hours Ref: http://www.maxim-ic.com/tools/calculators/index.cfm/calc_id/supercap" CreationDate="2010-10-04T14:57:59.640" UserId="588" />
  <row Id="5257" PostId="4818" Text="Excellent! Thanks." CreationDate="2010-10-04T15:05:50.117" UserId="1363" />
  <row Id="5258" PostId="4786" Text="Cool thanks!  I'm still gathering enough information to ask a reasonable question.  Looking through DigiKey and Mouser's catalogs and reading $5 chip's datasheets is like reading science-fiction.  I'm trying to get up to speed by reading the textbooks from our undergrad EE courses, but I haven't figured out how to get the lab experience yet." CreationDate="2010-10-04T15:25:19.817" UserId="1271" />
  <row Id="5259" PostId="4796" Text="The &quot;passive adder&quot; is the same circuit you'd use to bias the signal going into the analog switch.  The bias resistor should be large compared to the signal resistor, though, not equal, and there should be a large capacitor across the 1k to ground to filter out power supply noise." CreationDate="2010-10-04T15:42:24.040" UserId="142" />
  <row Id="5260" PostId="4809" Text="So the 1M resistor wouldn't divide the voltage at ADC to 0V? Does that mean the voltage dividing rule only applies when there are multiple loads in series?" CreationDate="2010-10-04T15:45:38.427" UserId="1333" />
  <row Id="5261" PostId="4796" Text="Thanks for your suggestions. How large should the cap be? I'm working on a size constrained board." CreationDate="2010-10-04T15:46:11.427" UserId="1225" />
  <row Id="5262" PostId="4812" Text="How much current does the DS1306 draw in its standby mode? I couldn't find that parameter in its datasheet." CreationDate="2010-10-04T15:51:21.183" UserId="1225" />
  <row Id="5263" PostId="4786" Text="If you were at Oklahoma State We have a really nice design lab staffed by employees, myself included, that help students with designs and general EE questions like this all the time." CreationDate="2010-10-04T15:55:13.133" UserId="230" />
  <row Id="5264" PostId="4794" Text="Kortuk does provide some essential information for that circuit, make sure you check out his post." CreationDate="2010-10-04T15:58:37.490" UserId="319" />
  <row Id="5265" PostId="4796" Text="Depends on how much noise is on the 5V line and how much you care about it.  The value of C sets the cutoff frequency of the RC filter, above which the noise will drop off with frequency.  Using a larger than necessary value will cause it to charge up slowly, so the device will take longer to become functional." CreationDate="2010-10-04T16:00:30.920" UserId="142" />
  <row Id="5266" PostId="4829" Text="What's a breakaway pin strip?" CreationDate="2010-10-04T16:02:21.477" UserId="1240" />
  <row Id="5267" PostId="4829" Text="I did not realize Joby posted while I was typing my answer. An example of breakaway pin strips is shown in the last link I gave." CreationDate="2010-10-04T16:07:10.297" UserId="319" />
  <row Id="5268" PostId="4829" Text="@Kellenjb Thanks! I know what they are now." CreationDate="2010-10-04T16:08:55.550" UserId="1240" />
  <row Id="5269" PostId="4828" Text="Are you sure you can't find solid wire? I just use solid CAT5e (Ethernet cabling) because I have tons of it left over from a networking project." CreationDate="2010-10-04T16:13:00.490" UserId="1363" />
  <row Id="5270" PostId="4803" Text="Measuring with `cm`; who does that? :P  Virtually everything in electronics is `mm` or `in`.  Terminal spacing is also fairly pointless, more characteristic for the pot might be the body diameter.  A part number on it would probably be better still." CreationDate="2010-10-04T16:33:27.520" UserId="1407" />
  <row Id="5271" PostId="4819" Text="TI's not one of those companies (e.g. Kingbright) where you buy it from their store then get a package from Thief River Falls? :P" CreationDate="2010-10-04T16:36:04.143" UserId="1407" />
  <row Id="5272" PostId="4823" Text="be cautious, if you spec to be at max current for your device, try to not stay there long." CreationDate="2010-10-04T16:39:45.413" UserId="230" />
  <row Id="5273" PostId="4809" Score="1" Text="The 1M resistor creates a voltage divider with the input impedance of the ADC input pin. If the input impedance is quite high (tens of megohms) then the 1M pull-up becomes insignificant. The fact that there's a small drop across the 1M is not likely important as if the ADC is also powered from +5, there's probably a dead band on the high-side a few hundred millivolts below the supply rail." CreationDate="2010-10-04T16:40:47.813" UserId="1293" />
  <row Id="5274" PostId="4830" Text="I almost always just put a bit of solder on the wire to make it a solid wire." CreationDate="2010-10-04T16:43:28.863" UserId="230" />
  <row Id="5275" PostId="4778" Score="2" Text="That's a tiny bit closer.  However, you can't tie the outputs together like that.  You can send an output to more than one input, but not more than one output to the same input, which is why you need 5 4-input NOR gates instead of your 5 inverters.  Look at latches for the 2 output case at http://en.wikipedia.org/wiki/Latch_(electronics)  You probably need to understand that before moving to a 3 output case.  Moving from 3 to 5 is then fairly trivial." CreationDate="2010-10-04T16:56:28.420" UserId="1425" />
  <row Id="5276" PostId="4812" Score="1" Text="Between 0.4uA and 1.0uA depending on VCC." CreationDate="2010-10-04T17:04:07.983" UserId="588" />
  <row Id="5277" PostId="4777" Text="I would have to agree with karl, but only user1424 can tell us to be sure." CreationDate="2010-10-04T17:13:46.487" UserId="230" />
  <row Id="5278" PostId="4777" Text="User1424, if you can be clear when you want the LED to turn on, I can help. Do you want each button to have an associated LED, or do you want an LED for the right answer." CreationDate="2010-10-04T17:14:50.397" UserId="230" />
  <row Id="5279" PostId="4803" Text="@Nick T You mean in this day and age there are people who use `in`? First time I heard about something like that... :) Anyway the point is that I had no easy way to measure diameter, so I put spacing between terminals. Also using `mm` in this case would mean bringing superfluous precision which is a bad thing." CreationDate="2010-10-04T17:25:23.370" UserId="1240" />
  <row Id="5281" PostId="4809" Text="Thank you for clearing that up." CreationDate="2010-10-04T17:52:43.280" UserId="1333" />
  <row Id="5282" PostId="4828" Text="@joeforker CAT5e seems like a good idea. When I take into account that there are 8 wires in CAT5e, it turns out to be a bit cheaper than stranded wire. " CreationDate="2010-10-04T17:59:16.493" UserId="1240" />
  <row Id="5284" PostId="4828" Text="Of course Ethernet cabling comes in both solid and stranded. Typically you put the solid wire in the walls and use the stranded wire to make patch cables." CreationDate="2010-10-04T18:26:24.417" UserId="1363" />
  <row Id="5285" PostId="4813" Text="Yeah, this is definitely the easiest way to get started." CreationDate="2010-10-04T18:29:43.517" UserId="131" />
  <row Id="5289" PostId="4839" Score="2" Text="You might check out some of the SMD soldering tutorials at http://CuriousInventor.com" CreationDate="2010-10-04T18:56:54.390" UserId="51" />
  <row Id="5290" PostId="4828" Text="Unfortunately in my area stranded CAT5e cables are a bit rare." CreationDate="2010-10-04T19:15:53.440" UserId="1240" />
  <row Id="5291" PostId="4842" Score="1" Text="Hmm, I may have solved my problem. Adding an 82 ohm termination resistor (close enough to 75 ohms) has significantly reduced the change from bright to dark." CreationDate="2010-10-04T19:18:45.153" UserId="1225" />
  <row Id="5292" PostId="4839" Text="See http://electronics.stackexchange.com/questions/1530/ and http://electronics.stackexchange.com/questions/4678. " CreationDate="2010-10-04T19:21:02.780" UserId="857" />
  <row Id="5294" PostId="4848" Text="That only applies if you have shorted the wiper to the A or B terminal. Unless there is a significant load on the wiper (which would change the voltage) the power rating is the same throughout the whole range." CreationDate="2010-10-04T19:27:28.933" UserId="1225" />
  <row Id="5296" PostId="4763" Text="Do you use the Microchip library to implement CANopen?" CreationDate="2010-10-04T19:43:31.750" UserId="588" />
  <row Id="5297" PostId="4848" Text="I don't think so. Power limits are constrained by localized heating which is driven by current density." CreationDate="2010-10-04T20:32:58.270" UserId="330" />
  <row Id="5298" PostId="4819" Text="If you order from digikey, and it's in stock, you'll get it right away. Downside: you pay shipping. I ordered from TI, and it took like 2 months. Upside: free shipping." CreationDate="2010-10-04T20:41:54.807" UserId="131" />
  <row Id="5299" PostId="4763" Score="1" Text="In the process of implementing it, it is a slow process because it requires many different people to commit for me to make a system change. I will update you when it is implemented if that will help." CreationDate="2010-10-04T20:48:09.477" UserId="230" />
  <row Id="5301" PostId="4852" Text="Be careful when modifying car lighting, if that doesn't go without saying." CreationDate="2010-10-04T21:16:02.503" UserId="1225" />
  <row Id="5303" PostId="4852" Text="Thanks,  I am safe because i wired the entire car.  its a 1950 studebaker streetrod.  If my blinkers dont operate at the correct speed i will install a solid state flasher and be set." CreationDate="2010-10-04T21:28:04.127" UserId="1400" />
  <row Id="5304" PostId="1692" Score="1" Text="got to love someone that never accepts answers." CreationDate="2010-10-04T21:28:30.350" UserId="230" />
  <row Id="5307" PostId="4847" Score="1" Text="Is it a button (push switch) or a rotary switch? In either case, it looks like it may be a proprietary part." CreationDate="2010-10-04T22:24:50.003" UserId="1229" />
  <row Id="5308" PostId="4746" Text="When you say it prefixes 0s before sending the file what do you mean? How do you know? Are you copying a working binary (that you can get working on a windows/mac) or are you copying a binary created on your Ubuntu machine? What steps do you go through to copy the binary across? What settings do you have in fstab for the usb-device? Are you doing it as root, or as a non-privileged user? Do you click and drag, or are you copying at the command line? If there is a problem with Ubuntu, executables and vfat devices why is it not more commonly known? You think there's a published standard for vfat?" CreationDate="2010-10-04T22:25:45.050" UserId="103" />
  <row Id="5309" PostId="4847" Text="@Dennis - You have a good point.  The 3 pads could indicate a rotary switch." CreationDate="2010-10-04T22:45:42.410" UserId="374" />
  <row Id="5310" PostId="4853" Score="2" Text="Massively useful, thanks." CreationDate="2010-10-04T23:00:58.187" UserId="566" />
  <row Id="5311" PostId="4793" Text="But it's oh so full of stuff &lt;3" CreationDate="2010-10-04T23:07:29.627" UserId="883" />
  <row Id="5312" PostId="4785" Text="Figuring out parasitic components will explain much of the effects." CreationDate="2010-10-04T23:11:08.570" UserId="883" />
  <row Id="5313" PostId="4847" Score="1" Text="I couldn't figure out any possible way to identify that button, since it looked like just a white piece of plastic. Then I noticed the footprint at the left.  Freehanded circles (http://meta.stackoverflow.com/questions/19478/19775#19775) would be nice." CreationDate="2010-10-04T23:25:35.947" UserId="857" />
  <row Id="5314" PostId="4851" Text="Joby - Shouldn't your 'edit' really be a second answer?  " CreationDate="2010-10-04T23:27:19.050" UserId="857" />
  <row Id="5315" PostId="4851" Text="Potato - potato. It was Amos' response that led to the understanding..." CreationDate="2010-10-04T23:36:09.810" UserId="566" />
  <row Id="5316" PostId="4793" Text="I think it is amazing, just warning." CreationDate="2010-10-05T00:50:52.170" UserId="230" />
  <row Id="5317" PostId="4823" Text="why not just use a FET for the transistor?  ditch all the biasing effort, not to mention reducing loading and current draw.  You can adjust for the needed 'on' voltage for the FET with the level and duty cycle of your input.  If you find the forward voltage drop for the averaging diode is too high look at using a schottky, it'll have a very low forward drop and i doubt reverse leakage will be an issue in this application." CreationDate="2010-10-05T00:53:45.133" UserId="1438" />
  <row Id="5320" PostId="4742" Text="The problem you will run into is that there will be input signal levels that will put the 3904 into linear operation. To control a relay you want the transistor to drop either all the supply voltage or (very nearly) none of it. Intermediate states will just waste power cooking your transistor and won't necessarily pull the relay in." CreationDate="2010-10-05T01:43:59.943" UserId="740" />
  <row Id="5321" PostId="4856" Text="Thanks  What about this transister? what should i do about the input voltage? split it with resistors?  " CreationDate="2010-10-05T02:03:45.937" UserId="1400" />
  <row Id="5322" PostId="4856" Score="1" Text="http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/KSC2752OSTU/?qs=ljbEvF4DwOOk8L3Xyre%252bEQ%3d%3d" CreationDate="2010-10-05T02:04:12.880" UserId="1400" />
  <row Id="5323" PostId="4856" Text="@Ed Owens - depends a bit on the transistor, but for example, if you assume Vbe-sat of 0.8V at the base, and want to get 1mA into the base from a 12V signal, your base resistor would be (12 - 0.8)/0.001 = 11.2K ohms" CreationDate="2010-10-05T02:09:05.567" UserId="740" />
  <row Id="5324" PostId="4861" Text="This is by far my favorite of the two." CreationDate="2010-10-05T02:26:44.253" UserId="230" />
  <row Id="5325" PostId="4856" Text="Looking at the data sheet on that KSC2752, taking Vbe-sat as 2.0V at Ib of 60mA, your base resistor would be (12-2)/0.06 = 167 ohms, and would dissipate just over 600mW, so you'd need a 1W part. Since your 170V supply would only be sourcing about 80mW per NE-2, burning 600mW in what amounts to a bias resistor seems wasteful.  Since the '2752 can dissipate a whole watt, and the 170V supply with 220K can't even source more than about 130mW, it might be better to operate the transistor NOT saturated, and choose a base resistor that lets the collector ride at 60 or 70V when the lamp is lit." CreationDate="2010-10-05T02:37:13.467" UserId="740" />
  <row Id="5326" PostId="4809" Text="@Kortuk - what I meant by 'antenna' is that when you have a floating input pin, especially one that's a high impedance input like an op-amp, it tends to pick up noise from adjacent circuitry, acting a bit like an antenna. If you load that pin with a resistor to an AC ground (the +5 rail is an AC ground), it attenuates that stuff." CreationDate="2010-10-05T02:44:05.200" UserId="740" />
  <row Id="5329" PostId="4842" Text="Interesting. Please let us know if this actually did it for you, I am very interested in your findings." CreationDate="2010-10-05T03:06:44.270" UserId="319" />
  <row Id="5330" PostId="4746" Text="We have send the same binary from a windows, a mac os, and a several linux machines. We have copied from command line, copy and past in file browser as well as drag and drop. The reason why it is not more commonly known, is because most usb devices tolerate these 0s (I guess just drop them), however, the vfat implemented on the lpc1343 does not (which is according to standard). When using mcopy from mtools in unix on the block device, instead of mounting the vfat, the file is transferred correctly." CreationDate="2010-10-05T03:21:34.873" UserId="936" />
  <row Id="5331" PostId="4862" Text="Kellenjb, I'd seen some references to the Sparkfun offerings before, but the link has a nice video showing some real-world range tests with the devices they sell. Thanks for that!" CreationDate="2010-10-05T04:11:16.580" UserId="1317" />
  <row Id="5332" PostId="4613" Text="Thanks, &quot;Pingswept&quot;. Also, what is different about our two answers? Is this just a case of the topmost effect?" CreationDate="2010-10-05T06:15:12.887" UserId="690" />
  <row Id="5333" PostId="4863" Score="2" Text="Your problem is that you are field-wiring." CreationDate="2010-10-05T06:48:01.513" UserId="1374" />
  <row Id="5334" PostId="4860" Text="the &quot;Strange Series Combination&quot; is somewhat understandable in this case. What they are doing is switching the duty cycle of the 555, and switching the 555 in or out of control. This lets the computer set several different speeds without having go constantly generate a PWM signal. It's a really crude way to do it, but it would work. Until the motor's inductive kickback blows up the 2N2222, anyways." CreationDate="2010-10-05T06:51:36.543" UserId="1374" />
  <row Id="5335" PostId="4842" Text="Well, it has made the change from bright to dark less than 200mV and this can be triggered on with the scope so I'm hopeful that the signal can be compared using a PIC comparator." CreationDate="2010-10-05T06:52:27.383" UserId="1225" />
  <row Id="5337" PostId="4860" Text="RB, which i assume this is what you meant by R8 is connected to pins 6 and 7 on IC3, these pins are definitely not electrically shorted, thats a standard astable configuration for a NE555.  Really the only error here is the lack of a flyback diode.  The rest of the circuit is pretty standard for interfacing to something as archaic as a parallel port." CreationDate="2010-10-05T07:57:04.050" UserId="1438" />
  <row Id="5338" PostId="4861" Score="1" Text="It may be a wacky way to do it.  But on the other hand your not getting 0.1mV offset measuring capability with your simple low pass filter either.  Also the size of the cap that would be required to get anywhere near that accuracy with a simple low pass filter would very much limit how quickly it responds to changes in offset.  Actually if what you wanted was high resolution and very fast response, this design isn't that crazy.  I can't immediately of another way to do it non-digitally." CreationDate="2010-10-05T08:19:53.673" UserId="1438" />
  <row Id="5339" PostId="4854" Text="it's the right description !" CreationDate="2010-10-05T09:00:06.077" UserId="1454" />
  <row Id="5340" PostId="4867" Score="1" Text="ok ok.. :) I'll update my question to reflect simulation instead of emulation" CreationDate="2010-10-05T10:57:59.477" UserId="1258" />
  <row Id="5341" PostId="4860" Text="@Mark: this is evidently a typo. In the printed magazine and the full PDF, pins 6 and 7 are shorted. In the Figure 1, they are not." CreationDate="2010-10-05T11:32:25.187" UserId="330" />
  <row Id="5342" PostId="4861" Score="2" Text="? This design offers no improvements over a simple RC low-pass filter. If the components are perfect, it is equivalent to a simple RC low-pass filter, and it offers several opportunities for imperfect components to ruin the circuit's performance." CreationDate="2010-10-05T11:34:53.153" UserId="330" />
  <row Id="5343" PostId="4861" Text="If I had to low-pass-filter out 50Hz AC, in an analog circuit, depending on performance requirements, I would either use a cascaded 2-pole RC filter, or a 3-pole filter consisting of a Sallen-Key LPF followed by a simple RC." CreationDate="2010-10-05T11:37:07.873" UserId="330" />
  <row Id="5344" PostId="4865" Text="All the components and values sound like they're ok. Just a brief point, did you connect all 5 Vcc connections to the positive of the battery? It's also worth checking to see if you put the electrolytic capacitor the right way round" CreationDate="2010-10-05T11:58:07.760" UserId="399" />
  <row Id="5346" PostId="4865" Text="i connected wires as it is shown in the circuit scheme." CreationDate="2010-10-05T12:18:21.813" UserId="1461" />
  <row Id="5348" PostId="4865" Score="2" Text="Try asking at http://forums.adafruit.com/" CreationDate="2010-10-05T12:32:16.330" UserId="566" />
  <row Id="5349" PostId="4860" Text="I have a cheap blood pressure monitor whose motor control transistors died after two years. There were no diodes across the motor terminals, so I can only presume this was the cause." CreationDate="2010-10-05T12:41:11.697" UserId="1225" />
  <row Id="5350" PostId="4865" Text="That design doesn't seem too robust on the audio amp section.  You might want to try hooking this up to a general purpose amplified speaker." CreationDate="2010-10-05T12:51:37.023" UserId="374" />
  <row Id="5351" PostId="4865" Text="After looking at the Drawdio website, they all seem to be quite loud even the one's using the circuit design you've linked to, you might need to post a picture of your circuit so we can check it visually for anything that's obvious. I also agree with Joby too, the Adafruit forum would be a good port of call." CreationDate="2010-10-05T13:16:37.153" UserId="399" />
  <row Id="5352" PostId="4874" Text="It would also be useful to know if it will be a passive no battery or an active type with a battery." CreationDate="2010-10-05T13:43:11.703" UserId="540" />
  <row Id="5353" PostId="4809" Text="I understood what you meant. When you add a load you are effectively adding termination. The reason I said something is that 1M is such a high load it has almost no affect on all but the weakest signals. This means that the 1M really does not affect an antenna very much, but that the pin is not much of an antenna." CreationDate="2010-10-05T14:04:13.957" UserId="230" />
  <row Id="5354" PostId="4809" Text="I still think you wrote a spot on answer, I just wanted to add about the antenna." CreationDate="2010-10-05T14:05:08.330" UserId="230" />
  <row Id="5355" PostId="4828" Score="2" Text="@AndrejaKo if you mean &quot;solid cat5e cables are not rare&quot; then good for you. Obviously I take it for granted that I can go down to the hardware store and buy cut lengths or entire boxes of either type of wire..." CreationDate="2010-10-05T14:06:43.970" UserId="1363" />
  <row Id="5357" PostId="4874" Text="I believe UHF is best and it can be done passive." CreationDate="2010-10-05T14:47:38.230" UserId="319" />
  <row Id="5358" PostId="2844" Text="I know I have the highest, but if you do not like mine, at least accepts someone's." CreationDate="2010-10-05T14:52:33.780" UserId="230" />
  <row Id="5359" PostId="4823" Text="He brought a schematic using a standard diode and a BJT. I did not see any significant gain to switching things like diodes. Normally when someone shows me a schematic with a BJT they are more comfortable with a BJT. You have to bias a FET properly also, but you are correct that it takes almost no gate current, removing a large part of the load problem. This does mean you then need a discharge path for your cap, but then you do have control over it." CreationDate="2010-10-05T15:04:17.377" UserId="230" />
  <row Id="5360" PostId="4823" Text="I Think there are a million ways to do this, I just tried to make minor edits to the original with the direction of functionality. " CreationDate="2010-10-05T15:04:52.120" UserId="230" />
  <row Id="5361" PostId="4866" Score="2" Text="See [What are the freeware SPICE simulators available?](http://electronics.stackexchange.com/questions/1206), [Simple Circuit Simulation tutorial](http://electronics.stackexchange.com/questions/1594), and the whole [ [simulation](http://electronics.stackexchange.com/questions/tagged/simulation) ] tag." CreationDate="2010-10-05T16:52:10.337" UserId="857" />
  <row Id="5362" PostId="4869" Text="Oh god, Handyboards, I hate those overpriced things :(" CreationDate="2010-10-05T17:05:48.357" UserId="536" />
  <row Id="5363" PostId="4871" Score="4" Text="That's almost in the same vein as the good ol' [LM0901A1411090451C](http://techpreservation.dyndns.org/beitman/abpr/LM0901A1411090451C%20Nat%20Semi%20%2778-8927.PDF) opamp...." CreationDate="2010-10-05T17:21:16.783" UserId="857" />
  <row Id="5364" PostId="4871" Text="@reemrevnivek Very good!" CreationDate="2010-10-05T17:41:33.887" UserId="938" />
  <row Id="5365" PostId="4879" Text="I actually have access to that book already (I work at an university) I guess I will keep mucking with the chip to see what I can figure out..." CreationDate="2010-10-05T17:53:10.250" UserId="1337" />
  <row Id="5366" PostId="4861" Score="1" Text="the response of the circuit he gave has little to nothing in common with the response of a simple low pass filter with the exception that 50hz is filtered.  Otherwise there is little to know commonality.  Try feeding a 50hz sine wave with DC offset that &quot;wobbles&quot; up and down at 100hz.  One circuit will be able to detect it, one will not." CreationDate="2010-10-05T18:37:37.520" UserId="1438" />
  <row Id="5368" PostId="4881" Text="Perhaps edit the question to include why it must be high-side sensing as opposed to using a shunt in the common return?" CreationDate="2010-10-05T19:06:25.187" UserId="974" />
  <row Id="5369" PostId="4882" Text="thanks for that ye I thought that a Infrared receiver was the way to go but I thought I would find out if my wii remote would work. what am basicly trying to do it create a IR remote for a robot i have created. " CreationDate="2010-10-05T19:26:27.520" UserId="1473" />
  <row Id="5370" PostId="4882" Score="1" Text="How is the robot connected to the computer? I'm confused about where you want the remote control... if the robot is controlled by the computer directly, you could use the Wiimote as the remote control, and a bluetooth receiver in the computer." CreationDate="2010-10-05T19:40:40.233" UserId="1363" />
  <row Id="5371" PostId="4871" Score="2" Text="OMG that OpAmp data sheet is a must see!" CreationDate="2010-10-05T19:43:41.157" UserId="930" />
  <row Id="5372" PostId="4881" Text="@Andrew, the idea is to protect against accidental shorts where the return path is different then return path to the supply (for example to shielding, through me to earth etc.) " CreationDate="2010-10-05T19:49:50.530" UserId="1471" />
  <row Id="5373" PostId="4863" Score="1" Text="In many industrial situations this is not, as a general case, avoidable." CreationDate="2010-10-05T21:08:07.627" UserId="259" />
  <row Id="5374" PostId="4746" Score="1" Text="Do you mean that the binary is padded with an unspecified number of 0 s at the start? You appear to have a working solution to this problem, why not post a more detailed answer below to allow others to share this knowledge more easily. I see from following the link in your profile that you've got over 10k of rep points from various SE sites so you know the drill by now." CreationDate="2010-10-05T21:57:44.510" UserId="103" />
  <row Id="5375" PostId="4881" Text="What power supply voltage / current range?" CreationDate="2010-10-05T22:37:23.420" UserId="330" />
  <row Id="5377" PostId="4866" Score="5" Text="It may help you to know that SPICE and it's ilk are 'analog' simulators - they can simulate things like resistors, capacitors, inductors and get their interactions more or less correct. Essentially, they simulate the voltages and currents on a real board. Things like klogic (digital logic simulators) are NOT simulating the voltages and currents. Instead, they just simulate hi vs. low vs unknown, vs conflict signals. Analog sims let you see what real components will do, but they tend to be on the slow side. Digital simulators can only simulate the logic, but that makes them faster (in general)." CreationDate="2010-10-06T02:27:32.043" UserId="259" />
  <row Id="5378" PostId="4866" Score="1" Text="The question is not so much &quot;can you simulate it&quot; as it is &quot;Can you find simulation models for all the components in your circuit&quot;. After that, it's just a matter of letting it process for a while." CreationDate="2010-10-06T03:03:17.993" UserId="1374" />
  <row Id="5379" PostId="4892" Score="1" Text="i almost said 'ignore the taps' but then freaked out that maybe the field sequence inside the motor would be wrong, but i think you are actually right. so +1 for that!" CreationDate="2010-10-06T03:38:36.823" UserId="740" />
  <row Id="5380" PostId="4886" Text="I was thinking the same thing. An Instrumentation Amplifier would be a good type of Differential Amplifier to look at. The designer needs to make certain that the amplifier has enough common mode rejection (CMMR), and that the device supports the common mode voltage of your hide side. e.g. If you are on a 24V high side, your maximum common mode voltage of the amplifier should be at least 24V, and the rejection capability should be such that very little of the 24V creeps through to offset the output." CreationDate="2010-10-06T04:16:42.143" UserId="1376" />
  <row Id="5381" PostId="4881" Score="1" Text="@Jason, 0-30V and 0-1A " CreationDate="2010-10-06T05:11:35.640" UserId="1471" />
  <row Id="5382" PostId="4886" Text="hard limiting a linear supply is usually not a good idea, especially for a hobby project.  The result will be the current limit being held at the max for the linear regulator which if proper thermal conditions are not met (usually the norm for hobby projects) the linear regulator will cook at max power dissipation." CreationDate="2010-10-06T05:23:08.503" UserId="1438" />
  <row Id="5383" PostId="4877" Text="Thanks a lot Duane :)" CreationDate="2010-10-06T05:44:30.300" UserId="1462" />
  <row Id="5384" PostId="4878" Text="Thanks a lot for suggesting the Teensy board, Joby :) I would have missed it otherwise :)" CreationDate="2010-10-06T05:45:12.497" UserId="1462" />
  <row Id="5385" PostId="2171" Text="I have done this, and it works nicely. I had a series resistor between the power rail and all of my valves. At startup I was able to turn each one on individually to measure its resistance and make sure it was within tollerance. Of course, if the space is available and you have the measurement channels, this can be done for every valve. " CreationDate="2010-10-06T06:48:14.767" UserId="1376" />
  <row Id="5386" PostId="4895" Text="since I do not have enough reputation points to create new tag, could somebody pls mark the question with &quot;PLL&quot; tag. thx." CreationDate="2010-10-06T08:31:21.523" UserId="1471" />
  <row Id="5387" PostId="4892" Score="3" Text="This will not work on motors where the center taps are connected together (They do exist)." CreationDate="2010-10-06T09:37:41.957" UserId="1374" />
  <row Id="5389" PostId="4899" Text="sounds very cool... could you provide a link to more info please?" CreationDate="2010-10-06T11:10:32.063" UserId="1258" />
  <row Id="5390" PostId="4857" Text="Beware that RFID sniffer in someone's pocket passing by at 3 feet could also read ID from your card and use it to identify as your self in front of your own house. Smart cards are much safer option. On the other side, a real burglar will just try to override electrical lock opening command voltage, so additional in house alarm is always recommended." CreationDate="2010-10-06T11:32:04.817" UserId="1129" />
  <row Id="5391" PostId="4902" Text="Thanks for the suggestion. But, my application needs to do some other stuff in the background, and can't be sampling the ADC continously." CreationDate="2010-10-06T12:31:36.830" UserId="1225" />
  <row Id="5392" PostId="4889" Text="Right, I knew I needed some kind of charging control circuit - thanks for the link." CreationDate="2010-10-06T12:50:09.377" UserId="1479" />
  <row Id="5394" PostId="4900" Text="This technique is actually used for races all over the place including the Olympics and the Boston Marathon. (Do a google search on RFID race timing) I don't know how they pull it off (that's what I am trying to figure out) maybe they use a directional antenna that only communicates straight up. Also, at running speed, 2 meters takes about .5 seconds so if that was the worst case, I could accept that for a 5k race!" CreationDate="2010-10-06T14:02:11.133" UserId="1235" />
  <row Id="5395" PostId="4874" Text="@REX: I am thinking passive  " CreationDate="2010-10-06T14:06:52.273" UserId="1235" />
  <row Id="5396" PostId="4870" Score="1" Text="+1 for Falstad sim, excellent simulator. Can also use it almost anywhere." CreationDate="2010-10-06T14:13:46.863" UserId="1225" />
  <row Id="5397" PostId="4900" Text="RFID is also used in triathlons using water proof RFID tags. It allows them to very easily track your time in and out of each stage of the race." CreationDate="2010-10-06T14:49:12.380" UserId="319" />
  <row Id="5398" PostId="4746" Text="I believe it is padded with 1024 0s. At least I have been told so. I will write an answer here with the solution when I have time." CreationDate="2010-10-06T16:37:22.097" UserId="936" />
  <row Id="5399" PostId="4857" Text="@avra: Is there such a thing as an RFID smart-card?" CreationDate="2010-10-06T17:48:04.683" UserId="1317" />
  <row Id="5400" PostId="4912" Text="But if they both grab the line at the same time, and wait for the same amount of time before transmitting, isn't it the same as not waiting at all?" CreationDate="2010-10-06T18:19:47.433" UserId="142" />
  <row Id="5401" PostId="4853" Text="She must be reading... ;)" CreationDate="2010-10-06T18:38:06.133" UserId="566" />
  <row Id="5402" PostId="616" Text="This should be community wiki, shouldn't it?" CreationDate="2010-10-06T18:50:06.973" UserId="1415" />
  <row Id="5403" PostId="4920" Text="He's using a dsPIC, not a PIC18." CreationDate="2010-10-06T19:35:24.830" UserId="305" />
  <row Id="5405" PostId="4920" Score="2" Text="he's using both, look at the schematics in the documentation he linked.  The PIC18 is running the buttons/interface and talking to the dsPIC over I2C.  The dsPIC just does the video processing." CreationDate="2010-10-06T20:10:44.760" UserId="1438" />
  <row Id="5406" PostId="4912" Text="The idea would be to wait for a few ms + a random few ms. Presumably they would be running different software and various latencies/interrupts/etc would contribute to the randomness of the delay." CreationDate="2010-10-06T20:27:47.000" UserId="974" />
  <row Id="5407" PostId="4900" Text="Then google also for &quot;miss rate&quot; and &quot;tag collision&quot; when googling for &quot;RFID race&quot;. I can just laugh at 20 times per second reading scan rate mentioned at respectable company's website: http://www.rfidtiming.com/?page=faq. There are so many problems with the technology that a lot of people think that world record will never be certified with such a system." CreationDate="2010-10-06T21:01:06.200" UserId="1129" />
  <row Id="5408" PostId="4899" Text="http://www.ni.com/academic/multisimse.htm" CreationDate="2010-10-06T21:13:01.150" UserId="1480" />
  <row Id="5409" PostId="4580" Text="That concern applies to my LED idea, though, too.  Worse, actually, since it needs constant current instead of constant voltage.  With high-impedance transmission gates you could multiplex analog voltages to each JFET gate, but it seems complex." CreationDate="2010-10-06T21:37:20.733" UserId="142" />
  <row Id="5410" PostId="4580" Text="The problem with storing the charge on the capacitor is that it will drop quickly due to the resistors. (R2 shunts to ground.) However, it may be possible to use a diode to isolate the gate capacitance to store a charge..." CreationDate="2010-10-06T21:40:17.420" UserId="1225" />
  <row Id="5411" PostId="4924" Score="2" Text="Third option is to get an actual current probe, but those can be pricey." CreationDate="2010-10-06T21:40:49.923" UserId="1225" />
  <row Id="5413" PostId="4897" Text="the usual way to drive a 5-wire motor is to put the common at +V and then use open collector drivers to pull the coil ends low one at a time in sequence, isn't it? So if you have a bipolar driver that is a pair of H-bridges, it has four low-side drive transistors; where's the problem?" CreationDate="2010-10-06T21:59:51.670" UserId="740" />
  <row Id="5414" PostId="4924" Score="3" Text="good scopes usually have the option of isolating or 'floating' the inputs, which would be exactly what you want in this situation." CreationDate="2010-10-06T22:02:18.780" UserId="740" />
  <row Id="5415" PostId="4923" Score="1" Text="what kind of scope are you using? a model number (or even better, a link) would be informative." CreationDate="2010-10-06T22:03:18.110" UserId="740" />
  <row Id="5417" PostId="4930" Score="2" Text="As cool as the Launchpad may be, it isn't for the Stellaris chip series the OP is looking for." CreationDate="2010-10-06T22:18:16.773" UserId="374" />
  <row Id="5419" PostId="4923" Score="4" Text="Why not just use a DMM?" CreationDate="2010-10-06T22:53:32.337" UserId="1301" />
  <row Id="5421" PostId="4924" Score="2" Text="You have nice scopes than I have used. It normally causes very large noise isolation problems by leaving that connection floating, and it needs to be very low inductance." CreationDate="2010-10-07T00:06:04.390" UserId="230" />
  <row Id="5423" PostId="4934" Text="@sernaj, I cannot use IAR to build or load the .out file. I will need to use another type of loader. We have an ST-Link, a J-Link and an R-Link (Raisonance). The J-Link is much more supported." CreationDate="2010-10-07T00:23:24.537" UserId="1411" />
  <row Id="5424" PostId="4929" Text="Do you remember what the price tag was?" CreationDate="2010-10-07T02:53:48.343" UserId="1182" />
  <row Id="5425" PostId="4923" Text="I would guess that the current varies with respect to time." CreationDate="2010-10-07T04:31:34.553" UserId="230" />
  <row Id="5426" PostId="4929" Score="2" Text="£46.63 http://uk.farnell.com/luminary-micro/ekt-lm3s6965/kit-eval-lm3s6965-enet-code-red/dp/1712253?Ntt=EKT-LM3S6965" CreationDate="2010-10-07T08:00:27.467" UserId="566" />
  <row Id="5427" PostId="4857" Score="1" Text="Google for &quot;rfid&quot; &quot;cryptographic&quot; &quot;protocol&quot; and you will see. Just remember that RFID sniffer can act as any RFID reader." CreationDate="2010-10-07T08:03:50.660" UserId="1129" />
  <row Id="5428" PostId="4912" Score="2" Text="In my experience, I2C works well in a multi-master environment. It isn't as fast as SPI, however, so if your performance goals require better than 400 kb/s burst transfers you should pursue SPI." CreationDate="2010-10-07T08:42:23.950" UserId="1494" />
  <row Id="5429" PostId="4924" Score="3" Text="The not-so-nice scopes can also generally do this as well. Just break the ground lead of the power cable off (or use one of those three-prong to two-prong adapters). Note: doing so can be dangerous, because a failure in the scope will no longer short to ground, and trip a circuit-breaker. I've never had any problems, but don't leave it like that all the time." CreationDate="2010-10-07T10:40:30.293" UserId="1374" />
  <row Id="5430" PostId="4897" Text="Hmmm. I suppose if you're doing full-stepping, and the unused winding is off **and floating**, it might work. However, if you're doing microstepping, or the driver clamps the unused winding, all sorts of weird stuff would happen. Basically, you would always be driving 1 1/2 windings, and possibly not in the right direction." CreationDate="2010-10-07T10:55:36.020" UserId="1374" />
  <row Id="5431" PostId="4938" Score="1" Text="Alternatively, learn to draw your own parts! (http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=110)" CreationDate="2010-10-07T11:01:45.977" UserId="1374" />
  <row Id="5432" PostId="4900" Text="That is interesting. " CreationDate="2010-10-07T11:07:35.473" UserId="1235" />
  <row Id="5433" PostId="4897" Text="ok, now what if you're half-stepping a regular bipolar motor; assume each coil is driven identically (except in phase, of course), and think about the voltage at the exact center of the windings. At some moments you have one coil hi-Z and one driven, other moments both coils are driven. With one coil off (hi/floating/etc) the floating coil is effectively out of the circuit. No prob. With both coils driven, no matter which direction, the voltage at the centers of the coils should be the same, and it wouldn't matter if you wired them together. " CreationDate="2010-10-07T11:23:36.900" UserId="740" />
  <row Id="5434" PostId="4935" Text="@Joby Taffey, objdump gives me an unrecognized format error. Even nm cannot recognize it. I am using the arm-none-eabi-xxx bin tools from my Code Sourcery toolchain for these attempts. I'm not sure if that would matter though. My guess is that IAR is doing something proprietary." CreationDate="2010-10-07T11:46:41.707" UserId="1411" />
  <row Id="5435" PostId="4952" Score="1" Text="So is that the total time? " CreationDate="2010-10-07T12:00:03.377" UserId="1235" />
  <row Id="5436" PostId="4952" Score="2" Text="wouldn't that be the time to dissipate 63 percent of the voltage?" CreationDate="2010-10-07T12:01:00.710" UserId="1235" />
  <row Id="5437" PostId="4952" Score="2" Text="@Jordan; T - yes that is total time; the 63% is the value change in one RC constant. In this case you are discharging through current not resistance." CreationDate="2010-10-07T12:08:52.260" UserId="1471" />
  <row Id="5438" PostId="4638" Text="lol loads of fun, I did find that application note, however I was unsure where Fpb came from. Thanks for clarifying that for me. I still am having trouble sending anything from the pic chip. I am using HyperTerminal on a pc to see if anything is transmitted. The settings I am using are 9600 baud, 8 data bits, parity none, stops bits 1, flow control none. I am newb to pic chips, so any help you can give would be great.  " CreationDate="2010-10-07T12:16:41.293" UserId="1337" />
  <row Id="5439" PostId="4935" Text="@JeffV it might be this format http://supp.iar.com/FilesPublic/UPDINFO/005173/simple_code.htm" CreationDate="2010-10-07T12:27:13.440" UserId="566" />
  <row Id="5440" PostId="4638" Score="3" Text="@Richard, you are mixing up the SPI and UART.  SPI is Serial Peripheral Interface and is designed for talking to chips that have an SPI interface with CS(chip select), SCK(clock), MOSI(master out/slave in) and MISO(master in/slave out) pins.   HyperTerminal communicates via RS-232, which is implemented through the UART (Universal asynchronous Receiver/Transmitter) interface via level shifters on your PIC32 Starter Kit.  I think you need to look at Chapter 19 in the datasheet, which describes the UART interface." CreationDate="2010-10-07T12:31:10.347" UserId="1322" />
  <row Id="5441" PostId="4936" Text="It's just regular 'ol AA rechargeables. So they're not hard to replace, and in this case the convenience of having the pack charging (or charged) when the AC adapter is used outweighs any battery lifespan (at least for me)." CreationDate="2010-10-07T12:42:51.363" UserId="1479" />
  <row Id="5442" PostId="4937" Score="1" Text="please post a sample of your code" CreationDate="2010-10-07T12:51:49.307" UserId="1416" />
  <row Id="5443" PostId="4953" Score="3" Text="&quot;Common simple loads tend to have relatively constant impedance&quot; -- these days switching power converters are common, and they tend to draw constant *power*, not constant current (meaning the current goes up w/ increasing voltage)" CreationDate="2010-10-07T12:51:54.520" UserId="330" />
  <row Id="5444" PostId="4946" Text="If the 4 things I could grep for, I think that's the only one I didn't..." CreationDate="2010-10-07T12:58:14.280" UserId="1182" />
  <row Id="5445" PostId="4638" Text="@tcrosley I will have a look. Thanks for your help. I will post here once I give it a read. " CreationDate="2010-10-07T13:05:21.473" UserId="1337" />
  <row Id="5446" PostId="4924" Text="It's a Tektronix TDS 210. A getting few years on it now but it's quality." CreationDate="2010-10-07T13:14:33.297" UserId="1235" />
  <row Id="5447" PostId="4924" Text="@JustJeff: Where would I find the setting to change the input isolation?" CreationDate="2010-10-07T13:16:58.480" UserId="1235" />
  <row Id="5449" PostId="4941" Score="1" Text="Apple violates the spec for their own products, though.  The MacBook Air supplies 1.5 A to a SuperDrive, for instance, probably after some proprietary negotiation.  Also, USB 3.0 ports can supply 900 mA instead of 500." CreationDate="2010-10-07T13:49:29.983" UserId="142" />
  <row Id="5450" PostId="4947" Score="2" Text="When plugged into a computer, the power is negotiated over USB signals, not electrically.  When plugged into a charger, the amount of current a device is allowed to draw is determined electrically, either by applying specific voltages to the D+ and D- pins (Apple) or shorting them together (USB.org Battery Charging spec).  Otherwise a good device will only draw 100 mA.  But it's really just the honor system, and many devices will draw more without asking and just hope that the computer's port doesn't shut down." CreationDate="2010-10-07T13:57:47.790" UserId="142" />
  <row Id="5451" PostId="4631" Score="1" Text="@Richard, pins 93 and 95 on J2 of your Starter Kit are indeed the SPI1 interface, but you cannot connect them to RS-232 per my comment in my answer below.  Pins 88 and 90 of J2 are the RX and TX leads of the UART1 interface, BUT you cannot connect them directly to RS-232 either without using a level-shifter (which is absent from your board).  You need a circuit like this: http://www.sparkfun.com/commerce/product_info.php?products_id=133 in between." CreationDate="2010-10-07T14:34:22.653" UserId="1322" />
  <row Id="5452" PostId="4689" Score="2" Text="Currently in public beta, the Secret Labs team is planning to ship the [NetDuino Plus](http://netduino.com/netduinoplus/specs.htm) by the end of the year.  The two main additions are built-in ethernet and micro-sd support." CreationDate="2010-10-07T14:39:51.843" UserId="1355" />
  <row Id="5453" PostId="4954" Text="Might take some work, but yes, should work." CreationDate="2010-10-07T14:52:42.213" UserId="319" />
  <row Id="5454" PostId="4952" Text="He is asking about 5v down to 3v. Not asking for the time constant." CreationDate="2010-10-07T15:02:17.467" UserId="319" />
  <row Id="5455" PostId="4961" Text="If the device is in sleep mode, and power slowly drops, will the device &quot;flicker&quot; on and off? If if does will that cause a problem? If it momentarily turns off, then turns back on, will it start back up in sleep mode?  " CreationDate="2010-10-07T15:10:55.243" UserId="1235" />
  <row Id="5457" PostId="4631" Text="@tcrosely, by level-shifter, do you mean to switch the voltages from 3.3 to 5 volts? Because if so, I have the device connected to an external power supply which I thought would do the job." CreationDate="2010-10-07T15:38:06.633" UserId="1337" />
  <row Id="5458" PostId="4934" Text="You can use the GNU utility [objcopy][1] to convert from elf to another format (e.g. binary or Intel-hex&quot;).&#xA;&#xA;&#xA;  [1]: http://www.gnu.org/software/binutils/" CreationDate="2010-10-07T15:49:52.150" UserId="529" />
  <row Id="5459" PostId="4964" Text="+1 for the answer. I have this kit http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,400,792&amp;Prod=S3EBOARD" CreationDate="2010-10-07T16:04:27.430" UserId="938" />
  <row Id="5460" PostId="4961" Text="The device will not brown out (i.e. suffer a loss of memory and state) if the voltage is above about 2V (the minimum supply voltage.) In practice you could probably go as low as 1.8V before the chip resets completely. If power is lost in sleep mode it could reset, but it depends on what type of brown out (e.g. voltage dipping from 3V to 2.5V would be okay but from 2V to 0V or 2V to 1.5V probably not.)" CreationDate="2010-10-07T16:08:59.483" UserId="1225" />
  <row Id="5462" PostId="4962" Score="2" Text="[This question](http://electronics.stackexchange.com/questions/3472/how-do-i-learn-hdl) has a number of boards in the answers.  " CreationDate="2010-10-07T17:09:43.100" UserId="857" />
  <row Id="5463" PostId="4631" Score="1" Text="@Richard, the issue is that your PC outputs RS-232 levels, and your PIC is using logic levels.  RS-232 uses +- 3v to +- 12v, with a negative voltage representing the idle (marking), and a positive voltage representing the active (spacing) state.  Your PIC's UART uses logic 1 (typically 3.3v) for idle (marking) and logic 0 (0v) for active (spacing).  You need a circuit in between like the one linked to above to invert the logic and shift the levels.  See &quot;Voltage Levels&quot; in this article: http://en.wikipedia.org/wiki/RS-232" CreationDate="2010-10-07T17:32:47.790" UserId="1322" />
  <row Id="5464" PostId="4631" Text="@tcrosely, Once I figure out how these UART registers work I will Put it on a scope to see how the levels act. I will be honest I am a pic32 newbie.. but looking at the pin diagrams it does say that the U1RTS and U1TCTS pins are 5 volt tolerant... I know that doesn't say anything about how their level's are triggered. If not I will do as you suggested and change the level's via a few transistors " CreationDate="2010-10-07T17:41:01.570" UserId="1337" />
  <row Id="5465" PostId="4954" Text="@Kellenjb: Doesn't it have sufficient gates to build the algorithm? what is the real issue to get it to work on a Spartan?" CreationDate="2010-10-07T18:21:27.367" UserId="444" />
  <row Id="5466" PostId="4967" Text="So if the voltage is &gt;= 3.3 V, it should pass through, but less than 3.3 V, it should be disconnected?" CreationDate="2010-10-07T18:42:51.387" UserId="142" />
  <row Id="5467" PostId="4631" Score="1" Text="@Richard, here is the schematic of the SparkFun level shifter: http://www.sparkfun.com/datasheets/Prototyping/RS232-Shifter-v2.pdf -- since the PIC can't generate a negative voltage for the marking state, the circuit stores negative voltage from the PC's TX line and uses that as the idle voltage for sending back to the PC.  Also, TX/RX on this circuit are relative to the PC, so RX connects to the PIC's TX and vice versa." CreationDate="2010-10-07T18:52:37.027" UserId="1322" />
  <row Id="5468" PostId="4967" Text="Yes that is what I am looking for." CreationDate="2010-10-07T19:04:49.367" UserId="1235" />
  <row Id="5469" PostId="4969" Text="That looks good but I really need it to be all passive. I does not need to be very precise. For example, if the voltage cut off was anywhere from 2.6 to 3.2 that would be fine." CreationDate="2010-10-07T19:07:23.687" UserId="1235" />
  <row Id="5470" PostId="4969" Score="2" Text="It's very unlikely you'll find something passive that does what you want." CreationDate="2010-10-07T19:22:16.870" UserId="330" />
  <row Id="5471" PostId="4969" Text="Yeah, I can't think of any way to do it without at least one transistor." CreationDate="2010-10-07T19:30:06.127" UserId="142" />
  <row Id="5472" PostId="4967" Score="5" Text="I'd call that an &quot;undervoltage lockout&quot;.  &quot;Regulate&quot; isn't really the right word." CreationDate="2010-10-07T19:31:27.743" UserId="142" />
  <row Id="5473" PostId="4969" Text="And if you're worried about current draw in shutdown mode, this op-amp draws 5 µA, and the resistors could be increased to draw even less." CreationDate="2010-10-07T19:36:01.557" UserId="142" />
  <row Id="5474" PostId="4970" Score="6" Text="This is a very very broad question. You almost need to ask multiple questions. I could give a full question for the LED power question." CreationDate="2010-10-07T19:36:03.433" UserId="230" />
  <row Id="5475" PostId="3586" Text="Two major HDLs. There are many less popular ones, such as CUPL, MyHDL and Lava. The Digital Design course at my university mentioned VHDL but used CUPL in a lab. More on wikipedia: http://en.wikipedia.org/wiki/Programmable_Array_Logic#Programming_languages" CreationDate="2010-10-07T19:45:08.680" UserId="1181" />
  <row Id="5476" PostId="4969" Text="I think the main problem with this solution is figuring out how to get the vref. " CreationDate="2010-10-07T19:45:24.153" UserId="319" />
  <row Id="5477" PostId="4970" Text="Cool, I'll split it up after office hours.  Maybe this one is just broad dos and don'ts.  I think such answers would be helpful to people just trying to get more out of a battery, but I guess giving any kind of authoritative or educational answer requires a narrower question." CreationDate="2010-10-07T19:45:43.193" UserId="1271" />
  <row Id="5478" PostId="4969" Text="@Kellenjb: Yes this is true, that's why I was thinking a zener. " CreationDate="2010-10-07T19:51:38.980" UserId="1235" />
  <row Id="5479" PostId="4970" Text="Yeah, i realized I was going to have to section my answer by your question and would take me an hour." CreationDate="2010-10-07T19:59:37.500" UserId="230" />
  <row Id="5480" PostId="4969" Score="1" Text="the chip Endolith mentions has an internal vref generator." CreationDate="2010-10-07T20:00:16.693" UserId="1225" />
  <row Id="5481" PostId="4952" Text="@Kellenjb, that is why I gave the equations on how the capacitor is discharged using constant current, the RC mention is to explain why he may think that T is 63% " CreationDate="2010-10-07T20:22:33.760" UserId="1471" />
  <row Id="5482" PostId="4953" Score="3" Text="with constant power, wouldn't current go up with *decreasing* voltage?" CreationDate="2010-10-07T22:00:44.790" UserId="740" />
  <row Id="5483" PostId="4969" Text="check out the '1381 voltage trigger' - it's a tiny (TO-92) 3 terminal package that does everything to the left of the PMOS depicted in the 1st schematic" CreationDate="2010-10-07T22:10:24.243" UserId="740" />
  <row Id="5485" PostId="4924" Score="1" Text="@Jordan S - I looked in the manual for the TDS-200 series, I don't think it has built-in capability to float inputs." CreationDate="2010-10-07T22:31:07.870" UserId="740" />
  <row Id="5486" PostId="4969" Text="Hmmm...  Looks like it's discontinued, and the datasheet seems to show a window comparator instead, so it will output if the voltage is within a specific range, not just below a threshold. http://industrial.panasonic.com/www-cgi/jvcr13pz.cgi?E+SC+4+BFA7001+MN1380+8+WW" CreationDate="2010-10-07T23:12:24.590" UserId="142" />
  <row Id="5487" PostId="4978" Text="Cool.  I've not used a scope before, but I suspect our local lab will be happy to show me this (right now I'm actually using the multi-meter in series to measure current; not very good). – Also, would you recommend the regulator even if I am only using 1-10mA, assuming I can find an appropriate part?  Is 90% efficiency good enough (I remember finding a cheap one in that range), or is it using more current than it saves me?" CreationDate="2010-10-07T23:40:17.723" UserId="1271" />
  <row Id="5488" PostId="4979" Text="You seem to be asking the question, how do I lower the current of an LED. If this is it, you could shorten the question a lot. People will point you in the right direction." CreationDate="2010-10-07T23:43:47.913" UserId="230" />
  <row Id="5489" PostId="4974" Score="1" Text="the important part of P=V^2/R is that as R goes up with a fixed voltage, power usage decreases." CreationDate="2010-10-07T23:46:07.097" UserId="230" />
  <row Id="5490" PostId="4976" Text="Cool, LED erased.  Having a hard time getting an accurate measurement.  Looks like 0.9mA right now, so maybe my software isn't powering down as much as I thought it was.  With Arduino (and heartbeat LED) involved it is more like 8-9mA, so at least the tiny is helping." CreationDate="2010-10-07T23:50:50.987" UserId="1271" />
  <row Id="5492" PostId="4974" Text="Cool, so to use more of the battery, I'll probably need higher voltage (possibly using the regulator suggested by Andrew).  I'll do some experiments to see how low of voltage the serial line will take.  I'll also make sure to set the unused pins to output.  Serial is only used occasionally, so I'll just check the rest state.  I've definitely tried to shutdown all the peripherals I can." CreationDate="2010-10-07T23:54:42.397" UserId="1271" />
  <row Id="5493" PostId="4974" Text="For capacitors: so probably I don't need any capacitor to help the battery out.  Check the battery chemistry, but assuming it can handle the pattern of current drain I have, then no need to try to adjust it, right?" CreationDate="2010-10-07T23:55:37.083" UserId="1271" />
  <row Id="5494" PostId="4974" Text="Thanks for the P thing.  I think I now understand.  P = I*V where V is the voltage drop, so I can measure the battery drain in P or I (or P-hours or I-hours) as long as the voltage can't be changed.  I'm still not sure if I can change V &quot;for free&quot;." CreationDate="2010-10-07T23:58:21.090" UserId="1271" />
  <row Id="5495" PostId="4970" Text="BTW my wife found http://makezine.com/makeitlast/ which might eventually be useful, as it is basically a contest to make this kind of thing.  I think it starts today, so they don't have any hints posted on how to do it.  At any rate, my project is independent, and I doubt I'd have time to enter anyways :)  Feel free to wait until the contest is over if you don't like such things.&#xA;" CreationDate="2010-10-08T00:01:15.630" UserId="1271" />
  <row Id="5496" PostId="4980" Score="1" Text="Nice idea.  I saw something about this for the IR transmitter leds (apparently they get hot if they are not PWM).  Cool, this effectively lowers the &quot;rms&quot; voltage, right?  Basically for free (in terms of battery life), other than a microcontroller or oscillator or something has to be running, right?" CreationDate="2010-10-08T00:03:30.070" UserId="1271" />
  <row Id="5497" PostId="4980" Score="1" Text="Along the same line of thinking, consider blinking the LED.  A 1% duty cycle (10 ms of on timer per second) is still visible and consumes only 1% of the power." CreationDate="2010-10-08T00:07:13.223" UserId="529" />
  <row Id="5498" PostId="4979" Text="Radically shortened.  I linked to the other question for context." CreationDate="2010-10-08T00:15:49.067" UserId="1271" />
  <row Id="5499" PostId="4980" Text="@Jack Yes, it's basically free. The power for an MCU should be far less than an LED." CreationDate="2010-10-08T00:17:09.443" UserId="566" />
  <row Id="5500" PostId="4935" Text="Thanks, @Joby Taffey, I will check the binary for the magic number in the morning." CreationDate="2010-10-08T00:31:03.930" UserId="1411" />
  <row Id="5501" PostId="4974" Text="The buck-boost regulator andrew mentioned is really the best solution.  I didn't mention it because the layout of such circuits is usually critical.  They are difficult to breadboard without funky performance or radiating tons of EMI.  Read the datasheet carefully, recommendations for layout and identification of critical paths is usually included.  There will also be tighter constraints on some of the parts used.  Low ESR capacitors and such." CreationDate="2010-10-08T02:18:11.123" UserId="1438" />
  <row Id="5502" PostId="4978" Score="1" Text="very good point on playing with the frequency, reminds me of how the wifi radio in my cell phone uses more power than the cellular modem does but wifi is so much faster it can sleep more and ends up being better overall on power because of it. " CreationDate="2010-10-08T02:31:22.260" UserId="1438" />
  <row Id="5503" PostId="4974" Text="Err another thing on the regulator: Try to find a part with an internal switch and fixed voltage if possible, it will remove a bunch of the critical path's you'd need to worry about in layout." CreationDate="2010-10-08T02:38:05.713" UserId="1438" />
  <row Id="5504" PostId="4947" Text="Isn't that what I said?" CreationDate="2010-10-08T02:38:52.980" UserId="1374" />
  <row Id="5505" PostId="4983" Score="2" Text="Sounds kind of like this blog post I stumbled across earlier today: http://www.starlino.com/imu_kalman_arduino.html&#xA;&#xA;&#xA;I have no connection with that site, just thought it looked relevant to what you're asking.&#xA;" CreationDate="2010-10-08T03:02:28.670" UserId="740" />
  <row Id="5506" PostId="4948" Text="I've done things like that [before](http://www.flickr.com/photos/rberteig/242960811/in/set-72057594052009402/). We were really hoping not to have to include JTAG in the factory bring-up process this time, however. " CreationDate="2010-10-08T06:44:01.800" UserId="1494" />
  <row Id="5507" PostId="4945" Text="So the issues with bad blocks make it simply not practical to get the NAND pre-programmed in bulk? That is plausible, but unfortunate." CreationDate="2010-10-08T06:45:07.620" UserId="1494" />
  <row Id="5508" PostId="4948" Text="The clamp idea is really clever." CreationDate="2010-10-08T07:52:38.350" UserId="1374" />
  <row Id="5509" PostId="4945" Text="You may well be able to buy NAND with no bad blocks. It's worth asking your supplier." CreationDate="2010-10-08T08:11:37.110" UserId="566" />
  <row Id="5510" PostId="4991" Text="If it's fixed, please close the question." CreationDate="2010-10-08T10:19:58.523" UserId="566" />
  <row Id="5511" PostId="4991" Score="2" Text="@Joby self answered questions cannot be marked as accepted by the OP for 2 days" CreationDate="2010-10-08T10:40:18.190" UserId="623" />
  <row Id="5512" PostId="4994" Score="1" Text="Isn't there a significant DC offset on the lines, too, which even better, flips polarity when the switching office detects your phone is off-hook? I forget what the number is but I want to say it's in somewhere in excess of 40V. Anyway the DC is easy to block, you're right it's that 90V AC that is the biggest problem." CreationDate="2010-10-08T11:09:42.727" UserId="740" />
  <row Id="5513" PostId="4994" Text="@csadam I don't think the legal thing is an issue in my country :)" CreationDate="2010-10-08T11:15:26.897" UserId="1258" />
  <row Id="5514" PostId="4631" Text="@tcrosely, Ok I see what you mean. I had just assumed that it would work of 5 volt logic, but this is obviously not the case. Thanks for sending me the link for the schematic. That is a definite help. " CreationDate="2010-10-08T11:22:21.940" UserId="1337" />
  <row Id="5515" PostId="4991" Text="Well, I've learnt something new today." CreationDate="2010-10-08T11:50:27.397" UserId="566" />
  <row Id="5516" PostId="4979" Score="1" Text="You still have 8 questions in your question. I think the most interesting one is if increasing the resistance of your current limiting resistor will extend your battery life." CreationDate="2010-10-08T12:37:17.477" UserId="588" />
  <row Id="5517" PostId="4996" Text="Part of the existing sign is animation, so it needs to update on the order of 10's of Hz. That said, the resolution of the sign is on the order of 24x64, so, sending over by one of FTDI chips would work. But I would prefer something with no explicit dependence on PC software. " CreationDate="2010-10-08T13:12:02.293" UserId="1507" />
  <row Id="5518" PostId="4999" Text="You underestimate my amatuer-ness... balancing inductor? could you please elaborate or provide a link :)" CreationDate="2010-10-08T13:26:46.453" UserId="1258" />
  <row Id="5519" PostId="4989" Score="2" Text="What's your goal of connecting your landline to your soundcard?  What do you wish to do with the phone line?" CreationDate="2010-10-08T13:44:16.567" UserId="374" />
  <row Id="5520" PostId="4981" Text="Do you know for certain that the DVI input really expects the same signals from a PC DVI output?  The connector may simply be a DVI connector, but not actually accept conventional DVI PC monitor signals." CreationDate="2010-10-08T13:59:13.887" UserId="374" />
  <row Id="5521" PostId="4994" Text="Which country. That sometimes help people give context." CreationDate="2010-10-08T14:13:22.517" UserId="230" />
  <row Id="5522" PostId="4980" Text="That depends on the MCU." CreationDate="2010-10-08T14:22:38.583" UserId="230" />
  <row Id="5523" PostId="4980" Score="2" Text="I think PWM is the way to go, saving energy in the same way that a class D amplifier does.  You can use a smaller resistor and send brief pulses of large current, and the LED doesn't care?  It only cares about the average power dissipation and the rate at which heat is removed?" CreationDate="2010-10-08T14:25:26.733" UserId="142" />
  <row Id="5524" PostId="4981" Text="The input on the other sign controller? Yes- there's a straight connection from the output of the video card to the DVI-IN on the controller; comes up as a monitor in windows, etc; video card is a cheap card ordered from newegg" CreationDate="2010-10-08T14:35:11.457" UserId="1507" />
  <row Id="5526" PostId="4989" Text="@sheepsimulator, recording, talking, answering machine,making strange noises on the line when other people try to phone from my line :)" CreationDate="2010-10-08T14:56:17.103" UserId="1258" />
  <row Id="5527" PostId="4994" Score="1" Text="South Africa, land of boerewors!" CreationDate="2010-10-08T14:57:39.407" UserId="1258" />
  <row Id="5528" PostId="5004" Text="Interesting idea. I don't think it would work well for the 'time/temperature' basics though, and there'd still need to be a way to easily update the sign (asking a Bank Manager to get on a ladder, open the sign and replace an SD card wouldn't work; wireless update could be done). " CreationDate="2010-10-08T16:20:24.233" UserId="1507" />
  <row Id="5529" PostId="4994" Text="When the phone is 'on hook' you should see about -48V on ring with tip at GND.  When your 'on line' you'll see ring around -28V and tip around -20V with 20-30mA of current flowing.  Voice information is sent by modulating the current in a big loop between the 2 connected lines, thats how you can duplex operation from 2 wires.  The ring signal is AC, ~30hz and can be up to 150V.  I can tell you this from experience, if your working on live phone lines and someone calls the line, it does not feel good at all." CreationDate="2010-10-08T17:05:17.590" UserId="1438" />
  <row Id="5530" PostId="5003" Text="The specific type of power supply required is a buck regulator. Switch-mode PSUs are a very broad term.  All that's really required to drive an LED is an inductor and a switch, nothing like the complex and expensive device shown on the Wikipedia page.  " CreationDate="2010-10-08T18:02:31.467" UserId="857" />
  <row Id="5531" PostId="5003" Text="I have helped someone whom needed high brightness to implement an LED Driver that was a buck-boost. They all fall under SMPS. The led driver would boost the voltage to get the required current if required. I consider it an advanced topic for someone whom is still learning about resistors and LEDs. We all start somewhere." CreationDate="2010-10-08T19:53:28.090" UserId="230" />
  <row Id="5533" PostId="5003" Text="I do wonder why I received a downvote, if whomever downvoted me could expand I would like to improve my post. I attempted to answer each question with some explanation but avoiding writing 10 pages and getting lost in details." CreationDate="2010-10-08T19:55:01.520" UserId="230" />
  <row Id="5534" PostId="5009" Text="@Al Katawazi: the output of Power-Bright-PW900-12-Inverter is 110 V (AC). Where do you plan to connect this high voltage? The input to PICOPSU-160-XT is 12 V (DC)." CreationDate="2010-10-08T20:17:52.457" UserId="804" />
  <row Id="5535" PostId="5011" Text="Did you miss a part of the last sentence?" CreationDate="2010-10-08T20:47:35.303" UserId="1240" />
  <row Id="5536" PostId="5011" Score="1" Text="Seems StackExchange doesn't like the less than symbol, parsing it as html." CreationDate="2010-10-08T20:48:38.700" UserId="1225" />
  <row Id="5537" PostId="5009" Text="Doesn't the unit invert 110 to 12vdc??" CreationDate="2010-10-08T20:53:10.183" UserId="1518" />
  <row Id="5538" PostId="5009" Score="2" Text="No, that's the opposite. An inverter converts 12Vdc or whatever to 110Vac or whatever. The important part is the DC to AC conversion. Something converting from AC to DC is known as rectification, and the stepping down is sometimes called regulation or just conversion." CreationDate="2010-10-08T20:58:54.833" UserId="1225" />
  <row Id="5539" PostId="3662" Score="1" Text="This ICE sounds more like an ICD." CreationDate="2010-10-08T21:04:18.987" UserId="374" />
  <row Id="5540" PostId="5016" Text="Thanks for the suggestion. I was considering an MC34063, but size is a concern, and the chip doesn't make the best use of inductor + capacitor size." CreationDate="2010-10-08T21:09:18.823" UserId="1225" />
  <row Id="5541" PostId="5010" Score="7" Text="If I were you I would consider repurposing a kitchen timer or an alarm clock." CreationDate="2010-10-08T21:34:26.167" UserId="1363" />
  <row Id="5542" PostId="5010" Score="1" Text="@joeforker Why should something be simple when it can be complicated:). Actually I never would have thought of finding a useful purpose for my stack of alarm clocks which I never used. While it definitely wouldn't be as educational as making a circuit from scratch, it would quickly solve my problem. I'll take it into consideration." CreationDate="2010-10-08T21:40:42.483" UserId="1240" />
  <row Id="5543" PostId="5009" Text="Interesting, nice catch I didn't see that, I assumed it was bi-directional. Are there cheap bulk 12vdc inverters out there?" CreationDate="2010-10-08T22:33:10.923" UserId="1518" />
  <row Id="5544" PostId="5010" Text="Use the open switch / closed switch / beeping to power a 555 circuit that will close a relay for just long enough to start the washing machine. Have it send you an SMS? No need to undercomplicate things just because you are using an off-the-shelf long delay timer." CreationDate="2010-10-08T22:37:36.237" UserId="1363" />
  <row Id="5545" PostId="5011" Score="1" Text="Yes, you need to use `&amp;lt;` or similar for HTML reserved characters.  See this [w3schools.com reference](http://www.w3schools.com/html/html_entities.asp) for all the characters.  Click 'Edit'-'View Source' if you want to see how I fixed it.  (Credit to Bill the Lizard from SO for fixing one of my posts there and thereby showing me how this works)." CreationDate="2010-10-08T22:46:18.373" UserId="857" />
  <row Id="5546" PostId="5017" Text="Drop-in is a compromise between size and cost as we're trying to find the 'best' solution here.  But, CUI drop-ins are certainly easy." CreationDate="2010-10-08T22:49:33.927" UserId="857" />
  <row Id="5547" PostId="5013" Score="1" Text="any particular reason it has to be wired?  Honestly there hasn't been a lot of advancement in wired systems for this use, most people are using ZigBee with the home automation profile.  You could try using CAN i guess, but ZigBee with the HA profile would probably allow you to interface to a lot of off the shelf devices." CreationDate="2010-10-08T22:52:45.967" UserId="1438" />
  <row Id="5548" PostId="5009" Text="@Al K - Do you still mean 'inverter' afte reading Thomas' correct comment? " CreationDate="2010-10-08T23:10:59.387" UserId="857" />
  <row Id="5549" PostId="4979" Text="I don't have time right now, but tomorrow I'll see if I can answer your question &quot;How can a regulator IC do what a resistor or diode cannot?&quot;" CreationDate="2010-10-08T23:37:10.963" UserId="857" />
  <row Id="5550" PostId="3662" Text="In circuit emulator and in circuit debugger are very different. The device ian talks about is an in circuit debugger." CreationDate="2010-10-09T00:05:54.507" UserId="230" />
  <row Id="5551" PostId="5022" Text="I think the simplest solution that is also the safest is to go with 4 wall warts, thanks for the great info." CreationDate="2010-10-09T01:40:26.680" UserId="1518" />
  <row Id="5553" PostId="5019" Text="+1 This chip also requires a minimal amount of external components so space can be conserved. Still not as small as you can get a linear regulator though." CreationDate="2010-10-09T02:53:34.010" UserId="319" />
  <row Id="5554" PostId="5026" Text="Agreed, learning a new environment can always be difficult, keeping the project to something you have already done before eliminates trying to decide if something isn't working because of a design flaw or if it is just how you are using the environment. " CreationDate="2010-10-09T02:58:24.043" UserId="319" />
  <row Id="5555" PostId="5010" Text="There are lots of timers that are used to turn lights on and off -- they have a switched 110v outlet (in the US).  You could use one of these, set it for the start time, and use the output to control a 110v relay which would operate the washer button.  Set the off time on the timer as close to the start time to release the relay.  (If you have to press and release the pushbutton to start the washer, you may need a little more complicated relay arrangement.)" CreationDate="2010-10-09T03:22:49.260" UserId="1322" />
  <row Id="5556" PostId="5025" Score="1" Text="Absolutely. For US$20 you can get the parts together to make some very accurate timing systems (e.g. Arduino bootloader, DS1307 RTC, etc) " CreationDate="2010-10-09T05:14:52.247" UserId="1307" />
  <row Id="5557" PostId="5025" Score="2" Text="In general I agree that microcontroller would be the best solution and plan on taking that route one day, but in my specific case that would require either buying one of the kits available in my country (which are 100€-150€ depending on accessories) or convincing one of my relatives to borrow me credit card (since I as a student don't have a steady source of income and can't get a credit card myself) and then pay more for shipping than for the components being shipped. Still, you get +1 for good suggestion." CreationDate="2010-10-09T08:45:00.890" UserId="1240" />
  <row Id="5558" PostId="5031" Score="1" Text="is this a place you wanted link to: http://www.beyondlogic.org/spp/parallel.htm?" CreationDate="2010-10-09T08:53:48.513" UserId="1471" />
  <row Id="5559" PostId="5033" Text="+1 Thanks for your contribution. I don't have time to learn tex/latex so this isn't really an option at the moment." CreationDate="2010-10-09T11:40:21.313" UserId="819" />
  <row Id="5560" PostId="5037" Text="Yes I tried, but I am not sure how to use it. Because if I try it on the same side, the solder cools down as I remove the solder pen and I have no time to suck up the solder. From the opposite side, it does not work also maybe because the hole is too small. Now i am trying to blow from the opposite side with a dust blower while heating the via. " CreationDate="2010-10-09T12:57:44.473" UserId="1514" />
  <row Id="5561" PostId="5037" Text="I'd recommend using it from the same side, and admittedly it's tricky, you have to practice at being quick enough. Also, you want to keep these beasties producing the maximum vacuum possible. Watch out for solder that freezes up in the tip, and if the spring/piston action seems slow, the tiniest (really, *tiny*) drop of WD40 can help speed that up." CreationDate="2010-10-09T13:11:11.533" UserId="740" />
  <row Id="5562" PostId="5031" Text="Yes, it is. I'm no longer new user so I can edit the question and add the hyperlink." CreationDate="2010-10-09T13:14:58.827" UserId="1528" />
  <row Id="5563" PostId="5027" Text="Two more things: you don' seem to be servicing the interrupts. If you have Tx and Rx inrerrupts you need to have an ISR that clears the interrupt flags. Also, the first time around I did not notice that you are trying to connect an SPI signal to a serial port in a PC. as tcrosley points out you can not do that directly. You need something like this http://www.maxim-ic.com/datasheet/index.mvp/id/2052 to change the protocol from a clocked SPI signal to an RS232. This is why even though you have the right baud rate you see garbage.   " CreationDate="2010-10-09T14:47:35.320" UserId="1526" />
  <row Id="5564" PostId="5037" Text="@csdam: as JustJeff has said, it takes practice, or have someone else hold the soldering iron, that way you will be quicker." CreationDate="2010-10-09T14:55:34.887" UserId="819" />
  <row Id="5565" PostId="5037" Score="1" Text="Also, I've often found solder gets inside the spring mechanism and this causes problems. You can disassemble them relatively easily and blow them out. I have to do this every few months; I do use my solder sucker a lot, though." CreationDate="2010-10-09T15:50:10.153" UserId="1225" />
  <row Id="5566" PostId="5042" Score="1" Text="Suction *before* you remove the components is the way to go.  " CreationDate="2010-10-09T16:13:50.023" UserId="857" />
  <row Id="5567" PostId="5042" Text="@reemrevnivek - well, yeah, if nothing else, because the extra mass of the component lead helps keep the solder molten longer, making it easier to get there in time with the suction tool. And besides, if the part you're de-soldering is destined for the trash can, you can really cook the joint and then even the body of the part itself will help keep things hot." CreationDate="2010-10-09T17:01:18.283" UserId="740" />
  <row Id="5568" PostId="5042" Score="1" Text="ah, should have added, don't go to hot for too long, or you can melt the trace off the board." CreationDate="2010-10-09T17:07:26.957" UserId="740" />
  <row Id="5569" PostId="5033" Text="I installed k-map which is not bad, although sadly lacking an export... Anyway I ended doing them in excel. " CreationDate="2010-10-09T17:14:37.693" UserId="819" />
  <row Id="5570" PostId="5046" Text="yes wiring is correct. im sure about pwm pins." CreationDate="2010-10-09T17:26:15.443" UserId="1461" />
  <row Id="5572" PostId="5046" Text="my arduino produces pwm output from:&#xA;5,6,3 pins&#xA;i choosed to use&#xA;pwm5 for first motor and&#xA;" CreationDate="2010-10-09T17:27:51.660" UserId="1461" />
  <row Id="5573" PostId="5046" Text="pwm3 for the second one" CreationDate="2010-10-09T17:28:29.397" UserId="1461" />
  <row Id="5575" PostId="5046" Text="if you have an o-scope, you can tell if you have the software lined up with the wiring pretty quickly by looking at the L298's Enable input. If you happen to have swapped the Enable with an 'In', you'd get exactly the symptom you mentioned." CreationDate="2010-10-09T17:33:02.060" UserId="740" />
  <row Id="5577" PostId="5046" Text="well you are right buddy. :D thank you so much" CreationDate="2010-10-09T17:54:34.360" UserId="1461" />
  <row Id="5578" PostId="5046" Text="i'll check if the second motor also have save problem" CreationDate="2010-10-09T17:55:26.193" UserId="1461" />
  <row Id="5581" PostId="5039" Text="This is what I use.  You need to wet the wick first and drag it across the hole to get it wick up." CreationDate="2010-10-09T19:07:45.323" UserId="142" />
  <row Id="5582" PostId="4979" Text="Linear regulators can't do anything that diodes or resistors can't do, in the sense that you mean.  They still waste power as heat.  Switching regulators can, however, because they either pass the current without resistance or block it completely, so nothing is wasted in the device itself." CreationDate="2010-10-09T19:10:27.317" UserId="142" />
  <row Id="5583" PostId="5030" Text="FYI Parallax is currently selling slightly blemished versions of their Propeller Professional Development Board, normally $169.99, for 41% off at $99.99, which could be used to do a lot of these experiments.  I just bought one myself.  http://www.parallax.com/Store/Microcontrollers/BASICStampModules/tabid/134/ProductID/698/List/1/Default.aspx?SortField=UnitCost,ProductName" CreationDate="2010-10-09T19:17:24.460" UserId="1322" />
  <row Id="5584" PostId="5039" Text="Don't forget - &quot;wet&quot; means &quot;with solder&quot; :-)" CreationDate="2010-10-09T19:37:21.950" UserId="566" />
  <row Id="5585" PostId="5042" Text="If you have a suction tip on your soldering station, you can put the lead inside the tip, and work around in little circles, reducing the area you have to suck air through and increasing the amount of solder which remains.  You can get the joint completely dry this way." CreationDate="2010-10-09T20:13:41.593" UserId="857" />
  <row Id="5586" PostId="5030" Text="$100 and it doesn't even include the microcontroller? Parallax always seemed overpriced to me." CreationDate="2010-10-09T22:06:48.877" UserId="131" />
  <row Id="5587" PostId="5051" Text="How flexible is your architecture? Even if (when) you find a micro that can do 50MHz SPI/SSI/SSP/4-Wire/etc., you're likely to have trouble with issues of DC bias, coupled noise, and EMI.  Have you considered (1) serial LVDS, if the number of wires are an issue or (2) parallel data? " CreationDate="2010-10-09T23:14:18.667" UserId="857" />
  <row Id="5588" PostId="5051" Text="Also, why are you having trouble with the word length?  Just because the device has a byte-oriented peripherial doesn't mean that you can't stuff into a 4-byte data structure.  Takes a little more work in your interrupt, but it doesn't have to be a kludge." CreationDate="2010-10-09T23:15:43.343" UserId="857" />
  <row Id="5589" PostId="5053" Text="I don't think you need to go as high as an A8 for 50MHz - That's 600MHz+ iPad/Droid territory.  Cortex M3 parts clock in at around 100MHz, and the ARM7TDMI mentioned in the question can probably do it as well, clocking 60-70MHz. " CreationDate="2010-10-09T23:16:10.770" UserId="857" />
  <row Id="5590" PostId="5022" Score="1" Text="@Al N - Before you go that route, take a look at [this photo](http://www.flickr.com/photos/linux-works/4150845200/).  I hope your PSUs have better quality than that!" CreationDate="2010-10-09T23:22:22.073" UserId="857" />
  <row Id="5596" PostId="3003" Text="The software is now classed as &quot;mature&quot; and it's all a lot easier." CreationDate="2010-10-10T00:10:19.613" UserId="566" />
  <row Id="5597" PostId="5053" Text="Its not a matter of doing it, its a matter of finding a production SoC with the capability, which i highly doubt is out there...why would a 100mhz core clocked SoC need a 50Mhz SSI bus?" CreationDate="2010-10-10T00:15:30.010" UserId="1438" />
  <row Id="5598" PostId="5039" Text="Another technique that has served me well is to first cut the solder braid/wick at a very acute angle. Then, poke it into the through hole/via, and apply both the soldering iron and a bit of solder. It sounds counter intuitive but it works well. You will need to repeat this several times to clear the holes, especially for capacitors (which are often connected to ground and power planes)." CreationDate="2010-10-10T03:06:05.200" UserId="906" />
  <row Id="5599" PostId="5057" Text="Fixed the format of the code in your post." CreationDate="2010-10-10T07:34:46.453" UserId="103" />
  <row Id="5600" PostId="3002" Text="Absolutely. I really get a lot of use out of mine. Much easier to use for beginners than the Bus Pirate. " CreationDate="2010-10-10T07:35:12.097" UserId="1307" />
  <row Id="5601" PostId="5034" Score="1" Text="PC motherboards seem to use some really annoying solder (some hard RoHS stuff?) IIRC. It might help to add some more normal solder and melt them together. Then try the answers. Suction might work better than capillary and poking a hot component lead through might indeed be the easiest." CreationDate="2010-10-10T09:02:02.913" UserId="883" />
  <row Id="5603" PostId="4980" Score="4" Text="LEDs are more tolerant of overcurrent if it is pulsed (heat dissipation, as you said.) But, it's probably best to not exceed the max current rating by too much, just the same. Use a current-limiting resistor to get your &quot;on&quot; current to close to max, then use a reduced duty cycle PWM to get average brightness where you want it. If the flicker is too much, try putting a cap in parallel with the LED (after the resistor.) The cap would also allow a lower-value resistor, because it would store some of the energy for the &quot;off&quot; portion of the PWM cycle." CreationDate="2010-10-10T10:09:36.013" UserId="965" />
  <row Id="5604" PostId="5003" Score="1" Text="I don't see what would be downvoted. You expanded the scope of possible solutions in such a way that much more efficient solutions could be considered." CreationDate="2010-10-10T10:13:29.570" UserId="965" />
  <row Id="5605" PostId="5059" Score="1" Text="@Soph: what does the circuit look like? E.g. is the op-amp used as a buffer (high input impedance unity gain voltage buffer)?" CreationDate="2010-10-10T10:22:21.353" UserId="804" />
  <row Id="5606" PostId="5059" Score="1" Text="What are you using for a reference voltage?" CreationDate="2010-10-10T10:22:51.680" UserId="305" />
  <row Id="5607" PostId="5059" Score="3" Text="Why are you still using an LM741? Running it from a single battery source will not work well; it is limited to V- + 1.5V to V+ - 1.5V, i.e. 1.5V to 6.5V with an 8V battery. Use something like an LM358." CreationDate="2010-10-10T10:22:58.510" UserId="1225" />
  <row Id="5608" PostId="5060" Score="1" Text="I'll take a look. It looks promising to me." CreationDate="2010-10-10T10:37:55.920" UserId="1240" />
  <row Id="5609" PostId="5059" Score="1" Text="educated guesses could be made (how does 10K grab you?), but it's difficult to say anything definitive about resistor values w/o seeing the circuit." CreationDate="2010-10-10T11:10:13.990" UserId="740" />
  <row Id="5610" PostId="5058" Text="Do you have a link to the 7 segment displays datasheet? Have you checked to see if it is common cathode or common anode?" CreationDate="2010-10-10T12:09:23.827" UserId="399" />
  <row Id="5611" PostId="5051" Text="The actual distance traveled is pretty small, and the device furthest from the source of the data is a little serial DAC; its maximum clock rate is 50MHz and with some of the data I'm pushing I come close to that rate, which is why I'm trying to find a microcontroller with a slave SSP interface that can handle it. I had looked at LVDS but it just wasn't necessary." CreationDate="2010-10-10T12:21:46.263" UserId="974" />
  <row Id="5612" PostId="5051" Text="As far as word length goes -- I only have one frame sync pulse every 32 bits, and I've found that the SSP interfaces will not pick up a second serial word unless there's a frame sync pulse to tell them to do so. I'm currently using a kludge with some external hardware to synthesize a second frame sync pulse 16 clocks later, and have also used two SSP ports with the interrupt of one generating a sync pulse for the second... It's just something I'd rather avoid if I can." CreationDate="2010-10-10T12:23:47.687" UserId="974" />
  <row Id="5613" PostId="5054" Text="Hmm, interesting. The XMOS devices are certainly higher end than the devices I've been using to date. They've also got free development tools for my preferred environment (Linux). I'm going to take a closer look at these devices, thank you!" CreationDate="2010-10-10T12:26:26.227" UserId="974" />
  <row Id="5614" PostId="5053" Text="Unfortunately I can't slow the data down; I'm driving a quad serial DAC and the microcontroller I'm trying to put on the bus is being used to drive some related I/O synchronous to the data being pushed out the DACs.  The ARMv4 devices I'm using (LPC21xx) can do a 35MHz SPI clock when in master mode without any trouble whatsoever, so I think that I might be able to hit 50 with a slightly beefier device.  SoCs are similar to FPGAs though; it's proving difficult to find low pin count devices with large amounts of configurable logic." CreationDate="2010-10-10T12:31:05.490" UserId="974" />
  <row Id="5615" PostId="5055" Text="It's a constant stream of data feeding a quad DAC. The microcontroller monitors the bus for control words to actuate some I/O synchronously to the data stream, with the eventual goal of being able to provide status and other information back to the master over the same 4-wire bus." CreationDate="2010-10-10T12:32:19.737" UserId="974" />
  <row Id="5616" PostId="5059" Text="@peter the op-amp will be used as a buffer " CreationDate="2010-10-10T12:34:06.640" />
  <row Id="5617" PostId="5059" Text="@Leon the vref will be 3.3v" CreationDate="2010-10-10T12:36:13.267" />
  <row Id="5618" PostId="5022" Score="1" Text="That is really concerning. Would [this][http://www.newegg.com/Product/Product.aspx?Item=N82E16817129006&amp;cm_re=mini_itx_psu-_-17-129-006-_-Product] be a better solution than the pico itx boards with bad soldering." CreationDate="2010-10-10T13:05:16.920" UserId="1518" />
  <row Id="5619" PostId="5052" Text="Looks good, sadly it costs three times more than the whole computer I am trying to repair :)" CreationDate="2010-10-10T13:06:46.767" UserId="1514" />
  <row Id="5620" PostId="5064" Score="4" Text="Why not just get one of those multi-packs of common values?" CreationDate="2010-10-10T13:53:49.897" UserId="740" />
  <row Id="5621" PostId="5067" Score="2" Text="but it simulates just 1 resistor... i need an good solution that can 'simulate' like 5 resistors..." CreationDate="2010-10-10T15:03:51.997" UserId="1539" />
  <row Id="5622" PostId="5067" Score="2" Text="Yes. It is used to test/tune a circuit by finding the correct value for one resistor. If you need more, then the assortment kit is the solution.&#xA;&#xA;There is one more thing, the potentiometer. This is the variable resistor used in analog controls like volume. If you buy 5 pieces of 1K, 10K, 100K, 1M values,  you will have more than enough variable resistors :)" CreationDate="2010-10-10T15:10:25.490" UserId="1514" />
  <row Id="5623" PostId="5067" Text="any link from some variable resistor kit in ebay? // thanks for your help" CreationDate="2010-10-10T15:32:21.017" UserId="1539" />
  <row Id="5624" PostId="5053" Text="generally a SoC will run faster in master mode than it will slave.  The processes of extracting the clock as the slave has to do usually isn't something you can do near your system clock rate.  Also isn't SSI single master single slave? how are you snooping on the data line to the DAC's? and how is the bus terminated?" CreationDate="2010-10-10T16:19:59.210" UserId="1438" />
  <row Id="5625" PostId="5067" Text="I've found only this assortment: http://cgi.ebay.com/Potentiometer-Assortment-Pot-Lot-1k-10k-50k-1M100k-/120631089653#ht_500wt_925&#xA;But it is US only. Anyways there are 5 pcs packs in each values if you search to &quot;5pcs 1K potentiometer&quot; then 10K, etc. And make sure to get linear ones, not the logarithmic type." CreationDate="2010-10-10T17:04:46.750" UserId="1514" />
  <row Id="5627" PostId="5052" Text="I know what you mean. I've been looking on eBay for the past year or so putting together a Pace setup. So far I have one SX-90 iron and an older 2-channel controller. I'm waiting for one of these to show up at the right price. One other item you might try is a bulb arrangement that goes on an iron like a regular tip, except it has the thru-hole so you can do hot suction. Lots cheaper, but not as convenient as the too-expensive Pace." CreationDate="2010-10-10T18:31:31.993" UserId="965" />
  <row Id="5628" PostId="5063" Score="1" Text="I used your tutorial as well, with some further study I have found out that I order the wrong part, my display is common anode not common-cathode. I will order a new part and see how I go thanks" CreationDate="2010-10-10T18:42:38.930" UserId="665" />
  <row Id="5629" PostId="5073" Text="According to the book, the PUT allows current to flow when the anode (top pin of Q1) has a higher voltage than the gate (middle pin of Q1). In my example, the voltage across the gate should be ~4.7v (I think). So as far as I can understand, the PUT shouldn't allow current through when the voltage across the capacitor is only 2.7v." CreationDate="2010-10-10T19:27:13.167" UserId="1540" />
  <row Id="5630" PostId="4924" Score="1" Text="@FakeName: One way I've seen used to isolate a scope is to use an  isolation transformer on the mains to the scope. Same cautions about hot chassis apply though, so be careful!" CreationDate="2010-10-10T20:02:18.953" UserId="965" />
  <row Id="5631" PostId="5073" Text="That's true-- the PUT stays off until the voltage rises above the gate threshold. However, if I understand it correctly, once it turns on, it stays on until the current drops below another threshold. I bet it's turning on right, but turning off wrong." CreationDate="2010-10-10T20:35:01.690" UserId="712" />
  <row Id="5632" PostId="5076" Text="Very interesting! I will test your hypothesis. Out of curiosity, how did you determine that &quot;the current through the PUT is dependent on the resistance between gate and ground&quot;? Was &quot;Figure 4. Effect of Supply Voltage&quot; in the data sheet?" CreationDate="2010-10-10T21:31:18.743" UserId="1540" />
  <row Id="5633" PostId="5078" Text="I think this is off topic but I'm not 100%. Any thoughts?" CreationDate="2010-10-10T22:07:43.920" UserId="103" />
  <row Id="5635" PostId="5070" Score="3" Text="I remember pulling a DC motor from a toy when I was young and hooking it up to the speaker output on my dad's stereo - It didn't drive (obviously in retrospect) but you could hear the Beatles playing through oscillations in the motor :)" CreationDate="2010-10-10T23:17:27.453" UserId="554" />
  <row Id="5636" PostId="5042" Text="I really only mentioned these methods to round out the answers a bit. I've only personally used the knock technique a couple of times, and not at all since I bought one of those spring-loaded piston solder suckers, about 20 years ago. Please, don't go banging on any board you're not ready to throw away. Get a sucker!" CreationDate="2010-10-10T23:37:48.927" UserId="740" />
  <row Id="5637" PostId="5070" Text="@Peter Gibson  I am sooo going to try that!" CreationDate="2010-10-10T23:48:38.067" UserId="1240" />
  <row Id="5638" PostId="5070" Score="2" Text="@AndrejaKo - make sure you use your _Dad's_ stereo then!" CreationDate="2010-10-11T00:27:31.540" UserId="554" />
  <row Id="5639" PostId="5078" Text="It's not phrased as an electronics question, really, but could be useful to someone building a touch display." CreationDate="2010-10-11T01:23:19.603" UserId="142" />
  <row Id="5640" PostId="5073" Text="According to the book - &quot;If anode voltage increases above the threshold point, current bursts through and flows from anode to cathode. If anode voltage drops back down below the threshold, the transistor stops the flow.&quot; So although I agree it's not turning off correctly, I'm not convinced it's because of a different threshold for closing the gate." CreationDate="2010-10-11T01:42:13.213" UserId="1540" />
  <row Id="5642" PostId="4924" Score="1" Text="I would prefer do that with the power supply because I only rarely touch my power supply. Does not sound like a great idea with either though." CreationDate="2010-10-11T02:37:33.290" UserId="230" />
  <row Id="5643" PostId="5059" Text="soph, is there something different that you needed then my answer, if you expand I will expand on my answer. Thomas, if it is a buffer for half the battery voltage it will not need to go much towards the limits you noted." CreationDate="2010-10-11T03:01:21.330" UserId="230" />
  <row Id="5644" PostId="5082" Score="2" Text="'grab bags' - look in the contents page for grab bags, or component cabinet kits. that will get you an assortment that should handle a few projects." CreationDate="2010-10-11T03:06:16.560" UserId="740" />
  <row Id="5645" PostId="5082" Score="4" Text="possible dupe http://electronics.stackexchange.com/questions/3744/what-are-the-best-starter-supply-kits" CreationDate="2010-10-11T03:08:55.290" UserId="740" />
  <row Id="5646" PostId="5076" Text="Did you mean smaller R3? If so I believe I confirmed your hypothesis (see my update to the question). An R1 of 6K at 6v actually takes a few seconds to charge a cap, but I'm wondering if it is taking very little time to charge it back above the gate voltage immediately after the voltage drops below the gate voltage." CreationDate="2010-10-11T03:50:23.603" UserId="1540" />
  <row Id="5647" PostId="5082" Text="i need a specific list for transistors and capacitors =x" CreationDate="2010-10-11T03:52:20.853" UserId="1539" />
  <row Id="5648" PostId="5076" Text="oops, yea i did, after further reading of the datasheet, the value of Rg = R2*R3 / (R2+R3) so lowering that resistance will increase the peak current, that is the current at the peak of the decay, which lowering R3 and maintaining the same ratio will result in." CreationDate="2010-10-11T04:34:05.773" UserId="1438" />
  <row Id="5649" PostId="5063" Text="Neat. If you have any feedback about the article please let me know. Thank you!" CreationDate="2010-10-11T04:53:53.650" UserId="1307" />
  <row Id="5650" PostId="5081" Score="2" Text="You may need an AGC circuit for this one. It would be more complex, but with the right settings, it would be much more reliable." CreationDate="2010-10-11T05:05:43.120" UserId="965" />
  <row Id="5651" PostId="5084" Score="3" Text="That's pretty cruel giving a beginner so few LEDS! :) " CreationDate="2010-10-11T08:14:25.983" UserId="1307" />
  <row Id="5652" PostId="5086" Text="If you're in the UK, I'd suggest looking at http://www.bitsbox.co.uk as they have components for a great price and stock all the kits I mentioned." CreationDate="2010-10-11T08:22:38.157" UserId="1333" />
  <row Id="5653" PostId="5084" Score="2" Text="Haha the first thing I did was burn out about 5 LEDs :) " CreationDate="2010-10-11T08:23:29.650" UserId="1333" />
  <row Id="5655" PostId="5080" Score="2" Text="Are you asking &quot;how do I set up this system (from phone line to LCD)?&quot; or &quot;how do I make a TV that is tuned to a single cable channel?&quot;" CreationDate="2010-10-11T10:51:35.610" UserId="638" />
  <row Id="5656" PostId="5080" Text="@W5VO: Sorry if I wasn't clear in my question. I'm asking the latter." CreationDate="2010-10-11T12:06:26.223" />
  <row Id="5657" PostId="4999" Text="Who the _ voted me down? The top answer uses an inductor. " CreationDate="2010-10-11T12:21:19.627" UserId="1033" />
  <row Id="5658" PostId="5078" Text="http://lmgtfy.com/?q=resistive+vs+capacitive" CreationDate="2010-10-11T12:44:28.707" UserId="938" />
  <row Id="5659" PostId="5086" Score="1" Text="I agree. A breadboard with a good jumper wire pack is essential.  And a good wire stripper makes the life easier.&#xA;If I were you I would buy this pack: http://cgi.ebay.com/200-Electronic-Component-Kit-1-LOT-FUN-1-Bargain-/220537247275?pt=UK_BOI_Electrical_Components_Supplies_ET&amp;hash=item33590b562b#ht_1524wt_1140" CreationDate="2010-10-11T13:40:48.167" UserId="1514" />
  <row Id="5660" PostId="5083" Text="That's interesting.  The kit is about the same price as a pre made one, though :(" CreationDate="2010-10-11T13:56:13.927" UserId="1544" />
  <row Id="5661" PostId="5080" Score="1" Text="It's a little tricky because you probably have to decode the digital cable signal. Do you have a cable box already? If so, what connectors are on the back? If not, what choices do you have for cable providers?" CreationDate="2010-10-11T14:01:25.620" UserId="712" />
  <row Id="5662" PostId="5082" Score="1" Text="If you want to &quot;create a lot fo things that there is shematic on the web&quot;, then buy the things shown in those schematics." CreationDate="2010-10-11T14:10:55.463" UserId="142" />
  <row Id="5663" PostId="5084" Text="You could augment that with a grab-bag of LEDs :)" CreationDate="2010-10-11T14:17:37.660" UserId="883" />
  <row Id="5664" PostId="5011" Score="1" Text="+1 for going to the effort of calculating your temperature rise at maximum power! :-) Much better than the try/melt alternative!" CreationDate="2010-10-11T14:20:20.113" UserId="1376" />
  <row Id="5665" PostId="5097" Text="so you want a PCI&lt;-&gt;SSP bridge with windows drivers?  What kind of SSP are you after? SPI? SSI? Microwire?" CreationDate="2010-10-11T14:58:03.473" UserId="1438" />
  <row Id="5666" PostId="5099" Text="Thanks. Yeah, these devices do have an address select, but only between two addresses and I want to connect 5+ devices, so I'd still end up with clashes. I hadn't thought of using a PIC. That should work. Is there nothing off the shelf that does this kind of thing?" CreationDate="2010-10-11T15:19:54.323" UserId="898" />
  <row Id="5667" PostId="5101" Score="2" Text="Conformal Coat will damn near protect your board from a nuclear strike. It's nasty, nasty stuff, but when I worked in industrial motor controls it was the only thing we could do for some customers.  If you only need protection from moisture, there is something called a humi-seal that is much lighter, easier to apply and helps protect the system against high humidity environments.  Both Conformal Coat and humi-seal make boards a real treat to try and rework/repair though, so don't count on being able to easily fix problems that come back from the field." CreationDate="2010-10-11T15:49:09.467" UserId="974" />
  <row Id="5668" PostId="5097" Text="If you are referring to the Microsoft thing, it is generally written '.NET' rather than 'dotNET'" CreationDate="2010-10-11T15:50:15.810" UserId="1182" />
  <row Id="5669" PostId="4980" Text="Here's some stuff about driving LED chains with PWM to get different brightnesses: http://www.reuk.co.uk/LED-Dimmer-Circuit.htm" CreationDate="2010-10-11T15:50:28.160" UserId="142" />
  <row Id="5670" PostId="5080" Text="@pingswept: there's no cable set-top box involved. It's simply coax to TV, so I guess it's just a traditional analogue signal." CreationDate="2010-10-11T16:02:40.353" />
  <row Id="5671" PostId="5103" Text="I thought of that at first, but I'd like to get my feet wet with building some non-trivial circuits." CreationDate="2010-10-11T16:03:50.200" />
  <row Id="5672" PostId="5098" Text="Thanks for the advice. You're right on the audio end as well. I'm only interested in the picture." CreationDate="2010-10-11T16:05:16.953" />
  <row Id="5673" PostId="5094" Score="1" Text="If you are wanting to know this from a sys admin perspective you might want to go here http://serverfault.com/" CreationDate="2010-10-11T16:08:56.570" UserId="319" />
  <row Id="5674" PostId="5099" Score="5" Text="NXP makes a bunch of multiplexers / switches for I2C, you may be able to rig something up out of those: http://ics.nxp.com/products/i2cmuxes/ for instance you could create in your case 3 sub branches, each with 2 devices on it, and use one of NXP's switches to achieve your goal." CreationDate="2010-10-11T16:12:32.580" UserId="1438" />
  <row Id="5675" PostId="5011" Text="Thanks! I recommend this video on EEVBlog, it taught me everything I need to know: http://www.youtube.com/watch?v=8ruFVmxf0zs" CreationDate="2010-10-11T16:36:19.107" UserId="1225" />
  <row Id="5676" PostId="5013" Text="@Mark, no particular reason." CreationDate="2010-10-11T16:40:20.837" UserId="938" />
  <row Id="5677" PostId="5081" Score="1" Text="Photodarlingtons are very sensitive and the IR led will definitely be on all the time, and fairly &quot;bright&quot; in the day. If I were just playing around I'd try it just with the resistor, LED, and PT in series. I would also try a capacitively coupled emitter follower to filter out the DC sunlight. http://en.wikipedia.org/wiki/Common_collector" CreationDate="2010-10-11T16:45:07.290" UserId="1363" />
  <row Id="5678" PostId="5106" Score="1" Text="I agree. I think cat5 will get the job done, shielding cannot hurt, only connect it on one side." CreationDate="2010-10-11T16:50:21.027" UserId="230" />
  <row Id="5679" PostId="5106" Text="Luckily, STP is a standard item." CreationDate="2010-10-11T16:51:53.123" UserId="1182" />
  <row Id="5680" PostId="5106" Score="1" Text="@Kortuk: That's an interesting thought, I wonder if a ground disconnect switch at each jack would be a good idea?" CreationDate="2010-10-11T16:53:03.763" UserId="1182" />
  <row Id="5681" PostId="5104" Score="1" Text="It would work well, or at least for your back pocket: http://www.amazon.com/Denon-AKDL1-Dedicated-Link-Cable/dp/B000I1X6PM/ref=cm_cr_pr_product_top" CreationDate="2010-10-11T16:53:26.040" UserId="1225" />
  <row Id="5682" PostId="5107" Score="3" Text="So it's actually used by people who know what they are doing?" CreationDate="2010-10-11T16:55:38.100" UserId="1182" />
  <row Id="5683" PostId="5104" Text="That cable is for the &quot;purest digital audio&quot;, not always great for line level analog audio." CreationDate="2010-10-11T17:00:07.923" UserId="319" />
  <row Id="5684" PostId="5083" Text="but what fun would that be? :)" CreationDate="2010-10-11T17:00:46.367" UserId="1307" />
  <row Id="5685" PostId="5106" Text="A switch on the aux device is typically what I have seen, but not one at the main device." CreationDate="2010-10-11T17:03:08.580" UserId="319" />
  <row Id="5686" PostId="5104" Score="1" Text="Look at the price tag. $999.99." CreationDate="2010-10-11T17:04:16.910" UserId="1225" />
  <row Id="5687" PostId="5107" Score="1" Text="I would think radio stations would use balanced xlr everywhere. If they are using CAT5 it is probably because it got converted to digital." CreationDate="2010-10-11T17:06:04.583" UserId="319" />
  <row Id="5688" PostId="5104" Text="ohhhhhhh, didnt see that. nice :)" CreationDate="2010-10-11T17:07:21.227" UserId="319" />
  <row Id="5689" PostId="5106" Score="1" Text="You want to ground the shield on the sending end of the link normally when its a 1 way link.  You may want to plan ahead for ground loops if you know up front the various devices have very different ground potentials (separate virtual grounds).  However, if your inputs are isolated well you should be fine.  Normally on an audio input i'll use an opamp in a differential configuration even if the incoming signal isn't differential.  This keeps the input ground from ever touching the device's ground.  " CreationDate="2010-10-11T17:08:50.870" UserId="1438" />
  <row Id="5690" PostId="5107" Score="1" Text="They are running analog audio over the CAT5.  It's cheaper, available, and works.  The only difference between CAT5 and Balanced XLR are the connectors and the shield." CreationDate="2010-10-11T17:12:19.397" UserId="204" />
  <row Id="5691" PostId="5107" Text="XLR is +, -, gnd, and shield. The combination of all of the pins make for really low noise. How would you map this to cat5? Also, in his case he has gnd and + audio which is not necessarily differential nor is it very well protected against noise." CreationDate="2010-10-11T17:16:43.540" UserId="319" />
  <row Id="5692" PostId="5080" Text="The encoding for a cable signal is usually different than a terrestrial TV signal, though, so you'll need to make sure that the tuning unit can accept the cable signal.  In the USA, at least, you usually have to select ANT or CBL when setting up your TV to ensure it decodes the signal correctly." CreationDate="2010-10-11T17:26:02.937" UserId="374" />
  <row Id="5693" PostId="5104" Score="1" Text="An audiophool is born every minute. " CreationDate="2010-10-11T17:26:37.270" UserId="1225" />
  <row Id="5694" PostId="3579" Text="I think David L. Jones commended this storage method." CreationDate="2010-10-11T17:29:17.347" UserId="374" />
  <row Id="5695" PostId="5104" Score="2" Text="$999.99?  Dang, it went up - used to be $500.  Times are tough." CreationDate="2010-10-11T17:33:11.180" UserId="374" />
  <row Id="5696" PostId="5099" Text="@Mark: Great, that's exactly the kind of thing I was looking for. I just didn't know the name. Thanks." CreationDate="2010-10-11T18:11:02.633" UserId="898" />
  <row Id="5697" PostId="5092" Text="looks like a nice program but unfortunately it doesn't do k-maps (as far as I can tell), which is what I want. Im not really bothered with having the app simplify them, I can easily do that my self. + 1 all the same for the suggestion, Thanks" CreationDate="2010-10-11T18:33:00.967" UserId="819" />
  <row Id="5698" PostId="5104" Score="2" Text="That is the refurb price. The new price is $9,999" CreationDate="2010-10-11T18:39:04.167" UserId="319" />
  <row Id="5699" PostId="5104" Score="1" Text="@Thomas O, I have been in the pro-audio line since I was 15, I was never around anyone who exposed me to things like that though." CreationDate="2010-10-11T18:48:04.987" UserId="319" />
  <row Id="5700" PostId="5092" Text="What are you using the k-maps for if not to simplify Boolean logic equations?" CreationDate="2010-10-11T19:17:47.680" UserId="588" />
  <row Id="5701" PostId="5107" Text="If he's doing single-ended signals, then there is going to have problems.  I'd start by going to balanced audio signals." CreationDate="2010-10-11T20:23:46.537" UserId="204" />
  <row Id="5702" PostId="5108" Text="Cat5 comes in many gages. What size is needed for line level stuff? It's not like I'll be driving any power through it. The kind of patch cord used to connect computer speakers to sounds cards can't be much bigger." CreationDate="2010-10-11T20:40:49.413" UserId="1182" />
  <row Id="5703" PostId="5107" Text="I haven't chosen a signaling yet. See edit. " CreationDate="2010-10-11T20:42:48.770" UserId="1182" />
  <row Id="5704" PostId="5108" Text="Also, one of the reason I'm looking for a multi channel cable it to reduce the real estate the jacks take up." CreationDate="2010-10-11T20:46:48.383" UserId="1182" />
  <row Id="5705" PostId="5084" Text="it's impossible to start with electronics without leds!!! hahaha" CreationDate="2010-10-11T20:52:14.067" UserId="1539" />
  <row Id="5706" PostId="5084" Text="few years ago i've put 24v to an led and 220v ac in an capacitor... shit happens" CreationDate="2010-10-11T20:53:31.063" UserId="1539" />
  <row Id="5708" PostId="5115" Score="1" Text="Do you know what the chip is in these? (I believe that the 2.4GHz ones use the Ember EM250)" CreationDate="2010-10-11T21:18:17.463" UserId="566" />
  <row Id="5709" PostId="5115" Text="Xbee-PRO sounds interesting. 1.6km range! However, that's only the US version; the EU version is only 10mW power... about 250m if it scales linearly." CreationDate="2010-10-11T21:18:43.863" UserId="1225" />
  <row Id="5710" PostId="5115" Score="2" Text="It does not scale linearly, but It should have a table/graph to give you info about range at different powers. Joby, I am not sure which they use." CreationDate="2010-10-11T21:38:53.347" UserId="230" />
  <row Id="5711" PostId="5111" Text="I tried to get a basic project someone could learn from, I think the math is interesting also. People dedicate their lives to it." CreationDate="2010-10-11T21:41:15.040" UserId="230" />
  <row Id="5712" PostId="5106" Text="Always use differential signaling." CreationDate="2010-10-11T21:45:21.987" UserId="230" />
  <row Id="5713" PostId="5115" Text="Sorry, I think Europe operates on 866MHz, not on 900MHz." CreationDate="2010-10-11T21:52:26.620" UserId="230" />
  <row Id="5715" PostId="5111" Text="What do you want to control the temperature of?" CreationDate="2010-10-11T22:07:23.137" UserId="374" />
  <row Id="5716" PostId="5117" Score="1" Text="Thanks Nick.  I tried some things tonight.  The LED was blinking on its own, and the power from the helicopter was not alternating as I originally suspected.  I soldered the power that originally was going to the LED right to the camera and tried to power everything up.  Sure enough, it wasn't enough to run the camera.  Prior to camera power-on, the voltage at the camera's input was 4.17V, and after attempted camera power-on, it was 1.7V.  I am going to follow your suggestion next.  Thanks!" CreationDate="2010-10-11T22:48:10.970" UserId="1554" />
  <row Id="5717" PostId="5114" Text="These are good suggestions to try to get the hang of the way PID loops behave." CreationDate="2010-10-11T22:56:47.197" UserId="374" />
  <row Id="5719" PostId="5120" Text="must be some power-company way of looking at things. i'd agree that MW-H per hour would be MW. maybe utilities look at it as buying and selling units of energy measured in MH-H, and then measure the rate of *that*, rather than just looking at it as straight power." CreationDate="2010-10-11T23:48:12.513" UserId="740" />
  <row Id="5720" PostId="5120" Score="1" Text="it could represent the rate of change of energy I suppose, but I agree it looks like they're just misusing" CreationDate="2010-10-11T23:50:07.313" UserId="566" />
  <row Id="5721" PostId="5108" Text="I was confused as to what you were asking. I was under the assumption you had prebuilt equipment and were going to solder connectors to the CAT5. In the case where you are soldering connectors on, since the wire is so small, it tends to break off easily when getting beat around like many connectors do." CreationDate="2010-10-12T00:41:54.237" UserId="319" />
  <row Id="5722" PostId="5108" Score="2" Text="If you are building both ends yourself then I think you can easily get away with CAT5 cable. If you are worried about noise you can create a differential signal to put on the lines. (Example: http://sound.westhost.com/project51.htm)" CreationDate="2010-10-12T00:48:18.810" UserId="319" />
  <row Id="5723" PostId="5120" Text="Yeah, I think they mean MW." CreationDate="2010-10-12T01:17:08.067" UserId="142" />
  <row Id="5724" PostId="3578" Score="2" Text="Oh man, if only I had an answer to this question...  It's like the effort involved in keeping things organized is more expensive than the parts themselves." CreationDate="2010-10-12T01:18:58.897" UserId="142" />
  <row Id="5725" PostId="1818" Text="I couldn't install it on Windows 7 x64. This is the first installer that tells me that I should ask for a platform specific version" CreationDate="2010-10-12T01:21:25.073" UserId="1298" />
  <row Id="5726" PostId="5106" Text="Ideally, you have the shield connected at both ends, at least at RF frequencies, and then the differential signaling and balanced impedances takes care of any interference or ground loops." CreationDate="2010-10-12T01:31:06.673" UserId="142" />
  <row Id="5727" PostId="5107" Score="1" Text="Choose balanced and differential for long lines." CreationDate="2010-10-12T01:34:29.810" UserId="142" />
  <row Id="5728" PostId="5113" Score="2" Text="or flying in complex formations?" CreationDate="2010-10-12T01:40:06.333" UserId="142" />
  <row Id="5729" PostId="5118" Text="could not remember where that link to PID without a PhD went. I had forgotten about its name and could not remember what I read so long ago. +1 sir." CreationDate="2010-10-12T01:46:53.987" UserId="230" />
  <row Id="5730" PostId="5101" Text="Conformal coating can actually have very very serious issues with high humidity. Most conformal coatings are permeable to water moisture. if there are even small pockets inside you can get condensation under the conformal coating." CreationDate="2010-10-12T01:58:31.690" UserId="230" />
  <row Id="5731" PostId="5101" Text="I am not saying I know this for every conformal coating, just most I have read about and all that I have used." CreationDate="2010-10-12T01:59:00.563" UserId="230" />
  <row Id="5732" PostId="5117" Text="I've tried connecting the camera to the battery, but the camera dies after about 40 seconds.  The camera shuts itself off if the battery voltage dips below 3.6V.  I think that the voltage drop while the main propeller motors spin up is a bit too much for it.  After the camera dies, the helicopter is fine flying around for several more minutes.  I think this project is dead." CreationDate="2010-10-12T02:54:32.580" UserId="1554" />
  <row Id="5735" PostId="5106" Text="@endolith you've confused your problems, at RF frequencies you shield to keep your signals from radiating EMI that could violate FCC, not to prevent noise entering the system (at least at RF frequencies).  Also at that point you ground at both ends to minimize inductance to ground." CreationDate="2010-10-12T06:13:27.687" UserId="1438" />
  <row Id="5736" PostId="5106" Text="You also want to prevent RF from entering the system, since it can be demodulated by nonlinear circuit elements and get into your audio.  http://www.rane.com/note165.html" CreationDate="2010-10-12T06:23:29.890" UserId="142" />
  <row Id="5737" PostId="4521" Text="Dupe? http://electronics.stackexchange.com/questions/952/electronics-blogs-and-podcasts" CreationDate="2010-10-12T06:25:40.417" UserId="142" />
  <row Id="5738" PostId="952" Score="1" Text="dupe? http://electronics.stackexchange.com/questions/4521/meta-share-your-favourite-reads" CreationDate="2010-10-12T06:25:59.587" UserId="142" />
  <row Id="5739" PostId="5113" Text="Yes, that could also be supported." CreationDate="2010-10-12T06:35:40.253" UserId="1225" />
  <row Id="5740" PostId="5097" Text="The data is RS422/485, uni-directional, externally clocked and fairly fast!" CreationDate="2010-10-12T07:42:22.927" />
  <row Id="5741" PostId="5097" Text="RS422/485 do not have a clock, they're asynchronous. So... what?" CreationDate="2010-10-12T09:18:20.757" UserId="1374" />
  <row Id="5742" PostId="5097" Text="RS422 doesn't have to be driven by a uart. It defines only the physical layer. I assume the interface has two RS422 channels operating in parallel. One for the clock and one for the data. (Although I don't know why you would then have start &amp; stop bits...)" CreationDate="2010-10-12T11:00:01.373" UserId="328" />
  <row Id="5743" PostId="5113" Text="1Km+ may be what your after, but in the UK it's illegal to fly more than 500m away or without a direct line of sight, see the DIY Drones site for more info -&gt; http://bit.ly/as8ZBx" CreationDate="2010-10-12T13:27:16.843" UserId="399" />
  <row Id="5744" PostId="5131" Text="Input voltage range is 4.8V to 20V." CreationDate="2010-10-12T13:33:15.687" UserId="1225" />
  <row Id="5745" PostId="5131" Text="I might be getting mixed up with frequencies. It is only rated for 1.6 MHz you're right." CreationDate="2010-10-12T13:33:52.533" UserId="1225" />
  <row Id="5746" PostId="5131" Text="I am using the configuration on page 18, of the datasheet: http://www.national.com/ds/LM/LM2734.pdf" CreationDate="2010-10-12T13:35:17.587" UserId="1225" />
  <row Id="5747" PostId="5113" Text="I'm not using UAV's, these will be piloted by people. If someone writes code for it which enables it to fly in a UAV config though it wouldn't be anything to do with me." CreationDate="2010-10-12T13:36:47.317" UserId="1225" />
  <row Id="5748" PostId="5097" Text="The interface specification was developed to read the data stream into an embedded 68000 - if there is a UART product out there capable of 10Mbps with a suitable interface then that would be perfect! " CreationDate="2010-10-12T13:45:04.073" />
  <row Id="5749" PostId="4521" Text="Naah, I think people got me wrong, I didn't want something totally related to electronics. " CreationDate="2010-10-12T14:04:11.020" UserId="1200" />
  <row Id="5750" PostId="5111" Score="1" Text="Since you cannot remove heat you need to make sure that your system  will still cool even when applying a small current or your pid could have regulation problems.  I would possibly add a fan or ice when you do your experiment.  You want it to go up when you are on full and to go down when you are off. If this is the case the feedback will regulate for you." CreationDate="2010-10-12T14:22:55.840" UserId="540" />
  <row Id="5751" PostId="5106" Text="that link doesn't talk about using shielding to keep RF EMI out.  It talks about improperly terminated shields acting as RF antennas which is a very much a concern.  However if the shield simply weren't there, its very doubtful there would be an RF pick up problem.  Quite a few times i've seen shields _cause_ RF noise problems in audio circuits due to poor implementation." CreationDate="2010-10-12T14:31:51.943" UserId="1438" />
  <row Id="5752" PostId="5106" Text="So, connect the sheathing to ground at both ends through a capacitor sized to pass somewhere around 0.25MHz and above?" CreationDate="2010-10-12T14:33:34.957" UserId="1182" />
  <row Id="5753" PostId="5106" Text="I would at least include a some sort of disconnect to allow you to play with connecting at only one end.  Connecting at both ends if fine as long as it doesn't case a ground loop, which is often does.  Also the ideal path from the shield to system ground is the one with the lowest resistance _AND_ lowest inductance.  It also shouldn't go through the circuit board.  Which really just means it should be tied to the chassis as soon as possible and the chassis should be tied directly to the system ground.  " CreationDate="2010-10-12T14:39:27.757" UserId="1438" />
  <row Id="5754" PostId="5106" Text="Well most RJ-45 jack mount on PCBs (or in wall plates but those are way to big) so I gues going through the PCB is going to be hard to avoid. OTOH, having a &quot;grounded&quot; board mount right next to it that is only used for the shielding should be somewhat close to a direct ground." CreationDate="2010-10-12T14:46:41.010" UserId="1182" />
  <row Id="5755" PostId="5107" Score="1" Text="@endolith: How long is long? I'm not expecting anything longer than a meter, two at the outside." CreationDate="2010-10-12T14:49:16.387" UserId="1182" />
  <row Id="5756" PostId="5106" Text="well, when i mean &quot;through&quot; i mean not having the ground return path going all the way across the PCB.  With board mount connectors the common way to handle it is to take the shield ground to the nearest chassis mounting screw, which is usually designed to be close to the connectors partially for this reason.  This gives you a pretty direct path to chassis ground without running all over the PCB.  Just keep the traces or copper pour from the connector to the screw as short and fat as possible." CreationDate="2010-10-12T15:02:16.250" UserId="1438" />
  <row Id="5757" PostId="5134" Score="4" Text="Does this have to be portable, or will it be connected to an AC supply?  If so, you could count 60 (or 50) Hz crossings, which are very accurate over the long run." CreationDate="2010-10-12T15:28:53.220" UserId="1322" />
  <row Id="5758" PostId="5122" Text="First, I'd just like an overview of general differences, since each can use many of the same switched fabrics.   In the end, performance and price, but I surmise the implementation of particular needed hardware on those architectures will generally dictate that? " CreationDate="2010-10-12T15:51:13.583" UserId="1297" />
  <row Id="5759" PostId="5138" Text="Thanks for your critiques. I will take them into account when designing the final version." CreationDate="2010-10-12T16:12:52.240" UserId="1225" />
  <row Id="5761" PostId="5130" Text="http://electronics.stackexchange.com/questions/4640/capacitors-and-motors" CreationDate="2010-10-12T16:34:01.690" UserId="142" />
  <row Id="5762" PostId="5131" Text="+1 for your edits, and thanks for doing the calcs. Accuracy is not critical - ±5% is fine. I'm not expecting great efficiency - anything greater than 50-60% is fine. " CreationDate="2010-10-12T17:25:31.317" UserId="1225" />
  <row Id="5763" PostId="5131" Text="When you say copper, would just drawing a polygon under the chip work well? Should it be on the same layer as the ICs?" CreationDate="2010-10-12T17:26:06.963" UserId="1225" />
  <row Id="5764" PostId="5134" Text="Don't try using the AC supply - you can't count on the power staying on for 6 months straight without taking extraordinary measures. " CreationDate="2010-10-12T17:45:06.437" UserId="259" />
  <row Id="5765" PostId="5134" Score="1" Text="I have seen this application used in water filters to alert you when the filter needs to be replaced. They can run for many years with out having to replace a battery so I assume they are able to do it very easily." CreationDate="2010-10-12T18:03:59.770" UserId="319" />
  <row Id="5766" PostId="5134" Score="1" Text="@Vincent Conlon: What precision do you need? In the water filter example, I am sure the precision is horrible, but I don't think anyone cares if you get alerted a week early or late." CreationDate="2010-10-12T18:06:16.267" UserId="319" />
  <row Id="5767" PostId="5092" Text="I was using them for simplifying... but on paper, I just needed  software to create something pretty for a report. Anyway I ended up using excel. Thanks" CreationDate="2010-10-12T18:20:26.133" UserId="819" />
  <row Id="5768" PostId="4956" Score="2" Text="@Jordan S You should consider accepting answers to questions you have asked. Your accept rate is currently 44% which is shown under your name. You will find that people will start to not answer your questions as much if you have a low accept rate." CreationDate="2010-10-12T18:31:03.677" UserId="319" />
  <row Id="5769" PostId="5131" Text="I added some skinny copper, would this work to remove the heat? http://i53.tinypic.com/2rr00f9.png" CreationDate="2010-10-12T19:06:30.613" UserId="1225" />
  <row Id="5770" PostId="5107" Text="@BCS: I'd consider that short, but I think the official definition of long if a function of the EMI noise frequency/strength you are worried about." CreationDate="2010-10-12T19:24:51.043" UserId="204" />
  <row Id="5771" PostId="5129" Text="AH, I figured out what I was talking about when I was saying the 3MHz frequency. That is for the LM2734Z, not the X or Y parts. Sorry for any confusion!" CreationDate="2010-10-12T19:41:26.547" UserId="1225" />
  <row Id="5772" PostId="5139" Score="1" Text="A hatched plane must weigh a tiny bit less... could that ever matter?" CreationDate="2010-10-12T20:05:27.533" UserId="1363" />
  <row Id="5773" PostId="5139" Score="1" Text="We've gone plaid!" CreationDate="2010-10-12T20:05:54.587" UserId="1363" />
  <row Id="5774" PostId="5022" Text="I don't know.  If you look at the authors' comments, he was trying to get in touch with the manufacturer.  You might ask him, or call them.  " CreationDate="2010-10-12T20:09:32.647" UserId="857" />
  <row Id="5776" PostId="5065" Score="1" Text="Talk about overkill. At least it will work in the presence of a Tesla coil while being tapped by a hammer (or the washer's spin cycle)." CreationDate="2010-10-12T20:13:01.990" UserId="1363" />
  <row Id="5777" PostId="5022" Text="Also, to do URLs in comments, use `[link text](url)` like this: [comment markdown](http://blog.stackoverflow.com/2010/01/new-improved-comments-with-reply/)" CreationDate="2010-10-12T20:13:28.987" UserId="857" />
  <row Id="5778" PostId="5141" Text="You shouldn't use a 555 with a period of 16 minutes; better to cascade two counters and run the 555 at a more-sane frequency (kHz or so).  Better to not use a 555 at all if you care about tolerance much." CreationDate="2010-10-12T20:13:30.347" UserId="1407" />
  <row Id="5779" PostId="5135" Text="Um...`double`?  Wrong.  You mean `long`, or preferably `int32_t`." CreationDate="2010-10-12T20:16:46.853" UserId="1407" />
  <row Id="5780" PostId="5141" Text="A CMOS 555 will easily run for hours. The OP seemed to suggest accuracy was not an issue." CreationDate="2010-10-12T20:29:28.777" UserId="1225" />
  <row Id="5781" PostId="5143" Text="Crosshatched should be used specifically for increasing impedance of the traces. With a small crosshatch(ie. no traces go over a gap together) there will not be many crosstalk problems but give you the impedance you need." CreationDate="2010-10-12T20:50:18.937" UserId="230" />
  <row Id="5782" PostId="5143" Text="I already gave you a +1, but please edit to note that the crosshatching should only be used in an impedance situations. It is still acceptable for high speed signals, you just need to make sure traces are sufficiently separated to stop crosstalk." CreationDate="2010-10-12T20:58:19.410" UserId="230" />
  <row Id="5783" PostId="5146" Text="Can you tell me how you use tip tinners? Maybe I'm doing something wrong. Also, for mixed plating, my tip seems to have it. Only small area of the tip's tip  seems to be working part and it looks different than the rest of the tip." CreationDate="2010-10-12T21:03:27.247" UserId="1240" />
  <row Id="5784" PostId="5145" Text="Unfortunately, they do not ship to my country." CreationDate="2010-10-12T21:08:19.323" UserId="1240" />
  <row Id="5785" PostId="5135" Score="3" Text="AH, you're right. Rude, but right." CreationDate="2010-10-12T21:09:13.113" UserId="712" />
  <row Id="5786" PostId="5146" Text="Also, my cleaner says: Sn96.5Ag3.5 which seems to be strange to me." CreationDate="2010-10-12T21:12:03.887" UserId="1240" />
  <row Id="5787" PostId="5146" Text="You should not use tip tinners unless necessary.  They will erode the tip plating incredibly fast if used often (meaning any more than once or twice a day).  *Ideally, you should never use them*, as you would maintain a small amount of solder on the tip at all times to prevent oxidation of the bare tip metal.  The world isn't perfect though, and sometimes you can't, so they can get you out of that bind." CreationDate="2010-10-12T21:14:50.810" UserId="1407" />
  <row Id="5788" PostId="5146" Text="@Nick T I understand that I should have some solder on the tip in order to protect it (and have always left part of the tip which would get wet covered in solder) and so on and that I should avoid using the cleaners, but how are they used? I thought that tip should just be dipped into the cleaner and that's it. Is there anything else?" CreationDate="2010-10-12T21:18:17.600" UserId="1240" />
  <row Id="5789" PostId="5146" Text="Assuming your tip tinner is the solid variety, the Sn/Ag is just the alloy it contains.  It's just some solder alloy it coats the tip with. -- Yeah, you should just have to stab it into the tinner and promptly wipe it off with a sponge or metal sponge.  If the oxidation is being really stubborn, the tip might be gone." CreationDate="2010-10-12T21:18:43.100" UserId="1407" />
  <row Id="5790" PostId="5106" Text="Placing the board mounts near the jacks is a good idea from a mechanical standpoint as well. I think I see where this is leading." CreationDate="2010-10-12T21:22:25.703" UserId="1182" />
  <row Id="5791" PostId="5146" Text="@Nick T  OK. Thanks! Wikipedia mentions that alloy, so I have a staring point for researching it's normal behavior." CreationDate="2010-10-12T21:24:19.537" UserId="1240" />
  <row Id="5792" PostId="5146" Text="The alloy doesn't really do anything to clean the tip; the action is due to the ammonium phosphate being mildly acidic, which reacts with the metal oxides--bases." CreationDate="2010-10-12T21:28:24.577" UserId="1407" />
  <row Id="5793" PostId="5145" Text="You can probably find some where you live. Where do you live?" CreationDate="2010-10-12T21:33:59.247" UserId="1225" />
  <row Id="5794" PostId="5145" Text="I'm in Serbia, as it is written in my profile. I'll take another look through stuff available in local stores here. Maybe there is something similar available." CreationDate="2010-10-12T21:54:59.353" UserId="1240" />
  <row Id="5795" PostId="5140" Text="This is not correct vikram. This is a confusion between hatched ground planes and thermal relief. Mark is correct here." CreationDate="2010-10-12T22:05:29.050" UserId="230" />
  <row Id="5796" PostId="5106" Text="Yep :) The place where shielding gets really complicated is when your stuck with non conductive enclosures.  Usually results in awkward ground strategies like a &quot;chassis&quot; ground around the edge of the PCB which isn't all that great from a number of stand points." CreationDate="2010-10-12T22:34:05.503" UserId="1438" />
  <row Id="5797" PostId="5065" Text="Yah, I know, it's kinda funny. I had the PLC around from another project. Works great though." CreationDate="2010-10-12T22:39:17.723" UserId="1411" />
  <row Id="5798" PostId="5143" Text="i don't completely agree, but i edited to replace my general language with more specific issues as frequency increases " CreationDate="2010-10-12T22:42:57.877" UserId="1438" />
  <row Id="5799" PostId="5106" Text="Or do what physicist do, wrap it in a ball of aluminum foil: http://www.reciprocalspace.net/files/dbdcc47f0f7492f83d42dc49c93ddbd4-59.html" CreationDate="2010-10-12T23:07:58.623" UserId="1182" />
  <row Id="5800" PostId="5131" Text="while i can't speak for him, your PCB layout program really should have yelled at you orphaning all that copper, something more like this is likely what he had in mind (excuse my poor photoshopping): http://tinypic.com/r/2q99ftu/7" CreationDate="2010-10-12T23:15:32.403" UserId="1438" />
  <row Id="5801" PostId="5140" Text="After doing much internet surfing for trying to figure this out I am still unsure. Pretty much everything I see online points to this being a fabrication issue. However, I was shown a book that talks about it being an impedance issue. Currently I am leaning toward trusting the book. If the book is correct, my answer is not the correct answer." CreationDate="2010-10-12T23:22:05.127" UserId="319" />
  <row Id="5802" PostId="5143" Text="the hatched ground plane does not have to decrease in size with frequency, it must decrease in size with relation to trace spacing to remove crosstalk." CreationDate="2010-10-13T01:34:03.230" UserId="230" />
  <row Id="5803" PostId="5143" Score="1" Text="In general, I agree. Never use hatched ground planes. This will be true for 99% of people. If you need one and realize it, you probably do not care our opinion, as you know your stuff." CreationDate="2010-10-13T01:34:53.773" UserId="230" />
  <row Id="5804" PostId="5139" Text="I cannot image a situation where the weight of the board would matter to that precision where a different change did not make it better." CreationDate="2010-10-13T01:37:18.823" UserId="230" />
  <row Id="5805" PostId="5139" Score="1" Text="I know large solid ground planes have a completely different heat up rate compared to non-ground plane. This effect reflow soldering. I could see hatching having an effect in this, but I would imagine it would be small." CreationDate="2010-10-13T03:02:44.367" UserId="319" />
  <row Id="5806" PostId="5140" Score="3" Text="http://www.amazon.com/High-Speed-Digital-Design-Handbook/dp/0133957241 covers it" CreationDate="2010-10-13T03:18:06.920" UserId="1438" />
  <row Id="5808" PostId="5131" Text="If I ran DRC it probably would yell at me. I will give your suggestion a try." CreationDate="2010-10-13T06:49:53.520" UserId="1225" />
  <row Id="5809" PostId="5063" Score="1" Text="+1 for the tutorial…" CreationDate="2010-10-13T07:09:36.427" UserId="1317" />
  <row Id="5810" PostId="5135" Score="6" Text="Um... int32_t? Wrong. You mean uint32_t, unless you're expecting time to go backwards too." CreationDate="2010-10-13T08:18:25.217" UserId="566" />
  <row Id="5811" PostId="5024" Text="Find a project you want to make, design a circuit for it using a propeller IC, build it." CreationDate="2010-10-13T08:44:44.290" UserId="1374" />
  <row Id="5812" PostId="5155" Text="Problem is the rechargeables are being switched out quite quickly to where my Excel spreadsheet tells me they won't even last two years. Am sure this is bad circuit design. Would really like to look into AC powered possibilities. Although, I will mention that a recharge circuit for a rechargeable battery in the rocker would definitely suite my needs." CreationDate="2010-10-13T09:35:58.583" UserId="1575" />
  <row Id="5813" PostId="5154" Score="1" Text="a time consuming, but inexpensive thing would be to re-wind the coil in the rocker with lighter gauge wire so that instead of slugs of current at 1.5V, it would operate on less current at 9V.  not very glamorous, borders on the mechanical, but in theory it should work." CreationDate="2010-10-13T11:21:53.957" UserId="740" />
  <row Id="5814" PostId="5122" Text="+1 on the basis of 'consider IO card availability' alone." CreationDate="2010-10-13T11:23:32.300" UserId="740" />
  <row Id="5815" PostId="5157" Score="1" Text="Do you know what the two chips are? If not exact part numbers, package size, general function, anything else?" CreationDate="2010-10-13T13:06:06.030" UserId="712" />
  <row Id="5816" PostId="5157" Text="@pingswept Updated question" CreationDate="2010-10-13T13:13:21.013" UserId="566" />
  <row Id="5817" PostId="5140" Text="That is what I referenced." CreationDate="2010-10-13T14:09:36.743" UserId="230" />
  <row Id="5818" PostId="5135" Text="True, you can double your range by using unsigned types, but it should be avoided if possible.  Arithmetic with unsigned types can cause irritating bugs from the type promotion that C does." CreationDate="2010-10-13T14:21:58.147" UserId="1407" />
  <row Id="5819" PostId="5162" Score="1" Text="Should work unless the master deasserts SS if tries and fails to contact the slave, but that just means you might have to use a scope instead of a multimeter." CreationDate="2010-10-13T15:08:45.853" UserId="1407" />
  <row Id="5820" PostId="5162" Score="1" Text="Good idea. If you reset the slave you should still see the CS line toggling on a scope. If you have reset the master the line will float." CreationDate="2010-10-13T15:15:40.900" UserId="588" />
  <row Id="5821" PostId="5115" Text="I'd stick with 2.4 GHz if you have justifiable cause to think international as that's a global ISM band versus the 8-900 bands.  XBee-PRO® DigiMesh™ 2.4 (Int'l): Line of sight range: 2500 ft (750 m)  http://www.digi.com/products/wireless/zigbee-mesh/xbee-digimesh-2-4.jsp#specs" CreationDate="2010-10-13T15:16:09.840" UserId="1407" />
  <row Id="5822" PostId="5030" Text="@davr - yeah, that seemed a little odd to me also, since there is only one Propeller chip that goes into that socket.  BTW they've sold almost 50 of these boards since I bought mine four days ago (currently 29 left)." CreationDate="2010-10-13T15:32:59.577" UserId="1322" />
  <row Id="5823" PostId="5115" Text="Yeah, I realize international you want 2.4GHz, but the issue here is per country you can have a variance in allowed radiated power. I believe that Europe keeps it lower. Less power gets better range at 866/900." CreationDate="2010-10-13T15:41:55.597" UserId="230" />
  <row Id="5824" PostId="5159" Score="2" Text="According to this ( focus.ti.com/lit/ds/symlink/cc1110f32.pdf  ) CC1110 datasheet, &quot;In SPI master mode, only the MOSI, MISO, and SCK should be configured as peripherals. If the external slave requires a slave select signal (SSN) this can be implemented by using a general-purpose I/O pin and control from SW.&quot;  Since you indicated the chip select comes off of a GPIO pin on the CC1110, this supports mjh2007's answer." CreationDate="2010-10-13T15:47:37.800" UserId="1322" />
  <row Id="5825" PostId="5111" Text="That is determined by the temperature of the water tank that is required. If he wants 80C then environment temp will be enough, if he wants 25C then he will have an issue. The PID when tuned properly should be able to deal with a slow temp loss. " CreationDate="2010-10-13T15:56:01.927" UserId="230" />
  <row Id="5826" PostId="5131" Score="1" Text="The copper should be as close as possible to the pin. The same layer is ideal as vias add thermal impedance. The copper should be exposed to free air (if possible) for maximum convection cooling. Any copper is better than none at all (as long as the copper isn't made hotter by something else and is heating, rather than cooling, the IC)" CreationDate="2010-10-13T16:38:29.120" UserId="1293" />
  <row Id="5827" PostId="5168" Score="1" Text="@pingswept - Yeah.  I'm asking around.  I'm like 80% sure stty will work - it's the traditional UNIX way of doing it.  But I was hoping someone who uses OS X and would know for sure. :)" CreationDate="2010-10-13T17:34:01.583" UserId="374" />
  <row Id="5828" PostId="5168" Text="Ah, I see. Very thorough." CreationDate="2010-10-13T17:35:08.307" UserId="712" />
  <row Id="5829" PostId="4297" Text="It is pretty simple to load the bootloader on a chip and solder up your own board if you want to give away a project. Or order a RBBB kit for $12.50(http://goo.gl/0yqr) no need to buy a $30+ board for each Arduino project." CreationDate="2010-10-13T17:43:23.040" UserId="1580" />
  <row Id="5830" PostId="5024" Text="For the uninitiated: [What is Parallax Propeller?](http://en.wikipedia.org/wiki/Parallax_Propeller)" CreationDate="2010-10-13T17:54:36.297" UserId="804" />
  <row Id="5831" PostId="5169" Score="1" Text="5 A linear regulator, woo...if you're actually thinking about using something like that because you need the current, I would *strongly* suggest a switching supply." CreationDate="2010-10-13T18:48:17.847" UserId="1407" />
  <row Id="5832" PostId="5113" Text="Sorry, it's all small unmanned aircraft including UAV's - I should have been more explicit, these regulations cover both RCs and drones." CreationDate="2010-10-13T18:49:15.217" UserId="399" />
  <row Id="5833" PostId="5163" Score="3" Text="Yeah, I'd be willing to bet the rocker doesn't really have any electronics anyways (probably just a switched coil/magnet).  I'd probably (check my earlier assumption first, then) grab some old cell-phone charger, chop the end off, and wire it up and see what happens.  Only problem might be that the current is higher than it should be and it heats up (catches fire, and burns your house down)." CreationDate="2010-10-13T19:02:23.920" UserId="1407" />
  <row Id="5834" PostId="5113" Text="I have never heard of that. But I will look it up. BTW, &quot;unmanned&quot; usually means no pilot, not just that the pilot doesn't fly with the aircraft, unless I'm missing something...?" CreationDate="2010-10-13T19:24:00.933" UserId="1225" />
  <row Id="5835" PostId="5115" Text="Thanks for the link. 750m would still be pretty good. " CreationDate="2010-10-13T19:25:43.457" UserId="1225" />
  <row Id="5836" PostId="5170" Text="Don't forget for regulators like the LM138, LM337 etc., you should always have a minimum load of about 3.5 to 10 mA (depending on operating conditions.) This is usually provided by the adjust resistor R1, but if it isn't provided, then the output voltage will rise." CreationDate="2010-10-13T19:59:21.923" UserId="1225" />
  <row Id="5837" PostId="5165" Text="thnx Scott, that brd_to_dsn.ulp worked prefectly. I was able to turn eagle's brds to dsn files and import it in TopoR. " CreationDate="2010-10-13T20:12:46.197" UserId="1568" />
  <row Id="5838" PostId="5173" Score="1" Text="antenna for what? RF? what frequency? are you should the metal band is even the proper size,shape,impedance for what your trying to transmit?" CreationDate="2010-10-13T21:08:23.380" UserId="1438" />
  <row Id="5839" PostId="5165" Text="now all I need is an ulp that can import SES files exported by TopoR back into eaglecad. " CreationDate="2010-10-13T21:11:23.980" UserId="1568" />
  <row Id="5840" PostId="5173" Text="Sorry, I didn't mention because assumed was implicit. Yes, RF, 2.4 GHz. No worries about the metal band size/shape: I can modify it to accomodate the antenna specs. My only concern is if the field coming from the magnet would affect the circuit." CreationDate="2010-10-13T21:39:06.457" UserId="1078" />
  <row Id="5841" PostId="5113" Text="To anyone who's interested, here's the proof of concept - the idea works: http://www.youtube.com/watch?v=V_fjUtqqX0M" CreationDate="2010-10-13T21:45:27.050" UserId="1225" />
  <row Id="5842" PostId="5170" Text="note also that whatever current you deliver to your load through one of these, also incurs a penalty for passing through the voltage drop across the regulator. For example, if you are dropping 9V to 5V and delivering 3A of that, your regulator dissipates (9-5)*3 = 12W" CreationDate="2010-10-13T22:02:19.257" UserId="740" />
  <row Id="5843" PostId="5178" Text="In fact it's a remote that just transmits, doesn't receive. How much necessary is degaussing in such case? What would you recommend for it?" CreationDate="2010-10-13T22:09:36.533" UserId="1078" />
  <row Id="5844" PostId="5178" Score="4" Text="unless you're running more than a watt, the RF probably won't bother the magnet. i'd actually be more concerned that the magnet is made of actual metal and not some ceramic that would possibly exhibit weird dielectric properties at those frequencies." CreationDate="2010-10-13T22:30:34.433" UserId="740" />
  <row Id="5845" PostId="5178" Text="OK, no worries. In this case is a metallic magnet with very low impedance." CreationDate="2010-10-13T22:35:56.287" UserId="1078" />
  <row Id="5846" PostId="5179" Text="Problem is, it can't be insulated since it is between the antenna and the circuit." CreationDate="2010-10-13T22:36:37.333" UserId="1078" />
  <row Id="5847" PostId="5169" Score="1" Text="This is a duplicate. I am voting to close. http://electronics.stackexchange.com/questions/922/how-does-an-lm7805-voltage-regulator-work" CreationDate="2010-10-13T22:57:58.833" UserId="230" />
  <row Id="5848" PostId="5179" Score="2" Text="it'll be a bit of a pain to match the impedance of the antenna through the magnetic.  The magnet to metal band contact connection will have resistive and inductive properties in addition to the affect of however you attach the signal to the magnet." CreationDate="2010-10-13T23:10:43.583" UserId="1438" />
  <row Id="5849" PostId="5179" Score="1" Text="Mark is correct, forget about connecting the magnet to the antenna. Think of another way to keep the enclosure shut." CreationDate="2010-10-13T23:23:38.123" UserId="305" />
  <row Id="5850" PostId="5159" Text="Accepted - this helped me understand what I was seeing. It turns out that the bus was not SPI, nor had I found the chip select. It was one of two attention lines used to signal the start of a data transfer. One of these terminates at CY7C63803:SSEL, the other on an (interrupt capable) pin of the CC1110. The attention line is briefly pulsed before each transfer, then data is clocked out over one of the two data lines. Though, I still don't know who's driving the shared clock ;-)" CreationDate="2010-10-14T00:00:53.017" UserId="566" />
  <row Id="5851" PostId="5121" Text="This sounds really tempting.  This is all personal project stuff, and saving a little money would be really nice." CreationDate="2010-10-14T00:28:16.547" UserId="213" />
  <row Id="5852" PostId="5101" Text="I'm accepting this - it seems to be the most solid conventional wisdom.  Having the right keyword to start searching gets me on the right path.  John Lopez's tip down below is probably where I'll start, though." CreationDate="2010-10-14T00:29:33.643" UserId="213" />
  <row Id="5853" PostId="5178" Score="3" Text="you're more likely to run into impedance matching issues with the geometry of the thing, than anything else." CreationDate="2010-10-14T00:45:31.703" UserId="740" />
  <row Id="5854" PostId="5179" Text="Well, then I could left the antenna as a PCB strip, totally disconnected from the magnet and the band. I was thinking about them as maybe being better to propagate the signal, but guess (given your thoughts) it's not worth the trouble." CreationDate="2010-10-14T00:46:34.883" UserId="1078" />
  <row Id="5855" PostId="5186" Score="7" Text="because 95-99% of parts are sold on reels with bar codes that just get inserted into pick in place machines.  Labeling cost increases for the tiny fraction of parts that actually get handled by a human isn't worth it." CreationDate="2010-10-14T01:58:24.130" UserId="1438" />
  <row Id="5856" PostId="5188" Score="2" Text="It might be helpful to know more about Device 1 2 and 3. If they have a defined protocol already, you would have to hook them up exactly as the device wants." CreationDate="2010-10-14T03:16:40.650" UserId="319" />
  <row Id="5857" PostId="5188" Score="1" Text="Hi, Chris. How many devices are we talking about? I know you say you won't know the total, but are we talking 10, 1000, or more? Also, what kind of environment will you be in-- clueful users, or not so much? How important is robustness?" CreationDate="2010-10-14T03:24:52.433" UserId="712" />
  <row Id="5858" PostId="5132" Text="If it is a PWM, you may also need to shield the wiring between the motor and controller to prevent EMI." CreationDate="2010-10-14T03:38:36.650" UserId="965" />
  <row Id="5859" PostId="5188" Score="3" Text="whats the PHY? I2C? SPI? something else?" CreationDate="2010-10-14T03:46:13.320" UserId="1438" />
  <row Id="5860" PostId="5186" Score="6" Text="I think most markings now are done by laser engraving, &quot;burning&quot; the epoxy package to make the brownish print, not sure though." CreationDate="2010-10-14T04:48:49.880" UserId="1407" />
  <row Id="5861" PostId="5163" Score="2" Text="You don't need to worry about the current rating on the power supply, as long as it is higher than what you need. It simply lists a maximum amount it can supply, it's not saying that whatever you connect your 9V/1A adapter to, will have 1 amp of current &quot;pushed&quot; through it." CreationDate="2010-10-14T05:45:34.063" UserId="131" />
  <row Id="5862" PostId="5165" Text="Please don't mark this answer as accepted since it doesn't fully answer the question (no info on how to import SES into Eagle). If you mark it accepted, then other people are unlikely to come and offer more help." CreationDate="2010-10-14T05:46:37.433" UserId="131" />
  <row Id="5863" PostId="5189" Score="1" Text="Yeah, wiping the part with fingers can also remove flux residues (if it was desoldered from somewhere, which is the most frequent, for me, case when I need to recognize the part name)." CreationDate="2010-10-14T07:52:20.380" UserId="1311" />
  <row Id="5864" PostId="5184" Text="How more is that a lot more? I used it maybe 5 times and that's why it's looking strange to me. I'm trying to avoid the file because I'm afraid I'll remove the iron plating and expose copper core of the tip." CreationDate="2010-10-14T09:58:56.637" UserId="1240" />
  <row Id="5865" PostId="5192" Text="I'll second that, I use a cheapo clear/blue LED torch, it works a treat, I've got magnifying glasses but the torch is normally enough " CreationDate="2010-10-14T10:04:18.030" UserId="399" />
  <row Id="5866" PostId="5189" Text="I use magnifying lamp, but the idea is same. I found that a quick rub with alcohol helps a lot. &#xA;&#xA;I have not tried, but theoretically a swipe with white chalk marks the rough surface created by the labeling and makes it easily readable :)" CreationDate="2010-10-14T10:20:36.737" UserId="1514" />
  <row Id="5867" PostId="5186" Score="2" Text="@Mark if that's the case why bother to print at all?" CreationDate="2010-10-14T11:30:47.660" UserId="1298" />
  <row Id="5868" PostId="5163" Text="I can't believe it doesn't have a inlet either. This sounds like the way to roll. Thanks all!" CreationDate="2010-10-14T11:38:27.130" UserId="1575" />
  <row Id="5869" PostId="5141" Text="Even if accuracy was not an issue a 555 running over such a long time span will be so wildly inaccurate as to make it essentially an arbitrary time. I like the MSP430 solution much better, cheap and the supplied crystal will be reasonably accurate over the required timespan." CreationDate="2010-10-14T12:28:19.950" UserId="611" />
  <row Id="5870" PostId="5189" Text="Flux can also be scraped off with a knife, and wiping the markings with spit can also help. &gt;.&lt;  It even helps with chips that have had the numbers lazily scraped off, strangely enough." CreationDate="2010-10-14T13:52:59.860" UserId="142" />
  <row Id="5871" PostId="5185" Score="3" Text="Sounds good, but a few searches turned up nothing. More details needed." CreationDate="2010-10-14T13:55:01.623" UserId="1181" />
  <row Id="5872" PostId="5188" Text="The phy hasn't been determined yet, this is still early in the process. It'll max out at 4 at a time right now I think but could be more in the future. The other thing is that there is potential that the 4 devices will be different every time. These will basically be swappable devices. " CreationDate="2010-10-14T14:20:49.173" UserId="404" />
  <row Id="5873" PostId="5193" Text="I think I'd trend towards the SPI solution because of the nature of the devices I'm working on. I'll be able to hardwire to a point but then it'd be unknown past that point (the devices will change out once in a while)" CreationDate="2010-10-14T14:27:33.733" UserId="404" />
  <row Id="5874" PostId="5193" Text="Another thing I thought of. Since I'm trying to make the devices swappable, I was also hoping they'd be the same board (layout with only the programmed unique ID being different). That's another issue because the CS lines wouldn't necessarily only be running to one of the devices. I'm really concerned that I'm setting myself up for a &quot;self organizing network&quot; which is waaaay more complicated than I want." CreationDate="2010-10-14T14:39:27.920" UserId="404" />
  <row Id="5875" PostId="5193" Text="If you have an MCU in each device, you might be able to do without the chip selects. All devices monitor the data+clock lines and only respond when addressed (eg. first byte received). Each device would need to have a unique address. If you're trying to cut down on wires (at the expense of speed), have a look at Maxim's 1-wire microlan bus." CreationDate="2010-10-14T14:45:51.497" UserId="566" />
  <row Id="5876" PostId="5183" Text="I tried using USBSnoop and every time I try to install the snooper on the device the device stops working. I can no longer connect to the COM port says bad COM port Id." CreationDate="2010-10-14T14:51:05.867" UserId="588" />
  <row Id="5877" PostId="5194" Score="1" Text="Also, shining the light sideways rather than head on tends to help a lot." CreationDate="2010-10-14T14:59:04.760" UserId="1181" />
  <row Id="5878" PostId="5196" Text="I will look up how much we paid for this last time we did it. It is reasonable, but it is not cheap." CreationDate="2010-10-14T15:16:09.087" UserId="230" />
  <row Id="5879" PostId="5196" Text="Are you referring to a device that has a wireless module in it, or are you just concerned about EMC/EMI testing?" CreationDate="2010-10-14T15:26:01.610" UserId="1322" />
  <row Id="5880" PostId="5183" Score="1" Text="USBsnoop seems to work with HID class devices only. I used SniffUSB (http://www.pcausa.com/Utilities/UsbSnoop/) instead." CreationDate="2010-10-14T15:50:43.603" UserId="588" />
  <row Id="5881" PostId="5180" Text="There is no way for me to check the OEER bit or setup the USB Processor as a loopback since I don't have control of that firmware. I already have the application processor echo what it receives and that is working. What would cause the OERR bit to get set? Can I clear it by resetting the USB processor?" CreationDate="2010-10-14T15:54:19.180" UserId="588" />
  <row Id="5882" PostId="5196" Text="@Kortuk I am only looking for a ballpark figure. @tcrosley let's stick to unintentional radiators for now." CreationDate="2010-10-14T16:16:55.907" UserId="1363" />
  <row Id="5883" PostId="5196" Text="let me ask the company, i am not at work and do not handle accounting so i cannot even remember ballpark." CreationDate="2010-10-14T16:28:32.940" UserId="230" />
  <row Id="5884" PostId="5206" Text="the university has a facility we are trying to rent in town for the same reason." CreationDate="2010-10-14T16:29:49.053" UserId="230" />
  <row Id="5885" PostId="5201" Score="2" Text="I think this is not really an appropriate question for this forum.  Not sure where it would go, but not here." CreationDate="2010-10-14T17:03:16.957" UserId="249" />
  <row Id="5886" PostId="5180" Text="The problem was with the UART on the USB processor. Once the UART on the USB processor had an error there was no way to reset it. The solution was to power-up the development board while holding the MCLR reset for the application processor. Then releasing the MCLR after the USB processor powered up." CreationDate="2010-10-14T17:04:20.223" UserId="588" />
  <row Id="5887" PostId="5175" Text="OK, slowly starting to make sense. So if I wanted to use your code to just write a utility in C to let me interact with my Arduino board, I'd create a command-line projected in XCode, based in C, and then paste that in. Compile it, then what would I do to run it? Just ./ProgramName /dev/tty.usbserial-XXX?" CreationDate="2010-10-14T17:23:41.757" UserId="1596" />
  <row Id="5888" PostId="5168" Text="Thanks for all your help, @sheep! I'm still having trouble with this and am beginning to think I'm just insane. Even using the various stty arguments, I put those in and it just hangs. I feel like there's some fundamental paradigm I'm not getting. &gt;&lt;" CreationDate="2010-10-14T17:26:49.633" UserId="1596" />
  <row Id="5889" PostId="5175" Text="Hmm, after much googling around I may have figured this out. I found this: http://todbot.com/blog/2006/12/06/arduino-serial-c-code-to-talk-to-arduino/&#xA;&#xA;Which I was able to modify to output the data I need, and compile. It seems to be working! :)" CreationDate="2010-10-14T18:19:34.567" UserId="1596" />
  <row Id="5893" PostId="5201" Score="1" Text="This is off topic. I would recommend closing this question." CreationDate="2010-10-14T19:07:30.870" UserId="965" />
  <row Id="5894" PostId="5175" Text="@Myk - To your first comment, yes.  To your second comment, good to hear!  You might want to read up/learn about the communication chain between the two ends (Mac &lt;-&gt; Arduino) and all the interfaces inbetween to ensure you have an idea of what's going on here.  There's a lot of interfaces between the USB port and the Arduino to understand.  :)  I take it from your blog that you dabble in a lot of different technological things.  If you plan on doing more with a serial port in the future, I'd either find an expert to help, or learn up on this stuff more." CreationDate="2010-10-14T20:21:19.807" UserId="374" />
  <row Id="5895" PostId="5167" Text="http://stackoverflow.com/questions/3918032/bash-serial-i-o-and-arduino" CreationDate="2010-10-14T20:22:15.247" UserId="374" />
  <row Id="5896" PostId="5175" Text="Yeah, I'm mostly a flash/flex guy - I'm just trying to find a way to build a reusable Arduino -&gt; Flash/Flex bootstrapper for use on a project I'm doing. Generally speaking the established practice is to run something like tinkerproxy or serproxy and just use local socket connections to interface with Arduino - but with AIR2 we have the ability to run native processes through ActionScript, so that's what birthed this experiment. Thanks!" CreationDate="2010-10-14T20:33:54.013" UserId="1596" />
  <row Id="5898" PostId="5186" Text="@Jader: Because people can still read the markings if they need to.  Yeah, it's hard, but far from impossible." CreationDate="2010-10-14T21:00:33.197" UserId="1407" />
  <row Id="5899" PostId="5208" Text="Chips...chip resistors...mmmm" CreationDate="2010-10-14T21:02:04.093" UserId="1407" />
  <row Id="5901" PostId="5165" Text="Do you actually need to import back from TopoR?  If TopoR can export gerbers, for example, then you could imagine a workflow where you do the schematic capture in Eagle, export to TopoR and do the routing and produce the gerbers (or perhaps pdf or whatever output you need).  It depends on what, exactly, you are trying to do." CreationDate="2010-10-14T22:23:22.853" UserId="1579" />
  <row Id="5903" PostId="5214" Score="1" Text="Always a good idea. High-speed Digital Design is one of the best books I have ever read for applied EM theory, just don't tell my professors." CreationDate="2010-10-14T23:58:11.013" UserId="230" />
  <row Id="5904" PostId="5186" Score="2" Text="@Jader as Nick said its still &quot;nice to have&quot; for debugging and such.  A laser engraver is a really, really cheap addition to the fab process compared to everything else and has zero ongoing costs with the exception of maintenance which probably just goes on as part of the overall system maintenance.  White ink, as cheap as it sounds, would be really expensive when talking about parts that often cost pennies to produce, not to mention that an ink stamper that can handle any sort of graphics is WAY more expensive than a laser engraver." CreationDate="2010-10-15T01:00:46.787" UserId="1438" />
  <row Id="5905" PostId="5207" Score="1" Text="Thanks!  NQC on ubuntu with a serial port just worked!  RIS (from Lego) on ubuntu with serial did not work.  So NQC looks good.  An old Windows XP with serial works with both NQC and RIS.  Bricxcc looks really cool!  The PL2303 usb-serial just acts broken no matter what.  Still no luck on mac, but maybe a new usb-serial will help.  " CreationDate="2010-10-15T01:11:17.437" UserId="1255" />
  <row Id="5906" PostId="5216" Text="I prefer to call it 'native' code. :-) Unsafe makes people scared" CreationDate="2010-10-15T02:17:43.820" UserId="1376" />
  <row Id="5907" PostId="5213" Score="3" Text="+1 for awesome ASCII circuit schematic" CreationDate="2010-10-15T02:20:51.393" UserId="1376" />
  <row Id="5908" PostId="5163" Text="+1 for the thrift store suggestion. " CreationDate="2010-10-15T03:02:32.963" UserId="906" />
  <row Id="5909" PostId="5218" Text="One note to point out...Both the heater and air condition system runs off of electric." CreationDate="2010-10-15T05:23:42.537" UserId="1575" />
  <row Id="5910" PostId="5219" Text="Hmm this config was recommended by TI's calculator..." CreationDate="2010-10-15T09:12:55.697" UserId="1225" />
  <row Id="5911" PostId="5219" Score="1" Text="I'd like to avoid wasting 100mA just in the TL431, is there any way to waste say only 10-20mA with the same output? The output 3V is high impedence, it is a Vref for an ADC." CreationDate="2010-10-15T10:50:13.693" UserId="1225" />
  <row Id="5912" PostId="5219" Score="3" Text="Clint, 1up for this very good answer. Just one tiny thing: The power dissipation in the TL431 needs to be taken into the calculation just as much as the current into the 431's output (&quot;Cathode&quot;)." CreationDate="2010-10-15T11:00:32.843" UserId="930" />
  <row Id="5913" PostId="5226" Text="I kind of like the 3rd and 5th points you made... But over-all I see you point." CreationDate="2010-10-15T11:21:18.427" UserId="1446" />
  <row Id="5914" PostId="4971" Text="They have pacman too - http://blog.gadgetfactory.net/2010/09/papilio-arcade-kit.html" CreationDate="2010-10-15T11:41:18.460" UserId="566" />
  <row Id="5915" PostId="5228" Text="Can you show the equations or at least a reference?" CreationDate="2010-10-15T11:52:19.517" UserId="142" />
  <row Id="5916" PostId="5231" Text="Thanks &amp; +1. I suspected this but thanks for confirming it." CreationDate="2010-10-15T12:42:23.337" UserId="1225" />
  <row Id="5917" PostId="5221" Text="In general, you shouldn't just go replacing one part with another unless there's a good reason to.  Do the relays have part numbers?  Could you take a picture of them?  You could put that in the question and we could help find replacements instead.  Or maybe they can be opened and cleaned." CreationDate="2010-10-15T13:58:21.797" UserId="142" />
  <row Id="5918" PostId="5217" Text="What does &quot;maximum strength&quot; mean in this case?  Ability to pick up metal objects stuck to one end?  A U-shaped magnet touching the object on both ends is stronger, for instance. http://en.wikipedia.org/wiki/Electromagnet#Magnetic_circuit_.E2.80.93_the_constant_B_field_approximation" CreationDate="2010-10-15T14:14:37.157" UserId="142" />
  <row Id="5919" PostId="2026" Text="It should be noted that the project Ed Baafi is working on is Modkit.  (Another answer has more details)." CreationDate="2010-10-15T14:42:09.770" UserId="106" />
  <row Id="5920" PostId="5222" Text="I'm afraid I'm not able to get into the site any more, either.  It would appear that they've done this to prevent spam (as there was a lot of comment spam when I could log in, in the past).  I found a cached link to the registration page ( http://scratchconnections.wik.is/index.php?title=Special:Userlogin&amp;register=true ) but new user registration appears to be disabled. :-(" CreationDate="2010-10-15T14:46:32.113" UserId="106" />
  <row Id="5921" PostId="5217" Text="This thread mentions some software tools used to optimize electromagnets: http://www.eng-tips.com/viewthread.cfm?qid=137215&amp;page=1" CreationDate="2010-10-15T15:16:58.307" UserId="142" />
  <row Id="5922" PostId="3879" Text="I wonder what causes the curves to plunge steeper right before the upswing?  Especially the green curve right above 10MHz." CreationDate="2010-10-15T15:44:41.783" UserId="1609" />
  <row Id="5923" PostId="5228" Text="B is proportional to N * I (http://en.wikipedia.org/wiki/Solenoid#Quantitative_description), so this seems correct, that magnetization doesn't change with different numbers of turns.  So for a given mass of copper, as wire diameter goes to zero, magnetization stays constant as current goes to zero?  What's the limiting factor?" CreationDate="2010-10-15T16:06:06.710" UserId="142" />
  <row Id="5924" PostId="3879" Text="Resonance, I would assume." CreationDate="2010-10-15T16:06:51.173" UserId="142" />
  <row Id="5925" PostId="5220" Score="1" Text="Why does it say no G and Y at the same time?  I would think you don't want W and Y at the same time (heating and cooling simultaneously)" CreationDate="2010-10-15T16:12:22.703" UserId="1278" />
  <row Id="5926" PostId="5242" Text="They don't make 'em like they used to." CreationDate="2010-10-15T16:43:44.893" UserId="566" />
  <row Id="5927" PostId="5242" Text="Just compare to an equivalent Rigol 100 MHz scope or even the 50 MHz models and you can see the difference. Then again, the scope did apparently cost $3,300 USD new." CreationDate="2010-10-15T16:55:09.227" UserId="1225" />
  <row Id="5928" PostId="5163" Score="1" Text="I've actually come across a 1.2V supply for slow charging Ni-MH batteries. Have a look at one of those. It's quite likely that 1.2V will satisfactorily run it. " CreationDate="2010-10-15T17:10:44.627" UserId="1225" />
  <row Id="5929" PostId="5241" Text="While a wire doesn't have much voltage drop, it isn't zero (unless you have a superconducting wire, which has zero resistance). A wire often just has a really low resistance which = a low voltage drop." CreationDate="2010-10-15T17:11:34.513" UserId="536" />
  <row Id="5930" PostId="5244" Text="Thanks &amp; +1 for the advice." CreationDate="2010-10-15T17:15:52.140" UserId="1225" />
  <row Id="5931" PostId="5221" Text="It says: DSY2Y-212L, and I'm pretty sure they are burnt or rusted from inside.." CreationDate="2010-10-15T17:17:00.750" UserId="1446" />
  <row Id="5932" PostId="5220" Text="Good eye. I think that was a mistype. In fact, I can now prove that the thermostat does run G and Y or G and W at the same time. Y and W however is a bad combination." CreationDate="2010-10-15T17:36:37.903" UserId="1575" />
  <row Id="5933" PostId="5163" Score="1" Text="Baby equipment almost never has a DC inlet aka strangle cord and very often runs on 3 inconvenient batteries. This kind of &quot;rocker&quot; is just a little chair with an oversized cellphone vibrate motor and a switch." CreationDate="2010-10-15T17:36:42.673" UserId="1363" />
  <row Id="5934" PostId="4405" Text="R4,5,6 are wired oddly" CreationDate="2010-10-15T17:41:44.563" UserId="1609" />
  <row Id="5935" PostId="3449" Text="Still needs work.  :D  Anything web-based that could output an image would be great, though." CreationDate="2010-10-15T17:43:49.530" UserId="142" />
  <row Id="5936" PostId="4405" Text="They are wired so that the noise gain decreases with the signal gain.  The signal gain as a function of pot position is the same, but the signal-to-noise is better." CreationDate="2010-10-15T17:55:28.733" UserId="142" />
  <row Id="5937" PostId="4193" Text="@edebill - On PICs, I've seen that happen a lot in production when BORV thresholds aren't set." CreationDate="2010-10-15T18:00:07.650" UserId="374" />
  <row Id="5938" PostId="5245" Text="Thanks. I will have a look. :)" CreationDate="2010-10-15T18:36:07.857" UserId="1225" />
  <row Id="5939" PostId="4954" Score="1" Text="@Kevin Boyd - That depends on your algorithm." CreationDate="2010-10-15T18:38:42.467" UserId="1374" />
  <row Id="5940" PostId="4954" Score="1" Text="Basically, this question is impossible to answer. MUCH more detail is needed. Fundamentally, it won't be possible to provide a conclusive answer until you have actually written the edge-detection algorithm. That is the only way to determine how many logic elements you need for your design, and therefore how big of an FPGA you need." CreationDate="2010-10-15T18:39:07.333" UserId="1374" />
  <row Id="5941" PostId="5226" Score="3" Text="+1 for clicking" CreationDate="2010-10-15T18:39:22.387" UserId="1610" />
  <row Id="5942" PostId="4954" Text="It may be possible to ball-park an estimate, but for that, we would need to know more about what you are doing. There are many edge-detection algorithms (canny, sobel, etc...). Also, environmental aspects come into consideration. How much preprocessing is needed? Do you have complete control of the lighting, or are you stuck with environmental lighting? How good is your programmer? You can optimise the crap out of your layout and VHDL/Verilog, but it takes someone with some skill to do so." CreationDate="2010-10-15T18:43:18.430" UserId="1374" />
  <row Id="5943" PostId="4954" Score="1" Text="Furthermore, do you really *need* the 5 mpix? In many industrial CV applications, the actual processing is done on a heavily downscaled (~200x200 px images) images, because any more precision is simply unnecessary. Now much precision do you need? Also, the imagedata is going to be flattened to at least greyscale, and likely pure B&amp;W (perhaps with an adaptive threshold) prior to processing. Therefore, are you doing something clever with color, which requires a RGB camera, or would a greyscale camera, perhaps with a color filter on the lens work?" CreationDate="2010-10-15T18:45:22.530" UserId="1374" />
  <row Id="5944" PostId="4954" Score="1" Text="http://en.wikipedia.org/wiki/Edge_detection is a good place to start for understanding how this stuff works" CreationDate="2010-10-15T18:47:56.863" UserId="1374" />
  <row Id="5945" PostId="5249" Text="This could also happen with processors which map some of the flash memory into the main memory space. I know at least the dsPIC's and PIC24's do this. If you had a corrupt pointer and the right circumstances you could overwrite flash." CreationDate="2010-10-15T18:58:53.350" UserId="1225" />
  <row Id="5946" PostId="5254" Text="What would the circuit look like using transistors?  Also, would I just use a voltage regulator to get my &lt;=5v supply for the switches?" CreationDate="2010-10-15T19:38:53.700" UserId="1610" />
  <row Id="5947" PostId="5253" Text="A fuse sounds like a good idea.  My understanding is that I can't just use a resistor because that would drop the voltage below what the cruise kit is expecting.  Does that sound right?" CreationDate="2010-10-15T19:40:01.140" UserId="1610" />
  <row Id="5948" PostId="5254" Text="A voltage regulator wouldn't really be an option for translating logic. It would be too slow. And you have to be careful of load dumps, which are voltage spikes produced when things in the car turn on and off (like the headlamps.) The spikes can be as high as +60V." CreationDate="2010-10-15T19:43:08.600" UserId="1225" />
  <row Id="5949" PostId="5254" Text="I'll draw up a circuit using transistors." CreationDate="2010-10-15T19:43:38.957" UserId="1225" />
  <row Id="5950" PostId="5243" Text="I don't mean to be rude, but you seem to know all of the relevant characteristics and have a complete understanding of what you need, so why not go to Digikey or Mouser and use the search feature to drill down and find what you need?  There's a whole subcategory for voltage references that I found easily and I used your criteria I came up with the same answer in less than 5 minutes.  Doing it this way seems roundabout and slow." CreationDate="2010-10-15T19:48:05.633" UserId="249" />
  <row Id="5951" PostId="5254" Score="1" Text="The reason I asked about the voltage regulator is that I don't currently have a +5v source.  I could probably find one but I'd rather just get it from the 12v if possible.  Also, I *think* the cruise kit is already doing some smoothing, since this 12v source normally powers a simple circuit including an LED and a few other components." CreationDate="2010-10-15T19:49:04.430" UserId="1610" />
  <row Id="5952" PostId="5254" Text="Yeah, there are probably regulators inside the unit. It will be a properly designed regulator able to handle such large load dumps, otherwise it wouldn't survive one day." CreationDate="2010-10-15T19:50:28.640" UserId="1225" />
  <row Id="5953" PostId="5243" Score="1" Text="I just wanted people's opinions on the best way to approach it. I'm still learning." CreationDate="2010-10-15T19:51:29.587" UserId="1225" />
  <row Id="5954" PostId="5254" Score="1" Text="Right, and I wasn't planning to use anything from outside the unit." CreationDate="2010-10-15T19:51:32.177" UserId="1610" />
  <row Id="5955" PostId="5254" Text="Circuit added for transistors. It's probably a roundabout way of going about it, but it should work. (That is, it is doubly inverted.)" CreationDate="2010-10-15T19:55:22.197" UserId="1225" />
  <row Id="5956" PostId="5254" Text="What program did you use to make that?" CreationDate="2010-10-15T19:58:05.893" UserId="1610" />
  <row Id="5957" PostId="5254" Text="Falstad circuit sim: http://www.falstad.com/circuit/" CreationDate="2010-10-15T19:58:34.137" UserId="1225" />
  <row Id="5958" PostId="5254" Text="Got it!  I was hoping to find a program like that.  Do you think I should even worry about scaling down the voltage, given that the current flowing through the switches is only ~10mA?" CreationDate="2010-10-15T20:15:44.617" UserId="1610" />
  <row Id="5959" PostId="5254" Text="For my reference, your circuit spec is at http://pastebin.com/i6ePpfDG." CreationDate="2010-10-15T20:28:19.347" UserId="1610" />
  <row Id="5960" PostId="3106" Score="1" Text="+1 for being the cheapest simplest way.  But as Jason S says, precision will take effort, if that matters." CreationDate="2010-10-15T20:34:20.663" UserId="1609" />
  <row Id="5961" PostId="5254" Text="Well, I don't think that 10mA is going to be considerably dangerous current. And remember, worst case the wires burn out. AFAIK, the airbag is designed to not explode in a fire, so even if the wire starts getting warm near it should not present a problem." CreationDate="2010-10-15T20:35:37.243" UserId="1225" />
  <row Id="5962" PostId="5254" Text="Also remember most wires have a minimum rating of 500mA, I've typically seen 1A, so I don't think 10mA is going to cause problems." CreationDate="2010-10-15T20:36:54.997" UserId="1225" />
  <row Id="5964" PostId="5228" Text="'magneto motive force' is the magnetic equivalent of voltage, and is proportional to current times number of turns, times some other stuff that depends on the geometry of the coil. the amount of flux you actually get depends on the magnetic reluctance in the magnetic circuit." CreationDate="2010-10-15T20:55:26.440" UserId="740" />
  <row Id="5965" PostId="5228" Score="1" Text="@endolith -- consider splitting your wire lengthwise, and then putting the two halves in series; the mass of copper stays constant; the resistance of each piece doubles b/c it has half the cross section; the *total* resistance quadruples, b/c you have two of these 2X resistance pieces in series; so if you put twice the voltage on, you get half the current, the same magnetization, and the same power. It's kind of like characteristic impedance; you can have the same magnet with more voltage and less current, or vice versa." CreationDate="2010-10-15T20:58:38.710" UserId="740" />
  <row Id="5966" PostId="2918" Score="1" Text="So, &quot;spaghetti code&quot; isn't just a software thing!" CreationDate="2010-10-15T21:18:19.107" UserId="1609" />
  <row Id="5967" PostId="3106" Score="2" Text="Any noise on your positive rail will show up in your ADC." CreationDate="2010-10-15T21:37:42.240" UserId="142" />
  <row Id="5968" PostId="5228" Text="Ah, I forgot about the resistance doubling when you halve the diameter." CreationDate="2010-10-15T21:43:09.573" UserId="142" />
  <row Id="5969" PostId="5238" Text="sometimes putting semiconductors in parallel works, sometimes it doesn't. the source-drain resistance of a mosfet goes up as the device gets hot; you can parallel mosfets b/c if one mosfet in a the group starts taking too much current, it gets hot, and the resulting resistance rise pushes the load to the other mosfets. BJT's respond opposite to that, and if one gets hot, it just hogs the current until it burns out, then the next one pops, etc." CreationDate="2010-10-15T22:04:19.483" UserId="740" />
  <row Id="5970" PostId="5257" Text="What voltage is it?  Old iPods charged from Firewire power, but that's deprecated and they all use the USB pins (+5 V) now." CreationDate="2010-10-15T22:48:48.300" UserId="142" />
  <row Id="5971" PostId="5253" Text="Measure the current on the hand controls side. A resistor will cause a voltage drop per Ohm's law V = IR but if the current (I) is small compared to the size of the resistor it won't matter." CreationDate="2010-10-15T22:59:34.937" UserId="1363" />
  <row Id="5972" PostId="5257" Text="I don't have it with me, but it's not old enough to have a firewire layout. It's got to be USB." CreationDate="2010-10-15T23:58:34.767" UserId="1611" />
  <row Id="5973" PostId="4845" Text="Reminds me of a radio project in Popular Electronics from way, way back... 1960s?  All built with components soldered point to point hanging on stiff wires for power, no PCB or terminal strips or anything.  It was pretty cool.  " CreationDate="2010-10-16T00:15:52.330" UserId="1609" />
  <row Id="5974" PostId="5228" Score="1" Text="So wind the hell out of it, is what your saying... Not quite the  answer I was looking for, there must be a point of saturation where the windings stop producing and start &quot;costing&quot; more $$$. Current draw is not really a concern, I'm guesstimating that it would probably be about 1.5-3 amps. I would like to optimize so as not to waste wire or money. " CreationDate="2010-10-16T01:34:18.257" UserId="1600" />
  <row Id="5975" PostId="5226" Score="1" Text="Relay clicks can have a functional use in terms of knowing the state of the system. Much like modems and fax machines, once you know what the relay pattern is supposed to sound like, anything &quot;not right&quot; really stands out." CreationDate="2010-10-16T01:54:55.330" UserId="906" />
  <row Id="5976" PostId="5228" Text="well if there's room enough to get enough windings, you might reach saturation in the core; saturation or just short of it would probably be the right place to design to." CreationDate="2010-10-16T01:56:15.217" UserId="740" />
  <row Id="5977" PostId="5226" Text="That's a good point. I know exactly how the autoset function on the scope sounds when the relays change: click/click, 1 second, click/click/click, 1 second, click. Occasionally it is different which does alert me." CreationDate="2010-10-16T09:49:21.390" UserId="1225" />
  <row Id="5978" PostId="5265" Score="3" Text="SciPy can do a lot of the same things as MATLAB, but for free.  http://www.scipy.org/doc/api_docs/SciPy.signal.filter_design.html  There's also more direct clones like Octave and FreeMat, but I don't know if they have all the filter design stuff built-in." CreationDate="2010-10-16T13:23:50.133" UserId="142" />
  <row Id="5979" PostId="5250" Text="50MHz oscillator - the PLLs can bring the FPGA much higher. And the 3A Starter comes with a 133MHz oscillator to feed its DDR2 ports. So it could do the I/O, but it depends on more design aspects. Depending on the algorithm, the 3A DSP may do better." CreationDate="2010-10-16T13:27:33.993" UserId="1181" />
  <row Id="5980" PostId="5166" Score="2" Text="Emacs Artist mode does that sort of thing too, without resorting to non-ASCII symbols. I still simply type these things, though overwrite, free placement and repetition commands can help." CreationDate="2010-10-16T13:36:04.560" UserId="1181" />
  <row Id="5981" PostId="5268" Text="Varistors aren't for ESD protection (they are for the protection of surges lasting 10's to 100's of milliseconds); the device's internal diodes are usually enough, but for when it isn't, adding some reverse-biased diodes to either rail (Vdd and GND) usually works, be careful though because this does add capacitance to the IO and can affect high speed stuff." CreationDate="2010-10-16T14:05:58.707" UserId="1225" />
  <row Id="5982" PostId="5268" Score="1" Text="Thomas have a look at the TDK datahseet, these devices are specifically designed for ESD counter measures, and they are proven to work in production for electronic communication devices.  We test our devices in house with up to 8 kV ESD and these devices do protect other components.  " CreationDate="2010-10-16T14:15:57.750" UserId="1397" />
  <row Id="5983" PostId="5268" Text="You are correct about the additional capacitance, and that does need to be considered." CreationDate="2010-10-16T14:17:01.603" UserId="1397" />
  <row Id="5984" PostId="5234" Text="Capsule?        (fifteen chars)" CreationDate="2010-10-16T15:56:12.533" UserId="1374" />
  <row Id="5985" PostId="4996" Text="Serial ports are serial ports. The FTDI devices are just a convenient way to add one." CreationDate="2010-10-16T17:19:28.253" UserId="1374" />
  <row Id="5986" PostId="4996" Text="Anyways, a 47*127 image @ 10 hz, with 8 bits per pixel (could be more, I doubt it) is only 477520 baud, so you could do it with a generic serial interface." CreationDate="2010-10-16T17:21:22.447" UserId="1374" />
  <row Id="5987" PostId="4996" Text="Besides, this is assuming the animation does not loop. If your display is a static sequence of x frames (30, 60, etc... even with 24 bit color, each frame would only be 17.9 kb) which repeat, you could just buffer those in the controller, and update them asynchronously." CreationDate="2010-10-16T17:23:34.723" UserId="1374" />
  <row Id="5988" PostId="5272" Text="The battery charging is usually built into the phone though.  The adapter just supplies a fixed voltage for it to use." CreationDate="2010-10-16T17:26:55.833" UserId="142" />
  <row Id="5989" PostId="5269" Text="Are you talking about the wall adapter only, or also the battery charging circuitry that's built into the phone?" CreationDate="2010-10-16T17:27:20.327" UserId="142" />
  <row Id="5990" PostId="5265" Text="I have a copy of MATLAB – will check it out, though I'm not sure if it yields electrical diagrams." CreationDate="2010-10-16T18:30:39.423" UserId="207" />
  <row Id="5991" PostId="5275" Text="+1 &amp; Thanks for this. " CreationDate="2010-10-16T18:48:23.920" UserId="1225" />
  <row Id="5992" PostId="5275" Text="OOC, are you the same &quot;luciani&quot; who develops the luciani library for gEDA? If so, thanks! I use those footprints lots." CreationDate="2010-10-16T18:49:14.737" UserId="1225" />
  <row Id="5993" PostId="5276" Text="Thanks for the reliability info. " CreationDate="2010-10-16T18:57:12.190" UserId="1225" />
  <row Id="5994" PostId="5220" Score="1" Text="On systems I'm familiar with, the thermostat is not responsible for controlling the blower in heat mode.   When heat is called for, the &quot;W&quot; lead is energized, turning on the burner(etc.).  When the temperature at the heat source reaches a specific point, the furnace turns the blower on via an internal thermostat.   This prevents the cold draft that would otherwise result if the blower is switched on immediately.   Similarly, the blower will continue to run after the heat is turned off, while the system cools down.  I don't know if all-electric systems work this way." CreationDate="2010-10-16T18:59:34.203" UserId="1295" />
  <row Id="5995" PostId="5277" Text="I have to use ceramics, as it is required by the buck regulator I am using. But I want to know if using a 25V cap is okay for a 20V supply." CreationDate="2010-10-16T19:08:21.053" UserId="1225" />
  <row Id="5996" PostId="5265" Score="2" Text="you will not get electrical diagrams into or out of matlab.  You have a few options, one of them being the filter design toolkit, which allows you to model filters directly, or perform a laplace transform of your circuit and model and simulate using laplace s parameter, then convert that back into electrical diagrams. Matlab will model the actual filter polynomials, and not the circuit, as filters are unviersal, and cross a few domains, where as eletrical circuits are exactly that.  They can however realise filter polynomials!" CreationDate="2010-10-16T19:16:14.917" UserId="1397" />
  <row Id="5997" PostId="5277" Score="2" Text="Ah, ok, buck regulator is different story, definite ceramic needed, I believe you want a 50V component, LOW K if possible. Parallel them to get up to the needed value if necessary." CreationDate="2010-10-16T19:18:32.800" UserId="1357" />
  <row Id="5998" PostId="5277" Text="Size is critical, which is why I'm looking to reduce voltage. " CreationDate="2010-10-16T19:21:51.647" UserId="1225" />
  <row Id="5999" PostId="4958" Text="Floating inputs, by the way, are inputs that aren't connected to a power source.  Depending on what you want your default voltage to be, you use pull up or pull down resistors to stabilise the inputs (Google it for more info or search this site)." CreationDate="2010-10-16T20:46:05.847" UserId="1333" />
  <row Id="6001" PostId="5282" Text="Cross coupled NAND gates give you an SR flip flop that changes state when you pull an input low (use pull-UP resistors). So you create a signal called 'READY' that is low when none of the stations has buzzed in, and give each player a push-button that can connect their 'set' input to the READY line. As soon as someone pushes their button, their flip-flop is set, lights the light, and importantly, drives the READY line high, thereby disabling the other stations. The quiz master then presses a button, as you said, to reset all the FF's." CreationDate="2010-10-16T20:53:34.090" UserId="740" />
  <row Id="6002" PostId="5250" Text="you are right about the PLL and running it faster, that will be possible.  However it may not be fast enough still for the amount of data that needs to be transferred in, also there is not enough in built RAM within the device, less than 2MB and the development kit has support for 64MB, which is not enough.  " CreationDate="2010-10-16T21:03:45.860" UserId="1397" />
  <row Id="6003" PostId="5275" Score="1" Text="That's me. Kemet (ceramic cap mfg) has some excellent app notes that explains the tolerancing of their caps. For power supplies I like the Nichicon PM series of electrolytics. I would check their website because they may have a new low ESR series." CreationDate="2010-10-16T21:34:10.800" UserId="424" />
  <row Id="6004" PostId="5220" Score="1" Text="That is a good observation and makes since. My HVAC unit was installed in 92. I noticed that when the current (home depot) thermostat turns on it blows cold air for a few minutes before it heats up (when on heat). Not sure if the thermostat is responsible for this or if the internal temp sensor as you noted does not work properly. I think I may grab an Arduino and setup a logging circuit for a week or so and take a look at the results before I start playing with everything. This will also give me a good idea on the timing used in an existing product to ensure the HVAC unit doesn't die." CreationDate="2010-10-16T21:34:57.110" UserId="1575" />
  <row Id="6005" PostId="5275" Text="I missed the buck regulator statement. If you require the low ESR of ceramic and small size I would go with an X5R or X7R dielectric. The tolerancing of the Y5V is quite bad over the voltage and temperature range." CreationDate="2010-10-16T21:37:49.210" UserId="424" />
  <row Id="6006" PostId="5272" Text="I may have misunderstood the question. I thought the question was about how the battery charging works not how to supply the battery charger circuitry in the phone with DC voltage." CreationDate="2010-10-16T21:42:13.833" UserId="424" />
  <row Id="6007" PostId="5275" Text="Thanks. I will use X5R or X7R then. " CreationDate="2010-10-16T21:48:47.163" UserId="1225" />
  <row Id="6008" PostId="5287" Score="1" Text="Are you talking about the ground lead on the probe itself? I know that needs to be connected to the circuit's ground, but I'm referring to the separate ground port under the CRT screen (on the GoldStar, at least)." CreationDate="2010-10-17T00:17:00.133" UserId="1616" />
  <row Id="6009" PostId="5288" Score="2" Text="Thanks &amp; +1 for your answer. A device like an LM339 may change quickly though and its current consumption may vary. Would decoupling be necessary here in some situations?" CreationDate="2010-10-17T00:17:38.060" UserId="1225" />
  <row Id="6010" PostId="5287" Score="1" Text="Both; the ground socket is connected to the ground probe and the earth ground. They should all be the same." CreationDate="2010-10-17T00:18:30.033" UserId="1225" />
  <row Id="6011" PostId="5287" Score="2" Text="you want the probe's ground connected to something that's a good ground for the signal you're probing. i think if there's a ground on the front of the scope, it would be for referencing a supply or another instrument like a signal generator that could have isolated output." CreationDate="2010-10-17T00:21:01.850" UserId="740" />
  <row Id="6012" PostId="5287" Score="1" Text="Ok. I guess my main question is can I connect my anti-static wrist-strap to it and if so, does the scope need to be on for it to be effective?" CreationDate="2010-10-17T00:24:34.840" UserId="1616" />
  <row Id="6013" PostId="5287" Score="1" Text="As long as it is plugged into the mains it should always be at earth ground. You can test this with a multimeter and the continuity test." CreationDate="2010-10-17T00:25:34.233" UserId="1225" />
  <row Id="6014" PostId="5288" Score="1" Text="Ah, a comparator. I'd be leaning towards includuing capacitors then; they should not hurt. " CreationDate="2010-10-17T00:32:20.967" UserId="1181" />
  <row Id="6015" PostId="5287" Score="4" Text="I wouldn't connect a anti-static strap to it.  Then entire point of the wrist strap is to route high voltage static spikes around sensitive electronics, why would you intentionally route it through your scope?" CreationDate="2010-10-17T00:33:39.037" UserId="1438" />
  <row Id="6016" PostId="5287" Score="1" Text="That's why I asked first. I thought it might be just a convenient ground connection specifically for things like that." CreationDate="2010-10-17T01:01:05.520" UserId="1616" />
  <row Id="6017" PostId="886" Text="+1 for a good answer but especially for the analog multimeter.  I have none currently, only a couple digital ones.  Oh sure, my brain is fast at interpreting numbers, but you just can't beat a swinging needle when monitoring certain things.  " CreationDate="2010-10-17T03:39:24.173" UserId="1609" />
  <row Id="6018" PostId="5294" Text="Doesn't this site have the &quot;community wiki&quot; concept?  This question ought to be one, but I see no button to make it so." CreationDate="2010-10-17T04:20:59.190" UserId="1609" />
  <row Id="6019" PostId="3645" Text="That's sort of like what Heathkit had available back when I was a kid, but it was way better - more caps and resistors, four transistors, more &quot;i/o&quot; devices.   I have not seen any kit since the 1980s that was much better than that one you link to, none anywhere near half as good as the Heathkit.  " CreationDate="2010-10-17T05:19:57.060" UserId="1609" />
  <row Id="6020" PostId="5269" Text="The battery charger circuit in the mobile will be extra credit yes." CreationDate="2010-10-17T05:45:43.143" UserId="1200" />
  <row Id="6021" PostId="5270" Text="These are very advanced type of things, What I need is a very simple circuit like that used in cheap chargers." CreationDate="2010-10-17T05:48:35.230" UserId="1200" />
  <row Id="6022" PostId="4193" Text="@Leon Heller: What is BOD? Brown Out Detection?" CreationDate="2010-10-17T08:03:22.210" UserId="804" />
  <row Id="6023" PostId="5286" Score="1" Text="Oh, and it's not limited to analog scopes, my digital scope has grounded probes." CreationDate="2010-10-17T08:34:08.513" UserId="1225" />
  <row Id="6024" PostId="1966" Text="High power RF amps are still valve based, so there would also be a delay from receiving an input signal at the gate to seeing a change in the power output at the electrode based on the speed the electrons are travelling through the vacuum between them." CreationDate="2010-10-17T09:51:06.537" UserId="1158" />
  <row Id="6025" PostId="5221" Text="In the UK, Farnell have them, eight for a tenner. SSRs are around five times as much. There's no reason not to replace the old ones with the same model. If you're very worried about them going rusty again, buy spares and store them in a non-humid environment. You also might want to put the board in a better sealed box. &#xA;&#xA;If you need to replace the relays every ten years, are you expecting the board to last another 50?" CreationDate="2010-10-17T10:08:59.740" UserId="1158" />
  <row Id="6026" PostId="5294" Text="It does normally but I couldn't see the tick box when I looked just a moment ago, and I appear to have no option to make your post a CW post." CreationDate="2010-10-17T12:45:00.690" UserId="103" />
  <row Id="6027" PostId="5302" Score="4" Text="This would be answered in pretty much any beginner's tutorial, and I fear a complete answer here would undermine your understanding more than help. What prior effort have you done to learn?" CreationDate="2010-10-17T12:51:21.100" UserId="1181" />
  <row Id="6028" PostId="5303" Score="1" Text="Cite your sources?" CreationDate="2010-10-17T12:57:16.083" UserId="1225" />
  <row Id="6029" PostId="5250" Text="So we're back at depends on the algorithm. An edge detection algorithm could possibly get away with only a few scanlines of memory, but that's assuming it outputs the data with very little delay as well. Kevin Boyd has not indicated that recording is necessary nor any additional details. I figure not enough information, still." CreationDate="2010-10-17T12:59:44.503" UserId="1181" />
  <row Id="6031" PostId="5302" Text="Not sure if you saw my post or are you able to see it (sorry still kinda confused about this site...) But i know the code, lets say my question is: do i just connect a pin to GND and its low?" CreationDate="2010-10-17T13:20:24.590" UserId="1619" />
  <row Id="6032" PostId="5250" Text="No we are not depending on the algorithm.  That demo board does not have enough RAM to be able to store images for any real length of time, four frames max, which equates to 375 mS.  Without considering if the edge detection will fit, the demo board is not suitable." CreationDate="2010-10-17T13:39:33.170" UserId="1397" />
  <row Id="6033" PostId="4595" Text="I decided to go with the circuit shown above except that I replace D1 and D2 with a 3.3Volt regulator. " CreationDate="2010-10-17T13:48:44.443" UserId="1235" />
  <row Id="6034" PostId="5302" Score="2" Text="Why not edit you post to more accurately reflect this and include the post below in the original post too." CreationDate="2010-10-17T14:13:23.650" UserId="103" />
  <row Id="6035" PostId="4193" Score="1" Text="Yes, it is Brown-Out Detection." CreationDate="2010-10-17T14:44:32.527" UserId="305" />
  <row Id="6036" PostId="5306" Text="even in final production the screen probably makes up 60-80% of the total cost of the device, LCD screen are still really expensive even at volume." CreationDate="2010-10-17T15:50:10.273" UserId="1438" />
  <row Id="6037" PostId="5272" Text="+1 for suggesting a specialized IC." CreationDate="2010-10-17T16:39:56.680" UserId="339" />
  <row Id="6038" PostId="5279" Text="Why are you saying that you would include a relay (actually I would need 3 of them) in addition to the transistor circuits?" CreationDate="2010-10-17T16:44:28.810" UserId="1610" />
  <row Id="6039" PostId="5280" Text="Short answer: because I don't know what I'm talking about :)  I don't want to take any risks with the thin wires running through the steering wheel area.  Since people here say it's the current I should worry about, I definitely want to limit it to a few mA." CreationDate="2010-10-17T16:46:06.717" UserId="1610" />
  <row Id="6040" PostId="5280" Text="even if its 20-22awg wire it can handle several amps without any danger.  If its short, like 3 feet, it can handle 10's of amps.  5V or 12V the draw is still going to be a few mA if that for most such applications.  " CreationDate="2010-10-17T16:57:24.660" UserId="1438" />
  <row Id="6041" PostId="5287" Score="1" Text="what i use is a anti-static mat, which has a plug for earth ground to an outlet.  The connector on the mat has an additional 2 banana plug inputs on it for earth grounding other devices, thats where the wrist strap gets plugged in. " CreationDate="2010-10-17T17:05:39.697" UserId="1438" />
  <row Id="6042" PostId="5303" Score="1" Text="This video has an excellent discussion on why the mercury content in CFL's isn't actually worse for the environment: http://www.youtube.com/watch?v=cA2E14uKyZY" CreationDate="2010-10-17T20:07:06.803" UserId="1225" />
  <row Id="6043" PostId="1966" Text="Hmm, really?  The speed at which electrons move is not usually relevant to the speed at which signals move." CreationDate="2010-10-17T20:58:09.140" UserId="142" />
  <row Id="6044" PostId="5303" Score="4" Text="theres lots of comical analysis when it comes to people trying to be &quot;green&quot;.  The Prius is a great example.  Everyone forgets how nasty the chemicals required to make the batteries are and how much more energy the thing takes to produce than your average compact car.  Not to mention disposing of said batteries. they only see 60mpg and think they are being green.  Buying a 1995 4 cylinder with 30mpg and overhauling the engine would have a far lower overall environmental impact. " CreationDate="2010-10-17T21:11:52.910" UserId="1438" />
  <row Id="6045" PostId="5303" Score="2" Text="Probably. I can't honestly see how the Prius is green given all its energy comes from gasoline (you can't recharge it can you?) Now a Tesla, that is green and awesome at the same time (second fastest vehicle in the world, 1st fastest is some Ferrari.)" CreationDate="2010-10-17T21:59:34.650" UserId="1225" />
  <row Id="6046" PostId="5303" Score="1" Text="The video was great, it cleared up a few things, but I guess it also proves that green living is very individual, If you use a green energy source then incandescent may be an option, but for the majority- I agree CFLs are still the best option  " CreationDate="2010-10-17T22:06:05.773" UserId="399" />
  <row Id="6047" PostId="5306" Score="2" Text="Could you please tell us the exact size and specification you're looking for? " CreationDate="2010-10-17T22:43:31.850" UserId="1307" />
  <row Id="6048" PostId="5317" Score="1" Text="`Without` is written without spaces" CreationDate="2010-10-17T23:45:54.643" UserId="1298" />
  <row Id="6049" PostId="5317" Text="Corrected for you." CreationDate="2010-10-18T00:08:44.897" UserId="319" />
  <row Id="6050" PostId="5315" Score="2" Text="Wow, they sell DIY electonics components without even giving you the schematic. Seed Studio sucks." CreationDate="2010-10-18T00:08:53.937" UserId="1374" />
  <row Id="6051" PostId="5301" Text="here too http://www.electronics-lab.com/action/submit_project/index.html" CreationDate="2010-10-18T00:09:37.490" UserId="142" />
  <row Id="6052" PostId="5315" Text="Fake Name: Agreed" CreationDate="2010-10-18T00:16:30.533" UserId="319" />
  <row Id="6053" PostId="5321" Text="Good schematic... I'll check it." CreationDate="2010-10-18T01:41:26.977" UserId="1298" />
  <row Id="6054" PostId="5315" Text="@Fake do you know a better alternative?" CreationDate="2010-10-18T01:42:18.460" UserId="1298" />
  <row Id="6055" PostId="5321" Text="What does this do, exactly? C1 must block the DC component of the signal, but why is that necessary?  Does the R1/R2 pair then bias the signal such that 0v becomes 2.5?" CreationDate="2010-10-18T01:48:23.910" UserId="51" />
  <row Id="6056" PostId="5321" Score="3" Text="@blalor strictly speaking 0V doesn't become 2.5V. The general rule is that the DC component of the signal becomes 2.5V" CreationDate="2010-10-18T01:54:40.690" UserId="1298" />
  <row Id="6057" PostId="5321" Score="3" Text="@blalor if you were able to put an infinitely large capacitor in there, you would see that your entire signal is shifted to be centered around 0v. Hence, removing the DC offset. This is a common method to make sure that there isn't any circuit adding an unwanted offset. R1 and R2 then just add back a known dc offset for ADC purposes in this case. Since we can't have infinitely large caps we settle for smaller caps that cause some of the low frequencies to get cut off." CreationDate="2010-10-18T02:22:30.203" UserId="319" />
  <row Id="6058" PostId="5291" Score="3" Text="This is actually a hard thing to say that it is always worth it to go with a 4 layer board. For Hobbyist, time doesn't usually have a huge value where as money out of pocket does. For large quantity there is always a trade off between employee time and pcb cost." CreationDate="2010-10-18T02:45:06.157" UserId="319" />
  <row Id="6059" PostId="5291" Text="One example of this that I see a lot is the cheap AC USB chargers. Typically they will use a single sided pcb. In this case the company decided it was worth the time to figure out how to route on 1 side because of the quantity that they would be producing in." CreationDate="2010-10-18T02:46:35.087" UserId="319" />
  <row Id="6061" PostId="5303" Text="This answer is mostly off topic and does not pertain to the question at hand. It may or may not be a good argument, but I do not think this is the place for it." CreationDate="2010-10-18T03:00:23.757" UserId="319" />
  <row Id="6062" PostId="4954" Text="@Kevin you should give your opinion on what Fake Name mentioned. I don't think you will get a good answer without addressing his points. Because you hadn't addressed his points is why I commented so vaguely." CreationDate="2010-10-18T03:04:32.037" UserId="319" />
  <row Id="6063" PostId="5324" Text="I retract my post for your much more well explained answer." CreationDate="2010-10-18T03:43:05.150" UserId="319" />
  <row Id="6064" PostId="5320" Score="1" Text="Not important until you are having to put your device in a case or stacking pcbs or other components, such as LCDs :-)" CreationDate="2010-10-18T03:45:59.213" UserId="319" />
  <row Id="6065" PostId="5277" Text="@Conrad the frequency response of each type of capacitor is different also." CreationDate="2010-10-18T04:02:28.130" UserId="319" />
  <row Id="6066" PostId="5315" Score="1" Text="@Jader It all depends on how much work you are wanting to do. Here are some options: http://www.sparkfun.com/commerce/product_info.php?products_id=8635 http://www.sparkfun.com/commerce/product_info.php?products_id=8872 " CreationDate="2010-10-18T04:11:12.660" UserId="319" />
  <row Id="6067" PostId="5291" Text="good point Kellenjb. I tend to base this on working with projects for the company, not from a hobbiests perspective. For me, making PCB's is a work thing to do, not a hobby haha" CreationDate="2010-10-18T05:33:46.740" UserId="1376" />
  <row Id="6068" PostId="5320" Score="1" Text="Yes, I believe the T in these stands for &quot;Thin&quot;." CreationDate="2010-10-18T06:18:06.733" UserId="883" />
  <row Id="6069" PostId="5287" Text="If you don't mind doing it, you could also open the scope and see exactly where it's connected (frame, power socket, ground rail...). That'll answer most questions." CreationDate="2010-10-18T06:24:38.430" UserId="883" />
  <row Id="6070" PostId="5287" Text="Of course it also won't hurt to check the scope manual and schematics if you have them :)" CreationDate="2010-10-18T06:25:01.457" UserId="883" />
  <row Id="6071" PostId="5303" Score="1" Text="... well, in my answer, I did put &quot;green&quot; in quotes, because the lamps or their electronics are often labelled &quot;green&quot;. The question wheter they are really green is a different topic indeed." CreationDate="2010-10-18T07:33:17.623" UserId="930" />
  <row Id="6072" PostId="5300" Text="You are not necessarily wasting a lot of energy to get to a high junction temperature.  If you leave your mobile on a car dashboard on a sunny day then its temperature can get to 60+ degrees Celsius.  Engine bay electronics can also need to work at high temperatures, in sealed enclosures with poor heat transfer properties. " CreationDate="2010-10-18T07:33:36.750" UserId="400" />
  <row Id="6073" PostId="5300" Text="I suppose, but I'm working with low temp stuff (i.e. consumer - living room kind of stuff) so I made a judgement." CreationDate="2010-10-18T07:40:00.750" UserId="1225" />
  <row Id="6074" PostId="5301" Text="Circuit Cellar (http://www.circuitcellar.com) also routinely has competitions - often sponsored by manufacturers who want to showcase new products. The top designs get published in Circuit Cellar." CreationDate="2010-10-18T08:07:34.980" UserId="1629" />
  <row Id="6075" PostId="5303" Score="1" Text="@Kellenjb, Ok so it might be off topic a little, but it does pertain to the question at hand and it does belong here! my statements are based around the green viability of CFLs - because it's stated in the question as the reason for adoption despite increased EMI - you shouldn't be over subjective, this is a place for open discussion." CreationDate="2010-10-18T09:46:40.533" UserId="399" />
  <row Id="6076" PostId="5324" Text="Is there any documentation available for the radio protocol used in AT (serial) mode? Is it some new ZCL cluster running on ZigBee? Or perhaps raw 802.15.4?" CreationDate="2010-10-18T11:10:22.597" UserId="566" />
  <row Id="6077" PostId="5256" Text="I couldn't understand what you meant here, a link to a schematic would help." CreationDate="2010-10-18T12:22:44.040" UserId="444" />
  <row Id="6078" PostId="5291" Text="The boards are also single sided because it is easier to meet EMC compliance and safety rules (re isolation between traces) afaik." CreationDate="2010-10-18T12:27:28.990" UserId="1225" />
  <row Id="6079" PostId="5328" Score="2" Text="+1 for EEVblog." CreationDate="2010-10-18T12:42:16.217" UserId="1225" />
  <row Id="6080" PostId="5328" Text="Looks interesting!" CreationDate="2010-10-18T12:49:17.480" UserId="1240" />
  <row Id="6081" PostId="4954" Text="@Fake Name: At the moment I need to the 5mp pix. Possibly the best route at the moment would be to simulate the whole process in VHDL/Verilog and see how many logic blocks I would need. Thanks for the comments." CreationDate="2010-10-18T12:50:42.703" UserId="444" />
  <row Id="6082" PostId="5250" Text="@smashtastic: With your calculations it seems that the speed of the Spartan3a is not sufficient for the 5MP @ 15fps can the Spartan3A DSP do the job (as LoneTech suggested)? If 15 fps is not feasible is it possible to get 5fps from the Spartan3A? Regarding the ram If the demo is not suitable can the spartan3A fpga be run at &gt; 50MHz when I make my own prototype and can it be interfaced to say 1GB of external ram?" CreationDate="2010-10-18T13:00:17.507" UserId="444" />
  <row Id="6083" PostId="5250" Text="Regarding the ram If the demo is not suitable can the spartan3A fpga be run at &gt; 50MHz when I make my own prototype and can it be interfaced to say 1GB of external ram?" CreationDate="2010-10-18T13:08:12.247" UserId="444" />
  <row Id="6084" PostId="5250" Text="Can the Spartan3A be clocked externally @100MHZ so that the internal PLL can then generate higher frequencies or are we limited to 133Mhz." CreationDate="2010-10-18T13:35:09.480" UserId="444" />
  <row Id="6085" PostId="5321" Score="1" Text="Infinitely large caps would take forever to charge up to the bias voltage anyway.  " CreationDate="2010-10-18T13:48:38.910" UserId="142" />
  <row Id="6086" PostId="4937" Text="Is this one of the new megas with the atmega-u8?" CreationDate="2010-10-18T14:59:52.893" UserId="566" />
  <row Id="6087" PostId="5321" Text="@endolith eh, just those minor issues." CreationDate="2010-10-18T15:02:53.137" UserId="319" />
  <row Id="6088" PostId="5321" Text="@endolith I really like how you linked to wolframalpha, I think that is a great idea for showing people what the math was that went into it." CreationDate="2010-10-18T15:05:27.087" UserId="319" />
  <row Id="6089" PostId="5321" Text="I do that a lot.  I love things like Google Calculator, Alpha, and Qalculate that can do freeform calculations with units and everything." CreationDate="2010-10-18T15:48:14.657" UserId="142" />
  <row Id="6090" PostId="5334" Text="That was it. I was concentrating so hard on the RC thing that I completely failed to examine the rest of the pins I wasn't using! Thanks!" CreationDate="2010-10-18T16:00:00.803" UserId="259" />
  <row Id="6091" PostId="5287" Text="You should never connect an anti-static wriststrap directly to ground! There must always be an impedance in series with the strap. Static *dissipation* is not the same as static *shorting*. In the manufacturing environments I've worked in there's often an additional 1 megohm between the strap connector and ground - this is still more than sufficient for ESD control and also prevents the strap from being a potential (no pun intended) hazard if whatever internal resistor there is in the strap fails. " CreationDate="2010-10-18T16:56:34.197" UserId="1293" />
  <row Id="6092" PostId="5329" Text="Chris, thanks! This is a very interesting alternative to explore. I can see now why the Arduino boards are so popular…" CreationDate="2010-10-18T16:56:37.457" UserId="1317" />
  <row Id="6093" PostId="5336" Score="11" Text="You say you do not care how they work, but you want to use one. You can learn transistors by rote, but with a basic understanding they are rather easy to use(barring special cases like &gt;100 Mhz operation)" CreationDate="2010-10-18T17:00:41.720" UserId="230" />
  <row Id="6094" PostId="5329" Text="Just a note for future interested persons: This board is using a Wiznet chip and doesn't (yet) have the capability to negotiate a power connection on a full-up PoE network. My understanding is that the Akros chips provide an integrated solution that includes power negotiation. So… still looking for a source for those protoboards." CreationDate="2010-10-18T17:04:49.367" UserId="1317" />
  <row Id="6095" PostId="4937" Score="2" Text="The mega has 4 serial connections, the one that goes through USB is the one that is on digital pins 0 and 1, I believe.  Make sure those pins are clear, and that your C program has selected the right baudrate." CreationDate="2010-10-18T17:23:15.543" UserId="1271" />
  <row Id="6096" PostId="5339" Text="&quot;Shag carpet in the dead of winter&quot; Love it!" CreationDate="2010-10-18T17:34:04.660" UserId="1225" />
  <row Id="6097" PostId="5271" Text="+1 embedded host - you can't talk to the flash drives without it.  This is the hard part...most of the literature that's available focuses on embedded devices or full-sized PC host controllers." CreationDate="2010-10-18T17:38:40.233" UserId="1278" />
  <row Id="6098" PostId="5292" Text="Two things I would add.  1) If you can't fit an 0402 on your PCB, you can skip this level of bypassing.  The rule of thumb is generally &quot;use the largest capacitance that you can afford for a given package size&quot; unless you're paranoid about inductance." CreationDate="2010-10-18T17:53:40.410" UserId="1278" />
  <row Id="6099" PostId="5292" Text="doh.  2) be careful with tantalum caps when used as a power input cap.  they don't like surge currents." CreationDate="2010-10-18T17:54:37.320" UserId="1278" />
  <row Id="6100" PostId="5324" Text="I haven't used the XBee Pro dev kit i have for awhile but as i recall the AT mode was just a way to communicate between 2 XBee modules in a very simple mode that mimicked AT modem communications.  I assume the radio PHY would still have to be something like 802.15.4 as i would think most of that decode is in hardware, but the rest of the protocol is likely something Digi worked up, proprietary i imagine." CreationDate="2010-10-18T19:04:06.140" UserId="1438" />
  <row Id="6101" PostId="5341" Text="what are the signals on the 9 wires?  is there USB running through this?" CreationDate="2010-10-18T19:30:16.313" UserId="1438" />
  <row Id="6102" PostId="5341" Text="serial TX and RX, +5v, GND, serial enable (500k ohm to +5v), audio L+ and R+, and USB D+/D-.  The USB lines are just set to the proper voltages so that my iPhone will charge." CreationDate="2010-10-18T19:33:58.890" UserId="51" />
  <row Id="6103" PostId="5342" Text="Thanks, Grant.  I don't see any cables that would fit my needs, however." CreationDate="2010-10-18T19:37:22.893" UserId="51" />
  <row Id="6104" PostId="5336" Score="10" Text="you need to at least figure out the differences between BJTs and FETs.  " CreationDate="2010-10-18T20:12:51.817" UserId="1438" />
  <row Id="6105" PostId="5343" Text="Wow the leakage current is a bit high, but will 2mA generally cause problems? I2C is the only thing I see potentially causing problems as it is open collector. I have 1k resistors, so 1k * 0.002 = 2V drop. Not good. Am I doing this right?" CreationDate="2010-10-18T20:13:54.373" UserId="1225" />
  <row Id="6106" PostId="5343" Score="1" Text="yep, there are devices specifically made for protecting serial data lines, for example: http://www.st.com/stonline/products/literature/ds/13569/esdalc6v1-5p6.htm leakage current of 70nA, 12pF capacitance (completely fine for I2C) and clamps at around 14V.  In addition an easy way to add extra protection to I2C is to place a series resistor on both the data and clock lines very close to each IC on the bus.  Ideally matched to the trace impedance - output impedance of the driver, which is usually like 7-9ohms.  So for a 50ohm trace, 41-43 ohms for the resister is good." CreationDate="2010-10-18T20:24:28.043" UserId="1438" />
  <row Id="6107" PostId="5343" Text="in addition using source termination on I2C is a good idea any time you have lots of devices or the bus will be long (like going through a cable).  It will minimize ringing and prevent reflections.  You may have to tweak the resistor values in an assembled device as you going trace-&gt;connector-&gt;cable-&gt;connector-&gt;trace, which unless you've matched all those impedances there will be some funkiness in the overall path impedance.  If the I2C bus is running quite slow compared to the length of the run this may not matter at all." CreationDate="2010-10-18T20:29:06.327" UserId="1438" />
  <row Id="6108" PostId="5343" Text="Thanks for answering my questions. I'm also working with higher speed stuff (UART, and maybe more), so I can't really have 12pF of capacitance on the bus. But I found this, http://uk.farnell.com/cooper-bussmann/0603esda-tr1/diode-tvs-bi-24v-0603/dp/1470613, is has &lt;0.1nA leakage and 0.15pF capacitance; the leakage sounds way too low, is this just marketing crap?" CreationDate="2010-10-18T21:34:19.173" UserId="1225" />
  <row Id="6109" PostId="5321" Text="@endolith where is this schematic from?" CreationDate="2010-10-18T21:36:26.373" UserId="1298" />
  <row Id="6110" PostId="5346" Score="1" Text="Hmm interesting. Why would TI produce different pinned versions? Is it to ease routing on crowded PCBs?" CreationDate="2010-10-18T21:44:31.250" UserId="1225" />
  <row Id="6111" PostId="5343" Score="1" Text="If your running any bus at a clock rate where 12pF is overly significant i really hope your paying very, very close attention to signal integrity as your clock rate must be very high.  At 10Mhz with 1k pull ups 100pF would be the bus limit without slew rate control, but anything running that fast would either have slew rate control or be differential.  I2C at 400khz allows 400pF of bus capacitance without slew rate control, more is possible with proper control.  So if your just using 16bit PIC's i highly doubt you have a bus running so fast that 14pF is a big deal." CreationDate="2010-10-18T21:54:06.453" UserId="1438" />
  <row Id="6112" PostId="5343" Text="okay, I guess not. Thanks. I'm not going faster than 1 MHz, probably only 400 kHz. The problem with that ESD device is it is quite big. Would the 0603 device I linked to be okay?" CreationDate="2010-10-18T21:59:45.603" UserId="1225" />
  <row Id="6113" PostId="5343" Score="1" Text="On that part, looks fine.  Don't know how they measure 0.15pF, i would guess that the package capacitance is somewhere in that neighborhood or higher.  In reality when you place these parts on a board there will be some amount of lead inductance as well which works to counteract the capacitance of the part.  This is why when working with very small caps, like 10nF, you have to make sure to use the smallest package available to negate as much of the effect of lead inductance as possible." CreationDate="2010-10-18T22:06:39.497" UserId="1438" />
  <row Id="6114" PostId="5343" Text="The one I linked had 5 protection diodes in it also, so 1 SOT666 could protect 5 signal lines.  1 SOT666 is smaller than 5 0603 unless you don't need that many signals protected or they can't be protected in 1 location." CreationDate="2010-10-18T22:09:24.957" UserId="1438" />
  <row Id="6115" PostId="5337" Text="with a 2n2222, Vbe at saturation of 0.8V is not uncommon. Typical Vce at saturation is around 0.2V, so if you see more than 0.25 or so, you need more base current." CreationDate="2010-10-18T22:10:50.533" UserId="740" />
  <row Id="6116" PostId="5343" Text="Yep, the connectors are in different places so it's not convenient to have one point for all the diodes. I'm guessing 0.15pF is measured using precision LCR bridges perhaps even $100k+ stuff, and is for high speed signals like USB 3.0 and HDMI." CreationDate="2010-10-18T22:12:28.517" UserId="1225" />
  <row Id="6117" PostId="5337" Text="That's why in my circuit I demonstrated connecting to +3V. No one voltage will fit for all transistors. Some transistors conduct well as low as 0.55V, and I've seen many bipolar transistor based circuits (like oscillators) that work well down to 0.5V. " CreationDate="2010-10-18T22:15:11.093" UserId="1225" />
  <row Id="6118" PostId="5343" Text="Wasn't questioning what equipment they use but rather the test conditions as they weren't defined in the data sheet." CreationDate="2010-10-18T22:20:25.803" UserId="1438" />
  <row Id="6119" PostId="5337" Score="3" Text="You should probably mention in 2nd paragraph that it's the current through the collector that is an amplification of the current through the base. I.e. `collector current = base current * HFE`." CreationDate="2010-10-18T22:39:31.643" UserId="1025" />
  <row Id="6120" PostId="5337" Text="Added, thanks..." CreationDate="2010-10-18T22:41:25.230" UserId="1225" />
  <row Id="6121" PostId="5343" Text="Haha, I'd laugh if they used a multimeter on the cap range. ;)" CreationDate="2010-10-18T22:47:23.517" UserId="1225" />
  <row Id="6122" PostId="5346" Score="2" Text="I guess?  Or maybe for compatibility with competing parts?" CreationDate="2010-10-18T23:40:13.490" UserId="142" />
  <row Id="6123" PostId="5321" Text="just a google image search, but now i can't find it." CreationDate="2010-10-19T00:09:38.600" UserId="142" />
  <row Id="6124" PostId="1224" Score="1" Text="It crashes every 5 minutes on my Win 7 x64" CreationDate="2010-10-19T00:33:11.920" UserId="1298" />
  <row Id="6125" PostId="5341" Text="Very good question blalor, I think the cabling needs are overlooked many times until very late in the prototyping stage. I know of a product from a company that required you to drill over a 1&quot; hole in your car in order to feed the connector on the cable through. The engineering who designed it didn't think about it until marketing had already set a price on the product and didn't want to budge." CreationDate="2010-10-19T01:53:33.253" UserId="319" />
  <row Id="6126" PostId="5330" Score="1" Text="There are still very vital servers running Windows 2000 and before. These machines usually don't ever get any OS changes on them because they don't want to risk messing up the application running on it. Because of things like this, there has been a lot of work put into trying to make ipv4 and ipv6 work side by side in order to buffer any adverse effects of the change over." CreationDate="2010-10-19T01:57:47.487" UserId="319" />
  <row Id="6127" PostId="5294" Text="I figured maybe it is a matter of having enough rep points?  But you have plenty..." CreationDate="2010-10-19T02:36:30.443" UserId="1609" />
  <row Id="6128" PostId="5323" Text="In other words - just include any noisy CFL or other household contraptions as part of your test equipment?" CreationDate="2010-10-19T02:39:00.723" UserId="1609" />
  <row Id="6129" PostId="5303" Text="I have heard the not-so-green argument about CFLs, and there may be some merit to some of the ideas - but surely to burn incandescents isn't a good idea, especially on a hot summer day when the A/C has to run longer.  Sigh, adding up all the little consequential factors..." CreationDate="2010-10-19T02:41:30.490" UserId="1609" />
  <row Id="6130" PostId="5303" Score="1" Text="I agree w Kellenjb this is going off topic, and I thought I saw a sustainable living proposal in Area 51, or maybe it was solar energy or something.   OTOH we are smart people who love understanding complex systems with science and technology, so we are prone to discuss such matters.  Surely electronics and green living will come up again and again here." CreationDate="2010-10-19T02:46:56.903" UserId="1609" />
  <row Id="6131" PostId="5294" Text="If anyone is lucky enough to see a CW button on this page, go for it!" CreationDate="2010-10-19T02:47:44.763" UserId="1609" />
  <row Id="6132" PostId="5296" Text="I saw something about a crystal radio competition, with some very creative designs.  I think it was ARRL, but wasn't the thing you link to (which shows up fine btw).   Neat stuff!" CreationDate="2010-10-19T02:54:31.483" UserId="1609" />
  <row Id="6133" PostId="5301" Text="Ah, Circuit Cellar!  Haven't browsed through one of those in a long time.  Darn, I just moved to a town w/o a Borders or B&amp;N!" CreationDate="2010-10-19T02:56:44.523" UserId="1609" />
  <row Id="6134" PostId="5088" Text="Yeah, someday, when QUCS has a &quot;print reality&quot; button to click and out pops the physical part you just drew!" CreationDate="2010-10-19T03:00:46.247" UserId="1609" />
  <row Id="6135" PostId="5091" Text="There's too much of a gap between 10 and 47, 100 and 470 etc for my taste - I like to have no more than a factor of two jump.  So add in 22, 220, 2.2k, etc. ohms." CreationDate="2010-10-19T03:03:27.220" UserId="1609" />
  <row Id="6136" PostId="5256" Text="Okay, i've got time now...and as I think about it, I'm not sure why it's better than some simpler circuits except as the detailed design might work out better numerically, perhaps.  Schematic will be attached soon." CreationDate="2010-10-19T03:23:23.930" UserId="1609" />
  <row Id="6137" PostId="5320" Text="@Kellenjb - As I said, it's not important from a board layout perspective. Packaging and mechanical design is a different can of worms." CreationDate="2010-10-19T03:27:09.147" UserId="1374" />
  <row Id="6138" PostId="5315" Score="1" Text="@Jader Dias - Yeah, a breadboard and a op-amp." CreationDate="2010-10-19T03:27:50.173" UserId="1374" />
  <row Id="6139" PostId="5272" Text="SparkFun sells a Polymer Lithium Ion battery charger based on the MAX1555 IC ( http://www.sparkfun.com/commerce/product_info.php?products_id=726 ).  The schematic is here: http://www.sparkfun.com/datasheets/Batteries/LiPo-USB-Charger-v13.pdf" CreationDate="2010-10-19T03:31:48.733" UserId="1322" />
  <row Id="6140" PostId="5350" Score="2" Text="Simulated in QUCS" CreationDate="2010-10-19T03:51:21.763" UserId="1609" />
  <row Id="6141" PostId="5349" Text="+1 for the thrift store. Thrift stores can be awesome. They can also suck, though. Shop around!" CreationDate="2010-10-19T04:25:34.133" UserId="1374" />
  <row Id="6142" PostId="3109" Text="@Kortuk - There is is never a perfect op-amp for *any* case. However, there is the best op-amp out of the available selection, when price is taken into consideration, for every project." CreationDate="2010-10-19T04:27:01.357" UserId="1374" />
  <row Id="6143" PostId="5348" Text="Many UPSs in particular will eat these batteries quickly." CreationDate="2010-10-19T05:29:08.297" UserId="883" />
  <row Id="6144" PostId="5336" Text="short answers: Beta is usually called hFE and maximum base and collector currents something like Ib(max) Ic(max). Mostly you're fine: 1k lets past 1mA per volt over it. Broadly speaking, yes. Do check the long answers, they'll be useful." CreationDate="2010-10-19T05:57:22.293" UserId="883" />
  <row Id="6145" PostId="4515" Text="The answers gave some good references for connecting to the circuit. I'd tend to think of the shield as an extension to the Faraday cage and make sure it connects as tightly as possible/sensible to the surrounding cage (enclosure). That way the electronics will be inside the shield in the device (enclosure), cable (shield) and host (enclosure) end without gaps. Does this seem sensible?" CreationDate="2010-10-19T06:12:37.993" UserId="883" />
  <row Id="6146" PostId="5346" Score="2" Text="They probably redesigned the die, which caused the pin connections to move about." CreationDate="2010-10-19T06:56:07.133" UserId="1374" />
  <row Id="6147" PostId="5348" Text="Specs: NP18-12B, 12V 17.2Ah, valve regulated, sealed lead-acid type, rechargeable battery, contains lead. Nothing else printed on it." CreationDate="2010-10-19T06:58:35.130" UserId="1225" />
  <row Id="6148" PostId="5256" Text="+1 - For your time and effort!" CreationDate="2010-10-19T10:02:45.170" UserId="444" />
  <row Id="6149" PostId="5328" Text="I bought my Fluke 85 Series III because of Dave's reviews - best electonics buy I have made to date." CreationDate="2010-10-19T10:30:44.993" UserId="1333" />
  <row Id="6150" PostId="5250" Score="1" Text="It can be clocked higher externally, and isn't limimted to 133MHz either - that's just what the second external oscillator on the 3A Starter board uses. Limits depend on logic complexity, but pipelining can push them quite high. The real question is still more what to do with the data after reading it. You certainly can connect to any amount of RAM, but eventually you'll want to use the data somewhere. " CreationDate="2010-10-19T11:04:27.270" UserId="1181" />
  <row Id="6151" PostId="5250" Score="2" Text="Remember you will also need to put an SDRAM/SDR/DDR/DDR2 controller in the FPGA as well..." CreationDate="2010-10-19T11:24:37.630" UserId="974" />
  <row Id="6152" PostId="5250" Text="Kevin, can you be clearer about your requirements, in particular how long you want to be able to shot bursts at 15 fps, what, if any processing you intend to do on the FPGA, and what your non volatile  storage is." CreationDate="2010-10-19T11:41:29.343" UserId="1397" />
  <row Id="6153" PostId="5357" Text="Is there anything wrong with having discussion on this forum?  I understand the intent may be to have questions and answers to draw in more users and traffic, but discussing the technical details is still helping the OP to work through their solution.  I am sure if the OP was able to answer all of the extra questions posed, they would not be asking anything on this forum, as the answer would have come out in the design process. just some thoughts ...." CreationDate="2010-10-19T11:44:32.443" UserId="1397" />
  <row Id="6154" PostId="5211" Text="It would appear Altera have rectified the problems I had with their tools earlier (web edition should no longer require a license file). I still didn't get them running, but now it looks doable. Thanks for the tip!" CreationDate="2010-10-19T11:44:45.313" UserId="1181" />
  <row Id="6155" PostId="5358" Text="You should post this as another question and link to this. Thanks for the answer and idea; I was thinking of doing something like this, but I didn't think that the internal reference had enough granularity. You can determine the difference between even and odd fields by the different patterns at the beginning of the field. If you have a scope with tv trigger (most good ones do), I recommend you probe it using the tv trigger, and you'll see what I mean." CreationDate="2010-10-19T11:44:46.403" UserId="1225" />
  <row Id="6156" PostId="5356" Score="1" Text="So the power figure is the power the capacitor is supplying? What happens when the power figure is negative, is that the power it is consuming?" CreationDate="2010-10-19T11:46:06.270" UserId="1225" />
  <row Id="6157" PostId="5346" Text="I suppose they probably redesigned the die to reduce costs and/or increase yield, but couldn't make it pin-compatible. Maybe the TL432 is cheaper than the TL431." CreationDate="2010-10-19T11:49:56.733" UserId="1225" />
  <row Id="6158" PostId="5355" Text="Can you show this &quot;Power&quot; figure?" CreationDate="2010-10-19T11:56:39.783" UserId="938" />
  <row Id="6159" PostId="5359" Text="I've seen circuits with rail to ground caps in addition to one across both rails. Is there any advantage to putting one across the rails?" CreationDate="2010-10-19T11:59:48.780" UserId="1225" />
  <row Id="6160" PostId="5355" Text="See attached image." CreationDate="2010-10-19T12:00:37.983" UserId="1225" />
  <row Id="6161" PostId="5359" Text="No advantage putting them across both rails.  Best to keep them rail to ground, as it provides a noise path from the rails back to the ground plane, as that is your 0 V potential source, and everything needs to be decoupled back to this!" CreationDate="2010-10-19T12:36:46.407" UserId="1397" />
  <row Id="6162" PostId="5357" Text="+1 for the healthy criticism." CreationDate="2010-10-19T13:35:30.457" UserId="444" />
  <row Id="6164" PostId="3109" Text="@Fake Name, I think this is a case of a communication error. If it meets the specs you need and is affordable then you have the perfect op-amp. That would be my wording, I understand what you mean though. I accept the limitation and use perfect because I am positive. &lt;3" CreationDate="2010-10-19T14:36:29.720" UserId="230" />
  <row Id="6165" PostId="5346" Text="TL431CDBVR and TL432CDBVR, for instance, are both $0.14 budgetary, so I don't think that's it.  http://focus.ti.com/docs/prod/folders/print/tl431.html#pricingpackaging  http://focus.ti.com/docs/prod/folders/print/tl432.html#pricingpackaging" CreationDate="2010-10-19T14:37:15.517" UserId="142" />
  <row Id="6166" PostId="5357" Text="Nothing wrong with discussion as such - just the layout isn't very good at it. There appear to be plans to add the function (Chat function under reputation), but it's not ready yet. I would have linked it but it seems to be in closed beta.&#xA;http://electronics.stackexchange.com/privileges/chat-rooms" CreationDate="2010-10-19T14:37:58.737" UserId="1181" />
  <row Id="6167" PostId="5251" Score="1" Text="This is awesome Endolith. You brought the goods with your answer. I will try it out and will consider it as an easier option then my selected as it looks nicer also." CreationDate="2010-10-19T14:39:16.433" UserId="230" />
  <row Id="6169" PostId="5360" Text="In the image you posted, the average power seems to be non-zero... so where is all this power going?" CreationDate="2010-10-19T14:54:25.657" UserId="1225" />
  <row Id="6170" PostId="5360" Score="2" Text="That's a resistive load.  The electrical energy is being converted into heat energy.  Energy flows, power doesn't.  Power is the *rate* at which energy flows." CreationDate="2010-10-19T14:55:48.100" UserId="142" />
  <row Id="6171" PostId="5360" Text="http://amasci.com/miscon/energ1.html" CreationDate="2010-10-19T15:34:03.537" UserId="142" />
  <row Id="6174" PostId="5321" Score="1" Text="@Jader: It was from here http://sites.google.com/site/ki4mcw/Home/arduino-tnc , but it's actually not a good circuit.  I'll redraw it." CreationDate="2010-10-19T15:44:10.593" UserId="142" />
  <row Id="6175" PostId="5360" Text="Oh okay that makes more sense. Thanks!" CreationDate="2010-10-19T16:12:15.923" UserId="1225" />
  <row Id="6177" PostId="5315" Text="The microphone is &quot;highly sensible&quot;, at least..." CreationDate="2010-10-19T16:22:18.507" UserId="142" />
  <row Id="6178" PostId="5315" Text="@endolith I bought it and it is not that sensible, lol" CreationDate="2010-10-19T16:31:19.827" UserId="1298" />
  <row Id="6179" PostId="5336" Score="2" Text="You may downvote me here but I wrote something answering this on my blog recently so I will shamelessly give the link here, http://www.lifeasparesh.co.cc/2010/10/do-i-have-to-study-all-this-theory.html" CreationDate="2010-10-19T16:32:49.173" UserId="1200" />
  <row Id="6180" PostId="5356" Score="3" Text="On average, a capacitor can't supply power. In an AC circuit, a capacitor can supply power during part of the cycle, but only because it absorbed power in the previous half of the cycle." CreationDate="2010-10-19T16:39:58.593" UserId="740" />
  <row Id="6181" PostId="5348" Text="The date of manufacture may be 'melted' into the casting somewhere (not printed on a label per se.)" CreationDate="2010-10-19T16:43:41.493" UserId="1293" />
  <row Id="6182" PostId="5190" Text="Lol I'm the guys in the form who asked that question. " CreationDate="2010-10-19T17:24:19.103" UserId="1568" />
  <row Id="6183" PostId="5292" Text="your first point is not applicable to bypassing to reduce EMI / noise ripple.  Rather than sticking the largest cap you can on the power pin you need to look at the frequencies your expecting ripple at and select capacitors that have their impedance minimum at those frequencies.  This depends on dialectic, package, construction and capacitance.  If your dealing with a 25Mhz system clock your danger frequencies will be 25,75,125,175,225.  The 0.1uf is generally chosen to cover the low end and 10nF is generally effective from 80-300mhz or so.  " CreationDate="2010-10-19T17:56:58.903" UserId="1438" />
  <row Id="6184" PostId="5250" Text="@Smashtastic: Here's what I've been thinking lately. Instead of doing everything realtime, I would aquire 5MP @ 15fps for about 15sec buffering the data into ram and keep dunking the buffered data into a MMC or some flash memory at the same time, considering the MMC is slower. If I could directly take data from the camera and route into the flash it would be wonderful. I wonder though if MMC or some other flash tech can achieve these data rates? After acqusition of the frames I can then do image processing, and capture again if necessary." CreationDate="2010-10-19T18:04:27.293" UserId="444" />
  <row Id="6185" PostId="5292" Text="The way I approach it is to identify my decoupling needs, both in size and frequency response.  So say I know i need coverage from 0 to 250mhz, I choose whatever grouping of caps results in the impedance to ground always being &lt;0.1ohm.  Using standard MLCC with X7R dialectic, 0.1uF and 10nF cover me from ~4Mhz to 250Mhz well which is where most concern is.  Down into the audio range, &lt;20khz the ESR of ceramics increases quiet a bit so using an electrolytic is beneficial, be it tantalum or aluminium.  Thus these are used for low frequency bulk bypass. " CreationDate="2010-10-19T18:10:02.890" UserId="1438" />
  <row Id="6186" PostId="5292" Text="Then you figure out how much capacitance you need based on the current draw on the various supplies.  If you know the current draw you know the represented resistance and can calculate the needed capacitance for the desired ripple reduction." CreationDate="2010-10-19T18:11:51.010" UserId="1438" />
  <row Id="6187" PostId="5366" Text="Okay, so would a rule of thumb be to avoid resonant frequencies within 3-6 odd harmonics (so 6-12x frequency?) What about resonant frequencies below the operational frequency? What happens at the resonant frequency? Thanks." CreationDate="2010-10-19T18:38:29.840" UserId="1225" />
  <row Id="6188" PostId="1026" Text="Update to this is you can use Google Drawing but it's not the BEST option." CreationDate="2010-10-19T18:42:26.723" UserId="404" />
  <row Id="6189" PostId="5366" Text="I usually use 5-10 as i include the fundamental as one of the first 3. In the example above a perfect square wave would have 1/29 (29th harmonic) or 3.45% of the magnitude at 63Mhz that it has at its fundamental, 3Mhz.  That is for a perfect square wave, with rise/fall times of 0.  In reality this harmonic is probably a lot smaller because the slew rate of the switcher can't move that fast, it can't produce content at frequencies that high." CreationDate="2010-10-19T18:46:04.630" UserId="1438" />
  <row Id="6190" PostId="5190" Text="Ok so dxf2scr is not working for me. I tried running the SCR it generates in a empty brd files.. and nothing happens. I looked at the dxf file that topor generates with a third part dxf viewer and it looks fine.  The description for dxf2scr says it only does &quot;board outlines from AutoCAD to Eagle&quot; so it may not import the routing anyway.&#xA;I tried dxf2scr-1 , its look like its just a clone with a gui , and it doesn't work too.&#xA;" CreationDate="2010-10-19T18:52:24.290" UserId="1568" />
  <row Id="6191" PostId="5337" Score="2" Text="+1 for the current comment in this answer. I feel like this was a major mistake during my learning of electronics (and not just limited to transistors). Current matters, you won't get anywhere without some electrons moving at some point." CreationDate="2010-10-19T18:53:09.360" UserId="404" />
  <row Id="6192" PostId="5190" Text="the DXF importer from EagleCad power tools, seems to be the only one that kinda works. It presemnts me a list of layers in the dxf and how they should be transfered to eaglecad like top to layer 1 , bottom to layer 16. But when i run it it only seems to translate the pads and not the traces and routing. Could be because I'm running it in demo mode. " CreationDate="2010-10-19T18:53:50.577" UserId="1568" />
  <row Id="6193" PostId="5366" Text="As to SRF less than your switching frequencies.  When you cross the SRF the inductor's impedance drops back to what your would expect in magnitude but takes on a negative phase shift.  It acts kinda like a capacitor that passes DC.  Weird mode of operation and I think it would probably screw with the filter response although i've never actually worked out the math on that." CreationDate="2010-10-19T18:55:51.977" UserId="1438" />
  <row Id="6194" PostId="5356" Text="In the case of your example, yes, the power is fluctuating between positive and negative because the capacitor is alternately absorbing and then supplying energy." CreationDate="2010-10-19T19:21:47.750" UserId="142" />
  <row Id="6195" PostId="5348" Text="There's a number stamped onto the top of it, near the contacts: 01072330... does this mean anything?" CreationDate="2010-10-19T20:01:02.357" UserId="1225" />
  <row Id="6196" PostId="5371" Score="1" Text="A fractional tolerance wouldn't be infinite though, it would be zero, and finite, right?" CreationDate="2010-10-19T20:19:04.200" UserId="1225" />
  <row Id="6197" PostId="5372" Text="Ah. The load is to an ADC's Vref so should be very high impedence (&lt;1µA). I will reduce the resistor, thanks for pointing that out. Either 56R or 51R." CreationDate="2010-10-19T21:20:56.690" UserId="1225" />
  <row Id="6199" PostId="5369" Score="8" Text="-1R, the answer to all our energy problems." CreationDate="2010-10-19T21:34:34.000" UserId="1333" />
  <row Id="6200" PostId="5369" Text="Next thing we know overunity.com will have a section on negative resistors." CreationDate="2010-10-19T21:39:48.297" UserId="1225" />
  <row Id="6201" PostId="5366" Text="Thanks for your edits explaining this. Much appreciated." CreationDate="2010-10-19T22:09:52.133" UserId="1225" />
  <row Id="6202" PostId="5376" Score="1" Text="Unfortunately I don't have 2 hours to spend per board. I want to sell these for about $70 and $45 of that is PCB+component cost so $25 for 2 hours painstaking soldering isn't worth it. I will probably do this for prototypes though, but not for production. Thanks for the ideas." CreationDate="2010-10-19T22:18:40.657" UserId="1225" />
  <row Id="6203" PostId="5376" Score="1" Text="Ah, I see. For production, doing it by hand would be insane." CreationDate="2010-10-19T22:20:29.523" UserId="712" />
  <row Id="6204" PostId="5376" Score="1" Text="Hah, I'd vote you up but I've reached my daily vote limit. On the plus side, I now have the &quot;Suffrage&quot; badge." CreationDate="2010-10-19T22:21:43.590" UserId="1225" />
  <row Id="6205" PostId="5376" Text="honestly which ever way you solder your probably spending a large chunk of time placing parts.  Especially when it comes to the passives, the vast majority of the time is spent placing the part on the correct pad, the actual soldering takes a couple seconds." CreationDate="2010-10-19T22:22:06.333" UserId="1438" />
  <row Id="6206" PostId="5376" Text="That's a good point Mark. I have to locate components (as there are many different values used on the board), place them, apply paste and reflow. It could get tedious, which is why I'm considering outsourcing this to a manufacturer, but it's only worth it for higher quantities (~50 or so.)" CreationDate="2010-10-19T22:25:25.777" UserId="1225" />
  <row Id="6207" PostId="5372" Score="1" Text="Thanks for your analysis of the tolerance - much better than expected! I didn't think they added together. In fact I remember asking this same question on AAC forums (all about circuits) and it went into really theoretical stuff. I'll try and dig up the post." CreationDate="2010-10-19T22:27:37.820" UserId="1225" />
  <row Id="6208" PostId="5376" Score="3" Text="When i have to assemble prototypes what i do is print off the silk screen layer.  Get a bunch of different color markers, one for each value, and color the the foot print on the printed off silk screen.  So all 0.1uF caps gets blue, etc.  Saves you a lot of time staring at a spreadsheet of part numbers and values." CreationDate="2010-10-19T22:34:44.427" UserId="1438" />
  <row Id="6209" PostId="5376" Text="Good idea. As there are lots of similar values this would work quite well. " CreationDate="2010-10-19T22:36:53.450" UserId="1225" />
  <row Id="6210" PostId="5378" Score="1" Text="They pulled them because they could be used as real 328's. I don't think there's much chance of me getting them." CreationDate="2010-10-19T23:18:06.450" UserId="1225" />
  <row Id="6211" PostId="5380" Text="what speed is the bus and does it have pull ups?  If its something like an I2C bus you can do this with 1 transistor for each line (data/clk).  You do need pull ups on both the 5V and 3.3V sides however." CreationDate="2010-10-19T23:43:38.300" UserId="1438" />
  <row Id="6212" PostId="5381" Score="2" Text="My tips to a beginner: use lots of flux, don't hang around with your iron and overheat components, buzz out all of the pins afterwards with a continuity checker." CreationDate="2010-10-20T00:05:53.983" UserId="566" />
  <row Id="6213" PostId="5371" Score="3" Text="if your in a situation where 10-50 mOhm matters, or comes even remotely close to mattering, don't use a 0 ohm resistor.  I mean a 1 inch 10mil trace on 1oz copper results in roughly 50 mOhm resistance." CreationDate="2010-10-20T00:23:17.873" UserId="1438" />
  <row Id="6214" PostId="5321" Text="@endolith I mounted your circuit and it mantained the digital value of the DC component fixed as 688 (in a 10 bit scale). The ideal would be 512, but 688 is much better than what I had before (0). Then I realized that the mic alone won't be sufficient to change that. So I'm adding an Amp-Op to the circuit" CreationDate="2010-10-20T01:34:15.800" UserId="1298" />
  <row Id="6215" PostId="5369" Score="1" Text="They already do. http://jlnlabs.online.fr/cnr/index.htm  This, of course, originated from some idiot journalists framing an experiment as a &quot;breakthrough in superconductors&quot; because they don't understand electronics.  You can't put a current through one branch of a circuit and measure a voltage across another branch and call it resistance." CreationDate="2010-10-20T01:50:47.027" UserId="142" />
  <row Id="6216" PostId="5321" Text="To get 512, change the upper resistor to something around 16.8K.  :D  The mic isn't changing the value at all?  In that case, then yes, you'd need some gain from an op-amp.  You still need to use this biasing circuit somewhere, though." CreationDate="2010-10-20T01:54:13.310" UserId="142" />
  <row Id="6217" PostId="5386" Score="2" Text="huh?...What exactly do you need to execute from ram for?  and what do you mean by 'static'?  you aren't actually trying to write self modifying code are you?  Are you talking about the lack of dynamic memory allocation? aka no malloc?" CreationDate="2010-10-20T03:22:55.547" UserId="1438" />
  <row Id="6218" PostId="5385" Text="many software packages will produce pick and place instructions automatically with the gerber and there is no 'tooling' involved.  If they have to produce the pick and place instructions you may pay a setup fee but after that loading the reels on the machine is usually included in the run cost." CreationDate="2010-10-20T03:25:48.990" UserId="1438" />
  <row Id="6219" PostId="5306" Text="Yes...3&quot;, 7&quot;, or 21&quot;? 320x240 or 1920x1080? It makes a big difference." CreationDate="2010-10-20T03:58:48.570" UserId="131" />
  <row Id="6220" PostId="5361" Text="i will check out 'c18'.. thank you.. " CreationDate="2010-10-20T04:04:48.133" UserId="1484" />
  <row Id="6221" PostId="5363" Text="i asked about the differences in statements while using different compilers.. anyways i came to know about 1 more compiler 'sdcc'.. thanks a lot.." CreationDate="2010-10-20T04:07:46.200" UserId="1484" />
  <row Id="6222" PostId="5336" Text="@Rick_2047: that was smart posting it as a comment. You can't downvote comments ;-)" CreationDate="2010-10-20T04:40:04.580" UserId="790" />
  <row Id="6223" PostId="5386" Score="2" Text="@Mark I want to be able to load a program from an external device, such as an SD card, and execute it. I'll try to explain better in my post." CreationDate="2010-10-20T04:46:02.170" UserId="790" />
  <row Id="6224" PostId="5386" Score="2" Text="gotcha, the only PIC that i know of that would allow this is a PIC32.  Unless you do something crazy like copy it from the SD card to the flash, which will eat flash cycles pretty fast if your switching programs often.  Most small 8/16bit uC are heavily segmented between data(ram) and program(flash) space and don't allow the program counter to address ram (Harvard architecture, no memory protection, etc). " CreationDate="2010-10-20T04:57:18.373" UserId="1438" />
  <row Id="6225" PostId="3109" Text="@Kortuk - I'm being pedantic. Perfect is *never* possible given we live in reality. it can only be aspired to." CreationDate="2010-10-20T05:25:01.317" UserId="1374" />
  <row Id="6227" PostId="5385" Text="The tooling I was referring to is for a solder past mask. Even if you provide a pick and place most times sent PO for manufacturing there has been a 'set up' free or 'engineering' fee. Whether it is listed separately or built into the unit cost you still have pay it." CreationDate="2010-10-20T06:44:13.210" UserId="328" />
  <row Id="6228" PostId="5380" Text="It's a low speed UART, not faster than 19200 bps." CreationDate="2010-10-20T09:14:58.653" UserId="1225" />
  <row Id="6229" PostId="5394" Text="that would certainly do it" CreationDate="2010-10-20T11:10:27.247" UserId="740" />
  <row Id="6230" PostId="5385" Text="I am using gEDA PCB and I think it produces a CNC pick and place output." CreationDate="2010-10-20T12:12:10.767" UserId="1225" />
  <row Id="6232" PostId="3109" Text="@Fake Name, One of the definitions of perfect is satisfying all requirements. If everyone gets what they need, then you have a &quot;perfect&quot; solution." CreationDate="2010-10-20T14:01:52.013" UserId="230" />
  <row Id="6233" PostId="5375" Score="2" Text="You clearly have not had to purchase enough capacitors if you have not heard of 50% tolerance. Supercaps can be hilarious in their specs." CreationDate="2010-10-20T14:06:32.717" UserId="230" />
  <row Id="6234" PostId="5381" Text="Thanks for your answer." CreationDate="2010-10-20T14:16:03.683" UserId="1225" />
  <row Id="6235" PostId="5375" Score="1" Text="-20% to +80% is often seen for super caps. " CreationDate="2010-10-20T14:17:12.260" UserId="1225" />
  <row Id="6236" PostId="2017" Text="Damn straight. You can go from idea to actual, working thing in a very short period of time. " CreationDate="2010-10-20T14:36:19.187" UserId="1307" />
  <row Id="6238" PostId="5399" Score="1" Text="Any particular reason?" CreationDate="2010-10-20T14:59:42.283" UserId="1225" />
  <row Id="6239" PostId="5400" Text="So. Reflow one side, apply epoxy, reflow other side. Sounds simple enough. :)" CreationDate="2010-10-20T15:01:00.453" UserId="718" />
  <row Id="6240" PostId="5399" Score="2" Text="It's always going to be difficult, either needing careful application of heat or some kind of glue." CreationDate="2010-10-20T15:02:04.107" UserId="566" />
  <row Id="6241" PostId="5400" Text="Can't hurt to try it. I hope it works well for you." CreationDate="2010-10-20T15:09:49.350" UserId="230" />
  <row Id="6242" PostId="4696" Text="@Peter, it was 5+5 - I've got a much greater understanding of this stuff now. It's fun to look back on myself. :)" CreationDate="2010-10-20T15:47:13.113" UserId="1333" />
  <row Id="6243" PostId="5389" Text="The mbed actually receives binaries by having them copied onto the inbuilt flash drive and then being reset. It shows up as a flash drive when connected to the USB port of a computer. If you can work out a method to either use the flash drive instead of the SD card, or set it up so that a binary from the SD card is automagically copied to the flash drive and a reset performed then you might be in luck. The  mbed does not require a hardware programmer." CreationDate="2010-10-20T15:53:03.297" UserId="103" />
  <row Id="6244" PostId="5393" Score="1" Text="Roll your own DSL. This option appeals to me the most of all the solutions suggested." CreationDate="2010-10-20T15:55:12.007" UserId="103" />
  <row Id="6245" PostId="5266" Text="It looks like their chips are branded by a subsidiary company: http://www.hli.com.my/Corp_Info/Semiconductor/Carsem/Carsem.asp" CreationDate="2010-10-20T16:05:16.363" UserId="690" />
  <row Id="6246" PostId="250" Text="Are you absolutely sure what kind of chip it is? Are there sites that let you search by pin numbers?" CreationDate="2010-10-20T16:05:52.497" UserId="690" />
  <row Id="6248" PostId="5407" Text="Yes but what does this mean to me? Sorry, I'm still a noob." CreationDate="2010-10-20T17:27:55.260" UserId="1225" />
  <row Id="6249" PostId="5337" Text="Wait, what? You mean a transistor in &quot;switch mode&quot; acts NOTHING LIKE A SWITCH? I.e., it's the current applied to the base multiplied by the Hfe which governs the current south of the emitter, rather than whatever load is hanging off the emitter and the voltage across the collector and emitter?" CreationDate="2010-10-20T17:37:05.803" UserId="1633" />
  <row Id="6250" PostId="5407" Text="The input will draw about 500nA (the current source).  The capacitors will limit the sample rate.  The Chold needs time to charge when it switches to the input pin." CreationDate="2010-10-20T17:42:26.300" UserId="204" />
  <row Id="6251" PostId="5337" Text="Imagine the base-emitter junction is a diode (it is, but it's a bit more complex.) The current through the diode determines the current coming into the collector. The emitter current is the sum of the base current and collector current. In saturation, which is what this is being used as, the transistor acts as a switch and drops 0.1-0.2V." CreationDate="2010-10-20T17:44:21.447" UserId="1225" />
  <row Id="6252" PostId="5407" Text="500nA would drop 50mV, which is quite high, but not much of my 0-30V full scale range, it would be about 5mV which is fine. Thanks!" CreationDate="2010-10-20T17:48:35.403" UserId="1225" />
  <row Id="6253" PostId="5409" Text="Unfortunately I can't spare space for an op-amp." CreationDate="2010-10-20T18:36:56.333" UserId="1225" />
  <row Id="6254" PostId="5410" Score="3" Text="+1 for using Microchip parts! (And a good example!)" CreationDate="2010-10-20T19:05:33.233" UserId="588" />
  <row Id="6255" PostId="2004" Text="possible duplicate of [Basic Electronics Book](http://electronics.stackexchange.com/questions/616/basic-electronics-book)" CreationDate="2010-10-20T20:26:28.477" UserId="142" />
  <row Id="6256" PostId="5400" Text="Is that right?  Wouldn't the steps be 1. Apply epoxy to components on side A 2. Reflow side A 3. Reflow side B?  If the first side doesn't have epoxy, the parts are going to fall off.  It doesn't matter if the second side has epoxy." CreationDate="2010-10-20T20:28:39.517" UserId="142" />
  <row Id="6257" PostId="5400" Text="I had a feeling that he was not going to place the second set of components until he had reflowed one side. there are 8 million ways to approach this." CreationDate="2010-10-20T21:10:44.407" UserId="230" />
  <row Id="6258" PostId="3400" Text="+1 for light sources, makes a lot of difference." CreationDate="2010-10-20T21:38:44.447" UserId="1333" />
  <row Id="6259" PostId="5414" Text="Already have 100 ms delay on start-up" CreationDate="2010-10-20T21:41:28.753" UserId="588" />
  <row Id="6260" PostId="5414" Text="Try my other suggestion then. You could even control the LCD power from a pin directly; it shouldn't draw more than a few mA." CreationDate="2010-10-20T21:51:53.037" UserId="1225" />
  <row Id="6261" PostId="5375" Score="2" Text="i guess i should have been more specific, and said who's ever heard of a 50% *resistor*; caps are notoriously widely spec'd." CreationDate="2010-10-20T22:01:40.967" UserId="740" />
  <row Id="6263" PostId="5410" Text="Valeu manow! Issoaeeeeee" CreationDate="2010-10-20T22:15:36.630" UserId="1298" />
  <row Id="6264" PostId="5416" Score="1" Text="Usually the Propeller chip is booted from a 32K EEPROM (24LC256), but here is a way to boot from an SD card instead: http://www.gadgetgangster.com/news/45-designer-news/313-tip-sd-card-bootloader.html" CreationDate="2010-10-20T22:53:17.997" UserId="1322" />
  <row Id="6265" PostId="5418" Text="That chip looks very nice and capable. Unfortunately, I only have the devel platform and programmer for AVR atm. As I don't have a lot of money to invest in tools and software, I would have to pass this nice piece of hardware up." CreationDate="2010-10-20T23:10:53.117" UserId="1575" />
  <row Id="6266" PostId="5418" Score="1" Text="Be careful -- this is not an actual PoE PD (powered device) -- it does not conform to the 802.3af spec and if you're using a 802.3af compliant PoE switch it will not supply voltage to this device." CreationDate="2010-10-20T23:53:13.363" UserId="974" />
  <row Id="6267" PostId="5424" Text="I think this may fall under community wiki, unless a single answer will probably clearly be correct, I think this will have many people posting different questions." CreationDate="2010-10-21T00:02:07.233" UserId="230" />
  <row Id="6271" PostId="5426" Text="The LM5071 sounds like it would be a great choice for the circuit I would like to build. I would like to find a chip that might support both 802.3af and 802.3at if possible. I will check out the sites you recommended. I also modified my post with additional details." CreationDate="2010-10-21T00:43:09.680" UserId="1575" />
  <row Id="6275" PostId="5427" Score="3" Text="does my bad soldering count?" CreationDate="2010-10-21T02:04:57.793" UserId="1438" />
  <row Id="6276" PostId="2017" Text="Also worth mentioning is that starting with Arduino allows you to move into a more advanced programming language, if you need it." CreationDate="2010-10-21T02:17:45.283" UserId="906" />
  <row Id="6277" PostId="5427" Text="How about sticking electronics in animals?" CreationDate="2010-10-21T02:51:35.750" UserId="319" />
  <row Id="6278" PostId="5400" Text="I have heard of people trying to using solders that have different melting points and using a different heat profile for each side, but I haven't actually seen any success doing it this way in house." CreationDate="2010-10-21T02:59:54.543" UserId="319" />
  <row Id="6279" PostId="5427" Text="@Kellenjb - ..... are you saying you do that? " CreationDate="2010-10-21T03:03:58.637" UserId="1374" />
  <row Id="6281" PostId="5427" Text="@Fake Name, yeah, all FDA approved though." CreationDate="2010-10-21T03:15:05.617" UserId="319" />
  <row Id="6282" PostId="5336" Text="I will post a gibberish answer, downvote that if you want to. I just don't like copy pasting things." CreationDate="2010-10-21T04:22:50.653" UserId="1200" />
  <row Id="6283" PostId="5425" Score="1" Text="The file searches won't catch everything, because different EDA packageshave different naming conventions. .pcb .pcbdoc .brd , .grb .gto .057 .gbl .gto .gbo .gts .gbs etc... off the top of my head" CreationDate="2010-10-21T05:17:28.760" UserId="1374" />
  <row Id="6284" PostId="5432" Text="Thanks for your suggestions! I noticed the diode silkscreens were the wrong way around too. I think I will start again. I am trying to use 2-layer for this version to cut down costs." CreationDate="2010-10-21T07:01:02.393" UserId="1225" />
  <row Id="6285" PostId="3109" Text="@Kortuk - Wow. Apparently my requirements are more stringent. I never have anything that satisfies *all* of my requirements, just enough that it works." CreationDate="2010-10-21T08:17:16.913" UserId="1374" />
  <row Id="6286" PostId="5337" Text="ARGH! I've just worked out what I'm doing isn't working! Instead of GROUNDING the emitter and putting the load (a string of LEDs) between the positive end of the power supply and the collector, I was putting the load between the emitter and the negative of the power supply. Sometimes it's hard because you just don't know what you don't know." CreationDate="2010-10-21T09:13:52.143" UserId="1633" />
  <row Id="6287" PostId="5439" Text="Ok, so how do I hook up my multimeter to the wires to verify the voltage that I am getting." CreationDate="2010-10-21T09:16:44.867" UserId="1657" />
  <row Id="6288" PostId="5439" Text="Added a measurement technique to the answer." CreationDate="2010-10-21T09:28:33.637" UserId="400" />
  <row Id="6289" PostId="5437" Text="Yes, I intend to do image/video processing and the Digilent Atlys looks tempting here, the Atlys also has a stronger LX45 FPGA vs the LX16 on the Avnet Spartan or the SP601. Considering that I've never worked on FPGA's before would it be any different getting started on a Spartan6?" CreationDate="2010-10-21T09:39:00.413" UserId="444" />
  <row Id="6290" PostId="5437" Score="1" Text="No, the development tools are the same. You may find a few examples don't translate directly to the board, though, like VGA generation or direct audio synthesis, as the Atlys uses digital video and an audio codec chip." CreationDate="2010-10-21T10:23:38.337" UserId="1181" />
  <row Id="6291" PostId="5425" Text="@Fake thanks, I edited the answer to include a link that searches for all those extensions" CreationDate="2010-10-21T10:34:09.490" UserId="1298" />
  <row Id="6292" PostId="5337" Text="Putting the load after the emitter would work but only if you could tolerate 0.7V of drop across the transistor. So if you had an LED that operated on 3V it would be no good after the emitter because the LED would only see 2.3V with a 3V supply." CreationDate="2010-10-21T12:12:23.480" UserId="1225" />
  <row Id="6293" PostId="5433" Text="Do you mean &quot;DS10*52*E&quot;?" CreationDate="2010-10-21T12:27:54.860" UserId="51" />
  <row Id="6294" PostId="5440" Text="The Freetronics shield is the same kind of design as the BD9001 one in one of the earlier answers; it is NOT 802.3af compliant, and even states such on the web site linked by you. If you want it to be compliant you need to add a daughterboard that is not yet available." CreationDate="2010-10-21T13:06:50.083" UserId="974" />
  <row Id="6295" PostId="5427" Text="@Kellenjb - are you talking about those ID chips they can embed in your dog's ear, that kind of thing?" CreationDate="2010-10-21T14:39:06.467" UserId="740" />
  <row Id="6296" PostId="5427" Text="@JustJeff more complex then that. Don't want to release any trade secrets though." CreationDate="2010-10-21T14:50:05.823" UserId="319" />
  <row Id="6297" PostId="5431" Score="1" Text="Ah, that's good but I can't see it at work :(  On a related note, does anyone else get tired of video reviews and posts?  I prefer reading." CreationDate="2010-10-21T14:56:18.843" UserId="249" />
  <row Id="6298" PostId="5436" Score="1" Text="Maybe a reflow toaster/skillet will allow an inexperienced person to remove parts without damage to parts or board - haven't used those. Other methods (hot air or manual iron removal) require more skill to remove a part (leaving the PCB and part undamaged) than it requires to install in the first place. It's a chicken and egg problem. " CreationDate="2010-10-21T15:20:52.263" UserId="906" />
  <row Id="6299" PostId="5443" Score="1" Text="This sensor is for 0-50A.  That is a lot of current to draw from a battery unless it is a Lead-Acid cell cranking a car engine - even then it will only drive this sort of current for a short time." CreationDate="2010-10-21T16:43:18.603" UserId="400" />
  <row Id="6300" PostId="5443" Score="1" Text="You can draw plenty from a LiPo - 40A isn't uncommon for some powerful RC motors." CreationDate="2010-10-21T16:46:41.897" UserId="1225" />
  <row Id="6301" PostId="5432" Text="Think carefully about going to 2-layer. The layout will be far superior not only electrically but thermally if you go with 4-layer and use planes to minimize loop sizes." CreationDate="2010-10-21T16:46:43.940" UserId="1293" />
  <row Id="6302" PostId="5442" Text="@XTL: yes, that was also the conclusion I came to after researching some more for several hours." CreationDate="2010-10-21T17:34:58.037" UserId="804" />
  <row Id="6305" PostId="5432" Text="Yeah, but it's twice the cost to prototype 4-layer, I can't afford that at the moment. " CreationDate="2010-10-21T18:03:25.557" UserId="1225" />
  <row Id="6307" PostId="3109" Text="Haha. I will accept that. I follow the idea that if the customer is happy and the system is maintainable, then it is perfect." CreationDate="2010-10-21T18:58:00.510" UserId="230" />
  <row Id="6310" PostId="3359" Text="Floating point on AVRs, lol." CreationDate="2010-10-21T19:06:37.830" UserId="1407" />
  <row Id="6311" PostId="5447" Text="So, I'm lookig for table-top vise? Looks very interesting. I'll definitely consider something like that." CreationDate="2010-10-21T19:07:47.917" UserId="1240" />
  <row Id="6312" PostId="5405" Text="Nice graph, easy enough to figure out, but you should probably explain how the examples work for completeness." CreationDate="2010-10-21T19:18:11.983" UserId="1407" />
  <row Id="6313" PostId="5438" Text="Remember that drawing any more than 50 mA before asking for more (if you do at all) is a violation of the spec and potentially damaging to the bus (and all other devices on it). With the USB Charging Specification, devices are also able to draw up to 1.8 A from a USB port (if allowed)." CreationDate="2010-10-21T19:18:46.710" UserId="1407" />
  <row Id="6314" PostId="5381" Text="I find soldering pin-by-pin is sometimes more convenient and cleaner.  0.015 solder and a good iron and I can hit the pins pretty fast.  It's how the tech did it where I worked, but I have no idea if she was certified." CreationDate="2010-10-21T19:23:43.307" UserId="1407" />
  <row Id="6315" PostId="5405" Text="Thanks @Nick T, I've done it in the text." CreationDate="2010-10-21T19:36:31.603" UserId="938" />
  <row Id="6316" PostId="5447" Text="+1 for the heavy base. I have one of those linked to in the question, and it keeps tipping over when I push the pcb with the soldering iron. It's crap!" CreationDate="2010-10-21T19:43:42.780" UserId="718" />
  <row Id="6319" PostId="5442" Score="1" Text="@XTL: I found this very useful list of AVR chips with 40 features/parameters: [Parametric Product Table for Atmel AVR microcontrollers](http://www.atmel.com/dyn/products/param_table.asp?family_id=607&amp;OrderBy=part_no&amp;Direction=ASC). It makes it very easy to see how a particular chip is different from similar chips with the same amount of SRAM/flash/EEPROM, for instance, if one chip is specified for a board and the other is the one that can be purchased from a supplier of ICs. Can you incorporate that link (and perhaps a description) into your answer? " CreationDate="2010-10-21T21:02:01.343" UserId="804" />
  <row Id="6320" PostId="4848" Text="I know this thread is old, but the potentiometer dissipates a constant amount of power if it has a constant voltage and no load on the wiper, because the resistance of the pot is constant no matter where the wiper is (it only changes the ratio of the two resistances.)" CreationDate="2010-10-21T21:24:53.270" UserId="1225" />
  <row Id="6321" PostId="4542" Text="@BCS - A computer-controlled analog EQ sounds oxymoronic to me. Please correct me if I'm wrong, but won't any digitally controlled pot be, well, digital, and the microcontroller and/or pot introduce switching noise when you change the pot's value?" CreationDate="2010-10-21T22:06:34.323" UserId="374" />
  <row Id="6322" PostId="4848" Text="We are both correct: I was talking about using it like a rheostat where you use the wiper + one end as a variable resistor, and leave the other terminal disconnected." CreationDate="2010-10-21T22:19:42.620" UserId="330" />
  <row Id="6323" PostId="5448" Score="2" Text="Would also like to add my 5c worth - I have the exact same thing as well (from the original question) and it is a piece of sh!t. People will probably laugh at me but I use blutac to hold things down on the bench when necessary, or a Panavise which has been ordered. " CreationDate="2010-10-21T22:33:42.337" UserId="1307" />
  <row Id="6324" PostId="4545" Text="the AD 6 wides have +/- 30% tolerance " CreationDate="2010-10-21T22:43:36.090" UserId="1438" />
  <row Id="6325" PostId="4545" Text="You'd have a really hard time getting any usable range out of those opto couplers.  Look at the LED current vs resistance curves: ~500ohm @ 20mA, 500-5K Ohm at 1mA, 500k-10M at 0mA.  I doubt you'd get much usable control range with a PWM LED driver.  I mean to get 256 steps in a usable range you'd need to control the current in 4uA steps. (probably a lot less actually as the current -&gt; resistance is non linear)" CreationDate="2010-10-21T22:54:00.903" UserId="1438" />
  <row Id="6326" PostId="4542" Text="@sheepsimulator: There is no reason that a digital pot would inherently add switching noise (I'd assume that a well designed one would attempt to minimize that) as for the rest of the system, while mixed signal applications are a problem, they are a *know* problem with know solutions, they make digital sounds boards after all and they have to go analog at some point. For that matter it could be setup so that you could turn off the digital parts and the analog parts would continue to function just fine. -- As to being oxymoronic, no it's not (*moronic* OTOH is a distinct possibility :)." CreationDate="2010-10-21T22:59:38.083" UserId="1182" />
  <row Id="6327" PostId="5447" Text="+1 for Panavise, my favorite bench clamps" CreationDate="2010-10-21T23:29:13.850" UserId="1438" />
  <row Id="6328" PostId="5450" Text="I'm very interested!" CreationDate="2010-10-21T23:30:11.383" UserId="1298" />
  <row Id="6329" PostId="5450" Text="It was started and maintained by Jon Oxer of Freetronics" CreationDate="2010-10-21T23:53:20.017" UserId="404" />
  <row Id="6330" PostId="5456" Text="Thanks. Noted. In this case, I know what signals will be going through them (about the same as you had) so all I need to check is that the pot is what i think it is." CreationDate="2010-10-22T00:11:18.003" UserId="1182" />
  <row Id="6331" PostId="5433" Text="Yes I do...apologizes. I bought it from TEquipment @ http://www.tequipment.net/RigolDS1052E.html. They had a sale about a month ago and dropped it from $400 to $330 + shipping. You can find the hack @ http://www.eevblog.com/2010/04/18/eevblog-77-rigol-ds1052e-ds1102e-oscilloscope-hack-update/. Hope that helps." CreationDate="2010-10-22T00:22:09.637" UserId="1575" />
  <row Id="6332" PostId="5440" Text="In my design 802.3af would be a requirement." CreationDate="2010-10-22T00:30:59.753" UserId="1575" />
  <row Id="6333" PostId="3109" Text="I would call that simply good enough." CreationDate="2010-10-22T00:38:21.813" UserId="1374" />
  <row Id="6334" PostId="5441" Score="1" Text="Ah, did not think about that. Here is the actual forum topic on EEVBlog discussing the hack: http://www.eevblog.com/forum/index.php?topic=553.0" CreationDate="2010-10-22T01:14:57.623" UserId="1575" />
  <row Id="6335" PostId="5458" Text="can you give a bit more detail about what you mean? are you doing delay for synchronization?" CreationDate="2010-10-22T02:45:29.603" UserId="230" />
  <row Id="6336" PostId="5458" Score="1" Text="It sounds like an adjustable echo or reverb effect he's going for." CreationDate="2010-10-22T02:48:52.627" UserId="965" />
  <row Id="6338" PostId="5438" Score="3" Text="it is 100mA without asking, not 50." CreationDate="2010-10-22T03:01:34.650" UserId="230" />
  <row Id="6339" PostId="5426" Text="TPS2370/LT1676: Very nice. Let me play around with that for a few hours and see if it fits what I am looking for. Thx for the help." CreationDate="2010-10-22T04:26:43.183" UserId="1575" />
  <row Id="6340" PostId="5459" Text="Are you wanting multiple cameras to take a picture at the exact same instance? Or are you just looking for a low latency trigger over IP?" CreationDate="2010-10-22T05:19:16.870" UserId="319" />
  <row Id="6341" PostId="5438" Score="2" Text="Just to make sure awakeFromNib is clear, the 100mA limit has nothing to do with measuring the voltage with a multimeter since the multimeter will not load the circuit much. The only case that this does come into play is if he connects a large load, such as a 10 ohm resistor, across the vbus and ground pins. Doesn't sound like this is what he is asking about though." CreationDate="2010-10-22T05:49:51.663" UserId="319" />
  <row Id="6342" PostId="5432" Text="I have had a few students make buck, boost, and book-boost circuits on only 2 layers and got it to work just fine. I would highly consider using a ground plane on the bottom with many vias connecting to your ground on the top. Pretty much, instead of looking for a way to route ground on the top, just place a via any where you need ground." CreationDate="2010-10-22T05:54:46.367" UserId="319" />
  <row Id="6343" PostId="5460" Text="Okay, 3% is quite high... is there any way to reduce this? I guess I could reduce the divider resistance..." CreationDate="2010-10-22T07:00:50.757" UserId="1225" />
  <row Id="6344" PostId="5425" Text="The list I gave is *not* comprehensive. It still may miss some results." CreationDate="2010-10-22T07:06:44.270" UserId="1374" />
  <row Id="6345" PostId="5445" Text="Madmanguruman, thank you very much, I don't knew what was that sensor..." CreationDate="2010-10-22T08:27:58.213" UserId="1660" />
  <row Id="6346" PostId="1524" Text="How do you order from the manufacturer? I can't see any purchase methods on their site." CreationDate="2010-10-22T11:18:14.180" UserId="1333" />
  <row Id="6347" PostId="5457" Text="I would like to add: that's a link to the Project development, ideas, and suggestions for Arduino section in the Dangerousprototypes.com forum." CreationDate="2010-10-22T11:35:07.247" UserId="1298" />
  <row Id="6348" PostId="5409" Text="you can't spare space for a SC70-6 component and you call yourself a noob? " CreationDate="2010-10-22T12:37:56.063" UserId="974" />
  <row Id="6349" PostId="5462" Text="Hmm, very interesting." CreationDate="2010-10-22T13:25:37.503" UserId="319" />
  <row Id="6350" PostId="5464" Text="Why not edit your original question and include this in there. StackExchange based sites don't support conversations in their responses (apart from in the Comments) and really all relevant info needs to go in the original question as a result." CreationDate="2010-10-22T13:33:10.453" UserId="103" />
  <row Id="6351" PostId="5457" Text="Added it into the post for you." CreationDate="2010-10-22T13:53:52.893" UserId="103" />
  <row Id="6352" PostId="5445" Text="@mtz: Don't worry about the sensor being discontinued, there is a drop-in replacement, the ACS758 which is pretty much identical but supports a wider voltage range with improved accuracy." CreationDate="2010-10-22T13:54:21.170" UserId="1407" />
  <row Id="6353" PostId="5459" Text="What are these &quot;slight delays&quot;?  Are you trying to synchronize them so that, e.g. all the shutters are open for a strobe?" CreationDate="2010-10-22T14:00:51.703" UserId="1407" />
  <row Id="6354" PostId="5404" Text="Input impedance is not what you should worry about at a 100 Hz sample rate with a sub-megaohm source, but things like aliasing or capturing transients (if it even matters)." CreationDate="2010-10-22T14:30:29.450" UserId="1407" />
  <row Id="6355" PostId="5460" Text="it is 3% if your smallest reading is 30V." CreationDate="2010-10-22T14:31:09.203" UserId="230" />
  <row Id="6356" PostId="5460" Text="extra information added." CreationDate="2010-10-22T14:35:06.170" UserId="230" />
  <row Id="6357" PostId="5468" Score="1" Text="Looks like it can be modded to 100MHz - very cool: http://www.eevblog.com/2010/03/31/eevblog-70-turn-your-rigol-ds1052e-oscilloscope-into-a-100mhz-ds1102e/" CreationDate="2010-10-22T14:36:52.683" UserId="1333" />
  <row Id="6358" PostId="5462" Score="1" Text="Something of a theory question: Is it even possible to create a frequency-independent time-shift circuit with just linear components?  (ideal resistors, op-amps, caps...)" CreationDate="2010-10-22T14:38:42.453" UserId="1407" />
  <row Id="6359" PostId="5468" Text="Yes, I forgot about that... :|" CreationDate="2010-10-22T14:54:14.167" UserId="1307" />
  <row Id="6360" PostId="5468" Text="I'll wait for some more opinions but the Rigol looks good (even if it does stretch the budget). Also, I can only find non-UK sources to buy it at £250 meaning I'm probably gonna be hit with an import charge. Any comments on the logic sniffer?" CreationDate="2010-10-22T15:17:35.647" UserId="1333" />
  <row Id="6361" PostId="3075" Text="Safety: http://electronics.stackexchange.com/questions/3506/safety-of-making-pcbs  How can I successfully make a PCB at home? http://electronics.stackexchange.com/questions/3320/how-can-i-successfully-make-a-pcb-at-home" CreationDate="2010-10-22T15:20:17.860" UserId="142" />
  <row Id="6362" PostId="5459" Text="What dedicated triggering solution are you using now? It seems odd that you would be getting delays like what you mentioned on a dedicated trigger line." CreationDate="2010-10-22T15:20:34.700" UserId="319" />
  <row Id="6363" PostId="3320" Text="Homebrew PCB tips? http://electronics.stackexchange.com/questions/3075/homebrew-pcb-tips" CreationDate="2010-10-22T15:20:36.390" UserId="142" />
  <row Id="6364" PostId="2829" Text="Cheap PCB manufacture  http://electronics.stackexchange.com/questions/1893/cheap-pcb-manufacture Where can you get PCBs fabricated in Australia?http://electronics.stackexchange.com/questions/1629/where-can-you-get-pcbs-fabricated-in-australia" CreationDate="2010-10-22T15:22:13.787" UserId="142" />
  <row Id="6365" PostId="1893" Text="Recommended PCB houses / Assemblers http://electronics.stackexchange.com/questions/2829/recommended-pcb-houses-assemblers Where can you get PCBs fabricated in Australia? http://electronics.stackexchange.com/questions/1629/where-can-you-get-pcbs-fabricated-in-australia" CreationDate="2010-10-22T15:22:46.263" UserId="142" />
  <row Id="6366" PostId="5458" Score="1" Text="Not offering this as a solution, but I remember back in the 1960's working with a band that had a reverb using a coiled spring with a transducer at one end and a pickup on the other.  Worked pretty well unless someone accidentally kicked the box with their shoe, then all hell broke loose.  http://en.wikipedia.org/wiki/File:Reverb-2.jpg" CreationDate="2010-10-22T15:22:53.583" UserId="1322" />
  <row Id="6367" PostId="5458" Text="That is awesome." CreationDate="2010-10-22T15:31:53.737" UserId="319" />
  <row Id="6369" PostId="4545" Text="@Mark: 30% tolerance in the total resistance of the pot shouldn't have any significant effect on an EQ.  It might change the taper of the control a little." CreationDate="2010-10-22T15:50:33.617" UserId="142" />
  <row Id="6370" PostId="5469" Score="1" Text="endolith, that answer is sexy." CreationDate="2010-10-22T16:12:36.043" UserId="230" />
  <row Id="6371" PostId="5462" Text="@Nick: How accurate does it need to be?  A frequency-independent time shift means a linear phase shift with frequency, right?  So I'd guess it's possible to approximate with all-pass filters." CreationDate="2010-10-22T16:25:29.107" UserId="142" />
  <row Id="6372" PostId="4545" Text="@Mark: You don't need 256 steps for an EQ.  ±15 dB in 1 dB steps is only 30 steps.  If the drive capability of the PWM IC has 4096 linear(?) steps from 0 mA to 60 mA, that's 15 µA for the smallest.  Since it's all run from a microcontroller, you can skip steps in firmware to get linear dB response or whatever you need." CreationDate="2010-10-22T16:44:08.767" UserId="142" />
  <row Id="6373" PostId="2138" Score="1" Text="I'd venture a guess that the SD card is going to be your limiting factor not the network interface.  You better make sure whatever dev board you get is running in 4bit mode and supports 50Mhz SD clock or you have no chance of getting 10MB/sec read/write out of it.  If the SD port is run in 1 bit or SPI mode you'll never get 10MB/sec out of it so the move to gigabit won't do anything." CreationDate="2010-10-22T16:48:06.787" UserId="1438" />
  <row Id="6374" PostId="5427" Text="@Kellenjb: Will a photo release a trade secret, or is it possible to get one (or X-ray) with it?" CreationDate="2010-10-22T17:18:45.813" UserId="1402" />
  <row Id="6375" PostId="5030" Text="@davr: The uController is another $7-8 so it's really not that big a deal. Yes, it's more money than an Arduino… But it's also a lot more capable." CreationDate="2010-10-22T18:03:41.280" UserId="1317" />
  <row Id="6376" PostId="5457" Text="Made it better." CreationDate="2010-10-22T18:05:38.667" UserId="1084" />
  <row Id="6377" PostId="5474" Text="Good suggestion! Thanks." CreationDate="2010-10-22T18:07:11.373" UserId="1333" />
  <row Id="6378" PostId="5463" Text="Good tip; the DE0 and DE1 boards look great to start out with. I haven't gotten Quartus running yet, but imagine it's not that hard. " CreationDate="2010-10-22T18:16:20.103" UserId="1181" />
  <row Id="6379" PostId="5479" Score="1" Text="Xilinx, Altera and Lattice all have gratis tools for GNU/Linux." CreationDate="2010-10-22T18:38:02.780" UserId="1181" />
  <row Id="6380" PostId="5463" Text="@allen houng: I must admit that I haven't given Altera a thought. Does the Altera DE2 / DE2-115 have equivalent features and performance of a Spartan6? Could you please elaborate on the user friendliness aspect of Quartus, I would like to go into a bit of detail before making a descision. Thanks for the suggestion though." CreationDate="2010-10-22T18:38:38.657" UserId="444" />
  <row Id="6381" PostId="5437" Text="@LoneTech: What choice would you have made? would it be Spartan6 or Spartan3?" CreationDate="2010-10-22T18:40:28.137" UserId="444" />
  <row Id="6382" PostId="5463" Text="Please download and evalutate the software! The most important step with any of the kits is that you get the tools to work on your own system, and they each have quirks that may or may not apply to you." CreationDate="2010-10-22T18:42:18.630" UserId="1181" />
  <row Id="6383" PostId="5437" Text="@LoneTech: I don't get the point you make of the Atlys not have many expansion pins? (As I haven't worked with FPGA dev kits before). Generally when I buy a microcontroller dev kit all the I/O pins are bought on to terminal headers for use? Isn't this the case with FPGA dev kits?" CreationDate="2010-10-22T18:43:28.130" UserId="444" />
  <row Id="6384" PostId="5472" Text="Thanks for sharing your experience, any comparison to the Spartan6 would help." CreationDate="2010-10-22T18:44:28.580" UserId="444" />
  <row Id="6385" PostId="5463" Text="What series of Altera is on similar lines to Spartan6 is it Stratix, Arria or Cyclone?" CreationDate="2010-10-22T18:49:49.053" UserId="444" />
  <row Id="6386" PostId="5475" Text="Futurlec is in Thailand, they just set up local 'paper' addresses in Australia and the US. " CreationDate="2010-10-22T18:50:56.220" UserId="1307" />
  <row Id="6387" PostId="5474" Text="Did not even think of pointing out bandwidth, I forget how often people do not realize how little bandwidth they need." CreationDate="2010-10-22T18:52:15.570" UserId="230" />
  <row Id="6388" PostId="5461" Text="I think it would be better if the devices referenced a world time through a protocol like NTP and then you broadcasted a future time(just need to give a half second for message propagation) and then they could sync very closely." CreationDate="2010-10-22T18:53:33.437" UserId="230" />
  <row Id="6389" PostId="5437" Text="The Atlys has expansion pins, but 40 of them are in an unusual connector that isn't very hobbyist friendly. For the Spartan 3 starter kit, at least you can get the FX2 lab board addons. In comparison the Avnet and Altera kits offer plenty of 0.1&quot; pin headers. Many pins aren't brought out but used for on-board peripherals like RAM, switches and LEDs. A MCU might have between 8 and 128 pins; your typical FPGA on a devboard has 484.&#xA;As for what I'd pick, it depends on what I'm aiming at. I'd go with Atlys for HDMI video handling, but only with confidence that I can learn that protocol." CreationDate="2010-10-22T19:22:27.450" UserId="1181" />
  <row Id="6390" PostId="5474" Text="How little bandwidth does one need?" CreationDate="2010-10-22T19:26:18.413" UserId="1333" />
  <row Id="6391" PostId="5479" Text="@LoneTech: As in binaries, I presume? Not source for the tools? Linux is better than Windows, at least. I will investigate that route…" CreationDate="2010-10-22T19:35:00.087" UserId="1317" />
  <row Id="6392" PostId="5474" Score="1" Text="@Nat, unless you are doing very high-speed digital, or RF work, you should be able to get by with 40 MHz.  That is typically about the highest clock rate of most microcontrollers, and most signals (SPI, I2C etc) will be much slower than that.  For looking at audio or PWM signals (for robotics), you don't need much at all.  In any case, make sure you get a good set of probes, which might run another £20 or more." CreationDate="2010-10-22T20:11:08.917" UserId="1322" />
  <row Id="6393" PostId="4117" Text="I think you should flag this up on Meta (unfortunately I'm on my phone so the simulation applet doesn't work)." CreationDate="2010-10-22T20:22:25.730" UserId="103" />
  <row Id="6394" PostId="5448" Text="@tronixstuff - did not think of that... has blutac, may try..." CreationDate="2010-10-22T20:24:57.523" UserId="374" />
  <row Id="6395" PostId="5413" Text="It seems no-one thought your question worth up-voting, quite odd." CreationDate="2010-10-22T20:39:22.780" UserId="230" />
  <row Id="6396" PostId="5432" Text="I may be misreading it, but the design seems to have a ground plane." CreationDate="2010-10-22T20:42:00.480" UserId="230" />
  <row Id="6397" PostId="5413" Text="The datasheets for some of the HD44780 clones are pretty poorly written. My goal was to get a conversation going on what the proper way to initialize them was. Maybe I'm the only one who's had problems using them in 4-bit mode." CreationDate="2010-10-22T20:42:13.177" UserId="588" />
  <row Id="6398" PostId="4117" Text="What do you mean &quot;flag it up&quot;?" CreationDate="2010-10-22T20:43:50.973" UserId="142" />
  <row Id="6399" PostId="5474" Score="1" Text="Think of wanting your bandwidth to be 3-10 times faster than your highest speed signal. it never hurts to have too much bandwidth, but it can really hurt to have too little." CreationDate="2010-10-22T21:49:25.933" UserId="230" />
  <row Id="6400" PostId="5479" Text="I just had a look at Xilinx and Altera - neither of these supply Modelsim for Linux on the webpack tool editions.  Modelsim is only available in the paid editions.  I have not checked lattice." CreationDate="2010-10-22T22:00:05.717" UserId="1397" />
  <row Id="6401" PostId="5409" Text="agreed, one op amp for filtering below the nyqusit rate and setting the gain, and the second optional one for buffering the input." CreationDate="2010-10-22T22:02:08.917" UserId="1397" />
  <row Id="6402" PostId="5399" Text="I've decided it will be best to place the majority of components on the top side, but the occasional component on the bottom side which will be added by myself manually using my temp-co soldering iron." CreationDate="2010-10-22T22:05:06.973" UserId="1225" />
  <row Id="6403" PostId="5462" Text="@Nick A bucket brigade is a sampling circuit. Although it is not digital it has the same sampling rate and frequency response limitations that digital techniques. Aside from those fundamental limitation (that apply to digital sampling techniques also) this is a frequency-independent time shift." CreationDate="2010-10-22T22:18:27.737" UserId="328" />
  <row Id="6404" PostId="5469" Score="1" Text="bucket brigade *are* analogue. They are a sampling circuit. What they don't do is quantize. Digital sampling is the combination of sampling (zero order hold) in the time axis, and quantisation (analogue to digital conversion) on the amplitude axis." CreationDate="2010-10-22T22:21:47.900" UserId="328" />
  <row Id="6405" PostId="5406" Text="go with these - IPC based :)" CreationDate="2010-10-22T22:24:10.347" UserId="1397" />
  <row Id="6406" PostId="5469" Text="@Clint: Yeah, but it's not &quot;really&quot; analog.  :)  PWM amplifiers are analog, too, but it's so different from what we usually mean by the word that they get sloppily called &quot;digital amplifiers&quot;." CreationDate="2010-10-22T23:40:54.023" UserId="142" />
  <row Id="6407" PostId="5495" Text="+1 - It's a good idea, but actual DIP's are far easier to work with. Is it me, or does that adapter not have all pins broken out?" CreationDate="2010-10-23T00:15:19.513" UserId="1225" />
  <row Id="6408" PostId="5030" Text="Of course, I also think arduino is overpriced for what's in it. :)" CreationDate="2010-10-23T00:27:30.447" UserId="131" />
  <row Id="6409" PostId="5479" Text="Xilinx webpack includes the ISE simulator, though. Do you need Modelsim specifically? In my quick check, Lattice didn't have simulation, but now they mention Aldec Lattice Web Edition II. Altera list a &quot;ModelSim Altera Starter Edition&quot; as part of Quartus II Web edition." CreationDate="2010-10-23T01:31:23.300" UserId="1181" />
  <row Id="6410" PostId="5479" Score="1" Text="Ah, premature submission strikes again. The Aldec simulator is Windows only. All of these are non-free binaries, yes, but there are a couple of free simulation tools such as Icarus Verilog, GHDL and FreeHDL." CreationDate="2010-10-23T01:40:46.480" UserId="1181" />
  <row Id="6411" PostId="5497" Text="I think the easiest way to get a large amount of memory is going to be microSD card in SPI mode." CreationDate="2010-10-23T01:56:49.990" UserId="230" />
  <row Id="6412" PostId="2835" Text="We use Screaming Circuits and haven't had any problems with them. They do assemble BGAs (though not as part of their cheapest service).  " CreationDate="2010-10-23T02:01:26.167" UserId="222" />
  <row Id="6413" PostId="5495" Score="3" Text="looks like a bunch are routed on the back.  No idea why, all they had to do was put the QFP at a 45deg angle and they could have routed it all on 1 side." CreationDate="2010-10-23T02:05:01.273" UserId="1438" />
  <row Id="6414" PostId="5438" Text="How do you get past the 100mA limit?" CreationDate="2010-10-23T05:24:56.807" UserId="1657" />
  <row Id="6415" PostId="5497" Text="Yeah I was thinking of doing this." CreationDate="2010-10-23T07:32:06.733" UserId="1225" />
  <row Id="6416" PostId="4999" Text="Don't vote people down just because you don't understand an answer. If you don't understand something, say so or look it up yourself. " CreationDate="2010-10-23T07:41:21.993" UserId="1307" />
  <row Id="6417" PostId="5495" Text="Yeah, but where do the pins from the top left to the top right go? There's a whole bunch that aren't connected... (as all pins are used up.) Same on the bottom." CreationDate="2010-10-23T08:20:38.150" UserId="1225" />
  <row Id="6418" PostId="5474" Text="Then wouldn't that mean that the DSO-2090 is too low bandwidth for my needs (considering most of the microcontrollers I will be looking at to begin with are in the 20-40MHz range?)" CreationDate="2010-10-23T10:55:43.207" UserId="1333" />
  <row Id="6419" PostId="4655" Text="I bought a barely used Fluke 85-III recently off of eBay for £85 - excellent buy and was the same price as many inferior mid-range multimeters new. If you can get one cheap, always buy a fluke &quot;used&quot; over another brand &quot;new&quot;." CreationDate="2010-10-23T11:00:06.527" UserId="1333" />
  <row Id="6420" PostId="5502" Score="1" Text="You just plug the cable into the socket on the mbed, and connect it to the computer." CreationDate="2010-10-23T11:06:46.737" UserId="103" />
  <row Id="6421" PostId="5497" Text="@lonetech why do you say it is costly for micro CD in SPI mode?" CreationDate="2010-10-23T11:40:43.327" UserId="1397" />
  <row Id="6422" PostId="5497" Text="@thomas_o  you need to be careful with this, as in my previous experience, microSD aint microSD, larger sizes can pose difficulties and some fat16 implementations on the micros, for example CCS for microchip have been a little half baked in the past (this may have changed).  Writing your own fat16 implementation is a lot of effort, so I do advice using something pre-existing." CreationDate="2010-10-23T11:42:49.797" UserId="1397" />
  <row Id="6423" PostId="5495" Score="2" Text="@Thomas O, as @Mark said, they're routed on the back, see the circular vias connecting them to the other side" CreationDate="2010-10-23T12:45:15.570" UserId="566" />
  <row Id="6424" PostId="5497" Text="Microchip make a Memory Disk Drive which implements a FAT32 filesystem for PIC's." CreationDate="2010-10-23T13:10:32.057" UserId="1225" />
  <row Id="6425" PostId="5504" Score="5" Text="Small correction: limit is 500 mA for USB 2.0 (load unit is 100 mA and maximum is 5 load units). On USB 3.0, load unit is 150 mA and maximum is 6 load units, so that's 900 mA. Computers usually do not support 1.8 A. You could get that much by placing a resistor between data wires (to signalize that device is only using power and not transmitting data) and use USB cell phone charger or similar device dumb power source." CreationDate="2010-10-23T13:23:16.820" UserId="1240" />
  <row Id="6426" PostId="5508" Text="I'm not sure this is accurate.  Radio tower patterns are spherical?  I thought they had high gain in the horizontal direction.  Why radiate sports radio upward into space? Why build a dish antenna?  Wouldn't a resonant antenna pick up more energy?  Would a 1 m dish really create a blind spot?  Wouldn't the waves just diffract around it?  I'm not sure what you mean by &quot;power lines conduct energy&quot;.  Energy is carried in the fields surrounding power lines, not within the lines themselves." CreationDate="2010-10-23T14:46:26.057" UserId="142" />
  <row Id="6428" PostId="5510" Text="+1, Very valid observation!" CreationDate="2010-10-23T15:28:15.263" UserId="444" />
  <row Id="6429" PostId="5508" Text="You are correct about the spherical pattern not being accurate to real world radiation pattern of radio towers.  It is a simplified example to give the OP some equations and appreciation of the real world situation.  Feel free to add a more accurate model!  Dish antenna, once again, for the purpose of the example, and simple equations, is why I used it.  About the resonant antenna, it may have a higher gain, but there is only so much energy to be harvested, and I assumed all potential energy was harvested, so this would not effect the equations! " CreationDate="2010-10-23T15:29:24.987" UserId="1397" />
  <row Id="6430" PostId="5508" Text="correct about the diffraction, I have not considered this in the above post. Not sure about your surround fields comment, I thought upto certain voltages, all the energy was actually conducted along the copper/aluminum wires, and is governed by P=I^2R for power loses. " CreationDate="2010-10-23T15:35:59.230" UserId="1397" />
  <row Id="6431" PostId="5474" Score="1" Text="@Nat, as I pointed out in my earlier comment, you generally won't be looking at any signals near the internal clock speed of the microcontroller.  SPI clocks generally run at a few MHz, and I2C clocks are usually only 400 KHz.  A fast UART is 115K baud.  A typical PWM frequency for motor control might be 40 KHz -- a 40 MHz scope would allow you to see very narrow PWM pulses." CreationDate="2010-10-23T15:40:23.333" UserId="1322" />
  <row Id="6432" PostId="5514" Score="7" Text="I have actually found the opposite. Almost every computer I have used will disable the USB port if too much power is drawn. They don't necessarily do it based off how much you have requested, but they do have a max current that once hit will notify the OS and shut off the port. Windows will even pop up a message notifying the user that this has happened. In my experience it takes a reboot of the computer for the port to be re-enabled." CreationDate="2010-10-23T16:19:15.633" UserId="319" />
  <row Id="6433" PostId="5508" Score="3" Text="&quot;In doing this, you are not &quot;stealing&quot; energy, just collecting waste, and recycling it&quot; - Is incorrect.  By placing energy collecting circuits along a transmission line you change the impedance (this is by definition - otherwise you wouldn't get any energy out) which removes more energy from the lines than the environment normally would.  If you excavated all the earth underneath them, and only changed the impedance as much as the earth was doing, then you could say that you aren't stealing more than the environment naturally does." CreationDate="2010-10-23T16:47:01.093" UserId="161" />
  <row Id="6434" PostId="4669" Score="2" Text="Nice answer, but I think at $5. the question you will be asking of the multimeter is &quot;why doesn't this switch work properly&quot;..." CreationDate="2010-10-23T16:50:10.603" UserId="1363" />
  <row Id="6435" PostId="5508" Score="3" Text="Power companies measure line loss, and if it's different than expected, they inspect the lines and surrounding land.  Changes in impedance often signal problems that should be examined prior to a failure." CreationDate="2010-10-23T16:51:38.473" UserId="161" />
  <row Id="6436" PostId="5514" Score="2" Text="@Kellenjb - I've seen this behavior as well, but usually only on laptops where power consumption is a concern.  Further, while the computer monitors the power consumption, it often doesn't actually shut the port power off, it just uses the USB control channel to tell the device to power down.  They often have polyfuses in line to prevent huge power consumption, but those are often 1A or greater.  So one can still pull a significant amount of current from the port, though windows might complain about it." CreationDate="2010-10-23T16:54:54.320" UserId="161" />
  <row Id="6437" PostId="5497" Text="Cost: The SD association demands membership to sell any SD compatible device, which costs thousands of dollars per year. Also, just because you use SD cards doesn't mean you must use FAT.. although the spec says SD use FAT, SDHC use FAT32 and SDXC use ExFAT, the cards are just block memories." CreationDate="2010-10-23T17:31:24.620" UserId="1181" />
  <row Id="6438" PostId="5507" Score="1" Text="Why do you need to calibrate? If you need to calibrate in order to prove to someone else that your meter is up to snuff, you might want to contact a calibration service - they have all that expensive equipment, so you don't have to." CreationDate="2010-10-23T17:40:24.470" UserId="259" />
  <row Id="6439" PostId="5494" Text="This isn't any better than the PIC, but AVR makes the ATMEGA1284P (128KB flash, 16KB RAM) in a 40-pin DIP: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=ATMEGA1284P-PU-ND" CreationDate="2010-10-23T18:04:11.540" UserId="1322" />
  <row Id="6440" PostId="5514" Text="I've seen the message in Windows, too, but only from a current spike, not continuous draw.  The USB spec has restrictions on both." CreationDate="2010-10-23T18:09:25.780" UserId="142" />
  <row Id="6441" PostId="5135" Text="@Nick while technically true most implementations of C on 8 bit micro-controllers do not follow ansi defined type promotion.  They often just use the largest type in the statement.      " CreationDate="2010-10-23T18:35:06.923" UserId="1438" />
  <row Id="6442" PostId="5495" Text="@thomas I guess i don't see what your talking about, there are obvious vias for 8 pins on the top and the traces are clear on the back.  Weirdest thing i see here is the pad under the IC with traces out to those side pins.  I guess its so if you have a QFP with a pad under it you could connect to it, but there are exposed via's under the IC.  Unless you were really careful with the size of the pad under the QFP i would think it would be really easy to short those vias out." CreationDate="2010-10-23T19:50:45.273" UserId="1438" />
  <row Id="6444" PostId="5521" Text="Although I like opencourseware, I find it difficult to learn just from the notes. But thanks for the reading list suggestion, it never occurred to me" CreationDate="2010-10-23T20:04:44.460" UserId="1200" />
  <row Id="6445" PostId="5507" Text="I'm only a hobbyist with low budget. The goal of the calibration is that my 3 different multimeters do not show three very different values for the same measured object :) I've already made same lenght measurement cables for them from low resistance silicone wire, next step is to calibrate them to a good reference." CreationDate="2010-10-23T20:06:59.087" UserId="1514" />
  <row Id="6446" PostId="5519" Text="Yeah, I was considering this, but my application needs speed, and it has interrupts, so the operations might be undefined if the code for writing to the memory gets interrupted mid write... would it write half a word? I couldn't have that." CreationDate="2010-10-23T21:02:07.037" UserId="1225" />
  <row Id="6447" PostId="5520" Text="Thanks for the links. Are there any standard I2C ones, or at least SPI?" CreationDate="2010-10-23T21:03:16.643" UserId="1225" />
  <row Id="6448" PostId="5497" Text="Wait, I thought you only needed to pay royalties if you made SD cards or you wanted to use the SD logo/name??" CreationDate="2010-10-23T21:04:08.887" UserId="1225" />
  <row Id="6449" PostId="5509" Text="I have to give props to mastech for my meter. Set it on ohms when plugged into 230V and it only shows &quot;OL&quot;, no damage, same for cap + continuity ranges (continuity range beeps at 50 Hz.) I suppose though it wouldn't stand a surge on the line. It only has a wimpy PTC and a two fuses for the current ranges (500mA and 10A.) I already have a second hand scope which is very nice (would be very expensive new, quad channel 100 MHz digitising.)" CreationDate="2010-10-23T21:05:53.267" UserId="1225" />
  <row Id="6450" PostId="3604" Text="Nice diagram.  I just used it in one of my answers and attributed it to you; hope you don't mind:" CreationDate="2010-10-23T21:24:41.353" UserId="1545" />
  <row Id="6451" PostId="5529" Score="1" Text="Anyone who upvotes my answer should upvote reemrevnivek for making this diagram!  http://electronics.stackexchange.com/questions/3599/basic-p-type-mosfet-question/3604#3604" CreationDate="2010-10-23T21:25:17.877" UserId="1545" />
  <row Id="6452" PostId="5519" Score="1" Text="@Thomas, assuming you are using SPI interface built into your MCU, your program will be writing and reading SPI registers as atomic operation and you will not use lose any data, even if interrupted.  (You could also implement a SPI handler using interrupts.)  The clocking and writing and reading of the SRAM will be handled by the hardware interface.  Since the MCU is the SPI master, you can't miss data coming from the SRAM." CreationDate="2010-10-23T21:26:39.193" UserId="1322" />
  <row Id="6453" PostId="2580" Text="This is a fun question.  What kind of device are you hacking?" CreationDate="2010-10-23T21:31:38.437" UserId="1545" />
  <row Id="6454" PostId="5519" Text="As far as speed goes, with a 2 MHz SPI clock (1/10 the rated SRAM speed), it shouldn't take more than 30 us to read or write a byte (even with subroutine overhead), so can write or read 30 bytes/ms, or the entire 32KB in a second.  (I haven't looked at the datasheet, just making some educated guess here.)" CreationDate="2010-10-23T21:32:48.630" UserId="1322" />
  <row Id="6455" PostId="5519" Text="Compared to the MCU's internal RAM that's way too slow. I need to clear 8KB in 1/30th second. The 8KB codes for a frame of video information and it needs to update around ~30 fps. At the moment the MCU can do around about 3000 fps when just clearing the screen, so 3000x faster. Can a dsPIC33FJ128GP802 do SPI at 20 MHz?" CreationDate="2010-10-23T21:36:05.193" UserId="1225" />
  <row Id="6456" PostId="5474" Text="I've decided to buy the DSO-2090 as it seems it'll do everything I need. Thanks!" CreationDate="2010-10-23T21:44:27.710" UserId="1333" />
  <row Id="6457" PostId="5466" Text="Thanks for the great answers. I bought the DSO-2090 as suggested in the accepted answer." CreationDate="2010-10-23T21:44:52.873" UserId="1333" />
  <row Id="6458" PostId="5497" Text="nope, you have to pay if you sell any product that supports SD cards, $2k a year last i knew, you have to join the SD association.  Additionally microSD cards aren't required to support SPI mode so make sure you check the cards you use." CreationDate="2010-10-23T22:08:15.587" UserId="1438" />
  <row Id="6459" PostId="5528" Text="I referred to 'trace lengths' but it just sank in you said 'wires'. Propagation delays still won't be a problem with wire, just don't coil up the excess, that would give you unwanted inductance which could take the nice sharp edges off the logic signals." CreationDate="2010-10-23T22:12:05.683" UserId="740" />
  <row Id="6460" PostId="5519" Text="@Thomas, I didn't realize you needed to do a block write of 8KB.  It turns out once you have sent the starting address to the SRAM, you can continue to write bytes sequentially.   So just a 5 MHz SPI clock, assuming you are using the SPI interrupt, would allow you to write around 600 bytes/ms, or 8 KB in about 1/60 of a second, about twice as fast as your requirement.  I wouldn't try to run it any higher than that on a breadboard using DIP's." CreationDate="2010-10-23T23:24:47.400" UserId="1322" />
  <row Id="6461" PostId="5519" Text="@Thomas, although it is possible to write 8KB to the SRAM in 1/60 of a sec as I discussed in over my last comment, it would probably tie up over half of the processor handling the interrupt, so it might not be a good idea.  Best to find a processor with more RAM for your application." CreationDate="2010-10-24T00:35:20.383" UserId="1322" />
  <row Id="6462" PostId="5533" Text="I found that link as well. The problem is, that looks like it is meant to work externally to the phone through the phone line. I am already in the phone. It looks like that is just generating an oscillating high voltage. How would I connect this directly to my ringer, rather than through the phone line?" CreationDate="2010-10-24T05:22:35.107" UserId="1686" />
  <row Id="6464" PostId="5535" Score="1" Text="Wow. Thats exactly what I need. A more detailed description of their build is at http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=50" CreationDate="2010-10-24T07:46:30.557" UserId="1686" />
  <row Id="6465" PostId="5497" Text="@Mark: Thanks for the reminder. Cards not supporting SPI mode complicates things." CreationDate="2010-10-24T09:00:44.767" UserId="1181" />
  <row Id="6466" PostId="5528" Text="Thanks - I am actually using traces on a PCB." CreationDate="2010-10-24T09:44:08.750" UserId="1225" />
  <row Id="6467" PostId="5538" Score="1" Text="Once applied to a component does it stay there for the time required to place say 80-100 components?" CreationDate="2010-10-24T10:59:52.327" UserId="1225" />
  <row Id="6468" PostId="5523" Score="1" Text="As described in JustJeff's answer, just measuring the voltage across a battery's terminal will not give the right answer. The battery must be discharging through a load appropriate for that type of battery." CreationDate="2010-10-24T12:32:27.007" UserId="387" />
  <row Id="6469" PostId="5529" Score="1" Text="Servo may be inductive, so you should add diodes to protect the MOSFETs" CreationDate="2010-10-24T13:52:40.373" UserId="330" />
  <row Id="6470" PostId="5529" Text="I always use these: http://www.physics.udel.edu/~watson/scen103/mos4.html http://www.physics.udel.edu/~watson/scen103/mos5.html" CreationDate="2010-10-24T14:00:01.133" UserId="142" />
  <row Id="6471" PostId="5533" Text="&quot;...do not use 60 Hz AC from your house outlet -- that won't work either.&quot; -- That's an understatement!" CreationDate="2010-10-24T16:04:08.827" UserId="906" />
  <row Id="6472" PostId="5514" Score="1" Text="I have seen this from both. current spikes and overcurrent. Current spike detection seems to vary by computer pretty heavily, but overdrawing current has made most every computer i have used turn it off. " CreationDate="2010-10-24T16:11:53.523" UserId="230" />
  <row Id="6473" PostId="5514" Text="My behavior may be because I was using name brand computers." CreationDate="2010-10-24T16:12:11.543" UserId="230" />
  <row Id="6474" PostId="5538" Score="1" Text="It's good for a few hours. This is what I use: http://www.warton-metals.co.uk/solderpaste.html. Warton states up to 24 hours after application and three days after the components have been mounted." CreationDate="2010-10-24T16:49:54.963" UserId="305" />
  <row Id="6475" PostId="5329" Text="From the Freetronics site: &quot;Note: this module does not provide proper, standards-compliant 802.3af PoE support. But it's a whole lot cheaper, and works with just about any home-brew PoE system.&quot;" CreationDate="2010-10-24T17:08:33.537" UserId="1317" />
  <row Id="6476" PostId="5514" Score="1" Text="We have some 6 year old Dell desktops used in a student lab. We have had students all of the time pull too much current and have the USB port shut down until a restart occurs. " CreationDate="2010-10-24T17:09:26.670" UserId="319" />
  <row Id="6477" PostId="5544" Text="Can you tell us a bit more about what you are wanting to do? Are you purely trying to stay in the coding world or are you wanting to learn about the hardware also?" CreationDate="2010-10-24T17:12:47.803" UserId="319" />
  <row Id="6478" PostId="5544" Text="I just edited the question.. are these different streams i mean can i learn about the hardware and not the software or vice-versa... what do you suggest ?" CreationDate="2010-10-24T17:23:50.857" UserId="1525" />
  <row Id="6479" PostId="5514" Score="2" Text="On my laptop, a dead (shorted) USB device caused all devices on the bus to shut down, but removing the malfunctioning device seem to fixed the problem. Linux dmesg mentioned overcurrent shut down." CreationDate="2010-10-24T17:27:03.800" UserId="1225" />
  <row Id="6480" PostId="3836" Text="+1 for the link to the Chronos!" CreationDate="2010-10-24T17:47:33.980" UserId="1317" />
  <row Id="6481" PostId="5553" Score="1" Text="Great. Thanks for your answer. Good point on the wire next to R8 and the via, I am able to spare the space for them so I will actually move the." CreationDate="2010-10-24T17:49:46.810" UserId="1225" />
  <row Id="6482" PostId="5553" Text="Are the traces too close for 50V signals maximum?" CreationDate="2010-10-24T17:50:28.777" UserId="1225" />
  <row Id="6484" PostId="5549" Score="4" Text="Setup your DRC rules with what ever fab method you are going to be using requires. Then work on removing all DRCs. " CreationDate="2010-10-24T18:10:16.067" UserId="319" />
  <row Id="6486" PostId="5553" Text="Andrew was focusing on the effects of putting a high speed signal in close proximity to another trace. Coupling will occur results in crosstalk. Voltage is a different can of worms. With voltage you will need to be concerned about arching between 2 traces. This will change depending on the fab process. http://www.smps.us/pcbtracespacing.html talks about the spacing required." CreationDate="2010-10-24T18:23:35.223" UserId="319" />
  <row Id="6487" PostId="5522" Score="1" Text="Are you wanting to do this independent of a circuit or with a microcontroller while it is running? As in reporting to the user how much battery life they have left." CreationDate="2010-10-24T18:28:17.917" UserId="319" />
  <row Id="6488" PostId="5559" Text="Very cool, I'll look into it :)" CreationDate="2010-10-24T19:58:56.137" UserId="1692" />
  <row Id="6489" PostId="5547" Text="spot on, good answer :)  This is used in some commercial products on Lion batteries to enable accurate battery gauges." CreationDate="2010-10-24T20:17:09.640" UserId="1397" />
  <row Id="6492" PostId="5533" Text="@captncraig -- as far as the interior wiring of the phone, here are some reference schematics.  The first one ( http://www.porticus.org/bell/images/503b_md_schematic.gif ) is for a data phone but shows the actually wiring of the ringer terminals.  The other two ( http://www.porticus.org/bell/images/500dm.gif, http://www.porticus.org/bell/images/500c_d_schematic.gif ) show how the four leads are connected: S-R and S from the ringer go to A and K of the network, which is a capacitor. R from the ringer connects to R of the telephone line, and BK connects to either Tip (G) or ground (Y)." CreationDate="2010-10-24T20:53:08.330" UserId="1322" />
  <row Id="6493" PostId="5533" Text="(continued) If the ringer leads aren't labeled, here is one color scheme I have seen: BK is gray(dark almost black), S-R is gray(whitish)/red, S is gray(whitish)and R is red.  I don't know what value capacitor is used in the network (across A and K), but would guess 0.1 or 0.33 uf at 250v." CreationDate="2010-10-24T20:54:27.970" UserId="1322" />
  <row Id="6494" PostId="5556" Text="What is Super OSD?  Is it a finished product for end consumers, or just a component for people to integrate in to their own things?" CreationDate="2010-10-24T20:57:15.570" UserId="1545" />
  <row Id="6496" PostId="5556" Text="It's a hobbyist thing. For model planes. Not intended for the average user, it requires additional components to work properly, such as a GPS and video transmitter." CreationDate="2010-10-24T21:16:17.257" UserId="1225" />
  <row Id="6497" PostId="5556" Text="see here: http://code.google.com/p/super-osd" CreationDate="2010-10-24T21:16:45.040" UserId="1225" />
  <row Id="6498" PostId="5564" Score="1" Text="The series resistance is very low, usually on the order of 1 ohm.  It's the thermal runaway that makes the thing work.   Also, you said it has to heat up, but remember that it also needs to cool down fast once the overcurrent causing condition is removed.  It's all about heat transfer!" CreationDate="2010-10-24T21:17:38.417" UserId="857" />
  <row Id="6500" PostId="5549" Score="1" Text="Why do you want them so close and so small?  You can make your traces just about as small and close as you like, but you're going to pay for it.  I use 12 mil if I don't have a compelling reason to do otherwise." CreationDate="2010-10-24T21:39:46.130" UserId="857" />
  <row Id="6501" PostId="5549" Text="Because I'm working on a small 40mmx60mm board, every mm is precious." CreationDate="2010-10-24T21:41:40.423" UserId="1225" />
  <row Id="6502" PostId="5514" Score="2" Text="On my Macbook pro, I can draw 500mA without even asking, without ill effects.  Same with the powered hubs coming from the Dell desktops at my school (and my powered hub for my laptop).  Neither computer issues a warning message of any kind." CreationDate="2010-10-24T21:47:55.350" UserId="857" />
  <row Id="6503" PostId="5504" Text="Do self-powered hubs require you to negotiate to higher current levels?   I'll have to go home and take mine apart to see what the circuit is..." CreationDate="2010-10-24T21:50:29.393" UserId="857" />
  <row Id="6504" PostId="5573" Text="In my simulations, I found the resistor only dissipated a few milliwatts when providing several hundred milliwatts, which is &gt;95% efficiency. The resistor is only there to comply with certain safety rules." CreationDate="2010-10-24T21:56:48.450" UserId="1225" />
  <row Id="6508" PostId="5573" Text="The 2.2M resistor will have small dissipation. The 47 ohm series resistor will be dissipating P=VI[RMS]=(IR)I=.2^2*47~=2W to deliver .2*3.3=.66W.   Not super efficient." CreationDate="2010-10-24T22:07:45.923" UserId="857" />
  <row Id="6510" PostId="5573" Text="Sorry, my idiocy drew the wrong schematic." CreationDate="2010-10-24T22:15:04.523" UserId="1225" />
  <row Id="6512" PostId="5559" Score="1" Text="@Andrew - While Joby's answer is a good one, you'll have more and better answers if you wait a while before accepting an answer.  48 hours is generally a reasonable amount of time to wait.  There are lots of other takes on this problem than this one." CreationDate="2010-10-24T22:40:41.577" UserId="857" />
  <row Id="6513" PostId="5570" Text="Ok thanks for the information. Been looking at JTAG programming devices on ebay they cost in excess of £200 so I will leave it. I might look in to the cortex stuff though. " CreationDate="2010-10-24T22:47:44.323" UserId="1623" />
  <row Id="6514" PostId="5529" Text="Thanks for the upvotes, but the diagram was the work of two minutes in LTSpice.  Which, by the way, would be a great tool to help simulate this problem.  Also, the link points to my answer for questions about the basics of using a MOSFET, which might be relevant.  Jason is right, this was a generic diagram, and didn't consider highly inductive loads like servos." CreationDate="2010-10-24T22:49:01.810" UserId="857" />
  <row Id="6515" PostId="5559" Text="I agree with reemrevnivek" CreationDate="2010-10-24T22:50:10.127" UserId="566" />
  <row Id="6516" PostId="5523" Score="2" Text="David, knowing the charge left in a battery is significantly more complex than this. Your question attempts to explain to the asker how to use a multimeter, they asked how to know how much charge is left. If you do not load the battery you can get a full voltage reading when it is dead." CreationDate="2010-10-24T23:11:53.067" UserId="230" />
  <row Id="6518" PostId="5579" Text="http://itp.nyu.edu/physcomp/Labs/DCMotorControl" CreationDate="2010-10-24T23:23:09.817" UserId="1480" />
  <row Id="6519" PostId="5570" Text="@Dean - The Luminary Micro LM3s6965 (A great Cortex M3 kit with a graphic display, Ethernet, USB, and other peripherials) includes a standard ARM JTAG header allowing the board to be used as a JTAG interface for $70 (about £44). " CreationDate="2010-10-24T23:26:56.753" UserId="857" />
  <row Id="6520" PostId="5570" Text="@Dean - Also, please don't accept my answer so fast!  I was 14 years old when that processor and board were out.  There are likely to be other users who have experience with it, and may be able to help you actually use it.  I'd strongly suggest waiting for at least 48 hours before accepting an answer." CreationDate="2010-10-24T23:29:41.167" UserId="857" />
  <row Id="6521" PostId="5577" Text="Do you have a load (working PC) attached to it?  Many ATX supplies require a minimum current draw to operate." CreationDate="2010-10-24T23:32:50.500" UserId="857" />
  <row Id="6522" PostId="5577" Text="I was told it was dead already, but good idea, I have a spare mobo + CDrom, would this be enough load?" CreationDate="2010-10-24T23:35:22.320" UserId="1225" />
  <row Id="6523" PostId="5577" Text="Tested it with a computer which works (mobo, processor, hdd, cd+dvd, fdd) with a 250W PSU and it still clicks, probably not drawing more than 50W but could this be insufficient still?" CreationDate="2010-10-24T23:44:44.850" UserId="1225" />
  <row Id="6524" PostId="5580" Text="Where are you located?" CreationDate="2010-10-24T23:50:06.870" UserId="857" />
  <row Id="6526" PostId="1990" Score="3" Text="Why do the fabs need to be close by?  If you're going across the ocean, it's going to be on a jet plane at 900 km/hr.  It's a small world." CreationDate="2010-10-24T23:53:09.257" UserId="857" />
  <row Id="6529" PostId="5572" Text="What frequency is your AC?" CreationDate="2010-10-25T00:02:17.997" UserId="230" />
  <row Id="6530" PostId="5572" Text="50Hz, but the circuit works well on 60Hz and with 100Vac to 265Vac." CreationDate="2010-10-25T00:03:11.803" UserId="1225" />
  <row Id="6531" PostId="5583" Score="1" Text="+1 for House reference." CreationDate="2010-10-25T00:03:53.843" UserId="1225" />
  <row Id="6532" PostId="5583" Text="Good point on the caps. But I would think they would only cause excessive ripple and not a complete failure of the supply. I am experienced enough to repair this, but I'm still uncertain if the caps could cause such a problem." CreationDate="2010-10-25T00:04:31.207" UserId="1225" />
  <row Id="6533" PostId="1598" Text="Car batteries can kick butt. Second, NiMH is pretty standard for this, it is low cost(relatively) and will get the job done." CreationDate="2010-10-25T00:04:59.477" UserId="230" />
  <row Id="6535" PostId="5584" Text="+1, thanks...... " CreationDate="2010-10-25T00:28:50.600" UserId="330" />
  <row Id="6536" PostId="3809" Text="cool, thx for the suggestion." CreationDate="2010-10-25T00:29:57.680" UserId="330" />
  <row Id="6537" PostId="5572" Score="1" Text="Where did you get this new circuit from? I can not get anything to simulate like it." CreationDate="2010-10-25T00:30:20.893" UserId="319" />
  <row Id="6538" PostId="5572" Text="Ah, I figured out another problem - this should use a full-wave rectifier instead of a half-wave." CreationDate="2010-10-25T00:33:23.030" UserId="1225" />
  <row Id="6539" PostId="5572" Text="It does work, see the link." CreationDate="2010-10-25T00:33:41.327" UserId="1225" />
  <row Id="6540" PostId="5583" Score="2" Text="Thomas, if the main capacitor only has 1% of it's capacity, the feedback loop will try to track the &quot;ripple&quot;, overload and will shut down.  In the last 5 years, it's all been either capacitors, or capacitors and the diodes &amp; transistors around them. Try it." CreationDate="2010-10-25T00:39:01.017" UserId="1481" />
  <row Id="6541" PostId="5553" Text="it's unlikely he is going to encounter anything that will have to worry him about creep and strike distances, but you're right, if he has to worry about ringup voltage and such he's going to have to take those into account when designing the distance between traces." CreationDate="2010-10-25T00:53:56.127" UserId="974" />
  <row Id="6543" PostId="5572" Score="2" Text="10K isn't really much of a load." CreationDate="2010-10-25T01:23:10.003" UserId="319" />
  <row Id="6545" PostId="5572" Score="2" Text="I think the simulation above is using Ideal components." CreationDate="2010-10-25T01:35:54.277" UserId="230" />
  <row Id="6547" PostId="5577" Text="Yes, that should be plenty.  If that's insufficient, then there's something else wrong with the PSU (but you knew that)." CreationDate="2010-10-25T01:59:31.917" UserId="857" />
  <row Id="6548" PostId="5587" Text="isn't 1N4001 spec'd at just 50V peak reverse voltage? i think you'd probably want the the 400V prv part. you know, in case someone left off the zener, the C1 cap got up to your 120V peak, in which case the off-state diodes get to look at twice that much voltage." CreationDate="2010-10-25T02:09:23.203" UserId="740" />
  <row Id="6550" PostId="5587" Text="@JustJeff, the 1N4001 is what he used in his original schematic so I kept it for this simulation." CreationDate="2010-10-25T02:11:03.720" UserId="319" />
  <row Id="6551" PostId="5587" Text="yeah, i only mentioned it in case someone wanted to try to build what they saw." CreationDate="2010-10-25T02:15:35.023" UserId="740" />
  <row Id="6552" PostId="5587" Text="Good call on the mention." CreationDate="2010-10-25T02:16:16.880" UserId="319" />
  <row Id="6554" PostId="5220" Text="I'd be interested in your circuit setup for logging - I'm interested in the same thing.   See my question http://electronics.stackexchange.com/questions/4606/is-arduino-a-good-platform-for-monitoring-24vac-thermostat-circuits/4630#4630" CreationDate="2010-10-25T02:28:06.930" UserId="1295" />
  <row Id="6555" PostId="5589" Score="1" Text="There is a series capacitor of 33nF in series with the line. This is what they are referring to on stepping it down." CreationDate="2010-10-25T02:42:03.923" UserId="230" />
  <row Id="6556" PostId="1639" Text="Re: cutting PCBs yourself - I've seen advice that you should use a metal hacksaw blade or (if you've lined things up) a guillotine, and that you'll wreck e.g. a bandsaw from both cutting and the dust that is produced." CreationDate="2010-10-25T02:59:40.940" UserId="1696" />
  <row Id="6557" PostId="5583" Text="Capacitors make up a large part of what causes failures in many parts of a CPU." CreationDate="2010-10-25T03:04:00.297" UserId="230" />
  <row Id="6558" PostId="5498" Text="I added a long post trying to explain what goes into each group. If you need 1.8A the short answer is that a computer will not do it." CreationDate="2010-10-25T03:05:45.257" UserId="230" />
  <row Id="6559" PostId="298" Text="I'd *love* to see a reputable reference for the term &quot;magnetics&quot;, as I've never heard of it." CreationDate="2010-10-25T03:20:00.307" UserId="1696" />
  <row Id="6560" PostId="5583" Text="@Thomas: While the capacitors are some of the most failure prone components, when they gave out they may have taken several other parts with them.  The safe bet to save a buck would be to get a new one.  If you don't really care about making it work but want an interesting experience, go for it." CreationDate="2010-10-25T03:46:02.497" UserId="1407" />
  <row Id="6561" PostId="5585" Text="There's no reason the silkscreen would magically &quot;disappear&quot; over a via unless your EDA package crops it off.  Naively, the fab may just do exactly what your gerbers say, expecting you know the consequences." CreationDate="2010-10-25T03:53:38.740" UserId="1407" />
  <row Id="6562" PostId="5507" Text="@csadam: How far apart do they read right now on what value resistor?" CreationDate="2010-10-25T03:59:18.553" UserId="1407" />
  <row Id="6563" PostId="5585" Score="1" Text="I've never worked with a fab that doesn't just chop off any silk screen over solder mask.  Its really not a good thing to get slik screen ink on your solder points, really screws with solder performance (at least in reflow, hand assembly it doesn't matter as much)." CreationDate="2010-10-25T06:22:18.577" UserId="1438" />
  <row Id="6564" PostId="5467" Text="The cameras are a variety of distances from the control room, some are 10m, others are about 75 meters away, line of site, but more like 100-150 meters cabled." CreationDate="2010-10-25T08:41:04.630" UserId="1665" />
  <row Id="6565" PostId="5459" Text="Kallenjp: The cameras don't have to take the picture at the same instance, but just need to be responsive so that they capture the action as fast as possible after the button is triggered. &#xA;&#xA;Nick T: The slight delay is when you trigger the camera through remote capture, when you click the &quot;release&quot; button on the software it doesn't take the picture instantly, but if you trigger the shutter release manually (or as we do at the moment with an extension to the cable trigger release). &#xA;" CreationDate="2010-10-25T08:43:06.967" UserId="1665" />
  <row Id="6566" PostId="5467" Text="I like the idea of using 485, but wanted to get around having to run dedicated network, just for triggering. I'd like to be able to put a camera almost anywhere and either plug it into network at that location. Some of the locations have fiber to them, and power, but no copper. If I end up having to install copper to each camera location, I would probably use the same method that we currently use to trigger, but have an arduino sending delays and pulses to relays to trigger the cameras." CreationDate="2010-10-25T09:04:16.113" UserId="1665" />
  <row Id="6567" PostId="5578" Score="1" Text="Thanks - great method.  I understand that you can get professional PCBs etched but I also know that it can take weeks and can quickly become costly if used a lot.  I'll definitely be using companies like BatchPCB for a polished final prototypes or one-off products but while I am doing early prototypes, breadboards and home etching will be a much faster solution." CreationDate="2010-10-25T09:38:14.617" UserId="1333" />
  <row Id="6568" PostId="5592" Score="4" Text="More transistors = more parallelism" CreationDate="2010-10-25T10:08:09.793" UserId="566" />
  <row Id="6569" PostId="5595" Text="As transistors get closer and closer together you get other undesired effects, such as increased leakage current, so it's a trade off between performance and low power - most manufacturers seem to have gone for performance." CreationDate="2010-10-25T11:19:50.840" UserId="1225" />
  <row Id="6570" PostId="5592" Text="@Joby Taffey: not sure if that was true in the old time of single core processors." CreationDate="2010-10-25T11:49:51.367" UserId="1702" />
  <row Id="6571" PostId="5577" Text="I have a 400W FSP with same symptoms. Please comment when you have fixed yours telling how :)" CreationDate="2010-10-25T11:54:16.477" UserId="1514" />
  <row Id="6572" PostId="5592" Score="2" Text="It's true no matter how many cores the processor has." CreationDate="2010-10-25T13:01:44.397" UserId="1225" />
  <row Id="6573" PostId="5543" Score="1" Text="This is THE textbook on computer organization and architecture." CreationDate="2010-10-25T13:06:25.757" UserId="588" />
  <row Id="6574" PostId="5598" Score="1" Text="Which micro are you using?" CreationDate="2010-10-25T13:16:46.023" UserId="938" />
  <row Id="6575" PostId="5472" Text="I haven't used it yet, but compare the clock sources, number of IO pins, number of gates(?) and registers. For the boards, check the peripherals: nowadays USB, DVI, VGA, ye olde DB9, Ethernet and maybe some DAC/ADC are desirable." CreationDate="2010-10-25T13:19:05.327" UserId="1673" />
  <row Id="6576" PostId="5605" Text="What were the results of doing this... did it work? or did you have to redo them?" CreationDate="2010-10-25T13:36:48.533" UserId="1225" />
  <row Id="6577" PostId="5604" Text="Is there anything easier than that with less componets? " CreationDate="2010-10-25T13:40:53.610" />
  <row Id="6578" PostId="5605" Text="As of now I just removed the silkscreen over the SMD pads with a knife (yeah, a TQFP64 plus 4 0805 and 4 0603, a mess of a jewellery work), I am about to fire it up, but the reflow was just fine." CreationDate="2010-10-25T13:46:04.997" UserId="1673" />
  <row Id="6579" PostId="5604" Score="12" Text="3-way switch, 3 bulbs and a battery?" CreationDate="2010-10-25T13:48:43.307" UserId="566" />
  <row Id="6580" PostId="5562" Text="Strange I used M M Mano as a Digital Electronics reference. But honestly I found the language way to ...umm.... wordy" CreationDate="2010-10-25T13:53:15.550" UserId="1200" />
  <row Id="6581" PostId="4669" Text="@joeforker - While I'd agree with you in principle, in practice I've never had that problem with my cheap multimeters, and I've had them for about 3 years now." CreationDate="2010-10-25T13:57:25.210" UserId="374" />
  <row Id="6582" PostId="5598" Score="1" Text="What are the specs of your integrated ADC?  I can guarantee that you'll get far better results with a discrete ADC." CreationDate="2010-10-25T14:30:01.290" UserId="857" />
  <row Id="6583" PostId="5603" Score="1" Text="Does simple mean discrete components only, or do you want to use integrated circuits like a 555 timer?  Also, a PIC is only one kind of microcontroller - You could also do this with an Atmel ATtiny, for instance. Are you looking for other micros? " CreationDate="2010-10-25T14:36:31.910" UserId="857" />
  <row Id="6584" PostId="5608" Text="This crystal is also a 4 pin, in the questions case, he does not need to ground out the extra 2 pins, but the layout should be similar." CreationDate="2010-10-25T14:40:08.163" UserId="230" />
  <row Id="6585" PostId="5598" Text="Im using an P89LPC938 which has a 10-bit ADC. I have considered using a discrete ADC and I may do if necessary, but for the moment though I'm concentrating my efforts on getting the signal conditioning right, if it turns out that the micros ADC doesn't cut it, it shouldn't be too difficult to change..." CreationDate="2010-10-25T14:40:19.163" UserId="819" />
  <row Id="6586" PostId="5583" Text="He said he wanted to sell it." CreationDate="2010-10-25T14:41:00.687" UserId="230" />
  <row Id="6587" PostId="5601" Text="+1 This is probably the approach I will take, thanks!" CreationDate="2010-10-25T14:42:17.197" UserId="819" />
  <row Id="6588" PostId="5607" Text="+1 Thanks for the link, exactly what I was looking for." CreationDate="2010-10-25T14:42:33.610" UserId="819" />
  <row Id="6589" PostId="5514" Text="what hardware were you using when you did that?" CreationDate="2010-10-25T14:48:36.683" UserId="230" />
  <row Id="6590" PostId="4332" Text="I've got an as-yet untouched Launchpad, OS X 10.6, and no time at the moment.  Looking forward to answers here." CreationDate="2010-10-25T14:50:21.227" UserId="857" />
  <row Id="6591" PostId="5550" Text="All processors work with some form of assembly.  It's the availability of compilers that's the sticking point.  C++, Forth, Lua (eLua), and really all other languages are also possibilities, not just .NET and C#.  However, C and assembler are the two most common languages, because they get you 'close to the metal'." CreationDate="2010-10-25T14:59:14.017" UserId="857" />
  <row Id="6592" PostId="4658" Score="1" Text="microcontrollers are raw hardware." CreationDate="2010-10-25T15:00:04.627" UserId="230" />
  <row Id="6593" PostId="5600" Text="I think this guard ring does the opposite. It is actually attempting to shield your board from the oscillator and reduce emissions." CreationDate="2010-10-25T15:05:19.770" UserId="230" />
  <row Id="6594" PostId="5242" Text="wow - it's like a sweet shop with all the bright colours :)" CreationDate="2010-10-25T15:07:05.260" UserId="399" />
  <row Id="6595" PostId="5550" Text="Not necessarily true, but holds for most processors. For example, some processors natively execute languages far away from being assembly, like Java (they do execute bytecodes though, which is similar to assembly.)" CreationDate="2010-10-25T15:13:27.433" UserId="1225" />
  <row Id="6597" PostId="5597" Score="1" Text="You have a trace from your crystal that runs very close to your RTC. This could result in not so great things." CreationDate="2010-10-25T15:32:01.623" UserId="319" />
  <row Id="6598" PostId="5604" Text="I agree with Joby - unless you want it automatic, in which case you'll need a few more components for sure" CreationDate="2010-10-25T15:33:11.780" UserId="399" />
  <row Id="6599" PostId="5480" Text="Hmmm... is &quot;ExtendedWeakReferences&quot; dangerous?  I'm trying to find the cheapest possible way to store (any) data." CreationDate="2010-10-25T15:35:17.100" UserId="1252" />
  <row Id="6601" PostId="3567" Score="1" Text="Stack Exchange now has a [network-wide pro account with imgur](http://blog.stackoverflow.com/2010/08/new-image-upload-support/).  Clicking the button above your answer will allow you to upload an image from your computer.  With this host, we won't loose images when other sites go down/out of business/expire.  Please don't host screenshots on your own site (or other image hosts, or anonymously on imgur)." CreationDate="2010-10-25T15:36:13.977" UserId="857" />
  <row Id="6602" PostId="5610" Score="1" Text="Thanks for referencing this to gEDA PCB!" CreationDate="2010-10-25T15:36:52.663" UserId="1225" />
  <row Id="6603" PostId="4117" Text="4000 character URLs!?" CreationDate="2010-10-25T15:38:59.093" UserId="857" />
  <row Id="6604" PostId="5609" Text="Please note you still need a simple clock source." CreationDate="2010-10-25T15:40:14.373" UserId="230" />
  <row Id="6605" PostId="5603" Text="I think he means microcontroller by PIC." CreationDate="2010-10-25T15:40:52.627" UserId="230" />
  <row Id="6608" PostId="1024" Text="@Kortuk - Can you explain your actions in removing the `meta` tag and then leaving the question here?  Your vote to close and move to meta should be a one-click deal, and the fact that you didn't do this suggests that you don't think that it's a question for meta.  It's indubitably a `meta` question in my mind, since it's about the use of the site.   I've cast the second vote to close and move to meta. " CreationDate="2010-10-25T15:48:47.413" UserId="857" />
  <row Id="6609" PostId="1024" Score="1" Text="I understand that when I asked it I specified I was going to use it for uploading schematics to chiphacker, but I consider a question about what tools are available for doing schematics easily to be a very valuable one to the community." CreationDate="2010-10-25T15:51:01.473" UserId="230" />
  <row Id="6612" PostId="5610" Text="That's cool, I've just been doing some basic tutorial videos on Geda, it's a fantastic design package, but it can be quite daunting chewing through the manual" CreationDate="2010-10-25T15:52:21.750" UserId="399" />
  <row Id="6613" PostId="1024" Text="I did not add the meta tag and I removed it because it did not make sense to me. This is my question, I was not attempting to act as a moderator in any way, I just feel this is a good question for ER. I think this is just as acceptable as a question about layout software." CreationDate="2010-10-25T15:54:17.850" UserId="230" />
  <row Id="6614" PostId="5613" Score="4" Text="You might want to clarify in your title that you want an audio book, and not a book on audio amplification.  I came here to recommend an appnote on creating clean audio with a PWM..." CreationDate="2010-10-25T15:54:55.240" UserId="857" />
  <row Id="6617" PostId="5610" Score="1" Text="Agreed, it's a very powerful package but takes considerable learning to work with - but it's one of the few programs to design open hardware on with open formats." CreationDate="2010-10-25T15:59:46.080" UserId="1225" />
  <row Id="6618" PostId="5610" Text="I press the k key and the via appears to bulge, if I keep pressing it the polygon gets distorted and PCB crashes eventually, how much is too much?" CreationDate="2010-10-25T16:01:03.677" UserId="1225" />
  <row Id="6619" PostId="1024" Text="This is not (as written, or as answered) a question limited to 'what tools are available for doing schematics easily'.  It definitely includes the goal of uploading the result to a website (namely, E&amp;R).  Do you agree?" CreationDate="2010-10-25T16:03:32.613" UserId="857" />
  <row Id="6620" PostId="1024" Text="It is specifically looking for a schematic drawing tool that makes sharing easy." CreationDate="2010-10-25T16:04:27.323" UserId="230" />
  <row Id="6621" PostId="1024" Text="I specified I wanted     Free.&#xA;    Extremely easy to draw schematics in.&#xA;    Allows simple production of waveforms for the inputs/outputs.&#xA;" CreationDate="2010-10-25T16:04:47.370" UserId="230" />
  <row Id="6623" PostId="1024" Text="Making sharing easy *with the goal of uploading to the site*.  The original title was &quot;Uploading Schematics for Chip Hacker&quot;, and the answers reflect that title." CreationDate="2010-10-25T16:17:17.327" UserId="857" />
  <row Id="6624" PostId="5610" Text="Just press it once and it should clear the metal ring of the via, press it a few times to get more clearance if desired, use *shift k* to make it smaller again.  " CreationDate="2010-10-25T16:30:25.677" UserId="399" />
  <row Id="6625" PostId="5610" Score="2" Text="i think you mean it covers all the vias with solder mask, not silk screen" CreationDate="2010-10-25T16:31:59.067" UserId="1438" />
  <row Id="6626" PostId="1024" Text="I accepted the only answer that made it easy to draw a schematic and worked for me. I do not have linux and some of the better options did not work. This is a very old question and I think that causes some of the issues. I still think it falls under the general chiphacker site as it is a nice tool. If I find somewhere where it says it should be meta I will move it for you." CreationDate="2010-10-25T16:33:47.923" UserId="230" />
  <row Id="6627" PostId="5610" Text="cheers mark! - I didn't spot that" CreationDate="2010-10-25T16:34:03.960" UserId="399" />
  <row Id="6628" PostId="1024" Text="I do think the number of upvotes shares the communities opinion on the value of the question." CreationDate="2010-10-25T16:34:46.300" UserId="230" />
  <row Id="6629" PostId="5585" Text="your image does not show the characteristic red solder mask overlay found in Geda PCB? (I assume this is the software your using) if you did apply the solder mask layer - by default it would cover all your vias with solder mask, unless you stated otherwise - see my answer below for more details" CreationDate="2010-10-25T16:37:46.467" UserId="399" />
  <row Id="6630" PostId="4669" Text="In that case, I'm off to pick up a $5 digital multimeter." CreationDate="2010-10-25T17:00:15.833" UserId="1363" />
  <row Id="6631" PostId="5469" Score="1" Text="3 classifications that are used in signal processing: Continuous, Discrete, and Digital" CreationDate="2010-10-25T17:07:20.210" UserId="319" />
  <row Id="6632" PostId="5615" Text="I would be more concerned about em effects then thermal as the thermal differences will be very small in this case." CreationDate="2010-10-25T17:10:51.860" UserId="319" />
  <row Id="6634" PostId="4332" Text="I found the &quot;codeless&quot; driver from the MSPDebug FAQ or so (which is just an Info.plist, no actual driver) worked &quot;best&quot;, as in got the farthest before not working.  My TI-Launchpad works great in windows, and no serial communication on OS X.  I am looking forward to an answer too." CreationDate="2010-10-25T17:17:28.170" UserId="1271" />
  <row Id="6635" PostId="4332" Text="Are you using the launchpad at all to do the programming, or are you attaching the FTDI cable directly to the MSP430 chip's pins (well, the breakout board pins)?  I'd like to program it from the mac *at all*." CreationDate="2010-10-25T17:18:55.607" UserId="1271" />
  <row Id="6636" PostId="5523" Text="Thank you both for setting me straight." CreationDate="2010-10-25T17:21:30.017" UserId="1545" />
  <row Id="6637" PostId="5611" Text="Thanks this explains alot to me... I love robotics I really want o shift in this field, But I dont't understand how to start it.. you answer is very helpful to me.. Thanks very much.. do you think Python is helpful in this field ? " CreationDate="2010-10-25T17:22:32.170" UserId="1525" />
  <row Id="6638" PostId="5521" Score="1" Text="Hennessy and Patterson is the required reading for this course. I see a trend developing here." CreationDate="2010-10-25T17:42:58.170" UserId="588" />
  <row Id="6639" PostId="4117" Text="That's one of the most complicated circuits in the examples.  Internet Explorer only accepts 2000 characters, unfortunately.  :)" CreationDate="2010-10-25T17:52:31.637" UserId="142" />
  <row Id="6641" PostId="5618" Text="As a note though, opamps still can have issues with over voltage." CreationDate="2010-10-25T18:18:07.720" UserId="319" />
  <row Id="6642" PostId="5594" Text="How do you dispose of the used acid/hydrogen peroxide mixture?" CreationDate="2010-10-25T18:19:12.923" UserId="51" />
  <row Id="6644" PostId="5618" Text="+1 for an alternative. What op-amp configuration do you suggest,  I was thinking two inverting configs in succession, one to deal with gain (+/-) (i.e so that I can either divide or multiply the input voltage), and another to cancel the inversion of the first, or? " CreationDate="2010-10-25T18:27:36.437" UserId="819" />
  <row Id="6645" PostId="5611" Text="C is going to be, far and away, the **most** helpful language.  However, Python (Look at Cython and [python-on-a-chip](http://code.google.com/p/python-on-a-chip/)) might be usable.  Python's &quot;batteries-included&quot; approach won't fit on small micros, but it's a good language and could work on micros with larger memory space.  Start with C, and move to other languages as you gain experience." CreationDate="2010-10-25T18:30:59.090" UserId="857" />
  <row Id="6647" PostId="5618" Text="What really makes this solution difficult to implement is that you may not have a negative voltage rail available to you.  " CreationDate="2010-10-25T18:49:37.637" UserId="319" />
  <row Id="6648" PostId="5619" Text="thanx for the edit, I didn't know that trick" CreationDate="2010-10-25T18:52:47.133" UserId="1673" />
  <row Id="6649" PostId="5622" Text="The voltage aspect of speed can be a somewhat interesting struggle. The larger your voltage spread between a logic 1 and a logic 0 the less chance there is of having noise mess up the logic. However, the less voltage you use the less time it takes for a component to switch between a logic 1 and a logic 0." CreationDate="2010-10-25T18:58:08.563" UserId="319" />
  <row Id="6651" PostId="5620" Text="Can you give us a bit more information about your application? Is the flex PCB going to be moving around a lot? I could see issues with placing a large rigid connector on the flex pcb and having the solder joints come loose." CreationDate="2010-10-25T19:01:28.090" UserId="319" />
  <row Id="6652" PostId="5618" Text="Ya your right... I forgot that Id need a negative supply, Doh!! In that case Its probably not worth the hassle." CreationDate="2010-10-25T19:08:45.270" UserId="819" />
  <row Id="6653" PostId="5618" Text="Nah, I didn't think it was, just wanted to throw that out as an option if you happened to be creating a more sophisticated meter." CreationDate="2010-10-25T19:09:48.953" UserId="319" />
  <row Id="6655" PostId="5618" Text="On further thought though a negative rail for a low power op-amp shouldn't be big deal- nothing a pair of 9V batteries can't handle." CreationDate="2010-10-25T19:25:08.487" UserId="819" />
  <row Id="6657" PostId="4332" Text="@Jack Schmidt I'm programming it from the Mac, mspdebug works for me, but I can't get serial output via the TUSB3410 - to do that I have to tap the RX/TX serial pins." CreationDate="2010-10-25T19:28:20.673" UserId="566" />
  <row Id="6658" PostId="5621" Score="1" Text="Thanks for the great answers.  One critical bit I was missing is that (1MHz Atmel style) CMOS doesn't actually use much current when it is not doing anything.  TTL does tend to use current all the time, and that is more what I was picturing.  I really like the capacitor charging answers; this gives a much clearer reason why &quot;calculations&quot; should require energy.  I wish I could accept multiple answers." CreationDate="2010-10-25T19:54:45.187" UserId="1271" />
  <row Id="6659" PostId="5632" Score="2" Text="Ouch, I can't afford that. " CreationDate="2010-10-25T20:07:11.940" UserId="1225" />
  <row Id="6660" PostId="5632" Text="I wonder if this applies only if you are selling many units?" CreationDate="2010-10-25T20:07:46.840" UserId="1225" />
  <row Id="6661" PostId="5583" Text="I don't want to sell it, I have a gaming rig to put it in. It's pretty poor quality when opened up inside, I'm kind of disappointed (apparently it was £100 new and it uses cheap CapXon capacitors and single sided FR4.)" CreationDate="2010-10-25T20:13:01.497" UserId="1225" />
  <row Id="6662" PostId="5631" Text="Good thought! I have a message that I print to RS-232 when I startup. The program does not appear to be resetting." CreationDate="2010-10-25T20:26:44.510" UserId="588" />
  <row Id="6663" PostId="5630" Text="Charging of caps?" CreationDate="2010-10-25T20:33:30.317" UserId="319" />
  <row Id="6664" PostId="5632" Text="If someone owns a patent you have to respect what ever terms they want to put on it." CreationDate="2010-10-25T20:35:55.603" UserId="319" />
  <row Id="6665" PostId="5630" Text="But *what* cap, and why does it do it every cycle?" CreationDate="2010-10-25T20:37:30.903" UserId="1225" />
  <row Id="6666" PostId="5628" Score="1" Text="Your &quot;just happens&quot; comment is highly unlikely. It would mean that you just happened to figure out something with out doing any reverse engineering or research on another groups intellectual property." CreationDate="2010-10-25T20:37:52.403" UserId="319" />
  <row Id="6667" PostId="5632" Score="2" Text="&quot;I wonder if this applies only if you are selling many units?&quot; there is no lower limit on the number of units, the SD group can set whatever requirements they want, they own the patents.  You can of course take the gamble that your volume and marketing will be so low profile that they won't bother suing you, but that gamble is completely on your shoulders to take." CreationDate="2010-10-25T20:39:30.513" UserId="1438" />
  <row Id="6668" PostId="5628" Score="1" Text="Well, the SD card standard has been reverse engineered in a clean room manner and it is well known how to use an SD card. So it &quot;just happens&quot; that my microcontroller works with it without me having to actually read the standards." CreationDate="2010-10-25T20:42:24.610" UserId="1225" />
  <row Id="6669" PostId="5632" Text="The problem I have with this is I don't think it is infringing patents - for example a car might have many patents involved but driving it is only using it for its intended purpose and not infringing patents. Do car manufacturers license you the right to use their patents when driving the car?" CreationDate="2010-10-25T20:43:41.363" UserId="1225" />
  <row Id="6670" PostId="5629" Text="Do you have an oscilloscope to view the analog signal?  Even if you don't have some expensive logging digital/analog MSO to capture the packet which contained the error, a few &quot;single sample&quot; runs can tell you (and people trying to help) a lot. " CreationDate="2010-10-25T20:59:33.523" UserId="857" />
  <row Id="6671" PostId="5634" Score="3" Text="What characteristics do you want?  You've mentioned capacity, but there are a lot of other categories with which to make the comparison: Charge time, internal series resistance, voltage, storage, durability, effects of temperature, cost, availability, size, toxicity...the list goes on.  What's important to you?" CreationDate="2010-10-25T21:02:27.577" UserId="857" />
  <row Id="6672" PostId="5632" Score="1" Text="you are using their patented SD technology to make money on a product, of course your using their patents.  You pay patent fees all the time on electronics components, but you don't realize it.  Many companies choose to only charge component makers for patent use, for instance purchasing an MP3 decoding IC, a decent chunk of the cost of that IC goes directly to the mp3 patent holders through the chip manufacturer.  The SD group decided to charge the product designers directly and that their free choice to make. " CreationDate="2010-10-25T21:02:37.237" UserId="1438" />
  <row Id="6673" PostId="5632" Text="@Thomas, I'm not sure your analogy is correct.  If I was building a car, and wanted to include some patented technology (e.g. blind-spot detection), I might have to pay a license fee to do so.  But as you said, the driver of the car does not have to pay to license the technology.  In our case, we are the car builder including the technology, and our end-user is the driver." CreationDate="2010-10-25T21:03:23.350" UserId="1322" />
  <row Id="6674" PostId="5632" Text="As for the car analogy, the manufacturer doesn't charge you to use their own patents, but they certainly do add enough cash in the price of the car to pay out to any patents they have licensed from third parties to use.  So yes, you are paying for patents when you buy a car, there just isn't a line item for it on your bill, there certainly is on the manufacturers cost analysis.  " CreationDate="2010-10-25T21:07:02.350" UserId="1438" />
  <row Id="6675" PostId="5628" Score="2" Text="Don't claim that it &quot;just happens&quot; to work.  The fact that it has been reverse engineered without the standard is different from the claim that it &quot;just happens&quot; to work.  See http://en.wikipedia.org/wiki/SD_card#Openness_of_standards" CreationDate="2010-10-25T21:07:33.533" UserId="857" />
  <row Id="6676" PostId="5628" Text="If this is the case, why do so many development boards, dataloggers, etc. include SD card slots? I was unaware that a license fee was required at all!  " CreationDate="2010-10-25T21:13:09.813" UserId="857" />
  <row Id="6677" PostId="5636" Score="2" Text="The charging a supercap and then using it for transmitter power is done by cell phones." CreationDate="2010-10-25T21:22:44.653" UserId="230" />
  <row Id="6678" PostId="5627" Score="2" Text="couples things i would add: higher voltage results in higher leakage current.  In high transistor count devices like a modern desktop CPU leakage current can account for the majority of power dissipation. as process size gets smaller and transistor counts rise, leakage current becomes more and more the critical power usage statistic.  " CreationDate="2010-10-25T21:25:47.380" UserId="1438" />
  <row Id="6679" PostId="5627" Score="1" Text="Secondly, higher voltage allows transistors to switch more rapidly because of how capacitors charge.  We know that a capacitor will charge to 63% of the input voltage in 1 time constant, well if we raise the input voltage then 63% of that voltage is obviously higher as well meaning the transistor will take less time to charge to the ON voltage for the transistor.  So the higher voltage doesn't make switching easier, but rather faster." CreationDate="2010-10-25T21:29:11.463" UserId="1438" />
  <row Id="6680" PostId="5627" Text="I meant faster when I said easier. Let me correct that and add your extra quote." CreationDate="2010-10-25T21:32:00.120" UserId="230" />
  <row Id="6682" PostId="5631" Text="Or flash a light on power up so it is obvious to you." CreationDate="2010-10-25T21:46:31.113" UserId="230" />
  <row Id="6683" PostId="5628" Text="The root of the question is: Are you violating any of their patents? If so, are those patents valid, and if they aren't, are you willing to fight them in court?" CreationDate="2010-10-25T21:46:36.337" UserId="1709" />
  <row Id="6684" PostId="5632" Score="14" Text="The barber is the last person you should ask whether or not you need a haircut..." CreationDate="2010-10-25T21:46:55.870" UserId="1709" />
  <row Id="6685" PostId="5632" Score="4" Text="@Sparr, frankly, I was expecting the answer I got, but it was a question I needed to ask, so I could pass it along to my client.  There are only 1000 members in the SD Association, so there must be a lot of companies ignoring this (or unaware of it) -- sort of like the mess with the GIF patent a few years ago." CreationDate="2010-10-25T22:00:28.963" UserId="1322" />
  <row Id="6686" PostId="5628" Text="@reemrevnivek, I'm imagine the license isn't required until you actually put an SD card in the slot and write code to access it -- so simply selling a development system with an SD slot (and no firmware) wouldn't require a license.  But all cell phone makers including SD cards amd firmware would need to be licensed, and presumably they are." CreationDate="2010-10-25T22:05:02.860" UserId="1322" />
  <row Id="6688" PostId="5642" Score="1" Text="thanks - but do you have any sources?" CreationDate="2010-10-25T22:48:48.197" UserId="1225" />
  <row Id="6689" PostId="5630" Score="1" Text="can you put the scope in a low impedance input mode? try it that way. most RF circuits expect a termination resistance like 50 or 75 ohms. (i think 75 ohms is the common value for video). if the scope doesn't have it built in, you could put a non-inductive resistor across the signal. the video card input ought to have that kind of impedance but you never know. " CreationDate="2010-10-25T22:57:14.170" UserId="740" />
  <row Id="6690" PostId="5630" Text="I don't have a 75 ohm termination option on the scope, but I do have two 150 ohm resistors in parallel. I'll try it." CreationDate="2010-10-25T22:59:20.690" UserId="1225" />
  <row Id="6691" PostId="5642" Score="2" Text="@mikeselectricstuff -- This was exactly the scenario I described to sd.org -- I am only going to access the SD card using SPI mode, and there is no need for the SD logo (the SD card is hidden inside the unit and the end user is not aware of its existence), and they said my client would need to sign the HALA." CreationDate="2010-10-25T22:59:26.213" UserId="1322" />
  <row Id="6692" PostId="5630" Text="Hmm I removed my resistors (as originally present) and it still swings, though the output voltage is much higher and there is some kind of weird noise on the signal." CreationDate="2010-10-25T23:04:29.717" UserId="1225" />
  <row Id="6693" PostId="5640" Score="1" Text="I think this may make a better comment." CreationDate="2010-10-25T23:58:23.913" UserId="230" />
  <row Id="6695" PostId="1639" Text="You will definitely wreck the bandsaw blade. I keep the bandsaw clean and haven't noticed any problems. I only use the bandsaw if the blade is near the end of its useful life." CreationDate="2010-10-26T00:45:36.440" UserId="424" />
  <row Id="6696" PostId="5646" Text="None of the items on the first three pages are useful at all.  Too many publishers call audiobooks an &quot;electronic&quot; resource. " CreationDate="2010-10-26T01:36:27.397" UserId="857" />
  <row Id="6697" PostId="5646" Text="I take that back: the &quot;Dating and Mating&quot; audio CD might be useful to some of us geeks." CreationDate="2010-10-26T01:37:00.050" UserId="857" />
  <row Id="6700" PostId="5637" Score="1" Text="If you want an easy way into NumPy/SciPy, give Spyder a shot, or the enthought package.  The enthought package isn't free, but you can get access with an educational e-mail address." CreationDate="2010-10-26T03:39:35.620" UserId="1477" />
  <row Id="6701" PostId="5642" Text="the patents cover the the protocol used, not just the PHY.  Aka what command do you send over SPI to read? to write? etc etc, thats all patented." CreationDate="2010-10-26T03:52:49.420" UserId="1438" />
  <row Id="6703" PostId="5630" Text="75 ohms for your coax cable, just as a note to those that are interested." CreationDate="2010-10-26T04:15:51.360" UserId="230" />
  <row Id="6704" PostId="298" Text="@Andrew I dunno any technical dictionary that has it. Googling it will find various references. That's just what I've seen it referred to. Basically the point of them is to isolate your circuit from the other devices connected to it via ethernet. Similar to how MIDI uses optical isolation." CreationDate="2010-10-26T05:16:14.387" UserId="131" />
  <row Id="6705" PostId="298" Text="@davr I get about half a million more results for &quot;ethernet isolator&quot; than &quot;ethernet magnetics&quot;, but I understand what you mean now." CreationDate="2010-10-26T06:29:10.087" UserId="1696" />
  <row Id="6706" PostId="5626" Text="that is almost right.  Generally you have the socket on the rigid pcb and plug (pins) on the end of the flex.  Sometimes flex straight into a connector, other time, rigid - flex -rigid combination and a small strip of rigid that goes into the connector on the rigid pcb." CreationDate="2010-10-26T06:35:15.910" UserId="1397" />
  <row Id="6707" PostId="5628" Score="2" Text="What about [MMC](http://en.wikipedia.org/wiki/MultiMediaCard) cards? I'm a bit n00bish in this area, but I remember that some routers running under GNU/Linux could read SD cards using MMC drivers, and MMC appears to be more or less open standard." CreationDate="2010-10-26T07:29:33.637" UserId="1240" />
  <row Id="6708" PostId="5634" Text="It's a curiosity thing, I'm not planning to make a product that uses either." CreationDate="2010-10-26T09:23:40.060" UserId="1225" />
  <row Id="6709" PostId="5649" Text="Are you setting up the prescaler for the WDT or for a timer?" CreationDate="2010-10-26T09:25:30.637" UserId="1225" />
  <row Id="6710" PostId="5649" Text="for timer only.. please help me.." CreationDate="2010-10-26T09:53:46.607" UserId="1484" />
  <row Id="6711" PostId="5649" Score="1" Text="Unfortunately it's not possible without some kind of software delay, so here's one way to do it: every 23 ms run a software interrupt which increments a counter, after 43 counts you will have reached 0.989 seconds; for more precise results use a faster timer setting and increase counts appropriately." CreationDate="2010-10-26T10:27:45.800" UserId="1225" />
  <row Id="6712" PostId="5649" Text="Sir, I agree with what you said.. I will work on it.. Thank you very much.." CreationDate="2010-10-26T10:43:43.083" UserId="1484" />
  <row Id="6713" PostId="5662" Text="Nice catch, that was an old schematic and I already fixed the bug, but but I forgot to mention it in my question. Sorry." CreationDate="2010-10-26T12:22:17.270" UserId="1675" />
  <row Id="6715" PostId="5629" Text="I've run the scope in single sample mode, but all the samples I capture look fine. The glitch happens so infrequently and for such short duration I have not been able to capture it on the scope only on the bus analyzer that does not show the analog voltages or pulse widths." CreationDate="2010-10-26T12:44:56.727" UserId="588" />
  <row Id="6716" PostId="5664" Text="You might try removing the Ethernet magnetics just to eliminate part of the circuit.  Also remove the LEDs.  At this point, your chip might be gone." CreationDate="2010-10-26T12:52:12.423" UserId="204" />
  <row Id="6719" PostId="5663" Text="I was looking at your product earlier. It looks quite nice but does not look very breadboard friendly. Am I wrong on this? I do not want a bunch of wires running everywhere. Just something I can easily plug in." CreationDate="2010-10-26T13:11:58.390" UserId="1575" />
  <row Id="6720" PostId="5661" Score="1" Text="Your two suggestions look like they just might fit the bill. I especially like the mbed! Has the form factor I was looking for." CreationDate="2010-10-26T13:15:18.027" UserId="1575" />
  <row Id="6723" PostId="5664" Text="You are right about the center tap on the receive side, I don't know how I could make that mistake, but that shouldn't do anything other than screw up my reception, there is no way that should give a huge power drain." CreationDate="2010-10-26T13:21:59.247" UserId="1675" />
  <row Id="6724" PostId="5667" Score="1" Text="UC Berkley offers similar courses online, with video, audio and mp3." CreationDate="2010-10-26T13:23:07.517" UserId="1720" />
  <row Id="6725" PostId="5664" Text="I'll try lifting the resistors for the LEDs, though the datasheet does mention that the LEDs are used to program some defaults, so they are not completely without side effects." CreationDate="2010-10-26T13:23:16.360" UserId="1675" />
  <row Id="6726" PostId="5667" Score="1" Text="Sorry...here's a link.  http://webcast.berkeley.edu/courses.php?semesterid=27" CreationDate="2010-10-26T13:23:27.437" UserId="1720" />
  <row Id="6728" PostId="5642" Score="1" Text="Likely the company will tell you you always need to pay for a license because that = more money for them." CreationDate="2010-10-26T13:52:06.730" UserId="536" />
  <row Id="6729" PostId="5663" Text="You use only the pins you need, but is more about what hardware features you are looking for and what programming environment you like more." CreationDate="2010-10-26T13:53:17.870" UserId="1084" />
  <row Id="6730" PostId="5637" Score="1" Text="In school, we used Matlab for everything, but on my own time, I use NumPy/SciPy for everything.  There's also the confusingly-named http://www.pythonxy.com/ project, which is based on(?) Spyder." CreationDate="2010-10-26T13:56:04.263" UserId="142" />
  <row Id="6731" PostId="5318" Text="Just wanted to mentioned that I placed an order for the 3.2&quot; LCD w/Touch &amp; SD a few minutes ago. I will leave a comment in a few weeks from now when it arrives!" CreationDate="2010-10-26T14:07:44.230" UserId="1575" />
  <row Id="6732" PostId="5663" Text="One benefit of the Maple is that it's completely open. The mbed uses an &quot;in-the-cloud&quot; compiler by default - though you can use GCC and drop in files directly over USB" CreationDate="2010-10-26T14:10:02.670" UserId="566" />
  <row Id="6733" PostId="4475" Score="1" Text="I manually route everything. It's an art if you can do it, but it's only worth it if you're going to make a very small board or something with high speed stuff involved." CreationDate="2010-10-26T14:23:30.170" UserId="1225" />
  <row Id="6734" PostId="5633" Text="I checked the rise times and fall times they are well below the datasheet maximum of 2 us. There does not appear to be any reflections or ringing on the signal." CreationDate="2010-10-26T14:26:04.120" UserId="588" />
  <row Id="6735" PostId="5659" Score="1" Text="Are you measuring with a scope or DMM?  A scope will show you the noise and any glitches on the power supply.  A DMM smooths everything out and you won't see it." CreationDate="2010-10-26T14:54:25.297" UserId="204" />
  <row Id="6737" PostId="5653" Text="Interesting, I'll try to find the episode... But rubbing a card with a cellphone may be very different from leaving a card on top of a cellphone for a few hours." CreationDate="2010-10-26T15:20:01.007" UserId="1715" />
  <row Id="6738" PostId="5673" Text="sure, write what i do in more detail. +1 as your reward." CreationDate="2010-10-26T15:50:23.630" UserId="230" />
  <row Id="6739" PostId="5673" Score="3" Text="My answer was posted 2 minutes before yours, I think it's more accurate to say that you summarized my answer, not that I elaborated on yours. :-)" CreationDate="2010-10-26T16:14:54.120" UserId="974" />
  <row Id="6740" PostId="5673" Text="An ideal diode will conduct almost unlimited current. Of course one would be damaged by excessive current. But how would being forward biased be different from being reverse biased - one drops 0.7V and one drops 0V (at the point of breakdown), right?" CreationDate="2010-10-26T16:21:15.627" UserId="1225" />
  <row Id="6741" PostId="5675" Text="If Thomas need only doing some square waves, he doesn't need it (a 555 or a tiny MCU can do that for under 10USD). But for precision sine wave generation is a must. Scope (or at least a fairly good multimeter, with AD/DC voltmeter and frequencymeter) and computer (for datasheet reading at least) are a must too." CreationDate="2010-10-26T16:30:38.860" UserId="1673" />
  <row Id="6742" PostId="5675" Text="Yes, but this comes back to whatever he wants to do. With a 555 and some filters I can create a precision sine wave for under 10USD." CreationDate="2010-10-26T16:45:02.617" UserId="319" />
  <row Id="6743" PostId="5673" Text="Take a look at the characteristic curves. Diodes do not conduct zero current when reverse-biased." CreationDate="2010-10-26T17:11:20.330" UserId="974" />
  <row Id="6744" PostId="5676" Score="7" Text="yep, critical for analog design.  I also highly recommend a scope/function generator that is controllable via USB or GPIB.  Throwing together a quick matlab script that running a fully automated frequency response test on a live circuits is a massive time saver." CreationDate="2010-10-26T17:12:30.617" UserId="1438" />
  <row Id="6745" PostId="5668" Score="1" Text="I can get the chinese made CR2032 at 3USD per strip of 8 (2USD each, weird economics, I know). But the capacity and discharge are very tight constraints in your design." CreationDate="2010-10-26T17:12:54.817" UserId="1673" />
  <row Id="6746" PostId="5668" Text="I picked up a blister pack of 12 cells for £3.50, or about $5.50, which is 45 cents each, but I can pick up AA alkalines for about half of that." CreationDate="2010-10-26T17:26:23.477" UserId="1225" />
  <row Id="6747" PostId="5603" Text="Since he hasn't objected to that statement in 24 hours, I assume that it was what he meant, and edited the question to reflect this.  Feel free to roll it back if it was not what you meant." CreationDate="2010-10-26T17:27:59.877" UserId="857" />
  <row Id="6748" PostId="5675" Text="well, that too, but for a wide range of freqs the changes in the filter can be very time consuming." CreationDate="2010-10-26T17:34:53.757" UserId="1673" />
  <row Id="6749" PostId="5672" Text="That's a pretty good price - maybe I can get one in the UK." CreationDate="2010-10-26T17:43:41.700" UserId="1225" />
  <row Id="6750" PostId="5683" Text="So how do you insert this info into the line - do you pulse it at the desired frequency? Doesn't this mean the adapter has to create a current that devices will consume?" CreationDate="2010-10-26T17:55:52.590" UserId="1225" />
  <row Id="6751" PostId="5682" Text="sorry for not being specific, the three rails can be independent" CreationDate="2010-10-26T18:18:13.827" UserId="1673" />
  <row Id="6752" PostId="5604" Text="Not sure how they used to do it, but I could imagine a geared motor turning brushes on a ring.  Easy synchronization for multiple lights by stacking up multiple levels." CreationDate="2010-10-26T18:18:38.913" UserId="1407" />
  <row Id="6754" PostId="5491" Text="Thanks for idea with Kalman filter. Wikipedia has an example application with truck - looks interesting. And yes, it seems to me, that INS on it's own wouldn't be enough.&#xA;What about visual pathfinding... Hmmm I think it would be too expensive in terms of CPU cost and programming time ;) &#xA;And instrumenting my room breaks autonomity - bad choice." CreationDate="2010-10-26T18:29:02.097" UserId="1651" />
  <row Id="6755" PostId="5654" Score="1" Text="With regards to the lower bound, some chips (mostly analog) will not start properly unless they are above a certain temperature.  I read some article (Bob Pease?) a while ago about how some NI part wouldn't start at some cryogenic temp, but if it was started then cooled it would be fine." CreationDate="2010-10-26T18:33:36.413" UserId="1407" />
  <row Id="6756" PostId="1422" Text="It's a 802.15.4 radio (ZigBee, etc), not 802.15.1 (BlueTooth)." CreationDate="2010-10-26T18:34:59.127" UserId="1407" />
  <row Id="6757" PostId="5492" Text="Yes, that's obvious. Moreover I think, that it would be good to make robot discover the worlds' bounds with sensors and approximate data from accelerometer and gyro at first, but later, having defined world's bounds, it could find out the error constant and the real coordinates using sensors and INS simultaneously - some kind of calibration." CreationDate="2010-10-26T18:40:33.280" UserId="1651" />
  <row Id="6758" PostId="5488" Text="Stationary set-ups are bad because I do not want to support my robot in his movements (in anything!), well at least the less help from me - the better :)" CreationDate="2010-10-26T18:43:55.227" UserId="1651" />
  <row Id="6761" PostId="5633" Text="I thought slew rate control only applied to I2C. I'm sampling the data at the middle of the output time (SMP=0). " CreationDate="2010-10-26T19:22:30.527" UserId="588" />
  <row Id="6762" PostId="5633" Text="CS setup and hold times are ~ 10 us datasheet says minimum time is 500 ns. Is there an issue with having too long a CS setup or hold time?" CreationDate="2010-10-26T19:24:54.600" UserId="588" />
  <row Id="6763" PostId="5676" Text="Seconded on both." CreationDate="2010-10-26T19:43:01.770" UserId="230" />
  <row Id="6764" PostId="5675" Score="1" Text="All about how much money your own time is worth." CreationDate="2010-10-26T19:43:35.810" UserId="230" />
  <row Id="6765" PostId="5668" Text="we pay 5 cents per CR2032 where I work." CreationDate="2010-10-26T19:45:50.287" UserId="230" />
  <row Id="6767" PostId="5668" Score="1" Text="We have done a large amount of testing and I have to disagree with 3 and 5. I do not know AA costs well enough." CreationDate="2010-10-26T19:47:39.673" UserId="230" />
  <row Id="6768" PostId="5668" Text="3. We purchase CR2032 that have a capacity of 400mAh. " CreationDate="2010-10-26T19:48:22.607" UserId="230" />
  <row Id="6769" PostId="5668" Text="5. We watch them degrade to 1.5 where we no longer get valuable power out of them. They do it in a rather easy to measure fashion if you load them while measuring." CreationDate="2010-10-26T19:49:15.117" UserId="230" />
  <row Id="6772" PostId="5668" Text="Hmm, interesting. Are these your typical lithium manganese cells or special types? Most coin cells I've found drop very suddenly near the end of the cell's life. " CreationDate="2010-10-26T20:01:17.210" UserId="1225" />
  <row Id="6773" PostId="5673" Text="Andrew, I did not mean to say that you expanded on mine. I wrote it in class and as I hit post the message popped up saying yours had been posted. It told me a minute before, but the concept of peak reverse voltage has one clear answer." CreationDate="2010-10-26T20:02:11.093" UserId="230" />
  <row Id="6774" PostId="5653" Text="They tried many things that did nothing. It was quite funny because they were writing the cards themselves and trying all kinds of things." CreationDate="2010-10-26T20:06:26.733" UserId="230" />
  <row Id="6775" PostId="5668" Score="1" Text="These were standard. It has a curve close to the one you have the lower the load. as the load increases it goes closer and closer to linear." CreationDate="2010-10-26T20:07:28.590" UserId="230" />
  <row Id="6776" PostId="5668" Text="It probably has something to do with increasing internal resistance of the battery as the chemical reaction ages, but this doesn't matter for small loads." CreationDate="2010-10-26T20:24:33.200" UserId="1225" />
  <row Id="6777" PostId="5679" Score="2" Text="Really, see all of http://electronics.stackexchange.com/questions/tagged/arm" CreationDate="2010-10-26T21:07:16.830" UserId="857" />
  <row Id="6778" PostId="5688" Text="@Randy it worked with my cellphone camera as well! Thank you!" CreationDate="2010-10-26T21:43:54.943" UserId="1298" />
  <row Id="6779" PostId="3837" Text="+1 for wittiness ;-)" CreationDate="2010-10-26T21:49:16.987" UserId="659" />
  <row Id="6780" PostId="4185" Text="great question." CreationDate="2010-10-26T21:56:42.913" UserId="1457" />
  <row Id="6781" PostId="4270" Text="awesome answer." CreationDate="2010-10-26T21:57:43.367" UserId="1457" />
  <row Id="6782" PostId="5693" Score="1" Text="+1 I was just writing about PandaBoard - here's a link to the design files: http://omapzoom.org/wiki/PandaBoard" CreationDate="2010-10-26T22:20:33.027" UserId="566" />
  <row Id="6783" PostId="5491" Score="1" Text="analog devices have these six dof imu units available. http://www.analog.com/en/mems/imu/adis16367/products/product.html.  We have used them on a project at work a few years back, there are ok, best used with the inbuilt filtering and low data rate output.  You can of course, if you are game, take the raw data out and filter it your self.  Either way it provides your main sensors in one unit with SPI output which is handy." CreationDate="2010-10-26T22:25:30.367" UserId="1397" />
  <row Id="6784" PostId="5694" Score="1" Text="-1: The mbed has no Ethernet magnetics or jack onboard.  There are dozens of other dev kits which include Ethernet functionality out-of-the box, but the mbed only has USB.  " CreationDate="2010-10-26T22:28:33.593" UserId="857" />
  <row Id="6785" PostId="5694" Text="+1 adding a magjack is not hard (there are also cheap breakout boards available)" CreationDate="2010-10-26T23:12:38.957" UserId="566" />
  <row Id="6786" PostId="5649" Text="I would like to specify, it is possibly to do it without using a software delay similar to delay_ms which is very inefficient. a counter in an interrupt is maybe 30 clock cycles every 20 mS." CreationDate="2010-10-26T23:13:33.997" UserId="230" />
  <row Id="6787" PostId="5696" Text="I'm very interested in knowing if there is anything as well." CreationDate="2010-10-26T23:53:26.327" UserId="319" />
  <row Id="6788" PostId="5691" Score="1" Text="you don't want to design for a BGA with that many balls with eagle, its really not designed to handling blind/buried vias very well." CreationDate="2010-10-27T00:32:06.917" UserId="1438" />
  <row Id="6789" PostId="5683" Text="@thomas check my edit" CreationDate="2010-10-27T00:45:47.993" UserId="1438" />
  <row Id="6790" PostId="5683" Score="1" Text="As to the current consumption, yes there will be some, the receiving ends will be high impedance and shouldn't draw much current but the sending end does have to source current.  It sounds to me like your not thinking about these issues in the frequency domain.  Current flowing in one direction providing power on a signal line doesn't mean that current can't flow in the opposite direction at a different frequency into a different load at the same time.  Remember electron drift at AC is almost zero, electrons aren't moving (much) your transferring energy through fields. " CreationDate="2010-10-27T00:57:36.980" UserId="1438" />
  <row Id="6791" PostId="5633" Text="shouldn't be an issue with long times on CS.  If the signal integrity is fine, i would look to a bug in the uC code, create a minimalist test case." CreationDate="2010-10-27T01:20:42.643" UserId="1438" />
  <row Id="6792" PostId="5690" Text="As a side note, RTCs still suffer from error and need to be calibrated." CreationDate="2010-10-27T01:31:06.530" UserId="230" />
  <row Id="6793" PostId="5623" Text="I think it is more accurate to say you are filling and emptying them more often, not to saw you are doing it faster. It is only when you get close to their frequency you increase voltage." CreationDate="2010-10-27T01:34:08.350" UserId="230" />
  <row Id="6794" PostId="5623" Text="I think you know what you are saying, but I just wanted to be clear in a comment about how you were comparing it." CreationDate="2010-10-27T01:34:34.200" UserId="230" />
  <row Id="6795" PostId="5698" Text="Are you wanting to make this to ultimately be a marketable product or just something you are doing for this once case? I only ask as it will probably make a difference in what chips to use and where to place it." CreationDate="2010-10-27T01:36:25.167" UserId="319" />
  <row Id="6796" PostId="5700" Text="There isn't a rule of thumb that I know of. I think there would have to be a different &quot;rule&quot; for every different type of circuit combination. What circumstance are you needing to actually have a rule that you can't just very easily compute?" CreationDate="2010-10-27T02:06:27.893" UserId="319" />
  <row Id="6797" PostId="5620" Text="So you are wanting something that will crimp down on the pads marked 12v, g, r, and b and have a screw that loosens/tightens the crimp?" CreationDate="2010-10-27T02:12:31.300" UserId="319" />
  <row Id="6798" PostId="5697" Text="I do not have time to answer right now. IT sounds like you are asking if super-sampling will allow you to overcome more of your noise. Is this the case? If it is I must give a different answer then if you are asking if reading faster than needed allows you to infer extra bits of precision(ie. 10 bits from an 8 bit adc)" CreationDate="2010-10-27T02:38:27.827" UserId="230" />
  <row Id="6799" PostId="5642" Score="1" Text="Wow. Does this mean that open source hardware projects can't use SD cards?" CreationDate="2010-10-27T02:42:53.690" UserId="504" />
  <row Id="6800" PostId="5697" Text="Can you explain what you mean by adding noise to the voltage reference? This isn't anything that I have heard of before and would like to learn more about it." CreationDate="2010-10-27T03:28:08.233" UserId="319" />
  <row Id="6801" PostId="5706" Text="Wouldn't the error of the lower-value resistor have greater effect on current flow? Or am I just confusing myself?" CreationDate="2010-10-27T03:36:48.700" UserId="965" />
  <row Id="6802" PostId="5707" Score="1" Text="Bringing out the statistics, very nice." CreationDate="2010-10-27T03:56:39.207" UserId="319" />
  <row Id="6803" PostId="5690" Text="With the guidance of Mr.Kortuk, Kellen and Thomas I have increased the delay.. The code goes like this:" CreationDate="2010-10-27T04:13:45.343" UserId="1484" />
  <row Id="6804" PostId="5690" Text="#int_timer0 timer0ISR() { x=x+1; if(x==43) {portd= ~portd; x=0;}}.. followed by 'main'.. I have connected LEDs to portd that blinks at an interval of 1 second, without any software delay.. thank you all.." CreationDate="2010-10-27T04:29:15.113" UserId="1484" />
  <row Id="6806" PostId="4332" Text="What drivers are you using? All that I have been able to find is that the drivers are still in a unsupported beta release, in which case you may just be having an issue that TI might be working on." CreationDate="2010-10-27T04:55:48.180" UserId="319" />
  <row Id="6807" PostId="5706" Text="No, I don't think the low-value resistor matters much. If you imagine a pipe with two constrictions, the flow is dominated by the tighter one. Another way to think of it is to imagine the error as a resistor being added in series. 5% of 100k is 5k, while 5% of 1k is only 50 ohms. Imagine adding each of those in series, and think about what would happen." CreationDate="2010-10-27T05:12:32.240" UserId="712" />
  <row Id="6808" PostId="5712" Score="1" Text="Are you saying they are exact duplicates of each other (like literally copy/paste) or just determine it is the same words or same person?" CreationDate="2010-10-27T05:48:54.950" UserId="319" />
  <row Id="6809" PostId="5712" Score="1" Text="How sensitive do you want the comparison to be?  File comparison is easy, but voice recognition - not so much." CreationDate="2010-10-27T05:50:44.440" UserId="504" />
  <row Id="6810" PostId="5701" Text="What is a &quot;Balance Board&quot; in this context?" CreationDate="2010-10-27T05:50:55.777" UserId="1374" />
  <row Id="6811" PostId="5712" Score="1" Text="Its not exact copy past of audio files,to determine same words.even it can be different person" CreationDate="2010-10-27T05:52:53.873" UserId="1730" />
  <row Id="6812" PostId="5709" Score="1" Text="I was just thinking I would give this answer. Damn, beaten..." CreationDate="2010-10-27T05:53:47.790" UserId="1374" />
  <row Id="6813" PostId="5712" Text="its for voice recognition,for eg i have saved a audio file with content &quot; please open&quot; so i want it to be password. so next time if any one say &quot;please open&quot; it should recognize both are equal." CreationDate="2010-10-27T05:57:54.837" UserId="1730" />
  <row Id="6814" PostId="5712" Text="you need to extract a signature for the audio clip, likely targeted to speech and compare, there are lots of ways of doing that, but this really isn't the correct forum for this question." CreationDate="2010-10-27T06:09:33.340" UserId="1438" />
  <row Id="6815" PostId="5712" Text="If you can define exactly what you mean when you say &quot;both are equal&quot; - to the point that you can explain it to a computer - you'll have solved your problem.  I know that's not really helpful, but you need to consider exactly what you want a bit more carefully." CreationDate="2010-10-27T06:12:34.210" UserId="504" />
  <row Id="6816" PostId="5719" Text="He specifically says &quot;just solder&quot; is not the answer he is looking for." CreationDate="2010-10-27T06:34:30.503" UserId="319" />
  <row Id="6817" PostId="5701" Text="Is this what you mean? http://nl.wikipedia.org/wiki/Wii_Balance_Board" CreationDate="2010-10-27T07:30:37.313" UserId="1124" />
  <row Id="6818" PostId="5713" Score="2" Text="Are the leds separately adressable or do you want to turn them all on/off at the same time?" CreationDate="2010-10-27T07:35:37.413" UserId="1124" />
  <row Id="6819" PostId="5716" Text="Thanks, this is exactly what I was looking for, but didn't know what they were called." CreationDate="2010-10-27T08:25:50.810" UserId="1725" />
  <row Id="6820" PostId="5713" Text="The leds are meant to be separately accessible. The microcontroller is not meant to be powering them, simply determining their state. Also, by &quot;digital port&quot; i mean pin." CreationDate="2010-10-27T08:27:47.373" UserId="1725" />
  <row Id="6821" PostId="5715" Text="Thanks, I've made the clarification, and the shift registers are what I'm looking for. Thank you. " CreationDate="2010-10-27T08:29:20.133" UserId="1725" />
  <row Id="6822" PostId="4332" Text="the &quot;TUSB3410 Mac OS X Virtual COM Port Driver&quot; from the wiki link above" CreationDate="2010-10-27T08:47:40.430" UserId="566" />
  <row Id="6823" PostId="5656" Score="2" Text="+1 because it is true that the best way to find out about the ESR of a certain capacitor will be a measurement with an LCR meter. The stupid thing is that only very expensive ESR meters work well with all types of electrolytic capacitors. Datasheet values are very (!) rough and tend to list only the ESR values that you get when all extreme circumstances play against the capacitor. Same is true for obtaining the ESR from tan(delta), at a certain frequency. You will usually get a value much too high. The best parameter from the datasheet is I_rms =&gt; The higher Irms, the lower the ESR." CreationDate="2010-10-27T10:36:55.083" UserId="930" />
  <row Id="6824" PostId="5719" Text="Yeah, sorry—the problem is not connecting the wires to the control box, but connecting the strips to eachother. I'd down vote, but I don't have the required reputation." CreationDate="2010-10-27T10:40:30.163" UserId="1633" />
  <row Id="6825" PostId="5719" Text="And yes, the strip pictured is the actual one I'm using. " CreationDate="2010-10-27T10:42:07.027" UserId="1633" />
  <row Id="6826" PostId="5626" Text="Can you give me a link to a picture of one of these &quot;flat flex connectors&quot; of which you speak?" CreationDate="2010-10-27T10:45:59.847" UserId="1633" />
  <row Id="6827" PostId="5699" Text="thank you, as I know the basics of supply design I can try generating +12/-24/-22Vdc (20% of the final values) and see all the voltages and currents for myself, and THEN maybe do it full scale. Also, I have a coworker that is a power E.E., I only do low &quot;power&quot; electronics, say less than 12Vdc. BTW: I'm a security nutjob too, I have a special rubber pad for my boards, plastic tools, etc." CreationDate="2010-10-27T10:56:01.720" UserId="1673" />
  <row Id="6828" PostId="5728" Text="Nice presentation dude, good clear images" CreationDate="2010-10-27T10:58:30.490" UserId="399" />
  <row Id="6829" PostId="5697" Score="1" Text="The idea is you add a small amount of noise (&lt;1mV) to the voltage reference; if the actual value for the input is 1/4 the way from say 512 and 513 a non-supersampled ADC would say 512 but a supersampled ADC would say 512.25; read up on dithering." CreationDate="2010-10-27T11:21:28.443" UserId="1225" />
  <row Id="6830" PostId="5730" Text="http://homepage.mac.com/johep/iblog/C1576959187/E20050720150247/Media/320x240.jpg" CreationDate="2010-10-27T11:26:26.113" UserId="566" />
  <row Id="6831" PostId="5730" Text="@Joby - dude that's funny, not seen that image in a long time! " CreationDate="2010-10-27T11:43:43.650" UserId="399" />
  <row Id="6832" PostId="5656" Text="good comment about the Irms" CreationDate="2010-10-27T12:01:45.397" UserId="1397" />
  <row Id="6833" PostId="298" Text="There's a discussion on the origin and use of the term on this Hack A Day post on [capacitive coupling](http://hackaday.com/2010/10/26/ethernet-connection-using-capacitive-coupling/)." CreationDate="2010-10-27T12:42:14.627" UserId="1696" />
  <row Id="6834" PostId="5698" Text="@Kellenjb just a once-off, the &quot;marketable product&quot; is called the licensed version of VMWare ESX ;)" CreationDate="2010-10-27T12:43:20.133" UserId="1696" />
  <row Id="6835" PostId="5719" Text="how is soldering then using epoxy for a mechanical connection &quot;just soldering&quot; ?" CreationDate="2010-10-27T13:04:18.440" UserId="1438" />
  <row Id="6836" PostId="5623" Text="At higher frequency you HAVE to do it faster - you can't afford a slow ramp because your square wave may turn into a triangle wave if it's too slow.  Doing it more often also makes it worse but that's AC power, and it confuses me :)" CreationDate="2010-10-27T13:05:27.567" UserId="249" />
  <row Id="6838" PostId="5696" Score="2" Text="I could give you a good example of two chips that would accomplish this but I know of none that do both." CreationDate="2010-10-27T13:42:28.547" UserId="1413" />
  <row Id="6839" PostId="5738" Score="2" Text="This makes the overall range ±10%." CreationDate="2010-10-27T13:52:34.713" UserId="1225" />
  <row Id="6842" PostId="5712" Score="1" Text="There are a few different ways that the files could be identical.  They could be binary equal, including the headers.  They could be the same audio data, but in different formats with different headers.  They could be the same waveform, but sampled differently.  They could be the same words spoken by different people.  For all of these cases, I think the question belongs on http://stackoverflow.com/, not here." CreationDate="2010-10-27T14:08:08.227" UserId="142" />
  <row Id="6843" PostId="5695" Score="1" Text="I'm not sure if it was the PIC18F4520 or the 25LC640 that didn't work quite right in SPI Mode 00, but they both work in Mode 11." CreationDate="2010-10-27T14:24:22.397" UserId="588" />
  <row Id="6844" PostId="3545" Score="1" Text="I note that on the evaluation board, they use a 40V 1000uF electrolytic (claiming 'low ESR') and parallel it with a 1uF low ESR film cap.  Putting caps in parallel will result in the resistance being smaller than the smallest resistance and the capacitance being higher than the highest capacitance.  I agree that 1,000uF is ridiculous." CreationDate="2010-10-27T14:29:18.497" UserId="857" />
  <row Id="6845" PostId="5738" Score="2" Text="No, 3.6 * 101% = 3.636, which rounds to 3.64.  It's 3.3 ±10%, and not 3.0 - 1% to 3.6+1%.  The two aren't equivalent." CreationDate="2010-10-27T14:31:47.500" UserId="857" />
  <row Id="6846" PostId="5737" Score="1" Text="I think this is false.  You would need &gt;30mV ripple to be 'safe', and, as Thomas O pointed out, it's just 3.3V ±10% (a contrived number). 'Safe' would be 3.3V, running near maxes or mins is dangerous." CreationDate="2010-10-27T14:33:12.507" UserId="857" />
  <row Id="6847" PostId="5710" Score="1" Text="Please do link to the 'pulse steal' design-there's no reason not to." CreationDate="2010-10-27T14:36:58.983" UserId="857" />
  <row Id="6848" PostId="5626" Text="http://www.imperial-connect.com/connectors/flat-flex-cable-connector.aspx They come in different pin counts and pin pitch. They usually have a clip that you slide on to lock the cable in place." CreationDate="2010-10-27T15:18:40.660" UserId="319" />
  <row Id="6849" PostId="5668" Text="Yes, the way that a battery fails is not by a decrease in voltage, but an increase of internal resistance." CreationDate="2010-10-27T15:19:39.380" UserId="230" />
  <row Id="6850" PostId="5719" Text="Ok, we're talking at crossed purposes: my original sentence was meant to read as &quot;'Just solder [you lazy/incompetent bastard, if you were any good at it the joints would be both mechanically and electrically sound]' isn't the answer I want to hear.&quot; I am both lazy and incompetent and I know that out of 120-odd joints I'd have to make, I'd screw at least one of them up and have no chance of finding the fault and repairing it onsite." CreationDate="2010-10-27T15:30:11.603" UserId="1633" />
  <row Id="6851" PostId="2786" Score="1" Text="http://www.adafruit.com/blog/2010/06/10/how-to-make-a-pogo-pin-testing-jig/" CreationDate="2010-10-27T15:33:27.097" UserId="142" />
  <row Id="6852" PostId="5741" Score="1" Text="Yeah, that's why I'm avoiding it. Microchip's memory disk drive has no support for long names." CreationDate="2010-10-27T15:40:30.023" UserId="1225" />
  <row Id="6853" PostId="5743" Score="1" Text="If it matters, the processor is Atmel AT91RM9200, PHY is Micrel KSZ8721" CreationDate="2010-10-27T16:10:17.430" UserId="1199" />
  <row Id="6854" PostId="5745" Score="1" Text="Good call, I didn't think about a switch, guess I wasn't thinking about it in that sense." CreationDate="2010-10-27T16:29:49.593" UserId="319" />
  <row Id="6855" PostId="5745" Text="Very good choice." CreationDate="2010-10-27T16:32:33.870" UserId="230" />
  <row Id="6857" PostId="5736" Text="Not sure how many hobby-sized servos use this, but some I've worked with used a DC voltage input to command their position. (These are pretty old servos.) Usually the voltage range was -5V to +5V." CreationDate="2010-10-27T16:38:53.350" UserId="965" />
  <row Id="6858" PostId="5706" Text="Good point, well explained." CreationDate="2010-10-27T16:40:56.437" UserId="965" />
  <row Id="6859" PostId="3545" Score="1" Text="the caps in parallel will also do the job of absorbing higher frequency transients. " CreationDate="2010-10-27T16:46:57.557" UserId="230" />
  <row Id="6860" PostId="5745" Text="I added a note to my answer to explain where I was coming from. It may or may not be helpful to him, but might be helpful to someone in the future." CreationDate="2010-10-27T16:47:06.727" UserId="319" />
  <row Id="6864" PostId="5736" Text="Thanks for the heads up about servos, saved me some research time on my next project and I have a couple lying around from old RC aeroplanes." CreationDate="2010-10-27T16:58:49.537" UserId="1333" />
  <row Id="6865" PostId="5716" Score="2" Text="That'll require at least one pin, tho.  Don't shift registers require at least two pins, for clock and data?" CreationDate="2010-10-27T17:11:25.943" UserId="51" />
  <row Id="6866" PostId="5706" Text="Thank you, sir." CreationDate="2010-10-27T17:11:45.703" UserId="712" />
  <row Id="6867" PostId="5696" Text="It's a shame that no one knows of a chip. Might just have to go with a 2 chip solution." CreationDate="2010-10-27T17:15:05.177" UserId="319" />
  <row Id="6868" PostId="5747" Text="Brownout (or, conversely, surges) could be possibilities, but you'd need to take some measurements before an EE can really make any comments.   Do you have a logging DMM?" CreationDate="2010-10-27T17:51:21.123" UserId="857" />
  <row Id="6869" PostId="5747" Text="@reemrevnivek Unfortunately, no. I did actaully do some measurements during brownouts, but effective voltage is around 220V according to my DMM, which is what it is supposed to be in my country. I know It's a brown-out mainly because my UPS keeps switching to its internal power source and effects this makes on lights." CreationDate="2010-10-27T17:58:52.940" UserId="1240" />
  <row Id="6870" PostId="5748" Text="Well it could be. A TV's power supply died suddenly and my air conditioning device keeps acting strangely. One time several power supplies with voltage auto-detection died, but I think that main reason for that is the fact that power company's technicians working at my power meter at that moment connected two phases together instead of a phase and zero." CreationDate="2010-10-27T18:03:50.407" UserId="1240" />
  <row Id="6871" PostId="5747" Text="@reemrevnivek It could be that my DMM doesn't update screen fast enough to get a relevant reading too." CreationDate="2010-10-27T18:05:11.933" UserId="1240" />
  <row Id="6872" PostId="5745" Text="A switch is exactly what I need; thanks!" CreationDate="2010-10-27T18:10:37.203" UserId="1199" />
  <row Id="6873" PostId="5748" Score="2" Text="I'd have it checked out by an electrician (in fact, as it's the power companies' equipment that usually affects the voltage the power co. may do it for free.)" CreationDate="2010-10-27T18:17:00.170" UserId="1225" />
  <row Id="6874" PostId="5748" Text="When you say the A/C acts strangely, what do you mean?" CreationDate="2010-10-27T18:17:21.933" UserId="1225" />
  <row Id="6875" PostId="4954" Text="http://www.xilinx.com/support/documentation/application_notes/xapp462.pdf says that i/p freq range to the freq synthesizer is 1 to 280Mhz and max out of freq syth is 280 * 32/1 = 8960Mhz. so even if the clock is 50Mhz, I should get an output of 50 * 32 = 1600Mhz. So am I getting these figures wrong? " CreationDate="2010-10-27T18:39:04.560" UserId="444" />
  <row Id="6876" PostId="5723" Text="Very heavily. Well written Archgoon, nothing blows up a mind like TE and TM modes. Most people are taught for a long time that it is always TEM then suddenly, blam, it is TM." CreationDate="2010-10-27T19:09:14.163" UserId="230" />
  <row Id="6877" PostId="5745" Score="1" Text="Switches are available as separate devices which work over Ethernet - See my answer below.  Also, it's generally a good idea to wait longer than an hour to accept an answer, 48 hours is probably better." CreationDate="2010-10-27T19:09:22.050" UserId="857" />
  <row Id="6878" PostId="5697" Text="&quot;Supersampling&quot; is the same thing as oversampling, right?" CreationDate="2010-10-27T19:19:44.090" UserId="142" />
  <row Id="6879" PostId="1024" Text="If this question isn't being moved to meta, can it be split?  Move the stuff specifically related to this site to meta, and leave the rest here for general web use?" CreationDate="2010-10-27T19:24:11.017" UserId="142" />
  <row Id="6880" PostId="1024" Text="@Kortuk - When the votes were cast, they weren't voting on it as a valuable question for E&amp;R, the parent site - there was no 'meta', and a question for meta can be valuable. " CreationDate="2010-10-27T19:35:50.687" UserId="857" />
  <row Id="6881" PostId="1024" Text="@endolith - As I've already stated, I think that all of these answers to the question &quot;Uploading Schematics for Chip Hacker&quot; should be moved to meta.  If we need a question on &quot;Good tools for drawing schematics&quot; (Which feels like a 'bad subjective' question to me).  We need more opinions. " CreationDate="2010-10-27T19:37:53.400" UserId="857" />
  <row Id="6882" PostId="5751" Text="I've been using CFLs in trouble lamps for a while - they're much more resistant to vibration than even heavy-duty incandescents.  " CreationDate="2010-10-27T19:45:23.737" UserId="857" />
  <row Id="6883" PostId="5725" Score="1" Text="I2C can be used if there are zero pins free, assuming that your I2C bus is being used as such and there are no address conflicts.  " CreationDate="2010-10-27T19:48:13.983" UserId="857" />
  <row Id="6884" PostId="5716" Text="@blalor - Yes, but these two pins are designed to be shared among multiple I2C devices." CreationDate="2010-10-27T19:49:02.593" UserId="857" />
  <row Id="6885" PostId="5752" Text="Where is your oscilloscope ground connected? It may be that the noise is in the ground reference." CreationDate="2010-10-27T20:19:08.910" UserId="328" />
  <row Id="6886" PostId="5752" Text="It's grounded to the same ground as the MCU, regulator and power supply. " CreationDate="2010-10-27T20:25:22.337" UserId="1225" />
  <row Id="6887" PostId="5752" Text="What does the input look like?" CreationDate="2010-10-27T20:26:58.320" UserId="712" />
  <row Id="6888" PostId="5752" Text="Input looks like 5.2V with occasional 80mVp-p &quot;bursts&quot; of noise but in general very low noise - N.B. supply is also powering a running computer." CreationDate="2010-10-27T20:30:47.207" UserId="1225" />
  <row Id="6889" PostId="5752" Text="If you say you have a ripple on your power rail why show us a scope of an I/O? You should show us the power rail ripple." CreationDate="2010-10-27T20:31:38.790" UserId="319" />
  <row Id="6890" PostId="5752" Text="Camera battery went dead, only picture I had. Found some batteries now - going to take a pic of the ripple on the 3.3V line." CreationDate="2010-10-27T20:33:08.707" UserId="1225" />
  <row Id="6892" PostId="5752" Text="What is the actual period of the noise? I see 10us/div, is that per major mark or minor mark? It looks like it is either 100 kHz or 20 kHz noise." CreationDate="2010-10-27T20:45:54.870" UserId="319" />
  <row Id="6893" PostId="5752" Text="Per major mark. (I'd turn on the grid lines but I don't count divs any more - the cursors make it easier and less error prone.)" CreationDate="2010-10-27T20:50:50.940" UserId="1225" />
  <row Id="6894" PostId="5752" Text="So it is a 20 kHz noise. Why not put a capacitor on the input of your voltage regulator? Also put some decade capacitors in to remove different frequencies of noise." CreationDate="2010-10-27T20:54:00.967" UserId="319" />
  <row Id="6895" PostId="5754" Text="Scope is grounded to breadboard ground rail which is connected to ATX power supply, MCU+reg is grounded to the same. Unfortunately I don't have a bench supply to test it with (it's on my wish list, or my list of things to build.)" CreationDate="2010-10-27T20:54:52.590" UserId="1225" />
  <row Id="6896" PostId="5754" Text="I added a 470µF/25V cap across the input line and left in place the output cap and I'm getting the same ripple. I'm going to try a 100n cap on both rails next." CreationDate="2010-10-27T20:55:24.680" UserId="1225" />
  <row Id="6897" PostId="5755" Text="It's breadboarded, so there's no ground plane. 100n caps on all supply pins." CreationDate="2010-10-27T20:57:25.177" UserId="1225" />
  <row Id="6898" PostId="5755" Text="I turned BW limit on my scope on (manual says 20 MHz BW limit, down from 100 MHz) and the noise is pretty much the same. " CreationDate="2010-10-27T20:58:08.577" UserId="1225" />
  <row Id="6899" PostId="5697" Text="I think so - supersampling is what I've always heard it called." CreationDate="2010-10-27T21:03:59.350" UserId="1225" />
  <row Id="6900" PostId="5752" Score="1" Text="I think I've discovered the source of the noise. My powerline networking adapters. One in my room. Just unplugged it - no bursts of noise! Though I'm not entirely sure how it's getting out - the ethernet cable is a distance away from my scope + probe." CreationDate="2010-10-27T21:11:28.047" UserId="1225" />
  <row Id="6901" PostId="5752" Score="2" Text="If you are powering your board from a computer then the computer is most likely hardwired into your powerline. The computer probably isn't designed to filter noise at that frequency so it is able to get through. Even on a motherboard there are many many capacitors and voltage regulators in order to get very clean power. You should be doing the same on your board if you are pulling power from the same source." CreationDate="2010-10-27T21:15:39.290" UserId="319" />
  <row Id="6902" PostId="5752" Text="Just thinking about the filtering though: line input cap (okay, does little for this noise), high frequency chopper transformer followed by high frequency LC filter - what would this noise do to something like a graphics card? The PC isn't anything special, just an old PIII Compaq Deskpro." CreationDate="2010-10-27T21:22:18.330" UserId="1225" />
  <row Id="6903" PostId="5707" Score="1" Text="+1 for statistics - love this stuff. (Took a GCSE in it.)" CreationDate="2010-10-27T21:33:05.337" UserId="1225" />
  <row Id="6904" PostId="5745" Text="@reemrevnivek I agree. With more time, we might get a better answer" CreationDate="2010-10-27T21:38:00.173" UserId="566" />
  <row Id="6905" PostId="1024" Text="I think that having a question on the site that discusses what options there are for doing schematics. How does a discussion of different options for pic programming or different versions of mplab fit better than versions of schematic tools. Specifically geared for quickly drawing schematics and allowing easy upload." CreationDate="2010-10-27T22:08:45.963" UserId="230" />
  <row Id="6906" PostId="5712" Score="2" Text="Note:  this site is primarily for questions related to embedded development, like solving this problem with a microcontroller connected to a voice recognition chip or a dedicated DSP.  The _algorithm_ to determine if the two &quot;files&quot; are similar, or you want to do this strictly in software, this is a question best asked on stackoverflow.  But if you want to get ideas on how to implement this in a quasi-hardware based way, this is a good place." CreationDate="2010-10-27T23:08:05.743" UserId="374" />
  <row Id="6907" PostId="5758" Text="Tried with the 12V rail and the same ripple occurs. Thanks for the suggestion - I'm working at room temperature with &lt;100mA load." CreationDate="2010-10-27T23:13:10.547" UserId="1225" />
  <row Id="6908" PostId="5760" Text="I found my ideal adapter: http://www.sparkfun.com/commerce/product_info.php?products_id=298" CreationDate="2010-10-27T23:53:13.960" UserId="1298" />
  <row Id="6909" PostId="5760" Text="They also provide a more detailed explanation that confirms your report: http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=103" CreationDate="2010-10-27T23:54:15.533" UserId="1298" />
  <row Id="6910" PostId="5729" Text="As I've said, I can farm the actual assembly out locally. However, I still need to do the PCB design." CreationDate="2010-10-28T00:06:55.643" UserId="1374" />
  <row Id="6911" PostId="5626" Text="I think I get the idea but I can't quite see how they work from the pictures on that page. Other problem is that supplier seems to carry maximum 1mm pitch, I'd need 2.5mm as that's the spacing on my solder pads. But I'll shop those pictures around Sim Lim Tower and see if anyone bites." CreationDate="2010-10-28T01:36:32.010" UserId="1633" />
  <row Id="6912" PostId="5620" Text="Precisely. (Then on the other side, either more screw terminals for the connecting wires, or 2.5mm pitch sockets/pins)" CreationDate="2010-10-28T01:38:18.203" UserId="1633" />
  <row Id="6913" PostId="5754" Score="1" Text="100kHz? sounds like a typical switching frequency from the ATX supply, try smaller decoupling caps and better placement of them (cutting leads or soldering on top of your MCU)" CreationDate="2010-10-28T01:41:08.333" UserId="1673" />
  <row Id="6914" PostId="5626" Text="That supplier was just found from a google images search. Here is an actual list of different types http://www.mouser.com/Interconnects/Rectangular-Connectors/FFC-FPC-Connectors/_/N-7auq6/" CreationDate="2010-10-28T02:24:59.827" UserId="319" />
  <row Id="6916" PostId="1024" Text="On the note of subjective, you can have subjective questions, you just cannot have a subjective AND argumentative question. " CreationDate="2010-10-28T02:50:56.837" UserId="230" />
  <row Id="6917" PostId="5709" Text="mee too, I'm not an expert (3 years doing PCBs, 5 months professionally) and in a couple of hours I can get a decently routed, sub 128 nets, sub 20MHz board." CreationDate="2010-10-28T03:06:31.643" UserId="1673" />
  <row Id="6918" PostId="5765" Text="Also, as a note, many phones provide a little bit of a loop back to your own speaker in order for you to feel like you aren't talking to nothing. To do this you will just need to do a combination of your mic plus the other persons mic, but keep it variable gain on each one separately in order to get the balance correct. " CreationDate="2010-10-28T03:29:54.697" UserId="319" />
  <row Id="6919" PostId="5611" Text="Thanks for you reply.. I have some basic knowledge of c, but i never worked on the chip level, can u suggest some books or articles for startup" CreationDate="2010-10-28T03:31:33.767" UserId="1525" />
  <row Id="6921" PostId="5765" Text="I have an LM741 op-amp, but I am having trouble wiring it up to through the arduino, which only has +5v and 0v. I have two input wires and two output wires, but I am not sure how to hook them all up or what resistors to use where. Could you point me at a good circuit to use?" CreationDate="2010-10-28T04:29:21.243" UserId="1686" />
  <row Id="6922" PostId="5745" Score="1" Text="As a bonus, some of these ethernet switch chips will add a VLAN tag so your processor can tell which port the traffic came in on.  (Typically when this is enabled it stops bridging traffic directly between ports, all ports can talk to your processor and it can choose to forward the traffic onward if desired.)" CreationDate="2010-10-28T06:40:37.717" UserId="1743" />
  <row Id="6923" PostId="5763" Score="1" Text="That's very interesting. The lamps which are problematic are all in enclosed fixtures." CreationDate="2010-10-28T07:41:49.640" UserId="1240" />
  <row Id="6924" PostId="5642" Text="I don't believe it is possible to patent SPI commands. All the stuff I've seen is to do with them requiring a license before they give you the spec, not actually using it.  Probably worth a look through their patents to see if they cover anything relevent." CreationDate="2010-10-28T08:37:34.243" UserId="1681" />
  <row Id="6925" PostId="5642" Text="Also SD has been around long enough that I think we would have heard about it by now if SD had actually persued anyone for this." CreationDate="2010-10-28T08:43:08.567" UserId="1681" />
  <row Id="6926" PostId="5626" Text="Mouser don't seem to stock any 4-pin 0.25mm pitch connectors at all. I think i need to see one of these things first hand before I can grok how they work, I can't get the idea from the diagrams on the data sheets." CreationDate="2010-10-28T09:36:30.650" UserId="1633" />
  <row Id="6927" PostId="5626" Text="Oh, or maybe this is what I want: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=609-2178-ND" CreationDate="2010-10-28T09:42:38.367" UserId="1633" />
  <row Id="6931" PostId="5763" Text="I thought I read the heat caused by the lamps in the enclosed area damaged the ballast, but I don't have any references to back it up." CreationDate="2010-10-28T12:32:42.707" UserId="536" />
  <row Id="6932" PostId="5769" Text="can you plot your array? (in a spreadsheet software perhaps?)" CreationDate="2010-10-28T12:59:39.543" UserId="1673" />
  <row Id="6933" PostId="5769" Text="There are 8192 values in the array.You want me to plot manually or spreadsheet will handle that.I am working on MAC" CreationDate="2010-10-28T13:05:17.893" UserId="1730" />
  <row Id="6934" PostId="5771" Text="I am working On MAC." CreationDate="2010-10-28T13:32:16.327" UserId="1730" />
  <row Id="6935" PostId="5763" Score="1" Text="I've seen the same repeated early failures on lamps that are not enclosed, and have enclosed ones that do not suffer these early failures.  At least in my case heat does not appear to be the root cause.  Still searching.  Could get real pricy continually blowing out expensive CFLs every month once we're forced to use only those (currently I just switched the offending locations back to incandescent which are lasting fine)." CreationDate="2010-10-28T13:41:19.523" UserId="1678" />
  <row Id="6936" PostId="5772" Text="Do you mean power spectrum value as the amplitude?" CreationDate="2010-10-28T14:02:00.450" UserId="1730" />
  <row Id="6937" PostId="5772" Text="t--&gt; with reference to the time?" CreationDate="2010-10-28T14:03:03.617" UserId="1730" />
  <row Id="6938" PostId="5769" Text="I have plotted tens of thousands samples in MS Excel; Gnumeric or another is suitable too. Or gnuplot too." CreationDate="2010-10-28T14:04:18.450" UserId="1673" />
  <row Id="6939" PostId="5772" Text="Don't worry about the time.  If you're just checking whether the FFT is working, all you need to do is check that the shape of the magnitude is similar to this." CreationDate="2010-10-28T14:06:47.880" UserId="142" />
  <row Id="6940" PostId="5773" Score="3" Text="What do you want to do with the board? That will affect your choice." CreationDate="2010-10-28T14:25:17.473" UserId="566" />
  <row Id="6941" PostId="5774" Text="Do you have a part number for that antenna?" CreationDate="2010-10-28T15:53:39.270" UserId="857" />
  <row Id="6942" PostId="5771" Text="@Warrior - Then use MacPorts or Fink to install Gnumeric (also see [this page](http://maururu.net/2007/gnumeric-wrapper-for-mac-os-x/comment-page-1/) for some info on a Platypus wrapper if you want that)" CreationDate="2010-10-28T16:28:13.943" UserId="857" />
  <row Id="6943" PostId="5774" Text="@reemrev yes http://www.antennafactor.com/documents/ANT-433-HETH_Data_Sheet.pdf" CreationDate="2010-10-28T16:29:09.693" UserId="771" />
  <row Id="6944" PostId="5774" Text="They say that &quot;HE Series antenna patterns have not been fully characterized as of this time. The patterns below illustrate typical patterns for antennas of this type.&quot;, and then give patterns and layouts.  What are you looking for beyond this information?" CreationDate="2010-10-28T16:33:07.613" UserId="857" />
  <row Id="6945" PostId="5777" Text="@reemre, can you add some explanation of how to &quot;read&quot; your drawing? as I look at the page, the coil axis would be facing me with the signal feed point being &quot;on the page&quot;, right? Signal strength in a direction is related to the distance from the origin to the curve in that direction?" CreationDate="2010-10-28T16:33:21.677" UserId="771" />
  <row Id="6946" PostId="5777" Text="@reemre Is the pattern symmetric if you were to visualize it in 3d?" CreationDate="2010-10-28T16:34:29.813" UserId="771" />
  <row Id="6949" PostId="5774" Text="@reemre see Edit2 above" CreationDate="2010-10-28T16:45:16.573" UserId="771" />
  <row Id="6950" PostId="5777" Text="@vicatu - I edited my picture to clarify what was going on.  The green line is the PCB, the thing with slashes is the antenna.  Ignoring the effects of the ground plane, the effect would (in theory) be the same if the PCB was rotated 90 degrees." CreationDate="2010-10-28T16:50:38.163" UserId="857" />
  <row Id="6951" PostId="5774" Text="@vicatu - Nice artwork. If you can control the orientation that precisely, why are you using helical antennas?  A directional antenna would give you better signal strength if you have that much control, the helical antenna will radiate it in all directions." CreationDate="2010-10-28T16:52:25.513" UserId="857" />
  <row Id="6952" PostId="5752" Text="@Thomas - You might want to add that the noise is coming from your powerline network adapters somewhere in the question.  That's important information." CreationDate="2010-10-28T16:58:03.360" UserId="857" />
  <row Id="6953" PostId="5774" Text="@reemre, cost, ease and availability... nevertheless, the antenna is rigid, so the way you mount it on the board is clearly a design decision, and I have to imagine the tx/rx orientation of the pair related to each other matters to the link quality... it might be &quot;omni&quot; directional, but the pattern surely isn't spherical..." CreationDate="2010-10-28T17:02:26.493" UserId="771" />
  <row Id="6954" PostId="5768" Text="I'm pretty sure I have the old style carbon mic. I took the network apart and there was a pretty nice hefty little coil pack under there that I assumed was a transformer of some kind as you describe. Alas, I threw it away, so I am back to square 1 with a mic and a speaker only. My bad." CreationDate="2010-10-28T17:02:51.193" UserId="1686" />
  <row Id="6955" PostId="5781" Text="Thanks! What happens if the trace doesn't meet this requirement? (e.g. extra noise, reduced transmission distance?) Also, is there any problem with trace length?" CreationDate="2010-10-28T17:23:36.993" UserId="1225" />
  <row Id="6956" PostId="5781" Text="Re width, is this radius or diameter?" CreationDate="2010-10-28T17:25:02.187" UserId="1225" />
  <row Id="6957" PostId="5781" Text="You don't care about length-- characteristic impedance is a measure of the ratio of inductance to capacitance at any point in the trace. Let me think about the effects of missing the 50 ohm target for a minute." CreationDate="2010-10-28T17:41:26.277" UserId="712" />
  <row Id="6958" PostId="5781" Text="Width means neither radius not diameter. I'm not sure what you mean with your second comment." CreationDate="2010-10-28T17:42:37.883" UserId="712" />
  <row Id="6960" PostId="5781" Text="Well, my PCB program has an input for &quot;Line Width&quot;. The line is like a circle being repeatedly drawn along a line, so the radius is the radius of this circle, and the same for diameter. I assume width means the diameter across the line. Radius could mean half the width." CreationDate="2010-10-28T17:59:04.403" UserId="1225" />
  <row Id="6961" PostId="5781" Text="You want the characteristic impedance to match the source and load impedance, or you'll get reflections back and forth down the line.  With analog video, I think this produces &quot;ghosting&quot;?  But if this is sending something modulated I'm not sure what the effect would be.  Some reduction in efficiency, too, since some energy would be wasted?" CreationDate="2010-10-28T18:01:55.500" UserId="142" />
  <row Id="6962" PostId="5773" Score="1" Text="The ARM7 microcontroller on the NetDuino and the 8-bit AVR on the Arduino are in a completely different class. It's like you're asking whether to buy a server or a netbook.  However, you're slowing down your server by running an ill-suited VM--the performance will be similar, and you're using both tools for the same task.  Do you really need that layer of abstraction? " CreationDate="2010-10-28T18:05:02.973" UserId="857" />
  <row Id="6963" PostId="5712" Text="@sheepsimulator, endolith - We've started [this meta question](http://meta.electronics.stackexchange.com/questions/126/does-dsp-fall-into-our-realm-or-stack-overflows-realm) to help determine whether this question is on-topic or not.  Please bring your points over there." CreationDate="2010-10-28T18:08:00.823" UserId="857" />
  <row Id="6964" PostId="5781" Score="4" Text="OK, here's my understanding of mismatched characteristic impedance. As a signal passes from source, through the trace, and into a load, the signal is attenuated in the trace, and some signal is reflected at each intersection. With matched impedance, there are no reflections. If the trace is too wide (too much capacitance) *or* too narrow (too much inductance), reflections and attenuation increase." CreationDate="2010-10-28T18:09:06.253" UserId="712" />
  <row Id="6965" PostId="5781" Text="Ah, I get the radius-diameter question now. Yes, width means diameter of your line-drawing circle. What PCB program, by the way?" CreationDate="2010-10-28T18:10:04.567" UserId="712" />
  <row Id="6966" PostId="5781" Text="I use the gEDA PCB package." CreationDate="2010-10-28T18:20:45.323" UserId="1225" />
  <row Id="6967" PostId="5777" Text="@vicatu - Did that *really* answer your question?  You approved it pretty fast.  I'd wait a while for someone with a better understanding to come in." CreationDate="2010-10-28T18:29:53.653" UserId="857" />
  <row Id="6968" PostId="5749" Text="That would be simpler except for the environment that my device will be in. A big point of my device is to consolidate all the discrete bits my client currently uses in a specific setup that they deploy in thousands of locations all over the country." CreationDate="2010-10-28T18:38:14.387" UserId="1199" />
  <row Id="6969" PostId="5772" Text="I said that already.  :)" CreationDate="2010-10-28T19:19:54.587" UserId="142" />
  <row Id="6970" PostId="5749" Text="My two takes on that bit of info: (1) That design goal and that kind of quantity make an onboard switch much more attractive.  (2) Doesn't a client like that already have Ethernet switches in your install locations?" CreationDate="2010-10-28T19:24:03.007" UserId="857" />
  <row Id="6972" PostId="5782" Text="Are you advocating the Wiring language used on the Arduino, or mooching off of (and contributing to) C code on [avrfreaks](http://www.avrfreaks.net/)?" CreationDate="2010-10-28T19:41:28.370" UserId="857" />
  <row Id="6973" PostId="5785" Text="I wonder how hard it is to patch the .NET libraries used on the NetDuino with a new feature.  It looks like they're using C++ to build their .NET SDK, way down in SecretLabs.NETMF.Hardware/Stubs - [source files](http://www.netduino.com/downloads/netduinosdk/NetduinoSDKSource.zip).  Sigh." CreationDate="2010-10-28T19:49:41.477" UserId="857" />
  <row Id="6974" PostId="5785" Text="@reemrevnivek Not my idea of fun. If you're patching the runtime, you might as well start out with C/C++" CreationDate="2010-10-28T19:53:01.123" UserId="566" />
  <row Id="6975" PostId="5786" Text="I don't think you can add more COM pins to the built in LCD module." CreationDate="2010-10-28T19:57:55.113" UserId="588" />
  <row Id="6976" PostId="5782" Score="1" Text="@reemrevnivek Arduino is just C++ with some libraries. I wouldn't class it as a &quot;language&quot; - it's C++ with a header and footer attached" CreationDate="2010-10-28T19:59:27.920" UserId="566" />
  <row Id="6977" PostId="5786" Text="So, does a 32x32 LCD glass actually have 1024 inputs, or are they wired in rows and columns and scanned?" CreationDate="2010-10-28T20:05:05.403" UserId="566" />
  <row Id="6978" PostId="5782" Text="Whoops, Wiring is what I meant." CreationDate="2010-10-28T20:12:11.730" UserId="857" />
  <row Id="6979" PostId="5785" Score="1" Text="@Joby - I'm a C luddite like yourself, but I just wanted to point out that it was possible - You said &quot;If a hardware feature isn't supported by the .NET libraries, you can't use it&quot;, which isn't quite true." CreationDate="2010-10-28T20:13:50.403" UserId="857" />
  <row Id="6981" PostId="5611" Text="The best way of learning is probably by doing.  AVRFreaks has a lot of example code in C for the AVR processors, and most toolchains come with some example code for their targets. Other than that, datasheets are your new best friend.  Arduino has a C-like (really C++-like) language called Wiring which is a bit of a diversion, but can be helpful if you're not getting the concepts." CreationDate="2010-10-28T21:17:04.740" UserId="857" />
  <row Id="6982" PostId="5786" Text="I don't have a specific display in mind, I'm just interested in low cost Tamagotchi type toys and the electronics in them. I assume they have a custom ASIC with built in LCD controller. But, I'm wondering how low cost a hobbyist can go?" CreationDate="2010-10-28T21:17:43.797" UserId="566" />
  <row Id="6983" PostId="5786" Text="Microchip application note AN658 in the section titled &quot;How are LCD Pannel's driven&quot; may help you understand why you can't just add more COMs or Segments using regular digital I/O pins." CreationDate="2010-10-28T21:47:19.437" UserId="588" />
  <row Id="6984" PostId="5786" Score="2" Text="Great link!  You should put that in your answer. Was &quot;The last time Microchip investigated high pin count packages, 30,000+ was not an option&quot; a bit of HUMOR in an application note? Edited my answer, BTW." CreationDate="2010-10-28T21:53:57.237" UserId="857" />
  <row Id="6986" PostId="5789" Text="I'm using a ground plane on my PCB's but I prototype on a breadboard. BTW, what is the cathode of a cap, I thought they were bipolar?" CreationDate="2010-10-28T23:09:31.237" UserId="1225" />
  <row Id="6987" PostId="5791" Text="Power supply is running a PC, should be enough load." CreationDate="2010-10-28T23:26:01.300" UserId="1225" />
  <row Id="6988" PostId="5794" Text="Every mm counts - but for hackers there is an I2C interface, two UART interfaces, and both chips have an ICSP interface for reprogramming." CreationDate="2010-10-28T23:36:50.387" UserId="1225" />
  <row Id="6989" PostId="5792" Text="I was considering an STM32. It would be ideal. I could live with 20KB RAM, but I wouldn't have as much resolution." CreationDate="2010-10-28T23:40:42.067" UserId="1225" />
  <row Id="6990" PostId="5793" Text="I wonder why these didn't show up in my Digikey search?  Their [parametric table](http://www.atmel.com/dyn/products/param_table.asp?family_id=605&amp;OrderBy=1234&amp;Direction=ASC#) is a nice way to select a part, I've never liked the rest of their site.  By the way, their mature SAM7 series (ARM7TDMI, not Cortex-M3) is going to be cheaper and better stocked-their Cortex M3 line (for this question, the SAM3S2A) is only sampling right now." CreationDate="2010-10-28T23:40:59.397" UserId="857" />
  <row Id="6991" PostId="5794" Text="If every mm really counts, go QFN ... or BGA" CreationDate="2010-10-28T23:42:05.357" UserId="566" />
  <row Id="6992" PostId="5790" Score="1" Text="&gt;Current candidates are the Parallax Propeller, but that only has 20 MIPS instruction cycle -- but thats 20 MIPS for each of eight cogs, for a total of 160 MIPS for the entire chip.  Of course you won't get high performance using their interpreted Spin language -- you'll need to go to assembly or C.  Note: you are probably already aware of this, but the Propeller can output NTSC/PAL/VGA with just a few resistors as an interfacem which might be useful for an OSD project." CreationDate="2010-10-28T23:42:36.480" UserId="1322" />
  <row Id="6993" PostId="5790" Text="I'm dealing with an OSD output stage which can't be made parallel. (Background things like line drawing could be &quot;queued&quot; and six of the eight cogs assigned to rendering them.) However, the chip DOES have an onboard TV scan line output stage which could be made to work with relative ease, I would need to disable the colour modulation though because without proper sync it will go all wrong." CreationDate="2010-10-28T23:44:20.003" UserId="1225" />
  <row Id="6994" PostId="5793" Text="The reason was that the referenced parts aren't in Digikey's inventory yet, and the 48-pin devices have too little RAM, and the chips with sufficient RAM have 64 pins." CreationDate="2010-10-28T23:44:29.610" UserId="857" />
  <row Id="6995" PostId="5794" Text="BGA? Good luck soldering that! I need proper reflow facilities to do that. Actually, it turns out TQFP-100 packages aren't as big as I thought, and I may be able to move some functions like servo control and ADC over to the TQFP-100, then I wouldn't be wasting so many pins; a second micro could do the lesser tasks and act as the bus master for I2C." CreationDate="2010-10-28T23:46:26.743" UserId="1225" />
  <row Id="6996" PostId="5795" Text="This is great - I'll check it out!" CreationDate="2010-10-28T23:47:09.003" UserId="1225" />
  <row Id="6997" PostId="5794" Text="Ah, missed the space part.  I just read 'waste of money'.  I've edited to link to the smaller packages for the Parallax and NXP chips instead.   " CreationDate="2010-10-28T23:47:45.373" UserId="857" />
  <row Id="6998" PostId="5795" Score="2" Text="I'm starting to like these AVR32's, they look pretty powerful. I might be losing my PIC religion. haha." CreationDate="2010-10-28T23:49:16.710" UserId="1225" />
  <row Id="6999" PostId="5794" Text="Money is important but not critical, as long as it's &lt;$20 USD it'll be fine." CreationDate="2010-10-28T23:50:00.530" UserId="1225" />
  <row Id="7000" PostId="5768" Text="I was thinking about the transformer more today. I think it would have kept the DC operating voltage off the ringer, and there may have been some trick that kept the AC ringing signal from clobbering the earpiece." CreationDate="2010-10-28T23:53:38.797" UserId="740" />
  <row Id="7001" PostId="5789" Text="I think it's being used as a name for the negative terminal of a device.  Ceramic and tantalum caps (which are the only two kinds I'd consider for a decoupling cap) are bipolar, while electrolytics (which have an ESR too high to be effective for decoupling) are polarized." CreationDate="2010-10-28T23:56:24.283" UserId="857" />
  <row Id="7002" PostId="5789" Text="electrolytics usually have a preferred polarity. the ones with the plastic covers usually have at least the negative side clearly marked with (-) signs." CreationDate="2010-10-28T23:56:27.077" UserId="740" />
  <row Id="7003" PostId="5789" Text="@JustJeff - (-) signs and/or a stripe which contrasts with the rest of the packaging, usually white. In addition, on through-hole parts, the cathode lead is shorter (like LEDs)" CreationDate="2010-10-29T00:06:00.537" UserId="857" />
  <row Id="7004" PostId="5789" Text="I would like to note, often people call a bulk filter cap a decoupling cap, this is often an electrolytic. Another common name for this is a tank capacitor. These are small power sources, meant to act as a source of power near your device with a capacitance normally exceeding .1uF(I often see these at 1uF or 10uF). You then place decoupling caps in parallel with this also, normally called decade capacitors or RF capacitors. These will be an order of magnitude less(1 decade)." CreationDate="2010-10-29T00:13:11.633" UserId="230" />
  <row Id="7005" PostId="5797" Text="I'm using a dsPIC33FJ128GP802, which has the odd number of Vdd and Vss pins. The *804 has an even number. As a side note, why does Microchip do this? There must be some reason for the unequal numbers." CreationDate="2010-10-29T00:19:05.670" UserId="1225" />
  <row Id="7006" PostId="5798" Score="2" Text="On a related note, you can't build this because it's patented for the next 7 years.   :P  " CreationDate="2010-10-29T00:20:13.313" UserId="857" />
  <row Id="7007" PostId="5789" Text="I have some 1µF ceramics and 10µF ceramics, they are in 0603 and 0805 packages - they are pretty good for filtering the supply from digital noise and act as little temporary power sources as you mention. I place a 1µF cap near each power connector, e.g. GPS, I2C, PSU out, to reduce the noise from these external devices." CreationDate="2010-10-29T00:21:09.067" UserId="1225" />
  <row Id="7008" PostId="5776" Text="Great answer. I hate picking motors, I know it must be done, but I much prefer just use a simple servo and deal with torque if it becomes a problem." CreationDate="2010-10-29T00:23:31.470" UserId="230" />
  <row Id="7009" PostId="5798" Score="4" Text="You can't build it and sell it" CreationDate="2010-10-29T00:23:39.033" UserId="566" />
  <row Id="7010" PostId="5797" Text="Oh, I wouldn't count the Vddcore pin as a power pin as it is for the internal regulator. There is one Vdd, one AVss, two Vss and one AVss, why are there two grounds but only one Vdd?" CreationDate="2010-10-29T00:25:11.810" UserId="1225" />
  <row Id="7011" PostId="5799" Text="Are you going to hack the firmware to bit-bang the SPI? Sounds like the OP would be interested in something which can be done without modifying the firmware, but maybe I'm wrong. " CreationDate="2010-10-29T00:26:33.587" UserId="1225" />
  <row Id="7012" PostId="5795" Text="p.s. Atmel has a $149 evaluation kit with the 64-pin 128KB flash, 32KB RAM version of the chip:  http://store.atmel.com/PartDetail.aspx?q=p:10500065" CreationDate="2010-10-29T00:28:19.263" UserId="1322" />
  <row Id="7013" PostId="5798" Text="You can still build it for &quot;research purposes&quot; but I believe patents would prevent you from selling it or even distributing it for free. (i.e. giving it to a friend.)" CreationDate="2010-10-29T00:28:25.037" UserId="1225" />
  <row Id="7014" PostId="5799" Text="@Thomas - I couldn't tell, and I don't know anything about hacking a Blackberry to understand if this is feasible or not. " CreationDate="2010-10-29T00:30:14.970" UserId="857" />
  <row Id="7015" PostId="5798" Score="1" Text="Then how is it distributed as a kit by Vellman?" CreationDate="2010-10-29T00:31:24.003" UserId="857" />
  <row Id="7016" PostId="5797" Text="Why?  You'd have to ask Microchip.  I'd guess it's to reduce the pin count.  Vddcore is definitely a power pin! See Sections 2.3 and 27.2 of the datasheet: *The VCAP/VDDCORE pin must not be connected to VDD, and must have a capacitor between 4.7 μF and 10 μF, 16V connected to ground. The type can be ceramic or tantalum.*" CreationDate="2010-10-29T00:36:39.113" UserId="857" />
  <row Id="7017" PostId="5799" Text="I would suspect it's buried in the kernel of the firmware, if not dedicated entirely to an SD card controller IC. But it's an interesting hack nonetheless, if it's possible. I'd be interested in any expansion interface on the phone, if it has any." CreationDate="2010-10-29T00:45:20.997" UserId="1225" />
  <row Id="7018" PostId="5798" Text="@Joby You can still get in trouble even if you aren't selling it @Thomas do you have any sources that say you can still build if for research purposes? @reemrevnivek if I were to guess, they either use a different method or they have a license to use the technology." CreationDate="2010-10-29T00:45:53.220" UserId="319" />
  <row Id="7019" PostId="5800" Text="I normally use mouser as they are close to me. I would also like to see what chips this turns up." CreationDate="2010-10-29T00:48:55.850" UserId="230" />
  <row Id="7020" PostId="5802" Text="The problem is, I can't interrupt the OSD processing or the video will break up and look awful. So during the OSD processing (about 80-90% of the processor's time) the chip is pretty much uninterruptable." CreationDate="2010-10-29T00:49:36.357" UserId="1225" />
  <row Id="7021" PostId="5802" Text="Ahh. I am sorry, I did not realize how intense your interrupt requirement was. I will leave the answer for people with a less critical process. I will write another soon." CreationDate="2010-10-29T00:50:56.607" UserId="230" />
  <row Id="7022" PostId="5798" Score="3" Text="It is very important to note someone with a patent can sue for building with non-commercial intent. You are stealing one sale." CreationDate="2010-10-29T00:57:01.323" UserId="230" />
  <row Id="7023" PostId="5801" Text="Do you need any of the gps data while your cpu is busy with the OSD processing? Is there anyway to make the OSD processing more interrupt driven?" CreationDate="2010-10-29T01:04:06.053" UserId="319" />
  <row Id="7025" PostId="5801" Text="The OSD processing *is* interrupt driven. On each comparator change it determines the current line of the video and outputs the sequence of pixels to embed on the video. However, it's this critical time during the output stage that the processor is busy." CreationDate="2010-10-29T01:06:49.937" UserId="1225" />
  <row Id="7030" PostId="5738" Text="@reem You can't round up maximum ratings, you will have to round it down." CreationDate="2010-10-29T01:46:51.047" UserId="1298" />
  <row Id="7031" PostId="5795" Text="I thought AVR32 was comparable to PIC32?" CreationDate="2010-10-29T02:21:43.463" UserId="230" />
  <row Id="7032" PostId="5805" Text="I would imagine the cost of an SPI/I2C UART bridge is probably close to the cost of an additional PIC." CreationDate="2010-10-29T02:40:39.347" UserId="319" />
  <row Id="7033" PostId="5719" Text="solder should never be used as a mechanical connection for anything more intense than holding an IC to a circuit board.  You solder for a strong electrical connection, and use other systems for mechanical attachment." CreationDate="2010-10-29T04:01:24.363" UserId="1438" />
  <row Id="7034" PostId="5802" Text="I added a bit more information specific to your pic." CreationDate="2010-10-29T04:09:16.197" UserId="230" />
  <row Id="7035" PostId="5788" Score="5" Text="I know saying look at the datasheet is frowned on as an answer, but I actually think this is a good case to bring it up. If a chip has any specific needs it will specify it in the datasheet. If you would have looked at the datasheet for this pic you would have found your answer." CreationDate="2010-10-29T04:47:07.367" UserId="319" />
  <row Id="7036" PostId="5788" Score="1" Text="I have actually seen a group who spent money on some pro-boards having not looked at the datasheet for any of the parts. When they hooked it up it didn't work. It ended up being that if they had looked at the datasheet they would have found that there was a layout consideration page that they needed to have followed." CreationDate="2010-10-29T04:48:50.217" UserId="319" />
  <row Id="7037" PostId="5785" Score="1" Text="Have you actually seen any benchmarks? It's hard for me to imagine that a 16MHz 8bit runs things at the same speed as a 60MHz 32bit micro. Especially since Arduino libraries slow things down too -- none of it is really optimized for speed either. And it's got objects as well (if not as many as are used in .NET). And is it much different from Arduino? If there's not an Arduino library supporting a feature...you have to implement it yourself (calling out directly to hardware registers etc)" CreationDate="2010-10-29T04:51:58.917" UserId="131" />
  <row Id="7038" PostId="5769" Text="Don't forget open office" CreationDate="2010-10-29T05:05:09.043" UserId="1374" />
  <row Id="7039" PostId="5781" Text="@pingswept, When the line does not match impedance you will have very big problems that will be very dependent on what the distance is. This is quite nasty in general. When you say intersection, I think i know what you mean, this is actually an impedance mismatch." CreationDate="2010-10-29T05:05:08.590" UserId="230" />
  <row Id="7040" PostId="5789" Text="You still probably should use decade caps, especially with GPS and high speed signals." CreationDate="2010-10-29T05:08:08.947" UserId="230" />
  <row Id="7041" PostId="5790" Score="1" Text="Not being parallelizeable is not necessarily an objection to the propeller. You could pipeline the operations, with each COG doing a small part of the computation, and passing the results off to the next COG through the hub ram." CreationDate="2010-10-29T05:08:30.543" UserId="1374" />
  <row Id="7042" PostId="5789" Score="1" Text="@reemrevnivek - Nonpolar tantalums? not common..." CreationDate="2010-10-29T05:10:00.480" UserId="1374" />
  <row Id="7043" PostId="5769" Text="@Fake Name: i am not able to plot the graph.." CreationDate="2010-10-29T05:11:15.877" UserId="1730" />
  <row Id="7044" PostId="5773" Text="@reemrevnivek - &quot;Ill-suited&quot; uh... it is a layer of abstraction, but it's certainly not ill suited (and not a vm, really, either). " CreationDate="2010-10-29T05:13:18.937" UserId="1374" />
  <row Id="7045" PostId="5773" Text="Basically, you get the same speed for the same price, but one is waaaay easier to program then the other. " CreationDate="2010-10-29T05:13:42.980" UserId="1374" />
  <row Id="7047" PostId="5810" Text="When you say side to side are you talking about your poll actually moving locations or is your poll fixed in a single location and you are just turning the poll?" CreationDate="2010-10-29T05:40:14.787" UserId="319" />
  <row Id="7048" PostId="5810" Text="Pole is fixed at one end, or rather, at the pivot point" CreationDate="2010-10-29T06:34:29.977" UserId="1665" />
  <row Id="7049" PostId="5812" Text="I tested my sine wave signal it is 1000 Hz. Mine  FFT gives right answer.Thanks for your help." CreationDate="2010-10-29T06:40:05.817" UserId="1730" />
  <row Id="7050" PostId="5772" Text="I am not able to plot anyway my FFT is working right. I will try to implement the graph in my free time definitely.Thanks a lot." CreationDate="2010-10-29T06:41:10.590" UserId="1730" />
  <row Id="7051" PostId="5790" Text="Farnell has a nice parametric search: http://export.farnell.com/microcontrollers-mcu" CreationDate="2010-10-29T07:47:01.760" UserId="339" />
  <row Id="7052" PostId="5795" Text="I have been using the AVR32B for over a year now.  They have worked really well.  They are approximately equivalent to the Cortex-M3 but (for me) a better peripheral fit and vastly superior low power modes." CreationDate="2010-10-29T08:27:47.597" UserId="400" />
  <row Id="7053" PostId="5794" Text="The AVR32 has what atmel call TWI (two wire interface) this is their implementation of I2C and I have used this as the master to talk to other I2C devices.  The SPI controller with multiple chip selects is also really neat.  It allows multiple devices to hang on the SPI clock/data lines with almost no software overhead." CreationDate="2010-10-29T08:34:38.260" UserId="400" />
  <row Id="7054" PostId="5798" Text="The idea for patents is that people can learn from your product; that's why you have to publish everything out in the open. " CreationDate="2010-10-29T08:43:39.143" UserId="1225" />
  <row Id="7055" PostId="5809" Text="Size would be important; that chip is quite big." CreationDate="2010-10-29T08:50:02.397" UserId="1225" />
  <row Id="7056" PostId="5797" Text="What I mean is it doesn't sink or source current (except as for the capacitor.)" CreationDate="2010-10-29T08:53:30.833" UserId="1225" />
  <row Id="7057" PostId="5815" Text="My MCU doesn't have an onboard comparator." CreationDate="2010-10-29T09:08:28.980" UserId="1225" />
  <row Id="7058" PostId="5799" Text="Applications on Blackberry live in a Java sandbox. So, you'd have to emulate an SD card with a filesystem. Possible, but challenging" CreationDate="2010-10-29T09:09:14.800" UserId="566" />
  <row Id="7059" PostId="4785" Text="+1 for a lovely friendship" CreationDate="2010-10-29T09:33:00.900" UserId="1333" />
  <row Id="7061" PostId="5804" Text="That's what I'm currently doing, using a dsPIC33F and a PIC24F. I2C can be paused, so that is how data is sent between the two devices." CreationDate="2010-10-29T10:05:11.890" UserId="1225" />
  <row Id="7062" PostId="5815" Text="Seems a waste just to have a PIC dedicated to this task." CreationDate="2010-10-29T10:13:18.653" UserId="1225" />
  <row Id="7063" PostId="5789" Text="@reemrevnivek: Came here to say what Fake Name has already done. Most tantalums are polarised." CreationDate="2010-10-29T10:32:33.103" UserId="1750" />
  <row Id="7064" PostId="5820" Text="+1 for your research. But it needs to be 6V input minimum. This doesn't seem to be a very fast buck controller either, but maybe I'm missing something?" CreationDate="2010-10-29T10:39:51.910" UserId="1225" />
  <row Id="7065" PostId="5819" Score="3" Text="Why SOIC8? What about other easy to solder packages? Simple switchers are monsters but can be soldered with your eyes closed. Part of your problem is not many vendors are making high switching frequency chips in SOIC8." CreationDate="2010-10-29T11:26:55.360" UserId="404" />
  <row Id="7066" PostId="5819" Text="I'm designing it for someone who only wants to solder 1206 packages (because 0603 and 0805 are too small), I imagine that anything smaller will be tricky for them." CreationDate="2010-10-29T11:29:40.743" UserId="1225" />
  <row Id="7067" PostId="5785" Text="@davr Edited answer" CreationDate="2010-10-29T12:01:40.010" UserId="566" />
  <row Id="7068" PostId="5773" Score="2" Text="@Fake Name It looks like netduino (TinyCLR) doesn't have a JIT compiler. So, it *is* a VM/interpreter. http://www.tinyclr.com/faq/#13" CreationDate="2010-10-29T12:10:11.967" UserId="566" />
  <row Id="7069" PostId="5822" Text="I'm using an RC receiver. I'm using a dsPIC33F or an AVR32. Either way, the number of input capture channels seems to be limited to around 8. Some have more but are in bigger packages. Thanks for the link to PPM, but I probably won't be able to use PPM as most RC receivers don't have this available without some soldering and I'd rather people didn't have to modify their receivers." CreationDate="2010-10-29T12:29:38.103" UserId="1225" />
  <row Id="7070" PostId="5822" Score="2" Text="Well, you could use 8 pins and use PCINT to trigger on changes, the signals are slow enough that it ought to work. Note a timers value when the signal goes high and note the difference when the signal goes low." CreationDate="2010-10-29T12:40:39.963" UserId="1675" />
  <row Id="7071" PostId="5822" Text="That could work, I suppose, but it wouldn't work when two servos are at the same position (simulatenous interrupts - one would fire before the other.)" CreationDate="2010-10-29T12:45:26.107" UserId="1225" />
  <row Id="7072" PostId="5786" Text="For humour in an app note, my favourite bit was in a National Semiconductor note, it went something along these lines: &quot;for a high voltage supply, tubes (remember them?) can be used.&quot; It was written in 1970, I'll try and find it. (It also had some other bits that tickled my senses.)" CreationDate="2010-10-29T12:47:17.477" UserId="1225" />
  <row Id="7073" PostId="5773" Text="@Fake Name - As Joby pointed out, it *is* a VM, and I said ill-suited because you're using it to interface with custom hardware, which isn't exactly a strong point of .NET" CreationDate="2010-10-29T12:56:40.040" UserId="857" />
  <row Id="7074" PostId="5799" Text="@Joby - Ah.  I had no idea how he was using a Java app on the Blackberry." CreationDate="2010-10-29T12:59:23.893" UserId="857" />
  <row Id="7075" PostId="5804" Text="Are you having any issue with this method?" CreationDate="2010-10-29T13:17:19.777" UserId="319" />
  <row Id="7076" PostId="5816" Text="You mentioned that 0 is no correlation and 1 is total correlations. I just want to note that -1 is complete negatively correlated. As in, -1 implies that sample 1 is the opposite of sample 2. If you think about it on an X,Y graph, it is a line with positive slope versus a line with negative slope. And as you get closer to 0 the line gets &quot;fatter&quot;." CreationDate="2010-10-29T13:23:14.683" UserId="319" />
  <row Id="7077" PostId="5823" Text="How does this work if multiple servos fire at the same time. Actually, it might work if you captured the timer on the event, then recorded which ones changed. Thanks. Also thanks to dren.dk for suggesting something similar." CreationDate="2010-10-29T13:24:24.123" UserId="1225" />
  <row Id="7078" PostId="5822" Score="1" Text="When the PCIE fires you have to read the entire port and act on all pin changes that you are interested in, that will naturally handle all changes that happen at the same time, but there is a fair chance that the servo inputs will be staggered in many cases because their outputs will come out of a 4017." CreationDate="2010-10-29T13:24:53.077" UserId="1675" />
  <row Id="7079" PostId="5822" Text="Okay, thanks for the suggestion - both you and Kellenjb have the same idea." CreationDate="2010-10-29T13:26:51.157" UserId="1225" />
  <row Id="7080" PostId="5785" Text="&quot;And, most of all, by using your C# skills on an embedded platform you're not really learning anything about embedded devices.&quot;&#xA;You mean &quot;old school&quot; embedded devices, yes?  I wish these fast 32bit ARM devices were available when I was younger." CreationDate="2010-10-29T13:34:47.110" UserId="1758" />
  <row Id="7081" PostId="5787" Text="Thanks.  That's what I was looking for." CreationDate="2010-10-29T13:52:54.487" UserId="1345" />
  <row Id="7082" PostId="5822" Text="I'm going to give the accepted answer to dren.dk, but Kellenjb has a good answer too - unfortunately I can't give both the accepted answer." CreationDate="2010-10-29T14:03:10.097" UserId="1225" />
  <row Id="7083" PostId="5800" Score="1" Text="Would an I2C DAC and a regular, non-programmable comparator solve your problem?" CreationDate="2010-10-29T14:18:22.357" UserId="857" />
  <row Id="7084" PostId="5800" Text="Yep, but it would be nicer to have a single IC solution because of a) reduced size, b) probably lower cost." CreationDate="2010-10-29T14:19:47.117" UserId="1225" />
  <row Id="7085" PostId="5826" Score="5" Text="The letters can vary depending on the company, but usually they are a minor difference between. Have you checked the datasheet?" CreationDate="2010-10-29T14:38:42.030" UserId="319" />
  <row Id="7086" PostId="5826" Text="But what datasheet? Many manufacturers make the same ICs. For example Fairchild I think make some CD series logic IC's." CreationDate="2010-10-29T14:40:29.820" UserId="1225" />
  <row Id="7087" PostId="5827" Score="1" Text="ROM actually is performing logic functions, it is a complicated look-up table. It used to be more common, but if you need a large size ROM and could be sure of what it would need for a long time you would implement it with fabricated logic. This means for each address it has the logic to generate the output with and/or/not gates. This type of function is also very fast." CreationDate="2010-10-29T14:43:08.593" UserId="230" />
  <row Id="7088" PostId="5804" Text="Well, it's more expensive, and it's bigger. If I can avoid doing it then it will be better." CreationDate="2010-10-29T14:43:19.617" UserId="1225" />
  <row Id="7090" PostId="5827" Text="I added that to my answer." CreationDate="2010-10-29T14:44:01.990" UserId="1225" />
  <row Id="7091" PostId="5826" Text="I can find the datasheet for CD4026B types and CD4026 types but they don't seem to reference each other." CreationDate="2010-10-29T14:45:43.067" UserId="1225" />
  <row Id="7092" PostId="5827" Text="@Thomas O: can I say that ROM is a fixed PLA?" CreationDate="2010-10-29T14:47:40.290" UserId="1760" />
  <row Id="7093" PostId="5827" Score="1" Text="Well, somewhat, but a ROM can be reprogrammed usually, you just have to erase it electronically (EEPROM) or using UV light (EPROM.) A PAL is not a ROM, but a ROM can act as a PAL." CreationDate="2010-10-29T14:50:31.600" UserId="1225" />
  <row Id="7094" PostId="5804" Score="1" Text="You seemed to have asked a question that you are unwilling to accept anything but magic as your answer. You say interrupts are not an option and adding extra cost or ICs is not an options. Also, you should have included in your question that you were already doing this method. If you continue on asking questions in this manner the community will assume you are asking questions just to gain more rep and treat you as spam. I don't think this will be good for anyone." CreationDate="2010-10-29T14:50:57.197" UserId="319" />
  <row Id="7095" PostId="5816" Text="@kellenjb, Yes, but I would probably word it, the magnitude of correlation what you are probably interested in. a 1 or a -1 mean the signals directly affect each other." CreationDate="2010-10-29T14:52:28.707" UserId="230" />
  <row Id="7096" PostId="5827" Text="@Thomas O: anyway a little bit difficult understand implementation of: EEPROM, EPROM, do You have some links with basics about ROM and it types, PLA and it types etc.?" CreationDate="2010-10-29T14:55:49.700" UserId="1760" />
  <row Id="7097" PostId="5826" Score="3" Text="I have actually told my students this a few times. If the manufacture you are using doesn't provide a datasheet to you, then you shouldn't be using them." CreationDate="2010-10-29T14:56:02.213" UserId="319" />
  <row Id="7098" PostId="5801" Text="I edited my answer thomas, did that help at all?" CreationDate="2010-10-29T14:57:45.597" UserId="230" />
  <row Id="7099" PostId="5802" Text="Thanks. My GPS device requires a minimum of 9600 baud but I may be able to sneak in reading the bits at the beginning of each line; I'm still unsure though." CreationDate="2010-10-29T15:09:57.770" UserId="1225" />
  <row Id="7100" PostId="5802" Text="You said you are already implementing a second pic, which is what my second option would have been, but others beat me to that. This way you can have the UART go to a FIFO when your other interrupt is not serviced without changing the way that the Video interrupts are handled." CreationDate="2010-10-29T15:12:12.583" UserId="230" />
  <row Id="7101" PostId="5827" Text="Well, I'm unsure about the various types of PAL/PLA, but EEPROM/EPROM/PROM and ROM are all just successive technology variations; ROM is built into the silicon, PROM is one-time only programmable (electronically), EPROM is erased using UV light and reprogrammable electronically and EEPROM is the current variant, which is programmable and eraseable fully electronically." CreationDate="2010-10-29T15:12:40.297" UserId="1225" />
  <row Id="7102" PostId="5781" Text="I was a little unclear. When I said &quot;You don't care about length,&quot; I meant it regarding characteristic impedance, i.e. characteristic impedance is an intrinsic property of a trace; it doesn't accumulate with length like resistance does. When it comes to getting your signal down a trace, you *do* care about length because of signal attenuation (the &quot;big problems&quot; you mentioned). Signal attenuation does increase with length." CreationDate="2010-10-29T15:16:18.333" UserId="712" />
  <row Id="7103" PostId="5829" Text="I think it's changed over the last few years. I can't find any non -B IC's. What is the difference between a non-buffered IC and a buffered IC? I mean, both outputs are from the drain/source of the internal CMOS fets, so what would adding buffering to them do?" CreationDate="2010-10-29T15:16:28.613" UserId="1225" />
  <row Id="7104" PostId="5829" Score="3" Text="The output (and, actually, input...) buffers might be built using larger FETs than those contained within the logic circuitry, allowing for higher currents or more precise thresholds.    http://en.wikipedia.org/wiki/4000_series#Design_considerations,     http://focus.ti.com/lit/an/scha004/scha004.pdf" CreationDate="2010-10-29T15:22:14.083" UserId="930" />
  <row Id="7105" PostId="5827" Text="When you build the logic hard into ROM you can get low latency and low cost. The size of the wafer can be almost nothing compared to a PLA or FPGA." CreationDate="2010-10-29T16:32:47.387" UserId="230" />
  <row Id="7106" PostId="5836" Text="I would vote you up but I've reached my daily vote limit!" CreationDate="2010-10-29T18:34:33.507" UserId="1225" />
  <row Id="7107" PostId="5834" Score="3" Text="I would suggest against learning that there is a set capacitance for things. I have used chips that need 10uF as a local current source." CreationDate="2010-10-29T18:40:46.500" UserId="230" />
  <row Id="7108" PostId="5834" Score="1" Text="Good point, but I would say 10µF is a bulk capacitor not really a decoupling capacitor." CreationDate="2010-10-29T18:42:04.643" UserId="1225" />
  <row Id="7109" PostId="5837" Text="I think you're overcomplicating this. Running Android on it is a bit much, and will require a decent processor. You could do this with just a small microcontroller. Sure, it wouldn't have as much power, but it will be much simpler to implement." CreationDate="2010-10-29T19:10:58.070" UserId="1225" />
  <row Id="7110" PostId="5837" Text="I'm needing to do a lot more than just barcode/rfid scanning..." CreationDate="2010-10-29T19:12:09.210" UserId="1763" />
  <row Id="7111" PostId="5837" Text="Like what? If you want to run Java on it, then that's possible, but why? Applications can be written in C if you want. It's a big project for &quot;a software guy&quot; to take on." CreationDate="2010-10-29T19:13:16.790" UserId="1225" />
  <row Id="7112" PostId="5837" Score="2" Text="I am sure Max has good reasons for wanting to make the RFID reader that high end. I will admit, it is good to point out that it may be over complicated, but if they seem sure then we just need to answer. when we show someone how, they may change their mind at this point." CreationDate="2010-10-29T19:15:39.083" UserId="230" />
  <row Id="7113" PostId="5789" Text="Whoops!  My bad.  Deleted that brain fart to prevent the spread of misinformation, the rest of it is here: 	&#xA;Cathode is being used as a name for the negative terminal of a device. Ceramic caps are bipolar, while **tantalum caps are polarized.**  Note that the electrolytics are also polarized, but are a poor choice for decoupling due to their high ESR." CreationDate="2010-10-29T19:17:09.973" UserId="857" />
  <row Id="7114" PostId="5811" Text="Would you use an accelerometer at the end to act as the sensor feeding back into the PID?" CreationDate="2010-10-29T19:23:19.577" UserId="142" />
  <row Id="7115" PostId="5819" Score="1" Text="But what about something larger?" CreationDate="2010-10-29T19:24:45.410" UserId="142" />
  <row Id="7116" PostId="5819" Text="Might be okay to go larger, but not much larger. I've used a TO-263 on the current design but it was a bit too big." CreationDate="2010-10-29T19:28:01.333" UserId="1225" />
  <row Id="7117" PostId="5834" Text="What's the difference between &quot;bulk capacitor&quot; and &quot;decoupling capacitor&quot;?  Which is a synonym for &quot;bypass capacitor&quot;?" CreationDate="2010-10-29T19:30:07.587" UserId="142" />
  <row Id="7118" PostId="5842" Text="It's a quite big inductor, I was looking at 20-30µH for most results." CreationDate="2010-10-29T19:40:38.833" UserId="1225" />
  <row Id="7119" PostId="5827" Text="Apparently PLAs can only implement combinational logic.  So neither of these can do logic that depends on prior states.  Is there anything that one can do that the other can't?  Or is it just a matter of cost and speed?" CreationDate="2010-10-29T19:40:46.153" UserId="142" />
  <row Id="7120" PostId="5840" Text="+1 I'd edit my answer to suggest this too." CreationDate="2010-10-29T19:43:44.617" UserId="938" />
  <row Id="7121" PostId="5827" Text="I'm not sure. I think a ROM would be faster, but more expensive, a PAL slower, but cheaper." CreationDate="2010-10-29T19:47:23.353" UserId="1225" />
  <row Id="7122" PostId="5841" Text="What model iPod is it?  For example, in the 2nd gen iPod nano (mine) the jack is on a [ribbon cable](http://guide-images.ifixit.net/igi/wRbEOwH1IKolfsXb.large).  Have you checked [ifixit](http://www.ifixit.com/)?" CreationDate="2010-10-29T19:51:58.300" UserId="857" />
  <row Id="7124" PostId="5842" Text="Yes, that is true. Given the voltage and current you need, you may be able to use a smaller inductor than 68 uH but probably not as low as 30. See formula on page 12 of the data sheet." CreationDate="2010-10-29T20:06:41.917" UserId="1764" />
  <row Id="7125" PostId="5844" Text="yeah , my soldering days were over a long long time ago and I did not do anything this small" CreationDate="2010-10-29T20:07:07.023" UserId="209" />
  <row Id="7126" PostId="5843" Text="Wow, that is great!  Unfortunately I don't have the manual dexterity or patience to make that fix...  I'll have to find someone who can." CreationDate="2010-10-29T20:13:21.317" UserId="209" />
  <row Id="7127" PostId="5811" Text="Stepper motors will give you feedback on their position, right?" CreationDate="2010-10-29T20:23:37.193" UserId="319" />
  <row Id="7128" PostId="5834" Text="a bypass capacitor, bulk capacitor, and decoupling can all mean the same thing. When someone says bulk, they will in general be using it as a &quot;power source&quot;. this is still a decoupling capacitor." CreationDate="2010-10-29T20:39:59.280" UserId="230" />
  <row Id="7129" PostId="5834" Score="3" Text="A bulk capacitor AFAIK is placed near the power rails of the battery/power source and next to large groups of components; a decoupling capacitor sits next to the Vdd pins. Both are bypass capacitors." CreationDate="2010-10-29T20:49:49.617" UserId="1225" />
  <row Id="7130" PostId="5824" Text="+1 for the the high resolution ADC" CreationDate="2010-10-29T21:16:40.383" UserId="1298" />
  <row Id="7131" PostId="5716" Text="I2C is also two lines." CreationDate="2010-10-29T21:39:34.113" UserId="883" />
  <row Id="7132" PostId="5511" Text="Doesn't the mbed need to to be powered by a power source?" CreationDate="2010-10-29T21:45:14.043" UserId="1657" />
  <row Id="7133" PostId="5827" Text="@endolith - they're vintage parts, but check out the PLA 16R8 or GAL 22V10 for example; they have register capable outputs which are also fed back into the input matrix, so you could get PLD devices to store states even back in 1988." CreationDate="2010-10-29T22:03:04.797" UserId="740" />
  <row Id="7134" PostId="5827" Text="My digitising oscilloscope has two or three PALs (the third IC is not mentioned in the service manual but it's in a similar package), it was manufactured in '93." CreationDate="2010-10-29T22:11:20.653" UserId="1225" />
  <row Id="7135" PostId="5851" Text="8 MHz could be divided by 69 to get 115,942 which is well within ±1%. I'm wondering if the PIC supports this type of division for its baud rate generator. I'm hoping so, but I don't think it will." CreationDate="2010-10-29T22:40:30.007" UserId="1225" />
  <row Id="7137" PostId="5851" Text="The PIC has a baud rate generator. It would work well but only for lower baud like 9600, it wouldn't work for high baud like 115,200, it becomes too imprecise." CreationDate="2010-10-29T22:44:21.873" UserId="1225" />
  <row Id="7138" PostId="5851" Text="Do you think I could use a 7.3728 MHz crystal? (I'm not going to use the internal 7.37 MHz oscillator because I'd like precision.) It allows me to divide by 64 to get a UART frequency of 115,200. It's the fastest I can go with a high tolerance." CreationDate="2010-10-29T22:49:58.390" UserId="1225" />
  <row Id="7139" PostId="5851" Text="if your UART supports it, it's preferable to give it an overclock (like 16x) so that it can oversample the start bit and find the center of the bit cell, but getting a 16x for 115K to within 1% could be a challenge, unless you use a baud-multiple crystal." CreationDate="2010-10-29T22:54:16.217" UserId="740" />
  <row Id="7140" PostId="5852" Text="Actually, from reading the comments on adafruit, the connectors could be to the keypad and LCD, with the bottom side of the board having the processor, but it's unclear." CreationDate="2010-10-29T23:44:38.657" UserId="1225" />
  <row Id="7141" PostId="1166" Text="Not as fast as a Metcal - small tips get up to temp in about 6 seconds, large ones maybe 10-15 secs max..." CreationDate="2010-10-29T23:54:08.370" UserId="1681" />
  <row Id="7142" PostId="5815" Text="Why? A low-end PIC is often cheaper and more flexible than a special-purpose IC. If you can live with a protocol simpler/slower than I2C, a 10F or 12F series device could easily do it. " CreationDate="2010-10-29T23:56:16.733" UserId="1681" />
  <row Id="7143" PostId="5827" Text="Well Wikipedia said it was combinational only.  So PLAs can do some things ROMs cant." CreationDate="2010-10-30T00:31:12.173" UserId="142" />
  <row Id="7144" PostId="5827" Text="Interesting. I'm only going by knowledge I've picked up on the 'net; most people seem to use FPGA's or CPLD's now anyway, not PLA's." CreationDate="2010-10-30T00:32:13.670" UserId="1225" />
  <row Id="7145" PostId="5853" Score="1" Text="How many wires per cable?" CreationDate="2010-10-30T00:37:05.333" UserId="1322" />
  <row Id="7146" PostId="5853" Text="Good point - I need 4 way. I've edited the question appropriately." CreationDate="2010-10-30T00:43:34.157" UserId="1225" />
  <row Id="7147" PostId="5827" Text="yeah, the old 16L8 'R8 PAL type things are pretty retro, and even the GAL series that replaced them is old school, but even so, they're pretty useful at scrunching together a few logic functions, without going all the way to an FPGA. They also have the advantage of not having to load up their config from a serial rom at power up." CreationDate="2010-10-30T00:52:55.337" UserId="740" />
  <row Id="7148" PostId="5851" Text="Thanks for your explanation on UART baud rates." CreationDate="2010-10-30T01:07:29.270" UserId="1225" />
  <row Id="7149" PostId="5719" Text="I know. Hence the original question." CreationDate="2010-10-30T01:13:45.850" UserId="1633" />
  <row Id="7150" PostId="5773" Text="I wasn't aware that interpreters were considered VMs. It makes sense, though." CreationDate="2010-10-30T01:15:59.527" UserId="1374" />
  <row Id="7151" PostId="5831" Score="3" Text="F.Y.I, the reason for decade capacitors is the ESR of the caps decreases as the cap gets smaller. Therefore, if you have a situation which is very noise-sensitive, or draws very large current spikes, a 0.01 uf cap might be more effective than a 0.1 uf cap." CreationDate="2010-10-30T01:19:48.540" UserId="1374" />
  <row Id="7152" PostId="5856" Text="Oh well, I suspected this.  I'll just have to keep doing things my slow and clunky way, I guess.  (Oh, and no chance getting Atmel to do pre-programming for me, I'm just a lowly hobbyist. :-) )" CreationDate="2010-10-30T01:31:13.067" UserId="504" />
  <row Id="7153" PostId="5856" Text="Microchip charges ~$40 &quot;setup fee.&quot; Again, unsure about Atmel. If you're ordering in the 10-100 range, it's probably worth it." CreationDate="2010-10-30T01:33:08.297" UserId="1225" />
  <row Id="7154" PostId="5832" Score="1" Text="The zero padding should be at least N = size(a)+size(b)-1, preferably rounded up to a power of 2. To get a value between -1 and 1, divide by norm(a)*norm(b), which gives the cosine of the angle between the two vectors in N-space for the given lag (i.e. circular shift modulo N). At the extreme lags, there aren't many overlapping samples (only one at the far extreme), so dividing by norm(a)*norm(b) will bias these correlations toward 0 (i.e. showing their relative orthogonality in N-space)." CreationDate="2010-10-30T01:41:59.713" UserId="721" />
  <row Id="7155" PostId="5640" Text="When you say rectifier, do you mean the input filter, or the output filters? It's an active PFC supply and uses a massive 470µF 400V capacitor." CreationDate="2010-10-30T01:57:51.147" UserId="1225" />
  <row Id="7156" PostId="5857" Text="Thanks for the link - that's exactly what I'm after.  I'm not actually using a real AVR ISP - just an appropriately programmed arduino. (!) I'm replacing this with a Bus Pirate in a few days, so throwing together a board with ZIF sockets is definitely something I'm planning to do. My current procedure is extremely ugly!" CreationDate="2010-10-30T02:23:32.673" UserId="504" />
  <row Id="7157" PostId="5768" Text="pondered some more, and recalled that actually, the 'switch hook' switch disconnects the handset and connects the ringer when the handset it is 'on the hook'. conversely, off the hook the handset is connected, and the local office circuits sense this and just don't send the 90V ringing signal." CreationDate="2010-10-30T02:28:06.783" UserId="740" />
  <row Id="7158" PostId="5859" Text="+1 - this looks neat and perfect for what I want. But I'm worried about Digi-Key in that they say that no taxes are included. I live in the UK, so who do I pay VAT to?" CreationDate="2010-10-30T02:29:24.987" UserId="1225" />
  <row Id="7159" PostId="5831" Text="Agreed, there is an impedance component also, but I would agree." CreationDate="2010-10-30T05:10:40.573" UserId="230" />
  <row Id="7160" PostId="5867" Text="I'm not sure what you are talking about in the circuit.  The link provided just brings up an RLC circuit example." CreationDate="2010-10-30T05:59:13.243" UserId="1477" />
  <row Id="7161" PostId="5860" Score="1" Text="What is the other end of the USB cable plugged into?" CreationDate="2010-10-30T06:34:25.293" UserId="712" />
  <row Id="7162" PostId="5866" Score="3" Text="I think Kortuk is on the right track. Try putting a 5 V / 0.1 A = 50 ohm resistor in series with the switch." CreationDate="2010-10-30T06:36:02.190" UserId="712" />
  <row Id="7163" PostId="5511" Score="1" Text="It's powered over the USB cable, although the pins are available so that you could power it separately." CreationDate="2010-10-30T07:09:39.193" UserId="103" />
  <row Id="7164" PostId="5856" Score="1" Text="I've programmed plenty of boards with other loads on the SPI pins, particularly LEDs, with no problems at all. Just be careful not to have anything else drive the signals.&#xA;This means, for instance, if you have an SPI device connected, give it a pull up resistor or similar to keep that too in reset or unselected." CreationDate="2010-10-30T07:54:19.373" UserId="1181" />
  <row Id="7165" PostId="5859" Text="VAT is paid to the UPS delivery guy on delivery. You can set up a UPS account to avoid this hassle.  " CreationDate="2010-10-30T09:27:41.070" UserId="1681" />
  <row Id="7166" PostId="5867" Text="This looks like a non-symmetrical relaxation oscillator, but it is drawn unusually. I've seen them drawn like this before." CreationDate="2010-10-30T10:07:27.773" UserId="1225" />
  <row Id="7168" PostId="5346" Text="Hardly any other part in the world is made by so many different companies as the 431. The differently pinned versions made by TI very likely reflect the fact that there are even some 431s out there (made by others than TI) that sell as 431s. I thin it's all about second sourcing and purchase departments constantly going for the cheapest option. By the way: I think that meanwhile the 431 outnumbers the 555. Just think about all the switchers for PCs, cell phones and the like. Most do use the 431." CreationDate="2010-10-30T10:11:24.510" UserId="930" />
  <row Id="7169" PostId="5880" Text="@Thomas O: but I read that You can't use these functions, but instead function 2*max(A,B) works perfect, can You explain this please?" CreationDate="2010-10-30T10:46:26.367" UserId="1760" />
  <row Id="7170" PostId="5880" Score="1" Text="What type of logic are you dealing with, are we dealing with theory or some kind of program for simulating logic?" CreationDate="2010-10-30T10:47:36.973" UserId="1225" />
  <row Id="7171" PostId="5880" Text="@Thomas O: I've just read it from one book(not in English), they are dealing with analog signals and functions of static discipline and there they are dealing with those kinds of functions to implement OR gate" CreationDate="2010-10-30T10:54:18.427" UserId="1760" />
  <row Id="7172" PostId="5871" Text="I suppose people will have these sort of questions during the start of their career.." CreationDate="2010-10-30T10:56:15.713" UserId="1484" />
  <row Id="7173" PostId="5882" Text="I encountered a similar problem with my PICkit 2 and some dsPICs. I had neglected to connect the Vdd and Vss connector on the PICkit 2 to my circuit Vdd/Vss, which was causing all sorts of intermittent problems. Adding my scope probe would sometimes make it work." CreationDate="2010-10-30T11:21:50.423" UserId="1225" />
  <row Id="7176" PostId="5880" Text="I'm unsure; I suppose you could use comparators to implement the max or min function..." CreationDate="2010-10-30T11:41:32.153" UserId="1225" />
  <row Id="7177" PostId="5847" Text="@Nat Ryall - well, 'smoothing' is practically the same thing as decoupling, just at a lot lower frequency. Basically if you have a nearly constant load on a decent size battery, you probably can get away w/o bulk capacitance, BUT, if your system is going to switch on motors or relays, turn on a transmitter, or do anything else to suddenly pull in gobs of current, or even just fluctuate over a wide range, bulk capacitors are a good idea, for the same basic principle as decoupling." CreationDate="2010-10-30T11:49:54.160" UserId="740" />
  <row Id="7178" PostId="5885" Text="Perfect. I'm just wondering if these are available from bigger distributors. Also if I can get them in the UK. These are pretty much what I'm looking for." CreationDate="2010-10-30T11:57:14.480" UserId="1225" />
  <row Id="7179" PostId="5886" Text="Thanks this the type of info Im looking for. How will you identify the start of the frame? " CreationDate="2010-10-30T12:12:52.927" UserId="819" />
  <row Id="7180" PostId="5878" Text="&quot;huge stage-machine&quot; - that sounds like a Broadway production." CreationDate="2010-10-30T12:13:55.360" UserId="1084" />
  <row Id="7181" PostId="5886" Text="Probably use some sequence like 0xff 0x00 0xff 0x00, or, I could use only a serial interface (Xbees transmit up to 8-bit parallel) and have a wire to specify when a radio is talking. " CreationDate="2010-10-30T12:18:13.200" UserId="1225" />
  <row Id="7182" PostId="5883" Text="You could use FETs instead of NPNs :)" CreationDate="2010-10-30T13:25:51.177" UserId="142" />
  <row Id="7183" PostId="5862" Score="1" Text="does it haves analog inputs?" CreationDate="2010-10-30T13:28:03.183" UserId="1539" />
  <row Id="7184" PostId="5831" Text="decade capacitors: http://electronics.stackexchange.com/questions/3879/frequency-dependence-of-electrolytic-capacitors" CreationDate="2010-10-30T13:49:31.043" UserId="142" />
  <row Id="7185" PostId="5879" Score="5" Text="This question needs more context." CreationDate="2010-10-30T13:51:24.897" UserId="142" />
  <row Id="7186" PostId="5798" Text="Thanks. You wouldn't happen to have any other links that aren't a wall of text and feature some schematics? :-)" CreationDate="2010-10-30T16:11:51.903" UserId="1124" />
  <row Id="7187" PostId="5860" Text="It's connected to the multimeter." CreationDate="2010-10-30T16:32:23.930" UserId="1657" />
  <row Id="7188" PostId="5862" Score="2" Text="What does &quot;It has got UART support which is the most economic one that makes burning code into it absolutely cool&quot; mean?" CreationDate="2010-10-30T16:53:07.293" UserId="883" />
  <row Id="7189" PostId="5888" Text="&quot;Now I don't see the battery voltage here&quot; -- if you hover over any of the components in the circuit, additional details appear in the lower right corner.  The battery is 9v." CreationDate="2010-10-30T17:21:54.990" UserId="1322" />
  <row Id="7190" PostId="5883" Text="That's why I added this: &quot;Real processors rarely use BJT's, but instead CMOS logic, but the same principles apply.&quot; n-JFETs and n-MOSFET's would probably work as well as more estoric forms like valves." CreationDate="2010-10-30T18:18:41.570" UserId="1225" />
  <row Id="7191" PostId="5798" Score="2" Text="This just goes to show that patents are evil and only hinder development. :)" CreationDate="2010-10-30T19:31:45.453" UserId="883" />
  <row Id="7193" PostId="5798" Text="There are two sides to that XTL, it also protects those that invent something amazing. I have quite a few problems with the patent system, but there are some things it does correctly." CreationDate="2010-10-30T20:25:24.613" UserId="230" />
  <row Id="7194" PostId="5905" Score="1" Text="* RST is tied high with a 10K resistor&#xA;* Power is good. 9v wall wart feeding a AP1086-33 regulator. There's no power coming from the USBtinyISP, as I have that jumper off&#xA;* Brownout fuses are all disabled&#xA;* There are 100uF decouping caps on both sides (Vin and Vout) of the regulator.&#xA;* It can blink an LED with the LCD both connected and disconnected" CreationDate="2010-10-30T20:56:35.583" UserId="746" />
  <row Id="7195" PostId="5905" Text="Can you post a schematic, or a picture of your circuit on a breadboard?" CreationDate="2010-10-30T20:58:52.963" UserId="566" />
  <row Id="7196" PostId="5905" Text="Schematic is available here: http://duksta.org/images/ProtoBreakout.png" CreationDate="2010-10-30T21:06:10.147" UserId="746" />
  <row Id="7197" PostId="5905" Text="sorry if you hit my hotlink image. just removed that rewrite rule. :/" CreationDate="2010-10-30T21:08:45.137" UserId="746" />
  <row Id="7198" PostId="1802" Text="I couldn't install it on Windows 7 x64. This is the first installer that tells me that I should ask for a platform specific version" CreationDate="2010-10-30T22:17:50.297" UserId="1298" />
  <row Id="7199" PostId="5888" Text="@tcrosley - ah. i normally run my browser with a boat load of script blockers, that must be why when i hover the mouse over a component it only just turns blue." CreationDate="2010-10-30T22:24:26.013" UserId="740" />
  <row Id="7201" PostId="5905" Text="You might want to try asking this question on avrfreaks.com - though, we'll do the best we can" CreationDate="2010-10-30T22:54:13.277" UserId="566" />
  <row Id="7202" PostId="5891" Text="Just to note, you make it sound like as soon as you hit 10k cycles the chip will just immediately fail. 10K is just the expect length. It is possible for your flash to last 100 million cycles, but it can also last just 100 cycles, and everything in between. Most manufactures try to hide their expected distribution though." CreationDate="2010-10-30T23:27:15.610" UserId="319" />
  <row Id="7203" PostId="5891" Text="I thought 10k was the minimum guaranteed value, that is some will do 10k, others will do 100k but under normal conditions they will do at least 10k." CreationDate="2010-10-30T23:33:25.163" UserId="1225" />
  <row Id="7204" PostId="3111" Text="I've been playing with the CC11xx too: http://blog.hodgepig.org/2010/10/22/im-me-usb-dongle-hacking/" CreationDate="2010-10-30T23:45:18.677" UserId="566" />
  <row Id="7205" PostId="5763" Text="Might be time to start stocking up on incandescent lamps..." CreationDate="2010-10-31T00:04:34.850" UserId="1307" />
  <row Id="7206" PostId="5913" Text="I thought SD and MMC were not compatible command wise?" CreationDate="2010-10-31T00:12:45.393" UserId="1225" />
  <row Id="7207" PostId="5915" Score="2" Text="PIC32's are not ARM processors. They are a mix of MIPS and a few custom features. An STM32 is an example of a microcontroller with an ARM processor." CreationDate="2010-10-31T00:16:49.353" UserId="1225" />
  <row Id="7208" PostId="5916" Text="atmel maybe????" CreationDate="2010-10-31T00:19:13.593" UserId="1539" />
  <row Id="7209" PostId="5914" Text="not a pic, but any microcontroller???????" CreationDate="2010-10-31T00:20:36.167" UserId="1539" />
  <row Id="7210" PostId="5916" Score="1" Text="Point me to an Atmel AVR (or AVR32) with at least 1MB onboard data memory and a supported architecture. They might exist, but I don't think so." CreationDate="2010-10-31T00:20:50.520" UserId="1225" />
  <row Id="7211" PostId="5914" Score="1" Text="@Andrew, it's OK for you to edit your question as you refine it" CreationDate="2010-10-31T00:26:17.880" UserId="566" />
  <row Id="7212" PostId="5914" Text="You might be able to use a more powerful microcontroller which is based on an ARM architecture, such an STM32 with external memory. You'd need at least 1 MB to even boot Linux to a shell prompt, and probably 32 MB+ to get Android up and running. However, that being said even if it does work, it will cost far more than a CPU+memory solution would, or a simple solution like the BeagleBoard which Joby Taffey suggested." CreationDate="2010-10-31T00:26:44.837" UserId="1225" />
  <row Id="7213" PostId="5918" Text="Thanks for your answer, so it looks like linear is out for this. I'd be okay using a DPAK. I think I'm getting SOT-89 confused with another type, SOT-223, which is much bigger." CreationDate="2010-10-31T00:29:12.773" UserId="1225" />
  <row Id="7214" PostId="5915" Text="Ugh, that was a rather large think-o. Yes, you're absolutely right, they're MIPS based, not ARM based. Sorry for the misinformation. The other points are still valid, though. :-)" CreationDate="2010-10-31T00:29:24.220" UserId="974" />
  <row Id="7215" PostId="5915" Text="Don't worry we all have them... like my &quot;why isn't my interrupt firing... oh crap it's plugged into the wrong pin&quot; moment which occurred after 2 days debugging a problem." CreationDate="2010-10-31T00:30:57.423" UserId="1225" />
  <row Id="7218" PostId="5881" Text="To test your data format you can simulate what radio will do to it. Drop random bytes and flip random bits. By doing this, you should be able to test your sync and checksum systems" CreationDate="2010-10-31T00:53:36.670" UserId="566" />
  <row Id="7219" PostId="5921" Text="i quit =x&#xA;&#xA;thanks for your experience" CreationDate="2010-10-31T02:08:38.717" UserId="1539" />
  <row Id="7220" PostId="5921" Text="ps.: what can I do with 2 or 3 altoids boxes?! must be an RCA adapter for video. thanks" CreationDate="2010-10-31T02:09:30.180" UserId="1539" />
  <row Id="7221" PostId="5921" Text="Can't do much with just 2 or 3 Altoids boxes. Maybe make 2 or 3 high-voltage, low-value capacitors? Or some sort of storage system for mints?" CreationDate="2010-10-31T02:26:01.647" UserId="712" />
  <row Id="7222" PostId="5921" Text="i want to do semething like the ybox http://www.ladyada.net/make/ybox2/" CreationDate="2010-10-31T02:43:55.537" UserId="1539" />
  <row Id="7223" PostId="5913" Score="1" Text="Well... it actually depends on the SD card, but most (not all, but almost, it is hard to find one SD that doesn't support mmc mode) of the SD cards support MMC commands, which is good.  Some info: http://www.freelabs.com/~whitis/sd_card/ and http://www.nxp.com/documents/application_note/AN10406.pdf " CreationDate="2010-10-31T03:08:25.413" UserId="1777" />
  <row Id="7224" PostId="5921" Score="2" Text="Maybe try the Chumby Hacker Board? http://www.adafruit.com/index.php?cPath=46&amp;main_page=product_info&amp;products_id=278" CreationDate="2010-10-31T03:27:51.837" UserId="712" />
  <row Id="7225" PostId="5904" Text="Thanks!  Moving the load closer to +6V and the transistor closer to +0V worked, though it was a pain to rewire the LED harness for common anode instead of common cathode.  PNP was too hard to test, as showtime is tomorrow." CreationDate="2010-10-31T05:10:07.990" UserId="1271" />
  <row Id="7226" PostId="5728" Text="I don't think BGAs are ever anything but &quot;High Density&quot;" CreationDate="2010-10-31T06:20:21.577" UserId="1374" />
  <row Id="7227" PostId="5918" Text="You have lots of vias for heatsinking.... but then you're thermally relieving the heatsink contact pad. Wut?" CreationDate="2010-10-31T06:21:29.343" UserId="1374" />
  <row Id="7228" PostId="5728" Text="High-density generally refers to packages with 1000 balls or more. Smaller packages are comparatively easy to work with. I've used a Telit BGA module with 84 balls on a double-sided PCB, that was very easy. Some of the new chip-scale packages only have 16 balls." CreationDate="2010-10-31T10:02:07.940" UserId="305" />
  <row Id="7230" PostId="5929" Score="6" Text="This is a community forum, answers should be posted here and not emailed to your personal email address, the questions and answers on this site are made public for the benefit of everyone  " CreationDate="2010-10-31T12:30:29.427" UserId="399" />
  <row Id="7231" PostId="5930" Score="3" Text="http://www.sillanumsoft.org/ has an oscilloscope / waveform generator that can output a sine wave to the sound card with whatever frequency you want" CreationDate="2010-10-31T14:58:56.387" UserId="142" />
  <row Id="7232" PostId="5932" Text="Microchip has stated that it's because the chip can be made cheaper, if it doesn't include the debug hardware." CreationDate="2010-10-31T16:06:57.620" UserId="305" />
  <row Id="7233" PostId="5936" Text="I've actually already built a capacitor, charging it is the only problem." CreationDate="2010-10-31T16:17:12.100" UserId="1781" />
  <row Id="7235" PostId="5834" Score="1" Text="it is still attempting to decouple groups of components from other groups of components, and often larger current pull ICs have a bulk capacitor to themselves." CreationDate="2010-10-31T16:52:32.350" UserId="230" />
  <row Id="7236" PostId="5930" Score="2" Text="He specifically said that it needs to control a variable oscillator, not be a variable oscillator." CreationDate="2010-10-31T17:14:36.937" UserId="319" />
  <row Id="7237" PostId="5932" Text="That too could be a factor." CreationDate="2010-10-31T17:18:00.927" UserId="1225" />
  <row Id="7238" PostId="5921" Score="1" Text="These comments have nothing to do with the original question. Pingswept, as a mod you should be identifying things like this and suggesting he creates a new question instead of answering him here." CreationDate="2010-10-31T17:18:12.067" UserId="319" />
  <row Id="7239" PostId="5930" Text="What would be the fundamental difference? (apart from this external oscillator probably being much more powerful.)" CreationDate="2010-10-31T17:18:29.927" UserId="1225" />
  <row Id="7240" PostId="5937" Text="Thermal vias increase thermal impedence - they are designed to make it easier to solder because they conduct less heat, right?" CreationDate="2010-10-31T17:19:45.293" UserId="1225" />
  <row Id="7241" PostId="5916" Text="@Thomas, you can always add memory to a microcontroller. You can then have your micro start up on a small amount of system memory and boot from the memory connected. The issue with getting linux to run on it is compiling it to do what you want it to do." CreationDate="2010-10-31T17:21:07.880" UserId="319" />
  <row Id="7242" PostId="5916" Text="Well, yeah, but why would you go to the bother of adding external logic to get a few megabytes extra when you could use a processor designed for the task in the first place? Microcontrollers are not CPUs and are not designed to run big kernels like Linux." CreationDate="2010-10-31T17:23:31.110" UserId="1225" />
  <row Id="7243" PostId="5930" Text="I would have to see what he has. He could have a chip that has SPI that you are able to set its frequency with. His question is very vague in this sense." CreationDate="2010-10-31T17:24:25.613" UserId="319" />
  <row Id="7244" PostId="5930" Text="In which case he could use an FTDI chip and communicate with an MCU on the same board as his oscillator IC..." CreationDate="2010-10-31T17:25:13.637" UserId="1225" />
  <row Id="7245" PostId="5930" Text="Excuse me for the lack of tact - But I don't think English is VAHID's first language, and I have heavily formatted their question to try make sense of it - therefore it's probably necessary to request more information before the question can be answered properly. " CreationDate="2010-10-31T17:28:29.917" UserId="399" />
  <row Id="7246" PostId="5930" Text="Yes, that is a very large fundamental difference though, which is my original point." CreationDate="2010-10-31T17:28:45.827" UserId="319" />
  <row Id="7247" PostId="5929" Text="@ VAHID - In order to answer your question properly it would help if you gave some more details. For example - Do you have an oscillator circuit in mind? Are you looking for a software based solution? Do you plan to use a micro controller with your project? Do you have any particular application in mind for your project? " CreationDate="2010-10-31T17:32:35.137" UserId="399" />
  <row Id="7248" PostId="5938" Score="2" Text="+1 for recommending 18F over 16F." CreationDate="2010-10-31T17:32:48.287" UserId="1333" />
  <row Id="7249" PostId="5939" Text="I'm trying to avoid a buck, but I think I'll have to go with buck anyway." CreationDate="2010-10-31T17:52:34.923" UserId="1225" />
  <row Id="7250" PostId="5939" Text="I have avoid bucks for awhile, but I have come to realize that I just have to use them some times. They do add some complexities and cost, but they are well worth it when you are having to step down a large voltage or output lots of current." CreationDate="2010-10-31T19:12:29.457" UserId="319" />
  <row Id="7251" PostId="5891" Score="1" Text="Nope, it actually is all statistical based. Light bulbs are rated in the same fashion. They will advertise x number of burning hours, but they might fail much earlier then x and still be statistically reasonable. A manufacture can't really guarantee a minimum number of cycles, they are just giving you what their expected life is." CreationDate="2010-10-31T19:19:58.030" UserId="319" />
  <row Id="7252" PostId="5918" Text="The vias are to connect the 4 layers of copper together as well as to add more metal. I thermally relieve the contact pad so I can actually solder the damn thing to the board. :-) The idea is to give it some mass for the heat to go but to keep a little bit of thermal resistance for actual manufacture." CreationDate="2010-10-31T19:38:40.927" UserId="974" />
  <row Id="7253" PostId="5921" Text="That seems heavy-handed to me, but I'm happy to go along with it if Andrew wants to turn his comment into a question." CreationDate="2010-10-31T19:53:24.097" UserId="712" />
  <row Id="7254" PostId="5903" Text="I've got some more data.&#xA;&#xA;It runs ok with the LCD attached and the ISP disconnected if I set it on a pad of anti-static material. However, if I touch it or hit one of the buttons, it hangs.&#xA;&#xA;If I use a 9v battery instead of the wall wart, it runs better and doesn't require the anti-static mat. So, I think I've got a grounding or ESD issue." CreationDate="2010-10-31T20:32:18.577" UserId="746" />
  <row Id="7255" PostId="5932" Text="I know both price and number of pins affect the decision on that." CreationDate="2010-10-31T20:32:49.497" UserId="230" />
  <row Id="7256" PostId="5943" Text="What does the trace look like when connected to the waveform generator?  Assuming it is a 1 KHz square wave, you should see a very clean waveform.  If not, something is wrong.  Also, CH1 and CH2 should both show the same thing." CreationDate="2010-10-31T20:58:23.290" UserId="1322" />
  <row Id="7257" PostId="5943" Text="I see a 1KHz waveform with the noise (added above)." CreationDate="2010-10-31T21:13:42.163" UserId="1333" />
  <row Id="7258" PostId="5916" Text="by nature of being a processor the memory must be external, at least to my knowledge. Sounds like in both cases you need external memory." CreationDate="2010-10-31T21:20:24.773" UserId="230" />
  <row Id="7259" PostId="5943" Score="3" Text="The second trace looks normal for a scope with an 8-bit resolution.  As Kortuk mentioned in his answer, the trace can normally jitter back and forth 1 step of the ADC even on a stable signal.  There are 256 steps for a 8-bit ADC, so that is what is causing the line not to be perfectly straight but have little bumps.  This is normal for any DSO.  More expensive ones have ADC's with more bits (9, 10, 14, and 16 are most common in addition to 8), so the effect isn't as noticeable.  As long as CH1 shows essentially the same thing, it appears to be working okay." CreationDate="2010-10-31T21:43:31.663" UserId="1322" />
  <row Id="7260" PostId="5945" Score="1" Text="+1 from me. Gives a great reference if others see the same thing. I tried to add more about how to reduce noise, but there is always a chance it is just the systems noise." CreationDate="2010-10-31T22:24:05.890" UserId="230" />
  <row Id="7261" PostId="5941" Text="They can get charge without loosing charge on the other plate with this method. If you charge something to a voltage and then touch one side of a cap with the other side held at a reference you will add extra charge to that side. The physical effects are not measurably different though." CreationDate="2010-10-31T22:26:27.073" UserId="230" />
  <row Id="7262" PostId="5942" Text="Tie one to ground, and just pop current in the other. There is not really a better method. Well done JustJeff." CreationDate="2010-10-31T22:26:48.180" UserId="230" />
  <row Id="7263" PostId="5941" Text="The reason a capacitor stores so much is because Capacitance is the measure of amount of charge moved for 1 V of difference. As you increase epsilon, A or decrease D it takes a much larger amount of charge to get 1V." CreationDate="2010-10-31T22:27:54.310" UserId="230" />
  <row Id="7264" PostId="5944" Text="As a side note, I clearly left out sources of noise that come from the circuit itself. There is not enough time in the day to cover all of that in one post someone will read." CreationDate="2010-10-31T22:31:06.040" UserId="230" />
  <row Id="7265" PostId="5930" Text="There are also VCO that when you vary a DC voltage the oscillator has a variance in frequency, this is something I know many people attempt to use a computer to control." CreationDate="2010-10-31T22:35:34.227" UserId="230" />
  <row Id="7266" PostId="5929" Score="1" Text="Since the original post asked for emails, I emailed him to check that he was not waiting for emails and would come back and add information. If he fails to add more details it would seem this question is too vague." CreationDate="2010-10-31T22:38:40.230" UserId="230" />
  <row Id="7267" PostId="5945" Text="Thanks for the reference. Another thing I noticed is the DSO-2090 can only enter &quot;rolling&quot; mode at a 1s/div which isn't very helpful when looking at fast oscillations (as the resolution just isn't available.) Is this likely to become a problem in the future? (I can still return it)" CreationDate="2010-10-31T22:42:58.323" UserId="1333" />
  <row Id="7268" PostId="5946" Score="1" Text="+1 Interesting note. I am so use to working at big stations I forget you could use a laptop and neglect the issue to some extent." CreationDate="2010-10-31T22:47:00.643" UserId="230" />
  <row Id="7269" PostId="5945" Text="@Nat, don't know what you mean by &quot;rolling mode&quot;." CreationDate="2010-10-31T22:47:41.887" UserId="1322" />
  <row Id="7270" PostId="5945" Text="You are going to really have to look at what you need it for. It is hard to say one way or another." CreationDate="2010-10-31T22:47:44.730" UserId="230" />
  <row Id="7272" PostId="5942" Text="@justjeff, Sorry if that was confusing. Your post was the first post I came across as I read down the list of posts that actually answered the question. Most people are telling how to build a capacitor or how capacitors work. He asked how to use it to charge a cap, that is what you answered." CreationDate="2010-10-31T22:50:22.717" UserId="230" />
  <row Id="7274" PostId="5916" Text="Some mobile processors have memory on the die, or in a die-on-die configuration." CreationDate="2010-10-31T22:52:24.367" UserId="1225" />
  <row Id="7275" PostId="5945" Text="@tcrosley: &quot;Rolling&quot; in this software is a continuous acquisition mode where it draws (and scrolls) across the screen as time passes." CreationDate="2010-10-31T22:53:06.873" UserId="1333" />
  <row Id="7277" PostId="5945" Score="2" Text="I don't think it is a very common feature, I looked up DSO + &quot;rolling mode&quot; on Google and found that it is primarily for looking at changes to slow-moving signals (e.g. see &quot;roll mode&quot; in www.crupower.fi/DSO.pdf ) -- so it isn't intended for fast signals." CreationDate="2010-10-31T22:58:15.367" UserId="1322" />
  <row Id="7278" PostId="5945" Text="Ah brilliant, thanks for clearing that up." CreationDate="2010-10-31T23:06:33.380" UserId="1333" />
  <row Id="7279" PostId="5919" Text="Thanks, some useful points if I end up using the API mode. " CreationDate="2010-10-31T23:09:40.613" UserId="819" />
  <row Id="7280" PostId="5945" Text="@Nat, note that the Rigol DS-1052E, which I believe you were also looking at, also has an 8-bit vertical resolution, so you are going to see some of the same 1-bit noise issues: http://www.rigolna.com/products/digital-oscilloscopes/ds1000e/ds1052e/" CreationDate="2010-10-31T23:09:44.887" UserId="1322" />
  <row Id="7281" PostId="5950" Score="4" Text="Please do remember, we rectify AC to DC and then use that in computers normally, This is our reference. they do technically run off of AC in that sense. I know this is not what you asked, which is why it is a comment." CreationDate="2010-10-31T23:30:05.597" UserId="230" />
  <row Id="7282" PostId="5950" Text="Not only is it impossible for transistors to work with AC, but many can be damaged by it." CreationDate="2010-10-31T23:30:12.230" UserId="1225" />
  <row Id="7283" PostId="5952" Text="Well, using a different via means a different drill size, right? Surely they can't have a drill size for everything, so do they have to make up drill bits?" CreationDate="2010-10-31T23:34:51.397" UserId="1225" />
  <row Id="7284" PostId="5950" Score="1" Text="It is not impossible for transistors to work with AC, just this specific application would be hell and a Half. " CreationDate="2010-10-31T23:35:25.463" UserId="230" />
  <row Id="7285" PostId="5952" Text="They could use a 5 mill drill bit and move it in a circle to generate almost any size. I have also seen methods that use a laser." CreationDate="2010-10-31T23:36:16.167" UserId="230" />
  <row Id="7286" PostId="5952" Text="Well, that solves that problem then. What about the via's rivets?" CreationDate="2010-10-31T23:37:20.380" UserId="1225" />
  <row Id="7287" PostId="5952" Text="Also, what's the average cost per via?" CreationDate="2010-10-31T23:37:36.840" UserId="1225" />
  <row Id="7288" PostId="5952" Text="You are getting into something that falls into &quot;too localized.&quot; This question is going to have an answer that varies by manufacturer. " CreationDate="2010-10-31T23:41:03.523" UserId="230" />
  <row Id="7289" PostId="5950" Text="I don't know of any transistor that can switch AC. Maybe a JFET because sometimes source and drain can be reversed." CreationDate="2010-10-31T23:47:32.073" UserId="1225" />
  <row Id="7290" PostId="5948" Score="1" Text="What are you wanting to do with the boards? I am sure each board has its own application where it thrives." CreationDate="2010-10-31T23:48:25.447" UserId="319" />
  <row Id="7292" PostId="5950" Score="1" Text="I used an AC wave that is has a zero mean value(no dc offset) but there is no reason that I could not use a DC offset signal. Also, I have seen rectifiers designed with MOSFETS, you just need to protect against a body-Diode problem. BJTs are normally doped to cause large negative reverse current, but that does not mean they would fail." CreationDate="2010-10-31T23:50:05.460" UserId="230" />
  <row Id="7293" PostId="5937" Text="Thermal relief on vias increase thermal impedance. A bed of vias to the ground plane on the other side really decreases thermal conductance." CreationDate="2010-10-31T23:54:05.037" UserId="230" />
  <row Id="7294" PostId="5953" Text="Basic things: power supply, programmer?" CreationDate="2010-11-01T00:22:01.997" UserId="1225" />
  <row Id="7295" PostId="5954" Text="Have you look at buck-boost ICs?" CreationDate="2010-11-01T00:38:13.030" UserId="319" />
  <row Id="7296" PostId="5954" Text="can you put numbers to things like &quot;minimize surface area&quot;? what kind of range would you consider acceptable?" CreationDate="2010-11-01T00:39:00.003" UserId="230" />
  <row Id="7297" PostId="5953" Score="1" Text="@Anonymous Type, I think you may have misunderstood Thomas O. I believe is he talking about a device that will actually program the board." CreationDate="2010-11-01T00:44:08.937" UserId="319" />
  <row Id="7298" PostId="5642" Score="1" Text="@mikeselectricstuff, Can I cite you as legal advice?" CreationDate="2010-11-01T01:54:23.387" UserId="230" />
  <row Id="7299" PostId="5952" Text="If you're smallest drill is 20 mil (roughly 17 mil vias after plating), most fab houses won't charge you extra. Some places will go as small as 12 mil after plating with no extra charge. But Kortuk is right-- each fab house has a list of 5-10 drills that are free, so there is no general answer to the question." CreationDate="2010-11-01T03:14:34.047" UserId="712" />
  <row Id="7300" PostId="3927" Text="You could also use Insteon, from smarthome.com, who offer plug-in modules, duplex outlets (top half remotely controlled), and wall switches (tap top for on, bottom for off; not exactly the same as a conventional switch, but may pass your transparency requirement." CreationDate="2010-11-01T03:21:24.007" UserId="1295" />
  <row Id="7301" PostId="1372" Text="With the MID400, does the resistor value vary with the anticipated input voltage range?" CreationDate="2010-11-01T03:24:09.870" UserId="1295" />
  <row Id="7302" PostId="5879" Text="It almost sounds like the questioner is asking how to implement a gate function in software." CreationDate="2010-11-01T04:33:40.723" UserId="965" />
  <row Id="7303" PostId="5892" Text="the link you posted was too good.. thanks.." CreationDate="2010-11-01T04:45:18.097" UserId="1484" />
  <row Id="7304" PostId="5893" Text="your strategy of explaining it by splitting the instructions made it really easy.. thanks.. " CreationDate="2010-11-01T04:48:12.060" UserId="1484" />
  <row Id="7305" PostId="5950" Score="1" Text="answers from Kortuk and Thomas are crisp and clear.." CreationDate="2010-11-01T04:54:26.510" UserId="1484" />
  <row Id="7306" PostId="5953" Text="my understanding is that boards such as tahoe can be hooked up to a PC and have a .net mf application copied across. I'm familiar with C# so this is the approach I'd like to take. I'll edit the question to try to be more specfic. Apologies to Thomas O." CreationDate="2010-11-01T05:13:37.803" UserId="1457" />
  <row Id="7307" PostId="2299" Text="In any automotive application you get nice spikes as other elements of the electrical system turn on and off (like the headlights).  Just spreading knowledge I learned elsewhere on this site :)" CreationDate="2010-11-01T05:23:51.260" UserId="1610" />
  <row Id="7308" PostId="5878" Text="Fortunately, the answers that these people had given doesn't make me scratch the surface as you mentioned, instead made it crystal clear.. Anyways, thanks pal.. " CreationDate="2010-11-01T05:35:55.477" UserId="1484" />
  <row Id="7309" PostId="1024" Text="I think it is to late to move this question, it is already part of this site.... If you would like to move this type of question it must be done before it gets this many upvotes. Focus on the new questions instead and make this question a exception..." CreationDate="2010-11-01T07:27:25.230" UserId="689" />
  <row Id="7310" PostId="5963" Text="spot on method for doing it.  Most distributors will offer this service directly or through an associate company, offer laser engraving (normally free) of the part, and re-reel to suit your manufacturer." CreationDate="2010-11-01T08:46:39.793" UserId="1397" />
  <row Id="7311" PostId="5945" Text="If you look at the screenshot though, the noise looks to be a bit more than 1-bit." CreationDate="2010-11-01T09:04:10.293" UserId="1333" />
  <row Id="7312" PostId="5945" Text="I think that is just due to the way the software is displaying the data.  I enlarged my screen capture, and most of the bumps are one line width high, except on the far right of each bottom trace which might be due to my probe compnesation being slightly off.  To make the trace more visible, the software is drawing the trace thicker than one pixel.  So the one-bit differences are exaggerated.  " CreationDate="2010-11-01T09:17:34.870" UserId="1322" />
  <row Id="7313" PostId="5954" Text="A buck boost would invert polarity." CreationDate="2010-11-01T09:36:01.500" UserId="1225" />
  <row Id="7314" PostId="5954" Text="I'm looking for &lt;250mm^2 area." CreationDate="2010-11-01T09:37:36.660" UserId="1225" />
  <row Id="7315" PostId="5930" Text="The output of a sound card is ac coupled so VAHID would need to modify a sound card to get it to work." CreationDate="2010-11-01T09:39:11.700" UserId="1225" />
  <row Id="7316" PostId="5945" Text="Righto, thanks." CreationDate="2010-11-01T10:17:36.443" UserId="1333" />
  <row Id="7317" PostId="5971" Score="2" Text="Of course, gEDA is Free Software - so you can fix it yourself :-)" CreationDate="2010-11-01T11:24:30.247" UserId="566" />
  <row Id="7318" PostId="5748" Text="@Thomas O  I wish I could give you more than one up-vote for mentioning electrician." CreationDate="2010-11-01T11:27:13.943" UserId="1240" />
  <row Id="7319" PostId="1372" Text="Yes.  The AC input is driving an LED, so you want to limit the current on the LED.  You can also set the current on the LED to control the saturation of the transistor…" CreationDate="2010-11-01T12:17:41.823" UserId="51" />
  <row Id="7320" PostId="1802" Text="I'm not sure. I've only used it in Windows XP." CreationDate="2010-11-01T12:40:03.270" UserId="588" />
  <row Id="7321" PostId="5971" Text="Hmm maybe it's a limitation of PCB..." CreationDate="2010-11-01T13:29:18.890" UserId="1225" />
  <row Id="7322" PostId="5696" Text="which wireless? zigbee?  what data rates for the ethernet?" CreationDate="2010-11-01T13:44:36.413" UserId="1397" />
  <row Id="7323" PostId="5696" Text="802.15.4 would be ideal, but Bluetooth, 433MHz/866MHZ/915MHz (DASH7 type stuff) is interesting too. 10mbit/s or higher for the ethernet" CreationDate="2010-11-01T13:49:37.927" UserId="566" />
  <row Id="7324" PostId="5950" Text="You can switch AC with a JFET or a transmission gate, which is made of two MOSFETs.  http://neatcircuits.com/audiosw/index.html  Transmission gates are used in &quot;split level charge recovery logic&quot;." CreationDate="2010-11-01T14:12:53.983" UserId="142" />
  <row Id="7325" PostId="1024" Text="I think it makes sense to discuss tools for drawing schematics here." CreationDate="2010-11-01T14:16:05.773" UserId="230" />
  <row Id="7326" PostId="5952" Text="Yeah, the one I most commonly use does a min of 8mil and does not charge extra no matter the size I pick." CreationDate="2010-11-01T14:17:47.190" UserId="230" />
  <row Id="7327" PostId="5955" Score="2" Text="This is the reason I like, you can play with the levels and devices all you like, but AC means you have to _wait_ some time before you know something about your signal.  At rf, you don't wait long. At AC Mains, you wait forever." CreationDate="2010-11-01T14:26:52.040" UserId="1266" />
  <row Id="7328" PostId="5974" Text="I'd like to add a 'burning smell, and definite pop sound' to the Aluminum foil description." CreationDate="2010-11-01T14:29:15.360" UserId="1266" />
  <row Id="7329" PostId="5975" Text="I think your answer may be more directed to someone using an Arduino. &quot;Shields&quot; is just a concept used by Arduino. He is using a board for semi-embedded .Net development. " CreationDate="2010-11-01T14:32:19.543" UserId="319" />
  <row Id="7330" PostId="5974" Score="1" Text="I hate the smell of a pop'ed electrolytic. " CreationDate="2010-11-01T14:36:51.363" UserId="230" />
  <row Id="7331" PostId="5696" Score="2" Text="Wow, big bounty, I wish I had an answer." CreationDate="2010-11-01T14:37:50.100" UserId="319" />
  <row Id="7332" PostId="5987" Score="1" Text="Also, when you go to pick out what sensors you are using, look for those protocol types as sticking to them will make your life easy." CreationDate="2010-11-01T14:42:49.827" UserId="319" />
  <row Id="7333" PostId="5696" Score="2" Text="@Kellenjb I wish I had an answer too" CreationDate="2010-11-01T14:43:00.390" UserId="566" />
  <row Id="7334" PostId="5696" Score="2" Text="Maybe I should pull some strings with a friend at TI and have them post a fake part that is the CC430 with ethernet built in." CreationDate="2010-11-01T14:46:09.807" UserId="319" />
  <row Id="7335" PostId="5749" Text="They do at already-installed locations, but they hopefully won't at future locations." CreationDate="2010-11-01T14:49:52.223" UserId="1199" />
  <row Id="7336" PostId="5980" Score="1" Text="I am somewhat interested in the answers for the questions. I think the act of decoding usb audio on a micro can have lots of uses, more then just sending it to a computer." CreationDate="2010-11-01T14:54:30.170" UserId="319" />
  <row Id="7337" PostId="5989" Text="Interesting, I really hadn't considered wifi - as I'm looking to connect with low power sensor nodes" CreationDate="2010-11-01T14:57:58.467" UserId="566" />
  <row Id="7338" PostId="5354" Text="If you can handle staying at or above pic18 then you should take a look at the c18 compiler. It has a large amount of support. IAR is dropping PIC support, they will no longer sell licenses with maintenance. " CreationDate="2010-11-01T14:58:11.650" UserId="230" />
  <row Id="7339" PostId="5361" Text="c18 for pic18, c30 for pic24 and dspic, c32 for pic32!" CreationDate="2010-11-01T14:58:41.367" UserId="230" />
  <row Id="7340" PostId="5975" Text="Ah you're right, I could've sworn I read 'netduino' somewhere :-) I removed that bit." CreationDate="2010-11-01T14:58:58.720" UserId="1124" />
  <row Id="7341" PostId="5988" Score="1" Text="Removing the digital stuff would be hard as it's a wireless headset and I doubt there is an easy way to get an analogue signal from the receiver." CreationDate="2010-11-01T14:59:37.607" UserId="1790" />
  <row Id="7342" PostId="5988" Text="I think the PIC is his way of ripping out the digital stuff without damaging the headset" CreationDate="2010-11-01T14:59:52.987" UserId="230" />
  <row Id="7343" PostId="5980" Text="Thanks for creating the usb-host tag; wanted to use that initially but didn't have enough rep for it." CreationDate="2010-11-01T15:00:49.743" UserId="1790" />
  <row Id="7344" PostId="5968" Score="1" Text="Cross correlation should work even in the presence of background noise.  In general, you can't remove noise from a recording, unless you have some idea of what that noise is.  If your answer is &quot;the noise is anything other than the specific signal I'm looking for&quot;, then that's what cross-correlation is for." CreationDate="2010-11-01T15:07:04.773" UserId="142" />
  <row Id="7345" PostId="5989" Text="Ah, I didn't read carefully enough." CreationDate="2010-11-01T15:46:33.640" UserId="1199" />
  <row Id="7346" PostId="5938" Text="thanks! But... there is no 8-pin pic that i can use with an easy-free c compiler? [must have analogical input]???? thanks ps.: this page you sent is too complicated for me [an beginner]" CreationDate="2010-11-01T15:48:28.200" UserId="1539" />
  <row Id="7347" PostId="5361" Text="CCS is nice in that certain things are simpler to do (interrupts and timers, for example - all the Microchip examples have you write ASM to get interrupts to work right in C18), but it is closer to ANSI C." CreationDate="2010-11-01T15:49:23.933" UserId="374" />
  <row Id="7348" PostId="5990" Score="1" Text="I think the not powering something while in an ESD bag comes from days when there were really cheap bags that were very conductive. The newer ones will not cause a problem." CreationDate="2010-11-01T16:00:12.397" UserId="230" />
  <row Id="7349" PostId="5954" Text="A buck stage (reducing the input to 4V) followed by a boost stage (4V to 12V) would not invert polarity. Efficiency wouldn't be great (cascaded converters) but it would do the job." CreationDate="2010-11-01T16:28:40.250" UserId="1293" />
  <row Id="7350" PostId="5991" Score="1" Text="Antistatic bags should be slightly conductive, but if you puncture, crease, or tear them, you'd break the conductivity of the material." CreationDate="2010-11-01T16:33:44.430" UserId="1084" />
  <row Id="7351" PostId="5954" Text="Yeah, but then I have to have a buck converter rated to deliver 3 amps (+inefficiencies) instead of a SEPIC at 1 amp. A 3 amp buck converter could be quite big, possibly bigger than the SEPIC itself." CreationDate="2010-11-01T17:02:00.953" UserId="1225" />
  <row Id="7352" PostId="5997" Text="why parallel? I've seen a slightly more complex diagram for wiring, involving one electrolytic and one diode. Does it make any difference ?" CreationDate="2010-11-01T17:04:04.767" UserId="1272" />
  <row Id="7353" PostId="5983" Text="The module draws up to 720mA for the more powerful 500mW version, but about 400mA for the 100mW version. I don't think such a cap is necessary. I mean, you can get a 1 amp 7805 working with a 10µF capacitor." CreationDate="2010-11-01T17:04:07.303" UserId="1225" />
  <row Id="7354" PostId="5998" Score="1" Text="Good question. I am leaning toward saying less solder on an smd causes less chance of cracking, but I have nothing to back me." CreationDate="2010-11-01T17:11:47.140" UserId="319" />
  <row Id="7355" PostId="5983" Text="I can get a 7805 to work with no capacitor, that doesn't mean it is good at having a stiff voltage rail. RF systems can be very susceptible to noise created by even the most minor dips in power." CreationDate="2010-11-01T17:17:31.060" UserId="319" />
  <row Id="7356" PostId="5983" Text="In general it will probably work with lower values but it will cause your SNR to be worse witch will decrease your range." CreationDate="2010-11-01T17:19:55.787" UserId="319" />
  <row Id="7357" PostId="5929" Text="@Korkut - Agreed, It's possible they're just fishing for email addresses and aren't really bothered about an answer, it could explain the lack of information or follow up. " CreationDate="2010-11-01T17:29:59.480" UserId="399" />
  <row Id="7358" PostId="5999" Text="Then again something with less mass requires less force to dislodge, right?" CreationDate="2010-11-01T17:33:30.460" UserId="1225" />
  <row Id="7359" PostId="5999" Score="6" Text="@Thomas O - not at all. The mass is only relevant in relationship to how much force is required to dislodge the object. All other things being equal (that is, same attachment method, thus same force required to dislodge), less mass is harder to dislodge by shaking it because the smaller mass makes for less force on a given amount of motion. " CreationDate="2010-11-01T17:37:38.627" UserId="259" />
  <row Id="7360" PostId="5990" Score="4" Text="I recently tested that anti-static foam chips are stuck into.  One of them has greater than 2MOhm resistance per mm.  One of them has about 1 Ohm per 5 cm.  I conclude that things that look identical and that are used in identical ways can be very different." CreationDate="2010-11-01T18:04:28.017" UserId="1271" />
  <row Id="7361" PostId="5997" Text="The diode is a good idea-- it's to prevent the battery from pushing current back through the solar panel when it's dark. I don't think the cap is necessary. If there were no battery, you'd want the cap as a mini-battery to smooth out fluctuations in the panel voltage, but the battery itself will act like a capacitor. (I'm assuming you're using a relatively large battery, not a coin cell.)" CreationDate="2010-11-01T18:05:00.013" UserId="712" />
  <row Id="7362" PostId="5640" Text="When I said rectifier, I meant the power supply board as a whole, which was a separate board from the main logic.  I think for the DVD player I fixed, it was a cap on the DC side, but in general just touch the tops of all of them and feel for a bulge.  I think designers have respect for AC and use higher-voltage caps, but think &quot;oh this is just 5V so I can use a 6V rated cap...&quot;" CreationDate="2010-11-01T18:36:17.143" UserId="1278" />
  <row Id="7363" PostId="5361" Text="You only need one assembly instruction and that is the GOTO that is used to setup the interrupt vector to point to the interrupt service routine." CreationDate="2010-11-01T18:50:16.670" UserId="588" />
  <row Id="7364" PostId="5997" Score="2" Text="If you run the Arduino at 3.3V (8MHz), you can use a 1W solar panel, 3.7V Li-Poly battery, and Li-Poly charging circuit. A 3.3V DC-DC converter circuit allows you to keep the 3.3V even with 1-3V (1-2 AA batteries)." CreationDate="2010-11-01T18:54:15.020" UserId="1084" />
  <row Id="7365" PostId="5965" Text="&#xA;All true, but my question is really about the production process: how do I arrange things so that on first power on a newly assembled board has enough software available to run self tests and reflash to a final version of the firmware." CreationDate="2010-11-01T18:54:57.830" UserId="1494" />
  <row Id="7366" PostId="5994" Score="1" Text="I already intented to use it as a digital switch, as it would only have an 'on' and 'off' state. I'll have to get to know Mr. Op-amp then :-) Thanks!" CreationDate="2010-11-01T19:18:35.050" UserId="1124" />
  <row Id="7367" PostId="5922" Text="I've seen large resistors used to &quot;drop&quot; the voltage so the regulator doesn't have to get as hot.  Ultimately, it's just moving the thermal dissipation to something else." CreationDate="2010-11-01T19:49:39.903" UserId="1278" />
  <row Id="7368" PostId="5994" Score="1" Text="Getting to know Mr. Comparator might serve you better, given that you want a digital output. His friends call him by the nickname LM339." CreationDate="2010-11-01T19:49:54.757" UserId="712" />
  <row Id="7369" PostId="5994" Text="Awesome, thanks!" CreationDate="2010-11-01T19:52:11.593" UserId="1124" />
  <row Id="7370" PostId="5922" Text="Yep, that's exactly what it's doing.  But the percentage dissipated by each component varies depending on the load.  The worst case for the regulator will occur when resistor and regulator are dissipating the same amount." CreationDate="2010-11-01T20:00:53.807" UserId="142" />
  <row Id="7371" PostId="5983" Text="I thought you needed smaller capacitors as the frequency increased? Big capacitors have little to no effect." CreationDate="2010-11-01T20:34:45.827" UserId="1225" />
  <row Id="7372" PostId="6011" Score="2" Text="I've actually seen arbitrary angles on a motherboard before. The RAM sockets were mounted at about 15 degrees in the middle of the motherboard (not a high performance computer, it was designed to be small.)" CreationDate="2010-11-01T20:39:51.047" UserId="1225" />
  <row Id="7373" PostId="5990" Text="@Jack your comment is an excelent warning! Thank you!" CreationDate="2010-11-01T21:07:48.340" UserId="1298" />
  <row Id="7374" PostId="6012" Text="Thanks for your answer. Please see the FAQ about signatures, they are generally not allowed, your userpage is the place for them." CreationDate="2010-11-01T21:23:26.267" UserId="1225" />
  <row Id="7375" PostId="6013" Score="2" Text="The solution here is not to use a TVS, but a regulator designed to handle these spikes. MIC2954 is one example of such a regulator, rated to handle -20V to +60V without damage." CreationDate="2010-11-01T21:25:54.940" UserId="1225" />
  <row Id="7376" PostId="6013" Score="2" Text="@Thomas O: I'm not sure how common they are in practice, but the inductive transients on standards I've seen go up to 300V, and there's also the mythic 100 V load dump that J1455 specifies (but that will never happen on anything but the largest trucks in the absolute worst conditions)." CreationDate="2010-11-01T21:29:56.853" UserId="1407" />
  <row Id="7377" PostId="6013" Text="I wouldn't expect any regulator to do that - the most I've seen is +75V and -30V, and those were automotive rated. (It was also rated to do 28V continuously for 2 minutes, &quot;double battery jump start&quot;, nominally it takes in 12V.)" CreationDate="2010-11-01T21:36:49.610" UserId="1225" />
  <row Id="7378" PostId="6013" Score="2" Text="@ThomasO: Exactly `:P`, hence the TVS, which between it and the supply's impedance kill the transient.  For some hobby thing I wouldn't bother with the TVS unless I had mysterious failures." CreationDate="2010-11-01T21:42:17.867" UserId="1407" />
  <row Id="7379" PostId="5862" Text="@VigneshRao: You fail to account for the cost of a $15 USB to 232 converter, as computers with RS232 ports haven't been manufactured for a long time." CreationDate="2010-11-01T21:47:38.030" UserId="1407" />
  <row Id="7380" PostId="5861" Score="1" Text="If you're just *learning*, why select such a minimal 8-pin part?  I'd rather start with something that has more capabilities/features, then scale down (often very easy if you stick within the same family) when you have a particular application in mind." CreationDate="2010-11-01T21:50:20.273" UserId="1407" />
  <row Id="7381" PostId="5987" Text="Should I preference GPIO over say I2C or UART, or is it more a case of just using whatever is available with that sensor type?" CreationDate="2010-11-01T21:51:23.783" UserId="1457" />
  <row Id="7382" PostId="6019" Text="That I understood, but I don't really see how the thingie actually straighten the current, and why there is a connection to ground. What I need is to understand the mechanism to discover why it works as a straightener." CreationDate="2010-11-01T21:59:30.427" UserId="1272" />
  <row Id="7383" PostId="5938" Text="The PIC18F1330 comes in an 18-pin DIP package and has a UART, 4 channel 10-bit ADC, 3 comparators with a programmable reference, 6 PWM channels and two 16-bit timers: http://ww1.microchip.com/downloads/en/DeviceDoc/39758D.pdf" CreationDate="2010-11-01T22:01:37.780" UserId="1322" />
  <row Id="7384" PostId="6019" Text="Diodes block current in one direction, so half the time one side of the transformer will be high, putting current through one of the top diodes, then other times the other side of the transformer will be high.  Click the &quot;full-bridge&quot; link, there's a nice graph that illustrates it.  The connection to ground provides a reference point that other voltages refer to." CreationDate="2010-11-01T22:04:01.427" UserId="1407" />
  <row Id="7385" PostId="6019" Text="When you are in front of an unknown configuration, maybe involving capacitors and inductions, how does it work ? Do you think in terms of current flowing ?" CreationDate="2010-11-01T22:06:29.460" UserId="1272" />
  <row Id="7386" PostId="6016" Score="2" Text="electrons don't flow, in many cases they never move appreciably, in cases where they do move, such as in circuits with a DC gradient, they move really slowly.  I wish intro electronics books would stop depicting electrons running around in circuits. " CreationDate="2010-11-01T22:08:52.110" UserId="1438" />
  <row Id="7387" PostId="6019" Text="First I try to figure out their general purpose, usually either a) filtering or b) power.  For filtering parts, imagine what happens at zero frequency (DC) by removing caps and shorting inductors and at infinite frequency by doing the opposite (shorting caps and removing inductors).  For power, the parts are usually storing energy (for discretes) or converting it (transformers)." CreationDate="2010-11-01T22:15:42.443" UserId="1407" />
  <row Id="7388" PostId="6016" Text="Yep, ok. I'm a quantum chemist and I understand this point, but I need a tool to understand how to reason on new circuits and understand what they do. Current flowing is the one I've been taught a loong time ago, but I was never really comfortable with it." CreationDate="2010-11-01T22:16:38.170" UserId="1272" />
  <row Id="7389" PostId="6019" Score="1" Text="So you think in patterns ?" CreationDate="2010-11-01T22:17:23.753" UserId="1272" />
  <row Id="7390" PostId="6014" Text="How would you wave solder a QFP? It's a surface mount package. Do you mean PLCC sockets?" CreationDate="2010-11-01T22:18:20.760" UserId="712" />
  <row Id="7391" PostId="6014" Score="1" Text="@pingswept: No, TQFPs up to 100 pins can be wave soldered, doesn't really answer &quot;how&quot;, but NXP has guidelines http://www.nxp.com/documents/wave_soldering/QFP-SQFP-TQFP-WAVE.pdf  Some paste alloy I used a while ago (SN100C) touts this ability as one of it's strengths http://www.dklmetals.co.uk/PDF%20Files/SN100C.pdf .  I don't know enough to extol the virtues of wave soldering, but I assume it's preferable to reflow in some cases." CreationDate="2010-11-01T22:23:12.497" UserId="1407" />
  <row Id="7392" PostId="6019" Score="1" Text="At the most basic level, I guess I think about why that part is there at all.  Clearly someone put it there for a reason (we hope it was a good reason)." CreationDate="2010-11-01T22:31:34.777" UserId="1407" />
  <row Id="7393" PostId="6016" Score="2" Text="The fun part is that the electrons &quot;flow&quot; opposite the conventional current, hence why current goes out of the &quot;drain&quot; into the &quot;source&quot; in FETs" CreationDate="2010-11-01T22:36:01.403" UserId="1407" />
  <row Id="7394" PostId="6016" Score="2" Text="@Nick T - is that true of all FETs? Look at BJTs - positive current goes collector to emitter in an NPN, and emitter to collector in a PNP. It's similar for PMOS vs NMOS." CreationDate="2010-11-01T22:47:51.937" UserId="740" />
  <row Id="7395" PostId="6025" Score="3" Text="Well put. Even just covering Kirchoff's Voltage Law, Kirchoff's Current Law, Superposition, Thevenin's equivalent, and Norton's equivalent wouldn't be a bad start, but would be a giant answer for this forum. And case analysis is definitely your friend, and can really only be learned from loads of practice." CreationDate="2010-11-01T22:55:55.953" UserId="740" />
  <row Id="7396" PostId="5988" Score="1" Text="Googling for the PIC24FJ64GB0004 only finds this question.. is there a typo in the name?" CreationDate="2010-11-01T23:11:25.133" UserId="1790" />
  <row Id="7397" PostId="6029" Text="Can you post an example circuit?" CreationDate="2010-11-02T00:02:06.333" UserId="857" />
  <row Id="7398" PostId="6014" Text="Fascinating. All the wave soldering I've seen has been on the underside of a board with through-hole components on the top. But, the first PDF you linked to definitely references wave soldering QFP components. I can't imagine why the plastic package doesn't melt as you run it through the solder wave. Anyone know how this works?" CreationDate="2010-11-02T00:13:10.370" UserId="712" />
  <row Id="7399" PostId="6029" Text="i once cracked open a power supply from a scrapped control system that used a bunch of 24VAC relays. The main transformer had *three* windings. A 120V primary, and a 24V secondary, which you'd expect. In addition, there was another secondary that was connected to ONLY a large 3uF oil filled capacitor. The o.c. voltage of that winding was 600V. I'm wondering if that wasn't something exactly like you're suggesting." CreationDate="2010-11-02T00:21:17.207" UserId="740" />
  <row Id="7400" PostId="5988" Text="sorry - remove one of the zeroes : http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en536118" CreationDate="2010-11-02T00:21:59.843" UserId="1681" />
  <row Id="7401" PostId="5965" Score="1" Text="You get the NAND preprogrammed by a programming house. Keeping the preprogrammed part to a minimum, in the guaranteed-good area, means the programming house doesn't need to deal with whatever bad-block system you are using. I don't know how standardised ECC algorithms are though - particularly on multi-level, I suspect even the 'guaranteed good' area may only be guaranteed with ECC." CreationDate="2010-11-02T00:25:46.943" UserId="1681" />
  <row Id="7402" PostId="6014" Score="2" Text="Wave solder temp won't  be much different to reflow, and may actually be exposed for less time. A particular issue is the higher rate-of-rise which can cause popcorning damage due to trapped moisture, but it would take a lot more to melt the plastic used for IC packages." CreationDate="2010-11-02T00:32:32.373" UserId="1681" />
  <row Id="7404" PostId="5983" Text="The small high frequency caps are usually on-board right next to the chips that need them. The large capacitor supplies bulk amounts of power." CreationDate="2010-11-02T00:55:36.003" UserId="319" />
  <row Id="7405" PostId="5983" Text="Essentially you have to think about it like your capacitors are supplying power to your circuit and then your main power supply just recharges your capacitors. The large bulk capacitor allows this to work in higher power draw environments." CreationDate="2010-11-02T00:58:43.940" UserId="319" />
  <row Id="7406" PostId="5987" Text="This somewhat depends on what you are wanting to do. Is just general purpose IO, these don't usually have a huge use in sensor networks. I suspect you will be using SPI/I2C and UART more often then just general IO. I also would guess that you will use the 2 ADC inputs." CreationDate="2010-11-02T01:07:39.420" UserId="319" />
  <row Id="7407" PostId="6028" Score="1" Text="I guess I have to ask, if your noise ripple is less then 2mVp-p, why do you need to see it on a scope? Seems to me like this is plenty small and there isn't much reason to show it." CreationDate="2010-11-02T01:12:22.113" UserId="319" />
  <row Id="7408" PostId="6028" Text="Guess I didn't read all of the way through Andrew's post first. I agree with him." CreationDate="2010-11-02T01:14:27.117" UserId="319" />
  <row Id="7409" PostId="6028" Text="@Thomas, you sure move fast on projects. It was just a couple days ago that I recommended going with a buck. Must be nice to jump on projects this fast." CreationDate="2010-11-02T01:18:13.383" UserId="319" />
  <row Id="7410" PostId="6028" Text="are you expecting the ripple to be at a frequency in the MHz?" CreationDate="2010-11-02T02:03:43.360" UserId="230" />
  <row Id="7411" PostId="6017" Score="1" Text="Okay, I have built a radar system before, I need one major thing, that I am not sure if you intended to answer. Do you plan to do this at a single frequency?" CreationDate="2010-11-02T02:07:34.853" UserId="230" />
  <row Id="7412" PostId="6023" Score="1" Text="stub tuning is messy, and you need to be at a pretty high frequency, like 2.4GHz for it to be at all effective. It is also a source of emissions along with being very very frequency dependent. " CreationDate="2010-11-02T02:09:18.767" UserId="230" />
  <row Id="7413" PostId="6031" Text="+1 I didn't know this. I don't think this would really be considered a battery in any since though, just a frequency generator." CreationDate="2010-11-02T03:13:41.570" UserId="319" />
  <row Id="7414" PostId="6031" Score="1" Text="A tank circuit is normally used to generate a frequency, and not really as a battery, but it is used as a power source." CreationDate="2010-11-02T03:53:52.280" UserId="230" />
  <row Id="7415" PostId="6034" Text="I don't even use these.  :/  I just break everything down into voltage dividers." CreationDate="2010-11-02T04:08:54.953" UserId="142" />
  <row Id="7416" PostId="6029" Text="http://en.wikipedia.org/wiki/Resonant_energy_transfer" CreationDate="2010-11-02T04:10:11.210" UserId="142" />
  <row Id="7417" PostId="6003" Text="I've seen boards with capacitors placed by through hole and the rest of components placed by smt.. I suppose its better to do it this way.. " CreationDate="2010-11-02T04:36:54.490" UserId="1484" />
  <row Id="7418" PostId="6031" Score="2" Text="@Kellenjb True-- it's like a battery with a capacity of 1 microwatt-hour, which is arguably not a battery." CreationDate="2010-11-02T05:08:08.073" UserId="712" />
  <row Id="7419" PostId="5813" Text="This really has nothing to do with electronics or robotics as far as I can tell. A shame that there are so many nice answers." CreationDate="2010-11-02T05:23:32.727" UserId="131" />
  <row Id="7420" PostId="6038" Text="PS: I used a $10 RadioShack iron. The headphone jack is actually one of the largest things in a small music player, it's quite easy to solder." CreationDate="2010-11-02T05:27:13.023" UserId="131" />
  <row Id="7421" PostId="5844" Text="You've given up soldering? Electronics &amp; Robotics might not be the site for you... :)" CreationDate="2010-11-02T05:27:35.193" UserId="131" />
  <row Id="7422" PostId="6032" Score="1" Text="Uhm, it can. Try the command &quot;:FreeRotateBuffer(45)&quot; when something is copied into the buffer. You need a new version to do this (I have 20091103), but it does work with squares. I do wish it were broken out to the UI though." CreationDate="2010-11-02T07:51:03.810" UserId="1225" />
  <row Id="7423" PostId="6028" Text="I've been working on the same buck for a few weeks now." CreationDate="2010-11-02T07:52:37.757" UserId="1225" />
  <row Id="7424" PostId="6033" Text="I just want to see this ripple." CreationDate="2010-11-02T07:53:06.117" UserId="1225" />
  <row Id="7425" PostId="6033" Text="My 54501A almost died on me. It kept power cycling a few months back and wouldn't work properly (if it worked, the trace was always maxed out.) Then I got a can of compressed air and blew it out. Working fine ever since." CreationDate="2010-11-02T07:54:09.987" UserId="1225" />
  <row Id="7426" PostId="6018" Score="1" Text="Interesting answer! The problem here is that so far I haven't actually seen CFL on whose box was printed if it was rated to be used in enclosed fixture or not. " CreationDate="2010-11-02T08:07:51.673" UserId="1240" />
  <row Id="7427" PostId="6035" Text="True. I sometimes find myself trying both, just to find out wich will yield the more convienent set of equations." CreationDate="2010-11-02T08:45:44.337" UserId="930" />
  <row Id="7428" PostId="6041" Score="2" Text="I am with you on this one, build stuff and bring it into your interviews and demonstrate it working.  Bring the schematics, and the detailed design documents too, to show how you calculate all the values of the circuit.  This is important as it will show that you actually designed the stuff and understand the design trade-offs of each component in the circuit.  Some employers in the UK science parks around cambridge will take on people with physics degrees as an alternative the EE degrees." CreationDate="2010-11-02T09:28:10.357" UserId="1397" />
  <row Id="7429" PostId="6041" Text="btw I do have a masters in EE and bachelor in software/communication engineering - made bugger all difference having the masters :)" CreationDate="2010-11-02T09:28:51.900" UserId="1397" />
  <row Id="7430" PostId="6029" Score="1" Text="of course .. maybe that was a power factor correction thing of some kind." CreationDate="2010-11-02T11:20:34.737" UserId="740" />
  <row Id="7431" PostId="6045" Text="So to find 'V' kcl and to find 'I' Kvl that whats used often?" CreationDate="2010-11-02T11:43:01.840" UserId="1799" />
  <row Id="7432" PostId="6043" Text="Can someone please help me upload both the pictures.In the edit option I see that everythings fine but when I post it the other picture and my details arent visible.Please edit this question for me." CreationDate="2010-11-02T11:45:21.913" UserId="1799" />
  <row Id="7433" PostId="6047" Text="Crossposted on [Arduino Forum](http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1288701627/0) and [SparkFun Forum](http://forum.sparkfun.com/viewtopic.php?f=13&amp;t=24491)" CreationDate="2010-11-02T12:46:57.003" UserId="1298" />
  <row Id="7434" PostId="6032" Text="Yup - you can rotate footprints to arbitrary values, you can even rotate less than a degree, If you want text at an arbitrary angle you can import a converted Postscript file, GEDA PCB can be very powerful and versatile and does far more than just &quot;simple rectilinear designs&quot; - if you can be bothered to learn it   " CreationDate="2010-11-02T12:49:14.303" UserId="399" />
  <row Id="7435" PostId="6046" Text="This will probably get lower resolution though, due to the need to put both channels at 1V/div." CreationDate="2010-11-02T13:05:23.493" UserId="1225" />
  <row Id="7436" PostId="5968" Text="How is this an electronics or robotics question?" CreationDate="2010-11-02T13:12:11.070" UserId="883" />
  <row Id="7437" PostId="5968" Text="If i can understand the concept for solving this using DSP, i will try to implement technically." CreationDate="2010-11-02T13:17:23.390" UserId="1730" />
  <row Id="7438" PostId="6033" Text="Nice. Mine needs a good cleaning, I have to play with the buttons to get any to register. I have a Tek 7854 too which is more just for cool factor than anything else, but since it's one of those old chassis scopes it can do some pretty amazing stuff with the right modules." CreationDate="2010-11-02T13:22:39.867" UserId="974" />
  <row Id="7439" PostId="5938" Text="@Andrew, if you want 8-pin check my answer.  You can download SourceBoost which has a free code-size limited C compiler (the 8-pin chips have less memory than you'll be allowed to compile using BoostC anyway.)" CreationDate="2010-11-02T14:08:51.427" UserId="1333" />
  <row Id="7440" PostId="6032" Score="1" Text="I am familiar with the PostScript converter.  I wrote it." CreationDate="2010-11-02T14:43:40.300" UserId="411" />
  <row Id="7441" PostId="6050" Score="2" Text="http://meta.stackoverflow.com/questions/18242/what-is-the-policy-here-on-homework" CreationDate="2010-11-02T14:55:21.760" UserId="566" />
  <row Id="7442" PostId="6041" Text="I certainly am not going to get a PhD - it would be good mostly for an academic career.  Teaching and research make a fine career but making something of practical value excites me more.  Ideally I'd be part of the design and manufacture of stuff for researchers." CreationDate="2010-11-02T14:56:09.633" UserId="1609" />
  <row Id="7443" PostId="6040" Text="Unless a wealthy girlfriend comes along, I won't be quitting my current job to study.  It will be the job + classes." CreationDate="2010-11-02T14:57:47.513" UserId="1609" />
  <row Id="7444" PostId="6032" Text="Here's why squares rotated at 45 degrees don't work in pcb. http://pcb.gpleda.org/pcb-cvs/pcb.html#ElementLine-syntax&#xA;&#xA;Lines are marked by their start and end points, and the line width.  A square is a line with identical start and end points.  Therefore, the orientation of the square is not able to be captured by the file format." CreationDate="2010-11-02T14:59:56.343" UserId="411" />
  <row Id="7445" PostId="6041" Score="1" Text="There are several projects from the past I can trot out to show skill and enthusiasm.  But these seem to not suffice for getting interviews.  Making more projects can't hurt, for sure.  I like the idea of bringing schematics etc - I'll put together a &quot;my projects&quot; notebook, like an artists' portfolio." CreationDate="2010-11-02T15:01:24.923" UserId="1609" />
  <row Id="7446" PostId="6040" Score="1" Text="The more interesting jobs - the keepers to stay in - on the job hunt sites all seem to want a Master's for equivalent industry experience. " CreationDate="2010-11-02T15:08:46.067" UserId="1609" />
  <row Id="7447" PostId="6049" Text="Getting a foot in is the trick.   " CreationDate="2010-11-02T15:11:00.793" UserId="1609" />
  <row Id="7448" PostId="6050" Score="2" Text="thats not homework!As the image shows I am trying to learn from a website.Anyhow thanks!" CreationDate="2010-11-02T15:26:07.680" UserId="1799" />
  <row Id="7449" PostId="6049" Text="&quot;Paid for by the school&quot;? o_O  Do you mean &quot;paid for by your employer&quot;?" CreationDate="2010-11-02T15:28:39.253" UserId="142" />
  <row Id="7450" PostId="6045" Text="I have taught that a million times, but somehow I forgot it in my post. You always solve for the opposite of what your intuition tells you. +1 to justjeff, spot on reason to choose one." CreationDate="2010-11-02T15:33:35.870" UserId="230" />
  <row Id="7451" PostId="6033" Text="I would check the connection to the keyboard PCB is secure. The connector is very long (about 1.5ft) and travels across the mainboard to the CPU." CreationDate="2010-11-02T15:58:07.470" UserId="1225" />
  <row Id="7452" PostId="6032" Text="@Markrages - I'm confused, did you write the Pstoedit converter? are you Wolfgang Glunz? I still don't understand why a square shouldn't or can't be rotated to an arbitrary angle? My version of PCB will allow whole circuits to be rotated. " CreationDate="2010-11-02T16:08:51.767" UserId="399" />
  <row Id="7453" PostId="6053" Text="have you built the previous? 3% was a worst case based on worst case leakage, unless you are fabbing a lot of these you can calibrate them." CreationDate="2010-11-02T16:11:00.577" UserId="230" />
  <row Id="7455" PostId="6017" Text="Yes, the system we built operated at a single frequency." CreationDate="2010-11-02T16:16:55.633" UserId="1614" />
  <row Id="7456" PostId="6032" Text="No, I just wrote the pcb converter plugin and Wolfgang added it to the distribution.  http://vivara.net/software/pstoedit_additions/README If you look at the file format documentation, you will see that a square and a rotated square would have exactly the same representation.  Therefore, squares can not be rotated in pcb.  See also http://vivara.net/images/Screenshot-PCB.png" CreationDate="2010-11-02T16:26:16.557" UserId="411" />
  <row Id="7457" PostId="6032" Text="Here's an example of a 45 deg QFP chip on a board designed with GEDA PCB - http://www.delorie.com/electronics/r8c-27-adapter/r8c27-dip600-pcb.png It's done by DJ Delorie who is the main contributor to GEDA PCB " CreationDate="2010-11-02T16:31:56.600" UserId="399" />
  <row Id="7458" PostId="6032" Text="DJ's footprint doesn't use any square pad." CreationDate="2010-11-02T16:33:19.383" UserId="411" />
  <row Id="7459" PostId="6054" Text="+1 use the op amp with a gain of 0.1 and make it double as the anti-aliasing filter" CreationDate="2010-11-02T16:34:41.573" UserId="1278" />
  <row Id="7460" PostId="6049" Score="1" Text="Nope, paid for by the school.  Lot's of jobs these days have the auto-sort or the HR wall, and if you don't list an EE degree, they don't even look at you. Sux, I agree." CreationDate="2010-11-02T16:40:04.843" UserId="1266" />
  <row Id="7462" PostId="6057" Text="I work in an ideal condition where measure does not perturb the system" CreationDate="2010-11-02T16:44:20.570" UserId="1272" />
  <row Id="7463" PostId="5831" Text="0.01 uF is only more effective than 0.1 uF if the former has a smaller package (or some other mechanism for reducing inductance).  All else equal, a 603 0.01 uF will not perform any better than a 603 0.1 uF" CreationDate="2010-11-02T16:48:04.527" UserId="1278" />
  <row Id="7464" PostId="6032" Text="Ahhh...I see what your on about now! When you say square you mean a pad drawn from a line without length - Your quite right they don't rotate! You can still make a rotated square thermal pad if you draw it as a rect or poly tho, it's not really a pain in the rear " CreationDate="2010-11-02T16:57:47.793" UserId="399" />
  <row Id="7465" PostId="6017" Text="i would assume its a continuous wave doppler radar?  what PCB dialectic are you using?  your stock PCB fab FR-4 isn't great for frequencies much over 1Ghz, there are of course specialty dialectics that fall into the FR-4 category which are good to much higher frequencies.  Either way make sure your dielectric constant at your frequency of operation is reasonable as this will greatly impact stray reactances and loses in traces.  That is it can amplify any impedance mis-match issues." CreationDate="2010-11-02T16:58:09.000" UserId="1438" />
  <row Id="7466" PostId="6036" Text="+1 for the Microwaves101 reference.  Thanks, looks to have lots of good stuff for a RF layperson like myself." CreationDate="2010-11-02T17:01:04.867" UserId="1614" />
  <row Id="7467" PostId="6023" Text="@vicatcu +1 for mentioning the stub.  Thanks." CreationDate="2010-11-02T17:11:08.287" UserId="1614" />
  <row Id="7468" PostId="6047" Text="and [SeeedStudio Forum](http://www.seeedstudio.com/forum/viewtopic.php?f=4&amp;t=1314&amp;start=0)" CreationDate="2010-11-02T17:14:45.407" UserId="1298" />
  <row Id="7469" PostId="6032" Score="1" Text="Only Pins, Pads, ElementLines and ElementArcs are allowed within Elements.  No Polys.  Therefore a rect or poly will not work.  Nor will a poly clear soldermask, if you were thinking about faking it that way." CreationDate="2010-11-02T17:16:10.273" UserId="411" />
  <row Id="7470" PostId="6054" Text="I can't afford an op-amp. I don't have enough space, unfortunately. I may be able to afford a buffer IC, if they are small enough and are available with 8 channels." CreationDate="2010-11-02T17:16:23.033" UserId="1225" />
  <row Id="7471" PostId="6053" Text="Kortuk, do you think I could adjust one of the resistors by 3% or handle it in software (scale by 1.03x?)" CreationDate="2010-11-02T17:16:52.597" UserId="1225" />
  <row Id="7472" PostId="6016" Text="@JustJeff: True, I suppose the naming is based on the charge carriers in whatever device (MOSFETs at least), which if they are electrons seem backwards, or &quot;holes&quot; which match the conventional current direction" CreationDate="2010-11-02T17:26:17.470" UserId="1407" />
  <row Id="7473" PostId="6047" Text="there is someone with a similar problem at [Digi Forum](http://forums.digi.com/support/forum/viewthread_thread,7969)" CreationDate="2010-11-02T17:30:08.853" UserId="1298" />
  <row Id="7474" PostId="6060" Text="@Mark, I'm streaming audio. Is there any more suitable protocol which uses the same hardware? Which protocol do you recommend? Bluetooth?" CreationDate="2010-11-02T17:32:10.923" UserId="1298" />
  <row Id="7475" PostId="6032" Text="Thanks for illustrating that for me, I see why you recommend a slightly offset square! I stand corrected...it is a pain in the rear " CreationDate="2010-11-02T17:38:39.833" UserId="399" />
  <row Id="7476" PostId="6036" Text="So if a quarter-wavelength long piece of coax will give me a 90 degree phase shift, then can I replicate that same effect with a PCB trace (like just tacking on an extra length of trace to the existing transmission line)? If so then it sounds like that could be something I could experiment with as getting exact lengths of COAX would be a pain in the butt." CreationDate="2010-11-02T17:46:13.867" UserId="1614" />
  <row Id="7477" PostId="6061" Text="My MCU doesn't have builtin flow control, so i'll have to implement it." CreationDate="2010-11-02T17:47:07.177" UserId="1298" />
  <row Id="7478" PostId="6047" Text="but [I crossposted there](http://forums.digi.com/support/forum/viewthread_thread,8263_lastpage,yes#24829) anyway" CreationDate="2010-11-02T17:49:05.147" UserId="1298" />
  <row Id="7479" PostId="6051" Text="Thanks.Very helpful." CreationDate="2010-11-02T17:49:51.137" UserId="1799" />
  <row Id="7480" PostId="6023" Text="For general reference Wikipedia article about stubs: http://en.wikipedia.org/wiki/Stub_%28electronics%29" CreationDate="2010-11-02T18:00:30.717" UserId="1614" />
  <row Id="7481" PostId="6057" Text="That is fine. In ideal conditions your DMM resistance will be infinity. In non-ideal it will be less then that." CreationDate="2010-11-02T18:01:08.050" UserId="319" />
  <row Id="7483" PostId="6053" Text="You are saying you want high precision, low power draw, at very little extra cost. Not sure that is possible. You can calibrate in software like kortuk has mentioned, but in a fab process that takes time which will equal money." CreationDate="2010-11-02T18:07:35.533" UserId="319" />
  <row Id="7484" PostId="6036" Text="You want to make sure that your COAX is an even number of wavelengths(no nets phase delay). Then you add a lamda/4 PCB trace. I had not heard if you were at a single frequency yet, so I did not add a number of techniques." CreationDate="2010-11-02T18:10:28.163" UserId="230" />
  <row Id="7485" PostId="6017" Text="Continuous wave radar normally needs frequency shifting to find the distance." CreationDate="2010-11-02T18:11:24.043" UserId="230" />
  <row Id="7486" PostId="6054" Text="Usually you just buy a tiny op-amp and connect it as a buffer.  http://www.national.com/mpf/LM/LMC7111.html SOT23 is too big?" CreationDate="2010-11-02T18:11:46.383" UserId="142" />
  <row Id="7487" PostId="6060" Text="If it's not already digital audio, use FM.  If you can find a premade transceiver with the right bandwidth then it's easy." CreationDate="2010-11-02T18:12:02.453" UserId="249" />
  <row Id="7488" PostId="6054" Text="Oh, you want 8 channels." CreationDate="2010-11-02T18:13:51.360" UserId="142" />
  <row Id="7489" PostId="6036" Text="In relation to turning the trace, you are going to want to us a mitered bend. http://www.microwaves101.com/encyclopedia/mitered_bends.cfm When you turn you are actually increasing your width at one area creating many reflections, the mitered bend can match at a small frequency range(this works very well when done properly, I have done this)" CreationDate="2010-11-02T18:14:57.070" UserId="230" />
  <row Id="7490" PostId="5831" Text="This is not completely true. there are ESR changes, and a different impedance dependent on the frequency chosen." CreationDate="2010-11-02T18:16:50.177" UserId="230" />
  <row Id="7491" PostId="6057" Text="In the case that your switch is open and you assume there is nothing connected to your output, then you don't have a circuit. A circuit by definition creates a complete loop. If you assume a resistance of infinity you can close your loop and use infinity in your standard circuits calculations." CreationDate="2010-11-02T18:19:20.780" UserId="319" />
  <row Id="7492" PostId="6054" Text="If you still use the voltage divider you will have the error he is talking about. I don't think this helps improve his precision at all." CreationDate="2010-11-02T18:23:49.343" UserId="319" />
  <row Id="7493" PostId="6017" Text="The radar is CW operating at around 6Ghz and the PCB that has the analog/digital circuits is FR-4. The antennas are of another material, not sure what it is." CreationDate="2010-11-02T18:26:30.773" UserId="1614" />
  <row Id="7494" PostId="6053" Text="Driving an MCU ADC input with a large impedance is bad, anyway. It increases the settling time and causes distortion, etc. &quot;The ADC is optimized for analog signals with an output impedance of approximately 10 kΩ or less. If such a source is used, the sampling time will be negligible. If a source with higher impedance is used, the sampling time will depend on how long time the source needs to charge the S/H capacitor, with can vary widely. The user is recommended to only use low impedance sources with slowly varying signals, since this minimizes the required charge transfer to the S/H cap&quot;" CreationDate="2010-11-02T18:32:40.807" UserId="142" />
  <row Id="7495" PostId="6053" Text="As mentioned in the previous question this is not important. It will be monitoring a battery voltage at a maximum of 100 samples per second." CreationDate="2010-11-02T18:33:46.650" UserId="1225" />
  <row Id="7496" PostId="5965" Text="They asked us to supply the image to program including all of the ECC bits, and they agreed to write a specific value to an offset in the extra bytes to mark pages that are not bit-identical with our image. Their default value and offset matched our SOC vendor's boot loader's requirements by &quot;coincidence&quot;. I assume they agreed to discard any chip where block 0 page 0 was bad." CreationDate="2010-11-02T19:06:37.827" UserId="1494" />
  <row Id="7497" PostId="6034" Text="And I dont even know voltage dividers properly.." CreationDate="2010-11-02T20:16:37.740" UserId="1799" />
  <row Id="7498" PostId="6058" Text="thanks a lot friend" CreationDate="2010-11-02T20:19:10.593" UserId="1799" />
  <row Id="7499" PostId="6053" Text="@Thomas O, you should always include all relevant question in each question you ask. These questions should be completely independent who comes across your question and answers from google can learn what to do." CreationDate="2010-11-02T20:28:46.100" UserId="319" />
  <row Id="7500" PostId="6053" Text="Sorry, I'll do that now." CreationDate="2010-11-02T20:34:08.573" UserId="1225" />
  <row Id="7501" PostId="6070" Score="6" Text="not to mention to make sure it's DC rated... opening up a DC circuit under load is nothing like opening up an AC circuit under load!" CreationDate="2010-11-02T20:39:52.433" UserId="974" />
  <row Id="7502" PostId="6060" Text="@Jader: How were you going to stream audio at 9600bps?  1.2Kbps is way too slow.  If you want to stick in the digital realm for some reason, Bluetooth has PCM interfaces designed for streaming audio." CreationDate="2010-11-02T20:47:30.853" UserId="1407" />
  <row Id="7503" PostId="6065" Score="1" Text="As a side note, This seems like a ton of work, but it is actually a relatively small amount of work to keep component cost down." CreationDate="2010-11-02T20:49:01.390" UserId="230" />
  <row Id="7504" PostId="6070" Score="2" Text="Very true, I've worked with some fairly high amperage contactors, both AC and DC. Make sure you have the right part for the job. " CreationDate="2010-11-02T21:04:22.657" UserId="1810" />
  <row Id="7505" PostId="6054" Text="using resistors of higher precision will reduce the voltage divider error, the second issue is driving that signal into an ADC.  This is where the inaccuracies will occur, hence the proposal to use a buffer. " CreationDate="2010-11-02T21:18:50.470" UserId="1397" />
  <row Id="7506" PostId="6067" Text="Thanks! Can you explain me what are the two &quot;unconnected&quot; lines between the 10k and 3.3k resistors? Is that where I connect my source power-supply?" CreationDate="2010-11-02T21:27:54.923" UserId="1691" />
  <row Id="7507" PostId="6054" Text="what about a two LFSCP packages which are 4.00 x 3.75 mm in size and each have four opamps in one package? Here is one from analog devices http://www.analog.com/en/amplifiers-and-comparators/operational-amplifiers-op-amps/ad8567/products/product.html" CreationDate="2010-11-02T21:27:57.463" UserId="1397" />
  <row Id="7508" PostId="6067" Text="That is just an oscilloscope probe, you don't need to connect anything there. " CreationDate="2010-11-02T21:29:26.857" UserId="1225" />
  <row Id="7509" PostId="6065" Text="good comment! a brilliant way to do it in software.  Your final method of look up table is probably the best method.  Only drawback is the ROM it consumes, but for a 8-10 bit ADC on an MCU it should be doable." CreationDate="2010-11-02T21:31:20.267" UserId="1397" />
  <row Id="7510" PostId="6078" Score="2" Text="Do you have gerbers or can't you release them?  PNG is not the best medium for this :P" CreationDate="2010-11-02T21:48:30.370" UserId="1407" />
  <row Id="7511" PostId="6078" Text="Open H/W: Gerbers are here: http://code.google.com/p/super-osd/source/browse/#hg/hardware/V3%20Lite/gerbers" CreationDate="2010-11-02T21:49:29.960" UserId="1225" />
  <row Id="7512" PostId="6081" Text="Is 2.718282 a joke, as it happens to be *e*?" CreationDate="2010-11-02T22:15:10.967" UserId="1225" />
  <row Id="7513" PostId="6081" Score="1" Text="Good idea on the vias for my scope probe. And for the vias for the EEPROM, though the EEPROM shares the same I2C bus as is broken out on CONN6." CreationDate="2010-11-02T22:16:26.740" UserId="1225" />
  <row Id="7514" PostId="6081" Text="I don't have space to fit some designators in the same direction, I know this will lead to me craning my neck but it's to save space and I only intend them to be used for repairs or rework." CreationDate="2010-11-02T22:17:17.923" UserId="1225" />
  <row Id="7515" PostId="6081" Text="Good idea on pin labelling. I could label them on the bottom of the board as there is space there." CreationDate="2010-11-02T22:17:38.610" UserId="1225" />
  <row Id="7516" PostId="6065" Text="It depends on data, I have many different cases a 1point calibration was sufficient. Just an offset. And then building in the hardware to calibrate automatically pays off." CreationDate="2010-11-02T22:19:07.347" UserId="230" />
  <row Id="7517" PostId="6039" Text="Many jobs can get you started in electronics with a physics background." CreationDate="2010-11-02T22:21:35.197" UserId="230" />
  <row Id="7518" PostId="6081" Text="@Thomas: If there isn't enough space to have all designators fit in the same direction, at least pick two directions instead of using all four `:P`  Look at the board without any a-priori knowledge and figure out if a mess of designators right next to each other is constructive (non-ambiguous).  If you'd have to look it up to find out which is which you might as well leave one out so at least another can be clear." CreationDate="2010-11-02T22:22:02.897" UserId="1407" />
  <row Id="7519" PostId="6082" Text="I could probably go with 0.2%. Accuracy isn't crucial, but if I can have it for not much more ($1 vs. 60 cents being one example) I'd spec it in." CreationDate="2010-11-02T22:22:26.703" UserId="1225" />
  <row Id="7520" PostId="6081" Text="Yeah, that's a result of me being quick and fast with them. I should rotate them to 0 and 90 degrees." CreationDate="2010-11-02T22:23:20.197" UserId="1225" />
  <row Id="7521" PostId="6080" Text="Wouldn't a diode drop 0.7V or 0.3V? Also, I suspect a SOD package would be bigger than a dedicated switching IC, and you'd need two diodes wouldn't you?" CreationDate="2010-11-02T22:41:24.220" UserId="1225" />
  <row Id="7522" PostId="6060" Text="@Nick I won't stream audio at those rates, I was just trying to solve one problem at a time. My concern now is to optimize the XBee. I'll look into Bluetooth, thanks!" CreationDate="2010-11-02T22:53:12.290" UserId="1298" />
  <row Id="7523" PostId="6081" Score="5" Text="@Thomas O: It might have been a joke, yes. But it's actually just an approximation of e-- I didn't have time to write e in full." CreationDate="2010-11-02T23:16:14.963" UserId="712" />
  <row Id="7524" PostId="6081" Text="One other thought-- maybe give a normal mechanical callout for the mounting holes (#4-40 or M2, or something like that?)." CreationDate="2010-11-02T23:18:13.233" UserId="712" />
  <row Id="7525" PostId="6081" Text="The holes are 60 mil / 1.4mm, what size would that be?" CreationDate="2010-11-02T23:29:04.603" UserId="1225" />
  <row Id="7526" PostId="6067" Score="3" Text="Watch the back emf from the relay coil - better stick a reverse biased diode across it - say a 1N4007. You'll also want to protect the relay contacts from arc damage with an RC snubber (resistor and capacitor in series across the contacts) or a transorb. Values will depend on the inductive nature of the load. Finally, don't forget a reservoir capacitor between power and ground.  http://en.wikipedia.org/wiki/Snubber" CreationDate="2010-11-02T23:29:44.837" UserId="1750" />
  <row Id="7527" PostId="6078" Score="1" Text="What are your design rules?  Does it pass DRC?  That via under D1 looks mighty close to the pads in the PNG image." CreationDate="2010-11-02T23:55:13.810" UserId="411" />
  <row Id="7528" PostId="6078" Text="I haven't set up DRC, because I haven't decided on my PCB fab. It fails DRC because it is set up with worst case rules." CreationDate="2010-11-02T23:58:34.860" UserId="1225" />
  <row Id="7529" PostId="6086" Text="Thanks for the link! (There is only one GND plane, I am not sure why PCB has put an edge on the image.)" CreationDate="2010-11-03T00:15:26.930" UserId="1225" />
  <row Id="7530" PostId="6086" Text="You're right, it's a pcb rendering artifact. I've removed my comment." CreationDate="2010-11-03T00:18:59.780" UserId="411" />
  <row Id="7531" PostId="6087" Text="It's actually mercurial. Thanks for your DRC run. Are there any other alerts I need to be aware of?" CreationDate="2010-11-03T00:24:10.743" UserId="1225" />
  <row Id="7532" PostId="6087" Score="1" Text="Try setting min space to 8.0 and min width to 8.0 (file-&gt;preferences-&gt;sizes) and run DRC again. You can go down to about 5/5, but you will pay for it.  Also in my experience, you will want to pay for electrical testing when you are pushing the fab's capabilities, which pushes up costs some more.  Keep tweaking the design and running the DRC (Connects-&gt;Design Rule Checker) until DRC shows no more design errors.  The submit the design to http://freedfm.com for a second opinion and fab quote.  Then pour yourself a beer. " CreationDate="2010-11-03T00:32:12.140" UserId="411" />
  <row Id="7533" PostId="6080" Text="check the datasheet, but I'm pretty sure the PIC24 doesn't need the full supply voltage to keep the RTC rolling.  Keep high-current devices shut off in firmware when the main power supply is missing." CreationDate="2010-11-03T00:44:13.580" UserId="411" />
  <row Id="7534" PostId="6090" Score="2" Text="possible duplicate of [Do I need to pay royalties to the SD card people if my device &quot;just happens&quot; to be compatible with SD cards?](http://electronics.stackexchange.com/questions/5628/do-i-need-to-pay-royalties-to-the-sd-card-people-if-my-device-just-happens-to-b) This is just an extension of a previous question, they should be grouped together." CreationDate="2010-11-03T00:57:48.703" UserId="319" />
  <row Id="7536" PostId="5879" Score="1" Text="what are you reading?? could you put a link to it? or otherwise explain why it is that you have both mathematical abstractions like max(a,b) *and* hardware implementation buzzwords like 'noise immunity' in the same question?" CreationDate="2010-11-03T01:29:19.813" UserId="740" />
  <row Id="7538" PostId="6031" Score="1" Text="A class C amplifier with a high-Q LC 'tank' draws power from the DC supply for 50% or less of the cycle, so the rest of the time the output power comes out of the energy stored in the LC tank. So, kind of a battery. On the other hand, it's a battery that gets a charge every cycle. I think I'd want something to source the AC for more than a few cycles without needing a charge before calling it a battery." CreationDate="2010-11-03T02:29:45.237" UserId="740" />
  <row Id="7539" PostId="6060" Score="2" Text="you should absolutely never, ever, ever, ever use zigbee for streaming audio or anything that is timing or throughput critical." CreationDate="2010-11-03T02:43:09.893" UserId="1438" />
  <row Id="7540" PostId="6061" Text="flow control will not solve the problems with throughput on zigbee, it was never designed for streaming data." CreationDate="2010-11-03T02:44:19.737" UserId="1438" />
  <row Id="7541" PostId="6041" Text="I think that the masters varies in value. It has helped me a large amount in job search." CreationDate="2010-11-03T02:55:55.483" UserId="230" />
  <row Id="7542" PostId="6097" Score="1" Text="http://en.wikipedia.org/wiki/MicroSD agrees" CreationDate="2010-11-03T04:18:49.810" UserId="1696" />
  <row Id="7543" PostId="2837" Text="If your new source code base is spitting out a lot of &quot;false positives&quot; it's sadly, usually broken. " CreationDate="2010-11-03T04:30:49.657" UserId="1481" />
  <row Id="7544" PostId="6088" Text="Resistance varies with temperature, and the noise generated by resistors increases with temperature, too.&#xA;&#xA;http://en.wikipedia.org/wiki/Electrical_resistance#Temperature_dependence&#xA;&#xA;http://en.wikipedia.org/wiki/Johnson%E2%80%93Nyquist_noise" CreationDate="2010-11-03T04:39:32.780" UserId="142" />
  <row Id="7545" PostId="6066" Text="duplicate: http://electronics.stackexchange.com/questions/4967/circuit-to-protect-against-undervoltage" CreationDate="2010-11-03T04:42:46.167" UserId="142" />
  <row Id="7546" PostId="5696" Score="1" Text="low power radio AND ethernet seems an odd combination. I don't think it's something that's common enough that there would be profit to be made to build a generic off the shelf part which combines them both. Pretty much any complex device is going to have multiple ICs in it, it's not something to avoid at all costs." CreationDate="2010-11-03T04:56:37.810" UserId="131" />
  <row Id="7547" PostId="6103" Text="btw, 'hFE' is another symbol for current gain." CreationDate="2010-11-03T06:11:39.780" UserId="1609" />
  <row Id="7548" PostId="6040" Text="But you are heading for a double with both physics and EE... " CreationDate="2010-11-03T07:15:02.043" UserId="689" />
  <row Id="7549" PostId="6072" Text="definitely contact the manufacturer for more details, or even better buy one sample in and measure it!!!! " CreationDate="2010-11-03T07:17:54.507" UserId="1397" />
  <row Id="7550" PostId="6093" Text="Amp and Volt symbols are both capital letters, btw. Sall v means velocity and small a is a rare tiny prefix." CreationDate="2010-11-03T08:43:59.273" UserId="883" />
  <row Id="7551" PostId="2481" Text="Thanks I didn't know about RS." CreationDate="2010-11-03T09:05:37.697" UserId="1333" />
  <row Id="7552" PostId="1904" Score="2" Text="Fume extractors are worth every penny IMO. Smoke goes in - no smoke comes out - and the best bit is that the air smells clean. Get the cheap Maplins one for £15. :)" CreationDate="2010-11-03T09:09:31.390" UserId="1333" />
  <row Id="7553" PostId="2479" Text="BitsBox has a good selection and the prices and delivery times are excellent." CreationDate="2010-11-03T11:07:39.743" UserId="1333" />
  <row Id="7555" PostId="6061" Text="Updated my answer. I use the device that I linked to and it is a cinch to work with. " CreationDate="2010-11-03T12:32:57.547" UserId="1033" />
  <row Id="7556" PostId="6116" Text="U4 is a HC-49 crystal." CreationDate="2010-11-03T13:05:34.993" UserId="1225" />
  <row Id="7557" PostId="6102" Text="This simple logic chip looks like it will do the trick.  I appreciate your solution.  I will try this and I will let you know how it works out.  I also like the size as size truly matters in micro-controller development." CreationDate="2010-11-03T13:09:35.817" UserId="1413" />
  <row Id="7558" PostId="6102" Text="This is a nice chip, small footprint.  I like that its simple in that its just a logic and amplifier together.  Good answer." CreationDate="2010-11-03T13:10:47.970" UserId="1414" />
  <row Id="7559" PostId="6080" Text="@Thomas: As mark mentions, you can be fairly loose with the supply voltage if you're just running the RTC.  If you're running the PIC at 5V, it's trivial as you just have a forward diode from the coin cell to the supply.  If it's 3.3V or thereabouts, it will be more difficult as the typical Li/Mn02 battery may exceed that when new." CreationDate="2010-11-03T14:42:25.373" UserId="1407" />
  <row Id="7561" PostId="6113" Text="As Andrey pointed out, you don't increase both the voltage and capacity when putting batteries in series-just the voltage. Also, you linked to the Dutch Wikipedia - I'm 50% Dutch, but can't read that.  [This page](http://en.wikipedia.org/wiki/List_of_battery_sizes#Button_.2F_coin_.2F_watch_.2F_micro_.2F_miniature) is the closest analog on the English Wikipedia.  Finally, the battery you mentioned is an alkaline battery, which isn't rechargeable like the CR2032.  I like the stacking idea, though!  Do you have a reference for a stacking battery holder?" CreationDate="2010-11-03T15:08:14.697" UserId="857" />
  <row Id="7562" PostId="6124" Text="Very cool. Looks much easier than typing numbers into a text editor! " CreationDate="2010-11-03T15:11:45.150" UserId="1225" />
  <row Id="7563" PostId="6108" Score="2" Text="Do you know the manufacturer? " CreationDate="2010-11-03T15:12:26.523" UserId="857" />
  <row Id="7564" PostId="6108" Text="No idea on the manufacturer." CreationDate="2010-11-03T15:12:47.847" UserId="1225" />
  <row Id="7565" PostId="6112" Text="+1 for &quot;8 channels @ 10 kHz is not a very high data rate&quot; - I can't believe no one has said that yet." CreationDate="2010-11-03T15:15:55.307" UserId="857" />
  <row Id="7567" PostId="6087" Score="1" Text="freedfm is great, even if you aren't going to have them fab your board." CreationDate="2010-11-03T15:28:59.190" UserId="1278" />
  <row Id="7568" PostId="6126" Score="1" Text="Do you have a source for those numbers?  I know that CEC Compliance requires a &lt;0.5W no-load dissipation, but I'm not sure about your guess." CreationDate="2010-11-03T15:29:03.610" UserId="857" />
  <row Id="7569" PostId="6126" Score="2" Text="&quot;Hand test&quot;: Most wall warts feel like they dissipate about 1...3 W. This is only a guess, though, I admit, but it seems reasonable: The bulk voltage at the primary side is often around 320 V. The typical supply voltage for the primary control circuit is around 12 V. In no-load, the aux winding will not provide enough energy to keep the primary side alive, so a resistor will have to drop ca. 300 V at ca. 2...5 mA, which is the typical current that a cheap design needs at the primary. 300 V * 4 mA = 1,2 W. The no-load efficiency of most cheap switchers is not good except for some newer designs." CreationDate="2010-11-03T15:35:06.853" UserId="930" />
  <row Id="7570" PostId="6113" Text="Woops, you're right about the capacity, sorry. CR2032 isn't rechargeable either, to my knowledge? The request was for batteries to be replaceable anyway, not rechargeable :-) Don't have a reference for a retail holder, but that should be easily achievable with a little DIY. Unless you're planning to produce a large amount of boards, of course..." CreationDate="2010-11-03T15:41:15.393" UserId="1124" />
  <row Id="7571" PostId="6126" Score="1" Text="&quot;Hand test&quot; - I like it." CreationDate="2010-11-03T15:48:27.000" UserId="857" />
  <row Id="7572" PostId="6091" Score="2" Text="Do you want an MSO (digital storage multi-signal oscilloscope) or a normal analog scope?   Also, ask yourself if you need the analog signals - Are you worried about DC variation and line noise, or is checking that the clock is a reasonably digital waveform with a few captures, and then pulling out the digital probes for some digital troubleshooting good enough?" CreationDate="2010-11-03T15:55:15.957" UserId="857" />
  <row Id="7573" PostId="6105" Score="1" Text="I used a two-channel scope at school to debug an SPI protocol.  Trigger on chip select, take screenshots of waveforms, translate to binary then hex, correlate with other two sets of screenshots...nasty. Then, I got to play with a 4-channel MSO with serial analysis tools at work.  Plug it in, tell it what channel is what SPI line, and download the hex in under a minute after power-on, as opposed to the hour-long struggle with the 2-channel analog scope.  Such a nice tool..." CreationDate="2010-11-03T15:59:10.250" UserId="857" />
  <row Id="7574" PostId="6111" Text="What does &quot;not too expensive&quot; mean?  We have both professionals and hobbyists on this site." CreationDate="2010-11-03T16:16:28.460" UserId="857" />
  <row Id="7575" PostId="6104" Score="1" Text="0.7V is from base (the resistor connected to the PIC) to the emitter.  You can get as low as 0.2V from the collector to the emitter in saturation." CreationDate="2010-11-03T16:19:03.140" UserId="857" />
  <row Id="7576" PostId="6103" Score="3" Text="If the variation in beta from transistor to transistor is important to your design, you're doing it wrong." CreationDate="2010-11-03T16:25:21.037" UserId="857" />
  <row Id="7577" PostId="6069" Text="In my opinion, it doesn't just pass as an appropriate question, this is an example of a great question!" CreationDate="2010-11-03T16:32:42.330" UserId="857" />
  <row Id="7578" PostId="6111" Text="The Agilent 2 analog / 16 digital arrangement has worked well for me also." CreationDate="2010-11-03T16:38:46.243" UserId="712" />
  <row Id="7579" PostId="6124" Text="Neat!  I've not seen that utility before, and imagined that subtle errors (height/width ratio, line thickness, not-to-scale etc) would be present with such an approach.  Has that worked well for you in the pas?  " CreationDate="2010-11-03T16:39:18.360" UserId="857" />
  <row Id="7580" PostId="3332" Text="+1 for Findchips." CreationDate="2010-11-03T16:40:56.100" UserId="857" />
  <row Id="7581" PostId="6071" Text="+1, the entire left side of that drawing is referenced on the center line defined on the right side (for vertical positions).  So start with GND1/2, find the center line, then do the left side." CreationDate="2010-11-03T16:45:31.683" UserId="1438" />
  <row Id="7582" PostId="6124" Text="I must confess, I've only tried this approach once.  I've got a Python script to write out footprints.  I write a little program for each footprint, which generates the pads based on the drawings dimensions.  This is not quite as insane as it sounds -- I'm prone to stupid arithmetic errors, so having a program do all the math lets me verify it." CreationDate="2010-11-03T16:55:36.777" UserId="411" />
  <row Id="7583" PostId="6123" Score="1" Text="I kept reading &quot;wall wart&quot; as &quot;wal mart&quot; and was very confused." CreationDate="2010-11-03T16:56:57.230" UserId="1822" />
  <row Id="7584" PostId="774" Score="2" Text="Also, in choosing Verilog or VHDL, consider the language in light of it being an investment in your future marketability.  In the US, Verilog is more popular in IC/chip development than VHDL so knowing Verilog (and its enhanced version, System Verilog) will likely be a better longterm investment.  It also seems that all the big EDA companies are investing in verilog and system verilog, whereas VHDL is not getting much attention. ( witness VCS mixed simulation with vhdl vs VCS verilog simulator performance differences ).   (que the flaming )  Yes you can learn both, but why not prioritize." CreationDate="2010-11-03T16:58:55.840" UserId="1708" />
  <row Id="7585" PostId="6130" Text="Gas/LP/oil is about half the cost of electricity per BTU of useful heat you get from them." CreationDate="2010-11-03T17:00:57.523" UserId="1407" />
  <row Id="7586" PostId="6124" Text="I have a question. How does the utility know that the pads are X mm's wide when the drawing may be made at any scale? " CreationDate="2010-11-03T17:15:42.183" UserId="1225" />
  <row Id="7587" PostId="774" Text="You can write it in either language.  I think the Xilinx tools can take Verilog and VHDL, even in the same project.  FWIW, I'm in the US and I've never used Verilog." CreationDate="2010-11-03T17:19:46.750" UserId="1278" />
  <row Id="7588" PostId="6112" Text="Not if he's doing 8-channel FFT..." CreationDate="2010-11-03T17:21:17.467" UserId="1278" />
  <row Id="7589" PostId="3036" Text="@DoxaLogos - You say that avoiding inheritance/virtual functions is a good thing - can you explain what you mean?  Does this idea exclude the possibility of writing classes to an abstract base class interface?" CreationDate="2010-11-03T17:39:01.973" UserId="374" />
  <row Id="7590" PostId="6100" Text="The original question specifically asks about fumes from lead-free solder." CreationDate="2010-11-03T17:45:37.093" UserId="103" />
  <row Id="7591" PostId="6131" Text="Good idea. I used to have a space for this but I omitted it." CreationDate="2010-11-03T17:55:55.973" UserId="1225" />
  <row Id="7592" PostId="6129" Text="Some very helpful answers here, but this one was the most helpful to me with the pointers about switch-mode PSUs. Thanks!" CreationDate="2010-11-03T18:04:14.557" UserId="1317" />
  <row Id="7593" PostId="6131" Text="&quot;This space intentionally left blank&quot; could be filled with this info." CreationDate="2010-11-03T18:34:45.877" UserId="204" />
  <row Id="7594" PostId="6130" Text="Half the cost of an inconsequential amount is still inconsequential :)" CreationDate="2010-11-03T18:45:32.213" UserId="142" />
  <row Id="7595" PostId="6134" Text="AC or DC inverter?" CreationDate="2010-11-03T18:48:17.123" UserId="1397" />
  <row Id="7596" PostId="6134" Text="I'm not sure. It plugs into the mains. When you turn up the voltage it whines very loudly. I'm thinking it's probably a flyback transformer with a variable oscillator for adjusting the voltage." CreationDate="2010-11-03T18:51:57.807" UserId="1225" />
  <row Id="7597" PostId="6138" Text="The EHT was a good five feet away from the projector, so it's pretty amazing it can cause problems that far away. It's possible noise got into the video cable though." CreationDate="2010-11-03T19:04:50.410" UserId="1225" />
  <row Id="7598" PostId="6138" Text="I've seen that plasma tweeter before. It looks pretty cool." CreationDate="2010-11-03T19:06:25.977" UserId="1225" />
  <row Id="7599" PostId="6138" Text="I'm not sure what it looked like, but if its of the 2 electrode type with a 'beam' of plasma flowing between the tips (like the tweeter) then both electrodes and the stream of plasma are acting a pretty good sized antenna with no shielding at all. " CreationDate="2010-11-03T19:10:16.357" UserId="1438" />
  <row Id="7600" PostId="6138" Text="No it was just an EHT power supply, like any normal supply but it produces 5kV. It wasn't a plasma generator." CreationDate="2010-11-03T19:13:43.050" UserId="1225" />
  <row Id="7601" PostId="6138" Text="well a &quot;plasma generator&quot; is nothing but a high voltage supply, all you do is place the probes close enough, and set the voltage high enough, to arc through the air and ionize it.  You can tweak it with tip metallurgy but thats the basics.  Additionally ionic liquids produce plasma at the liquid-air boundary when setup with a high voltage.  From your description the ionic liquid was directly under the microscope, so the leads from the EHT had to be right under the microscope also, the probes/plasma/liquid was radiating the interference, which was quite close to the USB scope." CreationDate="2010-11-03T19:32:46.447" UserId="1438" />
  <row Id="7602" PostId="6141" Text="That's a bit vague... I mean a voltage regulator is a power management IC." CreationDate="2010-11-03T19:50:20.447" UserId="1225" />
  <row Id="7603" PostId="5991" Text="What does &quot;Above 2 MΩ&quot; mean?  Is that the limit of your meter?  I tried the inside, outside, and steadily stabbing the lip of a brand new 3M (metallized) bag I have and never got any consistent reading within my meter's range, 500 MΩ, or any significant conductivity reading (&lt; 1 nS)." CreationDate="2010-11-03T19:52:05.687" UserId="1407" />
  <row Id="7604" PostId="6139" Text="Who would a) ship coin cells (or any batteries) loose, b) waste ESD-safe material on non-sensitive parts?  Please tell so I can never buy from them." CreationDate="2010-11-03T19:53:32.613" UserId="1407" />
  <row Id="7605" PostId="6081" Text="@Thomas - That would be a *really small* screw.  I couldn't source one.  M1.4 is the smallest I've heard of, and M2 is the smallest I've used.  You'd need an &quot;M1.2&quot; screw for a close fit, and an &quot;M1.1&quot; screw for a loose fit (you want the looser fit if your users will be making their own mounts).  A 4x40 screw would be much more user friendly; use a #30 drill/.1285&quot;/ 128.5 mil hole instead. " CreationDate="2010-11-03T19:53:56.107" UserId="857" />
  <row Id="7606" PostId="6081" Text="Okay, but a 128.5mil hole is much bigger than the 60mil one I'm using, so it takes up more space. What is the smallest screw you think I could get that a user could use?" CreationDate="2010-11-03T19:55:08.273" UserId="1225" />
  <row Id="7607" PostId="6086" Text="Care to upload high-res versions of those images?  I don't have PCB on the machine I'm using right now, and I suspect that many readers don't have it at all." CreationDate="2010-11-03T19:56:35.977" UserId="857" />
  <row Id="7608" PostId="6081" Score="1" Text="With a 4x40 hole size, drills, hex keys, and screws/washers/nuts will be in your users' toolboxes and local hardware stores.  You can go to 2x56 (#41/.0960&quot;) if you really want to, but that makes sourcing much more difficult." CreationDate="2010-11-03T19:59:44.850" UserId="857" />
  <row Id="7609" PostId="6143" Text="As mentioned in my previous question that wouldn't be suitable because diodes drop too much voltage. I'm looking for an IC to do this." CreationDate="2010-11-03T20:00:33.447" UserId="1225" />
  <row Id="7610" PostId="6086" Text="The image link is http://i.imgur.com/pw6xm.jpg .  Open it directly and you'll get a bigger size." CreationDate="2010-11-03T20:02:34.860" UserId="411" />
  <row Id="7611" PostId="6143" Text="@Thomas O: How much current are you drawing at peak and when in standby, and what are the voltages?" CreationDate="2010-11-03T20:02:53.553" UserId="1407" />
  <row Id="7612" PostId="6143" Text="Peak: 120mA, standby: 1µA, 3.3V." CreationDate="2010-11-03T20:05:06.513" UserId="1225" />
  <row Id="7613" PostId="6129" Text="@Kaelin - I'm glad that it was helpful, but you can feel free to wait a while for even more helpful answers to filter in.  24-48 hours (probably more while we're small) is a good reference.   You can click the green arrow again to remove/postpone your answer selection. " CreationDate="2010-11-03T20:05:45.107" UserId="857" />
  <row Id="7614" PostId="6129" Text="If it gives you a message about &quot;You can't revoke your choice until this answer has been edited&quot;, just add another comment and I (or another user with edit privileges) will do a `touch` or trivial edit to give you that ability for a few hours." CreationDate="2010-11-03T20:06:17.977" UserId="857" />
  <row Id="7615" PostId="6144" Text="Those require external fets, any with built in fets?" CreationDate="2010-11-03T20:07:14.687" UserId="1225" />
  <row Id="7616" PostId="6144" Text="@Thomas: See update.  I'd also think some supercapacitor IC managers might work as well, but couldn't find any off-hand." CreationDate="2010-11-03T20:12:18.953" UserId="1407" />
  <row Id="7617" PostId="6141" Text="+1 - That's what I would have called it.  Digikey apparently agrees with Thomas with [27 'PMIC' categories](http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&amp;site=US&amp;WT.z_homepage_link=hp_go_button&amp;KeyWords=PMIC&amp;x=0&amp;y=0), but this one - [Power Supply Controllers](http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=2556707&amp;k=PMIC) looks like it contains what he wants." CreationDate="2010-11-03T20:13:11.980" UserId="857" />
  <row Id="7618" PostId="6141" Text="@ree: PMIC is an incredibly general term that encompasses virtually all ICs that are not strictly logic/digital or analog.  Taking a brief look at the &quot;Power Supply Controllers&quot; they generally appear to be specialized logic chips that don't actually handle/pass any power." CreationDate="2010-11-03T20:30:07.793" UserId="1407" />
  <row Id="7619" PostId="6138" Text="The EHT leads went to a microscope slide with a bit of paper on it. Two ionic solutions were dropped on to the slide, each was a different colour. EHT of around 1kV was applied to opposite ends of the plate, and the ionic solutions crawled to either end very slowly. USB microscope was suspended 2 ft from test rig, but it still glitched, and projector was quite a distance away and it had problems too." CreationDate="2010-11-03T20:32:20.427" UserId="1225" />
  <row Id="7620" PostId="6141" Text="Yeah, that's my problem. They are sequencer IC's, not battery backup IC's. I'd hate to have to go to a multi chip solution as space is critical." CreationDate="2010-11-03T20:33:21.983" UserId="1225" />
  <row Id="7621" PostId="6100" Text="Thank you for pointing out my mistake." CreationDate="2010-11-03T20:47:57.537" UserId="1413" />
  <row Id="7622" PostId="6141" Score="1" Text="@Tho: What was the issue with having a diode from the battery to the supply line (no diode along the main supply)?  Li/MnO2 cells have an open voltage of 3.2-3.3 V, so the battery diode shouldn't conduct normally." CreationDate="2010-11-03T20:52:13.100" UserId="1407" />
  <row Id="7623" PostId="6141" Text="Well, I need to isolate my supplies. The switched voltage only needs to go to the MCU. There is also a DSP and LED on the board which would drain the battery pretty quick." CreationDate="2010-11-03T21:02:02.730" UserId="1225" />
  <row Id="7624" PostId="5991" Text="@Nick yes, that is the limit of my meter, but as Jack said, identically looking bags can have totally different characteristics" CreationDate="2010-11-03T21:24:08.350" UserId="1298" />
  <row Id="7625" PostId="6141" Score="1" Text="you need to use a multi-channel power management controller and just get it over with..." CreationDate="2010-11-03T21:24:08.550" UserId="1438" />
  <row Id="7626" PostId="6139" Text="@Nick coin cells aren't sensitive to ESD but they are sensitive to conductivity. That's the main reason you should send them back." CreationDate="2010-11-03T21:25:47.520" UserId="1298" />
  <row Id="7627" PostId="1904" Text="@Mr. Hedgehog - That comment should really be an answer." CreationDate="2010-11-03T21:33:33.050" UserId="857" />
  <row Id="7628" PostId="6143" Text="Schottky diodes would only drop 0.3-0.4 V at 120 mA (36 mW), and less at lower currents.  Will your IC do better?" CreationDate="2010-11-03T21:41:18.393" UserId="142" />
  <row Id="7629" PostId="6067" Text="Good point! I forgot to add that." CreationDate="2010-11-03T21:42:09.560" UserId="1225" />
  <row Id="7630" PostId="6070" Text="Also make sure its a really low contact resistance relay, preferably solid state i guess, I mean at 70A your load is 0.171 Ohms.  You don't need much resistance in the relay to get a large enough voltage drop to be a problem." CreationDate="2010-11-03T21:53:10.053" UserId="1438" />
  <row Id="7631" PostId="6138" Text="Tweeters?  You can do better than that. :D http://www.youtube.com/watch?v=-GJSH5Aw3yk" CreationDate="2010-11-03T22:02:25.197" UserId="1407" />
  <row Id="7632" PostId="6130" Score="1" Text="If you use a heat pump instead of wall warts you get 500% efficiency from electricity to heat during winter. 100% is not something to strive for when using electricity to get heat." CreationDate="2010-11-03T22:27:01.203" UserId="1448" />
  <row Id="7633" PostId="6149" Text="+10 if I could!  Great first post." CreationDate="2010-11-03T22:28:28.743" UserId="857" />
  <row Id="7634" PostId="6143" Text="http://www.falstad.com/circuit/#%24+1+5.0E-6+10.20027730826997+45+5.0+43%0Av+288+320+288+208+0+0+40.0+3.0+0.0+0.0+0.5%0A172+288+128+256+128+0+6+2.7+5.0+0.0+0.0+0.5+Voltage%0Ad+288+128+416+128+1+0.42%0Ar+416+208+416+320+0+25.0%0Aw+288+320+416+320+0%0Aw+416+208+416+128+0%0Ag+288+320+288+336+0%0Ad+288+208+416+208+1+0.42%0Ao+3+64+0+35+5.0+0.2+0+-1%0A" CreationDate="2010-11-03T23:04:42.410" UserId="142" />
  <row Id="7635" PostId="6133" Text="I think there's an unstated distinction between the two paragraphs in this response.  Testing refers to a procedure which is supposed to demonstrate that the soft, firm, and/or hard wares work properly.  Debugging is the process in which the code is stepped through instruction-by-instruction to see why it isn't working [yet]. " CreationDate="2010-11-04T00:25:42.677" UserId="857" />
  <row Id="7636" PostId="6134" Text="Your digital clock uses high voltages?  Is it a Nixie clock by any chance? :)" CreationDate="2010-11-04T00:26:26.657" UserId="857" />
  <row Id="7637" PostId="6138" Text="@nick yea but that doesn't look like the arcs are generating the audio, or not much of it and only the electronic sounding bits.  In the case of the plasma tweeter, the plasma is actually creating the sound and can actually be quite accurate." CreationDate="2010-11-04T00:50:53.910" UserId="1438" />
  <row Id="7638" PostId="126" Score="2" Text="unless you want to try sourcing the mating connector for that unusual NES plug, why worry about the pinout? I'd probably cut the original plug off and replace it with a DB-9, and wire it to suit." CreationDate="2010-11-04T00:51:14.440" UserId="740" />
  <row Id="7639" PostId="6154" Text="classic electromagnetic interference (EMI) " CreationDate="2010-11-04T01:20:01.467" UserId="740" />
  <row Id="7640" PostId="6151" Text="Not an answer, but just a double check. Could it be that diodes are actually just a half bridge say with common cathode. " CreationDate="2010-11-04T01:26:35.347" UserId="924" />
  <row Id="7641" PostId="6138" Text="don't discount interference via conduction; it could be getting back through the power feed, especially if things are all plugged into the same outlet." CreationDate="2010-11-04T01:30:38.353" UserId="740" />
  <row Id="7642" PostId="6133" Text="It's nice to have a choice. So the testing can cover more varieties/permutations with and without optimization. More the coverage, the better is testing" CreationDate="2010-11-04T02:08:15.217" UserId="924" />
  <row Id="7643" PostId="6029" Text="It could be a &quot;ferroresonant voltage stabiliser&quot; thing. It was not a transformer 100%, but some hybrid with air gap for saturation." CreationDate="2010-11-04T02:11:34.980" UserId="924" />
  <row Id="7644" PostId="6146" Text="Excellent. I'll check out the N-channel MOSFET, which looks to be exactly what I need. The tutorial was good. I found another great tutorial at http://digital-diy.com/Handy-Tips/digi-tip-logic-level-fets-n-channel.html that helped as well." CreationDate="2010-11-04T02:11:45.733" UserId="1206" />
  <row Id="7645" PostId="2468" Text="Not exactly an answer, but a pointer. There is shop near Boston on rt9/rt95 named &quot;YoudoItElectronics&quot;. " CreationDate="2010-11-04T02:17:41.777" UserId="924" />
  <row Id="7646" PostId="3031" Text="I agree with vicatsu. Why is he voted down ? I am software professional with 20+ years of expirience (non-embedded). And my opinion about C++ is that it is most expensive language, unfortunately popular because of early popularity of plain C. Plain C was popular just for one reason: there was a single really good book about this language which was written really well (the usability of C and C++ language is complete opposite)" CreationDate="2010-11-04T02:25:07.827" UserId="924" />
  <row Id="7647" PostId="6093" Text="Good units: A, amp, V, volt, s (for second)  Not units: a, Amp, v, Volt, S (when you think it means second but really means siemen)" CreationDate="2010-11-04T02:35:16.840" UserId="1407" />
  <row Id="7648" PostId="6160" Score="1" Text="I would not call a 3A/48V, 4-axis stepper controller &quot;low power&quot;.  Your requirements (Ethernet/DIN/motor control) seem fairly disparate so I would be surprised to find a single unit that does all that.  By &quot;$100 I/O ports&quot; do you mean an RS485 card?" CreationDate="2010-11-04T03:02:50.500" UserId="1407" />
  <row Id="7649" PostId="6163" Score="1" Text="Can't you light one LED or the other by driving their common return pins from digital outputs?" CreationDate="2010-11-04T03:22:59.233" UserId="142" />
  <row Id="7650" PostId="6165" Text="If the PWM pins on the uC can't provide enough current, then a few PMOS/PNP transistors are in order.   No biggie!" CreationDate="2010-11-04T03:40:03.627" UserId="857" />
  <row Id="7652" PostId="6157" Score="3" Text="I have a professor who does this often, he will take 1000 diodes, literally, and measure their VI curve. Then he will strain them to have a very precise match. He sorts them into matching bins. Then he keeps them heat-sinking together." CreationDate="2010-11-04T03:42:00.170" UserId="230" />
  <row Id="7653" PostId="6157" Text="It could be that the Diodes are the most common fail component and they slapped two in for higher reliability, but i doubt that." CreationDate="2010-11-04T03:42:44.940" UserId="230" />
  <row Id="7654" PostId="6096" Text="Robotics is always more fun than finance!  " CreationDate="2010-11-04T03:44:04.973" UserId="1609" />
  <row Id="7655" PostId="6096" Text="My education was fairly good, but others coming upon this question - YMMV.   My bachelor's  and graduate eduation was all physics.  I did some electronics lab instruction, design and troubleshooting as part of that.  20 years in software - and I've never had even one software class!" CreationDate="2010-11-04T03:46:08.750" UserId="1609" />
  <row Id="7656" PostId="6165" Text="yea but that may cut into the &quot;powered from the netduino&quot; bit, or at least as much as just using the external PWM driver would.  Both should only require tapping into the netduino's supply lines which shouldn't be hard but at all but....meh..." CreationDate="2010-11-04T03:57:10.030" UserId="1438" />
  <row Id="7657" PostId="6167" Text="Just some constructive criticism about your post. I think many people will gloss over your question because of such a big paragraph. You might want to consider editing your post to have some line breaks at meaningful points to make it easier to read. This will probably result in you getting better answers." CreationDate="2010-11-04T04:33:15.603" UserId="319" />
  <row Id="7658" PostId="6169" Text="I took it that the distance was controllable, if it is not, please test what I said, and if it does not work, look into other solutions." CreationDate="2010-11-04T04:49:02.107" UserId="230" />
  <row Id="7659" PostId="6158" Text="Your answer is nice. Do need to make sure the resistor is enough to stabilize the system, but it is a very small resistance at high current, so easy to do." CreationDate="2010-11-04T04:52:43.803" UserId="230" />
  <row Id="7660" PostId="6170" Text="It seems he needs to increase stack allocation, I thought even c18 allowed that. It does cost money for a corporation to use and should have nice optimizer and so forth. I have never seen a cost money compiler not allow stack allocation." CreationDate="2010-11-04T04:55:25.050" UserId="230" />
  <row Id="7661" PostId="6169" Text="unfortunately the distance is not uncontrollable to the disc. The device is merely placed on top of it. these discs also sometimes come with a rubber coating of unknown thickness (&lt; 1cm)." CreationDate="2010-11-04T05:03:30.310" UserId="1688" />
  <row Id="7662" PostId="6141" Text="or pepper your board with diodes, like noted." CreationDate="2010-11-04T05:08:35.977" UserId="230" />
  <row Id="7663" PostId="6172" Text="This should be community wiki - if only i had the magic button" CreationDate="2010-11-04T05:47:41.717" UserId="1609" />
  <row Id="7664" PostId="3438" Text="How close was your camera lens to the subject?" CreationDate="2010-11-04T06:05:51.443" UserId="1609" />
  <row Id="7665" PostId="6175" Score="2" Text="Oh Great Red Rocker Switch, thou Controller of all Power! We bow to thee!" CreationDate="2010-11-04T06:57:29.617" UserId="1609" />
  <row Id="7666" PostId="6151" Text="Each package contains two diodes I think." CreationDate="2010-11-04T07:56:27.877" UserId="1225" />
  <row Id="7667" PostId="6134" Text="My digital clock does not use high voltages, it operates off two AA's.  I should clarify, the plasma ball uses high voltages, as does the EHT." CreationDate="2010-11-04T07:58:15.770" UserId="1225" />
  <row Id="7668" PostId="6173" Score="10" Text="please google before posting" CreationDate="2010-11-04T08:12:19.433" UserId="1200" />
  <row Id="7669" PostId="1904" Text="@reemrevnivek - The reason I left it as a comment was because it didn't directly answer the question being asked (just his sub-question). But yeah, you may be right." CreationDate="2010-11-04T09:05:28.713" UserId="1333" />
  <row Id="7671" PostId="6173" Score="5" Text="@Rick_2047, I think that we'd answer here. See the Stackexchange FAQ: http://meta.stackoverflow.com/questions/8724/how-to-deal-with-google-questions" CreationDate="2010-11-04T11:03:35.207" UserId="938" />
  <row Id="7672" PostId="6185" Score="1" Text="+1 for glases! One time I was soldering a small part, I leaned in really close to it and then for some reason (manufacturing defect, I guess) solder released above average amount of fumes which got into my (unprotected) eyes. I was stunned for a couple of seconds and almost dropped the iron." CreationDate="2010-11-04T11:13:36.330" UserId="1240" />
  <row Id="7673" PostId="6166" Text="Yes, I know about this AMCI network piece with extra drives. But the price is prohibitive. Thank you for answer." CreationDate="2010-11-04T11:13:52.960" UserId="924" />
  <row Id="7674" PostId="6173" Score="4" Text="SE sites were meant to be the source for Google and similar search providers, just as agreed in @O Engenheiro♦'s link." CreationDate="2010-11-04T11:20:04.080" UserId="1240" />
  <row Id="7675" PostId="6185" Score="1" Text="+1 for glasses, I only had to get ferric chloride in my eye once before I bought some" CreationDate="2010-11-04T11:49:53.197" UserId="566" />
  <row Id="7677" PostId="5568" Text="See the Stackexchange FAQ: http://meta.stackoverflow.com/questions/8724/how-to-deal-with-google-questions" CreationDate="2010-11-04T12:17:21.697" UserId="938" />
  <row Id="7678" PostId="6175" Text="what kind of socket is on the power bar in the picture?" CreationDate="2010-11-04T12:18:01.260" UserId="1836" />
  <row Id="7679" PostId="6175" Text="@warren: European plugs, from when I used them they are a little nicer, but probably more expensive to manufacture and somewhat larger." CreationDate="2010-11-04T12:43:19.113" UserId="1407" />
  <row Id="7680" PostId="6178" Score="1" Text="+1 to having a 'test' box. " CreationDate="2010-11-04T12:47:35.013" UserId="1307" />
  <row Id="7682" PostId="6173" Text="-1 from me for such an ill-thought out question., but +1 for Rick_2047 for such a good comment. You should have posted it as an answer." CreationDate="2010-11-04T13:09:14.630" UserId="974" />
  <row Id="7683" PostId="6187" Text="This reminds me of what I tell my 6 year old: Engage the brain!  Good advice though - our brain is our number 1 piece of safety equipment." CreationDate="2010-11-04T13:48:25.263" UserId="1823" />
  <row Id="7684" PostId="6172" Score="1" Text="Safety is not my strong point. I have the fuses at the right rating if that counts. I keep soldering irons on the other side of the room." CreationDate="2010-11-04T13:48:54.307" UserId="1225" />
  <row Id="7685" PostId="6143" Text="It needs to interface to 3.3V logic, so loosing .3V on the supply is not good. " CreationDate="2010-11-04T13:52:58.233" UserId="1225" />
  <row Id="7686" PostId="6170" Text="PIC18 devices have a fixed stack.  We use the Hi-Tech PICC18 compiler which actually optimizes the stack for me.  The problem is, it is still possible to slow execution if care is not taken to keep call depth short." CreationDate="2010-11-04T13:54:47.310" UserId="1830" />
  <row Id="7687" PostId="3438" Text="I don't remember.  A few cm." CreationDate="2010-11-04T14:07:47.923" UserId="142" />
  <row Id="7688" PostId="6167" Text="Point taken, as well as corrective action :)" CreationDate="2010-11-04T14:18:19.283" UserId="1830" />
  <row Id="7689" PostId="6143" Text="A 220 Ω resistor will eliminate any ill effect from putting 3.3 V into a 3.0 V clamped chip." CreationDate="2010-11-04T14:20:54.427" UserId="1407" />
  <row Id="7690" PostId="1781" Text="&quot;Would this be any more useful or desirable than the current USB oscilloscopes available?&quot;  That depends on the software more than the hardware." CreationDate="2010-11-04T14:23:13.287" UserId="142" />
  <row Id="7691" PostId="6150" Text="Yes Id prefer the &quot;rigid route&quot; if possible. I had a look at the digi-key link but there were only 2 items with images http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=924217-24-20-I-ND I don't see how one of these will work? I also googled &quot;double-level mezzanine&quot; but it didn't yeild anything relevant." CreationDate="2010-11-04T14:41:14.687" UserId="819" />
  <row Id="7692" PostId="6139" Text="It's been too long.  I don't remember the details.  It might have been either Li batteries in small, individual pink bags, or a clock chip stuck in conductive foam. " CreationDate="2010-11-04T14:49:26.263" UserId="1824" />
  <row Id="7693" PostId="6150" Text="It's just like a standard 0.100&quot; header but with an additional plastic spacer.  More pictures at the mfc website (their docs seem to be down): http://www.tycoelectronics.com/catalog/bin/TE.Connect?C=10078&amp;M=FEAT&amp;P=&amp;U=&amp;BML=10576%2C17560%2C17540%2C17745&amp;LG=1&amp;LBOX=2339  What you use is highly dependent on the mechanical package you're fitting it into (if any).  If this is a 1-off/prototype thing, you could use a standard male/female header (a la Arduino) to allow easy removal/replacement." CreationDate="2010-11-04T14:51:46.870" UserId="1407" />
  <row Id="7698" PostId="6150" Text="Ya.. I just dont see how you would easily attach this to a cable. What I really would like is something similar to a IDC box header to solder on to GLCD, except obviously it would need to be a single row of pins (the standard Arduino type would probably work), and then some matching connector that can be crimped onto ribbon cable. Yes I know Im lazy... but I would like some simple and neat." CreationDate="2010-11-04T15:23:29.770" UserId="819" />
  <row Id="7699" PostId="6175" Text="The US version kind of don't fit here :)" CreationDate="2010-11-04T15:24:08.703" UserId="689" />
  <row Id="7701" PostId="6196" Score="1" Text="I believe your question could have some validity, can you please elaborate on the scope of your question.  Are you speaking in reference to the exchange of electrons or are you speaking in more of a supernatural aspect?" CreationDate="2010-11-04T15:28:12.503" UserId="1413" />
  <row Id="7702" PostId="6196" Text="@Michael yes, I am talking about physical reality, such as the exchange of electrons" CreationDate="2010-11-04T15:29:58.323" UserId="1840" />
  <row Id="7703" PostId="6150" Text="Does it have to be removable?  Do you want a rigid connection or flexible one?" CreationDate="2010-11-04T15:32:25.120" UserId="1407" />
  <row Id="7704" PostId="6196" Text="Good ol Ron Pease: http://www.national.com/rap/Story/0,1562,27,00.html  What is the actual capacitance from the earth to the moon? (at the bottom)" CreationDate="2010-11-04T15:33:49.173" UserId="1407" />
  <row Id="7705" PostId="1682" Text="Yeah, but all of those other scopes are 100x as big." CreationDate="2010-11-04T15:33:55.617" UserId="142" />
  <row Id="7706" PostId="1636" Text="You don't need to buy software to use your sound card as an oscilloscope. There are plenty of good free or open-source packages available." CreationDate="2010-11-04T15:34:23.687" UserId="1225" />
  <row Id="7707" PostId="6170" Score="1" Text="i will look into this. if i was your boss i would have purchased a new compiler a while ago." CreationDate="2010-11-04T15:38:39.063" UserId="230" />
  <row Id="7711" PostId="6150" Text="Removable would be good, but not essential, I just don't want to have to be solder ribbon cable directly to the GLCD or some connector. " CreationDate="2010-11-04T15:50:48.890" UserId="819" />
  <row Id="7712" PostId="6207" Text="So practically, it means it can only take in AC with a peak voltage of 250V?" CreationDate="2010-11-04T15:51:19.567" UserId="1225" />
  <row Id="7713" PostId="6175" Text="We have some benches that turn on when you login to the computer and turn off when you logoff. Pretty nice for an open lab." CreationDate="2010-11-04T15:51:59.683" UserId="319" />
  <row Id="7714" PostId="6143" Text="On *every* IO? It's a bit of a hack and doesn't allow for high speed signalling due to input capacitance." CreationDate="2010-11-04T15:52:28.787" UserId="1225" />
  <row Id="7715" PostId="6172" Text="community wiki now darenW." CreationDate="2010-11-04T15:52:34.277" UserId="230" />
  <row Id="7716" PostId="6207" Text="yes, but i would stay well below that threshold, i hate buying fuses." CreationDate="2010-11-04T15:54:34.667" UserId="230" />
  <row Id="7717" PostId="6207" Text="I think more than the fuse would blow, it would probably damage the inputs or at least reduce their performance." CreationDate="2010-11-04T15:55:17.257" UserId="1225" />
  <row Id="7718" PostId="6207" Text="in my experience a fuse blows, but play it safe." CreationDate="2010-11-04T15:56:19.750" UserId="230" />
  <row Id="7719" PostId="6207" Text="Hmm I haven't seen any fuses on the mainboard of my scope, but they could be hidden under the RF shielding." CreationDate="2010-11-04T16:01:30.387" UserId="1225" />
  <row Id="7720" PostId="6207" Text="i use relatively expensive scopes, they probably do not include this on cheaper scopes. all about cost." CreationDate="2010-11-04T16:03:21.740" UserId="230" />
  <row Id="7721" PostId="6173" Text="@O Engenheiro, &quot;Part of the thinking behind Stack Overflow was for those Google searches to link somewhere useful&quot;, but in most of the cases (i.e. when I will put such a comment) google already has the perfect answer." CreationDate="2010-11-04T16:04:27.880" UserId="1200" />
  <row Id="7722" PostId="6178" Score="3" Text="Camera phones are great for this" CreationDate="2010-11-04T16:13:47.207" UserId="1278" />
  <row Id="7727" PostId="6169" Text="i would suggest a basic patch or monopole then." CreationDate="2010-11-04T16:21:53.333" UserId="230" />
  <row Id="7728" PostId="6214" Score="2" Text="Yes, please don't have a fear of aluminum electrolytics without justification.  Just because some of them fail doesn't mean that the technology is fundamentally flawed and should be avoided.  CDE has some really nice literature on them http://www.cde.com/catalogs/AEappGUIDE.pdf  True, high temperatures can dry out the electrolyte, but as an example a cap rated for 2000 hr @ 105 °C will last 15 *years* at a quite balmy 45 °C.  +1" CreationDate="2010-11-04T16:35:30.250" UserId="1407" />
  <row Id="7730" PostId="6182" Text="They also don't have water soluble inks" CreationDate="2010-11-04T17:00:35.243" UserId="1407" />
  <row Id="7731" PostId="5696" Text="Could it be that it isn't possible to get one crystal frequency working with both?" CreationDate="2010-11-04T17:01:55.133" UserId="1225" />
  <row Id="7732" PostId="5696" Text="@Thomas O two crystals would not be problem the LM3S9xxx uses a separate crystal for the ethernet to the processor" CreationDate="2010-11-04T17:09:14.373" UserId="566" />
  <row Id="7733" PostId="6217" Text="Interesting device, but not what I'm looking for" CreationDate="2010-11-04T17:20:08.980" UserId="566" />
  <row Id="7734" PostId="6214" Score="1" Text="As for fans, consider magnetic bearing fans. The actually have no moving components in traditional sense and there's no wear during normal use. Still, it's a good idea to clean them once in a while just to make sure that dust doesn't go into the bearing. I have a couple of laptops with them and can say that they work great." CreationDate="2010-11-04T17:21:36.433" UserId="1240" />
  <row Id="7735" PostId="5696" Text="True, but adding an additional oscillator section adds cost, as does the crystal (for the end user.)" CreationDate="2010-11-04T17:24:23.153" UserId="1225" />
  <row Id="7736" PostId="5696" Text="@Joby: I'm curious why you want such a device; unless you are *extremely* space constrained it will command an enormous premium in cost due to being incredibly application specific (low-volume)." CreationDate="2010-11-04T17:28:20.357" UserId="1407" />
  <row Id="7737" PostId="6214" Score="1" Text="Better to avoid fans if at all possible using higher performing power handling components (supplies, switches, controllers).  I think his board is fairly low power so this isn't a major issue." CreationDate="2010-11-04T17:31:37.153" UserId="1407" />
  <row Id="7738" PostId="1638" Text="This would depend wildly on why you are looking at the signal; is it some analog trace or are you trying to look at the edges of your digital signal for overshoot, jitter, etc." CreationDate="2010-11-04T17:34:49.287" UserId="1407" />
  <row Id="7739" PostId="5696" Text="@Nick I work for a company which produces a high volume, low cost device featuring radio and ethernet. We currently have a 2 chip solution. I can't find a single chip and thought people might be able to help. Hence, the very specific question and bounty :-)" CreationDate="2010-11-04T17:39:03.697" UserId="566" />
  <row Id="7740" PostId="6210" Text="Both good chips, but they aren't what I'm looking for" CreationDate="2010-11-04T17:43:32.100" UserId="566" />
  <row Id="7742" PostId="6157" Score="1" Text="@Kor: Don't diodes usually fail closed?  True, it might &quot;open&quot; given enough power, but I'd think it would of taken something else out by then." CreationDate="2010-11-04T18:04:31.950" UserId="1407" />
  <row Id="7743" PostId="6157" Text="Good point, I forget that. You can get them that fail open, but sometimes we all say stupid things, I just do it more than most." CreationDate="2010-11-04T18:08:03.443" UserId="230" />
  <row Id="7744" PostId="6173" Score="2" Text="Giving him the benefit of the doubt, the OP might be trying to seed this forum with such useful reference info." CreationDate="2010-11-04T18:14:52.703" UserId="1844" />
  <row Id="7745" PostId="6220" Text="Please, put a link to the datasheet." CreationDate="2010-11-04T18:55:29.083" UserId="938" />
  <row Id="7746" PostId="6220" Text="I think this should apply for all dsPIC33F's but I've included a link to the product page anyway." CreationDate="2010-11-04T19:00:51.990" UserId="1225" />
  <row Id="7747" PostId="6179" Text="Repeat...e.g. you do it again anyways? :P" CreationDate="2010-11-04T19:23:03.957" UserId="1407" />
  <row Id="7748" PostId="6175" Score="1" Text="Way back in middle school, the wood shop had a Big Red Button to kill everything.  In college there were some giant (but boring) breakers in each electrical lab to cut all bench power." CreationDate="2010-11-04T19:26:09.070" UserId="1407" />
  <row Id="7749" PostId="6222" Text="Yeah, I want to measure pulse width from the comparator. Thanks for your note of experience." CreationDate="2010-11-04T20:18:35.673" UserId="1225" />
  <row Id="7750" PostId="6207" Text="My scope retailed for $3,300 USD new, but I only bought it for £150 (approx. $200.)" CreationDate="2010-11-04T20:33:58.603" UserId="1225" />
  <row Id="7751" PostId="6214" Text="Low power stuff. No fans necessary." CreationDate="2010-11-04T20:34:52.550" UserId="1225" />
  <row Id="7752" PostId="6139" Text="@NickT - Lots of parts which are not really ESD sensitive are treated as such by people that pack/ship them.   I don't think you'd have many suppliers left if you used that as a reason for a boycott!" CreationDate="2010-11-04T20:44:00.297" UserId="1844" />
  <row Id="7753" PostId="6104" Text="'Use a mosfet' is fair advice, but the bit about base and LED current being proportional is not right at all, when the transistor is being used as a switch (i.e. in saturation)" CreationDate="2010-11-04T20:47:08.487" UserId="1844" />
  <row Id="7754" PostId="6103" Text="When you're looking at current gain, you need to make sure you're looking at what it is in saturation, which is sometimes called hFE, but is not hfe which is for small-signal conditions." CreationDate="2010-11-04T20:49:36.530" UserId="1844" />
  <row Id="7756" PostId="6225" Score="3" Text="Why does it need to run code from RAM? (knowing this might help in answering)" CreationDate="2010-11-04T20:54:30.563" UserId="566" />
  <row Id="7757" PostId="6225" Score="1" Text="Why does it have to be exactly 44 pins, in that exact package?  That seems like a weird spec.  You know each micro has different pinouts, right?" CreationDate="2010-11-04T21:09:32.383" UserId="411" />
  <row Id="7758" PostId="6139" Text="@Will - Okay, they use high school dropouts to pull parts and have a high churn rate.  The resident EE should just tag the bins that need special/different packaging.  That way they don't ship spoiled parts and they keep their customers happy." CreationDate="2010-11-04T21:09:35.157" UserId="1824" />
  <row Id="7759" PostId="6224" Text="Every PIC I've ever seen configures all GPIO pins as inputs on power-up." CreationDate="2010-11-04T21:13:31.333" UserId="588" />
  <row Id="7760" PostId="6224" Text="Yes, quite.  I was just too lazy to go and look at the datasheet for that particular part.  Every time I guess what common-sense thing a modern micro is going to do with its I/O I get it wrong..." CreationDate="2010-11-04T21:15:17.043" UserId="1844" />
  <row Id="7761" PostId="6225" Score="1" Text="Sorry, 44 pins is just a cut-off size - I'd be okay with something bigger if it was about the same size." CreationDate="2010-11-04T21:16:26.350" UserId="1225" />
  <row Id="7762" PostId="6225" Text="I want to execute code from RAM so I can run programs off an SD card." CreationDate="2010-11-04T21:17:13.057" UserId="1225" />
  <row Id="7763" PostId="6197" Score="1" Text="I think users use stuff wrong in all phases of the moon." CreationDate="2010-11-04T21:17:52.567" UserId="588" />
  <row Id="7764" PostId="6226" Text="48 pins would be fine. Preferably a package with pins exposed, i.e. no QFN." CreationDate="2010-11-04T21:25:04.170" UserId="1225" />
  <row Id="7765" PostId="6224" Text="On that note, you may or may not want to be careful about adding a pull-up/-down resistor to that trace.  When the device comes up with both GPIO as inputs, it will be floating and this may or may not cause problems." CreationDate="2010-11-04T21:53:48.960" UserId="1278" />
  <row Id="7767" PostId="6230" Score="3" Text="For high bandwidth and long distance, you can't beat a 747 full of DVDs - high latency though" CreationDate="2010-11-04T22:30:18.193" UserId="566" />
  <row Id="7768" PostId="6230" Text="Good joke... somehow I'm thinking this is an impossible problem, which is why there are no small long distance HD video links." CreationDate="2010-11-04T22:36:14.160" UserId="1225" />
  <row Id="7769" PostId="6230" Text="Your question doesn't say wireless, is a wired solution acceptable?" CreationDate="2010-11-04T22:41:29.557" UserId="566" />
  <row Id="7770" PostId="6230" Text="It'd need to be wireless." CreationDate="2010-11-04T22:45:29.860" UserId="1225" />
  <row Id="7771" PostId="6170" Text="@nate you've still lost me, why would your solution to having a fixed length, relatively short stack be to make everything global so it takes up a memory location all the time rather than just when its needed on the stack?  You should minimize call depth and use as many local variables as you can within the target size of your stack to minimize memory use.  If theres one function that has a deep chain thats causing your stack to be large, optimize stack usage in that one function, not the entire project." CreationDate="2010-11-04T22:45:38.477" UserId="1438" />
  <row Id="7772" PostId="6230" Text="I was considering something like WAN or even WiFi with a directional antenna, but I'm not even sure if they can hit 80 Mbit/s peak at 10km distance, or even if it's possible to go that far." CreationDate="2010-11-04T22:46:28.983" UserId="1225" />
  <row Id="7773" PostId="6166" Score="2" Text="Cheap, Fast, Correct...choose 2." CreationDate="2010-11-04T22:47:03.953" UserId="1438" />
  <row Id="7774" PostId="6230" Text="Are the nodes stationary?" CreationDate="2010-11-04T22:47:26.057" UserId="566" />
  <row Id="7775" PostId="6230" Text="The nodes can move. One is an RC plane." CreationDate="2010-11-04T22:48:07.687" UserId="1225" />
  <row Id="7776" PostId="6215" Text="Ouch!   I love armless chairs for all kinds of reasons, snag prevention just one of them." CreationDate="2010-11-04T22:48:51.020" UserId="1609" />
  <row Id="7777" PostId="6231" Text="hall effect does not need motion." CreationDate="2010-11-04T22:52:02.560" UserId="1481" />
  <row Id="7778" PostId="6222" Score="4" Text="i'd toss a series resistor on the signal just to be safe" CreationDate="2010-11-04T22:52:42.683" UserId="1438" />
  <row Id="7779" PostId="1349" Text="Should this be closed?  The question depends on an image that isn't posted here and no longer exists.  Anyone in the future coming upon this question won't get any use from it." CreationDate="2010-11-04T22:53:56.903" UserId="1609" />
  <row Id="7781" PostId="6234" Text="Yeah, I didn't think it would be possible, but if it were, it would be awesome. I'm guessing that's why nobody has attempted it and always uses standard definition. Any chance of sending component video?" CreationDate="2010-11-04T22:57:11.310" UserId="1225" />
  <row Id="7782" PostId="6239" Text="And that goes triple for Robots. E-stop is the FIRST function. And it works in hardware. I've worked on big scary robots for years and never been so much as crushed to death. I wish some co-workers from my time in heavy industry had been so lucky." CreationDate="2010-11-04T23:02:31.707" UserId="1481" />
  <row Id="7783" PostId="6214" Text="If you want to taste the military-aerospace way, you replace all electrolytic caps with tantalum caps. " CreationDate="2010-11-04T23:04:54.280" UserId="1481" />
  <row Id="7785" PostId="6203" Score="2" Text="We used to measure drift in the fiber optic gyros...  (earths rotation). It precesses too so the rate varies. Astronomers do care about ( and measure) all this, and for them, phase of the moon matters. It was a joke at university, then I worked for astronomers. We even had to compute the phase of the moon to schedule important observations for dark nights. Star trackers go a bit wonky with phase of the moon too. The best star trackers work even in daylight for navigation. Better than GPS... sort of." CreationDate="2010-11-04T23:14:19.857" UserId="1481" />
  <row Id="7786" PostId="6222" Text="I agree with Mark. Nothing worse then accidentally managing to pull a pin when you didn't mean to causing stuff to over-current." CreationDate="2010-11-04T23:16:23.657" UserId="319" />
  <row Id="7787" PostId="6160" Text="Yes. Those RS485 cards are annoyance from software point of view. Cards like this are usually small batches no matter how big a manifacturer is. And so, the quality of drivers is always poor. for this reason alone, its worthy to use TCP/IP with zero proprietary software on PC host side." CreationDate="2010-11-04T23:17:42.570" UserId="924" />
  <row Id="7788" PostId="6207" Text="The one I have been using was bought at academic discount for $3,300 used. I believe it is significantly more new. No idea how much the others cost, but they have a fuse they blow if you do this to them." CreationDate="2010-11-05T00:34:29.177" UserId="230" />
  <row Id="7789" PostId="6133" Text="@reemrevnivek, when you're debugging, aren't you testing too?" CreationDate="2010-11-05T00:40:55.353" UserId="938" />
  <row Id="7790" PostId="6133" Text="@O Engenheiro - No.  I only debug if the test fails." CreationDate="2010-11-05T00:51:02.520" UserId="857" />
  <row Id="7791" PostId="6234" Text="The TV stream you get from an antenna is licensed to radiate 10kW(normally directivity gives a 10x multiplier on the power in the directions they have viewers). This allows very long distance transmission. This issue is that to transmit very high def, you need more bandwidth. Most people whom want high high def are just going to buy a cable modem, or get satellite(which is wireless with high def). " CreationDate="2010-11-05T00:53:43.023" UserId="230" />
  <row Id="7792" PostId="6093" Text="Units fixed. Thanks." CreationDate="2010-11-05T00:57:31.723" UserId="259" />
  <row Id="7793" PostId="6240" Text="This may not be true. When you read a thermocouple it is very important that the first device to amplify it's reading is designed for it. Small PCB trace missmatch can cause resistance changes which result in many errors." CreationDate="2010-11-05T01:00:50.890" UserId="230" />
  <row Id="7794" PostId="6236" Text="He won't be getting a license for that. :-)  Also ATSC is normally MPEG4-coded and transmitted at 18Mbps, which is a good deal smaller than the 80Mbps which he was looking for." CreationDate="2010-11-05T01:02:12.807" UserId="974" />
  <row Id="7795" PostId="6235" Text="&quot;Who says there's no software interrupt instruction?&quot; is the kind of humor I cannot get pure software or hardware guys to understand." CreationDate="2010-11-05T01:02:28.957" UserId="230" />
  <row Id="7796" PostId="6240" Text="In our case we don't need to worry about the thermocouples, we have a separate device reading those values, but this is good to know." CreationDate="2010-11-05T01:12:34.730" UserId="1846" />
  <row Id="7797" PostId="6240" Score="1" Text="Then +1 on the answer. I would suggest you use op-amps to give gain. I would suggest that you take time to research this. The point of senior design is to learn these methods. If i give you the answer I will be shorting you the learning process of finding application notes online. I think nothing could be better than you coming back and posting an answer explaining how to do this in detail with application notes and simulation." CreationDate="2010-11-05T01:58:20.383" UserId="230" />
  <row Id="7798" PostId="6233" Text="Sexy, no license required to operate?" CreationDate="2010-11-05T01:59:24.190" UserId="230" />
  <row Id="7799" PostId="6193" Text="The color varies by phone, what you added in all capitals makes up most of your post, which is really a comment. In just a little rep you will be able to post comments. I would suggest against all capitals in all situations. Bold if you want it to stand out." CreationDate="2010-11-05T02:07:56.237" UserId="230" />
  <row Id="7800" PostId="6211" Text="The bandwidth of two 500 kHz filters in series would be a little less than 500 kHz, though." CreationDate="2010-11-05T02:08:21.073" UserId="142" />
  <row Id="7801" PostId="6192" Text="It is not a range issue with the phone, it is the presence of an IR filter. High quality cameras have this." CreationDate="2010-11-05T02:08:38.060" UserId="230" />
  <row Id="7802" PostId="6180" Score="1" Text="IR Filters will block the IR. You actually want your camera to not have an IR filter." CreationDate="2010-11-05T02:11:02.770" UserId="319" />
  <row Id="7803" PostId="6192" Text="@Kortuk you are correct about the IR filter however most webcams and digital cameras don't have the filters. My iPhone sees IR just fine." CreationDate="2010-11-05T02:18:29.007" UserId="540" />
  <row Id="7804" PostId="6178" Text="The idea of making the trash can harder to use would prevent a lot of disasters!    Though maybe lead to more of others.." CreationDate="2010-11-05T02:20:12.097" UserId="1609" />
  <row Id="7805" PostId="6192" Text="I know that, I use them regularly. You stated &quot;Almost all digital cameras like the one in an iPhone has enough range to pick up IR.&quot;. It is not a range issue. That is what I am stating." CreationDate="2010-11-05T02:20:38.670" UserId="230" />
  <row Id="7806" PostId="6192" Score="1" Text="Unless you mean range as in percentage of the spectrum, in which case I would say no IR filter. Most people would call it bandwidth, I would at least." CreationDate="2010-11-05T02:21:47.467" UserId="230" />
  <row Id="7807" PostId="6245" Text="I always forget to tell people to use counter ICs. I have not had to get something like a binary counter for a project in years. +1" CreationDate="2010-11-05T03:27:13.737" UserId="230" />
  <row Id="7808" PostId="6240" Text="I completely agree. While I'm more in the software side of things, I definitely have a part in the electric portion of it as well. I came here not so much for a direct answer, but guidance because I wasn't sure who to trust for information." CreationDate="2010-11-05T04:02:35.610" UserId="1846" />
  <row Id="7809" PostId="6112" Text="DSPs are often single-threaded parallel processing units each capable of executing a different instruction (unlike SIMD where all units share the same instruction)." CreationDate="2010-11-05T04:21:10.153" UserId="1743" />
  <row Id="7810" PostId="6240" Text="@MGSoto from my experience when I had my Senior Design project, don't always trust grad students. Look at what the students specialization is and decide if that specialization would give him the ability to know what he is talking about on that subject. On the other hand, if he has any part in your grade, you should try to make him happy." CreationDate="2010-11-05T05:08:53.120" UserId="319" />
  <row Id="7812" PostId="6232" Text="This isn't really an answer. If you think it is a duplicate question just vote to close saying its a duplicate of that link." CreationDate="2010-11-05T05:13:59.150" UserId="319" />
  <row Id="7813" PostId="6228" Score="3" Text="I've always heard it rendered as &quot;Gate Array Logic&quot;. &quot;Generic Array Logic&quot; Is new to me." CreationDate="2010-11-05T05:42:54.460" UserId="1374" />
  <row Id="7814" PostId="6241" Text="&quot;AOI Chips&quot; - What?" CreationDate="2010-11-05T05:43:40.840" UserId="1374" />
  <row Id="7815" PostId="6157" Text="In most dual TO-220 packages, not only are the diodes thermally coupled together, they are generally both on the same die (e.g. made from the same chunk of silicon, in the same manufacturing run). This means they typically have very closely matching characteristics, which is why it works." CreationDate="2010-11-05T05:46:32.183" UserId="1374" />
  <row Id="7816" PostId="6157" Text="I took it as him saying it was 2 separate packages by him saying &quot;two schottky diode packages&quot;." CreationDate="2010-11-05T05:48:38.200" UserId="319" />
  <row Id="7817" PostId="6192" Text="Basically all camera have IR filters, including the iPhone, webcams, etc... However, the reason they can see IR anyways is because the filter is not perfect, and IR LEDs are generally very bright." CreationDate="2010-11-05T05:49:07.627" UserId="1374" />
  <row Id="7818" PostId="6192" Text="I have manually removed the IR filter from a few cheap cameras (and a nikon DSLR, but that's another story). A camera without an IR filter no longer renders images in proper color (The red channel is far more sensitive to IR than the blue or green, all pictures are almost completely red-saturated). Basically, any camera that takes normal color pictures **has to** have an IR filter." CreationDate="2010-11-05T05:50:40.857" UserId="1374" />
  <row Id="7819" PostId="6193" Score="1" Text="CAPS-LOCK: IT'S CRUISE CONTROL FOR COOL!" CreationDate="2010-11-05T05:51:19.110" UserId="1374" />
  <row Id="7820" PostId="740" Text="I don't think FPGAs are any more difficult to use than micros, they simply have a different set of caveats." CreationDate="2010-11-05T05:53:47.130" UserId="1374" />
  <row Id="7821" PostId="6232" Text="At first I thought this question was an exact duplicate, but on closer look it's not -- the other question is asking about &quot;hobbyist-friendly&quot; micros, e.g. DIP packages and this question is okay with SMDs." CreationDate="2010-11-05T05:53:57.597" UserId="1322" />
  <row Id="7822" PostId="6200" Score="2" Text="Not True! Precise Gravimeters will see the variation in the local gravity caused by the moon's gravity." CreationDate="2010-11-05T06:01:08.910" UserId="1374" />
  <row Id="7823" PostId="6179" Text="You can't run from the inevitable ;-)" CreationDate="2010-11-05T06:52:13.833" UserId="1124" />
  <row Id="7824" PostId="6247" Text="I don't want to have to flash it as loading programs may be like an OS. It also makes my project unreliable." CreationDate="2010-11-05T07:50:48.533" UserId="1225" />
  <row Id="7825" PostId="6249" Text="I'm not sure, &gt;16KB would probably be good, even better, something like ~64KB. Reasonable would not be say 1KB, because you'd be hard pressed to even fit an MCU program in that." CreationDate="2010-11-05T08:13:47.070" UserId="1225" />
  <row Id="7827" PostId="6258" Text="michael, the part listed is an op amp (a very powerful one, but an op amp nonetheless). My question is more to do with the rating of high power amplifier chips and their empirical use rather than amplifier design. I am an EE student so I have a reasonable amount of knowledge of amplifiers already." CreationDate="2010-11-05T10:55:54.853" UserId="417" />
  <row Id="7828" PostId="6257" Score="1" Text="Thanks for your help! The resistance was measured across the two speaker terminals (including the crossover circuit) with my multimeter and is actually written on the box as 2.5 ohm. unfortunately rare speakers make for rare problems!" CreationDate="2010-11-05T10:57:02.293" UserId="417" />
  <row Id="7829" PostId="6255" Text="Ok, but why? Is there a practical reason or is it just convention?" CreationDate="2010-11-05T11:34:28.713" UserId="1633" />
  <row Id="7830" PostId="6253" Text="Yep, I'm using 22u/10V caps in 0805 packages on the output." CreationDate="2010-11-05T11:43:12.577" UserId="1225" />
  <row Id="7831" PostId="6259" Text="Related http://electronics.stackexchange.com/questions/4348/how-to-go-about-sensing-ac-power-in-existing-wiring" CreationDate="2010-11-05T12:14:34.570" UserId="566" />
  <row Id="7832" PostId="6262" Score="1" Text="I used to work in industrial power electronics; you have to sample voltage and current simultaneously in order to get &quot;real power&quot; -- the current and voltage can be out of phase and if you make assumptions or don't sample them at the same time you can skew your results considerably.  Another thing that must be taken into account is crest factor. You alluded to it by talking about the frequency of measurements but if you have strong harmonic currents you must be able to capture these waveforms or your measurements again can be considerably far from reality." CreationDate="2010-11-05T12:38:06.407" UserId="974" />
  <row Id="7833" PostId="6250" Text="You only have 2 speakers, right?  You can't wire multiple speakers in series per side?" CreationDate="2010-11-05T12:52:44.007" UserId="142" />
  <row Id="7834" PostId="6265" Text="Can you please elaborate a bit more?" CreationDate="2010-11-05T13:27:36.450" UserId="1200" />
  <row Id="7835" PostId="6250" Text="you're correct, only 2. I understand this is not optimal but it is more of a learning experience then anything else" CreationDate="2010-11-05T13:29:20.780" UserId="417" />
  <row Id="7836" PostId="6273" Text="I like it. Good idea. +1" CreationDate="2010-11-05T13:32:56.297" UserId="938" />
  <row Id="7837" PostId="6255" Text="Interesting, I didn't know that." CreationDate="2010-11-05T13:38:27.407" UserId="982" />
  <row Id="7838" PostId="6270" Score="3" Text="Rentacoder is now called vWorker, and they have a dedicated Electronics/hardware section.  http://www.vworker.com/RentACoder/misc/BidRequests/ShowBidRequests.asp?lngBidRequestListType=3&amp;txtMaxNumberOfEntriesPerPage=10&amp;lngBidRequestCategoryId=83&amp;optSortTitle=2&amp;optBidRequestPhase=2&amp;lngSortColumn=-6&amp;blnModeVerbose=True&amp;optBiddingExpiration=1" CreationDate="2010-11-05T13:43:42.307" UserId="142" />
  <row Id="7839" PostId="6265" Text="@Rick_2047 Not really, I know that we contract out those things at work. But, I'm not an EE" CreationDate="2010-11-05T13:54:35.393" UserId="566" />
  <row Id="7840" PostId="6238" Score="1" Text="I just think it's a bit ridiculous that the programmers are more than twice as much as the kit itself." CreationDate="2010-11-05T13:57:44.677" UserId="876" />
  <row Id="7841" PostId="6228" Score="1" Text="http://en.wikipedia.org/wiki/Generic_array_logic That's what they always called them in my EE classes." CreationDate="2010-11-05T13:58:28.670" UserId="876" />
  <row Id="7842" PostId="6270" Score="1" Text="oDesk has an Engineering &amp; Technical Design section, too.  http://www.odesk.com/jobs/design-multimedia/sc/engineering-technical-design/#filter/c1=Design+%26+Multimedia&amp;c2[0]=Engineering+%26+Technical+Design&amp;skip=10" CreationDate="2010-11-05T14:01:49.547" UserId="142" />
  <row Id="7843" PostId="6255" Score="9" Text="The idea is that you don't want live power in a place that you can accidentally touch and/or short (such as pins). So you put your active power protected in a socket. Then your pins are only active when you have them plugged in." CreationDate="2010-11-05T14:36:39.140" UserId="319" />
  <row Id="7845" PostId="6232" Text="Most microcontrollers are offered in both DIP and SMD for the same part number. The only time I haven't seen this is with high end micros that need to be in an SMD package only. Thomas even commented on his question about how the reason he wants this is to run programs off an SD card, just like the previous question." CreationDate="2010-11-05T14:40:42.147" UserId="319" />
  <row Id="7847" PostId="6268" Score="1" Text="http://electronics.stackexchange.com/questions/4678/what-tools-equipments-and-techniques-do-you-use-to-solder-microminiature-smd-par is the same question. Good question Stefan, but it seems it is a duplicate." CreationDate="2010-11-05T14:48:06.163" UserId="230" />
  <row Id="7848" PostId="6268" Text="@Kortuk - I saw that, but didn't try to close it as a duplicate because it looked like this one was targeted to a bare minimum to do one job, while the other was for a hobbyist or professional who wanted to move from through-hole to small SMD stuff.  &quot;What are good tools for a garage looking to add an oil-change only bay&quot; and &quot;What tools do I need to change the oil in my car&quot; are very different questions." CreationDate="2010-11-05T14:56:05.427" UserId="857" />
  <row Id="7849" PostId="6268" Text="&quot;I was hoping to get a few pointers. Also, what gear would I need for this job? &quot; the other may be more encompassing, but I do not think that it will be a good idea to start allowing duplicates if they want a lower level of detail. If you notice, the answer he accepted just linked to the other question." CreationDate="2010-11-05T14:57:58.803" UserId="230" />
  <row Id="7850" PostId="6225" Text="You can also have interpreter executing scripts from SD card. That way small 8-bit MCU like AVR/PIC can also fit your needs." CreationDate="2010-11-05T14:58:14.420" UserId="1129" />
  <row Id="7851" PostId="6268" Text="The answer being a link to the other question sums it up in my opinion." CreationDate="2010-11-05T14:58:19.333" UserId="230" />
  <row Id="7852" PostId="6278" Text="I have seen a 4 mat solution deployed at the last ultra marathon I was at." CreationDate="2010-11-05T15:00:26.833" UserId="230" />
  <row Id="7853" PostId="6236" Text="I don't understand the vote down, the technology used to transmit 720p video over a long-distance wireless link exists and is used.  Doing research into what equipment and methods they use would be worthwhile." CreationDate="2010-11-05T15:27:04.383" UserId="249" />
  <row Id="7854" PostId="6238" Text="Chips are cheap.  Well, cables ought to be cheap, but there is a bit of intelligence in the cable. And it's proprietary.  So yeah, it is a little ridiculous." CreationDate="2010-11-05T15:28:25.957" UserId="249" />
  <row Id="7855" PostId="5694" Text="Actually, you can just cut a cable and connect the bare wires. Magnetics are important if you plan to deploy on untested networks/use PoE, but it's not required for development." CreationDate="2010-11-05T16:01:05.017" UserId="1082" />
  <row Id="7857" PostId="6227" Score="1" Text="as i put, 2 sensors will detect a field in any direction." CreationDate="2010-11-05T17:03:41.890" UserId="230" />
  <row Id="7859" PostId="6225" Text="For any likely device in a 44-pin package, you're going to have a spectacular (several orders of magnitude) mismatch between the amount of RAM it will have and the size of your SD card, but I guess you already knew that..." CreationDate="2010-11-05T17:08:20.467" UserId="1844" />
  <row Id="7860" PostId="6265" Score="2" Text="emc and rf are rough, you need good equipment and expertise." CreationDate="2010-11-05T17:09:22.337" UserId="230" />
  <row Id="7861" PostId="6268" Text="I'm with Kortuk, while I appreciate specific advice for my problem, the other question did solve it. " CreationDate="2010-11-05T17:12:08.780" UserId="1258" />
  <row Id="7862" PostId="6268" Text="glad you understand" CreationDate="2010-11-05T17:12:50.183" UserId="230" />
  <row Id="7863" PostId="6273" Text="Ya but that would require me to pay for shipping and stuff" CreationDate="2010-11-05T17:35:32.457" UserId="1200" />
  <row Id="7864" PostId="6281" Score="2" Text="you just went over my head." CreationDate="2010-11-05T17:57:27.130" UserId="1799" />
  <row Id="7865" PostId="6284" Text="+1 for hacker spaces, definitely worth checking out, they're springing up everywhere at the moment. " CreationDate="2010-11-05T18:14:41.070" UserId="399" />
  <row Id="7866" PostId="6253" Text="You can also create problems, too - if your PCB is subject to mechanical stress (specifically flex) your SM caps can easily become non-fusible heat sources and burn holes into the board." CreationDate="2010-11-05T18:35:12.827" UserId="1293" />
  <row Id="7867" PostId="6281" Score="2" Text="Wouldn't this be FSK? I suppose that's what fahad was getting at, though." CreationDate="2010-11-05T18:43:27.453" UserId="965" />
  <row Id="7868" PostId="6255" Text="Gotcha. Makes perfect sense. Kellenjb, can we edit this into the original answer?" CreationDate="2010-11-05T18:51:51.403" UserId="1633" />
  <row Id="7869" PostId="6281" Text="By &quot;more frequent wave&quot; I figured that meant a wave at a higher frequency. I initially thought fahad may be learning about modulation in class and just needed a push, I think I may have guessed wrong though." CreationDate="2010-11-05T19:36:18.143" UserId="319" />
  <row Id="7870" PostId="6276" Text="You're right, hysteresis is good, but I think I actually want a linear hall effect sensor so I can do it in software." CreationDate="2010-11-05T19:43:24.920" UserId="1278" />
  <row Id="7871" PostId="6243" Text="You're right, I will need more than one to calculate the field intensity.  I may be able to make an assumption about how the field *won't* be oriented, so I may be able to do with two axes anyway." CreationDate="2010-11-05T19:45:27.057" UserId="1278" />
  <row Id="7872" PostId="6267" Text="Thanks!  That's perfect, and will hook up just fine to an ADC input.  It looks like Allegro has a nice collection of sensors...they even have a PWM one that might work well with a PIC." CreationDate="2010-11-05T19:47:33.903" UserId="1278" />
  <row Id="7873" PostId="6281" Text="Fahad, I can try to write something that is a bit simpler. This is FSK, but it makes more sense to me to teach that. My bad if that does not help." CreationDate="2010-11-05T20:36:51.020" UserId="230" />
  <row Id="7874" PostId="3036" Text="It really depends on your system and how much memory you have available.  Are you writing code on an 8-bit micro with very little RAM? Then you might be better off avoiding going crazy on abstract interfaces.  If you're writing something like 32-bit embedded systems with slabs of memory, go for it.  You really have to weigh it out. For instance, every time you stick the world &quot;virtual&quot; on that class, you get an extra pointer, which could be 8-bit, 16 bit or 32 bit depending on system, for every single instance you declare of that object.  You won't even realize, and man, " CreationDate="2010-11-05T20:47:43.453" UserId="625" />
  <row Id="7875" PostId="3036" Text="did I get bit by that one.  I probably shouldn't have said avoid, but more like make sure you really need it in the design.  The problem with C++ is how it &quot;hides&quot; the amount of memory it uses, compared to looking at straight C code, and I'm not even referring to the STL library either which will suck up RAM fast when in use." CreationDate="2010-11-05T20:50:18.817" UserId="625" />
  <row Id="7876" PostId="3036" Text="excuse me... make sure you really need it and can AFFORD it in your design. " CreationDate="2010-11-05T20:58:37.713" UserId="625" />
  <row Id="7877" PostId="6289" Text="Yeah, but what about gate charge? I've heard that's quite important..." CreationDate="2010-11-05T21:17:22.983" UserId="1225" />
  <row Id="7878" PostId="6280" Score="7" Text="When modulating from a digital signal, this is referred to as &quot;frequency-shift keying&quot;.  &quot;Frequency modulation&quot; usually applies to analog signals, I believe." CreationDate="2010-11-05T21:40:41.187" UserId="142" />
  <row Id="7879" PostId="6267" Text="FYI, I settled on the A1362; programmable sensitivity up to 16 mV/Gauss (I guess 75 Gauss isn't as large as I thought it would be!), and a filter pin to constrain bandwidth/noise" CreationDate="2010-11-05T22:28:36.697" UserId="1278" />
  <row Id="7880" PostId="6289" Text="@Thomas - It's only important if you have a weak driver and are very sensitive to the transition times.  Is that the case?" CreationDate="2010-11-05T22:32:30.233" UserId="857" />
  <row Id="7881" PostId="6289" Text="I don't know. I'm using an LT3757. " CreationDate="2010-11-05T22:36:52.677" UserId="1225" />
  <row Id="7882" PostId="6188" Text="I'm an artist too - perhaps acrylic paint will work?  There's no shortage of it at my house, and I have plenty of fine brushes.   " CreationDate="2010-11-05T22:41:06.663" UserId="1609" />
  <row Id="7883" PostId="6284" Text="Thanks, will look into it. The hard part is figuring out how to build my own lab (like what kind of equipment I would need, etc.)" CreationDate="2010-11-05T22:58:52.137" UserId="1598" />
  <row Id="7884" PostId="6285" Text="I guess what's that got me down a bit when I started looking into this... the price of oscilloscopes and equipment like that. They are pricey!" CreationDate="2010-11-05T23:06:06.273" UserId="1598" />
  <row Id="7885" PostId="6200" Score="1" Text="thats not the moon having an impact on the operation of your electronics, thats the moon's influence on gravity having an impact on your sensor reading.  Regardless of the moons position your electronics are operating properly, you have to account for its impact on your sensor readings, aka a software problem." CreationDate="2010-11-05T23:21:38.507" UserId="1438" />
  <row Id="7886" PostId="4610" Score="2" Text="It costs $74.95" CreationDate="2010-11-06T00:01:12.527" UserId="1298" />
  <row Id="7887" PostId="4610" Text="User free FLASH About 148KB, User free RAM About 62KB" CreationDate="2010-11-06T00:03:27.827" UserId="1298" />
  <row Id="7888" PostId="6303" Score="6" Text="http://batteryuniversity.com/learn/article/lithium_ion_safety_concerns http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries" CreationDate="2010-11-06T01:12:17.850" UserId="142" />
  <row Id="7889" PostId="6170" Text="@Mark: The compiler places non-static local variables into a banked section of ram (psect, or program section) - that is 256 bytes wide.  The compiler optimizes these variables as best it can to reuse the available memory in this psect.  I run into problems when the call depth becomes deeper than 3 and the associated local vars, parameters, and return values creep upward.  The compiler does optimize the stack, and the code will compile and run, but at a reduced speed due because the compiler is forced to use ram locations that are &quot;further&quot; (slower) away.  I believe it does this via pointers." CreationDate="2010-11-06T02:32:10.447" UserId="1830" />
  <row Id="7890" PostId="6170" Text="@Mark:  My thinking is, if I have a display width of 21 characters on my LCD, and have a module that needs access to such a buffer in multiple functions, isn't it a better idea for me to declare it global static within the module and have all the functions use the same 21 bytes?  I should clarify that I have plenty of RAM available.  My thinking is, by reserving 21 bytes for a buffer within a module that can serve many functions, I actually require 1 byte on the stack (a pointer), instead of incurring the possibly problematic situation of a call depth &gt; 3 and the associated overhead." CreationDate="2010-11-06T02:35:58.930" UserId="1830" />
  <row Id="7891" PostId="3444" Text="Another thing to consider with regard to USB is that the latency is not fixed. " CreationDate="2010-11-06T03:10:32.650" UserId="1374" />
  <row Id="7892" PostId="6284" Text="+1000 for building your own lab. When you leave college, you loose access to the tools. If you build your own lab, they're yours forever." CreationDate="2010-11-06T03:20:07.753" UserId="1374" />
  <row Id="7893" PostId="4610" Text="The firmware is not open source, which has always put me off." CreationDate="2010-11-06T03:20:52.450" UserId="1374" />
  <row Id="7894" PostId="6297" Text="Oh wow. RF Engineering here we come!" CreationDate="2010-11-06T03:21:30.827" UserId="1374" />
  <row Id="7895" PostId="6281" Text="Actually I am learning it from the very basics and I dont have the idea of bitrate etc..I read in my notes how frequency modulation is done and it was just that the more frequent waves(more waves in a time period) represents a '1' and normal frequencies(less waves) represent a '0'.As its very basic so please be to the point." CreationDate="2010-11-06T06:29:59.613" UserId="1799" />
  <row Id="7896" PostId="6314" Text="Just to make sure I'm correct: Amps = Watts/Volts. So, for a fixed voltage (for example, 120V), a computer which uses 400 Watts will &quot;use&quot;(is this the right terminology, it seems wrong, but I can't think of anything better?) 400/120 = 3.33 amps? Thank you, your answer was pretty much perfect!" CreationDate="2010-11-06T07:40:23.310" />
  <row Id="7897" PostId="6312" Text="Is it acceptable practice to add more questions on to an answered question? I have more basic questions, and, seeing as how quickly and succinctly this one was answered, I'd love to ask more, just wondering if I have to open a new question for those, or fit them in here under the theme of &quot;basic&quot; questions as stated by the title." CreationDate="2010-11-06T07:47:41.837" />
  <row Id="7898" PostId="6273" Text="No it wouldn't - your client pays all expenses plus your margin for labour and relevant local taxes. " CreationDate="2010-11-06T08:57:26.880" UserId="1307" />
  <row Id="7899" PostId="6318" Text="I understand the relations better now, as well as what an amp is thanks to endolith, but still fail to understand in any &quot;real&quot; tangible way what a volt is (in the electrical sense, that is, not just as a converted unit for instance, with amps to HP). In addition, I would still love some answers (or a smack) for the hypothetical questions (as idiotic as they might be to others). Thank you for the link, nonetheless." CreationDate="2010-11-06T10:17:42.223" />
  <row Id="7901" PostId="6311" Text="I've found a SOIC-8 sensor for 0-5A, which would be good enough, but it would be better if I could go even smaller." CreationDate="2010-11-06T12:18:34.833" UserId="1225" />
  <row Id="7902" PostId="6324" Text="The RMS current is 3A but the pulse power is 1.2W. It pulses at about 10 amps so that seems right." CreationDate="2010-11-06T13:06:56.083" UserId="1225" />
  <row Id="7903" PostId="6289" Text="Seems like all 60 V MOSFETs with with about equal on resistance should work in your application. Qg is mentioned in the data sheets, so you could of course go for one that is very similar. What could cause more trouble than Qg is the gate threshold voltage, Vg,th. Make sure that the driver will always put the gate above the MOSFET's Vg,th. Check the IC's UVLO level. It must be higher than the Vg,th to make sure this is also true during start-up." CreationDate="2010-11-06T13:08:37.080" UserId="930" />
  <row Id="7904" PostId="6314" Score="1" Text="@Jon Binder - sometimes people say 'draw' or 'pull' for current, but 'uses' is just fine, too." CreationDate="2010-11-06T13:18:42.117" UserId="740" />
  <row Id="7905" PostId="6281" Text="Yes, That is called FSK if you decide you want to look into it at all. I am going to have to look at this a bit later and see if there is a way I can get you a real simulation  that should make more sense." CreationDate="2010-11-06T13:20:54.207" UserId="230" />
  <row Id="7906" PostId="6312" Text="your follow-on questions seem to be aimed at the concept of resistance. The ratio of the current you get, for the voltage you apply, is the item's resistance, usually specified in ohms. &quot;Ohm's Law&quot;, V=IR, is just the algebraic expression of this." CreationDate="2010-11-06T13:24:26.013" UserId="740" />
  <row Id="7907" PostId="6312" Score="2" Text="It might be more effective to break your questions up into separate postings, as it will help organize focused answers in a way that makes the material more accessible to future users. But that's just my 2 cents." CreationDate="2010-11-06T13:27:05.277" UserId="740" />
  <row Id="7908" PostId="6322" Text="Agreed. it is not possible." CreationDate="2010-11-06T13:28:04.123" UserId="230" />
  <row Id="7909" PostId="6320" Text="They still store it." CreationDate="2010-11-06T13:29:06.663" UserId="230" />
  <row Id="7910" PostId="6312" Text="I think justJeff is correct. We will still answer questions quickly." CreationDate="2010-11-06T13:32:04.820" UserId="230" />
  <row Id="7912" PostId="5336" Text="Are you going to accept an answer on this question?" CreationDate="2010-11-06T13:50:08.340" UserId="1225" />
  <row Id="7913" PostId="6318" Score="1" Text="+rep for the link. After so many years, finally something that helps me understand these concepts better." CreationDate="2010-11-06T14:16:08.540" UserId="1598" />
  <row Id="7914" PostId="6332" Text="+1, seems i posted almost the same answer ;-)" CreationDate="2010-11-06T14:41:21.287" UserId="930" />
  <row Id="7915" PostId="5934" Text="I am happy to report back that the High Voltage Programmer firmware linked above aloud me to use the Arduino Nano to fix the ATMEGA168P I had messed up. Today I will be conducting tests on the JTAG ICE MKII to determine if it has a hardware problem." CreationDate="2010-11-06T15:08:07.430" UserId="1575" />
  <row Id="7916" PostId="6299" Text="I'm not using a campiler yet because I want to know in which would be easier to implement the filter. What do you actually mean by &quot;really easy&quot;?" CreationDate="2010-11-06T15:10:39.190" UserId="1613" />
  <row Id="7917" PostId="6329" Text="You say that I can export C code directly from matlab?" CreationDate="2010-11-06T15:11:09.940" UserId="1613" />
  <row Id="7918" PostId="6338" Text="The sense resistor is also used for overcurrent protection, so it would shut down if the output shorted out or hit the current limit." CreationDate="2010-11-06T16:01:43.683" UserId="1225" />
  <row Id="7919" PostId="6335" Score="3" Text="What is &quot;tombstoning&quot;?" CreationDate="2010-11-06T16:02:02.573" UserId="1225" />
  <row Id="7920" PostId="6328" Score="1" Text="Here's another example of a water analogy applied to electricty: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/watcir.html" CreationDate="2010-11-06T16:02:14.923" UserId="1322" />
  <row Id="7921" PostId="6335" Score="5" Text="If the solder paste and/or heat is not distributed evenly on the two pads, then one will melt first, tilting the component.  The other pad never joins, and so the component sits perpendicular to the board, with only one pad attached, looking like a tombstone." CreationDate="2010-11-06T16:07:29.057" UserId="1271" />
  <row Id="7922" PostId="6341" Text="LM317 in a TO-220 package - too big for my application. And the smaller packages have issues with heat dissipation. Thanks for your suggestion. Heat produced in a regulator is a function of power dissipation, not necessarily load current, though - a regulator dropping 12V to 3.3V will dissipate more than one dropping 5V to 3.3V and hence get hotter." CreationDate="2010-11-06T16:11:08.723" UserId="1225" />
  <row Id="7923" PostId="6341" Text="I'm using an LM317 on my breadboard prototypes though, to do the same thing, but those don't have to be small." CreationDate="2010-11-06T16:11:38.663" UserId="1225" />
  <row Id="7924" PostId="6329" Text="Yes you can export to ANSI C from Matlab, however i don't know of a compiler for the dsPIC that is actually ANSI compliant." CreationDate="2010-11-06T16:13:26.333" UserId="1438" />
  <row Id="7925" PostId="6299" Text="just check out the documentation for the DSP library on Microchip's website, i'd give ya a link but their site is down for maintainance right now." CreationDate="2010-11-06T16:14:53.243" UserId="1438" />
  <row Id="7926" PostId="6341" Text="Just becasue it is rated for 1.5A doesn't mean it won't melt if you drop too much power in it. An LM317 will get as hot as any LDO or other linear reg in the same package for the same current and voltage drop. " CreationDate="2010-11-06T16:15:23.477" UserId="1681" />
  <row Id="7927" PostId="6170" Text="yea thats a place where you can use a global for the LCD character buffer.  You can put whatever data you want in access (non banked) ram with the 'near' key word when you define the variable but there is limited access ram.  Banked ram doesn't require a pointer its simply banked, meaning accessing it may require a bank switch,  so access just requires more instructions.  The 256byte sections of ram are not fixed, you can change the layout of these sections in the linker script.  " CreationDate="2010-11-06T16:20:13.803" UserId="1438" />
  <row Id="7928" PostId="6340" Text="I bought a phototransistor but it looks like the dude one the shop gave me a photodiode. How can I know which one is it? (it looks like a white led)" CreationDate="2010-11-06T16:20:32.707" UserId="1613" />
  <row Id="7929" PostId="6340" Text="They look identical. I suppose the only way to test it is to wire up this circuit - if it works, then you have a phototransistor." CreationDate="2010-11-06T16:32:24.407" UserId="1225" />
  <row Id="7930" PostId="6188" Text="It should be OK. Cellulose paint is probably easier to remove after etching." CreationDate="2010-11-06T16:44:14.330" UserId="305" />
  <row Id="7931" PostId="6340" Text="Ok. I'll try your circuit. Just on more thing: the emitter in your circuit would be the cathode (the short leg), right?" CreationDate="2010-11-06T16:47:37.027" UserId="1613" />
  <row Id="7932" PostId="6329" Text="More information has been added to my answer." CreationDate="2010-11-06T16:51:02.347" UserId="230" />
  <row Id="7933" PostId="6340" Text="I'm not sure. Try it both ways, there should be no harm due to the low voltages and very low current." CreationDate="2010-11-06T16:51:55.727" UserId="1225" />
  <row Id="7934" PostId="6335" Text="Always a hilarious effect. I have a friend who hand solders 0201. He uses a microscope, but it can be done." CreationDate="2010-11-06T17:01:35.080" UserId="230" />
  <row Id="7935" PostId="6332" Text=".4W is not a massive heat sink. I have dissipated 1W with a ground plane without a problem." CreationDate="2010-11-06T17:05:28.623" UserId="230" />
  <row Id="7936" PostId="6343" Text="Yeah... but most buck's I've seen have &lt;5mVp-p output, which is very good, sure it's not as good as an LDO but does it really matter?" CreationDate="2010-11-06T17:23:44.713" UserId="1225" />
  <row Id="7937" PostId="6343" Text="I agree with you on the simplicity factor though." CreationDate="2010-11-06T17:24:03.250" UserId="1225" />
  <row Id="7938" PostId="6284" Text="@luis.espinal, take a look here: http://electronics.stackexchange.com/questions/3382/which-equipments-for-electronics-should-i-always-have-on-hand" CreationDate="2010-11-06T17:37:29.930" UserId="938" />
  <row Id="7939" PostId="6332" Text="Yeah, well, &quot;massive heat sink&quot; depends entirely on how large the PCB is, mine didn't have enough room for a full groundplane, so I lost." CreationDate="2010-11-06T17:37:48.267" UserId="1675" />
  <row Id="7940" PostId="6343" Text="As we are talking I am currently reading EMC books. Yes, it does matter, and 5mVp-p may be what you see, but I have seen awful transients. You must remember they are switching pretty quickly for high efficiency. emissions will increase with a large load normally, especially a quickly time changing load, They also put significant conducted emissions on your power line. Both of these things can kill a device when it is put in front of the FCC testing." CreationDate="2010-11-06T17:41:39.557" UserId="230" />
  <row Id="7941" PostId="6332" Text="Sorry to hear that Dren.dk. I guess we get by with what we can. You could always required chilled helium for the device." CreationDate="2010-11-06T17:42:24.500" UserId="230" />
  <row Id="7942" PostId="6343" Text="Also, please note, as you get higher frequency transients you can start having a very hard time measuring the transients with an oscope. Any inductance can and will block the high frequency transients." CreationDate="2010-11-06T17:56:31.290" UserId="230" />
  <row Id="7943" PostId="6329" Text="The gcc compiler Microchip uses for the dsPIC is supposed to be ANSI-compliant." CreationDate="2010-11-06T17:56:47.480" UserId="305" />
  <row Id="7944" PostId="6340" Text="I tried it. The behaviour is very weird (I'm not using the transistor circuit yet). When I measure voltage in the output, it goes from 200 mV to 4V, but the change is not when I turn the led on, the change is when I cover it from normal light with my fingers." CreationDate="2010-11-06T20:02:48.023" UserId="1613" />
  <row Id="7945" PostId="6340" Text="Well, the sensitivity is very high. Replace the 47k with a 4.7k - it might work better." CreationDate="2010-11-06T20:16:20.940" UserId="1225" />
  <row Id="7946" PostId="6318" Text="I've found it useful to think of voltage as pressure." CreationDate="2010-11-06T20:39:05.767" UserId="712" />
  <row Id="7947" PostId="6299" Text="The maintenance made looking things up hard." CreationDate="2010-11-06T20:48:55.500" UserId="230" />
  <row Id="7948" PostId="6344" Text="Why can't you fix the IR sensor? " CreationDate="2010-11-06T21:18:50.817" UserId="1225" />
  <row Id="7949" PostId="6344" Text="Have you actually checked the remote is working anyway... use a digital camera and you should see some bright flashing lights (from the remote) on the image." CreationDate="2010-11-06T21:19:38.070" UserId="1225" />
  <row Id="7950" PostId="6344" Text="Yep, remote works fine.  That's the first thing I checked.  Also tried new universal remote when it quit working.  Also, the TV's LED used to blink when any IR signal was received, even if the signal was for a different device.  It stopped doing that.  As for why I can't fix the IR sensor... well I don't know how!  I'm more of a software guy than anything, but wouldn't turn down tips on how to fix the IR issue without frying my TV." CreationDate="2010-11-06T21:27:19.743" UserId="1554" />
  <row Id="7951" PostId="6346" Score="2" Text="I said it, but you kept it short and sweet! +1!" CreationDate="2010-11-06T21:27:54.063" UserId="230" />
  <row Id="7952" PostId="6222" Text="Maybe it's OK for PICs, but the question is about MCUs in general. For a counterexample the FEZ (.NET based MCU devboards) manual contains the following:&#xA;&#xA; &quot;Important note: Never connect two output pins together. If they are connected and one is &#xA;set to high and the other is set to low, you will damage the processor. Always connect an &#xA;output pin to an input, driving circuit or a simple load like an LED.&quot;&#xA;&#xA;It may be ok until you (accidentally or not) change the both ports to output, but then... So use current limiting resistor as Mark said, just to be sure." CreationDate="2010-11-06T21:33:07.560" UserId="1514" />
  <row Id="7953" PostId="6344" Text="Well, if you were okay with disassembling your TV, then you could try fixing the solder joints around the IR sensor. " CreationDate="2010-11-06T21:33:47.380" UserId="1225" />
  <row Id="7954" PostId="5934" Text="JTAG ICE MKII works perfectly after HVP. No true damage done so case closed on my problem." CreationDate="2010-11-06T22:10:30.673" UserId="1575" />
  <row Id="7955" PostId="6337" Text="+1 because this explains well what is said in the data sheet. Thanks." CreationDate="2010-11-06T23:19:34.563" UserId="930" />
  <row Id="7956" PostId="6348" Text="Unfortunately the 38 kHz receiver you linked to is only capable of receiving 38 kHz encoded signals. It is designed to not pick up ambient light, or in this case, slow pulsing IR." CreationDate="2010-11-06T23:20:56.980" UserId="1225" />
  <row Id="7957" PostId="12" Text="Excellent answer, thanks! Helped me picking my wire gauge and flux type too!" CreationDate="2010-11-06T23:32:29.010" UserId="1333" />
  <row Id="7960" PostId="6335" Text="Here's an example of tombstoning - http://www.flickr.com/photos/mightyohm/5051676871/in/photostream/" CreationDate="2010-11-06T23:49:37.817" UserId="566" />
  <row Id="7961" PostId="6349" Score="3" Text="Actually you're wrong. Li-Ion shouldn't heat up much when charged. Also those extra wires are breakout connectors for each individual cell so each cells voltage can be measured and so that that it's possible to do cell balancing. Inbuilt circuit is there as a safeguard so you can't draw too much current and over-charge/discharge the battery pack. It also includes temperature safeguard, but the funny thing is that heat generated by the cell when charged is insignificant compared to heat generated resistive elements on the circuit. If you charge it with 0.8C it should be fine." CreationDate="2010-11-07T00:09:47.800" UserId="1607" />
  <row Id="7962" PostId="6308" Score="1" Text="It can only explode when exposed to high temperatures, the integrated safeguard circuit shouldn't let you to do that via charging unless you do something horribly wrong." CreationDate="2010-11-07T00:12:59.733" UserId="1607" />
  <row Id="7963" PostId="6309" Text="Max safe temp when charging is about 45°C. It should be fine if it goes over it, but I wouldn't risk it." CreationDate="2010-11-07T00:16:04.817" UserId="1607" />
  <row Id="7964" PostId="6348" Text="Exactly. I need something more simple." CreationDate="2010-11-07T00:23:50.047" UserId="1613" />
  <row Id="7965" PostId="6340" Text="Yes, but looks like it is receiving any kind of light, not just IR. Do I need some kind of filter?" CreationDate="2010-11-07T00:26:00.950" UserId="1613" />
  <row Id="7966" PostId="6340" Text="You can pick up a phototransistor with an IR filter on it. Be aware it will still pick up some ambient light as ambient light contains IR. Here is one example: http://uk.farnell.com/vishay/bpw85/phototransistor-t1/dp/1045380" CreationDate="2010-11-07T00:33:54.457" UserId="1225" />
  <row Id="7967" PostId="6323" Text="More important: Do you trust the simulation? Until you actually measure the current pulse, I would assume that it is just the system settling at the beginning of the sim." CreationDate="2010-11-07T01:36:01.937" UserId="1374" />
  <row Id="7968" PostId="6321" Text="Short answer: No. Long answer: Yes, but you're going to have to modify the cores, and at least partially rewind both of them/" CreationDate="2010-11-07T01:38:48.303" UserId="1374" />
  <row Id="7969" PostId="6348" Text="Agree, but. Attempt to transmit 1-bit DC over noisy channel (ambient IR environment) is not small feat. Unless your range and optical path is fixed and around few millimeters. In reality the Db range involved can vary up to 80-100Db. Its more like true AM radio. " CreationDate="2010-11-07T03:07:13.530" UserId="924" />
  <row Id="7970" PostId="6363" Text="What's the max current I reasonably put out from power supply? I've been using 400 mA before I started worrying about supply current." CreationDate="2010-11-07T04:36:17.570" UserId="1510" />
  <row Id="7971" PostId="6200" Score="2" Text="Unless, if your electronics's behavior is dictated by sensors (like, well, almost everything)." CreationDate="2010-11-07T04:49:53.783" UserId="1374" />
  <row Id="7972" PostId="6363" Score="1" Text="The specced current is exceeded ? And voltage is ok. then blame extra current on outside load. Your chip is spending some extra current on communication. And it is normally expected by design. This extra current is not counted into specs. I read your datasheet btw." CreationDate="2010-11-07T04:50:21.380" UserId="924" />
  <row Id="7973" PostId="6349" Text="Yes. They should. But &quot;heat much&quot; or &quot;heat less&quot; is subjective thing, depending on legal environment for particular geographies and engineering/consumer cultures" CreationDate="2010-11-07T04:52:59.147" UserId="924" />
  <row Id="7974" PostId="6359" Text="ESR is the sum of Rsd (dielectric loses) and Rsm (loses in the contact metals), Which one is &quot;most&quot; is frequency dependent, under 1Mhz Rsd is generally dominant, over ~250Mhz or so, Rsm is dominant.  The actual calculation of Rsm or Rsd involves a lot of factors of construction, as I said only one of them is the thickness of dielectric, however it still holds that increasing dielectric thickness will increase ESR, how much or if its even meaningful is entirely frequency dependent." CreationDate="2010-11-07T06:30:00.517" UserId="1438" />
  <row Id="7975" PostId="6200" Text="Which sensors, apart from a superconducting gravimeter?" CreationDate="2010-11-07T09:11:05.573" UserId="305" />
  <row Id="7976" PostId="6361" Text="So it's a massive scam by Big Transformer Co and Big Science?? what?" CreationDate="2010-11-07T10:29:04.633" UserId="1225" />
  <row Id="7977" PostId="6297" Text="I'm interested in distances in the 1-5 metre range - I've seen a few neat tricks for pulse-width to voltage conversion but no full schems. GHz bandwidths aren't necessary as you're looking at changes in pulse edge delay. You can buy handheld laser tape measures that have ~2mm accuracy for $100, and I somewhat doubt that they 300GHz electronics inside. " CreationDate="2010-11-07T11:34:24.183" UserId="1681" />
  <row Id="7978" PostId="6361" Text="I mean the answer is &quot;no difference&quot;." CreationDate="2010-11-07T14:07:36.197" UserId="924" />
  <row Id="7979" PostId="6315" Text="You should consider accepting some answers, it will be more conductive to getting better answers..." CreationDate="2010-11-07T15:51:26.327" UserId="1225" />
  <row Id="7982" PostId="1179" Score="1" Text="I haven't been able to get this working effectively on 1.6mm FR4, just a warning." CreationDate="2010-11-07T16:56:39.650" UserId="1333" />
  <row Id="7984" PostId="6369" Text="Two questions: 1) arduino can access sd cards, but I guess there's no filesystem support, am I right? 2) How does BeagleBoard compare with another similar object, Gumstix ? http://www.gumstix.com/" CreationDate="2010-11-07T18:08:13.970" UserId="1272" />
  <row Id="7985" PostId="6340" Text="If you place what you think is the emitter in a simple circuit with a power supply and a resistor then with a phone camera look at it it should look lit up(this doesn't work with iPhones but does with sonys and nokias)." CreationDate="2010-11-07T18:13:10.027" UserId="1623" />
  <row Id="7986" PostId="6369" Score="1" Text="i don't use ardunios but a quick google turned up a FAT16/32 library: http://code.google.com/p/sdfatlib/" CreationDate="2010-11-07T18:15:04.970" UserId="1438" />
  <row Id="7987" PostId="6369" Text="as for the gumstix, the overo series uses the same SoC that the beagleboard does, the OMAP 3530.  If the beagleboard has all the peripherals you need i'd go that way (its cheaper), if there is some peripheral you need thats only on one of the gumstix expansions boards, that may be the way to go." CreationDate="2010-11-07T18:17:11.163" UserId="1438" />
  <row Id="7988" PostId="6370" Text="what frequency range?" CreationDate="2010-11-07T18:22:49.660" UserId="1438" />
  <row Id="7989" PostId="6370" Text="I am looking at 2.4GHz, but would consider lower (434 or 900) if it was the only way to tune myself." CreationDate="2010-11-07T18:25:17.900" UserId="319" />
  <row Id="7990" PostId="6313" Score="3" Text="I don't think you have added anything to this question that is specific to Simulating or NI Multisim. Seems like you are still just trying to get an answer for this questions http://electronics.stackexchange.com/questions/6241/making-a-binary-counter-for-my-breadboard" CreationDate="2010-11-07T18:29:41.220" UserId="319" />
  <row Id="7991" PostId="5696" Text="TI has some Micro + Wireless + USB. None with ethernet though." CreationDate="2010-11-07T18:36:55.703" UserId="319" />
  <row Id="7992" PostId="6359" Text="Yes. and yes. With thickness increase the ERS increases, Agree. But to maintain same capacitance value you add area (effectively putting more of thick capacitors in parallel). And. It negates the ESR increase to exactly same vlaue you started with when dielectric was thin." CreationDate="2010-11-07T19:26:59.183" UserId="924" />
  <row Id="7993" PostId="6373" Score="2" Text="I think you'll find that the 150MHz component is not part of the lasing as such. Apparently, the power of the entire laser is modulated at that frequency, and the idea is to treat the optical path as a delay line, and use that delay to set a frequency of oscillation. Dead clever. An object 1m away gives 6.667ns of delay, 150MHz. An object 2mm further away, 6.680 ns, or 149.7MHz. Trying to measure the actual *time of flight* would require high performance electronics, but make the thing into an oscillator, and you can easily distinguish 149.7MHz from 150MHz. Brilliant!" CreationDate="2010-11-07T21:30:07.700" UserId="740" />
  <row Id="7994" PostId="6180" Text="And, they also make filters that block everything above IR.  Most folks can see IR (barely) to a certain extent, making this solution perfectly valid.  But yes, one of the digital camera options is probably better." CreationDate="2010-11-07T21:31:09.300" UserId="1554" />
  <row Id="7995" PostId="6180" Text="Sorry - they are sometimes called IR filters. For example, you can sometimes get a red filter, which only allows red, or which blocks red. It's just terminology." CreationDate="2010-11-07T21:51:20.250" UserId="1225" />
  <row Id="7996" PostId="6380" Text="But my oscilloscope's fan doesn't blow out, neither does my computer's fan..." CreationDate="2010-11-07T22:22:00.540" UserId="1225" />
  <row Id="7998" PostId="6380" Score="1" Text="@Thomas I have always seen fans blowing in on heat sinks and pulling air out of enclosures." CreationDate="2010-11-07T22:37:43.983" UserId="319" />
  <row Id="7999" PostId="6381" Text="Can you isolate that it is the breadboard? Like can you pull the 2nd pin out of the board and see if there is this same signal?" CreationDate="2010-11-07T22:39:21.453" UserId="319" />
  <row Id="8000" PostId="6380" Score="1" Text="Every PC power supply with a fan has it blowing out of the case.  If yours doesn't, then it is on backwards.  If you have case fans on the front, they should be blowing in, pulling cool air in, where it is exhaust out the back." CreationDate="2010-11-07T22:39:27.680" UserId="1554" />
  <row Id="8001" PostId="6380" Text="Then why does my scope's fan suck air into its power supply and onto the mainboard (acquisition area), not blow it out?" CreationDate="2010-11-07T22:39:54.840" UserId="1225" />
  <row Id="8002" PostId="6380" Text="As Brad said, it's more about the flow of the air than the direction of the fan. Air needs to come in from somewhere if it's being blown out and to go out somewhere if it's being sucked in." CreationDate="2010-11-07T22:40:25.900" UserId="1333" />
  <row Id="8003" PostId="6380" Text="@Brad, my PC only has two fans, a CPU fan and a PSU fan. It is a very quiet unit." CreationDate="2010-11-07T22:40:27.320" UserId="1225" />
  <row Id="8004" PostId="6380" Text="No idea.  Perhaps when they designed that scope, they found it to be a more efficient way of getting heat out?" CreationDate="2010-11-07T22:40:48.073" UserId="1554" />
  <row Id="8005" PostId="6381" Text="The pin is set as an input, is there anything else I can do? it's going to be tricky to remove only one pin without damaging the MCU, and I only have one spare." CreationDate="2010-11-07T22:41:24.150" UserId="1225" />
  <row Id="8006" PostId="6380" Text="All depends on if they want to rely on negative pressure or positive pressure to create airflow." CreationDate="2010-11-07T22:41:53.683" UserId="319" />
  <row Id="8007" PostId="6381" Score="1" Text="I have found DIP components very easy to just bend one lead and then bend it back." CreationDate="2010-11-07T22:44:15.863" UserId="319" />
  <row Id="8008" PostId="6381" Text="You can also change where the MCU is located on the bread board as well as take the MCU out and measure the resistance between the 2 rows." CreationDate="2010-11-07T22:45:16.017" UserId="319" />
  <row Id="8009" PostId="6381" Text="is that input just floating? if so, and you put a 10k to one of the rails, it should suppress some of the noise." CreationDate="2010-11-07T22:54:07.643" UserId="740" />
  <row Id="8010" PostId="6381" Text="@JustJeff I will try that, good idea." CreationDate="2010-11-07T22:57:54.333" UserId="1225" />
  <row Id="8011" PostId="6381" Text="I tried it and the noise dropped to zero but has been replace by spikes at the transition points between on and off." CreationDate="2010-11-07T23:29:32.017" UserId="1225" />
  <row Id="8013" PostId="6233" Text="The 900Mhz is no-license, the 54MBps is in the WIFI band. (No license either)" CreationDate="2010-11-08T00:27:01.840" UserId="1481" />
  <row Id="8014" PostId="6381" Text="As kellenjb says, this is coupling. as you decrease the inductance and resistance of your termination it will decrease those spikes, I would guess you are using a through hole resistor for termination." CreationDate="2010-11-08T00:38:11.867" UserId="230" />
  <row Id="8015" PostId="6382" Score="1" Text="All old Class-A computer hardware used to have dust filters and sucking fans. Positive air pressure kept the machinery clean. But you had to service the filter. For consumer gear like the PC, they went with blow, and no filter to forget to change. Chux multicloths are AC filter cloth ( re-purposed in 'NAM IIRC) When the stripes are invisible, change the filter cloth." CreationDate="2010-11-08T00:47:03.070" UserId="1481" />
  <row Id="8016" PostId="6377" Score="3" Text="spectrum analyzers are not what is needed for tuning, you want a VNA." CreationDate="2010-11-08T00:54:25.060" UserId="230" />
  <row Id="8017" PostId="6384" Score="1" Text="Rough is the operative word." CreationDate="2010-11-08T00:54:57.823" UserId="230" />
  <row Id="8018" PostId="6297" Score="1" Text="All the handheld &quot;Laser&quot; tape measures you find commonly are a sonar tape measure with a laser pointer stuck to it." CreationDate="2010-11-08T01:20:15.793" UserId="1374" />
  <row Id="8019" PostId="6297" Text="Oh, it's OT, but your user profile webpage link is misspelled, mikeselectricstuff. (Ans I can't find any way to send a PM)" CreationDate="2010-11-08T01:22:13.297" UserId="1374" />
  <row Id="8020" PostId="6373" Text="Basically, any &quot;Laser&quot; tape measure you buy at Home depot is actually an ultrasonic sonar ranger with a laser pointer stuck to it." CreationDate="2010-11-08T01:24:37.417" UserId="1374" />
  <row Id="8021" PostId="6297" Score="1" Text="It's very likely that any solution for this sort of thing is going to use interferometry. As I understand it, most short-distance &quot;Time-of-flight&quot; measurement systems actually modulate the laser at a high frequency, and use the phase-difference generated by the period of time the laser takes to travel the distance to actually compute how far the object is away." CreationDate="2010-11-08T01:27:02.643" UserId="1374" />
  <row Id="8022" PostId="6297" Text="That's how the laser ranging cameras work, anyways." CreationDate="2010-11-08T01:27:27.653" UserId="1374" />
  <row Id="8023" PostId="6372" Score="1" Text="Tape the PCB to your work bench?" CreationDate="2010-11-08T01:28:07.247" UserId="1374" />
  <row Id="8024" PostId="6385" Score="1" Text="Capacitive coupling, in particular." CreationDate="2010-11-08T01:29:21.740" UserId="1374" />
  <row Id="8025" PostId="6385" Text="if a rising signal causes positive spikes, it is capacitive. It could be reverse traveling noise otherwise that is reflecting off of a low impedance driver." CreationDate="2010-11-08T01:38:21.027" UserId="230" />
  <row Id="8026" PostId="6320" Text="Much like a flyback 'transformer' is actually a coupled inductor, it's more a reference to how the device is used (energy storage and transfer during different cycles, vs. energy transfer during on-time) AFAIK" CreationDate="2010-11-08T02:32:51.337" UserId="1293" />
  <row Id="8027" PostId="6394" Score="1" Text="Thanks for the suggestions, I can definitely try most of them, except the one for string constants. It is purely an embedded device, with no UI and so there are no calls to printf() within the code. Hoping that those suggestions should tide me over to get my 1400 Bytes Flash/200 bytes RAM that I need." CreationDate="2010-11-08T04:00:33.813" UserId="1785" />
  <row Id="8028" PostId="6394" Text="@IntelliChick you would be amazed at how many people use printf() inside of an embedded device to print for either debugging or sending to a peripheral. It seems as you know better then this, but if anyone has written code on the project before you, it wouldn't hurt to check for it." CreationDate="2010-11-08T05:06:20.253" UserId="319" />
  <row Id="8029" PostId="6173" Score="3" Text="@Rick_2047, @Andrew Kohlsmith - Google won't give me the answers but it gives the links where I can get the answers. I am getting extremely very good answers in this stackoverflow.com site. I know you people are all experts in different technologies and domains. I am sure I will get a very good response here itself. Of course I am not sure whether I will get the good answer in any other site by googling." CreationDate="2010-11-08T05:07:17.183" UserId="1731" />
  <row Id="8030" PostId="6394" Score="4" Text="And just to expand on my previous comment, you would also be amazed at how many people add debugging statements, but never remove them. Even people who do #ifdefs still get lazy at times." CreationDate="2010-11-08T05:08:07.163" UserId="319" />
  <row Id="8031" PostId="6394" Score="1" Text="Awesome, Thanks! I have inherited this codebase, so ill definitely have a look for those. I will keep you guys posted, on the progress, and try to keep track of how many bytes of memory or Flash I gained by doing what, just as a reference for anyone else who might need to do this in the future." CreationDate="2010-11-08T05:20:48.343" UserId="1785" />
  <row Id="8032" PostId="6394" Text="Just a question on this - what about nested function call hops from layer to layer. How much overhead does that add? Is it better to keep the modularity by having the multiple function calls or reduce the function calls, and save some bytes. And is that significant?" CreationDate="2010-11-08T05:25:07.863" UserId="1785" />
  <row Id="8033" PostId="6388" Text="standard transformer-&gt; bridge rectifier is actually *very* quiet, for the most part. As you load it, you will get some 120 hz noize, but there is little to no high-frequency noise. However, the output voltage will vary significantly as the load changes." CreationDate="2010-11-08T05:27:25.553" UserId="1374" />
  <row Id="8034" PostId="6368" Score="2" Text="Arduino is a *development board*.  AVR is a microcontroller." CreationDate="2010-11-08T06:59:27.663" UserId="1407" />
  <row Id="8035" PostId="6389" Text="&quot;Most microcontrollers are as open as the AVR&quot;--which is to say &quot;not at all&quot;.  While they have good documentation, that's not what's usually meant when people say &quot;open&quot; nowadays. :P" CreationDate="2010-11-08T07:00:31.657" UserId="1407" />
  <row Id="8036" PostId="6173" Text="@iRobot, First of all I am no expert, I wouldn't even call myself an medium level person. Did you try searching the exact same sentence which you have posted as the question title? I did, and found this http://www.csgnetwork.com/resistcolcalc.html, I never had to ask anyone again. I know there are some questions which do have answers when you google, but they are moderately hard or bear a personal preference angle (like book suggestions and board suggestions) but asking such a basic question here would be just stupid in my view." CreationDate="2010-11-08T07:27:34.560" UserId="1200" />
  <row Id="8037" PostId="6173" Score="3" Text="@Rick_2047 - Of course I can get the answer in other sites also. I think I can get the answer in a text book also. I am a student learning about all these things. And I don't know if there is a rule which says you should post a question after googling and if you don't get any answer elsewhere. if there is such kind of rule then I am sorry." CreationDate="2010-11-08T07:40:23.573" UserId="1731" />
  <row Id="8038" PostId="6394" Text="A.F.A.I.R.: The overhead for a recursive function will be in the orders of magnitude of tens of flops, that depends in how the change of context is handled by your particular CPU architecture, generally it implies saving all the local vars and moving the stack pointer back and forth." CreationDate="2010-11-08T08:24:08.200" UserId="1673" />
  <row Id="8039" PostId="6368" Text="@Nick : what's the difference ? Sorry, I'm a newb ;)" CreationDate="2010-11-08T08:29:26.650" UserId="1272" />
  <row Id="8041" PostId="6373" Text="Yes - there are a lot of cheap ultrasonics with pointers, but at around $100 there are some real laser ones, e.g. from Bosch. I just bought one one Ebay to investigate." CreationDate="2010-11-08T09:27:27.450" UserId="1681" />
  <row Id="8043" PostId="6406" Text="dsPIC33F's and PIC24F's have 2.5V regulators to run the core at, some AT32's have 1.8V regs." CreationDate="2010-11-08T10:10:14.287" UserId="1225" />
  <row Id="8044" PostId="6406" Text="This doesn't explain how everyone chose the same voltage though? I know manufacturers have to use similar voltages, but why did they pick them in the first place?" CreationDate="2010-11-08T10:10:50.200" UserId="1225" />
  <row Id="8046" PostId="6406" Text="I have no idea, my guess is that there were specific reasons for every voltage that the IC designers chose, when they first chose them, but that the strongest reason that &quot;everybody&quot; seems to use the same voltage is that &quot;everybody&quot; else seems to use that voltage." CreationDate="2010-11-08T11:13:18.163" UserId="1675" />
  <row Id="8048" PostId="6332" Text="At low voltage (e.g. 3V3) output, the freewheel diode in supplies like the MC34063A can be a significant cause of inefficiency too.  If getting rid of 400mW in an LDO is a 'massive' task, then the 100mW in the diode might not be negligible either." CreationDate="2010-11-08T11:49:33.937" UserId="1844" />
  <row Id="8049" PostId="6331" Text="A lot of common switching regulator designs do not do very well in terms of efficiency as their output voltage falls, because they tend to have a fixed-voltage loss through a schottky diode which becomes more and more important as the output voltage approaches the diode forward voltage.  Just something to look out for." CreationDate="2010-11-08T11:54:23.307" UserId="1844" />
  <row Id="8051" PostId="6409" Text="@O Engenheiro, thanks!" CreationDate="2010-11-08T12:28:17.113" UserId="1877" />
  <row Id="8052" PostId="6409" Text="What sort of computer is it?" CreationDate="2010-11-08T12:44:36.210" UserId="1307" />
  <row Id="8053" PostId="6409" Text="@tronixstuff, an ABC 80." CreationDate="2010-11-08T12:47:04.013" UserId="1877" />
  <row Id="8054" PostId="6368" Text="@stefano Borini, the AVR is the biggest black chip with the most pins, on your Arduino. Or to use a bad car analogy, Arduino is a car, with an AVR engine from the Atmel company." CreationDate="2010-11-08T13:00:14.343" UserId="1877" />
  <row Id="8055" PostId="6208" Text="I'm not sure about that.  The Sun has an effect on your noise levels because it has magnetic explosions fairly often (and picking up now) that absolutely affect our electronics. (check out the movies taken by the Solar Dynamics Observatory, SDO) The moon has no similar characteristics. If -if- there were any gravitational effects, the moon is SO MUCH SMALLER." CreationDate="2010-11-08T13:13:11.167" UserId="1266" />
  <row Id="8058" PostId="6413" Text="Thanks! :-D Happy now." CreationDate="2010-11-08T13:39:58.617" UserId="1877" />
  <row Id="8059" PostId="6413" Text=":) (Is it working?)" CreationDate="2010-11-08T13:43:12.310" UserId="1225" />
  <row Id="8060" PostId="6413" Text="@Thomas O, no, I need to order them first. Looking at where I could do that. Sweden has ELFA, which has EVERYTHING but they charge a lot for freight." CreationDate="2010-11-08T13:48:11.473" UserId="1877" />
  <row Id="8061" PostId="6361" Text="Isn't the difference that the transformer can have a different number of turns on each side and is thus capable of stepping down voltages?  I'm not sure coupled inductors work this way.  If you're only interested in 1:1 then I think I agree they're the same." CreationDate="2010-11-08T14:08:59.340" UserId="249" />
  <row Id="8062" PostId="6413" Text="Ordered some regulators now." CreationDate="2010-11-08T14:21:23.870" UserId="1877" />
  <row Id="8063" PostId="6420" Text="Charging the gate capacitance to 0.9*Vdd takes 2.3 time constants, regardless of Vdd. A smaller gate has less capacitance, yielding a shorter RC time constant and less 0.5C*V^2 switching energy. Moreover, minimizing the leakage currents for a smaller gate requires a lower gate voltage, which further reduces power consumption. On the other hand, a higher gate voltage increases the charging current in fanout (decreasing R in the time constant). Thus overclockers increase Vdd -- at the expense of power consumption and more elaborate cooling." CreationDate="2010-11-08T15:01:50.780" UserId="721" />
  <row Id="8064" PostId="6406" Text="@thomas o Have you considered going into engineering history? Seems like you are interested in this." CreationDate="2010-11-08T15:16:40.543" UserId="319" />
  <row Id="8065" PostId="6414" Text="+1: I code mostly in verilog, and used this book to get up to speed with VHDL when we had to integrate a bit of VHDL IP into our designs. IMHO, the book is organized well and it has good exercises at the end of each chapter." CreationDate="2010-11-08T15:20:33.083" UserId="814" />
  <row Id="8066" PostId="6405" Text="I like that they call it an NA." CreationDate="2010-11-08T15:23:28.930" UserId="230" />
  <row Id="8067" PostId="6405" Text="I worked with a guy whom could look at the smith chart every time and put the components on that would tune to 50 ohm. He had been doing it for years he could tell how the parts would react." CreationDate="2010-11-08T15:24:51.520" UserId="230" />
  <row Id="8068" PostId="6410" Text="I find when I write something this long I have to use headings to get people to read it. The headings allow people to see organization and it looks like a shorter answer while still getting the message across." CreationDate="2010-11-08T15:31:18.877" UserId="230" />
  <row Id="8069" PostId="6418" Text="Any decent compiler should do this automatically for funcitons that are called only once." CreationDate="2010-11-08T15:39:01.853" UserId="1681" />
  <row Id="8070" PostId="6173" Text="@iRobot, The goal is to generate the answers that google would give you on this site. Please ignore Rick_2047" CreationDate="2010-11-08T15:41:37.813" UserId="230" />
  <row Id="8071" PostId="6348" Text="I understand now, the ambient IR contamination, makes my  DC channel impossible. I'll have to go for the modulated channel." CreationDate="2010-11-08T15:51:53.463" UserId="1613" />
  <row Id="8072" PostId="6398" Text="Does this actually work?  [The docs](http://gcc.gnu.org/onlinedocs/gcc-4.0.4/gcc/Optimize-Options.html#index-ffunction_002dsections-545) say &quot;When you specify these options, the assembler and linker will create larger object and executable files and will also be slower.&quot;  I understand that having separate sections makes sense for a micro with Flash and RAM sections - Is this statement in docs not applicable to microcontrollers?" CreationDate="2010-11-08T15:55:27.800" UserId="857" />
  <row Id="8073" PostId="6389" Text="+1 for the Stellaris kits. [Here's a link](http://www.luminarymicro.com/products/lm3sxxx_development_kits.html) to their page." CreationDate="2010-11-08T15:59:42.793" UserId="857" />
  <row Id="8074" PostId="6369" Text="@Stefano - &quot;Filesystem support&quot; is a very high level concept.  You can interface with filesystems using nearly any microcontroller with enough memory to contain a library (Like Mark's link), but it lacks two key features which you'll want for heavy filesystem stuff: Direct Media Access[DMA] and a Memory Management Unit[MMU].  You can't point execution at a file on your SD card and have the AVR run it without first copying it into RAM on the AVR, but on a micro with DMA and an MMU you can tell it how to fetch the next instruction." CreationDate="2010-11-08T16:06:15.510" UserId="857" />
  <row Id="8075" PostId="6401" Score="1" Text="If you do this, you will need to retest EVERYTHING!  Optimizations can cause working code to not work because of new assumptions the compiler makes." CreationDate="2010-11-08T16:10:42.223" UserId="204" />
  <row Id="8077" PostId="6421" Text="Am I understanding correctly that the inputs will not be floating?" CreationDate="2010-11-08T16:12:24.623" UserId="857" />
  <row Id="8078" PostId="6297" Text="For those who don't have the number on tap, the speed of light in vacuum is roughly 1 foot per nanosecond. So 3.3 ns per meter. That means that nanosecond is about 8 inches in cable or fiber, which is important if you do any plug-board computing. *::Ah...the joy of building particle physics triggers with [NIM](http://en.wikipedia.org/wiki/Nuclear_Instrumentation_Module) crates::*" CreationDate="2010-11-08T16:12:25.747" UserId="1882" />
  <row Id="8079" PostId="6300" Score="1" Text="This is actually a harder problem, because you need sub-nanosecond timing resolution that is good over second-scale spans." CreationDate="2010-11-08T16:14:52.983" UserId="1882" />
  <row Id="8080" PostId="6374" Text="Your link points to an out-of-stock Adafruit page. I also like Panavise, and their site [Panavise.com](http://www.panavise.com/index.html?pageID=1&amp;page=full&amp;--eqskudatarq=1) has it in stock for less.  " CreationDate="2010-11-08T16:17:19.117" UserId="857" />
  <row Id="8081" PostId="6426" Text="Why are color codes obsoletes?" CreationDate="2010-11-08T16:21:18.963" UserId="938" />
  <row Id="8082" PostId="6426" Text="They are only used on small, leaded resistors.  Small, leaded resistors are not used in new designs." CreationDate="2010-11-08T16:26:07.903" UserId="411" />
  <row Id="8084" PostId="6374" Text="Thanks, edited." CreationDate="2010-11-08T16:49:44.903" UserId="566" />
  <row Id="8085" PostId="6398" Text="My experience is that it works well for AVR" CreationDate="2010-11-08T16:50:48.477" UserId="566" />
  <row Id="8086" PostId="6401" Text="@Robert, that is only true if you use undefined statements: e.g. a = a++ will compile differently in -O0 and -O3." CreationDate="2010-11-08T16:53:45.353" UserId="1225" />
  <row Id="8088" PostId="6208" Text="I was thinking about a reflection off of the moon that changes based off of phase." CreationDate="2010-11-08T17:36:08.627" UserId="319" />
  <row Id="8089" PostId="6432" Text="These are very good choices. I will note you should not ever ever use malloc in an embedded system." CreationDate="2010-11-08T17:37:46.767" UserId="230" />
  <row Id="8091" PostId="6405" Text="Very helpful. Still requires expensive equipment though." CreationDate="2010-11-08T17:41:14.213" UserId="319" />
  <row Id="8092" PostId="6396" Text="You mean web pages aren't generated by supernatural entities living inside my computer?" CreationDate="2010-11-08T17:41:42.677" UserId="142" />
  <row Id="8093" PostId="6399" Score="2" Text="It is very important that you know what your compiler does. You should see what divide is on my compiler. It makes babies cry(myself included)." CreationDate="2010-11-08T17:42:31.207" UserId="230" />
  <row Id="8094" PostId="6398" Score="1" Text="This does not work well in most of the compilers I have used. It is like using the register keyword. You can tell the compiler that a variable goes into a register, but a good optimizer will do this much better than a human (argue as some may, it is considered not acceptable to do this in practice)." CreationDate="2010-11-08T17:47:46.243" UserId="230" />
  <row Id="8095" PostId="6401" Score="3" Text="@Thomas not true. If you have a for loop to delay clock cycles, many optimizers will realize your not doing anything in it and remove it. This is just 1 example." CreationDate="2010-11-08T17:47:52.420" UserId="319" />
  <row Id="8096" PostId="6398" Score="1" Text="When you start assigning locations you are forcing the compiler to place things in certain locations, very important for advanced boot-loader code, but awful to deal with in the optimizer, as you make decisions for it you are taking away a step of optimization it could do. In some compilers they design it to have sections for what code is used for, this is a case of telling the compiler more information to understand your use, this will help. If the compiler does not suggest it, do not do it." CreationDate="2010-11-08T17:50:33.137" UserId="230" />
  <row Id="8097" PostId="6428" Text="&quot;I want to say one word to you. Just one word... Are you listening?&quot; Graphene. The MOSFET is dead; long live the graphene FET... up to 100 GHz." CreationDate="2010-11-08T17:53:10.327" UserId="721" />
  <row Id="8098" PostId="6394" Text="@intellichick, you have to strike a balance. Your compiler can tell when a function would be better in-lined(better the compiler the better it does) which removes the overhead at cost of ROM, Compilers like IAR let you optimize for speed or size or balanced. There are many amazing options in a great compiler, and they do great things, but please make sure you use things like volatile." CreationDate="2010-11-08T17:56:05.877" UserId="230" />
  <row Id="8099" PostId="6401" Score="1" Text="@thomas O,You also need to make sure that you are careful about volatile function definitions. Optimizers will blow up those that think they know C well but do not understand the complexities of atomic operations." CreationDate="2010-11-08T18:00:41.303" UserId="230" />
  <row Id="8100" PostId="6348" Text="This is definitely the right approach - there is a tremendous amount of 'hard stuff' done in that little 3-pin can, and it costs peanuts to buy.   If you're only trying to convey on or off, then you don't have to worry about any of the IR signalling schemes - just flash your LED at 38K in one condition and leave it off in the other." CreationDate="2010-11-08T18:06:42.497" UserId="1844" />
  <row Id="8101" PostId="6428" Text="Yes, graphene is promising. Still plenty of problems to be solved though (the last thing to do in an IC chip is to place each transistor one by one)." CreationDate="2010-11-08T18:08:57.380" UserId="1880" />
  <row Id="8103" PostId="6401" Score="1" Text="All good points. Volatile functions/variables, by definition, must NOT be optimised. Any optimiser which performs optimisations on such (including call-time and inlining) is broken." CreationDate="2010-11-08T18:15:10.773" UserId="1225" />
  <row Id="8104" PostId="2938" Text="I posted on the question on SO inviting the user to come to E&amp;R for help!" CreationDate="2010-11-08T18:15:45.547" UserId="230" />
  <row Id="8105" PostId="6281" Text="&quot;which in engineering we can get by as approximating as 10.&quot; LOL!" CreationDate="2010-11-08T18:51:58.180" UserId="974" />
  <row Id="8106" PostId="6430" Score="1" Text="Well I was considering a helping hand, but users here told me [NO](http://electronics.stackexchange.com/q/5446/1240), so I gave up on the idea for now. I'm thinking about getting something like [this](http://www.velleman.eu/distributor/products/view/?id=344980), since I can't find a local Panavise distributor. Oh and what would I do with wire?" CreationDate="2010-11-08T19:08:34.020" UserId="1240" />
  <row Id="8107" PostId="6436" Text="I would be very interested in this, I am planning to do much the same thing." CreationDate="2010-11-08T19:11:55.460" UserId="1225" />
  <row Id="8108" PostId="6281" Text="@andrew, You wish I was joking." CreationDate="2010-11-08T19:46:40.587" UserId="230" />
  <row Id="8109" PostId="6439" Text="The Datasheet for AD584 is : http://www.analog.com/static/imported-files/data_sheets/AD584.pdf   and the datasheet for OPA548 is http://focus.ti.com/lit/ds/symlink/opa548.pdf" CreationDate="2010-11-08T19:56:33.823" UserId="1581" />
  <row Id="8110" PostId="6369" Text="I think ya mean low level :)" CreationDate="2010-11-08T20:10:31.610" UserId="1438" />
  <row Id="8111" PostId="6430" Text="@Andreja - If it's a question of nothing vs. helping hands, then helping hands are better. That linked vise looks like a better tool than the helping hands, for the same reason the users in the other question told you &quot;no&quot;.  With wire, you could do something like [endolith's answer](http://electronics.stackexchange.com/questions/5446/what-to-look-for-when-buying-a-helping-hand-device/5452#5452) in a few minutes just by screwing/soldering some alligator clips to the wire while you wait for the better tool to come in the mail and/or the money for the better tool to come in your paycheck." CreationDate="2010-11-08T20:26:32.560" UserId="857" />
  <row Id="8112" PostId="6442" Text="I suspect it's determined by your compiler. What compiler are you using? Try looking in the .h files that come with the compiler." CreationDate="2010-11-08T20:39:32.737" UserId="712" />
  <row Id="8113" PostId="6442" Text="I'm using MPLAB C30, and I've checked the .h file already. I think it's part of the linker, so not included in .h files." CreationDate="2010-11-08T20:47:44.780" UserId="1225" />
  <row Id="8114" PostId="6443" Text="what do you mean by level shifters for my digital inputs? If you mean that my analog voltage will not be the same for the same binary value, then I got it. But if you are trying to warn me about something else, please explain.                                                                            Yeah there is no way I can use AD584. I was looking for a replacement. Do you know of any?" CreationDate="2010-11-08T20:53:26.863" UserId="1581" />
  <row Id="8117" PostId="6425" Text="Perhaps they are trying to ask what state the outputs will be in if the inputs are left floating?" CreationDate="2010-11-08T21:56:12.040" UserId="588" />
  <row Id="8118" PostId="6444" Text="I'll link you to Meta where I received approval, albeit not from a moderator. This is still electronics and the Microchip forums are so slow, it takes days to get a response." CreationDate="2010-11-08T22:08:41.480" UserId="1225" />
  <row Id="8120" PostId="6401" Text="We are using the IAR C Compiler 3.40 for the M16C family. I recently upgraded to this from 3.21d to get some memory for a bug fix, and we did get some significant Flash space (~1K), by upgrading (IAR had made some optimisation improvements), but it also broke some existing functionality. We have fixed the issues, but I doubt there is much more to gain from compiler optimisation in this case. Thanks for the suggestion though!" CreationDate="2010-11-08T22:42:25.937" UserId="1785" />
  <row Id="8121" PostId="6424" Text="Thanks Mike! I have tried this in the past, and the space gained has already been used! :) Moved up from IAR C compiler 3.21d to 3.40." CreationDate="2010-11-08T22:45:47.873" UserId="1785" />
  <row Id="8122" PostId="6416" Score="1" Text="Currently optimised to the Maximum for Size. :) Thanks for the suggestion though. :)" CreationDate="2010-11-08T22:47:12.867" UserId="1785" />
  <row Id="8123" PostId="6392" Score="1" Text="Thanks everyone for the suggestions. I will keep you updated with my progress and list the steps that worked, and those that didnt." CreationDate="2010-11-08T22:53:57.300" UserId="1785" />
  <row Id="8124" PostId="6418" Score="2" Text="I've found inlining is usually more useful for speed optimisations, and usually at the cost of increased size." CreationDate="2010-11-08T23:35:02.630" UserId="1025" />
  <row Id="8125" PostId="6437" Text="I basically just want to make sure that I won't &quot;outgrow&quot; whatever specific areas of the electronics discipline I put the effort into learning. Basically, if I decide to learn X, Y, or Z hardware programming, I want to make sure that if one of my ideas is good enough, it can easily translate into something to be manufactured without me having to learn an entirely new set of hardware in order to make that transition. Does that clarify?" CreationDate="2010-11-08T23:42:59.587" UserId="1886" />
  <row Id="8126" PostId="6445" Score="1" Text="Thanks! I wish I could +10 you. _CMPInterrupt is what I'm looking for. I was calling it __CMPinterrupt, note the extra underscore and case difference." CreationDate="2010-11-08T23:43:22.627" UserId="1225" />
  <row Id="8127" PostId="6432" Text="@Kortuk That depends on your definition of embedded and the task being performed" CreationDate="2010-11-09T00:40:12.423" UserId="566" />
  <row Id="8128" PostId="6447" Text="Thanks Mike. The code is already using unions in most places, but I will have a look at some other places, where this might still help. I will also have a look at the stack size chosen and see if that can be optimised at all." CreationDate="2010-11-09T00:59:07.293" UserId="1785" />
  <row Id="8129" PostId="6444" Text="@Leon - There are forums all over the net for Microchip devices, AVRs, your LPC2000 group, etc.   E&amp;R is a place for asking and answering questions about Microchip devices as well as others.  It's ironic, though, that the answer to this question was a link to a forum...." CreationDate="2010-11-09T01:43:39.770" UserId="857" />
  <row Id="8130" PostId="6443" Text="Yes, that's what I meant by level shifters at inputs. Normally I would generate the reference voltage with a basic 1.2V (or any other for that matter) reference and an opamp, but that would bring you back to the starting point regarding the part count. Maybe something like TL1431 would be good enough?" CreationDate="2010-11-09T02:17:44.017" UserId="1880" />
  <row Id="8131" PostId="6432" Score="1" Text="@joby, Yeah, I understand that. In a system with 0 restarts and the absence of an OS like linux, Malloc can be very very bad." CreationDate="2010-11-09T02:29:04.490" UserId="230" />
  <row Id="8132" PostId="6426" Text="He is correct here, SMD is standard now." CreationDate="2010-11-09T02:30:25.097" UserId="230" />
  <row Id="8133" PostId="2938" Text="I think we &quot;got&quot; the question on SO, it was asking something different but related to this question. As for your comment there about certification; that depends on many things. Looking at the answers here, I like DoxaLogos's answer referring to QP-nano; my experience leads me to prefer event driven code over threads and implicit context switching of threads." CreationDate="2010-11-09T02:59:29.283" UserId="1892" />
  <row Id="8134" PostId="6281" Text="@Kortuk.waiting.." CreationDate="2010-11-09T03:02:03.837" UserId="1799" />
  <row Id="8135" PostId="6409" Text="Ah - http://en.wikipedia.org/wiki/ABC_80. Nice one, have fun!" CreationDate="2010-11-09T03:31:16.860" UserId="1307" />
  <row Id="8136" PostId="6447" Text="@Mike - How do I know what Stack size size is appropriate?" CreationDate="2010-11-09T03:56:37.860" UserId="1785" />
  <row Id="8137" PostId="6424" Text="I moved up one more version, and have managed to get some more Flash to fit the feature in.  I am really struggling with the RAM though, that has remained unchanged. :(" CreationDate="2010-11-09T04:14:21.860" UserId="1785" />
  <row Id="8138" PostId="6432" Text="There is no dynamic memory allocation, no place where malloc, calloc is being used. I have also checked the heap allocation, and it has been set to 0 already, so there is no heap allocation. Currently allocated Stack size is 254 Bytes and the interrupt stack size in 128 bytes." CreationDate="2010-11-09T04:16:23.793" UserId="1785" />
  <row Id="8139" PostId="6281" Text="@fahad, This is on my list of todos, but I have not had a chance to write it up." CreationDate="2010-11-09T04:29:58.207" UserId="230" />
  <row Id="8140" PostId="6395" Score="4" Text="personally i wear a tinfoil hat and hence am safe " CreationDate="2010-11-09T05:25:57.503" UserId="1438" />
  <row Id="8141" PostId="6446" Text="very informative, thanks for the link!" CreationDate="2010-11-09T06:32:47.180" UserId="1886" />
  <row Id="8142" PostId="6448" Text="There are 2 small lookup tables, neither of which will amount to 10K unfortunately. And no floating point maths is being used either. :( Thanks for the suggestions though. They are good." CreationDate="2010-11-09T06:41:46.303" UserId="1785" />
  <row Id="8143" PostId="6449" Text="Very thorough answer, thanks!... a couple quick questions though: As far as programmable controllers (Arduino, or some other PIC). Which models are &quot;most supported&quot; by manufacturers? How does the programmed logic work into the equation? (i.e.: fab houses make the board while assemblers put together the components, but who would make the programmed circuits at manufacture scale to provide to the assemblers?)" CreationDate="2010-11-09T07:01:59.200" UserId="1886" />
  <row Id="8144" PostId="5728" Text="I know. I was being a smart-ass." CreationDate="2010-11-09T07:20:04.723" UserId="1374" />
  <row Id="8145" PostId="6437" Text="As someone who has worked with &quot;Industrial robotic subsystems&quot;, I can assure you that most of what's on the market is *already* not really industrial quality." CreationDate="2010-11-09T07:32:32.417" UserId="1374" />
  <row Id="8146" PostId="6428" Score="1" Text="@eryksun - You invent the process to create graphene wafers and do photolithographic fabrication of circuitry on them. I'll do the marketing for you. Ok?" CreationDate="2010-11-09T07:45:13.187" UserId="1374" />
  <row Id="8147" PostId="6403" Text="Long story short, the voltages are dictated by the process the silicon is fabbed on. As the process size gets smaller, so does the breakdown voltage, and therefore operating voltage (Though there are many other process considerations)." CreationDate="2010-11-09T07:48:52.483" UserId="1374" />
  <row Id="8148" PostId="6403" Text="I just want to point out that a number of the answers here (even some with lots of upvotes) are just blatantly **wrong**, or at least uninformed guesses." CreationDate="2010-11-09T07:49:37.290" UserId="1374" />
  <row Id="8151" PostId="6460" Score="4" Text="this would be better asked on SU. However, if its not detected by anything (it at least needs to be detected as a piece of hardware) its probably going to be near impossible to recover the data short of getting an exactly identical stick and swapping the memory chip... which is pretty difficult, and is the reason recovery labs cost so much." CreationDate="2010-11-09T08:21:32.783" UserId="1870" />
  <row Id="8152" PostId="6441" Text="Idle loops are not relevant. There are some MCU uses where cycles matter, like video signal capturing or generation, making your own oscilloscope, real time FFT analysis of input signal, and many others. You can forget C# for these. On the other hand, if your requirements are more toward making &quot;pc like software just in a small package&quot;, then C# and .NET MF are not a bad choice at all..." CreationDate="2010-11-09T08:22:39.520" UserId="1129" />
  <row Id="8153" PostId="6441" Score="1" Text="...For such a experience I would rather choose some linux based embedded ARM board, but that is a topic for some other discussion. THe point is that for someone just entering the embedded world with a C# background, .NET MF is not a bad first step at all." CreationDate="2010-11-09T08:23:04.370" UserId="1129" />
  <row Id="8154" PostId="6421" Text="@reemrevnivek - Yes, thats correct, the input is properly defined, and will not be floating. I should probably have noted that." CreationDate="2010-11-09T08:50:41.643" UserId="1605" />
  <row Id="8155" PostId="6332" Text="Good point, there are tons of extra footprint needed for the 34063 as well, so it might not end up being the best possible solution, but for my application I don't have the room for the copperplane needed to get rid of the 425 mW, but the open area can hold the switcher and it simplifies my system to be able to go directly to 3.3V from m y input voltage, YMMV and all that." CreationDate="2010-11-09T10:11:54.207" UserId="1675" />
  <row Id="8156" PostId="6414" Text="@Marty, how did you learn verilog?courses or books?" CreationDate="2010-11-09T10:16:22.770" UserId="1200" />
  <row Id="8157" PostId="6173" Score="1" Text="No personal offense, but that is a stupid goal. I can understand doing this for hard problems, but hey even in the answers nobody gave a comprehensive description of the solution. They just posted a link and was selected as the right answer." CreationDate="2010-11-09T10:18:14.173" UserId="1200" />
  <row Id="8158" PostId="6460" Score="1" Text="Almost everyone learns this lesson the hard way (myself included). Always have more than one copy of your most important data and especially do not rely on portable data retention devices. Generally, recovery labs are your only option." CreationDate="2010-11-09T10:52:40.797" UserId="1333" />
  <row Id="8159" PostId="6368" Text="Many hardware options : [products for .NET Micro Framework ](http://www.helloapps.com/MF/HW/)" CreationDate="2010-11-09T11:24:55.350" UserId="1888" />
  <row Id="8160" PostId="6449" Text="@DJ_R, if you are building your own board with a microcontroller on it in large quantities, then you can either have the micro programmed by the chip manufacturer (for a fee) before assembly, or have it programmed by your contract manufacturer (assembly house), or program it yourself after receiving it back from the assembly house.  In the latter two cases, you would have some sort of small header (typically four pins) to connect a programming pod connected to a PC.  Contract manufacturers are like assembly houses, except they can also provide services such as testing and packaging." CreationDate="2010-11-09T11:50:18.167" UserId="1322" />
  <row Id="8161" PostId="6463" Score="2" Text="Definitely, use a separate MP3 decoder.  You will have enough to do with dealing with the SD-card and file-system and USB." CreationDate="2010-11-09T12:30:26.867" UserId="1844" />
  <row Id="8162" PostId="6403" Text="@Fake Name, correct them with your comments then." CreationDate="2010-11-09T12:56:44.037" UserId="1225" />
  <row Id="8163" PostId="6382" Text="In theory you don't have to clean out a PC, but if you've ever had to deal with a chain smoker's computer..." CreationDate="2010-11-09T13:27:48.033" UserId="1225" />
  <row Id="8164" PostId="6475" Score="9" Text="I don't know about one that goes to 0, but I know what the pot that goes to 11 is called - awesome." CreationDate="2010-11-09T13:30:53.990" UserId="1823" />
  <row Id="8165" PostId="6475" Score="5" Text="For $2,000 I'll build you one that goes to 12. http://xkcd.com/670/" CreationDate="2010-11-09T13:33:05.317" UserId="1225" />
  <row Id="8167" PostId="6459" Text="Not a bad idea.  I didn't even consider this!  Perhaps I will tear into it this afternoon.  Thanks for the advice." CreationDate="2010-11-09T13:45:06.890" UserId="1554" />
  <row Id="8168" PostId="6475" Score="1" Text="FWIW, your pot is out of tolerance, or your measurement tools are confusing you." CreationDate="2010-11-09T13:49:55.690" UserId="374" />
  <row Id="8171" PostId="6476" Text="The pot may be +/-10% but the offset is 150 ohms (typ.), this is across multiple potentiometers. " CreationDate="2010-11-09T13:57:33.173" UserId="1225" />
  <row Id="8172" PostId="6477" Score="1" Text="Zero reading on meter is 1.1 ohms, it's a cheap meter. But it checks out against some 330 ohm +/-1% resistors, reading 331 ohms. The pot is made by &quot;ALPHA&quot; and has a small encircled &quot;a&quot; stamped on it. They only cost about 25p each though, so you're right, they are cheap." CreationDate="2010-11-09T14:07:50.997" UserId="1225" />
  <row Id="8174" PostId="6473" Text="That may save code but it will eat RAM." CreationDate="2010-11-09T14:46:50.433" UserId="1681" />
  <row Id="8175" PostId="6449" Text="@DJ_R: Atmel AVR, Microchip PIC, Freescale HCS08/11 are all very well supported by their respective companies in my experience.  The chip you pick is usually based on its peripherals and the price you can get for it." CreationDate="2010-11-09T15:01:57.927" UserId="1407" />
  <row Id="8176" PostId="6460" Score="1" Text="@Mr.: You can't always have two copies of data; what if he took a bunch of photos and didn't have time to move them to a computer yet?" CreationDate="2010-11-09T15:09:08.043" UserId="1407" />
  <row Id="8178" PostId="6473" Text="It will only eat RAM if that function call is in the longest branch of the call trace.  Otherwise, it is reusing stack space that some other function already needs." CreationDate="2010-11-09T15:16:09.657" UserId="204" />
  <row Id="8179" PostId="6473" Score="2" Text="Usually true providing it's a local variable.  If short on RAM, the size of global vars, especially arrays, is a good place to start looking for savings. " CreationDate="2010-11-09T15:19:56.497" UserId="1681" />
  <row Id="8180" PostId="6388" Score="2" Text="Do you mean &quot;bridge rectifier&quot;?" CreationDate="2010-11-09T15:22:12.440" UserId="142" />
  <row Id="8181" PostId="6281" Text="@Kortuk nope, as an engineer I know you're 100% correct. Approximation is the heart and soul of engineering." CreationDate="2010-11-09T15:25:46.547" UserId="974" />
  <row Id="8182" PostId="6281" Text="@andrew, keeps life interesting." CreationDate="2010-11-09T15:36:35.897" UserId="230" />
  <row Id="8183" PostId="6173" Text="I understand your point Rick, but this has been discussed in detail on SO and this is the decision they have come to. This site answers all questions, and in theory needs to be the goto place for answer. Google is how we get most of our traffic to grow. How often is someone going to google something that we have in a very specific advanced question, not often (although these are important). Answers like reading resistor color code is what will pull in large numbers of people. Forgive me if you disagree, but you need to take this up on meta.stackoverflow.com" CreationDate="2010-11-09T15:39:26.563" UserId="230" />
  <row Id="8184" PostId="6414" Text="@Rick_2047: Did a Doulous course, then picked it up on the job. Come to think of it, Doulous do have decent training stuff on their website: http://doulos.com/knowhow/verilog_designers_guide/" CreationDate="2010-11-09T16:04:50.457" UserId="814" />
  <row Id="8186" PostId="6483" Score="2" Text="This question is probably better asked at superuser.com." CreationDate="2010-11-09T16:25:19.683" UserId="374" />
  <row Id="8187" PostId="6483" Score="2" Text="Jeff Atwood has a good tangential question on this at http://superuser.com/questions/131580/replacement-mouse-feet" CreationDate="2010-11-09T16:26:54.050" UserId="374" />
  <row Id="8188" PostId="6485" Score="1" Text="Thanks very much for your reply. I didn't specify the location of the MOSFET because I didn't think this part through. I guess I put it between the freewheeling diode and the RC snubber. I believe The diode should then protect the MOSFET.  " CreationDate="2010-11-09T16:37:04.110" UserId="1900" />
  <row Id="8189" PostId="6485" Score="2" Text="I wouldn't want to use the PS_ON control on the supply since I don't want to depend on the supply to do anything but supply the right voltage and current. If I ask it to do more, then I might have a hard time choosing a supply." CreationDate="2010-11-09T16:37:23.597" UserId="1900" />
  <row Id="8190" PostId="6485" Text="When the TVS fails though, it fails in a short circuit mode, i.e. clamping the supply. I would still need to cut the current coming through the supply. This TVS is sounding like too much trouble. I think I need the polyswitch anyway just in case the motor gets mechanically jammed and draws to much current." CreationDate="2010-11-09T16:38:05.390" UserId="1900" />
  <row Id="8191" PostId="6485" Text="Well, in the shorted condition the TVS still has some resistance, it will probably glow red hot then melt." CreationDate="2010-11-09T16:56:04.307" UserId="1225" />
  <row Id="8192" PostId="6425" Text="@mjh - Nope, the poster said *the input is properly defined, and will not be floating.* in a comment to the question." CreationDate="2010-11-09T16:56:07.980" UserId="857" />
  <row Id="8193" PostId="6490" Score="1" Text="wish it were that simple. Measuring max power requires that load resistance be equal to the internal impedance, which changes &#xA;as the lighting increases or decreases in solar panels. Since the load changes with time this simple formula won't give me the most accurate value." CreationDate="2010-11-09T18:15:01.680" UserId="245" />
  <row Id="8194" PostId="6486" Score="1" Text="Thanks! I hadn't considered that. Is there a work around you know of? I can do obvious things like limit the angular acceleration of the motor. i.e. ramp up the speed slowly to keep average current draw down. But, to stop large current transients, what about some sort of low pass filter connected directly to the power supply, with everything else I talked about connected to its output, i.e, all the circuit protection and motor?" CreationDate="2010-11-09T18:28:53.973" UserId="1900" />
  <row Id="8195" PostId="6411" Score="2" Text="If you want to go about it like that, I'd rather think of it from a similar point of view as IC feature shrinks, each decreasing by a factor of `sqrt(2)/2`.  Still not perfect, but within 10% and it makes a lot more sense than your arbitrary fractions :P" CreationDate="2010-11-09T18:42:38.450" UserId="1407" />
  <row Id="8196" PostId="6428" Score="1" Text="@eryksun: You must be a Popular Science writer; always talking up the &quot;next big thing&quot; without any consideration of the feasibility or cost." CreationDate="2010-11-09T18:45:56.073" UserId="1407" />
  <row Id="8197" PostId="6429" Text="Wouldn't the voltage fluctuation caused by switching be proportional to the supply voltage if the supply impedance is similar?" CreationDate="2010-11-09T18:54:57.310" UserId="1407" />
  <row Id="8198" PostId="6463" Score="3" Text="Another reason to use a separate decoder is that if you choose to use the Helix MP3 decoder, you still have to pay royalties  (min $15,000 US/year!) to use the format - See http://www.mp3licensing.com/royalty/hardware.html.  For this reason, an external chip (such as those made by VLSI), with that fee paid by the IC manufacturer and distributed across all of their ICs is a nice option that keeps you out of legal trouble." CreationDate="2010-11-09T19:15:56.333" UserId="857" />
  <row Id="8199" PostId="6492" Text="How thick is your FFC, and how many conductors does it have?" CreationDate="2010-11-09T19:27:30.760" UserId="857" />
  <row Id="8201" PostId="6475" Text="1k + 10% &lt; 1.2k. You must be introducing some resistance in the contacts of your ohmmeter." CreationDate="2010-11-09T20:07:43.757" UserId="1217" />
  <row Id="8202" PostId="6494" Score="5" Text="This question is better asked on a consumer electronics AV forum, like AVSForum or Audioholics forum.  The folks here are focussed on electronics + robotics, doing things like hacking, wiring circuits and the like.  You'll get significantly more helpful answers by asking at one of the sites I mentioned." CreationDate="2010-11-09T20:11:29.870" UserId="374" />
  <row Id="8203" PostId="6492" Text="On a side note, I just finished tombstoning an 0402 resistor between the pad and pin of a 0.5mm pitch part that a few of my coworkers had just about given up on.  Then I found that there were 8 more boards to do.  Don't offer it as a solution if you're not willing to do it again!" CreationDate="2010-11-09T20:11:34.043" UserId="857" />
  <row Id="8204" PostId="6492" Text="it's an 8-conductor cable. Not sure the actual thickness." CreationDate="2010-11-09T20:16:33.540" UserId="245" />
  <row Id="8205" PostId="6490" Score="1" Text="Well in reality it really is that simple; the problem is, as you said that both I and V change with the lighting conditions. This is the exact reason why Maximum Power Point (MPP)-tracking solar chargers exist; they alter their input impedance to always extract maximum power from the panel." CreationDate="2010-11-09T20:20:43.120" UserId="974" />
  <row Id="8206" PostId="6497" Text="I was able to find this at seeedstudios http://www.seeedstudio.com/depot/index.php?main_page=product_reviews&amp;products_id=200&amp;cPath=60_39 but I wonder if I can still use the 8 pin ribbon without too much fuss?" CreationDate="2010-11-09T20:36:44.217" UserId="245" />
  <row Id="8207" PostId="6481" Text="Thanks Mike. Yea I had already checked that - its called the 'Writeable constants' option for the M16C IAR C compiler. It copies the constants from ROM to RAM. This option is unchecked for my project. But a really valid check! Thanks." CreationDate="2010-11-09T20:45:03.500" UserId="1785" />
  <row Id="8208" PostId="6463" Score="1" Text="this one seems pretty ubiquitous http://www.vlsi.fi/en/products/vs1003.html (from VLSI as reemrevnivek said)" CreationDate="2010-11-09T20:53:46.053" UserId="1673" />
  <row Id="8210" PostId="6502" Text="What happens if you try to compare in this range?" CreationDate="2010-11-09T21:30:32.733" UserId="1225" />
  <row Id="8212" PostId="6497" Text="Well, you could get a much smaller version of the same thing (anything with &gt;= 8 pads at .5mm pitch).    I suspect for 8 conductors you'd be able to put the flexy face down onto the PCB and then just reflow each tinned pad with an iron.  Liquid flux might help, and I'd probably push the relevant bit of the flexy down with a screwdriver or similar as I went." CreationDate="2010-11-09T21:59:22.580" UserId="1844" />
  <row Id="8213" PostId="6502" Text="You can't complain to Microchip if it doesn't work." CreationDate="2010-11-09T22:00:21.627" UserId="1844" />
  <row Id="8215" PostId="6493" Text="I wouldn't call this a duplicate, I don't have $200 to spend!" CreationDate="2010-11-09T23:00:21.450" UserId="1225" />
  <row Id="8216" PostId="6502" Text="@Thomas - If you want to be able to complain, you need to use a voltage divider to get it in the required range." CreationDate="2010-11-09T23:27:47.667" UserId="857" />
  <row Id="8217" PostId="6502" Text="I don't want to complain, I want to know what actually happens, like does it no longer compare properly or is it slower than usual, or what...?" CreationDate="2010-11-09T23:34:09.910" UserId="1225" />
  <row Id="8218" PostId="6509" Score="1" Text="i thought the question mentioned having a 2200 ohm between the logic output and the base?" CreationDate="2010-11-10T00:07:46.947" UserId="740" />
  <row Id="8219" PostId="6493" Score="1" Text="My answer over there is $40" CreationDate="2010-11-10T00:13:38.053" UserId="142" />
  <row Id="8220" PostId="6500" Score="1" Text="Can you look at it with a scope?" CreationDate="2010-11-10T00:18:03.937" UserId="142" />
  <row Id="8221" PostId="5847" Score="1" Text="I would add, this decision is mostly affected by the inductance and current. If you inductance gives a 500ohm load a the frequency you want to pull it at, but your current is still less then 500uA then your voltage drop can probably be ignored. If the drop is too much, you need to have caps to deliver high frequency power, and use your inductive power lines for currents closer to DC." CreationDate="2010-11-10T01:00:42.343" UserId="230" />
  <row Id="8222" PostId="6361" Text="No. Two inductances with different values and loose coupling will still be a transformer with some N:M ratio. The model of non-ideal transformer (goodle for &quot;wiki leakage inductance&quot;) covers all cases between decoupled inductances to ideal transformer with everything in between." CreationDate="2010-11-10T02:05:42.103" UserId="924" />
  <row Id="8223" PostId="6493" Text="We cannot create a new question for every couple dollar increment. This would fall under too localized otherwise. I mean no disrespect, but this is too close." CreationDate="2010-11-10T02:44:04.207" UserId="230" />
  <row Id="8224" PostId="6502" Text="If you operate outside the common-mode range, you can see things like oscillating output or an outright incorrect output. " CreationDate="2010-11-10T03:05:18.650" UserId="1293" />
  <row Id="8225" PostId="6173" Text="@Rick_2047 - Please see the answer posted by &quot;csadam&quot;. I am looking for this kind of answers. Now the answer is very clear. I feel this is not compulsory to post an image but sometimes you don't get an option at that time you may need to select the one which is very close to the answer(Of course it doesn't matter its a reference or not). " CreationDate="2010-11-10T03:15:35.317" UserId="1731" />
  <row Id="8226" PostId="6471" Text="@csadmin - It would be helpful if you take and explain wit an example." CreationDate="2010-11-10T03:18:25.487" UserId="1731" />
  <row Id="8227" PostId="6173" Text="@iRobot, that answer was not there when I posted that comment, you changed you selected answer from that of DarenW to this one. And the fact remains that you were satisfied with a link to another page.&#xA;&#xA;@Kortuk, I didn't know that the chief purpose of this community was to generate traffic. But hey, when the community is this big the majority wins. Who cares about the opinion of a single user." CreationDate="2010-11-10T03:59:39.943" UserId="1200" />
  <row Id="8228" PostId="6315" Text="@Thomas, I accepted Mark's answer but I think Schedler's was also good. I selected mark because his book suggestions were more relevant to Verilog." CreationDate="2010-11-10T04:05:08.227" UserId="1200" />
  <row Id="8229" PostId="6273" Text="@tronixstuff, I would like to get such jobs in my holidays to generate some income. " CreationDate="2010-11-10T04:06:33.117" UserId="1200" />
  <row Id="8230" PostId="6463" Text="@reemrevnivek The link you posted is not accessible" CreationDate="2010-11-10T04:25:27.037" UserId="1484" />
  <row Id="8231" PostId="6173" Text="@Rick_2047 - Thats what I said. If there is no such kind of answers then I have to select the one which is very close to my expected answer even though it has a link." CreationDate="2010-11-10T04:25:46.677" UserId="1731" />
  <row Id="8232" PostId="6463" Text="@Vicky Rao, works for me." CreationDate="2010-11-10T05:21:05.713" UserId="319" />
  <row Id="8233" PostId="6500" Score="1" Text="Do you have DS (datasheet) of buzzer part?" CreationDate="2010-11-10T06:01:41.763" UserId="1471" />
  <row Id="8234" PostId="6460" Text="@Nick T, that is exactly what happen, normally I have about 3 copies of a data, including Online backup as well, but this time my card backfired on me before I could transfer it" CreationDate="2010-11-10T06:11:00.723" UserId="1895" />
  <row Id="8235" PostId="6460" Text="I thought this was related to electronics, isn't it?" CreationDate="2010-11-10T06:11:48.193" UserId="1895" />
  <row Id="8236" PostId="6470" Text="Thanks for that - yes the power-up sequence does seem to be reasonably demanding but with both supplies tied together it should be within spec. I've tried both a very quick turn-on using an MCU-controlled FET, and a slower rise direct from a voltage regulator; also tried controlling Vlogic separately. Have you used the ITG3200?" CreationDate="2010-11-10T07:42:35.230" UserId="1897" />
  <row Id="8237" PostId="6469" Text="OK, glad its worked for you! I don't even get an acknowledge from the address byte, so its hard to get any further!" CreationDate="2010-11-10T07:45:10.547" UserId="1897" />
  <row Id="8238" PostId="6511" Text="I want to replace the feedback resistors with a digital pot. I don't think I can do this without making it unstable, but I'd like to know otherwise." CreationDate="2010-11-10T07:46:12.867" UserId="1225" />
  <row Id="8239" PostId="6512" Text="That's a good idea - only changing the bottom resistor. I will have to consider that." CreationDate="2010-11-10T07:46:49.013" UserId="1225" />
  <row Id="8240" PostId="6469" Text="That Bus Pirate looks pretty cool though - might have to get one." CreationDate="2010-11-10T07:48:15.583" UserId="1897" />
  <row Id="8241" PostId="6428" Text="@Nick_T Just because I think graphene is the &quot;next big thing&quot; doesn't mean I think it's easy. @Fake_Name It's not my area, but I've seen an increasing number of articles on graphene that show steady progress -- among other competing technologies. I was just offering a potential 'better device' with a joking allusion to the famous line about plastics in &quot;The Graduate&quot;." CreationDate="2010-11-10T08:10:51.837" UserId="721" />
  <row Id="8243" PostId="6516" Text="Nice, clear answer! Thank you!" CreationDate="2010-11-10T08:57:16.490" UserId="914" />
  <row Id="8244" PostId="6265" Text="The adafruit job board is a great idea, I got a nice little earner from it very quickly. " CreationDate="2010-11-10T09:12:09.593" UserId="1307" />
  <row Id="8245" PostId="6463" Text="Sparkfun sell a number of MP3 decoder ICs, and have breakout and demo boards for most of them. http://www.sparkfun.com/commerce/advanced_search_result.php?keywords=mp3&amp;search_section=products&amp;x=0&amp;y=0" CreationDate="2010-11-10T09:39:33.903" UserId="1374" />
  <row Id="8247" PostId="6486" Score="1" Text="The inductance of the motor winding will act as a low pass filter for the switching currents. It is just the voltage when the fet turns off that you need to worry about." CreationDate="2010-11-10T10:42:49.260" UserId="328" />
  <row Id="8248" PostId="6467" Text="thanks for the link! I will definitely check this one out, looks like it should have some valuable insight." CreationDate="2010-11-10T11:45:22.913" UserId="1886" />
  <row Id="8249" PostId="6469" Text="The read address command looks a bit funny to me, with the two start-conditions, but if you did the same then I guess I'm out of ideas. The BP is quite handy for these kinds of things. I didn't do anything funny with the power at all and I've never had it go strange like your seems to be." CreationDate="2010-11-10T12:02:31.230" UserId="1675" />
  <row Id="8250" PostId="6468" Text="I've done some further testing and found that the gyro mounted on the breakout board will reliably acknowledge an I2C command when the supply voltage is reduced right down to 1.5V, which is below the minimum specified operating voltage. Above about 1.7V the gyro only acknowledges intermittently. Above about 2.1V it never responds. Is that weird or what?" CreationDate="2010-11-10T12:06:11.930" UserId="1897" />
  <row Id="8251" PostId="6522" Score="1" Text="Unfortunately, I don't have another useless USB cable at the moment." CreationDate="2010-11-10T12:07:52.457" UserId="1240" />
  <row Id="8252" PostId="6521" Text="I'll get some heatshrink too then." CreationDate="2010-11-10T12:08:19.930" UserId="1240" />
  <row Id="8253" PostId="6521" Text="+1 for cutting up another cable. Terminating to a usb connector properly *really* requires the ability to do injection overmoulding." CreationDate="2010-11-10T12:23:11.423" UserId="1374" />
  <row Id="8254" PostId="6522" Score="2" Text="Be careful to note which wires belong to which pin in the connector and to connect the new connector accordingly." CreationDate="2010-11-10T12:27:40.287" UserId="339" />
  <row Id="8255" PostId="6522" Score="2" Text="You can also use some bigger heatshrink for the outer layer. I find that more durable and pleasant than tape." CreationDate="2010-11-10T12:28:17.153" UserId="339" />
  <row Id="8256" PostId="6396" Text="Pretty good summery. I used to work with Electronic Warfare Equipment and we had systems with enough power to be dangerous. It all depends on the power and frequency. The higher the frequency the less power was needed to be dangerous. " CreationDate="2010-11-10T13:16:44.617" UserId="1810" />
  <row Id="8257" PostId="6509" Text="Whoops! I read that bullet point as if the 2200 ohm resistor was between the collector and base.  Ignore this answer." CreationDate="2010-11-10T13:39:16.753" UserId="857" />
  <row Id="8258" PostId="6516" Text="You could validate this theory (which is what sprung to my mind also) by removing R2 and putting a diode across the collector and emitter of your NPN (cathode on the collector).  This would make the bipolar behave a bit more like the MOSFET in this respect.  You should find the sound &quot;comes back&quot;." CreationDate="2010-11-10T13:40:47.343" UserId="763" />
  <row Id="8259" PostId="6522" Score="1" Text="There is a standard for USB cable colours. +5V should be red, D- white, D+ green, and ground black. " CreationDate="2010-11-10T14:20:30.060" UserId="776" />
  <row Id="8260" PostId="6523" Text="There may be some useful stuff in this question: http://electronics.stackexchange.com/questions/2300/so-i-have-a-lego-mindstorms-8547-and-10-kids-for-an-hour-a-week-what-should-i-do" CreationDate="2010-11-10T14:35:40.730" UserId="103" />
  <row Id="8261" PostId="6449" Text="@DJ_R, When you do very large quantities they can fab your chips with the program already loaded. This is done by masking what goes into the ROM. It is a requirement for super-cheap on any major product. You should just leave a programing header though so that when you make it the geeks on E&amp;R can hook up and change the code in your device &lt;3" CreationDate="2010-11-10T15:07:54.087" UserId="230" />
  <row Id="8262" PostId="6463" Text="+1 @reemvnick to the royalty tip! never thought about!" CreationDate="2010-11-10T15:26:33.847" UserId="1757" />
  <row Id="8263" PostId="6533" Text="Pretty much the same idea I was going with but with some useful additions.  All the parts besides R1 and the 317 are &quot;optional&quot;; D1, T1, R2 just provide a charging indicator, C1 for some basic filtering." CreationDate="2010-11-10T15:59:11.450" UserId="1407" />
  <row Id="8264" PostId="6522" Text="@gorilla - I don't think it's a &quot;standard&quot; so much as convention.  Manufacturers are under no requirement to obey a color scheme, and I've found a few that don't." CreationDate="2010-11-10T16:01:50.650" UserId="1407" />
  <row Id="8265" PostId="6520" Text="Could just buy an iPod shuffle connector `:P`" CreationDate="2010-11-10T16:03:29.713" UserId="1407" />
  <row Id="8266" PostId="6521" Text="How is splicing a USB cable that different?  Acutally it's probably worse because you're not shielding it at the splice point, while the connector @Andreja linked appears to be metalized at the connection point" CreationDate="2010-11-10T16:06:00.613" UserId="1407" />
  <row Id="8267" PostId="6520" Text="I would **strongly discourage** splicing an existing cable if this is for a company and at all important (e.g. production).  The connector you linked looks quite good, if you use it with shielded wire, it should be just about ideal." CreationDate="2010-11-10T16:11:41.980" UserId="1407" />
  <row Id="8268" PostId="6493" Text="100 GBP is about 160 USD, so it's not *that* different." CreationDate="2010-11-10T16:14:03.117" UserId="1407" />
  <row Id="8269" PostId="6533" Text="I was having internet issues. Sorry, did not see yours. They have similarities, but I was focused on giving a simple solution while you focused on a general explanation of the problem, +1 to you also!" CreationDate="2010-11-10T16:18:31.940" UserId="230" />
  <row Id="8270" PostId="6330" Text="I love LEDs but to have a realistic amount of illumination throughout the house is yet too $$$.  " CreationDate="2010-11-10T16:20:26.423" UserId="1609" />
  <row Id="8271" PostId="6330" Text="BTW, a few years ago I did rewire a camping trailer to use LEDs in place of incandescent.  Used a mix of red, orange, yellow, green and white for balance.  Cut the amps pulled from the sun-fed batteries to something like 1/5th or 1/10th of what it was." CreationDate="2010-11-10T16:22:52.820" UserId="1609" />
  <row Id="8272" PostId="4721" Text="Sounds like a bug." CreationDate="2010-11-10T16:24:22.057" UserId="230" />
  <row Id="8273" PostId="6388" Score="1" Text="@Fake: Hmm?  I was talking to the questioner.  Said &quot;Wheatstone bridge&quot; (used to measure resistances), when I think they mean &quot;bridge rectifier&quot;." CreationDate="2010-11-10T16:49:43.453" UserId="142" />
  <row Id="8274" PostId="6535" Score="1" Text="efficiency gain from a buck regulator at only 10mA would be questionable as well, especially at the 35V point, the duty cycle would be really low." CreationDate="2010-11-10T16:50:33.280" UserId="1438" />
  <row Id="8275" PostId="6535" Score="1" Text="350mW is a lot for small surface mount components. " CreationDate="2010-11-10T16:51:44.863" UserId="1225" />
  <row Id="8276" PostId="6493" Text="@Nick T, I suppose 40 dollars to you isn't anything? (poor student here who saved up for his £49 iron.)" CreationDate="2010-11-10T16:52:19.637" UserId="1225" />
  <row Id="8277" PostId="6535" Text="350mW absolutely worse case is not that bad. that is if you are at 38V in. If you get a good ground plane to conduct heat, or use through hole with a heat sink(which I can put watts into without a problem) you can handle this. The question of heat dissipation we have had other places. This will easily be handled with small surface-mount linear regulator(I have done this much power that way)." CreationDate="2010-11-10T17:04:05.470" UserId="230" />
  <row Id="8278" PostId="6511" Text="I am suggesting that you purchase an SMPS with a set resistance that is external of the loop and is designed for this feature. I am suggesting against modifying the control loop while running to change voltage. I am not saying it cannot be done, I am suggesting against it." CreationDate="2010-11-10T17:05:12.880" UserId="230" />
  <row Id="8279" PostId="6495" Text="I wish you had gone into greater detail." CreationDate="2010-11-10T17:06:56.967" UserId="230" />
  <row Id="8280" PostId="6535" Text="Yeah, but I can't spare space for through hole. It's also a waste of space in that the micro is in a tiny SO20 package but the reg is in a TO-220... How would zener diodes work? they have higher dissipation ratings, maybe it would work better?" CreationDate="2010-11-10T17:07:03.970" UserId="1225" />
  <row Id="8281" PostId="6535" Text="It's also not a worst case scenario, a lot of people will be using 30V battery packs with this." CreationDate="2010-11-10T17:10:21.547" UserId="1225" />
  <row Id="8282" PostId="6519" Text="The SMPS will be built to handle the highest output voltage of 15V." CreationDate="2010-11-10T17:18:00.960" UserId="1225" />
  <row Id="8283" PostId="6476" Text="The question did not said anything about price. Also some specific equipment are tailored to be as best as possible, ex: astronomical instrumentation. Some cases 10% tolerances are not acceptable." CreationDate="2010-11-10T17:18:49.073" UserId="1757" />
  <row Id="8284" PostId="6520" Text="Nick, the connector he showed is just the insides of a connector - it needs an injection-moulded part on top which it doesn't include.  This is for a 1-off repair anyway, by my reading of the OP." CreationDate="2010-11-10T17:20:53.303" UserId="1844" />
  <row Id="8285" PostId="6535" Score="1" Text="something like a http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1040,P86928 in a DFN package with the thermal pad tied to the ground plane with 3-4 vias would work fine.  Based on the data sheet you would need something like 25cm^2 of copper to allow operation up to ~90C ambient.  Which if you have a ground plane in the board and the board is bigger than 5cm x 5cm should be fine.  If you can do a ground pour on the surface layer around the IC, even better." CreationDate="2010-11-10T17:27:20.783" UserId="1438" />
  <row Id="8286" PostId="6535" Text="@thomas, telling me that the 35V could be continuous is something I did not account for. I would have given the same answer though. I have used in excess of 30V with a small surface mount package and more than 10mA. I give a nice big ground plane." CreationDate="2010-11-10T17:36:47.803" UserId="230" />
  <row Id="8288" PostId="6533" Text="I understand that. They also note that most people are doing trickle charge for months. I specified you can get away with a few extra hours. They suggest never ever trickle charging for extended periods, and I agree." CreationDate="2010-11-10T17:41:18.123" UserId="230" />
  <row Id="8289" PostId="6388" Score="1" Text="the layout of the grounds in the circuit will probably cause more noise issues than a switching power supply.  Just use a high frequency (~400khz-&gt;2mhz) buck-boost switcher and put a decent LC filter on the output.  If you find you need it &quot;ultra clean&quot; use a higher order LC filter on the output." CreationDate="2010-11-10T17:45:59.630" UserId="1438" />
  <row Id="8290" PostId="6541" Text="Atoms form bonds with electrons, the electrons themselves (&quot;electrons are bonded by...&quot;) don't." CreationDate="2010-11-10T18:38:07.477" UserId="1407" />
  <row Id="8291" PostId="6531" Text="Shouldn't the Charge rate be equal to the total of all the batteries to 12000? As they are connected in series to give me a voltage of 12 volts." CreationDate="2010-11-10T18:47:00.800" UserId="1623" />
  <row Id="8292" PostId="6531" Text="@Dean - No, your battery's capacity is 1200 mAh @ 12 V.  Assembled in parallel, the current capacity increases, in series, only the voltage increases.  By your logic the power contained in a battery increases with the square of the number of cells (your voltage *and* current capacity increased by 10x, yielding 100x the energy.) If you build this charger, let me reemphasize that the &quot;LM317 + 1 resistor charger&quot; is more of an academic curiosity, not something to be used for everyday use." CreationDate="2010-11-10T18:54:17.097" UserId="1407" />
  <row Id="8293" PostId="6531" Text="Yes i know i'm just implementing it in to my project so i don't have to take out 12 batteries and charge them i can just plug it in to my power supply and let it charge." CreationDate="2010-11-10T18:57:52.193" UserId="1623" />
  <row Id="8294" PostId="6537" Text="tcrosley disproved you without much effort `:P`.  LTC3631 has a maximum `Iq` of 0.22 mA in active state.  `Iq` is usually proportional to the full-load capability, so while you're probably right for a 5A supply, smaller ones exist." CreationDate="2010-11-10T18:59:38.433" UserId="1407" />
  <row Id="8295" PostId="6537" Text="The OP said &quot;Cost effective&quot; - LTC3631 costs maybe  3-4x what the &quot;small micro&quot; is likely to. " CreationDate="2010-11-10T19:07:57.953" UserId="1681" />
  <row Id="8296" PostId="6520" Text="@Nick T It was just a single repair, but I did do my best to make it as good as I could. @Will Dean I couldn't find an injection-molded part, so I had to do without." CreationDate="2010-11-10T19:27:18.840" UserId="1240" />
  <row Id="8297" PostId="6521" Text="In the end I couldn't find injection-moulded part, so I soldered connector shut and used lots of masking tape to since connector is very smooth and hard to unplug just by itself. I also used heatshrink at joint between connector and cable." CreationDate="2010-11-10T19:30:34.890" UserId="1240" />
  <row Id="8298" PostId="6520" Text="@Andrejako - the injection molded part is something you would have to make, using an expensive tool and an even more expensive molding press.  What you've done with tape/heatshrink is the right thing." CreationDate="2010-11-10T20:06:43.173" UserId="1844" />
  <row Id="8299" PostId="6511" Text="I'm building the supply myself, using an LT3757, to output 1A with a variable range of at least 9V-12V (if not 6.5V-15V.)" CreationDate="2010-11-10T20:28:05.327" UserId="1225" />
  <row Id="8300" PostId="6511" Text="I have seen buck-boost chips that have a pin that you tie through a resistor to ground. This resistance can be varied, they often give a digital pot reference design, to change your output voltage over a wide range and they are designed for it." CreationDate="2010-11-10T21:23:53.030" UserId="230" />
  <row Id="8301" PostId="6471" Text="I think the picture speaks for itself :) There are already two examples on it." CreationDate="2010-11-10T21:48:46.347" UserId="1514" />
  <row Id="8302" PostId="6554" Text="I'm with Mark on this one. it's a neat (as in tidy) design, but it's not a very good one. I recently designed a PoE board and used the LM5071 PoE switchmode controller; it was a breeze to build, works very well and would give you the types of voltages at the current levels you are asking for. Also, your large electrolytic caps are overlapping other parts/access screws, it might be tricky to mount." CreationDate="2010-11-10T22:21:52.237" UserId="974" />
  <row Id="8304" PostId="6515" Text="Thanks! I'll try using a small boost converter. It'll end up being a trickle charger, that's for sure." CreationDate="2010-11-10T23:28:29.167" UserId="1907" />
  <row Id="8305" PostId="6556" Text="+1 for the board heater.  Also, the package looks like a DPAK to me, and it does look like it's shorting out.  " CreationDate="2010-11-10T23:53:46.157" UserId="857" />
  <row Id="8306" PostId="6550" Score="1" Text="Its the time to ack that is critical, the address has to be shifted out of the receive register, compared to the slave address register and then an ack or nack generated.  The ack is checked by the master on the 9th clock so the shift+comparison+ack set has to take place in &lt; 1 I2C clock cycle, which would be much faster than the system clock in this example." CreationDate="2010-11-11T00:11:37.000" UserId="1438" />
  <row Id="8308" PostId="6542" Text="N-type, excess Negative charge. P-type, excess Positive charge(missing electronic charges." CreationDate="2010-11-11T00:26:35.253" UserId="230" />
  <row Id="8309" PostId="6552" Score="1" Text="Get a bigger soldering iron." CreationDate="2010-11-11T00:54:43.163" UserId="1374" />
  <row Id="8310" PostId="6538" Text="Did you mean to include a link?" CreationDate="2010-11-11T00:56:08.013" UserId="1374" />
  <row Id="8311" PostId="6330" Text="@DarenW(0), see edit." CreationDate="2010-11-11T01:19:16.610" UserId="1859" />
  <row Id="8313" PostId="6532" Text="thankyou I like your answer straight forward and to the point." CreationDate="2010-11-11T01:41:42.280" UserId="1457" />
  <row Id="8314" PostId="6485" Text="TVS actually is inevitable to use. With motors there is a need to absorb regenerative energy no matter what. Just use good 1000A/ms TVS diode. It will work." CreationDate="2010-11-11T02:54:43.770" UserId="924" />
  <row Id="8315" PostId="6502" Text="If you exceed the 2.15V on any of the inputs the comparator will give you unpredictable output. Software way to say this is that part will have catastrophic loss of precision with very high probability of wrong result. If you exceed about 3.5..4V the input protection diodes will pass the excessive current to power line and dissipate energy elsewhere over all circuit." CreationDate="2010-11-11T03:27:33.600" UserId="924" />
  <row Id="8316" PostId="6527" Text="Which ones should I purchase? I would want to buy at least 25." CreationDate="2010-11-11T04:19:01.607" UserId="1687" />
  <row Id="8317" PostId="6527" Text="The Freetronics TwentyTen is a great board. I'm sure you could get a discount for &gt;25 units. (http://www.freetronics.com/products/twentyten)" CreationDate="2010-11-11T05:33:00.960" UserId="1307" />
  <row Id="8318" PostId="6564" Text="Looks like the 90W numbers are wrong, since device is not efficient. Could it be that 90W is the total consumption figure when effective cooling is about 50% of this ? (by some fundamental physics law, I forgot which) " CreationDate="2010-11-11T05:34:30.590" UserId="924" />
  <row Id="8319" PostId="6564" Text="Peltier devices are normally rated by the power they draw, I believe. Your device is probably good for chilling a &lt;5W load, or cooling a &lt;10-20w load more efficiently than a heatsink alone." CreationDate="2010-11-11T05:36:42.363" UserId="1374" />
  <row Id="8320" PostId="6547" Text="Clock stretching would be absolutely required in some form; IIC takes 9 clocks/byte, so 400 KHz IIC byte rate would be 45 Kbyte/sec, even if the processor blindly read the I2C data register at 32 KHz cycle after cycle, one might slip through." CreationDate="2010-11-11T06:35:25.483" UserId="1407" />
  <row Id="8321" PostId="6566" Text="Soldering wire (usually 30 AWG Kynar/wire-wrap wire) leads to the board is compact, handy, and almost always do-able (if you use leadless packages you might have to scrape solder resist off a trace).  However, as the OP mentions, some probes can't hold fine wire well, but at least you can abuse the other end of that wire all you like." CreationDate="2010-11-11T06:39:59.593" UserId="1407" />
  <row Id="8322" PostId="6552" Text="It looks like the entire board is covered in soldermask" CreationDate="2010-11-11T06:43:30.693" UserId="1407" />
  <row Id="8323" PostId="6551" Score="1" Text="What does &quot;passive POE&quot; mean?  Some sort of non-standard wiring that looks almost exactly like standard Ethernet that may cause severe damage to anything that is inadvertently plugged into it?  802.3af POE has intelligence for good reason." CreationDate="2010-11-11T06:58:38.320" UserId="1407" />
  <row Id="8324" PostId="6551" Text="passive POE is the non-standard way of doing POE that simply uses the two extra pairs for power, it's very common in certain fields because it's cheap and efficient at both ends of the cable." CreationDate="2010-11-11T08:02:37.153" UserId="1675" />
  <row Id="8325" PostId="6554" Text="About the power planes: I'm not going to use more than two layers of PCB, so I can't spare two layers for power, but I will certainly reorganize the Ethernet components to allow me to get a largeish local groundplane under them, tighten up the power supply around it and to get the crystal+caps tightened up." CreationDate="2010-11-11T08:17:50.073" UserId="1675" />
  <row Id="8326" PostId="6554" Text="About the POE: Yes, I'm not using standard POE, but the, in some fields, more common non-standard passive POE." CreationDate="2010-11-11T08:20:58.743" UserId="1675" />
  <row Id="8327" PostId="6554" Text="About R5&amp;R6: They aren't connected to the center tap, I'm just sloppy at drawing, sorry." CreationDate="2010-11-11T08:22:15.263" UserId="1675" />
  <row Id="8328" PostId="6554" Text="About the switcher: Yes, it's sort of spread out, but other than to turn the MC34063 90 degrees to get a shorter wire from pin 2 to the coil and the diode I don't see how I could possibly tighten it up." CreationDate="2010-11-11T08:32:28.173" UserId="1675" />
  <row Id="8329" PostId="6546" Text="Hi. I've tryed to use piklab-prog.exe, but it depends on LubUSB, which somehow didn't worked for me." CreationDate="2010-11-11T09:18:15.533" UserId="1757" />
  <row Id="8330" PostId="6555" Text="Then i think that I'll should wait a little more with my project!" CreationDate="2010-11-11T09:20:50.973" UserId="1757" />
  <row Id="8331" PostId="6520" Text="@Will Dean I assumed it can be found prefabricated because I was [this](http://www.showmecables.com/viewItem.asp?idProduct=4351) product which looked interesting." CreationDate="2010-11-11T10:27:32.287" UserId="1240" />
  <row Id="8332" PostId="6520" Text="Very interesting.  I didn't know you could buy them." CreationDate="2010-11-11T10:31:38.740" UserId="1844" />
  <row Id="8333" PostId="6567" Score="1" Text="I do something very similar using a dental-pick. They're sharp, have a nice right angle which makes them easy to hold, and are generally stainless. You just clip a test lead to the bottom, and poke away." CreationDate="2010-11-11T10:54:33.690" UserId="1374" />
  <row Id="8334" PostId="6567" Text="Also, they're great when doing SMT soldering." CreationDate="2010-11-11T10:55:07.123" UserId="1374" />
  <row Id="8336" PostId="6484" Text="I'm not sure that these 'huge inductive spikes' are a given.  Your freewheel diode (in anti-parallel across the motor) will prevent the voltage at the FET's drain rising more than one diode drop above the supply rail.  Provided it's sized to carry the rated current of the motor, where does the higher voltage come from?" CreationDate="2010-11-11T11:02:05.703" UserId="1844" />
  <row Id="8337" PostId="6552" Text="@Nick T - Quite the opposite. This looks like a raw proto board, with no soldermask at all." CreationDate="2010-11-11T11:02:19.667" UserId="1374" />
  <row Id="8338" PostId="6537" Text="Micro is a PIC16F690, about $1.80 in quantity." CreationDate="2010-11-11T13:41:25.690" UserId="1225" />
  <row Id="8339" PostId="6575" Text="Yeah, everything I've seen is very expensive and very fragile. :/" CreationDate="2010-11-11T14:38:00.120" UserId="142" />
  <row Id="8340" PostId="6566" Text="Yeah, putting a loop in the wire makes it easy to grab reliably with bigger clips." CreationDate="2010-11-11T14:38:34.927" UserId="142" />
  <row Id="8341" PostId="6552" Text="@Nick T It is a barebones order from advanced circuits" CreationDate="2010-11-11T14:58:52.187" UserId="319" />
  <row Id="8342" PostId="6556" Text="The regulator is fine. I have a board heater, but I was worried about this method since I already have parts on the bottom side. I think this would be apply a lot of unneeded heat directly to the parts" CreationDate="2010-11-11T15:00:12.327" UserId="319" />
  <row Id="8343" PostId="6572" Text="We do have a very nice Weller WD1002. I think I do have a bigger tip to try." CreationDate="2010-11-11T15:04:28.647" UserId="319" />
  <row Id="8344" PostId="6552" Text="Which layout software let that pass DRC?" CreationDate="2010-11-11T15:32:05.707" UserId="411" />
  <row Id="8345" PostId="6554" Text="anything short of at least a full, solid, ground plane is a waste of time.  The sectional pours do little to nothing to solve the problem unless they extend all the way, unbroken, to the supply ground connection, even then if signals pass over the edge of the plane you've created another problem.  You don't need 2 separate power layers, you can split the plane for +3.3V and +12V just be careful about routing over the split on adjacent layers.  The only way you'll get this design to be reliable is a 4 layers board." CreationDate="2010-11-11T15:48:04.863" UserId="1438" />
  <row Id="8346" PostId="6574" Text="Are there any other power rails you can tap off?  And did efficiency genuinely matter?  An SOT-223 should sit at ambient+50°C at 35 V @ 10 mA." CreationDate="2010-11-11T16:18:44.013" UserId="1407" />
  <row Id="8348" PostId="3462" Text="So a bus isn't for serial communication between two devices?  Are you discounting it because it's sometimes just used point-to-point?  PCIe, SATA, HT are all generally point-to-point.  Regardless, most UART peripherals can be used for RS-422, RS-485, or LIN which are multi-drop." CreationDate="2010-11-11T16:47:32.853" UserId="1407" />
  <row Id="8349" PostId="6330" Text="LEDs are no better (generally worse) than CFLs as far as power use per lumen.  They can be convenient if directed light is needed, but for general illumination they are a novelty." CreationDate="2010-11-11T16:56:57.210" UserId="1407" />
  <row Id="8350" PostId="6572" Text="Metcal is in a different class than Weller.  Yes, use the biggest tip you can find for this." CreationDate="2010-11-11T17:11:38.957" UserId="411" />
  <row Id="8351" PostId="6580" Text="Do you know what the impedance of the tape is?" CreationDate="2010-11-11T17:33:57.963" UserId="319" />
  <row Id="8352" PostId="6577" Text="And they're only $16 each!" CreationDate="2010-11-11T17:42:40.743" UserId="142" />
  <row Id="8353" PostId="6574" Text="@Nick T It's a power supply controller, so has to start up before the other rails and sequence/set up them. Efficiency is not really critical, so long as it's not producing too much heat. I may be able to go the linear route." CreationDate="2010-11-11T17:54:00.150" UserId="1225" />
  <row Id="8354" PostId="6576" Score="1" Text="It would not adhere - you'd still get a cold joint." CreationDate="2010-11-11T18:16:18.273" UserId="857" />
  <row Id="8355" PostId="6583" Score="4" Text="This question would be better asked @ superuser.com" CreationDate="2010-11-11T18:21:06.543" UserId="588" />
  <row Id="8356" PostId="3141" Score="1" Text="Buffer? What? @starblue seems like the only sane one suggesting you use a diode.  In fact, your answer would be much improved if you replaced every instance of &quot;buffer&quot; with &quot;diode&quot;. -1 till then." CreationDate="2010-11-11T18:22:17.680" UserId="1407" />
  <row Id="8357" PostId="6585" Text="I was hoping I won't have to buy anything :) can I make my own conductive-paint-replacement?" CreationDate="2010-11-11T18:23:55.933" UserId="1921" />
  <row Id="8358" PostId="6584" Score="2" Text="You may want to take the remote apart and look at it first.  That link only describes one of many different ways that buttons can be built." CreationDate="2010-11-11T18:29:49.603" UserId="1438" />
  <row Id="8359" PostId="6586" Score="1" Text="A few places seem to recommend isopropanol (100%) or citrus cleaner if you don't want to buy a special cleaner." CreationDate="2010-11-11T18:31:01.197" UserId="1407" />
  <row Id="8360" PostId="6583" Score="1" Text="true but with a little reformatting this question could be helpful to people here as the answer is applicable to mounting a heatsink on any chip that may need one, such as an LDO." CreationDate="2010-11-11T18:31:55.140" UserId="1438" />
  <row Id="8361" PostId="6586" Score="1" Text="isopropanol may work, depends on the formulation of the thermal compound.  As i recall their cleaner is only like $5-10 which is about what 100ml of 100% isopropanol is going to cost, at least thats what it runs at my local electronics store.  The rubbing alcohol you get at the  grocery store is not that strong, usually 70% max, may be scrubbing for awhile with that stuff.  " CreationDate="2010-11-11T18:38:13.560" UserId="1438" />
  <row Id="8362" PostId="6588" Text="What do you mean by equivalent - Are you trying to do some CMOS logic and need a near-perfect match, or do you just want to have the same package, Rds-on, voltage tolerances, and gate capacitance?" CreationDate="2010-11-11T18:59:38.817" UserId="857" />
  <row Id="8363" PostId="6588" Text="MOSFETs aren't that difficult to flip through at all the major manufacturer sites (Infineon, ST, IRF, Diodes, ON, Fairchild), they all have decent parametric filtering." CreationDate="2010-11-11T19:05:03.260" UserId="1407" />
  <row Id="8364" PostId="6590" Text="I don't really have control over the PCBs.  I suppose I could *request* that they add test points, but I don't know how successful I would be....  I've seen those test point loops on eval boards.  They work well.  I have a Chip Clip, and did exactly the same thing to program maybe a hundred EEPROMs by removing the EEPROM from the eval board and connecting the chip clip in place of it.  :D" CreationDate="2010-11-11T19:09:34.217" UserId="142" />
  <row Id="8365" PostId="6589" Score="2" Text="Digi-Key is probably the most convenient method, but don't pick exact values, but all those less than/greater than what you need.  If you're trying to replace an older part you are almost guaranteed to find a part with better performance/smaller package." CreationDate="2010-11-11T19:09:37.060" UserId="1407" />
  <row Id="8366" PostId="6146" Text="@Nick - Follow up: the logic-level N-channel MOSFET works like a champ! Thanks again!" CreationDate="2010-11-11T19:11:10.970" UserId="1206" />
  <row Id="8367" PostId="6588" Text="@reemrevnivek, the 2nd option." CreationDate="2010-11-11T19:16:15.950" UserId="938" />
  <row Id="8368" PostId="6586" Text="@Nick T, I have the citrus cleaner Goo Gone, I'll give it a try and report back on how it worked. " CreationDate="2010-11-11T19:26:34.487" UserId="1919" />
  <row Id="8369" PostId="6586" Text="@Mark, thanks for the good information." CreationDate="2010-11-11T19:26:56.827" UserId="1919" />
  <row Id="8370" PostId="6588" Score="2" Text="&quot;Decent&quot; parametric filtering, but I have yet to see a manufacturer site with &quot;good&quot; parametric filtering." CreationDate="2010-11-11T19:27:07.137" UserId="142" />
  <row Id="8371" PostId="6586" Text="@Nick T, the Goo Gone worked, but I had to apply it directly to the heat sink and let it sit for a moment and then it took my fingernail to scrub it off completely.  I ordered the ArtiClean just in case, hopefully it'll make getting the paste off of the chip easier than having to use my fingernail." CreationDate="2010-11-11T19:32:43.410" UserId="1919" />
  <row Id="8372" PostId="6583" Text="Before you try to fix it, can you return/replace it from where you bought it from?  That's probably the best way `:P`" CreationDate="2010-11-11T19:34:04.813" UserId="1407" />
  <row Id="8373" PostId="6586" Text="You should be able to (carefully) use a razor/knife to remove the bulk of it, cleaners are probably meant to just remove the residue." CreationDate="2010-11-11T19:35:48.383" UserId="1407" />
  <row Id="8374" PostId="6593" Score="1" Text="What are you doing with this data?  The AVR isn't designed to handle a huge amount of data, if you could optimize your communications that would be preferable regardless of how you talk with the thing.  Buffering 800 bytes may not even be possible." CreationDate="2010-11-11T19:40:00.173" UserId="1407" />
  <row Id="8375" PostId="6591" Score="1" Text="I think you need to dissect one, in order to find out what it is doing..." CreationDate="2010-11-11T19:47:56.047" UserId="689" />
  <row Id="8376" PostId="6593" Text="800 bytes is the minimum I can send I believe.  I have 400 LEDs hooked up an arduino and each one has its own 15bit color.  I'm not compressing the 800 bytes yet, I guess I could do that if I had an efficient way to do it.  Is there an arduino library for that?" CreationDate="2010-11-11T19:49:04.413" UserId="954" />
  <row Id="8377" PostId="6577" Text="I have some of these, they are quite nice for the price. They work on 0.5mm pitch, but not on adjacent pins." CreationDate="2010-11-11T19:56:02.557" UserId="339" />
  <row Id="8378" PostId="6592" Text="Can I use aluminum foil used to cover food?" CreationDate="2010-11-11T20:01:03.293" UserId="1921" />
  <row Id="8379" PostId="6584" Text="Yes, but once it's apart I'd like to be able to fix it if I can... ie, be prepared" CreationDate="2010-11-11T20:01:45.247" UserId="1921" />
  <row Id="8380" PostId="6552" Text="I had to place several different boards into a single set of gerber files. When you do this in Ultiboard it causes stuff like that to happen and it doesn't keep the netlist with it so no DRC to find it. I now know to use gerbtool." CreationDate="2010-11-11T20:08:21.940" UserId="319" />
  <row Id="8381" PostId="6593" Score="1" Text="So a 20x20 RGB array at 50 Hz?" CreationDate="2010-11-11T20:18:40.640" UserId="1407" />
  <row Id="8382" PostId="6593" Score="1" Text="Precisely but I could probably drop down to around 30ms (~33hz) if 50 Hz is too ambitious." CreationDate="2010-11-11T20:24:59.807" UserId="954" />
  <row Id="8383" PostId="6597" Text="Hmmm interesting, I'll have to look at that chip.  Unfortunately I can't use SPI because I am already using it to control the LEDs hooked to the arduino (via pins 11 and 13)." CreationDate="2010-11-11T21:24:48.607" UserId="954" />
  <row Id="8384" PostId="6554" Text="I'm sorry to say that I don't have more then two layers to play with, so there is no full ground plane in the future of this design. The old layout actually works and there are plenty of cases where people use EN28J60 on two layer boards, which btw. is a 10 megabit part." CreationDate="2010-11-11T21:33:25.243" UserId="1675" />
  <row Id="8385" PostId="6597" Text="Sorry, I miss-communicated. The FT2232H chip is UART. I shall correct my post." CreationDate="2010-11-11T21:45:09.810" UserId="230" />
  <row Id="8386" PostId="6595" Text="Then why even bother specifying it? :/" CreationDate="2010-11-11T21:46:36.697" UserId="142" />
  <row Id="8387" PostId="6554" Text="Thank you for your feedback, even the budget forbids anything more than 2 layers. I have been able to tighten up the ENC28J60 and the switcher layouts quite a bit and fatten up the power traces, so there ought to be some chance that it will all work out." CreationDate="2010-11-11T21:51:26.610" UserId="1675" />
  <row Id="8388" PostId="6595" Text="So that someone has an idea of the different torque that will be required over a lifetime without having to run their own tests." CreationDate="2010-11-11T21:51:55.077" UserId="230" />
  <row Id="8389" PostId="6591" Text="In the past a lot of the technology behind different Christmas light displays has had patents to how they translate different independence from failure and lifetime/safety features. I know this may not be the case with most simple designs, but just dropping a warning from what I have seen." CreationDate="2010-11-11T21:53:52.890" UserId="230" />
  <row Id="8390" PostId="6588" Text="It is hard to do, they do their best, and have to depend on suppliers letting them know what their specs are to a reasonable accuracy" CreationDate="2010-11-11T21:55:01.907" UserId="230" />
  <row Id="8391" PostId="6595" Text="Or why not specify each individual factor separately?" CreationDate="2010-11-11T22:03:07.277" UserId="142" />
  <row Id="8392" PostId="6595" Text="They do not probably have factors down that reliably, there is a large cost to thorough characterization. It is relatively affordable to characterize it." CreationDate="2010-11-11T22:24:51.073" UserId="230" />
  <row Id="8393" PostId="6567" Text="I'm not sure insulin comes in that &quot;form factor&quot; any more. My wife is diabetic and uses these type of pens: http://commons.wikimedia.org/wiki/File:Insulin_pen.JPG" CreationDate="2010-11-11T22:25:10.297" UserId="103" />
  <row Id="8394" PostId="6564" Text="@Rocket Surgeon, 5 or 10% of it, not 50%." CreationDate="2010-11-11T22:28:31.933" UserId="230" />
  <row Id="8395" PostId="6567" Text="@Amos I bet you could also get free syringes from a &quot;needle exchange&quot; for heroin users :-)" CreationDate="2010-11-11T22:30:43.250" UserId="566" />
  <row Id="8396" PostId="6595" Text="Where the friction comes from shouldn't be a concern of anyone that uses it (designers or end users), and businesses aren't in the habit of disclosing anything they don't need to.  If you really need to know, you can contact their engineering department." CreationDate="2010-11-11T22:30:44.970" UserId="1407" />
  <row Id="8397" PostId="6597" Text="Are you using programmable drivers to actually control the LEDs or are you using shift registers?  How much processor time are you using up just manipulating the data to send out the SPI?" CreationDate="2010-11-11T22:33:38.430" UserId="1407" />
  <row Id="8398" PostId="6579" Score="1" Text="Where can I buy it?" CreationDate="2010-11-11T22:40:07.640" UserId="1298" />
  <row Id="8399" PostId="6592" Text="That is exactly what I used.  I don't remember how long it lasted me but it was definitely a huge improvement." CreationDate="2010-11-11T23:44:48.647" UserId="1819" />
  <row Id="8400" PostId="6599" Text="Consider a boost reg, like MCP1640 to convert 1.5V to 5V to run an MCU off." CreationDate="2010-11-11T23:49:21.283" UserId="1225" />
  <row Id="8401" PostId="6554" Text="I know the part, there is a fairly long list of people that have tried to use it and failed FCC miserably at 200Mhz.  I had problems with a pic18f97J60 which shares the same current mode drive circuitry and had to be very careful with it on a 6 layer controlled impedance board to clear FCC.  Look at the ethernet output around 200Mhz, you'll probably find a nasty ~50mV ripple on it.  For your application it may be fine but i'd be curious to see what happens when the ethernet port is driving and the relay switches." CreationDate="2010-11-12T00:05:57.397" UserId="1438" />
  <row Id="8402" PostId="6600" Text="Find any through hole MCUs like those, that's what I need. " CreationDate="2010-11-12T00:09:53.180" UserId="1687" />
  <row Id="8403" PostId="6579" Text="I suspect that you can't buy it. Contact Microsoft Research, perhaps it's going to be open source..." CreationDate="2010-11-12T00:11:37.390" UserId="566" />
  <row Id="8404" PostId="6600" Text="I'd go for the MSP430G2211. Here's a couple of my projects which might be relevant: http://blog.hodgepig.org/2010/09/12/577/ http://blog.hodgepig.org/2010/09/30/jam-jar-lamp/" CreationDate="2010-11-12T00:17:48.273" UserId="566" />
  <row Id="8405" PostId="6601" Text="Great. Looks like more or less mainstream piece with very opened platform." CreationDate="2010-11-12T00:34:32.333" UserId="924" />
  <row Id="8406" PostId="6600" Text="What would you suggest using to power this? I want it to be a low profile and small as possible? Think 4 double A's would work good?" CreationDate="2010-11-12T00:44:55.520" UserId="1687" />
  <row Id="8407" PostId="6600" Text="4 x AA would be fine, but I'd go with 2 x 1.5v coin cells or a CR2 for 3v" CreationDate="2010-11-12T00:55:14.140" UserId="566" />
  <row Id="8408" PostId="6566" Text="One way to quickly get a bunch of wires is to take apart a stranded cable." CreationDate="2010-11-12T01:11:36.277" UserId="1256" />
  <row Id="8409" PostId="6602" Text="I'd choose the cheaper MSP430G2211, unless you need the ADCs" CreationDate="2010-11-12T01:18:50.203" UserId="566" />
  <row Id="8410" PostId="6607" Text="I've seen some netduino forum posts saying that it is not possible with a given version of the firmware. I wonder if the latest versions enable this feature." CreationDate="2010-11-12T02:27:57.003" UserId="1298" />
  <row Id="8411" PostId="6609" Text="you need to clarify the question.  Are you talking about generating a DC voltage from the PWM? " CreationDate="2010-11-12T03:04:35.460" UserId="1438" />
  <row Id="8412" PostId="6595" Text="not to over simplify things here, but in my mind the difference between 10 and 150gf-cm is likely not detectable to a human, at least over the life span on the product.  Therefore the point of the datasheet is &quot;its really easy to turn&quot; and will remain so over the life of the product.  Which is really the only reason to look at this value." CreationDate="2010-11-12T03:10:19.900" UserId="1438" />
  <row Id="8413" PostId="6599" Text="Consider an MCU with a wide supply range and no regulator, with a battery that operates over that supply range.  If the intent is as cheap as it sounds like it is, just don't bother with regulator." CreationDate="2010-11-12T03:17:09.833" UserId="1438" />
  <row Id="8414" PostId="6597" Text="@NickT, I am very confused by your comment. He can use UART to get the data and set the LEDs, I am sure it is a full workload." CreationDate="2010-11-12T03:18:41.937" UserId="230" />
  <row Id="8415" PostId="6535" Text="Do not use a zener. They will not give you regulated voltage like you get with a wonderful linear regulator and they will kill power." CreationDate="2010-11-12T03:29:31.117" UserId="230" />
  <row Id="8416" PostId="6597" Text="I was curious how he was driving the 1200 LEDs; there's no way I could see it being done with an AVR without auxiliary controllers.  He said he was using the SPI to communicate, so it might be a controller but possibly a basic shift register(s)." CreationDate="2010-11-12T03:55:52.770" UserId="1407" />
  <row Id="8417" PostId="6030" Text="To add, the operating current usually doesn't have anything to do with it being an inductor per-se, but simply the maximum current you can shove through it within the rated temperature range.  And finally, unless you're relying on some of the non-ideal effects of inductors (namely resistance), you can freely use ones with higher current ratings." CreationDate="2010-11-12T04:03:18.137" UserId="1407" />
  <row Id="8418" PostId="6597" Text="@NickT, I think you may misunderstand, he said he cannot use SPI and you are having the discussion on an answer, not on the question. Your comment is for the question, not for my answer." CreationDate="2010-11-12T04:07:16.577" UserId="230" />
  <row Id="8420" PostId="6597" Text="It was relevant to information that popped up earlier in the comment thread on this answer to the question." CreationDate="2010-11-12T04:13:50.527" UserId="1407" />
  <row Id="8421" PostId="6597" Text="@NickT, Where did he say he is using SPI?" CreationDate="2010-11-12T04:14:54.853" UserId="230" />
  <row Id="8422" PostId="6612" Score="1" Text="The PCB is 0.8&quot; thick? You're including components, yes?" CreationDate="2010-11-12T05:00:48.060" UserId="712" />
  <row Id="8423" PostId="6613" Text="Thanks. I saw both of those questions and found the answers helpful for our internal and prototyping needs, but they won't work for our final product. Is that many thousands of dollars PER case? If so that would be excessive." CreationDate="2010-11-12T05:15:59.557" UserId="1913" />
  <row Id="8424" PostId="6612" Score="1" Text="Yes, I'm including components. It also has a fan that brings it up to about 1.7&quot;, but we'd like to remove it and add a large heatsink or a shallower fan (CPU pulls only a few watts so it should be fine.)" CreationDate="2010-11-12T05:17:14.140" UserId="1913" />
  <row Id="8425" PostId="6595" Text="We want one that's *not* as easy to turn, but the one we're replacing is &quot;20~100&quot;, and the one we like is &quot;20~200&quot;.  Seems kind of meaningless." CreationDate="2010-11-12T05:35:49.460" UserId="142" />
  <row Id="8426" PostId="6612" Score="2" Text="considering audio components often use rack-mounts, and are often made of nice materials, and such, poking around audio-diy sites might have some useful leads." CreationDate="2010-11-12T05:43:28.693" UserId="1870" />
  <row Id="8427" PostId="6388" Text="All the answers are equally good, but well, its impolite if i don't select a best one. Thanks all - i'll be keeping this in mind when i build my amp ^^" CreationDate="2010-11-12T05:45:37.710" UserId="1870" />
  <row Id="8428" PostId="6567" Text="Sewing pins aren't good?" CreationDate="2010-11-12T05:50:10.307" UserId="142" />
  <row Id="8429" PostId="6615" Score="1" Text="I'm in a similar position. I have spent a while in the field, actually done all the design work for a number of projects, and can only describe what I do as engineering. If you engineer electronic projects, I can't see how you would describe it as anything other than &quot;Electrical Engineering&quot;." CreationDate="2010-11-12T06:40:40.353" UserId="1374" />
  <row Id="8430" PostId="6612" Score="1" Text="**Always** keep your target enclosure in mind **from the outset of design**. Trying to fit an enclosure around an existant board layout is always a pain in the ass." CreationDate="2010-11-12T07:10:27.053" UserId="1374" />
  <row Id="8431" PostId="6554" Text="Thankfully it's not going to be a consumer product, so it will not have to pass FCC or be CE certified. I will stick the board in a nice tight metal box to keep the EMI inside, so I'm mainly concerned with getting something that works for me than something that works for the FCC:)" CreationDate="2010-11-12T08:28:30.110" UserId="1675" />
  <row Id="8432" PostId="6618" Score="2" Text="In Brazil for example, working as an engineer without the BSEE or MSEE is illegal." CreationDate="2010-11-12T09:55:43.060" UserId="1757" />
  <row Id="8433" PostId="6618" Text="Interesting.  I am a registered UK engineer (CEng) but my degree is an MA.  My degree certificate has no indication of the subject(s) studied - I actually did Engineering/Electrical sciences. Without the professional registration there would be no evidence that would allow me to practice in many countries.  " CreationDate="2010-11-12T10:53:08.547" UserId="400" />
  <row Id="8434" PostId="6593" Text="If you aren't doing with AVR anything else during data receive, then AVR can handle it without problems, if fed with data over 921600 or 460800 bps serial connection." CreationDate="2010-11-12T11:59:00.207" UserId="1129" />
  <row Id="8435" PostId="6562" Text="This is what I was going to suggest. Plenty of cheapo pos available with switch." CreationDate="2010-11-12T13:33:11.637" UserId="611" />
  <row Id="8436" PostId="6622" Score="2" Text="Fuses (of any type) aren't really meant to protect sensitive electronics from overcurrent or overvoltage, but to protect against fire." CreationDate="2010-11-12T13:39:21.593" UserId="1407" />
  <row Id="8437" PostId="6484" Score="1" Text="Startup current is a large concern.  I'd doing something somewhat similar, except the motor wants around 12A at 12V.  The 500W ATX PSU is not able to start the motor, it seems like it trips the over current protection circuitry.  You shouldn't have to worry about shorting the PSU, computer power supplies are required to have over current protection.  The supply will just shut off.  Check out this document for more info on ATX supplies: http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf" CreationDate="2010-11-12T14:19:15.100" UserId="1819" />
  <row Id="8438" PostId="6618" Score="3" Text="The jurisdicition is a big factor. In the US it is even a state to state thing. Even though I have a EE degree, some states wont let me call myself an engineering unless I have become a Professional Engineer in their state." CreationDate="2010-11-12T14:35:51.710" UserId="319" />
  <row Id="8439" PostId="6615" Score="1" Text="I don't know all of the legal ramifications of this, but I do know some places will allow you to say &quot;Engineering&quot; while not being able to say &quot;Engineer&quot;." CreationDate="2010-11-12T14:37:04.423" UserId="319" />
  <row Id="8440" PostId="6576" Text="Yeah, the heat gun and hot air rework stations are actually very effective at not getting shorts when soldering. This is great for most cases, not so great for me." CreationDate="2010-11-12T14:39:03.997" UserId="319" />
  <row Id="8441" PostId="6618" Text="It seems like the legal requirements are more applied to civil engineering than electrical?  True or not?" CreationDate="2010-11-12T14:49:39.057" UserId="142" />
  <row Id="8443" PostId="6621" Text="They have the positive rail connected to the *bottom* of the op-amp?  Grr.  http://opencircuitdesign.com/xcircuit/goodschem/goodschem.html" CreationDate="2010-11-12T14:52:55.437" UserId="142" />
  <row Id="8444" PostId="6625" Text="Can someone edit this so that the image is embedded." CreationDate="2010-11-12T14:58:17.967" UserId="1333" />
  <row Id="8445" PostId="6625" Text="Your wish is my command. 8-)" CreationDate="2010-11-12T15:00:42.177" UserId="305" />
  <row Id="8446" PostId="6618" Text="@endolith - I would guess that this perception is because civil engineers are more public facing than other areas.  However, New Mexico (the poster's state), has the same requirements for certification in Chemical, Civil, Control Systems, Electrical, Environmental, Fire Protection, Mechanical, Mining &amp; Mineral, and Structural engineering. " CreationDate="2010-11-12T15:12:57.560" UserId="857" />
  <row Id="8447" PostId="6618" Text="@Ian - If I'm working as a doctor (perhaps administering some medication to a family member), is it OK for me to advertise myself as a surgeon?  I think that's an accurate analogy to the engineering profession.  Most of our members come from places where the title is legally protected." CreationDate="2010-11-12T15:16:10.800" UserId="857" />
  <row Id="8448" PostId="6627" Score="1" Text="But companies that require someone to have a Professional Engineer license will require a Professional Engineer license.  That's not universal." CreationDate="2010-11-12T15:27:25.760" UserId="142" />
  <row Id="8449" PostId="6630" Text="Good idea in general and I'll definitely try it later, but at the moment, I'd like to avoid use of microcontrollers. If I'm right, blinking of the LEDs should be very hard  to notice at high frequencies, right?" CreationDate="2010-11-12T15:55:30.177" UserId="1240" />
  <row Id="8450" PostId="6615" Text="Use &quot;Systems Engineer&quot; that title pays better anyway." CreationDate="2010-11-12T15:56:43.980" UserId="1438" />
  <row Id="8451" PostId="6627" Score="6" Text="the only EE's that get their PE license that i've met only did so because it was required by their company, which was doing power system design for large buildings.  They haven't seen a microcontroller since college.  You can call yourself and EE all you want, you'd get in trouble claiming you are a PE without the license." CreationDate="2010-11-12T16:00:08.067" UserId="1438" />
  <row Id="8452" PostId="6627" Text="It is specifically state to state. In some states using the term engineer is protected. This means that if you place engineer on your resume, you need a PE." CreationDate="2010-11-12T16:00:46.393" UserId="230" />
  <row Id="8453" PostId="6627" Text="In certain states you must have a PE to say electrical engineer. In all states you should be able to say electrical engineering." CreationDate="2010-11-12T16:01:32.960" UserId="230" />
  <row Id="8454" PostId="6627" Score="3" Text="Take a look at the controversies(http://en.wikipedia.org/wiki/Controversies_over_the_term_Engineer). I specifically know of states where engineers must put engineering on their business card unless they are licensed." CreationDate="2010-11-12T16:03:25.750" UserId="230" />
  <row Id="8455" PostId="6627" Score="2" Text="I believe most of the protection of the term 'Engineer' applies not necessarily to individual people, but businesses.  I know in Florida you can't call yourself an engineering firm unless there's sufficient PEs on staff and if you're self-employed you can't claim to practice engineering unless you have your PE.  That said, I don't think this is what he intends, but I find it disingenuous to say you're an engineer without an engineering degree, or at LEAST one position where the title includes 'engineer'." CreationDate="2010-11-12T16:08:20.560" UserId="249" />
  <row Id="8456" PostId="6618" Text="@endolith, they are all protected. I have not heard of a state that does not apply them to all." CreationDate="2010-11-12T16:09:24.900" UserId="230" />
  <row Id="8457" PostId="6627" Score="2" Text="In the UK I believe that there is no problem with calling yourself &quot;engineer&quot; with no qualifications. I am a &quot;Software Engineer&quot; because it's in my job title. Only the title of Chartered Engineer (CEng) is protected." CreationDate="2010-11-12T16:10:13.573" UserId="566" />
  <row Id="8458" PostId="6629" Score="2" Text="That LED calculator is pretty slick!  I like how it shows the power wasted in the resistor along with power used by the LED." CreationDate="2010-11-12T16:32:07.573" UserId="1609" />
  <row Id="8459" PostId="6636" Text="I'll  look into that." CreationDate="2010-11-12T16:37:32.790" UserId="1240" />
  <row Id="8460" PostId="6627" Text="@angryEE, almost every state has requirements that a firm with engineering in the name must have registered PEs. This is very common, some states(not nearly as many) have laws that state calling yourself an engineer is specifically not allowed without professional engineer. Canada has this as a whole from what I have read before." CreationDate="2010-11-12T16:40:04.113" UserId="230" />
  <row Id="8461" PostId="6595" Text="Pot torque can change noticeably over temperature.  (I think that spec is the manufacturer's way of saying &quot;we don't care about torque that much.&quot;  In many datasheets, unflattering information ends up as a number rather than called out explicitly in the text.)" CreationDate="2010-11-12T16:51:20.807" UserId="411" />
  <row Id="8462" PostId="6639" Text="In reverse, the dielectric breaks down, and they eventually become a short.  Initially, though, they'll behave just like a normal capacitor.   " CreationDate="2010-11-12T16:53:19.277" UserId="857" />
  <row Id="8463" PostId="6635" Text="Google indicates that the ReadyNAS NV+ is a RAID controller.  Can you link to the product you're using?" CreationDate="2010-11-12T16:55:53.127" UserId="857" />
  <row Id="8464" PostId="6638" Text="6LR61 is 9 V battery. As for 555 circuit, I was thinking about using something like [TS555](http://www.st.com/internet/analog/product/65434.jsp) since it has wide voltage range for input. I'm also debating on 9 V battery versus 4*1.5 V pack. LR6 appear to have higher capacity then 6LR61. Wouldn't they work longer? According to ledcalc, I'd get ~10 h with simple 9 V circuit and ~32 h with simple 6 V circuit." CreationDate="2010-11-12T17:08:09.333" UserId="1240" />
  <row Id="8465" PostId="6627" Score="1" Text="@Kortuk, In Canada you must be a Professional Engineer (pretty similar as the requirements listed above) to use 'engineer' (or any variation thereof) in your title etc. Businesses must also not use the term 'engineer' or 'engineering' unless they have a P.Eng on staff. The only exception might be if you drive a train." CreationDate="2010-11-12T17:24:42.673" UserId="536" />
  <row Id="8466" PostId="6627" Text="Kortuk - I agree, I'm just wondering whether a resume is going to be regarded as an offer for professional services (which would certainly make putting 'engineer' on it a violation of many laws) or merely an unofficial expository device.  Since he's not really offering the services to the public that may count for something, but that would be lawyer territory. On the whole I think this is an interesting question and I wouldn't mind a legal expert weighing in if one is hanging around." CreationDate="2010-11-12T17:28:34.327" UserId="249" />
  <row Id="8467" PostId="6627" Score="1" Text="@angryEE, My boss at work is a PE and lived in a state before now that had a law to this extent. Everyone had to change their business cards, and could not put on their resume that they were engineers, they could only say they did engineering. Minor difference though." CreationDate="2010-11-12T17:43:19.773" UserId="230" />
  <row Id="8468" PostId="6643" Text="I'll take a look into that. Maybe I'll be able to find a similar circuit." CreationDate="2010-11-12T17:55:33.643" UserId="1240" />
  <row Id="8469" PostId="6643" Score="2" Text="Joule thief could work, but I think it only works for one or two LED's. Give it a go." CreationDate="2010-11-12T17:57:15.670" UserId="1225" />
  <row Id="8470" PostId="6629" Score="2" Text="9V batteries are rubbish capacity wise - use AA's/LR6, much better." CreationDate="2010-11-12T17:57:52.877" UserId="1225" />
  <row Id="8471" PostId="6641" Text="Can you say a little more about the series of flip flops / divider?  Since some people say &quot;flip flop&quot; for any kind of multi-vibrator, I am having hard time sorting the results.  I know about clock dividers and prescalers from the &quot;software&quot; side, as in, this little chunk of code turns one on, but I don't actually know how to build one." CreationDate="2010-11-12T18:07:00.743" UserId="1271" />
  <row Id="8472" PostId="6644" Text="The best one is the one between your ears." CreationDate="2010-11-12T18:08:47.143" UserId="1225" />
  <row Id="8473" PostId="6641" Text="Also, probably I should just get the larger ceramic capacitors to fix the leakage?  0.1μF to 1μF capacitors seem like they would be fine, especially if I get a few more megaohm range resistors." CreationDate="2010-11-12T18:09:50.833" UserId="1271" />
  <row Id="8474" PostId="6642" Text="I had a pretty hard time figuring out why a certain analog capture ISA card only worked on certain legacy computers until I figured this no -5V on many power supplies thing.  Ugly." CreationDate="2010-11-12T18:11:06.900" UserId="1270" />
  <row Id="8475" PostId="6641" Text="Ceramics should be fine, but check the datasheet." CreationDate="2010-11-12T18:12:46.463" UserId="411" />
  <row Id="8476" PostId="6641" Score="1" Text="Consider the diagram on the humble 4020 divider: http://www.st.com/stonline/books/pdf/docs/1961.pdf  The clock goes in, and a frequency of clock/2, clock/4, etc comes out.  The lowest frequency is clock/32768.  So if you have a 32.768 kHz input, that last pin on the divider chain will be a 1 Hz square wave.  (Not coincidentally, if you take the back off your watch you will find a crystal cut to oscillate at 32.768 kHz.)" CreationDate="2010-11-12T18:21:13.737" UserId="411" />
  <row Id="8477" PostId="6642" Text="I have a sound card which uses the -12V rail of PCI, so it's not unusual - it regulates -12V to -5V for the audio amp, I think." CreationDate="2010-11-12T18:32:04.627" UserId="1225" />
  <row Id="8478" PostId="6641" Text="Oh, a counter! Marvelous.  It's fun to see that the impossible-to-imagine device is something I've looked at a hundred times.  How to divide by 2?  Wait for every other one.  How to divide by 4, count 4 between each tick.  Amazing.  I've also wondered about that strange frequency, now it makes perfect sense.  I wish I could +2." CreationDate="2010-11-12T18:33:48.003" UserId="1271" />
  <row Id="8479" PostId="6641" Text="Correction:  the '4020 will only divide to clock/16384." CreationDate="2010-11-12T18:38:17.773" UserId="411" />
  <row Id="8480" PostId="6649" Text="Could I add ESR with a series resistor? At this point it might be worth considering a tantalum anyway, because it's going to be smaller than cap+resistor." CreationDate="2010-11-12T19:00:50.780" UserId="1225" />
  <row Id="8483" PostId="6644" Score="11" Text="I don't agree with you. The argument for the use of checklists is that any human can failure, even the experts. Please, read &quot;The CheckList Manifesto&quot; (http://gawande.com/the-checklist-manifesto) to understand why." CreationDate="2010-11-12T19:30:49.317" UserId="938" />
  <row Id="8484" PostId="6649" Score="1" Text="The answer to your question is yes, but why would you want to?  I can't understand why there would be a minimum ESR.  Perhaps to prevent people from paying too much for ultra-low ESR caps in 2002?" CreationDate="2010-11-12T19:38:33.370" UserId="857" />
  <row Id="8485" PostId="6648" Text="Regarding the 4-way ties, do you have a reference for that? You might have something to contribute to [this question](http://electronics.stackexchange.com/questions/6625/layouts-would-a-joint-at-1-point-or-2-be-the-same)." CreationDate="2010-11-12T19:40:41.887" UserId="857" />
  <row Id="8486" PostId="6595" Score="1" Text="I don't know about rotary pots, but some slide pots I've seen use an oil/grease between the wiper and housing to provide a very smooth feel.  There, the friction force (fluid shear?) isn't linear, and the thixotropic properties probably change drastically even from 10°C to 30°C." CreationDate="2010-11-12T19:41:22.930" UserId="1407" />
  <row Id="8487" PostId="6652" Text="Yeah, I am going to be doing assembly with hot plates or toaster ovens, but I'd like to do the first few prototypes with an iron." CreationDate="2010-11-12T19:49:41.203" UserId="1225" />
  <row Id="8488" PostId="6649" Score="3" Text="@ree: Some (generally older/cheaper) regulators require a minimum level of capacitor ESR to maintain stability." CreationDate="2010-11-12T19:50:03.700" UserId="1407" />
  <row Id="8489" PostId="6649" Score="4" Text="Some regulators become unstable with a very low ESR capacitor." CreationDate="2010-11-12T19:50:44.947" UserId="305" />
  <row Id="8490" PostId="6649" Text="@reemrevnivek: TC59 is only stable with ESR &gt; 0.1 ohms and ESR &lt; 5 ohms, see Mark's answer below." CreationDate="2010-11-12T19:52:13.590" UserId="1225" />
  <row Id="8491" PostId="6652" Text="@Thomas - The easy option is to not do it at all.  If the pad is electrically connected to one of the pins, you could get away with it for prototyping, where you'll be running it in a very controlled environment (25°C mostly) for not very long." CreationDate="2010-11-12T19:53:08.267" UserId="1407" />
  <row Id="8493" PostId="6655" Text="There are variants with MSOP10 EP, e.g. LT3757." CreationDate="2010-11-12T19:57:50.903" UserId="1225" />
  <row Id="8494" PostId="6613" Score="1" Text="Yeah, several thousand per case. You can probably get SLA's or something like that for something in the hundreds per case, but I doubt you can get it under $100 for an enclosure that large without going to plastic parts, or at least higher volume machined parts." CreationDate="2010-11-12T20:31:40.793" UserId="712" />
  <row Id="8495" PostId="6554" Text="well, the metal enclosure won't help much, the emissions will radiate from the various wires that will be attached to this.  The noise in the ethernet portion won't be contained to the ethernet section.  It will propagate throughout the design and present on all signals and wires going in or out of the design.  Additionally its not just an FCC issue.  Ground bounce and supply ringing will impact the reliability of the entire design.  This is a door lock after all, there is a large difference between it working on your bench and it working to secure your space for months on end." CreationDate="2010-11-12T20:33:19.770" UserId="1438" />
  <row Id="8496" PostId="6618" Text="It's Britain it's also illegal to use the title 'engineer' without an accredited degree." CreationDate="2010-11-12T20:48:16.603" UserId="1212" />
  <row Id="8497" PostId="6648" Score="1" Text="That was a layout question, this is about schematics.  The reason I say this is when copies are made it can be hard to tell between two wires crossing, but not connecting and a 4-way tie where they connect." CreationDate="2010-11-12T20:53:21.993" UserId="206" />
  <row Id="8498" PostId="6626" Score="1" Text="&quot;Only for high speed&quot; isn't quite true. You may have a low-frequency signal with a fast edge rate. This is particularly important for clocks since they are edge sensitive." CreationDate="2010-11-12T21:00:59.073" UserId="206" />
  <row Id="8499" PostId="6658" Text="This is at maximum load (1.1 amps) so I expect the current ripple to be high." CreationDate="2010-11-12T21:16:11.670" UserId="1225" />
  <row Id="8500" PostId="6658" Text="I increased the inductor to 5.6µH, peak current is lower, but RMS is the same." CreationDate="2010-11-12T21:20:19.933" UserId="1225" />
  <row Id="8501" PostId="6658" Text="Ok, but that doesn't change anything, you should be looking at max load and the datasheet's calculation are at max load, X should be 0.2-0.4 not 2.0." CreationDate="2010-11-12T21:20:59.187" UserId="1438" />
  <row Id="8502" PostId="6658" Text="exactly, increasing the value of the inductors reduces the swing of Isw, it shouldn't change RMS or average current.  reducing the peak current reduces strain on components, noise, supply ripple, etc." CreationDate="2010-11-12T21:22:40.440" UserId="1438" />
  <row Id="8503" PostId="6658" Text="I'm working off the datasheet's example on page 31. It's rated for 2A, I'm only needing 1.1A, so I've reduced the inductor's rating (from DRQ127 to DRQ73) and I've chosen a smaller FET." CreationDate="2010-11-12T21:37:49.207" UserId="1225" />
  <row Id="8504" PostId="6658" Text="Well the point and getting back to your original question here, is that your only considering average or RMS current, and what i'm saying is that you need to also consider peak current and that you can reduce the peak current you need to deal with by using a higher inductance part for L1/L2." CreationDate="2010-11-12T21:41:29.930" UserId="1438" />
  <row Id="8505" PostId="6603" Text="A favourite at school electronics clubs was a 4017 CMOS decade counter clocked by a 555 timer. The best variant I saw was with the 4017 being used as part of the resistor timing chain on a second 555 timer running in astable mode. By using the 4017 to switch between up to 10 variable resistors you could make a simple tone sequencer that drove everyone mad after a few minutes!" CreationDate="2010-11-12T22:10:04.193" UserId="1750" />
  <row Id="8506" PostId="6622" Text="I think the 0.1 seconds rating is the time to maximum off resistance. It will reduce the current in a significantly shorter time, both due to the resistance of the PTC and the device's characteristics. Also, the resistance of the PTC will also limit the current to less than 25A." CreationDate="2010-11-12T22:10:16.613" UserId="1225" />
  <row Id="8507" PostId="6600" Score="1" Text="Using a microcontroller for a simple LED sequencer seems like overkill. The most complex I'd go for would be a 555 timer driving a binary counter used to run through some of the address lines of a PROM/EPROM programmed with the required bit/LED patterns. By using switches on the higher address lines and putting the required patterns at the relevant locations in the (E)PROM you could even switch between patterns." CreationDate="2010-11-12T22:15:07.037" UserId="1750" />
  <row Id="8508" PostId="6659" Score="1" Text="dot orientation matters, for example, when transformers are part of feedback circuits in oscillators." CreationDate="2010-11-12T22:19:59.243" UserId="740" />
  <row Id="8509" PostId="6644" Score="1" Text="I mean, a program won't catch everything. I verify all my net namess before going to routing, for example, even though gEDA has the ability to search for net names." CreationDate="2010-11-12T22:26:45.600" UserId="1225" />
  <row Id="8511" PostId="6633" Text="i was thinking physically - the schematic has it as a + shape, but being able to use the latter topology should make it easier when i lay it out. i'd consider the latter topology easier since if i make a major mistake and don't want to rework it from scratch, i can cut the trace and make one parallel to it, and i have more options anyway" CreationDate="2010-11-12T22:29:44.193" UserId="1870" />
  <row Id="8512" PostId="6625" Text="my bad. I wasn't sure if the image was too big ;p" CreationDate="2010-11-12T22:31:47.170" UserId="1870" />
  <row Id="8513" PostId="6615" Text="@Mark only if you pay your INCOSE subscription" CreationDate="2010-11-12T22:50:34.210" UserId="1158" />
  <row Id="8514" PostId="6659" Text="@JustJeff Indeed! On the other hand, if the load was just a simple resistor, it wouldn't matter." CreationDate="2010-11-12T23:21:30.623" UserId="1240" />
  <row Id="8515" PostId="6630" Text="Yes, but flashing, even at high frequencies, will decrease the amount of light generated." CreationDate="2010-11-12T23:30:30.703" UserId="1757" />
  <row Id="8516" PostId="6665" Text="Yeah I know... but check out the other results, there are only a few 1206 packages, most are 2220 or stacked, and these are often cheaper than the bigger ones. These are great caps." CreationDate="2010-11-12T23:38:06.467" UserId="1225" />
  <row Id="8517" PostId="6666" Text="Capacitance Tolerance: ±10% plus Temperature Coefficient: ±15%, for a capacitor that's pretty good..." CreationDate="2010-11-12T23:38:25.640" UserId="1225" />
  <row Id="8518" PostId="6626" Score="3" Text="&quot;Low Speed&quot; &lt;&gt; &quot;Fast Edge&quot;. Anything with very fast edges is, by definition, high speed." CreationDate="2010-11-13T00:21:45.570" UserId="1374" />
  <row Id="8519" PostId="6626" Text="Whether your project warrants fast edges is another issue." CreationDate="2010-11-13T00:22:29.377" UserId="1374" />
  <row Id="8520" PostId="6622" Text="You will never, ever, get 20A if the device has a USB cable anywhere in the power connections." CreationDate="2010-11-13T00:29:59.887" UserId="1374" />
  <row Id="8521" PostId="6658" Text="@JustJeff: The dielectric of what? the DC capacitor or something else? The peak voltage across C3 and M1 is &lt;50V." CreationDate="2010-11-13T00:30:17.263" UserId="1225" />
  <row Id="8522" PostId="6644" Score="2" Text="Hah! I verify my netlists by keeping the schematic in mind while routing the board." CreationDate="2010-11-13T00:36:57.320" UserId="1374" />
  <row Id="8523" PostId="6648" Score="2" Text="If you have trouble distinguishing between 4-way wire crossings and junctions, your EDA package sucks." CreationDate="2010-11-13T00:38:06.883" UserId="1374" />
  <row Id="8524" PostId="6667" Text="I can't find the ESR rating for those caps anywhere. The datasheet is the same for a million other types." CreationDate="2010-11-13T00:59:18.460" UserId="1225" />
  <row Id="8525" PostId="6658" Text="@Thomas O -- ok, nevermind. i was just generalizing." CreationDate="2010-11-13T01:11:30.920" UserId="740" />
  <row Id="8526" PostId="6670" Score="1" Text="I think things like fans, lights, etc. are the sources of load dumps and thus no protection is mandated for them. High voltage dumps can cause relays to arc, which shortens their life. SOme relays can weld themselves shut - the arcing causes the contacts to stick together. Relays operating in the engine cabinet have to meet strict requirements including operating temperature, vibration resistance, life span, failure mode (if any) and electrical durability." CreationDate="2010-11-13T01:18:54.517" UserId="1225" />
  <row Id="8527" PostId="6644" Score="1" Text="I do the same, but it never hurts to check it once you're done..." CreationDate="2010-11-13T01:22:57.727" UserId="1225" />
  <row Id="8528" PostId="6671" Text="Hmm, possible. But then how can I avoid excessive humidity by design?" CreationDate="2010-11-13T01:27:18.640" UserId="1514" />
  <row Id="8529" PostId="6671" Text="In most cases it's not a problem. If you're operating in a high humidity environment, it could pose issues. Someone with more experience in designing for extremes would be useful here." CreationDate="2010-11-13T01:39:02.160" UserId="1225" />
  <row Id="8530" PostId="6617" Text="Its funny to think that it will count not the vehicles, but how many axles passed the spot. Reading wiki about railroad train Axle counter can humble any ordinary software/hardware guy on aspects of reliability and safety." CreationDate="2010-11-13T02:36:52.483" UserId="924" />
  <row Id="8531" PostId="6626" Text="Or for low-noise circuits, where ground currents cause voltage drops in the traces that get into the signal." CreationDate="2010-11-13T02:56:59.467" UserId="142" />
  <row Id="8532" PostId="6675" Text="Hooray. thanks!" CreationDate="2010-11-13T03:59:28.580" UserId="924" />
  <row Id="8533" PostId="6642" Score="2" Text="Thanks, that sucks" CreationDate="2010-11-13T04:32:51.163" UserId="1937" />
  <row Id="8534" PostId="6640" Text="Thanks... snipped thewires, but no luck" CreationDate="2010-11-13T04:33:07.263" UserId="1937" />
  <row Id="8535" PostId="970" Text="While I agree that better tolerance is useful, I've already collected too many &quot;weird value resistors&quot; that I'll probably never use." CreationDate="2010-11-13T05:26:21.840" UserId="813" />
  <row Id="8536" PostId="6617" Text="True. I would think that axles would be a good metric, though. An 18 wheeler with 5 axles takes more space than a car with 2." CreationDate="2010-11-13T05:58:49.243" UserId="965" />
  <row Id="8537" PostId="6627" Text="@pyfon, Yes, I read that online. there are states exactly like this in the US. The state I am in, OK, businesses must be registered to have engineer or engineering." CreationDate="2010-11-13T06:26:12.710" UserId="230" />
  <row Id="8538" PostId="6667" Score="4" Text="The ESR is rated using graphs. It's ESR vs Frequency. I found it on both links provided in the question, and the bigger cap is indeed lower ESR." CreationDate="2010-11-13T06:44:02.300" UserId="1374" />
  <row Id="8539" PostId="6627" Score="1" Text="Wow, strong comments - but this seems focused entirely on the particular PE designation.  I have no intent on that anyway, though others reading this question might want to know.  My work is more likely to be on the scale of quantum particle, not skyscrapers and power grids." CreationDate="2010-11-13T08:21:26.677" UserId="1609" />
  <row Id="8540" PostId="6618" Text="Interesting points about protection of the term &quot;Engineer&quot;.  Somehow, there doesn't seem to be an analogous protection of the term &quot;Software Developer&quot; or &quot;Programmer&quot; or even &quot;Software Engineer&quot; despite Engineer being in the latter - but that's a whole different discussion itself, already covered plenty elsewhere.  So, what can someone say instead of &quot;Engineer&quot; until they've got the BS/MS/PhD?" CreationDate="2010-11-13T08:25:29.077" UserId="1609" />
  <row Id="8541" PostId="6648" Text="All software sucks." CreationDate="2010-11-13T10:05:52.800" UserId="883" />
  <row Id="8542" PostId="6682" Text="I'm getting confused with the 595 and 596 - it's the 596 which has open collector/open drain." CreationDate="2010-11-13T12:33:13.690" UserId="1225" />
  <row Id="8543" PostId="6685" Text="Yes That is the case, I have edited the question to include that info. Is there a quick way to tell which type I am facing (I am trying to find a quick way to tell if my antenna is broken). BTW Thanks for the answer." CreationDate="2010-11-13T12:33:17.497" UserId="1471" />
  <row Id="8544" PostId="6684" Score="1" Text="Do you mean impedence? Are you looking for a 50 ohm antenna?" CreationDate="2010-11-13T12:33:50.303" UserId="1225" />
  <row Id="8545" PostId="6684" Text="No I mean really DC resistance, not at the 2.4GHz. (I believe it should be 50Ohm at band of interest but not necessary at DC)." CreationDate="2010-11-13T12:39:10.877" UserId="1471" />
  <row Id="8546" PostId="6685" Score="2" Text="Not really. RF Impedance is significantly different than DC resistance." CreationDate="2010-11-13T12:41:43.473" UserId="1374" />
  <row Id="8547" PostId="6688" Text="Would this be suitable for lead-based **and** lead-free solders then? With my cheap £30 soldering iron, they need very different temperatures." CreationDate="2010-11-13T14:42:11.343" UserId="1333" />
  <row Id="8548" PostId="6673" Score="2" Text="some have diode's some don't, look through the bosch automotive relay catalog." CreationDate="2010-11-13T16:00:15.397" UserId="1438" />
  <row Id="8549" PostId="6688" Text="while there is better feedback in a metcal style iron they aren't magic, the iron doesn't know what temperature the joint needs to be to do whatever it is your doing.  You select soldering temperature by choosing among the various tip series." CreationDate="2010-11-13T16:07:37.110" UserId="1438" />
  <row Id="8550" PostId="6692" Text="Interesting variations on that would be to make radio which does not use external power sources or to make a radio which works by temperature difference. If I remember correctly, both should be relatively simple to produce." CreationDate="2010-11-13T17:12:45.860" UserId="1240" />
  <row Id="8551" PostId="6688" Score="1" Text="You don't need different temps. LF needs a higher temp, but that higher temp is also fine for leaded, because Metcal's can't overshoot. People who have used conventional irons have become used to different temps due to inadequacies of the thermal coupling. Once you have good coupling, you just don't need to change the temp for LF or leaded - the only time you may want to is if using exotic stuff like indium low-temp solders on laser diode chips, and how many people ever do that..?" CreationDate="2010-11-13T17:13:29.750" UserId="1681" />
  <row Id="8552" PostId="6692" Score="1" Text="With a long antenna enough power could be generated from it to supply a simple amplifier." CreationDate="2010-11-13T17:20:36.917" UserId="305" />
  <row Id="8553" PostId="6632" Score="1" Text="Wow, this just makes sense. Once I drew it out I realized how simple it would be. Thanks for your help, sometimes the simplest of things escape me!" CreationDate="2010-11-13T17:47:51.247" UserId="1935" />
  <row Id="8554" PostId="6688" Score="1" Text="always use the lowest temp tip that does the job.  There is zero reason to impart more heat to a component than absolutely necessary.  The specific selling point of a metcal type iron, and why they are so loved is that their thermal coupling allows using a lower temp than would be required for other irons.  This reduces the chances of component damage.  Start with the lowest temp tip and only move up if you need to.  There are tons of applications that may require a hotter tip, its certainly not limited to exotic components.   " CreationDate="2010-11-13T17:55:53.110" UserId="1438" />
  <row Id="8555" PostId="6693" Text="Well, OP  specifically said no kits, but you still get +1 form me. Snap Circuits do look well thought out and simple enough for use." CreationDate="2010-11-13T18:36:51.237" UserId="1240" />
  <row Id="8556" PostId="6612" Text="I'm still hoping someone can point me to some good industrial design firms for this sort of thing, which is why I haven't marked this question answered yet." CreationDate="2010-11-13T19:25:49.677" UserId="1913" />
  <row Id="8557" PostId="6686" Score="7" Text="i know it was just an example but i'd skip the laser idea, the laser in a dvd drive is actually quite dangerous, i wouldn't want kids playing with it, pointing it at each other, etc." CreationDate="2010-11-13T19:31:28.807" UserId="1438" />
  <row Id="8558" PostId="6484" Text="Sounds like a cool project." CreationDate="2010-11-13T21:16:23.887" UserId="813" />
  <row Id="8559" PostId="6649" Text="@reemrevnivek I expanded my answer to include the reasons why the ESR does needs to be in a particular range to maintain stability." CreationDate="2010-11-13T21:28:22.997" UserId="1438" />
  <row Id="8560" PostId="6650" Text="+1 for &quot;error amp is basically thrown for a loop&quot;" CreationDate="2010-11-13T21:45:15.443" UserId="1322" />
  <row Id="8561" PostId="6650" Score="1" Text=":) I almost deleted that because it could be confusing but I couldn't resist." CreationDate="2010-11-13T21:50:54.217" UserId="1438" />
  <row Id="8562" PostId="6707" Text="Hmm yeah, good theory on the video. I think the chip that burnt on mine was the IDE controller, as it has loads of traces going to the IDE connector." CreationDate="2010-11-13T22:48:36.420" UserId="1225" />
  <row Id="8563" PostId="6707" Text="your average computer supply can provide ~150W of power at +5V also, almost impossible to guess what caused the short inside the IC but unless there was obvious damage i would assume that ESD hit it and fused some transistors causing the sort." CreationDate="2010-11-13T22:52:17.560" UserId="1438" />
  <row Id="8564" PostId="6707" Text="some more entertainment: http://www.youtube.com/watch?v=JCPXckfT-6g&amp;feature=related I think exploding aluminum caps are my favorite" CreationDate="2010-11-13T23:05:23.467" UserId="1438" />
  <row Id="8565" PostId="2272" Text="Should this be merged with http://electronics.stackexchange.com/questions/2262/smoothing-capacitors-what-size-and-how-many ?" CreationDate="2010-11-13T23:06:35.667" UserId="813" />
  <row Id="8566" PostId="6686" Score="3" Text="it's perhaps more correct to say one can *liberate* a laser from a DVD burner.. but those things can easily blind a person, which would not be very much fun." CreationDate="2010-11-13T23:28:43.517" UserId="740" />
  <row Id="8567" PostId="6692" Score="2" Text="it's fairly easy to build a crystal sets that doesn't require any power, provided you use one of those high impedance earphones. the tricky part is getting the frequency on something interesting." CreationDate="2010-11-13T23:31:18.600" UserId="740" />
  <row Id="8568" PostId="6703" Text="I recall Giotto http://en.wikipedia.org/wiki/Giotto_mission had three on its dust shield to triangulate impacts and these being plotted in real time on the TV, though obviously that's a much faster projectile hitting a hard surface." CreationDate="2010-11-14T00:02:43.437" UserId="1158" />
  <row Id="8569" PostId="6618" Text="&quot;Engineer in Training&quot; (if part of the EIT program in Canada), Engineering graduate (if you have a B.Eng/B.A.Sc maybe), maybe hardware/software/system architect/designer? As far as I know, software engineer is protected the same way as other engineers (in Canada at least). You could also have a tag line as part of your resume that you are looking to become a professional engineer or equivalent in your area." CreationDate="2010-11-14T00:28:02.567" UserId="536" />
  <row Id="8570" PostId="6714" Text="I imagine it has far more to due with separate cables / board connections.  You need a seriously fat cable to pass 100A at 12V." CreationDate="2010-11-14T00:35:04.420" UserId="1438" />
  <row Id="8571" PostId="6712" Score="4" Text="could be any or all of the above, very dependent not only on the device but on which pins of said devices the voltage is applied to." CreationDate="2010-11-14T00:41:55.307" UserId="1438" />
  <row Id="8572" PostId="6717" Text="Good suggestion, but I didn't connect the drive to anything except the power supply." CreationDate="2010-11-14T00:45:27.363" UserId="1225" />
  <row Id="8573" PostId="6714" Text="@Mark: Sure you do, but each rail splits into about 5 or 6 wires to go to Molex, SATA, PCI-e etc., it's not like each wire for each rail is carrying 16A." CreationDate="2010-11-14T00:47:17.567" UserId="1225" />
  <row Id="8574" PostId="6714" Score="1" Text="you'd be surprised,  Nvidia GX480 graphics card requires a minimum of 38A @ 12V." CreationDate="2010-11-14T00:52:54.427" UserId="1438" />
  <row Id="8575" PostId="6714" Score="1" Text="@Mark: well, doesn't PCI-e's power expansion have 4x 12V conductors, allowing for ~64A according to my calculations, if not more?" CreationDate="2010-11-14T00:56:49.667" UserId="1225" />
  <row Id="8577" PostId="6712" Text="It is almost always power that damages things, by overvoltaging enough current flows to allow power to transfer to damage things." CreationDate="2010-11-14T01:00:57.513" UserId="230" />
  <row Id="8579" PostId="6639" Text="@reemrevnivek , have you seen the people who claim that such back-to-back electrolytics cause &quot;no problems&quot;? See http://electronics.stackexchange.com/questions/3062/what-are-some-reasons-to-connect-capacitors-in-series" CreationDate="2010-11-14T01:42:25.233" UserId="813" />
  <row Id="8580" PostId="6722" Score="5" Text="Someone tore a set apart so that you can see the patterns: http://www.adafruit.com/blog/2010/11/08/digital-calipers-tear-down/" CreationDate="2010-11-14T01:44:26.640" UserId="259" />
  <row Id="8581" PostId="6722" Score="1" Text="Nice. I can imagine how early inventor discovered it. He(she) was tuning the radio by turning gauge/capacitor contraption by one hand, having the logarithmic ruler in other hand, then looked at LCD watches on a wrist on yet another hand and said ... Eureka!" CreationDate="2010-11-14T01:55:34.243" UserId="924" />
  <row Id="8582" PostId="6612" Text="@Fake Name: Trying to shoehorn a pile of electronics into an enclosure that custom-designed to look &quot;pretty&quot; and &quot;curvy&quot; and &quot;swoopy&quot; with zero input from the electronics guy is no walk in the park either." CreationDate="2010-11-14T02:29:50.373" UserId="813" />
  <row Id="8583" PostId="6712" Score="2" Text="I want to know the answer to this question to.  Another way of rephrasing it would be &quot;Suppose I have a 20V power supply but one end of it has a 100kOhm resistor on it, so it can't supply much current.  Is it possible to damage a microcontroller board with this power supply?" CreationDate="2010-11-14T02:42:20.320" UserId="1545" />
  <row Id="8584" PostId="6716" Text="You claim that some semi-conductor devices are sensitive to over-voltage per se, but why is that true?  Can you cite a source?  What will happen to the device that can permanently damage it, if not heat?" CreationDate="2010-11-14T02:44:37.057" UserId="1545" />
  <row Id="8585" PostId="6715" Score="2" Text="How will internal shorts damage a microcontroller permanently?  What exactly about the silicon will change, and what causes it to change?" CreationDate="2010-11-14T02:47:57.727" UserId="1545" />
  <row Id="8586" PostId="6716" Text="@David: I'm drawing on rather rusty memories of my Stat Mech classes back in school...on top of which I think, I've been imprecise. I'll go read and either elaborate or retract." CreationDate="2010-11-14T03:38:17.873" UserId="1882" />
  <row Id="8587" PostId="6688" Score="2" Text="@Mark - I disagree. Using a hotter tip generally lets you create a good joint much faster, resulting in less component heating." CreationDate="2010-11-14T06:59:01.067" UserId="1374" />
  <row Id="8588" PostId="5952" Text="@Thomas O - Actually, they often do. Usually most fab houses have drill sets from 0.001&quot; to 0.250&quot; in 0.001&quot; increments." CreationDate="2010-11-14T07:00:17.837" UserId="1374" />
  <row Id="8589" PostId="5952" Text="Generally, holes smaller than 0.010 increase the cost, because you break a lot more bits once you start getting **really** small." CreationDate="2010-11-14T07:01:07.320" UserId="1374" />
  <row Id="8590" PostId="6704" Text="Conductive fabric is the way to go. If you're using this in a paintball match, it means the person wearing it will likely have a paintball gun, which will drown out the impact sounds in the microphone option." CreationDate="2010-11-14T07:02:41.967" UserId="1374" />
  <row Id="8591" PostId="6698" Text="headphones do not have ground, just left, right, and common." CreationDate="2010-11-14T07:05:42.760" UserId="1374" />
  <row Id="8592" PostId="6698" Text="The common wire is the ground. It also acts as the shield for the other two wires to prevent picking up noise." CreationDate="2010-11-14T07:25:36.667" UserId="965" />
  <row Id="8594" PostId="6730" Text=":( Shipping is 53 dollars from their store" CreationDate="2010-11-14T10:19:07.950" UserId="1688" />
  <row Id="8595" PostId="6733" Text="That is what I have done so far. The lamp in the right and the power in the left doesn't seem to work. I have also tried to switch around the blue and brown wires. Someone told me that I might not need to use all 4 wires (two on the cable from the lamp and two on the cable to the power plug) don't know if that is correct? With regards to safety I have a one year old so I am very cautious." CreationDate="2010-11-14T10:38:26.703" UserId="1949" />
  <row Id="8596" PostId="6733" Text="I can also add the dimmer box is called Rondo from from Relco i tried to look it up but haven't been able to find the brand anywhere " CreationDate="2010-11-14T10:48:51.827" UserId="1949" />
  <row Id="8597" PostId="6731" Text="I solved it thanks for your help I found an actual illustration. It turns out I should only use 3 of the slots, the fourth (the one with the circle and the lines) was for earthquake. And I needed to take the two neutral wires and put them in the same slot (N)" CreationDate="2010-11-14T11:12:14.100" UserId="1949" />
  <row Id="8598" PostId="6731" Text="It seems that your question got cut off at the bottom. Could you fix the missing info? I may then be able to improve my answer." CreationDate="2010-11-14T11:13:54.587" UserId="965" />
  <row Id="8599" PostId="6731" Text="Could you post the illustration, then post an answer with what you did? After you post your answer, accept it. This way, others will be able to learn from your experiences." CreationDate="2010-11-14T11:16:41.167" UserId="965" />
  <row Id="8600" PostId="6731" Text="&quot;the fourth (the one with the circle and the lines) was for earthquake.&quot; -- actually, it would be &quot;earth&quot;, or as we say in the US, ground, which would be used if you had a three terminal plug instead of two." CreationDate="2010-11-14T12:08:16.063" UserId="1322" />
  <row Id="8602" PostId="6733" Text="This is the correct way to solve it and you are right it's second possibility (3 way lamp)&#xA;&#xA;000fff.org/uploads/82200800_RONDO.pdf" CreationDate="2010-11-14T13:03:46.283" UserId="1949" />
  <row Id="8603" PostId="6731" Text="You are right of course. Earth not earthquake :) " CreationDate="2010-11-14T13:05:24.923" UserId="1949" />
  <row Id="8604" PostId="6717" Text="Whoops, missed that." CreationDate="2010-11-14T15:52:17.777" UserId="536" />
  <row Id="8605" PostId="6627" Score="1" Text="@darenW, We are specifically saying that in some states you may not say Engineer in your title unless you have a PE. It seems new mexico is that way also." CreationDate="2010-11-14T17:51:22.463" UserId="230" />
  <row Id="8606" PostId="6728" Score="2" Text="Out of curiosity, why won't Digikey sell to Australia on export regulations?? Is an accelerometer considered military equipment or something?" CreationDate="2010-11-14T18:23:26.970" UserId="1225" />
  <row Id="8607" PostId="6738" Text="LT1765-5.0 looks very interesting, as does TPS54232, thanks for the links!" CreationDate="2010-11-14T19:28:09.340" UserId="1225" />
  <row Id="8608" PostId="6742" Text="Well, I'd like the highest reliability possible because I hate unreliable products, I've had so many and I don't think it will be too difficult to reach such a high reliability." CreationDate="2010-11-14T23:02:47.627" UserId="1225" />
  <row Id="8609" PostId="6742" Text="It's a fully solid state design and all components are 1.5x to 2x rated where necessary." CreationDate="2010-11-14T23:03:49.980" UserId="1225" />
  <row Id="8610" PostId="6712" Text="@davidEGrayson, it is not simple to broadly define that." CreationDate="2010-11-14T23:29:13.237" UserId="230" />
  <row Id="8611" PostId="6728" Text="They are told that stuff." CreationDate="2010-11-14T23:32:31.970" UserId="230" />
  <row Id="8612" PostId="6744" Score="1" Text="We do the same - drive the LED's with less than half the specified current. This increases the lifetime of the LED's significantly by many years, before the LED starts to reduce in noticeable brightness, and many more years before the LED completely dies." CreationDate="2010-11-15T00:32:34.797" UserId="1785" />
  <row Id="8613" PostId="6748" Score="2" Text="....Microchip? Go with Linear tech or Burr-Brown if you're looking for ultra-high sound quality." CreationDate="2010-11-15T00:53:40.450" UserId="1374" />
  <row Id="8614" PostId="6698" Score="1" Text="It may be common, but it's still not ground. Also, it has nothing to do with noise pickup." CreationDate="2010-11-15T01:15:17.397" UserId="1374" />
  <row Id="8615" PostId="6698" Score="1" Text="The low impedance of the headphones is what is responsible for their general noise-immunity." CreationDate="2010-11-15T01:15:40.220" UserId="1374" />
  <row Id="8616" PostId="6742" Score="1" Text="Does it have software in it?  You're totally hosed then." CreationDate="2010-11-15T01:16:30.530" UserId="1407" />
  <row Id="8617" PostId="6715" Score="1" Text="The shorts allow large currents to flow, which, because nothing is a perfect conductor, causes a temperature increase, which eventually melts things." CreationDate="2010-11-15T02:07:02.820" UserId="142" />
  <row Id="8618" PostId="6752" Text="The memory options computer.howstuffworks.com has seem to be more directed at a user of a computer, not someone whom is going to be using microcontrollers." CreationDate="2010-11-15T02:34:56.643" UserId="230" />
  <row Id="8619" PostId="6740" Score="1" Text="Make sure your system can withstand all sorts of possible faults and input transients, otherwise being concerned with MTBF for discretes and passives is asinine." CreationDate="2010-11-15T03:41:32.737" UserId="1407" />
  <row Id="8620" PostId="6750" Score="1" Text="People don't usually listen to sine waves.  :)  The highest theoretical slew rate you would need is a full-scale square wave bandlimited to the audible range.  http://en.wikipedia.org/wiki/Rise_time  says the rise time is something like 0.35/bandwidth, so the slew rate would be the voltage rails divided by the rise time?" CreationDate="2010-11-15T03:43:08.937" UserId="142" />
  <row Id="8621" PostId="6750" Score="8" Text="of course you don't listen to sine waves, however music, as with any remotely periodic signal, can be devolved into a sum of sinusoids, so looking at the highest band-limited frequency is all thats needed.  If your trying to say that you need to consider the impulse response, i disagree, any wave form with content outside ~20-20khz won't be in the source material anyway." CreationDate="2010-11-15T04:18:14.923" UserId="1438" />
  <row Id="8622" PostId="6618" Text="@pfyon, I am waiting on references to get my EIT(called Engineering Intern here in OK). In certain states Engineer is protected in general, other states it is not at all.  Some states just protect a company using it in job titles. Almost all required that you have a PE to put engineer or engineering in your company name." CreationDate="2010-11-15T05:04:59.233" UserId="230" />
  <row Id="8623" PostId="2300" Text="Sorry, bumped to standardize tag for lego-mindstorms." CreationDate="2010-11-15T06:19:22.383" UserId="230" />
  <row Id="8624" PostId="6715" Text="The thinnest insulating layer (and thus the most susceptible to a voltage breakdown) is the gate oxide in a field effect transistor. I'm not sure what the failure mode is when the gate oxide is punctured (open or short), but the transistor will not function as intended. This failure would not be thermally induced, since the gate current (and thus power dissipation) should be negligable.&#xA;As Endolith mentions, any short allows uncontrolled current flow, and open circuits or unactivated transistors can let internal circuitry float or get into states that can be self destructive." CreationDate="2010-11-15T06:29:11.937" UserId="638" />
  <row Id="8625" PostId="6744" Text="Would it be sensible to increase the LED's current once the brightness starts decreasing? Or would that shorten the LED's life faster? Will pulse-width modulation vs. DC make a difference in lifetime?" CreationDate="2010-11-15T07:50:36.577" UserId="1450" />
  <row Id="8626" PostId="6742" Text="Yep, but the micros have flash retention of 40 years." CreationDate="2010-11-15T07:57:50.783" UserId="1225" />
  <row Id="8627" PostId="6748" Text="Not ultra-high sound quality, just acceptable THD." CreationDate="2010-11-15T07:58:43.043" UserId="1225" />
  <row Id="8628" PostId="6618" Text="@Noldorin - In the UK ANYONE can call themselves an engineer.  The term has no protection.  If you call yourself a &quot;Chartered Engineer&quot;, &quot;Incorporated Engineer&quot; or &quot;EurIng&quot; without actually being registered as such you could get into trouble in the same way as you could for falsely claiming to have a degree but the term &quot;Engineer&quot; is not protected here." CreationDate="2010-11-15T08:33:16.243" UserId="400" />
  <row Id="8629" PostId="6618" Text="@Ian: Ah, fair enough. I guess people here are just always on the lookout for the 'chartered' word more than anything." CreationDate="2010-11-15T10:08:39.980" UserId="1212" />
  <row Id="8630" PostId="6449" Text="You don't necessarily have to do hand soldering. Reflow, using a toaster oven or skillet, is very popular. " CreationDate="2010-11-15T11:08:17.050" UserId="1225" />
  <row Id="8631" PostId="6740" Text="The more expensive version has input transient protection from -40V to +60V, the other version is rated to go from -40V to +24V." CreationDate="2010-11-15T11:14:08.123" UserId="1225" />
  <row Id="8633" PostId="6762" Text="Stereo support is not going to be used. Thanks for the suggestion though." CreationDate="2010-11-15T13:06:45.747" UserId="1225" />
  <row Id="8634" PostId="6761" Score="2" Text="This doesn't explain why isolation is important though... " CreationDate="2010-11-15T13:08:43.733" UserId="1225" />
  <row Id="8635" PostId="6628" Score="2" Text="Thank you. This will work fine. I would give you a vote up but my reputation says I cannot." CreationDate="2010-11-15T14:34:59.060" UserId="1637" />
  <row Id="8636" PostId="6621" Text="Thanks for the edit." CreationDate="2010-11-15T14:37:32.520" UserId="1637" />
  <row Id="8637" PostId="6765" Score="4" Text="*Electrolysis* (in title) is often used to split water into H2 and O2--distinct from *generating electricity* (in text).  Which is your aim?" CreationDate="2010-11-15T14:41:37.420" UserId="1407" />
  <row Id="8638" PostId="6669" Text="Three answers so far, each of them seems possible. How can I decide which worth the checkmark?:)" CreationDate="2010-11-15T15:51:05.380" UserId="1514" />
  <row Id="8639" PostId="6723" Text="There should (must by code?) be separate wires from each CB/fuse to whatever gang of outlets/switches/lights.  True, the average house can draw 100-200 A without much problems, but you can't jam more than 15 A through 14 AWG, or 20 A through 12 AWG, safely in confined spaces." CreationDate="2010-11-15T18:31:04.163" UserId="1407" />
  <row Id="8640" PostId="6777" Text="Good point on the LPF ( or any filter ).  Depending on the tolerance for non-constant group delay the designed for bandwidth may need to be higher.  However if he's not after 'hifi' performance non-constant group delay, on the high end especially, may not matter." CreationDate="2010-11-15T19:43:12.957" UserId="1438" />
  <row Id="8641" PostId="6712" Text="@David - Consider asking that as a separate question if you want to know the answer to it.  When you do so, add some more specifics." CreationDate="2010-11-15T20:17:23.027" UserId="857" />
  <row Id="8642" PostId="6780" Text="I don't have the batteries yet, but it's an idea for a future project. I'd have some proper fuses on it I suppose. Would 250V fuses not be good enough?" CreationDate="2010-11-15T20:54:03.620" UserId="1225" />
  <row Id="8643" PostId="6721" Text="How does dV/dt damage the device though? Say that you have a few microamps flowing through it, would it still be damaged, even though the current is very low?" CreationDate="2010-11-15T20:56:29.560" UserId="1225" />
  <row Id="8644" PostId="6784" Text="Much more precise answer!" CreationDate="2010-11-15T21:35:07.733" UserId="1757" />
  <row Id="8645" PostId="6741" Text="@Kortuk: Do we really not have code highlighting on Electronics and Robotics??" CreationDate="2010-11-15T21:55:44.330" UserId="1217" />
  <row Id="8646" PostId="6780" Score="1" Text="You must make sure the **DC** current interrupting rating for the fuse will be acceptable.  The AC rating is usually ~50% higher than the DC rating as the zero-crossings can help to extinguish the arc." CreationDate="2010-11-15T21:58:58.073" UserId="1407" />
  <row Id="8647" PostId="6722" Text="[Here's the Flickr page](http://www.flickr.com/photos/50241702@N04/) with them all on it if you were confused like me going 'WHERE DA PICS??'" CreationDate="2010-11-15T22:02:37.197" UserId="1407" />
  <row Id="8648" PostId="6740" Text="Shorting outputs together, shorting outputs to the battery/ground, inductive spikes on power lines, also coupled into signal lines, ESD on every pin and more are all things that our finished modules must take without ill effect as per SAE standards and customer requirements." CreationDate="2010-11-15T22:10:17.923" UserId="1407" />
  <row Id="8649" PostId="6744" Text="@user1450 If you have a fixed current source driving the LED, the brightness should stay fairly even until total failure (not accounting for things like phosphor degradation in white LEDs).  Most LEDs in this world are probably driven from a voltage source through a resistor, however, which is the cheapest way possible and sufficient for almost every application.  Adding additional circuitry to account for the aging of the LED would make no sense in the vast majority of these instances." CreationDate="2010-11-15T22:12:33.270" UserId="1407" />
  <row Id="8650" PostId="6740" Text="Shorting outputs together: check - 1 kohm resistors in series." CreationDate="2010-11-15T22:58:04.293" UserId="1225" />
  <row Id="8651" PostId="6740" Text="Shorting outputs to battery/ground: check - resistors with the clamping diodes in the MCU's." CreationDate="2010-11-15T22:58:32.327" UserId="1225" />
  <row Id="8652" PostId="6740" Text="ESD on every pin: yep, have TVS ESD diodes, see my previous Q on this." CreationDate="2010-11-15T22:58:52.543" UserId="1225" />
  <row Id="8653" PostId="6740" Text="I'm not rating the module against idiocy though. If some idiot tries to measure mains voltage with the 30V inputs, the module will go bang. I'm not going to add MOV's or something to shield against that." CreationDate="2010-11-15T22:59:43.060" UserId="1225" />
  <row Id="8654" PostId="6791" Score="7" Text="I was thinking pretty much the same thing, perhaps the off state could be achieved by tristating the output pin of the micro." CreationDate="2010-11-15T23:32:43.860" UserId="1322" />
  <row Id="8655" PostId="6792" Score="1" Text="See also my Design Con paper, Designing a Simple FPGA-Optimized RISC CPU and System-on-a-Chip [http://fpgacpu.org/papers/soc-gr0040-paper.pdf], which presents the annotated Verilog source code for an FPGA CPU and SoC." CreationDate="2010-11-15T23:33:20.300" UserId="1962" />
  <row Id="8656" PostId="6791" Score="1" Text="An awesome suggestion...tri-stating the pin should turn it off without the fancy PWM.  However, you must be careful about letting the input float, probably need a pull down (NOT divider, don't let the input pin see mid-rail voltages!)" CreationDate="2010-11-15T23:40:37.850" UserId="1278" />
  <row Id="8657" PostId="6789" Score="2" Text="would guess that the through-hole stuff is generally higher wattage" CreationDate="2010-11-15T23:43:25.633" UserId="740" />
  <row Id="8658" PostId="6721" Score="1" Text="Damage is always thermal. Its several watt or kilowatt of peak power, which irreversibly ruins the part. But the cause of applying such power (say in bridge with hight side shorted to low by accident) is unexpected opening of side, which supposed to be closed. The opening can happen with help of microamp current if it exceeded the dv/dt. It sure, makes no damage for first nanoseconds because its microamperes, but after parasitic thyristor (or parasitic inverse BJT) opens wide, the avalanche current is counted in amperes" CreationDate="2010-11-16T01:30:48.780" UserId="924" />
  <row Id="8659" PostId="6456" Text="Nice explanation. I'd add that flexible electrodes can help for noise critical applications, where non-destructive vibration can be picked up by ceramic caps, acting like condenser microphones." CreationDate="2010-11-16T01:33:39.760" UserId="924" />
  <row Id="8660" PostId="6797" Score="1" Text="They don't wave solder them?  I'm not sure how much quality you can get from hand-soldering if it's being done en masse, though there are lots of stupidly shaped parts that may not be amenable to machine insertion." CreationDate="2010-11-16T02:59:34.163" UserId="1407" />
  <row Id="8662" PostId="6791" Score="1" Text="You could use a high-value (470k) resistor pulled high or low. The LED will be biased or one colour or the other, but the current flow will be so low that you won't see the LED as on." CreationDate="2010-11-16T03:02:00.353" UserId="974" />
  <row Id="8664" PostId="6789" Score="2" Text="And they always use cheap phenolic PCB's instead of FR4!" CreationDate="2010-11-16T03:10:59.937" UserId="1688" />
  <row Id="8667" PostId="6790" Score="1" Text="You can do just about anything with one pin of a micro.  More specific please?" CreationDate="2010-11-16T03:16:17.950" UserId="1407" />
  <row Id="8668" PostId="6791" Score="5" Text="@ajs410 - I think MCUs are much more intelligently designed than a dumb logic chip.  On your average 8-bit micro, the vast majority of the pins can be used as analog inputs (without explicitly configuring them as such) so there should be no ill effect (gate oscillation, excessive current draw) so long as the voltage remains within GND and VDD." CreationDate="2010-11-16T03:20:50.720" UserId="1407" />
  <row Id="8669" PostId="6778" Text="Depends if there is an isolation transformer on the input.  Bypassing one that's there would be...dubious." CreationDate="2010-11-16T03:24:09.390" UserId="1407" />
  <row Id="8670" PostId="6791" Score="1" Text="As long as the voltage does not exceed the rails, tristated pins can handle anything." CreationDate="2010-11-16T06:48:07.047" UserId="1374" />
  <row Id="8671" PostId="6765" Text="Thanks. Changed the title." CreationDate="2010-11-16T07:30:38.050" UserId="1957" />
  <row Id="8672" PostId="6797" Score="1" Text="they are hand soldered, never seen an Asian CM bother with wave soldering." CreationDate="2010-11-16T07:47:48.667" UserId="1438" />
  <row Id="8673" PostId="6793" Text="Problem is with this is that the batteries will discharge at different rates and it then doesn't allow me to power other high voltage equipment." CreationDate="2010-11-16T07:55:43.277" UserId="1225" />
  <row Id="8674" PostId="6805" Text="Do you need a negative voltage? couldn't you just manipulate the 0v for what you need with a not gate. " CreationDate="2010-11-16T08:08:26.260" UserId="1623" />
  <row Id="8675" PostId="6806" Text="try stackoverflow.com if you haven't, i doubt you'll get much information on this board (but maybe)." CreationDate="2010-11-16T08:42:59.390" UserId="1438" />
  <row Id="8676" PostId="6788" Score="1" Text="If you could see the LED flashing, then it wasn't switching on and off 'rapidly' ;-)" CreationDate="2010-11-16T08:48:52.583" UserId="1844" />
  <row Id="8677" PostId="6765" Text="Why newspapers?" CreationDate="2010-11-16T08:56:39.913" UserId="1374" />
  <row Id="8678" PostId="6806" Text="Okay, thanks! I'll ask there too." CreationDate="2010-11-16T08:57:29.600" UserId="1965" />
  <row Id="8679" PostId="6806" Text="@Heinrich This is offtopic for Electronics &amp; Robotics. It's a much better question for stackoverflow.com" CreationDate="2010-11-16T09:38:32.877" UserId="566" />
  <row Id="8680" PostId="6768" Text="Thanks for all the answers. I will research further with these informations." CreationDate="2010-11-16T09:47:07.947" UserId="1957" />
  <row Id="8681" PostId="6468" Text="Another update: it seems it is only the Vlogic voltage that is causing the problem, and only voltages below about 1.8V works. I've tested Vdd up to 3.3V and that doesn't seem to matter. " CreationDate="2010-11-16T10:15:43.103" UserId="1897" />
  <row Id="8682" PostId="6806" Text="I was just about to suggest http://stats.stackexchange.com/ but I see you've already posted there." CreationDate="2010-11-16T10:25:07.453" UserId="103" />
  <row Id="8683" PostId="6770" Text="Thanks!  So, to borrow from Mythbusters, plausible, but not likely." CreationDate="2010-11-16T12:11:45.427" UserId="1877" />
  <row Id="8684" PostId="6791" Score="1" Text="if the pin is being used as an *output* you don't have to worry about it doing things that input pins do. Sure, maybe if you leave it unconnected and tri-stated, the voltage may bob around a bit on that pin, but, here's the thing, *you're not going to be reading it*. But the pin wouldn't be unconnected anyway, since you'd already have the LED between it and a supply rail." CreationDate="2010-11-16T12:16:40.867" UserId="740" />
  <row Id="8686" PostId="6767" Text="What does &quot;recad&quot; mean?" CreationDate="2010-11-16T13:01:46.570" UserId="103" />
  <row Id="8687" PostId="6797" Text="I've been working in power for years. All CMs that I've seen do indeed have wave soldering, not to mention comparable SMD placement capabilities to domestic builders. If you're doing big power with multilayer boards you simply cannot get enough heat into the PCBs to get the solder to properly wet. Cheap ATX supplies are a different animal." CreationDate="2010-11-16T14:26:09.043" UserId="1293" />
  <row Id="8688" PostId="2173" Text="That's all structural VHDL though, so not great as a teaching tool" CreationDate="2010-11-16T14:35:08.150" UserId="763" />
  <row Id="8689" PostId="6819" Text="Is there a &quot;most common&quot; layout? I'm using an AVR32 processor." CreationDate="2010-11-16T14:46:27.550" UserId="1225" />
  <row Id="8690" PostId="6816" Score="2" Text="What is so difficult about using parametric search?  This is the third question like this (&quot;find me a part&quot;) in less than a day with no apparent effort done." CreationDate="2010-11-16T14:51:20.030" UserId="1407" />
  <row Id="8691" PostId="6823" Text="That's a dual color LED, not a bicolor LED. Bicolor has two LEDs in inverse parallel." CreationDate="2010-11-16T14:55:09.310" UserId="1225" />
  <row Id="8692" PostId="6816" Text="I *have* spent effort trying to find these parts using Farnell and Digikey's parametic search, but to no luck. So I'd thought I'd ask for some help. Is that too wrong?" CreationDate="2010-11-16T14:55:39.137" UserId="1225" />
  <row Id="8693" PostId="6823" Score="2" Text="So?  Connect the diodes anti-parallel." CreationDate="2010-11-16T14:59:03.347" UserId="1407" />
  <row Id="8694" PostId="6823" Score="1" Text="That may have a shared common by the looks of that. It's also not standard 0603, because it has 4 pins, I don't think I have a footprint for that. (And I dislike drawing footprints, even though I have to sometimes...)" CreationDate="2010-11-16T15:00:23.817" UserId="1225" />
  <row Id="8695" PostId="6823" Score="1" Text="[Their datasheet](http://www.avagotech.com/docs/AV02-0584EN) claims &quot;0603 industry standard footprint&quot; and on page 2 it shows they are isolated." CreationDate="2010-11-16T15:05:28.410" UserId="1407" />
  <row Id="8696" PostId="6819" Score="1" Text="I'd use what is used by Atmel on their AVR32 boards." CreationDate="2010-11-16T15:07:06.757" UserId="305" />
  <row Id="8697" PostId="6814" Score="3" Text="[Look what happens](http://lmgtfy.com/?q=Control+a+bicolor+LED+with+just+one+pin) when you Google the question title verbatim.  #1 before this question." CreationDate="2010-11-16T15:10:13.210" UserId="1407" />
  <row Id="8698" PostId="6821" Text="Wow, thank you. I had the ink in mind, but didn't know it has been changed from metals to soy. I guess, this is not going to be the solution for our project then." CreationDate="2010-11-16T15:14:06.867" UserId="1957" />
  <row Id="8699" PostId="6815" Text="So AUDIO_L_OUT is an output, and AUDIO_L_EXT is an input?  But where are the signals coming and going?  And R53 passes the output back to the input?  Or it passes from input directly to output?  I don't get what Q2 and Q3 are for, though.  Can you explain the function with a little more detail?" CreationDate="2010-11-16T15:19:34.887" UserId="142" />
  <row Id="8700" PostId="6815" Text="AUDIO_L_EXT is the external audio channel input. Q2 and Q3 mux the amplifier's input between the external audio and the internally generated audio. " CreationDate="2010-11-16T15:23:40.623" UserId="1225" />
  <row Id="8701" PostId="6815" Text="R53 is placed only when there is no audio amplifier (on some boards, it is an option) and acts as a pass-through between the input and output." CreationDate="2010-11-16T15:24:53.710" UserId="1225" />
  <row Id="8702" PostId="6815" Text="R56 is similar - it completely disables the input by grounding it. You'll notice &quot;DNP&quot; next to the resistors, this indicates &quot;do not place&quot; for the standard board." CreationDate="2010-11-16T15:26:05.910" UserId="1225" />
  <row Id="8703" PostId="6797" Text="They just have warehouses full of people hand-soldering on assembly lines.  I don't understand the economics, but that's how they do it there.  :/  They use jigs to hold the parts in place, though, it's not like they're holding each one in their hands." CreationDate="2010-11-16T15:30:52.773" UserId="142" />
  <row Id="8704" PostId="6791" Score="2" Text="One of the (possibly significant) downsides of this topology is that you will always have a fairly significant current draw which will (without modification) nix it for any long-term battery powered applications." CreationDate="2010-11-16T15:32:41.960" UserId="1407" />
  <row Id="8705" PostId="6807" Text="You don't need to buffer the bias voltage for an inverting amp.  You're just connecting it to the non-inverting input, which is a high input impedance.  What you need is a lot of capacitance between the bias voltage and audio ground, to eliminate any power supply noise." CreationDate="2010-11-16T15:34:42.677" UserId="142" />
  <row Id="8706" PostId="6823" Text="It might be 0603 standard size, but it's not a standard symbol, because of the 4 pins. I don't even know if my PCB manufacturer can make tracks thin enough to connect to that." CreationDate="2010-11-16T15:34:43.673" UserId="1225" />
  <row Id="8707" PostId="6632" Score="1" Text="You can also use a single transistor and resistor pull-up as an inverter if a whole inverter chip is overkill." CreationDate="2010-11-16T15:35:17.400" UserId="638" />
  <row Id="8708" PostId="6820" Score="1" Text="If anyone knows of a cheap supply of 10 way ribbon cables with 2x5 female headers in this size, please say" CreationDate="2010-11-16T15:36:38.117" UserId="566" />
  <row Id="8709" PostId="6731" Text="This seems like a very good question for the home improvement SE. http://diy.stackexchange.com/ is pretty much dedicated to working on houses, setting up wiring and such." CreationDate="2010-11-16T15:39:22.423" UserId="230" />
  <row Id="8711" PostId="6815" Text="Oh, internally generated audio is from pin 25?  Is that PWM?" CreationDate="2010-11-16T15:41:53.573" UserId="142" />
  <row Id="8712" PostId="6818" Text="They are also asking about a standard pin-out." CreationDate="2010-11-16T15:42:16.090" UserId="230" />
  <row Id="8713" PostId="6815" Text="It's a DAC output... I guess I should have made it clear." CreationDate="2010-11-16T15:42:46.620" UserId="1225" />
  <row Id="8714" PostId="6816" Score="1" Text="This falls under both &quot;a specific moment in time, or an extraordinarily narrow situation &quot; In 1 month there may be 15 offered on digikey that meet your specs with people finding this question through google misleading them." CreationDate="2010-11-16T15:45:04.433" UserId="230" />
  <row Id="8716" PostId="6815" Score="1" Text="Are you saying you want to make your own IC?" CreationDate="2010-11-16T15:45:47.200" UserId="319" />
  <row Id="8717" PostId="6815" Text="No, I want to use some standard IC's." CreationDate="2010-11-16T15:47:30.703" UserId="1225" />
  <row Id="8718" PostId="6572" Text="Try a soldering gun. Something like this doesn't require a lot of precision or a certain tip size, just a lot of power. " CreationDate="2010-11-16T15:47:34.007" UserId="638" />
  <row Id="8719" PostId="6824" Text="Also a great answer, joby, you should put this on the other question." CreationDate="2010-11-16T15:47:57.897" UserId="230" />
  <row Id="8720" PostId="6583" Text="LDO and IC heatsinks will generally have a very different answer then computer motherboard heat sink. This question really doesn't belong here." CreationDate="2010-11-16T15:48:52.937" UserId="319" />
  <row Id="8721" PostId="6829" Text="Most PSU's I've found have a voltage doubler option to select between 115VAC/230VAC. In that case, the voltage may be as high as 400V (dc.)" CreationDate="2010-11-16T15:51:08.283" UserId="1225" />
  <row Id="8722" PostId="6829" Text="It's rare for a computer power supply to have an isolation transformer, but afaik, they are all isolated." CreationDate="2010-11-16T15:52:14.883" UserId="1225" />
  <row Id="8723" PostId="6827" Text="Input voltage 1Vp-p max (typ. 500mVp-p), 1V offset (or AC, if it can take AC in.)" CreationDate="2010-11-16T15:54:21.013" UserId="1225" />
  <row Id="8724" PostId="6827" Text="Output voltage: line level (about 1Vp-p.)" CreationDate="2010-11-16T15:55:48.767" UserId="1225" />
  <row Id="8725" PostId="6827" Text="Load impedence I don't know, max 600 ohms." CreationDate="2010-11-16T15:56:04.680" UserId="1225" />
  <row Id="8726" PostId="6826" Score="1" Text="If you are using voltages in between the positive and negative rails, you don't need a special op-amp to operate with unbalanced supplies.  The single-supply op-amps are named that because their common mode range includes the negative supply.  In any case, check the minimum operating voltage carefully!" CreationDate="2010-11-16T15:57:24.397" UserId="411" />
  <row Id="8727" PostId="6805" Text="@Dean, how does one use a not gate to manipulate 0V? (I suppose a charge pump might be an option, but there are simpler ways of solving the problem.)" CreationDate="2010-11-16T16:03:26.780" UserId="1225" />
  <row Id="8728" PostId="6807" Text="@endolith, that doesn't apply for noninverting amplifiers." CreationDate="2010-11-16T16:04:32.007" UserId="1225" />
  <row Id="8729" PostId="6827" Text="max 600 or minimum 600?" CreationDate="2010-11-16T16:04:35.987" UserId="142" />
  <row Id="8730" PostId="6833" Text="The bias resistors are making the AC signal DC, right?" CreationDate="2010-11-16T16:06:14.767" UserId="1225" />
  <row Id="8731" PostId="6827" Text="600 ohms is a minimum value, but a maximum load (confusing terminology I agree.)" CreationDate="2010-11-16T16:07:02.473" UserId="1225" />
  <row Id="8732" PostId="6816" Text="Honestly, I don't think this is localised. If you find one part from one distributor, chances are you can find it from another distributor. And many distributors are international, for example Farnell and Digikey both ship internationally..." CreationDate="2010-11-16T16:08:20.150" UserId="1225" />
  <row Id="8733" PostId="6741" Text="@Eric, I thought we did, but it seems I could be wrong." CreationDate="2010-11-16T16:11:03.580" UserId="230" />
  <row Id="8734" PostId="6807" Text="@Thomas Oh, I misread the question.  Do this for non-inverting single supply: http://www.analog.com/library/analogDialogue/archives/35-02/avoiding/Fig2.gif" CreationDate="2010-11-16T16:11:28.057" UserId="142" />
  <row Id="8735" PostId="5952" Text="@FakeName, Makes sense, most of the fab I do we do not have large enough quantity for them to take effects like this into account." CreationDate="2010-11-16T16:13:48.773" UserId="230" />
  <row Id="8736" PostId="6833" Text="It DC offsets the audio signal, yes." CreationDate="2010-11-16T16:16:00.113" UserId="142" />
  <row Id="8737" PostId="6827" Text="DAC needs a resistor, too, or the external input won't get through." CreationDate="2010-11-16T16:22:00.433" UserId="142" />
  <row Id="8738" PostId="6827" Text="the DAC is a pin on a micro.  This pin can be switched to analog input (high impedance)" CreationDate="2010-11-16T16:24:38.020" UserId="411" />
  <row Id="8739" PostId="6831" Text="Some devices draw power from the hardware handshaking pins defined in RS232 (DTR, RTS, etc.). Using less then 5 volts, even though allowed by the RS232 standard, may not be enough to power them. We had an issue with serial mouse that would work reliably on a new system and had to use RS 232 transceiver to make it work." CreationDate="2010-11-16T16:28:50.443" UserId="1810" />
  <row Id="8740" PostId="6816" Score="3" Text="Look at the comment right above yours--localized doesn't only refer to geographics." CreationDate="2010-11-16T16:30:48.460" UserId="1407" />
  <row Id="8741" PostId="6742" Text="@Thomas - Flash is hardware.  I'm talking about how you would prove that the software will never fail." CreationDate="2010-11-16T16:32:19.910" UserId="1407" />
  <row Id="8742" PostId="6827" Text="Oh, ok.  If you were actually mixing them it wouldn't work, but it's fine if you're switching.  The external input can still bleed through if the DAC's output impedance is high, though." CreationDate="2010-11-16T16:34:14.370" UserId="142" />
  <row Id="8743" PostId="6815" Text="I think saying minimizing your component count is a better way to phrase it." CreationDate="2010-11-16T16:42:52.510" UserId="319" />
  <row Id="8744" PostId="6583" Text="i agree with the flags i have seen and the domain of question and answer. superuser.com fits this much better." CreationDate="2010-11-16T16:47:20.943" UserId="230" />
  <row Id="8745" PostId="6827" Score="1" Text="the DAC's impedance should be reasonably low because it has an internal buffer amp." CreationDate="2010-11-16T16:47:23.313" UserId="411" />
  <row Id="8746" PostId="6807" Text="Be careful with how close to the rail you can output." CreationDate="2010-11-16T16:47:43.037" UserId="319" />
  <row Id="8747" PostId="6826" Text="To operate with unbalanced supplies you need a rail-to-rail op-amp, and it usually helps to check the data sheet to ensure they say they'll operate with a single supply.  I've seen both on several data sheets so it's not an odd thing and seems fairly standard." CreationDate="2010-11-16T17:04:38.317" UserId="249" />
  <row Id="8748" PostId="6742" Text="The software could fail, I suppose. " CreationDate="2010-11-16T17:26:39.583" UserId="1225" />
  <row Id="8749" PostId="6840" Score="2" Text="I have seen many places that leave off the m, I think it's a poor lazy practice though." CreationDate="2010-11-16T17:40:15.777" UserId="319" />
  <row Id="8750" PostId="6841" Score="1" Text="assumptions make an ass of u and me. most transceivers have output in dBm. most amps have a gain in dB as a function of input dBm or a set gain with max output power." CreationDate="2010-11-16T17:43:41.800" UserId="230" />
  <row Id="8751" PostId="6841" Text="I've seen a data sheet for a Sony high power amp that left off the m everywhere. " CreationDate="2010-11-16T17:45:56.973" UserId="319" />
  <row Id="8752" PostId="6840" Score="5" Text="Transmit power cannot be 10dB, 10dB is a multiplication factor not an absolute value. Attenuation or amplification can be 10dB." CreationDate="2010-11-16T18:07:01.780" UserId="718" />
  <row Id="8753" PostId="6843" Score="4" Text="Shouldn't 0 dBm always be equivalent to 1 mW irrespective of how it's being used?  If your antenna isn't an efficient radiator, that doesn't change how much power is being jammed into it." CreationDate="2010-11-16T18:15:22.287" UserId="1407" />
  <row Id="8755" PostId="3782" Score="1" Text="Most [power supply eval boards from National](http://www.national.com/analog/power#boards) are laid out quite well, typically optimizing area (which is often the selling point) while minimizing high current loop area.  Your layout may dictate a differently shaped area or other considerations, but it's a good medium to start with." CreationDate="2010-11-16T18:34:23.893" UserId="1407" />
  <row Id="8756" PostId="6841" Text="Sony amp; for audio?  Most of the core audio amp parameters I'd think of would be relative (SNR, max gain...) versus absolute (noise floor, max output?)." CreationDate="2010-11-16T18:38:14.810" UserId="1407" />
  <row Id="8757" PostId="6823" Text="@Tho - You can connect it just fine with 12 mil trace-space using vias, or 8 mil without.  2-pin 0603 is not a fine-pitch part, 4-pin is barely so.  Have you even looked at the datasheet?&#xA;" CreationDate="2010-11-16T18:46:25.427" UserId="1407" />
  <row Id="8758" PostId="6840" Score="3" Text="@Kortuk: Your 10 dBm = 10 mW example is correct, but maybe misleading for people who aren't familiar with logarithmic scales. For example, 3 dBm is roughly 2 mW. 6 dBm roughly 4 mW. Just trying to make the nonlinearity clear." CreationDate="2010-11-16T18:53:05.750" UserId="712" />
  <row Id="8759" PostId="6843" Text="The design impedance can get to be important. If you have an amplifier which is designed to feed a high-impedance load (say 600 ohms) and you connect it to a low-impedance load (say 50 ohms) the load will be badly mismatched, resulting in inefficiency and possible damage. Feeding an antenna with a 200 ohm feedpoint impedance with a transmitter and feedline designed for 50 ohms will result in a 2.0 VSWR, and lots of reflected power getting your transmit amplifier's finals nice and fried." CreationDate="2010-11-16T18:59:57.133" UserId="965" />
  <row Id="8760" PostId="6841" Text="Sony amp for RF." CreationDate="2010-11-16T19:01:39.763" UserId="319" />
  <row Id="8761" PostId="6843" Score="1" Text="I have seen many power meters read in dBm which were designed to use 50 ohm systems. They still were referenced to 0dBm = 1mW, though." CreationDate="2010-11-16T19:03:16.800" UserId="965" />
  <row Id="8762" PostId="6843" Text="@Jesse - 0 dBm is equivalent to 1 mW under any and all conditions.  If you hook your amp designed to deliver 0 dBm into 600 Ω into a 50 Ω load, it will not likely provide it with just 0 dBm anymore, but that doesn't change what 0 dBm is--1 mW--correct?" CreationDate="2010-11-16T19:16:40.673" UserId="1407" />
  <row Id="8763" PostId="6843" Text="True. I think the confusion came from smashtastic specifying a particular impedance. I remember no such specified impedance, but my memory isn't the best anyway. " CreationDate="2010-11-16T19:22:31.310" UserId="965" />
  <row Id="8764" PostId="6840" Text="@pingswept, I am so used to it I did not think of that, I have changed it to 20dBm which is a more interesting value anyway. @Bjarkef, that is my point, I have heard many people say dB and think it was of value. you could reference nanaoWatts." CreationDate="2010-11-16T19:29:29.227" UserId="230" />
  <row Id="8765" PostId="6843" Text="@Jesse AC2DE, you are partially correct, different load, different delivered power to the load. The amount of power it outputs does not change though, it should still output to spec, and then will have to absorb the reflected power itself. In microwave engineering students would regularly mix this up." CreationDate="2010-11-16T19:36:31.127" UserId="230" />
  <row Id="8766" PostId="6845" Text="There are already multiple answers that say this." CreationDate="2010-11-16T19:41:41.873" UserId="230" />
  <row Id="8767" PostId="6845" Score="4" Text="Except none highlight the common misconception that it is a unit by itself.  This is a problem many people have (including the OP) and it needs to be driven home." CreationDate="2010-11-16T19:43:58.187" UserId="1297" />
  <row Id="8768" PostId="6831" Text="There aren't even connections for the serial handshaking lines on the transceiver so it wouldn't be an issue for it, but the system surrounding it.  I can't believe someone actually used them for something.  I've never hooked up a serial port with more than Tx, Rx and GND." CreationDate="2010-11-16T19:55:15.187" UserId="249" />
  <row Id="8769" PostId="3781" Text="@Fake Name, that is true, although some companies make compatible chips (consider the Z80 as an example), and firmware wise, many things are portable, like FFT libraries." CreationDate="2010-11-16T20:10:42.110" UserId="1225" />
  <row Id="8770" PostId="6814" Text="@Nick T, please see the FAQ on &quot;just google it.&quot; It is discouraged. What if someone gets an E&amp;R result on Google, clicks on it only to find someone has put &quot;just google it.&quot; Imagine the frustration." CreationDate="2010-11-16T20:14:24.837" UserId="1225" />
  <row Id="8771" PostId="6849" Text="The output stage is branchless, but the computations (e.g. draw line) are typically not. Does this mean I'll get 60 MIPS most of the time, except when doing branches? (In which case, it would be very similar to PICmicros, and in fact many other processors.)" CreationDate="2010-11-16T20:21:59.417" UserId="1225" />
  <row Id="8772" PostId="6844" Text="EEVblog #49 – Decibels (dB’s) for Engineers – A Tutorial" CreationDate="2010-11-16T20:23:17.000" UserId="1514" />
  <row Id="8773" PostId="6848" Text="Execution from RAM is impossible in AVRs, though I haven't used AVR32s.  Are you using an OSD IC (e.g. MAX4455) for your OSD or bit banging a micro?" CreationDate="2010-11-16T20:23:21.507" UserId="1407" />
  <row Id="8774" PostId="6848" Text="This is actually something that is very typical everywhere. This is partially why computer CPUs have a cache. You can pull data from a slower methods and stick it in cache that can be accessed very fast when the instruction needs it." CreationDate="2010-11-16T20:24:56.790" UserId="319" />
  <row Id="8775" PostId="6848" Text="@Nick T MAX7456 is the new version :-)" CreationDate="2010-11-16T20:26:06.773" UserId="319" />
  <row Id="8776" PostId="6850" Score="1" Text="He has actually mentioned before that on his lower end version he is at 80-90% CPU usage (on a slower processor I believe) and can't even have UART interrupt him. But here he says he needs all 60 MIPS. Not sure if hes trying to say hes at 100% cpu usage now or not." CreationDate="2010-11-16T20:29:17.643" UserId="319" />
  <row Id="8777" PostId="6850" Text="Well then the very best of British to him - he will need it!!" CreationDate="2010-11-16T20:31:32.093" UserId="400" />
  <row Id="8778" PostId="6850" Text="This is quickly becoming a case of updating to better hardware, or make some sort of front end to service the I/O while you update a buffer." CreationDate="2010-11-16T20:32:43.097" UserId="230" />
  <row Id="8779" PostId="6849" Text="Yes, you are correctly interpreting that. when you are not having branches it should run without wait states." CreationDate="2010-11-16T20:33:21.457" UserId="230" />
  <row Id="8781" PostId="6848" Text="@Nick T - AVR32 is very different to AVR.  They are more like Cortex M3 but with better low power modes (IMHO)" CreationDate="2010-11-16T20:34:18.300" UserId="400" />
  <row Id="8782" PostId="6850" Text="Yeah, but that would require higher cost and board space which I am sure Thomas doesn't want." CreationDate="2010-11-16T20:34:55.920" UserId="319" />
  <row Id="8783" PostId="6851" Text="&quot;Matching the output impedance of a driver to the input impedance of a load allows max power transfer.&quot;  Not quite.  Matching the load to a *fixed* source impedance maximizes power transfer, but if you have control over the output impedance, you want it as small as possible to increase the power in the load." CreationDate="2010-11-16T20:36:48.873" UserId="142" />
  <row Id="8784" PostId="6850" Text="MIPS is million of Instructions Per Seconds. For a comparison an Intel 486DX is about 54 MIPS.  An Intel i7 is above 75,000 MIPS. " CreationDate="2010-11-16T20:36:51.493" UserId="1810" />
  <row Id="8785" PostId="6741" Text="@muntoo - Did you mean NXT? " CreationDate="2010-11-16T20:47:51.513" UserId="857" />
  <row Id="8786" PostId="6546" Text="Although I'm having some troubles, it seems the best alternative until MPLAB X." CreationDate="2010-11-16T20:48:53.403" UserId="1757" />
  <row Id="8787" PostId="6845" Score="2" Text="&quot;I have a 10 dB attenuator&quot;  I used decibel without a reference point." CreationDate="2010-11-16T20:49:44.760" UserId="1407" />
  <row Id="8788" PostId="6741" Text="@Kortuk, Eric - We definitely do. Not sure why it's not working right now, but the lack of highlighting is not limited to this question." CreationDate="2010-11-16T20:50:52.173" UserId="857" />
  <row Id="8789" PostId="6851" Score="1" Text="I disagree, the value of the output impedance being lower doesn't increase power transfer unless you can lower the load resistance to match, it would just mean you would need a source resistor added to the mix to match the load resistance.  Assuming the load is mostly resistive.  Maximizing voltage on the load and maximizing power are two different things." CreationDate="2010-11-16T20:52:38.770" UserId="1438" />
  <row Id="8790" PostId="6850" Text="@Kellenjb, 80% - 90% is an estimate. More optimised code is going to drop that down to 60% (for example, setting up a timer during the horizontal blanking interval instead of using a busy loop gives us an extra 200 * 15kHz = 3 MIPS.) That was with a 40 MIPS dsPIC, I'm using two chips on this board." CreationDate="2010-11-16T21:00:17.543" UserId="1225" />
  <row Id="8791" PostId="6850" Text="@Ian, thanks, it's working well." CreationDate="2010-11-16T21:01:05.560" UserId="1225" />
  <row Id="8792" PostId="6850" Text="@Kortuk, I'm not sure that is relevant. I'm using a two chip solution, one handles IO and background tasks, one is dedicated entirely to the display." CreationDate="2010-11-16T21:01:46.293" UserId="1225" />
  <row Id="8793" PostId="6850" Text="@Kellenjb, board space is not critical, though smaller is better... again, this isn't really relevant to the question at hand." CreationDate="2010-11-16T21:02:11.550" UserId="1225" />
  <row Id="8794" PostId="6850" Text="@Jim C, you are comparing a highly pipelined architecture and extremely expensive power hungry processor to an AVR32 - there is no comparison really." CreationDate="2010-11-16T21:02:59.617" UserId="1225" />
  <row Id="8795" PostId="6848" Text="@Nick T, I am using a software OSD layer, written by myself. If you're interested, it is open source: http://code.google.com/p/super-osd." CreationDate="2010-11-16T21:03:57.683" UserId="1225" />
  <row Id="8796" PostId="6850" Text="@ThomasO, Stating that I think your solution may not exist with your hardware is relevant. When you said 80-90% before you stated it was heavily optimized." CreationDate="2010-11-16T21:03:58.643" UserId="230" />
  <row Id="8797" PostId="6850" Text="@Jim C - I know that MIPS is a theoretical statement of performance.  The problem is that no processor EVER produces the theoretical MIPS level that the datasheet promises.  Real world factors like memory access and pipeline stalls together with interrupts all conspire to turn the MIPS number into a Meaningless Indicator of Processing Speed. " CreationDate="2010-11-16T21:04:30.377" UserId="400" />
  <row Id="8798" PostId="6850" Text="@ThomasO, @JimC, There is a comparison, it was done in MIPS.@Ian, I think he was just trying to give a reference scale." CreationDate="2010-11-16T21:05:28.923" UserId="230" />
  <row Id="8799" PostId="6645" Score="2" Text="I like to add that every outside connector uses one side of the schematic: Top for power, Left for principal I/O, Right for slave I/O" CreationDate="2010-11-16T21:05:29.860" UserId="1673" />
  <row Id="8800" PostId="6804" Text="but that requires a minimum of two pins.  OP asked for a solution using one pin." CreationDate="2010-11-16T21:06:02.513" UserId="1322" />
  <row Id="8801" PostId="6850" Text="@Kellenjb, also, I certainly can't afford to run at 30 MIPS. The output resolution has increased from 192x128 to 360x270 (about the highest possible, really) which squeezes me for every last instruction. The pixel clock is a mere 167ns (max), and I have to execute at least 7 instructions in this, so a minimum clock of 41 MHz." CreationDate="2010-11-16T21:07:22.630" UserId="1225" />
  <row Id="8802" PostId="6850" Text="@Ian, that does not apply for microcontrollers, which DO meet their MIPS specifications, as they usually do not have complex pipelines. You are probably talking about DMIPS? " CreationDate="2010-11-16T21:08:55.513" UserId="1225" />
  <row Id="8803" PostId="6850" Text="I am using a 96 KB device. Even if I take up 2 bytes for each pixel to be output (as an instruction) it is just under 1 KB and I plan to use about 48 KB for the video memory." CreationDate="2010-11-16T21:10:05.677" UserId="1225" />
  <row Id="8804" PostId="6853" Text="Except when you're bit banging (which I am), in which case you use every last MIP!" CreationDate="2010-11-16T21:12:04.113" UserId="1225" />
  <row Id="8805" PostId="6850" Score="2" Text="@Thomas O - Microcontrollers are often worse having variable instruction processing times.  MSP430 has 1,2 and 3 clock instructions, 8051 has the same problem." CreationDate="2010-11-16T21:12:13.020" UserId="400" />
  <row Id="8806" PostId="6850" Text="@Thomas O - is that the AT32UC3B512 part?  They are as rare as rocking horse poo.  min 6 months lead time" CreationDate="2010-11-16T21:14:14.217" UserId="400" />
  <row Id="8807" PostId="6850" Text="@Ian, not true for many processors. E.g., PIC for all instructions except branch are 4 cycle, similar for dsPIC (but 2 cycle instead of 4.) A microcontroller *must* have predictable timing as it is often used to bitbang serial protocols." CreationDate="2010-11-16T21:15:22.847" UserId="1225" />
  <row Id="8808" PostId="6850" Text="@Ian, using a AT32UC3B0512. The Pro version is at least 6 months from release. Lite version is using dsPIC33F, which is available now." CreationDate="2010-11-16T21:18:29.933" UserId="1225" />
  <row Id="8809" PostId="6850" Text="@Thomas O - If you have just 7 instructions per pixel clock then this sounds like one of those places where you have to use assembler and hand optimise to get the performance." CreationDate="2010-11-16T21:22:22.273" UserId="400" />
  <row Id="8810" PostId="6850" Text="@Ian, which is exactly why I am using assembler! Other (graphics, drawing) code is written in C." CreationDate="2010-11-16T21:28:51.353" UserId="1225" />
  <row Id="8811" PostId="6851" Score="3" Text="By that logic, you'd just make everything 0 ohms and get infinite power.  :)  Maximum power theorem only applies when the source impedance is fixed.  In that condition, you make the load equal to the source to get the most power out of it.  http://en.wikipedia.org/wiki/Maximum_power_theorem  But if you have a fixed load (loudspeaker) and you can change the source's output impedance, you want to make it as small as possible.  A 0 ohm source drives the entire supply into a 4 ohm load, while a 4 ohm source into a 4 ohm load would just waste half the available power." CreationDate="2010-11-16T21:39:20.953" UserId="142" />
  <row Id="8812" PostId="6853" Text="@thomas, I think you misunderstood mark. He is telling you that directly using mips to correlate to operations is not a great practice as it will not reach that point, especially with memory pipelines and stall instructions. " CreationDate="2010-11-16T21:42:12.340" UserId="230" />
  <row Id="8813" PostId="6850" Text="@thomas, saying that microcontrollers must have specific timing for functional reasons is more of a pipe-dream then a reality." CreationDate="2010-11-16T21:44:31.573" UserId="230" />
  <row Id="8814" PostId="6850" Text="@Kortuk, it's not a pipe-dream for many MCU's! It's quite possible. I am doing it on a 40 MIPS dsPIC33F and it's working really well. I am not using branches for the output, just and/ior/mov." CreationDate="2010-11-16T22:02:34.973" UserId="1225" />
  <row Id="8815" PostId="3780" Text="Is this really the place to ask about legal advice? Some companies, probably almost all will allow this, but make sure you ask them first." CreationDate="2010-11-16T22:13:57.867" UserId="1225" />
  <row Id="8816" PostId="6848" Text="I am wondering about the -1, can the voter please justify their choice? " CreationDate="2010-11-16T22:48:21.987" UserId="1225" />
  <row Id="8817" PostId="6853" Text="yep, in addition you can't take an algorithm that work on a 50 MIPS PIC architecture and assume it would work on a 50MIPS AVR32 architecture.  The performance on various architectures can vary widely, especially in the microcontroller space where architectures themselves vary quite a lot." CreationDate="2010-11-16T23:28:48.107" UserId="1438" />
  <row Id="8819" PostId="6778" Score="1" Text="I've never seen an isolation transformer on the input to a computer SMPS. Maybe a filter choke, but never a transformer." CreationDate="2010-11-16T23:45:33.183" UserId="1225" />
  <row Id="8820" PostId="6850" Text="@Thomas, I use PICs normally at my campus job, I know, but as you go higher end they become less dependable. " CreationDate="2010-11-17T00:41:51.280" UserId="230" />
  <row Id="8821" PostId="6850" Text="@Kortuk I haven't tried the PIC32 but I can confirm that all the way up to dsPIC33F the instruction execution is very much predictable." CreationDate="2010-11-17T00:47:50.260" UserId="1225" />
  <row Id="8822" PostId="6741" Text="@reemrevnivek No, NXC [ http://bricxcc.sourceforge.net/ ] is a programming language. It stands for *Not eXactly C*." CreationDate="2010-11-17T00:47:52.527" UserId="1940" />
  <row Id="8823" PostId="6857" Score="1" Text="Are you looking for single wire or specifically a composite cable?" CreationDate="2010-11-17T00:48:42.163" UserId="319" />
  <row Id="8824" PostId="6850" Text="@Thomas, I meant processors in general. It is significantly easier to make a improvement that happens 90% of the time then one that affects system wide." CreationDate="2010-11-17T00:49:26.670" UserId="230" />
  <row Id="8825" PostId="6850" Text="@Kortuk, but if that improvement harms predicable code it is not implemented, which is my point - all the way up to the dsPIC33F series each instruction is entirely independent to the other in regards to timing." CreationDate="2010-11-17T00:53:03.720" UserId="1225" />
  <row Id="8826" PostId="6850" Text="@Thomas, If predictable was the most important things they would not be starting to make microcontrollers with a cache." CreationDate="2010-11-17T01:19:34.303" UserId="230" />
  <row Id="8827" PostId="6866" Text="Consumer parts can be the bane of an embedded product." CreationDate="2010-11-17T01:28:41.910" UserId="230" />
  <row Id="8830" PostId="6845" Text="@NickT, You referenced your input. @Eruditass, I did in the last section of my post." CreationDate="2010-11-17T01:35:34.087" UserId="230" />
  <row Id="8831" PostId="6848" Text="@Thomas O, I think this is actually a really good question to be asking on here. However, you seem to be arguing with people about the answer. Usually that means that you already know the answer and are just posting to post. This usually will make people mad." CreationDate="2010-11-17T02:01:39.620" UserId="319" />
  <row Id="8832" PostId="6868" Score="1" Text="please note when I say programmer, I mean the device and the program you use." CreationDate="2010-11-17T02:28:02.450" UserId="230" />
  <row Id="8833" PostId="6858" Score="3" Text="@Thomas O I think you need to be careful with spamming the site trying to promote your product. It is fine to talk about it and link to items that are relevant to your questions, but the video you linked to has nothing to do with how many transistors an IC has. You should strongly consider editing this out and just giving the needed information for &quot;How many transistors on an IC?&quot;" CreationDate="2010-11-17T02:28:53.013" UserId="319" />
  <row Id="8834" PostId="6870" Text="&quot;Interesting&quot;... that's all I have to say." CreationDate="2010-11-17T02:44:20.767" UserId="319" />
  <row Id="8835" PostId="6858" Score="4" Text="@kellenjb given the number of questions that have been asked related to this for-sale product i assumed chiphacker was getting a cut for design consultation and paying dividends to members based on points :p" CreationDate="2010-11-17T03:53:22.973" UserId="1438" />
  <row Id="8836" PostId="6872" Text="Good idea. I just checked over the schematic and the PCB layout. I don't see any accidental address line crossings or misconnections. I did notice that the JTAG connector is directly under the RAM, but they're separated by two power planes, and the board boots correctly under JTAG control. It's when the JTAG is inactive that the problem occurs." CreationDate="2010-11-17T04:02:02.333" UserId="712" />
  <row Id="8837" PostId="6872" Text="you are pulling the jtag tclk and trst to safe states ?" CreationDate="2010-11-17T04:30:06.060" UserId="1481" />
  <row Id="8838" PostId="6858" Text="@Mark, I am looking forward to my cut, I would settle for an honorable mention (at-least you can tell the other members this)." CreationDate="2010-11-17T04:42:54.853" UserId="230" />
  <row Id="8839" PostId="6868" Score="3" Text="The programmer validates the ROM, but it doesn't validate the RAM. You'd need to write a program which does a RAM test, ie writing the usual patterns, all 1, all 0, mixed, and checking to ensure that they're retrievable. " CreationDate="2010-11-17T05:15:57.300" UserId="776" />
  <row Id="8840" PostId="6870" Score="1" Text="probably a dumb question but your reset circuit (the button) does have a pull up resistor on it right?  I mean when the button isn't pressed the reset pin isn't left to float.   In addition you could also try a debounce cap on the reset button to rule out odd behavior due to bouncing of the reset line." CreationDate="2010-11-17T05:25:09.653" UserId="1438" />
  <row Id="8841" PostId="6848" Text="@Kellenjb I'm disagreeing about some things that aren't true, like PIC MCU's being unpredictable. Some MCU's aren't predictable but most are. The original question wasn't about this though, it was about whether wait states affect me." CreationDate="2010-11-17T08:01:41.783" UserId="1225" />
  <row Id="8843" PostId="6858" Text="I removed the link. I didn't realise there was discontent against my questions. I'm a student and I'm just trying to learn." CreationDate="2010-11-17T08:03:02.907" UserId="1225" />
  <row Id="8844" PostId="6857" Text="@Kellenjb, a single wire." CreationDate="2010-11-17T08:04:42.280" UserId="1225" />
  <row Id="8847" PostId="6869" Text="+1. I'm watching regular (non-HD) TV on a rather smallish set, and when there are very bright parts in the picture, they blur to the right. If a 15m composite cable of regular quality (shielded, but not high-end) can degrade the quality of a regular picture, I would say that it is not suitable for HD." CreationDate="2010-11-17T08:19:23.750" UserId="930" />
  <row Id="8848" PostId="6648" Text="@XTL - Yes, but there are different types of suck. There is &quot;How to make 350 different options available intuitively while only using 18 pixels of menubar space&quot; suck, and there is &quot;Can't figure out how to draw a dot where two lines intersect&quot; suck. Once is significantly easier to fix than the other." CreationDate="2010-11-17T08:36:13.120" UserId="1374" />
  <row Id="8849" PostId="6767" Text="@Amos, to change the CAD layout from ATX to something suitable for laptops." CreationDate="2010-11-17T08:53:40.680" UserId="1877" />
  <row Id="8850" PostId="6750" Text="According to Fourier, a square wave is approximately an infinite sum of sine waves as well :)" CreationDate="2010-11-17T09:02:01.760" UserId="883" />
  <row Id="8851" PostId="6820" Text="@Joby Taffey, I'd be interested too." CreationDate="2010-11-17T10:13:32.787" UserId="1225" />
  <row Id="8852" PostId="6868" Text="Kortuk, that is flash memory - I'm talking about RAM." CreationDate="2010-11-17T10:14:28.153" UserId="1225" />
  <row Id="8854" PostId="6063" Text="Mike, did @Andrew Kohlsmith's answer work for you?  If it did it is customary to accept the answer else respond as to why it did not so the community can continue to search for an answer for you." CreationDate="2010-11-17T11:41:33.403" UserId="1413" />
  <row Id="8856" PostId="1225" Score="1" Text="The free version of Eagle is lacking much of the functionality of the full version." CreationDate="2010-11-17T12:57:43.027" UserId="1413" />
  <row Id="8857" PostId="6868" Text="You might want to read his comment again." CreationDate="2010-11-17T13:01:30.013" UserId="1333" />
  <row Id="8858" PostId="6868" Text="Okay, here's a related question: assume the MCU was fully checked at the factory, and assuming the memory actually had a bit error: what would cause this?" CreationDate="2010-11-17T13:15:06.600" UserId="1225" />
  <row Id="8859" PostId="6873" Text="I don't think this is a long shot at all.  It may not be LVP or similar pin, but any input floating.  We've had a PowerPC go dead with general I/O input floating just because the input's level would be checked early on in the code." CreationDate="2010-11-17T13:26:52.643" UserId="1819" />
  <row Id="8860" PostId="6879" Text="Nice read. Was very surprised about the breakdown rate though!" CreationDate="2010-11-17T13:35:24.070" UserId="1124" />
  <row Id="8861" PostId="6858" Text="@Thomas O: Personally, I think your questions are generally quite good and add value to the site.  So, keep them coming.  :)   ...  That said, I do agree with Kellenjb that this could be rewritten as a simple &quot;how many transistors in a microcontroller&quot; question." CreationDate="2010-11-17T13:45:09.710" UserId="1270" />
  <row Id="8862" PostId="5341" Text="Thanks for the feedback, everyone, and sorry for not flagging this answered a long time ago.  I ended up making a board to live inside of the iPod dock connector housing, which got me down to 7 wires. I'm now using a 8-pin Mini-DIN connector, and pre-made cables are readily available; they're the same as the old Apple serial cables." CreationDate="2010-11-17T14:02:34.737" UserId="51" />
  <row Id="8863" PostId="2213" Text="Just a side note.  The hardware portion of JTAG is the same for all devices, it's the actual instructions that differ between manufacturer's.  One can make a JTAG cable fairly easily, it's just 4 wires that you can assert slowly, so bit banging works.  The tricky part is in getting these instruction sets.  A lot of manufacturers don't want to tell you their instruction sets." CreationDate="2010-11-17T14:25:55.180" UserId="1819" />
  <row Id="8865" PostId="6848" Text="@Thomas O, I didn't down vote you, I am just giving a possibility as to why you may have been. I think wait state very much is part of the discussion. It is telling you that for an instruction you place, you may have to wait an extra instruction cycle before getting your data. This wait state means that effectively you have instructions that take different amounts of time." CreationDate="2010-11-17T14:40:20.380" UserId="319" />
  <row Id="8866" PostId="4484" Text="Please don't do this!  Use numeric_std (see LoneTech's and my answers)" CreationDate="2010-11-17T14:46:10.083" UserId="763" />
  <row Id="8867" PostId="6872" Text="Yes, all the JTAG inputs are pulled up to 3.3 V, so their state shouldn't change unless JTAG is attached and driving them." CreationDate="2010-11-17T14:54:05.317" UserId="712" />
  <row Id="8868" PostId="6870" Text="(Not a dumb question-- it was one of the first things I checked.) Yeah, there's a pull-up on the button. There's no debouncing cap, but I've looked closely at the rising edge, and it's not bouncing detectably. The error occurs almost 1 second after I release the button, so I think I can rule that out." CreationDate="2010-11-17T15:09:43.520" UserId="712" />
  <row Id="8870" PostId="6868" Text="SRAM has a very very low error rate, run the program on a debugger and see if your RAM matches up. Sorry If I was not clear, SRAM has almost zero error rate. the fact that it continues after multiple restarts makes me think it is something else, but it never hurts to check." CreationDate="2010-11-17T15:38:56.060" UserId="230" />
  <row Id="8871" PostId="6887" Text="Thanks for this.  I appreciate your comments very much.  I was in a TA position of sorts, learning VHDL to help a prof get started who was a little shakey on programming concepts.  I'm going to pass on your info to him - the textbook we used didn't delve into VHDL 'morality' questions." CreationDate="2010-11-17T15:41:17.020" UserId="374" />
  <row Id="8875" PostId="6877" Text="The next thing I was going to go read was about the watchdog timer, they can cause odd problems, but I was not sure if the JTAG would disable the Watchdog and cause the problem to stop." CreationDate="2010-11-17T15:45:36.540" UserId="230" />
  <row Id="8877" PostId="6868" Text="@Kortuk, thanks for the info. I'm fairly certain it's a bug in the program or the RAM. It was repeatable, and only happened on one of the two video buffers (two video buffers of 6KB each.) So I'm just wondering is there any way I could have burnt out a memory bit? Also, I did have a memory test routine but I never could get it working, I suppose it could have been failing due to the faulty bit." CreationDate="2010-11-17T15:46:56.763" UserId="1225" />
  <row Id="8879" PostId="6868" Text="You could not have done something in code to burn out a memory bit. you need the test routine to write to each byte then read it out, if it fails a byte, you need it to print over serial the byte, or assert a pin, or hit a breakpoint." CreationDate="2010-11-17T15:49:00.640" UserId="230" />
  <row Id="8880" PostId="6886" Text="I was going to go get a link to ganssle when I saw the question." CreationDate="2010-11-17T15:50:08.750" UserId="230" />
  <row Id="8881" PostId="6868" Text="@Kortuk, I had it jump to an error screen warning about memory failure. I'm talking about environmental conditions. Although I'm fairly sure it had a fixed 3.3V supply, perhaps a voltage spike could have caused damage? Although you say software can't damage hardware, it's not entirely true, for example, writing one cell in the flash for more than 10k cycles could easily have damaged it (especially if, for example, the cell contained configuration bits for the chip.) I don't think this applies to SRAM, but maybe it does?" CreationDate="2010-11-17T15:51:58.693" UserId="1225" />
  <row Id="8882" PostId="6858" Score="3" Text="I have seen you ask many good questions Thomas, you sometimes spam them when you ask 4 questions in 15 minutes. You need to also try to avoid asking questions that have already been asked. Otherwise, I do not mind having a few more questions." CreationDate="2010-11-17T15:52:43.070" UserId="230" />
  <row Id="8883" PostId="6858" Text="@Kortuk I ask many questions in 15 minutes (or so) because I usually go to classes then, or go to bed, or something like that. The idea is when I have a break I get to read them all at once, instead of waiting for new answers and wasting away my break. I hope this doesn't cause problems." CreationDate="2010-11-17T15:54:03.780" UserId="1225" />
  <row Id="8884" PostId="6868" Text="@ThomasO, I said you could not have burned out the memory bit, you took it out of context of what we are discussing and added writing the same flash byte 10k times in a row, of coarse that damages the flash, there is a reason they have warnings against doing it. SRAM is a few transistors changing state, you did not damage them by using them. I have never seen a voltage spike damage RAM without anything else, but it also could have been radiation that damaged it. Do you work near a proton accelerator?" CreationDate="2010-11-17T15:55:31.353" UserId="230" />
  <row Id="8885" PostId="6868" Text="@Kortuk I was providing it as an example of how software can be damaged by hardware. My house is probably full of radiation...! But probably not enough to do some damage to my MCU's. Thanks for the information. So the only thing I can think of is either the software was (is?) faulty, or the chip was faulty from the start. " CreationDate="2010-11-17T16:00:53.403" UserId="1225" />
  <row Id="8886" PostId="6868" Text="@thomasO, Software could not be performing to spec, or you have damaged hardware. I am not saying that the environment could not have damaged it, just that there is absolutely no way to know if you cannot be sure if there are Voltage spikes or such on your system." CreationDate="2010-11-17T16:02:22.407" UserId="230" />
  <row Id="8887" PostId="6889" Text="Read Joby's answer; apparently everything I thought I knew was inverted. :-)" CreationDate="2010-11-17T16:04:47.520" UserId="51" />
  <row Id="8888" PostId="6890" Text="Thanks, Joby.  So even though the line idles high, a 0 bit is still 0v.  Does the receiver typically have an internal pull-up on the RX line, so that it doesn't float?" CreationDate="2010-11-17T16:06:47.860" UserId="51" />
  <row Id="8889" PostId="6890" Text="@blalor the line won't float, the sender is driving it (assuming both ends are connected)" CreationDate="2010-11-17T16:21:05.010" UserId="566" />
  <row Id="8890" PostId="6870" Score="2" Text="I'd probably start ripping code out of u-boot to find out where it crashes... Perhaps your JTAG adapter does a reset then halts the CPU for a while - giving something else on the board time to powerup properly" CreationDate="2010-11-17T16:26:19.593" UserId="566" />
  <row Id="8891" PostId="6883" Score="2" Text="I have yet to see/read of a off-the-shelf LED-based DLP projector fitting in that form factor." CreationDate="2010-11-17T16:33:33.787" UserId="374" />
  <row Id="8892" PostId="6889" Text="Real RS232 is the other way around 0 = 12v, 1 = -12v, that's why it's confusing" CreationDate="2010-11-17T16:34:28.433" UserId="566" />
  <row Id="8893" PostId="6858" Score="1" Text="It has not, I was just commenting that you drop a very large number of questions and it can look like spam if multiples are duplicates. I would like it if you watched for duplicates more carefully, otherwise, no worries." CreationDate="2010-11-17T16:53:39.617" UserId="230" />
  <row Id="8894" PostId="6797" Text="Big components, like transformers, caps and inductors must be added by hand, but I suppose small caps and resistors could be machine inserted." CreationDate="2010-11-17T16:59:02.920" UserId="1225" />
  <row Id="8895" PostId="6803" Text="In which case, why don't they make the primary side with through hole, but the secondary side with SMT? " CreationDate="2010-11-17T16:59:28.893" UserId="1225" />
  <row Id="8896" PostId="6890" Text="@Joby Taffey Arduino's NewSoftSerial enables the AVR's internal pull-up on the RX pin.  I assume this *is* required if there isn't an attached sender.  Thanks for the info, and the added Adafruit link." CreationDate="2010-11-17T17:11:50.933" UserId="51" />
  <row Id="8897" PostId="6892" Text="+1 on size, the USB socket is going to be bigger than a QFN32 anyway" CreationDate="2010-11-17T17:40:37.517" UserId="566" />
  <row Id="8898" PostId="6894" Text="Would it really be 8 digit if it is an LCD wouldn't that be LED?" CreationDate="2010-11-17T17:51:52.020" UserId="1413" />
  <row Id="8899" PostId="6894" Text="No I am looking for LCD not LED. Unless you can find what I'm asking in LED format with low power consumption." CreationDate="2010-11-17T18:00:02.913" UserId="1936" />
  <row Id="8900" PostId="6870" Score="1" Text="JTAG is affecting it, this just tells you for sure you should be able to find something related in the uboot code." CreationDate="2010-11-17T18:13:19.983" UserId="230" />
  <row Id="8901" PostId="6879" Text="So an antiparallel pair of LED strings--guess powering them off rectified AC won't work that well; only half will ever be on." CreationDate="2010-11-17T18:25:30.490" UserId="1407" />
  <row Id="8902" PostId="6892" Text="@Joby With a micro-USB connector it should be pretty close." CreationDate="2010-11-17T18:27:11.190" UserId="1407" />
  <row Id="8903" PostId="6845" Text="@Kortuk - That's somewhat my point; there it's implicit, in many other contexts the reference is as well (yes, it can suck)." CreationDate="2010-11-17T18:31:32.950" UserId="1407" />
  <row Id="8904" PostId="6890" Text="Being somewhat pedantic, but doesn't &quot;TTL&quot; just imply levels?  You describe a point-to-point serial link, but could it just as well be a multi-master topology with open collector drivers and a pullup (like LIN but with TTL levels)?  &quot;TTL serial&quot; seems like an *incredibly* broad term that's almost useless without some context." CreationDate="2010-11-17T18:36:29.467" UserId="1407" />
  <row Id="8905" PostId="6889" Text="Point of terminology: &quot;TTL serial&quot; is a severely over-broad term, &quot;(point-to-point) asynchronous serial (at TTL levels)&quot; seems to be what you're asking about.  (Though that's still probably lacking, but at least better)" CreationDate="2010-11-17T18:42:21.207" UserId="1407" />
  <row Id="8906" PostId="6883" Text="Well I don't need an off the shelf, it's only going to be a design but it must realistic. So if it's not possible to currently fit any projector within that size then I can't design it." CreationDate="2010-11-17T18:42:54.250" UserId="1982" />
  <row Id="8907" PostId="6883" Text="Maybe one like that projector they sent down to the Chilean miners, it had to fit into a 5.5&quot; borehole..." CreationDate="2010-11-17T18:49:30.827" UserId="1407" />
  <row Id="8908" PostId="6881" Score="1" Text="For a small embedded processor if your memory is permanently damaged in any way you are going to be hosed.  There is no way you could do full memory verification and avoid damaged sections without drastically slowing down code and ballooning it's size.  The easy way to fix transient bit errors is with watchdog, illegal address access, and illegal opcode resets." CreationDate="2010-11-17T18:56:07.017" UserId="1407" />
  <row Id="8909" PostId="6865" Score="1" Text="Before this is taken too generally, there are some linear regulators that are unstable with an output cap that has too low of an ESR.  In these (older) regulators, the capacitor resistance is assumed to be some minimum level in their feedback response.  This is rare in newer parts as they are generally designed to be smaller and use smaller ceramic caps with low ESR." CreationDate="2010-11-17T19:06:43.183" UserId="1407" />
  <row Id="8910" PostId="6894" Score="1" Text="LCD power consumption will always be orders of magnitude lower than LED, regardless of how many superlatives they add to &quot;low power&quot; LED display." CreationDate="2010-11-17T19:10:10.187" UserId="1407" />
  <row Id="8911" PostId="6895" Text="[Zebra connection](http://en.wikipedia.org/wiki/Zebra_connector), for better or worse." CreationDate="2010-11-17T19:12:06.003" UserId="1407" />
  <row Id="8912" PostId="4484" Text="If you have a better way to do it, that's fine, but my suggestion works so I think your down-vote was unnecessary.  I have used std_logic_arith for years and I never had any problems with it.  I think fears about vendors changing their implementations are unfounded; what vendor in their right mind will risk breaking their customers' designs?" CreationDate="2010-11-17T19:15:40.080" UserId="1278" />
  <row Id="8913" PostId="6896" Text="Thanks, it's perfect - QFN25 or SO20! :)" CreationDate="2010-11-17T19:21:09.567" UserId="1225" />
  <row Id="8914" PostId="6871" Score="2" Text="&quot;It has more transistors so its better&quot; at a previous company it was a rule to use as many 2N2222 transistors as possible (or at least a few) on every test circuit.  Purchasing accidentally bought the wrong temperature grade, so we had a bag of a couple thousand TO-92 2N2222s laying around in the lab." CreationDate="2010-11-17T19:21:43.093" UserId="1407" />
  <row Id="8915" PostId="6892" Text="The micro USB connector is easily the biggest thing on the board, however, it is good to make all other components smaller to accomodate it." CreationDate="2010-11-17T19:22:08.180" UserId="1225" />
  <row Id="8916" PostId="6791" Text="@NickT/JustJeff - I guess my PIC is a dumb logic chip, then.  The datasheet explicitly says that the pin must be configured as an analog input with ANSEL before applying non-logic voltages to them, _even if you aren't reading the pin!_  And what if the only pin left in the design isn't an analog pin?" CreationDate="2010-11-17T19:22:57.363" UserId="1278" />
  <row Id="8917" PostId="6791" Text="@ajs410 Which PIC? One made 80 years ago still in production (Microchip seems to love doing that) or a newer one?" CreationDate="2010-11-17T19:24:53.213" UserId="1407" />
  <row Id="8919" PostId="6845" Text="@NickT, I understood your point, I was just saying that for fun." CreationDate="2010-11-17T19:32:21.303" UserId="230" />
  <row Id="8920" PostId="6892" Text="Problem solved, use the microcontroller you already have." CreationDate="2010-11-17T19:33:23.233" UserId="230" />
  <row Id="8921" PostId="6896" Text="Please do not use a signature. I am editing it." CreationDate="2010-11-17T19:33:42.393" UserId="230" />
  <row Id="8922" PostId="6893" Text="I had to highlight your answer to see that you answered 20 seconds after me, no wonder I missed yours. Same idea, different explanation +1" CreationDate="2010-11-17T19:34:26.010" UserId="230" />
  <row Id="8923" PostId="6888" Text="Sure did. Fixed." CreationDate="2010-11-17T19:35:46.887" UserId="319" />
  <row Id="8924" PostId="6791" Text="16F690.  See the datasheet, section 4.2.1 - &quot;the ANSEL and ANSELH registers are used to disable the input buffers of I/O pins, which allow analog voltages to be applied to those pins without causing excessive current.&quot;" CreationDate="2010-11-17T19:39:25.700" UserId="1278" />
  <row Id="8925" PostId="6896" Text="The MCP2200 uses an external crystal.  Make sure you plan for that." CreationDate="2010-11-17T19:40:44.670" UserId="411" />
  <row Id="8926" PostId="6896" Text="@Markrages, I'm planning for that. Is there any way to have an MCU and the USB chip share a crystal?" CreationDate="2010-11-17T19:41:54.543" UserId="1225" />
  <row Id="8927" PostId="6892" Text="@Kortuk, My MCU's operate at 36.864 and 60 MIPS respectively, neither of which is compatible with USB. The 60 MIPS one does divide into USB's frequency of 12 MHz, but it would probably interfere with my OSD processing." CreationDate="2010-11-17T19:43:27.053" UserId="1225" />
  <row Id="8928" PostId="6896" Score="4" Text="@Thomas: Hilarious, I think this proves you never read datasheets.  The Microchip MCP2200 QFN20 and FTDI FT232R QFN32 are the exact same size, 5 x 5 mm" CreationDate="2010-11-17T19:43:38.970" UserId="1407" />
  <row Id="8929" PostId="6888" Text="I scoped an image of switch bounce and posted it on Wikipedia: http://en.wikipedia.org/wiki/File:Switch_bounce.JPG" CreationDate="2010-11-17T19:44:28.190" UserId="1225" />
  <row Id="8930" PostId="6896" Score="3" Text="@Nick T and crystals tend to take a lot of space." CreationDate="2010-11-17T19:45:41.797" UserId="319" />
  <row Id="8931" PostId="6892" Score="1" Text="Some processors offer a separate internal USB clock they generate. I did not say you could do it without replacing a processor." CreationDate="2010-11-17T19:46:41.907" UserId="230" />
  <row Id="8932" PostId="6888" Text="@Thomas O that is a pretty fun picture of bounce. I just want to make sure @Vincent Van Den Berghe understands that not all bounce will look like that. That bounce is limited to 0-5v, it wont always look like that." CreationDate="2010-11-17T19:47:45.540" UserId="319" />
  <row Id="8933" PostId="6893" Text="@Kor: &quot;highlight your answer&quot; what's that?  The &quot;answered xx yyy ago&quot; alt-text timestamp?" CreationDate="2010-11-17T19:48:47.173" UserId="1407" />
  <row Id="8934" PostId="6888" Score="1" Text="@Thomas O, as a side note, we have created a practice of failing students who take Oscope images like that. Flash on a screen is horrible. We also take it a step further and push students to collect actual data points, using something like a CSV or labview, so that it can then easily be used in reports and data analysis." CreationDate="2010-11-17T19:50:47.880" UserId="319" />
  <row Id="8935" PostId="6896" Score="1" Text="Instead of the MCP2200, you could get the PIC18F13K50 and add Microchip's CDC firmware yourself.  I think this is pretty much what the '2200 is.  By compiling yourself, you might have more flexibility with I/O assignments and clock selection." CreationDate="2010-11-17T20:14:33.500" UserId="411" />
  <row Id="8936" PostId="6888" Text="@Kellenjb, I'm getting a printer soon for my scope which supports HP-IB. Also I've discovered the &quot;Sports&quot; mode on my camera can take good pictures of the scope screen without a flash and with no blurring." CreationDate="2010-11-17T20:27:19.447" UserId="1225" />
  <row Id="8937" PostId="6883" Text="well it seems it is possible :)" CreationDate="2010-11-17T20:27:32.717" UserId="1982" />
  <row Id="8938" PostId="6896" Text="@Nick T.  the 0.65mm pitch of the QFN20 will be easier to assemble than the 0.50mm pitch of the QFN32.  Also the QFN20 land pattern can be made with 8/8 design rules, and the QFN32 will need at least 6/6 rules, so the PCB is more expensive." CreationDate="2010-11-17T20:47:54.590" UserId="411" />
  <row Id="8939" PostId="6896" Text="@Nick T, I'm not using a QFN, because it's difficult to solder. I'm using a SO20, most likely, which is smaller. I *do* read datasheets. I am not sure if this counts, but I have about 1.2GB of them on my hard disk. I didn't look at the mechanical dimensions though, because I'm not a mechanical engineer, and from my previous postings on this, it should be obvious. And, even though I'm not using it, as previous commenters have noticed, the QFN25 has smaller lead pitch." CreationDate="2010-11-17T20:54:28.177" UserId="1225" />
  <row Id="8940" PostId="6896" Text="@markrages, cost may eventually be a concern. And, last time I checked, the PIC18F*K* processors had long lead times." CreationDate="2010-11-17T20:55:38.037" UserId="1225" />
  <row Id="8941" PostId="6896" Score="1" Text="@markrages, also, I'm trying to keep this product as open source as possible, so if I were to add USB, it would be using a dedicated IC or a FOSS USB library for PICs." CreationDate="2010-11-17T20:58:44.303" UserId="1225" />
  <row Id="8942" PostId="6858" Text="@Kortuk, I have only duplicated one question once AFAIK. I found my college's stupid internet filter blocked me from viewing it once I entered it, so I couldn't delete it." CreationDate="2010-11-17T21:01:36.110" UserId="1225" />
  <row Id="8943" PostId="6896" Score="1" Text="@markrages - True, assembly considerations are another ball of wax, but if you're strictly concerned about area that's a frequent price to pay.  The recommended pad/pad spacing for the QFN32 is 0.30/0.20 mm.  Shift 4 µm around and you can maintain 8 mil trace/space  Though in turn you could do the same with the QFN20, but it seems like you could easily do 10, maximum 12 mil trace/space, where's 8 come from?" CreationDate="2010-11-17T21:03:41.943" UserId="1407" />
  <row Id="8944" PostId="6896" Text="@Nick T, The 20 pin SO avoids all these problems and is probably what I'll be using." CreationDate="2010-11-17T21:12:44.790" UserId="1225" />
  <row Id="8945" PostId="6858" Text="No worries then. No punishment was given, we just closed the question. I was just letting you know since you are up in rep. Sounds like a crappy internet filter." CreationDate="2010-11-17T21:38:53.797" UserId="230" />
  <row Id="8946" PostId="6885" Text="Why are people voting this down?" CreationDate="2010-11-17T21:40:42.227" UserId="566" />
  <row Id="8947" PostId="6900" Text="Obligatory topical reference http://hackaday.com/2010/11/17/newest-hardware-bounty-the-open-lidar-project/" CreationDate="2010-11-17T21:47:53.597" UserId="566" />
  <row Id="8948" PostId="6890" Text="It's just the standard serial port interface with the voltage converters removed." CreationDate="2010-11-17T21:47:57.090" UserId="339" />
  <row Id="8949" PostId="6900" Text="I think LIDAR in robotics/metrology is synonymous with [SICK](http://www.sick.com/)" CreationDate="2010-11-17T21:49:06.430" UserId="1407" />
  <row Id="8950" PostId="6900" Text="It seems that the one they bought was cheap, I remember it being around 40$. They had to rotate it as it had a very small angle." CreationDate="2010-11-17T21:52:06.993" UserId="230" />
  <row Id="8953" PostId="6889" Score="1" Text="@Nick The kind the OP means is whatever is fed into a MAX232, I'd call that &quot;RS232 at TTL levels&quot;" CreationDate="2010-11-17T21:56:11.407" UserId="566" />
  <row Id="8954" PostId="6896" Text="@Thomas.  mcp2200 and pic18f13k50 are both about $1.50 @ 1k.  This is about a dollar less then FTDI or SiLabs." CreationDate="2010-11-17T22:00:34.417" UserId="411" />
  <row Id="8955" PostId="6858" Text="@Kortuk you haven't seen the worst of it - it blocks any mention of &quot;game&quot;, and some content is merely blocked under the category of &quot;Useless.&quot;" CreationDate="2010-11-17T22:01:14.827" UserId="1225" />
  <row Id="8956" PostId="6896" Text="@Markrages, lead time is up until January 2011 for PIC18F13K50, but thanks for the suggestion." CreationDate="2010-11-17T22:03:21.813" UserId="1225" />
  <row Id="8957" PostId="6896" Score="2" Text="@Thomas They're in stock at microchipdirect.com, all four package types. " CreationDate="2010-11-17T22:10:46.470" UserId="411" />
  <row Id="8958" PostId="6858" Text="@ThomasO, I cannot even imagine how that helps anyone." CreationDate="2010-11-17T22:12:57.077" UserId="230" />
  <row Id="8959" PostId="6896" Text="@Nick I was doing the mils-&gt;mm conversion wrong." CreationDate="2010-11-17T22:13:18.997" UserId="411" />
  <row Id="8960" PostId="6902" Score="1" Text="well written and thorough!" CreationDate="2010-11-17T22:13:41.523" UserId="230" />
  <row Id="8961" PostId="6858" Text="@Kortuk, given that most people there have already signed a disclaimer about content on the internet, I don't see the point either." CreationDate="2010-11-17T22:15:29.963" UserId="1225" />
  <row Id="8962" PostId="6902" Text="I can give you more information, code, and sensor recommendations if you are interested.  Budget is a huge concern in mobile robotics.  I've been doing hobby robotics for the past 10 years, so if you need additional clarification, don't hesitate to ask." CreationDate="2010-11-17T22:17:10.393" UserId="1477" />
  <row Id="8963" PostId="6888" Text="@Thomas O I know the cost of Oscopes can be hard to deal with, but don't expect to ever get a paper published that includes any oscope images that are obtained by any process other then csv or equivalent methods." CreationDate="2010-11-17T22:34:00.310" UserId="319" />
  <row Id="8964" PostId="6886" Text="The ganssle article was the reason I asked this question, it's linked in my question :) Thanks for the link to the debounce code snippets." CreationDate="2010-11-17T22:34:42.667" UserId="1124" />
  <row Id="8965" PostId="6888" Text="@Kellenjb Thanks for the pointers!&#xA;@Thomas O Nice bounce :)" CreationDate="2010-11-17T22:37:22.777" UserId="1124" />
  <row Id="8966" PostId="6885" Text="Good point about key release debouncing!" CreationDate="2010-11-17T22:38:55.193" UserId="1124" />
  <row Id="8967" PostId="6886" Text="Would you mind summing up a few use cases to illustrate when to use soft/hardware? (this is probably subjective, but I'd like some examples anyway)" CreationDate="2010-11-17T22:41:39.187" UserId="1124" />
  <row Id="8968" PostId="6902" Text="Thanks, this is great stuff! I am working on a budget - LIDAR looks like exactly what I need but $1000 is a bit too expensive.  Are there cheaper LIDAR options?  I'm working with a Netduino so I was hoping to find Arduino compatible shields to reuse.  I'd happily shell out $150 for a Kinect to rip apart but I think it'll need more processing power than the Netduino to analyze the data.  What I want to do is very Roomba-ish, maybe I should look into that platform." CreationDate="2010-11-17T22:53:34.297" UserId="1841" />
  <row Id="8969" PostId="6902" Text="I thought that the team at my school had a small one for &lt;100. I can check into it." CreationDate="2010-11-17T23:01:29.420" UserId="230" />
  <row Id="8970" PostId="6888" Text="@Kellenjb, ahem, I suggest you read old datasheets (pre 1980's), you'll find plenty of scope screens. Albeit, oscilloscope cameras are used. In fact some newer datasheets just use screenshots from digitising scopes. " CreationDate="2010-11-17T23:16:49.897" UserId="1225" />
  <row Id="8971" PostId="6886" Score="1" Text="@Vincent, Kellenjb summed it up on his answer how to decide. I did not click your link because it had a funny name, now that I clicked it I see ganssle!" CreationDate="2010-11-17T23:17:05.827" UserId="230" />
  <row Id="8972" PostId="6885" Score="1" Text="I did not downvote it, but just saying to do it in software is an awful idea. It is a good idea to characterize." CreationDate="2010-11-17T23:19:17.197" UserId="230" />
  <row Id="8973" PostId="6791" Text="while it may be that in a feature-rich micro you could have some input circuits wired directly to a pin, such that if you set the pin as an output and then tri-stated it, you could get the input circuits oscillating, in this case having the LED and resistors connected to that pin should load it down enough to prevent that." CreationDate="2010-11-17T23:28:02.300" UserId="740" />
  <row Id="8974" PostId="6883" Text="@Jonathan - Now I have seen/read of one. :)" CreationDate="2010-11-17T23:30:51.567" UserId="374" />
  <row Id="8975" PostId="6888" Text="@Thomas O Old Papers != New Papers != Datasheets" CreationDate="2010-11-18T00:19:52.263" UserId="319" />
  <row Id="8976" PostId="6905" Text="Heh, at the Aluminium smelter we had to checksum the data structures in ram continuously for single bit errors. The watchdog reset the MCU if the stack or registers got bent. 169000 Amperes has a way of making itself felt nearby." CreationDate="2010-11-18T00:59:20.767" UserId="1481" />
  <row Id="8977" PostId="6723" Text="Let me be clear: Nick is right, you can't safely replace a fuse with a penny." CreationDate="2010-11-18T01:36:53.500" UserId="813" />
  <row Id="8978" PostId="5913" Text="Thomas: yes, the &quot;SD commands&quot; are different from (and require more pins to be connected) than &quot;MMC commands&quot;. However, most companies that actually manufacture &quot;SD card&quot; design them such that the same card works with either command set." CreationDate="2010-11-18T02:06:48.940" UserId="813" />
  <row Id="8979" PostId="5642" Text="@mikeselectricstuff, while your answer may be technically correct, it is useless: The original poster telling his co-workers &quot;This is perfectly legal; some anonymous poster on the Internet told me so&quot; isn't helpful." CreationDate="2010-11-18T02:14:54.360" UserId="813" />
  <row Id="8980" PostId="5642" Text="@Thomas O, @tcrosley, check out the Wikipedia articles on MultiMediaCard and Secure_Digital and File_Allocation_Table . Those articles have many sources that seem to confirm what mikeselectricstuff says: the MMC standards are now open. If your system (using a MMC card) is perfectly legal, and you never claim your system is &quot;SD compatible&quot;, then I don't see how yanking out the MMC card and cramming in a SD card could make it illegal. Of course, the system would stop working unless the manufacturer happened to include &quot;backwards compatibility MMC mode&quot;, but most manufacturers do." CreationDate="2010-11-18T03:03:12.287" UserId="813" />
  <row Id="8981" PostId="6882" Text="Most likely a program bug. But stuck-at faults are not completely impossible. I hear rumors that practically all DRAM has at least one or two permanent errors; but the chip tester detects the errors, and blows the fuses to disable the bad/rows columns and subsitutes spare rows or columns (or both). Perhaps somehow your chip, like many/most chips, had such a failure, but it somehow got around the test machine that is supposed to keep such chips from escaping the factory. Or perhaps ultra-high-energy cosmic ray damage. http://en.wikipedia.org/wiki/Talk:Dynamic_random_access_memory#spare_cells ." CreationDate="2010-11-18T05:25:11.097" UserId="813" />
  <row Id="8982" PostId="6905" Text="@Tim: Sounds like that would call for a solid mu-metal box before anything too extreme" CreationDate="2010-11-18T05:30:51.867" UserId="1407" />
  <row Id="8983" PostId="6902" Score="1" Text="James, if you are using something the size of the Arudino, processing power becomes a limitation.  I don't know if you are going to be able to build an entire map with just the Arduino platform.  If this is something that you are considering reusing, it may be worth it to step up to a netbook.  The higher-end sensors are typically USB.  We had a Roomba, Netbook, and LIDAR working together with ROS to do SLAM (Simultaneous Localization and Mapping) and navigation." CreationDate="2010-11-18T06:05:50.820" UserId="1477" />
  <row Id="8984" PostId="6905" Score="1" Text="Noooo the eddy currents would make it hot. A wire longer than about 1m (3feet) tended to get 100's of volts on it. Engineering student came in with dead laptop one day, they'd used a parallel cable to make the data logger a more convenient distance from the laptop's parallel port. Everything was toasted. Memories..." CreationDate="2010-11-18T06:19:50.910" UserId="1481" />
  <row Id="8985" PostId="6886" Text="If that is the consensus/general rule then indeed, there is no need for more examples." CreationDate="2010-11-18T08:10:49.667" UserId="1124" />
  <row Id="8986" PostId="6892" Score="1" Text="this answer is spot on, either FTDI, or use a processor with USB support.  The advantage of the FTDI is also its drivers are really good and easy to access for serial port applications, proved reliability.  Using a uP with USB support and software stack will require limit your uP selection, and require drivers and more software effort.  The advantage would be one less device!" CreationDate="2010-11-18T08:38:49.377" UserId="1397" />
  <row Id="8987" PostId="6814" Text="@Thomas I think Nick's point is you seem to be asking any old question that pops into your head without bothering to research it yourself first. The guys and gals here aren't purposed to do your research for you." CreationDate="2010-11-18T08:55:32.500" UserId="1333" />
  <row Id="8988" PostId="6845" Text="Thanks, this got to the core of my misunderstanding about dB vs dBm" CreationDate="2010-11-18T09:18:36.927" UserId="566" />
  <row Id="8989" PostId="6907" Score="2" Text="Is the video and 555 stuff really relevant to the question?" CreationDate="2010-11-18T09:27:28.243" UserId="566" />
  <row Id="8990" PostId="6910" Text="I want a small water fountain which would sprinkle water enough for a sunbird (which is equivalent to a humming bird in size). What kind of motor should I buy? What panels should I get? How do I modulate the voltage so that it is constant always? Details appreciated :-)" CreationDate="2010-11-18T10:26:42.923" UserId="2002" />
  <row Id="8991" PostId="6755" Text="@W5VO, that family of parts looks pretty useful. Thank you for telling me about it." CreationDate="2010-11-18T12:23:00.243" UserId="813" />
  <row Id="8992" PostId="6903" Text="Do you have the link?" CreationDate="2010-11-18T12:49:16.717" UserId="938" />
  <row Id="8994" PostId="6907" Text="@Joby Taffey, I thought I'd share a video of how it looked last time, to show how I hope it to come out, and to provide justification for asking this question, but do you think I should remove the video?" CreationDate="2010-11-18T13:04:48.963" UserId="1225" />
  <row Id="8995" PostId="6885" Text="I said &quot;generally&quot;, which is the case, and gave the reason. It also minimizes BOM cost and increases reliability." CreationDate="2010-11-18T13:06:53.470" UserId="305" />
  <row Id="8996" PostId="4614" Text="Congratulations for getting it working. Thank you for your detailed post, I hope this helps many other people with their ATtiny projects." CreationDate="2010-11-18T13:27:34.593" UserId="813" />
  <row Id="8997" PostId="6907" Text="@Thomas I think it'd be wise to ask the question first and put the background underneath - like you find in journalism. Everything important is in the first paragraph with details following" CreationDate="2010-11-18T13:34:44.290" UserId="566" />
  <row Id="8998" PostId="6907" Score="2" Text="@Thomas, asking where to buy something or how to buy it cheaper is the definition of too localized. The issue is that in a month it is not valid, and that we could have one question for each country in the world. I am closing this as such." CreationDate="2010-11-18T14:21:17.820" UserId="230" />
  <row Id="8999" PostId="6910" Text="@Raj For the most basic version I wouldn't worry about any regulation if you can tolerate fluctuations in the output and keep your supply close to what the motor requires.  DC motors are fairly robust." CreationDate="2010-11-18T15:11:04.987" UserId="1407" />
  <row Id="9000" PostId="6914" Text="I have a radio module with 4 I/O lines. As you say, it's probably easier to control the H-Bridges properly with another micro and wire the radio into the micro" CreationDate="2010-11-18T16:06:42.473" UserId="566" />
  <row Id="9002" PostId="6852" Text="I don't see anything in that article about impedance matching" CreationDate="2010-11-18T16:14:21.407" UserId="142" />
  <row Id="9003" PostId="6854" Score="1" Text="You're missing part of the big picture. Impedance matching was done in the old days *because loads and drivers were reactive.* In the example of audio, it was common for transformers to be in the signal path, and if you didn't match impedance, it simply would not work. You can get away with not matching impedance today because most modern electronic equipment has *resistive* inputs and outputs, not reactive ones. But for equipment where reactive components are in the signal path, impedance matching is still an important consideration." CreationDate="2010-11-18T17:31:36.860" UserId="544" />
  <row Id="9004" PostId="6854" Text="@Robert: Can you give some example circuits?  Seems like that would make a good answer." CreationDate="2010-11-18T17:44:22.010" UserId="142" />
  <row Id="9005" PostId="6895" Text="Thanks this hits the size requirements but where can I buy this? I've tried searching for the model and no sellers are popping up. Plus the zebra connection is a bit pants..." CreationDate="2010-11-18T17:55:20.780" UserId="1936" />
  <row Id="9006" PostId="6895" Text="according to Densitron's website, they have both a rep and sales office in the UK: &#xA;2001 Electronic Components Ltd,&#xA;Eastman Way,&#xA;Stevenage Business Park,&#xA;Pin Green,&#xA;Stevenage Hertfordshire SG1 4SZ UK,&#xA;Telephone: +44 1438 742001,&#xA;Fax: +44 1438 742002,&#xA;k.bull@2k1.co.uk, &#xA;www.2k1.co.uk; &#xA;sales office:  Densitron Europe Ltd,&#xA;5th Floor,&#xA;145 Cannon Street,&#xA;London EC4N 5BP,&#xA;Tel: +44 20 7648 4200,&#xA;Fax: +44 20 7648 4201,&#xA;sales@densitron.co.uk, &#xA;www.densitron.com " CreationDate="2010-11-18T18:10:12.890" UserId="1322" />
  <row Id="9007" PostId="6914" Text="That would be an easy way to get any feature you want." CreationDate="2010-11-18T18:55:54.090" UserId="230" />
  <row Id="9008" PostId="6915" Text="I assume _MY_ISR is defined as __attribute__((interrupt)) or similar?" CreationDate="2010-11-18T18:57:15.657" UserId="1322" />
  <row Id="9009" PostId="6886" Text="You need to make sure to debounce any signal that could damage your controller in software. Then you strike a balance between processor time and hardware cost." CreationDate="2010-11-18T18:59:53.757" UserId="230" />
  <row Id="9010" PostId="6885" Text="@Leon Heller, it only increases reliability if the signal stays within safe bounds of your controller. This action will increase reliability if you decrease component count without increases components wear. I was not saying that I disagreed with your posts concept, but I constantly work with engineers just coming into the field and an answer like this and they will debounce everything in software. You always must characterize. I also did not downvote you, but I did not upvote either, I think a broad answer like software risks newer developers risking their hardware." CreationDate="2010-11-18T19:04:11.957" UserId="230" />
  <row Id="9011" PostId="6914" Text="You could also just add the XOR gate and use two pins and always coast. Do you need to be able to both break and stop? If you do, it is only 3 lines. Although, with 4 lines you could do wireless uart to a micro and get any feature you dream of." CreationDate="2010-11-18T19:05:12.020" UserId="230" />
  <row Id="9012" PostId="6917" Score="1" Text="Does &quot;Hobby Friendly&quot; include an oscilloscope?  Also, do you wish to know the physical output impedance, or calculate the theoretical output impedance?" CreationDate="2010-11-18T19:09:35.960" UserId="857" />
  <row Id="9013" PostId="6915" Text="@tcrosley: correct" CreationDate="2010-11-18T19:10:40.467" UserId="1225" />
  <row Id="9014" PostId="6916" Text="_MY_ISR is defined as __attribute__((interrupt, shadow, auto_psv))" CreationDate="2010-11-18T19:13:17.487" UserId="1225" />
  <row Id="9015" PostId="6916" Text="I tried disabling the timer before config and then reenabling it but it doesn't work, and has the same problem (resetting I suspect.)" CreationDate="2010-11-18T19:13:49.997" UserId="1225" />
  <row Id="9016" PostId="1720" Text="Minor improvement on the state machine code: it often helps reliability to queue state changes and only ever change the actual state right before the switch statement.  That way you don't have to worry about an interrupt changing your state to STATE_INIT right after you thought you changed it to STATE_COMPLETE. " CreationDate="2010-11-18T19:17:20.457" UserId="249" />
  <row Id="9017" PostId="6852" Text="Very relevant, nonetheless.  Read Kellenjb's answer and try to think like an audiophile - Do you get the impression that impedance matching is a good thing?" CreationDate="2010-11-18T19:17:38.340" UserId="857" />
  <row Id="9018" PostId="6917" Text="Well, yes, I consider oscilloscopes in the hobby friendly zone. However I don't think a spectrum analyzer is in the hobby friendly zone, and I know any oscilloscope which has a high enough bandwidth to measure UHF and above (directly)." CreationDate="2010-11-18T19:20:51.613" UserId="718" />
  <row Id="9019" PostId="6917" Text="I asked a similar question about trace impedance: http://electronics.stackexchange.com/questions/5778/characteristic-impedance-of-a-trace. I think the answer is to design in the 50 ohms impedance, not to calibrate it after manufacture." CreationDate="2010-11-18T19:21:53.470" UserId="1225" />
  <row Id="9020" PostId="6915" Text="If the processor is resetting only with your interrupt routine enabled, this is often a stack problem.  You don't need the explicit return instruction, but it should be optimized out.  In any case, you might want to look at the disassembly code (View -&gt; Disassembly Listing) for the interrupt routine and post it." CreationDate="2010-11-18T19:26:30.900" UserId="1322" />
  <row Id="9021" PostId="6915" Text="@tcrosley I've discovered it only crashes if I uncomment the PR2 statement. The code already has one interrupt which works perfectly, could it still be a stack issue?" CreationDate="2010-11-18T19:30:32.463" UserId="1225" />
  <row Id="9022" PostId="6916" Text="@Thomas, since you are not accessing data in the auto_psv space in your interrupt routine, you can use no_auto_psv instead of auto_psv." CreationDate="2010-11-18T19:30:49.510" UserId="1322" />
  <row Id="9023" PostId="6916" Text="@tcrosley: thanks for the suggestion but no luck..." CreationDate="2010-11-18T19:33:09.870" UserId="1225" />
  <row Id="9024" PostId="6917" Text="Hi Thomas. I looked at your question, but I still do not understand how to actually measure what output impedance I have achieved, or how to design that in for that matter. Your question concerns the characteristic impedance for a transmission line. I am interested in the output impedance of a RF generator circuit (+ possibly the transmission line), and I don't understand how this relates. Please enlighten me? :)" CreationDate="2010-11-18T19:34:47.577" UserId="718" />
  <row Id="9025" PostId="6915" Text="If the period register is 0, it probably never matches and so it never triggers the interrupt.  With PR2 line uncommented, can you trigger on a breakpoint set inside the interrupt routine?" CreationDate="2010-11-18T19:42:39.817" UserId="1322" />
  <row Id="9026" PostId="6915" Text="@tcrosley Tried it - breakpoint never reached, first line of code in ISR. I'm not entirely sure if the processor IS resetting, but the ISR certainly isn't being reached." CreationDate="2010-11-18T19:48:30.513" UserId="1225" />
  <row Id="9027" PostId="6916" Text="Perhaps it's my ignorance of that specific environment, but how does that interrupt routine get mapped to the timer2 overflow event?  Usually there some vector table offset number, a name of the interrupt to tie to, etc." CreationDate="2010-11-18T19:59:49.053" UserId="2004" />
  <row Id="9028" PostId="6916" Text="is _T2Interrupt() a special function name?" CreationDate="2010-11-18T20:00:35.153" UserId="2004" />
  <row Id="9030" PostId="5725" Text="+1 good answer." CreationDate="2010-11-18T20:02:46.973" UserId="813" />
  <row Id="9033" PostId="6916" Text="@Darron, yes -- _T2Interrupt() along with the __attribute__(interrupt) does the mapping." CreationDate="2010-11-18T20:10:12.707" UserId="1322" />
  <row Id="9034" PostId="6916" Text="Ah.  Odd...  but I suppose that's somewhat less C-grammar-mangling than &quot;interrupt 0xC myTimer()&quot;" CreationDate="2010-11-18T20:16:45.817" UserId="2004" />
  <row Id="9035" PostId="6920" Text="Thanks for the answer. However this is where I get lost when I try to put theory into practice: I don't really have a Vin, this is not some passive circuit with an input and an output. It is a circuit with a microcontroller, and a radio IC, and some RF low-pass filters, and some sensors, and maybe other things. Sure the input is a battery with around 2.7v, but that may vary with time, and I don't really think that is meant by Vin." CreationDate="2010-11-18T20:23:12.777" UserId="718" />
  <row Id="9036" PostId="6920" Text="Vin is the voltage at the output with no load attached.  If you measure with a high enough input impedance, the effect of the source's impedance should be negligible.  Vout is the voltage with a load attached.  In other words, Vin and Z1 are inside your source that you're measuring, and Z2 is the test load you connect across its output." CreationDate="2010-11-18T20:27:26.113" UserId="142" />
  <row Id="9038" PostId="6925" Text="Thanks for this code. I will try to match it." CreationDate="2010-11-18T20:35:23.233" UserId="1225" />
  <row Id="9042" PostId="6907" Text="See also http://electronics.stackexchange.com/questions/6599/what-is-the-simplest-way-to-make-a-small-low-power-and-low-price-circuit-that-fla" CreationDate="2010-11-18T20:47:51.240" UserId="813" />
  <row Id="9047" PostId="6600" Text="The [Atmel ATtiny43U](http://www.atmel.com/dyn/products/product_card.asp?part_id=4523) has an integrated charge pump that runs down to 0.7 V and provides up to 30 mA (@ 1.0 V, 10 mA @ 0.7 V).  Alas, it is SMD only, but such is the price of high integration." CreationDate="2010-11-18T21:16:39.377" UserId="1407" />
  <row Id="9048" PostId="6920" Text="This is great information, but as I note, this is applicable at RF frequencies, I note that you say this, I am just adding and extra note." CreationDate="2010-11-18T21:17:11.750" UserId="230" />
  <row Id="9050" PostId="6795" Text="I wonder if you could mix TH on one side, SMD the other, and wave solder it all in one pass." CreationDate="2010-11-18T21:21:55.707" UserId="1407" />
  <row Id="9051" PostId="6932" Text="This particular technique is called locked anti-phase PWM. The downside is that it does not allow coasting, and a MCU lockup will cause the motors to default to full speed in one direction." CreationDate="2010-11-18T21:35:02.100" UserId="1374" />
  <row Id="9052" PostId="6932" Text="The alternative control technique, which uses two pins (Direction and PWM) is called Sign-Magnitude." CreationDate="2010-11-18T21:37:01.367" UserId="1374" />
  <row Id="9053" PostId="6928" Score="1" Text="Can you add another 250 ohms resistor in the loop? I thought from the question that the maximum load is only 250 ohms." CreationDate="2010-11-18T21:41:57.810" UserId="1757" />
  <row Id="9054" PostId="6919" Text="I was discussion electrically controlled electrical relays, http://en.wikipedia.org/wiki/Solid_state_relay, http://en.wikipedia.org/wiki/Silicon-controlled_rectifier. I understand now that you only care about mechanical relays, I never use them, they have poor mean expected lifetimes, but I forget others do. Unless you get into megaWatts, normally an SCR is one of the best devices for switching power. I deleted since it seemed to confuse others." CreationDate="2010-11-18T21:45:48.563" UserId="230" />
  <row Id="9055" PostId="6919" Text="On that note, with AC power an SCR or Triac are significantly better than mechanical relay in power efficiency. " CreationDate="2010-11-18T21:47:48.357" UserId="230" />
  <row Id="9056" PostId="6917" Text="@bjarkef, Thomas is incorrect here, although they are both RF related, your applications are fundamentally different. I have done both, designing a trace to be 50 ohms is very easy, getting an RF generator to match can be quite challenging. " CreationDate="2010-11-18T21:51:57.743" UserId="230" />
  <row Id="9057" PostId="6928" Score="1" Text="That's the whole point of current loops -- you can several receivers in series, because the source (current generator) generates a constant current, not a constant voltage.  For a 20 ma loop, each 250 Ω resistor will develop .020A*250Ω = 5 volts across it.  The power supply must output a voltage equal to or greater than all the voltage drops in the system combined. " CreationDate="2010-11-18T21:57:55.040" UserId="1322" />
  <row Id="9058" PostId="6917" Text="@bjarkef, what frequency are you at that you define as UFC." CreationDate="2010-11-18T22:16:41.190" UserId="230" />
  <row Id="9059" PostId="6918" Text="Do you have a data sheet for the sensor?" CreationDate="2010-11-18T22:20:09.477" UserId="1322" />
  <row Id="9061" PostId="6919" Text="@Kortuk, why? An SCR or TRIAC drops at least 1V in operation, while a relay or switch may only drop a few millivolts." CreationDate="2010-11-18T23:06:10.000" UserId="1225" />
  <row Id="9062" PostId="6935" Text="anything I should worry about with having two voltage regulators in parallel?" CreationDate="2010-11-18T23:10:50.733" UserId="2006" />
  <row Id="9063" PostId="6920" Text="Good information for low frequencies but you would have a really hard time taking this approach to design a matching circuit for RF frequencies.  At least without some really expensive equipment." CreationDate="2010-11-18T23:55:10.023" UserId="1438" />
  <row Id="9064" PostId="6854" Text="@endolith: Anything with a transformer on both sides requires impedance matching.  Granted, most modern electronic equipment has resistive inputs and outputs, so the goal becomes high impedances on inputs, and low impedances on outputs.  That does not always produce ideal conditions, however; if you are building a microphone input for a mixing desk, you don't want a 10 megohm input impedance, because an input that sensitive will pick up all kinds of noise.  Instead, you want something more along the lines of 10K ohms." CreationDate="2010-11-18T23:55:46.103" UserId="544" />
  <row Id="9065" PostId="6854" Text="@Robert: That doesn't sound like impedance matching, though, it sounds like using a transformer to produce an impedance bridging connection.  You're still using low output impedances into high input impedances, no?" CreationDate="2010-11-19T00:13:35.880" UserId="142" />
  <row Id="9066" PostId="6938" Text="There are different varieties of LM317, some good for 1A, some for 1.5A. Also, if you're dropping a lot of voltage in the reg, you need to derate it a bit." CreationDate="2010-11-19T00:39:20.203" UserId="1374" />
  <row Id="9067" PostId="5716" Score="2" Text="Dallas 1-wire only needs one pin, expands to N devices." CreationDate="2010-11-19T00:55:30.777" UserId="1481" />
  <row Id="9068" PostId="6943" Text="That's really helpful. Thank you. Do you know if the converter would work with PWM?" CreationDate="2010-11-19T01:46:21.443" UserId="2006" />
  <row Id="9069" PostId="4484" Text="You already have an answer to what vendor will willfully put vendor specific stuff in IEEE's namespace. It remains crude, particularly when dealing with signed *and* unsigned values. " CreationDate="2010-11-19T02:36:21.227" UserId="1181" />
  <row Id="9071" PostId="6938" Text="Hey, I've seen heat-sinked TO-92." CreationDate="2010-11-19T03:26:46.243" UserId="411" />
  <row Id="9072" PostId="6919" Text="@ThomasO, When I say gain I am referring to power delivered to load as a function of power delivered to turn on the relay. SCRs have unbelievable gains in this respect." CreationDate="2010-11-19T04:27:57.803" UserId="230" />
  <row Id="9073" PostId="6944" Score="1" Text="How does this question relate to electronics and robotics?  There are a number of ways you can get reliable flame, like propane torches, gas lines to bunsen burners, etc. but I don't see how they're within the scope of E&amp;R." CreationDate="2010-11-19T04:30:12.657" UserId="857" />
  <row Id="9074" PostId="6935" Score="1" Text="They aren't in parallel. You only have the inputs connected to the same supply." CreationDate="2010-11-19T04:34:27.770" UserId="305" />
  <row Id="9075" PostId="6938" Text="There is a heat sink for almost everything online. now at radio shack, you are out of luck. We have used heat sinks on some weird packages at work." CreationDate="2010-11-19T04:59:15.560" UserId="230" />
  <row Id="9076" PostId="6947" Text="I get 5.37v when plugged directly into a motor" CreationDate="2010-11-19T04:59:51.603" UserId="2006" />
  <row Id="9077" PostId="6940" Score="1" Text="This may make sense as a community wiki. This is up to you stanigator." CreationDate="2010-11-19T05:00:28.960" UserId="230" />
  <row Id="9078" PostId="6947" Score="1" Text="hahahahahaha. Okay, point taken. I will leave the answer and write another, this is honestly what it will be in 99% of people that have this problem." CreationDate="2010-11-19T05:00:56.073" UserId="230" />
  <row Id="9079" PostId="6947" Text="That's ok, thanks for the help +1" CreationDate="2010-11-19T05:04:06.547" UserId="2006" />
  <row Id="9080" PostId="6946" Text="I added the picture to automatically display." CreationDate="2010-11-19T05:04:21.937" UserId="230" />
  <row Id="9081" PostId="6948" Text="double checking..." CreationDate="2010-11-19T05:04:23.113" UserId="2006" />
  <row Id="9082" PostId="6948" Text="Also check the caps as I just noted. I have to head to sleep, got an early morning, I will check back in the morning." CreationDate="2010-11-19T05:05:44.150" UserId="230" />
  <row Id="9083" PostId="6948" Text="Hmmm, I get 4.3v if I reverse vout and vin...." CreationDate="2010-11-19T05:10:17.973" UserId="2006" />
  <row Id="9084" PostId="6940" Text="I don't know how to decide whether this should be a community wiki though." CreationDate="2010-11-19T05:11:08.037" UserId="1944" />
  <row Id="9085" PostId="6944" Score="1" Text="its about the best way to remove laquer insulation, for example for fixing headphones." CreationDate="2010-11-19T05:23:38.647" UserId="1870" />
  <row Id="9086" PostId="6944" Score="3" Text="Sandpaper is a better way.  (Although lazy me usually cranks up the soldering iron with a big blob of solder on the tip and sticks the wires in there until the insulation melts off.)" CreationDate="2010-11-19T05:28:12.067" UserId="411" />
  <row Id="9087" PostId="6949" Text="Yeah, this is it. I get 4.95v when I use a 9v alkaline as the power source. Thanks!" CreationDate="2010-11-19T05:28:26.217" UserId="2006" />
  <row Id="9088" PostId="6948" Text="Thanks a lot for the help. Im pretty sure the issue is the 2v dropout. +1 for hanging in there with me :)" CreationDate="2010-11-19T05:30:23.750" UserId="2006" />
  <row Id="9089" PostId="6949" Text="You could use a fresh 4-cell NiMH battery pack with a low-dropout (LDO) regulator and get 5 volts out.  But note that battery pack voltage will be about 4.5 volts at the end of discharge." CreationDate="2010-11-19T05:37:09.410" UserId="411" />
  <row Id="9090" PostId="6917" Text="@Kortuk: 868MHz, in the ISM band (for Europe at least, &quot;corresponding&quot; ISM band is 900 MHz for US I think.)." CreationDate="2010-11-19T05:52:05.020" UserId="718" />
  <row Id="9091" PostId="6950" Score="1" Text="I've never had any luck with using microtorches. The copper gets too hot, then cools rapidly, and winds up very brittle. Also, since it is so hot, you typically get a very thick oxide layer." CreationDate="2010-11-19T06:40:13.727" UserId="1374" />
  <row Id="9092" PostId="6941" Text="This. Oh god this..." CreationDate="2010-11-19T06:40:56.330" UserId="1374" />
  <row Id="9093" PostId="6169" Text="Antenova Mica -- http://www.antenova.com/?id=408&#xA;&#xA;or&#xA;&#xA;Taoglas --&gt; http://www.taoglas.com/images/product_images/original_images/PA.15%20FR4%20SMT%202.4GHz%20Antenna%20090810.pdf. Which one should I get? Both allow ground planes underneath the chip antenna which is good." CreationDate="2010-11-19T06:43:52.763" UserId="1688" />
  <row Id="9094" PostId="6910" Text="Cool, thanks for the suggestions. Will start working and get back if I have any doubts." CreationDate="2010-11-19T07:10:11.627" UserId="2002" />
  <row Id="9095" PostId="6940" Text="EPE Magazine has a nice column about recycling all sort of electronic devices..." CreationDate="2010-11-19T07:34:03.380" UserId="1129" />
  <row Id="9096" PostId="6919" Text="@Kellenjb, SCR stands for silicon controlled rectifier and not silicon controlled relay or something like that." CreationDate="2010-11-19T07:54:45.570" UserId="1225" />
  <row Id="9097" PostId="6941" Text="It's okay to keep things, but you also have to know when to throw it away.  I typically keep transformer blocks from just about anything (you never know when you need 12 VDC from AC mains), but recently I purged a massive amount of waste electronics.  Sometimes, scavenging through everything you have to find one part is a bit like looking through LEGOs.  You know what you are looking for, you know that you have it, but you'll never find it.  I suggest buying a resistor and capacitor set off of eBay, and you'll never have to keep &quot;junk&quot; electronics and makes life easier." CreationDate="2010-11-19T08:07:17.150" UserId="1477" />
  <row Id="9098" PostId="6852" Text="The article is in reference to the last part of the question &quot;...or modifying the cable&quot;.  It also addresses the effects of connectors, reflections from impedance mismatch points etc." CreationDate="2010-11-19T08:39:10.930" UserId="400" />
  <row Id="9099" PostId="6953" Text="I commited the same error. The voltage is not applied on the relay when the current is passing. This is the maximum power for the load only." CreationDate="2010-11-19T09:30:34.227" UserId="1757" />
  <row Id="9100" PostId="6913" Text="Thanks for suggestions, illuminating indeed. I know that the question is quite abstract and broad, but I needed some initial pointers. Failing to ask this question, I would never have got these suggestions. I will proceed in the said direction and get back when I have doubts, thanks a ton!" CreationDate="2010-11-19T09:57:31.190" UserId="2002" />
  <row Id="9101" PostId="6953" Text="I too made same error. Power on the switch is current * potential difference between two sides of a switch. Voltage on the switch is probably going to be low. For example, one (very broken) switch I have which is rated at 6 A @ 125 V and 3A @ 250 V has internal resistance of around 47,5 Ω." CreationDate="2010-11-19T10:00:57.600" UserId="1240" />
  <row Id="9102" PostId="6919" Text="@Kennenjb Almost everyone takes relay to mean an electromagnetic relay. Solid state relays are sometimes called SSRs, but rarely would someone refer to them just as a relay. SCRs aren't relays, pure and simple, and the word relay is not in the name. The intention of the question is clear - it states contacts and switches." CreationDate="2010-11-19T11:12:48.953" UserId="2005" />
  <row Id="9103" PostId="6950" Text="had it work pretty well - my repair job lasted until i decided to rewire said headphones, and then it went badly to non microtorch related reasons... overenthusasm with a dremel clone, specfically" CreationDate="2010-11-19T11:18:46.470" UserId="1870" />
  <row Id="9104" PostId="6953" Text="6A at 125Vac(rms) is the same as 6A at 125VDC; there is no need to assume DC. The switch, ideally, dissipates no power - that is done by the load." CreationDate="2010-11-19T11:41:26.990" UserId="1225" />
  <row Id="9105" PostId="6953" Text="This answer doesn't state that 750W is the power dissipated in the swith, just that the load is max 750W. It's correct." CreationDate="2010-11-19T12:50:16.807" UserId="2005" />
  <row Id="9106" PostId="6956" Score="1" Text="Just out of curiosity, why would one want soldermask over a pad?" CreationDate="2010-11-19T13:15:18.747" UserId="1819" />
  <row Id="9107" PostId="6961" Text="I was half way through writing more or less the same. You beat be to it :-(" CreationDate="2010-11-19T14:11:00.107" UserId="400" />
  <row Id="9109" PostId="6961" Text="@Ian it's happened to me plenty of times. Feel free to post it anyways, sometimes a slightly different perspective gets understood better by the community." CreationDate="2010-11-19T14:24:54.863" UserId="319" />
  <row Id="9110" PostId="6958" Text="What load impedance? Is the audio meant to be &quot;hi-fi&quot;? (hi-fi people are very picky about capacitor types.)" CreationDate="2010-11-19T14:25:35.793" UserId="411" />
  <row Id="9111" PostId="6928" Text="Of course, but the sensor in the question can have a maximum load of 250 ohms." CreationDate="2010-11-19T14:31:34.407" UserId="1757" />
  <row Id="9112" PostId="6958" Text="@markrages He is at 1Vp-p so I assumed this is a signal running through a filter or maybe into a A/D and he just wants to remove the DC offset and then add a fixed known offset back. If this is the case, asking for the load impedance isn't tons of help as he is probably inputting into a very high impedance device. @Thomas O please correct me if I am wrong." CreationDate="2010-11-19T14:36:06.650" UserId="319" />
  <row Id="9114" PostId="6950" Text="@Fake: You don't need to hold it directly in the hottest part of the flame." CreationDate="2010-11-19T14:48:12.147" UserId="142" />
  <row Id="9115" PostId="6917" Text="@Bjarke, You are correct, I should have just said 868. That is what I get for not looking at your profile." CreationDate="2010-11-19T14:49:40.557" UserId="230" />
  <row Id="9117" PostId="6959" Score="2" Text="@kellenjb, he means attenuated to 70.7% which is 1/root(2)" CreationDate="2010-11-19T14:52:17.450" UserId="230" />
  <row Id="9118" PostId="6948" Text="@MattWilliamson, I have been doing this so long that I forget to check the dropout voltage. If it was still a problem today I was going to open the datasheet. Last night I just dropped a couple things that it often is." CreationDate="2010-11-19T14:54:08.323" UserId="230" />
  <row Id="9119" PostId="6948" Text="NP, you gave me more stuff to look for when I have other issues." CreationDate="2010-11-19T14:54:54.523" UserId="2006" />
  <row Id="9120" PostId="6948" Text="Got another question for you though ;) http://electronics.stackexchange.com/questions/6963/can-i-use-an-amp-before-my-voltage-regulator-to-ensure-i-get-5v" CreationDate="2010-11-19T14:59:51.757" UserId="2006" />
  <row Id="9121" PostId="6169" Text="The larger one, http://www.antenova.com/?id=408, has better radiation characteristics(more power out for the same power in), http://www.taoglas.com/images/product_images/original_images/PA.15%20FR4%20SMT%202.4GHz%20Antenna%20090810.pdf is smaller. You will need to tune the matching circuit for the Mica one. For the Taoglas it seems they have a set matching circuit. You need a VNA for designing the matching circuit, so if you do not have one you may have bad results with the Mica antenna." CreationDate="2010-11-19T14:59:57.743" UserId="230" />
  <row Id="9122" PostId="6169" Text="@cksa361, I see you have a bounty now, does my answer not meet what you need?" CreationDate="2010-11-19T15:00:31.113" UserId="230" />
  <row Id="9124" PostId="6964" Text="Interesting, did not know." CreationDate="2010-11-19T15:06:58.837" UserId="319" />
  <row Id="9125" PostId="6956" Score="2" Text="@Andrey - Tented vias prevent traces from being shorted with a blob of solder or stray shaving of metal, reducing your risk of shorts to the actual IC pins instead of a random via on the other side of the board.  He's not masking the pad itself, just the via." CreationDate="2010-11-19T15:16:25.200" UserId="857" />
  <row Id="9126" PostId="6940" Score="2" Text="I learned a new word today, thanks!  " CreationDate="2010-11-19T15:18:27.753" UserId="857" />
  <row Id="9127" PostId="6967" Text="This thing should work then, right? http://www.sparkfun.com/products/317" CreationDate="2010-11-19T15:19:18.143" UserId="2006" />
  <row Id="9128" PostId="6956" Text="In that case, this tutorial may help: http://www.sparkfun.com/tutorials/115  I'm not sure if you can do individual vias in Eagle like that, but you can play around with the limit value in the Masks tab of DRC, as well as the size of the vias." CreationDate="2010-11-19T15:40:04.037" UserId="1819" />
  <row Id="9129" PostId="6958" Score="1" Text="Hi-fi people are picky about *everything*.  Doesn't mean their concern is actually legitimate.  http://sound.westhost.com/articles/coupling-caps.htm" CreationDate="2010-11-19T15:44:36.393" UserId="142" />
  <row Id="9130" PostId="6967" Text="Yes, if you can get the layout fabricated properly. " CreationDate="2010-11-19T15:49:06.697" UserId="230" />
  <row Id="9131" PostId="6967" Text="I will note, since it is sparkfun it is probably very easy to get fabricated, just noting, buck/boosts depend on capacitance and inductance, so they will have issues if you add large capacitance or inductance with your layout." CreationDate="2010-11-19T15:50:32.933" UserId="230" />
  <row Id="9132" PostId="6967" Text="I've got a video to help me out here http://www.eevblog.com/2010/09/10/eevblog-110-lets-design-a-dc-to-dc-switchmode-converter/ but I think I may just get a bigger battery and use my linear regulator, haha" CreationDate="2010-11-19T15:50:58.370" UserId="2006" />
  <row Id="9133" PostId="6967" Score="1" Text="I would suggest it, it is easier." CreationDate="2010-11-19T15:51:32.810" UserId="230" />
  <row Id="9135" PostId="6919" Text="@kellenjb, @thomasO, @Cybergibbons, Their power efficiency is very low." CreationDate="2010-11-19T15:59:13.677" UserId="230" />
  <row Id="9136" PostId="6956" Text="@Andrey, When you do not have tented via's underneath a chip the amount of solder you need to put the chip down can be variable, as it can flow out through vias. This type of action can be suggested by the chip manufacturer. the CC1100 for example had a warning to use about this." CreationDate="2010-11-19T16:11:18.720" UserId="230" />
  <row Id="9137" PostId="6964" Text="I do want to make a point that although this answers the specific question that he asked, he is seeing 15% attenuation at 20KHz which seems rather large to me. I suspect hes got something more going on then just the wrong type of cap." CreationDate="2010-11-19T16:42:19.270" UserId="319" />
  <row Id="9138" PostId="6919" Text="@kellenjb, relays are not just used for high power. My oscilloscope, and most I have used, have relays in the attenuation circuit. These are likely low current high speed relays. Coil current is not significant for mains powered appliances, but I've seen as low as 50mA." CreationDate="2010-11-19T17:03:48.300" UserId="1225" />
  <row Id="9139" PostId="6964" Text="@Kellenjb, that is a simulation using ideal capacitors." CreationDate="2010-11-19T17:04:38.893" UserId="1225" />
  <row Id="9140" PostId="6958" Text="The load is a maximum of 1kohm (short circuit), typically it will be driving an audio/video transmitter which will amplify the audio anyway." CreationDate="2010-11-19T17:05:23.510" UserId="1225" />
  <row Id="9141" PostId="6854" Text="@endolith: If your mixing console has transformers, the input impedance on a balanced input is going to be about 600 ohms, because that is what the impedance is for balanced microphones having transformers. The key is *resistance* vs *reactance.* In practice, nobody thinks about this stuff anymore because inputs and outputs on modern electronic gear are resistive, not reactive." CreationDate="2010-11-19T17:21:48.067" UserId="544" />
  <row Id="9142" PostId="6961" Text="Okay, but why does half power matter to an oscilloscope? The power dissipated by the inputs should be very low - in fact, due to the 1 Mohm resistance, it should be constant no matter what the frequency is (at least ignoring parasitic effects.)" CreationDate="2010-11-19T17:28:53.427" UserId="1225" />
  <row Id="9143" PostId="6961" Text="The oscope is going to have many things internal to it that will all be somewhat frequency dependent. When they rate the scope they are just saying that you will be able to get accurate readings within 3db up to that frequency. " CreationDate="2010-11-19T17:37:04.283" UserId="319" />
  <row Id="9144" PostId="6940" Text="@stanigator, if we expect it to be an ongoing question where one answer will not be correct and users will read answers in order of community votes." CreationDate="2010-11-19T17:39:12.623" UserId="230" />
  <row Id="9145" PostId="6941" Text="@mjcarroll, I agree. @pingswept, the cost of mouser is significantly outweighed in my case by saving 2 hours." CreationDate="2010-11-19T17:40:15.803" UserId="230" />
  <row Id="9146" PostId="6971" Text="When my friends have a virus I normally help them fix it. I guess I could just take it." CreationDate="2010-11-19T17:40:58.737" UserId="230" />
  <row Id="9147" PostId="6941" Text="Salvaging ICs is very dubious; the only thing I might consider ripping out are very large, expensive passives (screw/snap terminals), or high power transformers." CreationDate="2010-11-19T17:42:35.803" UserId="1407" />
  <row Id="9148" PostId="6972" Text="I'd think the most significant factor would be the heat capacity (thermal mass) of your surface, plus the junction, plus the cooler." CreationDate="2010-11-19T17:45:16.597" UserId="1407" />
  <row Id="9149" PostId="6961" Text="@Kellenjb: +1 for (mildly) emphasizing that 3 dB reduction in power is different from voltage." CreationDate="2010-11-19T17:47:59.947" UserId="1407" />
  <row Id="9150" PostId="6961" Text="@Thomas O it is also very very common to put a low pass filter on all inputs. Regardless of a digital or discrete system it is usually good to filter out frequencies you don't care about. This way you don't have to worry about anything happening outside of the range you care about." CreationDate="2010-11-19T17:51:43.637" UserId="319" />
  <row Id="9152" PostId="6972" Text="The cooler thermal mass won't matter, will it?" CreationDate="2010-11-19T18:35:33.387" UserId="411" />
  <row Id="9153" PostId="6854" Text="@Robert: Transformers aren't reactive, though, other than the leakage inductance, no?  A unity-gain transformer connected to a 1 kohm load will still look like a resistive 1 kohm load.  How would you match to the reactance of a transformer, and why?  You should really post an answer with some circuits explaining this, I'd like to understand it.  :)" CreationDate="2010-11-19T18:46:20.053" UserId="142" />
  <row Id="9154" PostId="6971" Text="@Kortuk They just give them to me, telling me they've already upgraded or are going to get a new computer anyway. Sometimes I get them because they are just a few years old and &quot;getting slow&quot;, even though I tell them it's an easy fix: usually a reinstall or a cleanup of Windows." CreationDate="2010-11-19T18:47:35.170" UserId="1225" />
  <row Id="9155" PostId="6973" Score="1" Text="It sounds like you have an IR reciever that is tuned to 38.5kHz and you are wanting to transmit digital data to it?" CreationDate="2010-11-19T18:48:21.580" UserId="319" />
  <row Id="9156" PostId="6971" Text="@ThomasO, Their loss." CreationDate="2010-11-19T20:32:06.337" UserId="230" />
  <row Id="9157" PostId="6977" Score="2" Text="My guess is that the testing lab doesn't want to buy a -50C refrigerator. AMD Phenom II overclocking at -170C: http://www.youtube.com/watch?v=0Ggt9pA8X_c" CreationDate="2010-11-19T21:24:44.113" UserId="1363" />
  <row Id="9158" PostId="6977" Score="2" Text="@joeforker: Where does the &quot;-170 °C&quot; figure come from?  There's bound to be a tremendous difference between &quot;ambient&quot; (liquid nitrogen) and the actual junction temperature when the processor is dissipating a few hundred watts of power." CreationDate="2010-11-19T21:31:38.553" UserId="1407" />
  <row Id="9159" PostId="6966" Text="Sometimes an option; some AVRs will run just fine from 1.7 to 5.5 V" CreationDate="2010-11-19T21:39:00.357" UserId="1407" />
  <row Id="9160" PostId="6980" Text="I always forget to note that to people. I just meant it stopped working, but It could damage it." CreationDate="2010-11-19T21:50:45.610" UserId="230" />
  <row Id="9161" PostId="6961" Text="You make sure whatever device is sampling is not aliasing, This can happen in an analog o-scope where the drawing element goes a certain speed." CreationDate="2010-11-19T21:51:49.420" UserId="230" />
  <row Id="9162" PostId="6962" Score="2" Text="Never done any audio stuff, but you don't have to use a non-polarized capacitor to pass AC so long as you give it a DC bias." CreationDate="2010-11-19T22:01:05.947" UserId="1407" />
  <row Id="9163" PostId="6977" Score="1" Text="It comes from the description on the Youtube video of course, only exceeded by the comments as an accurate and insightful source of information." CreationDate="2010-11-19T22:08:57.620" UserId="1363" />
  <row Id="9164" PostId="6962" Text="@Nick T a coupling capacitor removes the DC bias." CreationDate="2010-11-19T22:26:45.473" UserId="319" />
  <row Id="9165" PostId="6962" Text="You could bias the amp's output before the cap, though I guess your output could have some unknown bias." CreationDate="2010-11-19T22:32:55.670" UserId="1407" />
  <row Id="9166" PostId="6958" Score="1" Text="C=1/(2 * pi * F * R), so an 8 uF cap to pass 20 Hz and above.  Standard practice would be electrolytic with &quot;+&quot; terminal toward the 1V bias." CreationDate="2010-11-19T22:50:26.887" UserId="411" />
  <row Id="9167" PostId="6985" Text="Hmm, so it's not possible with an average iron, only with hot air?" CreationDate="2010-11-19T22:58:32.683" UserId="1225" />
  <row Id="9168" PostId="6981" Text="Thanks - I've tried to do this with the PWM pins but had trouble getting the frequency correct." CreationDate="2010-11-19T22:58:39.890" UserId="1841" />
  <row Id="9170" PostId="6989" Text="Never heard of a so small linux capable board! Perfect name also." CreationDate="2010-11-20T00:09:50.527" UserId="1757" />
  <row Id="9171" PostId="6996" Text="It feels like a waste to use a hex inverter IC, is there any way to invert the signal with a maximum output load of ~50mA?" CreationDate="2010-11-20T00:30:46.003" UserId="1225" />
  <row Id="9172" PostId="6996" Score="2" Text="if you have any spare NOR or NAND in your circuit you can use that.  Or a common-emitter transistor and two resistors." CreationDate="2010-11-20T00:36:46.257" UserId="411" />
  <row Id="9173" PostId="6996" Text="@Markrages, no spare NOR/NAND, I need to turn on and off the supply IC which draws 50mA average the gates of the fets. Unfortunately it doesn't have an on/off input." CreationDate="2010-11-20T00:39:17.510" UserId="1225" />
  <row Id="9174" PostId="6996" Score="1" Text="Try an inverting op amp. Set the non-inverting side to halfway between logic 0 and 1 using a resistor divider, and feed the inverting side directly from the 555." CreationDate="2010-11-20T00:40:04.403" UserId="965" />
  <row Id="9176" PostId="6996" Text="@Jesse AC2DE, why spec in an op-amp? Seems like a waste. There must be a simpler way. Besides, not many op-amps can source or sink 50mA." CreationDate="2010-11-20T00:41:56.587" UserId="1225" />
  <row Id="9177" PostId="6996" Score="1" Text="A FET gate that draws 50 mA DC?  I'm confused.  Can you sketch the schematic and post it?" CreationDate="2010-11-20T00:44:51.820" UserId="411" />
  <row Id="9178" PostId="6996" Score="1" Text="I went for that just for simplicity of design. You could also use an NPN. Ground the emitter. You may need a resistor on the base to control base current. (As long as it saturates, it's got enough.) Supply the collector through a suitable resistor which will allow 50ma at logic 1 to your reset line. Connect the reset line (output) at the collector." CreationDate="2010-11-20T00:46:48.533" UserId="965" />
  <row Id="9179" PostId="6995" Score="1" Text="It's synchronous to the power frequency.  So 4 revs per minute at 50 Hz power and 4.8 at 60 Hz. " CreationDate="2010-11-20T00:46:50.103" UserId="411" />
  <row Id="9180" PostId="6940" Text="@Kortuk: I don't know how to make it a community wiki though. Can you help?" CreationDate="2010-11-20T00:55:25.610" UserId="1944" />
  <row Id="9182" PostId="6980" Text="+1 just for the link. I may be designing boards to go in a liquid argon environment (just a wee bit colder than liquid nitrogen) very soon, so I'm going to need practical advice..." CreationDate="2010-11-20T01:19:55.547" UserId="1882" />
  <row Id="9183" PostId="6995" Text="100-120 is what you will get out of a wall outlet in the USA. 60Hz is what you will get in the USA also." CreationDate="2010-11-20T01:22:53.300" UserId="230" />
  <row Id="9184" PostId="7000" Text="I love a man whom knows his analog design!" CreationDate="2010-11-20T01:36:47.227" UserId="230" />
  <row Id="9185" PostId="6983" Score="2" Text="I hope you do not mind thomas, I edited your title to be a bit more clear." CreationDate="2010-11-20T01:39:21.000" UserId="230" />
  <row Id="9186" PostId="6972" Text="@NickT, He specifies how much energy he must remove, by doing this he is specifying the heat capacity I believe." CreationDate="2010-11-20T01:40:21.107" UserId="230" />
  <row Id="9187" PostId="6940" Text="@stanigator, I set it to wiki. A moderator has to set it to wiki." CreationDate="2010-11-20T02:30:31.910" UserId="230" />
  <row Id="9188" PostId="6995" Text="Does this mean that I will need 100-120 volts in order to get it to spin?" CreationDate="2010-11-20T02:41:07.600" />
  <row Id="9189" PostId="6285" Score="1" Text="You can usually find good deals on old lab equipment on eBay. I bought a GoldStar analog oscilloscope there for about $75 and it works great." CreationDate="2010-11-20T02:42:33.163" UserId="1616" />
  <row Id="9190" PostId="6988" Score="2" Text="That is how I do them, except that I put a large via in the central pad so that I can feed solder in with a soldering iron tip. I also extend the pads, to make soldering easier." CreationDate="2010-11-20T02:57:18.483" UserId="305" />
  <row Id="9191" PostId="6995" Text="@walt, dependent on where you live, you get this from a wall socket. In the USA you get 110+-10 from a wall socket. This is why it is spec'ed 100 to 120." CreationDate="2010-11-20T03:29:52.100" UserId="230" />
  <row Id="9192" PostId="4877" Text="The USB Bit Whacker - 18F2553 Development Board might be a good starting point, if your goal is to learn how to communicate using USB and 8 bit Microchip PIC microcontrollers. http://www.sparkfun.com/products/762" CreationDate="2010-11-20T04:31:06.817" UserId="813" />
  <row Id="9193" PostId="6940" Text="Thanks. I guess it's somewhat different from the rest of the Stack Exchange." CreationDate="2010-11-20T05:45:00.727" UserId="1944" />
  <row Id="9194" PostId="6995" Score="1" Text="@Walt - Yes. Also, it HAS to be AC." CreationDate="2010-11-20T06:13:24.663" UserId="1374" />
  <row Id="9195" PostId="6958" Text="@markrages - .... *Electrolytic?* WTF? Use a good quality film cap." CreationDate="2010-11-20T06:17:02.787" UserId="1374" />
  <row Id="9196" PostId="6958" Text="'lytics are fine.  It's not hi-fi and film caps are 10dB more expensive." CreationDate="2010-11-20T07:11:59.200" UserId="411" />
  <row Id="9197" PostId="6964" Text="Post your schematic then. There's soomething wrong with your circuit or sim.&#xA;" CreationDate="2010-11-20T07:21:10.897" UserId="411" />
  <row Id="9198" PostId="6996" Text="@markrage: fet gates can draw up to an amp when they charge up - the controller IC handles this, but average current is still 50mA." CreationDate="2010-11-20T08:53:33.760" UserId="1225" />
  <row Id="9199" PostId="7004" Score="1" Text="Why do you need to do this? Maybe there is a better way." CreationDate="2010-11-20T09:23:32.690" UserId="1225" />
  <row Id="9200" PostId="7000" Text="I tried your circuit and couldn't get it working. The problem is when on, it only provides ~3V to the switcher IC, and it needs at least 6V to work properly. Any idea on why?" CreationDate="2010-11-20T10:24:29.407" UserId="1225" />
  <row Id="9201" PostId="7005" Score="3" Text="+1 for searching in E&amp;R before ask!" CreationDate="2010-11-20T11:50:35.370" UserId="1757" />
  <row Id="9202" PostId="7004" Score="1" Text="I don't think *any* relay can switch at 20 khz." CreationDate="2010-11-20T12:46:35.357" UserId="1374" />
  <row Id="9203" PostId="6995" Text="Yikes! I never though such a small motor would need that much juice in order to work. Makes me a bit squeamish on using it for simple hobby electronic projects." CreationDate="2010-11-20T12:47:32.207" />
  <row Id="9204" PostId="7010" Text="http://export.farnell.com/bipolar-transistors-bjt-arrays" CreationDate="2010-11-20T12:51:37.533" UserId="339" />
  <row Id="9205" PostId="7014" Score="6" Text="I can have a board ready for assembly in under an hour. At £30 an hour for my time, it's very cost-effective for me. I could get a nicer board made for that, but I'd have to wait a couple of weeks for it." CreationDate="2010-11-20T13:02:49.597" UserId="305" />
  <row Id="9206" PostId="7007" Text="thanks for your answer. some parts were a little above me, but it helped a lot. accepted." CreationDate="2010-11-20T13:33:21.913" UserId="2017" />
  <row Id="9207" PostId="7013" Text="Nice answer (I'm sure it's going to be helpful to others!), but that's not what I was asking. While your answer is helpful, it is a bit too general. I'm asking about assembling a heatsink, not about design of a cooling system. The video is also good, but it is more about designing a heat dissipation system. It just mentions that it would be good to have a thermal paste. " CreationDate="2010-11-20T14:24:53.160" UserId="1240" />
  <row Id="9209" PostId="7015" Score="2" Text="reference please?" CreationDate="2010-11-20T14:57:38.813" UserId="142" />
  <row Id="9210" PostId="7015" Text="What do you mean by surface mount assembly? Reflow soldering, wave soldering or hand soldering? I mean is it easier to solder to rounded pads with lead-free solder generally, or using particular technology like reflow or hand-soldering?" CreationDate="2010-11-20T15:07:11.297" UserId="1177" />
  <row Id="9211" PostId="7019" Text="I had a very similar problem when using transistors to switch power components off an Ardurino's TTL output. On a hunch I connected all the grounds and it worked. I understand the concept on a practical level, but it's still kind of odd theoretically. Has anyone got a good link explaining the &quot;relativeness&quot; of voltage?" CreationDate="2010-11-20T15:45:08.133" UserId="1633" />
  <row Id="9212" PostId="7000" Text="What is Vcc?  Which transistors did you use?  What values of R and C?" CreationDate="2010-11-20T15:58:30.343" UserId="411" />
  <row Id="9213" PostId="7015" Text="he is stating it is easier with lead free solder and SMT/SMD chips. He is not specifying if it is hand or automated." CreationDate="2010-11-20T16:17:17.253" UserId="230" />
  <row Id="9214" PostId="7015" Text="I tried to get a reference for this, IPC would like you to pay to see any of their standards, so I am not sure Leon will be able to get your a good reference for this." CreationDate="2010-11-20T16:21:11.107" UserId="230" />
  <row Id="9215" PostId="6995" Text="@Walk, they Intentionally use a motor that works directly off of AC so that there are no electronics required to step down voltage." CreationDate="2010-11-20T16:22:09.967" UserId="230" />
  <row Id="9216" PostId="6981" Text="@JamesCadd, I have helped people do this, there was debug time in their software, but it was well worth saving the hardware in every case I have helped." CreationDate="2010-11-20T16:23:30.077" UserId="230" />
  <row Id="9217" PostId="7017" Text="At first I thought I was going to see another google answer for someone. +1 for teaching a process that I know, but do not think about, and is probably the most effective way to find a component." CreationDate="2010-11-20T16:27:43.660" UserId="230" />
  <row Id="9218" PostId="7006" Score="1" Text="Interesting..I am running with the Samsung ML-2250. I have not replaced the toner in a few years. I'll try your suggestion plus replace that toner.&#xA;&#xA;I would be very interested in seeing your site/videos. Please leave a link in the comments when its up. Look forward to checking it out." CreationDate="2010-11-20T17:23:40.230" UserId="1575" />
  <row Id="9219" PostId="7019" Score="3" Text="&quot;Ground&quot; is just a label.  Another word for &quot;voltage&quot; is potential difference.  It's the difference in potential between two points.  For convenience, we choose a point in the circuit and call it ground (0 V), and measure all other voltages relative to that point.  That point is conventionally chosen in a specific way, but you could really choose any point and measure all voltages relative to it." CreationDate="2010-11-20T17:24:40.400" UserId="142" />
  <row Id="9220" PostId="7014" Score="2" Text="Fake Name: I agree that you can get great results from a pcb mfg...however, I have to go with Leon on this one. If I get a wild hair up my ***, I want to be able to build it out in a few hours versus waiting 2+ days. If I am going to make a few of them, however, I am definitely sending the PCB to the MFG." CreationDate="2010-11-20T17:28:14.297" UserId="1575" />
  <row Id="9221" PostId="7008" Text="So far I have used the Muriatic Acid + Hydrogen Peroxide method. How messy is the process you use? What kind of disposal is require? Thx for the link, I am going to take a look at that right now." CreationDate="2010-11-20T17:31:09.567" UserId="1575" />
  <row Id="9222" PostId="4516" Text="Shields should be connected at one single place to ground, otherwise you will create ground loop. Note app notes referenced in other answers recommend connecting shield through significant resistor (for that exactly reason). I would not go as far to recommend having it not connecting mainly beacouse of hot-plugging reasons." CreationDate="2010-11-20T17:37:18.200" UserId="1471" />
  <row Id="9223" PostId="7008" Text="Ferric chloride stains things badly. It lasts a very long time, and the life can be prolonged by adding hydrochloric acid. Small amounts used at home can be flushed down the lavatory, the copper content is minimal and ferric chloride is used by water companies." CreationDate="2010-11-20T17:37:50.963" UserId="305" />
  <row Id="9224" PostId="7017" Text="The problem is, I didn't know that &quot;transistor array&quot; was what I needed to search for, I think I found the above part by searching &quot;lots of transistors on a chip&quot;. And as I said, as mentioned in the other thread I linked, a &quot;buffer&quot; chip might be what I actually want. I don't even know the right questions to ask!" CreationDate="2010-11-20T17:47:17.673" UserId="1633" />
  <row Id="9225" PostId="6980" Text="@dmckee You got me curious now `:P`, what sort of application are you using liquid argon for?  I'd imagine liquid nitrogen would be much cheaper (and slightly colder? N2 b.p. 77 K, Ar b.p. 87 K)" CreationDate="2010-11-20T18:08:03.060" UserId="1407" />
  <row Id="9226" PostId="7015" Text="I thought lead-free solders flowed worse?  Or do you mean the corners are rounded so the solder will cover more of the pad as a whole--&quot;better fill?&quot;" CreationDate="2010-11-20T18:10:49.157" UserId="1407" />
  <row Id="9227" PostId="7004" Text="2 kV × 30 A = 60 kW...don't know what it is but it sounds fun." CreationDate="2010-11-20T18:13:53.833" UserId="1407" />
  <row Id="9228" PostId="7009" Text="Here's a good [IRF whitepaper on MOSFET vs. IGBT](http://www.irf.com/technical-info/whitepaper/choosewisely.pdf) (PDF) which recommends IGBT for applications above 1 kV.  It is somewhat old and MOSFETs have creeped higher in voltage, and it doesn't bother to mention other technologies (as IRF doesn't make them)" CreationDate="2010-11-20T18:20:24.573" UserId="1407" />
  <row Id="9229" PostId="7024" Score="1" Text="It's basically a modification of Falstad's circuit sim: http://www.falstad.com/circuit which I use often." CreationDate="2010-11-20T18:30:28.967" UserId="1225" />
  <row Id="9231" PostId="7008" Text="Good to know...Here in the states, I would hate to have the EPA knocking on my door." CreationDate="2010-11-20T19:21:37.587" UserId="1575" />
  <row Id="9232" PostId="6980" Text="@Nick: A particle physics detector called a time projection chamber. Traditionally they've been gas phase, but it will work with the right liquids. Put a strong field across the fluid, and the charge tracks left by ionizing radiation will drift (many cm and at a reliable rate) to the field (and induction) wires where it can be detected and used to reconstruct the 3D geometry of the event. [Argoneut](http://t962.fnal.gov/) has [pictures](http://t962.fnal.gov/Images.html) from a test stand device. And I could have sworn the boiling point was 74 K. Ah well..." CreationDate="2010-11-20T19:31:22.357" UserId="1882" />
  <row Id="9233" PostId="7001" Text="Kortuk, I have a similar question and you appear to be the resident RF expert. :-) I've got an IFA at the edge of a small board and the board is mounted in a metal &quot;bowl&quot; with a glass top. (imagine a watch case made of metal) - the metal case is NOT grounded. I know the metal case will seriously impede the antenna's abilities, but would it be better to select something like the Mica antenna or a more conventional IFA that requires the lack of ground plane under it? The board is a tight fit (mm of gap) in the case and the antenna is in the one corner." CreationDate="2010-11-20T20:28:30.157" UserId="974" />
  <row Id="9235" PostId="7028" Text="What are you connecting to the inputs?" CreationDate="2010-11-20T20:53:07.190" UserId="305" />
  <row Id="9238" PostId="7028" Text="The segment outputs of a MAX7221 ledmatrix driver are connected to the 2981, and it drives a big 7 segment LED display. Then the segments that should be off are dimming, and they are brighter when I touch the connector wire." CreationDate="2010-11-20T21:12:35.690" UserId="1514" />
  <row Id="9239" PostId="7031" Text="but it does not work good even if I don't touch :)" CreationDate="2010-11-20T21:51:27.547" UserId="1514" />
  <row Id="9244" PostId="7007" Text="That might be a bit fast to accept it, especially if you still need clarification. Was there something particular that needs expanding on?" CreationDate="2010-11-20T23:16:47.170" UserId="1181" />
  <row Id="9245" PostId="7031" Text="There must be something wrong with your design!" CreationDate="2010-11-20T23:22:49.120" UserId="305" />
  <row Id="9246" PostId="7028" Score="2" Text="this would be much easier to answer if you post the schematic." CreationDate="2010-11-20T23:57:47.580" UserId="1438" />
  <row Id="9247" PostId="7035" Text="What about unregulated DC supplies? (e.g. 12V with a cap and two diodes using a centre tapped transformer.) Why are these unregulated?" CreationDate="2010-11-21T00:06:21.173" UserId="1225" />
  <row Id="9248" PostId="7035" Score="1" Text="Why should they be? They are followed by a voltage regulator, or regulation isn't needed." CreationDate="2010-11-21T00:21:48.663" UserId="305" />
  <row Id="9250" PostId="7035" Score="1" Text="@Thomas O -- regulation doesn't just happen by accident, and you have to start somewhere, don't you?" CreationDate="2010-11-21T02:11:40.897" UserId="740" />
  <row Id="9251" PostId="7017" Text="Yeah, neither do I.  :)  Just comes from experience." CreationDate="2010-11-21T02:18:00.193" UserId="142" />
  <row Id="9252" PostId="7022" Text="kinda duplicate? http://electronics.stackexchange.com/questions/1206/what-are-the-freeware-spice-simulators-available" CreationDate="2010-11-21T02:19:06.493" UserId="142" />
  <row Id="9253" PostId="7028" Score="1" Text="Can you draw your circuit?" CreationDate="2010-11-21T02:23:12.547" UserId="142" />
  <row Id="9255" PostId="7014" Score="1" Text="@Leon Heller - Under an hour? Really? Including drilling? I guess your boards have fewer holes than almost all my projects. " CreationDate="2010-11-21T04:08:25.633" UserId="1374" />
  <row Id="9256" PostId="7001" Text="This is a messy situation. If the antenna is going to be right next to your bowl, you might have something that you cannot tell about. I would guess the chip antenna would do better, but you really might just have to test. Also note that this will screw up your tuning, you will need to re-tune when you place the board in location. Do you own a VNA?" CreationDate="2010-11-21T04:09:21.857" UserId="230" />
  <row Id="9257" PostId="6995" Score="1" Text="@Walt - High voltage **does not** mean lots of juice, it just means high voltage. Power (or juice, if you will), is voltage * current." CreationDate="2010-11-21T04:09:39.033" UserId="1374" />
  <row Id="9258" PostId="5318" Text="I received my 3.2&quot; LCD w/touch &amp; sd yesterday. I went ahead and ordered the arduino shield to quickly test the display. I had to fight a bit with the code itead provides but i am happy to say that it is working perfectly. Great source for cheap displays and the customs cost must have been included in the price as I did not have to pay any additional money when picking it up from USPS. I will also mention that their support has been pretty good. They respond within 24 hours and whoever is answering the email knows his stuff. Great vendor!" CreationDate="2010-11-21T06:34:00.473" UserId="1575" />
  <row Id="9259" PostId="7030" Score="1" Text="Do you mean: Is there an IDE, which will allow me to develop with the .net Micro Framework on Linux? Or do you mean:  Is it possible to use the .net Micro Framework under Linux?" CreationDate="2010-11-21T08:20:38.133" UserId="103" />
  <row Id="9260" PostId="7030" Text="@Amos the first option" CreationDate="2010-11-21T12:08:12.220" UserId="1298" />
  <row Id="9261" PostId="7030" Text="Edited the question to make this clearer." CreationDate="2010-11-21T12:28:26.430" UserId="103" />
  <row Id="9263" PostId="7033" Text="Are you looking at the actual AC output, or a smoothed DC output?" CreationDate="2010-11-21T13:24:39.703" UserId="1374" />
  <row Id="9264" PostId="7033" Score="1" Text="He said it's 23V AC!" CreationDate="2010-11-21T14:05:53.163" UserId="305" />
  <row Id="9265" PostId="7043" Text="For now it is only a prototype and will not be manufactured in high numbers (less than 5). The device has a lot of people lines though, atleast 10 analog that need proper grounding. " CreationDate="2010-11-21T14:48:05.230" UserId="1476" />
  <row Id="9266" PostId="7043" Text="I agree. You want to keep a good solid ground plane on bottom, but put the decoupling directly under the chip, if you can get the 100nF on top that would be better, as it is to decouple RF noise and the VIAs will add a bit of inductance and make that job hard." CreationDate="2010-11-21T15:32:48.217" UserId="230" />
  <row Id="9267" PostId="7041" Score="1" Text="The analog is coming in differential, or is it single ended? When you get to higher precision like 16bit it is near impossible to pull it off without a differential signal coming in." CreationDate="2010-11-21T15:33:29.587" UserId="230" />
  <row Id="9268" PostId="7044" Text="Every person I have explained you get closer to 170V ac to from 120 rectified has looked at me like I am crazy at first." CreationDate="2010-11-21T15:38:31.597" UserId="230" />
  <row Id="9270" PostId="6962" Score="1" Text="@Nick T I was assuming he was putting this cap on his input (so the offset would be unknown), now I realize it is on his output so he should have a known DC offset." CreationDate="2010-11-21T15:45:49.520" UserId="319" />
  <row Id="9271" PostId="7015" Text="@Nick T, I think the design is supposed to improve how well lead-free solders work. I know they do not re-flow as well, they are hard as hell to heat." CreationDate="2010-11-21T16:11:14.907" UserId="230" />
  <row Id="9272" PostId="7004" Text="@Warren, What is the frequency of your AC, I have a suggestion, but my solution only turns off when the AC switches direction." CreationDate="2010-11-21T16:12:52.847" UserId="230" />
  <row Id="9273" PostId="7044" Text="That should be 170V DC." CreationDate="2010-11-21T16:15:23.347" UserId="305" />
  <row Id="9274" PostId="6958" Text="@Thomas O have you looked at a Bode Plot of your system? You might want to post a schematic if you want any more help." CreationDate="2010-11-21T16:15:45.517" UserId="319" />
  <row Id="9275" PostId="7041" Text="The signal is single ended. The source is a differential signal with relative high common mode voltage (about 12V) and very weak (gain up to 5000x with very low noise pre-amps). Yes I know the A/D converter has a SNR of 'only' 84dB which is more like 14 bits." CreationDate="2010-11-21T16:43:22.980" UserId="1476" />
  <row Id="9276" PostId="7035" Text="What I'm asking is why doesn't the transformer keep a fixed ratio, why does it vary under load?" CreationDate="2010-11-21T17:22:52.120" UserId="1225" />
  <row Id="9277" PostId="6919" Text="@Kellenjb - I'm not sure where you've gained your experience, but relay means electromechanical relay practically everywhere in the world. Every factory, ship, train, office building, car, plane all are full of relays and they call them relays or contactors. SSRs are still not used in a lot of locations due to their on resistance being several orders of magnitude higher than electromechanical relays, which means they need to dissipate power. This causes big problems in equipment designed for normal relays." CreationDate="2010-11-21T17:58:39.083" UserId="2005" />
  <row Id="9278" PostId="6919" Text="@kellenjb - you also have huge capacitance on SSRs compared to EMRs, which limits their use with high frequencies such as in oscilloscopes." CreationDate="2010-11-21T18:02:10.780" UserId="2005" />
  <row Id="9279" PostId="7043" Score="1" Text="to add to what kortuk said, in a production design you'd probably want 10nF caps as well, anything under 100nF really needs to be on the surface, the inductance of the via would completely nullify its capacitance at the frequencies its there to decouple." CreationDate="2010-11-21T18:23:24.157" UserId="1438" />
  <row Id="9280" PostId="7033" Text="It seems a lot of the answers are for a &quot;transformer&quot; i.e. a wall-wart power supply of some form, and not just a transformer. May be worth clarifying." CreationDate="2010-11-21T18:50:03.270" UserId="2005" />
  <row Id="9281" PostId="7045" Text="As a side note, I know when a company makes a batch of ICs, like a transciever or such it is in the range of 1Million for all of the associated set up to make it fast to fab millions of ICs." CreationDate="2010-11-21T19:13:34.160" UserId="230" />
  <row Id="9282" PostId="7022" Text="@endolith, I think they are similar, but I see this showing up in search, I am going to edit the title, I hope Brian is okay with it?" CreationDate="2010-11-21T19:14:28.937" UserId="230" />
  <row Id="9283" PostId="7022" Text="This also may be a better community wiki that people will continue to update and vote on in the long term, that is your option brian. If you would like to get a specific answer and accept it then the question is correct how it is." CreationDate="2010-11-21T19:16:24.383" UserId="230" />
  <row Id="9284" PostId="7023" Text="Multisim is not industry standard. It is actually targeted at education. NI does not use the software for their on development, they get theirs from mentor graphics." CreationDate="2010-11-21T19:17:31.623" UserId="230" />
  <row Id="9285" PostId="7043" Text="@Mark, Spot on, I stopped as my comment already seemed long enough. As a side note for others, research has been done to show that most of the time (more than 90%) that people think they have signal integrity issues they actually have power integrity. This study was done of those already following professional practices, I am sure laymen such as ourselves will have signal integrity problems also, but just an interesting sidenote." CreationDate="2010-11-21T19:19:01.280" UserId="230" />
  <row Id="9286" PostId="7043" Score="1" Text="@kortuk I believe it, its not taught much.  The first time i did a full power supply ripple/coupling analysis was just the after the first time i had a product fail FCC.  " CreationDate="2010-11-21T19:23:34.027" UserId="1438" />
  <row Id="9287" PostId="7023" Text="@Kortuk♦ Well, I thought it was since several engineers I talked to told me they use it all the time. Still, it's nice to hear information from other sources too." CreationDate="2010-11-21T19:30:49.840" UserId="1240" />
  <row Id="9288" PostId="7046" Text="I tried with 10K and 33K Iset resistors, but the result is the same. However I missed that the DIG line is not tristate, that could be the problem. I will try to control a ULN2803 sink driver with the DIG lines to make high current-high voltage switch for the leds." CreationDate="2010-11-21T19:36:18.083" UserId="1514" />
  <row Id="9289" PostId="7024" Text="Seems it's available for the iPhone too - but it's expensive." CreationDate="2010-11-21T19:38:22.597" UserId="1333" />
  <row Id="9290" PostId="7046" Text="or have the DIG0 output control a PMOS FET that switches the common cathode to ground.  Just get a fet that is low voltage drop, is rated for your voltage/current and can be switched by +5V, should be easy to find." CreationDate="2010-11-21T19:40:56.793" UserId="1438" />
  <row Id="9291" PostId="7042" Text="Have a look at MOSIS http://www.mosis.com/" CreationDate="2010-11-21T19:42:52.940" UserId="566" />
  <row Id="9292" PostId="7023" Text="@AndrejaKo, I am impressed you got the Star, you do not need to do that to reference me, that just says I am a mod. Second, I could understand thinking that. NI does not use it that way, and When I was at NI week they were clearly trying to make it an educational standard, not a professional one. It is not bad, but the ones I am more used to have signal integrity and many other nice features that I actually need regularly." CreationDate="2010-11-21T20:13:03.970" UserId="230" />
  <row Id="9293" PostId="7043" Text="@Mark, That is a painful way to learn, that is why I sleep at night with high speed digital design at my side. It is my own little handbook of black magic." CreationDate="2010-11-21T20:13:48.620" UserId="230" />
  <row Id="9294" PostId="7000" Text="C = 1u, R = 1k, Vcc = ~6.5V." CreationDate="2010-11-21T20:13:59.047" UserId="1225" />
  <row Id="9295" PostId="7042" Text="@Joby, That is the link I had lost." CreationDate="2010-11-21T20:16:46.573" UserId="230" />
  <row Id="9296" PostId="7049" Score="3" Text="@ThomasO, This is not nearly enough information. If you post some code we could review the function, you could explain more about the situation, or you could expand on what your issue is with the PICkit 2." CreationDate="2010-11-21T20:18:16.213" UserId="230" />
  <row Id="9297" PostId="7049" Text="@Kortuk, I'm asking how to trace the problem, not what the problem is. Once I find the line of code or even the type of crash (division by zero, memory access violation, etc.) I can begin fixing it myself." CreationDate="2010-11-21T20:20:11.103" UserId="1225" />
  <row Id="9298" PostId="7040" Text="This doesn't answer my question - how does the TL431 operate as a comparator in the circuit, or is there something I'm missing? " CreationDate="2010-11-21T20:24:33.767" UserId="1225" />
  <row Id="9299" PostId="7049" Score="2" Text="Yes, but there is such an expansive set of options available with your description I doubt you can get a concise path. Currently you are telling us your debugger and asking us to tell you every possibility that causes an embedded system to crash, we do not even know your compiler." CreationDate="2010-11-21T20:42:02.133" UserId="230" />
  <row Id="9300" PostId="7049" Text="@Kortuk, you misunderstand my question. I am asking how to find out what the problem  is, not what the problem actually is." CreationDate="2010-11-21T20:44:30.410" UserId="1225" />
  <row Id="9301" PostId="7040" Score="2" Text="the triangle is a comparator" CreationDate="2010-11-21T20:49:31.817" UserId="411" />
  <row Id="9302" PostId="7000" Text="which transistors?" CreationDate="2010-11-21T20:50:19.460" UserId="411" />
  <row Id="9303" PostId="7049" Score="2" Text="@Thomas O Are you asking how to use a debugger?" CreationDate="2010-11-21T20:55:01.353" UserId="319" />
  <row Id="9304" PostId="7049" Text="@kellenjb, I suppose, specifically the PICkit 2. I've used it for basic debugging but the problem is, it never tells you why the chip crashed - only &quot;Target Halted&quot; when it does." CreationDate="2010-11-21T20:59:19.477" UserId="1225" />
  <row Id="9305" PostId="7042" Text="Kortuk, feel free to stick it in your answer - it's about all I can offer for this question" CreationDate="2010-11-21T21:05:48.907" UserId="566" />
  <row Id="9306" PostId="7049" Text="@Thomas O This is one of the main things that makes embedding programming difficult. It is a lot to expect a microcontroller to know why it crashed. There really isn't any better advice then what @kortuk has already answered." CreationDate="2010-11-21T21:07:10.233" UserId="319" />
  <row Id="9308" PostId="7049" Score="2" Text="@ThomasO, Asking how to find the solution is the same as asking for it. We will have to list every possible problem that you could have, you are not giving enough detail for this to be answered. I understand that you want to learn how to debug these issues, but there is no way we can tell you to just &quot;Do A, then B, and if nothing else, Do C&quot;. This does not exist in the embedded world. It is a bit easier to do on computer programming but you have never lived until you have a resource lock between threads." CreationDate="2010-11-21T21:17:34.690" UserId="230" />
  <row Id="9309" PostId="7049" Text="@Kellenjb, so it would seem a limitation of the debug hardware? The processor has interrupts/traps for things like divide by zero, so I was thinking of setting up an ISR... maybe get it to pulse an IO indicating the type of crash." CreationDate="2010-11-21T21:19:16.887" UserId="1225" />
  <row Id="9310" PostId="7049" Text="@Thomas O side note, dividing on a microcontroller is very poor practice unless you absolutely have to. It is much better to do bit shifting." CreationDate="2010-11-21T21:21:59.380" UserId="319" />
  <row Id="9311" PostId="7052" Text="Agreed, There is no magic way to have the debugger halt on crash, you can only get it to halt on reset. Cut the code, although most of the bugs I wish I could find have been due to the large amount of things running." CreationDate="2010-11-21T21:23:23.093" UserId="230" />
  <row Id="9312" PostId="7053" Text="He said he was already pretty sure what function it was in. Hopefully his functions aren't very long." CreationDate="2010-11-21T21:24:55.103" UserId="319" />
  <row Id="9313" PostId="7053" Text="Regardless, I forget to mention this, in a nicer code I have written before when it powers up it records what interrupted the device on last run and logs or TX's it so that debugging is easier." CreationDate="2010-11-21T21:31:02.467" UserId="230" />
  <row Id="9314" PostId="7049" Text="@kellenjb, the dsPIC33F has a 19-cycle hardware divider, I don't use it often, but never... that would be wrong." CreationDate="2010-11-21T21:46:46.427" UserId="1225" />
  <row Id="9315" PostId="7053" Text="@kellenjb, Unfortunately my functions are very long - one is 500 instructions!" CreationDate="2010-11-21T21:47:42.993" UserId="1225" />
  <row Id="9316" PostId="7049" Text="@ThomasO, I use MSP430s without multiply hardware. I found a way to remove all divides, excluding binary ones." CreationDate="2010-11-21T21:51:26.217" UserId="230" />
  <row Id="9317" PostId="7053" Text="@Thomas: Divide and conquer.  Are you writing in assembly?  By &quot;instruction&quot; do you actually mean assembly instruction or line of C?" CreationDate="2010-11-21T21:53:25.310" UserId="1407" />
  <row Id="9318" PostId="7048" Text="cool. That completely explains why it is not stable without pulldown resistors. I have put pulldown resistors to segment outputs and it is not dimming now. But when I touch the inputs it dims again, I checked with scope and switches on with some noisy waveform, so... i will not touch it and should be ok :)" CreationDate="2010-11-21T21:54:13.470" UserId="1514" />
  <row Id="9319" PostId="7053" Text="@Nick T, they are mostly C." CreationDate="2010-11-21T21:55:33.453" UserId="1225" />
  <row Id="9320" PostId="7046" Text="I can see that this desing has too many errors :) There is no current limitation at all, the 7221 will burn if I add more digits in the current configuration." CreationDate="2010-11-21T22:01:09.690" UserId="1514" />
  <row Id="9321" PostId="7053" Text="@ThomasO, The solution to long functions is more short ones." CreationDate="2010-11-21T22:09:11.763" UserId="230" />
  <row Id="9322" PostId="7009" Text="I would suggest and IGBT as a good choice. I like SCRs a lot, but I am not sure that switching frequency would bode well." CreationDate="2010-11-21T22:20:41.197" UserId="230" />
  <row Id="9323" PostId="7053" Text="@kortuk, and making it slower... the code is about 40-50 lines, it's just it uses complicated instructions and bit math." CreationDate="2010-11-21T22:32:24.983" UserId="1225" />
  <row Id="9324" PostId="7042" Text="I don't know how relevant it is, but the EFF (Electronic Frontier Foundation) built &quot;Deep Crack&quot;, a machine to break DES. They used 1856 custom &quot;Deep Crack&quot; ASICs - including manufacture and implementation, it cost them less than $250k." CreationDate="2010-11-21T22:36:53.700" UserId="1225" />
  <row Id="9325" PostId="7053" Text="@thomasO, Are you not using an optimizer? even if you are not you should be able to inline functions. More functions can actually speed up code. A good optimizer can take advantage of the new space to make your system more optimized. for example, if most of your math is on one variable in a subsection they can smack it in a register and take care of it." CreationDate="2010-11-21T22:37:03.857" UserId="230" />
  <row Id="9330" PostId="7042" Text="@Joby, Thanks, and I linked to your profile!" CreationDate="2010-11-22T01:38:36.133" UserId="230" />
  <row Id="9332" PostId="7051" Text="@W5VO, Very well written. Thank you for bringing light, I put down an answer to help out, but yours is both clear and detailed!" CreationDate="2010-11-22T01:45:19.870" UserId="230" />
  <row Id="9333" PostId="7044" Text="And in the 230VAC world we get even more" CreationDate="2010-11-22T02:07:11.150" UserId="1481" />
  <row Id="9334" PostId="7052" Text="When I first started in embedded I did not know the volatile keyword in C. May did I hate having to turn on the optimizer, nothing ever worked." CreationDate="2010-11-22T02:16:11.340" UserId="230" />
  <row Id="9335" PostId="7052" Text="The quickest way to divide and conquer is to get the diff between the working and nonworking code from version control. Some guys like to write the entire program in one step and then debug it in a marathon debugging session. That doesn't work in embedded programming. Make small changes and tst thoroughly before moving on." CreationDate="2010-11-22T02:23:53.047" UserId="411" />
  <row Id="9336" PostId="6958" Text="@Thomas O can you let us know what it was that fixed your issue?" CreationDate="2010-11-22T02:55:56.847" UserId="319" />
  <row Id="9337" PostId="6826" Text="@angry you have made two slightly incorrect statements.  (1) You do not need a rail-to-rail amp for unbalanced supplies, although with only 3.3V you probably will find rail-to-rail input and output useful.  (2) Because no op-amp requires dual supplies, looking for the phrase &quot;works with single supply&quot; on the datasheet is unnecessary.  (I think the phrase was coined when the first amplifiers that included the negative rail in the common-mode input range were introduced.) Instead, look at the datasheet for the common-mode range and the output swing to decide if it will work with your supply." CreationDate="2010-11-22T03:26:59.677" UserId="411" />
  <row Id="9338" PostId="4861" Text="@Mark, work through the math.  The response is identical to an RC filter." CreationDate="2010-11-22T03:38:05.600" UserId="411" />
  <row Id="9339" PostId="7051" Score="1" Text="Thanks. It's hard to give precise answers to that question, especially since so many bits of the pie are covered by NDA's. Thankfully, CMP publishes their prices." CreationDate="2010-11-22T04:22:32.093" UserId="638" />
  <row Id="9340" PostId="7057" Text="Nice, I like it. I still thinking using shorter functions is a better method, but this method works." CreationDate="2010-11-22T04:22:55.240" UserId="230" />
  <row Id="9341" PostId="7054" Text="I updated the post with definitions and a link to one of my sensor resources.  there are commercial sensors as well, but they try and sell you their own version of a &quot;transmitter box&quot; that will convert the reading into a 4-20mA Analog output.  Frankly id rather develop my own for a lot cheaper" CreationDate="2010-11-22T04:28:05.410" UserId="2034" />
  <row Id="9342" PostId="7054" Text="quick second edit:  Kortuk, maybe it is better if I post each one as their own question? " CreationDate="2010-11-22T04:32:09.897" UserId="2034" />
  <row Id="9343" PostId="7054" Text="@Zero0ne, That might be a good idea, make this one thermistor, since you already have an answer, and make the others, you will get more detailed answers for each subject." CreationDate="2010-11-22T04:36:26.407" UserId="230" />
  <row Id="9344" PostId="7054" Text="@Zero0ne, It takes a bit to ask the questions, but the responses the community gives are worth it, I promise." CreationDate="2010-11-22T04:38:02.153" UserId="230" />
  <row Id="9345" PostId="7059" Text="how do I connect the 8535 to this board? do i just plug in the first 6 pins or is the something I need to make up?" CreationDate="2010-11-22T04:55:41.770" />
  <row Id="9346" PostId="7059" Text="@Dale I added some more explanation." CreationDate="2010-11-22T05:04:17.767" UserId="319" />
  <row Id="9347" PostId="7051" Text="This is the place where bits of the pie come together, in theory, sometimes in practice." CreationDate="2010-11-22T05:25:04.423" UserId="230" />
  <row Id="9348" PostId="5892" Text="@endolith : You have explained that DAC is not used, 1 and 0 are just mathematical abstraction we use to make programming easier. Can you add little more detail on this with reference to &quot;Compiler&quot;? the compiler converts high level language to 1 and 0. You said that these 1 and 0 are stored in memory as digital logic, a digital logic circuit transfers them from memory to the processor.. What is the name of the device that does this function? And again, the processor's input will be 5v or 0v. So what device converts the 1 and 0 from memory(actually from the compiler) into 5v and 0v?" CreationDate="2010-11-22T07:18:06.497" UserId="1484" />
  <row Id="9349" PostId="7054" Score="1" Text="Let me guess, trying to sense the condition of hydroponic growing solutions?  Some of the things you listed are rather complicated to measure.  Dissolved Oxygen sensors for instance use some rather exotic materials and trying to measure an absolute value requires constant calibration (same with PH).  I'd consider looking at the project goal and seeing which of these you really need.  The nitrates,ammonium,etc for instance could be replaced with total dissolved solids (TDS) in many cases." CreationDate="2010-11-22T07:33:43.413" UserId="1438" />
  <row Id="9350" PostId="5896" Text="@JustJeff : Now I have understood that Transistors are the base on which processors are created i.e with a gate like nand, we can create flipflops, registers, counters, alu and all these together make the computing system.                                     Transistors input can be high or low(over2.4v 0r under0.8v)..  My question is, what is the device that interprets 1 and 0 from the Compiler as corresponding logic to these transistors if no DAC is used?" CreationDate="2010-11-22T07:34:06.857" UserId="1484" />
  <row Id="9351" PostId="7054" Score="1" Text="In general you need to buy most of the sensors you mentioned.  If the ones your looking at are similar to the ones you linked then the signal that comes out of the sensor body has already been pre-processed in some form.  That is your not measuring the resistance of those wires (maybe on the temperature) but rather it will be presented in some other form.  Voltage, frequency, digital data, there are several ways it could come out, all would be specific to the sensor vendor. " CreationDate="2010-11-22T07:35:46.547" UserId="1438" />
  <row Id="9352" PostId="7054" Score="1" Text="here is a better company:  http://www.jencostore.com/  As they sell just the probes.  If EC / pH can be done by a $30 meter I would hope i can get the same accuracy of readings on the PC.  A routine that walks through the calibration process would be easy to develop." CreationDate="2010-11-22T08:18:16.423" UserId="2034" />
  <row Id="9353" PostId="7051" Text="Thank you so much for answering! :) Btw, MOSIS has a form that you can fill out and it'll send you a quote estimate. I asked for 20 dies, 1mm square each with ON I2T100 (whatever it means, but it was the coarsest process in the list, 0.7um). The quote estimate was $10000." CreationDate="2010-11-22T09:17:30.577" UserId="1850" />
  <row Id="9354" PostId="7042" Text="@Thomas, I wonder how they managed that :)" CreationDate="2010-11-22T09:20:24.567" UserId="1850" />
  <row Id="9355" PostId="7064" Text="Could you describe in a bit more detail the method you use for double sided boards? Do you have pictures of your process or a link(s) you perfected your process from? Also I would be very interested in more details concerning the use of solder paste. Thx!" CreationDate="2010-11-22T09:29:07.333" UserId="1575" />
  <row Id="9356" PostId="7047" Text="Good insights! The on/off state for velocity sensing may be enought! I'll test with my students and post the results here." CreationDate="2010-11-22T10:17:01.587" UserId="1757" />
  <row Id="9357" PostId="7037" Text="This is really nice as a cheap force sensor, but seems a little complicated to make the &quot;piano&quot; keys with this." CreationDate="2010-11-22T10:22:57.653" UserId="1757" />
  <row Id="9358" PostId="7040" Text="I thought it was an op-amp configured as a shunt reference." CreationDate="2010-11-22T10:36:10.953" UserId="1225" />
  <row Id="9359" PostId="7070" Score="2" Text="Wouldn't the losses be cancelled out by the fact that a capacitor ideally doesn't waste energy (http://electronics.stackexchange.com/questions/5355/does-an-ideal-capacitor-dissipate-power)? Therefore any losses would be resistive and irrelevant of frequency (ignoring for now the skin effect.)" CreationDate="2010-11-22T10:47:13.117" UserId="1225" />
  <row Id="9360" PostId="7070" Text="No. The transmission line is a capacitor that needs to be charged and discharged twice with each cycle, current flows due to this changing and that current is a pure loss." CreationDate="2010-11-22T11:13:56.333" UserId="1675" />
  <row Id="9361" PostId="7064" Score="1" Text="Yes, that was a bit sketchy! I've added some pictures to illustrate the process." CreationDate="2010-11-22T11:15:19.953" UserId="1897" />
  <row Id="9362" PostId="7071" Text="Ah, you beat me to it. :)" CreationDate="2010-11-22T11:27:13.097" UserId="1850" />
  <row Id="9363" PostId="7070" Score="4" Text="Technically, the charging current isn't the loss, it's passing the current through the resistance of the cable (and everywhere else it passes on its way) which is where the loss is." CreationDate="2010-11-22T12:13:31.563" UserId="1844" />
  <row Id="9364" PostId="7071" Score="3" Text="My favorite structure :), need to remember that it will not work with input down to gnd level (below 0.7V) and have gain slightly less than one. Also for higher input impedance you can replace npn win n-mos. " CreationDate="2010-11-22T12:37:34.763" UserId="1471" />
  <row Id="9365" PostId="7070" Text="Well, let's say you had super-conductors everywhere in the system, even in the generator, the capacitative load on the line would still mean a loss for the system, it would just be pushed back to the mechanical side of the generator. You are right that the resistance of the wires in real systems means that losses mainly show up as heat, but eliminating that resistance does not eliminate the loss caused by capacitance of the transmission line." CreationDate="2010-11-22T12:55:33.353" UserId="1675" />
  <row Id="9366" PostId="7051" Text="Try checking the ON C5N process. It is a straight CMOS process, with no fancy features.  Their 0.7 um process has high voltage transistors and appears to be BiCMOS, which may bump up the price. Also, don't forget to add in packaging!" CreationDate="2010-11-22T13:03:27.507" UserId="638" />
  <row Id="9367" PostId="7073" Text="I need 6x SC70 packages then. Space is very constrained, I struggled to fit in the voltage divider resistors. Plus don't forget the traces, as I'm dealing with 2-layer." CreationDate="2010-11-22T13:04:53.800" UserId="1225" />
  <row Id="9368" PostId="7071" Score="1" Text="The problem with this configuration is that the BJT draws current (probably greater than the 500nA on the MCU inputs); also, the output will have an offset, reducing the dynamic range..." CreationDate="2010-11-22T13:06:03.207" UserId="1225" />
  <row Id="9369" PostId="6067" Score="1" Text="I'd work the relay in the opposite sense - the problem with the circuit above is as the voltage continues to drop down towards 0V, the relay coil loses power, and the load is connected back up again. This may cause issues. It's only the holding current, but I'd avoid the possibility of the situation occuring." CreationDate="2010-11-22T13:15:09.317" UserId="2005" />
  <row Id="9370" PostId="7053" Score="3" Text="The PIC equivalent is the RCON register." CreationDate="2010-11-22T13:38:13.107" UserId="588" />
  <row Id="9371" PostId="7019" Text="For starters, all the power you have in your house comes from the AC plugs in your wall.  AC doesn't have a 'ground' as a common reference.  On top of that, many power supplies to convert AC to DC are completely isolated from the wall power, so even if there was a 'ground' reference for AC, you wouldn't have access to it from the DC (because of isolation).  And lastly, I can put 'ground' anywhere I want in a circuit it's just a reference.  It could at 5V or 1000V but as long as everyone IN THAT CIRCUIT agrees on what it is, it will work." CreationDate="2010-11-22T13:39:39.983" UserId="249" />
  <row Id="9372" PostId="6070" Text="Mark - can you find examples of solid state relays that have lower on resistance than typical electromechanical relays?" CreationDate="2010-11-22T14:11:07.487" UserId="2005" />
  <row Id="9373" PostId="7000" Text="Simulated using 2N3904 and 2N3906." CreationDate="2010-11-22T15:01:01.910" UserId="1225" />
  <row Id="9374" PostId="7071" Text="@Thomas O so you need a buffer that will load less then connecting direct to the MCU would?" CreationDate="2010-11-22T15:01:15.873" UserId="319" />
  <row Id="9375" PostId="7071" Text="@kellenjb, Ideally, yes." CreationDate="2010-11-22T15:02:16.447" UserId="1225" />
  <row Id="9376" PostId="7069" Text="With less current then the MCU, as small as a voltage divider, and unity gain, faster then a bullet going the speed limit, it is &quot;super buffer&quot;. Thomas, please remember the reason they pay engineers so well is that we are able to take a problem and find solutions that meet criteria, sometimes you need to make a product larger, go to 4 layers, and/or mount components on both sides of the board." CreationDate="2010-11-22T15:48:53.353" UserId="230" />
  <row Id="9377" PostId="7070" Score="2" Text="@dren.dk, I think you may have some misunderstandings about transmission lines, in real life they match all of the transmission lines, and if everything was lossless the power would be pushed down the line without losing any power. Everyone is correct that if you pushed the line to 1kHz you would lose power, but that would be to resistive and radiation losses." CreationDate="2010-11-22T15:52:26.050" UserId="230" />
  <row Id="9379" PostId="7073" Score="2" Text="@Thomas: What voltage divider resistors?  For a buffer, you just short the inverting input to the output." CreationDate="2010-11-22T15:55:08.913" UserId="142" />
  <row Id="9380" PostId="7052" Text="I love version control. There is no single thing that increases productivity more than version control for myself." CreationDate="2010-11-22T15:55:13.583" UserId="230" />
  <row Id="9381" PostId="7000" Text="What current does the supply need?  Maybe the 3906 isn't stout enough.   The PNP transistor should be turned on hard and at saturation voltage.  What base and collector currents do you see on it in your sim?" CreationDate="2010-11-22T15:58:55.023" UserId="411" />
  <row Id="9382" PostId="5892" Text="@Vicky: There is no conversion from &quot;1&quot; to 5 V.  &quot;1&quot; and &quot;0&quot; are just labels we give to high and low voltages when doing math with binary numbers.  For simple low-level logic that's not operating on binary numbers, it's more common to call them &quot;H&quot; (high) and &quot;L&quot; (low)." CreationDate="2010-11-22T16:00:30.687" UserId="142" />
  <row Id="9383" PostId="7040" Text="look at the diagram carefully.  See the open collector transistor?  Notice that &quot;cathode&quot; can be pulled lower than &quot;reference&quot;.  Notice that the op-amp/comparator is running without feedback. " CreationDate="2010-11-22T16:01:38.907" UserId="411" />
  <row Id="9384" PostId="7073" Score="1" Text="Think about a pair of quad op-amps.  Each package needs one power and one ground connection.  And the standard layout puts the output pin next to the (-) input. A gain-of-1 buffer would only save one pin per channel." CreationDate="2010-11-22T16:14:15.410" UserId="411" />
  <row Id="9385" PostId="7070" Score="2" Text="@dren.dk - I don't agree - with perfect conductors/generators and a perfect capacitor, the reactive power would cost nothing to make, but that's all irrelevant, as if you have one lot of stuff impossibly perfect, you might as well specify free fuel while you're at it..." CreationDate="2010-11-22T16:31:54.360" UserId="1844" />
  <row Id="9386" PostId="7070" Text="@WillDean, I have free fuel, Get a company car." CreationDate="2010-11-22T16:34:06.730" UserId="230" />
  <row Id="9387" PostId="7077" Score="1" Text="Your poor poor modem. I cannot give a concise answer, but I can tell you that your device did not enjoy it." CreationDate="2010-11-22T16:35:10.553" UserId="230" />
  <row Id="9388" PostId="7054" Score="1" Text="@Zero0ne, you would probably have to have hardware to do the calibration process." CreationDate="2010-11-22T16:38:17.600" UserId="230" />
  <row Id="9389" PostId="7079" Score="1" Text="That is about what I would have said also." CreationDate="2010-11-22T16:39:08.583" UserId="230" />
  <row Id="9390" PostId="7022" Text="Totally ok with the title change, I don't think I have enough rep to mark this community wiki." CreationDate="2010-11-22T16:42:38.433" UserId="2024" />
  <row Id="9391" PostId="7014" Text="@Fake Name: SMT is the future." CreationDate="2010-11-22T16:44:34.383" UserId="1333" />
  <row Id="9393" PostId="7078" Text="Cheap alarm clocks I've found use transformers. Also, an older scope I had used one. But SMPS supplies are becoming cheaper than transformers nowadays so you see them more." CreationDate="2010-11-22T17:21:20.153" UserId="1225" />
  <row Id="9394" PostId="7073" Text="@markrages: 1 pin per channel might not sound like much but for my project it is a lot!" CreationDate="2010-11-22T17:23:30.323" UserId="1225" />
  <row Id="9395" PostId="7069" Text="@Kortuk 4 layers is twice the cost. I'm still learning. If I don't know where to start, how am I supposed to learn? I do not need high speed. I am not requiring it to be as small as a voltage divider - I did not mention any of these. I said it should be small, but I did not specify a lower bound. I was looking for a chip which would basically be six op-amps configured as buffers. " CreationDate="2010-11-22T17:23:59.807" UserId="1225" />
  <row Id="9396" PostId="7083" Text="Thank you very much for your response. I'm looking forward to hear from you again." CreationDate="2010-11-22T17:29:01.947" UserId="2041" />
  <row Id="9397" PostId="7073" Text="Quad op-amp requires 3.5 pins per channel.  An emitter follower requires 5 pins per channel (three pins of transistor, two &quot;pins&quot; for resistor.)  The CA3082 isn't available in really small packages last I looked.  (BTW, a bunch of SC70 packages might be a pain to hand-solder)." CreationDate="2010-11-22T17:29:12.667" UserId="411" />
  <row Id="9398" PostId="7069" Text="@ThomasO, There are chips like that, if you had just said that someone would have found it for you. I am trying to give you feedback and help you laugh a little." CreationDate="2010-11-22T17:33:32.113" UserId="230" />
  <row Id="9399" PostId="7079" Score="1" Text="That is my guess as well." CreationDate="2010-11-22T17:38:45.070" UserId="319" />
  <row Id="9400" PostId="7082" Text="Are you needing to do counterfeit detection also?" CreationDate="2010-11-22T17:45:39.400" UserId="319" />
  <row Id="9401" PostId="7069" Score="1" Text="@ThomasO, if you want to sell a product please remember that FCC validation is hell to pay with a board that is 2 layer and has higher speed signals. Also remember that your signal speed is determined by your slew rate, not by the clock rate which is normally much lower." CreationDate="2010-11-22T17:53:59.640" UserId="230" />
  <row Id="9402" PostId="7079" Score="2" Text="Good lesson to learn here for those that design electronics, a check-sum probably just allowed a product to save itself from non-standard behavior." CreationDate="2010-11-22T17:56:36.953" UserId="230" />
  <row Id="9403" PostId="7082" Text="At the moment not really but i welcome that idea also. If you have any idea, then kindly let me know. Thanks" CreationDate="2010-11-22T18:00:22.277" UserId="2041" />
  <row Id="9404" PostId="7085" Text="Thanks for the reply" CreationDate="2010-11-22T18:02:11.637" UserId="2041" />
  <row Id="9405" PostId="7085" Text="I want i bill counter i can develop a software for it to process the counting information it receives from the counter." CreationDate="2010-11-22T18:07:03.317" UserId="2041" />
  <row Id="9406" PostId="7073" Score="1" Text="6x SC70 for the buffers/opamps vs ... 6x SC70 for the transistors and 6x for the emitter resistors? I'm not sure why you think that using parts like this will be larger than the discrete solution." CreationDate="2010-11-22T18:07:14.413" UserId="974" />
  <row Id="9407" PostId="7085" Score="1" Text="@kap, some of the bill counters listed there may have external interfaces -- you'd have to look at the descriptions.  Or you could tear a used one apart and just use the bill counting mechanism." CreationDate="2010-11-22T18:12:53.487" UserId="1322" />
  <row Id="9408" PostId="7085" Text="Thank you very very much. This answer helps." CreationDate="2010-11-22T18:18:17.807" UserId="2041" />
  <row Id="9409" PostId="7069" Text="@Kortuk, the product will be open source and I am not going to do FCC validation as it is very rare in the hobbyist market - given I am selling only 50-100 it's not worth it." CreationDate="2010-11-22T18:22:53.220" UserId="1225" />
  <row Id="9410" PostId="7033" Text="This sounds suspiciously like a homework question to me...." CreationDate="2010-11-22T18:31:57.860" UserId="249" />
  <row Id="9411" PostId="7033" Text="@AngryEE It's not, but I don't know how I'd prove it... we're only doing op-amps at the moment in electronics!" CreationDate="2010-11-22T18:33:40.620" UserId="1225" />
  <row Id="9412" PostId="7035" Text="An ideal transformer wouldn't vary under load, but a real one does because it's a passive device governed by the laws of electromagnetics.  To maintain a constant ratio in the real world it would need feedback and compensation - but then it wouldn't be passive.  If you don't understand it yet it's because you haven't had the right physics/circuit analysis classes.  For an idea of what the differences between ideal and practical transformers are visit here: http://en.wikipedia.org/wiki/Transformer - look under &quot;Equivalent Circuit&quot;" CreationDate="2010-11-22T18:44:03.883" UserId="249" />
  <row Id="9413" PostId="7087" Score="4" Text="Cautions about those buffer amps: Most of them are made for video signals and so they are high bandwidth / high current designs.  That's a consideration if the circuit is battery powered.  Also note that (the ones I looked at) are specialized, single vendor parts.  More expensive and more availability risk than op-amps or transistors with standardized footprints.  Engineers have a duty to only use oddball parts when their special features are necessary and relevant to the design." CreationDate="2010-11-22T19:29:02.780" UserId="411" />
  <row Id="9414" PostId="7087" Score="1" Text="@markrages, I specifically got this part due to conversation on the question about what Thomas needs. He specifically wants a buffer chip to save the traces to use an op-amp. I agree with your feedback. I will add it as a section in the answer if that is okay with you." CreationDate="2010-11-22T19:31:40.913" UserId="230" />
  <row Id="9415" PostId="7069" Text="@ThomasO, I have added an answer with a buffer chip. I hope it helps. I do not know what the liability is in your case, I am not legal advice, but I always design with the FCC in mind." CreationDate="2010-11-22T19:32:48.933" UserId="230" />
  <row Id="9416" PostId="7087" Score="2" Text="go for it.  The question specifically excludes op-amps, for specious reasons, but they are exactly the solution to the problem here.  In my opinion." CreationDate="2010-11-22T19:43:13.193" UserId="411" />
  <row Id="9417" PostId="7070" Score="1" Text="@dren.dk - One thing that should be pointed out is that in most areas, high-voltage DC transmission lines are all but unheard of. The most common method of long distance overland transmission is 3-Phase AC. While I grew up in the USA, I've been living in Bavaria for the past 4 years. During my time here, I've only seen 3-Phase transmission lines. Granted, there is probably more need for DC systems in other areas of Europe (closer borders, underwater runs, and such) but I've not personally seen it." CreationDate="2010-11-22T19:56:09.707" UserId="965" />
  <row Id="9418" PostId="7087" Text="@markrages, he agreed that he wanted a buffer amplifier in the comments, which he specified he did not want the overhead of mapping the proper pins together." CreationDate="2010-11-22T20:16:20.493" UserId="230" />
  <row Id="9419" PostId="7078" Text="A lot of inexpensive clocks count the cycles from their mains supply to use as their timebase. Turns out that while not super-precise over short time spans, the mains supply is very accurate when measured over days. They have to keep precise frequency to aid in load balancing and synchronizing generators." CreationDate="2010-11-22T20:19:40.623" UserId="965" />
  <row Id="9420" PostId="7070" Text="@Jesse AC2DE, The USA is quickly moving to HVDC transmission, it is becoming very common." CreationDate="2010-11-22T20:19:51.163" UserId="230" />
  <row Id="9421" PostId="7078" Score="3" Text="@Markrages, nice, most people do not understand that our ears bias certain frequencies." CreationDate="2010-11-22T20:20:51.053" UserId="230" />
  <row Id="9423" PostId="7087" Score="2" Text="yes, I saw that.  note &quot;the proper pins&quot; are two adjacent pins on the opamp package, so it's not like there are extra traces running across the board to connect them." CreationDate="2010-11-22T20:21:58.807" UserId="411" />
  <row Id="9424" PostId="7087" Text="@markrages, You are not alone on this, but I thought, why not, I will link a buffer amp. I still think for what is being done a 4 layer board will really help signal quality, EMC problems, and routing." CreationDate="2010-11-22T20:23:09.103" UserId="230" />
  <row Id="9425" PostId="7087" Text="@Markrages - the cost is also in the extra pins, which take up space. I'm looking for a minimal pin count solution" CreationDate="2010-11-22T20:23:14.270" UserId="1225" />
  <row Id="9426" PostId="7087" Text="@kortuk It's a low speed board." CreationDate="2010-11-22T20:23:44.600" UserId="1225" />
  <row Id="9427" PostId="7087" Text="@Thomas O, What is your fastest slew rate?" CreationDate="2010-11-22T20:26:44.327" UserId="230" />
  <row Id="9428" PostId="7069" Score="1" Text="are these signals going to an ADC?  If So a simple unity gain buffer is not the proper solution to preprocessing a signal intended for an ADC.  At least not if your after resolution greater than maybe 7 or 8 bits." CreationDate="2010-11-22T20:29:26.510" UserId="1438" />
  <row Id="9429" PostId="7087" Text="@Thomas its' your design, do what you want.  Intersil have some buffers, EL5227 and friends.  These parts need 4.5V supply." CreationDate="2010-11-22T20:30:21.877" UserId="411" />
  <row Id="9430" PostId="4504" Score="1" Text="@endolith, better yet, a resistor from output to the &quot;zero&quot; level will ensure that the signal goes to zero." CreationDate="2010-11-22T20:33:53.793" UserId="411" />
  <row Id="9431" PostId="7066" Score="1" Text="Skin effect has a massive effect at 50Hz, never mind 1kHz." CreationDate="2010-11-22T20:35:37.990" UserId="2005" />
  <row Id="9432" PostId="7090" Score="1" Text="http://neatcircuits.com/audiosw/index.html has a schematic using a JFET for fading in and out as a mute" CreationDate="2010-11-22T20:42:18.557" UserId="142" />
  <row Id="9433" PostId="7087" Text="@markrages, I have a 5V supply so that should be okay, but that is only in the pro version. " CreationDate="2010-11-22T20:45:48.340" UserId="1225" />
  <row Id="9436" PostId="7090" Text="Nice, those circuits are a lot easier to read than my description." CreationDate="2010-11-22T21:09:41.797" UserId="411" />
  <row Id="9437" PostId="7080" Score="1" Text="Why the down vote?  That answers part of the question." CreationDate="2010-11-22T21:14:51.837" UserId="206" />
  <row Id="9438" PostId="7089" Score="1" Text="I think this question is probably too broad. There are tons of options because everyone uses the software in there own way. You need to learn how all of them apply to you and determine if it is something you care to get an error or warning about." CreationDate="2010-11-22T21:27:40.043" UserId="319" />
  <row Id="9439" PostId="7069" Text="@Thomas O as a future engineer, you probably don't want to take the chance of getting government agencies mad at you. Although 50-100 is small there is still the possibility of getting caught if it does break regulations. Is it really worth potentially large fines and even possibly ruining your career just for a small project. Talk with a lawyer and make sure you have yourself covered before bringing anything to market." CreationDate="2010-11-22T21:39:33.087" UserId="319" />
  <row Id="9440" PostId="7076" Text="@mjh2007, yes, as I said, I'm not considering getting an ASIC, I'm just curious as to how much it costs." CreationDate="2010-11-22T21:47:46.570" UserId="1850" />
  <row Id="9441" PostId="7069" Score="1" Text="@kellenjb, I understand the risk I am taking. I live in Europe (UK), so CE is really the only thing that could come after me. But then how do things like magazines (say Silicon Chip magazine) get away with it...? Surely not all their projects are FCC certified, that's at least $5k each? IIRC, there is an exception for hobbyist things, I need to check it out." CreationDate="2010-11-22T21:48:37.130" UserId="1225" />
  <row Id="9442" PostId="7087" Score="3" Text="@Thomas O We have students who like to think there boards are low speed and don't need to worry about signal quality, EMC problems, and routing. It is amazing how many of those same students run into weird issues that are extremely hard to debug and happen on random occurrences. As @kortuk was asking, your slew rate has a HUGE effect on the bandwidth of your board." CreationDate="2010-11-22T21:49:13.463" UserId="319" />
  <row Id="9443" PostId="7069" Text="@thomas o it doesn't matter where you live, it matters where you sell to. The EU actually has very strict regulations. Is it considered a hobby if you are marketing and selling it?" CreationDate="2010-11-22T21:54:46.063" UserId="319" />
  <row Id="9444" PostId="7089" Text="@Leon Heller - DxDesigner is not Altium. It's made by Mentor Graphics." CreationDate="2010-11-22T22:33:26.467" UserId="1374" />
  <row Id="9445" PostId="7069" Text="@Kellenjb, I don't know. I plan to sell assembled versions, but these are kits - parts of a larger subsystem - a model plane. I have a previous question on this stuff - perhaps you should check that or post there." CreationDate="2010-11-22T22:42:06.257" UserId="1225" />
  <row Id="9446" PostId="7084" Text="Doesn't reset have an internal pull-up?" CreationDate="2010-11-22T22:42:55.707" UserId="1850" />
  <row Id="9447" PostId="6555" Text="MPLAB X has entered public beta: http://ww1.microchip.com/downloads/mplab/X_Beta/index.html" CreationDate="2010-11-22T22:43:23.303" UserId="245" />
  <row Id="9448" PostId="7079" Text="Yes, better to return to a known-good configuration instead of one of dubious quality that may cause problems." CreationDate="2010-11-22T22:43:44.537" UserId="1407" />
  <row Id="9449" PostId="7074" Text="Can you give me more information on the Pic16707 sensor board? I'm having trouble finding it online." CreationDate="2010-11-22T22:53:16.927" UserId="131" />
  <row Id="9450" PostId="7078" Text="The chart seems to indicate 1kHz AC or so would actually be quieter than 50/60 Hz." CreationDate="2010-11-22T22:56:55.453" UserId="1225" />
  <row Id="9451" PostId="7069" Text="@Thomas O the answers on your previous question seem pretty full, which is why I am confused why you aren't testing. Why even ask the question if you weren't going to follow the answer. My comment about the hobby was supposed to be a rhetorical question." CreationDate="2010-11-22T22:58:47.480" UserId="319" />
  <row Id="9452" PostId="7069" Score="1" Text="depends on who you market and sell to actually.  You don't need FCC certification to sell development kits, parts, modules.  That is parts that are not intended for sale to or use by the general public.  You are always bound by FCC rules to not knowingly exceed emissions limits (thats on the user's head), however you don't have to get your product certified until you market it or sell it as a contained device to the general public.  This is why you'll almost never see FCC stamps on dev boards, i've had a few that i know would not have passed (PICDEM.net 2 for instance)" CreationDate="2010-11-22T23:05:06.463" UserId="1438" />
  <row Id="9453" PostId="7069" Text="Thats not universal for all devices however.  If your interfacing with some public systems that malfunctioning of your device could effect, you may need certification, but those devices don't generally fall in the 'incidental radiator' category we're talking about here." CreationDate="2010-11-22T23:06:20.237" UserId="1438" />
  <row Id="9454" PostId="7069" Text="@Mark: thanks for your comments." CreationDate="2010-11-22T23:08:20.587" UserId="1225" />
  <row Id="9455" PostId="7069" Text="@kellenjb: I will follow the advice as well as my own gut feeling. " CreationDate="2010-11-22T23:10:29.010" UserId="1225" />
  <row Id="9456" PostId="7069" Text="@kellenjb: I don't know if you know how much it costs to get FCC/CE testing, but here it's about £5,000-10,000. That's about what I'd earn in 10 years with my current income." CreationDate="2010-11-22T23:11:10.677" UserId="1225" />
  <row Id="9457" PostId="7089" Text="He should be using Mentor support, then." CreationDate="2010-11-22T23:13:03.447" UserId="305" />
  <row Id="9459" PostId="7092" Score="6" Text="@Leon Heller why can't anyone look up most of the questions on this site? This should be the place that people look up the answer to questions." CreationDate="2010-11-22T23:16:28.203" UserId="319" />
  <row Id="9460" PostId="7089" Score="2" Text="@Leon Heller this doesn't sound like a product support question, rather a question about what DRC checks he should set." CreationDate="2010-11-22T23:19:43.830" UserId="319" />
  <row Id="9461" PostId="7069" Score="1" Text="How much it costs depends on the device and category it falls into.  In both cases if its a &quot;low risk&quot; device you can get by with a Certification of Conformance.  Basically you say to FCC/CE &quot;I've tested it, its ok&quot; you just better be able to provide test data if they come asking for it.  If its a higher risk device, they will require testing by a known good lab, which is where the higher costs come in.  " CreationDate="2010-11-22T23:20:34.100" UserId="1438" />
  <row Id="9462" PostId="7069" Score="1" Text="@Mark these are good answers for http://electronics.stackexchange.com/questions/5556/is-fcc-testing-necessary-for-all-devices" CreationDate="2010-11-22T23:22:18.653" UserId="319" />
  <row Id="9463" PostId="7069" Score="1" Text="You are tip-toeing a very narrow line with all this, everything i've heard of this product so far would indicate it does need certification.  The line between &quot;dev tool not for public use&quot; and &quot;fully commercial device&quot; is pretty blurred.  For instance all the Ardunio's i've see are FCC/CE stamped.  They would have a hard time arguing in court that they didn't intend the product for the general public when their main selling point is bringing microcontrollers to everyone.  If your intent is a plug and play device, you'd have just as hard a time arguing its not a full commercial product." CreationDate="2010-11-22T23:23:51.367" UserId="1438" />
  <row Id="9464" PostId="7092" Score="3" Text="@leon heller - sometimes subjects can be hard to approach, especially with regards to theory and nomenclature, it can just be easier to ask someone a question.    " CreationDate="2010-11-22T23:29:17.230" UserId="399" />
  <row Id="9465" PostId="7069" Text="@Mark, it is not aimed at the general public. It requires considerable set up and configuration to work properly. It requires you to solder wires to it, and wire in your own battery. It's a dev tool of the Super OSD firmware, I suppose. If I could afford it, I would do so, but I can't. Either way, this isn't very relevant to the original question." CreationDate="2010-11-22T23:30:14.390" UserId="1225" />
  <row Id="9466" PostId="7069" Score="1" Text="@Thomas O Can you address my question about why you asked http://electronics.stackexchange.com/questions/5556/is-fcc-testing-necessary-for-all-devices if you weren't going to follow the advice? If you found something out that caused you to not follow the answers it is acceptable, even encouraged, to post it as an answer to your own question." CreationDate="2010-11-22T23:36:48.923" UserId="319" />
  <row Id="9467" PostId="7066" Text="It's about 2 millimeters at 1 kHz in copper, which would effectively limit what you could safely carry to ~40 A." CreationDate="2010-11-22T23:40:47.877" UserId="1407" />
  <row Id="9468" PostId="7066" Text="@Nick T, normally you are pushing almost 0 current in high power lines as the current is what causes loss." CreationDate="2010-11-22T23:46:03.370" UserId="230" />
  <row Id="9469" PostId="7093" Score="3" Text="from wikipedia:At 60 Hz in copper, skin depth is about 8.5 mm. this means as you pass this depth the extra thickness does not help." CreationDate="2010-11-22T23:46:50.967" UserId="230" />
  <row Id="9470" PostId="7069" Text="@kellenjb, the advice was mixed (esp. the Q linked by Kortuk), and it put me off, due to the high cost." CreationDate="2010-11-22T23:54:41.093" UserId="1225" />
  <row Id="9471" PostId="7069" Score="1" Text="@Thomas O 1. I am not seeing what is mixed about the answers. Am I missing something? 2. So you are willing to admit that you might be regulations because you don't want to deal with cost? Engineering is still a field that very much respects ethics. You wont get far if you don't." CreationDate="2010-11-22T23:59:52.640" UserId="319" />
  <row Id="9472" PostId="7089" Score="2" Text="@Brian Carlton: Suggestion: list off 5 or 10 rules that you're curious about. There are probably plenty of us who could give decent answers, but we don't know what DxDesigner calls the rules." CreationDate="2010-11-23T00:09:53.470" UserId="712" />
  <row Id="9473" PostId="5896" Text="@Vicky Rao - I think what's confusing you is that you're mixing levels of abstraction. Nothing is required to convert compiler output to logic levels for transistors, because software 1's and 0's, and hardware 1's and 0's, are just different views of the same physical reality. What at one level looks like millions of transistors changing states, at another level looks like a processor running software." CreationDate="2010-11-23T00:10:22.127" UserId="740" />
  <row Id="9474" PostId="7066" Score="2" Text="@Kortuk - a common misconception. The voltage is high to reduce current, but nowhere near 0. Thousands of amps will flow in a 400kV transmission line. High voltage brings problems and loses itself." CreationDate="2010-11-23T00:17:23.463" UserId="2005" />
  <row Id="9475" PostId="7078" Score="1" Text="read the chart more carefully.  The Y-axis is SPL and the lines are equal loudness.  So a 20 dB SPL at 1 kHz sounds as loud as a 57 dB SPL at 60 Hz." CreationDate="2010-11-23T00:42:44.543" UserId="411" />
  <row Id="9476" PostId="7066" Text="@Cybergibbons, I could believe that. No worries mate. I had always been taught that, but never in a detailed fashion." CreationDate="2010-11-23T01:35:34.877" UserId="230" />
  <row Id="9477" PostId="7094" Text="Interesting. We are getting ready to set this up at my university to use as the standard. I was hoping to implement high speed rules, but this set is good advice pingswept." CreationDate="2010-11-23T01:52:56.960" UserId="230" />
  <row Id="9478" PostId="7093" Text="Thanks for that Thomas O" CreationDate="2010-11-23T02:19:09.940" UserId="1457" />
  <row Id="9479" PostId="7095" Score="3" Text="Can you give pictures and measurements, even a ruler can be pretty helpful if it is .1 inch spacing or not." CreationDate="2010-11-23T02:35:58.470" UserId="230" />
  <row Id="9480" PostId="7095" Text="Seconding the call for pictures; if this is a standard ribbon cable you can probably just add an IDC connector." CreationDate="2010-11-23T02:54:29.457" UserId="70" />
  <row Id="9481" PostId="7094" Text="Thank you, sir." CreationDate="2010-11-23T04:08:10.130" UserId="712" />
  <row Id="9482" PostId="7078" Score="2" Text="Switch mode power supplies use frequencies 50kHz - 1MHz+ to reduce the size of transformers and inductors." CreationDate="2010-11-23T04:18:26.343" UserId="638" />
  <row Id="9483" PostId="7022" Text="@brian, you cannot mark community wiki. Do you have a specific answer that you are looking for?" CreationDate="2010-11-23T04:43:38.673" UserId="230" />
  <row Id="9484" PostId="7007" Text="@LoneTech: nope, your explanation that &quot;the master-slave  arrangement is user to cross-over different clock domains&quot; and that regarding asynchronous logic there seemingly isnt an improvement essentially answered my question. add to that your last paragraph which explains that there is indeed place for delayed-pulse circuits over clock-synched ones, and we arrive at the conclusion that, as per my suspicion, the necessity for a master-slave latch is not inherent in all circuits. as per my second question, you confirmed that the T latch is a more complete package." CreationDate="2010-11-23T10:36:44.507" UserId="2017" />
  <row Id="9485" PostId="7070" Text="{citation needed}" CreationDate="2010-11-23T10:42:44.247" UserId="883" />
  <row Id="9486" PostId="7077" Text="It could be worse. http://www.flickr.com/photos/xtl/4072175061/" CreationDate="2010-11-23T10:45:57.940" UserId="883" />
  <row Id="9487" PostId="7100" Text="This is so simple and effective I never would have thought of it." CreationDate="2010-11-23T13:25:17.903" UserId="249" />
  <row Id="9488" PostId="7000" Text="@markrages: I'll have to dig out the circuit again. I think I got it working with one model of transistor, but I need to check. I'll award the accepted answer to you for the most useful answer." CreationDate="2010-11-23T14:02:58.050" UserId="1225" />
  <row Id="9489" PostId="7040" Text="Ah, I get it now. See, I was thinking of it as an op-amp configured as a shunt reference, but it's actually a comparator. Quite neat!" CreationDate="2010-11-23T14:05:24.227" UserId="1225" />
  <row Id="9490" PostId="7069" Text="@kellenjb, I simply can't afford it. There is no way for me to cough up £5k-£10k to get my product FCC/CE tested, so I will have to risk it - like every other hobby OSD I've seen. I do like to keep professional standards. I'm fairly sure it would pass FCC/CE, but as I said, I can't verify it. It will be flying up in the clouds, in the sky, so the only thing it could interfere with would be the plane itself, if it operates on 27 MHz or so." CreationDate="2010-11-23T14:10:24.863" UserId="1225" />
  <row Id="9491" PostId="7057" Text="This doesn't cover for the very real possibility of a pointer being corrupted in one part of memory affecting another entirely unrelated function." CreationDate="2010-11-23T14:17:38.620" UserId="1225" />
  <row Id="9492" PostId="7092" Score="2" Text="@Jim I gave you a vote because that is true, but users should also attempt to educate themselves before asking the question. **As it stands, this question is a dictionary or encyclopedia lookup**, either of which should satisfactorily answer the question, and possibly produce a more refined question. Frankly I didn't find Thomas' answer so accessible or accurate, and in the end he simply linked to [the first Google hit for the term](http://www.google.com/search?q=skin+effect)." CreationDate="2010-11-23T14:23:20.030" UserId="690" />
  <row Id="9493" PostId="7092" Score="4" Text="@Kellenjb (and @jim) (continued) **This is called a &quot;lazy&quot; question** and it is generally agreed that it is wiser to spend our resources (brainpower, knowledge, experience, and time) on providing answers to more difficult and useful questions. Also see [Area51 FAQs](http://area51.stackexchange.com/faq) (search for &quot;expert[ise]&quot; and the design principle of a StackExchange site](http://area51.stackexchange.com/proposals/create) (click in the second text area to see the fade-in text)." CreationDate="2010-11-23T14:30:54.200" UserId="690" />
  <row Id="9494" PostId="7103" Score="2" Text="Are you asking us to find a suitable part for you, or comment on the idea of illuminated buttons? Or both?" CreationDate="2010-11-23T14:30:59.810" UserId="566" />
  <row Id="9495" PostId="7100" Text="Here's a tutorial on how to crimp these connectors: http://hubbard.engr.scu.edu/embedded/guide/ribbon/" CreationDate="2010-11-23T14:31:51.463" UserId="566" />
  <row Id="9496" PostId="7101" Text="I have to disagree with point 3, don't use active cooling. My 20 year old scope's fan is going strong - not even had to clean it out yet." CreationDate="2010-11-23T14:31:56.663" UserId="1225" />
  <row Id="9497" PostId="7103" Text="@Joby Taffey: parts would be helpful, as I haven't found any by browsing Farnell's catalog, but also if anyone has done this before it would be interesting to know which approach was taken." CreationDate="2010-11-23T14:32:52.247" UserId="1225" />
  <row Id="9498" PostId="4854" Text="It looks like a three-position rotary switch to me, not any kind of push-to-make dome switch." CreationDate="2010-11-23T14:58:11.377" UserId="1844" />
  <row Id="9499" PostId="7070" Score="2" Text="@XTL, Here is a list of projects, http://en.wikipedia.org/wiki/List_of_HVDC_projects, I read about this type of thing regularly in the magazines I get like EDN. I am sorry to say it has been almost 5 months since I have had time to read one and me finding which it has been is a lost cause. HVDC is one of the major steps being taken to allow many different renewable sources to connect. They all connect at DC, then the system is relayed and switched back to AC." CreationDate="2010-11-23T15:34:12.857" UserId="230" />
  <row Id="9500" PostId="7057" Text="@Thomas, if that is the problem, this technique should still narrow down where the pointer is affecting the code.  You may have to extend the scope beyond your suspected function.  Because of the log base 2 nature of the search, you can even use this to track down errors in a several thousand line program fairly efficiently." CreationDate="2010-11-23T15:46:39.147" UserId="1322" />
  <row Id="9501" PostId="7101" Score="3" Text="@Thomas O - all you need to do is look at MTBF hrs for fans and see they are prone to failure. It's always best to base your judgements on evidence rather than anecdote." CreationDate="2010-11-23T17:09:07.260" UserId="2005" />
  <row Id="9502" PostId="7106" Text="Those look nice. I'd prefer to have a button with overall illumination instead of concentrated LED light, but they would also work. I tried searching under categories for what I wanted but didn't think to use the search text. " CreationDate="2010-11-23T17:15:37.353" UserId="1225" />
  <row Id="9504" PostId="7097" Score="3" Text="Are you asking specifically about the manufacturing process or component selection as well?" CreationDate="2010-11-23T17:17:07.537" UserId="319" />
  <row Id="9505" PostId="7101" Text="I have a counter-example.  I rescued a Tek 454 from being thrown out.  All it needed was disassembly and relube of the fan." CreationDate="2010-11-23T17:19:49.200" UserId="411" />
  <row Id="9506" PostId="7014" Score="1" Text="I still need at least 20 vias on my most basic boards." CreationDate="2010-11-23T17:23:34.860" UserId="230" />
  <row Id="9507" PostId="7106" Score="3" Text="This seems rather localized." CreationDate="2010-11-23T17:30:38.390" UserId="319" />
  <row Id="9508" PostId="7095" Text="ok, I'll get pictures on when I get home tonight. But it is .1&quot; spacing" CreationDate="2010-11-23T17:44:01.077" UserId="1686" />
  <row Id="9509" PostId="7080" Score="2" Text="people get angry about statements like that, but i have to agree." CreationDate="2010-11-23T17:45:40.110" UserId="230" />
  <row Id="9510" PostId="7100" Text="sorry, maybe ribbon cable is the wrong word. It is a thin sheet of plastic with tiny flat contacts running through it. " CreationDate="2010-11-23T17:46:14.260" UserId="1686" />
  <row Id="9511" PostId="7069" Text="If the board runs at 27Mhz then your trouble frequencies for FCC are more likely around 175Mhz-300Mhz which is a fairly well populated region (in the US at least)." CreationDate="2010-11-23T18:01:39.713" UserId="1438" />
  <row Id="9512" PostId="7022" Text="No I'm not looking for a specific answer, I'd rather it be community wiki." CreationDate="2010-11-23T18:06:47.830" UserId="2024" />
  <row Id="9513" PostId="7106" Text="@kellenjb, Please elaborate, he gave an example of a part that would work, but happened to link it to Farnell, does that make it localised? I am looking for ideas on how to accomplish this." CreationDate="2010-11-23T18:29:11.753" UserId="1225" />
  <row Id="9515" PostId="7106" Text="@Mr. Hedgehog, is that directed to me?" CreationDate="2010-11-23T18:32:32.033" UserId="1225" />
  <row Id="9516" PostId="1096" Text="I started to edit this, posting, but I don't think it's really redeemable.   The accepted answer to this question has the essence of the difference, which is basically 'integrated memory' or 'no integrated memory'.   I'm afraid this lot is largely a list of generalisations, a number of which are just plain wrong." CreationDate="2010-11-23T18:32:36.343" UserId="1844" />
  <row Id="9517" PostId="7104" Text="This sounds like a good idea. Putting bits of acrylic over the buttons. However, I don't know how I'd cut them down; I don't have the equipment here. Also, any idea on how to fit them to the buttons?" CreationDate="2010-11-23T18:54:21.030" UserId="1225" />
  <row Id="9518" PostId="7097" Score="5" Text="is there a question in there somewhere?" CreationDate="2010-11-23T19:24:52.590" UserId="1438" />
  <row Id="9519" PostId="4504" Text="@markrages: Agreed.  Something like this: http://tinyurl.com/26nb4j2" CreationDate="2010-11-23T19:28:20.827" UserId="142" />
  <row Id="9520" PostId="2830" Text="We usually let them handle sourcing their own parts and people other than me haggle with them over profit margins. When I need to make something really low-cost, though, I have trouble figuring out how much each solution is going to cost on their end. FindChips and OEMsTrade both include Arrow, along with many other suppliers, so you can compare between all of them. But if the lowest price I can find on there is $0.25, for instance, they'll come back with something more like $0.06, and a solution that I thought saved money actually doesn't." CreationDate="2010-11-23T19:48:12.127" UserId="142" />
  <row Id="9522" PostId="5508" Text="@smashtastic: I just mean that energy is carried by the electromagnetic fields around the wires, not inside the wires themselves.  &#xA;&#xA;http://amasci.com/elect/poynt/poynt.html" CreationDate="2010-11-23T19:53:49.940" UserId="142" />
  <row Id="9523" PostId="5238" Text="Where are you getting the 10ms from? It says &quot;t w = 10ms Single Pulse&quot;, which seems rather cryptic to me..." CreationDate="2010-11-23T20:03:15.413" UserId="1217" />
  <row Id="9524" PostId="7111" Text="Thanks! Exactly what I was looking for." CreationDate="2010-11-23T20:05:38.380" UserId="1078" />
  <row Id="9525" PostId="7106" Text="@kellenjb I agree, I just wanted to point out that such devices exist and are available - hence community wiki" CreationDate="2010-11-23T20:07:10.777" UserId="566" />
  <row Id="9526" PostId="7104" Text="Laser engraving shops should be able to do the cutting, provided the acrylic is not too much thick." CreationDate="2010-11-23T20:24:47.333" UserId="1078" />
  <row Id="9527" PostId="7104" Text="Attaching acrylic pieces on top of the push buttons can be difficult depending on the material the button is made. Usually it is a kind of plastic to which glues don't stick well, and there aren't many other options in this case. But instead consider cutting holes in the acrylic for the buttons, in order to have an acrylic &quot;frame&quot;. If you engrave the surface and place LEDs at the edges, the engraving will direct their light upwards." CreationDate="2010-11-23T20:29:48.343" UserId="1078" />
  <row Id="9528" PostId="7107" Text="yeah! I feel thats the easiest :)" CreationDate="2010-11-23T20:33:13.433" UserId="1839" />
  <row Id="9529" PostId="7107" Text="and if needed you can use a opto-coupler for reading the signal if you have difference in voltage levels." CreationDate="2010-11-23T20:34:03.540" UserId="1839" />
  <row Id="9530" PostId="7104" Text="No you don't have to cut and stick them, just use this board to mount the switch on... and etch one side of it (you can use a drembel rotary tool if you want some fancy designs n stuffs) or make holes on it(using drill machine or something) and let the switch fit on it so when you fix the LED at the corner those cut edges will glow as a neon. I have done it believe me it looks COOL :)&#xA;to cover up the buttons you can use standard covers for those switches so it will have a very good finish." CreationDate="2010-11-23T20:39:39.107" UserId="1839" />
  <row Id="9531" PostId="3951" Text="There are some pitfalls to generating waveforms digitally, so you need to design the firmware well to produce low-distortion waveforms, but that goes for analog circuits, too.  So relatively, this is cheap, simple, and easy.  :)" CreationDate="2010-11-23T20:56:55.370" UserId="142" />
  <row Id="9532" PostId="4549" Text="Hmmm....  Is there a substance through which acoustic waves travel very slowly (without being absorbed)?  Then you could make a miniature room out of it and use transducers to simulate the reverb of a much larger room.  When I first heard of plate reverbs I thought this is what they're doing, but sound travels more quickly through metal, not more slowly." CreationDate="2010-11-23T21:09:28.283" UserId="142" />
  <row Id="9533" PostId="7107" Text="@Zaxx or if you wanted isolation between the computer and another system." CreationDate="2010-11-23T21:10:30.260" UserId="1225" />
  <row Id="9534" PostId="7106" Score="1" Text="@ThomasO, Who is Mr. Hedgehog?" CreationDate="2010-11-23T21:43:07.033" UserId="230" />
  <row Id="9535" PostId="7092" Score="4" Text="@MarK C, These are not reasons to close a question, if you dislike it, a downvote is a fair course of action. remember a major thing we need to do to bring users in is become a definitive source for the basic and challenging questions, an all in one source for information. If the answer seems poor, answer in a better way. I think this question was answered by someone whom normally asks questions and gave this user a chance to be the 'expert'. As the question becomes easier, the group that answers it should move to those that are not as experienced but know those basics." CreationDate="2010-11-23T21:50:32.940" UserId="230" />
  <row Id="9536" PostId="7069" Text="@Mark, Remember that most people reference clock rates, not signal skew rates, even though your signal skew rates are significantly more important." CreationDate="2010-11-23T21:52:11.503" UserId="230" />
  <row Id="9537" PostId="7069" Text="@Mark, I believe FCC tests from 30MHz to 10 GHz, but I always mess up the upper bound." CreationDate="2010-11-23T21:52:38.490" UserId="230" />
  <row Id="9538" PostId="7106" Text="@Kortuk, apparently he deleted his comment. " CreationDate="2010-11-23T22:04:18.013" UserId="1225" />
  <row Id="9539" PostId="7069" Score="1" Text="@kortuk yea 30Mhz is the lower bound, don't remember the upper either.  However the acceptable levels at the lower end are pretty high, you have to seriously screw up to have a problem there.  Around 175-200Mhz (analog TV channels 7-14 started at 175 in the US) is where the acceptable levels start getting pretty low hence many begin to have problems.  Of course the slew rate issue is included in this statement.  Higher slew rates simply means increased level in the higher order harmonics, which are what cause the problems at frequencies higher than your fundamental (the clock rate)." CreationDate="2010-11-23T22:12:02.950" UserId="1438" />
  <row Id="9540" PostId="7106" Score="2" Text="It's a mystery!" CreationDate="2010-11-23T22:18:31.603" UserId="1333" />
  <row Id="9542" PostId="7014" Text="If you can spend 'n' days prototyping, drawing a schematic and laying out the components - I don't see why you can't spend an hour or two making a board. You guys must have the patience of a rock because when I have finished my design I want nothing more than to hold the finished board in my hands and try it out." CreationDate="2010-11-23T22:28:01.907" UserId="1333" />
  <row Id="9544" PostId="7114" Score="2" Text="What value would you use?" CreationDate="2010-11-23T22:32:00.647" UserId="319" />
  <row Id="9545" PostId="7114" Score="1" Text="This is a conducted emission, but how to isolate it is nasty." CreationDate="2010-11-23T22:32:05.710" UserId="230" />
  <row Id="9546" PostId="7064" Score="3" Text="Excellent answer John. Hope this takes top spot." CreationDate="2010-11-23T22:32:10.220" UserId="1333" />
  <row Id="9547" PostId="7113" Score="4" Text="You bring the most interesting questions Joby. This can be a very common occurrence, but most people are not able to reproduce it so well." CreationDate="2010-11-23T22:32:43.573" UserId="230" />
  <row Id="9548" PostId="7069" Text="@Mark, I think we are on the same page, I thought we were before I put the comment, but I thought for others it may help." CreationDate="2010-11-23T22:35:26.037" UserId="230" />
  <row Id="9549" PostId="7115" Text="Interesting idea. I do have powerline ethernet adapters, but they're connected to a different wall socket" CreationDate="2010-11-23T22:38:09.597" UserId="566" />
  <row Id="9550" PostId="7097" Score="1" Text="Cost, reliability, performance, pick two.  Making a design as &quot;reliable as possible&quot; is often cost prohibitive and not necessary.  You need to design to the requirements of the application." CreationDate="2010-11-23T22:46:36.057" UserId="1407" />
  <row Id="9551" PostId="7101" Text="@AngryEE - So cost is no object in your world?" CreationDate="2010-11-23T22:49:12.030" UserId="1407" />
  <row Id="9552" PostId="7114" Text="Why would that help?" CreationDate="2010-11-23T22:56:20.463" UserId="566" />
  <row Id="9553" PostId="7116" Text="Re: the 5V suggestion - There are two chips on the board, one has an internal 3.3V regulator and supplies power to the second - a CC1110. I am trying to power this chip directly (more detail http://blog.hodgepig.org/2010/11/23/im-me-dongle-uart/)" CreationDate="2010-11-23T23:00:49.790" UserId="566" />
  <row Id="9555" PostId="7119" Text="This is a good point - check the mains voltage. If necessary, probe it through an isolation transformer, like a cheap wall wart. (Don't plug your scope straight into mains because you could get all sorts of horrible transients destroying your scope - a 12V xformer will at least divide by 10 or 20 any transient.)" CreationDate="2010-11-24T00:17:23.763" UserId="1225" />
  <row Id="9556" PostId="7113" Text="How far apart are the board and the lamp ?? and does the voltage fluctuation change if the lamp is further away from it ?" CreationDate="2010-11-24T00:19:36.960" UserId="1839" />
  <row Id="9557" PostId="7119" Text="I've added scope pictures to the question, thanks" CreationDate="2010-11-24T00:22:48.580" UserId="566" />
  <row Id="9558" PostId="7119" Text="@Mark Yes, that wall socket is overloaded, I also have a 1500W electric heater on it. I tried unplugging everything but the lamp, it didn't seem to help" CreationDate="2010-11-24T00:25:41.293" UserId="566" />
  <row Id="9559" PostId="7113" Text="@Zaxx They were 1ft away, I've just tried 3ft and seen no voltage difference on the scope spikes" CreationDate="2010-11-24T00:27:23.367" UserId="566" />
  <row Id="9560" PostId="7118" Score="2" Text="Allowances for board creepage distances will make this larger, too." CreationDate="2010-11-24T01:02:16.547" UserId="1374" />
  <row Id="9561" PostId="7114" Score="7" Text="I think the speculation is that it's a current spike causing the problem. Inductors resist rapid changes in current, like caps resist changes in voltage." CreationDate="2010-11-24T01:06:57.883" UserId="712" />
  <row Id="9562" PostId="7114" Score="2" Text="You've already got some capacitance, so adding an inductor turns into a better low-pass filter." CreationDate="2010-11-24T01:09:20.460" UserId="1481" />
  <row Id="9563" PostId="7119" Text="@joby Those scope images make it look like the the LDO is oscillating, that parts claims no external components needed for stability but you may try some more decoupling on the input and output of the regulator.  Can you make similar measurements at the input to the regulator and post them?" CreationDate="2010-11-24T01:32:28.750" UserId="1438" />
  <row Id="9564" PostId="7117" Text="I don't know a rule off the top of my head, if you decide to look at actual regulations then IEC 60950 is what your after but i don't think you can get that for free." CreationDate="2010-11-24T02:26:28.027" UserId="1438" />
  <row Id="9565" PostId="7092" Text="@Mark C, while not calling your electronics knowledge into question Mark (I'm sure mine is much lower), really Thomas didn't just &quot;link to google&quot; as you assert. Certainly wiki link is the first link on google, however his answer is worded differently and he met my goal of asking the question which was to present the answer in an accessible form to a layperson. This topic (electronics and robots) in particular has alot of interest from sections of the public that do not have university level electronics/mechatronics knowledge. Maybe you should remember that. :)" CreationDate="2010-11-24T02:30:03.923" UserId="1457" />
  <row Id="9566" PostId="7114" Text="@Tim Williscroft What value of inductor are you thinking? " CreationDate="2010-11-24T02:43:31.167" UserId="319" />
  <row Id="9567" PostId="7113" Score="1" Text="@Joby Taffey how hard is it to move it further away from the lamp? Also can you hook one or the other up to a different outlet, preferably one on a different circuit? This might tell you a bit more about what is going on." CreationDate="2010-11-24T02:46:44.797" UserId="319" />
  <row Id="9568" PostId="7097" Text="@Kellenjb - My question is about the Component selection. Sorry if I haven't conveyed that in the question." CreationDate="2010-11-24T03:18:53.463" UserId="1731" />
  <row Id="9569" PostId="7097" Text="@Mark - Sorry if there is a similar question exists in this forum. I haven't searched for this question." CreationDate="2010-11-24T03:20:18.203" UserId="1731" />
  <row Id="9570" PostId="7064" Score="1" Text="syringing solder paste is kind of slow.  Your local hardware store probably has some sheets of 0.003&quot; or 0.005&quot; brass shim stock.  If you etch it like a PCB you can make a stencil with it.  Here's a picture of a stencil I made: http://imgur.com/UulSo (This one has been used on about a hundred boards.)  more here: http://www.delorie.com/pcb/brass/" CreationDate="2010-11-24T03:24:02.460" UserId="411" />
  <row Id="9571" PostId="7091" Text="Capacitance introduces no losses.  Transmission lines could incorporate inductors to keep the power factor up, just like today at 60 Hz they incorporate banks of capacitors." CreationDate="2010-11-24T03:30:37.803" UserId="411" />
  <row Id="9572" PostId="7123" Score="3" Text="you've got some confusing things going on here between Peak, Average and RMS.  RMS is what you need to use for calculating power.  When he says 250VAC i would assume that is RMS and RMS != Average.  250Vrms is ~707V peak to peak." CreationDate="2010-11-24T04:33:14.503" UserId="1438" />
  <row Id="9573" PostId="7113" Text="and just connect a 10K load resistor to the output of the regulator and check whats the results.&#xA;and whats the capacitance you have used for the filter capacitor ??? hope its at least 1000mico at the power supply end." CreationDate="2010-11-24T04:34:52.457" UserId="1839" />
  <row Id="9574" PostId="7092" Text="@Kortuk I said nothing about &quot;closing the question&quot;. As I have [pointed out above](http://area51.stackexchange.com/faq), The designers of StackExchange [disagree](http://area51.stackexchange.com/proposals/create); these sites are not intended to be &quot;all-in-one sources of information&quot;, but sources of expertise, rather. I do not know if you were just guessing, but Thomas is certainly not &quot;just someone who normally asks questions&quot;, let alone basic ones." CreationDate="2010-11-24T05:11:59.440" UserId="690" />
  <row Id="9575" PostId="7092" Text="@Anon No, in honesty, my knowledge of low-level (i.e. micro) electronics is scant, but this is a physics question. Please be accurate; I did not &quot;merely assert&quot; he linked to Google. Please note, as you and Kortuk seem to have overlooked, that **my point (though not emphasized) is that a little bit of research would produce a refined and more useful question, which would contain this question as a basic element.** We are not competing with Wikipedia; there are untold peta(?)bytes of unrefined information on the Internet." CreationDate="2010-11-24T05:35:54.743" UserId="690" />
  <row Id="9576" PostId="7113" Text="@Joby - do you get the same noise if you use the switch on the lamp, or the switch on the wall? The noise looks fairly wideband, I'm wondering if it is arcing in the contacts, being made worse by the inductance in the transformer. " CreationDate="2010-11-24T07:17:51.773" UserId="2005" />
  <row Id="9577" PostId="7123" Text="The 100k resistor wouldn't be connected straight across the mains - I'd probably use a similar 2.2Mohm resistor. Either way, I need to know if it can handle going straight from live to neutral in some kind of fault condition, say a component shorted." CreationDate="2010-11-24T08:40:28.423" UserId="1225" />
  <row Id="9578" PostId="7014" Text="Hurrying can ruin *anything*." CreationDate="2010-11-24T09:31:08.540" UserId="1374" />
  <row Id="9579" PostId="7014" Text="@Mr. Hedgehog - The boards I am talking about are *entirely* SMT. I guess I just do complex stuff." CreationDate="2010-11-24T09:32:40.487" UserId="1374" />
  <row Id="9580" PostId="7118" Text="Wait, Is this for insulation *thickness*? Cause it's **insane** for adjacent traces on a PCB (even with soldermask)." CreationDate="2010-11-24T09:34:03.323" UserId="1374" />
  <row Id="9581" PostId="7124" Score="2" Text="The creepage distance for 700V, (or even 350V) is **longer than the entire length of the resistor** (0805 part). The 400V rating is almost definitely a transient thing, and may require conformal coating to even manage that." CreationDate="2010-11-24T09:37:20.653" UserId="1374" />
  <row Id="9582" PostId="7119" Text="@Mark In the photos, the top trace is the input to the regulator, the bottom is the output" CreationDate="2010-11-24T09:40:42.007" UserId="566" />
  <row Id="9583" PostId="7119" Text="Mark - these little 20W halogens aren't normally that bad, mainly due to the transformer limiting the inrush current significantly. Mains voltage halogens can be very bad." CreationDate="2010-11-24T11:03:11.360" UserId="2005" />
  <row Id="9584" PostId="7124" Score="1" Text="In the EU the specification for the mains supply is 230V (-6%, +10%), 50 Hz (±1%). ie a range of 216.2 - 253V rms" CreationDate="2010-11-24T12:05:00.960" UserId="400" />
  <row Id="9585" PostId="7092" Text="@Mark C, the way you came across you were asking to close it. I would agree with a little research this could be a better question. I am very active on this site and Thomas O normally asks questions, for this he got to answer one. I have had discussions with the guys that are paid to keep SO running and they intend the site to be an all in one source for google results and such. In an ideal world when you google something related to E&amp;R you would get one of our questions and answers." CreationDate="2010-11-24T14:09:34.083" UserId="230" />
  <row Id="9586" PostId="7006" Score="2" Text="I think the #1 problem anyone making their own boards has is that they don't actually start with *CLEAN* copper.  Clean copper is pinkish, not copper-ish.  Wash it down thoroughly and give it 15 seconds in an etchant bath, then wash it off immediately with distilled water.  You'll notice the board is hot pink. This is clean copper." CreationDate="2010-11-24T14:12:07.990" UserId="974" />
  <row Id="9587" PostId="7014" Score="2" Text="Anything that I could make that needs a single layer of copper I can do with veroboard and point-to-point wiring. Anything else I have sent out to either apcircuits.com (single/double layer, extremely fast turnaround) or sunstone.com (multilayer, larger boards, higher volume). It's not worth my time to try and etch my own boards, *especially* double-sided." CreationDate="2010-11-24T14:12:29.533" UserId="974" />
  <row Id="9588" PostId="7125" Score="1" Text="How do you plan on adding solder mask to the boards using the CNC? Are you buying pre-masked copper boards and effectively &quot;sanding off&quot; the soldermask for pads, then going a little deeper to remove soldermask and copper for traces?" CreationDate="2010-11-24T14:25:29.563" UserId="974" />
  <row Id="9589" PostId="7123" Text="@Thomas O your question says you need a part for 250VAC. I think you need to change your question." CreationDate="2010-11-24T15:01:49.867" UserId="319" />
  <row Id="9590" PostId="7123" Text="@kellenjb Well, say the capacitor shorted, this would leave 250VAC across the resistor. I need to know if it can handle this. It doesn't matter too much if it burns out but it's important it doesn't arc." CreationDate="2010-11-24T15:08:52.777" UserId="1225" />
  <row Id="9591" PostId="7125" Text="Unless you spend a lot of money, milling PCBs is very slow." CreationDate="2010-11-24T15:33:20.243" UserId="305" />
  <row Id="9592" PostId="7127" Text="BLDC ESCs are going to output some form of three-phase AC, and unless you have a True-RMS meter it might give garbage readings.  @Thomas: What is &quot;virtual resistance&quot; from switching MOSFETs?" CreationDate="2010-11-24T16:14:55.810" UserId="1407" />
  <row Id="9593" PostId="7100" Text="@captncraig: Do you mean a [flat-flexible cable (FFC)](http://www.parlex.com/products/ffc.php)?" CreationDate="2010-11-24T16:41:51.187" UserId="1407" />
  <row Id="9594" PostId="7095" Score="1" Text="Standard ribbon cable is 0.050&quot; spacing" CreationDate="2010-11-24T16:43:28.220" UserId="1407" />
  <row Id="9595" PostId="7127" Text="@Nick T Ah, it's a BLDC? Most ESC's I've found just switch a motor on or off using a single high or low side MOSFET. Virtual resistance refers to the transition from low to high. Poor quality ESC's have a slower transition from low to high. This acts like a resistance on the motor and produces heat inside the ESC and wastes energy." CreationDate="2010-11-24T16:54:11.737" UserId="1225" />
  <row Id="9596" PostId="7099" Text="Good point about ESD.  An ESD event may not cause a chip to fail immediately, but may degrade its performance or life." CreationDate="2010-11-24T16:56:16.910" UserId="206" />
  <row Id="9597" PostId="7129" Score="1" Text="Why don't you use a timer?" CreationDate="2010-11-24T17:22:02.277" UserId="305" />
  <row Id="9598" PostId="2050" Text="@DoxaLogos, For making a schematic or PCB, it is actually very easy to get accustomed to. Is there any way to get more parts added, or do I need to add them myself?" CreationDate="2010-11-24T17:23:33.753" UserId="230" />
  <row Id="9599" PostId="7127" Text="The question specifies BLDC, and unless the controller is very poorly designed or attempting to do some special waveform control, the switching time should be orders of magnitude lower than the on time." CreationDate="2010-11-24T17:35:12.887" UserId="1407" />
  <row Id="9600" PostId="7130" Text="On that note, when you get complete clock speed indifference in a module someone wrote it is because they spent a large amount of time designing for you to have the feature." CreationDate="2010-11-24T17:38:59.687" UserId="230" />
  <row Id="9601" PostId="7129" Text="@Leon - I've had cases where no more timers were available.  I've also had cases where the interrupt latency was greater than the desired delay time." CreationDate="2010-11-24T17:59:41.057" UserId="529" />
  <row Id="9602" PostId="7130" Text="This will be very dependent on compiler, if you change versions for example the delay may change as well." CreationDate="2010-11-24T18:11:19.157" UserId="1225" />
  <row Id="9603" PostId="7119" Text="@cybergibbons Well, its obviously going something nasty to the mains line, as if that 5V trace is the output from the wall wart then those transients are coming from the mains line." CreationDate="2010-11-24T19:13:21.847" UserId="1438" />
  <row Id="9604" PostId="7119" Text="@joby Are you sure thats a halogen bulb and not compact florescent?  I would think that type of noise would be more indicative of a cheaply designed inductive ballast for fluorescents.  " CreationDate="2010-11-24T19:19:11.750" UserId="1438" />
  <row Id="9605" PostId="7114" Score="2" Text="I can't tell the capabilities of that scope but if it can FFT the 5V line you should be able to tell at what frequencies your noise exists.  Choose your LC filter corner frequency based on that." CreationDate="2010-11-24T19:27:22.620" UserId="1438" />
  <row Id="9606" PostId="7119" Text="@Mark It's a small bulb, it runs very hot" CreationDate="2010-11-24T19:28:09.610" UserId="566" />
  <row Id="9607" PostId="7114" Score="1" Text="Additionally I would add a reverse current protection diode around the LDO.  Based on the appearance of the traces at this scale it looks like there are some instances where the input to the regulator is spiking lower than the regulator output.  Without a path for this current to flow it will travel back into the LDO and depending on the LDO design it could screw with its operation quite a bit.  This actually could be causing some of the ringing." CreationDate="2010-11-24T19:31:29.373" UserId="1438" />
  <row Id="9608" PostId="7130" Text="@Kortuk, this would likely work better if you coded the loop in assembly too. As the optimiser might not always pick the same branch instructions" CreationDate="2010-11-24T20:37:52.017" UserId="566" />
  <row Id="9609" PostId="7130" Text="@Thomas O, Yes, when you update versions of a compiler many other things can go out the window also, normally this type of thing is kept consistent, but the first step after upgrading compilers(which I would need a reason to do for a project) it testing that the system still works." CreationDate="2010-11-24T20:45:08.910" UserId="230" />
  <row Id="9610" PostId="7130" Text="@JobyTaffey, That is an option, most of the nicer compilers, like iar.com for example, allow you to change optimization settings per file. I would disable them for this function. If you macro it in you will have to make sure your compiler does not optimize it out. IAR when set to max optimization will detect this loop and remove it. The best way to do timing is a timer function, be the asker wanted to avoid it for some reason." CreationDate="2010-11-24T20:46:44.963" UserId="230" />
  <row Id="9611" PostId="7116" Text="@JobyTaffey, When I have worked with the CC1100 if you do not have excellent decoupling they throw a fit, but that probably has something to do with your question." CreationDate="2010-11-24T20:49:01.170" UserId="230" />
  <row Id="9612" PostId="7129" Text="Using a timer doesn't necessarily mean using an interrupt - you can usually just read the timer directly for short timings, and that's much better than a software-timed loop.  But obviously if you've run out of timers, then that's not an option." CreationDate="2010-11-24T21:01:15.687" UserId="1844" />
  <row Id="9613" PostId="7135" Text="Near perfect, if only they were slightly smaller!" CreationDate="2010-11-24T22:10:37.970" UserId="1225" />
  <row Id="9614" PostId="7134" Text="Yeah, that's some cool stuff. I really like the capacitance one. How much range can you get with that?" CreationDate="2010-11-24T23:03:06.757" UserId="2006" />
  <row Id="9615" PostId="7134" Text="An inch or so..." CreationDate="2010-11-24T23:19:24.717" UserId="566" />
  <row Id="9616" PostId="6313" Score="2" Text="Have you read the data sheet for the chip? It all in there." CreationDate="2010-11-24T23:31:42.930" UserId="305" />
  <row Id="9617" PostId="7139" Score="1" Text="Can you post a picture of it?" CreationDate="2010-11-24T23:32:28.800" UserId="566" />
  <row Id="9618" PostId="7139" Text="What sort of hexahedron is it? a cuboid? http://mathworld.wolfram.com/Hexahedron.html" CreationDate="2010-11-24T23:34:38.593" UserId="566" />
  <row Id="9619" PostId="7139" Text="@Joby Taffey♦ Well, I don't have a camera which can catch the inscription on the part. I'll try to post an image anyway. It's a cuboid hexahedron." CreationDate="2010-11-24T23:35:11.263" UserId="1240" />
  <row Id="9620" PostId="7101" Text="@Nick - Depends how reliable/durable you want it.  If you want high reliability you should be prepared to spend for it." CreationDate="2010-11-24T23:40:14.760" UserId="249" />
  <row Id="9621" PostId="7134" Text="@Matt You will get more and better answers by not accepting a question for 24-48hrs" CreationDate="2010-11-24T23:41:07.420" UserId="566" />
  <row Id="9623" PostId="7139" Score="1" Text="@Joby Taffey♦ @Turbo J I've managed to add an image of the part." CreationDate="2010-11-25T00:10:38.623" UserId="1240" />
  <row Id="9624" PostId="7137" Text="That is how they rule and what I use them for." CreationDate="2010-11-25T02:09:28.427" UserId="230" />
  <row Id="9625" PostId="7140" Text="I've been looking for some capacitors in that range, and polyester film capacitor from [Wikipedia ](http://en.wikipedia.org/wiki/File:Condensators.JPG) looks just like the thing I've got. Another [link](http://www.piclist.com/images/www/hobby_elec/e_capa.htm) under Metallized Polyester Film Capacitors." CreationDate="2010-11-25T02:27:47.013" UserId="1240" />
  <row Id="9626" PostId="7134" Score="1" Text="@jobyTaffey, you may have just written that great of an answer." CreationDate="2010-11-25T04:59:35.230" UserId="230" />
  <row Id="9627" PostId="7141" Text="Hobby/prototype/production?" CreationDate="2010-11-25T05:37:00.570" UserId="1407" />
  <row Id="9628" PostId="7129" Score="1" Text="Previously I used IAR Embedded Workbench for AVR. It has very nice intrinsic __delay_cycles() kind of macro function which compiler substituted with blocking delay of exact processor cycles time. Using #define FCPU 5000000UL for example I could implement clock independent fixed delays like this __delay_cycles(FCPU*1e-3) compiler substituted for correct 1ms delay. If I needed that part of code to work for another clock speed, I just changed FCPU and recompiled. AVR-GCC has delay.h with functions _delay_us() and _delay_ms() with simular functionality but with several limitations." CreationDate="2010-11-25T06:08:06.493" UserId="1736" />
  <row Id="9629" PostId="7129" Text="So I'm looking for a similar way to make small blocking delays in KEIL like IAR or AVR-GCC have." CreationDate="2010-11-25T06:09:16.180" UserId="1736" />
  <row Id="9630" PostId="7131" Text="Thanks, but it is obvious and inconvenient if you are writing an interface module to be compiled for unknown and various clock speed in the future." CreationDate="2010-11-25T06:11:00.953" UserId="1736" />
  <row Id="9631" PostId="7143" Text="Are you looking for general C programming tutorials? Or architecture specifics?" CreationDate="2010-11-25T12:23:05.133" UserId="566" />
  <row Id="9632" PostId="7142" Text="Thanks, but that's basically the same principle shown at the link I mentioned in my question. The main problem was not how to do, but how to make the circuit compact when you have too many signal lines." CreationDate="2010-11-25T12:56:27.833" UserId="1078" />
  <row Id="9633" PostId="3404" Score="1" Text="complementary to this answer: buy an Arduino (the USB Boarduino clone will work with your software via a virtual serial port) a breadboard, 10 1kOhm 1/4W Resistors, 5 LEDs and 5 tactile switches. Probably your tutor will make you buy some extra discrete components." CreationDate="2010-11-25T13:31:43.047" UserId="1673" />
  <row Id="9634" PostId="7141" Text="ultimately, production." CreationDate="2010-11-25T14:13:32.420" UserId="1938" />
  <row Id="9635" PostId="7143" Text="Its not just C programming, the students had alredy a background on C. I'd like some thing more specific to the architecture." CreationDate="2010-11-25T15:26:35.060" UserId="1757" />
  <row Id="9636" PostId="7134" Text="@Joby, I'll vote you up if you give good ones :)" CreationDate="2010-11-25T16:35:05.307" UserId="2006" />
  <row Id="9637" PostId="7134" Text="Oh you did. I would have felt guilty if there were a bunch of answers and could only accept one. I'm too humane." CreationDate="2010-11-25T16:36:22.670" UserId="2006" />
  <row Id="9638" PostId="7144" Text="I read the datasheet back to front to learn the PIC, I think building embedded linux systems sounds interesting." CreationDate="2010-11-25T16:55:32.643" UserId="230" />
  <row Id="9639" PostId="2050" Text="Peter, you say &quot;despite its UI&quot;. Can you elaborate on that?" CreationDate="2010-11-25T17:07:01.870" UserId="2064" />
  <row Id="9640" PostId="7125" Text="@LeanHeller, @ThaKidd, We use cnc mills at my school as the simple process(also chemical etching). They are slow and the bits are expensive to replace." CreationDate="2010-11-25T17:24:52.807" UserId="230" />
  <row Id="9641" PostId="7014" Text="@AndrewKohlsmith, I had not seen apcircuits before, they are perfect if you just want 2 simple ones. Sunstone is pretty affordable for lightly larger number.@FakeName, will you add them to your list of good suppliers? @FakeName, on the note of board complexity, I use SMD almost exclusively and have many vias just to number of components. " CreationDate="2010-11-25T17:30:15.390" UserId="230" />
  <row Id="9642" PostId="7092" Text="@All, point taken Mark I will try to improve my questions, but at the same time I won't shy away from asking questions especially when I believe that I can get more value from an answer here than on reading a wiki post." CreationDate="2010-11-25T21:46:19.147" UserId="1457" />
  <row Id="9643" PostId="7144" Text="&quot;by a good friend&quot; Can you get my copy autographed? =)" CreationDate="2010-11-25T21:58:58.163" UserId="1757" />
  <row Id="9644" PostId="739" Text="I agree with geschema; you may not need an FPGA. Maybe a DSP is a better solution. In any case they're easier to get started with if you only have experience in uCs. FPGAs are very different!" CreationDate="2010-11-26T09:48:01.733" UserId="2064" />
  <row Id="9645" PostId="7154" Text="That's what I had guessed, but I wasn't sure." CreationDate="2010-11-26T10:27:39.517" UserId="965" />
  <row Id="9646" PostId="7157" Text="Can you cite your sources?" CreationDate="2010-11-26T13:27:29.923" UserId="566" />
  <row Id="9647" PostId="7157" Score="3" Text="Yes Joby. http://cellphonerepairtutorials.blogspot.com/2010/05/familarization-components-and-parts-on_9689.html" CreationDate="2010-11-26T13:35:57.033" UserId="938" />
  <row Id="9648" PostId="7157" Text="Muito obrigado! :-)" CreationDate="2010-11-26T14:33:23.003" UserId="2064" />
  <row Id="9649" PostId="7157" Text="De nada. Do you speak Portuguese @stevenvh?" CreationDate="2010-11-26T15:05:49.090" UserId="938" />
  <row Id="9650" PostId="7149" Text="Having the same operational system on all boards is a really nice study case!" CreationDate="2010-11-26T15:07:39.383" UserId="1757" />
  <row Id="9651" PostId="7159" Score="2" Text="This question seems to be duplicated: http://electronics.stackexchange.com/questions/724/what-are-the-best-beginner-project-using-an-arduino" CreationDate="2010-11-26T15:11:11.283" UserId="938" />
  <row Id="9652" PostId="7157" Text="@o engenheiro: only what I look up :-). But I figured from your nick that you would be portuguese/brasilian, which was confirmed when I looked at your profile." CreationDate="2010-11-26T15:18:15.397" UserId="2064" />
  <row Id="9653" PostId="7164" Text="At [GBP 65](http://www.amazon.co.uk/Rapid-Prototyping-Digital-Systems-Tutorial/dp/0792374398/ref=sr_1_1?ie=UTF8&amp;qid=1290796605&amp;sr=8-1) for &lt;300 pages not exactly cheap :-(, but thanks for the suggestion." CreationDate="2010-11-26T18:47:04.240" UserId="2064" />
  <row Id="9655" PostId="7162" Score="2" Text="I can second this. The C30 compiler is probably the best one you'll find for the price (free).  As for Hi-tech C, I suspect it is deprecated as Microchip seem to own the compiler now and the C30 is what they focus on." CreationDate="2010-11-26T19:07:02.710" UserId="1333" />
  <row Id="9656" PostId="7164" Text="There is also an Altera edition.  Useful but out of date with the current software, at least in the NIOS section." CreationDate="2010-11-26T20:19:30.853" UserId="206" />
  <row Id="9657" PostId="7170" Score="1" Text="The new MPLAB X supports Linux and OSX with GCC" CreationDate="2010-11-26T20:39:01.187" UserId="566" />
  <row Id="9658" PostId="7162" Text="I haven't used the C30 compiler but the libraries that came with the C18 compiler were really bad, very inefficient and buggy, even simple stuff like the SPI library.  So i would recommend looking through the code before you use their libraries." CreationDate="2010-11-26T21:09:22.807" UserId="1438" />
  <row Id="9659" PostId="7170" Text="@Joby Taffey really? I didn't know there was an MPLAB X. Off to download it! (n.b. I run Ubuntu and currently run MPLAB in VirtualBox under XP.) I never thought I'd see the day: Microchip and Linux. :)" CreationDate="2010-11-26T22:25:42.803" UserId="1225" />
  <row Id="9660" PostId="7169" Text="The MSP430G2231 has only 128 bytes RAM.  All the SD+FAT libraries I've seen need at least 512 bytes.  So you'll want a better processor." CreationDate="2010-11-26T22:40:11.323" UserId="411" />
  <row Id="9661" PostId="7169" Text="@markrages That'll be because SD cards have a flash page size of 512 bytes. But, I'm sure it would be possible with some thought" CreationDate="2010-11-26T23:02:00.997" UserId="566" />
  <row Id="9662" PostId="7169" Score="2" Text="@JobyTaffey, @Markrages, I think it can be done with 128, it is just a much larger development time on the poor engineers. If only a couple devices will be sold, you are better off getting better hardware, but if it is going to be 1 million devices, the engineering is cheaper. I think you both know that, but no harm in writing down for others." CreationDate="2010-11-26T23:26:12.013" UserId="230" />
  <row Id="9663" PostId="7162" Text="@Mark, always good advice with anyone's libraries. " CreationDate="2010-11-26T23:27:05.803" UserId="230" />
  <row Id="9664" PostId="7161" Text="sorry - didn't spot the PIC24 in the quesiton - comments refer to PIC16!" CreationDate="2010-11-26T23:50:07.070" UserId="1681" />
  <row Id="9665" PostId="7180" Score="1" Text="If you're using it as an input it will definitely cause erratic inputs, but does it really affect other parts of the chip and cause startup issues?" CreationDate="2010-11-27T03:12:35.273" UserId="142" />
  <row Id="9666" PostId="7183" Text="Thanks Lonetech! Makes a lot of sense." CreationDate="2010-11-27T03:22:41.210" UserId="1785" />
  <row Id="9667" PostId="7180" Score="1" Text="If I'm ignoring the pin and not using it for any peripherals would it still cause problems?" CreationDate="2010-11-27T10:04:58.397" UserId="1225" />
  <row Id="9668" PostId="7181" Score="1" Text="If I set it to an output, 0 or 1, it will ground out the video signal and cause a loss of video." CreationDate="2010-11-27T10:05:50.190" UserId="1225" />
  <row Id="9670" PostId="3647" Text="Great detail, Andrew, but you don't introduce the term &quot;thyristor&quot; like you do triac and SCR, which is a confusing.  Is a thyristor a type of triac?  What's the difference between the three?" CreationDate="2010-11-27T12:27:56.370" UserId="51" />
  <row Id="9672" PostId="7184" Text="Please read this blog article: [Q&amp;A is Hard, Let's Go Shopping](http://blog.stackoverflow.com/2010/11/qa-is-hard-lets-go-shopping/) before posting to this shopping recommendation question." CreationDate="2010-11-27T14:56:46.970" UserId="857" />
  <row Id="9673" PostId="7163" Text="The Hamblen et al book I mentioned is very up to date, and uses the latest Altera software with a current VHDL compiler." CreationDate="2010-11-27T15:57:11.747" UserId="305" />
  <row Id="9674" PostId="3437" Score="2" Text="You may as well add reliability to that. Every software has one remaining bug after the last one was removed." CreationDate="2010-11-27T16:00:00.160" UserId="2064" />
  <row Id="9676" PostId="7196" Text="I added a link to the first spec in PDF form - Not sure if the URL was the one you wanted.  Good answer, though!" CreationDate="2010-11-27T16:13:57.217" UserId="857" />
  <row Id="9677" PostId="7199" Text="The IR LEDs use automatic gain when I have used them. This means you need to not continuously send a signal because if it constantly receives one with will remove it in the gain stage. A continuous modulation is calibrated out over time. if you just need a signal to go low when you approach an object then the pulse should go low when you approach the object, but you may find that if you approach it too slowly it will be calibrated out." CreationDate="2010-11-27T16:31:22.213" UserId="230" />
  <row Id="9679" PostId="7199" Text="Sorry for the mistake; it should have been 38kHz. Why do you need to set the timer at twice the frequency required? What's the logic behind that?" CreationDate="2010-11-27T17:12:47.750" UserId="2074" />
  <row Id="9680" PostId="7163" Score="2" Text="1996 won't be a big problem; VHDL was revised in 1993, and that will probably be covered. There's a newer edition in the works called VHDL-200X, but learning the updates will certainly not be as big an effort as learning the technology and design style. " CreationDate="2010-11-27T17:15:26.453" UserId="1181" />
  <row Id="9681" PostId="7202" Text="Thanks! I guess I'll have to use *less* advanced methods (bluetooth?) for now." CreationDate="2010-11-27T17:15:50.400" UserId="2074" />
  <row Id="9682" PostId="7199" Text="I just tried doing this but it didn't work. I just tried modifying the Blink sample which came with the Arduino IDE to blink every 13.16us but the TSOP sensor didn't sense it." CreationDate="2010-11-27T17:34:23.403" UserId="2074" />
  <row Id="9684" PostId="7199" Text="@gomek: You need twice the frequency because you have two level changes in 1 period: signal goes low, wait 13us, signal goes high, wait 13us, signal goes low again. So your total period is 2 x 13us = 26us, which gives you 38kHz = 1 / 26us." CreationDate="2010-11-27T17:43:00.303" UserId="2064" />
  <row Id="9685" PostId="7202" Text="@gomek, I added more information." CreationDate="2010-11-27T17:44:29.077" UserId="230" />
  <row Id="9686" PostId="7206" Text="Interesting approach, It seems like it would not feasible for a real project, but for tinkering, very good idea." CreationDate="2010-11-27T18:06:39.893" UserId="230" />
  <row Id="9687" PostId="7209" Text="I just discussed a method but I agree with Stevenvh, if there is a device to do it you are much better off. +1" CreationDate="2010-11-27T19:08:20.033" UserId="230" />
  <row Id="9688" PostId="7208" Score="1" Text="TSOP is a series of IR receivers by [Vishay](http://www.vishay.com/ir-receiver-modules/), here it doesn't mean &quot;thin small outline package&quot; or something like that. Right, gomek?" CreationDate="2010-11-27T19:14:50.677" UserId="2064" />
  <row Id="9689" PostId="7211" Text="This is not really the right SE, nor does this type of question fit the SE system well. This is a very localized question(in time and probably also in location) causing the stackechange system to not match it well." CreationDate="2010-11-27T19:41:03.217" UserId="230" />
  <row Id="9690" PostId="7186" Score="1" Text="btw, what kind of small jobs are we talking about here? just curious." CreationDate="2010-11-27T19:58:26.850" UserId="1200" />
  <row Id="9691" PostId="1306" Score="1" Text="btw RS485 is not a protocol!  it defines the physical layer only.  Having said that, you can definitely use SPI over RS485!!! It would be a neat solution to keep the communications in SPI mode if needed ( I am assuming it is, might be connected to a remote ADC or similar). Using SPI over RS485 you will need to check the transceiver slew rates are compatible with the proposed SPI datarates " CreationDate="2010-11-27T20:13:24.060" UserId="1397" />
  <row Id="9692" PostId="7211" Score="1" Text="@Kortuk: While I'll stay mute on the rest, I don't think that this is localized in either time or space. Virtually any material that can be had, can be ordered by phone or internet and the kinds of places that it can be ordered from tend to stay in business for a while. Will edit to clarify." CreationDate="2010-11-27T20:22:20.290" UserId="1182" />
  <row Id="9693" PostId="7184" Text="Thank for all the answers guys! :) My price limit for an ARM dev kit is ~$100." CreationDate="2010-11-27T20:32:29.080" UserId="2077" />
  <row Id="9694" PostId="7211" Text="@BCS, I could agree to that, I would not close on that note either. I just do not think this is the correct SE for this. That is my primary concern." CreationDate="2010-11-27T20:51:57.547" UserId="230" />
  <row Id="9695" PostId="7211" Text="@Kortuk: If you can think of a better SE, then go ahead and move it." CreationDate="2010-11-27T20:58:21.087" UserId="1182" />
  <row Id="9697" PostId="7211" Text="@BCS, it seems that http://diy.stackexchange.com/ is the best we can find, no site seems to be a perfect fit, but this is definitely not an E&amp;R question." CreationDate="2010-11-27T21:01:38.483" UserId="230" />
  <row Id="9698" PostId="7185" Text="python, although I am sure someone does it, is not a standard way to enter hardware. If you want wanting to start with embedded, arduino's are one of the best methods." CreationDate="2010-11-27T21:03:12.043" UserId="230" />
  <row Id="9699" PostId="7211" Text="McMaster-Carr #7237K16 ($\$$10.38 for twelve 12&quot; pieces)&#xA;McMaster-Carr 7237K26  ($\$$6.03 for 6' piece)" CreationDate="2010-11-27T21:03:42.680" UserId="411" />
  <row Id="9700" PostId="7129" Score="1" Text="@x4mer, what I have written is what they are doing in the background. They may be doing it in assembly, but it is almost the same in C. There is a decent bit of work to add something like this and get it working perfectly, this is no simple command that C has." CreationDate="2010-11-27T21:05:22.447" UserId="230" />
  <row Id="9701" PostId="7211" Text="@markrages, Sorry, did not mean to stop you from answering mid research." CreationDate="2010-11-27T21:06:37.127" UserId="230" />
  <row Id="9702" PostId="7213" Text="+1, but they don't seem to have small enough stock." CreationDate="2010-11-27T21:06:53.167" UserId="1182" />
  <row Id="9703" PostId="7211" Text="@kortuk That's OK, it's a wrong answer anyhow." CreationDate="2010-11-27T21:10:09.747" UserId="411" />
  <row Id="9705" PostId="7196" Text="Yes, that's exactly the one I'd listed. Thank you! :)" CreationDate="2010-11-27T21:53:29.180" UserId="2081" />
  <row Id="9706" PostId="7206" Text="yeah, probably, would at the least be rather large for a uav" CreationDate="2010-11-27T22:23:06.730" UserId="2006" />
  <row Id="9707" PostId="7217" Score="1" Text="This would be the correct way to go about this." CreationDate="2010-11-27T22:28:28.087" UserId="230" />
  <row Id="9708" PostId="7206" Text="The size would probably be prohibitive on a plane." CreationDate="2010-11-27T22:29:24.560" UserId="230" />
  <row Id="9709" PostId="7169" Text="This sounds like a good solution. I think as long as I don't use fat and use `dd` to get the data off we can keep the program size down. I was hoping to write to a file, but it's not critical." CreationDate="2010-11-27T22:33:51.430" UserId="2006" />
  <row Id="9710" PostId="7134" Text="BTW. I found out why they are always out of stock... you bought em all, hahaha" CreationDate="2010-11-27T22:35:12.630" UserId="2006" />
  <row Id="9711" PostId="7217" Text="Please provide a citation for the &quot;production programmer&quot; comment.  Clearly, the Pickit isn't physically robust enough for an industrial application.  But the signals it presents to the target are the same as any other programmer. (The original meaning of &quot;production programmer&quot; is that certain programmers were able to vary the supply voltage and read back the program contents to verify correct programming.  Microchip hasn't mentioned this in their datasheets for about a decade, but the folklore lives on.  Ironically, the PICkit 2 *can* vary the supply voltage...) " CreationDate="2010-11-27T23:32:09.367" UserId="411" />
  <row Id="9712" PostId="7214" Text="15 boards per hour is four minutes per board.  How long does the PICkit 2 take to program your part?" CreationDate="2010-11-27T23:36:11.283" UserId="411" />
  <row Id="9713" PostId="7219" Text="You don't even need pogo pins:  I put a header pin in the PICkit 2 and I can program by inserting it into the holes in the board and pressing sideways a little bit, then maintaining this pressure until programming is complete." CreationDate="2010-11-27T23:37:58.523" UserId="411" />
  <row Id="9714" PostId="7217" Text="This cropped up on the Microchip forum recently. The ICD 3 documentation states that it is a production programmer, unlike the PICkit 2/3 which someone from Microchip stated were not production programmers." CreationDate="2010-11-27T23:45:34.743" UserId="305" />
  <row Id="9715" PostId="7214" Text="@markrages: It's about 20 seconds with a small code base (~6KB). I imagine with more code, it could take up to a minute and a half for each board, which doesn't give me much breathing room." CreationDate="2010-11-28T00:17:01.707" UserId="1225" />
  <row Id="9716" PostId="7222" Text="I use Python lots, but never for general scripting - usually I leave that up to bash/shell or Perl. Thanks for the tips." CreationDate="2010-11-28T00:19:28.567" UserId="1225" />
  <row Id="9717" PostId="7214" Score="2" Text="@Markrages, I can vouch, I wrote a very large project with the ICD2 LE and it would take 2 or 3 minutes to program. Quite annoying. With the pickit 3 however, it is screaming fast." CreationDate="2010-11-28T00:20:21.857" UserId="230" />
  <row Id="9722" PostId="7162" Score="1" Text="@Mr. Hedgehog, Hi-Tech C is only for the 8-bit range, whereas C30 is for the 16-bit range." CreationDate="2010-11-28T02:39:10.833" UserId="1225" />
  <row Id="9723" PostId="7227" Score="2" Text="Why do you want to do that?" CreationDate="2010-11-28T02:42:10.087" UserId="305" />
  <row Id="9724" PostId="7186" Text="http://electronics.stackexchange.com/questions/6263/what-kind-of-skills-as-electronics-engineer-are-marketable-for-small-freelance-wo/6270#6270" CreationDate="2010-11-28T05:08:09.317" UserId="142" />
  <row Id="9725" PostId="6270" Text="http://electronics.stackexchange.com/questions/7186/any-reliable-site-where-hardware-engineers-can-be-hired-for-small-work-from-ho" CreationDate="2010-11-28T05:08:52.857" UserId="142" />
  <row Id="9726" PostId="7208" Text="That's right stevenvh." CreationDate="2010-11-28T05:26:58.007" UserId="2074" />
  <row Id="9727" PostId="7219" Text="@Markrages, that is how I do it at work." CreationDate="2010-11-28T06:00:53.463" UserId="230" />
  <row Id="9728" PostId="6280" Text="But the word modulation,itself means the process of conversion of digital signals to analog signals.Applying this logic,it should be frequency modulation and the opposite should be frequency demodulation" CreationDate="2010-11-28T06:10:59.073" UserId="1799" />
  <row Id="9729" PostId="6900" Text="Kortuk - A $40 LIDAR would be awesome, a small field of view is not a problem.  Could you let me know if you find out what product your school team used?  Anything would be better than IR." CreationDate="2010-11-28T06:28:07.763" UserId="1841" />
  <row Id="9730" PostId="7188" Text="i'd add www.freelancer.com to the list also." CreationDate="2010-11-28T06:38:32.493" UserId="1438" />
  <row Id="9731" PostId="7227" Score="1" Text="This is one of the old style keyboards with a great feel to it. It was also my keyboard throughout college. I'd like to be able to use it again." CreationDate="2010-11-28T07:21:15.297" UserId="2089" />
  <row Id="9733" PostId="7199" Text="Thanks, it worked!! How do I optimize the frequency so as to measure long and short distances?" CreationDate="2010-11-28T07:51:59.353" UserId="2074" />
  <row Id="9734" PostId="7231" Score="2" Text="What's the problem with registering for Freescale's IDE?" CreationDate="2010-11-28T07:53:31.053" UserId="2064" />
  <row Id="9735" PostId="7117" Score="1" Text="It pisses me off that IEC, ISO and the like want money for their standards documentation. They already get membership fees, don't they? And if I had the rights to some standard, I would love to see it spread as much as possible. A job for wikileaks, maybe? :-)" CreationDate="2010-11-28T08:08:26.063" UserId="2064" />
  <row Id="9736" PostId="7233" Text="Do you want to receive/decode remote control commands or is this on/off as in obstacle detection?" CreationDate="2010-11-28T08:26:59.200" UserId="2064" />
  <row Id="9737" PostId="7162" Text="@Thomas, Ah, yes, you are right." CreationDate="2010-11-28T09:20:57.327" UserId="1333" />
  <row Id="9738" PostId="7179" Text="Have you checked the datasheet and MCU family documentation? They should have some pretty definite answers and you can see how the pins are implemented internally." CreationDate="2010-11-28T10:50:07.360" UserId="883" />
  <row Id="9739" PostId="7179" Text="@XTL, I scanned through them, but didn't find any references to it. They do say that floating pins can enter undefined states but don't mention whether it could cause problems." CreationDate="2010-11-28T10:52:26.420" UserId="1225" />
  <row Id="9740" PostId="7187" Text="So what exactly is the problem?" CreationDate="2010-11-28T11:13:11.937" UserId="883" />
  <row Id="9741" PostId="7236" Text="It's a DC motor. Change in direction is required and so is change in speed. Is that possible with the circuit you provided above?" CreationDate="2010-11-28T11:23:07.460" UserId="2074" />
  <row Id="9742" PostId="7236" Text="To change the direction can I use just any PNP transistor or do I have to use specific ones? Also can I use this motor driver with an Arduino?" CreationDate="2010-11-28T11:36:02.140" UserId="2074" />
  <row Id="9743" PostId="7199" Text="You can't really measure distances this way, see [my answer](http://electronics.stackexchange.com/questions/7208/tsops-to-measure-distance/7209#7209) to your other question about this. The only thing you can do is use a slightly different frequency, like 36kHz, which will reduce sensitivity. But it's not like you can detect objects at 1m @ 38kHz and at 70cm @ 36kHz, for instance. Too much depends on the texture, material and orientation of the reflecting surface." CreationDate="2010-11-28T11:40:31.233" UserId="2064" />
  <row Id="9744" PostId="7227" Text="Have you opened the keyboard and measured the cable. Maybe you can see hints about which pins should have ground and power at least. Maybe identify dead pins and data lines.  If it's a rare item, it would be nice if you took and posted pictures of it somewhere along with all text markings and part numbers visible." CreationDate="2010-11-28T11:53:34.583" UserId="883" />
  <row Id="9745" PostId="7227" Text="If this was your keyboard, you should know what it was connected to. What was it?" CreationDate="2010-11-28T11:55:02.087" UserId="883" />
  <row Id="9746" PostId="7231" Score="4" Text="Jumping through hoops to have the privilege of using their chips that you've bought?" CreationDate="2010-11-28T12:15:19.287" UserId="883" />
  <row Id="9747" PostId="5817" Score="1" Text="If I had to choose between these two I'd go for the STM32. It uses the more future oriented Cortex M3 core vs. the older ARM7TDMI used in the LPC2119." CreationDate="2010-11-28T12:19:15.630" UserId="2064" />
  <row Id="9748" PostId="5817" Text="Nice to see an opinion. I should have a closer look some day." CreationDate="2010-11-28T12:21:22.013" UserId="883" />
  <row Id="9749" PostId="7190" Text="If it's a very *very* small motor, yes." CreationDate="2010-11-28T13:19:18.813" UserId="1374" />
  <row Id="9751" PostId="4381" Text="Controlling the pump is probably the best option." CreationDate="2010-11-28T13:21:02.167" UserId="1374" />
  <row Id="9752" PostId="4453" Score="1" Text="@avra.... *What?* the fact that water is slower than electrons means that rapid cycling of the valve will integrate the  PWM **more**, not less. All you need is an accumulator tank or basin (basically a hydraulic capacitor) and it'll work fine." CreationDate="2010-11-28T13:23:09.310" UserId="1374" />
  <row Id="9753" PostId="7208" Text="Please do not use the TSOP acronym as a general purpose noun for infrared receivers. TSOP is **far** more commonly used to refer to a specific type of IC package, and it makes the question very confusing." CreationDate="2010-11-28T13:31:16.663" UserId="1374" />
  <row Id="9754" PostId="7235" Score="8" Text="Yes.           (Trade you a better answer for more details)." CreationDate="2010-11-28T13:34:28.920" UserId="1374" />
  <row Id="9755" PostId="7236" Text="You don't need a PNP transistor, it just makes the circuit easier." CreationDate="2010-11-28T13:35:12.880" UserId="1374" />
  <row Id="9756" PostId="7238" Score="3" Text="9V batteries suck for, well.. just about everything. Go with 4 AAs or a lithium pack." CreationDate="2010-11-28T13:36:33.067" UserId="1374" />
  <row Id="9757" PostId="7236" Text="@gomek If you want to reverse the direction you can install the motor backwards. But if you want to be able to change the direction with your Arduino when you want, without removing the motor and installing it backwards, you can use a H-bridge." CreationDate="2010-11-28T13:37:46.840" UserId="1225" />
  <row Id="9758" PostId="7236" Text="@Fake Name, the circuit is designed for an NPN. Using a PNP would probably not work well." CreationDate="2010-11-28T13:38:07.183" UserId="1225" />
  <row Id="9759" PostId="7236" Text="@gomek You can use this with any device that can supply a few mA (&lt;5mA) of current and at least 1 volt. That means Arduino, a PIC microcontroller, even a parallel port on your computer. You mustn't apply an input voltage higher than the power supply voltage though." CreationDate="2010-11-28T13:39:37.853" UserId="1225" />
  <row Id="9760" PostId="7244" Text="Be aware that they are virtually identical, except the 4007 is more expensive and may have a slightly higher capacitance (which shouldn't matter anyway, because 1N400x's are not designed to be operated in high speed circuits.)" CreationDate="2010-11-28T13:43:15.510" UserId="1225" />
  <row Id="9761" PostId="7248" Text="Which engineering degree should i get? Mechanical, Electronics, and Mechatronics seem to be the best option for someone who wants to build robots? What would you suggest?" CreationDate="2010-11-28T14:23:38.343" />
  <row Id="9762" PostId="7245" Score="2" Text="&quot;not exactly fast&quot; could be an issue with higher frequency PWM. There are a lot of PWM projects that run at 300 or 400Hz, for which 1N400x would be ok, but then there are designs with 8, 10, even 20kHz PWM where the 1N400x just won't cut it." CreationDate="2010-11-28T14:45:44.660" UserId="740" />
  <row Id="9763" PostId="7231" Text="Yeah, well, they will say they need to know who you are to provide better service, read to sell their stuff. It gets worse if you have to register just to download a datasheet (happened to me a few times). Life's tough :-)" CreationDate="2010-11-28T15:01:21.823" UserId="2064" />
  <row Id="9764" PostId="7248" Text="Mechatronics looks best to me; it covers both mechanics and electronics. In mechanics you'll learn little about electronics and vice versa." CreationDate="2010-11-28T15:10:29.663" UserId="2064" />
  <row Id="9766" PostId="7141" Text="How much power can you spare for the display? Do you need colour? Is semi-static OK? Resolution?" CreationDate="2010-11-28T15:34:15.787" UserId="2064" />
  <row Id="9768" PostId="7188" Text="@Mark, I'm a member at freelancer.com also.  I tried searching for Electrical Engineering and only came up with a couple of listings, which is why I left them out.  But if you go to their home page and scroll down to Engineering &amp; Science, turns out there are quite a few jobs listed (19, plus 28 under Electronics).  So I was mistaken.  I don't know how to search providers there however.  On iFreelance.com, when you search providers for Electrical Engineering you get 62 hits." CreationDate="2010-11-28T15:50:34.710" UserId="1322" />
  <row Id="9769" PostId="7236" Text="If you need higher power, I would step up to a darlington pair or a FET.  The 2222 will probably not stand up to most motors stall current (the condition where the motor is running at full power and is stalled out)" CreationDate="2010-11-28T15:55:32.543" UserId="1477" />
  <row Id="9770" PostId="7187" Text="I have some code that must execute uninterrupted until a command is received on a port(or a button press indication is received, then the code must pause until the afore mentioned is received again." CreationDate="2010-11-28T16:04:55.700" UserId="1413" />
  <row Id="9771" PostId="7244" Text="Some prof once told me that 1N400x's are all made the same, just graded differently based on how they turn out.  Not sure how much I believe that, but if you look at [some datasheets](http://www.diodes.com/datasheets/ds28002.pdf) all specified parameters are the same except Vr and only two different capacitances (maybe they just make 1N4004 and 7's?)" CreationDate="2010-11-28T16:11:47.070" UserId="1407" />
  <row Id="9772" PostId="7236" Text="@Thomas O- Is it possible to build a H-bridge using only the 2N2222 transistors? Currently, I happen to have only these transistors at hand. " CreationDate="2010-11-28T16:14:57.190" UserId="2074" />
  <row Id="9773" PostId="7141" Text="I was going to recommend trying to get away with a custom segmented LCD, but if you want a 10&quot; screen, that's a ton of real estate." CreationDate="2010-11-28T16:34:20.367" UserId="1407" />
  <row Id="9774" PostId="7231" Text="Having to &quot;register&quot; for things online, surely an unprecedented move.  FWIW, their forums require that registration as well, so it's nice to be set for that as well." CreationDate="2010-11-28T16:38:04.653" UserId="1407" />
  <row Id="9775" PostId="7236" Text="@gomek - See my edit for a schematic." CreationDate="2010-11-28T16:57:52.813" UserId="1225" />
  <row Id="9776" PostId="7141" Text="resolution - preferably a high DPI; colour - mono/gray; static - low refresh rate/static is fine; power - enough to last 12 hours on a ~1000 mAH battery assuming 80% static usage." CreationDate="2010-11-28T16:59:57.883" UserId="1938" />
  <row Id="9777" PostId="7236" Text="problem there -- you wouldn't be able to drive that H-bridge directly with logic levels. the low-side transistors (2 and 4) yes, but the high side transistors will have problems. To get the high side of the motor anywhere near the +12V rail, you'd have to have a control signal at least Vbe,sat (say 0.8V) above the 12V. Using logic directly on transistors 1 and 3, the high side of the motor will only be able to come up to about Vbe,sat BELOW the logic high level, perhaps about 4V at best." CreationDate="2010-11-28T17:18:38.440" UserId="740" />
  <row Id="9778" PostId="7236" Text="@JustJeff Good point! To solve this you could use some open collector drivers with 1k pull ups. Or you could try replacing them with PNPs and grounding them (with pull-ups so they float to the supply rail.)" CreationDate="2010-11-28T17:19:55.837" UserId="1225" />
  <row Id="9780" PostId="7251" Text="+1 just for helping dispel the myth that 9V batteries are good for anything =P  .. though the other points are good too." CreationDate="2010-11-28T17:25:35.503" UserId="740" />
  <row Id="9781" PostId="7188" Text="@tcrosley agreed their search isn't as good when using the term &quot;electrical engineering&quot; most of the jobs that would interest folks from this board fall under &quot;electronics&quot; or similar headings." CreationDate="2010-11-28T17:33:17.417" UserId="1438" />
  <row Id="9782" PostId="7227" Score="1" Text="It was connected to an AT&amp;T branded PC-AT computer circa 1988. The computer is long-gone. I've seen these keyboards online with PS2 connectors, so I think it should be a simple adaptor to make. " CreationDate="2010-11-28T17:41:17.193" UserId="2089" />
  <row Id="9783" PostId="7141" Text="You are going to have a hard time buying something like this due to the rate at which phone and tablet manufacturers are ripping displays out of warehouses and shipping projects." CreationDate="2010-11-28T18:16:37.193" UserId="230" />
  <row Id="9784" PostId="7250" Text="Many universities offer a Controls engineering course which is actually a very direct fit for robotics. If you can do controls engineering from the EE department you will get all of the knowledge the ME would help you with on controls, and you will know the electronics and the programing. I would say that in my schools undergraduate program you can specialize in controls (as a EE) and build most of this knowledge without a problem." CreationDate="2010-11-28T18:23:32.887" UserId="230" />
  <row Id="9785" PostId="7238" Text="9V Ni** batteries are different beasts compared to 9V primaries, though." CreationDate="2010-11-28T18:41:06.653" UserId="883" />
  <row Id="9786" PostId="6900" Text="@JamesCadd, It seems the reason they got it so cheap is that they replaced it with a different sensor. They instead used a ping sensor. It has a narrow acceptance angle and they were able to rotate it to keep an image of the field. http://www.parallax.com/tabid/768/ProductID/92/Default.aspx" CreationDate="2010-11-28T18:58:56.677" UserId="230" />
  <row Id="9787" PostId="7245" Score="1" Text="There are fast recovery diodes that are not Schottky, if you need a higher reverse voltage.  Search your favorite distributor for &quot;fast recovery.&quot;  These are not as fast as a real Schottky, but much faster than 1N400x." CreationDate="2010-11-28T19:54:24.510" UserId="411" />
  <row Id="9788" PostId="7244" Text="&quot;maybe they just make 1N4004 and 7's?&quot; Probably the manufacturing process has improved so much that it is not worthwhile to make the others." CreationDate="2010-11-28T20:06:49.843" UserId="339" />
  <row Id="9789" PostId="7227" Score="1" Text="I've opened the keyboard up; it uses five wires in the cable, one of which is grounded to a large metal mounting plate for the keys. The other four (yellow, clear, brown, red if that matters) are in a plug-in connector on the circuit board that is mounted under the plate. There are a number of ICs on the board, the two large ones are an XR 22-00958-000 which I believe is a voltage regulator, and the other has Signetics and Intel trademarks: 20417-8, QFJ5219 8805KJ, 20-8031-0000. I'm guessing a micro-controller. There are two P8742/DM7404N ICs, and an 8-pin DIP switch that's set to all off." CreationDate="2010-11-28T20:42:54.837" UserId="2089" />
  <row Id="9790" PostId="7227" Score="1" Text="I've emailed keytronic for help. Here's the full set of identifiers: The keyboard has the following identifiers on it:&#xA;- FCC ID CIG8AVE03417&#xA;- AT&amp;T SN 885303011589&#xA;- COMCODE # 405748401&#xA;- M/N E03417212&#xA;- P/N 34287&#xA;- S/N 1521381" CreationDate="2010-11-28T20:47:08.263" UserId="2089" />
  <row Id="9791" PostId="7227" Text="Same keyboard, but with a 5-pin DIN. This is why I think an adaptor would work: http://cgi.ebay.com.sg/Dell-Enhanced-Keyboard-FCC-ID-CIG8AVE03417-Key-Tronic-/190456060106?pt=PCA_Mice_Trackballs&amp;hash=item2c5810d8ca" CreationDate="2010-11-28T21:01:11.123" UserId="2089" />
  <row Id="9792" PostId="7227" Text="This one is nearly an exact match: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&amp;item=320492001347#vi-content" CreationDate="2010-11-28T21:04:58.780" UserId="2089" />
  <row Id="9793" PostId="7006" Text="@ThaKidd: I added a new answer as it's related to this topic (too long for a comment). I haven't done the walkthrough yet - that'll be next hopefully. " CreationDate="2010-11-28T21:42:26.580" UserId="1333" />
  <row Id="9794" PostId="7180" Text="@endolith and Thomas - I think mikeselectricstuff has answered this for you! It could cause problems simply by introducing noise into other parts of the system. I know it was because of the floating pin, because as soon as I configured it to an output, the problems went away!  " CreationDate="2010-11-28T22:31:41.777" UserId="1785" />
  <row Id="9795" PostId="7208" Text="Have you considered using an Ultrasonic Sensor for distance measurement? There are a few that are out there and being used in the industry to do the same. Or is that you have to/want to use IR Receivers?" CreationDate="2010-11-28T22:43:19.797" UserId="1785" />
  <row Id="9798" PostId="7252" Score="1" Text="I feel like I did a good job answering this here: http://electronics.stackexchange.com/questions/7247/what-to-study-to-get-into-robotics/7250#7250" CreationDate="2010-11-28T22:54:09.513" UserId="1477" />
  <row Id="9799" PostId="7258" Score="1" Text="Agreed, try it and see.  Its not uncommon to use the +5V line to trigger an interrupt or use it in some other manor to indicate to the device processor that a USB cable has been connected.  If your device is designed in this manor it may not activate it's USB functions." CreationDate="2010-11-28T22:58:25.907" UserId="1438" />
  <row Id="9800" PostId="7259" Text="Hmm, what would a 0.4V drop do to a LiPo? The device would probably think the voltage was too low. This is of course assuming the OP has a device with a LiPo, but it's difficult to find any other type of battery in a device these days." CreationDate="2010-11-28T23:49:24.753" UserId="1225" />
  <row Id="9801" PostId="7260" Text="I have a feeling a number of devices do not wait for V+ to be connected to communicate, but my designs have always required USB power due to design. Just makes everything work better. +1" CreationDate="2010-11-28T23:53:31.027" UserId="230" />
  <row Id="9802" PostId="7260" Score="1" Text="@LoneTech, I still think there is a good chance it could work. But I also think there is a good chance it will not. It is very hard to tell without looking at hardware." CreationDate="2010-11-28T23:54:40.387" UserId="230" />
  <row Id="9804" PostId="6392" Text="Ok so here are the things I have tried that worked: Moved up compiler versions. The optimisation had improved drastically which gave me roughly 2K of Flash. Went through the list files to check for redundant and unused functionality (inherited because of the common code base) for the particular product and gained some more Flash. " CreationDate="2010-11-29T00:07:04.390" UserId="1785" />
  <row Id="9805" PostId="6392" Text="For RAM I did the following: Went through the map file, to check functions/modules that were using the most RAM. I found a really heavy function (12 channels, each with a fixed amount of allocated memory), of legacy code, understood what it was trying to achieve, and optimised the RAM usage, by sharing information between the channels that was common. This gave me ~200 Bytes that I needed." CreationDate="2010-11-29T00:14:14.787" UserId="1785" />
  <row Id="9806" PostId="7259" Text="@ThomasO, almost all good battery chargers are boost/buck, but there is no way for us to tell that and is almost completely pointless to discuss it." CreationDate="2010-11-29T00:59:46.673" UserId="230" />
  <row Id="9807" PostId="7252" Score="1" Text="@MJcarroll, I think the question is not specifically answerable, but as a moderator I would rather let the community decide. You can vote to close as a duplicate and with 4 others you will close the question automatically. " CreationDate="2010-11-29T01:09:24.403" UserId="230" />
  <row Id="9808" PostId="7225" Text="The pickit 3 also runs at USB 2.0 which is why I love it. ICD3 is a little expensive for me. My company uses MSP430s so it is quite different." CreationDate="2010-11-29T01:18:28.857" UserId="230" />
  <row Id="9809" PostId="7236" Text="@ThomasO, BJTs do not have an issue with floating like FETs can. This is an important advantage when bread boarding as far as I am concerned. " CreationDate="2010-11-29T02:27:03.447" UserId="230" />
  <row Id="9810" PostId="7250" Text="@Kortuk - I'll agree that a specific controls/mechatronics/robotics curriculum is definitely the way to go, but some schools (like mine!) don't offer it.  If the coursework is not an option, then I would definitely say that hands-on participation in undergraduate projects is the way to learn.  Book knowledge can only get you so far." CreationDate="2010-11-29T02:43:19.160" UserId="1477" />
  <row Id="9811" PostId="7250" Text="@mjcarroll, I understand that, degrees of the same name can vary heavily between universities. Naming a degree is not a great path. At my university Computer engineering still does almost all of EE with a few electives chosen for the person. I know of many universities that this is not true and that computer engineering does almost exclusively software with only a few basic EE classes." CreationDate="2010-11-29T02:50:49.263" UserId="230" />
  <row Id="9812" PostId="7233" Text="It's on/off as in obstacle detection." CreationDate="2010-11-29T03:27:16.567" UserId="2074" />
  <row Id="9813" PostId="7236" Text="Thanks. So does this work with the Arduino or not?" CreationDate="2010-11-29T03:42:04.170" UserId="2074" />
  <row Id="9814" PostId="7183" Text="The inputs don't have hysteresis?" CreationDate="2010-11-29T05:38:32.633" UserId="142" />
  <row Id="9815" PostId="7268" Text="+1: Didn't know about YAGARTO, thanks. Microbuilder is also a nice site. thanks again. Not interested in their reference boards, since they are in the same category as mbed, and YAGARTO was for windows. I know I can build an arm toolchain under linux, I've already done it, but I don't know if there are any special things I need to do to a toolchain for NXP micros. Also have no idea how to use a JTAG programmer/debugger under linux. " CreationDate="2010-11-29T05:54:48.477" UserId="2092" />
  <row Id="9816" PostId="7233" Text="I just realized that you also asked this question: http://electronics.stackexchange.com/questions/7208/using-38-khz-ir-receivers-to-measure-distance  I guess my answer doesn't really help here. Apologies." CreationDate="2010-11-29T06:47:53.083" UserId="1477" />
  <row Id="9817" PostId="7270" Score="1" Text="The easiest way would be to use a computer and a webcam. The computer runs motion tracking along where your head and shoulders are then controls the servo. The tracking algorithm is as simple as looking for the mean of the location of the pixels with the most change....Or do you not have a computer available?" CreationDate="2010-11-29T06:57:18.180" UserId="2092" />
  <row Id="9818" PostId="7183" Text="Schmitt trigger inputs do, but generally, no. " CreationDate="2010-11-29T06:59:26.653" UserId="1181" />
  <row Id="9819" PostId="7272" Text="What is physically/virtually saturating? What is the maximum/minimum of the input signal? Is the entire signal saturated, or is it only the peaks? " CreationDate="2010-11-29T08:16:45.763" UserId="638" />
  <row Id="9821" PostId="7266" Text="Additionally, using a 555 would limit the range of resistances that could be measured. Over and under range conditions are difficult to detect at the extremes, such as open circuit and short circuit. " CreationDate="2010-11-29T08:45:59.813" UserId="638" />
  <row Id="9822" PostId="7260" Text="What would happen if you just placed a (relatively) large resistor in series with V+? Assuming that there is a power source keeping a brownout from happening, would that starve the charging circuit? Maybe 470 - 2k2 ohms is what I'm thinking." CreationDate="2010-11-29T08:52:56.357" UserId="638" />
  <row Id="9823" PostId="7268" Text="Have you looked at OpenOCD?" CreationDate="2010-11-29T09:30:26.483" UserId="883" />
  <row Id="9824" PostId="7259" Text="@Kortuk, there would be no way to compensate for the 0.4V drop without overcharging the LiPo or any other cell for that matter. All I'm saying is I don't think it would work unless the device could tolerate such a drop in voltage." CreationDate="2010-11-29T11:16:38.790" UserId="1225" />
  <row Id="9825" PostId="7236" Text="@Kortuk, yep, but you need to make sure they have a logic signal to switch off. PNPs switch on when they have no b-e current, so you need to make sure that b-e current is present." CreationDate="2010-11-29T11:17:56.807" UserId="1225" />
  <row Id="9826" PostId="7236" Text="@Gomek, it *should* work. You may need to find some PNPs and use the pull-up idea I mentioned. I'd recommend you buy an actual H-bridge IC though when you can - they're only a few bucks." CreationDate="2010-11-29T11:18:48.757" UserId="1225" />
  <row Id="9827" PostId="7260" Text="You'd get a voltage drop when power is drawn, which might starve the charger while heating the resistor. It's also possible, however, that the device will see Vbus drop below a threshold (it's supposed to be over 4.5V, after all) and see that as getting unplugged, turning communication off, or cycling plug/unplug events. Depends on the device." CreationDate="2010-11-29T11:28:50.973" UserId="1181" />
  <row Id="9828" PostId="7250" Text="So, if your uni offers it, a bachelors in mechatronics engineering would be the way to go? Since it covers all the 3 components you mentioned (mechanics, electrical, &amp; software)" CreationDate="2010-11-29T12:55:54.937" UserId="1999" />
  <row Id="9829" PostId="7179" Text="There's a difference  between a floating digital input and an input defined as analogue. Sounds like this is an analogue input." CreationDate="2010-11-29T13:13:41.763" UserId="2110" />
  <row Id="9830" PostId="7179" Text="@Martin I'm unable to make the pin an analog input. I have a ~125ns time slice for each pixel on the video (25ns instruction clock), so can't expend a single nanosecond more." CreationDate="2010-11-29T13:16:04.567" UserId="1225" />
  <row Id="9831" PostId="7118" Score="2" Text="Sounds about right for adjacent tracks and pads. Not insane, required to prevent flashover. Dirt and moisture levels affect the distance required. If you don't use these sort of creepage distance, you are creating a safety hazard. In Europe, that comes under the Low Voltage Directive and associated standards; equivalent in US is UL." CreationDate="2010-11-29T13:22:41.787" UserId="2110" />
  <row Id="9832" PostId="7259" Text="@ThomasO, stating that there is no way to compensate &quot;unless the device can tolerate the drop&quot; does not say anything. if they have a buck/boost style intelligent charger it means their efficiency is high and it means they can design to work over a large range of input voltages and they can vary their output to suite what the battery wants. I am not saying they use this, just that they are becoming significantly more predominant for chargers." CreationDate="2010-11-29T13:29:28.400" UserId="230" />
  <row Id="9833" PostId="6795" Text="@Nick T - sure, have a look inside a linear high frequency fluorescent ballast, its very similar to a switched mode PSU and made for low cost. Single sided board, all the SMT underneath, all the through hole on top." CreationDate="2010-11-29T13:33:13.273" UserId="2110" />
  <row Id="9834" PostId="7236" Text="@ThomasO, NO, Both PNP and NPN need base emitter-current to get emitter-collector current. They both operate on taking base-emitter current and multiplying. I am not sure whom told you otherwise but they are very very wrong. If you leave either base floating they turn off." CreationDate="2010-11-29T13:33:43.640" UserId="230" />
  <row Id="9835" PostId="7272" Text="the values of the signal frames (post addition operation) saturate. the output of the above operation is double, but has to be made into short. hence, the problem with saturation." CreationDate="2010-11-29T13:40:05.613" UserId="2103" />
  <row Id="9836" PostId="7282" Text="yes. that is my problem. i dont have any long-term statistics (not in a real-time environment anyway). is there some technique in the literature that gives a way to do this? right now, i just choose a number at random (very high) and scalar multiply with the signal. that takes care of the problem but fares miserably when a signal with different stats is used. please also read the previous comment (above) for some more details about the problem." CreationDate="2010-11-29T13:43:10.603" UserId="2103" />
  <row Id="9837" PostId="7287" Text="our school makes students mill &quot;firefly&quot; boards to get certified to mill, we make them etch them to get certified to etch, we make them solder them to get certified in soldering. We have about 75 now I believe. " CreationDate="2010-11-29T14:58:03.583" UserId="230" />
  <row Id="9838" PostId="7287" Text="We use a variant that uses a 555timer to synchronize to each other slowly." CreationDate="2010-11-29T14:58:29.340" UserId="230" />
  <row Id="9839" PostId="7250" Text="I would say that if offered, mechatronics would be the way to go." CreationDate="2010-11-29T14:59:36.133" UserId="1477" />
  <row Id="9840" PostId="7251" Text="Agreed. I use a 4AA holder with 4 rechargables." CreationDate="2010-11-29T15:05:28.393" UserId="2006" />
  <row Id="9841" PostId="7280" Text="Could you use measured grid paper in the picture or measure them off and give dimensions." CreationDate="2010-11-29T15:13:07.833" UserId="230" />
  <row Id="9842" PostId="7283" Score="1" Text="I'm afraid not. I corrected the package, it's MSOP rather than SOIC, but they're higher than IL5xx. Were you thinking about them because of the &quot;511&quot;-&quot;115&quot; similarity? It's most definitely &quot;115&quot;, as you can see in the picture. Thanks for the reply anyway." CreationDate="2010-11-29T15:17:28.690" UserId="2064" />
  <row Id="9843" PostId="7280" Text="Use a diode function on a meter and see what's connected where." CreationDate="2010-11-29T15:21:15.303" UserId="1407" />
  <row Id="9844" PostId="7283" Text="Yeah, bad guess - never mind." CreationDate="2010-11-29T15:33:59.520" UserId="566" />
  <row Id="9846" PostId="7236" Text="@ThomasO, without base current it is two diodes. With base current you manage to trick current across the barrier of the reverse biased diode." CreationDate="2010-11-29T15:48:11.723" UserId="230" />
  <row Id="9847" PostId="7204" Score="1" Text="First,  to answer your inference, I have indeed researched the use of interrupts.  It still remains unclear to me how to utilize them.  As for this forum, Is it not the purpose of this forum to provide a platform for those whom are seeking guidance to seek assistance from others with experience?  Your answer is simply a curt suggestion that i have not researched enough and that if I had I wouldn't need to ask a question here.  If everyone could answer their own questions, there would be no need for any of the stackexchange sites!" CreationDate="2010-11-29T15:54:46.490" UserId="1413" />
  <row Id="9848" PostId="7280" Text="If that's 5mm grid, those aren't MSOP (0.65 mm pitch), they're SOIC (1.27 mm).   They look way to big, even setting aside height, to be MSOP anyways." CreationDate="2010-11-29T16:01:00.073" UserId="1407" />
  <row Id="9849" PostId="7270" Text="@Chris H, if you have info on such an easily available functional program I think it would make a perfect answer." CreationDate="2010-11-29T16:01:38.950" UserId="230" />
  <row Id="9850" PostId="7266" Text="Open circuit wouldn't oscillate at all" CreationDate="2010-11-29T16:25:15.793" UserId="1407" />
  <row Id="9851" PostId="7271" Text="Time to buy some &quot;uniquely colored&quot; shirts." CreationDate="2010-11-29T16:27:32.030" UserId="1407" />
  <row Id="9852" PostId="6787" Text="I like the idea of stand-out alternative titles like Bit Wrangler.    Not sure what phrase would best suit my resume. Need ideas!" CreationDate="2010-11-29T16:38:40.587" UserId="1609" />
  <row Id="9853" PostId="7204" Text="@michael Eakins, I am glad you found the help you need. The point of this site is not only to help but become the definitive source for what you need help with." CreationDate="2010-11-29T16:59:05.077" UserId="230" />
  <row Id="9854" PostId="7291" Text="This is almost exactly how I would have approached this." CreationDate="2010-11-29T16:59:57.480" UserId="230" />
  <row Id="9855" PostId="7204" Text="I may have taken a needlessly harsh approach, yes. But I saw very little of planning - the chip is presented, code needs are not. For instance, the compiler question is still unanswered and does affect how you use interrupts. If I did not think at least some of what I mentioned or linked could provide a little guidance, I would not have posted as an answer." CreationDate="2010-11-29T17:03:20.573" UserId="1181" />
  <row Id="9856" PostId="7270" Text="Well, I don't know of any specifically, but consider OpenCV. You can apply a crop then a motion tracking function. Cropping is just to make sure that you don't pick up other things moving. It should come out to about 100 lines of code total. Probably easier to code it yourself than to configure and learn another program, especially since you need to interface with a motor afterwards. " CreationDate="2010-11-29T17:05:57.760" UserId="2092" />
  <row Id="9857" PostId="7187" Text="@Michael Eakins, From your original post this action is not perfectly clear. When you just say you want it to stop there is no reason that the code could not be peppered with statements to wait on a button to go high. your comment makes clear that you specifically need this interrupt functionality. It may seem minor but clarification like that can avoid posts like lonetech's." CreationDate="2010-11-29T17:06:49.440" UserId="230" />
  <row Id="9858" PostId="7290" Text="I've tried this actually, works unless there are large windows." CreationDate="2010-11-29T17:07:10.613" UserId="2092" />
  <row Id="9859" PostId="7204" Text="@LoneTech, when I first saw the question without any extra detail I assumed that the asker had not thought it through, with more info I see otherwise. It happens. I would like to say that assuming the asker always knows what they want is valid, but often answers like yours are accepted as they did not think it through." CreationDate="2010-11-29T17:07:54.977" UserId="230" />
  <row Id="9860" PostId="7271" Score="2" Text="Upon further consideration, I believe that Kortuk and user1498's solution of IR LEDs and sensor would be a more robust approach.  This is true because of the point that Nick T raises, the color space is already pretty crowded, so picking yourself out would be difficult." CreationDate="2010-11-29T17:08:43.040" UserId="1477" />
  <row Id="9861" PostId="7290" Text="@Chris H, a large window is just a challenge for me to get a brighter IR emitter. Often modulation can significantly help with the background IR problem of Sunlight or florescent lights. " CreationDate="2010-11-29T17:09:26.147" UserId="230" />
  <row Id="9862" PostId="7271" Text="@mjcarroll, that sounds like an engineer backing down from a problem." CreationDate="2010-11-29T17:10:07.830" UserId="230" />
  <row Id="9863" PostId="7286" Text="Ugh, even if you use 5$ worth of components per device, isn't that a 2500$ project?" CreationDate="2010-11-29T17:10:13.340" UserId="2092" />
  <row Id="9864" PostId="7163" Text="I recommend _not_ using this book:  http://www.amazon.com/Digital-Electronics-VHDL-Quartus-Version/dp/0131714902" CreationDate="2010-11-29T17:14:01.633" UserId="374" />
  <row Id="9865" PostId="7271" Text="@Kortuk, Not necessarily backing down. I still think that my solution may be the &quot;best,&quot; as far as an entirely self-contained system (no external sensors, no more hardware than explicitly stated in the problem statement).  As far as ease-of-implementation and robustness (vision algorithms being somewhat finicky), I think that your solution would be much better." CreationDate="2010-11-29T17:16:37.200" UserId="1477" />
  <row Id="9866" PostId="7271" Text="@mjcarroll, I knew what you meant, I think the hardware solution is more self contained but there is a large tradeoff to both." CreationDate="2010-11-29T17:36:00.030" UserId="230" />
  <row Id="9867" PostId="7298" Text="Is there any public link to this?" CreationDate="2010-11-29T17:40:18.857" UserId="319" />
  <row Id="9868" PostId="7298" Text="I read this, and I am sorry to say I understood most of it. I do not understand how it fixes anything. It seems you are saying if you give a greater delay you can compensate for the volume better." CreationDate="2010-11-29T17:40:40.697" UserId="230" />
  <row Id="9869" PostId="7272" Text="Is this for music or voice?" CreationDate="2010-11-29T17:43:30.333" UserId="319" />
  <row Id="9870" PostId="7294" Text="he specified that he does not know the signal before he is receiving it and is in a real time environment. he also specified he was keeping the same hard limit for the entire signal, which is where the saturation comes from. " CreationDate="2010-11-29T17:43:34.783" UserId="230" />
  <row Id="9871" PostId="7299" Text="http://www.instructables.com/id/H-Bridge-on-a-Breadboard/step7/Getting-a-Clear-Picture/       this is the link" CreationDate="2010-11-29T17:43:35.157" UserId="2074" />
  <row Id="9872" PostId="7299" Text="Yes I cut and pasted it before, I still find it confusing. " CreationDate="2010-11-29T17:45:40.990" UserId="689" />
  <row Id="9873" PostId="7299" Text="@Gomek, it is not the best design I have seen. And the design is to allow bread-boarding, not for designing a real circuit." CreationDate="2010-11-29T17:46:29.010" UserId="230" />
  <row Id="9874" PostId="7299" Score="1" Text="It doesn't even have a schematic, which should be the first step to understanding. I only see the drawing of an unconnected transistor. If you follow the instructions you may have built an H-bridge driver, but most likely have learned nothing." CreationDate="2010-11-29T17:52:26.607" UserId="2064" />
  <row Id="9875" PostId="7281" Text="The past questions about lego NXT methods have not done well here. There are two sites starting up that both probably fit this better. http://area51.stackexchange.com/proposals/4105/lego-mindstorms-robotics  or http://area51.stackexchange.com/proposals/10919/lego" CreationDate="2010-11-29T17:55:20.847" UserId="230" />
  <row Id="9876" PostId="7281" Text="They are not active yet, but this does not seem to fit this community well as it has not received any active answers in the past." CreationDate="2010-11-29T17:55:44.963" UserId="230" />
  <row Id="9877" PostId="7236" Text="question- do I connect the switches (s1,s2....) to the Arduino inputs?" CreationDate="2010-11-29T18:08:33.987" UserId="2074" />
  <row Id="9878" PostId="7298" Text="No pubic link, sorry, but I know the DAFX book is available online somewhere. (google for an ebook) I'm not adding delays, except for the delays to implement the filter in the second figure, which is used to recreate the sound at a later time. This only deals with encoding. It transforms an input signal into a filter and a residual. The residual has a tiny amplitude and can be encoded with a small number of bits. Filters can be added by using them in series. The residuals can be added without overflow since they have small values, and stored as such as an intermediate step before the final out" CreationDate="2010-11-29T18:13:22.543" UserId="2092" />
  <row Id="9879" PostId="3141" Text="@Nick, yes a diode would also do the trick. However, a diode would also have a induce a voltage drop (~0.4V typical for a schottky) . If the device can still run under the reduced voltage condition, then you're ok. The most important ingredient here is really the capacitor, and something to mitigate its discharge when the data line goes low. I will however concede and change the answer to diode instead of buffer." CreationDate="2010-11-29T18:21:58.263" UserId="771" />
  <row Id="9880" PostId="7296" Score="2" Text="Please add more detail to your question. We will be glad to help, but we need more then &quot;Help&quot;. Tell us what you know and what part you are struggling with." CreationDate="2010-11-29T18:22:12.440" UserId="319" />
  <row Id="9881" PostId="7290" Text="This sounds like a very nice solution, I do not know what you mean when you suggest I modulate my IR though.  Do you mean I should pulse the IR LED at a known frequency, and then try do detect just that frequency with the receiver?" CreationDate="2010-11-29T18:23:00.153" UserId="1773" />
  <row Id="9882" PostId="7296" Text="If you use NPN BJTs (or N-ch FETs) on the high side it can be kind of a pain in the ass to control." CreationDate="2010-11-29T19:02:22.197" UserId="1407" />
  <row Id="9883" PostId="7294" Text="+1 auto-gaining / basic signal division by max gain is what i would probably do.  No need to know the input signal ahead of time for that." CreationDate="2010-11-29T19:04:49.220" UserId="1438" />
  <row Id="9884" PostId="7236" Text="@gomek, yes, and don't forget the 1k resistors!" CreationDate="2010-11-29T19:06:14.177" UserId="1225" />
  <row Id="9885" PostId="7281" Text="If you can't get any answer, you may want to try the forums at mindboards.net [ https://sourceforge.net/apps/phpbb/mindboards/index.php ]" CreationDate="2010-11-29T19:23:49.133" UserId="1940" />
  <row Id="9886" PostId="7281" Text="Post a picture of your code. The site I mentioned earlier is a much better place for these types of questions." CreationDate="2010-11-29T19:24:51.003" UserId="1940" />
  <row Id="9887" PostId="7296" Score="3" Text="How about a proper schematic?" CreationDate="2010-11-29T19:46:40.917" UserId="305" />
  <row Id="9888" PostId="7290" Text="@kasterma, Yes, that is what I mean. You pulse the IR LED at 40KHz for example, and then make a filter at 40KHz on the receivers so that you ignore the broadband IR the Sun and lights emit. You may need to adjust the frequency to avoid the frequency that your florescent lights give off. you can try it without this modulation first to see if it meets specs as it is easier to do." CreationDate="2010-11-29T20:17:26.940" UserId="230" />
  <row Id="9889" PostId="7187" Text="@Kortuk I agree, I was very vague in my statement of needs, I then provided little of my background work or example code.  In the future I will try to be less vague and more clear regarding the design of my questions. Thank you for your comment." CreationDate="2010-11-29T20:53:30.963" UserId="1413" />
  <row Id="9890" PostId="7303" Text="What is the thickness you need to put the heat shrink around? I've seen some at 24mm if that helps. " CreationDate="2010-11-29T21:19:18.027" UserId="1623" />
  <row Id="9891" PostId="7187" Text="@Michael Eakins, Just trying to help out. I am glad you still got the answer you were needing. often people on this site over complicate." CreationDate="2010-11-29T21:38:37.103" UserId="230" />
  <row Id="9892" PostId="7303" Text="@Dean the problem with that is the ratio that it shrinks is usually not enough." CreationDate="2010-11-29T21:45:03.933" UserId="319" />
  <row Id="9893" PostId="7261" Text="Thanks! Great Answer!" CreationDate="2010-11-29T22:22:39.877" UserId="1688" />
  <row Id="9894" PostId="7303" Text="Well I want to put it around a circular object so there is no opening." CreationDate="2010-11-29T23:25:15.420" UserId="2115" />
  <row Id="9895" PostId="7307" Text="If it is a commercial product they probably protected their code." CreationDate="2010-11-29T23:42:00.477" UserId="230" />
  <row Id="9897" PostId="7312" Text="or the loop creates an inductive loop that picks up interference. Otherwise, I agree, and it is nasty to explain." CreationDate="2010-11-30T02:22:31.400" UserId="230" />
  <row Id="9898" PostId="7313" Text="Try asking this question at http://superuser.com/" CreationDate="2010-11-30T02:51:27.753" UserId="319" />
  <row Id="9899" PostId="7314" Text="@eruditass, I changed your title, as you want to know if a product is conductive, not if a product marketed as conductive tape is conductive." CreationDate="2010-11-30T03:20:34.040" UserId="230" />
  <row Id="9900" PostId="7314" Text="@Kortuk, any product that will serve the purpose is a viable option that I want to know about." CreationDate="2010-11-30T03:25:55.167" UserId="1297" />
  <row Id="9902" PostId="7312" Text="Please expand with the actual answer.  Nobody reading this site should be afraid to learn that wires and ground connections have some resistance." CreationDate="2010-11-30T04:05:04.140" UserId="411" />
  <row Id="9903" PostId="7314" Text="I know, but your question implied that you have conductive tape and want to know if it is conductive. Another good question might be, Is there a conductive tape product and then have details in the question about what you need specifically?" CreationDate="2010-11-30T04:09:25.230" UserId="230" />
  <row Id="9904" PostId="7307" Text="It is in a light-gun controller from an arcade machine, I'll look at your schematic tomorrow. Thanks for the info" CreationDate="2010-11-30T04:11:38.863" UserId="1673" />
  <row Id="9906" PostId="7295" Text="Looks like an optocoupler to me, too. I guess you're right, and I also guess the part was assembled in the 1st week of 2005 (-&gt; 5 01 -&gt; 501)" CreationDate="2010-11-30T06:58:02.580" UserId="930" />
  <row Id="9907" PostId="7272" Text="@Kellenjb: for both." CreationDate="2010-11-30T07:03:59.590" UserId="2103" />
  <row Id="9908" PostId="7295" Text="@zebonaut: I've been thinking about a date code too, but that usually appears below the part number, which would then be 501, week 15 of 2001." CreationDate="2010-11-30T07:47:35.250" UserId="2064" />
  <row Id="9910" PostId="7236" Text="I built it but it doesn't seem to be working!! :(" CreationDate="2010-11-30T07:58:01.037" UserId="2074" />
  <row Id="9911" PostId="7236" Text="Sorry for the mistake. The cicruit works fine. Thank you." CreationDate="2010-11-30T09:24:51.927" UserId="2074" />
  <row Id="9912" PostId="3174" Text="Curiously, what that 1wire.org page says is &quot;Do NOT change this page. It is NOT visible to customers.&quot; I guess I'm not a customer. At a guess, &quot;shopfactory&quot; do not know what happens if their javascript does not run." CreationDate="2010-11-30T09:54:21.080" UserId="1181" />
  <row Id="9913" PostId="3139" Text="To follow up and enhance the question - what about power on reset of MCU? How this is addressed? (For sensors specifically designed for 1-wire this should be handled by the device itself as it is prepared for it). Should MCU be equipped with brownout detection? Is this enough?" CreationDate="2010-11-30T11:31:55.863" UserId="1471" />
  <row Id="9914" PostId="3139" Text="@macurnification - that sounds like a new question to me" CreationDate="2010-11-30T11:58:38.217" UserId="566" />
  <row Id="9915" PostId="3172" Text="Will Ideal Diode be fast enough to turn off when transmitting data?" CreationDate="2010-11-30T12:22:51.720" UserId="1471" />
  <row Id="9916" PostId="7236" Text="@gome, Glad to hear! enjoy. Then get a real h-bridge on your next components order, they are very useful." CreationDate="2010-11-30T14:56:33.020" UserId="1225" />
  <row Id="9917" PostId="7319" Text="I think this belongs in the original question." CreationDate="2010-11-30T14:58:27.683" UserId="1225" />
  <row Id="9918" PostId="7317" Text="I enjoyed &quot;As a hobbyist, this forum is enough.&quot; Interesting, I did not even think about AI." CreationDate="2010-11-30T14:59:15.513" UserId="230" />
  <row Id="9919" PostId="7319" Score="1" Text="The CTL signal turns the motor on or off. Set the output of your arduino connected to this pin high to turn the motor on, and set it low to turn the motor off." CreationDate="2010-11-30T14:59:33.487" UserId="1225" />
  <row Id="9920" PostId="7314" Text="@Eruditass, Glad to see people are finding you answers now." CreationDate="2010-11-30T15:00:43.983" UserId="230" />
  <row Id="9921" PostId="7319" Text="@THomasO, you can vote to close as duplicate if you think it is." CreationDate="2010-11-30T15:01:23.860" UserId="230" />
  <row Id="9922" PostId="7319" Score="1" Text="@Kortuk, I'm not sure it's a duplicate - but more an extension of the original question that belongs on the original question page." CreationDate="2010-11-30T15:02:51.190" UserId="1225" />
  <row Id="9923" PostId="7319" Text="I think it's a new question - &quot;How to I control that driver with an Arduino&quot;" CreationDate="2010-11-30T15:03:45.133" UserId="566" />
  <row Id="9924" PostId="7319" Text="@ThomasO, that is the definition of a duplicate that you just told me. If it should be with the first, vote to close as duplicate. I am a moderator and trying to avoid closing everything, more trying to get the community to vote for closing, remember, you will not close it on your own. It takes 4 more people agreeing, or s/he will see the vote to close and will edit his question to show why s/he considers it a different topic." CreationDate="2010-11-30T15:05:11.097" UserId="230" />
  <row Id="9925" PostId="7289" Score="1" Text="I agree this may be the most straight forward but not the cheapest" CreationDate="2010-11-30T15:05:43.887" UserId="2006" />
  <row Id="9926" PostId="7320" Score="1" Text="Thanks, I've added this to the question" CreationDate="2010-11-30T15:06:01.700" UserId="566" />
  <row Id="9927" PostId="7319" Score="1" Text="http://electronics.stackexchange.com/questions/7296/connecting-h-bridge-with-arduino-closed this question was closed for not enough detail, what makes you think asking it again will help?" CreationDate="2010-11-30T15:10:51.117" UserId="319" />
  <row Id="9928" PostId="7319" Text="@kellenjb, in this question he actually referenced a schematic, I would bet people do not vote close it for detail." CreationDate="2010-11-30T15:12:20.267" UserId="230" />
  <row Id="9929" PostId="7320" Text="Thanks!! Beginner question; but that really confused me for quite a while." CreationDate="2010-11-30T15:16:38.007" UserId="2074" />
  <row Id="9930" PostId="7319" Score="1" Text="@kortuk, its still a duplicate regardless. He can vote to reopen the other and add detail. Instead hes just creating lots of duplication." CreationDate="2010-11-30T15:18:22.017" UserId="319" />
  <row Id="9931" PostId="7319" Text="Surely, this is a different question, that's not an H-Bridge" CreationDate="2010-11-30T15:19:32.157" UserId="566" />
  <row Id="9932" PostId="7319" Text="@joby taffey true. " CreationDate="2010-11-30T15:20:23.433" UserId="319" />
  <row Id="9933" PostId="7180" Text="@IntelliChick: I don't understand how a floating piece of metal can introduce noise to other parts of the system.  It picks up noise, certainly, but if you're not paying attention to the input, that shouldn't matter.  Are the problems with waving hands nearby really related to *unused* floating inputs?" CreationDate="2010-11-30T15:22:25.087" UserId="142" />
  <row Id="9934" PostId="7191" Text="What exactly would oscillate, and why?" CreationDate="2010-11-30T15:22:49.953" UserId="142" />
  <row Id="9935" PostId="7181" Text="Can you enable an internal pull-up and be done with it?" CreationDate="2010-11-30T15:23:17.377" UserId="142" />
  <row Id="9936" PostId="7314" Text="There's no option to have the object roll using conductive wheels? It would make it a lot easier on the contacts." CreationDate="2010-11-30T15:26:20.773" UserId="536" />
  <row Id="9937" PostId="7314" Score="1" Text="Thanks for your help, Kortuk.  @pfyon, this is a DIY hack for objects that are already made.  However, I don't believe the durability requirements are very high: the pins appear to be dampened with a spring and foil does not appear to rip with the first couple insertion cycles and occasional replacement is not a big deal." CreationDate="2010-11-30T15:35:36.167" UserId="1297" />
  <row Id="9938" PostId="7307" Text="A side question: do you use this JTAG pinout http://www.hardwarebook.info/JTAG#Pinout_.2810_pin.29 ?" CreationDate="2010-11-30T15:38:06.257" UserId="1673" />
  <row Id="9940" PostId="3139" Text="asked:http://electronics.stackexchange.com/questions/7323" CreationDate="2010-11-30T15:42:09.130" UserId="1471" />
  <row Id="9941" PostId="7181" Text="Enabling the internal pull-up should be good.  The point is to put it into a known state and leave it there." CreationDate="2010-11-30T16:14:38.050" UserId="204" />
  <row Id="9942" PostId="7325" Text="how big is N? &#xA;&#xA;..." CreationDate="2010-11-30T16:22:03.823" UserId="411" />
  <row Id="9943" PostId="7325" Text="Arbitrarily Large. Between One Hundred Thousand and One Million." CreationDate="2010-11-30T16:26:46.777" UserId="2085" />
  <row Id="9944" PostId="7322" Score="1" Text="Great question, I'm also interested in this one." CreationDate="2010-11-30T16:28:43.000" UserId="1333" />
  <row Id="9945" PostId="7325" Score="3" Text="This is going to be very very very hard and yes you will need a digital filter." CreationDate="2010-11-30T16:29:26.500" UserId="230" />
  <row Id="9946" PostId="7326" Text="This will help alot if I ask the question, &quot;Where do I learn portuguese online in time to learn to write drivers?&quot; Thanks for helping out." CreationDate="2010-11-30T16:30:22.973" UserId="230" />
  <row Id="9948" PostId="7324" Score="4" Text="Linux Device Drivers is a good book.  Unfortunately, these things are highly OS-specific.  Linux is probably easiest to write for, because there are so many drivers in the source tree already for reference.  If you have written embedded code to drive a microprocessor's peripherals, you probably have a decent grasp of device driver fundamentals." CreationDate="2010-11-30T16:34:59.860" UserId="411" />
  <row Id="9949" PostId="7325" Score="2" Text="Do you need it to filter in real time? This makes a difference with processing power." CreationDate="2010-11-30T16:45:10.283" UserId="319" />
  <row Id="9950" PostId="7331" Text="So basically, it cant be done without a gigantic filter... That answers my question pretty well. Would it change the answer if the phase was known for all N frequencies?" CreationDate="2010-11-30T16:48:25.980" UserId="2085" />
  <row Id="9952" PostId="7314" Text="Question title makes it sounds like you want tape that doubles as a diode :P" CreationDate="2010-11-30T16:50:03.480" UserId="1407" />
  <row Id="9953" PostId="7331" Text="no, the phase makes little difference." CreationDate="2010-11-30T16:50:17.567" UserId="230" />
  <row Id="9954" PostId="7335" Text="you will need a huge number of points in the fft for that many frequencies or need to implement a wavelet technique. " CreationDate="2010-11-30T16:52:19.190" UserId="230" />
  <row Id="9955" PostId="7326" Score="2" Text="Don't worry about learn Portuguese. The links about drive development that I passed are in English. Even DriveEntry is written in English too. Unfortunately the post about books is in Portuguese, but the books are in English. And what matters most are the books, not the post." CreationDate="2010-11-30T16:52:31.243" UserId="938" />
  <row Id="9957" PostId="7336" Text="i also do not have the datasheet. i would bet markrages is spot on." CreationDate="2010-11-30T16:56:37.703" UserId="230" />
  <row Id="9958" PostId="7331" Score="1" Text="The FFT can be considered a bank of N filters (where N is a power of 2.)  So don't recreate the wheel.   Allowing N to be a power of 2 simplifies the number of multiplies necessary." CreationDate="2010-11-30T16:57:40.940" UserId="411" />
  <row Id="9960" PostId="7325" Text="Yeah... Real time. However, I don't necessarily need the output signal to look like the input signal. The input signal is an impulse where each frequency only goes through half a period, but the integral of the wave function of each frequency is the same. All I need to get out at the end is a summation of sorts where I can chose which frequencies affect the final sum and by how much." CreationDate="2010-11-30T16:58:36.313" UserId="2085" />
  <row Id="9961" PostId="7335" Text="True. ... ... ..." CreationDate="2010-11-30T16:59:26.477" UserId="411" />
  <row Id="9962" PostId="7331" Text="yes, i understand your approach, i was explaining for retaining phase. if you just fft a signal where you need to find 100000 different frequencies, scale them separately, and then recreate the signal, especially if they vary in time, you need as much ram and still have a ton of work." CreationDate="2010-11-30T17:03:11.790" UserId="230" />
  <row Id="9963" PostId="7335" Text="this also is very challenging if the sigals change with time. hell, it is alot of work if they do not." CreationDate="2010-11-30T17:05:56.610" UserId="230" />
  <row Id="9964" PostId="7325" Text="can you link us to the problem you are given. just in case something is lost in translation." CreationDate="2010-11-30T17:09:29.167" UserId="230" />
  <row Id="9965" PostId="7338" Text="This sounds like a question for StackOverflow" CreationDate="2010-11-30T17:11:12.980" UserId="566" />
  <row Id="9966" PostId="7338" Text="this is purely programming. SO will be more help." CreationDate="2010-11-30T17:11:46.450" UserId="230" />
  <row Id="9967" PostId="7334" Text="@Keegan - you will have to let us know which Freescale part you are using to give you an accurate answer." CreationDate="2010-11-30T17:14:49.840" UserId="529" />
  <row Id="9968" PostId="7338" Text="@Joby &amp; @Kortuk I posted this here as it relates more to hardware than to software people.  I will post it on Stack also.  Thanks." CreationDate="2010-11-30T17:14:56.470" UserId="1413" />
  <row Id="9969" PostId="7332" Text="In the diagram I'm looking at, they are using 3 1uf electrolytic caps. How do I determine what I can use? Can I use ceramic? 25uf?" CreationDate="2010-11-30T17:16:43.567" UserId="2006" />
  <row Id="9970" PostId="7336" Text="@markrages - Could you please explain why the desired ratio is half?" CreationDate="2010-11-30T17:17:19.200" UserId="529" />
  <row Id="9971" PostId="7338" Score="1" Text="if this is too much hardware for SO then please come back. i would bet they can help. taking c code and making vb is very software." CreationDate="2010-11-30T17:18:29.583" UserId="230" />
  <row Id="9972" PostId="7336" Text="it is correlated to an unavoidable hardware divide by 2." CreationDate="2010-11-30T17:20:35.853" UserId="230" />
  <row Id="9973" PostId="7342" Text="Yes, that was my idea as well, but they're not DOF; you can have a change in the magnetometer's reading unless you move in at least one of the other DOF. Unless your magnetic field moves with respect to your reference system. But then they're not real DOF. Otherwise you could add a light sensor and call it a 10th DOF. It isn't. You may call it a parameter though." CreationDate="2010-11-30T17:21:23.343" UserId="2064" />
  <row Id="9974" PostId="7340" Score="1" Text="please do not use a signature." CreationDate="2010-11-30T17:21:41.110" UserId="230" />
  <row Id="9975" PostId="7336" Score="1" Text="I'd guess that the divide by two is because the hardware is oversampling the RS232 bits" CreationDate="2010-11-30T17:23:37.697" UserId="566" />
  <row Id="9976" PostId="7324" Text="yeah, i am removing my comments. my bad." CreationDate="2010-11-30T17:25:55.040" UserId="230" />
  <row Id="9977" PostId="7336" Score="1" Text="@Joby, I don't believe this is correct.  For an asynchronous port such as RS232, the hardware typically oversamples by a factor of 16x, not 2x." CreationDate="2010-11-30T17:27:26.100" UserId="529" />
  <row Id="9978" PostId="7340" Text="@ Kortuk: I was only being polite! :-)" CreationDate="2010-11-30T17:30:47.970" UserId="2064" />
  <row Id="9979" PostId="7332" Score="2" Text="The max232 datasheet is a free download." CreationDate="2010-11-30T17:31:45.690" UserId="411" />
  <row Id="9980" PostId="7336" Score="1" Text="@semaj 2^4=16 so assuming you don't divide to be less then 1 the percent error will work out the same." CreationDate="2010-11-30T17:33:21.660" UserId="319" />
  <row Id="9981" PostId="7332" Score="1" Text="page 17. http://datasheets.maxim-ic.com/en/ds/MAX220-MAX249.pdf" CreationDate="2010-11-30T17:35:31.430" UserId="230" />
  <row Id="9982" PostId="7336" Text="semaj is probably right.  Maybe somebody should pull up the datasheet and check?  The same error appears with oversampling ratios 2,3,4,6,8,12,13,16,24,26,39,78,156, and 312." CreationDate="2010-11-30T17:40:08.803" UserId="411" />
  <row Id="9983" PostId="7326" Text="thanks for clarification." CreationDate="2010-11-30T17:44:52.877" UserId="230" />
  <row Id="9984" PostId="7336" Text="@Kellenjb - I agree, the percent error does work out to be the same.  Divisors of 4 and 8 would also yield the same error; however, the value of the baud rate generator is different.  I'm guessing that the OP is looking the correct formula so which divisor do you pick?  Not having the part number of data sheet to look it up, we have to guess.  All of the implementations I have worked with sample at 16x.  This could be wrong but it is my best guess." CreationDate="2010-11-30T17:50:55.020" UserId="529" />
  <row Id="9985" PostId="7342" Score="2" Text="The Sparkfun sensor has a &quot;fake&quot; extra three degrees of freedom with the magnetometer.  If you were using the input from the IMU in a Kalman filter or state-space representation, you would have 9 sources of data, but only 6 possible mechanical directions of motion.  The additional data sources may provide you with a more accurate idea of how you have moved, though." CreationDate="2010-11-30T17:52:30.480" UserId="1477" />
  <row Id="9986" PostId="7337" Text="Yeah, I've seen that some charge extra. But I'm pretty sure the one I am using do it without extra charge since cards from different people are manufactured in the same batch, they have to mill out the cards anyway, or something like it." CreationDate="2010-11-30T18:23:44.513" UserId="1605" />
  <row Id="9987" PostId="7332" Text="I see, so it's a fixed number for capacitance for each particular model..." CreationDate="2010-11-30T18:25:38.803" UserId="2006" />
  <row Id="9988" PostId="7343" Text="I used the miter tool on the outline rectangle in the dimention layer. That seem to work. Do you also know how to specify a small rectangle (ca 20 x 10 mm) to be milled in the middle of the card?" CreationDate="2010-11-30T18:25:50.207" UserId="1605" />
  <row Id="9989" PostId="7325" Text="Well, its part of one of my own projects... It's not really a book problem.. Would you like the context of the problem?" CreationDate="2010-11-30T18:36:13.297" UserId="2085" />
  <row Id="9990" PostId="7332" Text="I suppose a little higher capacitance won't hurt.  It's not really a place where precision capacitance is required." CreationDate="2010-11-30T18:39:53.450" UserId="411" />
  <row Id="9991" PostId="7344" Text="You are wasting a lot of power in the 150 ohm resistors.  What is the 555 for?" CreationDate="2010-11-30T18:55:24.513" UserId="411" />
  <row Id="9992" PostId="7344" Text="@markrages Well, idea was to have it run PWM in order to conserve power. I'm not quite sure which resistors to use, so I'll probably get some weaker after I take into account transistor's voltage drop. The 150Ω value was given to me by an LED calculation program. There was some discussion about this on the question I linked." CreationDate="2010-11-30T18:59:56.990" UserId="1240" />
  <row Id="9993" PostId="7342" Score="1" Text="@mjc: Specifically, the long-term integral error of the magnetic sensor (compass) is effectively nil, which can be used to eliminate that error from the gyroscope." CreationDate="2010-11-30T19:10:31.143" UserId="1407" />
  <row Id="9994" PostId="7340" Score="2" Text="@Stevenvh, I was just letting you know because I have edited it out many times. Signatures are not allowed, but I understand your want to do them." CreationDate="2010-11-30T19:18:19.323" UserId="230" />
  <row Id="9995" PostId="7325" Text="@Ned, I would enjoy it, I may be able to help you in a more substantial way. If you would rather email me then give everything away in general on the internet I am fine with that." CreationDate="2010-11-30T19:20:04.173" UserId="230" />
  <row Id="9996" PostId="7343" Text="Unless you are milling the board yourself, you will need to work with your board manufacturer to understand their requirements. I have not seen anyone doing internal routing / cutouts in their basic offerings for free, so you would be getting a quote anyways. You may be able to get away with overlapping drill hits, but no guarantees there, and board houses may not like it. " CreationDate="2010-11-30T19:23:06.560" UserId="638" />
  <row Id="9997" PostId="7344" Score="3" Text="small suggestion: It looks like you are using multisim, you can create hierarchical blocks to simplify your schematic some. For this design you could put the resistor and LED in a block, you would then past 10 copies of the block into your schematic. It may not seem like it would help for something like this, but when you start having cases where you want to change out the footprint of all of the LEDs and then add a single mosfet to each led set, or whatever may happen, then it becomes very nice to change it once and have it repeat for all of them." CreationDate="2010-11-30T19:32:58.253" UserId="319" />
  <row Id="9998" PostId="7344" Text="@Kellenjb Thanks a lot! I'll explore that option. " CreationDate="2010-11-30T19:38:10.700" UserId="1240" />
  <row Id="9999" PostId="7344" Text="@AndrejaKo No problem, I teach Multisim and Ultiboard as part of our capstone class so I have taught plenty of people about that. It's been a huge help for a lot of people." CreationDate="2010-11-30T19:41:20.620" UserId="319" />
  <row Id="10000" PostId="7332" Score="1" Text="@Matt: The main difference between the whole swath of MAX232-related chips is ones that either operate faster and/or with less capacitance (to allow physically smaller--and cheaper--caps)  @mark: I think the MAX232 is actually two charge pumps, a voltage doubler (to get ~+9 V) and voltage inverter (for -9 V)" CreationDate="2010-11-30T19:53:36.537" UserId="1407" />
  <row Id="10001" PostId="7345" Score="1" Text="Would 2N2222A be a suitable replacement for 2N2222?" CreationDate="2010-11-30T19:55:26.823" UserId="1240" />
  <row Id="10002" PostId="7345" Score="1" Text="Yeah, the letters behind part numbers typically indicate variants (of minor parameters or packages) or different grades of parts.  I think the only difference between the basic and -A part is a lower saturation voltage, which is a useful thing." CreationDate="2010-11-30T19:58:37.843" UserId="1407" />
  <row Id="10003" PostId="7345" Text="@Nick T OK then. Thanks a lot! I'll pick 2N2222A then." CreationDate="2010-11-30T20:00:54.030" UserId="1240" />
  <row Id="10004" PostId="7312" Text="Thanks for the explanation! I installed the unit today and was able to test the difference between connecting that wire and leaving it disconnected. When disconnected and hooked up to my iPhone, the audio was barely audible and basically just static. When connected to chassis ground, the audio was crystal clear. The only problem now is that when I have my phone plugged in and charging there is some minor static. It's barely noticeable, but worth noting for the purposes of this question." CreationDate="2010-11-30T20:03:50.270" UserId="2024" />
  <row Id="10005" PostId="7345" Text="@AndrejaKo: I'm not sure about what sort of technical level your project is for, but see my edit regarding LED drivers." CreationDate="2010-11-30T20:06:05.840" UserId="1407" />
  <row Id="10006" PostId="7340" Text="@stevenvh: There's usually a distinction between *sensing* degrees of freedom and *actuating* them.  For sensing a single point (or rigid body?) you only need 6, three each for translation and rotation.  A robotic arm could have as many as you want (though typically 6-7, the same as a human arm, excluding phalanges)" CreationDate="2010-11-30T20:23:17.103" UserId="1407" />
  <row Id="10007" PostId="7342" Text="As an additional note, you may find that actually measuring more degrees of freedom can be a detriment in some controls applications.  This is especially true with cheaper sensors and high-noise environments.  If you only need to control one degree of freedom, then the added noise from the other 5-8 measurements may make the control more difficult." CreationDate="2010-11-30T20:26:56.650" UserId="1477" />
  <row Id="10008" PostId="7345" Text="@Nick T  They do look very interesting. I'm currently looking what local electronics shops here have and am thinking about [LM3914](http://www.national.com/mpf/LM/LM3914.html#Overview) at the moment. " CreationDate="2010-11-30T20:28:45.590" UserId="1240" />
  <row Id="10009" PostId="7345" Score="1" Text="@AndrejaKo: That's a different kind of LED driver, one that deals more with logic, not the power." CreationDate="2010-11-30T20:39:56.263" UserId="1407" />
  <row Id="10010" PostId="7345" Text="@Nick T Yeah, but as far as I can see from its datasheet, it should be able to drive my LEDs and I can't find any non-logic drivers in local shops at the moment. I think that I should be able to set it to show all LEDs all the time." CreationDate="2010-11-30T20:44:47.953" UserId="1240" />
  <row Id="10011" PostId="7345" Score="1" Text="@AndrejaKo: There's no point in using it then; just use a single transistor if you want something that basic.  Your &quot;local shop&quot; restriction is somewhat odd; you will never have a decent selection of special parts" CreationDate="2010-11-30T21:01:07.960" UserId="1407" />
  <row Id="10012" PostId="7310" Text="That looks like it should do the trick, only down side is it seems a bit expensive.  Thanks!" CreationDate="2010-11-30T21:43:50.153" UserId="2115" />
  <row Id="10013" PostId="7347" Text="Its only got to power my device for less than 10 minutes then can be recharged. It also has to be as light as possible. Thats why i am using AAAs not AAs. " CreationDate="2010-11-30T22:05:59.230" UserId="1623" />
  <row Id="10014" PostId="7346" Score="2" Text="Also please note that there is no guarantee that you'll actually get 12V form batteries. I've seen 1.2 V batteries which give out as much as 1.6 V if the load isn't large enough." CreationDate="2010-11-30T22:09:20.620" UserId="1240" />
  <row Id="10015" PostId="7352" Text="@markrages feel free to pick a concrete example... :)" CreationDate="2010-11-30T22:09:47.373" UserId="771" />
  <row Id="10016" PostId="7346" Text="The load should be large enough as i'm driving 2 stepper motors and then using a voltage regulator(7805) to power my circuit(which consists of a microcontroller, 3 sharp distance sensors and a ULN2803a). " CreationDate="2010-11-30T22:15:20.823" UserId="1623" />
  <row Id="10017" PostId="7312" Text="@Brian, Yeah, if you imagine cutting the ground line between the car battery and interface as well as car battery and audio source. This will leave the ground floating with no fixed reference, which is why you didn't get much out. The static you hear when you are charging is probably just something you will have to deal with. This is probably a combination of a small ground loop and power noise." CreationDate="2010-11-30T22:15:43.830" UserId="319" />
  <row Id="10018" PostId="7347" Text="A step-up regulator is not going to be 100% efficient so the question is how do the losses associated with a step-up regulator compare with the difference of energy density between AA and AAA cells?  A regulator also adds cost but using 4 AA cells with a regulator compared to 10 AAA cells without would save money in the long run." CreationDate="2010-11-30T22:16:16.940" UserId="529" />
  <row Id="10019" PostId="7347" Text="How much current does your device actually require at 12 V?  If it's less than 300 mA or so, you could get away with 2 AA cells, or possibly 4xAAAs as their internal resistance is about double." CreationDate="2010-11-30T22:26:22.330" UserId="1407" />
  <row Id="10020" PostId="7347" Text="It wouldn't produce enough current this is from just looking at a few quickly. " CreationDate="2010-11-30T22:28:47.980" UserId="1623" />
  <row Id="10021" PostId="7347" Text="@Dean: How much current does your device require at 12 V/5 V?" CreationDate="2010-11-30T22:30:58.690" UserId="1407" />
  <row Id="10022" PostId="7347" Text="If I remember correctly each coil requires 32mA theres 8 of them then unsure on the circuit yet to test it. " CreationDate="2010-11-30T22:31:04.223" UserId="1623" />
  <row Id="10023" PostId="7352" Text="done, for msp430f2013 and cr2032 cell." CreationDate="2010-11-30T22:37:07.420" UserId="411" />
  <row Id="10024" PostId="7346" Score="1" Text="@Dean, please do not write a signature." CreationDate="2010-11-30T22:37:39.980" UserId="230" />
  <row Id="10025" PostId="7356" Text="I agree on that the platform is not a major issue, a cool project will get people involved, regardless of what platform." CreationDate="2010-11-30T22:56:03.297" UserId="230" />
  <row Id="10026" PostId="7358" Score="1" Text="I agree on that the platform is not a major issue, a cool project will get people involved, regardless of what platform." CreationDate="2010-11-30T22:58:11.953" UserId="230" />
  <row Id="10027" PostId="7324" Score="1" Text="As markrages mentioned, the guts of a driver, which controls the actual hardware, will be the same whether you have an OS or not.  The main differences when writing drivers is 1) the interfaces need to fit in a standard model (e.g. open, close, read, write, ioctl) for the OS, and 2) the method in which the driver is installed and activated." CreationDate="2010-11-30T23:08:51.727" UserId="1322" />
  <row Id="10028" PostId="7358" Text="ARM *Cortex M3* is a micro-controller version of ARM, it runs THUMB instructions and lacks things like an EBI/MMU.  I am not debating between an AVR and a vastly more powerful applications processor specific processor like OMAP3 with an arm926.  for your reference: http://www.arm.com/products/processors/index.php" CreationDate="2010-11-30T23:21:51.080" UserId="2115" />
  <row Id="10029" PostId="7356" Text="I suppose you are correct in that Arduino developers may not have that much experience in strictly embedded programming/debugging, but I think it may attract a lot of other developers such as Web/Windows/Linux developers who could contribute usefully at the application level.  Also, wouldn't the skilled ARM developers be a subset of those willing to work on an Arduino version?" CreationDate="2010-11-30T23:26:05.243" UserId="2115" />
  <row Id="10030" PostId="7352" Text="We use Cr2032 at my work with the ACLK at 32768, waking every 2 seconds. We use a Transceiver every 90 seconds. We take a temp measurement every 10 seconds. We can last in excess of 4 years with a new CR2032." CreationDate="2010-11-30T23:26:43.203" UserId="230" />
  <row Id="10031" PostId="7356" Score="1" Text="@stbtra, I know many different microcontrollers and consider myself skilled, I do not use arduino. I have never had need as I was originally taught other technologies and there is not competitive advantage to me. Short answer, ARM developers are not a subset." CreationDate="2010-11-30T23:28:36.167" UserId="230" />
  <row Id="10032" PostId="5294" Text="@FakeName, it is not removed, but it requires a moderator so we can decide when it is a bad question someone is trying to sneak by. I have made it. You just have to flag for moderator attention and request it." CreationDate="2010-11-30T23:45:44.020" UserId="230" />
  <row Id="10033" PostId="7341" Text="Why the down vote?" CreationDate="2010-12-01T00:15:57.087" UserId="529" />
  <row Id="10034" PostId="7356" Text="For me, an ARM is preferred, but it really does depend on what you're trying to build." CreationDate="2010-12-01T00:56:19.113" UserId="712" />
  <row Id="10035" PostId="7328" Text="Power management ICs are very good at this and can be a very important part of a resilient device." CreationDate="2010-12-01T01:55:23.320" UserId="230" />
  <row Id="10036" PostId="7356" Text="@pingswept, not surprising, but I agree." CreationDate="2010-12-01T02:58:51.340" UserId="230" />
  <row Id="10037" PostId="7318" Text="Can you clarify &quot;simultaneously&quot; and give a little better idea of the setup?" CreationDate="2010-12-01T03:29:59.057" UserId="1477" />
  <row Id="10038" PostId="5165" Text="I have yet to find an autorouter that didn't need any touching up after it has finished the job.  So in all likelihood, you'll want to take the design back into Eagle." CreationDate="2010-12-01T03:53:59.083" UserId="1477" />
  <row Id="10039" PostId="7370" Score="1" Text="If you output pin floats when it is not connected then you will want to have a pullup on the P channel MOSFET." CreationDate="2010-12-01T04:00:17.377" UserId="230" />
  <row Id="10040" PostId="7324" Text="@tcrosley, If you have a lot of information about those specifics I would love to see an answer about it." CreationDate="2010-12-01T04:02:32.103" UserId="230" />
  <row Id="10042" PostId="7371" Text="Thanks, I would suggest you made your post also have a link to &quot;Linux Device Drivers.&quot; Otherwise, Very thorough." CreationDate="2010-12-01T05:54:26.310" UserId="230" />
  <row Id="10043" PostId="7288" Text="But what if my output has again got to be in 8 bits?? that is my problem. it is not the saturation of the data type used for addition that is the problem, it is the constraints imposed by the size of the output that is." CreationDate="2010-12-01T06:02:19.293" UserId="2103" />
  <row Id="10044" PostId="7361" Text="Yes, they cut my school a good deal, it was still in the thousands after a 95% price cut." CreationDate="2010-12-01T06:24:03.533" UserId="230" />
  <row Id="10045" PostId="7367" Text="People forget this, but giving a shake keeps them from getting locked in place." CreationDate="2010-12-01T06:24:33.283" UserId="230" />
  <row Id="10046" PostId="7298" Text="@Chris: I am not sure how LPC would solve the problem. even if adding the residuals does not overflow, convolving it with the filter to obtain the original frame and then having to cast it into a data type with shorter range would cause saturation. this algo must happen in real-time (or at least simulated real-time), so my time limit for processing is also very low." CreationDate="2010-12-01T06:37:19.797" UserId="2103" />
  <row Id="10047" PostId="7285" Text="yes, real-time or at least simulated real-time dsp with audio is what i am trying to do. unfortunately, i am not sure if i can provide any more details :(. i am interested in knowing a little more about the slow response average that you mention. what about automatic gain control?" CreationDate="2010-12-01T06:48:27.317" UserId="2103" />
  <row Id="10048" PostId="7340" Text="@Kortuk: I don't think a little sig like that is inappropriate. Something with an image, or a link, or other such non-sense, sure... but a tiny little sign off like that? Does it really detract from the site so much?" CreationDate="2010-12-01T08:02:21.847" UserId="2137" />
  <row Id="10049" PostId="5330" Text="Basically, as long as we have NAT, no." CreationDate="2010-12-01T11:01:32.950" UserId="1374" />
  <row Id="10050" PostId="7375" Score="1" Text="Smells a bit like homework." CreationDate="2010-12-01T11:03:25.880" UserId="1374" />
  <row Id="10051" PostId="7374" Text="@Runtime Analysis - Not as viable on a separate embedded system, particularly when there is no underlying OS running at the same time, for example, a bootloader, which this is." CreationDate="2010-12-01T11:04:33.663" UserId="1374" />
  <row Id="10052" PostId="7375" Score="1" Text="guess it does look kinda like homework. wish it was then i could at least ask a tutor or lecturer. &#xA;&#xA;Its for a project im working on.  &#xA;&#xA;Thanks for the tag for electromagnetism didn't notice that one and it is one of the uses i thought of." CreationDate="2010-12-01T11:39:45.967" UserId="2138" />
  <row Id="10053" PostId="7286" Score="1" Text="@Chris: Yes, it was in the back of my mind. That's why I didn't abandon the supercomputer idea completely yet. There are other issues; the little bastards eat 25mA @ 12MHz, so that's a not-so-low power of 62W in toto. But at least I should get a good price for purchasing a lot of 500 LEDs. :-)" CreationDate="2010-12-01T11:43:35.890" UserId="2064" />
  <row Id="10054" PostId="7340" Score="2" Text="@Ralph, I am sorry if you feel otherwise, SO had a very large discussion, if you have a question with 4 answers and everyone adds a little signature then you greatly increase the length of the page. And what does the signature add? I am the rule enforcer, I am sorry if you do not like them. Every post is signed by the user with his name and ID. On your profile you can post information related to your specific background. By signing, you are doubling the space this takes per page. I would love to discuss this in chat if you still have concerns." CreationDate="2010-12-01T14:42:36.660" UserId="230" />
  <row Id="10055" PostId="7294" Text="@Mark, @kellenjb, now that I see that he has absolutely no control over your input, and you are not getting input, i would suggest auto-gain. I am not sure this is another method. I would make the gain level determined slowly over a long time frame." CreationDate="2010-12-01T14:43:51.497" UserId="230" />
  <row Id="10056" PostId="7382" Text="I'm not sure if it applies directly to electronics but code reuse is a big thing in the software world. Wikipedia has an article on code reuse: http://en.wikipedia.org/wiki/Code_reuse" CreationDate="2010-12-01T15:21:14.753" UserId="1225" />
  <row Id="10057" PostId="7382" Score="2" Text="I believe the reuse concept applies but while it is difficult in software to manage it is an all together different beast in hardware. Software is trying to crack the problem of global reuse, where code is shared between companies and somewhat between languages. Hardware engineering hasn't even solved the local reuse in any smooth manner that I know of. Given all the different proprietary schematic and CAD formats in the mix I think it would be better to solve local reuse first and then move on to global hardware reuse. " CreationDate="2010-12-01T15:28:57.263" UserId="2140" />
  <row Id="10058" PostId="7382" Score="1" Text="@Funkyeah, you may find that many companies have not solved local code reuse. It is a different beast with hardware, much different." CreationDate="2010-12-01T15:43:10.553" UserId="230" />
  <row Id="10059" PostId="7382" Score="1" Text="I would love to know if there is a method for hardware." CreationDate="2010-12-01T15:43:32.237" UserId="230" />
  <row Id="10060" PostId="7374" Text="You can still step through it with a debugger as Joby suggests.  Depending on the complexity it may or may not be helpful." CreationDate="2010-12-01T16:04:46.860" UserId="1407" />
  <row Id="10061" PostId="7383" Text="I have seen those features before, how well do they actually work?" CreationDate="2010-12-01T16:19:17.457" UserId="230" />
  <row Id="10062" PostId="7383" Score="1" Text="@Kor: Personally I've just reused other people's and my own 'normal' sheets, owing to a mix of unfamiliarity with the process to create them (though it seems easy enough), having to make minor modifications because of different requirements, or the sheet not being thought of beyond the single project." CreationDate="2010-12-01T16:21:58.080" UserId="1407" />
  <row Id="10063" PostId="7380" Score="1" Text="I see a gateway effect where NAT is used to map IPv4 addresses on a local domain and map them to global IPv6. This way most hardware can be kept the same locally. " CreationDate="2010-12-01T16:25:16.783" UserId="230" />
  <row Id="10064" PostId="7383" Text="We use Altium Designer as well and I love the tool for schematic capture and layout. I haven't used the snippet tool at all for our own IP and would be interested to here if other people use it/like it." CreationDate="2010-12-01T16:27:56.457" UserId="2140" />
  <row Id="10065" PostId="7286" Text="The C52 doesn't have SPI ISP like the S52, right?" CreationDate="2010-12-01T16:30:47.943" UserId="883" />
  <row Id="10066" PostId="7382" Score="1" Text="I think the ability of software developers to refactor their code aids greatly to the viability of reuse. They can use an externally developed module or library for proof of concept and quick functionality and then refactor to gain performance where it is needed. Hardware does not have this benefit in that hardware refactoring (what I would basically call respinning a board) is financially unviable if done on a case by case basis. The other fact I would point out is that hardware modules are inherently tightly coupled due to the real world cost of over designing components." CreationDate="2010-12-01T16:34:20.413" UserId="2140" />
  <row Id="10067" PostId="7382" Text="A second note though is that there is no real reason why the &quot;Snippets&quot; concept in Altium as mentioned below could not be cross-platform and highly reusable so long as there functionality and extensibility is clearly defined. An example might be for a power supply where &quot;this switching supply is for high efficiency low cost generation of 5V @ 3A... it can be configured to provide X-Y output by changing the feedback resistors&quot;" CreationDate="2010-12-01T16:37:16.953" UserId="2140" />
  <row Id="10068" PostId="7374" Text="+1 for the great links." CreationDate="2010-12-01T16:48:06.453" UserId="529" />
  <row Id="10069" PostId="7385" Text="sell them. wait, or you could build a room full of synchronizing lights. the college student in my is giving a +1, the engineer is crying." CreationDate="2010-12-01T16:51:02.800" UserId="230" />
  <row Id="10070" PostId="7348" Score="1" Text="Have you seen http://focus.ti.com/lit/wp/slay015/slay015.pdf ? Some interesting points beside the absolute sleep power numbers." CreationDate="2010-12-01T16:59:29.940" UserId="883" />
  <row Id="10071" PostId="7287" Text="Along this line, work with an engineering student society at a college to come in after hours/on a weekend and do an event to with students on creating the fireflies. It would probably fly with undergrads or students in a program that don't get much exposure to electronics." CreationDate="2010-12-01T17:28:05.247" UserId="536" />
  <row Id="10072" PostId="7287" Text="@kortuk, dude what school are you talking about? Sounds awesome." CreationDate="2010-12-01T17:31:22.190" UserId="1200" />
  <row Id="10073" PostId="7287" Text="@Rick_2037, okstate.edu if you ever want a tour let me know. I am one of the students that runs the &quot;Design Commons&quot; a large room with all the equipment you need to rapid prototype and TAs to assist you with technical issues(related to EE or fab). As a freshmen you can come do projects here, we cover cost of things like etchant, and we have programmers available for you for a couple different processors, a 3D printer to make cases, soldering stations, milling and etching stations, nice test and measurement stations, general stations, microcontroller stations. ece.okstate.edu is our department." CreationDate="2010-12-01T17:57:30.433" UserId="230" />
  <row Id="10074" PostId="7368" Text="Thanks for the great answer. For anyone who wants more info, I got pretty much the same answer plus more at http://www.reddit.com/r/robotics/comments/ee7ze/does_anyone_know_where_to_find_the_datasheet_for/c17hida" CreationDate="2010-12-01T18:00:05.957" UserId="2133" />
  <row Id="10075" PostId="7388" Text="I've heard rumors of Pb-Sn solder being incompatible with certain RoHS PCB finishes.  Does anyone have real data about this?" CreationDate="2010-12-01T18:01:37.233" UserId="411" />
  <row Id="10076" PostId="7375" Text="What are you actually trying to do?  Make a geophone/seismometer?" CreationDate="2010-12-01T18:01:43.207" UserId="1407" />
  <row Id="10077" PostId="7375" Text="not quite. similar to some ways to a Seismometer.&#xA;I am trying to determine the waveform of the deflection of a vibrating beam via non contact methods. I have used a vibrometer for similar stuff in the past but they are very expensive and due to setup are not suitable outside of lab conditions and i do not need as precise a setup as that." CreationDate="2010-12-01T18:08:26.197" UserId="2138" />
  <row Id="10078" PostId="7383" Text="I've used Altium too and done a bigger project with it. It's very very easy to manage bigger projects, and if you think beforehand about reusable components I bet you can set up your hardware very flexible. Atleast, for the schematic, the PCB is something you probably have to redraw every time. I like Altium's Device Sheet system a lot." CreationDate="2010-12-01T18:15:24.313" UserId="1476" />
  <row Id="10079" PostId="4618" Text="Does your home-brew hardware programmer allow debugging?  You might be fine programming alone, but would need a hardware programmer if you wanted to do on-chip debugging (setting breakpoints in code and halting execution when you reach that point) as that operation might do funny things with the reset line.  " CreationDate="2010-12-01T18:22:24.627" UserId="1571" />
  <row Id="10080" PostId="7383" Text="@hans, I have not gotten to use altium design, but they showed a way you could paste a hardware system in and have its PCB match. It looked nice." CreationDate="2010-12-01T18:35:08.017" UserId="230" />
  <row Id="10081" PostId="7389" Text="Sounds great, we do something similar in the design labs at our university. The issue is when something that does not work get added. I hate it, but it gets the job done." CreationDate="2010-12-01T18:37:21.243" UserId="230" />
  <row Id="10082" PostId="7387" Text="Yes, they do, but I think that Altium does it in a more advanced way, but h blocks is how I have seen it done." CreationDate="2010-12-01T18:38:19.743" UserId="230" />
  <row Id="10083" PostId="7389" Score="2" Text="A reuse strategy needs a lot of discipline, sorta like a version control system. It doesn't work as well if everyone doesn't understand how and when to use it." CreationDate="2010-12-01T18:50:20.293" UserId="638" />
  <row Id="10084" PostId="7383" Text="I've used the multichannel design features to duplicate circuitry fairly easily within a single design, that may also be extensible across PCBs." CreationDate="2010-12-01T18:50:29.047" UserId="1407" />
  <row Id="10085" PostId="7388" Text="@mark: I found [this page](http://www.uyemura.com/solder_joint_reliability.htm) that suggests ENEPIG (EN, electroless paladium, IG) finishes don't get along with Pb-Sn that well.  The question seems to be more about just adding RoHS parts to an otherwise PbSn process though." CreationDate="2010-12-01T19:07:25.367" UserId="1407" />
  <row Id="10086" PostId="7389" Score="1" Text="I have taken some ASIC classes and know FPGA design quite well so I definitely would say that the design and reuse of analog ASIC components are a direct allegory to discrete component solutions at the schematic level. My questions to you would be how does the designer of any given building block disseminate the usefulness and flexibility of said building block? Using your voltage reference example, do others in your team know about the voltage reference IP because its a small team or because it can be searched for? If the voltage reference is flexibile how do you convey that information?" CreationDate="2010-12-01T19:22:42.247" UserId="2140" />
  <row Id="10087" PostId="7392" Text="Thank you. I can't up vote your answer unfortunately. No rep" CreationDate="2010-12-01T19:24:40.340" UserId="2143" />
  <row Id="10088" PostId="7392" Score="4" Text="@user2143: You can accept the answer" CreationDate="2010-12-01T19:26:36.020" UserId="1407" />
  <row Id="10089" PostId="7374" Text="Cscope is the sort of thing I was imagining. I was hoping for something a little more shiny, but it's a good start. Thanks." CreationDate="2010-12-01T20:05:48.013" UserId="712" />
  <row Id="10090" PostId="7381" Text="Yeah, I've spent some quality time with arch/arm/cpu/arm926ejs/at91/*, but thanks for the suggestion. It turns out that the code I was looking for was actually in the processor boot ROM, which only Atmel can access. The gory details are here: http://www.at91.com/forum/viewtopic.php/f,9/t,19732/start,0/st,0/sk,t/sd,a/" CreationDate="2010-12-01T20:10:02.017" UserId="712" />
  <row Id="10091" PostId="7381" Score="1" Text="By the way, overall, I've been pretty impressed with U-boot. For the vast number of boards and CPUs that it supports, it's pretty well organized. The documentation is sparse, but that seems to be par for the course for bootloaders." CreationDate="2010-12-01T20:11:57.273" UserId="712" />
  <row Id="10092" PostId="1970" Text="Electrons moving faster than the speed of light in a medium cause a [cool blue glow](http://en.wikipedia.org/wiki/Cherenkov_radiation)" CreationDate="2010-12-01T20:30:42.627" UserId="1407" />
  <row Id="10093" PostId="7389" Text="In the larger groups I've worked in, we have a datasheet repository for relevant parts. Each datasheet would have enough information for someone to use the design without spending a week reading up on relevant literature. For my work, the different IC processes we use limits the sharing our whole team can do, so a better organization of the blocks wasn't necessary. We usually don't do duplicate designs, unless the design requirements are significantly different - we had only one bandgap voltage reference, for example." CreationDate="2010-12-01T20:31:57.837" UserId="638" />
  <row Id="10094" PostId="7386" Text="No, I'm not sure. I just read it somewhere. I went along with it because I didn't see anything spit out of the UART, but last night I discovered a short between the serial out and ground on the GPS due to poor soldering of male headers on my part.I'm still working on getting it fixed." CreationDate="2010-12-01T20:42:06.953" UserId="2006" />
  <row Id="10095" PostId="7381" Text="@pingswept: hey, Linux on 4 layers.  Nice.  Maybe I should look into that chip instead of the iMX233.  I was having a hell of a time trying to get my ARM + two SDRAM chips on 4 layers and shelved it to work on other projects.  I'm an Altium user too." CreationDate="2010-12-01T20:58:37.830" UserId="1270" />
  <row Id="10096" PostId="5523" Text="&quot;If you have more than one mode with &quot;V&quot; in the name, just try all of them&quot; should be &quot;use the V DC mode; starting with the highest range (e.g. 20 V) and going down (e.g. next 2V, etc.)" CreationDate="2010-12-01T21:41:11.450" UserId="206" />
  <row Id="10097" PostId="7381" Text="The 9G20 and the iMX233 are pretty close. I chose the 9G20 because the Ethernet MAC is built in, and the chips are a little cheaper in low quantity, but the iMX233 was a close runner up." CreationDate="2010-12-01T22:30:08.880" UserId="712" />
  <row Id="10098" PostId="7381" Text="Also, take a look at the Chumby Hacker Board-- might be a good place to start if you do decide to build a system around the iMX233. The Altium files are on this wiki page: http://wiki.chumby.com/mediawiki/index.php/Chumby_hacker_board_beta" CreationDate="2010-12-01T22:31:12.137" UserId="712" />
  <row Id="10099" PostId="7402" Score="2" Text="Do you always double check that they did not update it since you last downloaded?" CreationDate="2010-12-01T23:05:40.673" UserId="230" />
  <row Id="10100" PostId="7402" Score="1" Text="I don't usually bother, unless I have a problem." CreationDate="2010-12-01T23:24:06.293" UserId="305" />
  <row Id="10101" PostId="7373" Text="Have you tried asking on the uboot developers mailing list?" CreationDate="2010-12-02T00:20:55.283" UserId="1938" />
  <row Id="10102" PostId="7401" Score="1" Text="Spotlight is awesome for datasheets." CreationDate="2010-12-02T00:23:12.067" UserId="411" />
  <row Id="10103" PostId="7403" Score="13" Text="This is good, but if I actually use a part in a project (as opposed to browsing around to see what's out there) I download the datasheet and keep it in SVN with the rest of the project's design files.  Then whoever looks at the project a decade from now doesn't have to hunt down a bunch of obsolete datasheets to understand how the circuit is meant to work." CreationDate="2010-12-02T00:24:13.363" UserId="411" />
  <row Id="10104" PostId="7390" Score="1" Text="I think the rule still stands that youneed to always check the datasheet." CreationDate="2010-12-02T00:34:18.023" UserId="230" />
  <row Id="10105" PostId="7390" Text="@Kortuk: True, though when it says matte tin plated, all systems go." CreationDate="2010-12-02T00:42:17.823" UserId="1407" />
  <row Id="10106" PostId="3655" Score="1" Text="Naming a (more or less true) RNG, &quot;-PRNG&quot; is unfortunate." CreationDate="2010-12-02T00:54:36.297" UserId="1407" />
  <row Id="10107" PostId="7390" Text="@NickT, I thought your info was rock solid, was your first +1, but I thought I would add that for others." CreationDate="2010-12-02T01:18:32.050" UserId="230" />
  <row Id="10108" PostId="3019" Text="(shameless plug) the AEMB is known to run uC/OS-II in Altera FPGAs too -- http://www.aeste.my/node/7" CreationDate="2010-12-02T01:31:12.230" UserId="1938" />
  <row Id="10109" PostId="2641" Text="(shameless plug) the GNU radio (USRP2) uses an AEMB bundled with a bunch of DSP blocks. It does software-defined radio really well -- http://www.aeste.my/node/29" CreationDate="2010-12-02T01:33:38.780" UserId="1938" />
  <row Id="10110" PostId="2701" Text="There are also flash-based FPGAs (ACTEL) and some SRAM-based ones with built-in flash (Xilinx Spartan3AN, LatticeXP)." CreationDate="2010-12-02T01:37:54.737" UserId="1938" />
  <row Id="10111" PostId="7234" Text="No luck. Here's their response: &quot;Unfortunately the product you have is so old, we no longer have any of the specifications for the product. I’m sorry that we couldn’t be of more assistance.&quot;" CreationDate="2010-12-02T01:59:52.830" UserId="2089" />
  <row Id="10112" PostId="7340" Text="@Kortuk: I'm not concerned :) I agree that we shouldn't have sigs on a site like this, I just didn't this one was a big enough deal to warrant editing it out. However, maybe you're right. Take care of before it becomes a problem, right? ;)" CreationDate="2010-12-02T02:22:10.677" UserId="2137" />
  <row Id="10113" PostId="7340" Text="@Ralph, I have edited9 out in the last 48 hours, I am notifying people to get it to stop." CreationDate="2010-12-02T02:56:39.850" UserId="230" />
  <row Id="10114" PostId="7413" Score="1" Text="I have found that this stuff is usually warped and comes out poorly. It's fine for some people, but be warned." CreationDate="2010-12-02T03:34:34.120" UserId="319" />
  <row Id="10115" PostId="7413" Text="You mean the super-thin 0.010&quot; stuff, or the 0.0625&quot; material too?" CreationDate="2010-12-02T03:53:07.867" UserId="411" />
  <row Id="10116" PostId="7403" Score="1" Text="I'll second that. Relevant project datasheets have a directory in my svn directory to keep everything together. You don't have to search for something if you know where it is to begin with. " CreationDate="2010-12-02T03:54:19.343" UserId="638" />
  <row Id="10120" PostId="7413" Text="The .0625&quot; stuff is what I have seen it in." CreationDate="2010-12-02T04:41:08.630" UserId="319" />
  <row Id="10122" PostId="7408" Score="4" Text="Why are people voting this up?  Yes, it's humorous, no, it does nothing to answer the question.  Put droll like this in comments if you insist." CreationDate="2010-12-02T04:43:45.867" UserId="1407" />
  <row Id="10123" PostId="7415" Text="No way it's for strain relief, it's not even touching the leads." CreationDate="2010-12-02T04:56:43.073" UserId="2006" />
  <row Id="10124" PostId="6688" Text="@Mark, your comment is confusing; heat and temperature are only distantly related, through things like specific heat, time, mass...  Presumably a 250°C iron might do the job and form a joint (eventually), but a 400°C iron would impart much less heat for the same joint." CreationDate="2010-12-02T05:02:56.997" UserId="1407" />
  <row Id="10128" PostId="7418" Score="1" Text="You don't think 35v would arc?" CreationDate="2010-12-02T05:28:10.973" UserId="2006" />
  <row Id="10129" PostId="7421" Score="1" Text="Interesting! Certainly didn't know that could happen!" CreationDate="2010-12-02T05:53:58.640" UserId="1688" />
  <row Id="10130" PostId="7408" Score="1" Text="Your diagram does not show a part protruding above the &quot;curled section,&quot; which is what I am talking about. Are you saying the rubber-bakelite can extend above the curled section?" CreationDate="2010-12-02T08:07:30.950" UserId="1256" />
  <row Id="10131" PostId="7417" Text="Well, foam is textured plastic. I used the word foam because it definitely has some give to it if you push it. Do you have a source to point to about this venting?" CreationDate="2010-12-02T08:14:30.587" UserId="1256" />
  <row Id="10132" PostId="7408" Score="2" Text="Dang I'm good. *whistles* (Thanks markrages!)" CreationDate="2010-12-02T08:22:23.577" UserId="2118" />
  <row Id="10133" PostId="7408" Score="1" Text="Yes, it looks like the pad is the rubber seal protruding a little bit.  I would guess that vibration is handled better when the cap is sitting on the pad, rather than the sleeve part." CreationDate="2010-12-02T08:28:34.197" UserId="411" />
  <row Id="10134" PostId="7420" Text="Good find... I've tried out a few other organization tools in OSX, but never been struck by them. I do like Delicious Library, though it won't do PDFs!" CreationDate="2010-12-02T08:36:11.850" UserId="2118" />
  <row Id="10135" PostId="7400" Text="I'm pretty sure it's not foam, but plastic or rubber." CreationDate="2010-12-02T08:51:22.030" UserId="1374" />
  <row Id="10136" PostId="7393" Text="Thank you Tyblu, Looks like it could be interesting. i will research that further. Sorry if i gave the impression of measuring two points at the same time. It should only measure one point. " CreationDate="2010-12-02T08:58:16.823" UserId="2138" />
  <row Id="10137" PostId="7413" Text="ebay is great for copper clad. Some of the ebay stores also have their own websites." CreationDate="2010-12-02T09:11:09.980" UserId="2118" />
  <row Id="10138" PostId="7369" Text="Will it work on FS mode only or in HS mode too?" CreationDate="2010-12-02T09:21:51.443" UserId="1471" />
  <row Id="10139" PostId="966" Score="4" Text="I wonder if this could be made a wiki, incorporating answers with a minimum number of votes. Disagreements can be settled by duel." CreationDate="2010-12-02T11:22:12.893" UserId="2118" />
  <row Id="10140" PostId="7426" Text="Of course, many microcontrollers contain internal pullups (which may need enabling in software)" CreationDate="2010-12-02T12:31:17.047" UserId="566" />
  <row Id="10142" PostId="7428" Text="Without knowing anything about @stbtra's project requirements, it's premature to recommend a SunSPOT" CreationDate="2010-12-02T13:11:50.630" UserId="566" />
  <row Id="10143" PostId="7432" Score="2" Text="I like the intercepting a major sensor, that's a great idea, not many thieves will sit and troubleshoot a car's system to figure out why it's not starting, if they can't bypass the ignition or pop a cable back on the battery, they're not going to stick around much longer." CreationDate="2010-12-02T13:29:58.133" UserId="982" />
  <row Id="10144" PostId="7425" Text="Nice addition of diagrams!" CreationDate="2010-12-02T13:31:32.080" UserId="982" />
  <row Id="10145" PostId="2641" Text="@sybreon Oddly enough I'm using USRP2 on my Senior Design project -- Nice" CreationDate="2010-12-02T13:35:09.223" UserId="982" />
  <row Id="10146" PostId="7431" Score="1" Text="I'd like to prevent unauthorised access to the car." CreationDate="2010-12-02T13:50:03.003" UserId="1938" />
  <row Id="10147" PostId="7436" Score="1" Text="It unfortunately doesn't work that way. If one diode heats up, the forward voltage *falls*, allowing it to conduct more current, heating it up more, causing the forward voltage to fall... eventually leading to diode failure." CreationDate="2010-12-02T15:12:14.943" UserId="1225" />
  <row Id="10148" PostId="7436" Text="@Thomas: That's why I mention thermal coupling. If temperatures are the same, the diode carrying the higher current will have the higher voltage drop." CreationDate="2010-12-02T15:20:02.547" UserId="2064" />
  <row Id="10149" PostId="7434" Text="There may be fuel in the line near the engine and so the engine might run for a bit and then suck air. Not good for the engine." CreationDate="2010-12-02T15:21:04.947" UserId="2006" />
  <row Id="10150" PostId="7358" Text="ARM is a different class completely. I mean look at this: &quot;The Cortex-M3 NVIC is highly configurable at design time to deliver up to 240 system interrupts with individual priorities, dynamic reprioritization and integrated system clock.&quot; ATMega328 has 2 interrupts for comparison." CreationDate="2010-12-02T15:24:34.617" UserId="2006" />
  <row Id="10152" PostId="7340" Text="@Kortuk: a single &quot;TIA&quot; per post doesn't double the page length. To me it's good manners, and good manners is the best way to prevent people smashing each other's heads in an overcrowded and overstressed world. :-) I hope we don't need a police to prevent us from being nice." CreationDate="2010-12-02T15:29:10.810" UserId="2064" />
  <row Id="10153" PostId="7417" Text="@Ryan When you use the word &quot;foam&quot; it generally implies some level of compliance, versus plastic." CreationDate="2010-12-02T15:45:00.967" UserId="1407" />
  <row Id="10154" PostId="7418" Score="2" Text="35 V can't arc in air (takes minimum ~300V), not sure about along some dielectric interface though." CreationDate="2010-12-02T15:47:27.690" UserId="1407" />
  <row Id="10155" PostId="7435" Text="They do make low-leakage diodes - on Digikey I found a diode with 1nA leakage at 125V, and if you want to spend $16, you can get one that has only 3pA leakage. If powered-down operation takes 250nA, then one of the low-leakage diodes will lose less than 0.4%. " CreationDate="2010-12-02T15:52:26.227" UserId="638" />
  <row Id="10156" PostId="7434" Text="@Matt: I'd imagine a fuel pump failing (or running out of fuel) should not cause actual engine damage.  Automotive engineers aren't that brilliant, but they like their DFMEAs." CreationDate="2010-12-02T15:54:00.287" UserId="1407" />
  <row Id="10157" PostId="7431" Score="1" Text="@sybreon: A brick will still allow someone &quot;access&quot; to your car.  Or do you mean start and drive it?" CreationDate="2010-12-02T15:55:54.547" UserId="1407" />
  <row Id="10158" PostId="7432" Text="Thanks for the edit Nick.  I need to learn how to do that myself at some point." CreationDate="2010-12-02T16:03:23.603" UserId="1819" />
  <row Id="10159" PostId="7434" Text="That's a good idea Jim C.  I knew I'd forget some things.  Sucking in air with fuel pump off shouldn't damage the engine at all, in fact modern engines shut off injectors (effectively same as shutting off fuel pump) when at high RPM with no load to save gas.  The only real negative would be the fact that the engine will require a little bit more cranking on the first start after someone tries to start it with the pump off as the pump will have to pressurize the fuel lines first." CreationDate="2010-12-02T16:06:33.087" UserId="1819" />
  <row Id="10161" PostId="7440" Score="1" Text="Can you find out the atmel model numbers if so have a look at the datasheet." CreationDate="2010-12-02T16:45:21.817" UserId="1623" />
  <row Id="10162" PostId="7440" Score="4" Text="The difference between button cells and LiPo's is extreme; the current they can deliver is just about as far apart as you can get (few milliamps for a button cell, dozens of amps for some LiPo)  Substituting one for another sounds like a bad idea." CreationDate="2010-12-02T16:49:51.457" UserId="1407" />
  <row Id="10163" PostId="7440" Text="Some of the parts were deliberetly painted over&#xA;" CreationDate="2010-12-02T16:49:59.723" />
  <row Id="10164" PostId="7440" Score="1" Text="@Nick- Why not put your comment as an answer?" CreationDate="2010-12-02T16:54:25.697" UserId="1235" />
  <row Id="10165" PostId="7408" Text="@tyblu: +1 for good answer and incorporating magic smoke!" CreationDate="2010-12-02T16:55:38.910" UserId="1235" />
  <row Id="10166" PostId="7425" Text="And to complement &quot;pull-&quot; (a gentle force), usually something else will *force* (drag, etc) the line in the opposite direction, e.g. here, the switches." CreationDate="2010-12-02T16:56:00.640" UserId="1407" />
  <row Id="10167" PostId="7403" Text="It is a big project if the one project needs a few hundred data-sheets; for such a big project I would hope that it itself is organised in a way that results in good places to store them." CreationDate="2010-12-02T16:59:54.350" UserId="1773" />
  <row Id="10168" PostId="7440" Text="@Nick T the heli is a bit unusual it has add on telemetry box smaller than a matchstick box which I plug in a slot in the heli this small box has the dead battery it only reads some sensors.what do you think,is that too much?&#xA;" CreationDate="2010-12-02T17:04:03.257" />
  <row Id="10169" PostId="7440" Text="Possible duplicate: http://electronics.stackexchange.com/questions/6008/use-diodes-to-obtain-lowered-dc-voltage" CreationDate="2010-12-02T17:12:02.890" UserId="1333" />
  <row Id="10170" PostId="7442" Text="I can't know,whitout doing to much work,how the circuit behaves.when it was new the 250mah battery lasted for 2-3 hours " CreationDate="2010-12-02T17:15:02.690" />
  <row Id="10171" PostId="7440" Text="@Felix, so your button cell wouldn't power any motors?  Radios would be borderline, depending on power, etc.  See my answer about how the LiPo voltage can drift extremely wildly anyways." CreationDate="2010-12-02T17:16:43.523" UserId="1407" />
  <row Id="10172" PostId="7440" Text="Please, edit your question because it's unclear." CreationDate="2010-12-02T17:33:09.963" UserId="938" />
  <row Id="10173" PostId="7403" Score="1" Text="octopart.com is your friend." CreationDate="2010-12-02T17:39:38.780" UserId="1661" />
  <row Id="10174" PostId="7434" Text="I once heard of a system based of this idea for Yugo (which is famous for it's unreliability). Unless it's turned off, after about 5 minutes it would intermittently start cutting power to the fuel pump and after couple of minutes more cut power completely. In the end, it looks like the car broke down (which isn't uncommon for that type of car). On the bad side, it's unsafe and you have to search the ~10 minute radius if someone does steal your car." CreationDate="2010-12-02T17:40:55.550" UserId="1240" />
  <row Id="10175" PostId="7444" Score="1" Text="Among other things, this would be totally unregulated and is a bad idea." CreationDate="2010-12-02T17:44:23.873" UserId="1407" />
  <row Id="10176" PostId="7432" Score="1" Text="Pretty good answer, needed to look pretty. `:P`" CreationDate="2010-12-02T17:59:03.333" UserId="1407" />
  <row Id="10177" PostId="4551" Text="Is PWM output (with some additional filtering) a good way to dump audio?  I'd think the &quot;right&quot; way would be to kick it out via I²S or similar to a purpose built DAC (though I don't know what they cost)" CreationDate="2010-12-02T18:06:21.547" UserId="1407" />
  <row Id="10178" PostId="7444" Text="but if the 5v is regulated, wouldn't the 3v be regulated since its on the vout? Others suggested this to me in questions I had asked in the past" CreationDate="2010-12-02T18:21:54.457" UserId="2006" />
  <row Id="10179" PostId="7442" Score="1" Text="@Felix: That suggests it draws about 100 mA, which most button cells can't deliver.  Some *may* be able to, but it would be at the edge of their capability, and eat your money.  Why can't you find a replacement rechargeable battery?" CreationDate="2010-12-02T18:25:06.507" UserId="1407" />
  <row Id="10180" PostId="7444" Score="1" Text="In fact there is something similar in tip #13 of this document by microchip: https://docs.google.com/viewer?url=http://www.microchip.com/stellent/groups/techpub_sg/documents/devicedoc/en026368.pdf" CreationDate="2010-12-02T18:27:29.287" UserId="2006" />
  <row Id="10181" PostId="7444" Score="1" Text="The 5V is regulated, but dropping it down to 3v with a resistor isn't. As you sink more current, your 3v will sag. I discovered this while trying to power an XBee pro using a voltage divider. The voltage sagged down to ~2.some V from 3.3ish due to the large current spikes from transmitting." CreationDate="2010-12-02T18:29:44.417" UserId="536" />
  <row Id="10182" PostId="7444" Text="Thanks for clearing it up" CreationDate="2010-12-02T18:31:07.003" UserId="2006" />
  <row Id="10183" PostId="7444" Text="I wondered if putting a cap on the 3v side of the resistor would provide the necessary current during spikes to keep the voltage from sagging. Never tested it though." CreationDate="2010-12-02T18:40:06.307" UserId="536" />
  <row Id="10184" PostId="7448" Text="Buzz or *tssss*?  The lines are usually quite warm, so they might rapidly evaporate the water that falls on them." CreationDate="2010-12-02T18:48:58.873" UserId="1407" />
  <row Id="10185" PostId="7444" Text="@pfyon: Assuming your average current draw remained constant, yes, a capacitor (with size proportional to the frequency of spikes and allowable voltage tolerance) would accomplish that.  However, maintaining a constant average draw (including during things like sleep/shutdown) is often untenable (or incredibly wasteful), and in any case the massive capacitor might cost more than a voltage regulator." CreationDate="2010-12-02T18:58:15.310" UserId="1407" />
  <row Id="10186" PostId="7450" Text="Quite true, you often pay for integration.  However some highly integrated parts are cheaper if you're using every single feature to it's full potential, e.g. door-zone ICs" CreationDate="2010-12-02T19:01:01.500" UserId="1407" />
  <row Id="10187" PostId="7448" Text="You're right, it was more of a 'hissing'. Edited" CreationDate="2010-12-02T19:09:55.787" UserId="536" />
  <row Id="10188" PostId="7442" Text="Thanks that cleared it up for me.I guess I'll have to order one " CreationDate="2010-12-02T19:10:38.033" />
  <row Id="10189" PostId="7449" Text="What is a partial discharge?" CreationDate="2010-12-02T19:26:25.733" UserId="712" />
  <row Id="10190" PostId="3887" Text="So everything acts as an inductor at high enough frequency?  Is the inductance primarily from the coiled foil layers?" CreationDate="2010-12-02T19:29:28.737" UserId="142" />
  <row Id="10191" PostId="7451" Text="These other chemistries would have to be magical because they don't directly push electrons through metal?" CreationDate="2010-12-02T19:35:12.293" UserId="142" />
  <row Id="10192" PostId="7448" Text="those birds must have some tough feet then" CreationDate="2010-12-02T19:49:31.697" UserId="2006" />
  <row Id="10196" PostId="7451" Score="1" Text="Mostly because they aren't electrochemical cells, so the energy to electricity conversion would have to happen some other way (e.g. power plants or [plant plants](http://nexus404.com/Blog/2010/04/16/stanford-university-succesfully-generates-electricity-from-plants-stanford-scientists-harness-energy-in-algae-photosynthesis/).)" CreationDate="2010-12-02T20:10:37.637" UserId="1407" />
  <row Id="10197" PostId="7449" Score="3" Text="http://en.wikipedia.org/wiki/Partial_discharge ?" CreationDate="2010-12-02T20:16:24.497" UserId="1407" />
  <row Id="10198" PostId="7340" Text="@Stevenvh, I am trying to be polite, in general you will notice I do not remove someone saying, &quot;Hope this helps&quot;. It is not worth it. However, removing signatures is not a matter that is up for discussion, it is a hard rule that existed before I started moderating and one that had a large amount of discussion before a decision was met." CreationDate="2010-12-02T20:24:46.763" UserId="230" />
  <row Id="10199" PostId="7442" Score="1" Text="@NickT, @Felix. I work in button cells, You cannot easily pass 10mA with one. They suggest you do not pass 1mA." CreationDate="2010-12-02T20:35:35.180" UserId="230" />
  <row Id="10200" PostId="7442" Text="@Kortuk, in what aspect (do you work in button cells)?" CreationDate="2010-12-02T20:41:26.847" UserId="1407" />
  <row Id="10201" PostId="7442" Text="@NickT, they are the primary power source for a number of the sensor nodes used at my work. we have made and deployed over 2000 devices using them and have done extensive lifetime testing with them. Different loads, pulsed loads compared to continuous. It is interesting." CreationDate="2010-12-02T21:10:02.777" UserId="230" />
  <row Id="10202" PostId="4328" Score="1" Text="depending on how theoretical you want to be, an anti-mater battery would be the theoretical highest i believe as when it reacts with mater you get a perfect or near perfect conversion from mass to energy." CreationDate="2010-12-02T21:19:52.320" UserId="1438" />
  <row Id="10203" PostId="7402" Text="Personally, I try to organize files by their content rather than their file type.  A PDF and PPT file for an electronics part go in a &quot;Datasheets&quot; folder, rather than being segregated arbitrarily into &quot;PDF&quot; and &quot;Powerpoint&quot; folders.  An e-book in PDF format would go in a &quot;Books&quot; folder, not in the same folder as a datasheet." CreationDate="2010-12-02T21:37:33.560" UserId="142" />
  <row Id="10204" PostId="7403" Text="@markrages: You use SVN for electronics projects?  That sounds... organized." CreationDate="2010-12-02T21:39:53.323" UserId="142" />
  <row Id="10205" PostId="4328" Text="Do antimatter-matter reactions count as chemical reactions?" CreationDate="2010-12-02T21:42:47.817" UserId="142" />
  <row Id="10206" PostId="7456" Text="Brilliant. I could hack these myself, or, do you know of someone selling pre-hacked cables? " CreationDate="2010-12-02T21:51:43.337" UserId="1225" />
  <row Id="10207" PostId="7457" Text="Space restrictions." CreationDate="2010-12-02T21:53:12.417" UserId="1225" />
  <row Id="10209" PostId="7456" Text="Sorry, I don't, I just remembered the article" CreationDate="2010-12-02T21:55:39.683" UserId="566" />
  <row Id="10210" PostId="7459" Text="You beat me to it by one minute.  Cheers." CreationDate="2010-12-02T22:05:00.317" UserId="1477" />
  <row Id="10211" PostId="7455" Text="You could just make the user supply their own &quot;batteries not included&quot;" CreationDate="2010-12-02T22:05:01.957" UserId="566" />
  <row Id="10212" PostId="7455" Text="@Joby Taffey, that is an option if I can't find a cheap one. But the cable brings a lot more features; without it, you can only use the default settings of the module, and you can't download the data from the datalog." CreationDate="2010-12-02T22:06:53.637" UserId="1225" />
  <row Id="10213" PostId="7457" Text="Having it off-board might be useful for users that have several of the products... maybe." CreationDate="2010-12-02T22:07:23.577" UserId="566" />
  <row Id="10215" PostId="7448" Text="are these the big bad cross-country lines? how many conductors?" CreationDate="2010-12-02T22:16:28.283" UserId="740" />
  <row Id="10216" PostId="7449" Text="@Nick T - nice link!" CreationDate="2010-12-02T22:18:55.023" UserId="740" />
  <row Id="10217" PostId="7442" Text="@NickT, we use other technologies, but due to their cost and our number of sensor nodes, I know button cells the best." CreationDate="2010-12-02T22:22:17.953" UserId="230" />
  <row Id="10218" PostId="7450" Text="what are door-zone ICs?" CreationDate="2010-12-02T23:07:13.033" UserId="1688" />
  <row Id="10219" PostId="4551" Text="He isn't all that concerned with quality. PWM should be fine, and will keep the cost down to his required $5." CreationDate="2010-12-02T23:10:29.117" UserId="305" />
  <row Id="10220" PostId="7462" Text="Yeah I was considering this but adding a USB port will be bigger than the 6 pin header and the USB/UART would only be used while on the ground (normally is flying in a plane.)" CreationDate="2010-12-02T23:12:52.910" UserId="1225" />
  <row Id="10221" PostId="7462" Score="3" Text="@Thomas: Micro USB is smaller than a 6-pin header." CreationDate="2010-12-02T23:17:52.563" UserId="1407" />
  <row Id="10222" PostId="7449" Text="That is some weird stuff. Thanks for the link." CreationDate="2010-12-02T23:17:57.797" UserId="712" />
  <row Id="10223" PostId="7444" Text="This technique may work better if the 3.3V is buffered using an op-amp or transistor buffer.  Anything with high-input and low-output impedance." CreationDate="2010-12-03T00:27:16.883" UserId="820" />
  <row Id="10225" PostId="7465" Text="From what i understand then from your answer 14.5 is the maximum input voltage. How does it go from a Maximum dropout voltage to a minimum input voltage?" CreationDate="2010-12-03T00:43:49.263" UserId="1623" />
  <row Id="10226" PostId="7462" Text="@Nick T, Micro USB, never heard of it! I was thinking of using a Mini USB type B socket. Either way directly adding USB probably isn't an option at the moment, I don't think my MCU supports it." CreationDate="2010-12-03T00:46:09.087" UserId="1225" />
  <row Id="10227" PostId="7465" Score="1" Text="The maximum dropout voltage Vd is 2.5 volts, meaning the input has to be at least 2.5 volts above the output.  Since the output is 12 volts, you add the two together to get a minimum input of 14.5 volts.  Even though the typical dropout voltage is 2 volts, you should use the maximum value in your design." CreationDate="2010-12-03T00:50:45.997" UserId="1322" />
  <row Id="10229" PostId="7468" Score="1" Text="You're killing me, Smalls! :-) I dislike programs written in assembly, too hard to maintain for any decently sized project." CreationDate="2010-12-03T00:53:58.317" UserId="319" />
  <row Id="10230" PostId="7468" Score="1" Text="@JustJeff he is saying that he doesn't think the fact it is for pics makes a difference for code conventions, but included it anyways." CreationDate="2010-12-03T00:54:37.690" UserId="319" />
  <row Id="10231" PostId="7468" Text="@JustJeff, @Kellenjb is right." CreationDate="2010-12-03T01:02:24.647" UserId="938" />
  <row Id="10232" PostId="7468" Text="@Kellenjb, I use assembly to reduce costs." CreationDate="2010-12-03T01:09:35.347" UserId="938" />
  <row Id="10233" PostId="7453" Score="1" Text="...but if it gets annoying, you could just think of it as a million electrons clapping their hands &amp; cheering you on in your journey home" CreationDate="2010-12-03T01:11:39.967" UserId="1571" />
  <row Id="10234" PostId="7455" Score="1" Text="The FTDI FT232RL device is $4.50 alone, so I don't think you will have any luck, at least with FTDI devices. (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=768-1007-1-ND )" CreationDate="2010-12-03T01:11:44.190" UserId="1374" />
  <row Id="10236" PostId="7468" Text="@JustJeff - Because assembly is normally rigidly structured, and has no variable indentation/traditional loops, etc.... Therefore, coding practices which are designed for languages with normal indentation/flow-control/hierarchical structure are not really applicable." CreationDate="2010-12-03T01:15:35.963" UserId="1374" />
  <row Id="10237" PostId="7468" Text="@O Engenheiro I understand there are times it's needed, I just always favor C. Any good optimizer can make assembly smaller and faster then I could ever imagine writing. Good optimizer cost money though." CreationDate="2010-12-03T01:15:53.983" UserId="319" />
  <row Id="10238" PostId="7468" Text="This question is a almost a duplicate of http://stackoverflow.com/questions/4094227/books-on-best-practices-conventions-in-assembly" CreationDate="2010-12-03T01:19:04.157" UserId="566" />
  <row Id="10239" PostId="7448" Text="They do? I never noticed." CreationDate="2010-12-03T01:19:41.153" UserId="1940" />
  <row Id="10240" PostId="7431" Text="hehe.. yes, start and drive it. :)" CreationDate="2010-12-03T01:20:09.977" UserId="1938" />
  <row Id="10241" PostId="7403" Text="Cheers, SVN comrade! I use it too. It's great if you work on multiple computers. Organizationally, it really only as good as your underlying folder structure." CreationDate="2010-12-03T01:27:49.677" UserId="1374" />
  <row Id="10242" PostId="7468" Text="@Joby Taffey, I have the same question on Stackoverflow: http://stackoverflow.com/questions/946950/are-there-a-code-conventions-for-assembly-mainly-pic. I've made a question about how to transfer it to E&amp;R on meta (http://meta.electronics.stackexchange.com/questions/173/transfer-question-from-so-to-er) and I'm trying to follow that suggestions. If I'm doing something wrong, please help me fix it." CreationDate="2010-12-03T01:32:39.767" UserId="938" />
  <row Id="10243" PostId="7358" Text="@Matt  That's the ARM Cortex NVIC *Core* that Keil licenses. Most implementations don't use all 240 interrupts.  also if you're going to count all interrupt sources the avr has ~ 21.  In any case I think the complexity of the interrupt controller isn't super game changing." CreationDate="2010-12-03T02:23:20.360" UserId="2115" />
  <row Id="10244" PostId="7358" Score="1" Text="@stbtra: Yes, we all know that ARM licenses cores to companies to build controllers with.  Our point is that ARM is generally a step up from even the high-end AVRs, and is *categorically steps above* the limited AVRs used by Arduino platforms." CreationDate="2010-12-03T02:26:38.387" UserId="1407" />
  <row Id="10245" PostId="7470" Text="+1 for the good comments - more important in assembly than elsewhere!" CreationDate="2010-12-03T02:40:10.280" UserId="1938" />
  <row Id="10246" PostId="4328" Score="1" Text="If you consider them physics, everything is physics - even chemistry." CreationDate="2010-12-03T02:48:25.127" UserId="1938" />
  <row Id="10247" PostId="7468" Text="Using assembly with the low, low end MCUs is a great way to save cost; usually the volume will be so high that the pain is worth it.  A former co-worker spent weeks trying to crush code to add microstepping to a LIN instrument gauge (essentially a stepper motor controller) running a 1.5KB Freescale MC08QT1 (was already quite full) and succeeded with a whopping ~30 bytes left." CreationDate="2010-12-03T02:53:53.407" UserId="1407" />
  <row Id="10248" PostId="3361" Text="+1 for Mercurial. I like it, though I have a feeling that proficiency with git would be more valuable. Getting to know the basics with SVN is fairly important if you want to contribute or pull from other projects, as that is what many of them use." CreationDate="2010-12-03T03:29:33.657" UserId="2118" />
  <row Id="10249" PostId="7470" Text="Too many comments can be just as bad as no comments, though. How many times have you seen a pukeload of asterix and line breaks just to highlight the title of a function? Then every line thereafter has more mind-numbing dribble. (eg. &quot;/* SETS a to ONE&quot;)" CreationDate="2010-12-03T03:33:05.227" UserId="2118" />
  <row Id="10250" PostId="7473" Text="I have a wireless transciever on there which would draw heaps of current intermittently. However, can i get away with this by NEVER operating the transciever when datalogging from the sensors, and only transmit data after logging has finished?" CreationDate="2010-12-03T03:40:06.367" UserId="1688" />
  <row Id="10251" PostId="7424" Text="this is a really helpful suggestion - thanks ducksauz!" CreationDate="2010-12-03T03:57:19.397" UserId="991" />
  <row Id="10252" PostId="7408" Text="I think I owe markrages an ebeer or something." CreationDate="2010-12-03T04:35:08.713" UserId="2118" />
  <row Id="10253" PostId="7298" Text="Obviously if you're adding huge numbers you're not going to be able to play them. You'll have to normalize. What I'm saying is that you can use these residuals as temporary storage to avoid overflow and maintain dynamic range until you finally reach your output signal. This runs in realtime in embedded systems. It's cheaper than an FFT even. " CreationDate="2010-12-03T04:39:26.537" UserId="2092" />
  <row Id="10254" PostId="7473" Text="@cksa: That would definitely help, though your MCU will also be another source of noise, but good bypass capacitors will limit it.  The interesting part of that solution is it's in software, so you could see if it actually matters without much trouble.  If you're going to avoid dual regulators, a simple LC filter for your analog circuitry may be prudent." CreationDate="2010-12-03T04:45:05.563" UserId="1407" />
  <row Id="10255" PostId="7270" Text="Could someone tell me what the right way to act is if there are two answers given that are equally valid; do I just choose one at random to be *the* answer?" CreationDate="2010-12-03T04:53:02.807" UserId="1773" />
  <row Id="10256" PostId="7480" Score="1" Text="Is the question asking about microelectronic component lifetimes, valid digital logic output delay, or distribution grid scheduled maintenance?" CreationDate="2010-12-03T05:31:43.507" UserId="2118" />
  <row Id="10257" PostId="7290" Text="I've seen this done with a Nintendo Wii. Very cool. +1" CreationDate="2010-12-03T05:33:22.723" UserId="2118" />
  <row Id="10258" PostId="7480" Score="1" Text="There's MTBF (useless for most things with software), the &quot;bathtub failure curve&quot;, etc..." CreationDate="2010-12-03T05:35:59.407" UserId="1407" />
  <row Id="10259" PostId="7478" Text="Could always make it a crafts project: http://sites.google.com/site/khromtor/ ... Windows does still support PS2, I'm typing this on a ~10 year old PS2 keyboard on Win7 x64" CreationDate="2010-12-03T05:37:18.793" UserId="1407" />
  <row Id="10260" PostId="7468" Text="@NickT, I have done that with C, with a very nice compiler, it was cheaper than paying an engineer for weeks. And  the code can be maintained." CreationDate="2010-12-03T05:37:39.303" UserId="230" />
  <row Id="10261" PostId="7468" Text="Are there any better compilers for HC08 besides CodeWarrior?  I think the project started out as C but underwent a few mutations because of feature creep." CreationDate="2010-12-03T05:45:13.497" UserId="1407" />
  <row Id="10262" PostId="7290" Text="Our school had a virtual window project a bit back. did it with a Wii, was fun." CreationDate="2010-12-03T05:54:11.707" UserId="230" />
  <row Id="10263" PostId="7270" Text="@kasterma: Yes, though if you actually implemented one instead of another, I'd pick that.  You can always vote them both up." CreationDate="2010-12-03T05:54:57.587" UserId="1407" />
  <row Id="10264" PostId="7479" Text="From the AVR32 line, or the Atmel ARM line?" CreationDate="2010-12-03T06:37:38.177" UserId="2118" />
  <row Id="10265" PostId="7479" Text="Talking about 8-bit AVRs." CreationDate="2010-12-03T06:40:26.723" UserId="1688" />
  <row Id="10266" PostId="7479" Score="1" Text="Well, I think you've got a couple hundred pages of datasheets to bone up on, then! I also just got the LPCXpresso board and am looking forward to many Christmas holiday evenings curled up by the fire with an e-reader. (Note to self: get e-reader.) This is the group to join: http://goo.gl/hz6Rd ." CreationDate="2010-12-03T06:44:06.750" UserId="2118" />
  <row Id="10267" PostId="7479" Score="1" Text="Here are 2 relevant AVRFreaks topics: http://goo.gl/Yv2aa , http://goo.gl/NTWtI" CreationDate="2010-12-03T07:07:00.647" UserId="2118" />
  <row Id="10268" PostId="7478" Text="Common USB drivers won't connect to 2 hosts, but perhaps you can rewrite your own? LUFA is open source." CreationDate="2010-12-03T07:22:23.113" UserId="2118" />
  <row Id="10269" PostId="7478" Text="For Windows to recognise new PS/2 devices you usually have to reboot it with the keyboard plugged in. Either way, I don't see it working: PS/2 has to transmit data to the keyboard as well (to change settings and keyboard LEDs), not just receive it. " CreationDate="2010-12-03T07:52:45.037" UserId="1225" />
  <row Id="10270" PostId="7483" Text="You could use a single MCU so long as it could differentiate between the physical connections." CreationDate="2010-12-03T07:54:48.560" UserId="2118" />
  <row Id="10271" PostId="7439" Text="3 pA vs. 5 nA, what the heck?! That's a factor 1000! But I admit, I should/could have had a look at low-leakage diodes first. That said, the JFET doesn't do bad at all, even better than the BAS416 (1nA vs. 5nA, max. values, which are the only ones that count)" CreationDate="2010-12-03T08:09:38.097" UserId="2064" />
  <row Id="10272" PostId="7480" Score="1" Text="It depends on how you classify failure. For example, say it's a power supply; would it have failed if the output got a bit noisier because the electrolytic capacitors had dropped in value slightly? Or would it have to be a catastrophic failure?" CreationDate="2010-12-03T08:09:38.767" UserId="1225" />
  <row Id="10273" PostId="7480" Text="Could you post one of your circuit diagrams? That would also be helpful. A &quot;circuit&quot; is a very vague reference." CreationDate="2010-12-03T08:09:45.890" UserId="638" />
  <row Id="10275" PostId="7340" Text="FTW, this sig was just my name, 6 chars, below the &quot;TIA&quot;, no 4 line quotations with decorations or so." CreationDate="2010-12-03T08:26:51.780" UserId="2064" />
  <row Id="10276" PostId="7461" Text="The Windows drivers for these can be very shaky, though. " CreationDate="2010-12-03T09:12:36.100" UserId="883" />
  <row Id="10277" PostId="7485" Score="1" Text="@cksa361: &quot;...will never result anyway&quot;. I don't agree here. Since they're mentioned as maximum values it means they _may_ occur, you just don't know how often. Maybe some statistic like standard deviation (typical value should be the mean) would help." CreationDate="2010-12-03T09:14:38.603" UserId="2064" />
  <row Id="10278" PostId="7485" Score="1" Text="@cksa361: re battery life. Suppose you design a handheld device which according to typical values would work for 10 hours on a single battery charge. If the current may be 100 times as large (not even the 1000 like in the BAS416) on some devices the battery will be drained in 6 minutes. Is the device defective? No, you say, it was designed according to the given specs. Yes, I say, your product looses credibility and you'll have to give the customer another one. Which may also be defective. How about 10% of your production?...." CreationDate="2010-12-03T10:00:25.973" UserId="2064" />
  <row Id="10279" PostId="7485" Score="2" Text="but then if you start working with maximum's it's not useful. Go design a product with a 10 hour battery life based on maximum current ratings. You'd end up compromising on increased price, increased battery size and weight, and a battery life that is typically far more in excess than what the user needs." CreationDate="2010-12-03T10:05:52.880" UserId="1688" />
  <row Id="10280" PostId="7485" Text="i think being a perfectionist and overengineering products is counter productive. Take into account typical values because it is what would typically happen (i.e. most of the time). " CreationDate="2010-12-03T10:09:14.873" UserId="1688" />
  <row Id="10281" PostId="7485" Text="@cksa361: &quot;most of the time&quot;. Exactly, like in 90% of the time. Which means 10% rejects, which is unacceptable in any production IMO. Let's see what others have to say about this." CreationDate="2010-12-03T10:28:50.287" UserId="2064" />
  <row Id="10282" PostId="7483" Score="2" Text="what is the issue with the license?" CreationDate="2010-12-03T12:10:50.960" UserId="1397" />
  <row Id="10283" PostId="7481" Text="So in this scenario, I'd be running PyKeyLogger on the computer with the keypad (to detect the keypresses), adding an app in the middle to receive the keypresses and connect to the remote computer, and an app on the remote computer to receive the signals from the keypad server that uses SendKeys to &quot;press&quot; the keys on the remote computer?" CreationDate="2010-12-03T14:32:52.393" UserId="2163" />
  <row Id="10284" PostId="7483" Text="Wow. This is the perfect scenario. But it's probably too late for me to build out. Thanks for the input." CreationDate="2010-12-03T14:34:38.850" UserId="2163" />
  <row Id="10285" PostId="7427" Text="There is a product made that is designed to be a simple switch between the battery and the car. You have to pop the hood to get to it, but I would bet most people who steal cars don't want to go to this trouble. I have always seen it used for people who have 2 home and leave a car unused for months at one or the other and don't want the battery to be drained by all of the little things that the car always has on." CreationDate="2010-12-03T14:48:13.800" UserId="319" />
  <row Id="10286" PostId="7432" Text="You could lock up the breaks, really effective, especially if the car is capable of locking up all 4 wheels. Makes it very difficult to tow." CreationDate="2010-12-03T14:49:46.717" UserId="319" />
  <row Id="10287" PostId="7489" Score="2" Text="I'm guessing you mean insulation instead of isolation." CreationDate="2010-12-03T14:51:13.890" UserId="319" />
  <row Id="10288" PostId="7468" Text="@O Engenheiro, I think StackOverflow is the right place for this question. The only reason it would be a better fit here is if PICs had any change on the answer, but it doesn't appear to make any difference, so its purely programming related." CreationDate="2010-12-03T14:56:30.933" UserId="319" />
  <row Id="10289" PostId="7461" Text="@XTL Agreed, I have found this also." CreationDate="2010-12-03T15:00:23.473" UserId="319" />
  <row Id="10290" PostId="7489" Text="@Kellenjb  Nice catch! In some languages isolation is the proper word and when you take it directly to English, you get [false friend](http://en.wikipedia.org/wiki/False_friend) problem." CreationDate="2010-12-03T15:39:51.430" UserId="1240" />
  <row Id="10291" PostId="7439" Text="@steven: Added more to answer about the JFET.  It may be an interesting use, but it seems somewhat odd.  Using maximum/minimum parameters when characterizing the power use of your device is extremely conservative and is more of an engineering-side thing than sales-side." CreationDate="2010-12-03T15:48:04.573" UserId="1407" />
  <row Id="10292" PostId="7489" Text="@AndrejaKo yep. Insulation does provide isolation, so its not a horribly wrong word, but still technically means something else." CreationDate="2010-12-03T15:49:20.157" UserId="319" />
  <row Id="10293" PostId="7489" Text="@oneat: There are two levels of insulation in most headphone cords, the outer plastic sheath and enamel/lacquer on the individual strands.  The answers are referencing both, but I assume you mean the enamel." CreationDate="2010-12-03T15:51:45.850" UserId="1407" />
  <row Id="10294" PostId="7491" Score="1" Text="Sounds like you need a pair of wire strippers." CreationDate="2010-12-03T15:53:22.930" UserId="1407" />
  <row Id="10295" PostId="7481" Text="@ebynum Yes.  There might be software that does this already for software multiboxing (see the link in the comment to the question, though that's hardware).  Search for &quot;multiboxing software&quot; and see what you get." CreationDate="2010-12-03T15:55:56.330" UserId="1407" />
  <row Id="10296" PostId="7468" Text="@Kellenjb I agree in part with you, but when I use Assembly or C for microcontrollers, I have to take in count memories, oscilators, timers, comparators, etc. This is why I've done this question here. And I think that this community can have more people working with Assembly for embedded than StackOverflow." CreationDate="2010-12-03T16:07:20.987" UserId="938" />
  <row Id="10297" PostId="7461" Text="@XTL, odd, I've used it on Windows and Linux with no issues.  Interesting.  Perhaps I am using an older driver version?  I haven't updated in a few years." CreationDate="2010-12-03T16:11:06.953" UserId="1554" />
  <row Id="10299" PostId="7482" Text="Pretty much all the current NXP parts have fast IO, - many of the older ones (213x, 2106) have been updated with /01 suffix versions to add the fast IO and also fractional baudrate dividers. " CreationDate="2010-12-03T17:03:37.657" UserId="1681" />
  <row Id="10300" PostId="7490" Score="2" Text="sandpaper works well too." CreationDate="2010-12-03T17:04:12.683" UserId="411" />
  <row Id="10301" PostId="7286" Text="@XTL: No, programming the C52 is certainly not as straightforward as more modern controllers. Maybe I should make it a project to build a programmer, then at least I can program all these devices :-)" CreationDate="2010-12-03T17:27:26.360" UserId="2064" />
  <row Id="10304" PostId="7485" Text="The other thing is that the specifications define a device operating envelope that can be much larger than what your design will allow. For example, that diode that you're talking about has a 3pA reverse leakage under normal conditions - at 75V reverse bias. If you're using it in a circuit with a 3.3V regulator, you might not need to worry so much." CreationDate="2010-12-03T19:24:51.977" UserId="638" />
  <row Id="10305" PostId="7491" Text="Even a cheap pair of strippers works far better than a knife or scissors or teeth or whatever." CreationDate="2010-12-03T19:35:55.080" UserId="411" />
  <row Id="10306" PostId="7490" Score="2" Text="Sandpaper doesn't really work that well.  :)" CreationDate="2010-12-03T19:52:02.043" UserId="142" />
  <row Id="10308" PostId="5676" Text="@Mark Did you write your own driver for matlab to talk to your USB devices, or was it provided by mfg.? Sounds like a great idea." CreationDate="2010-12-03T20:19:27.570" UserId="2118" />
  <row Id="10309" PostId="7491" Text="@Nick T @markrages I agree that strippers would normally be a better choice then scissors but here strippers either have wire marking in AWG and we use surface area of the cross-section here or are those which need to be manually adjusted and I can never adjust that type well enough for thin wires." CreationDate="2010-12-03T20:44:47.900" UserId="1240" />
  <row Id="10310" PostId="7286" Text="I could probably use one of those, too :)" CreationDate="2010-12-03T20:49:58.537" UserId="883" />
  <row Id="10311" PostId="7491" Text="I have a pair of basic basic adjustable strippers (kinda like [these](http://www.amazon.com/Klein-Tools-74007-Dial-Stripper/dp/B000GTP0LE)) that I use for everything from about 16 AWG down to 30.  They're always set on 30 (for stripping Kynar), and I have a pretty good feel of how far to slice into wire and yank so I just &quot;score and rip&quot; the insulation instead of nicking the wire.  For mass stripping I have fixed-size tools." CreationDate="2010-12-03T21:35:19.220" UserId="1407" />
  <row Id="10312" PostId="7490" Text="@markrages: The enamel wire in most headphones is practically hair thin (probably 40 AWG?), so sandpaper would probably cause excessive damage" CreationDate="2010-12-03T21:37:27.360" UserId="1407" />
  <row Id="10313" PostId="7481" Text="Wow. If only I had heard about this multiboxing earlier. Thanks. Looks like HotkeyNet is going to do exactly what I wanted." CreationDate="2010-12-03T22:03:19.943" UserId="2163" />
  <row Id="10314" PostId="7508" Score="1" Text="Probably the best option unless you're going really far (though at 5 cm/min, kinda doubt it)  Some sort of split nut would be a good idea so you can attach it wherever without having to thread it the whole way." CreationDate="2010-12-03T22:41:54.213" UserId="1407" />
  <row Id="10316" PostId="7490" Score="1" Text="@endolith.  It works well, and doesn't foul the air and the iron tip like burning enamel.  Fold a bit of sandpaper over the end of the wire, hold it together, then pull the wire out.  It works better than you think it will." CreationDate="2010-12-03T23:30:15.850" UserId="411" />
  <row Id="10317" PostId="7503" Text="That's a great idea, thanks!" CreationDate="2010-12-03T23:53:14.917" UserId="117" />
  <row Id="10318" PostId="7490" Score="1" Text="@markrages: I mean that I've done it and it doesn't work well.  Holding your breath and melting the lacquer with the soldering iron works better." CreationDate="2010-12-04T00:02:36.150" UserId="142" />
  <row Id="10319" PostId="4244" Score="1" Text="Solder will stick to aluminum, if the oxide coating is removed. One way is to scrape the surface under a small pool of oil, and tin the aluminum under the oil." CreationDate="2010-12-04T00:08:49.300" UserId="305" />
  <row Id="10321" PostId="7510" Score="2" Text="RC is a time constant, not a frequency. In your case: tau = RC = (1 uF)(1 kohm) = 1 ms. This time constant doesn't correspond to the cutoff frequency directly, only to the point where the signal reaches 1-1/e or 63% in magnitude. The cutoff frequency is where your signal is at 50%. This is at 1/(2π*tau)." CreationDate="2010-12-04T02:41:11.927" UserId="2118" />
  <row Id="10322" PostId="7421" Text="It sure surprised me. It was fun to try soldering with safety glasses." CreationDate="2010-12-04T02:57:55.967" UserId="1374" />
  <row Id="10323" PostId="7508" Score="1" Text="Even with coarse thread and 7/16&quot; threaded rod, you get 1.8mm per rotation, so, if you don't need better resolution than that, a stepper is not required. Just a magnet and hall switch with a regular motor." CreationDate="2010-12-04T03:37:53.857" UserId="2118" />
  <row Id="10324" PostId="7403" Text="I like Mercurial even better than SVN, and am resolved to take on git sometime in the near future. No central repository connection required." CreationDate="2010-12-04T03:40:15.230" UserId="2118" />
  <row Id="10325" PostId="7508" Text="Actually, I do intend for the car to move several meters or more over time. I'll edit my question to reflect this." CreationDate="2010-12-04T03:42:55.960" UserId="2172" />
  <row Id="10326" PostId="7511" Score="1" Text="http://www.wolframalpha.com/input/?i=1%2F%282+pi+1+uF+1+kohm%29" CreationDate="2010-12-04T03:52:10.907" UserId="142" />
  <row Id="10327" PostId="7507" Score="2" Text="Being born back in the 1960s and a tinkerer of radios from a young age, I'm brainwashed to use only plastic tweaker tools for inductors, and by irrational extension, only plastic for other adjustable parts.  But if I don't have a plastic screwdriver handy, the ordinary metal kind will do for trimpots." CreationDate="2010-12-04T04:00:23.110" UserId="1609" />
  <row Id="10328" PostId="7494" Score="2" Text="As long as it's not a finicky high frequency circuit already touchy about stray inductance and capacitance." CreationDate="2010-12-04T04:03:31.330" UserId="1609" />
  <row Id="10330" PostId="7414" Text="While the idea is nice, the cost of the service (evidenced by your choice not to link to http://www.dropbox.com but instead to your referral account so you can get more space) is a pain. " CreationDate="2010-12-04T05:42:26.340" UserId="857" />
  <row Id="10331" PostId="7406" Text="I have the same 'Disorganized' folder, with the same automatically incremented filenames all over the place." CreationDate="2010-12-04T05:45:39.067" UserId="857" />
  <row Id="10332" PostId="7403" Text="@Mark - Do you check for changes to all the datasheets the next time you order new parts or build a new batch?  Leaving them on the internet guarantees that you're not left out of updates." CreationDate="2010-12-04T05:55:09.950" UserId="857" />
  <row Id="10333" PostId="7420" Text="Yep looks cool, but it's $40.  Out of my price range when I have folders and Spotlight, unfortunately." CreationDate="2010-12-04T05:56:07.623" UserId="857" />
  <row Id="10334" PostId="7395" Text="This is a fine answer.  No reason to make it a comment." CreationDate="2010-12-04T06:01:47.963" UserId="857" />
  <row Id="10335" PostId="7510" Text="yeah I meant 1/RC thanks, was missing the conversion w=2*pi*f anyway" CreationDate="2010-12-04T07:19:15.710" UserId="2175" />
  <row Id="10336" PostId="6931" Text="I'm interested in the mixer method... got any more links? Thanks." CreationDate="2010-12-04T07:56:50.940" UserId="1688" />
  <row Id="10337" PostId="7494" Score="2" Text="You wouldn't use that pot in a HF application, anyways." CreationDate="2010-12-04T09:28:39.520" UserId="1374" />
  <row Id="10338" PostId="7490" Score="1" Text="@markrages &amp; @endolith - there are different types of lacquer. Some is solder-meltable, some is completely unperturbed by a soldering iron. Because something has worked on one product does not mean it will work on the other. Generally, you want to try a soldering iron, and fall back to sandpaper if you have to." CreationDate="2010-12-04T09:30:59.907" UserId="1374" />
  <row Id="10339" PostId="7489" Text="Specifically, for stranded wire with insulation on the individual strands, the term is **Litz wire** (http://en.wikipedia.org/wiki/Litz_wire)" CreationDate="2010-12-04T09:33:07.470" UserId="1374" />
  <row Id="10340" PostId="7514" Text="Do you have the manpages for those calls?" CreationDate="2010-12-04T09:44:39.653" UserId="883" />
  <row Id="10342" PostId="4746" Text="got time? :P I would be very interested in the solution. thanks." CreationDate="2010-12-04T10:49:49.157" UserId="1688" />
  <row Id="10343" PostId="7514" Text="Unfortunately not. All I have is the header file for the DLL, which is where I copied the above from." CreationDate="2010-12-04T12:17:30.733" UserId="2178" />
  <row Id="10345" PostId="6900" Text="Thanks Kortuk, that would explain the low cost." CreationDate="2010-12-04T16:56:54.750" UserId="1841" />
  <row Id="10346" PostId="5658" Text="http://voltsandbytes.com/lpc1343-breakout-board/ Something I ran into." CreationDate="2010-12-04T17:24:30.737" UserId="883" />
  <row Id="10348" PostId="7518" Text="Exactly what I needed - thanks!" CreationDate="2010-12-04T17:46:40.957" UserId="1841" />
  <row Id="10349" PostId="7509" Score="1" Text="Me too. Also a common cigarette lighter will do the job." CreationDate="2010-12-04T17:47:26.830" UserId="244" />
  <row Id="10351" PostId="7403" Score="1" Text="@endolith.   I'm far from an organized person, but version control is just helpful for projects, especially if others are working on the project too.  Otherwise you end up with the &quot;versioned zip file&quot; problem.  And for firmware, it's pretty much a necessity. When the firmware breaks, I can either spend a couple days troubleshooting with a debugger, or just pull up the diff from version control and see what I broke." CreationDate="2010-12-04T18:32:52.987" UserId="411" />
  <row Id="10352" PostId="7403" Score="4" Text="@reemrevnivek.  I normally just leave the datasheets on the web and get them with Google (it's faster than navigating the filesystem.) They are there in SVN for archival purposes, and when I am on a plane or somewhere without internet access.  (Off topic:  Someone should start a website where you register the parts you are using, and it would email you when the datasheet or errata is updated.)" CreationDate="2010-12-04T18:35:20.627" UserId="411" />
  <row Id="10353" PostId="5105" Text="It looks something of a bother to have individual boxes in contrast to a divided box, but then that's a good point about spillage.  I once had a cat run into the room and leap on the table, causing 100s of resistors to go flying all over." CreationDate="2010-12-04T18:47:44.613" UserId="1609" />
  <row Id="10354" PostId="7403" Text="Oh, and why do I use SVN?  Because distributed version control doesn't handle binary files well.  With electronics projects, many of the files are binaries like compiled firmware images and datasheets.  git is really designed for small text files like source code." CreationDate="2010-12-04T18:50:10.240" UserId="411" />
  <row Id="10355" PostId="7519" Score="1" Text="With the Crydom I picked a type which doesn't have expensive parts like heatsinks or screw terminals. I added a picture in my question. And packaging is also required for the other solution (the triac is in TO-220, which _does_ have a heatsink). In other words, I'm not convinced. :-)" CreationDate="2010-12-04T18:53:17.773" UserId="2064" />
  <row Id="10356" PostId="7403" Text="Subversion grinds to a slow crawl if you put too many large binaries in it.  I would probably suggest against keeping gigabytes of PDF files in it, but maybe separate them by project or use.  You can then use externals to make it run a little smoother." CreationDate="2010-12-04T19:09:13.087" UserId="1477" />
  <row Id="10359" PostId="6931" Text="@cksa361, There are a number of options here. I would suggest you look into a &quot;gilbert cell&quot; to design this yourself, but there are many different approaches. Here http://www.google.com/url?sa=t&amp;source=web&amp;cd=1&amp;ved=0CCEQFjAA&amp;url=http%3A%2F%2Fwww.edaboard.com%2Fthread47405.html&amp;rct=j&amp;q=designing%20my%20own%20RF%20mixer&amp;ei=Yqn6TNyDJYKKlweR0_CNDA&amp;usg=AFQjCNFwxdfpf24UKlTRsU4b0_dqvzBYJQ&amp;sig2=aWEamqsyJLeAGDdWOx64TQ&amp;cad=rja they have someone trying to analyze one. You will probably need a signal generator, like a Phased-locked-loop to generate your signal. This will not be any easy task." CreationDate="2010-12-04T20:53:07.220" UserId="230" />
  <row Id="10360" PostId="6931" Text="What is your budget like? I think I can find you some hobbyist projects that actually make most of what you need, then you only need to do a tiny bit of design." CreationDate="2010-12-04T20:55:42.960" UserId="230" />
  <row Id="10361" PostId="7493" Text="'Scope probes often come with a small plastic screwdriver. Do yours fit?" CreationDate="2010-12-04T21:20:13.077" UserId="2118" />
  <row Id="10362" PostId="7519" Text="it still has circuit board in there .... I am not here to convince you, but to try to explain where the cost goes ..... think about it if it was you selling them, BOM cost 2 Euro + pcb and package comes to circa 4 euros, how much would you want to sell it for???" CreationDate="2010-12-04T21:39:30.437" UserId="1397" />
  <row Id="10363" PostId="7515" Text="That is messier, at 1mW you get much less power, but they are trying to keep their system matched at 50ohm, which is not perfectly efficient." CreationDate="2010-12-04T21:43:50.487" UserId="230" />
  <row Id="10364" PostId="7519" Text="@stevenvh how much does it cost you to fab a board and fab the case for it to go in? Don't forget to include labor costs even if it is your own labor." CreationDate="2010-12-04T21:45:45.737" UserId="319" />
  <row Id="10365" PostId="7519" Text="@Stevenvh Also, do you know if the relay adds and protection that isn't in your circuit." CreationDate="2010-12-04T21:47:52.520" UserId="319" />
  <row Id="10366" PostId="7414" Score="1" Text="Free is too expensive for you?" CreationDate="2010-12-04T22:54:23.370" UserId="222" />
  <row Id="10367" PostId="7493" Text="@tyblu Unfortunately, I'm still using my sound as oscilloscope. Once I get a real one, I'll be sure to report here, but that could take a year or two." CreationDate="2010-12-04T23:12:42.520" UserId="1240" />
  <row Id="10368" PostId="7496" Text="I think I'm going to take one of these. " CreationDate="2010-12-04T23:14:06.857" UserId="1240" />
  <row Id="10369" PostId="7523" Text="I think tyblu is correct here. I was planning to come back later and find a project with a preamp. He has done so, take advantage of it. The major thing here is that you need your SWR meter to have the same input impedance as your chip antenna, otherwise you are tuning the circuit to a missmatch." CreationDate="2010-12-04T23:18:06.433" UserId="230" />
  <row Id="10370" PostId="7516" Text="This sounds like people who complain that they sell iPods for 150% the component cost, which if true, is totally amazing.  They should probably be selling them for at least 300-500%.  Design, manufacturing, marketing, logistics is not cheap." CreationDate="2010-12-04T23:29:17.320" UserId="1407" />
  <row Id="10371" PostId="4248" Score="1" Text="Aluminum rust is [commonly used in jewelry](http://en.wikipedia.org/wiki/Corundum). " CreationDate="2010-12-04T23:31:33.603" UserId="1407" />
  <row Id="10372" PostId="7501" Text="Someone downvoted me. I could see many reasons someone would disagree with me, although I would like to know which one they chose." CreationDate="2010-12-04T23:34:06.020" UserId="230" />
  <row Id="10373" PostId="6579" Score="1" Text="Channel 9 said &quot;Sometime next spring&quot; though OEM's.  Does that mean Spring 2011?" CreationDate="2010-12-04T23:39:14.657" UserId="2180" />
  <row Id="10374" PostId="7505" Score="1" Text="5 cm/minute = 3 meters an hour; what needs to travel so blindingly slow?  I'd almost think it would be better to move a little faster do you don't have to be &quot;on&quot;, moving a motor, for so long." CreationDate="2010-12-05T00:09:03.557" UserId="1407" />
  <row Id="10375" PostId="7505" Text="What kind of translation resolution do you need?" CreationDate="2010-12-05T00:41:36.240" UserId="2118" />
  <row Id="10377" PostId="5676" Text="@tyblu Every device supports its own set of commands but the low level communication functions are generally provided by the manufacturer, or you can use one of several free GPIB libraries that are out there, I like pyVISA." CreationDate="2010-12-05T01:36:10.750" UserId="1438" />
  <row Id="10379" PostId="7529" Text="I'm a bit new to all of this, and I'm self-teaching almost everything.  Can you tell me a little more?  IE specific products, or other tips.  I'm browsing all the FTDI products now looking for the right USB solution. " CreationDate="2010-12-05T02:21:52.420" UserId="2180" />
  <row Id="10380" PostId="7529" Score="1" Text="I'll sketch the circuit for you later." CreationDate="2010-12-05T02:25:44.107" UserId="411" />
  <row Id="10381" PostId="7529" Text="No Kidding?! Thank You! " CreationDate="2010-12-05T03:08:10.990" UserId="2180" />
  <row Id="10382" PostId="7525" Text="Would a sprinkler valve work? Do you need the solenoid to use a 120V coil, or could you use a lower voltage (e.g. 6V, 12V)?" CreationDate="2010-12-05T04:42:55.207" UserId="638" />
  <row Id="10383" PostId="7525" Text="I can use a lower voltage... but a purely mechanical (non computer controlled) sprinkler valve probably won't cut it.  What would determine my required voltage?  " CreationDate="2010-12-05T04:57:51.287" UserId="2180" />
  <row Id="10385" PostId="7525" Text="Sprinkler valves are not that simple. They actually won't work without significant pressure, and they take a while to close as well." CreationDate="2010-12-05T06:29:17.553" UserId="1374" />
  <row Id="10386" PostId="7529" Text="FT245 is probably better than FT232" CreationDate="2010-12-05T06:31:43.747" UserId="1374" />
  <row Id="10387" PostId="7531" Score="1" Text="Yeah. with a pure decoder you can only open 1 valve at a time." CreationDate="2010-12-05T06:32:10.390" UserId="1374" />
  <row Id="10389" PostId="7525" Text="This may give you a better idea of what I'm working on: http://physics.stackexchange.com/questions/1642/low-pressure-pulsating-series-of-water-droplets " CreationDate="2010-12-05T06:50:14.763" UserId="2180" />
  <row Id="10390" PostId="7531" Text="How expensive are latching relays?" CreationDate="2010-12-05T06:57:32.727" UserId="2183" />
  <row Id="10392" PostId="7519" Text="@Kellenjb: I don't think it has extra protection circuitry, like a snubber, otherwise it would probably be visible on the print. It would be a feature, wouldn't it? Now it shows just the LED and the photo-triac." CreationDate="2010-12-05T08:12:56.767" UserId="2064" />
  <row Id="10393" PostId="7505" Score="2" Text="I'm trying to do time-lapse photography with a moving camera. So I need the car to move very slowly, and I need it to be stationary during exposures." CreationDate="2010-12-05T08:16:49.430" UserId="2172" />
  <row Id="10394" PostId="7505" Text="I'm not familiar with the terminology, but if &quot;translation resolution&quot; means the degree of accuracy to which I can control the car's position, I'm hoping for error of no more than +/- 2 mm. Does that sound reasonable with hobby components?" CreationDate="2010-12-05T08:25:09.983" UserId="2172" />
  <row Id="10395" PostId="7505" Text="Quite reasonable." CreationDate="2010-12-05T08:43:57.317" UserId="2118" />
  <row Id="10396" PostId="7516" Score="2" Text="@Nick: I'm comparing components with components, not with end user products. In the final product the SSR may cost 30 euros, while the other solution would still cost only 6 euros." CreationDate="2010-12-05T09:30:08.913" UserId="2064" />
  <row Id="10397" PostId="4549" Score="2" Text="@endolith: that's where the springs come in; the effective length of a 30cm spring is several meters." CreationDate="2010-12-05T10:03:22.770" UserId="2064" />
  <row Id="10398" PostId="7073" Text="@Thomas: I wouldn't focus too much on the presumed big opamps. A quad opamp in TSSOP-14 package takes 32mm2 (5x6.4). I doubt you can do better with discrete components. " CreationDate="2010-12-05T10:17:06.300" UserId="2064" />
  <row Id="10399" PostId="3526" Text="In `The soul of a new machine` Tracy Kidder says (paraphrasing) that cavemen used an oscilloscope to see why the fire wouldn't burn. :-)" CreationDate="2010-12-05T10:26:16.137" UserId="2064" />
  <row Id="10400" PostId="4328" Score="1" Text="@sybreon: [Disciplines arranged by purity.](http://xkcd.com/435/)" CreationDate="2010-12-05T10:43:45.787" UserId="1407" />
  <row Id="10402" PostId="7535" Text="I think you've killed it. Best not to fix it 'til you know it's broken, anyway." CreationDate="2010-12-05T12:09:53.700" UserId="2118" />
  <row Id="10403" PostId="7534" Text="definite duplicate, but dilzx needs a few points anyway. +1" CreationDate="2010-12-05T12:20:32.833" UserId="2118" />
  <row Id="10404" PostId="7525" Text="I don't think off-the-shelf valves will be fast enough to achieve that unless it's on a large enough scale that small variations in actuation time don't matter. I think you'd need to be looking at more specialised valves specifically designed for fast and consistent on/off times. How to turn them mon/off will likely be the least of your problems. " CreationDate="2010-12-05T12:23:02.470" UserId="1681" />
  <row Id="10405" PostId="7531" Text="@krapht only slightly more expensive, but it would be a band-aide fix for poor system design. Better to use a serial-to-parallel device, which latches automatically, in the first place." CreationDate="2010-12-05T12:23:35.857" UserId="2118" />
  <row Id="10406" PostId="7537" Text="But surely the other components have to be assembled, packaged, tested and approved as well. I think my comparison is fair; just different components, all other things equal." CreationDate="2010-12-05T12:40:47.760" UserId="2064" />
  <row Id="10408" PostId="7535" Text="@tyblu: I'm sure there are other measures I haven't thought of. Anyway, comments are welcome too. For instance, am I exaggerating when I decouple via RCs?" CreationDate="2010-12-05T13:08:28.390" UserId="2064" />
  <row Id="10409" PostId="7403" Text="Not having your own copies is dangerous. Data sheets get updated frequently, and more than once, I found a bug on a board only because I was able to compare an older version of a data sheet with the current one; the changes were indeed the hint to the detail that caused the trouble. I try to store all versions and updates of a data sheet from the moment I evaluate a certain part.&#xA;&#xA;Also, the only place to look for a data sheet is the manufacturer's website. Other sources are good for obsolete parts or versions of data sheets that you want to read when you are curious about its revision history." CreationDate="2010-12-05T13:15:15.607" UserId="930" />
  <row Id="10410" PostId="7537" Text="&quot;and don't call me Shirley&quot;. Yes, it crossed my mind as well :-)" CreationDate="2010-12-05T13:18:50.783" UserId="2064" />
  <row Id="10411" PostId="7525" Text="here another coil gun?" CreationDate="2010-12-05T13:36:57.090" UserId="2187" />
  <row Id="10412" PostId="7540" Text="I don't know where you get that `TK-19` name, when the datasheet is about `TSOP11xx`." CreationDate="2010-12-05T15:08:12.377" UserId="2064" />
  <row Id="10413" PostId="7541" Score="2" Text="i think that's actually the definition of half-stepping. at least, that's what it was back in the days of moving the head in a floppy drive." CreationDate="2010-12-05T15:25:47.497" UserId="740" />
  <row Id="10414" PostId="7544" Score="1" Text="_I_  know how the trace burned away. I once had a newly populated PCB sitting on my workbench and hadn't noticed a few leftovers of cut off pins on the table. One caused a short between two 230V~ traces. Result when I plugged it in: trace literally evaporated over a length of 5cm and board jumping a centimeter high. The copper from the trace was deposited on the sheet of paper the board was sitting on." CreationDate="2010-12-05T15:42:56.370" UserId="2064" />
  <row Id="10416" PostId="7535" Text="Later I will try to make an answer that links to all of the good answers I have seen strew about in relation to this." CreationDate="2010-12-05T15:46:37.423" UserId="230" />
  <row Id="10417" PostId="7545" Text="Leon, thanks for the link, but I'm not sure the question belongs on the mbed forum; it's about programming a device when I _move away_ from mbed." CreationDate="2010-12-05T15:52:57.937" UserId="2064" />
  <row Id="10418" PostId="7545" Text="@leon, this is the place to ask all technical questions. We should not turn people away because their are other options." CreationDate="2010-12-05T15:54:20.650" UserId="230" />
  <row Id="10419" PostId="7529" Text="What advantage does the 245 give over the 232R?" CreationDate="2010-12-05T16:02:22.063" UserId="411" />
  <row Id="10420" PostId="7542" Score="3" Text="If you can control the ratio of current to the two coils, you can get other &quot;in-between&quot; positions.  This is called &quot;microstepping.&quot;  Accuracy varies." CreationDate="2010-12-05T16:09:20.563" UserId="411" />
  <row Id="10422" PostId="7543" Score="1" Text="When testing the receiver, you can use any off the shelf remote as a transmitter." CreationDate="2010-12-05T16:39:28.017" UserId="2052" />
  <row Id="10423" PostId="7545" Text="I did point him to the correct answer, though, on the mbed web site. I found it by searching the mbed forum, which he could have done in a few seconds." CreationDate="2010-12-05T16:42:03.370" UserId="305" />
  <row Id="10424" PostId="7548" Score="1" Text="I remember to ground only on one side, to avoid ground loops." CreationDate="2010-12-05T17:10:00.837" UserId="2064" />
  <row Id="10425" PostId="7548" Text="Ooh that's good 'gotcha' to watch out for." CreationDate="2010-12-05T18:22:35.657" UserId="249" />
  <row Id="10426" PostId="4328" Text="But my question's about chemical batteries.  Nuclear batteries are not chemical batteries, and I don't think antimatter reactions count, either." CreationDate="2010-12-05T18:22:37.910" UserId="142" />
  <row Id="10427" PostId="7539" Score="1" Text="Star grounds are actually very uncommon on PCBs of this type. Having a single good ground plane eliminates this need. In high power applications there can be a need for separate grounds connected at one point, but that isn't what he has here." CreationDate="2010-12-05T18:26:42.063" UserId="319" />
  <row Id="10428" PostId="7539" Text="@kellenjb, I've seen it on some smaller applications, like sound cards, where space is at a premium." CreationDate="2010-12-05T18:47:28.490" UserId="1225" />
  <row Id="10430" PostId="7414" Text="who's not going to want extra space?" CreationDate="2010-12-05T18:55:20.843" UserId="2006" />
  <row Id="10431" PostId="7545" Text="@Leon: you make it sound as if I'm too lazy too look it up on mbed. I didn't because I didn't expect to find it there, as it doesn't have anything to do with the mbed module; that you program over USB." CreationDate="2010-12-05T19:12:33.023" UserId="2064" />
  <row Id="10432" PostId="7549" Text="Are you going to have a port available for people to add I2C devices as they wish or will it always be devices you add?" CreationDate="2010-12-05T19:20:13.327" UserId="319" />
  <row Id="10433" PostId="7549" Text="@kellenjb, There will be an expansion port to allow the addition of devices, but only some will be supported. i.e. it won't support a motor control IC, but it will support an accelerometer." CreationDate="2010-12-05T19:45:48.557" UserId="1225" />
  <row Id="10434" PostId="7403" Text="@Mark - That makes sense.  From your comment, I couldn't tell if you left them online for current projects or not.  Also, good business plan!  It could be slightly improved if they hosted the datasheets as well.  I wonder how well a big, public, version-controlled repository of that information could work." CreationDate="2010-12-05T19:48:13.203" UserId="857" />
  <row Id="10435" PostId="7488" Text="Often, the only useful information on the first page is the part number - The rest is marketing mumbo-jumbo." CreationDate="2010-12-05T19:51:09.053" UserId="857" />
  <row Id="10436" PostId="7553" Text="+1 for configurable address. I have seen this on slaves that will have several of the same thing on the same bus." CreationDate="2010-12-05T19:58:15.480" UserId="319" />
  <row Id="10437" PostId="7543" Score="1" Text="transmitter will have to be slightly more complicated than that.  The receiver has &quot;noise&quot; signal detection and won't respond to a constant square wave at the carrier frequency. " CreationDate="2010-12-05T20:13:38.503" UserId="1438" />
  <row Id="10438" PostId="7548" Text="actually the &quot;ground one side&quot; must be qualified. There are benefits to grounding the &quot;transmit&quot; side, the &quot;receive&quot; side and sometimes both; it had to do with the relationship between the signal frequency and the length of the cable, but I can't for the life of me find the reference now. I'll update my comment if I can find it, I think it was in one of my old EDN magazines." CreationDate="2010-12-05T20:17:05.400" UserId="974" />
  <row Id="10439" PostId="7525" Text="Looking at alibaba.com for far-east suppliers, some are offering water solenoid valves for $7 upwards with minimum order qtys of 100. Just a thought. eg: http://www.alibaba.com/product-gs/249331163/Water_engineer_solenoid_valve.html" CreationDate="2010-12-05T20:45:18.247" UserId="1750" />
  <row Id="10441" PostId="7529" Text="That solenoid comes in a wide variety of coil voltages, from 6V to 240V. I would probably pick the 12V coil, such as the 8262G002  12/DC. However, the 120V coil was 6-8W, so something a bit bigger than a 2n2222 might be safer. " CreationDate="2010-12-05T22:03:03.210" UserId="638" />
  <row Id="10442" PostId="7549" Text="Interesting bit of info: NXP says it'll only cost you 2500 EUR for a I2C address allocation. What a bargain!" CreationDate="2010-12-05T22:12:00.897" UserId="638" />
  <row Id="10443" PostId="7556" Text="Here's the legal situation for the UK http://diydrones.com/profiles/blogs/uk-caa-clarify-things" CreationDate="2010-12-05T22:17:15.060" UserId="566" />
  <row Id="10444" PostId="7556" Text="Ah, yes.  Sorry, I don't know the legal situation worldwide, as I only do things in the states.  The FAA is still pretty nervous about people operating drones in American airspace, so it's best to CYA when doing this type of project." CreationDate="2010-12-05T22:20:03.657" UserId="1477" />
  <row Id="10445" PostId="7560" Text="Is there a particular kind of flux that you're referring to?" CreationDate="2010-12-05T23:16:08.467" UserId="638" />
  <row Id="10446" PostId="7560" Text="This does sound like a perfect case for flux to be used. Most solder has flux in it, but it can burn off very quickly if not careful. There are many types of flux that you can use, all should work for you, but look to see what you will need to clean the board with after soldering to remove flux." CreationDate="2010-12-05T23:19:19.550" UserId="319" />
  <row Id="10447" PostId="7540" Text="@Stevenvh thanks for being on top of editing tags, but it was agreed to not use the homework tag here http://meta.electronics.stackexchange.com/questions/115/what-meta-tags-on-er-should-be-axed and will be going away at some point." CreationDate="2010-12-05T23:26:46.767" UserId="319" />
  <row Id="10448" PostId="7546" Score="1" Text="Well, you were right on the &quot;throw this meter in the trash part&quot;: the tin wire was indeed acting as a fuse trying it on 230V evaporated it :), but it was worth the try..." CreationDate="2010-12-05T23:31:39.320" UserId="2189" />
  <row Id="10449" PostId="7549" Score="1" Text="@W5VO. Yep, right next to the SD card people only wanting $3,000." CreationDate="2010-12-05T23:56:04.810" UserId="1225" />
  <row Id="10450" PostId="7560" Score="2" Text="You put flux down when you are ready to solder. There is no need to worry about oxidation before you are soldering. The flux does the job then." CreationDate="2010-12-06T00:17:16.220" UserId="230" />
  <row Id="10451" PostId="7549" Score="1" Text="@ThomasO, you do not need to pay them to get an address reserved, like an identifier, you do not have to pay this to make a device, they are selling a service. SDcard they are enforcing their intellectual property, they can tell you to do it or choose a different technology." CreationDate="2010-12-06T00:18:58.030" UserId="230" />
  <row Id="10452" PostId="7403" Text="@mjcarroll. Never had a problem with large binaries in SVN.  On the other hand, I once tried to check in a configured Linux source tree into SVN and it came to a sudden halt halfway through the commit.  That was a mess to clean up." CreationDate="2010-12-06T00:19:53.833" UserId="411" />
  <row Id="10453" PostId="7549" Text="@kortuk, I was making a sarcastic comment on the cost of these things." CreationDate="2010-12-06T00:33:33.500" UserId="1225" />
  <row Id="10454" PostId="7560" Text="The runny liquid type that comes in flux pens - you can also buy it by the bottle. " CreationDate="2010-12-06T00:34:46.717" UserId="1681" />
  <row Id="10455" PostId="7563" Text="No, you do absoltely do NOT want conformal coating!" CreationDate="2010-12-06T00:35:26.217" UserId="1681" />
  <row Id="10456" PostId="7556" Text="This is called FPV and is quite legal in most parts of the world, including the US or UK, regardless of line-of-sight." CreationDate="2010-12-06T00:36:11.703" UserId="1225" />
  <row Id="10457" PostId="7564" Text="Do you have any references for that?  " CreationDate="2010-12-06T01:41:03.203" UserId="857" />
  <row Id="10458" PostId="7490" Text="@Fake Name - Good advice.  I'm usually with the 'burn it off' crowd, but I have also seen the non-burnable lacquer (if that's what it is)." CreationDate="2010-12-06T02:04:53.417" UserId="857" />
  <row Id="10459" PostId="7491" Text="@Andreja - Where are you working that you use the cross-sectional area of the wires? AWG does give you the cross-sectional area, just on a different scale.  It shouldn't be too hard to make up a simple conversion chart for that." CreationDate="2010-12-06T02:07:28.673" UserId="857" />
  <row Id="10460" PostId="7544" Text="@steven - Yup, I've seen it as well, on a motor controller.  This one had 120V AC over a 20-mil trace.  Result: Evaporation, right through the soldermask." CreationDate="2010-12-06T02:08:09.327" UserId="857" />
  <row Id="10461" PostId="7546" Text="@jpjacobs - Do you believe that it was an intentional fuse trace?  If so, you could probably glue on a fuseholder or PTC." CreationDate="2010-12-06T02:09:29.153" UserId="857" />
  <row Id="10462" PostId="7448" Text="@JustJeff, 4 conductors on one side (I'm assuming 3 phase + 1 neutral), two conductors on the other side, 3 tiers of them." CreationDate="2010-12-06T03:00:08.297" UserId="536" />
  <row Id="10463" PostId="7403" Score="1" Text="@markrages: not a webpage, but for many purposes as good (or better b/c you can adjust it to your needs) from your suggestion I wrote a python script that does what you want from your own computer (keep a list of pdfs---or anything on the web---can check for changes when you run it; since was easiest for me I wrote it using couchdb, but should be easy to change for other db).  You can find it at: http://kasterma.wordpress.com/2010/12/05/track-pdfs-or-webpages-on-the-internet-for-changes/" CreationDate="2010-12-06T03:39:05.240" UserId="1773" />
  <row Id="10464" PostId="7402" Text="See my comment to my answer above, I wrote a little script to automate checking for updated pdfs  (http://kasterma.wordpress.com/2010/12/05/track-pdfs-or-webpages-on-the-internet-for-changes/)" CreationDate="2010-12-06T03:41:33.350" UserId="1773" />
  <row Id="10465" PostId="2050" Score="1" Text="@Kortuk, It has some libraries you can download, but I think most you'll have to add them yourself." CreationDate="2010-12-06T03:45:17.383" UserId="625" />
  <row Id="10466" PostId="7549" Score="1" Text="@ThomasO, I was making a point that there is something that you are paying for in this case. Also, two thousand is not much in a real product." CreationDate="2010-12-06T03:54:53.840" UserId="230" />
  <row Id="10467" PostId="7549" Score="1" Text="@Thomas O $3,000 is actually very reasonable for products. This is a drop in the bucket for any company making products." CreationDate="2010-12-06T03:58:16.563" UserId="319" />
  <row Id="10468" PostId="7555" Text="Here is a video of people flying such around New York: http://www.youtube.com/watch?v=M9cSxEqKQ78  Maybe not the best place to experiment, but a nice video for sure." CreationDate="2010-12-06T04:06:28.507" UserId="1773" />
  <row Id="10469" PostId="7572" Score="1" Text="perhaps &quot;high-current&quot; rather than &quot;high-amperage&quot;" CreationDate="2010-12-06T04:37:29.717" UserId="1688" />
  <row Id="10470" PostId="7523" Text="how can I find out the input impedance of my chip antenna cheaply? Is it even possible without a VNA?" CreationDate="2010-12-06T04:43:17.077" UserId="1688" />
  <row Id="10471" PostId="7573" Text="so basically everything will work just the same, unless there is a short in which case everything explodes? :) " CreationDate="2010-12-06T04:49:12.597" UserId="708" />
  <row Id="10472" PostId="7559" Text="Use more flux! (15 chars)" CreationDate="2010-12-06T04:52:17.240" UserId="1374" />
  <row Id="10473" PostId="7529" Text="@markrages - FT245 has more IO. Since the bit-bang mode updates all the IO simultaneously, you can run multiple shift-registers in parallel." CreationDate="2010-12-06T05:02:28.910" UserId="1374" />
  <row Id="10474" PostId="7529" Text="Also, the above schematic needs bypass caps on every IC (0.1uF Ceramic)." CreationDate="2010-12-06T05:02:46.430" UserId="1374" />
  <row Id="10475" PostId="7525" Text="Thanks @Linker3000 ! - I wonder how those valves fit with @mikeselectricstuff 's comment. What kind of valve would be precise enough (and physically cool enough) to handle a frequent precise change.  From a cost perspective I like your link best!" CreationDate="2010-12-06T05:13:35.750" UserId="2180" />
  <row Id="10476" PostId="7529" Text="You may event need to go bigger than 0.1uF or have additional caps because the circuit is switching some fairly large currents." CreationDate="2010-12-06T05:17:56.900" UserId="411" />
  <row Id="10477" PostId="7529" Text="FT245 can bit-bang 8 IO lines.  FT232R can bit-bang 8 IO lines.  Am I counting wrong?" CreationDate="2010-12-06T05:21:33.903" UserId="411" />
  <row Id="10478" PostId="7525" Text="&quot;Rapid Sucession&quot; might be misleading. You can't switch solenoids fast enough to put any burden on the speed of the digital interface; the issue is in the hardware costs and design." CreationDate="2010-12-06T06:13:23.920" UserId="857" />
  <row Id="10479" PostId="7577" Text="This is an improved schematic for markrages' answer, correct? You should probably just put it as an edit there. " CreationDate="2010-12-06T06:15:43.153" UserId="857" />
  <row Id="10480" PostId="7525" Text="@reemrevnivek - I see.  Perhaps I should open a new question.  Do you mind helping me phrase the question correctly?  I think this forum (electronics) may still be a good fit.  Let me know if you think otherwise." CreationDate="2010-12-06T06:20:55.240" UserId="2180" />
  <row Id="10481" PostId="7523" Text="Time for a proper RF engineer, I'd say. I have a hunch that you don't actually have to match the input, just calibrate it properly --I'll take a peek tonight." CreationDate="2010-12-06T06:54:05.633" UserId="2118" />
  <row Id="10482" PostId="7561" Text="Sometimes I'll just put a thin layer of solder on the pads to &quot;tin&quot; them, right after etching." CreationDate="2010-12-06T06:57:56.207" UserId="2118" />
  <row Id="10483" PostId="7577" Text="my sample code takes 1+2*8*N FTDI periods for a full shift.  So sixteen 595's would take 257 periods.  The FT232R just uses the async baudrate for clocking in bitbang samples.  So at 115200 baud, a register update is 2.24 msec." CreationDate="2010-12-06T07:05:45.710" UserId="411" />
  <row Id="10484" PostId="7578" Score="1" Text="The underlying C in Arduino is basically this: `int main() {setup(); for(;;) {loop();}}`  " CreationDate="2010-12-06T07:23:28.627" UserId="1407" />
  <row Id="10485" PostId="7516" Score="1" Text="@steven: So components made with other components aren't designed, manufactured, marketed, or shipped and warehoused?" CreationDate="2010-12-06T07:37:23.193" UserId="1407" />
  <row Id="10486" PostId="7568" Text="I did have two but I managed to kill the other one (long story.)" CreationDate="2010-12-06T07:59:07.213" UserId="1225" />
  <row Id="10487" PostId="7564" Text="@reemrevnivek: It's called FPV. Have a look at suppliers like HobbyKing. They have kits including a camera, transmitter and receiver for about $40 US." CreationDate="2010-12-06T08:06:41.050" UserId="1225" />
  <row Id="10488" PostId="7546" Text="No I don't think so; there are real fuses present, and it was a connection from near the terminals to the function selection dial." CreationDate="2010-12-06T08:46:03.990" UserId="2189" />
  <row Id="10489" PostId="7577" Text="Ideally, yes, but the USB interface is the slow part. I have a project based around a FT245 in bit-bang mode, and I get ~10 updates per second. Now, I'm doing this in python, so there is almost definitely some interpreter overhead, but I have trouble imagining you's get better than 1000 updates per second, considering each update takes a full USB packet. Unless you're doing something different in C than calling the FT_Write command from the driver, I can't see it being much faster." CreationDate="2010-12-06T09:20:17.327" UserId="1374" />
  <row Id="10492" PostId="7569" Text="Not for production. Just for testing/prototyping." CreationDate="2010-12-06T09:35:01.287" UserId="1225" />
  <row Id="10493" PostId="7573" Text="@user708 yes. And you may develop an insatiable need to make something explode." CreationDate="2010-12-06T09:36:16.070" UserId="2118" />
  <row Id="10494" PostId="7491" Text="@reemrevnivek There's actually a nice chart at [Wikipedia](http://en.wikipedia.org/wiki/American_wire_gauge), but the problem is that in my part of Europe, cross section area is in nice round metric sizes. For example we have 0.50 mm² instead of AWG 20 or 1.00 mm² instead of AWG 17, but sizes don't actually match and that can cause problems. A big problem is 0.75 mm² which is between AWG 18 and 19 and there's no close match for it. Another popular cable has area of 2.5 mm² but again it's a bit smaller than AWG 13." CreationDate="2010-12-06T09:37:23.517" UserId="1240" />
  <row Id="10495" PostId="7549" Text="@kortuk, @kellenjb In 10 years time maybe when it is a drop in the bucket, and I'm not a poor student any more. :) Then I could buy me one of those Agilent InfiniScopes, now only $133,000!" CreationDate="2010-12-06T09:46:08.380" UserId="1225" />
  <row Id="10496" PostId="7553" Text="Yeah I was thinking of configurable addresses. It could be updated by changing settings from the menu system. One important thing is that safeguards need to be added to prevent someone changing the address and the master MCU losing communication with the slave, so some kind of protocol needs to be established which resets the addresses (e.g. after 5 seconds have no communication so reset address.)" CreationDate="2010-12-06T09:48:08.893" UserId="1225" />
  <row Id="10497" PostId="7545" Text="@stevenv: mbed is posed as a prototype module. Naturally they'd want you to use it as a base for production units, and tell exactly how to do it." CreationDate="2010-12-06T10:04:28.003" UserId="1082" />
  <row Id="10498" PostId="7573" Text="you got my +1 b/c this is nice and succinct, which i think is what's needed most in these cases." CreationDate="2010-12-06T11:55:48.770" UserId="740" />
  <row Id="10499" PostId="7573" Score="1" Text="it should be pointed out, though, that if you short a 500mA supply, you get a hot wire, whereas if you short a 22A supply, you get a cloud of hot metal vapor. Overcurrent protection, e.g., fuses, are your friend!" CreationDate="2010-12-06T11:58:34.090" UserId="740" />
  <row Id="10501" PostId="7490" Text="having encountered the un-meltable stuff, and having been told by some excellent technicians to 'always work with clean surfaces', i'll say +1 for the fine-grain sandpaper idea. alternately, there are those tiny 'jewelers files' that work pretty well too. THAT said, 1/2 a second in the flame of a lighter beforehand makes the sandpaper work really well, even the un-meltable stuff. =P" CreationDate="2010-12-06T12:18:46.233" UserId="740" />
  <row Id="10502" PostId="7576" Score="2" Text="not sure the elephants and oranges are making your point .." CreationDate="2010-12-06T12:20:21.443" UserId="740" />
  <row Id="10503" PostId="7529" Text="+1 - Very nice. Minimal parts and experience required with a reliable a outcome." CreationDate="2010-12-06T13:01:32.930" UserId="1414" />
  <row Id="10505" PostId="7483" Text="@smashtastic: If I remember well you are allowed to use it for free with non-commercial projects, and to pay fee if you need to use it in commercial projects." CreationDate="2010-12-06T14:47:17.777" UserId="1129" />
  <row Id="10506" PostId="7556" Text="Thanks for the link, I'm thinking about this one: http://hobbywireless.com/cart/index.php?main_page=product_info&amp;products_id=404" CreationDate="2010-12-06T14:49:30.270" UserId="2006" />
  <row Id="10508" PostId="7539" Text="No stars - single ground *plane*!" CreationDate="2010-12-06T15:55:50.350" UserId="763" />
  <row Id="10510" PostId="7576" Text="@JustJeff I have tried many different analogies when trying to teach an electronics class that is taught to all engineering majors. Amazingly this is the best that I have been able to come up with. Sometimes using water in lines is helpful, but some people get confused by that also." CreationDate="2010-12-06T16:13:05.120" UserId="319" />
  <row Id="10511" PostId="7588" Score="4" Text="This is correct. You will also see this on some resistors were it will say 4k2 and mean 4.2k ohm." CreationDate="2010-12-06T16:14:44.120" UserId="319" />
  <row Id="10512" PostId="7590" Text="Agreed, and that's how I2C devices are usually configured, but figure 7 suggests that A[6:3] can be anything between 0000 and 1111, and the text also expressly says that 111 1100 is excluded." CreationDate="2010-12-06T16:24:48.947" UserId="2064" />
  <row Id="10513" PostId="7588" Score="1" Text="I suspect the M is probably some kind of indication of the dielectric temperature characteristic or voltage rating. It's probably a manufacturer specific code." CreationDate="2010-12-06T16:25:53.173" UserId="771" />
  <row Id="10514" PostId="7589" Text="How often will the cable need to be unplugged and plugged back in?  What maximum voltages are involved?  What frequency range?  Will the cable need to flex?  Is a fraction of an ohm contact resistance acceptable?  Is this a one-off project, a prototype for dozens or hundreds of units, or eventually for big-time mass production?  These are just some starter questions." CreationDate="2010-12-06T16:27:07.613" UserId="1609" />
  <row Id="10515" PostId="7578" Text="good answer - I agree 100%" CreationDate="2010-12-06T16:28:10.987" UserId="771" />
  <row Id="10516" PostId="7590" Text="@stevenvh Figure 7 is merely establishing the bit-order (i.e. bit 6 is the most significant bit and bit 0 is the least significant bit and should be followed by the r/w flag) with respect to the transmission on the bus. 111 1100 is excluded because the only allowed addresses are 011 1xxx and 010 0xxx. The exclusions for general call is that it is just &quot;not supported&quot; by the device. I couldn't say what's &quot;special&quot; about the address 0b1111100 == 0x7C, I don't think it has any meaning in I2C protocol... probably just an FYI from the manufacturer to please keep that value &quot;off the bus.&quot;" CreationDate="2010-12-06T16:30:54.090" UserId="771" />
  <row Id="10517" PostId="7590" Text="@stevenvh Conservatively, I think what they are saying is that you cannot use the PCA8574A in a system that (a) uses general call, or (b) has some other device with the address 0x7C - as the PCA8574A can't tolerate that condition &quot;for some reason.&quot; If the PCA8574A is the only I2C device on your bus, it's probably not a restriction that you care about." CreationDate="2010-12-06T16:38:04.150" UserId="771" />
  <row Id="10519" PostId="7591" Text="Beware people who use m for mega- and M for milli-.  Not always that difficult to distinguish, but harder than (capital) S for seconds people." CreationDate="2010-12-06T16:42:27.497" UserId="1407" />
  <row Id="10520" PostId="7589" Text="Mouser categories are nauseatingly bad in my opinion.  If you looked on [Digi-Key](http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en), they have a &quot;Board to Board&quot; group of subcategories under Connectors, though they aren't ribbon-type things, usually rigid connections." CreationDate="2010-12-06T16:43:31.940" UserId="1407" />
  <row Id="10521" PostId="7584" Text="Do you need to make sure your source impedance is relatively low if using that?" CreationDate="2010-12-06T17:04:57.243" UserId="1407" />
  <row Id="10522" PostId="7591" Text="Good point, but most of the time this can be derived from context; 1m0 on an inductor will be milli rather than mega :-)" CreationDate="2010-12-06T17:33:03.583" UserId="2064" />
  <row Id="10523" PostId="7593" Score="1" Text="I was more thinking about markings on components than documents, but you're right. However, in SMD markings a decimal point gets lost even more easily." CreationDate="2010-12-06T17:35:38.527" UserId="2064" />
  <row Id="10524" PostId="7592" Text="Wow, those are nice.  Thanks" CreationDate="2010-12-06T17:36:45.780" UserId="1414" />
  <row Id="10525" PostId="7592" Text="Looking for the actual FFCs on Mouser was irritating; the *cables* are grouped under Mouser » Interconnects » Rectangular Connectors » FFC / FPC *Connectors*" CreationDate="2010-12-06T17:40:39.053" UserId="1407" />
  <row Id="10526" PostId="7584" Text="Leon, why not use a capacitor instead of the 1k resistor?" CreationDate="2010-12-06T17:41:36.713" UserId="2064" />
  <row Id="10527" PostId="7589" Text="@ DarenW - 3.3V Max, 4 Mhz max freq, once plugged should stay in unless repairing, haven't considered resistance (doubt its too much of an issue unless something out of the ballpark), 10 or so made (will probably use them on other projects), could be mass production eventually." CreationDate="2010-12-06T17:44:14.697" UserId="1414" />
  <row Id="10528" PostId="7589" Text="@ Nick T - Those are very nice connectors.  Never considered that kind, not that I could have found them myself anyway.  I was looking at this one (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=A100258CT-ND)  its pitch is 1mm and 10 position.  I can't seem to find the spool of ribbon for it (At least at digikey).  Just wanted to make sure pitch is what I think it is.  Ive always used it to denote the pin spacing." CreationDate="2010-12-06T17:46:29.843" UserId="1414" />
  <row Id="10529" PostId="7592" Text="	&#xA;@ Nick T - Those are very nice connectors. Never considered that kind, not that I could have found them myself anyway. I was looking at this one (search.digikey.com/scripts/DkSearch/…) its pitch is 1mm and 10 position. I can't seem to find the spool of ribbon for it (At least at digikey). Just wanted to make sure pitch is what I think it is. Ive always used it to denote the pin spacing" CreationDate="2010-12-06T17:55:45.390" UserId="1414" />
  <row Id="10531" PostId="7592" Text="Yeah, forgot, sorry.http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=A100258CT-ND" CreationDate="2010-12-06T17:58:24.390" UserId="1414" />
  <row Id="10532" PostId="7584" Text="It's a DC-coupled solution. The series resistor is needed for proper operation." CreationDate="2010-12-06T18:07:04.200" UserId="305" />
  <row Id="10533" PostId="7589" Text="That connector in the FFC/FPC (flexible printed cicuit) domain.  It calls itself FPC, so it would be intended to connect to one, either custom or (e.g.) part of an LCD panel--there aren't any &quot;FPC spools&quot;.  You could use FFC, the only real difference is the thicknesses they desire, though they overlap.  If you cut your own cables, you will need to add some sort of a rigid backer where it enters the connector (not sure what exactly), and strip it somehow--not really worth it for low-volume, IMHO." CreationDate="2010-12-06T18:08:35.737" UserId="1407" />
  <row Id="10534" PostId="7595" Score="2" Text="I predict pathological fear of &quot;M$&quot; will prevent widespread adoption, even though people are frequently just as &quot;locked in&quot; when they choose particular MCUs." CreationDate="2010-12-06T18:11:44.283" UserId="1407" />
  <row Id="10535" PostId="7597" Score="5" Text="Can you just use a voltage divider?  What kind of ADC are you looking for (MCU peripheral, ADC IC, analog DAQ...)" CreationDate="2010-12-06T18:25:10.950" UserId="1407" />
  <row Id="10536" PostId="7546" Text="I like to use Kynar (wire-wrap) wire for PCB jumpers.  30 AWG, insulation is reasonably heat resistant (it won't just fall off when you touch it with a soldering iron)." CreationDate="2010-12-06T18:27:43.303" UserId="1407" />
  <row Id="10537" PostId="7483" Text="License for what? HIDkeys? The USB HID spec?" CreationDate="2010-12-06T18:30:27.077" UserId="2163" />
  <row Id="10538" PostId="7481" Text="And, in fact, HotkeyNet did do exactly what I wanted. I would still prefer the hardware solution (not dependent on network latency), but this was a perfect in-between solution." CreationDate="2010-12-06T18:31:03.643" UserId="2163" />
  <row Id="10541" PostId="7591" Text="Most circuit simulation packages will also accept this format, but beware that they may not be case-sensitive, so a &quot;1M0&quot; resistor could work out as a 1.0 milliohm resistor, so use 1Meg in this case." CreationDate="2010-12-06T20:12:36.133" UserId="2110" />
  <row Id="10542" PostId="7593" Score="1" Text="And in some European countries, a comma is used instead of a decimal point for the seperation of the fractional part, and a point is used for seperating out the thousand part instead of a comma." CreationDate="2010-12-06T20:14:22.447" UserId="2110" />
  <row Id="10543" PostId="7563" Score="1" Text="Citation needed. OK - let me rephrase that..what's wrong with PS60? &quot;Film can be soldered through to facilitate spot repairs&quot;. I have used this on many occasions for simple to complex circuit boards and have never had a problem soldering components." CreationDate="2010-12-06T20:17:05.657" UserId="1750" />
  <row Id="10544" PostId="7597" Text="@Nick - You should consider making that an answer." CreationDate="2010-12-06T20:43:34.500" UserId="857" />
  <row Id="10545" PostId="7546" Text="@Nick - I use 30-gauge wire-wrap wire with the least heat-resistant insulation I can find for the opposite reason - Touching it with a soldering iron is much easier than stripping it." CreationDate="2010-12-06T20:45:30.803" UserId="857" />
  <row Id="10546" PostId="7582" Text="No, he said &quot;How they did it, I don't exactly know&quot; - They probably connected it to 230VAC in a mode that didn't support that." CreationDate="2010-12-06T20:46:36.620" UserId="857" />
  <row Id="10547" PostId="7549" Text="@Kortuk, @Kellenjb - Sure, thousand-dollar licenses are a drop in the bucket for an *established* company *already* making products, but they're a huge, possibly insurmountable barrier to students (Like Thomas and myself), to new startups, and to open hardware." CreationDate="2010-12-06T20:49:38.960" UserId="857" />
  <row Id="10548" PostId="7546" Text="@ree: Likewise, I often strip small pieces using an iron's help, but it's nothing like some PVC wire where it will shrink a good 1/8th of an inch when you touch it with an iron.  Wire-wrap wire usually seems to be Kynar all-round.  The difference may be due to the manufacturing process (less stress?) than the actual material properties, however." CreationDate="2010-12-06T20:54:53.580" UserId="1407" />
  <row Id="10549" PostId="7525" Text="It is a fine forum; electronics is more than just the digital interface.  I've made an edit which should help bring the focus on the interface rather than the speed constraints." CreationDate="2010-12-06T20:54:56.913" UserId="857" />
  <row Id="10550" PostId="7577" Text="You know you can write more than one byte at a time, right?" CreationDate="2010-12-06T21:06:40.013" UserId="411" />
  <row Id="10551" PostId="7600" Text="Analog devices also has a pretty nice lineup.  Here is their product selector: http://www.analog.com/en/analog-to-digital-converters/products/index.html  You should be able to use a resistor divider to get your signal range down to 5V." CreationDate="2010-12-06T21:39:56.927" UserId="1477" />
  <row Id="10552" PostId="7600" Text="Spec'ing Maxim parts is a newbie mistake.  The datasheet looks good, the samples work well, and then you go to production and find there's a six month lead time and no second sources." CreationDate="2010-12-06T21:46:04.740" UserId="411" />
  <row Id="10553" PostId="7580" Text="http://au.element14.com/jst-japan-solderless-terminals/sm02b-srss-tb-lf-sn/header-r-a-2way/dp/1679117&#xA;&#xA;do these look right?" CreationDate="2010-12-06T22:04:58.923" UserId="1688" />
  <row Id="10554" PostId="7604" Text="4.7k on both to 3.3V." CreationDate="2010-12-06T22:33:59.770" UserId="1225" />
  <row Id="10555" PostId="7604" Text="The I2C line isn't connected to anything except two scope probes going to my oscilloscope." CreationDate="2010-12-06T22:36:28.753" UserId="1225" />
  <row Id="10556" PostId="7604" Text="@Thom: If nothing is there to send ACKs it may cause problems" CreationDate="2010-12-06T22:39:00.357" UserId="1407" />
  <row Id="10557" PostId="7604" Text="Does it work if you disconnect the scope probes?" CreationDate="2010-12-06T22:39:19.487" UserId="566" />
  <row Id="10558" PostId="7605" Text="Heck, I'm already running a 40 MIPS dsPIC33F with no problems. It runs my software OSD slightly over clocked at 41.5 MIPS. This is a tiny 16 MIPS 24F device. All Vdd/Vss pins have 100n caps." CreationDate="2010-12-06T22:39:28.923" UserId="1225" />
  <row Id="10559" PostId="7604" Text="I swapped to using 1.2k (closest to 1k I had on hand) and the edge transitions are sharper but it still won't work until I run the screwdriver along the pins." CreationDate="2010-12-06T22:40:14.273" UserId="1225" />
  <row Id="10560" PostId="7604" Text="Which pin in particular makes it work? What does that tell you?" CreationDate="2010-12-06T22:41:31.107" UserId="566" />
  <row Id="10561" PostId="7606" Text="ENVREG grounded, VDDCORE has 10u/25V tant. bead, 100n caps on both Vdd/Vss pairs. MCLR thru 4.7k, and to PICkit 2." CreationDate="2010-12-06T22:42:27.610" UserId="1225" />
  <row Id="10562" PostId="7604" Text="@Joby Taffey I'm unsure. I suspect it's either the SCL/SDA pair or PGEC3/INT0." CreationDate="2010-12-06T22:43:09.420" UserId="1225" />
  <row Id="10563" PostId="7604" Text="@Joby Taffey, If I disconnect the scope probes I'm acting blind. How do I know if it works then?" CreationDate="2010-12-06T22:44:29.717" UserId="1225" />
  <row Id="10564" PostId="7604" Text="If it were INT0 - I'd go look at my ISRs, if it were SCL/SDA I'd look at how my I2C driver handles ACK/NAK timeouts" CreationDate="2010-12-06T22:44:49.450" UserId="566" />
  <row Id="10565" PostId="7604" Text="@Joby Taffey The code is very basic and has no interrupts and just continuously polls the I2C peripheral until it is ready to receive or send data." CreationDate="2010-12-06T22:45:35.550" UserId="1225" />
  <row Id="10566" PostId="7606" Score="1" Text="For now, I would replace the I2C code with a simple loop that slowly toggles an LED and see if that works (or fails in the same way)." CreationDate="2010-12-06T22:46:37.267" UserId="1322" />
  <row Id="10567" PostId="7605" Score="2" Text="There might be differences between chips, the dsPIC might just happen to be more tolerant of poor layout. I always use PCBs." CreationDate="2010-12-06T22:47:24.147" UserId="305" />
  <row Id="10568" PostId="7604" Text="If the pin in question was SCL/SDA, I'd look carefully at my I2C driver" CreationDate="2010-12-06T22:48:29.917" UserId="566" />
  <row Id="10570" PostId="7605" Text="@Leon Heller, I suppose so. But that doesn't help me because I can't afford to prototype a PCB for every design. Maybe you can, but I can't. Any ideas on how to get it working with a breadboard?" CreationDate="2010-12-06T22:54:07.573" UserId="1225" />
  <row Id="10571" PostId="7605" Text="The 24F has *virtually* the same layout as the dsPIC with regards to pin placement. They are essentially pin compatible, but one is of course less powerful." CreationDate="2010-12-06T22:57:36.857" UserId="1225" />
  <row Id="10572" PostId="7536" Score="1" Text="Thanks. Direct link to PDF http://www.xilinx.com/support/documentation/application_notes/xapp453.pdf" CreationDate="2010-12-06T23:01:49.833" UserId="566" />
  <row Id="10573" PostId="7605" Score="3" Text="I make my own PCBs for simple circuits and never have problems like that. It only takes about an hour." CreationDate="2010-12-06T23:07:50.283" UserId="305" />
  <row Id="10574" PostId="7597" Text="What is the required resolution?  Using voltage divider resulting in a 0 - 5V range with a 16 bit ADC gives you 5/65536 = 76.3 uV per bit.  Is that sufficient?  Resolution is a key spec. for an ADC." CreationDate="2010-12-06T23:18:15.550" UserId="529" />
  <row Id="10575" PostId="7605" Text="@Leon, I considered doing this but it's pretty tricky to do PCBs at home, I don't have the capital to invest in them, so I just use a breadboard. I'm not going to drop £200 and start making PCBs at home. I don't have the money." CreationDate="2010-12-06T23:41:59.077" UserId="1225" />
  <row Id="10576" PostId="7605" Score="2" Text="It cost me a lot less than that." CreationDate="2010-12-06T23:46:57.750" UserId="305" />
  <row Id="10577" PostId="7605" Text="@Leon Heller, I need a PCB drill+xformer+stand = £60, UV exposure unit = £120, ferric chloride = £20, it all adds up! Either way I'm happy with breadboards and for the foreseeable future I don't see me changing. I will be producing the final product on a PCB." CreationDate="2010-12-07T00:02:22.033" UserId="1225" />
  <row Id="10578" PostId="7603" Text="Hmm I've been reading the datasheet in some more depth and it looks like I might need a cap on MCLR. (because the power supply doesn't rise instantly, the chip needs to be held in reset briefly.) I'll have to jumper this for programming, although the transition may be sharp enough for the PICkit 2 or PIC to not care. If this is the problem, I'm unsure on why it isn't affecting the dsPIC." CreationDate="2010-12-07T00:04:21.890" UserId="1225" />
  <row Id="10579" PostId="7583" Score="2" Text="Possible duplicate: http://electronics.stackexchange.com/questions/3105/how-do-i-measure-a-negative-voltage-with-a-adc" CreationDate="2010-12-07T00:06:12.123" UserId="1225" />
  <row Id="10580" PostId="7509" Text="@Axeman - yeah, only takes about a second" CreationDate="2010-12-07T00:16:13.163" UserId="740" />
  <row Id="10581" PostId="7607" Score="1" Text="20 pF, not 20 nF!" CreationDate="2010-12-07T00:21:23.070" UserId="305" />
  <row Id="10582" PostId="7603" Text="Interesting -- I'm using a PIC24FJ256GB110 and wasn't aware of the cap.  Turns out Microchip has put out a newer version of the datasheet for the PIC24FJ256GB110 than I had, which includes a new section on the MCLR pin.  Board rev time." CreationDate="2010-12-07T00:22:02.337" UserId="1322" />
  <row Id="10583" PostId="7607" Text="Heh, whoops. I was thinking pF as I typed that.. Corrected thanks." CreationDate="2010-12-07T00:24:31.673" UserId="554" />
  <row Id="10584" PostId="7603" Text="@tcrosley: It probably only applies for situations like mine where I have a linear reg and two 470u caps (for bulk filtering as my power supply is a bit touchy.)" CreationDate="2010-12-07T00:25:27.607" UserId="1225" />
  <row Id="10585" PostId="7577" Text="In bit-bang mode? No I didn't realize. Well, nevermind, then. Crap." CreationDate="2010-12-07T00:29:06.180" UserId="1374" />
  <row Id="10586" PostId="7577" Text="Hahahahaha. Don't I feel clever. Anyways, I've been using these in a application where there are multiple interconnects to the hardware, so the important aspect is propagation time out to the IO pins, not raw throughput. Basically, a hardware write causes the device to respond through another channel, and the response time was all I was looking at." CreationDate="2010-12-07T00:32:11.857" UserId="1374" />
  <row Id="10587" PostId="7597" Text="If you're unfamiliar with the hardware, I strongly recommend using a discrete ADC. That way, if you have problems, you can just stick a logic analyzer on the ADC interconnects, and see exactly what is going on." CreationDate="2010-12-07T00:34:32.853" UserId="1374" />
  <row Id="10588" PostId="7591" Text="It gets even worse... Have you ever heard of a 100 uuF cap? That's micro-micro-farads. Nowadays, we call them picofarads." CreationDate="2010-12-07T00:37:59.387" UserId="1374" />
  <row Id="10589" PostId="7604" Score="1" Text="I agree with joby, i'm betting your not handling NACK properly at some point in the driver." CreationDate="2010-12-07T02:26:52.073" UserId="1438" />
  <row Id="10590" PostId="7603" Text="What clock are you using? (see Peter Gibson's answer.)" CreationDate="2010-12-07T03:08:24.810" UserId="411" />
  <row Id="10591" PostId="7549" Score="1" Text="@reemrevnivek, but the patent holder chose that they would rather require that and cause open-hardware not to be able to allow use, and require paying this fee. as the patent holder, they have that right. I am, until laws change, going to make sure this is clear. I would like patent and copyright overhaul, but until they are, this is how engineers whom have good ideas are protected and rewarded." CreationDate="2010-12-07T03:50:22.267" UserId="230" />
  <row Id="10593" PostId="7608" Text="Sorry @Aaron, superuser.com is the correct place. " CreationDate="2010-12-07T04:24:26.447" UserId="230" />
  <row Id="10594" PostId="7608" Text="Awesome, thanks for the help :)" CreationDate="2010-12-07T04:26:51.137" UserId="2207" />
  <row Id="10595" PostId="7577" Text="Yup. latency is the killer with USB, 1 msec best-case.  I'm not sure what polling interval the FTDI chips request." CreationDate="2010-12-07T04:44:06.647" UserId="411" />
  <row Id="10596" PostId="7608" Text="Here it is, for those interested: http://superuser.com/questions/219258/setting-up-local-media-share-with-ps3-and-pc" CreationDate="2010-12-07T06:49:09.143" UserId="2118" />
  <row Id="10597" PostId="7605" Score="2" Text="prototyping on PCB is valuable. Hope you can get into it soon." CreationDate="2010-12-07T06:58:14.393" UserId="2118" />
  <row Id="10598" PostId="7594" Text="If you use capacitive coupling you get rid of the DC component, but the negative part of the signal will still go below ground, unless you provide a bias on the input pin by a resistive divider, like in Leon's circuit." CreationDate="2010-12-07T08:27:58.747" UserId="2064" />
  <row Id="10599" PostId="7613" Text="Do you have the motor part number?" CreationDate="2010-12-07T08:33:02.643" UserId="2118" />
  <row Id="10600" PostId="7613" Text="its a 370 Motor, i looked for more info but not too much on it " CreationDate="2010-12-07T08:50:10.547" UserId="2060" />
  <row Id="10601" PostId="7580" Text="Yes, they do. I think so." CreationDate="2010-12-07T10:18:05.260" UserId="938" />
  <row Id="10602" PostId="7617" Score="1" Text="Europe switched eons ago from 220V~ to 230V~, but I often hear people talk about 220 still." CreationDate="2010-12-07T10:51:59.433" UserId="2064" />
  <row Id="10603" PostId="7602" Text="I saw your comment about 1MSps dsPICs and thought it seemed high so I looked it up. Turns out they go up to 10bit x 4MSps (dsPIC33FJ64GS608). Holy smokes." CreationDate="2010-12-07T10:54:29.133" UserId="2118" />
  <row Id="10604" PostId="7619" Text="Noise and loss of sound quality was indeed one factor I spotted in a blind experiment. My friend made a pattern of positions, while I listened to the produced sound with speakers in another room. I felt a difference, although really small." CreationDate="2010-12-07T11:22:53.353" UserId="1272" />
  <row Id="10605" PostId="7618" Score="1" Text="Audio CDs have very little error correction data. The CD format was designed when extensive error correction was to expensive to implement (1980s). There is software that tries to make as accurate a reading as possible (EAC, http://www.exactaudiocopy.de/ comes to mind)" CreationDate="2010-12-07T11:24:42.370" UserId="1374" />
  <row Id="10606" PostId="7618" Text="But if only one integer of data was changed, the MD5sum is completely different. I'm guessing that it is one or two bits that are changed." CreationDate="2010-12-07T11:31:32.677" UserId="1757" />
  <row Id="10607" PostId="7623" Score="1" Text="A UART packet is [START][DATA][PARITY][STOP], so 0x00 would be [0b1][0x00][0b0][0b00] (parity optional, stop variable length). That exception makes sense for some I2C/TWI situations, though." CreationDate="2010-12-07T13:05:59.990" UserId="2118" />
  <row Id="10608" PostId="7597" Text="This is for a micro.  I want to read the data in digitally.  I will use any method that gets me the requirements.  Didn't know if there was a simpler way, or an &quot;approved&quot; method.  I am not unfamiliar with hardware, just unfamiliar with &quot;approved&quot; and standards when using it." CreationDate="2010-12-07T13:26:52.000" UserId="1414" />
  <row Id="10609" PostId="7597" Text="Sorry it took so long for me to comment.  I couldn't be on yesterday evening." CreationDate="2010-12-07T13:33:35.987" UserId="1414" />
  <row Id="10610" PostId="7592" Text="Found the cables, just not spool of it. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=WM10028-ND " CreationDate="2010-12-07T13:39:01.893" UserId="1414" />
  <row Id="10611" PostId="7592" Text="@Jim, I had a link to that category in the question, hope you didn't spend much time finding it :P" CreationDate="2010-12-07T14:32:27.433" UserId="1407" />
  <row Id="10612" PostId="7597" Score="2" Text="24bit is not easy to design, we're talking 0.06ppm for the last bit! Poor layout may cause something like 6-8 LSB to be useless." CreationDate="2010-12-07T14:51:29.790" UserId="2064" />
  <row Id="10613" PostId="7617" Text="@stevenh &quot;240V&quot; is common here." CreationDate="2010-12-07T15:03:16.950" UserId="1225" />
  <row Id="10614" PostId="7619" Text="Your amp doesn't use a capacitive supply.  That's kind of a hack for low-power electronics.  Also, this noise wouldn't be very audible while playing music, just would introduce some hum during silence." CreationDate="2010-12-07T15:16:51.233" UserId="142" />
  <row Id="10615" PostId="7597" Text="Getting real data out of all 24-bits is extremely difficult.  Professional Pro Tools $1000 24-bit audio converters, for instance, have a dynamic range of 113 dB, which is really only 19-bit.  The other bits are just representing noise." CreationDate="2010-12-07T15:28:43.377" UserId="142" />
  <row Id="10617" PostId="7636" Text="Thank you! I think I will go for the downfacing camera option as I'll be powering the drone via an LPC1768. That's enough processing power to do basic line detection at 640x480 right? Thanks for your alternate solution of using gyroscopes and GPS for long term drift. Also, do you know of any sensors that would be able to sense drift? " CreationDate="2010-12-07T15:50:34.010" UserId="2212" />
  <row Id="10618" PostId="7636" Score="1" Text="In addition to the 6 degree of freedom IMU, I've heard of people using magnetometers to determine long-term drift by sensing changes in the Earth's magnetic field.  I don't know that this is necessarily a good option, as the field can fluctuate rapidly around high-current devices (like 4 motors) and doesn't vary in a linear manner." CreationDate="2010-12-07T15:55:50.783" UserId="1477" />
  <row Id="10619" PostId="7622" Text="Why are they advisable?" CreationDate="2010-12-07T16:06:46.307" UserId="1623" />
  <row Id="10620" PostId="7640" Text="I knew it was the &quot;M&quot; from Micro, but the rest... :-). Damn Quick Answer, BTW. Thanks." CreationDate="2010-12-07T16:07:56.260" UserId="2064" />
  <row Id="10621" PostId="7622" Score="1" Text="It's still a coil, which means inductance.  Abruptly changing the current through the coil will still cause spikes, same as a normal motor." CreationDate="2010-12-07T16:10:54.603" UserId="249" />
  <row Id="10622" PostId="7548" Text="You want both sides grounded to act as a continuous enclosure for RF though.  http://www.rane.com/note165.html" CreationDate="2010-12-07T16:25:53.850" UserId="142" />
  <row Id="10623" PostId="7594" Text="The supply voltage was not specified - it would work with a 5V ADC. If you were using a smaller Vdd, then you would need to scale the input. It would turn into Leon's circuit with a capacitor at that point." CreationDate="2010-12-07T16:44:07.150" UserId="638" />
  <row Id="10624" PostId="7641" Score="2" Text="Could you (well, a mod) make this CW and people could add a logo per answer, maybe include a link to the mfc's website?  Not sure if that would be a proper use" CreationDate="2010-12-07T16:47:27.927" UserId="1407" />
  <row Id="10625" PostId="7641" Score="2" Text="CW = continuous wave? Clockwise?" CreationDate="2010-12-07T16:53:30.977" UserId="2064" />
  <row Id="10627" PostId="7642" Score="14" Text="It would be helpful if you posted a link to the circuit and if you gave us details of what you actually made. Circuit diagrams, detailed parts lists and pictures would help. Also, you should edit your account details and put your name there instead of signature." CreationDate="2010-12-07T17:17:27.183" UserId="1240" />
  <row Id="10628" PostId="7643" Text="Looks very interesting!" CreationDate="2010-12-07T17:19:38.820" UserId="1240" />
  <row Id="10629" PostId="7641" Score="2" Text="@stevenvh CW = Community wiki. It means that almost anyone can edit the question and answers.  It is also used when the question doesn't actually have an answer (like this one) and needs long discussion or lots of answers. @Nick T I think that the idea is good and agree on the CW part. I flagged it for CW, so hopefully we'll see results soon." CreationDate="2010-12-07T17:20:24.453" UserId="1240" />
  <row Id="10630" PostId="7641" Score="2" Text="Community wikified!" CreationDate="2010-12-07T17:28:53.740" UserId="712" />
  <row Id="10631" PostId="7642" Score="1" Text="If you put a P-ch FET in place of an N-ch FET, matching drain-source-gate to what the N-ch uses, it might explode as you would forward bias the body diode and conduct loads of current.  Without knowing the circuit we can't tell." CreationDate="2010-12-07T17:33:04.237" UserId="1407" />
  <row Id="10632" PostId="7636" Score="3" Text="The problem with camera at higher altitudes is that very small amounts of roll will produce increasingly large shifts in the image as altitude increases, unless the camera is on a self-levelling mount." CreationDate="2010-12-07T17:51:58.387" UserId="1681" />
  <row Id="10633" PostId="7604" Text="@Mark, this is probably correct - I narrowed it down to an infinite loop somewhere, which was waiting forever for some event. I'm trying to figure out how to fix it now." CreationDate="2010-12-07T19:16:33.743" UserId="1225" />
  <row Id="10634" PostId="7595" Text="Normally it is harder to change MCUs then it is to change OS or development platform for the MCU." CreationDate="2010-12-07T21:13:06.153" UserId="230" />
  <row Id="10635" PostId="7626" Text="Did you mean to make this a single answer?" CreationDate="2010-12-07T21:33:28.780" UserId="857" />
  <row Id="10636" PostId="7549" Score="1" Text="@Kortuk - I wasn't trying to advocate anything illegal.  I was disagreeing not with your support of the right of patent holders to impose those fees, or our obligation to pay those fees, but with your support of the fees as reasonable, a good value, and inconsequential.  " CreationDate="2010-12-07T21:41:35.593" UserId="857" />
  <row Id="10637" PostId="7636" Text="@mikeselectricstuff - Couldn’t you adjust the image-processing algorithm based on altitude?" CreationDate="2010-12-07T21:45:49.560" UserId="588" />
  <row Id="10638" PostId="7627" Text="I had to use some devices with asynchronous FPGA designs. They were hard to work with. Please at least use timing constraints" CreationDate="2010-12-07T22:00:55.070" UserId="1481" />
  <row Id="10639" PostId="7643" Score="2" Text="http://www.chipdocs.com/logos/logotypes.html http://www.elnec.com/support/ic-logos/" CreationDate="2010-12-07T22:51:49.207" UserId="142" />
  <row Id="10640" PostId="7549" Text="@reemrevnivek, I think you may have typo'ed because I am confused by your sentence. 2 grand could be a lot more for an SD card which many project have a necessity. When you are making a product you are selling, 2 grand should be almost nothing, costs less than paying your engineers for a week, which is significantly less time then it would take your engineers to redesign it. Think, 1 month (short estimate) to get flash memory set up, then add in other features, or 2 grand to get sd card." CreationDate="2010-12-07T23:02:24.103" UserId="230" />
  <row Id="10641" PostId="7636" Score="1" Text="@mjh I think that the problem is best seen in an example.  At an altitude of 50 feet, a 5 degree roll or pitch (pretty typical for moving in the X or Y direction on a quadrotor) will cause ground features to move (tan(5 deg) * 50 feet) = 4.25 feet (rough math).  Even without the quadrotor moving, all of the ground features will shift by 4 feet.  This could be compensated for, but it becomes difficult with resolution and computation restrictions." CreationDate="2010-12-07T23:03:51.317" UserId="1477" />
  <row Id="10642" PostId="7614" Text="I am measuring a voltage drop of about 0.4V between the two sides. The resistance from 5V to 3V is about 2.7 kOhms. I know that these tiny things are really sensitive and break often (which brings up the question of an alternative), but I have three of those level shifters on a manufactured (i.e. not self-etched) board and already switched the MOSFETs with new ones and they behave all the same." CreationDate="2010-12-07T23:07:08.490" UserId="1950" />
  <row Id="10643" PostId="7648" Text="It's 30-40 mV for the level shifter in the above schematics. I have another one on the board missing the 3V pullups (they are in an external module not yet plugged in), there the Vgs is about 600 mV." CreationDate="2010-12-07T23:22:06.073" UserId="1950" />
  <row Id="10644" PostId="7549" Text="No, I did not make a typo.  I'm advocating that NXT should get back to selling ICs, some which might have a communication bus of which they are the author, and sell support for and moderate that communication bus, allowing them to sell more ICs.  They should avoid discouraging potential new users with fees.  However, they don't, so we have to live within the system." CreationDate="2010-12-08T01:08:57.960" UserId="857" />
  <row Id="10645" PostId="7369" Text="LPC1343 has no HS support" CreationDate="2010-12-08T02:29:28.420" UserId="1472" />
  <row Id="10646" PostId="7649" Text="@Jeff Osier-Mixon, Thank you for giving us feedback on your book. We are happy to see you come visit our corner of the internet. Try not to use signatures though, every post you make automatically has yours tagged in the bottom corner!" CreationDate="2010-12-08T02:56:46.193" UserId="230" />
  <row Id="10647" PostId="7649" Text="@Jeff Osier-Mixon, When you get more rep you will be able to leave comments, but for now, you should edit your answer and give us more information about why your book is the best guide available!" CreationDate="2010-12-08T02:57:46.850" UserId="230" />
  <row Id="10648" PostId="7649" Text="@Jeff Osier-Mixon Please note than on this site and others on Stack Exchange, there is no up or down . Over time, arrangement of answers will change and there are also user options for sorting answers. If you need to refer to an actual answer, you can copy it's link which is available on the bottom left of the answer area. In my case for example, your answer was above O Engenheiro's with default settings. Yes, we're a bit different that traditional forums." CreationDate="2010-12-08T03:43:47.827" UserId="1240" />
  <row Id="10649" PostId="7586" Text="Thanks guys. I'm not sure I have seen this before (although the answers do seem vaguely familiar). The explanations for it also make sense. Thanks again." CreationDate="2010-12-08T06:08:52.687" UserId="2042" />
  <row Id="10650" PostId="7642" Score="2" Text="We need a &quot;magic smoke&quot; tag!  :-)" CreationDate="2010-12-08T07:13:05.417" UserId="1990" />
  <row Id="10652" PostId="7647" Text="Thanks for the wisdom but it is not helpful in this particular situation. The devices are different(LPC2368 and AVR-something ) so they need to be set up separately." CreationDate="2010-12-08T08:17:04.153" UserId="2213" />
  <row Id="10653" PostId="7654" Score="5" Text="Well, it was a bit funny once. Don't kill it." CreationDate="2010-12-08T08:20:05.423" UserId="2064" />
  <row Id="10654" PostId="7646" Text="Thanks Thomas O, very helpful. I'll look into your suggestions." CreationDate="2010-12-08T08:54:34.630" UserId="2215" />
  <row Id="10655" PostId="7646" Text="Thanks to all for yourr suggestions. I will post a link to the circuit diagram as this might help others with the same interest too." CreationDate="2010-12-08T09:07:33.900" UserId="2215" />
  <row Id="10656" PostId="7144" Text="Which PIC families does that PIC book cover? The PIC18 family is the one I'd try to program in C; not the PIC16 family." CreationDate="2010-12-08T09:19:03.577" UserId="1025" />
  <row Id="10658" PostId="7613" Text="well the design works, but i dont know the limitations or what could fail. http://www.youtube.com/watch?v=fGv7ZcKn0Z0  tested with 5v through the motor, 5 volts on gate" CreationDate="2010-12-08T09:54:57.070" UserId="2060" />
  <row Id="10659" PostId="7295" Text="It passes the diode test on pins 5-6, but fails on pins 1-2. It may be a TR115, though." CreationDate="2010-12-08T09:56:23.063" UserId="2064" />
  <row Id="10660" PostId="7601" Text="Thanks heaps for your help guys. I'm thinking of going with something like this, http://www.daycounter.com/Circuits/OpAmp-Level-Shifter/OpAmp-Level-Shifter.phtml. Also do you guys know whether these circuits would introduce a phase shift into my signal?" CreationDate="2010-12-08T09:58:54.770" UserId="2200" />
  <row Id="10661" PostId="7657" Text="If the PSU has two 12V connectors (and it should), maybe you could just use them connected together?" CreationDate="2010-12-08T11:15:13.680" UserId="1240" />
  <row Id="10663" PostId="7617" Text="@stevenvh 220 V is still used in some countries." CreationDate="2010-12-08T11:29:11.177" UserId="1240" />
  <row Id="10664" PostId="7658" Text="Is there any reason why it wouldn't be possible to connect two 12 V grounds together and use two +12 V wires as a 24 V source?" CreationDate="2010-12-08T11:46:32.160" UserId="1240" />
  <row Id="10665" PostId="7658" Score="2" Text="Yes, there is a reason it will not work. That would be putting two 12V sources in parallel, which would still give you 12V. You would need to put the two supplies in series, but that is probably impossible since the grounds are connected internally." CreationDate="2010-12-08T11:57:27.430" UserId="638" />
  <row Id="10666" PostId="7657" Score="3" Text="If you connect two +12V supplies together in parallel, you will get a +12V supply that can source more current." CreationDate="2010-12-08T11:59:53.467" UserId="638" />
  <row Id="10667" PostId="7658" Score="1" Text="@W5VO I meant, use the two +12 V wires as + and - connectors, that is to put them in series. Still, I missed the internal GND connection." CreationDate="2010-12-08T12:04:00.170" UserId="1240" />
  <row Id="10669" PostId="7658" Text="@W5V0, unless I do not know something about computer power supplies it should be 24V from -12V to 12V. This will do what @Andrejako wants." CreationDate="2010-12-08T14:18:35.817" UserId="230" />
  <row Id="10670" PostId="7660" Text="As your ISR does nothing is it just being optimized away?  Perhaps you could try disabling optimization or declaring something `volatile` in it." CreationDate="2010-12-08T14:44:05.023" UserId="1407" />
  <row Id="10671" PostId="7658" Score="3" Text="Be aware that the -12 V rail (and all negative rails in modern PSUs) are relatively very weak.  It is not likely able to sink 3 A." CreationDate="2010-12-08T14:46:18.953" UserId="1407" />
  <row Id="10672" PostId="7617" Text="@Thomas @Andreja, I would be impressed if the power company could keep a +/-5% tolerance on line voltage." CreationDate="2010-12-08T14:48:43.320" UserId="1407" />
  <row Id="10673" PostId="7656" Score="1" Text="@Andreja: Are you sure the AVRISP mkII can do HVSP?  The documentation says nothing about it and I don't see any sort of HV source on the one sitting at my desk." CreationDate="2010-12-08T14:54:19.337" UserId="1407" />
  <row Id="10674" PostId="7660" Text="Optimization is set to -level0, Optimize for Time - deselected. __NOP() is not nothing. But I also tried changing global vars in interrupt handler or calling for functions. The code provided above was simplified to be just so small to reproduce the problem." CreationDate="2010-12-08T15:02:31.643" UserId="1736" />
  <row Id="10675" PostId="7656" Text="@Nick T I'll do some more research and look for sources on that. I remember that couple years ago when I was researching AVR devices, I found info about mkII ISP doing high voltage programming, but I didn't savve the link." CreationDate="2010-12-08T15:04:56.823" UserId="1240" />
  <row Id="10676" PostId="7660" Score="1" Text="Filed a technical support request to Keil, will repost here any answer." CreationDate="2010-12-08T15:06:52.843" UserId="1736" />
  <row Id="10677" PostId="7656" Text="@Nick T It turns out that I confused AVRISP for some other programmer. I apologize for spreading misinformation. I did find couple of other programmers which do support HV like [this](http://www.scienceprog.com/avr-serial-and-parallel-high-voltage-programmer/) or [this](http://mightyohm.com/blog/2008/09/arduino-based-avr-high-voltage-programmer/)." CreationDate="2010-12-08T15:14:05.773" UserId="1240" />
  <row Id="10678" PostId="7617" Text="@Nick T Mine can't. :( Anyway the whole point is that there are just two popular voltage ranges. The one around 230 V @ 50 Hz and the one around 115 V @ 60 Hz, so it's irrelevant if the voltage is actually 220 V or 230 V or 240 V." CreationDate="2010-12-08T15:15:52.060" UserId="1240" />
  <row Id="10679" PostId="7143" Text="What is that background?  A brief course on &quot;This is a `for` loop&quot; etc., writing simple console apps, or OS/systems programming?" CreationDate="2010-12-08T15:28:10.820" UserId="857" />
  <row Id="10680" PostId="7617" Text="@Andreja - Did you really mean 230V @ 60Hz?  In the US, we get 115/110/120 by taking half of the 230/220/240V input.  In fact, half of the 120VAC circuits in my house are out of phase with the others.  One is precisely half of the other, and the frequencies are identical." CreationDate="2010-12-08T15:31:02.220" UserId="857" />
  <row Id="10681" PostId="7624" Text="I know Simon Moore at the university of Cambridge did a lot of research into asynchronous design, including getting a test chip fabricated.  It requires an entirely new set of design tools, and has strange side effects: execution speed inversely proportional to temperature, for example." CreationDate="2010-12-08T15:32:06.653" UserId="2228" />
  <row Id="10682" PostId="7660" Text="Why do you need an __NOP(); call?  Can't you just use a simple semicolon?" CreationDate="2010-12-08T15:34:11.623" UserId="857" />
  <row Id="10683" PostId="7617" Text="@reemrevnivek  In large part of the world, the frequency is 50 Hz, so I meant 230 V @ 50 Hz. Take look at [this](http://en.wikipedia.org/wiki/List_of_countries_with_mains_power_plugs,_voltages_and_frequencies) chart. Only few countries actually use 230V @ 60Hz." CreationDate="2010-12-08T16:06:58.027" UserId="1240" />
  <row Id="10684" PostId="7666" Score="5" Text="As to why sinking is easier, it's because N-channel MOSFETs (used to sink in CMOS) have better carrier mobility (electrons flow better than holes)" CreationDate="2010-12-08T16:27:40.707" UserId="1407" />
  <row Id="10685" PostId="7664" Text="As a side note, if you don't have a good ground, your ground can oscillate also. If you were using a pulldown configuration you could still need a capacitor on MCLR." CreationDate="2010-12-08T16:30:49.627" UserId="319" />
  <row Id="10686" PostId="7666" Score="2" Text="I'm not entirely sure on this; most ICs nowadays can sink ±20mA, and does it really matter? 4.7k (typ.) is going to be less than 1mA which most ICs can do." CreationDate="2010-12-08T16:43:52.173" UserId="1225" />
  <row Id="10687" PostId="7460" Text="If it's due to this, wouldn't I hear the hum/buzz whether it was raining or not?" CreationDate="2010-12-08T16:43:55.233" UserId="536" />
  <row Id="10688" PostId="7453" Text="@Joel B, as per my comment to mjcarroll, why do I hear the hum/buzz only when it's raining?" CreationDate="2010-12-08T16:44:56.777" UserId="536" />
  <row Id="10689" PostId="7658" Text="-12V usually uses a 7912 regulator. That can pass a maximum of 1A, but probably much less in practice." CreationDate="2010-12-08T17:36:32.257" UserId="1225" />
  <row Id="10690" PostId="7665" Text="This is what I was going to ask." CreationDate="2010-12-08T17:37:29.847" UserId="230" />
  <row Id="10691" PostId="7663" Text="I did exactly this with one of my supplies. You'll also have to disable the overvoltage protection, if it has any. In my case it was just an SCR so bridging gate-anode stopped it from tripping off. Before disabling that, mine was limited to about 13.5V. I made mine adjustable, using a potentiometer. See: http://www.youtube.com/watch?v=mK_rIs7uFlo" CreationDate="2010-12-08T17:38:37.157" UserId="1225" />
  <row Id="10692" PostId="7659" Score="1" Text="The ground on most computer power supplies should be completely isolated from any mains conductor, including earth/safety ground. You can safely parallel two supplies together." CreationDate="2010-12-08T17:39:28.433" UserId="1225" />
  <row Id="10693" PostId="7460" Text="I seem to recall that it was more likely in humid air, but I'm not particularly sure." CreationDate="2010-12-08T17:56:43.143" UserId="1477" />
  <row Id="10694" PostId="7666" Score="3" Text="@Thomas - 'Sinking ±20mA' is not an accurate way of stating what happens.  The source and sink currents go through separate transistors, which have different specs for a given chip area." CreationDate="2010-12-08T18:09:49.417" UserId="857" />
  <row Id="10695" PostId="7653" Score="1" Text="have you tried banging it firmly on the side?" CreationDate="2010-12-08T18:16:42.560" UserId="771" />
  <row Id="10696" PostId="7642" Score="1" Text="@PeterLoron Done." CreationDate="2010-12-08T18:22:18.947" UserId="588" />
  <row Id="10697" PostId="7667" Score="1" Text="A promising candidate, however please refrain from using all capital letters as it coveys the impression you are shouting." CreationDate="2010-12-08T18:37:39.550" UserId="1407" />
  <row Id="10698" PostId="7666" Text="@reemrevnivek - Sorry, my mistake, I guess sinking/sourcing is more appropriate. But either way, they can sink and source a lot of current." CreationDate="2010-12-08T19:09:53.273" UserId="1225" />
  <row Id="10699" PostId="7669" Score="2" Text="+1 for the note about &quot;Thieving&quot;.  I always get a question from the Fab House about this." CreationDate="2010-12-08T21:10:02.477" UserId="204" />
  <row Id="10700" PostId="7636" Text="I've been  thinking about this and have come to the same conclusion. I want it to hover ideally indoors, so the height isn't really an issue, thankfully. " CreationDate="2010-12-08T21:21:20.647" UserId="2212" />
  <row Id="10701" PostId="7671" Text="Brilliant! Thanks for the great answer; ultrasound looks to be the way to go. I will use an altimeter as well, so I can get a larger range of measurements (but less accurate ones obviously)." CreationDate="2010-12-08T21:38:45.300" UserId="2212" />
  <row Id="10702" PostId="7670" Score="1" Text="Why do you need to know the height?  Because the speed scenery moves by will vary by height?  I think that could be compensated for by a feedback controller, though, couldn't it?  It's just seeking to minimize the movement of the ground, not calculate speed from it." CreationDate="2010-12-08T22:15:11.893" UserId="142" />
  <row Id="10703" PostId="7666" Score="3" Text="even if today's parts are more robust, by now it may just be convention." CreationDate="2010-12-08T22:34:01.790" UserId="740" />
  <row Id="10704" PostId="7618" Text="if there's an embedded time/date stamp in the file, that will hose checksum reproducibility" CreationDate="2010-12-08T22:40:43.300" UserId="740" />
  <row Id="10706" PostId="7597" Text="@endolith, isn't [1 LSB out of a 24-bit value just 72 dB?](http://www.google.com/search?hl=&amp;q=10*log%281%2F%282\*\*24%29%29)" CreationDate="2010-12-08T23:22:36.020" UserId="1407" />
  <row Id="10707" PostId="7648" Score="1" Text="What happens if you remove the two MOSFETs altogether? It sounds stupid, yes, but it's a sure-fire way to prove that the 'leak' is through the MOSFETs somehow. " CreationDate="2010-12-08T23:29:01.887" UserId="1293" />
  <row Id="10708" PostId="2984" Text="I've never found a potted wall wart. Where are you from JustJeff?" CreationDate="2010-12-08T23:41:27.347" UserId="2118" />
  <row Id="10709" PostId="7673" Text="Read my edit. I got it to start. And yes, I've read that it won't supply correct voltages without a minimum load. But what resistors and such do I need for that minimum load on which lines?" CreationDate="2010-12-08T23:55:45.650" UserId="708" />
  <row Id="10710" PostId="7673" Text="@user708 I'll try to add some more info." CreationDate="2010-12-09T00:07:55.253" UserId="1240" />
  <row Id="10711" PostId="7653" Text="Is it possible to set fuses in the Arduino environment? It doesn't look like the Freakduino-chibi has an external oscillator, which would be a problem if the ext. osc. fuses are set. Just put a 1MHz clock on the XTAL pin." CreationDate="2010-12-09T00:09:45.323" UserId="2118" />
  <row Id="10712" PostId="2984" Score="2" Text="A word of warning. I shorted out a 6Vac transformer/wall wart, obviously shorted something in the transformer windings, and it's now outputting ~40Vac. So don't rely on the transformer burning out." CreationDate="2010-12-09T00:12:04.490" UserId="1225" />
  <row Id="10713" PostId="7673" Text="@user708 I added some more information. Still, read the articles I linked. " CreationDate="2010-12-09T00:16:27.623" UserId="1240" />
  <row Id="10714" PostId="7636" Text="@JamWaffles Consider this and your other post, you may want to consider getting one of the Parrot drones to play with.  We got two for demonstrations and playtime, and they are pretty capable little machines.  With the configuration software, you can see/change the PID gains and camera data.  It's a good starting point for your experimentations." CreationDate="2010-12-09T01:40:55.870" UserId="1477" />
  <row Id="10715" PostId="7674" Text="Could you give a link to exactly the Vex kit that you have? It looks like it would be possible, but it depends on the details." CreationDate="2010-12-09T02:18:42.430" UserId="712" />
  <row Id="10717" PostId="7675" Score="8" Text="I must say, that's a well-exposed picture for the combination of extreme lights and darks!" CreationDate="2010-12-09T07:58:53.630" UserId="2118" />
  <row Id="10718" PostId="7667" Text="Link seems to be dead, but I found the datasheet [here](http://www.fairchildsemi.com/ds/HC/HCPL0501.pdf). This one has very complete information on device marking (wish they were all so detailed), and it doesn't fit: it lacks the Fairchild logo, and the assembly package code. May be the same device from another manufacturer, actually the type number reminds me of HP. Passes the diode test on pins 2-3, but also on 5-6 :-(" CreationDate="2010-12-09T10:29:36.823" UserId="2064" />
  <row Id="10720" PostId="7676" Text="Relay logic was being used at least as recently as the mid 90's in trains (locomotives, trams etc), at least in Europe, using the train battery supply, typically 48 to 110V d.c. This was in addition to microprocessor logic. It's bulky but reliable, at least it can be designed to avoid dangerous states when it fails, which was/is almost impossible with software. (An example of a dangerous state might be allowing the train to depart with the doors open)." CreationDate="2010-12-09T11:26:41.767" UserId="2110" />
  <row Id="10721" PostId="7676" Score="1" Text="The photo reminds me of a &quot;computer&quot; made from relays at my school in the '70s. I believe it was a binary adder and had been made a decade or so earlier by some enterprising students. It caught fire around '76. Seems like only yesterday :o{" CreationDate="2010-12-09T11:32:24.803" UserId="2234" />
  <row Id="10722" PostId="7679" Score="3" Text="A barometric sensor with a 9cm resolution sounds too good to be true, and I think it should be taken with more than a pinch of salt. First, they're absolute pressure sensors, so they have to be recalibrated for height with changing air pressure (weather). Then this is _resolution_, which means the theoretical height (pressure) change represented by 1 LSB. That's not _accuracy_, however. That depends on a number of factors, like linearity, and noise. If your LSB is drowned by 5 bits of noise your effective resolution reduces to 3m. Which would still be very good by any standard." CreationDate="2010-12-09T12:56:12.843" UserId="2064" />
  <row Id="10723" PostId="734" Text="The link to the ebook is no longer working" CreationDate="2010-12-09T13:15:48.643" UserId="1497" />
  <row Id="10724" PostId="733" Text="The link to the starter kit is no longer working" CreationDate="2010-12-09T13:16:18.097" UserId="1497" />
  <row Id="10725" PostId="2952" Text="@John Burton, you could use a zener in reverse across the supply and an inline fuse. Choose a zener slightly greater than typical operating voltage and one rated for about 3W-5W dissipation. When it conducts either the voltage on the output drops or the fuse blows." CreationDate="2010-12-09T13:31:14.543" UserId="1225" />
  <row Id="10726" PostId="7676" Text="One of the first examples of relay logic was telephones. electromechanical relays replaced the telephone operator and her plug board. " CreationDate="2010-12-09T13:44:46.967" UserId="1810" />
  <row Id="10727" PostId="7679" Score="1" Text="GPS note: actually, there's a second way to get precise height out of GPS: sit still for a day or so. Not useful for the project at hand, but the technique is used by folks like the National Geodetic Survey in some of their equipment." CreationDate="2010-12-09T16:06:48.467" UserId="259" />
  <row Id="10728" PostId="7597" Text="No, it's 20*log10.  10*log10 is for powers, not voltages.  The easier rule of thumb is &quot;6 dB per bit&quot;.  http://en.wikipedia.org/wiki/Dynamic_range#Audio  http://en.wikipedia.org/wiki/Quantization_error" CreationDate="2010-12-09T16:32:24.750" UserId="142" />
  <row Id="10729" PostId="7672" Score="1" Text="You need a multimeter; don't depend on the fan to know it is on." CreationDate="2010-12-09T16:35:49.363" UserId="206" />
  <row Id="10730" PostId="7669" Text="awesome website thanks for the link :)" CreationDate="2010-12-09T17:57:51.760" UserId="1397" />
  <row Id="10731" PostId="7682" Text="How long are the traces? (wires?)" CreationDate="2010-12-09T19:31:10.507" UserId="2118" />
  <row Id="10732" PostId="7682" Score="1" Text="@tyblu, They may be up to 50 cm long going over twisted pair, but in general &lt;6cm for the rest of the board. I was thinking of using 400 kHz for external sensors though, and 1 MHz for internal logic only." CreationDate="2010-12-09T19:57:06.257" UserId="1225" />
  <row Id="10733" PostId="7687" Text="The 16F PICs don't have LAT registers, hence the problem." CreationDate="2010-12-09T20:22:01.750" UserId="305" />
  <row Id="10734" PostId="7688" Score="1" Text="It's nothing to do with that!" CreationDate="2010-12-09T20:44:25.123" UserId="305" />
  <row Id="10735" PostId="7689" Text="Do you think it would be possible to clock addresses at 400 kHz but data at 1 MHz? So the slow devices ignore the address if necessary." CreationDate="2010-12-09T20:51:57.120" UserId="1225" />
  <row Id="10736" PostId="7685" Score="1" Text="I'm going to be pessimistic and say no. Do feel free to prove me wrong, though. First, how are you going to track the card? Bluetooth has extremely low range. GPS can't be used to actually rack anything, it just gives you your location. RFID may be the right way to go. What is &quot;long range&quot;? How much money do you want to invest into it? How are you going to solve the power problems? RFID could be powered by radio, but the rest are going to need dedicated power sources. I doubt you could make it out of PVC, but maybe two thin PCBs sandwiched together could work" CreationDate="2010-12-09T21:35:43.560" UserId="1240" />
  <row Id="10737" PostId="7674" Text="Certainly: http://www.vexrobotics.com/catalog/product/view/id/12217/s/dual-control-starter-bundle/category/1579/" CreationDate="2010-12-09T21:41:36.160" UserId="2231" />
  <row Id="10738" PostId="7561" Text="Worked like a charm. After using a Scotchbrite pad, I could easily tell that my copper had been oxidized quite a bit. Another stupid thing, the iron I had been using wasn't being kept clean and the sponge was completely ineffective." CreationDate="2010-12-09T21:51:02.963" UserId="638" />
  <row Id="10739" PostId="7685" Score="3" Text="Quantify what you mean by &quot;a relatively long range&quot;. Also, if you could fill in more details in your example use-case, that would help. From reading your question, I'm not clear who is tracking the card, what data communication needs to occur, or what the scale of the map is. " CreationDate="2010-12-09T21:59:55.370" UserId="638" />
  <row Id="10740" PostId="7689" Text="I don't think so. According to post #9 in this thread http://www.picaxeforum.co.uk/showthread.php?t=8535, &quot;You cannot run mixed speed devices on the same bus and use the higher baud rate - the slow device will simply get confused and can hang or give corrupt data.&quot;.  On a project I am working on, which has a chip that only works at I2C clock rates below 50 KHz, the manual for the chip states that if you want to use it on the same bus as faster devices, you must put it to sleep or hold it in reset while talking to the higher speed devices." CreationDate="2010-12-09T22:09:32.373" UserId="1322" />
  <row Id="10741" PostId="2984" Text="@Thomas O: I +1'd your comment b/c though it may seem blindingly obvious, &quot;don't rely on the transformer burning out&quot; will be of inestimable value to some." CreationDate="2010-12-09T22:12:32.747" UserId="740" />
  <row Id="10742" PostId="7689" Text="@tcrosley, Thanks for that. It might actually be better to have a fast internal bus and a slow external one. My MCU has two I2C controllers." CreationDate="2010-12-09T22:36:55.463" UserId="1225" />
  <row Id="10743" PostId="2984" Text="@tyblu: the few times i tried it, i encountered potting material, so i lost interest in getting them open - but that was (ugh) 30 years ago. Northeast US btw." CreationDate="2010-12-09T22:44:03.120" UserId="740" />
  <row Id="10744" PostId="7689" Text="&quot;might actually be better to have a fast internal bus and a slow external one&quot; -- sounds good to me." CreationDate="2010-12-09T22:54:41.617" UserId="1322" />
  <row Id="10745" PostId="7322" Text="I accepted on the broadest answer. For getting information for each OS, i liked the answer. Joby's answer was excellent specific to Linux. I had a hard time deciding." CreationDate="2010-12-10T05:02:19.647" UserId="230" />
  <row Id="10746" PostId="7653" Text="Banging it had no effect.  :-(" CreationDate="2010-12-10T08:14:07.010" UserId="1990" />
  <row Id="10747" PostId="7656" Text="Interesting. I'll see if I can cobble together something that will do the HV programming and see if I can clear the fuses." CreationDate="2010-12-10T08:48:17.027" UserId="1990" />
  <row Id="10748" PostId="7693" Text="Some ICs are rated to high temps: 150C Schottky diode (APT60S20); 200C temp. sensor (LM95172; $$!); 150C c.c.-source (PSSI2021SAY; BJT); 160C SMPS FET (FS6S1565RB); 225C linear reg. (HTPLREG)." CreationDate="2010-12-10T09:31:51.600" UserId="2118" />
  <row Id="10749" PostId="7667" Text="Found an HP, erm, Agilent, erm [Avago datasheet](http://www.avagotech.com/docs/AV02-0171EN). Marking matches completely!" CreationDate="2010-12-10T11:44:11.173" UserId="2064" />
  <row Id="10750" PostId="7566" Text="It survived, I guess. It stills sends out data and executes code. I did it again for about 10 seconds accidently, it got really hot, but didn't fail, so I let it cool down, and it's being working for a few days." CreationDate="2010-12-10T12:14:32.083" UserId="1225" />
  <row Id="10751" PostId="7496" Text="Me too. It's very cheap." CreationDate="2010-12-10T12:28:51.457" UserId="938" />
  <row Id="10752" PostId="7699" Text="I'd say you should ask your potential users that. Since it's open hardware, JTAG would add to the feeling of openness, but if your target audience isn't interested, it would be a waste of time." CreationDate="2010-12-10T12:48:38.090" UserId="1240" />
  <row Id="10753" PostId="7699" Text="@AndrejaKo, I'd ask, but I'm selling to both EE's and non-EE's - the EE's will probably say &quot;yes please&quot;, the non-EE's will probably say &quot;I don't care.&quot;" CreationDate="2010-12-10T12:59:25.713" UserId="1225" />
  <row Id="10754" PostId="7699" Text="@Thomas O As I feared. Unfortunately, I don't have anything smart to say. :( " CreationDate="2010-12-10T13:05:59.780" UserId="1240" />
  <row Id="10755" PostId="7703" Score="1" Text="The ICSP headers are used for programming, not JTAG... unless I'm missing something(?)" CreationDate="2010-12-10T13:21:49.260" UserId="1225" />
  <row Id="10756" PostId="7706" Score="3" Text="Agree.  I've never used the JTAG interface on any of my PIC projects.  The ICSP interface is quite adequate for debugging via MPLAB." CreationDate="2010-12-10T13:45:17.023" UserId="1322" />
  <row Id="10757" PostId="7695" Text="Thank you. This works exactly as you wrote in example. And also I can declare function in header file as &#xA;    extern &quot;C&quot; void SysTick_Handler(void); &#xA;and later write my interrupt handler in classical form i.e. without extern &quot;C&quot;.&#xA; &#xA; " CreationDate="2010-12-10T14:22:52.943" UserId="1736" />
  <row Id="10758" PostId="7696" Score="1" Text="What are the specifications on the output signal? It would be helpful to know the output voltage range, the maximum current load, and the maximum allowable voltage ripple. " CreationDate="2010-12-10T14:31:40.243" UserId="638" />
  <row Id="10759" PostId="7701" Text="We do this even on products that are never intended to be modified by the end user. Makes them easier to debug if something goes wrong in the field. Connector is expensive, so we just leave the pads." CreationDate="2010-12-10T15:18:46.223" UserId="875" />
  <row Id="10760" PostId="7710" Score="1" Text="Brian, Thanks for the answer! One more thing though. Is there a rule of thumb for the size of the resistor?" CreationDate="2010-12-10T16:56:18.157" UserId="1235" />
  <row Id="10761" PostId="7710" Text="@Jordan S, you want the voltage drop across it, V = IR, to be lower than your maximum allowable drop. You also need to consider the characteristics of the filter, such as break frequency. If the IC manufacturer suggests it they will include possible values in the datasheet." CreationDate="2010-12-10T17:17:15.310" UserId="1225" />
  <row Id="10762" PostId="7709" Score="2" Text="What value resistor?  In what kind of signal circuit?" CreationDate="2010-12-10T17:37:38.170" UserId="142" />
  <row Id="10763" PostId="7701" Text="Good idea. I'm going to do this as well." CreationDate="2010-12-10T18:43:58.487" UserId="2118" />
  <row Id="10764" PostId="7708" Text="Know what?  This isn't what the OP is looking for, despite its coolness.  He wants something that will generate ASCII art for him... I can't downvote my own post..." CreationDate="2010-12-10T18:52:19.543" UserId="374" />
  <row Id="10765" PostId="7710" Text="For Vcc resistors on a low-power chip, 10 ohms is a good starting point.  This works pretty well (for its cost) in reducing noise from digital chips to analog chips supply.  Important in things like digital radio, where it might be powered by a battery with its own 10 ohms resistance, and any noise in the supply will AM-modulate the RF signal." CreationDate="2010-12-10T18:59:18.903" UserId="411" />
  <row Id="10766" PostId="7704" Text="+1 for random Dutch mutterings." CreationDate="2010-12-10T19:06:47.180" UserId="2118" />
  <row Id="10767" PostId="7715" Score="3" Text="The things that immediately come to mind is do the same thing an old modem running at 300 baud (or some other slow speed).  Some other thoughts include using the same type circuit / audio format as the old tape based storage retrieval systems (think CLOAD / CSAVE).  " CreationDate="2010-12-10T19:12:38.367" UserId="1823" />
  <row Id="10768" PostId="7711" Text="The experienced opinion is the final word! I will push trace temperatures when I need to, then (necking down, etc.). The article looks like a good read." CreationDate="2010-12-10T19:12:49.110" UserId="2118" />
  <row Id="10770" PostId="7720" Text="My next planned soldering iron to buy is this one: http://www.sparkfun.com/products/9450 it's butane which I think I'd like cause the cord on electric soldering iron's annoy me hugely. " CreationDate="2010-12-10T20:05:48.663" UserId="708" />
  <row Id="10771" PostId="7307" Text="I use the standard Altera pinout. Details are included in those design files." CreationDate="2010-12-10T20:09:26.533" UserId="305" />
  <row Id="10772" PostId="7720" Score="2" Text="That's OK for simple field repairs and other jobs like heat-shrink tubing, but you should get a proper temperature-controlled iron for reliable soldering." CreationDate="2010-12-10T20:13:47.030" UserId="305" />
  <row Id="10773" PostId="7720" Score="1" Text="@user708 Better irons have better cords.  The insulation is usually silicone rubber so they don't melt from a brush with the tip, and the wires are more highly stranded so they're much more flexible.  If the cords still irritate you, make sure you're working at a proper space with enough room, lighting, and other tools (3rd hands, etc)." CreationDate="2010-12-10T20:24:01.123" UserId="1407" />
  <row Id="10774" PostId="7678" Text="This is photoconductive mode. Can also use photovoltaic, basically open-circuit, which is what the OP's link describes. Photoconductive is faster as the relatively large forward bias 'sweeps' the injected carriers away, but also noisier." CreationDate="2010-12-10T20:42:13.480" UserId="2118" />
  <row Id="10775" PostId="7715" Text="If your jitter is so bad that transmitting at a few hundred baud is going to be problematic, I'd hate to know what your audio is going to sound like." CreationDate="2010-12-10T21:08:40.167" UserId="1407" />
  <row Id="10776" PostId="7715" Text="Ignoring the hardware side of noise immunity (blasphemy), high noise immunity means error correction. On top of hardware parity checks and DC-balancing, such as with Manchester, you can include checksums/CRC: http://goo.gl/RwDlt . Choosing one may need another topic!" CreationDate="2010-12-10T21:11:58.757" UserId="2118" />
  <row Id="10777" PostId="7715" Text="@Nick T, Think about a telephone line. It's pretty poor quality. It's about what the quality you get from cheap RC transmitters, but it's enough to hear that your propeller is working or to hear voice messages from your OSD system." CreationDate="2010-12-10T21:13:38.303" UserId="1225" />
  <row Id="10778" PostId="7715" Text="@tyblu, I was considering using Hamming(7,4) plus parity for error correction, on top of a CRC16 checksum for the entire message; the CRC16 can be generated in about 16 cycles on my processor using the onboard CRC generator." CreationDate="2010-12-10T21:15:06.993" UserId="1225" />
  <row Id="10779" PostId="7685" Text="ok.. well say I lost this fake credit card somewhere in my house and I would want to find it. What kind of range would a RFID module have, and is the almost credit card shape and thickness feasable? Just so you know, I don't have much electronics knowledge, but I do know programming." CreationDate="2010-12-10T21:16:38.240" UserId="2236" />
  <row Id="10780" PostId="7685" Text="@AndrejaKo Well im not looking necessarily to track it. Although it would be nice, the basic functionanality im looking for is to see only the location of this potential card." CreationDate="2010-12-10T21:19:16.787" UserId="2236" />
  <row Id="10781" PostId="7715" Text="@Thomas, telephone lines have practically zero jitter.  Audio must have very low jitter or it will sound *terrible*.  If your data path has latency issues, the packets must be delayed and resynchronized to &quot;de-jitter&quot; the signal.  If one fails to arrive in time, it is thrown away.  (This all seems moot for your application, which sounds analog, which implies negligible jitter AFAIK)" CreationDate="2010-12-10T21:20:16.693" UserId="1407" />
  <row Id="10782" PostId="7722" Score="1" Text="+1 for dirty irons. Just need a thin layer. I had a &quot;yo momma&quot; joke typed up, but I wussed out." CreationDate="2010-12-10T21:24:53.910" UserId="2118" />
  <row Id="10783" PostId="7715" Text="@Nick T, the plane may be distances of many km (up to 25 km in some cases) from the receiver introducing about 8 us delay in some cases; and the PLL on some of the cheaper transmitters isn't that stable. Telephone lines don't need to have PLLs so don't suffer from this." CreationDate="2010-12-10T21:26:02.323" UserId="1225" />
  <row Id="10784" PostId="7726" Score="1" Text="is this a homework problem?" CreationDate="2010-12-10T21:29:53.640" UserId="411" />
  <row Id="10785" PostId="7726" Text="More of a project that has some insane limitations." CreationDate="2010-12-10T21:41:26.657" UserId="2188" />
  <row Id="10786" PostId="7726" Text="@Brian: Homework tag was agreed on meta not to be used because it does not specify the contents. I used projects in that purpose." CreationDate="2010-12-10T21:46:57.757" UserId="2188" />
  <row Id="10787" PostId="7636" Text="As I said in http://electronics.stackexchange.com/questions/7670/how-accurate-are-altimeters, you shouldn't need to know the height.  You're seeking to minimize movement of the ground, not measure speed from it.  A good feedback controller should work regardless of the height, no?" CreationDate="2010-12-10T21:56:50.520" UserId="142" />
  <row Id="10788" PostId="7731" Text="Welcome to Electronics.SE, glad to hear this site is useful :P  I'm afraid this question is a duplicate of a few others however, try checking them: [How to become an embedded software developer?](http://electronics.stackexchange.com/questions/3343/how-to-become-an-embedded-software-developer), [Steps to learning Arduino Programming](http://electronics.stackexchange.com/questions/1015/steps-to-learning-arduino-programming) out first.  If you have a particular target in mind as far as what you want to do or specifically on what, that might be useful to add to your question." CreationDate="2010-12-10T22:08:51.050" UserId="1407" />
  <row Id="10789" PostId="7715" Text="Wait, a plane? So this is RF. Now you're in ham radio/RF territory; they have loads of tricks, and I know none of them." CreationDate="2010-12-10T22:10:01.640" UserId="2118" />
  <row Id="10790" PostId="7726" Text="DC, Homework, Projects are all *way* too broad" CreationDate="2010-12-10T22:13:34.120" UserId="1407" />
  <row Id="10791" PostId="7718" Text="Related: [Going through soldering tips quickly](http://electronics.stackexchange.com/questions/4470/going-through-soldering-tips-quickly)" CreationDate="2010-12-10T22:20:46.577" UserId="1407" />
  <row Id="10792" PostId="7715" Text="@tyblu, I mention in my original question &quot;I'm looking for a way to send binary data over an audio channel on a video/audio transmitter.&quot;" CreationDate="2010-12-10T22:23:37.693" UserId="1225" />
  <row Id="10793" PostId="7730" Text="doesn't a charge pump require two diodes, as well?" CreationDate="2010-12-10T22:27:55.663" UserId="740" />
  <row Id="10794" PostId="7730" Score="1" Text="Yep, 2 diodes, and smoothed out with another RC." CreationDate="2010-12-10T22:32:39.967" UserId="2118" />
  <row Id="10795" PostId="7731" Score="4" Text="@Nick T: not sure those are exact dupes. the 1st one you cite is a starting-from-scratch, the 2nd one is arduino specific, whereas this seems to be asking, &quot;what among the current offerings would be most in line with 8 bit stuff circa 1980&quot;" CreationDate="2010-12-10T22:38:49.557" UserId="740" />
  <row Id="10796" PostId="41" Score="2" Text="Does the work since twitter moved to oauth?" CreationDate="2010-12-10T22:53:01.870" UserId="1623" />
  <row Id="10798" PostId="7715" Text="@Thomas O: Hamming on top of a CRC? Do you mean underneath? The CRC should be on hamming-encoded data otherwise you're wasting a lot of bits for no reason. CRC on a lower level would make any error correction above it useless.  (unless you ignore it, then the CRC's useless)" CreationDate="2010-12-10T23:15:55.127" UserId="1270" />
  <row Id="10800" PostId="7715" Text="@darron: The CRC is for the message, then the message is hamming(8,4) (7,4 plus parity) encoded." CreationDate="2010-12-10T23:27:43.810" UserId="1225" />
  <row Id="10801" PostId="7734" Text="The CR2016 coin cell is 1.6mm thick and common." CreationDate="2010-12-10T23:52:40.960" UserId="2118" />
  <row Id="10802" PostId="7674" Text="Please link the datasheet of the rangefinder" CreationDate="2010-12-11T00:06:32.273" UserId="2246" />
  <row Id="10803" PostId="7720" Text="@Leon well, the butane irons apparently do have temperature control, though I would assume not as fine grained as a high price digital iron. @Nick Well that's also the thing. I don't have a lot of room for doing this. I live in a 1 bedroom apartment, so my soldering station doubles as my kitchen table. " CreationDate="2010-12-11T00:19:33.847" UserId="708" />
  <row Id="10804" PostId="7725" Text="No, I mean I've tinned it(or tried to, it's very difficult cause the solder just blobs up) before I got the tip tinner. I just used regular solder instead." CreationDate="2010-12-11T00:21:41.943" UserId="708" />
  <row Id="10805" PostId="7739" Text="I can discard bad packets or messages. They are monolithic containing a GPS position, voltages, currents etc." CreationDate="2010-12-11T00:47:20.340" UserId="1225" />
  <row Id="10806" PostId="7740" Text="A linear regulator wastes 44% of battery energy. Consider using a lower voltage battery (pack), such as 4-5 AA's, and/or a switching regulator. There are even some 7805 pin-compatible packages (3-SIP): http://goo.gl/ly5bw ." CreationDate="2010-12-11T01:28:06.370" UserId="2118" />
  <row Id="10807" PostId="5369" Score="1" Text="and it has a temperature coefficient!" CreationDate="2010-12-11T01:36:22.277" UserId="1609" />
  <row Id="10808" PostId="7448" Text="i was just wondering whether it was a DC or an AC line and thought the number of conductors might be the best indicator. sounds like almost certainly AC." CreationDate="2010-12-11T01:40:05.180" UserId="740" />
  <row Id="10809" PostId="7742" Text="yeah, usb charging spec has a resistor between D+ and D- and devices that use it will check for it." CreationDate="2010-12-11T01:40:08.817" UserId="230" />
  <row Id="10810" PostId="7742" Text="Well, they always describe it as a resistance (&quot;RDCP_DAT&quot; = &quot;Dedicated Charging Port resistance across D+/-&quot;), but then the spec for that variable is, I think, anything less than 200 ohms, including a short." CreationDate="2010-12-11T01:50:14.317" UserId="142" />
  <row Id="10812" PostId="7722" Text="+1 for the temperature comment.  I've been using a low wattage iron for so long (for IC work) that I've forgotten that if the iron is too hot it will oxidize the solder quicker also.  Good call and since he's using a cheap iron that could be the OP's problem as well.  @Earlz Do exactly as Leon says and buy a new temp controlled iron.  He knows what he's talking about - He's a regular poster over on the parallax boards as well." CreationDate="2010-12-11T02:03:48.430" UserId="2203" />
  <row Id="10814" PostId="7692" Text="I wonder if there would be an issue with running a 150C trace across a board, then expanding it 1cm or so from an IC pin that requires a lower temperature? Issues other than signal integrity (changing impedance). I'll have to try it out." CreationDate="2010-12-11T02:26:33.213" UserId="2118" />
  <row Id="10815" PostId="7739" Text="Since this is simple data, could you use a variation on a Kalman filter to throw out bad data, either on top of or instead of some of the error detection? This would prevent corrupt packets from causing issues and would also cover hardware hiccups: http://goo.gl/MlK5q ." CreationDate="2010-12-11T02:34:01.023" UserId="2118" />
  <row Id="10816" PostId="7741" Text="+1 Mintyboost. If you're eligible, sample an LT1302 from Linear. Then the cost is very cheap. " CreationDate="2010-12-11T02:52:38.063" UserId="1307" />
  <row Id="10817" PostId="7742" Text="Yes, the element actually checks for the voltage swing, when pushing a current, being below a certain voltage." CreationDate="2010-12-11T02:59:35.753" UserId="230" />
  <row Id="10818" PostId="1023" Text="Should be a comment." CreationDate="2010-12-11T03:40:40.233" UserId="1374" />
  <row Id="10819" PostId="815" Text="There are RTOS projects that will run on an *ATMega*, but anything similar is not likely to use the arduino environment." CreationDate="2010-12-11T03:42:36.093" UserId="1374" />
  <row Id="10820" PostId="7540" Text="Fixed the title" CreationDate="2010-12-11T03:45:15.813" UserId="1374" />
  <row Id="10821" PostId="7543" Text="Basically you have to gate a square wave with a slower square wave. Think to 555 timers." CreationDate="2010-12-11T03:47:24.730" UserId="1374" />
  <row Id="10822" PostId="7745" Score="5" Text="Otherwise known as conjugate impedance matching." CreationDate="2010-12-11T05:06:02.603" UserId="2118" />
  <row Id="10823" PostId="7744" Score="1" Text="May want to peek at this: [link](http://www.heathhofmann.me/IEEETransPelvol17no5sept2002.pdf)" CreationDate="2010-12-11T05:39:02.747" UserId="2118" />
  <row Id="10824" PostId="7741" Text="I'm just glad I don't have to worry about iPod charging. I'm mainly just concerned about cellphones(non-iPhone). Also this is my regulator: http://docs.google.com/viewer?a=v&amp;q=cache:g9oqgH4Gsh8J:www.kitronik.co.uk/pdf/7805reg.pdf+l7805cv+pin+out&amp;hl=en&amp;gl=us&amp;pid=bl&amp;srcid=ADGEESi-4ptYS2qa5WNynyYnfyoZ5lg3dUE8eZ4H5KdDs0xFqcy6vp91pnhVCe32gsj3yI9HEE69Fj1o80NSN0pk2LoxnmzXd2OaonbkHNVYhJ49qf9jXhcNYPTRZ9KMR9w-0ivxsbxK&amp;sig=AHIEtbTVfbAOIDbqTQzF6r_thMNAlkyU4A&amp;pli=1" CreationDate="2010-12-11T06:02:37.997" UserId="708" />
  <row Id="10825" PostId="7740" Text="@tyb yea, I'm using a simple linear regulator right now. I'm going to be ordering some of these( http://www.sparkfun.com/products/317 ) soon though. " CreationDate="2010-12-11T06:06:02.800" UserId="708" />
  <row Id="10826" PostId="7697" Text="Those auto-darkening welding goggles claim to be able to go dark in 1/25000 seconds. How are they able to switch so quickly?" CreationDate="2010-12-11T06:18:32.733" UserId="2240" />
  <row Id="10827" PostId="6524" Score="1" Text="Bed of Nails testers are only viable on *very* large production runs, since the tester has to be custom designed and manufactured for the board." CreationDate="2010-12-11T09:17:04.567" UserId="1374" />
  <row Id="10828" PostId="7692" Score="1" Text="It's not so much shear stress. What hurts is that the (organic) resin of the FR4 material will start to degrade and burn at elevated temperatures. For high-temp applications, use ceramic board material." CreationDate="2010-12-11T09:20:42.537" UserId="930" />
  <row Id="10829" PostId="7747" Text="The filter blocks the infra-red which would interfere with the image but still allows a considerable amount through, which is why you can see the IR light from a remote because it's bright enough to matter." CreationDate="2010-12-11T09:46:59.717" UserId="1225" />
  <row Id="10830" PostId="7748" Score="2" Text="How much current do your SSRs need? And what is the sensor -- a photoresistor? Or is that what you're calling the optical isolation in the SSR?" CreationDate="2010-12-11T09:55:45.850" UserId="2118" />
  <row Id="10831" PostId="7750" Text="i want to see the sine wave 'with' spikes in order to calculate frequency and amplitude, as you mentioned using a transformer would filter this out. a resistor divider is the way to go from what i see (i took my multimeter apart and saw a R divider also)" CreationDate="2010-12-11T11:12:15.877" UserId="2245" />
  <row Id="10832" PostId="7751" Text="great point with the transformer way of behaving, brings back memories form university. Long answers are better than shorter ones ;) 10x for the input ! waiting for your response tomorrow also ;)" CreationDate="2010-12-11T11:16:28.227" UserId="2245" />
  <row Id="10833" PostId="7750" Text="Just to make sure you understand clearly: if you go for the resistor divider solution **nothing in your arduino project is touch-safe!** as it is connected to the mains voltage!" CreationDate="2010-12-11T11:28:25.160" UserId="2064" />
  <row Id="10834" PostId="4426" Text="Would you like to give a example on HOW this could be done..." CreationDate="2010-12-11T11:47:24.073" UserId="689" />
  <row Id="10835" PostId="5030" Text="All of parallax's MCU boards are waaaaaaay overpriced. Some of their sensors are reasonable, and the bare MCU ICs are also reasonable." CreationDate="2010-12-11T12:12:13.680" UserId="1374" />
  <row Id="10836" PostId="7617" Text="There's always a tolerance on it. It used to be 220V for most of Europe and 240V for the UK before it was changed to 230V nominal, +/- 10%." CreationDate="2010-12-11T12:32:13.813" UserId="2064" />
  <row Id="10837" PostId="7750" Text="i mean voltage divider in order to connect the IL300" CreationDate="2010-12-11T12:49:18.187" UserId="2245" />
  <row Id="10838" PostId="7750" Text="for U1 and U2 what would you recommand i use ? (i always have a hard time picking components due to the noobiness and full A4 page of characteristics)" CreationDate="2010-12-11T12:49:43.507" UserId="2245" />
  <row Id="10839" PostId="5153" Text="I *think* it's Bart's Spin Tool." CreationDate="2010-12-11T13:01:23.180" UserId="1374" />
  <row Id="10840" PostId="5153" Text="Note, it's Brad. Link: http://www.fnarfbargle.com/bst.html" CreationDate="2010-12-11T13:01:59.840" UserId="1374" />
  <row Id="10842" PostId="7758" Text="I'm using a 9v battery as it was convenient - I have some for an arduino board that I am also using. Arduino does give me the option of a 5.5v and 3v output - would it be better to use these?" CreationDate="2010-12-11T14:11:16.413" UserId="2254" />
  <row Id="10843" PostId="7756" Text="Could I use 5 pairs of 2 LEDs in parallel? Would the resistor for each branch be 90 Ohm? " CreationDate="2010-12-11T14:16:19.030" UserId="2254" />
  <row Id="10846" PostId="7756" Text="@cor - assuming 3.6V across each LED and exactly 9V from the battery, 90 ohms will give you 20mA" CreationDate="2010-12-11T14:25:27.340" UserId="740" />
  <row Id="10847" PostId="7756" Text="Ok - thanks; just checking I calculated it correctly." CreationDate="2010-12-11T14:31:25.290" UserId="2254" />
  <row Id="10848" PostId="7750" Score="1" Text="The [datasheet for the TLC271](http://focus.ti.com/lit/ds/symlink/tlc271.pdf) is only 81 pages, so what are you complaining about? :-) BTW, the TLC271 may be a good choice: it's not the cheapest but neither too expensive, it runs from a single supply, doesn't need much power and has a high impedance input (so your voltage divider will not be loaded). But others may suggest other types (which may make the choice even harder :-( )" CreationDate="2010-12-11T15:02:57.213" UserId="2064" />
  <row Id="10849" PostId="7758" Text="You could use the 5.5V output for a boost converter, enabling you to put all your LEDs in series." CreationDate="2010-12-11T15:08:45.443" UserId="305" />
  <row Id="10850" PostId="7756" Text="Note that if you only use 1.4V of drop voltage, a variation of 0.7V (50% more voltagedrop on resistor) will increase the current by approx. 50% as well, so that will be 30mA. It might be wise to have a higher drop voltage or lower current to not overload the LED if your battery is not 9V but 9,6V for example." CreationDate="2010-12-11T15:23:10.690" UserId="1476" />
  <row Id="10851" PostId="7756" Text="@Hans, what do you mean by a 'higher drop voltage'? Should I use a larger resistor to prevent the current from reach 30 mA?" CreationDate="2010-12-11T15:25:45.663" UserId="2254" />
  <row Id="10852" PostId="4703" Text="That figure will likely be over the whole temp range, so endurance at normal temps is unlikely to be an issue. " CreationDate="2010-12-11T15:32:44.143" UserId="1681" />
  <row Id="10853" PostId="7737" Text="Thank you for all of the detail. That is very helpful. So on the 2.5V PICs when they have IO pins that are 5V tolerant is this how they do it? Just using a zener or something?" CreationDate="2010-12-11T15:45:41.497" UserId="1235" />
  <row Id="10854" PostId="7710" Text="How come all the EE books that I want cost 100 bucks?!?" CreationDate="2010-12-11T15:46:35.723" UserId="1235" />
  <row Id="10855" PostId="7735" Score="2" Text="+1 for mentioning the 6809, probably the most beautiful 8-bitter ever." CreationDate="2010-12-11T15:48:04.320" UserId="2064" />
  <row Id="10856" PostId="7754" Score="2" Text="What - My first edition dog eared of K&amp;R's C isn't good enough :-) Thanks these posts have been very useful for someone like me somewhere in the middle." CreationDate="2010-12-11T15:51:12.717" UserId="2243" />
  <row Id="10857" PostId="7756" Score="1" Text="@cor: yes, unless you're pretty sure that the 9V will not go higher. Also, if the LED voltage would be lower, you'd also have a higher voltage drop over the resistor, resulting in a higher current. Always calculate for worst case. Note that most LEDs can eat more than 20mA, but won't light much brighter above 20mA. Since you mention about 3.5V I assume you're using blue or white LEDs. I don't know what max. current for those are." CreationDate="2010-12-11T16:00:17.117" UserId="2064" />
  <row Id="10858" PostId="7738" Text="Thanks - this has been very helpful. In the 80's I wrote a lot of embedded 80xx family applications professionally, but the industry was moving to more formal languages and I needed to keep a job. Now I want to twiddle bits for fun, I do not plan to make a living out of it." CreationDate="2010-12-11T16:02:22.483" UserId="2243" />
  <row Id="10859" PostId="7735" Text="Thanks this is great information. I've been studying the 24FJ's the last few days as with the dsPIC. The lead on the 68H is great as I fell more comfortable with the (old) 68xx instruction set." CreationDate="2010-12-11T16:07:41.837" UserId="2243" />
  <row Id="10860" PostId="7736" Text="Thanks - good info - I have written device drivers for earlier version of Windows, it was not my strong point but I also had deadlines to meet." CreationDate="2010-12-11T16:10:13.377" UserId="2243" />
  <row Id="10863" PostId="7756" Text="@stevenvh: yes - I'm using blue LEDS. So typically at 20mA, what is their resistance? I'll measure it when I'm making my circuit but I'm also concerned about destroying them all so I'm erring on the cautious side." CreationDate="2010-12-11T16:40:08.913" UserId="2254" />
  <row Id="10864" PostId="7756" Text="@stevenvh: +1 for &quot;always calculate for worst case&quot;" CreationDate="2010-12-11T16:48:21.483" UserId="740" />
  <row Id="10866" PostId="7756" Text="@cor: there's no such thing as the resistance of a LED. In a resistor there's a linear relationship between the voltage applied and the current; their ratio is the resistor value. The voltage over a LED is more or less constant, so you could say it's resistance depends on the current through it. The higher the current, the lower the &quot;resistance&quot; (since V = I*R). There's no way to say what the max. allowed current is from measurements, you'll have to consult the datasheet." CreationDate="2010-12-11T17:02:02.693" UserId="2064" />
  <row Id="10867" PostId="7746" Score="6" Text="Badly automating something best done by hand just so you can claim it is more sophisticated is not being professional, it's being silly." CreationDate="2010-12-11T17:09:22.003" UserId="2246" />
  <row Id="10868" PostId="7737" Text="_NOT A ZERNER_   An ordinary diode.  The need for a series resistor or not depends on how much current that diode can tolerate in relation to the voltage drop and existing impedance." CreationDate="2010-12-11T17:12:24.260" UserId="2246" />
  <row Id="10872" PostId="7756" Text="Ok - I understand a little better how it works. So if I create a circuit with 20mA, using a resistor and one LED, I should be able to measure the resistance of the LED? Then I can apply that value to create a circuit with all 10? " CreationDate="2010-12-11T17:48:26.060" UserId="2254" />
  <row Id="10874" PostId="7756" Score="1" Text="@Cor - No, what you'll be measuring will be the voltage across the LED, which will be fairly constant.  Think of the LED as a 3.6V voltage source when it's conducting. With one resistor, one LED, and one 9V battery, the voltage across the resistor is 9-3.6=5.4V.  With 2 LEDs in series, it's 9-2*3.6=1.8V." CreationDate="2010-12-11T18:14:43.067" UserId="857" />
  <row Id="10875" PostId="7756" Score="1" Text="@cor: try not to think of diodes as resistors though. they behave differently. a resistor has the same resistance no matter what, but a diode's &quot;resistance&quot; changes with circuit conditions. the usual way to treat a diode is to look at the V-I curve in the datasheet, select an operating point that you want (e.g., if you have to have 20mA, the graph will tell you the voltage), and then use operating point's voltage or current as needed in your circuit analysis." CreationDate="2010-12-11T18:19:28.883" UserId="740" />
  <row Id="10876" PostId="7756" Text="+1 to this answer for explaining that you can put things in parallel. " CreationDate="2010-12-11T19:23:32.520" UserId="708" />
  <row Id="10877" PostId="7755" Score="1" Text="You may want to look here for future LED math questions: http://led.linear1.org/led.wiz" CreationDate="2010-12-11T19:24:21.643" UserId="708" />
  <row Id="10878" PostId="7679" Score="1" Text="You should be able to get down to ~1m with a single-ended GPS setup, assuming a relatively decent sensor (I believe that the uBlox line is pretty good for the cost).  If a higher degree of precision is necessary for GPS measurements, you can move to a differential GPS setup.  This is VERY expensive, on the scale of hobby projects, but very accurate (sub-decimeter or centimeter accuracy, depending on algorithm used)" CreationDate="2010-12-11T19:35:29.677" UserId="1477" />
  <row Id="10879" PostId="7685" Text="@Andrei TheGiant Haxtor  After reading your question, I got the idea that you need to track the card. I think that it would be a good idea to put that you need the card to know its location in the question body." CreationDate="2010-12-11T20:05:35.383" UserId="1240" />
  <row Id="10880" PostId="7758" Text="Why the downvote?" CreationDate="2010-12-11T20:08:02.560" UserId="1240" />
  <row Id="10882" PostId="7755" Text="@Earlz, thanks that is really helpful." CreationDate="2010-12-11T20:30:02.800" UserId="2254" />
  <row Id="10883" PostId="7648" Text="When I remove all the MOSFETs and the regulator the two sides are complitely isolated (applying voltage on either of them has no effect on the other side)." CreationDate="2010-12-11T20:44:09.590" UserId="1950" />
  <row Id="10886" PostId="7745" Score="3" Text="@tyblu, always the showoff. Yes, this is how you max a complex load. You want the C and L to resonate and the Rs to match." CreationDate="2010-12-11T21:51:11.730" UserId="230" />
  <row Id="10887" PostId="7699" Text="This is a rather subjective and localized question. The answers will all depend on who your audience is and what could be done in your particular application. If you don't know what all a JTAG connector can do for you then you can ask that and then decide on your own if the features that you get are worth it." CreationDate="2010-12-11T21:53:25.077" UserId="319" />
  <row Id="10888" PostId="7747" Text="Why'd I get a downvote? I have the same answer as Fake Name." CreationDate="2010-12-11T23:39:51.987" UserId="2118" />
  <row Id="10889" PostId="7732" Text="I actually did think about that today(well, the reverse where i dub 12V as 24V, GND as 12V and -12 as GND), and was surprised to see you come up with this answer too. I believe that my circuit will behave well with this configuration as it will not require that much modifying, thanks anyway." CreationDate="2010-12-12T01:01:44.143" UserId="2188" />
  <row Id="10890" PostId="7746" Text="@Chris Stratton, you could argue that an automated process does not operator bias, which is more professional. I would agree with your statement, but I think anubis221 is still learning, a good answer with constructive feedback would be productive, but a downvote on an honest question where someone is trying to solve a technical issue may not be the best approach, and may even scare potential contributors away from our site." CreationDate="2010-12-12T02:11:10.593" UserId="230" />
  <row Id="10891" PostId="7753" Text="+1 For completion." CreationDate="2010-12-12T02:56:48.730" UserId="2118" />
  <row Id="10892" PostId="7732" Score="2" Text="you've got to be kidding me." CreationDate="2010-12-12T03:00:38.570" UserId="2118" />
  <row Id="10893" PostId="7746" Text="@Kortuk it would be a lot of work to come up with an even remotely reliable algorithm for evalating IR sensitivity, but it's pretty easy to do a go/no-go as a human equipped with a TV remote. The only time it would really make sense to automate this would be in a factory test setting; otherwise simply getting some calibration to a manual process would be enough.  Nonetheless I _did not vote the question down_" CreationDate="2010-12-12T03:07:59.920" UserId="2246" />
  <row Id="10894" PostId="7746" Text="@chris Stratton, I actually thought your comment's wording implied you did not vote it down. I am not trying to make you feel like you need to defend yourself. I thought your feedback was very good, I was just suggesting it be done in a way that seems less aggressive. I also thought it was worthy of an answer, but I can understand making it a comment. I do not disagree on the IR algorithm, on top of that, nicer cameras have algorithms implemented internally to filter IR because it is cheaper than a filter. I would suggest having a bright IR light to test for the filter." CreationDate="2010-12-12T07:03:35.383" UserId="230" />
  <row Id="10895" PostId="7746" Text="@Chris Stratton, on that note, please forgive me if I seemed aggressive. I was only trying to help keep the community friendly. Good questions are not as important as good answers, and users, like yourself, make up those whom can make good answers." CreationDate="2010-12-12T07:07:11.233" UserId="230" />
  <row Id="10896" PostId="7754" Score="1" Text="K&amp;R is the only book good enough for C." CreationDate="2010-12-12T08:09:43.200" UserId="883" />
  <row Id="10897" PostId="7182" Score="3" Text="Using Python in embedded programming!? This is lovely blasphemy." CreationDate="2010-12-12T08:29:47.390" UserId="2118" />
  <row Id="10898" PostId="7698" Text="The size of the capacitor would depend a lot on the PWM frame rate." CreationDate="2010-12-12T09:00:10.187" UserId="2246" />
  <row Id="10899" PostId="7490" Text="If you get a big blob of solder on the iron, and poke the wire into it, and keep feeding in more solder (largely for the flux), even enamel that's not designed to melt off may do so in a minute or two.  The advantage is that you save the risk of mechanically damaging the wire, especially if you are in close quarters and can't replace the wire if damaged." CreationDate="2010-12-12T09:30:27.680" UserId="2246" />
  <row Id="10900" PostId="7753" Text="I didn't know making an IR camera was that easy. Of course, taking apart the (actual) digital camera I had was definitely more difficult than I had hoped due to extremely small screws and the hot mirror was made of glass and in a container which was soldered. I ended up having to just chip out the glass, so now there is some permanent dust and a small scratch in the pictures, but it works great and is very impressive. Thanks!" CreationDate="2010-12-12T11:05:45.643" UserId="708" />
  <row Id="10901" PostId="7747" Score="1" Text="#Thomas I've never been able to see a remote's IR light from any camera I've owned? " CreationDate="2010-12-12T11:07:03.193" UserId="708" />
  <row Id="10902" PostId="7182" Score="1" Text="Python is a very nice language, but has a high overhead and isn't really suitable for running on an MCU. It's possible, but pretty tricky." CreationDate="2010-12-12T11:19:36.213" UserId="1225" />
  <row Id="10903" PostId="7771" Text="Note that 850nm is closer to visible spectrum. Also, that won't matter as the CCD/CMOS pixels simply map intensity, regardless of wavelength. Color is determined by filtering." CreationDate="2010-12-12T11:20:40.453" UserId="2118" />
  <row Id="10904" PostId="7771" Score="2" Text="Not true - all light sensors have some difference in sensitivity at different wavelengths. You'd normally expect wavelengths closer to visible to be better, however other factors like different LED efficiency and possible slight eye visibility may mean that 950nm is a better choice. LEDs are cheap - just buy both types and try it.  " CreationDate="2010-12-12T11:51:03.123" UserId="1681" />
  <row Id="10905" PostId="7771" Text="Actually, yeah, buy both." CreationDate="2010-12-12T11:54:16.057" UserId="2118" />
  <row Id="10906" PostId="7772" Score="2" Text="Check out how Microsoft has *solved* the backwards battery dilemma, [here](http://www.microsoft.com/hardware/mouseandkeyboard/licensing/instaloadoverview.mspx)." CreationDate="2010-12-12T11:56:32.577" UserId="2118" />
  <row Id="10907" PostId="7769" Text="Can you load a custom C program onto it, like a [blinky LED](http://imakeprojects.com/Projects/avr-tutorial/)? Or can you download the fuse data from the chip (within AVR Studio)? This would guarantee communication, first." CreationDate="2010-12-12T12:33:46.523" UserId="2118" />
  <row Id="10908" PostId="7776" Text="Note that a linear regulator will burn more than 11W doing that.&#xA;Also, regulated supply stability is still an issue." CreationDate="2010-12-12T13:04:58.540" UserId="2118" />
  <row Id="10909" PostId="7773" Text="&quot;esp. if it's electronic&quot; what else can you can you power batteries with that aren't electronic?" CreationDate="2010-12-12T13:59:59.640" UserId="1623" />
  <row Id="10910" PostId="7773" Score="1" Text="@Dean: small motors?" CreationDate="2010-12-12T15:58:49.153" UserId="2064" />
  <row Id="10911" PostId="7182" Text="Could you clarify what you're hoping to do? Are you wanting to control electronics from a PC, or are you hoping to have a stand-alone system running python?" CreationDate="2010-12-12T16:03:12.670" UserId="638" />
  <row Id="10912" PostId="2187" Text="@W5VO, ballpark is about 2 digits, but I was interested in seeing solutions that could do more, as it is a case to increase the visual output of the project. I passed on the answers, but I was done with the project because the person I was being paid to help was taking too long. He has a different student helping him over the summer." CreationDate="2010-12-12T16:40:21.493" UserId="230" />
  <row Id="10913" PostId="7773" Text="@Stevenvh &quot;Electronics is the branch of science and technology which makes use of the controlled motion of electrons through different media.&quot;-wikipedia If you have an electric motor, you are controlling the motion of electrons in the motor." CreationDate="2010-12-12T16:54:41.593" UserId="319" />
  <row Id="10914" PostId="7167" Text="Accepted as answer for the first two titles. `VHDL made easy` doesn't seem to be received so well, sic Amazon." CreationDate="2010-12-12T17:14:57.193" UserId="2064" />
  <row Id="10915" PostId="7773" Score="1" Text="@Kellenjb: lighting an incandescent lamp also involves the movement of more than a few electrons, but I don't think anyone will call the electrical circuit in your house electronics." CreationDate="2010-12-12T17:30:17.540" UserId="2064" />
  <row Id="10916" PostId="7595" Text="I wonder why there is a negative vote on this question (with no comment)" CreationDate="2010-12-12T17:30:32.140" UserId="2180" />
  <row Id="10917" PostId="7778" Text="I wouldn't say that `Almost all consumer electronics have protection in place`. Consumer electronics is often about producing at extremely low cost. A common remote control for your stereo (produced by tens of millions) has 3 or 4 electronic components and can be produced for less than 1 dollar. I don't think there's room there for protection." CreationDate="2010-12-12T17:35:23.167" UserId="2064" />
  <row Id="10918" PostId="7774" Text="Sadly this is an el cheapo camera without a raw output function. But I will get one or two of both wavelengths and see which one works best. " CreationDate="2010-12-12T17:46:24.427" UserId="708" />
  <row Id="10920" PostId="7778" Score="1" Text="I can say that I have put batteries in my remotes backwards and haven't had a single issue (other then it not working until I swap them). In a remote, the current draw is very little, because of this the diode used can easily be less then half a cent at those large quantities." CreationDate="2010-12-12T18:14:41.527" UserId="319" />
  <row Id="10921" PostId="7773" Text="@Stevenvh its all relative to who looks at it. Power distribution engineers and Electricians would definitely consider them electronics. Just because you consider it something so simple or something that is just a given doesn't mean its still not electronics." CreationDate="2010-12-12T18:20:13.097" UserId="319" />
  <row Id="10922" PostId="7747" Text="@earlz, I have never used a camera that filtered it. Darn cell phone cameras." CreationDate="2010-12-12T18:38:19.227" UserId="230" />
  <row Id="10923" PostId="7778" Text="@stevenvh here's another way to think of it. Let's say the extra diode costs $0.10. Now let’s say that 10% of people will accidentally put their batteries in the wrong direction. These people will then call saying their remote doesn't work. The company will then have to pay for all of the overhead and employee time dealing with the call. I could easily see this adding up to $1. The company would then probably have to assume that it wasn't the consumers fault and will send you out a new remote." CreationDate="2010-12-12T18:39:36.420" UserId="319" />
  <row Id="10924" PostId="7778" Text="This will then cost them an extra $1 for the remote plus some more overhead associated with packing and sending out the new remote. So if you look at the net numbers now for 10 people, $0.10*10=$1 extra in parts for 10 remotes, out of these 10 remotes you can guess that 1 will be hooked up wrong, earlier I showed how this could cost the company $2 (and that’s assuming the company is making the customer pay for the shipping)." CreationDate="2010-12-12T18:40:14.360" UserId="319" />
  <row Id="10925" PostId="7778" Text="So the company put $1 up to save $2. Sounds like a good deal to me. Now, I mentioned earlier that diodes can actually be purchased for half a cent. If I use that number it’s more like it cost the company 5 cents to save $2. It’s a no brainer to me. Even if only 1% of people put their batteries in wrong it still makes sense." CreationDate="2010-12-12T18:40:44.357" UserId="319" />
  <row Id="10926" PostId="7773" Score="1" Text="@Dean -- You can put the batteries in a flashlight with an incandescent bulb the wrong way without any damage.  I wouldn't call that electronic." CreationDate="2010-12-12T19:01:35.757" UserId="1322" />
  <row Id="10927" PostId="7773" Score="1" Text="@dean, @kellenjb, you all understood what Stevenvh meant. Just be argumentative for fun. @Stevenvh, I think they tricked you into a pyrrhic victory. You may be right, but the argument was not worth it." CreationDate="2010-12-12T19:56:06.587" UserId="230" />
  <row Id="10928" PostId="7732" Text="@tyblu - I was, but I'm not sure if Cem is...." CreationDate="2010-12-12T20:40:03.703" UserId="857" />
  <row Id="10929" PostId="7783" Score="1" Text="It is relatively easy to design Eagle parts in Eagle. You will probably find it easier to draw them yourself." CreationDate="2010-12-12T21:24:52.870" UserId="1225" />
  <row Id="10930" PostId="7732" Text="@reemrevniek, heh - sorry, was not directed at your answer; I like it!" CreationDate="2010-12-12T21:33:27.500" UserId="2118" />
  <row Id="10931" PostId="7784" Score="3" Text="Looks tri-stated to me, instead of an I/O." CreationDate="2010-12-12T21:41:12.020" UserId="2118" />
  <row Id="10932" PostId="7784" Text="@tyblu - I've posted the code." CreationDate="2010-12-12T21:45:09.163" UserId="1225" />
  <row Id="10933" PostId="7783" Score="1" Text="You'll find that you have to create custom parts for almost every project. It's pretty easy once you do it a few times. The first time, just copy a similar part then edit it. When doing production work (yes, many use EAGLE for production work) you may find that it is faster to do create your own footprints and silkscreen symbols rather than double-check the given library." CreationDate="2010-12-12T21:53:52.070" UserId="2118" />
  <row Id="10934" PostId="7781" Score="4" Text="I like Microsoft's mind-blowing invention, [here](http://www.microsoft.com/hardware/mouseandkeyboard/licensing/instaloadoverview.mspx)." CreationDate="2010-12-12T21:56:23.270" UserId="2118" />
  <row Id="10935" PostId="7782" Text="Careful with these circuits though: if you attempt to use a reverse supply voltage over the maximum voltage of the MOSFET gate (usually ±20V) it won't be pretty." CreationDate="2010-12-12T22:14:38.603" UserId="1225" />
  <row Id="10936" PostId="7785" Text="how does this protect the circuit? it just tells me that i've plugged it in the wrong way." CreationDate="2010-12-12T22:27:16.467" UserId="1623" />
  <row Id="10937" PostId="7781" Text="@tyblu, Interesting how it has been invented already: US Patent 5431575. " CreationDate="2010-12-12T22:44:21.710" UserId="1225" />
  <row Id="10938" PostId="7787" Text="I think this is the correct answer. It is working now. Channel 4 is RB12." CreationDate="2010-12-12T22:45:06.017" UserId="1225" />
  <row Id="10939" PostId="7778" Text="Don't forget that for most remotes, the battery likely only connects to the controller IC (which runs every other part). Therefore, they can just fab the diode into the IC die to reduce the costs even further." CreationDate="2010-12-12T22:48:11.743" UserId="1374" />
  <row Id="10940" PostId="7785" Text="@Dean, Good point. Skip the fuse and put a diode that can handle a s/c." CreationDate="2010-12-12T22:48:14.783" UserId="2118" />
  <row Id="10941" PostId="7781" Score="4" Text="@Thomas O, Must have either sold his soul to MS or conveniently *disappeared*." CreationDate="2010-12-12T22:51:41.553" UserId="2118" />
  <row Id="10942" PostId="7773" Text="+1 For learning a new term: [Pyrrhic victory](http://en.wikipedia.org/wiki/Pyrrhic_victory). Flippin' histogeographic catchphrases..." CreationDate="2010-12-12T22:56:19.053" UserId="2118" />
  <row Id="10943" PostId="7785" Text="Why doesn't it protect the circuit?" CreationDate="2010-12-12T22:58:18.177" UserId="305" />
  <row Id="10944" PostId="7781" Text="@tyblu Either that, or Microsoft didn't do a thorough check on possible prior art - OR - Microsoft knows it's prior art, but knows the small company or individual doesn't stand a chance against their small army of lawyers." CreationDate="2010-12-12T23:24:01.053" UserId="1225" />
  <row Id="10945" PostId="7785" Text="After the fuse blows, the battery will still be in backwards and the diode disconnected." CreationDate="2010-12-12T23:27:16.747" UserId="2118" />
  <row Id="10946" PostId="7789" Score="1" Text="@Wonko The Sane, This question is a few months old..." CreationDate="2010-12-12T23:29:03.843" UserId="2118" />
  <row Id="10947" PostId="7756" Text="All true, good answer. Plus you could replace five resistors with one and split it to parallel after it. 1,4V/100mA = 14 ohm." CreationDate="2010-12-12T23:41:49.750" UserId="2271" />
  <row Id="10948" PostId="7758" Score="3" Text="What makes 9V poor choice? Why should he go for lower voltage and then compensate it with some DC/DC converter?" CreationDate="2010-12-12T23:45:37.250" UserId="2271" />
  <row Id="10949" PostId="7785" Score="3" Text="@tyblu The fuse is in series with the battery line and the diode is in reverse across the supply. It will work. I think you're thinking of putting the fuse in series with the diode and the load across the battery, which wouldn't serve any purpose. I have done this before and it works, but it's obviously annoying to have to replace fuses." CreationDate="2010-12-13T00:03:36.760" UserId="1225" />
  <row Id="10950" PostId="7785" Text="That is indeed what I'm thinking. Thanks for clearing that up!" CreationDate="2010-12-13T00:07:48.290" UserId="2118" />
  <row Id="10951" PostId="7791" Text="Is the location you are retransmitting have no GPS and so you are wanting to simulate gps in the building?" CreationDate="2010-12-13T00:28:34.620" UserId="319" />
  <row Id="10952" PostId="7686" Text="Thanks. I think this was the problem." CreationDate="2010-12-13T01:03:29.053" UserId="1900" />
  <row Id="10953" PostId="7773" Text="&quot;If you put one of two batteries the wrong way, then there's no problem&quot;. How about two out of three?" CreationDate="2010-12-13T01:26:52.383" UserId="2266" />
  <row Id="10954" PostId="7792" Score="2" Text="Wouldn't I have to be concerned about the legality of any RF amplifier transmitting at GPS frequencies, even though an indoor antenna?  That's why I asked if some passive means might work." CreationDate="2010-12-13T02:12:04.390" UserId="1908" />
  <row Id="10955" PostId="7790" Text="I think that answers my question about the schematic, thanks!  I am going to have to email the manufacture for the exacts, about the motor, but it looks pretty close to the r370." CreationDate="2010-12-13T02:28:36.363" UserId="2060" />
  <row Id="10956" PostId="7792" Text="@hotpaw2, I forget things like that. I cannot easily find any information about the band which means you should not radiate at it. When you do it passively you should be able to avoid someone noticing, but in realize absorbing and re-radiating a signal can violate these rules also if they can tell you are doing it. Now, it is not feasibly for you to passively radiate a signal into a building and someone notice it outside." CreationDate="2010-12-13T03:14:43.247" UserId="230" />
  <row Id="10957" PostId="7792" Text="@hotpaw2, the long and the short of it is that you will not be able to do this with any ease. I would give a 95% chance that you cannot at all with a decent bit of work." CreationDate="2010-12-13T03:15:20.780" UserId="230" />
  <row Id="10959" PostId="7792" Text="@Kortuk, How can passive re-radiation possibly be illegal, since, if I remember my physics correctly, almost every metal object of about the right size re-radiates to some degree?" CreationDate="2010-12-13T05:04:23.290" UserId="1908" />
  <row Id="10960" PostId="7772" Score="1" Text="But it requires licensing, so no one else will ever use it." CreationDate="2010-12-13T05:36:03.713" UserId="142" />
  <row Id="10961" PostId="7792" Text="@hotpaw2, If it is illegal, I'd would imagine the regulation would be aimed at intent. I wouldn't be worried about it for meter-sized broadcast radii, but I'm not from the US." CreationDate="2010-12-13T05:37:25.430" UserId="2118" />
  <row Id="10962" PostId="7791" Text="I've often wondered if it would be possible to augment GPS with land-based &quot;satellites&quot; to give finer resolution than the space ones for nearby locations, but that would still be backwards compatible with an old GPS receiver." CreationDate="2010-12-13T05:43:36.207" UserId="142" />
  <row Id="10964" PostId="7797" Text="Can you give me a book also explaining an HDL then? I've tried many times to learn them but it's just such a different form of programming than I'm use to. " CreationDate="2010-12-13T05:54:55.873" UserId="708" />
  <row Id="10965" PostId="7785" Score="1" Text="@Leon Heller I hope you don't mind, I added a picture since it seemed some people weren't fully clear what was happening. Feel free to remove or replace if you aren't happy with it." CreationDate="2010-12-13T05:57:53.277" UserId="319" />
  <row Id="10966" PostId="7791" Score="1" Text="@endolith - yes, there were articles about GPS &quot;pseudolites&quot; even back in the late 1990's." CreationDate="2010-12-13T06:04:06.017" UserId="2246" />
  <row Id="10967" PostId="7781" Text="@tyblu are you sure you haven't sold your soul to MS since this is the second time you have linked it? :-) @ThomasO That patent is for the mechanical aspects of the holder and not the electronics. I am sure MS is capable of designing a different holder or licensing it." CreationDate="2010-12-13T06:04:41.150" UserId="319" />
  <row Id="10970" PostId="145" Text="Yes... if it never needs to go in a pc, or the pc runs something capable like linux, you don't need a file system.  You can just treat it as a big addressable collection of memory blocks.  Also if you get a cheap microSD kit that comes with the full size adapter, you can just solder onto the adapter and use that as your socket." CreationDate="2010-12-13T06:17:02.153" UserId="2246" />
  <row Id="10971" PostId="7739" Text="Rejecting packets with a bad checksum is going to be less and faster math than a kalman filter, question is what you want to do with an outage - hold the last telemetry values and grey them out, or let it keep estimating based on heading and velocity and gradually gray it out, or?" CreationDate="2010-12-13T06:23:01.837" UserId="2246" />
  <row Id="10972" PostId="7756" Text="@Lukas: that's not a good idea. If there are small differences in LED voltages (which you'll always have) you'll have one branch of LEDs lighting bright, and another hardly lighting at all." CreationDate="2010-12-13T07:09:23.557" UserId="2064" />
  <row Id="10973" PostId="7756" Text="@Lukas, Wiring like that can lead to [thermal runaway and current hogging](http://tigerhawkt3.com/welcomemat/ledfaqs.htm#9). Especially when the dissipated power will change the LED's temperature, one should use a resistor for each parallel strand." CreationDate="2010-12-13T07:13:29.373" UserId="2118" />
  <row Id="10976" PostId="7785" Text="Since reversing the power supply won't damage the circuit, Leon's solution does indeed protect it. It may not work with reversed power supply, but it won't be damaged." CreationDate="2010-12-13T07:45:25.070" UserId="2064" />
  <row Id="10977" PostId="7768" Text="The only thing funnier than giving the arduino an identical twin cpu as a storage co-processor is realizing that the SD card itself may contain a 32 bit arm core!  see http://www.bunniestudios.com/blog/?p=898" CreationDate="2010-12-13T07:48:33.853" UserId="2246" />
  <row Id="10978" PostId="7679" Text="Thank you all for your comments. I will definitely take these into account when designing the stability system." CreationDate="2010-12-13T08:33:01.940" UserId="2212" />
  <row Id="10979" PostId="7800" Text="Try googling temperature compensated crystals (TCXO) and ovenned crystals (OCXO)." CreationDate="2010-12-13T09:23:26.353" UserId="1688" />
  <row Id="10980" PostId="7756" Text="Thanks for those remarks, thinking about it more carefully it really could cause troubles in non-ideal conditions..." CreationDate="2010-12-13T09:35:07.140" UserId="2271" />
  <row Id="10981" PostId="7802" Text="accelerometer = http://www.sparkfun.com/products/9652" CreationDate="2010-12-13T10:16:40.117" UserId="2060" />
  <row Id="10982" PostId="7800" Text="Thanks for the answers. Sorry I wasn't clear enough: TCXO and OCXO are going to be to expensive. In what I could find I saw a lot of people using 20 ppm crystals without compensating, which surprised me." CreationDate="2010-12-13T10:36:47.743" UserId="2275" />
  <row Id="10983" PostId="7801" Text="The possible solutions so far are a 5 ppm crystal (the clock is meant to be used indoors, so temperature dependency is not critical), and the other solution a SW tuning matched to an OCXO. I am happy to read that you have seen the SW tuning before, I am a bit worryied not to find anything on it..." CreationDate="2010-12-13T10:38:29.520" UserId="2275" />
  <row Id="10985" PostId="7800" Score="1" Text="@Gauthier: (temperature) compensation compensates for variations, but don't improve basic accuracy. The latter are usually much worse than variations due to temperature changes, and you can often adjust for it with a trimmer capacitor." CreationDate="2010-12-13T10:42:35.693" UserId="2064" />
  <row Id="10986" PostId="7800" Score="2" Text="Wrist watch crystals have some kind of temperature compensation due to the temperature of your skin. I'm often surprised at the precision of (even cheap) wrist watches. I once had a Casio LCD watch which was less than 5 seconds off per year, that's better than 1 ppm!" CreationDate="2010-12-13T10:46:35.207" UserId="2064" />
  <row Id="10987" PostId="7801" Score="1" Text="I used software tuning on a clock based on a timer of the microcontroller. So instead of using a timer prescaler of 1000000, I'd use for instance 1000005 if the clock is 5ppm fast. If you're using a RTC IC you'd have to set the RTC by one second every so many seconds. In this case your clock can be 0.5 second off, in the first case every second is exact (inasmuch as you can calibrate it)." CreationDate="2010-12-13T11:05:10.853" UserId="2064" />
  <row Id="10988" PostId="7800" Text="Point taken about TCXO. And about the cheap wrist watches, I agree, that's why I am so surprised! 20 ppm seems to be the standard for 32.768 kHz crystals, and these are often used for time display, and yet these watches have much better precision! Any idea how casio and the like managed this? Trimming capacitor is not very likely in a mass production..." CreationDate="2010-12-13T11:46:45.893" UserId="2275" />
  <row Id="10989" PostId="7801" Text="You cold also add a cheap GPS module or TCP/IP sync. against a timer server." CreationDate="2010-12-13T11:57:35.893" UserId="1832" />
  <row Id="10990" PostId="7772" Text="As a comment, Ni* batteries can put out hefty currents. I've had a small two AA battery holder melt when the wires got shorted for a few seconds." CreationDate="2010-12-13T12:00:44.847" UserId="883" />
  <row Id="10991" PostId="7286" Text="Building a sculpture comes to mind..." CreationDate="2010-12-13T13:09:28.843" UserId="1823" />
  <row Id="10992" PostId="7801" Text="Once you have recalibrated your clock a few times with a reference you can add automatic recalibration to compensate for crystal frequency error &quot;offline&quot;, in your widget." CreationDate="2010-12-13T13:22:57.943" UserId="2118" />
  <row Id="10993" PostId="7805" Text="@Gauthier, Easy mistake to make, but this question is from June. It's at the top from &quot;tag cleanup&quot; duties. You'll see waves of old questions pop to the top as people fix old tags." CreationDate="2010-12-13T13:26:17.503" UserId="2118" />
  <row Id="10994" PostId="7809" Score="3" Text="Gotcha: don't get trapped into thinking you don't need the load caps when you see a happy oscillation, though, as your probes load the lines with 5pF+ (20pF for me)." CreationDate="2010-12-13T14:02:03.040" UserId="2118" />
  <row Id="10995" PostId="7800" Text="The main reason why they are so accurate is that the watch is in close contact to the skin most of the time, and is therefore at a constant temperature. If you leave it in a cold room for a few days you will probably see a large error." CreationDate="2010-12-13T14:22:28.390" UserId="305" />
  <row Id="10996" PostId="7788" Text="It seems wasteful but de facto. Guess I have no choice :/" CreationDate="2010-12-13T14:22:46.090" UserId="2006" />
  <row Id="10997" PostId="7685" Text="@Andrei: Using GPS indoors is fraught with peril.  If you do get a signal, it's error would be so large (~10 m) it would be useless.  The best bet would be to have some sort of triangulation like @Adam suggests; you could do it with RFID or more broadly, a radio beacon--like for tracking animals which could be made *very* small and likely thin." CreationDate="2010-12-13T14:31:26.277" UserId="1407" />
  <row Id="10998" PostId="7800" Score="1" Text="I don't mean that they are temperature accurate. I mean that they seem to have a good basic accuracy (from a crystal to another, at the same temperature). See stevenvh's comment above." CreationDate="2010-12-13T14:37:28.007" UserId="2275" />
  <row Id="10999" PostId="7791" Text="@endolith, @Chris, [WAAS?](http://en.wikipedia.org/wiki/WAAS)" CreationDate="2010-12-13T14:38:44.943" UserId="1407" />
  <row Id="11000" PostId="7812" Text="@Jim C - Yeah, I thought about that too, but I figured it might be too much work.. Since I am not paying, I'm rather looking for someting &quot;off the shelf&quot;. " CreationDate="2010-12-13T15:02:00.207" UserId="1605" />
  <row Id="11001" PostId="7814" Text="@Mark - Yeah, I checked out the MakerBot store, but unfortunately they are not selling the linear drive units as individual parts. Good suggestion though. And, yes, I am looking to find something that is as off the shelf as possible." CreationDate="2010-12-13T15:06:06.113" UserId="1605" />
  <row Id="11002" PostId="7814" Text="@theodor In that case i think your best bet is a used part from ebay or similar.  " CreationDate="2010-12-13T15:12:53.583" UserId="1438" />
  <row Id="11003" PostId="7807" Text="Related: http://electronics.stackexchange.com/questions/4225/crystals-and-load-capacitance" CreationDate="2010-12-13T15:30:16.727" UserId="142" />
  <row Id="11004" PostId="7786" Score="1" Text="Linear has many &quot;ideal diode&quot; type things IIRC." CreationDate="2010-12-13T15:42:25.130" UserId="883" />
  <row Id="11005" PostId="7785" Score="2" Text="I believe this would be called a crowbar." CreationDate="2010-12-13T15:43:05.427" UserId="883" />
  <row Id="11006" PostId="7792" Text="@hotpaw2, It could violate regulations, I should not say illegal. if you used a large receiver up top, and a directive small radiator inside, the directed beam of energy could constitute violating regulations with too powerful of a broadcast. I was just giving some technical insight. I also agree with @tyblu here. If you used a driver just to cancel out line loss you could get a much better signal." CreationDate="2010-12-13T16:34:26.687" UserId="230" />
  <row Id="11007" PostId="7798" Score="2" Text="Sounds like you passed up a perfectly good excuse to get a window seat." CreationDate="2010-12-13T16:35:53.643" UserId="1407" />
  <row Id="11008" PostId="7792" Score="1" Text="@hotpaw2, If you are doing this for iPhone apps, they use cell towers for their first lock, and you will find that you are getting into a mess faking towers and GPS. I would suggest you take code that is considered &quot;proven&quot; and treat the interface as function and when you need fake locations you fake the results from that interface." CreationDate="2010-12-13T16:47:19.857" UserId="230" />
  <row Id="11009" PostId="4220" Score="1" Text="[UK power line frequency meter](http://www.dynamicdemand.co.uk/grid.htm), pretty interesting" CreationDate="2010-12-13T17:10:20.040" UserId="1407" />
  <row Id="11010" PostId="7754" Score="1" Text="Let Us C cited as worst programming book: http://programmers.stackexchange.com/questions/6974/whats-the-worst-programming-book-youve-ever-read/12192#12192" CreationDate="2010-12-13T17:16:12.407" UserId="1407" />
  <row Id="11011" PostId="7816" Score="3" Text="A resistor value will not give you the maximum luminance for a given amount of power. You need to pulse a constant current driver at a few hundred hertz instead.  By using a small duty cycle, you can run the LED at much more than its maximum sustainable power level, which will make it appear brighter on average.  I'd recommend editing the title to reflect this, something like &quot;Calculating resistor values for maximum LED luminance&quot;.  See [this Intersil app note](http://www.intersil.com/data/an/an1411.pdf) for an example of a more complex, efficient, and bright driver." CreationDate="2010-12-13T17:37:57.507" UserId="857" />
  <row Id="11012" PostId="7816" Score="3" Text="@reemrevnivek: Pulsing LEDs doesn't increase the apparent brightness.  http://members.misty.com/don/ledp.html  The eye perceives the average brightness over time." CreationDate="2010-12-13T17:47:37.340" UserId="142" />
  <row Id="11013" PostId="7816" Score="1" Text="@reemrevnivek in particular, LEDs have a peak current rating which is typically higher than the maximum DC current rating - however, this limit is often caveated by a maximum duty cycle (often &lt;=30%). So it's a tradeoff and really depends on the particular device parameters." CreationDate="2010-12-13T18:49:16.227" UserId="771" />
  <row Id="11014" PostId="7816" Score="1" Text="Also note that pulse width regulation is a lot more power efficient than using a resistor, so it's going to be preferred when trying to get a lot of light from something battery powered like a bicycle safety light." CreationDate="2010-12-13T19:00:07.090" UserId="2246" />
  <row Id="11015" PostId="7800" Text="@steven, @Gauthier, just because one sample has excellent precision doesn't mean that they all do.  Within a +/-20 ppm grade of components some are bound to be spot on; they aren't all way off." CreationDate="2010-12-13T19:18:39.180" UserId="1407" />
  <row Id="11016" PostId="7782" Text="If you need to survive larger voltages, you can either add a resistor divider or zener." CreationDate="2010-12-13T19:21:01.893" UserId="1407" />
  <row Id="11017" PostId="7806" Score="1" Text="Some of the possible key requirements you should consider are backlash (slop between thread engagement on one side or the other in a screw system), number of cycles (potentially an issue if you use tighter or polymer nuts to limit backlash), stiffness (particularly if you use a belt system instead of a screw), environment (dirt contamination) and consequences of positioning failure.  Two pieces of round shafting and a screw driven by a stepper is pretty cheap, but not always the right answer.  But then neither is a cast iron way, ballscrew, and brushless servo controller." CreationDate="2010-12-13T19:22:17.407" UserId="2246" />
  <row Id="11018" PostId="7815" Text="I can't access dropbox where I'm at right now, but I know one thing that stinking messed with me was making sure I was using a pullup or pulldown...have you checked that? (It might not be your actual code at all that is causing the problem, but this is just speculation)" CreationDate="2010-12-13T20:33:46.177" UserId="982" />
  <row Id="11019" PostId="7781" Text="@kellenjb, InstaLoad is entirely mechanical (with virtually the same design verbatim), there are no electronic parts in it. Microsoft have patented page up and page down already. So it wouldn't surprise me." CreationDate="2010-12-13T20:39:24.990" UserId="1225" />
  <row Id="11020" PostId="7786" Score="1" Text="@XTL, Indeed, although some of them are overkill for this application." CreationDate="2010-12-13T20:40:54.943" UserId="1225" />
  <row Id="11021" PostId="7820" Score="1" Text="This is very similar to http://electronics.stackexchange.com/questions/6773/good-checklist-for-pcb-design-to-be-used-by-the-ee-not-by-the-pcb-designer" CreationDate="2010-12-13T21:10:02.510" UserId="566" />
  <row Id="11022" PostId="7821" Text="I agree.  But what should I check for with that or another tool that isn't present in the CAD files?" CreationDate="2010-12-13T21:38:18.643" UserId="206" />
  <row Id="11023" PostId="7820" Text="That was about designing the PCB.  This is specific to Gerber generation.  The issue that caused this question to be asked wasn't present in the CAD files." CreationDate="2010-12-13T21:39:03.277" UserId="206" />
  <row Id="11024" PostId="7781" Text="@ThomasO I am not sure if I should think you are agreeing with me or disagreeing with me." CreationDate="2010-12-13T21:42:10.897" UserId="319" />
  <row Id="11025" PostId="7781" Text="@thomasO, @kellenjb, @tyblu. Holding a patent does not give validity. It is designed to require a court case to uphold it before it is considered &quot;valid&quot;. Researching prior art increases your fine if they turn down your patent for prior art. The idea being that you should have seen it. In reality it is very very hard to find prior art and much easier to file a patent." CreationDate="2010-12-13T21:43:53.987" UserId="230" />
  <row Id="11026" PostId="7821" Score="2" Text="It's just an independent check that the Gerbers have been generated OK. The full version can be used to check clearances and so on. It has been known for Gerbers to be wrong." CreationDate="2010-12-13T21:45:05.263" UserId="305" />
  <row Id="11027" PostId="7820" Score="4" Text="@Brian Carlton I don't think he was trying to be critical of your question. He is a mod so could close it on the spot if he thought it was an exact duplicate. Even if he thinks it is, he is letting the community decide. It is nice to get things that are related to each other linked in some form or another." CreationDate="2010-12-13T21:45:09.850" UserId="319" />
  <row Id="11028" PostId="7686" Text="Are you sure this is the problem?  I would imagine that RA0 = 1 should generate ASM that uses BSF, which shouldn't affect bits 1-7.You should check the assembly listing file.  I think Hi-Tech C generates it automatically as the .lst file." CreationDate="2010-12-13T22:02:24.513" UserId="1278" />
  <row Id="11029" PostId="7813" Text="I would suggest this as a comment on Leon's post." CreationDate="2010-12-13T22:16:02.727" UserId="230" />
  <row Id="11030" PostId="7822" Text="@tyblu - Well, thank you! I wonder if they have an european supplier?" CreationDate="2010-12-13T22:19:57.967" UserId="1605" />
  <row Id="11031" PostId="7790" Text="370 is a standard size of 'toy' motor - it appeared in radio controlled cars in about the late 1970's - there were a couple of motors that were used - the big one was the 540 can size. - the main difference between the motors was how the coils inside were wound. For racing cars a thicker wire would be used that would take a lot more current, but the downside was the batteries would run down quicker... (And everything would have to take a lot higher current) " CreationDate="2010-12-13T22:28:56.583" UserId="2192" />
  <row Id="11032" PostId="7790" Text="As you motor is from a model helicopter, the motor is a more standard design - and won't have specs much off the ones quoted for the R370 - I would say a max stall current of no more than 5 Amps... " CreationDate="2010-12-13T22:31:01.917" UserId="2192" />
  <row Id="11033" PostId="7790" Text="You could test the stall current by just connecting the motor across a supply with a meter and stall it - but only for less than 2 seconds..." CreationDate="2010-12-13T22:32:07.360" UserId="2192" />
  <row Id="11034" PostId="7813" Score="1" Text="I should have been more clear-- I'm suggesting using a Schottky diode in series with the battery, not in parallel. I think that's different from what Leon is suggesting. (I think what Leon suggests is pretty good, but blowing fuses annoys some people.)" CreationDate="2010-12-13T22:32:46.517" UserId="712" />
  <row Id="11035" PostId="7790" Text="Your design for a motor controller is simple, it seems to work and should be capable of handling the stall current from your motor. :-) " CreationDate="2010-12-13T22:33:46.687" UserId="2192" />
  <row Id="11036" PostId="4740" Text="@Ed Owens did you make hack-a-day or something like that for your nixie clock? Or did you just copy their idea? " CreationDate="2010-12-13T22:57:56.700" UserId="708" />
  <row Id="11037" PostId="7781" Text="@kellenjb, I am disagreeing with &quot;electronic&quot;, as it is the same as calling a battery holder &quot;electronic&quot;." CreationDate="2010-12-13T23:27:01.383" UserId="1225" />
  <row Id="11038" PostId="7795" Text="I will probably do this next time but this is more suited to be a comment than an answer as it doesn't solve my primary issue." CreationDate="2010-12-13T23:48:36.803" UserId="1225" />
  <row Id="11039" PostId="7754" Text="@Nick - have you had a chance to read it? What is it that you don't like about the book? I have had a chance to read a few books on C in my time, and have to say, that I have really liked this book. It is a really easy read and explains some core concepts really well. But ofcourse it is my opinion, and you are definitely entitled to yours! :)" CreationDate="2010-12-14T00:20:17.787" UserId="1785" />
  <row Id="11040" PostId="7813" Text="@pingswept, I thought that might be what you meant. I Would suggest editing that into your answer." CreationDate="2010-12-14T01:26:59.800" UserId="230" />
  <row Id="11041" PostId="7781" Text="@ThomasO I said it's not electronic, then you said it's not electronic, then you said you are disagreeing with me. I am rather confused." CreationDate="2010-12-14T01:27:22.047" UserId="319" />
  <row Id="11042" PostId="7188" Text="@mark, @tcrosley, elance seems to be the only site that when I am actually writing proposals it seems worth it." CreationDate="2010-12-14T01:59:49.787" UserId="230" />
  <row Id="11043" PostId="7836" Text="PrimeSense is the company, PrimeSensor is what happened in the first sentence of the question to make it more readable.  Fixed it for you." CreationDate="2010-12-14T02:56:03.717" UserId="857" />
  <row Id="11044" PostId="7834" Text="What is your application?" CreationDate="2010-12-14T02:56:26.183" UserId="857" />
  <row Id="11045" PostId="7836" Text="@reemrevnivek my bad. Thanks for the catch." CreationDate="2010-12-14T03:16:23.747" UserId="319" />
  <row Id="11046" PostId="7834" Text="@reemrevnivek Updated" CreationDate="2010-12-14T04:01:49.460" UserId="2180" />
  <row Id="11047" PostId="7834" Text="@maker - Thanks!  Kellenjb offered a good answer on the relationship between the Kinect and PrimeSense, but I'm not sure I understand your application.  Perhaps it's because you have an idea that I can't come up with, but I'm not following how 3D imaging can be used with the X10 system and relay activation.  In any case, hobby projects that have to choose between the two will be better off with the Kinect because most of the hard work is done for you and it's readily available in single quantities." CreationDate="2010-12-14T04:11:27.410" UserId="857" />
  <row Id="11048" PostId="7834" Text="@reemrevnivek I could see it being kind of cool to make some hand motion and then have lights dim as you lower your hands. Or something like that." CreationDate="2010-12-14T04:15:44.193" UserId="319" />
  <row Id="11049" PostId="7754" Text="@Intel: It's not my opinion, just someone else's.  I knew I heard of the book before, I was trying to remember where :P" CreationDate="2010-12-14T04:21:59.560" UserId="1407" />
  <row Id="11050" PostId="7754" Text="@Nick - sure np! I have read your valuable and insightful answers/questions from time to time, so will definitely be interested to know your opinion of the book. Have a read and tell me what you think of it! :)" CreationDate="2010-12-14T04:26:21.130" UserId="1785" />
  <row Id="11051" PostId="7822" Text="@Theodor, I doubt they have a Euro supplier. The price is $650." CreationDate="2010-12-14T05:05:50.867" UserId="2118" />
  <row Id="11053" PostId="6900" Text="Do you mean servo? I'm not sure why you would want a distance ranger on a server." CreationDate="2010-12-14T05:51:33.557" UserId="1374" />
  <row Id="11054" PostId="7804" Text="would a battery supply cause any electrical interference?  " CreationDate="2010-12-14T06:21:55.063" UserId="2060" />
  <row Id="11055" PostId="7804" Score="1" Text="just depends on what is connected to it, using batteries for your sensors is almost ideal - especially if it is an ideal battery!  If you have noisy devices also connected, mount them closer to the batteries than the quieter devices.   So the noise will travel along a smaller length of wire and not radiate everywhere." CreationDate="2010-12-14T07:33:35.077" UserId="1397" />
  <row Id="11056" PostId="7648" Text="Now, you could put in diodes (*4148, for example), in the direction of the MOSFETs' inverse diodes (i.e Anode=Source, Cathode=Drain) and see what happens." CreationDate="2010-12-14T07:51:59.460" UserId="930" />
  <row Id="11057" PostId="7822" Text="@tyblu - Thats pretty fair, given that it has similar specs to the $1700 Zaber slide. Cheers!" CreationDate="2010-12-14T08:53:50.817" UserId="1605" />
  <row Id="11058" PostId="7800" Text="@Nick: sure. But I have not seen even a cheap wrist watch having such an off frequency, and I don't think casio would let a watch with 20 ppm off crystal out of their production line. It is naturally a good question to ask what the distribution across this +/-20 ppm is." CreationDate="2010-12-14T09:25:36.550" UserId="2275" />
  <row Id="11059" PostId="7780" Text="Yes, an enclosure is worth an extra cost for me too." CreationDate="2010-12-14T10:10:09.903" UserId="2064" />
  <row Id="11060" PostId="7798" Score="2" Text="A window seat may not be the solution :-( One problem that I have seen is that most modern double glazed units use coated glass (such as Pilkington K-Glass).  This has a metallised coating on the two inner surfaces which gives an attenuation of more than 40dB in the GPS frequency range.  You often get a better signal through the window frame than the glass." CreationDate="2010-12-14T10:20:00.630" UserId="400" />
  <row Id="11061" PostId="7798" Text="I have done exactly the same thing.  Sometimes the radiating antenna is in a RAM box that we use for testing the receivers." CreationDate="2010-12-14T10:23:11.593" UserId="400" />
  <row Id="11062" PostId="4207" Text="(I have completely forgotten that I've posted this here, sorry!) Thanks for your answer, shortly after asking the question I've realised the silly mistake :)" CreationDate="2010-12-14T12:22:09.337" UserId="1098" />
  <row Id="11063" PostId="4240" Text="Thanks for your answer and the sample code." CreationDate="2010-12-14T12:22:38.510" UserId="1098" />
  <row Id="11064" PostId="4218" Text="Thanks for your answer." CreationDate="2010-12-14T12:23:16.107" UserId="1098" />
  <row Id="11066" PostId="7846" Text="I just tried to do so in MSVC with no crosscompiler.. but I see this is no good!&#xA;I'm using the PIC18F87J11.&#xA;Right now I gave up with MSVC and imported all the .h and .c files into MPLAB and trying to build the whole thing together (the vendor suggested to first build the library and then the application, loading the library in it) but I am experiencing a number of errors I'm trying to correct one by one.. is this somehow the right thing to do?&#xA;&#xA;I've some experience with PICs but I never had to implement some external library and to adapt it so any hint is super welcome!" CreationDate="2010-12-14T12:27:47.947" UserId="2285" />
  <row Id="11067" PostId="7846" Text="If it's of any help, I'm using the C18 compiler from Microchip" CreationDate="2010-12-14T12:33:15.043" UserId="2285" />
  <row Id="11068" PostId="7794" Text="This is not a lot of use if you are trying to test a GPS receiver indoors within a system.  The whole point is that you need the GPS being tested to convert the RF into the position data.  The fact that it will produce a solution based on the position of the external antenna is not normally a problem." CreationDate="2010-12-14T13:49:42.150" UserId="400" />
  <row Id="11069" PostId="1892" Text="Shift register worked great for me in the past to drive several 5x7 LED arrays with an HC11, so I recommend this approach!" CreationDate="2010-12-14T14:16:38.617" UserId="2288" />
  <row Id="11070" PostId="7814" Text="@Theodor As a MakerBot owner and one that also uses high quality linear slides for work, I don't think want their mechanism anyway because there is a fair amount of roll and pitch.  Although the resolution in the general direction of the axis is good (better than the 1mm you want), the amount of deflection under loads will be pretty unaccceptable." CreationDate="2010-12-14T14:29:59.973" UserId="2288" />
  <row Id="11071" PostId="7822" Text="@tyblu - nice find!" CreationDate="2010-12-14T14:30:55.183" UserId="2288" />
  <row Id="11072" PostId="7806" Text="what about footprint / formfactor?  And quantities?  Have you considered looking for a small local US shop to design one for you?" CreationDate="2010-12-14T14:34:58.547" UserId="2288" />
  <row Id="11073" PostId="7850" Score="3" Text="Try to use static allocation if possible." CreationDate="2010-12-14T14:42:54.517" UserId="1407" />
  <row Id="11074" PostId="7850" Text="Why? The problem really is that I'm writing the bottom layer (the platform specific one) of a pretty huge library and a lot of functions I have no idea what they are for are using this.. and I have no idea how to change from dynamic to static.." CreationDate="2010-12-14T14:48:33.087" UserId="2285" />
  <row Id="11075" PostId="7781" Text="@kellenjb, I don't think I ever said it was elctronic, I may have misread you. &quot;That patent is for the mechanical aspects of the holder and not the electronics&quot; would seem to indicate there are some electronics in it, but I may have misunderstood." CreationDate="2010-12-14T14:48:35.537" UserId="1225" />
  <row Id="11076" PostId="7853" Text="I see what you mean.. I'm using the PIC18F87J11, which has 128K of ram, can it be enough?" CreationDate="2010-12-14T15:02:50.693" UserId="2285" />
  <row Id="11077" PostId="7834" Text="Yes, somthing like the &quot;clapper&quot; but by sign language.  It's also good for making a haloween &quot;robot&quot;; Check out the website &quot;Kinect Hacks&quot; " CreationDate="2010-12-14T15:09:03.437" UserId="2180" />
  <row Id="11078" PostId="7836" Text="Thanks!  I also found drivers from the Manufacturer themselves that works with the XBox Kinect http://openni.org/" CreationDate="2010-12-14T15:10:48.893" UserId="2180" />
  <row Id="11079" PostId="7853" Text="Stefano, that chip has 3,904 bytes of RAM. It has 128K of program flash memory." CreationDate="2010-12-14T15:13:52.820" UserId="638" />
  <row Id="11080" PostId="6900" Text="@Fake Name, nice catch, i missed my typo completly and everyone else just had faith." CreationDate="2010-12-14T15:22:03.243" UserId="230" />
  <row Id="11081" PostId="7828" Text="Headers are fairly robust (metal and plastic), so the only thing you really need to worry about is melting the plastic holding the pins together.  You would have to be using something absurd to damage ICs while soldering them." CreationDate="2010-12-14T15:26:17.990" UserId="1407" />
  <row Id="11082" PostId="7754" Text="@IntelliChick, I like Ganssle's site enough I actually bought one of his books, it was quite a fun read." CreationDate="2010-12-14T15:27:49.090" UserId="230" />
  <row Id="11083" PostId="7853" Text="@Stefao Salati - 3.8KB is tiny." CreationDate="2010-12-14T15:29:31.023" UserId="1225" />
  <row Id="11084" PostId="7853" Text="Right sorry.. do you think it can be enough anyway?" CreationDate="2010-12-14T15:31:17.297" UserId="2285" />
  <row Id="11085" PostId="7844" Score="1" Text="Regarding `.lib`'s: [Not only is a `.lib` file CPU specific, it is toolchain specific.](http://stackoverflow.com/questions/3120308/is-a-c-lib-file-platform-specific)" CreationDate="2010-12-14T15:32:03.680" UserId="1407" />
  <row Id="11086" PostId="7853" Text="@Stefano Salati, no need to apologise. I think you'd be pushing it really. It might work, but it would take a chunk out of performance and your free memory." CreationDate="2010-12-14T15:33:26.670" UserId="1225" />
  <row Id="11087" PostId="7853" Text="@Stefano, to make a cup of coffee, sure.  To fly a 787?  No." CreationDate="2010-12-14T15:33:43.817" UserId="1407" />
  <row Id="11088" PostId="7819" Text="Sorry, the real code is correct, it was only a typo. " CreationDate="2010-12-14T15:45:42.420" UserId="2276" />
  <row Id="11089" PostId="7857" Score="1" Text="A circuit besides a full adder?  You could just use one where one set of inputs is static, either 00...01 (++) or FF...FF (--)  You could optimize/eliminate some of the input gates with the knowledge of constant inputs." CreationDate="2010-12-14T15:45:48.627" UserId="1407" />
  <row Id="11090" PostId="7858" Text="Thanks. I'm considering building a transistor computer so whereever I can save transistors it is good." CreationDate="2010-12-14T15:53:10.890" UserId="1225" />
  <row Id="11091" PostId="7857" Text="@Nick T, I was thinking of doing this but wasn't certain how to approach it." CreationDate="2010-12-14T15:53:33.617" UserId="1225" />
  <row Id="11092" PostId="7858" Score="3" Text="Transistor computers are easy to make when you're building the transistors on a single silicon wafer :)" CreationDate="2010-12-14T16:07:29.463" UserId="638" />
  <row Id="11093" PostId="7849" Text="Just flip the sensor and pull resistor to get the opposite level.  No need for an extra IC." CreationDate="2010-12-14T16:34:44.187" UserId="142" />
  <row Id="11094" PostId="7794" Text="@Ian: I think you misunderstand my comments about subtracting the apparent length of the waveguide from the distance calculations.  Each satellite is in a different position in the sky, so if the waveguide is say 50 ft long, then the distances to the satellite will be 50 ft too long *in different directions for each satellite*.  I doubt the GPS receiver would be able to lock on at all in that situation, because it would be calculating distances that don't line up, and therefore make no sense.  I don't think it would calculate the position of the antenna - it simply wouldn't lock at all.&#xA;" CreationDate="2010-12-14T16:36:58.387" UserId="2257" />
  <row Id="11095" PostId="7858" Text="Food for thought, if you're talking about making a discrete transistor CPU: The Intel 4004 (4 bit CPU) has 2300 transistors (excluding main ROM/RAM, and I/O." CreationDate="2010-12-14T17:01:49.530" UserId="638" />
  <row Id="11096" PostId="7858" Text="@Thomas: I don't want to discourage you, but even the most simple CPU needs a few thousand transistors and the more components the greater the chance that something is wrong somewhere. _I_ wouldn't want to debug it anyway. Why don't you build one with standard 74HCxx logic? This may increase your chances considerably, and it should be a serious challenge too." CreationDate="2010-12-14T17:14:43.107" UserId="2064" />
  <row Id="11097" PostId="7785" Score="1" Text="You could use a Resettable Fuse (aka PTC or polyfuse), then no need to replace blown fuses. http://en.wikipedia.org/wiki/Resettable_fuse" CreationDate="2010-12-14T17:26:02.233" UserId="131" />
  <row Id="11098" PostId="7858" Score="1" Text="@stevenvh Actually I should have written relay computer and it's been done before (http://web.cecs.pdx.edu/~harry/Relay/.) I doubt I'd actually build it, but it would be a design project to do in my spare time." CreationDate="2010-12-14T17:29:49.733" UserId="1225" />
  <row Id="11099" PostId="7842" Text="What is the audio processor on the kinect do? I knew the primesense unit provides audio, I figured they were having the Xbox do the interpretation of the audio." CreationDate="2010-12-14T17:32:22.507" UserId="319" />
  <row Id="11100" PostId="7860" Text="I didn't think the Arduino was itself an ISP programmer - I thought it has an ISP header on it so that you can burn a new bootloader onto a fresh ATMega328 in circuit..." CreationDate="2010-12-14T17:33:02.577" UserId="771" />
  <row Id="11101" PostId="7861" Text="The way that GPS receivers get designed is with a GPS simulator system, as far as I know.  National Instruments offers one, among other companies, but they are not cheap.  Something on the order of 30-40k, as I recall.  But, if you are shipping 100k+ units of your GPS chip, then the 40k for a GPS simulator isn't too bad." CreationDate="2010-12-14T17:33:08.467" UserId="1477" />
  <row Id="11102" PostId="7859" Text="by the way this is really cool, thanks for sharing!" CreationDate="2010-12-14T17:38:27.597" UserId="771" />
  <row Id="11103" PostId="7860" Text="reading the article more closely, it does seem like you can use the ArduinoISP sketch to do this - you learn something new every day! :)" CreationDate="2010-12-14T17:42:27.187" UserId="771" />
  <row Id="11104" PostId="7791" Score="1" Text="@Nick T - Close, but not quite.  WAAS isn't compatible with old GPS receivers as Endolith specified." CreationDate="2010-12-14T18:19:37.823" UserId="857" />
  <row Id="11105" PostId="7858" Text="@Thomas: I wouldn't want to debug that one either :-). And it's been done before indeed: the world's first computer, Konrad Zuse's Z3 was built with relays. Unfortunately for him he lived on the &quot;wrong side&quot;, so he hardly got the recognition he deserved. BTW, the Z3 held 2000 relays and ran at a 5Hz clock. Maybe some relay manufacturer wants to sponsor your project :-)" CreationDate="2010-12-14T18:26:17.147" UserId="2064" />
  <row Id="11106" PostId="7858" Text="@stevenh, I am doing this because my main computer is out of action right now (with my main project's schematics and software on it), but it will soon be fixed so it was just a passing thing to do in my spare time." CreationDate="2010-12-14T18:37:47.410" UserId="1225" />
  <row Id="11107" PostId="7869" Text="This question is off-topic, please see the FAQ. I'm afraid that there is no appropriate stack exchange in existence, but you could propose one on Area51 - eg. http://area51.stackexchange.com/proposals/614/electronic-gadgets" CreationDate="2010-12-14T20:04:56.620" UserId="566" />
  <row Id="11108" PostId="7865" Score="1" Text="And the datasheets show the basic idea of how you would implement this if you were building it yourself.  An amplifier followed by a band-pass filter for the frequency you want, demodulator, etc." CreationDate="2010-12-14T20:22:20.653" UserId="142" />
  <row Id="11109" PostId="7859" Text="Hats off! I've never managed to program my attiny85 this way.. I always have &quot;programmer out of sync&quot; errors when avrdude attempts to write the flash. Swapping the arduino with a bus pirate works though..." CreationDate="2010-12-14T20:27:39.963" UserId="595" />
  <row Id="11110" PostId="7841" Text="Well, it won't go from off to on, it will go from probably off to more and more on, in a linear fashion. You'll need a comparator or trigger circuit to have a digital switching action - this one uses an op-amp: http://www.sentex.ca/~mec1995/circ/sensor2.htm and this one uses two transistors: http://www.electronickits.com/kit/complete/elec/ck1602.pdf but this one can suffer from problems if the light levels change slowly (see the text). The op-amp circuit is a classic implementation." CreationDate="2010-12-14T20:32:21.283" UserId="1750" />
  <row Id="11111" PostId="840" Text="Thankyou, @ArduinoFun" CreationDate="2010-12-14T21:31:28.487" UserId="1457" />
  <row Id="11112" PostId="7876" Text="Thanks for the MOSFET idea. The pot is actually a placeholder for an analogue sensor board which hasn't been designed yet, it won't be user controllable." CreationDate="2010-12-14T21:59:01.477" UserId="566" />
  <row Id="11113" PostId="7794" Text="@Eric Cox : If this were true, then how do the active GPS repeaters (sold for International markets or shielded test room use) work at the end of their long coax connections?" CreationDate="2010-12-14T22:07:32.357" UserId="1908" />
  <row Id="11114" PostId="7855" Text="Thanks for the answer. Unfortunately it did not work as I explained it in the update." CreationDate="2010-12-14T22:21:23.060" UserId="1649" />
  <row Id="11115" PostId="7855" Text="Can you connect to the BT module?  Hold the AVR in reset (keep button down or short it) and connect RX and TX together, open a terminal and it should echo everything you type." CreationDate="2010-12-14T22:24:43.260" UserId="1407" />
  <row Id="11116" PostId="7876" Score="2" Text="@Joby: If you want a fairly accurate reading (&gt;8-bit)?, I'd connect the switched analog supply to another analog pin and use that to scale the pot signal.  Or, if you have a separate Vref, you could simply use that." CreationDate="2010-12-14T22:49:52.863" UserId="1407" />
  <row Id="11117" PostId="7857" Text="You could feed the carry-in line, but I suspect you don't have access to silicon..." CreationDate="2010-12-14T22:50:58.603" UserId="2118" />
  <row Id="11118" PostId="7850" Score="6" Text="@Stefano It sounds like a PIC microcontroller with &lt; 4KB RAM may be wrong for your application. On a PC measure the memory usage of your PC library before beginning a port. You may be better off with something beefier like an ARM Cortex-M3. Rule of thumb: if the codebase you're porting is too big to understand then it won't fit in a PIC." CreationDate="2010-12-14T23:16:23.687" UserId="566" />
  <row Id="11119" PostId="7876" Text="@Nick 12bit. You mean wire the GPIO pin supplying the pot to Vref? Makes sense - I hadn't been getting the full ADC range since moving the pot to a GPIO." CreationDate="2010-12-15T00:00:57.627" UserId="566" />
  <row Id="11120" PostId="7882" Text="I have an answer, but not the time to place it. short answer, yes, you can combine them, but it is not as easy as not matching to an intermediate impedance. Can you place a link to your chip antenna for me?" CreationDate="2010-12-15T00:16:57.077" UserId="230" />
  <row Id="11121" PostId="7871" Score="2" Text="@Joby Taffey I wonder when malloc IS considered a good thing in embedded." CreationDate="2010-12-15T00:19:26.043" UserId="319" />
  <row Id="11122" PostId="7871" Text="I still agree you do not want dynamic allocation in programs, as others have said, but this is a great way to go about it. Third party malloc designed for embedded is by far the best choice. Avoiding segmentation is a must. @jobyTaffey Well written. " CreationDate="2010-12-15T00:21:07.167" UserId="230" />
  <row Id="11123" PostId="7871" Score="1" Text="@Kellenjb well, that's a whole new question :-)" CreationDate="2010-12-15T00:23:53.030" UserId="566" />
  <row Id="11124" PostId="7881" Score="2" Text="When you place a resistor down, you are effectively putting the wire a little higher above the ground plane. When you do it with two devices near each other you will get both devices having increased cross-sectional area next to each-other, but gaining inductance and a large portion a mutual inductance. This can hurt signal integrity a lot, as you will bounce the other traces signal. @kellenjb, just expanding on your signal integrity section a bit." CreationDate="2010-12-15T00:24:08.427" UserId="230" />
  <row Id="11125" PostId="7882" Text="This antenna --&gt; http://www.antenova.com/?id=742, but the datasheet does not specify the nominal matching circuit, I had to email Antenova to obtain the above matching circuit on their reference board." CreationDate="2010-12-15T00:56:10.580" UserId="1688" />
  <row Id="11126" PostId="7841" Text="I knew that this was the way to make it turn &quot;on&quot; in the daylight. I'm asking how to get it to turn off in the daylight and on at night" CreationDate="2010-12-15T01:02:33.823" UserId="708" />
  <row Id="11127" PostId="7799" Text="I really wish FPGAs weren't so expensive" CreationDate="2010-12-15T01:14:48.277" UserId="708" />
  <row Id="11128" PostId="7880" Score="2" Text="Are the resistors on the same signal (in series, end-to-end or parallel) or on different signals?" CreationDate="2010-12-15T01:33:06.153" UserId="857" />
  <row Id="11129" PostId="7884" Score="2" Text="I think he wants to remove some of the network, I do not think he is asking if the current circuit works." CreationDate="2010-12-15T02:47:38.100" UserId="230" />
  <row Id="11130" PostId="7799" Text="You should be able to get a project board with a small-medium xilinx or altera part and handy I/O peripherals and connectors for $60 - 100 and the tools are free for all but the largest parts." CreationDate="2010-12-15T03:54:18.387" UserId="2246" />
  <row Id="11131" PostId="7769" Text="I can load a blinky LED to the chip using the AVR Studio with AVR ISP.. But I am not able to burn it using the Arduino Software.." CreationDate="2010-12-15T05:09:48.883" UserId="2264" />
  <row Id="11132" PostId="7777" Text="@Leon Heller&#xA;I  have tried to burn it using the Arduino software with the AVR ISP but it gave no result.. Also I have tried to ask in the arduino forum but nobody can answer it as well.." CreationDate="2010-12-15T05:11:43.797" UserId="2264" />
  <row Id="11133" PostId="7889" Text="so high == 1 == Vss? Or is high == Vdd?" CreationDate="2010-12-15T05:43:46.233" UserId="790" />
  <row Id="11134" PostId="7889" Score="3" Text="high == 1 == Vdd (+ve supply, +3.3V or +5V or +1.8V (rarely)), low == 0 == Vss (-ve supply, ~0V).  " CreationDate="2010-12-15T05:50:55.663" UserId="2292" />
  <row Id="11135" PostId="7887" Text="what part is confusing?  everything?  Have you used a breadboard before?  The key things to remember here are that the center divider electrically isolates the left and right sides for ICs.  The most important thing here is to make sure you have the GND from the Arduino connected to the GND of the 9V supply.  If you don't do this, you might end up with a dead Arduino." CreationDate="2010-12-15T07:13:15.920" UserId="2288" />
  <row Id="11136" PostId="7849" Text="good point.  :)  But if it's a photoresistor, isn't it just a matter of where you put it in the voltage divider?  You wouldn't actually pull one of the resistors, would you?" CreationDate="2010-12-15T07:18:18.317" UserId="2288" />
  <row Id="11137" PostId="7888" Text="[This link will be useful for you.](http://www.avrfreaks.net/index.php?name=PNphpBB2&amp;file=viewtopic&amp;t=37871)" CreationDate="2010-12-15T08:00:59.377" UserId="2118" />
  <row Id="11138" PostId="7794" Text="@Eric.  The signals from the satellites all arrive at the outside antenna with their different path lengths and hence signal delays up to that point.  The onward transmission of the signal through whatever transmission medium used (waveguide/co-axial cable/RF amplifier) will ideally only add a consistent time delay to all of the signals.  This will make the GPS receiver, that can only see the re-radiated signals, think that it is actually outside and a couple of nanoseconds earlier.  " CreationDate="2010-12-15T08:11:41.203" UserId="400" />
  <row Id="11139" PostId="7863" Text="Thanks for the heads up about the UNO, I'm actually using a Duemilanove with the 168 chip swapped for a 328, and can get the normal ATtiny sketches to upload properly via ArduinoISP. I'll be trying your /16 tip!" CreationDate="2010-12-15T09:02:00.500" UserId="623" />
  <row Id="11140" PostId="7804" Text="The whole device will be running on batteries,and keeping the sensors away from the main motor and servos will be very tough. I guess its now on to experimenting with the positions, thanks for the help! " CreationDate="2010-12-15T09:13:38.677" UserId="2060" />
  <row Id="11141" PostId="7889" Score="4" Text="The `d` in Vdd refers to the drain of a MOSFET (in CMOS), the `s` in Vss to the source. You'll often see Vcc instead of Vdd. Here the `c` is for collector (of a bipolar transistor), a remainder from the older TTL (transistor-transistor logic) circuits." CreationDate="2010-12-15T10:14:44.633" UserId="2064" />
  <row Id="11142" PostId="3145" Text="I wouldn't trust 20-bit A/D on the same die as a microcontroller. Noise from the uC will probably render at least 4 bits useless." CreationDate="2010-12-15T12:23:59.967" UserId="2064" />
  <row Id="11143" PostId="1205" Text="I second the PIC16 comments. Old, quirky, memory organised in banks, not C-friendly. Microchip uses the fact that it has very few instructions to learn as an asset, which is just stupid, IMO. MPLAB IDE is a joke, it feels like it's still 1998." CreationDate="2010-12-15T12:27:46.593" UserId="2275" />
  <row Id="11144" PostId="1213" Text="the PIC32 uses a MIPS M4K core - similar to ARM in that the core is licensed to other manufacturers - such as microchip to pack and add peripherals to." CreationDate="2010-12-15T13:26:03.750" UserId="1397" />
  <row Id="11145" PostId="7893" Text="I'm positive that I have the baud rate and other parameters set properly -- 9600,8,N,1, according to the specs.  And the dead giveaway is that I get ASCII back and not complete garbage.  I'd wire it up to my PC, but I have to get the components for the MAX232 first.  It would be helpful if you can post pseudocode for what you've done.  Or if you want, I can post mine for commenting.  But it really seems so dead simple.  What are you doing regarding time delays, etc?" CreationDate="2010-12-15T13:43:09.260" UserId="2288" />
  <row Id="11146" PostId="7893" Text="my code was very simple, wait and read serial data, then echo out on the other serial port, nothing fancy. i had no delays, why are you sending 0x0F? are you trying to read a legacy tag? Try 0x01 with a tag and see if you get anything back. " CreationDate="2010-12-15T14:01:05.450" UserId="2060" />
  <row Id="11147" PostId="7893" Text="sry the full command to send would be &quot;!RW&quot;+ &quot;0x01&quot; +&quot;[1-33]&quot; the data sheet will give the specifics for the command, but i believe you should be sending everything at once, no delays" CreationDate="2010-12-15T14:16:42.463" UserId="2060" />
  <row Id="11148" PostId="7893" Text="ok, thanks.  I solved my problem, I think.  I've added my answer to help others in general debugging techniques." CreationDate="2010-12-15T15:01:36.900" UserId="2288" />
  <row Id="11149" PostId="7890" Score="2" Text="The USB spec is not a flat 500mA, it's that the device can ASK for up to 500mA.  If the mbed tells the PC that it only needs 110mA as part of the USB configuration process then it's possible the USB chipset will current limit to that." CreationDate="2010-12-15T16:33:00.800" UserId="1270" />
  <row Id="11150" PostId="7903" Text="I figured you would answer this one :-). Thanks" CreationDate="2010-12-15T17:07:05.200" UserId="2064" />
  <row Id="11151" PostId="7766" Text="Upvote for the first part of the answer.  I would make the second part stronger - putting power supplies in parallel is *almost* never a good idea..." CreationDate="2010-12-15T17:33:28.027" UserId="2117" />
  <row Id="11152" PostId="7888" Text="@tyblu thanks, but I'm already pretty familiar with binary and the actual software side. I was only confused about how a binary value is communicated electronically to another device." CreationDate="2010-12-15T18:21:01.197" UserId="790" />
  <row Id="11153" PostId="7905" Score="4" Text="One of my favorite comic strips I have ever enjoyed." CreationDate="2010-12-15T19:09:07.190" UserId="230" />
  <row Id="11154" PostId="7906" Score="2" Text="Direct links: [dis'vun](http://www.techstreet.com/cgi-bin/detail?doc_no=IPC|7351B&amp;product_id=1725406) and [dis'vun](https://portal.ipc.org/Purchase/ProductDetail.aspx?Product_code=987caa7f-ff93-df11-9e60-002219545fd5)." CreationDate="2010-12-15T19:10:38.800" UserId="2118" />
  <row Id="11155" PostId="7906" Score="1" Text="[Mentor Graphics' LP Wizard](http://www.mentor.com/products/pcb-system-design/library-tools/lp-wizard/) is IPC-compliant and has a 10-day trial." CreationDate="2010-12-15T19:15:19.747" UserId="2118" />
  <row Id="11156" PostId="7905" Score="1" Text="Mmm, cool-aide.  +1" CreationDate="2010-12-15T19:19:20.397" UserId="2118" />
  <row Id="11159" PostId="7908" Score="1" Text="To be more precise, it is (most likely) the most popular programming environment with hobbyists, but not necessarily over all AVR developers." CreationDate="2010-12-15T20:31:25.393" UserId="536" />
  <row Id="11160" PostId="7908" Score="1" Text="I'd assert that Arduino is most popular by the number of users, but not by number of product units shipped containing Arduino firmware. There are a *lot* of Arduino users out there" CreationDate="2010-12-15T20:36:20.073" UserId="566" />
  <row Id="11161" PostId="7901" Score="13" Text="Say someone was selling a big floating skirt and some long poles they said you could use with your car to go fishing on a lake. After struggling for three days to put it on, you get about 15 feet into the lake before your car flips over and sinks. You're dad's going to be -really- pissed. You had passed up the local boat shop with a nice canoe. The canoe is the micro's C compiler, and the floaty car with sticks is Java on an 8-bit microcontroller. Luckily, this didn't happen... you're asking us where you can find the floats. So, as your dad, let me say &quot;What are you thinking?! Get a canoe!&quot;" CreationDate="2010-12-15T20:44:18.920" UserId="1270" />
  <row Id="11162" PostId="7905" Text="+1 Arduino makes AVRs accessible to a broader audience" CreationDate="2010-12-15T20:44:21.447" UserId="771" />
  <row Id="11163" PostId="7883" Text="At a range of 30 feet... you could run an extention chord out there and run a heater in an enclosure with the 'duino j/k :)" CreationDate="2010-12-15T20:52:47.930" UserId="771" />
  <row Id="11164" PostId="7883" Text="Actually my second question would have been if it's worth it to have the board monitor and maintain it's own temperature. I do have 120 at the pond on the pole I would mount the monitor to. Thanks - good suggestion." CreationDate="2010-12-15T21:12:44.530" UserId="2243" />
  <row Id="11165" PostId="7908" Text="Although &quot;sketches&quot; are compiled, IO access speed can be greatly improved using C or assembly." CreationDate="2010-12-15T21:13:17.707" UserId="2118" />
  <row Id="11166" PostId="7909" Text="ah yes, I saw that at the Maker Faire two years ago!  Pretty cool device." CreationDate="2010-12-15T21:28:28.270" UserId="2288" />
  <row Id="11167" PostId="7905" Text="+1 very nice answer to this question." CreationDate="2010-12-15T21:29:24.837" UserId="2288" />
  <row Id="11168" PostId="7878" Text="Thanks.I will try sinking it. If it does not work I will go out in the snow and find me some driver. I don't know anything about the motor other than that it is used to make the phone vibrate and maybe I can just remove the transistor from the phone as well. " CreationDate="2010-12-15T21:29:26.473" UserId="1637" />
  <row Id="11169" PostId="7898" Score="2" Text="I think I got better than a 50% space savings per part by using 4x0402 arrays instead of discrete parts" CreationDate="2010-12-15T21:44:41.363" UserId="1407" />
  <row Id="11170" PostId="7908" Score="1" Text="C++ and Java look very different to me.  (&quot;Arduino&quot; is *just* C++ with some bizarre include structure to hide some of the technical bits.)" CreationDate="2010-12-15T21:50:19.393" UserId="1407" />
  <row Id="11171" PostId="7908" Text="@Nick similar in the sense that it's all Algol-like http://en.wikipedia.org/wiki/Comparison_of_ALGOL_68_and_C%2B%2B#Comparison_of_the_assignment_and_equality_operators Java and C++ are much closer to each other than either are to BASIC or assembly" CreationDate="2010-12-15T22:05:23.103" UserId="566" />
  <row Id="11172" PostId="7907" Text="Most electrolytic caps suck near and below 0C." CreationDate="2010-12-15T22:09:18.003" UserId="2118" />
  <row Id="11173" PostId="7901" Score="1" Text="I'm having trouble visualizing the floaty skirt car with sticks.  Do you have any pictures?" CreationDate="2010-12-15T22:11:30.653" UserId="142" />
  <row Id="11174" PostId="7908" Text="but I cry over it's lack of pointers." CreationDate="2010-12-15T22:16:21.633" UserId="1407" />
  <row Id="11175" PostId="7855" Text="You are right. I have connected RX and TX together started minicom, and found that keeping reset button down caused the echoing of the typed key. After reset connection was lost as yesterday. Does it mean that the BT connection is alive, doesn't it? What could I do next? Thx in advance." CreationDate="2010-12-15T22:23:50.940" UserId="1649" />
  <row Id="11176" PostId="7901" Score="3" Text="@darron - Shouldn't that be a `big_floating_skirt` object which implements the `boat` interface in the `org.buoyant` package, and `pole` objects, which have some sort of weird inheritance pattern with `java.net` that I can't remember now (but is clearly described in the UML)?" CreationDate="2010-12-15T22:27:31.997" UserId="857" />
  <row Id="11177" PostId="7855" Text="It sounds like your problem might be in the AVR, either the chip is damaged, unprogrammed, or doesn't have the Arduino bootloader.  You would have to connect to it with an ISP to find out.  If you have an additional Arduino, you could put [ArduinoISP](http://arduino.cc/en/Tutorial/ArduinoISP) on that and give it a whirl." CreationDate="2010-12-15T22:28:44.430" UserId="1407" />
  <row Id="11178" PostId="7890" Text="@darron good point!  I forgot about that.  So that totally makes sense now.  thank you." CreationDate="2010-12-15T22:46:05.583" UserId="2288" />
  <row Id="11179" PostId="7915" Score="5" Text="To add to this: as you do your routing on a fixed grid, parallel lines will be at least 1 gridmark away. If they make a corner together a 45° angle gives the most space between those two tracks on the diagonal. Different angles may require that these tracks start farther apart to ensure minimum spacing, resulting in less dense routing than optimal. [Note that I'm not saying that more dense is better, but often desirable.]" CreationDate="2010-12-16T00:15:35.880" UserId="2118" />
  <row Id="11180" PostId="7863" Text="@fearoffours You know another thing you could try is writing a sketch based on ArduinoISP that sets the fuses to a certain value. If ArduinoISP can write the Flash, there's no reason I can think of that you couldn't bit-bang the ISP protocol described in the AVR datasheets to set the Fuses." CreationDate="2010-12-16T00:42:56.733" UserId="771" />
  <row Id="11181" PostId="7863" Score="1" Text="@fearoffours, also I just realized (and update post) to say multiply by 16 instead of divide by 16 (your running a slower clock it will take more ticks to get the same duration)" CreationDate="2010-12-16T00:45:14.203" UserId="771" />
  <row Id="11182" PostId="7915" Score="1" Text="I said &quot;a 45° angle gives the most...&quot; and should have said &quot;a 45° angle gives more... than if the angle were less.&quot;" CreationDate="2010-12-16T01:14:27.110" UserId="2118" />
  <row Id="11183" PostId="7483" Text="@ebynum: HIDkeys" CreationDate="2010-12-16T01:24:02.907" UserId="1129" />
  <row Id="11184" PostId="7911" Text="'never do that on an embedded C system' ???  Do what? 1 uS latency? High speed? Hardly. I think you're forgetting 1GHz+ DSPs, lots of ARMs, and quite a few others. Plenty of people write for these with just bare metal C (no OS, etc). I will grant you that this type of thing is a halfway rational way to use Java in embedded (outside a full Linux-scale OS)... although after taking a quick look at Systronix I'd say it appears you're paying a good premium for that little convenience. I'd go embedded ARM for sure. Also, a lot of the links to those projects off Systronix are dead." CreationDate="2010-12-16T01:52:53.753" UserId="1270" />
  <row Id="11185" PostId="7911" Text="Oh, and TINI is insanely dumb. JVM in ROM on an 8051. I stupidly tried one way back when I wanted easy Ethernet, and even in C the thing was just swamped by the broadcast traffic of a normal corporate LAN. It'd be a fine product if they marketed it like Parallax's Basic Stamps, but they don't. It's not fit for any non-hobbyist purpose." CreationDate="2010-12-16T01:59:01.677" UserId="1270" />
  <row Id="11186" PostId="7901" Text="@sterz: I think with no microprocessor background it's perfectly understandable that you might have not realized how out of place Java on an 8-bit micro really is. Sorry if my first comment sounded harsh... A simple &quot;Don't do that&quot; seemed way too weak." CreationDate="2010-12-16T02:10:43.640" UserId="1270" />
  <row Id="11187" PostId="7914" Text="The last time I bothered to look at my motherboard up close I think I noticed that all the traces were radiused at all corners" CreationDate="2010-12-16T02:16:39.377" UserId="1407" />
  <row Id="11188" PostId="7859" Text="@Jon: I'm not sure of the root cause behind &quot;programmer out of sync&quot;, but with AVR Studio you can adjust the programming frequency.  There may be a similar option in avrdude, might be worth a look if you ever give it a whirl again" CreationDate="2010-12-16T02:19:37.593" UserId="1407" />
  <row Id="11189" PostId="7914" Score="3" Text="i wouldn't say &quot;marginally better signal quality&quot;.  Radiused corners to the point of laser trimmed &quot;rounding&quot; may be mandatory for operation at high frequency." CreationDate="2010-12-16T02:40:58.507" UserId="1438" />
  <row Id="11190" PostId="7883" Text="I have a Davis Instruments (davisnet.com) soil temp sensor with one probe at the bottom of my pond and another in shallower water.  I have a USB interface on a computer in the basement that logs the data and updates a web page.   I've been thinking about setting up a water &quot;too low&quot; sensor that would manipulate a 3rd input on the soil temp station.   I like the idea of detecting pump failure as well." CreationDate="2010-12-16T03:06:52.513" UserId="1295" />
  <row Id="11191" PostId="3314" Text="Mind linking to that PDF? Seems interesting" CreationDate="2010-12-16T03:58:33.727" UserId="1688" />
  <row Id="11192" PostId="7919" Score="1" Text="Is this what you are looking for? http://electronics.stackexchange.com/questions/532/where-can-i-source-extra-long-headers-from" CreationDate="2010-12-16T04:31:03.173" UserId="319" />
  <row Id="11193" PostId="7921" Score="2" Text="nice, If I have a dishwasher... :(" CreationDate="2010-12-16T04:47:18.977" UserId="1800" />
  <row Id="11195" PostId="3314" Text="Short, *correct* answer: use whatever the majority of your device package's mechanical drawings are done in." CreationDate="2010-12-16T06:02:41.007" UserId="1374" />
  <row Id="11196" PostId="3314" Text="Of course, most modern software can export to either from either, so it really doesn't matter anyways." CreationDate="2010-12-16T06:03:37.467" UserId="1374" />
  <row Id="11197" PostId="7924" Text="It's easy to find parts on Digi-Key, finding ones *in stock* is something else :P  In any case, I'd post on the duplicate of this question if it would add there (linked by Kellen in a comment)" CreationDate="2010-12-16T06:03:45.220" UserId="1407" />
  <row Id="11198" PostId="7921" Text="+1 for dishwasher! After cleaning, it may be necessary to lubricate keys since sometimes lubricant can be removed by the dishwasher." CreationDate="2010-12-16T09:49:51.890" UserId="1240" />
  <row Id="11200" PostId="7915" Text="@tyblu I'm sorry but this makes no sense whatsoever. Firstly, diagonal lines on gridmarks are NOT spaced 1 gridmark away but only 0.7 gridmarks away, and secondly, if you have more angles you ALWAYS have more opportunity for denser routing. How can you possibly have less chance to route densely by routing in a way that entirely contains 45 degree routing as a special case?" CreationDate="2010-12-16T10:55:27.460" UserId="1951" />
  <row Id="11201" PostId="7921" Score="1" Text="Dishwasher ist good, but: Take the keyboard apart, rinse everything that has electrical contacts with alcohol, and put only the plastic parts (top w/ keys and bottom) in the dishwasher. The detergent in the dishwasher is quite aggressive and may eat the conducting traces and contacts underneath the keys and corrode all the other contacts." CreationDate="2010-12-16T11:48:25.997" UserId="930" />
  <row Id="11202" PostId="7855" Text="This board was working on an other machine, so it is programmed and at that time it was not damaged. There is a chance that we can try it tomorrow on that machine." CreationDate="2010-12-16T12:40:25.773" UserId="1649" />
  <row Id="11203" PostId="7930" Score="3" Text="Not really vents so much as scored lines that rip open.  On the other side the elastomeric seal vents hydrogen" CreationDate="2010-12-16T12:56:34.787" UserId="1407" />
  <row Id="11204" PostId="7915" Text="@romkyns, There are some misunderstandings. Following common design principles, you are limited to &lt;45° corners, follow a fixed grid and an xy orientation. Achieving transitions from horiz. to vert. using &lt;45° on a fixed grid uses more space than 45°." CreationDate="2010-12-16T13:58:03.030" UserId="2118" />
  <row Id="11206" PostId="7926" Score="1" Text="great idea with the conductive glue.  I tried to fly wires once on my MS 4000 and melted the mylar layer.  :)" CreationDate="2010-12-16T14:09:13.633" UserId="2288" />
  <row Id="11209" PostId="7930" Score="1" Text="yup - Since electrolytic caps that malfunction release hydrogen. If you had one of the ill fated capasitor rot capasitors, this would fail, and you'd have somenasty gunk on top" CreationDate="2010-12-16T14:33:17.740" UserId="1870" />
  <row Id="11210" PostId="7930" Text="@The - Electrolytic caps that function perfectly release hydrogen." CreationDate="2010-12-16T15:02:50.960" UserId="1407" />
  <row Id="11211" PostId="7930" Text="If they don't have vents, the capacitor explodes violently and can launch the casing at your forearm hard enough to draw blood.  :D" CreationDate="2010-12-16T15:19:56.370" UserId="142" />
  <row Id="11213" PostId="7921" Text="Take a picture of it first so you remember where the keys go? :D" CreationDate="2010-12-16T15:23:40.890" UserId="142" />
  <row Id="11214" PostId="7927" Text="can someone help and fix the links?" CreationDate="2010-12-16T15:34:01.387" UserId="689" />
  <row Id="11215" PostId="7931" Text="+1 I actually did this" CreationDate="2010-12-16T15:38:35.503" UserId="2006" />
  <row Id="11217" PostId="7930" Text="@endolith, is that a personal experience?" CreationDate="2010-12-16T15:58:07.537" UserId="771" />
  <row Id="11218" PostId="7938" Score="3" Text="`Don't try this at home...` Too late :-) I once had one such an elco wrongly connected and it exploded while I was bent over the board. The cap of the cap :-) only missed my left eye by a few centimeters and left a dent in the ceiling. And it smelled!  Under more controlled circumstances we held contests at school: shoot the cap as far as possible." CreationDate="2010-12-16T15:58:09.713" UserId="2064" />
  <row Id="11219" PostId="5550" Text="If the processor executes java bytecode, then that is its assembly." CreationDate="2010-12-16T16:00:55.180" UserId="2284" />
  <row Id="11220" PostId="7927" Score="1" Text="@Johan fixed links - good deed for the day complete!" CreationDate="2010-12-16T16:05:39.653" UserId="771" />
  <row Id="11221" PostId="7930" Text="@vicatcu: How could you tell? :)" CreationDate="2010-12-16T16:20:28.167" UserId="142" />
  <row Id="11222" PostId="7940" Score="1" Text="are you asking how to build something from scratch, or what to buy off the shelf? personally, I wouldn't mess around with home brew at those voltage levels (&gt; 40VDC is generally considered dangerous)" CreationDate="2010-12-16T16:34:46.270" UserId="771" />
  <row Id="11223" PostId="7939" Text="I liked the &quot;MOSFET = Metal Oxide Semiconductor Fire Emitting Transistor&quot; comment by kkristss.  " CreationDate="2010-12-16T16:37:08.890" UserId="857" />
  <row Id="11224" PostId="7898" Text="The `law of conservation of misery` says that the other resistors with the same value are the completely other side of the board :-( (OT: stronger law than conservation of energy or momentum, BTW; another observation of this law is that every wire cut to measure is too short)" CreationDate="2010-12-16T16:40:57.570" UserId="2064" />
  <row Id="11225" PostId="7944" Text="How would you generate the +176V? Wouldn't you still have the issue of making a circuit that &quot;drops&quot; roughly 176V?" CreationDate="2010-12-16T16:58:39.150" UserId="638" />
  <row Id="11226" PostId="7921" Text="This sounds like a cool idea, when I was at high school the IT technicians used to clean all the cola and gunk off the keyboards with a bucket of warm water and washing up detergent (dunk and soak), they then put them out to dry on the radiators. Personally I'd use the contact cleaner/rubbing alcohol method first, I've done this on my macbook pro three times now, for some reason the girlfriend keeps knocking whole pint glasses of juice on it ;( " CreationDate="2010-12-16T17:01:04.637" UserId="399" />
  <row Id="11227" PostId="7913" Text="As a side note, when using 45 degree routing, octagonal vias will give you the greatest clearance while maintaining more copper area on the annular ring. " CreationDate="2010-12-16T17:05:01.170" UserId="857" />
  <row Id="11228" PostId="7913" Text="I'd also point out that the free gEDA PCB program has a toporouter - Not just this one.  Does the same thing, and I don't think that it's due to its removal of the 45 degree limitation." CreationDate="2010-12-16T17:06:31.950" UserId="857" />
  <row Id="11229" PostId="7944" Text="When you say float do you mean running the control electronics at +200V and GND referenced to 197V~ish?" CreationDate="2010-12-16T17:07:43.617" UserId="2183" />
  <row Id="11230" PostId="3315" Text="I'm not sure that historical arguments are valid here, because an increasing number of new parts are dimensioned in mm, while older parts were dimensioned in mils." CreationDate="2010-12-16T17:11:06.940" UserId="857" />
  <row Id="11231" PostId="7940" Score="1" Text="What you call `powering themselves from the output` is probably a voltage feedback so that the controller can control the output voltage by varying the duty cycle of the PWM driving the transformer." CreationDate="2010-12-16T17:14:19.240" UserId="2064" />
  <row Id="11232" PostId="7941" Score="2" Text="I take it your using a Microsoft Windows only system? There's good free CAD tools on Linux that don't have restrictions, do Gerbers,  and are relatively stable, GEDA PCB and Kicad are great - you could always consider a dual boot with a light weight Linux distro" CreationDate="2010-12-16T17:16:35.173" UserId="399" />
  <row Id="11233" PostId="7911" Score="1" Text="These chips are running at several hundred megahertz.  1uS latency is possible when programmed in C on a processor running 100 times slower than these devices.   You can do some pretty cool things (like iPads and Droid phones) with equivalent processors, but posting this as an alternative to the 8-bit AVR in the question is hardly an apples-to-apples comparison." CreationDate="2010-12-16T17:17:52.397" UserId="857" />
  <row Id="11234" PostId="7920" Text="Do the switches use rubber domes, or is it a quality keyboard with mechanical switches?  Open it up, and post a picture." CreationDate="2010-12-16T17:30:24.200" UserId="857" />
  <row Id="11235" PostId="541" Text="I think it would be more appropriate to look at their [board stackers](http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1442852) page.  Basically the same thing, but (usually) with two insulating strips with some space between them.  We use some 1&quot; 50-position headers on som relay boards at work, and they are a pain because the ends are always getting bent out of alignment." CreationDate="2010-12-16T17:35:14.120" UserId="857" />
  <row Id="11236" PostId="533" Text="@Amos - Littlebirdceo and mad_z are no longer admins since the SE 2.0 switch." CreationDate="2010-12-16T17:37:15.757" UserId="857" />
  <row Id="11237" PostId="7946" Text="Also, I'll make a prediction-- if Cadsoft really does release an open format for boards and libraries, GEDA and Kicad will add import filters. This will finally break the chicken-egg problem of getting users who are making complicated boards to motivate improvements to the software." CreationDate="2010-12-16T17:46:18.760" UserId="712" />
  <row Id="11238" PostId="7940" Text="Out of curiosity, what is providing a 200 V input where you also need a 12/24 V, 50 mA source?" CreationDate="2010-12-16T17:54:35.900" UserId="1407" />
  <row Id="11239" PostId="7940" Score="1" Text="@Nick T, an array of high voltage batteries." CreationDate="2010-12-16T18:10:17.643" UserId="1225" />
  <row Id="11240" PostId="7945" Text="But *how* does the controller operate off 200V? Where does it generate its Vcc from?" CreationDate="2010-12-16T18:11:07.067" UserId="1225" />
  <row Id="11241" PostId="7947" Score="1" Text="I'd agree, I guess it depends on what kind of work your doing and what your budget is, but to me $1000 here and $500 there is a bit too rich for me" CreationDate="2010-12-16T18:16:21.103" UserId="399" />
  <row Id="11242" PostId="7946" Score="1" Text="I'll add that Eagle can be way cheaper if you tolerate reasonable restrictions on schematic page counts and board sizes. $50 gets you 1 sheet / 2 layer capability with autorouter. $750 gets you 99 sheets / 6 layer capability. $1500 gets you 999 sheets / 16 layer capability..." CreationDate="2010-12-16T18:42:38.723" UserId="771" />
  <row Id="11243" PostId="1213" Text="I vote ARM as well. completely standard compilers and debuggers, an almost-universal JTAG interface, no dependence on proprietary binary stuff like PICASM and C18. :-)" CreationDate="2010-12-16T18:51:05.673" UserId="974" />
  <row Id="11244" PostId="7947" Score="1" Text="I hear KiCAD is really awesome if you want something to use on Windows. GEDA on Windows is a 2nd class citizen.. I use it in a virtual Linux machine." CreationDate="2010-12-16T18:56:10.340" UserId="2183" />
  <row Id="11245" PostId="7944" Text="@krapht - I believe that is what he is saying (Well, ground referenced to 188V-176V, but pretty close.)" CreationDate="2010-12-16T18:57:16.263" UserId="857" />
  <row Id="11246" PostId="7944" Score="1" Text="@W5VO - No, a simple LM317 linear regulator will work fine, and be perfectly happy operating at 200V above earth ground.  It would do fine generating 0.6W, and is cheap and simple.  That's why 317s are often used as pre-regulators.  Heck, you could put 10 of them in a row, let each dissipate a watt of power, and get your 20V that way." CreationDate="2010-12-16T18:59:30.413" UserId="857" />
  <row Id="11247" PostId="7952" Text="You don't need to tap the AC switcher after the rectifier, as DC will go through the rectifier unchanged." CreationDate="2010-12-16T19:10:49.143" UserId="411" />
  <row Id="11248" PostId="7946" Text="To add to @vicatcu the $750 version has a max routing area of 160x100mm and for the $50 it is 100x80mm routing area." CreationDate="2010-12-16T19:27:38.440" UserId="319" />
  <row Id="11249" PostId="7915" Text="@tyblu Right, indeed, there was a misunderstanding on my part. Under those constraints a 45 degree joint makes sense, but those seem like very artificial constraints to me. I guess my question could then be rephrased to &quot;why do PCB professionals still operate under these artificial constraints of x/y orientation and a fixed grid?&quot; (I think I got my answer though: too much legacy software in this industry)" CreationDate="2010-12-16T19:30:10.537" UserId="1951" />
  <row Id="11250" PostId="7913" Text="@reem never seen an octagonal via, and Google Images isn't being helpful... if you post a link I'll be grateful! Also thanks for mentioning gEDA, looks very promising." CreationDate="2010-12-16T19:36:37.580" UserId="1951" />
  <row Id="11251" PostId="7915" Text="Fixed grid and xy-orientation: faster design time while ensuring spacing and alignment. &lt;45°: [avoids acid](http://www.pwtpcbs.com/glossary/acidtrap.html) [traps](http://www.cadence.com/Community/forums/p/11497/15062.aspx); high-freq. considerations (500MHz+ sine or 50MHz+ digital)." CreationDate="2010-12-16T19:37:32.270" UserId="2118" />
  <row Id="11252" PostId="3090" Text="You can program for WINAVR (i.e. avr-libc) from the Eclipse IDE using the AVR Eclipse plugin. Eclipse makes everything better!" CreationDate="2010-12-16T20:01:46.847" UserId="771" />
  <row Id="11253" PostId="7962" Score="5" Text="The $50 devkit looks good http://processors.wiki.ti.com/index.php/EZ430-Chronos" CreationDate="2010-12-16T21:31:06.280" UserId="566" />
  <row Id="11254" PostId="7958" Text="The CC1110 is the kind of thing I'm after" CreationDate="2010-12-16T21:34:21.973" UserId="566" />
  <row Id="11255" PostId="7956" Score="1" Text="can you give any more detail about your application context? do you need a one way link or two way link? are you looking to be on a network or just point to point?" CreationDate="2010-12-16T21:54:26.343" UserId="771" />
  <row Id="11256" PostId="7962" Score="1" Text="They are very affordable and offer a lot in processing power. Most people think of an MSP430 as a 8-bit due to cost, but they are actually 16-bit uC." CreationDate="2010-12-16T21:57:28.620" UserId="230" />
  <row Id="11257" PostId="7963" Text="you can always use a software uart implementation if you have the cycles to spare if you don't have a hardware uart as well..." CreationDate="2010-12-16T21:57:49.350" UserId="771" />
  <row Id="11258" PostId="7963" Score="1" Text="This is not a SoC, this is a two device solution." CreationDate="2010-12-16T22:04:10.457" UserId="230" />
  <row Id="11259" PostId="7969" Text="Do chips actually use the Gilbert cell, though? Looks prone to noise, thermal variations, and high power consumption..." CreationDate="2010-12-16T22:23:07.820" UserId="2118" />
  <row Id="11260" PostId="7969" Text="@tyblu, How many low power receivers have you seen. This is the foundation of IC modulation and demodulation. They have a lot of factors in their design." CreationDate="2010-12-16T22:32:10.807" UserId="230" />
  <row Id="11261" PostId="7764" Text="Thanks darron - after your message I started to (re)investigate FPGA's thanks to you and it's not too far out of my technology range (okay at the very egde), but would require some think power (and that is good). This is not out of the realm of possibilities for me and I like being &quot;at&quot; the metal, rather than &quot;on the metal&quot;. I need to do more research, do you have some reading you would recommend? many thanks ddm" CreationDate="2010-12-16T22:34:36.230" UserId="2243" />
  <row Id="11262" PostId="7963" Text="As a side note I believe you can buy an XBEE that comes with external ADC pins so that you do not have to have a microcontroller and their protocol allows you to poll them." CreationDate="2010-12-16T22:41:51.203" UserId="230" />
  <row Id="11263" PostId="7945" Text="the controller operates off the 200V supply.  Internally these devices are very simple, it doesn't take many transistors.  There is normally a precision internal reference set at some nominal voltage that is used for the comparator.  In other words, there is no Vcc, just the supply voltage.  The reference can be created in various ways, but is very, very low current so little power is wasted, I'm not sure what they use to create it, maybe a zener, maybe some other construct." CreationDate="2010-12-16T22:44:03.390" UserId="1438" />
  <row Id="11264" PostId="7883" Text="Very cool. I could run cables to the pond from a basement Microcontroller, then make available via webpage for monitoring. The big problem in winter is detecting icing as I need to plug in the horse trough heater (that if left too long heats the pond too much and activates the Koi, goldfish and maybe the frogs in February at -5C). I've run 120, why not underground cables as well. Thanks." CreationDate="2010-12-16T22:48:11.597" UserId="2243" />
  <row Id="11265" PostId="7907" Text="From all the responses I think I need to move the controller inside, the sensor cabled outside. Good point - thanks." CreationDate="2010-12-16T22:49:49.143" UserId="2243" />
  <row Id="11266" PostId="7961" Text="+1 to offset downvote, as Pulsonix certainly does look excellent." CreationDate="2010-12-16T23:02:00.033" UserId="2118" />
  <row Id="11267" PostId="7952" Text="Unchanged except a diode drop or two." CreationDate="2010-12-16T23:06:42.790" UserId="206" />
  <row Id="11268" PostId="7969" Text="Gilbert cells are definitely legit. The major benefit of a Gilbert cell is that you can get gain out of it." CreationDate="2010-12-16T23:20:04.010" UserId="638" />
  <row Id="11269" PostId="7952" Text="Right, and a diode drop or two isn't really significant when you are starting with 200V." CreationDate="2010-12-16T23:46:13.533" UserId="411" />
  <row Id="11270" PostId="7945" Text="The reference is frequently our old friend the TL431.  http://electronics.stackexchange.com/questions/7038/tl431-as-a-comparator" CreationDate="2010-12-16T23:48:30.943" UserId="411" />
  <row Id="11271" PostId="7973" Text="Interesting, I focused mostly on modulation. I enjoyed what you added." CreationDate="2010-12-16T23:49:15.543" UserId="230" />
  <row Id="11272" PostId="7969" Text="@tyblu, @w5vo, I believe you can cause a gilbert cell to be lower power but require a higher received power from the RX line. Also, most IC RX circuity can be placed in low-power mode." CreationDate="2010-12-17T00:05:55.373" UserId="230" />
  <row Id="11273" PostId="7921" Text="@Jim - Note: not recommended for keyboards still attached to laptops :)" CreationDate="2010-12-17T00:16:03.873" UserId="554" />
  <row Id="11274" PostId="7851" Text="Thanks man - I had to laugh, I downloaded and wrote some Ar* compiler/code/emulator and wrote some K&amp;R C for the Arduino emulator and didn't remember that a bool didn't exist yet. (Don't ask me about access to struct members!) Took me an hour with K&amp;R rev. 1 to realize I had to define it. (Back to the future for me :-) Very kewl! " CreationDate="2010-12-17T00:36:21.443" UserId="2243" />
  <row Id="11275" PostId="7944" Text="@reemrevnivek So if I were to use a 7812 instead of a 317, how would that be connected? I'm not really following how you're dodging the 175V+ drop. The current has to go somewhere, that's the LAW!" CreationDate="2010-12-17T00:59:49.420" UserId="638" />
  <row Id="11276" PostId="7973" Text="I don't think your answer actually gets at what he is asking. There is a difference between data rate and carrier frequency. The logic/transistors only need to be able to handle the data rate. Modulation and demodulation occur as the first last thing and very first thing in your system. &#xA;" CreationDate="2010-12-17T01:15:53.923" UserId="319" />
  <row Id="11277" PostId="7973" Text="Also just because a computer is able to run at 2.4ghz doesn't mean it can handle 2.4ghz of bandwidth. This starts to come into play with sampling theory, size of each sample, etc. " CreationDate="2010-12-17T01:17:48.570" UserId="319" />
  <row Id="11278" PostId="7973" Text="@Kellenjb, I disagree with that statement. While there certainly is a difference between the data rate and the carrier frequency, it would still be OK if there wasn't a difference - i.e. if the data rate was 2.4GHz. I would argue that at the very minimum, a 2.4 GHz computer would have a bandwidth of 2.4GHz * number of data lines clocked at 2.4GHz. If the clock signal (which is generated on-chip) is 2.4 GHz, then the signal would have harmonics in the 7.2GHz range. I am addressing only one part of his question: : &quot;how an IC can communicate at such speeds.&quot; " CreationDate="2010-12-17T02:44:39.973" UserId="638" />
  <row Id="11279" PostId="7851" Score="1" Text="try mbed next!  I am relatively new to both platforms, but I find the mbed environment much more familiar and less quirky of an IDE.  And the feature set on that micro is very impressive." CreationDate="2010-12-17T03:10:45.950" UserId="2288" />
  <row Id="11280" PostId="7962" Text="Yeah, the Chronos devkit is great way to start" CreationDate="2010-12-17T04:12:09.553" UserId="2292" />
  <row Id="11281" PostId="7931" Score="1" Text="@Matt Williamson any code you'd be willing to share from this project? I'd love to take a look!" CreationDate="2010-12-17T04:26:43.497" UserId="81" />
  <row Id="11282" PostId="7973" Text="@kellenjb, @w5vo, you are both saying something different. Yes, modulation steps down the frequency to a frequency that is cheaper to operate at. Yes, circuits can go that fast, but it increases cost. I think both are important concepts." CreationDate="2010-12-17T04:29:39.933" UserId="230" />
  <row Id="11283" PostId="3110" Text="@Joby Maybe you should update your link to point to the Butterfly One? Also, do you know how well supported these are(like how many people use them and if they're good for beginners)?" CreationDate="2010-12-17T05:55:23.730" UserId="708" />
  <row Id="11284" PostId="7799" Text="Finally FPGAs seem to be a bit more hobbyist friendly in price. Last I checked like a year ago I couldn't find anything cheaper than $100. I got two or three found for about $60 though and that's about the amount I have to spend :)" CreationDate="2010-12-17T06:13:33.177" UserId="708" />
  <row Id="11285" PostId="7799" Text="They were there at that price a year ago, and the year before that and the year before that too.  Over time the size of the chip you can get on a board at those prices changes, but something will be in that niche because it's important to getting the technology into the hands of students, getting it purchased without a lot of corporate red tape (or just giving away to larger customers), etc." CreationDate="2010-12-17T07:24:02.710" UserId="2246" />
  <row Id="11286" PostId="7981" Text="The chips are cheap too, ~$7.50 in single quantities, for the single core, TQFP packaged device." CreationDate="2010-12-17T09:18:18.323" UserId="1374" />
  <row Id="11287" PostId="7963" Text="@Kortuk: you're right, I must have missed the SoC requirement in the question." CreationDate="2010-12-17T09:20:27.120" UserId="2064" />
  <row Id="11288" PostId="7956" Text="Ideally, two-way and network capable, though one way non networked would also be interesting" CreationDate="2010-12-17T09:52:37.280" UserId="566" />
  <row Id="11289" PostId="7982" Text="The RFM12 looks nice, but it's not a SoC" CreationDate="2010-12-17T09:53:50.430" UserId="566" />
  <row Id="11290" PostId="7901" Score="1" Text="@darron: thanks for the &quot;shooting birds with a cannon&quot; analogy" CreationDate="2010-12-17T10:59:38.440" UserId="2296" />
  <row Id="11291" PostId="7974" Score="2" Text="Doesn't seem to be a specific question. As you said, [.NET M.F. supports WCF](http://msdn.microsoft.com/en-us/library/ee437142.aspx). 3 people's answers: [yes](http://goo.gl/Bjrev), [maybe](http://goo.gl/FBYst), [no](http://goo.gl/qKuPp). So you'll have to find out if it fits yourself!" CreationDate="2010-12-17T11:07:19.087" UserId="2118" />
  <row Id="11292" PostId="7985" Text="If you want a cross-plataform ready library, libUSB is the way to start. Just write your code linked dinamically." CreationDate="2010-12-17T11:16:00.360" UserId="1757" />
  <row Id="11293" PostId="7986" Score="1" Text="Assuming a LiPo battery?" CreationDate="2010-12-17T11:25:48.627" UserId="1225" />
  <row Id="11294" PostId="7986" Score="2" Text="@Thomas If you mean li-polymeter then yes, it says that on the back of the battery." CreationDate="2010-12-17T11:38:12.813" UserId="1999" />
  <row Id="11295" PostId="7989" Text="Time to go drain some batteries!" CreationDate="2010-12-17T11:48:51.687" UserId="2118" />
  <row Id="11297" PostId="7990" Text="How old is the battery? " CreationDate="2010-12-17T11:53:34.840" UserId="1225" />
  <row Id="11298" PostId="7989" Text="@Thomas that would be a little too low because I'd need to pick up this battery and plug it in whenever the primary dies out and I'm away from a power source. What would you recommend for that?" CreationDate="2010-12-17T11:54:45.210" UserId="1999" />
  <row Id="11299" PostId="7986" Text="Actually the primary battery is li-polymeter, the spare one that this question is about, says Li-ion." CreationDate="2010-12-17T11:55:35.040" UserId="1999" />
  <row Id="11301" PostId="7990" Text="@Thomas Almost Brand new, just got it yesterday" CreationDate="2010-12-17T11:57:54.147" UserId="1999" />
  <row Id="11302" PostId="7989" Text="@Click Upvote, it applies to Li-ion and Li-po batteries. It would seem it is not possible to store a battery at full charge for any long period of time." CreationDate="2010-12-17T12:07:43.350" UserId="1225" />
  <row Id="11303" PostId="7990" Text="@Click Upvote, very likely then it's fine, the phone's charging system obviously is a bit cheap." CreationDate="2010-12-17T12:27:18.303" UserId="1225" />
  <row Id="11304" PostId="7992" Text="possible duplicate of [Could my Cell Phone Battery be degrading?](http://electronics.stackexchange.com/questions/7990/could-my-cell-phone-battery-be-degrading)" CreationDate="2010-12-17T12:55:25.620" UserId="330" />
  <row Id="11305" PostId="7992" Score="2" Text="@Jason S, IMO it is not a duplicate." CreationDate="2010-12-17T12:58:12.940" UserId="2118" />
  <row Id="11306" PostId="7995" Text="I was using an ideal model. This makes sense." CreationDate="2010-12-17T13:18:52.533" UserId="1337" />
  <row Id="11307" PostId="7986" Text="Nice name and picture @Click!" CreationDate="2010-12-17T14:11:30.880" UserId="2117" />
  <row Id="11308" PostId="7850" Text="Windows drivers (and applications in general) essentially are written with an 'unlimited RAM' paradigm, since if physical RAM is exhausted, virtual memory can be swapped in. Depending on what the library is doing, it may very well consume more than the 4kB available in your PIC18F87J11. I suspect that you won't be able to gauge how much memory the driver is going to use." CreationDate="2010-12-17T14:14:21.613" UserId="1293" />
  <row Id="11309" PostId="7850" Text="Another potential issue: a Win32 int is 32 bits, whereas with the MCC18 compiler, it's only 16 bits. You could get weird overflow problems if you're not careful." CreationDate="2010-12-17T14:17:03.180" UserId="1293" />
  <row Id="11310" PostId="7945" Text="@Mark, Most show things like logic gates, comparators, etc. Is the entire circuit designed to run off 200V-300V, or does it generate its supply elsewhere?" CreationDate="2010-12-17T14:39:17.053" UserId="1225" />
  <row Id="11311" PostId="7944" Text="@W5VO, The regulator floats, as it requires no ground reference. However, if you short circuit to ground it will pop. You can do it with a 7812, it's just more difficult as you have to create your own ground point." CreationDate="2010-12-17T14:40:33.043" UserId="1225" />
  <row Id="11312" PostId="7998" Text="Yes, I supposed that designing a circuit for that would involve a microcontroller, but I'm looking for a finished solution - either a product that does that or an open source project that has it. Otherwise it would be &quot;building a car from scratch because I need one&quot;. I assumed my need would be very common, so there should be products and/or projects doing that." CreationDate="2010-12-17T15:04:58.240" UserId="1078" />
  <row Id="11313" PostId="7998" Text="As for the sample rate, the more the better. Ideally at least the same achieved by the Saleae product." CreationDate="2010-12-17T15:06:38.083" UserId="1078" />
  <row Id="11314" PostId="7963" Text="@stevenvh, you give great answers, I was sure you had just missed it in passing." CreationDate="2010-12-17T15:30:56.547" UserId="230" />
  <row Id="11315" PostId="7989" Text="@clickUpvote, it would hold about 40% charge for months, you should freeze them." CreationDate="2010-12-17T15:33:40.647" UserId="230" />
  <row Id="11316" PostId="7993" Score="1" Text="http://electronics.stackexchange.com/questions/3879/frequency-dependence-of-electrolytic-capacitors " CreationDate="2010-12-17T15:37:31.337" UserId="142" />
  <row Id="11317" PostId="7992" Text="@jasonS, it seems to be different enough. I know them being asked this close together seems fishy, but if they were asked days apart I would not have been critical. I think the time delay is what is making you critical.@clickUpvote, I think in the future you should take the time to ask one question and see if the answer possibly answers your other questions before you ask them." CreationDate="2010-12-17T15:46:27.123" UserId="230" />
  <row Id="11318" PostId="7946" Score="1" Text="I've always wondered what the value proposition for Eagle is.  Does it do something that other programs don't do?  Is it the availability of libraries?  Is it really easy to use?" CreationDate="2010-12-17T15:52:43.343" UserId="249" />
  <row Id="11319" PostId="7994" Text="@Stevenvh didn't mean to steal your answer. I didn't see it until just now." CreationDate="2010-12-17T16:01:55.350" UserId="319" />
  <row Id="11320" PostId="7993" Text="@endolith, If you think it is a duplicate, vote to close. In this case I think no-one else would vote and it would go away without an issue, if other people thought so, they would vote also. You will not hurt anything by voting to close, if it gets closed, but everyone disagrees there can be a vote to reopen. No harm done." CreationDate="2010-12-17T16:04:33.240" UserId="230" />
  <row Id="11321" PostId="8007" Text="What would be the maximum sample rate in this approach?" CreationDate="2010-12-17T16:06:36.230" UserId="1078" />
  <row Id="11322" PostId="8005" Score="1" Text="Thanks, that's what I was looking for. Although the model you mentioned is quite expensive, I found more affordable one (obviously with less features/capacity) at http://www.byteparadigm.com/product-gp-22050-14.html - knowing the exact denomination for the product helped a lot." CreationDate="2010-12-17T16:10:05.277" UserId="1078" />
  <row Id="11323" PostId="7993" Score="2" Text="I don't.  Just linking to related topic" CreationDate="2010-12-17T16:11:55.867" UserId="142" />
  <row Id="11324" PostId="7992" Text="@community, does this question really seem off topic? I think it is a boundary question, but asking about battery technology is not off topic. " CreationDate="2010-12-17T16:14:07.367" UserId="230" />
  <row Id="11325" PostId="7944" Text="@w5VO, [Yep, would have to generate +176V, which can be done with common regulators. Can use a zener to boost GND, and need S/C protection.](http://www2.renesas.com/maps_download/pdf/G12702EJAV0UM00.pdf) Guess this is still just a linear solution. I think the LM723 can be used as a switcher and float, but I've never seen it done." CreationDate="2010-12-17T16:15:01.173" UserId="2118" />
  <row Id="11326" PostId="8005" Score="1" Text="I want one. No, two -- I want two!" CreationDate="2010-12-17T16:17:18.347" UserId="2118" />
  <row Id="11327" PostId="7984" Score="1" Text="Give us a bit more information about it before you just link to your videos. This is no more than an add right now. We are glad you have taken the time to come to our site, but lets make this a long term high quality answer." CreationDate="2010-12-17T16:46:01.130" UserId="230" />
  <row Id="11328" PostId="8007" Score="2" Text="@fceconel well the Arduino runs at 16MHz, there's going to be some overhead for the program that &quot;executes the pattern&quot; but if you implemented the code running on the Arduino intelligently making use of hardware peripherals, I would think you could achieve something approaching 16MHz." CreationDate="2010-12-17T16:48:58.783" UserId="771" />
  <row Id="11329" PostId="8001" Score="3" Text="this question seems awfully simple... do you have some context that makes this answer less obvious?" CreationDate="2010-12-17T16:51:19.450" UserId="771" />
  <row Id="11330" PostId="7913" Text="Modern tools support arbitrary angles, so that's no longer the reason." CreationDate="2010-12-17T16:52:47.267" UserId="206" />
  <row Id="11331" PostId="8013" Text="Beaten to the punch! ;)" CreationDate="2010-12-17T17:06:12.377" UserId="2118" />
  <row Id="11332" PostId="8016" Score="2" Text="by basically, you mean it is an amplifier circuit with positive feedback." CreationDate="2010-12-17T17:25:48.443" UserId="230" />
  <row Id="11333" PostId="8016" Score="4" Text="@Kortuk yes, basically :p" CreationDate="2010-12-17T17:28:16.783" UserId="771" />
  <row Id="11334" PostId="8007" Text="Thanks, sounds like a good candidate for a basic solution when you need just the basic functionality at a low clock. But I wouldn't be so optimistic about the maximum sample rate. To give an example, I am currently experimenting with a BeagleBoard C3, which runs at 600 MHz, and the maximum I was able to get at its GPIO was about 4 MHz - and in that case just flipping a bit in a tight loop." CreationDate="2010-12-17T17:38:03.207" UserId="1078" />
  <row Id="11335" PostId="8003" Score="2" Text="great answer!  very enlightening." CreationDate="2010-12-17T17:45:20.517" UserId="2288" />
  <row Id="11336" PostId="8004" Text="Lithiums are charged with constant-voltage, so it may just be that it takes exponentially longer to charge as it gets closer to 100%; e.g. 10% to 50% may take as long as 95% to 100%." CreationDate="2010-12-17T17:47:07.410" UserId="1407" />
  <row Id="11337" PostId="8013" Text="+1 especially for the 2x2 array, which I wasn't aware of." CreationDate="2010-12-17T17:48:04.747" UserId="1739" />
  <row Id="11338" PostId="8007" Text="The Arduino will be very limited. Even using [the most powerful one](http://www.arduino.cc/en/Main/hardware), the [ATmega2560](http://www.atmel.com/dyn/products/product_card.asp?PN=ATmega2560), its 12 hardware PWM modules can only do about 60kHz [(&quot;fast PWM&quot;](http://goo.gl/voq0b); f_clk/256 max). Some AVRs can do 200kHz, which still doesn't come close to your 24MHz. Bit-banging IO's won't do faster PWM, but you can get up to f_clk/2 on a single IO if that is all the chip does. I think the Netduino uses an ARM - maybe it could do something more?" CreationDate="2010-12-17T18:00:14.780" UserId="2118" />
  <row Id="11339" PostId="7080" Score="1" Text="Really need both a Linux and Windows OS nowadays to get the best tools." CreationDate="2010-12-17T18:02:32.547" UserId="2118" />
  <row Id="11340" PostId="8007" Text="@fceonel Sure to approach the maximum rate, you'd probably have to use timer/PWM capability and maybe some optimized interrupt service routines (probably compare/match interrupts)... 4MHz out of a 600MHz CPU strikes me as something not quite right there..." CreationDate="2010-12-17T18:04:01.107" UserId="771" />
  <row Id="11341" PostId="8015" Score="1" Text="Do you mean sense an edge transition or the supply voltage?" CreationDate="2010-12-17T18:04:32.747" UserId="2118" />
  <row Id="11342" PostId="7946" Text="@AngryEE: I think the value proposition is &quot;Much cheaper and only a little worse, plus you can start with a free version.&quot;" CreationDate="2010-12-17T18:10:45.687" UserId="712" />
  <row Id="11343" PostId="8007" Text="@tyblu interesting yes I agree it's probably only good for one I/O line of emulation and I concede that I was overly optimistic with the 16MHz hypothesis..." CreationDate="2010-12-17T18:14:22.797" UserId="771" />
  <row Id="11344" PostId="7992" Text="@Kortuk the question is clearly from the point of view of a user of consumer electronics  which does not fit on this site. If the question is reword to be not so consumer oriented it would be fine; however, in its current state it should be closed." CreationDate="2010-12-17T18:20:40.517" UserId="319" />
  <row Id="11345" PostId="8016" Score="2" Text="@vicatcu, your response just made my day." CreationDate="2010-12-17T18:21:33.373" UserId="230" />
  <row Id="11347" PostId="8004" Text="This answer just got alot better. +1" CreationDate="2010-12-17T18:28:05.237" UserId="2118" />
  <row Id="11348" PostId="8009" Text="3. More power dissipation before the resistors burn." CreationDate="2010-12-17T18:32:25.910" UserId="712" />
  <row Id="11349" PostId="7990" Text="Please discuss the subject of if this is on-topic here: http://meta.electronics.stackexchange.com/questions/193/what-line-do-we-draw-for-consumer-electronics" CreationDate="2010-12-17T18:37:36.103" UserId="230" />
  <row Id="11350" PostId="7992" Text="@kellenjb, discussion location here:http://meta.electronics.stackexchange.com/questions/193/what-line-do-we-draw-for-consumer-electronics" CreationDate="2010-12-17T18:37:54.980" UserId="230" />
  <row Id="11351" PostId="8013" Text="@mskfisher, for every chain in parallel you should add one in series. 3X3 or 4X4, the divide factor is 1/N so you need N in a row to cancel it out." CreationDate="2010-12-17T18:41:16.677" UserId="230" />
  <row Id="11352" PostId="8019" Text="Can you take a picture of the USB and sensor connections on the board? These type of issues are quite interesting, at least on day 1 of the investigation! (Not so interesting on day 32.)" CreationDate="2010-12-17T18:45:14.257" UserId="2118" />
  <row Id="11353" PostId="7994" Text="@Kellenjb: No problem. I think you were writing it the moment I posted it." CreationDate="2010-12-17T18:58:12.653" UserId="2064" />
  <row Id="11354" PostId="8022" Text="@tyblu, good answer, I've actually used a 4-wire meter... are you suggesting that this technique can provide 12-18 significant digits of precision (i.e. detect variations in excess of pico-Ohms for small resistances)?" CreationDate="2010-12-17T19:06:00.607" UserId="771" />
  <row Id="11355" PostId="7943" Score="1" Text="But &quot;grid spacing&quot; is just begging the question, as the concept of a &quot;grid&quot; is just an artifact of XY design." CreationDate="2010-12-17T19:06:20.340" UserId="411" />
  <row Id="11357" PostId="8022" Text="@vicatu, Unfortunately even thermal noise overcomes measurements in that range. The devices used in fab houses don't have wires, but do the measurements right at the 'tips'. They are well-protected against EMI as well. [This](http://www.nanofab.ualberta.ca/site/?page_id=447) is the one I used." CreationDate="2010-12-17T19:10:33.063" UserId="2118" />
  <row Id="11358" PostId="8013" Score="1" Text="+1 for complete details." CreationDate="2010-12-17T19:11:37.170" UserId="2194" />
  <row Id="11359" PostId="8004" Text="Saying &quot;your battery is degrading&quot; is like saying &quot;you're dying&quot;.  While technically true, it seems like an overstatement without additional justification.  The information presented in the question is fairly thin." CreationDate="2010-12-17T19:12:45.823" UserId="1407" />
  <row Id="11360" PostId="8015" Text="Yes, I mean the edge - transition from low to high and vice versa." CreationDate="2010-12-17T19:16:35.483" UserId="1651" />
  <row Id="11361" PostId="8023" Text="@Nick right I wasn't talking about distinguishing them physically/visually, I meant could you somehow tell the differnece indirectly through measurement." CreationDate="2010-12-17T19:16:44.750" UserId="771" />
  <row Id="11362" PostId="8023" Text="@vicatcu: That's my point, you can't determine it from a two-terminal measurement of a &quot;black-box&quot;  Sure, you could CAT scan it..." CreationDate="2010-12-17T19:18:13.963" UserId="1407" />
  <row Id="11363" PostId="8022" Text="@tyblu fascinating, the meter looks pretty big (similar to what I've used), have you ever heard of implementations of the components involved in a 4-wire measurement directly 'in circuit' to avoid all the issues associated with probes?" CreationDate="2010-12-17T19:25:15.153" UserId="771" />
  <row Id="11364" PostId="8022" Text="@vicatcu: IMO there's no environment where you can measure 18 significant digits where the last digit is indeed significant. Just think of keeping temperature constant to within 1/1000th of a degree. It's just not possible. And pardon me saying, but I can see no reason why somebody would want to measure with such accuracy either." CreationDate="2010-12-17T19:26:18.510" UserId="2064" />
  <row Id="11365" PostId="8022" Text="@tyblu yea, i agree nobody would probably ever care about that kind of accuracy, i was just asking out of curiosity what level of accuracy is practically possible." CreationDate="2010-12-17T19:32:48.317" UserId="771" />
  <row Id="11366" PostId="8002" Text="yeah, the tolerance part makes sense because it is multiplied as well. thanks for the answer!" CreationDate="2010-12-17T19:32:56.473" UserId="2006" />
  <row Id="11367" PostId="8022" Text="@vicatu, Do you mean implementing a 4-point measurement using some of the metal layers on the silicon? I haven't, but I wouldn't have, either, as I'm a young'un in industry." CreationDate="2010-12-17T19:33:14.793" UserId="2118" />
  <row Id="11368" PostId="7865" Text="that should work perfectly, thanks!" CreationDate="2010-12-17T19:35:40.587" UserId="2006" />
  <row Id="11369" PostId="7943" Text="Hadn't thought of it that way. You're right" CreationDate="2010-12-17T19:44:42.853" UserId="638" />
  <row Id="11370" PostId="8004" Text="@nickT, I realized something that I should have been more clear about." CreationDate="2010-12-17T19:47:21.427" UserId="230" />
  <row Id="11371" PostId="8022" Text="I've seen resistor characterization over temperature setups where Kelvin connections (4-wire) were used because the wire length in and out of the thermal chamber was significant." CreationDate="2010-12-17T19:49:45.657" UserId="638" />
  <row Id="11372" PostId="8022" Text="@tyblu, by the way I just read about the uCurrent gadget - thanks for the reference really interesting reading - might have to buy me one of those :) " CreationDate="2010-12-17T20:01:14.130" UserId="771" />
  <row Id="11373" PostId="7945" Text="@thomas yea, logic gates are just transistors, as are comparators, as always just use transistors rated for your operational voltage.  Its not like they have to switch fast in this application." CreationDate="2010-12-17T20:07:15.023" UserId="1438" />
  <row Id="11374" PostId="8023" Text="The volt is defined down to about 1nV. Current measurement accuracy depends on the shunt resistor; let's say it's a &quot;6.5 digit&quot; meter that gives 0.5nA precision. This gives a maximum resistance accuracy of 1.5nΩ. Seems kinda low. Thermal noise is [1nV/50Ω over 1Hz bandwidth](http://en.wikipedia.org/wiki/Johnson%E2%80%93Nyquist_noise), which will dominate the measurements." CreationDate="2010-12-17T20:15:01.370" UserId="2118" />
  <row Id="11375" PostId="7945" Text="@Mark, it just surprises me, the die would be so big for 200V tolerances(?)" CreationDate="2010-12-17T20:24:51.443" UserId="1225" />
  <row Id="11376" PostId="7952" Text="@Brian - I didn't want to differentiate between power supplies with an without transformers, although, now that I think about it, a transformer-based power supply would likely cook if you tried to connect 200V after the rectification." CreationDate="2010-12-17T20:37:34.580" UserId="857" />
  <row Id="11377" PostId="7913" Text="@rom - Eagle has octagonal vias and pads, and they're also available in gEDA." CreationDate="2010-12-17T20:42:16.543" UserId="857" />
  <row Id="11378" PostId="7945" Text="@Mark, also, I was reading the datasheet for one chip (Viper17) and it says it requires 14V Vdd. http://www.st.com/internet/analog/product/204720.jsp" CreationDate="2010-12-17T20:51:03.583" UserId="1225" />
  <row Id="11379" PostId="7982" Text="why using a SoC is a must ? " CreationDate="2010-12-17T20:56:56.500" UserId="2245" />
  <row Id="11380" PostId="6365" Text="Good answer!  It's the questioner's responsibility to state such unguessable details as the electronics being on Earth or not :)  " CreationDate="2010-12-17T21:09:33.903" UserId="1609" />
  <row Id="11381" PostId="8001" Text="You should read an introduction to electronics." CreationDate="2010-12-17T21:12:04.853" UserId="339" />
  <row Id="11382" PostId="6208" Text="Noise for one antenna user is signal for another. Some radio astronomers are watching the moon, waiting for noise pulses that are Cerenkov radiation due to neutrinos interacting with moon matter.  So far they've observed nothing, last I heard." CreationDate="2010-12-17T21:12:11.200" UserId="1609" />
  <row Id="11383" PostId="7981" Text="Or about $41 for prototyping board: http://www.sparkfun.com/products/10113" CreationDate="2010-12-17T21:13:44.227" UserId="708" />
  <row Id="11384" PostId="8025" Text="&quot;the primary winding will have a higher resistance&quot;  Is that always true?  They don't necessarily have the same wire gauge.  " CreationDate="2010-12-17T21:25:11.620" UserId="142" />
  <row Id="11385" PostId="8021" Score="1" Text="How much money do you have?" CreationDate="2010-12-17T21:33:36.337" UserId="1374" />
  <row Id="11386" PostId="8025" Text="The primary winding of an N:1 transformer will have a smaller cross section and be longer, both by approximately a factor of N. So the resistance grows very roughly by the square of N." CreationDate="2010-12-17T21:36:27.243" UserId="339" />
  <row Id="11387" PostId="8025" Text="Would phase relationship have any impact if I want to connect two inner coils serially?" CreationDate="2010-12-17T22:06:32.377" UserId="1240" />
  <row Id="11388" PostId="8025" Text="@endolith: Not necessarily, but if it's a step-down transformer, the primary will probably have a higher gauge (thinner wire) than the secondary if the wire is going to be different. In a step-down, the secondary has a higher current than the primary." CreationDate="2010-12-17T22:18:13.507" UserId="638" />
  <row Id="11389" PostId="8025" Score="1" Text="@AndrejaKo: Yes, the phase will matter. If there really aren't any diagrams and you have two identical 12V secondaries, then you could hook them up &quot;backwards&quot; which would give you 0V in series. If you want to use them in series, connect the two windings in series and measure the AC voltage from end to end. If it's 24V, good! Otherwise, swap the wires of one of the secondaries." CreationDate="2010-12-17T22:24:37.537" UserId="638" />
  <row Id="11390" PostId="8025" Text="@W5VO  OK. Thanks!" CreationDate="2010-12-17T23:11:57.027" UserId="1240" />
  <row Id="11391" PostId="8008" Text="Or just implement the USB-to-serial in the PIC and not add another processor." CreationDate="2010-12-17T23:25:31.893" UserId="2157" />
  <row Id="11392" PostId="7825" Text="This has been my experience t0o. Especially true of many of the analog mux built into the PICs." CreationDate="2010-12-17T23:51:18.023" UserId="2157" />
  <row Id="11393" PostId="8027" Score="1" Text="This is for Electronic Speed Control?" CreationDate="2010-12-17T23:51:58.980" UserId="2118" />
  <row Id="11394" PostId="8027" Text="What type of motor are you wanting to drive? (I.e.: amperage, wattage.)" CreationDate="2010-12-17T23:55:42.940" UserId="2118" />
  <row Id="11396" PostId="8026" Text="[Here](http://upload.wikimedia.org/wikipedia/commons/c/cc/TSPC_FF_R.png);now we've gotten into digital logic fundamentals. ;)" CreationDate="2010-12-18T00:14:54.903" UserId="2118" />
  <row Id="11397" PostId="8038" Score="2" Text="A question on E&amp;R wouldn't be a trap. If it was, it would be edited by another member to remove the confusion. Questions have to be as clear as possible." CreationDate="2010-12-18T00:54:03.030" UserId="2118" />
  <row Id="11398" PostId="8004" Text="So, in Summary, nothing is actually wrong?" CreationDate="2010-12-18T02:02:19.767" UserId="1999" />
  <row Id="11399" PostId="7997" Text="Its the first (i.e I use one till its dead, then put the other in), but I only need to do this once every day or such." CreationDate="2010-12-18T02:06:39.217" UserId="1999" />
  <row Id="11400" PostId="7911" Text="@reemrevnivek: Given the OP wanted Java, I'd consider the Ajile part to be appropriate in that it's one of the only reasonable ways to run embedded Java (outside a full Linux OS or something). If the last paragraph and TSTIK bits weren't there I'd even upvote it." CreationDate="2010-12-18T03:26:38.967" UserId="1270" />
  <row Id="11401" PostId="8042" Text="The adapter that came with it is marked as STM-12.0/5.0-2000 and should be like this one:http://www.e-techsiliconvalley.com/store/index.php?main_page=product_info&amp;cPath=7_2817_401_341&amp;products_id=17370" CreationDate="2010-12-18T03:44:25.690" UserId="2320" />
  <row Id="11402" PostId="7976" Text="Thanks heaps. This worked for me!" CreationDate="2010-12-18T04:02:48.390" UserId="1785" />
  <row Id="11403" PostId="7976" Score="1" Text="Wouldn't that be 'Thanks stacks'? ;)" CreationDate="2010-12-18T04:09:54.493" UserId="746" />
  <row Id="11404" PostId="8004" Text="@clickUpvote, yes. Your battery is fine. Your charger is probably a cheaply engineered one." CreationDate="2010-12-18T05:07:13.470" UserId="230" />
  <row Id="11405" PostId="8039" Text="0.003 V/us slew rate.  9kHz gain-bandwidth product.   650nA is very low current, and it is impressive that it works at all, but I can't think of many applications for such a poorly-spec'ed op-amp." CreationDate="2010-12-18T05:09:06.203" UserId="411" />
  <row Id="11406" PostId="8044" Text="OK. I am wrong by assuming the ICs contains resistors inside. " CreationDate="2010-12-18T05:49:47.597" UserId="2179" />
  <row Id="11407" PostId="8042" Score="1" Text="Safe for what?  I don't think a UL certification cares at all about the actual output (other than isolation), but is more concerned that the thing can't catch fire very easily." CreationDate="2010-12-18T07:12:59.810" UserId="1407" />
  <row Id="11408" PostId="8044" Score="2" Text="ICs can contain just about whatever the designer wants.  Even little 'tuning forks' (MEMS accelerometers)." CreationDate="2010-12-18T07:14:36.810" UserId="1407" />
  <row Id="11409" PostId="8039" Score="1" Text="@mark It's terrible slew/GBP might be handy for some inherent low-pass filtering.  I can think of plenty applications for such an op-amp, likely because I've never really done a full-blown analog design, but usually signal massaging to interface with MCUs or other management ICs (power)." CreationDate="2010-12-18T07:20:33.027" UserId="1407" />
  <row Id="11410" PostId="8004" Text="@click or just lying to you somewhat.  It may be in a &quot;charge cycle&quot;, but not necessarily charging the battery." CreationDate="2010-12-18T08:09:56.023" UserId="1407" />
  <row Id="11411" PostId="7982" Text="Because I'm designing a low cost product for high volume manufacture" CreationDate="2010-12-18T08:39:10.593" UserId="566" />
  <row Id="11412" PostId="8039" Text="@markrages, Like a multimeter? That doesn't need high speed. The point is, well analog ICs don't have to consume more current than micro-controllers or other logic." CreationDate="2010-12-18T09:07:46.897" UserId="1225" />
  <row Id="11413" PostId="8047" Text="Indeed, mistaking milli for mega can make you 100,000,000x out. One example I've seen is people writing things like, PAL line time is 64uS and the clock period is 100pS etc." CreationDate="2010-12-18T09:18:02.743" UserId="1225" />
  <row Id="11414" PostId="8046" Score="4" Text="What kind of answer do you expect to this question?" CreationDate="2010-12-18T09:39:46.357" UserId="718" />
  <row Id="11415" PostId="533" Text="I posted this over 12 months ago when they still were, do you need me to delete/edit the comment to bring it up to date. It might take me a while to check every post or comment I've made on this site." CreationDate="2010-12-18T10:01:19.320" UserId="103" />
  <row Id="11416" PostId="8047" Text="Even 1,000,000,000x! :-) Luckily this is such an absurd difference that it's easy to understand what's meant." CreationDate="2010-12-18T10:02:36.823" UserId="2064" />
  <row Id="11417" PostId="8022" Text="You don't even need a current source; just a voltage source with a series limiting resistor will work." CreationDate="2010-12-18T10:03:52.097" UserId="1225" />
  <row Id="11418" PostId="8047" Text="@stevenh, of course, my error!! I use 0.01 for milli instead of the correct 0.001." CreationDate="2010-12-18T10:05:46.103" UserId="1225" />
  <row Id="11419" PostId="8046" Score="5" Text="I think this is a &quot;let go of some steam&quot; question since a lot of people really loath this kind of abuse... And the answer is &quot;since they are stupid&quot; ;)" CreationDate="2010-12-18T10:36:46.403" UserId="689" />
  <row Id="11420" PostId="8046" Text="There is also some blame to typewriter history and convention. Poor typography systems can't always provide e.g. lower case or greek symbols when needed. Writing mho and ohm are from the same, I believe. Certain people in certain cultures typically ignore correct spelling and writing rules as a rule. Today, not learning is pure stupidity." CreationDate="2010-12-18T11:14:21.830" UserId="883" />
  <row Id="11421" PostId="8042" Score="1" Text="What's required most likely entirely depends on where you live or who otherwise sets your requirements." CreationDate="2010-12-18T11:30:36.360" UserId="883" />
  <row Id="11422" PostId="8054" Text="Thanks! I like the idea with the printer! I have a bunch of broken ink jets laying around, so finally I can reuse them. Maybe just mount the whole guide rail with the motor at the bottom of the box and use the motion with a string to open the flap gate." CreationDate="2010-12-18T11:55:59.333" UserId="1957" />
  <row Id="11423" PostId="7976" Text="hahaha! True, very true. :P" CreationDate="2010-12-18T11:58:10.437" UserId="1785" />
  <row Id="11424" PostId="7975" Text="Do you have a simulator for the chip you can (step) run the code in?" CreationDate="2010-12-18T12:10:37.683" UserId="883" />
  <row Id="11425" PostId="8027" Text="@tyblu, yes electronic speed controller for RC plane sized brushless motor. (updated question to reflect)" CreationDate="2010-12-18T12:11:43.807" UserId="1756" />
  <row Id="11426" PostId="7962" Text="There's also the EZ430 RF kits. Chronos is not that good if you want to wire stuff into it as neither the base station or the watch is very open to prototyping hw. It's a nice way to try the radios, though, of course. And good value." CreationDate="2010-12-18T12:13:20.443" UserId="883" />
  <row Id="11427" PostId="7940" Text="Electric/hybrid vehicle?" CreationDate="2010-12-18T12:15:11.037" UserId="883" />
  <row Id="11428" PostId="7940" Text="@XTL, Considering that or the possibility of a DC home." CreationDate="2010-12-18T12:38:27.110" UserId="1225" />
  <row Id="11429" PostId="8037" Score="1" Text="I disagree. Resistors are used in IC design. I've seen them used in frequency compensation networks, input/output protection, op-amp circuits, and biasing circuits. The nice thing about resistors is that you (usually) don't have to bias them to work. " CreationDate="2010-12-18T14:14:44.217" UserId="638" />
  <row Id="11430" PostId="8045" Text="an example of the nmea string is below&#xA;&#xA;$GPRMC,135908.000,A,3750.8538,S,14515.4185,E,0.34,60.41,181210,,*2C&#xA;$GPRMC,135909.000,A,3750.8534,S,14515.4187,E,0.59,21.54,181210,,*29&#xA;$GPRMC,135910.000,A,3750.8530,S,14515.4189,E,0.56,15.31,181210,,*20&#xA;$GPRMC,135911.000,A,3750.8531,S,14515.4187,E,0.09,89.37,181210,,*27&#xA;" CreationDate="2010-12-18T14:19:00.633" UserId="2321" />
  <row Id="11431" PostId="8033" Text="That MikroKopter link is pretty slick. The bare PCB price is reasonable, but the shipping is pretty high. The US site has the ESC assembled... not sure if that's defeating the purpose of your question..." CreationDate="2010-12-18T14:44:29.140" UserId="638" />
  <row Id="11432" PostId="8037" Text="@W5VO, I forgot about that. I've even implemented them myself in a fab on a simple IC wafer. :P" CreationDate="2010-12-18T14:59:18.580" UserId="2118" />
  <row Id="11433" PostId="8060" Text="Your specs do not have span adjustment. Is there a typo?" CreationDate="2010-12-18T15:16:19.157" UserId="2118" />
  <row Id="11434" PostId="8062" Score="2" Text="-1. Sorry, krapht, but this isn't helpful if Mokhtar doesn't have the book, and you can't presume he does." CreationDate="2010-12-18T15:33:23.137" UserId="2064" />
  <row Id="11435" PostId="8034" Score="1" Text="@xport, in digital clocked circuits the resistance of the mosfet's dissipate the power. it is not resistors that dissipate power, it is resistance. So a resistor theoretically is completely a resistive device, and I understand why you want to remove them, but when CMOS switches it has to discharge caps, and the mos absorbs the charge difference." CreationDate="2010-12-18T16:05:42.313" UserId="230" />
  <row Id="11436" PostId="8061" Text="+1 for the link. (I'm still reading the document)" CreationDate="2010-12-18T16:09:54.557" UserId="2064" />
  <row Id="11437" PostId="8062" Text="@krapht can you provide a link, I found multiple copies of the book online for free, but the author and book varied. I guessed you meant http://www.google.com/url?sa=t&amp;source=web&amp;cd=2&amp;ved=0CCsQFjAB&amp;url=http%3A%2F%2Fwww.analog.com%2Flibrary%2Fanalogdialogue%2Farchives%2F39-05%2Fop_amp_applications_handbook.html&amp;rct=j&amp;q=Handbook%20of%20Operational%20Amplifier%20Applications&amp;ei=aeMMTfGECcWblgewk9nZCw&amp;usg=AFQjCNH3hH0MS7N0aIPiBe5-xLk-HHcDLQ&amp;sig2=85e8mycI-xpOWpx9WcYhKA&amp;cad=rja" CreationDate="2010-12-18T16:41:25.650" UserId="230" />
  <row Id="11439" PostId="8064" Score="3" Text="Power dissipation in a diode chain is equal to any resistor it would replace. We simply can't get away from `P = I*V`. :(" CreationDate="2010-12-18T17:06:27.003" UserId="2118" />
  <row Id="11440" PostId="8054" Text="+Inf: &quot;...answering them in a straightforward way will keep you from learning how to do it yourself, which is presumably why you're going to college in the first place.&quot;" CreationDate="2010-12-18T17:12:55.563" UserId="2118" />
  <row Id="11441" PostId="8064" Text="Perhaps you could divide voltage with an electron gun, deflector magnets 1 (or more) grids and one ground behind it. What efficiencies do HV CR tubes run at?" CreationDate="2010-12-18T17:17:07.070" UserId="2326" />
  <row Id="11442" PostId="8062" Text="Ah, with the link in your answer it's completely different. When I saw the title of the book I was rather thinking of Amazon than a freely downloadable document. And _that_ wouldn't have been helpful. Point restored." CreationDate="2010-12-18T17:40:25.653" UserId="2064" />
  <row Id="11443" PostId="8061" Text="That's a pretty good read for the fractional N system. I didn't know that's how it worked. Thanks!" CreationDate="2010-12-18T17:42:17.717" UserId="638" />
  <row Id="11444" PostId="7955" Text="Do you know what the restrictions for the Light version are?" CreationDate="2010-12-18T18:03:31.873" UserId="2064" />
  <row Id="11445" PostId="7955" Text="@stevenh, I think it's only double-sided, 100x160mm. That's from memory 1.5yr ago, so it may be different now." CreationDate="2010-12-18T18:06:45.787" UserId="2118" />
  <row Id="11446" PostId="8045" Text="@Nathan: From the linked webpage, and from a brief look at the data, `RMC` (Recommended Minimum) sentences don't appear to contain altitude information.  `GGA` (Fix info) and other proprietary sentences have it.  I'm guessing that you need to request specific info from the GPS receiver (don't know part number so I can't look it up)." CreationDate="2010-12-18T18:28:12.120" UserId="1407" />
  <row Id="11447" PostId="8062" Text="@stevenvh, I thought I had remembered it as a free-book i had seen before, so I decided I should step in." CreationDate="2010-12-18T18:36:38.950" UserId="230" />
  <row Id="11448" PostId="8064" Text="@dannyStaple, all output devices have some method of absorbing power, otherwise they could not output." CreationDate="2010-12-18T18:59:49.127" UserId="230" />
  <row Id="11449" PostId="7855" Text="Unfortunately we could not test it, so I left the board at my colleague and he will continue the attempts for a while." CreationDate="2010-12-18T19:09:38.227" UserId="1649" />
  <row Id="11450" PostId="8060" Score="6" Text="This smells a bit like homework... ?" CreationDate="2010-12-18T19:30:07.907" UserId="1448" />
  <row Id="11454" PostId="8068" Score="1" Text="Are you sure it's SSOP? .65mm pitch?" CreationDate="2010-12-18T22:14:25.557" UserId="2118" />
  <row Id="11456" PostId="8068" Text="What is the device?" CreationDate="2010-12-18T22:37:31.837" UserId="305" />
  <row Id="11457" PostId="8068" Text="Common package dimensions [here](http://www.national.com/packaging/parts/). Sounds like [TSSOP](http://www.national.com/packaging/mkt/mtc24.pdf). " CreationDate="2010-12-18T22:40:24.413" UserId="2118" />
  <row Id="11460" PostId="8060" Score="3" Text="@marcus, no rule against homework, we should just avoid giving out solutions directly." CreationDate="2010-12-19T00:07:43.783" UserId="230" />
  <row Id="11461" PostId="8058" Text="I understand how 45 degrees is better than 90 degrees, but I meant to ask why it's still used in preference to arbitrary angles and curves." CreationDate="2010-12-19T00:18:17.377" UserId="1951" />
  <row Id="11462" PostId="7918" Text="Accepted. For the record, TopoR claims to be able to push groups of traces better than standard tools do - although I haven't tried myself. I take your point that it's harder to program arbitrary angle autorouters, but people have done much harder things... there just isn't enough demand for this somehow (and I still don't know why :D)." CreationDate="2010-12-19T00:20:59.353" UserId="1951" />
  <row Id="11463" PostId="8015" Text="@PF4Public, The title &quot;Raise/Fall sense&quot; is a little vague. Perhaps incorporate some of [ *Fake Name's* previous edits](http://electronics.stackexchange.com/posts/8015/revisions) into the current version. Different MCUs (microcontrollers) will detect edges in various ways, not excluding any of those used in other ICs. You won't be able to copy their methods exactly using discrete components, but you can come close (or *mimic*)." CreationDate="2010-12-19T00:40:11.860" UserId="2118" />
  <row Id="11464" PostId="8015" Text="But &quot;Integrated Circuit&quot; - is just like usual circuit, except it's extremely compact - &quot;Integrated&quot;. So it employs usual elements with slightly different parameters. Well, until you're looking deep inside at microscopic effects. I agree, the title is not just &quot;little vague&quot; - it ambiguous :( I'm thinking about better replace." CreationDate="2010-12-19T00:48:43.310" UserId="1651" />
  <row Id="11465" PostId="7962" Text="TI have also recently released their low power bluetooth parts, CC2540.  A dev kit is also available." CreationDate="2010-12-19T01:24:03.087" UserId="2308" />
  <row Id="11466" PostId="8068" Text="Thanks.  The data sheets says SSOP, .650 spaced lands with nominal 5.3mm spcing for the centres of the lands. Silicon labs si4734/35. http://www.sparkfun.com/datasheets/Components/General/Si4734-35-C40.pdf" CreationDate="2010-12-19T01:47:04.563" UserId="2327" />
  <row Id="11467" PostId="7962" Text="@AustinPhillips, I hope to play with them soon." CreationDate="2010-12-19T03:27:47.143" UserId="230" />
  <row Id="11468" PostId="8073" Text="Thanks, they like they will do.  I looked at the sparkfun ones, but the rows looked a little far apart, as did others I'd found." CreationDate="2010-12-19T04:39:35.737" UserId="2327" />
  <row Id="11470" PostId="7918" Text="Also, I've tried the TopoR demo, and it feels *very* &quot;alpha&quot; to me. The interface is very clumsy." CreationDate="2010-12-19T04:54:32.620" UserId="1374" />
  <row Id="11471" PostId="8015" Text="You rolled back all my clarifications: **MCUs are a type of IC**, edge-trigging is used in all of them. Furthermore, sense is a very inaccurate description. The term &quot;Edge-Triggering&quot; **specifically refers** to exactly what you are describing. It is **the correct term** for what you are asking about." CreationDate="2010-12-19T05:01:31.113" UserId="1374" />
  <row Id="11472" PostId="8015" Text="@&quot;But &quot;Integrated Circuit&quot; - is just like usual circuit, except it's extremely compact&quot; - Well, what do you think MCUs are made of? Pixie dust and ground up unicorns?" CreationDate="2010-12-19T05:15:16.150" UserId="1374" />
  <row Id="11473" PostId="8015" Text="@inaccurate - &quot;The exact point of transition start, transition end and the intermediate state.&quot; Logic compares two values. The question is to find out dV/dt - it's not logical job. Is there any difference: V1==V2 and dV/dt&gt;0?    &#xA;@MCU vs IC - doesn't matter, but if you insist. This way better?" CreationDate="2010-12-19T06:42:44.943" UserId="1651" />
  <row Id="11474" PostId="8040" Text="*not have an &quot;intermediate state&quot;*. My question demands to feel that state, notice that at last." CreationDate="2010-12-19T06:47:38.093" UserId="1651" />
  <row Id="11475" PostId="8062" Text="Thanks  Kortuk,  Marcus Lindblom, stevenvh, and tyblu for your efforts. It looks the propsal of stevenvh is more likely what I required but how to limit the output of the sensors 0-5 V. I think you required the complete senario. " CreationDate="2010-12-19T10:33:51.027" UserId="2325" />
  <row Id="11476" PostId="8066" Text="xxx Petroleum company required a circuit for the boiler control system which needs the average temperature from four locations. The temperature sensors make the temperature information available as voltage V1, V2, V3, and V4. Develop an operational amplifier circuit to measure avarage temperature with following specification: 1) The output voltage range of each sensor is 0-5 V. 2) The output range of average temperature meassurement circuit is 0-5 v. 3) The span adjustment range is +/- 1 v and zero adjustment range is =/- 1 v. 4) Total system accuracywith +/-0.1% of FSO." CreationDate="2010-12-19T10:49:10.463" UserId="2325" />
  <row Id="11477" PostId="8063" Text="Thanks Kortuk, Marcus Lindblom, stevenvh, and tyblu for your efforts. It looks the propsal of stevenvh is more likely what I required but how to limit the output of the sensors 0-5 V. I think you required the complete senario. " CreationDate="2010-12-19T10:49:37.187" UserId="2325" />
  <row Id="11478" PostId="8060" Text="@Kortuk: That's what I meant. :)" CreationDate="2010-12-19T11:18:15.323" UserId="1448" />
  <row Id="11482" PostId="8054" Text="Nope, this is not why I go to college in first place as this part of the project has nothing to do with my major nor my minor. I just need to solve the problem." CreationDate="2010-12-19T12:42:32.533" UserId="1957" />
  <row Id="11486" PostId="8077" Text="Thats strange. Are there different versions of the parallax ping hardware? should the room be quiet? does ambient noise count?" CreationDate="2010-12-19T15:23:26.577" UserId="2331" />
  <row Id="11487" PostId="8063" Text="@Mokhtar, There are a few ways to limit a node to a specific voltage range, each with advantages and disadvantages. Why not open a new question to get some complete answers?" CreationDate="2010-12-19T15:36:48.473" UserId="2118" />
  <row Id="11488" PostId="8060" Text="@marusLindblom, I only posted that because someone down-voted the question." CreationDate="2010-12-19T15:38:56.850" UserId="230" />
  <row Id="11489" PostId="8060" Text="@Kortuk: It's just good to tag as homework so the answers can adjust!" CreationDate="2010-12-19T15:43:21.980" UserId="689" />
  <row Id="11490" PostId="8054" Text="Interesting! If you don't mind explaining a little, what are you trying to do with the ice cubes? Some kind of science experiment? Something artistic?" CreationDate="2010-12-19T15:53:21.150" UserId="712" />
  <row Id="11492" PostId="8054" Text="It's both - the result will be an artistic installation with all the other student projects. The installation is about the various states of water and the process while transforming from one to another." CreationDate="2010-12-19T16:51:49.420" UserId="1957" />
  <row Id="11493" PostId="8040" Text="@FakeName, I would call an MCU the opposite of specialty IC. You make an IC that can be programmed to do many different things so that the company can fabricate one chip for many many different applications. " CreationDate="2010-12-19T16:55:45.940" UserId="230" />
  <row Id="11498" PostId="8034" Score="1" Text="sounds like your after perfect efficiency or something.  Your missing that all components have resistance and dissipated power, transistors, capacitors, inductors, etc." CreationDate="2010-12-19T17:21:39.827" UserId="1438" />
  <row Id="11499" PostId="8060" Score="1" Text="@Mokhtar, Read through [this link: SO: How to ask and answer homework questions?](http://meta.stackoverflow.com/questions/10811/how-to-ask-and-answer-homework-questions). It should help you better define your questions in the future." CreationDate="2010-12-19T17:22:07.010" UserId="2118" />
  <row Id="11500" PostId="8042" Text="I live in the US. Not sure which rules apply though. I mentioned EU certification because that tends to be tougher, so I wouldn't care if it had EU certification but not US certification." CreationDate="2010-12-19T17:36:07.963" UserId="2320" />
  <row Id="11501" PostId="8051" Score="1" Text="@Thomas:by UL I meant electrical certification... UL, ETL or some other company." CreationDate="2010-12-19T17:38:20.910" UserId="2320" />
  <row Id="11502" PostId="8079" Text="Ah, I forgot, I did use 120ohm terminal resistance." CreationDate="2010-12-19T17:49:16.443" UserId="1200" />
  <row Id="11503" PostId="8051" Text="@Thomas:&#xA;Yes, the adapter plugs into a 110V line. It converts 110 V AC to 12V and 5V DC.&#xA;&#xA;Some say electrical certification is necessary (http://www.thetestlab.com/pdf/pce1099.pdf):&#xA;Electrical and electronic items sold within the United States must meet the US National Electrical Code (NEC) as well as various city, country and state electrical codes. In order to comply with these codes, electrical and electronic products must be &quot;listed&quot; as being compliant by an &quot;authority having jurisdiction to identify a listed product&quot;." CreationDate="2010-12-19T17:52:09.497" UserId="2320" />
  <row Id="11504" PostId="8051" Text="others seem to indicate it is not:&#xA;http://www.sensorcentral.com/worldsupport/standards03.php&#xA;&#xA;&quot;Although adopting the UL certification system is basically on a voluntary basis, many U.S.-made electrical appliances have obtained the certification.&quot;" CreationDate="2010-12-19T17:53:06.203" UserId="2320" />
  <row Id="11505" PostId="8078" Text="What's the baud rate? When you say it works for a 6V battery but not 12V, you are using a regulator down to 5V, right? Can you use an oscilloscope to look at the waveforms?" CreationDate="2010-12-19T17:56:53.977" UserId="638" />
  <row Id="11506" PostId="8051" Score="1" Text="and others seem to suggest that the US National Electrical Code (NEC) and the Occupational Safety and Health Act (OSHA Article 29 CFR 1910.xxx; CFR: Code of Federal Regulations) require that &quot;all electrically controlled devices or systems in the USA must be approved&quot; but at the same time &quot; there is no law which makes UL certification mandatory&quot; (http://www.festo.com/cms/nl-be_be/9836.htm)" CreationDate="2010-12-19T17:59:24.810" UserId="2320" />
  <row Id="11507" PostId="8078" Text="I am using a 5v regulator, the input to the regulator varies. No I do not have an oscilloscope at hand. The baud rate is 9600" CreationDate="2010-12-19T18:00:13.320" UserId="1200" />
  <row Id="11508" PostId="8001" Score="2" Text="@vicatu: It may be simple to YOU, but everyone has to start somewhere - and the best start anyone interested in a subject can make is to ask questions." CreationDate="2010-12-19T18:21:17.753" UserId="1750" />
  <row Id="11509" PostId="8051" Text="@Thomas: Can you elaborate on FCC certification?" CreationDate="2010-12-19T18:28:27.263" UserId="2320" />
  <row Id="11510" PostId="8078" Score="1" Text="@Rick_2047, Time to needle the boss for an o'scope! It really helps to be able to send `UUUU...` and verify baud-rate, slew-rate, ringing, etc." CreationDate="2010-12-19T18:43:34.553" UserId="2118" />
  <row Id="11511" PostId="8081" Text="Wow this is nice, (I heard from the other developer who is working the graveyard shift that the problem is solved with more delays inserted). BTW my prescale was 256 and 1024 (tested both) on a 7.something something type xtal (don't remember the exact number)." CreationDate="2010-12-19T18:43:36.450" UserId="1200" />
  <row Id="11512" PostId="8081" Text="@tyblu A newbie comment, but how do we know that CAT5 cable is shielded?" CreationDate="2010-12-19T18:44:13.937" UserId="1240" />
  <row Id="11513" PostId="8080" Text="With bad time between messages it will mess up your filtering. Jitter is the end of all excellently designed digital filters." CreationDate="2010-12-19T18:46:47.587" UserId="230" />
  <row Id="11514" PostId="8078" Score="1" Text="@tyblu, do you know the funny thing? we also manufacture an oscilloscope for kids. It hurts I know." CreationDate="2010-12-19T18:46:55.073" UserId="1200" />
  <row Id="11515" PostId="8081" Text="@AndrejaKo, to tell you the truth, I just assumed it all was, since any 5e cable I've stripped has had the sheath - [but now I see that you can get unshielded CAT5](http://en.wikipedia.org/wiki/Category_5_cable). 'Suppose you had best simply check!" CreationDate="2010-12-19T18:51:09.757" UserId="2118" />
  <row Id="11516" PostId="8081" Text="@tyblu OK. Thank you for clarifying that. I thought that there could be some other way to remotely identify if cable is shielded or not. " CreationDate="2010-12-19T18:53:40.983" UserId="1240" />
  <row Id="11517" PostId="8082" Text="http://electronics.stackexchange.com/questions/4287/i-understand-arduino-now-what might help. Not really an answer." CreationDate="2010-12-19T19:15:55.827" UserId="230" />
  <row Id="11518" PostId="8082" Score="2" Text="Are you going to have much time for hobby circuitry? I certainly didn't. Make sure you don't compromise your studies, even though I agree that a *hands-on* approach is a better way to learn, it can't keep up to the fast pace of many classes." CreationDate="2010-12-19T20:07:28.410" UserId="2118" />
  <row Id="11519" PostId="8037" Text="resistors are heavily used in ICs, mainly in analog and quasi analog circuits (like ESD protection)" CreationDate="2010-12-19T20:16:17.157" UserId="1471" />
  <row Id="11521" PostId="8084" Text="Thanks! For some reason I wasn't thinking about this in the right mindset." CreationDate="2010-12-19T21:34:28.793" UserId="319" />
  <row Id="11522" PostId="8048" Text="@shashtastic interesting, can you elaborate on your claim that it is more accurate than a 4-wire measurement?" CreationDate="2010-12-19T23:29:22.023" UserId="771" />
  <row Id="11523" PostId="8077" Text="ambient noise should not affect it and I don't think that there are different versions.  Have you tried another pin on the arduino?" CreationDate="2010-12-20T00:10:45.277" UserId="2060" />
  <row Id="11524" PostId="8077" Text="I've tried almost all the digital pins on the arduino...is there an alternative for analog? or is the ping digital pin only? Thanks again" CreationDate="2010-12-20T01:15:54.047" UserId="2331" />
  <row Id="11525" PostId="8089" Text="You're incorrect.  An MMU allows you to interface with external memory (likely more than the 4kB on the PIC).  There is very little difference in dynamic and static allocation with and without an MMU.  Once you start getting into virtual memory, there's a difference, but that's only tangentially related to malloc." CreationDate="2010-12-20T01:37:28.960" UserId="857" />
  <row Id="11526" PostId="8088" Text="Fixed that for you.  Welcome to the site! " CreationDate="2010-12-20T01:42:11.997" UserId="857" />
  <row Id="11527" PostId="8044" Text="@xport, no you're not. Many ICs include resistors, made by long, thin, winding traces with a small resistance.  This technique takes a lot of space on the die, so it's only used for small value resistances (&lt;&lt;100k), but it's possible.  Mark is stating that *some* digital ICs consist only of transistors, not that it's the rule or even the norm." CreationDate="2010-12-20T02:03:26.957" UserId="857" />
  <row Id="11528" PostId="8092" Score="1" Text="Different fab houses will specify number of decimal places, too. I've never thought of that as a grid, but I guess that's basically what it is. I'm used to &quot;6 decimals&quot;." CreationDate="2010-12-20T02:48:43.267" UserId="2118" />
  <row Id="11529" PostId="8077" Text="the Ping is digital. Is the activity light turning on when sending a signal? I can double check your code tomorrow and hook it up to my ping and arduino." CreationDate="2010-12-20T03:57:21.797" UserId="2060" />
  <row Id="11530" PostId="8077" Text="The parallax light? Yeah, I think the green light turns on everytime a reading or pulse is done. I doubt its the code because the reading is the same even if there are objects or no objects infront of it" CreationDate="2010-12-20T06:16:54.267" UserId="2331" />
  <row Id="11531" PostId="8064" Text="Well yes - but those output devices could absorb power while doing work of some kind.. That is the point." CreationDate="2010-12-20T07:29:48.400" UserId="2326" />
  <row Id="11532" PostId="8040" Text="A MCU is a specialty IC which implements a very complicated, specialty logic system which, when fed specific sequences of bits, can do many different things. It's still very specialized, and very much an IC. The *applications* may be general in nature, but the hardware is specialized." CreationDate="2010-12-20T08:24:40.563" UserId="1374" />
  <row Id="11533" PostId="8015" Text="Logic, as implemented in just about everything, is fundamentally analog. However, under certain circumstances, much of the analog nature can be simplified away. When I say logic, I am not referring to the simplified version." CreationDate="2010-12-20T08:27:13.463" UserId="1374" />
  <row Id="11534" PostId="8015" Text="It seems to me that we have a language gap here. Reading your comments, are you trying to ask what happens with logic devices when you have a very slowly transitioning, or even static intermediate signal on an input to a logic gate?" CreationDate="2010-12-20T08:28:23.133" UserId="1374" />
  <row Id="11535" PostId="8092" Text="PCB, the tool I am using, exports to 1/100th of a mil, or 1/100000th of an inch." CreationDate="2010-12-20T11:18:13.017" UserId="1225" />
  <row Id="11536" PostId="8083" Text="good advice. thank you." CreationDate="2010-12-20T11:48:16.537" UserId="2332" />
  <row Id="11537" PostId="8087" Text="You definitely understood what I meant by &quot;Playing with oscilloscopes&quot;. And there are some digital electronics courses at my school. In fact, we were required to take a basic digital circuits course at the start of the 1st year, but at this point (mid-way through the 2nd year) we haven't had any other digital electronics courses. However, from what you're mentioned, it looks like digital is where I want to go.  thank you, very much." CreationDate="2010-12-20T11:55:09.523" UserId="2332" />
  <row Id="11538" PostId="8095" Text="I twisted the leads and solder after that, so soldering is fine. Also, my continuity test says so." CreationDate="2010-12-20T12:11:36.377" UserId="1240" />
  <row Id="11539" PostId="8095" Score="3" Text="@AndrejaKo, Note that continuity test will often pass despite cracked or 'lifted' (poor trace contact) solder joints, and leads to horrible pseudo-random types of faults. Won't happen in this case, since you soldered after bending, but good to know!" CreationDate="2010-12-20T13:58:58.453" UserId="2118" />
  <row Id="11540" PostId="8044" Score="1" Text="@markrages, when a digital IC is clocked, and state changes, you dissipate power stored in capacitors through the NMOS." CreationDate="2010-12-20T14:01:32.533" UserId="230" />
  <row Id="11541" PostId="8093" Text="I love your question, I am not a controls guy(been 3 years since I took the class), if you break up your question just a little so that it is not one large paragraph it improves the number of people whom read it. This is just a suggestion, I read it, and it seems at least 3 others have." CreationDate="2010-12-20T14:50:24.383" UserId="230" />
  <row Id="11542" PostId="8034" Score="2" Text="Don't think of it as wasted energy.  It's just supplementing your home's heating!" CreationDate="2010-12-20T14:54:17.937" UserId="142" />
  <row Id="11543" PostId="8100" Text="500 Hz to 5000 kHz is 1 *decade*, not octave (would be 500-1000)" CreationDate="2010-12-20T15:13:39.750" UserId="1407" />
  <row Id="11544" PostId="8100" Text="Opps it's 20db per decade 6db per octave, changed it." CreationDate="2010-12-20T15:23:04.343" UserId="319" />
  <row Id="11545" PostId="8097" Text="I don't think your BPM detection is going to work very well.  You should try simulating it on a computer first.  " CreationDate="2010-12-20T15:49:14.597" UserId="142" />
  <row Id="11546" PostId="8106" Text="Yeah just for playing really." CreationDate="2010-12-20T15:56:00.200" UserId="1623" />
  <row Id="11547" PostId="8097" Text="I hadn't thought of that but it'd be easy to do, good tip." CreationDate="2010-12-20T16:22:35.987" UserId="1633" />
  <row Id="11548" PostId="8100" Text="I did read the Wikipedia entry, but it does get very theoretical very quickly which I find clouds my practical understanding. Do op-amp low pass filters exist as discrete parts or do I have to make my own?" CreationDate="2010-12-20T16:26:28.367" UserId="1633" />
  <row Id="11549" PostId="8101" Text="Derp. I completely misread the frequency graph I made, I'm looking more at 50-60 Hz. Maybe I want a band pass filter instead?" CreationDate="2010-12-20T16:35:25.737" UserId="1633" />
  <row Id="11550" PostId="8044" Text="@Kortuk I typo'ed my answer to say the opposite of what I meant.  Fixed now." CreationDate="2010-12-20T16:45:34.083" UserId="411" />
  <row Id="11551" PostId="8044" Text="@Markrages, I was 99% sure you had typed the opposite of what your head said, but I did not feel comfortable editing it for you. Glad to see it is fixed, +1 time." CreationDate="2010-12-20T16:46:48.620" UserId="230" />
  <row Id="11553" PostId="8095" Text="It is also possible to crack the case by bending leads (tubes, ceramic caps especially) but I think the L200 and other IC's can take considerable abuse without damage." CreationDate="2010-12-20T17:13:47.120" UserId="883" />
  <row Id="11554" PostId="8015" Text="&quot;are you trying to ask...&quot; - No." CreationDate="2010-12-20T17:57:22.343" UserId="1651" />
  <row Id="11555" PostId="8107" Text="Why are smaller gerber files better than larger ones?" CreationDate="2010-12-20T18:18:57.167" UserId="2118" />
  <row Id="11556" PostId="8101" Text="@Rob, a low-pass filter would be fine.  Audio will already be bandlimited to 20-20k.  Added some more to my answer as well" CreationDate="2010-12-20T18:26:08.660" UserId="1407" />
  <row Id="11557" PostId="8110" Text="As an extension to this, if one doesn't know what XTAL to use in their widget, don't select one at all. Just leave the PCB spot unpopulated and wait 'til you need the stability (calibration of internal RC oscillator isn't good enough at the desired baud rate, for example) or speed. Don't fix what ain't broke!" CreationDate="2010-12-20T18:33:41.680" UserId="2118" />
  <row Id="11558" PostId="8110" Text="Agreed - if your MCU has an internal oscillator, try and use that first. Make sure to set config words/fuses correctly. Also, you should consider using a socket on your PCB so you don't have to deal with soldering/desoldering crystals... bonus is that you can swap them easily." CreationDate="2010-12-20T18:39:11.337" UserId="2344" />
  <row Id="11559" PostId="8110" Text="@isaac, a crystal is one of the largest sources of EMI on a board, it should be as close to the ground plane as possible, not go through connectors, and have shield traces around it." CreationDate="2010-12-20T19:09:37.687" UserId="230" />
  <row Id="11560" PostId="8110" Text="@isaac, also, if you have 10ppm clock drift it will not matter what crystal speed you have. They all will divide down to the same potential error, as a higher speed clock must have a larger divide. A slower crystal means worse resolution on other things." CreationDate="2010-12-20T19:10:50.743" UserId="230" />
  <row Id="11561" PostId="7526" Text="Can you clarify what you mean by holding a rail captive? I'm having a hard time picturing a lego construction that could follow a rail and provide support for a kilogram of load." CreationDate="2010-12-20T19:22:48.583" UserId="2172" />
  <row Id="11562" PostId="8113" Text="What power supply would you suggest instead? -- I'm curious to know what you would suggest as a good power supply for using during development as well." CreationDate="2010-12-20T19:23:26.557" UserId="2172" />
  <row Id="11563" PostId="7526" Text="@Isaac: My link was just for wheels, not really Legos." CreationDate="2010-12-20T19:31:46.420" UserId="1407" />
  <row Id="11564" PostId="8113" Score="3" Text="Four AA cells would be a lot better, with an LDO if you need 5V. I use a bench power supply for development." CreationDate="2010-12-20T19:40:46.377" UserId="305" />
  <row Id="11565" PostId="7505" Text="Is this going to be strictly linear (no curves/bends)?  Do you care where the drive mechanism is--on car vs. track?  What sort of budget?" CreationDate="2010-12-20T19:45:59.993" UserId="1407" />
  <row Id="11566" PostId="8113" Score="2" Text="@Issac Sutherland, [AA batteries](http://data.energizer.com/PDFs/E91.pdf) are simply better batteries than [9V cells](http://data.energizer.com/PDFs/522.pdf). A boost regulator would allow you to follow a &quot;constant power performance&quot; curve on a battery datasheet and drain it to just over 1V/battery (fully drained), whereas a linear regulator would follow a &quot;constant current performance&quot; curve and drain each to ~5.35V/#batteries (best for 5+ AA's). You have to run the numbers to figure out for sure which solution is best, but it's usually the switcher that comes out on top." CreationDate="2010-12-20T20:21:45.690" UserId="2118" />
  <row Id="11567" PostId="8104" Score="2" Text="I would qualify &quot;unsupported&quot; as &quot;unsupported by Atmel&quot; - there is a vast and growing community of Arduino users, not to mention the extensive resources available at http://www.arduino.cc/" CreationDate="2010-12-20T20:32:06.833" UserId="771" />
  <row Id="11568" PostId="8106" Text="@Dave I agree about the IDE quirks. Developing avr-gcc in eclipse makes programming a lot less painful. Ctrl-space auto-completion in particular is missing in my opinion." CreationDate="2010-12-20T20:34:36.527" UserId="771" />
  <row Id="11569" PostId="8099" Text="with great care... :)" CreationDate="2010-12-20T20:37:46.773" UserId="771" />
  <row Id="11570" PostId="8113" Text="a 9V battery isn't a bad choice in terms of physical size if you can live with the inferior mAh they tend to provide." CreationDate="2010-12-20T20:39:21.760" UserId="771" />
  <row Id="11571" PostId="8106" Text="Arduino has an IDE? lol." CreationDate="2010-12-20T21:00:01.490" UserId="1407" />
  <row Id="11572" PostId="8050" Text="Three hours at 1 cube a minute is 180 ice cubes.  Figuring out how to squeeze them in a shoe box in a way that they are dispensable and not going to freeze together is going to be rather tricky.  I think you need to figure out a plausible mechanical design before anything else." CreationDate="2010-12-20T21:04:38.727" UserId="2246" />
  <row Id="11573" PostId="8110" Text="@isaac I have never had issues with 40MHz crystals before. I just stick them as close to the micro as I can. and @kortuk response is the same reason why I didn't think clock drift was an issue. I figured higher clock speeds would let me able to get closer to 1 ms exactly." CreationDate="2010-12-20T21:09:42.700" UserId="319" />
  <row Id="11575" PostId="8106" Score="1" Text="@Nick: haha, yeah more like Notepad with a different skin." CreationDate="2010-12-20T21:17:25.680" UserId="2288" />
  <row Id="11576" PostId="8034" Text="Removing (refunding) bounty at request of @Kortuk ♦ ; I'm relying on his judgement here, as I'm not qualified to judge the merits here..." CreationDate="2010-12-20T21:18:02.607" UserId="2166" />
  <row Id="11577" PostId="8117" Score="3" Text="If the micro ever went to sleep, the sudden drop in current would cause the voltage to easily rise over 5 V." CreationDate="2010-12-20T21:20:31.770" UserId="1407" />
  <row Id="11578" PostId="8034" Text="@xport, I have closed this question, almost every answer is reading it in a completely  way. You clearly have something you are looking for in the answer, but right now it is not clear enough. If you can clean it up and make the point more clear I would suggest a new question as this has many answers that will probably not help." CreationDate="2010-12-20T21:21:03.610" UserId="230" />
  <row Id="11579" PostId="8117" Score="1" Text="You can use combinations of LEDs, too, if you can't quite get the right number with typical silicon diodes. For example, you can use a red ~1.7V drop LED to get 3.3V from 5V. This also removes some of the heat dissipation." CreationDate="2010-12-20T21:21:56.060" UserId="2118" />
  <row Id="11580" PostId="8034" Text="@MarcGravell, thank you, @community, the revoking bounty got moved to dev only somehow, so I had to ask Marc to help me out." CreationDate="2010-12-20T21:22:12.597" UserId="230" />
  <row Id="11581" PostId="8118" Text="+1 for the *best* solution." CreationDate="2010-12-20T21:24:12.220" UserId="2118" />
  <row Id="11582" PostId="8117" Score="2" Text="This is not the right way to do it: the voltage will vary widely with load, temperature and supply input." CreationDate="2010-12-20T21:26:10.933" UserId="1225" />
  <row Id="11583" PostId="8117" Score="1" Text="@Thomas I agree, it's not the *right* way to do it, but it is *a* way to do it in principle under some constrained contexts." CreationDate="2010-12-20T21:31:00.743" UserId="771" />
  <row Id="11584" PostId="8117" Score="1" Text="I think it's a reliable and simple way of accomplishing a task, and not one I'd shy away from. So long as you have a minimum load, it'll be &quot;good enough&quot;." CreationDate="2010-12-20T21:33:33.023" UserId="2118" />
  <row Id="11585" PostId="8118" Text="yea this is almost certainly the way to go, on the other hand the QA is asking specifically about using a 9V battery..." CreationDate="2010-12-20T21:34:31.677" UserId="771" />
  <row Id="11586" PostId="8117" Score="2" Text="If you really want to use series diodes, a single zener would be a better choice in terms of load regulation and temperature.  It wouldn't help with line regulation. Nick T's caution is important, though." CreationDate="2010-12-20T21:57:33.087" UserId="857" />
  <row Id="11587" PostId="8113" Score="1" Text="A 7805 (as shown in Dean's answer) is simpler because it doesn't require any resistors. " CreationDate="2010-12-20T21:58:54.693" UserId="857" />
  <row Id="11588" PostId="8104" Text="@vicatcu, unsupported implies by the company, it might be worth adding that there is a large community, but there is not a team of applications engineers waiting for your call, which is what a company normally requires in support." CreationDate="2010-12-20T22:02:35.133" UserId="230" />
  <row Id="11589" PostId="8095" Text="I finally managed to get the circuit working, and the chip seems undamaged." CreationDate="2010-12-20T22:02:35.453" UserId="1240" />
  <row Id="11590" PostId="8097" Score="1" Text="@Robert Atkins - You can do it with LTspice.  Save your audio file as a WAV file, and point a voltage source in your schematic at this file.  Simulation will take a LONG time, probably at least 4x the length of your audio file.  However, this is still quite speedy compared with the &quot;build/code/compile/program/test&quot; sequence." CreationDate="2010-12-20T22:02:57.810" UserId="857" />
  <row Id="11591" PostId="8117" Score="1" Text="If you're going to do it this way, you might as well use a single zener diode." CreationDate="2010-12-20T22:10:44.547" UserId="1225" />
  <row Id="11592" PostId="8116" Text="Most compilers and assemblers insert a reset type instruction after main finishes anyway, causing main to effectively run in an infinite loop - like running setup() then loop() once and then going back to the start." CreationDate="2010-12-20T22:13:56.963" UserId="1225" />
  <row Id="11593" PostId="8100" Text="@Robert - You can buy them as discrete parts, but it will probably be better for this special purpose just to make your own.  Op amps come in (mostly) single, dual, or quad packages.  You need to put in the capacitors and resistors to make a filter, and don't forget to power the opamp." CreationDate="2010-12-20T22:14:38.380" UserId="857" />
  <row Id="11594" PostId="8116" Text="@vic, the main problem I have with the &quot;Arduino system&quot; is that once you grow beyond a single user module it's nauseating to manage as it just dumps all the code into a single file, so you can't hide anything.  You can use normal files and `#include`, but if you bring them into the IDE it fails miserably.  @Thom, not that one should ever relinquish control to...whatever is after `main` in an embedded system...but I'd expect the micro to just wait until it gets a reset or some interrupt." CreationDate="2010-12-20T22:24:35.240" UserId="1407" />
  <row Id="11595" PostId="8123" Text="High frequency can you explain that term please." CreationDate="2010-12-20T23:04:54.393" UserId="1623" />
  <row Id="11596" PostId="8123" Score="1" Text="@dean, bluetooth uses 2.4GHz frequency power. If you were powering this circuit you would want decade caps to ensure you stop power from radiating over traces at that frequency." CreationDate="2010-12-20T23:09:35.297" UserId="230" />
  <row Id="11597" PostId="8121" Score="2" Text="FYI, 0.1 µF is the same as 100 nF.  (So the small cap on the right in both figures is the same).  The cap on the left in the top figure is equal to 330 nf." CreationDate="2010-12-20T23:21:44.653" UserId="1322" />
  <row Id="11598" PostId="8120" Score="3" Text="If you have kids, leave them out of the loop. They will ruin this plan due to their inherently evil nature. ;)" CreationDate="2010-12-20T23:24:06.873" UserId="2118" />
  <row Id="11599" PostId="8124" Text="If I no longer have the original box, what sort of label would you recommend?" CreationDate="2010-12-20T23:32:10.080" UserId="106" />
  <row Id="11600" PostId="8125" Text="Different voltages and different currents, but a good reference." CreationDate="2010-12-20T23:33:59.737" UserId="230" />
  <row Id="11601" PostId="8121" Text="Also are one set electrolytic then the other not?" CreationDate="2010-12-20T23:34:01.017" UserId="1623" />
  <row Id="11602" PostId="8124" Text="Anything that makes it look official and disarming. pingswept's link used an ESD sticker and wrote &quot;prototype&quot; on it -- good ideas! I bet airport security have more ideas, wherever you're touching down, and are used to questions like this." CreationDate="2010-12-20T23:36:29.797" UserId="2118" />
  <row Id="11603" PostId="8121" Text="@Dean, Small, general purpose caps, like any nF-value ones, are typically [~5mm^2 yellow ceramic blobs](http://store.fundamentallogic.com/ecom/bmz_cache/0/01f78b2da7d6db11696370a1210bd5a5.image.325x325.jpg). It's worth getting to know the differences between capacitor dielectrics and plate materials (eg. tantalum vs. aluminum), especially as they relate to polarity and ESR." CreationDate="2010-12-20T23:49:58.910" UserId="2118" />
  <row Id="11604" PostId="8117" Text="@Thomas O but then you don't get the extra feature of having a power LED." CreationDate="2010-12-21T00:21:39.533" UserId="319" />
  <row Id="11605" PostId="8114" Score="6" Text="And for reference, here is how to decide what value to make the capacitors http://electronics.stackexchange.com/questions/8121/capacitor-sizes-for-7805-regulator" CreationDate="2010-12-21T00:23:12.573" UserId="319" />
  <row Id="11606" PostId="8117" Text="@Kellenjb, it will cost less to have a zener+LED than it will to have two or three LEDs." CreationDate="2010-12-21T01:37:54.880" UserId="1225" />
  <row Id="11607" PostId="8117" Text="@ThomasO But 2 or 3 leds makes it easier to see! Sorry, my sarcasm didn't shine through as well as I had hoped it would." CreationDate="2010-12-21T01:49:05.263" UserId="319" />
  <row Id="11608" PostId="7953" Text="These look pretty neat. I may use them in my next project." CreationDate="2010-12-21T01:49:05.840" UserId="1225" />
  <row Id="11609" PostId="8117" Text="@Kellenjb. Actually, you make a good point. On some devices (esp. safety related, e.g. fire/burglar alarm) I've seen two or three LEDs for major functions. I'm not sure if this is for redundancy in case one LED fails or if it's just for additional visibility. " CreationDate="2010-12-21T01:51:12.643" UserId="1225" />
  <row Id="11610" PostId="8128" Text="The only thing I can think of is that your diodes may be faulty or misorientated. For example, if you connected the top left diode backwards you would have a straight path to the transformer (-) output. One way this could happen would be human error, so double check that; another way could be through choosing diodes with a rating too low, or if the diodes are damaged; they could conduct when they are not supposed to." CreationDate="2010-12-21T02:06:28.407" UserId="1225" />
  <row Id="11611" PostId="8128" Text="If the fuses are blowing due to inrush current, shouldn't they blow when you turn it on? Remember fuses have an I²T rating. In general, if you double the current you need to drop the time by 4. So even if you aren't pulling 315mA through the fuse, it may blow, it just may take longer." CreationDate="2010-12-21T02:09:28.653" UserId="1225" />
  <row Id="11613" PostId="8128" Text="@Thomas O I'm using KBL10 rectifier which is a single component with 4 connectors (2* AC, DC+, DC-), so I don't have any discrete diodes. It's rated at 1 kV @ 4 A. I'm 100% sure I connected it correctly, simply because it seems to be working. It could be internally damaged. As for fuses, the behavior is very strange. Most of them die within first 2 seconds of power-on, but couple of them died later. Can you provide me some sources on fuse calculations? I don't really know anything about that field. " CreationDate="2010-12-21T02:28:58.897" UserId="1240" />
  <row Id="11614" PostId="8128" Text="It's a bit of a dark art. Your fuse manufacturer will often give a table. But if you don't know the manufacturer, go for a similar type. Here is one datasheet: http://uk.farnell.com/cooper-bussmann/s500-315-r/fuse-quick-blow-315ma/dp/1123085 On the first page we can see 1.5x rated current will blow the fuse in 60 minutes, given that you're less than 1x rated current it's *unlikely* to be the cause as you are reporting fuses blowing in 2 minutes. The second page gives exact time-current curves." CreationDate="2010-12-21T02:29:27.820" UserId="1225" />
  <row Id="11615" PostId="8128" Text="As your rectifier is 1kV and 4A rated, I'd doubt it's the cause. Still, you can test it with a multimeter, on the diode test range. If your multimeter doesn't have a diode range, you can do it with the ohms range: expect no reading backwards, and a relatively low reading forwards." CreationDate="2010-12-21T02:32:50.860" UserId="1225" />
  <row Id="11616" PostId="8128" Text="If inrush current is a problem, then you can also get use an NTC device, which will limit the startup current. There are NTCs designed exclusively for this task." CreationDate="2010-12-21T02:33:35.180" UserId="1225" />
  <row Id="11617" PostId="8129" Score="5" Text="Place the answers you have already made in an answer, not in the question." CreationDate="2010-12-21T02:40:57.750" UserId="230" />
  <row Id="11618" PostId="8128" Score="2" Text="Are you sure your multimeter was on the AC current range?  (not DC range.)  Also, you can save fuses by wiring an incandescent light bulb in series with the fuse.  Now overcurrent will make the lamp turn on... make sure the bulb doesn't draw more current than the fuse rating of course." CreationDate="2010-12-21T02:48:13.190" UserId="411" />
  <row Id="11619" PostId="8128" Text="@Thomas O Kortuk♦ I just checked the rectifier with diode check. It turns out that when connected backward, I get 1.9 V of forward voltage. Usually, I get out of range on diodes when I do something like that. @markrages I'm sure that I set range correctly." CreationDate="2010-12-21T02:57:51.317" UserId="1240" />
  <row Id="11620" PostId="8128" Text="@Thomas O  Could you give me a starting point for NTCs? They seem interesting." CreationDate="2010-12-21T03:01:02.157" UserId="1240" />
  <row Id="11621" PostId="8130" Text="Could you give me a pointer for chokes? Wikipedia doesn't mention inrush currents in choke coil article." CreationDate="2010-12-21T03:02:47.803" UserId="1240" />
  <row Id="11622" PostId="8102" Text="Wouldn't it be nice if there was some nice crystal frequency that everyone used." CreationDate="2010-12-21T04:14:38.587" UserId="319" />
  <row Id="11623" PostId="8130" Text="@andrejako, have you checked your diodes?" CreationDate="2010-12-21T04:51:39.403" UserId="230" />
  <row Id="11624" PostId="8110" Text="@kellenjb, you pick your crystal to divide to exactly what frequency you need. speed makes no difference there, but what one tic equals will be affected by that decision." CreationDate="2010-12-21T05:02:00.383" UserId="230" />
  <row Id="11625" PostId="8130" Text="A common mode choke is used to stop common mode eneergy from propagating. This will allow differential signals(what you want), but block common mode signals(what you do not want for EMI reasons, not really a problem for you, just extra info)." CreationDate="2010-12-21T05:10:30.767" UserId="230" />
  <row Id="11626" PostId="8019" Text="Sure: http://roastlog.com/tour/databridge/" CreationDate="2010-12-21T06:26:35.557" UserId="2307" />
  <row Id="11627" PostId="7526" Text="@Isaac: I think what Nick is referring to is having wheels above and below the rail.  Basically like a roller coaster." CreationDate="2010-12-21T06:46:37.883" UserId="2288" />
  <row Id="11628" PostId="8115" Text="Looks like a ServoBelt to me." CreationDate="2010-12-21T06:49:31.970" UserId="2288" />
  <row Id="11629" PostId="8115" Text="Hmmm... not *exactly*, I guess.  I assume the idlers are somewhere around 10 and 2 o'clock to keep the drive pulley in place.  This is a very cool approach since you can let the belt be floppy as it goes over any sort of &quot;hills&quot; or up &quot;cliffs&quot;.  +1 for this approach." CreationDate="2010-12-21T06:51:42.060" UserId="2288" />
  <row Id="11630" PostId="8015" Text="If that's not what you are trying to ask, I'm at a loss for what you are talking about." CreationDate="2010-12-21T07:14:58.257" UserId="1374" />
  <row Id="11631" PostId="7913" Text="@romkyns - Octagonal pads are a option in Altium as well." CreationDate="2010-12-21T07:16:42.327" UserId="1374" />
  <row Id="11632" PostId="7918" Text="As for why there isn't much demand? The EDA software market is *tiny* is why. " CreationDate="2010-12-21T07:17:09.500" UserId="1374" />
  <row Id="11633" PostId="8107" Text="Used to be an issue, not really one any more." CreationDate="2010-12-21T07:18:00.640" UserId="1374" />
  <row Id="11634" PostId="8107" Text="Another argument highlighting that the problem is ancient legacy software. @Fake, do you mean that Gerbers can now represent arcs efficiently, or that nobody cares if the design is a few tens of MB?" CreationDate="2010-12-21T10:12:52.267" UserId="1951" />
  <row Id="11635" PostId="7915" Text="I still don't see how 45 degree routing enables &quot;the most tracks to be put into a given area&quot;. Nor why it's better for controlled impedance tracks. @Leon, were you comparing to arbitrary angles or to 90 degree routing?" CreationDate="2010-12-21T10:15:13.110" UserId="1951" />
  <row Id="11636" PostId="8130" Text="@Kortuk♦ It turns out that when connected backward, I get 1.9 V of forward voltage. Usually, I get out of range on diodes when I do something like that, so the result is a bit strange. Should I replace the rectifier? I'll check on common mode chokes." CreationDate="2010-12-21T11:19:57.407" UserId="1240" />
  <row Id="11637" PostId="8128" Score="1" Text="@AndrejaKo See here: http://uk.farnell.com/jsp/search/browse.jsp;jsessionid=ONXBMLNNR24R0CQLCIPZLTQ?N=0&amp;Ntk=gensearch_001&amp;Ntt=NTC+inrush+limiter&amp;Ntx=mode+matchallpartial&amp;suggestions=false&amp;ref=globalsearch&amp;_requestid=49016 These are inserted in-line with the mains and reduce in-rush current." CreationDate="2010-12-21T11:24:30.197" UserId="1225" />
  <row Id="11638" PostId="8128" Text="@Thomas O OK. Thanks. " CreationDate="2010-12-21T12:00:06.263" UserId="1240" />
  <row Id="11639" PostId="8118" Text="@tyblu: it can't be the best solution since it doesn't comply with the given input voltage of 9V. Isaac may have his reasons to use a 9V battery instead of AA cells, like a stock of 2000 of them :-)" CreationDate="2010-12-21T12:10:34.753" UserId="2064" />
  <row Id="11640" PostId="8129" Text="Good question! Will have to talk about s/c protection and the like." CreationDate="2010-12-21T12:27:36.660" UserId="2118" />
  <row Id="11641" PostId="2610" Text="Yebo also have a store in Midrand (Jhb) and will do mail order anywhere in South Africa. And also in Jhb: AP Electronics (http://www.apelectronics.co.za)." CreationDate="2010-12-21T12:31:57.340" UserId="1629" />
  <row Id="11642" PostId="8134" Text="This is exactly why she's asking: &quot;... but there are hundreds of models...&quot;" CreationDate="2010-12-21T14:24:11.287" UserId="2118" />
  <row Id="11644" PostId="8138" Text="I've killed plenty of ICs and I've *never* personally had one melt or burn.  Typically because my power supply has some sort of current limit in it or other feature to prevent fire." CreationDate="2010-12-21T14:59:13.253" UserId="1407" />
  <row Id="11645" PostId="8145" Text="do you have to build the OBD interface yourself?  There are quick a few relatively cheap OBD interfaces that handle the variations in signaling and provide serial/bluetooth interfaces for your micro-controller to talk with." CreationDate="2010-12-21T15:12:02.133" UserId="1438" />
  <row Id="11646" PostId="8145" Text="@Mark, Ideally it would be me building the OBD interface, as I don't want to rely on external modules, and cost is not a massive concern (product may retail for ~£500.)" CreationDate="2010-12-21T15:13:08.513" UserId="1225" />
  <row Id="11647" PostId="8130" Text="@andrejako, test the resistance through the diodes in your rectifiers, one my have fried. Try replacing the rectifier, this might make a large difference." CreationDate="2010-12-21T15:20:56.743" UserId="230" />
  <row Id="11649" PostId="8145" Text="Is this OBD2 or just OBD?" CreationDate="2010-12-21T15:27:07.487" UserId="319" />
  <row Id="11651" PostId="8142" Text="Agree you do not need to do this in hardware.  45 baud is 22 ms per bit, so this is a simple task for any modern micro." CreationDate="2010-12-21T15:43:42.177" UserId="1322" />
  <row Id="11652" PostId="8145" Text="Do also may need access to the CAN bus on the vehicle." CreationDate="2010-12-21T15:49:49.887" UserId="1810" />
  <row Id="11653" PostId="8145" Text="@Kellenjb, OBD-II." CreationDate="2010-12-21T15:53:53.487" UserId="1225" />
  <row Id="11654" PostId="8145" Text="@Jim C - OBD-II sometimes provides access to CAN, but support for plugging into CAN bus will be included." CreationDate="2010-12-21T15:54:42.457" UserId="1225" />
  <row Id="11655" PostId="8146" Score="1" Text="Sigh.  You can't check lithium batteries, but you can carry them into the passenger compartment?  How ridiculous is that? &#xA;Also, what kind of tools?  Isn't a toothbrush a tool, and don't most people carry those?  &#xA;References would be greatly appreciated." CreationDate="2010-12-21T15:57:57.820" UserId="857" />
  <row Id="11656" PostId="8119" Text="I like this textbook - found it at the local university library and I'm reading it right now." CreationDate="2010-12-21T16:07:36.237" UserId="2183" />
  <row Id="11657" PostId="8130" Text="@Kortuk♦ Just checked diodes and I get around 4 MΩ in the right direction and out of scale in the wrong direction for all diodes. Should I replace the rectifier? I'm still reading on chokes and NTCs. " CreationDate="2010-12-21T16:12:10.357" UserId="1240" />
  <row Id="11658" PostId="8130" Text="@andrejako, 4MOhm seems a little high in the forward direction, but I could be wrong. I would try replacing your rectifier and see if your issue is mitigated." CreationDate="2010-12-21T16:14:29.537" UserId="230" />
  <row Id="11660" PostId="8130" Text="@Kortuk♦ OK, I'll try doing that." CreationDate="2010-12-21T16:20:17.827" UserId="1240" />
  <row Id="11661" PostId="8146" Text="@ree: I'm sure if you would like to point that out to the Friendly TSA Officer, they would be happy to take it and get even more &quot;friendly&quot; with you." CreationDate="2010-12-21T16:26:25.050" UserId="1407" />
  <row Id="11662" PostId="8144" Text="+1 for Atmel AVR" CreationDate="2010-12-21T16:30:44.640" UserId="771" />
  <row Id="11663" PostId="8140" Text="edit this into an answer about ceramics. Make a nice solid answer about ceramics. Find references if you can!" CreationDate="2010-12-21T16:49:01.410" UserId="230" />
  <row Id="11664" PostId="8138" Text="@Nick T, Probably applies for most circuits, but LiPos and computer power supplies can pack a punch." CreationDate="2010-12-21T16:49:06.593" UserId="1225" />
  <row Id="11665" PostId="8138" Text="@ThomasO, lets make this multiple answers, one per components type, I think IC may be a bit too broad." CreationDate="2010-12-21T16:49:38.883" UserId="230" />
  <row Id="11666" PostId="8142" Score="3" Text="it's always easier to load a buffer, set a flag and let hardware tell you when it's done (in the case of transmit)... or to let hardware tell you there is something new to deal with (in the case of receive)" CreationDate="2010-12-21T16:51:46.930" UserId="771" />
  <row Id="11667" PostId="8138" Score="1" Text="@Kortuk, Why? It would just create clutter." CreationDate="2010-12-21T16:53:25.640" UserId="1225" />
  <row Id="11668" PostId="8129" Text="@tyblu, lets keep this one about how components fail, make it one page you can go to to keep track of how they fail." CreationDate="2010-12-21T16:53:33.980" UserId="230" />
  <row Id="11669" PostId="8138" Score="1" Text="@ThomasO, this is a short list, no citations, and no real detail. If you have MOSFET on one, Capacitors(Electrolytic) on one and so forth real detail can be added, citations can be added, and we can have a very nice question that can be used as a general reference by others, as it is you are just putting in your opinion." CreationDate="2010-12-21T16:54:39.690" UserId="230" />
  <row Id="11670" PostId="8152" Text="I cannot give a really solid answer yet, but there is a section defined in your code that data/variables/code is going into(probably variables) that is not defined as a large enough section in the linker." CreationDate="2010-12-21T16:57:13.180" UserId="230" />
  <row Id="11671" PostId="8116" Text="@Nick, have you read the &quot;how to make an Arduino library tutorial&quot;... I just made my first recently and it worked fine for me." CreationDate="2010-12-21T17:04:40.570" UserId="771" />
  <row Id="11672" PostId="8148" Text="Coincidentally, the first 3 datasheets/families I looked at don't. Microchip 16-18F, 8051, and MSP430 processors don't support 5-bit fields." CreationDate="2010-12-21T17:11:26.793" UserId="638" />
  <row Id="11673" PostId="8136" Text="Hey, I don't get reputation for the up-votes! :-(" CreationDate="2010-12-21T17:27:33.327" UserId="2064" />
  <row Id="11674" PostId="8144" Text="@vicatcu, I think it is a great answer, which is +1, why choose because they use a microcontroller you like, who cares, many micros will live and die before your career is finished." CreationDate="2010-12-21T17:30:32.387" UserId="230" />
  <row Id="11676" PostId="8144" Text="@Kortuk, I agree - forgive my bigotry :) " CreationDate="2010-12-21T17:33:13.023" UserId="771" />
  <row Id="11677" PostId="8145" Text="@thomas O when I first read the shifter tag I thought you were wanting to interface with the cars transmission and do auto-shifting or something" CreationDate="2010-12-21T17:34:42.150" UserId="319" />
  <row Id="11678" PostId="8144" Score="1" Text="@vicatcu, just thought I would drop a note, I think many people vote on the micro they use because they are happy others use it. The fact that you say it out loud means you recognize your bigotry and are coping with it. We can avoid the intervention for now." CreationDate="2010-12-21T17:39:24.503" UserId="230" />
  <row Id="11679" PostId="8154" Score="1" Text="+1: Good story." CreationDate="2010-12-21T17:39:25.487" UserId="204" />
  <row Id="11680" PostId="8101" Text="I don't see why a cymbal crash would show up as a peak under my 60Hz cutoff though. Are there significant low-end harmonics down there even for cymbals?" CreationDate="2010-12-21T17:47:48.200" UserId="1633" />
  <row Id="11681" PostId="8155" Text="At higher speeds, this might struggle, because the series resistors form an RC circuit with the pins capacitance. Good idea on the dual MOSFET though. I am just considering whether or not to just signal at 5V and use an input driver which can handle signals up to the battery voltage." CreationDate="2010-12-21T17:48:10.687" UserId="1225" />
  <row Id="11682" PostId="8155" Text="@thomasO, what is your pin capacitance, just trim the resistor divider, this is one of the fastest ways to do shifting. Use 1K resistors, you will not run into problems." CreationDate="2010-12-21T17:50:19.673" UserId="230" />
  <row Id="11683" PostId="8101" Score="1" Text="@Rob, there are some, but the main point is that they're relatively loud, and unless you have a fairly high-order LPF, they may get through (and other loud hits) and still have a high enough amplitude to get confused with a bass thump." CreationDate="2010-12-21T18:13:47.797" UserId="1407" />
  <row Id="11685" PostId="8145" Text="@Thom: I changed your question title as it seems like this is *only* about ODB-II.  If I'm wrong, please clarify in the question itself rather than additional comments." CreationDate="2010-12-21T18:23:48.800" UserId="1407" />
  <row Id="11686" PostId="1203" Text="16-bit ​​​​​​byte?" CreationDate="2010-12-21T18:26:08.970" UserId="1407" />
  <row Id="11688" PostId="8155" Text="@thomasO 100kbps seems like it is plenty slow." CreationDate="2010-12-21T19:26:21.077" UserId="319" />
  <row Id="11689" PostId="8146" Text="I would probably go into nerdy-ninja mode if someone tried to take my crimp tool." CreationDate="2010-12-21T19:29:08.443" UserId="2118" />
  <row Id="11690" PostId="8144" Text="@Nickt, you worked for the answer credit here, 2 edits to keep adding things you found. well done." CreationDate="2010-12-21T19:29:22.743" UserId="230" />
  <row Id="11691" PostId="8155" Text="@kellenjb, I'm dealing with 400kHz I2C and with 1k pull-ups it's hitting the limits, so it might be okay with 1k resistors, but I want to make sure it will work. What if the input was 5V, and the divider was configured for 28V? " CreationDate="2010-12-21T19:38:09.640" UserId="1225" />
  <row Id="11692" PostId="8155" Text="@thomasO, build it, use smaller resistors, if you start to have speed issues go to smaller resistors. Use 140 ohm and 1k, see if it works for you." CreationDate="2010-12-21T20:00:13.963" UserId="230" />
  <row Id="11694" PostId="8160" Score="1" Text="There could be multiple fuses. Some may have one for high current and one for low current, but I'm not sure about voltage and resistance check. They could be there too, but problem with current through multimeter is usually solved with huge resistors on the voltage measurement side. Still, the only way to find anything out is to open the meter. I think that checking current in the 10 A range would tell if the fuses are the problem, since that port is unfused." CreationDate="2010-12-21T20:06:25.553" UserId="1240" />
  <row Id="11695" PostId="8152" Text="What PIC18 are you using? Does it have enough RAM for your application? Which compiler/assembler are you using for your code?" CreationDate="2010-12-21T20:08:28.530" UserId="588" />
  <row Id="11696" PostId="8155" Text="@Kortuk, How do I handle the possibility of the transmitter using 5V or 7V signalling?" CreationDate="2010-12-21T20:14:39.683" UserId="1225" />
  <row Id="11697" PostId="8161" Text="Add to this the PTC device which some multimeters include which is supposed to prevent damage to the meter, although it probably wouldn't do much and certainly wouldn't make it CAT certified." CreationDate="2010-12-21T20:16:56.610" UserId="1225" />
  <row Id="11698" PostId="8155" Text="@ThomasO, I am not sure what you mean. Whom are you referencing as a transmitter, why could you not tie directly to a 5V line?" CreationDate="2010-12-21T20:45:05.687" UserId="230" />
  <row Id="11699" PostId="8155" Text="@Kortuk, As I mentioned in my original question, the signals may range from 5V to 28V and I need to handle ALL possibilities." CreationDate="2010-12-21T20:52:43.690" UserId="1225" />
  <row Id="11700" PostId="8155" Text="@thomasO, I am sorry, I thought you meant on different line they varied, I did not know you meant that they could vary that much on a single line. Welcome to digital pots. I thought there was some spec to which pins had which signal possibility." CreationDate="2010-12-21T20:59:17.737" UserId="230" />
  <row Id="11701" PostId="8155" Text="@thomasO, why are you not buying a simple OBD connector?" CreationDate="2010-12-21T20:59:38.000" UserId="230" />
  <row Id="11702" PostId="8152" Text="@Stefano: What does your VS library do?  The chip you mention **only communicates with I2C**, and the only way I could imagine VS having any direct access to it (or one like it) would be via SMBus (the chip would be on your motherboard).  Does the VS library communicate with the ARM dev board?" CreationDate="2010-12-21T21:04:33.223" UserId="1407" />
  <row Id="11703" PostId="8160" Score="1" Text="Likely only the one fuse for a cheap meter like this, on the 'Volt' terminal, and the 10A range will only be a bar that's been 'clipped' to a certain width, making it a particularly inaccurate, slow fuse. Doubt there is even any input protection (MOVs, etc.)." CreationDate="2010-12-21T21:31:41.263" UserId="2118" />
  <row Id="11704" PostId="8163" Text="At which point are you lost? Hardware; software; both? Do you mean something specific by &quot;BUS&quot;?" CreationDate="2010-12-21T21:42:10.287" UserId="2118" />
  <row Id="11705" PostId="8158" Text="You can steal a bunch of components from a meter. The zebra connectors (if it uses them), LCD, battery clip and buzzer come to mind." CreationDate="2010-12-21T21:45:34.513" UserId="2118" />
  <row Id="11706" PostId="8155" Text="@Kortuk, because I am designing a product. It costs too much to include one of those devices mentioned. I need to have a simple solution, not a complex one involving me integrating a special device." CreationDate="2010-12-21T21:46:13.230" UserId="1225" />
  <row Id="11707" PostId="8155" Text="@Kortuk, digital pots would probably not work, as they would require a supply voltage greater than 5V, and how many operate off ~28V? Not many." CreationDate="2010-12-21T21:46:56.270" UserId="1225" />
  <row Id="11708" PostId="8163" Text="I would say both... when i say BUS i mean communication bus...to transfer data." CreationDate="2010-12-21T21:47:50.403" UserId="2354" />
  <row Id="11709" PostId="8155" Text="@thomasO, you can give them supply voltage, and then they can handle higher on their Resistor lines..." CreationDate="2010-12-21T21:53:27.127" UserId="230" />
  <row Id="11710" PostId="8165" Text="How big fuse should I use? Rating is my biggest problem because 315 mA fuse I used, as far as I can see, is already too much for the transformer and won't be able to protect it in case something downstream fails. I already have &quot;precise&quot; current control in L200CV, so I'm not using fuse for that." CreationDate="2010-12-21T21:53:56.190" UserId="1240" />
  <row Id="11711" PostId="8155" Text="@Kortuk, Most digipots I've found only handle up to Vcc. Either way, it seems far more expensive than using a zener. Would there be any unforeseen problems with a zener and resistor? I imagine capacitance could be one. In which case protection diodes could be used. This still doesn't solve the problem of transmitting back to the vehicle at up to 28V, although 5V may work. " CreationDate="2010-12-21T22:09:39.723" UserId="1225" />
  <row Id="11712" PostId="8155" Text="@thomasO, you can do it with a zener, but you will need to use a large enough resistor to never cause problems. it will work just fine." CreationDate="2010-12-21T22:14:41.430" UserId="230" />
  <row Id="11713" PostId="8146" Text="@Nick - Thanks for the sources!  I edited it to reflect that they are permitted in checked luggage (according to the site you linked.) Also, you can carry on pliers and wrenches longer than 7 inches - you might be able to convince them that crimpers are a special kind of pliers." CreationDate="2010-12-21T22:17:21.717" UserId="857" />
  <row Id="11714" PostId="8163" Score="2" Text="What is the state of your software on the iPhone?  Can you get a microphone reading from the iPhone, or set a voltage on the headphone pins?  Until you're there, this isn't really an electronics problem.  Ask at http://stackoverflow.com." CreationDate="2010-12-21T22:22:41.463" UserId="857" />
  <row Id="11715" PostId="8146" Text="@ree: Both the lines for pliers/wrenches and drivers say &quot;(seven inches or less in length)&quot;  I know not to carry that with me now on trips, but every time I fly they find something else in my bag when I leave, and on my way back I take it out and toss it on my coat or whatever.  They actually thanked me for doing that once." CreationDate="2010-12-21T22:23:50.627" UserId="1407" />
  <row Id="11716" PostId="8169" Text="One fuse has cut wire, others have vaporized and cover insides with remains of the wire. As far as I can see, there were no problems with range changing, but only first fuse survived long enough for me to change range. I tried with slow-blow fuses, but they didn't help me (T series, I've seen other slow fuses too, but didn't have any available to try out)." CreationDate="2010-12-21T22:24:41.900" UserId="1240" />
  <row Id="11718" PostId="8169" Text="Actually, it turned out that the slow fuse was a 160 mA fuse, so they might work. I'll do some more testing with them." CreationDate="2010-12-21T22:29:47.793" UserId="1240" />
  <row Id="11719" PostId="8146" Text="@Nick - dur, I somehow misread that.  No tools OR screwdrivers, pliers, or wrenches less than 7 inches in length.  Thanks for clarifying that, TSA." CreationDate="2010-12-21T23:12:29.803" UserId="857" />
  <row Id="11720" PostId="8155" Score="1" Text="@ThomasO @Mark and @NickT gave very good reasons as to why just buying one or contacting a manufacture is the better then building your own. If your budget is £500 for the end retail device I don't know how you are going to be able to compete with devices that sell for £29." CreationDate="2010-12-21T23:40:26.583" UserId="319" />
  <row Id="11721" PostId="8128" Score="1" Text="&quot;I also noticed that when power switch is in OFF position, I get around 3 V AC at the rectifier output and around 3 V DC at the rectified output. These only disappear when I pull the power plug.&quot; - this needs checking out!? " CreationDate="2010-12-21T23:54:47.333" UserId="1750" />
  <row Id="11722" PostId="7715" Text="@Thomas O: Sounds nice. The wireless chips I toyed with had built in, brain-dead CRC-based protocol layers. I really wanted to improve my range with FEC, but the implementation prevented it." CreationDate="2010-12-22T00:02:27.373" UserId="1270" />
  <row Id="11723" PostId="7764" Text="I'm not terribly happy with what I've got, but this question is about FPGA book recommendations: http://electronics.stackexchange.com/questions/7163/book-recommendations-on-fpga" CreationDate="2010-12-22T00:10:12.343" UserId="1270" />
  <row Id="11724" PostId="8172" Text="AFAIK, these are just rebranded PIC microcontrollers. Look at the datasheet - they have MCLR, Vss, Vdd and Xtal pins in exactly the same positions as 24F chips (and possibly 18F chips, though I don't have a datasheet on hand.) So I doubt they actually handle the high voltages, although they do handle the various protocols, which is useful for me, so I might get one just to see how it works." CreationDate="2010-12-22T00:17:37.713" UserId="1225" />
  <row Id="11725" PostId="8155" Text="@Kellenjb because it will do much more than talk, the plan is to make a fully functional unit with a touchscreen LCD or PC interface. But the project is proprietary (for now, although open source is on the table), so I can't go into much detail other than this." CreationDate="2010-12-22T00:22:06.710" UserId="1225" />
  <row Id="11726" PostId="8128" Text="@Linker3000  I think so too! After looking at some devices I have at home, I decided to place switch only on one wire. Should I replace it with double pole switch which would cut off both AC wires? Also, that was supposed to be 3 V AC at rectifier input." CreationDate="2010-12-22T01:05:20.700" UserId="1240" />
  <row Id="11727" PostId="8128" Score="1" Text="@AndrejaKo. Do an experiment. Take your multimeter and plug the prongs into the mains on volts AC. You will measure 115 or 230V (you are in Europe, so probably 230V.) Now turn the mains off with the switch. Here, I measure 6V with the mains off, and I think I know why. It boils down to the multimeter and the switch resistance. The multimeter has approximately 10 Mohm resistance. To get 6V out from 230V in you need to divide by 38, so the switch has a resistance of ~380 Mohm, which sounds about right. You will probably find if you connect a 47k 5W resistor the voltage will drop to almost zero." CreationDate="2010-12-22T01:58:23.310" UserId="1225" />
  <row Id="11728" PostId="8128" Text="Well, I just reassembled the switch (I actually have two, one at the cable itself and one at the transformer), and the problem disappeared. It's not clear to me what I did wrong when assembling it first time. This entire project is getting very very weird. Also, how would I have measurable resistance on a mechanical switch is there are couple of millimeters between contacts? By the way, would 100 ohm, 3200 beta be a good value for NTC thermistor or should I take one form the &lt;20 ohm range? Oh and when I do the experiment, I get 225 V and 0 V now." CreationDate="2010-12-22T02:21:10.383" UserId="1240" />
  <row Id="11729" PostId="8128" Text="@AndrejaKo, to your first question, most switches have insulation resistances in 100's of millions of ohms (simply due to air resistance and resistance of the plastic casing/switches/etc), which is more than enough to be safe. I doubt you could kill a bacterium with 100Mohm impedence. Multimeters are designed to have high impedence, so they don't load down the circuit under test. When you combine the two you get a voltage divider which gives surprising results." CreationDate="2010-12-22T02:47:09.933" UserId="1225" />
  <row Id="11730" PostId="8157" Score="1" Text="How big are you planning on making it? what is the size of the projectile?" CreationDate="2010-12-22T03:41:50.947" UserId="2060" />
  <row Id="11731" PostId="8172" Text="Looking more closely at the datasheet you're probably correct.  That said however, you can see that the connections to the various vehicle signals either go through IC drivers (for example J1939/CAN) or discrete transistor level shifters.  All recevied signals are simply passed to the microcontroller pins using only series resistors for protection.  Most input pins include parasitic diodes so you can supply higher voltages to these pins as long as you limit the current." CreationDate="2010-12-22T04:02:33.743" UserId="820" />
  <row Id="11732" PostId="8175" Text="+1, probably the most robust option if you've got the parts, and can easily be extended to arbitrary length." CreationDate="2010-12-22T05:11:23.867" UserId="1859" />
  <row Id="11733" PostId="8081" Text="@And: the cable should say &quot;STP&quot; on it, instead of &quot;UTP&quot;" CreationDate="2010-12-22T05:22:54.893" UserId="1407" />
  <row Id="11734" PostId="8176" Text="I'm jealous that you even have a netduino.  I'm still waiting for one to be in stock!" CreationDate="2010-12-22T05:32:28.727" UserId="2288" />
  <row Id="11735" PostId="8176" Text="Amazon's got them. http://www.amazon.com/Secret-Labs-Netduino/dp/B003XT25TY/ref=sr_1_2?ie=UTF8&amp;qid=1292996297&amp;sr=8-2" CreationDate="2010-12-22T05:38:50.597" UserId="2354" />
  <row Id="11736" PostId="8177" Text="@tyblu the Netduino advertises &quot;input: 7.5 - 12.0 VDC or USB powered&quot; They are being smart on making sure that the regulator power doesn't fight with the USB power." CreationDate="2010-12-22T06:27:14.417" UserId="319" />
  <row Id="11737" PostId="8077" Text="Turns out the module's hardware was defective and replacing it seem to have fixed it. Thanks again for all your help" CreationDate="2010-12-22T08:14:03.180" UserId="2331" />
  <row Id="11738" PostId="3110" Text="The schematics and all are open source for the Butterfly One and I got this running completely on my Arch Linux computer. You have to manually compile a few things, but I wouldn't say it's harder than most FPGAs to get started with. (and probably easier because it comes programmed as an AVR softcore" CreationDate="2010-12-22T08:26:41.560" UserId="708" />
  <row Id="11739" PostId="8179" Text="s/2011/2010  :) lol" CreationDate="2010-12-22T09:14:46.430" UserId="708" />
  <row Id="11740" PostId="8152" Text="@mjh2007 I just have 2K, that's the problem I suppose.. I will try to reduce the need of it.." CreationDate="2010-12-22T09:25:17.600" UserId="2285" />
  <row Id="11741" PostId="8152" Text="@Nick T The library provided by Invensense communicates via the ARM board with the chip. I am modifing it to be used on the the PIC18. The I2C communication is just the bottom layer, then there is all the register setting and DMP (Dynamic Motion Processor) settings and use (you cannot use without this library, stright register use is not provided in the datasheet). Basically, there's a whole processor embedded into the IMU which must the controlled, and from this comes the huge RAM need." CreationDate="2010-12-22T09:29:42.730" UserId="2285" />
  <row Id="11742" PostId="8127" Text="I think this is just plain good advice for flying in general, but especially when carrying anything that's not illegal but could be suspicious in some contexts" CreationDate="2010-12-22T09:54:10.950" UserId="708" />
  <row Id="11743" PostId="8136" Text="@steven that is because this question is marked Community Wiki see http://meta.stackoverflow.com/questions/11740/what-are-community-wiki-posts" CreationDate="2010-12-22T10:07:23.243" UserId="708" />
  <row Id="11744" PostId="8179" Text="Well, 2010 is about to over ;-)" CreationDate="2010-12-22T10:16:12.000" UserId="2062" />
  <row Id="11745" PostId="4614" Text="+1 for giving a thorough write up of how you did it :)" CreationDate="2010-12-22T10:30:26.333" UserId="708" />
  <row Id="11746" PostId="8180" Text="Could the reason be excessive vibration perhaps? My multimeter shipped with a blown fuse inside, so chaining it was the first thing I did. It'd be interesting to find out what else can cause fuses to blow." CreationDate="2010-12-22T10:47:07.873" UserId="1240" />
  <row Id="11747" PostId="8104" Score="1" Text="+1 for the pointless use of C++ and hiding main(). I took a look at using the Arduino IDE when I first got mine. Then I decided I'd rather do it on my own and went straight to avr-gcc and avrdude for programming. It should be noted that the Wiring library can be used very easily without the Arduino IDE also. " CreationDate="2010-12-22T11:02:48.103" UserId="708" />
  <row Id="11748" PostId="8116" Text="I would almost argue and say that the setup-loop pattern fits all programs, embedded and otherwise. " CreationDate="2010-12-22T11:04:32.110" UserId="708" />
  <row Id="11749" PostId="8154" Text="Apparently someone found it a good idea to make all answers CW. While I agree that the list provided by the OP should indeed be CW, other answers are too specific for that. It could be that the question was already CW when I posted this answer, I don't recall." CreationDate="2010-12-22T11:42:38.187" UserId="2064" />
  <row Id="11750" PostId="8114" Score="2" Text="+1 since the 7805 is simple and good for rapid prototyping. But remember that this solution will drain the battery really fast! So if you are thinking about power management go with another solution. " CreationDate="2010-12-22T12:13:23.963" UserId="689" />
  <row Id="11751" PostId="8158" Text="Also, even for cheapo multimeters, precise resistors come to mind." CreationDate="2010-12-22T12:13:38.363" UserId="930" />
  <row Id="11752" PostId="8133" Text="+1 for something with a LDO, but how about a example?" CreationDate="2010-12-22T12:16:31.933" UserId="689" />
  <row Id="11753" PostId="8182" Score="2" Text="What's a &quot;throwie&quot;?" CreationDate="2010-12-22T12:42:07.560" UserId="305" />
  <row Id="11754" PostId="8182" Score="1" Text="@Leon: &quot;LED Throwies are an inexpensive way to add color to any ferromagnetic surface in your neighborhood. A Throwie consists of a lithium battery, a 10mm diffused LED and a rare-earth magnet taped together. Throw it up high and in quantity to impress your friends and city officials.&quot; [source](http://www.instructables.com/id/LED-Throwies/)" CreationDate="2010-12-22T12:56:16.057" UserId="2064" />
  <row Id="11755" PostId="8182" Text="Did you consider making improved throwies with photoresistors? This way you'll save some power during daylight." CreationDate="2010-12-22T13:38:42.557" UserId="1240" />
  <row Id="11756" PostId="8181" Text="Just be careful when doing so! The switch could contain some very small components which can easily get lost. Mine had two 2 mm balls which are really easy to lose." CreationDate="2010-12-22T13:44:57.373" UserId="1240" />
  <row Id="11757" PostId="8181" Text="Yeah. Avoid disassembly in rooms with rough or colorful carpets. They !#@@@ when it comes to finding tiny parts." CreationDate="2010-12-22T13:53:29.507" UserId="930" />
  <row Id="11758" PostId="8177" Text="@Kellenjb, I think I could learn something by studying their supply setup a bit more. It does look pretty smart." CreationDate="2010-12-22T14:03:42.900" UserId="2118" />
  <row Id="11759" PostId="8101" Text="Ah, I see—you're saying the critical thing is having a sharp cutoff at my target frequency. I'm not too proud to use an opamp IC with a higher-order low pass filter included, maybe with a trimpot to adjust the cutoff frequency. Now to see if it exists..." CreationDate="2010-12-22T15:02:21.510" UserId="1633" />
  <row Id="11760" PostId="8168" Text="Yes, and I even tried power them both with the same supply (independent of the supply circuit of the atmegas)." CreationDate="2010-12-22T15:21:50.010" UserId="1200" />
  <row Id="11761" PostId="8182" Text="You may be interested in reading up on the spectral response of the human eye or [luminosity function](http://en.wikipedia.org/wiki/Luminosity_function)." CreationDate="2010-12-22T15:26:12.453" UserId="2118" />
  <row Id="11762" PostId="8177" Text="@tyblu Agreed, me too. I am not positive as to what exactly they are doing, but I trust that it works as advertised." CreationDate="2010-12-22T15:29:32.123" UserId="319" />
  <row Id="11763" PostId="8179" Text="Why I need them?  &quot;[F]or use as basic resistive position sensor.&quot; I'm aware of companies that print resistors onto PCBs to reduce the number of discrete that need placement, but that's not what I'm looking for.  There are obviously companies that print resistive traces onto phenolic, ceramic, and other surfaces for use in slide and rotary pots.  I'm looking for those" CreationDate="2010-12-22T15:32:02.637" UserId="1407" />
  <row Id="11764" PostId="8155" Text="@thomasO, sort of like http://gopointtech.com/blog/products/landing-page-usa-desktop?gclid=CMa9786XgKYCFY9l7AoduU2_rA ? This product interfaces with OBD and connects to an iPhone and gives useful readouts, but using pre-existing hardware the cost is only hardware, and it can be very affordable. This is bad news for your solution." CreationDate="2010-12-22T15:34:39.857" UserId="230" />
  <row Id="11765" PostId="8182" Score="1" Text="get the blinking LEDs -- they are *awesome* for throwies!!!" CreationDate="2010-12-22T15:38:00.920" UserId="2288" />
  <row Id="11766" PostId="8152" Text="@Stefano, so you're going to attach a PIC to an ARM and do the processing on the PIC?  That seems like a wanton waste of resources.  The [IMU3000 datasheet](http://invensense.com/mems/gyro/documents/ps-imu-3000a-00-01.1.pdf) lists a bunch of registers (0 to 0x3E), is there something else to it?  It just looks like a 3-axis gyro that can also read another I2C device (ideally an accelerometer)." CreationDate="2010-12-22T15:58:38.293" UserId="1407" />
  <row Id="11767" PostId="8133" Text="A example is always nice :)" CreationDate="2010-12-22T16:15:36.787" UserId="689" />
  <row Id="11768" PostId="8183" Text="@joe, The community often takes simple redirect to a companies site poorly, I am really happy you have taken the time to join our little community, but why not expand here on what the product is and its value, then give us a link if we want to learn &quot;more.&quot;" CreationDate="2010-12-22T16:51:20.047" UserId="230" />
  <row Id="11769" PostId="8179" Text="I wonder how many items you need? If it's &lt;1000, I would try extreme solution: use usual copper PCB and amplify signal using precision opamp. Will be waaaay cheaper and more reliable than ordering these custom things." CreationDate="2010-12-22T17:01:30.270" UserId="2062" />
  <row Id="11770" PostId="8157" Text="Do you have a design, and are looking for something specific, or are you looking for general ideas as to how to compress and release a spring? A sketch would help." CreationDate="2010-12-22T18:11:06.913" UserId="2118" />
  <row Id="11771" PostId="3567" Text="@reemrevnivek, now when you link a picture from your own site it automatically takes it and uploads it with their account." CreationDate="2010-12-22T18:12:40.957" UserId="230" />
  <row Id="11772" PostId="8165" Score="1" Text="@Andr: Fuses are meant to guard against fire, not really anything else." CreationDate="2010-12-22T18:31:52.450" UserId="1407" />
  <row Id="11773" PostId="8036" Text="I'm starting a bounty on this question." CreationDate="2010-12-22T18:55:16.927" UserId="1225" />
  <row Id="11775" PostId="8187" Text="@jsolarski: Please don't just provide a link, it provides little to no information on its own, and worse, if the link dies (fairly common for blogs), your post becomes worthless, and this question is significantly harmed as a result.  Copy and quote (**and provide attribution**) to key parts from the page you link.  I copied my post over yours, which I initially overlooked due to it's overwhelming blandness." CreationDate="2010-12-22T20:58:00.250" UserId="1407" />
  <row Id="11776" PostId="8106" Text="Yes - must...   have...     autocomplete" CreationDate="2010-12-22T20:59:42.157" UserId="1823" />
  <row Id="11777" PostId="8115" Text="You could get this stuff from McMaster pretty easily, I might suggest XL-series [pullies](http://www.mcmaster.com/#xl-timing-belt-pulleys) (~$8-10) and [belts](http://www.mcmaster.com/#xl-series-timing-belts) (~$2/ft)" CreationDate="2010-12-22T21:20:11.400" UserId="1407" />
  <row Id="11778" PostId="8193" Text="This looks to be the best solution. I'd probably use this on the Pro (more expensive) version of my OSD, but since space is critical on the Lite (cheapest) version I'll stick with low resistance switches, as W5VO suggests." CreationDate="2010-12-22T21:22:18.387" UserId="1225" />
  <row Id="11779" PostId="8175" Text="+1, Nice solution as your track can be fairly cheap per foot if made out of angle iron or rectangular tube.  However, the spacing between the wheels needs to be much wider to reduce the difference in moment arm between your camera and track and wheels and track.  The mechanical advantage it gives will drastically amplify any slop in bearings, doubly so because it will also increase the force that you can exert on them." CreationDate="2010-12-22T21:41:37.340" UserId="1407" />
  <row Id="11780" PostId="8187" Text="@Nick Thanks, I will next time, I appreciate the advise" CreationDate="2010-12-23T00:19:07.433" UserId="2060" />
  <row Id="11781" PostId="8197" Score="1" Text="Can you give us a link to information about the adapter?" CreationDate="2010-12-23T01:50:16.093" UserId="2118" />
  <row Id="11782" PostId="2077" Text="I've got one of these. The only real complaint I have is that you have to be really careful with your settings - if you set it up incorrectly (the software has NO idea what the limits on the board's buffer really are), you get garbage results with no warning. Otherwise it works like a charm." CreationDate="2010-12-23T02:28:28.900" UserId="259" />
  <row Id="11783" PostId="8197" Score="2" Text="Do you have a multimeter you can use to check the output?" CreationDate="2010-12-23T03:01:34.953" UserId="2365" />
  <row Id="11784" PostId="8131" Text="I'm picturing a linear boom with a track fixed to it. The boom could be propped up with a tripod on one end to determine its incline. The track itself can be perfectly straight, if curves would make things too complicated." CreationDate="2010-12-23T04:35:15.517" UserId="2172" />
  <row Id="11785" PostId="8115" Text="I wasn't thinking of anything as elaborate as a ServoBelt. I've always seen them made out of parts and plates. (McMaster I guess in USA)" CreationDate="2010-12-23T05:19:47.820" UserId="1481" />
  <row Id="11786" PostId="8194" Text="Thst NJM2244 looks like a perfect solution to Thomas's original question.  And for a good price too. " CreationDate="2010-12-23T05:29:34.667" UserId="411" />
  <row Id="11787" PostId="8194" Text="No kidding. I found it interesting that the low resistance switches were found in the digital logic families." CreationDate="2010-12-23T05:32:51.670" UserId="638" />
  <row Id="11788" PostId="8196" Text="@Wonko The Sane  I'm using a toroidal transformer. I don't think I have a short in it. The transformer itself is covered in around 1mm thick layer of transparent plastic. The mounting equipment which shipped with it consists of two rubber disks of same diameter as transformer, a plastic disk and a screw. The screw itself goes through the rubber disk, transformer, second rubber disk and ends inside the plastic disk which has a threaded hole for screw. I'll try today with new bridge and T fuses." CreationDate="2010-12-23T10:01:21.980" UserId="1240" />
  <row Id="11789" PostId="8134" Text="I had the same issue looking for them. digikey, newark or any of the suppliers have a lot of the connectors but sorting them out and finding the correct one for you application is tough." CreationDate="2010-12-23T11:59:13.920" UserId="2060" />
  <row Id="11790" PostId="8211" Text="Hmm... Optra R+ seems to have 1200... Why don't use use it for routine boards too?" CreationDate="2010-12-23T12:29:40.330" UserId="2062" />
  <row Id="11791" PostId="8211" Text="Because it's slower, so 600dpi is my default setting for normal paper printing jobs, which is what the printer is used for 99% of the time, and as 600 is fine for most PCBs I don't bother changing it." CreationDate="2010-12-23T14:16:23.643" UserId="1681" />
  <row Id="11792" PostId="8196" Score="2" Text="T400mA fuse solved the problem." CreationDate="2010-12-23T14:27:53.477" UserId="1240" />
  <row Id="11793" PostId="8197" Text="I just realized that a user needs a certain minimum rep to be able to comment -- not sure if chuanose can even reply to us! So.. +1!" CreationDate="2010-12-23T16:05:26.383" UserId="2118" />
  <row Id="11794" PostId="8203" Score="1" Text="see also http://electronics.stackexchange.com/questions/7489" CreationDate="2010-12-23T16:15:47.210" UserId="411" />
  <row Id="11795" PostId="8211" Text="Do you get different results using toner transfer paper?" CreationDate="2010-12-23T16:20:19.627" UserId="2118" />
  <row Id="11796" PostId="8204" Text="[£1.35/sheet](http://www.megauk.com/artwork_films.php) -- expensive, and about par with competition." CreationDate="2010-12-23T16:23:17.567" UserId="2118" />
  <row Id="11797" PostId="8218" Text="PWM can be done purely in software and since the program would be doing very little there isn't much hurt by having it in software. You can probably get a micro much cheaper when you remove the hardware PWM requirement." CreationDate="2010-12-23T16:40:49.357" UserId="319" />
  <row Id="11798" PostId="8218" Text="If I wanted to create these in quantity could I do it cheaply or are Atmega uC's for more of a hobbyist type thing?" CreationDate="2010-12-23T16:42:18.217" UserId="2366" />
  <row Id="11799" PostId="8078" Text="@Rick_2047 - This is clearly a job for an oscilloscope.  It sounds like between yourself and the graveyard shift developer, your company has already burned up more money of engineering time than a simple oscilloscope would cost.  Even a cheap USB scope can be immensely helpful for problems like this.  Your boss's job is to make sure you have the right tools for the job! " CreationDate="2010-12-23T16:59:58.393" UserId="529" />
  <row Id="11800" PostId="8218" Score="1" Text="@Blankasaurus, The Arduino is mostly a hobbyist's tool, but [the ATmega line](http://www.atmel.com/dyn/products/param_table.asp?family_id=607&amp;OrderBy=part_no&amp;Direction=ASC) isn't limited to that demographic. They are used in industry, just like [Renesas](http://am.renesas.com/), Motorola, or [Microchip](http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&amp;nodeId=2551)." CreationDate="2010-12-23T17:12:01.953" UserId="2118" />
  <row Id="11801" PostId="8219" Score="2" Text="Sorry, I can't help with the driver, but that is a sweet VFD tube.  Post another picture once you get it lit up." CreationDate="2010-12-23T17:16:14.400" UserId="411" />
  <row Id="11802" PostId="8221" Score="1" Text="Looks like they still list the segmented VFDs on their website.  The 16 character alphanumeric display is here: http://www.futaba.com/products/displays/full/30-full.pdf" CreationDate="2010-12-23T18:01:28.200" UserId="411" />
  <row Id="11803" PostId="8222" Score="1" Text="Good story! Did it cost much to fix? :D" CreationDate="2010-12-23T18:23:19.867" UserId="2118" />
  <row Id="11804" PostId="8223" Score="1" Text="That website simply screams *scam*." CreationDate="2010-12-23T18:41:32.050" UserId="2118" />
  <row Id="11805" PostId="8204" Text="Other film I've tried doesn't work nearly as well. I cut it to size and tape it to a carrier sheet." CreationDate="2010-12-23T18:55:45.347" UserId="305" />
  <row Id="11806" PostId="8218" Text="@Kellenjb: true, but he said 'as simple as possible' :-)&#xA;&#xA;@Blankasaurus: what @tyblu said" CreationDate="2010-12-23T19:17:13.287" UserId="1124" />
  <row Id="11807" PostId="8219" Text="Yes, and it's rather big too: 21cm long, character height 12.7mm (1/2&quot;). I think it was used in cash registers or something like that." CreationDate="2010-12-23T19:26:41.543" UserId="2064" />
  <row Id="11808" PostId="8205" Text="Might as well drive an even bigger, mechanical relay that can handle the current, with your SSR." CreationDate="2010-12-23T20:11:41.207" UserId="2118" />
  <row Id="11809" PostId="8223" Text="I know, but it appeared somewhat credible, was mentioned on other green energy sites and at least one news site (which helps a lot), and they include the patents in an appendix. Try it and see what happens. Perhaps someone can provide more details." CreationDate="2010-12-23T20:16:09.487" UserId="794" />
  <row Id="11810" PostId="8223" Text="[Site registered Dec 7, 2010](http://www.moniker.com/pub/Whois?domain=teslassecret.com) by &quot;Henry Reinders&quot; of Williams Lake, BC.  Phone number (+1.2503982280) is disconnected " CreationDate="2010-12-23T21:00:27.667" UserId="1407" />
  <row Id="11811" PostId="8205" Text="you can always monitor the current level and turn it off should it exceed rating.  If you've already got a microcontroller sitting next to the SSR for control this is fairly easy without too many additional components as long as the uC has an ADC or can measure pulse widths in some manor.  Or just use a X10 or Zigbee outlet, thats likely the only option if you actually care about complying with electrical codes." CreationDate="2010-12-23T21:02:44.537" UserId="1438" />
  <row Id="11812" PostId="8223" Text="I haven't had such a good laugh in a while. @tyblu: 100% Scam, 100% Spam. Also, I love how the sun is showering us with only 5 megawatt-hours of energy.... It's all a ploy to sell their book. I'll bet someone a dollar that Arlen is a member of said company or of their scamming referral network. " CreationDate="2010-12-23T21:11:33.610" UserId="638" />
  <row Id="11813" PostId="8222" Text="That's interesting that the slope changes from the first graph to the second graph. Any theories? Does tuning the DCO lower in frequency give it a worse temperature coefficient?" CreationDate="2010-12-23T21:19:30.420" UserId="638" />
  <row Id="11814" PostId="8222" Text="Notice that the y-axis changes between the two graphs.  And don't read too much into them generally.  The part was frozen in a domestic freezer and the temperature was measured during warmup to room temperature with a thermocouple on a cheap MAS-345 (http://www.elexp.com/tst_s345.htm) which only reads integer degrees.  Then I linearly interpolated between whole-degree changes to make the plot." CreationDate="2010-12-23T21:24:49.133" UserId="411" />
  <row Id="11815" PostId="8225" Text="http://iteadstudio.com/store/index.php?main_page=product_info&amp;cPath=3&amp;products_id=155" CreationDate="2010-12-23T21:37:57.357" UserId="2118" />
  <row Id="11816" PostId="3441" Score="2" Text="Some LCD connectors are pads directly on the glass, and require zebra connectors. Zebra con.'s are great to have, though." CreationDate="2010-12-23T21:39:06.747" UserId="2118" />
  <row Id="11817" PostId="8223" Text="Just to say.. Astron is a European astronomers group which study stars. They harvest the signals from outer space, which is really small power. They operate for years in huge scale (big receivers etc.) and in a few decades years they finally harvested the amount of energy to light a bulb for not even a second." CreationDate="2010-12-23T22:33:53.570" UserId="1476" />
  <row Id="11818" PostId="8215" Score="1" Text="I always thought XC was Xilinx and MC was motorola." CreationDate="2010-12-23T22:44:22.777" UserId="2371" />
  <row Id="11820" PostId="8218" Text="@tyblu don't forget the TI micros. @Vincent Van Den Berghe He put cheap in () after the simple, so I figured by simple he meant cheap, not simple program. Either way, software PWM is rather simple. @Blankasaurus You can get micros for very cheap. The cost is usually pretty closely tied to how much memory it has and since you don't need much you can get a very cheap one. In large quantities you can get micros for less then $1." CreationDate="2010-12-24T01:43:36.700" UserId="319" />
  <row Id="11821" PostId="8232" Text="@Jay, This is a pretty old question (July 10') -- not that I haven't made the same mistake myself! ;)" CreationDate="2010-12-24T01:59:05.323" UserId="2118" />
  <row Id="11822" PostId="7472" Score="2" Text="glad you asked that question.  I also have that kit.  :)" CreationDate="2010-12-24T03:33:56.313" UserId="2288" />
  <row Id="11823" PostId="8223" Text="Site is a free-energy scam." CreationDate="2010-12-24T04:00:33.130" UserId="1374" />
  <row Id="11824" PostId="8206" Text="I don't think this is true, I mean I can break the wire apart with my bare hands very easily. (and when trying to strip it, I commonly break it off accidentally. Some of the enamel comes off with my fingernails though)" CreationDate="2010-12-24T05:19:03.170" UserId="708" />
  <row Id="11825" PostId="6803" Text="@Thomas O - well, they do. Have you looked at any SMPS recently? They're almost all mixed SMT/TH." CreationDate="2010-12-24T06:52:55.440" UserId="1374" />
  <row Id="11826" PostId="6797" Text="@Mark - I've never seen an entirely hand-soldered SMPS. Ever. Generally, things like Computer PSes have hand soldered  *leads*, but everything else is done with wave soldering. The leads **have** to be hand soldered because they have too much thermal mass for wave soldering, and you don't get proper solder penetration." CreationDate="2010-12-24T06:54:53.973" UserId="1374" />
  <row Id="11827" PostId="7753" Text="I've actually replaced the hot mirror with a hand-cut cold mirror (transmits *only* IR) in a very expensive camera (Nikon D80 SLR). It was an adventure. OTOH, it takes beautiful pictures." CreationDate="2010-12-24T06:56:19.023" UserId="1374" />
  <row Id="11828" PostId="8236" Score="2" Text="Can you provide a part number or link for the LED?" CreationDate="2010-12-24T07:03:35.530" UserId="2118" />
  <row Id="11829" PostId="8236" Text="Note that battery voltage drops as soon as you provide a load, modeled by an equivalent series resistance (ESR) or internal resistance (IR). One must obey the datasheet -- stay below the maximum allowed constant current and voltage ratings. There will be graphs to illuminate these values." CreationDate="2010-12-24T07:05:53.157" UserId="2118" />
  <row Id="11830" PostId="8237" Text="So [&quot;120Ω or to taste&quot;](http://xkcd.com/730/) is not acceptable?" CreationDate="2010-12-24T07:09:40.407" UserId="2118" />
  <row Id="11831" PostId="8237" Text="Since it doesn't have a specific definition, no." CreationDate="2010-12-24T07:12:04.170" UserId="1374" />
  <row Id="11832" PostId="8238" Text="I've also come across several American schematics with no units for Henries or Farad; one must deduce the power, which is a pain." CreationDate="2010-12-24T07:13:25.723" UserId="2118" />
  <row Id="11833" PostId="8237" Score="1" Text="Should probably be CW, but I can't seem to set it as such, even though I have moderator tools." CreationDate="2010-12-24T07:13:39.907" UserId="1374" />
  <row Id="11834" PostId="8238" Text="That even more fun! At least with resistors, it's generally assumed that no units means it's in ohms." CreationDate="2010-12-24T07:16:11.917" UserId="1374" />
  <row Id="11835" PostId="8238" Text="Also I've seen capacitors labeled 100MF - for 100 micro Farads" CreationDate="2010-12-24T07:42:28.420" UserId="638" />
  <row Id="11836" PostId="8233" Text="extendeding your answer slightly, I would be inclined to group PAL/PLA/GAL into the same basket as PLD/CPLD for the reason of instant start up with no configuration time, and that vendors are starting to push CPLDs ahead of PAL/PLA/GAL devices.  For example I am working with some lattice devices and their CPLD family IC are significantly cheaper and offer more gates then the PAL/GAL/PLA cousins.  The cost of the latter is prohibitive for what they offer when compared to the former." CreationDate="2010-12-24T07:44:49.753" UserId="1397" />
  <row Id="11837" PostId="8233" Text="The line is definitely blurring a bit. I didn't think PAL/PLA/GALs had storage elements, or CLPD's had SRAM until I looked up the parts tyblu listed. It seems like the PAL/PLA/GALs are more like duck tape in a design than being a core part. " CreationDate="2010-12-24T07:56:27.577" UserId="638" />
  <row Id="11838" PostId="8238" Score="3" Text="@W5VO A lot of people seem to be blind for lower vs upper case, which is significant in units of measurement (another common mistake is using S for seconds)." CreationDate="2010-12-24T08:32:28.417" UserId="339" />
  <row Id="11839" PostId="8238" Text="It's remarkable how young much of the SI system is. Most of the electrical units are standardized only in 1948, the micro and pico prefixes and Hertz are from 1960. http://en.wikipedia.org/wiki/General_Conference_on_Weights_and_Measures" CreationDate="2010-12-24T08:36:51.673" UserId="339" />
  <row Id="11840" PostId="8244" Text="What datarate are you thinking of?" CreationDate="2010-12-24T10:17:59.190" UserId="2064" />
  <row Id="11841" PostId="8244" Text="10Mbit initially, than I'll see what I can reach. I can do processing on FPGA &amp; fast ADC/DAC." CreationDate="2010-12-24T10:26:54.833" UserId="2062" />
  <row Id="11842" PostId="8246" Text="You mean it's in separate case? There is a metallic laser case, and somewhere there there is also a photodiode? Hmm... Do you have any info on freq response?" CreationDate="2010-12-24T10:45:57.320" UserId="2062" />
  <row Id="11843" PostId="8196" Text="Toroidal transformers have a very high surge / inrush current compared with 'standard' transformers." CreationDate="2010-12-24T11:32:27.440" UserId="2192" />
  <row Id="11844" PostId="8196" Text="The problem with mounting toroidal is to make sure you don't create a conductive loop which will act as a extra winding that is shorted out. - to avoid this either use a plastic disk, plastic screws or plastic cable ties... " CreationDate="2010-12-24T11:37:23.817" UserId="2192" />
  <row Id="11845" PostId="7084" Text="I didn't see anything like this on the datasheet. As the reset pin can be use as general I/O, it has the generic pull up, but it's useless as you have to turn on the micro to activate it, and you need to activate it to turn on the micro..." CreationDate="2010-12-24T13:15:23.520" UserId="2040" />
  <row Id="11846" PostId="8242" Text="Where is the URL?" CreationDate="2010-12-24T14:08:18.333" UserId="305" />
  <row Id="11847" PostId="8252" Text="I am doing a lot of porting lately (atmega32 to lpc2148) and had to port code for driving an lcd to lpc. Now on atmega32 it just used two ports (its 16-bit data bus). So I figured I would just access FIO1 with two words (FIO1DIR2 etc.) but to my horror I had to solder wires instead of using the male headers as all the pins are not together." CreationDate="2010-12-24T16:12:02.967" UserId="1200" />
  <row Id="11849" PostId="8232" Text="I knew how old it was, but Lars still hadn't accepted an answer, and the other two answers had guessed the wrong pin out (understandably), so it still seemed very much worthwhile to answer." CreationDate="2010-12-24T16:57:29.487" UserId="1213" />
  <row Id="11850" PostId="8257" Text="&quot;It's an ideal op amp to learn the basics on due to its non-ideal nature.&quot;  That's fine in an academic environment, but in a commercial enterprise it's cost-efficiency and risk reduction that count. Better specs may help reducing design risks." CreationDate="2010-12-24T17:29:21.823" UserId="2064" />
  <row Id="11851" PostId="8257" Text="I agree with you on that. It's a relatively simple chip where you will be able to see where practical parts leave theory. If you want a lab test and get a 100MHz GBW opamp, you would need incredible high frequent signals to show the problem of bandwidth. Or things like slew rate etc.&#xA;Furthermore, the NE555 is also still used widely today. It's a timer IC which will be outperformed in many ways by other ICs, but still it's a very useful bit of kit. Same for Lm311. If it's 'good enough' and cheapest way to do, then do it." CreationDate="2010-12-24T18:09:17.587" UserId="1476" />
  <row Id="11852" PostId="8250" Text="@Andrey I think this is a good answer. I would recommend you copy it into an answer and remove the comment." CreationDate="2010-12-24T18:39:07.660" UserId="319" />
  <row Id="11853" PostId="8238" Text="@Fake Name I used to work in an electronics supply shop where my boss always said micro-micro-farads. Took me a bit to get used to. He was a retired Navy electronics technician. I never knew others said this, I thought it was just his weird little quirk." CreationDate="2010-12-24T18:43:19.777" UserId="319" />
  <row Id="11854" PostId="8237" Text="@Fake Name you have to be a ♦ mod to change it. I flagged it for their attention." CreationDate="2010-12-24T18:45:03.563" UserId="319" />
  <row Id="11855" PostId="8255" Score="1" Text="I have to disagree with some of these points, though. 1.) Amplifiers like TL081, LM358, etc. are all available from many suppliers and 4.) I don't know of any modern non-power op-amp without short circuit protection. Could you point out one?" CreationDate="2010-12-24T18:51:25.343" UserId="1225" />
  <row Id="11856" PostId="8250" Text="Thanks Kellenjb.  I did as you suggested." CreationDate="2010-12-24T19:13:34.277" UserId="1819" />
  <row Id="11857" PostId="8260" Text="This should be on audio.stackexchange or electronics.stackexchange." CreationDate="2010-12-24T16:40:20.697" UserId="1229" />
  <row Id="11858" PostId="8257" Text="@Hans: I don't think you can compare the 555 with the evolution in opamps. Over time the 555 has seen few variants, I can only think of the CMOS version 7555, which improves on power consumption. IMO there's little else you can change. OTOH there are hundreds of opamps which can be a direct replacement for the 741 in certain designs." CreationDate="2010-12-24T19:51:41.073" UserId="2064" />
  <row Id="11859" PostId="8260" Score="1" Text="What do you mean by &quot;digital regenerator&quot;? Schmitt-trigger, latch, or comparator?" CreationDate="2010-12-24T20:01:26.103" UserId="2118" />
  <row Id="11860" PostId="8263" Text="Your question reads as if you've already found a solution. What is the problem?" CreationDate="2010-12-24T20:03:26.820" UserId="2118" />
  <row Id="11861" PostId="8256" Text="+1 for this! In some languages condenser and its derivatives are still used." CreationDate="2010-12-24T21:12:06.920" UserId="1240" />
  <row Id="11863" PostId="8164" Score="1" Text="it would probably require a current made of magnetic monopoles to link the two, somehow.  =P" CreationDate="2010-12-24T21:46:59.163" UserId="740" />
  <row Id="11864" PostId="8265" Text="Your answer seems spot on, means that I have to go back to the drawing board... :(" CreationDate="2010-12-24T21:51:42.420" UserId="2068" />
  <row Id="11865" PostId="8265" Text="I think I've seen some CPLD or even ASIC options for SATA downconversion -- might have even been a built-in ARM peripheral." CreationDate="2010-12-24T22:35:07.030" UserId="2118" />
  <row Id="11866" PostId="8237" Text="@fakeName, yeah, just flag it and we will come take care of it, thanks all the users whom flagged it for attention. There were many." CreationDate="2010-12-24T22:48:38.453" UserId="230" />
  <row Id="11867" PostId="8270" Score="1" Text="What does MCB mean?" CreationDate="2010-12-25T01:57:19.773" UserId="2118" />
  <row Id="11868" PostId="8270" Text="Microcontroller board? Is that not a standard name?" CreationDate="2010-12-25T02:11:35.377" UserId="1360" />
  <row Id="11869" PostId="8272" Text="This looks promising" CreationDate="2010-12-25T02:12:02.960" UserId="1360" />
  <row Id="11870" PostId="8272" Text="So is this windows only? That's a problem. Even if it's not open source, it needs to work on linux." CreationDate="2010-12-25T02:20:42.687" UserId="1360" />
  <row Id="11871" PostId="8263" Text="I can't seem to be able to make this work? Is this supposed to work ? Am i doing anything wrong.. ?" CreationDate="2010-12-25T07:19:47.037" UserId="2245" />
  <row Id="11872" PostId="8223" Text="@W5VO, I am not in any way related to them. I bought the document and it made sense." CreationDate="2010-12-25T14:14:29.870" UserId="794" />
  <row Id="11873" PostId="8010" Text="I thought about this but I don't know USB very well and I have to investigate if I can do what I wanna do. Anyway, thank you ;)" CreationDate="2010-12-25T14:45:04.780" UserId="2316" />
  <row Id="11874" PostId="8272" Score="1" Text="Does anything *really* work on Linux?" CreationDate="2010-12-25T14:59:20.690" UserId="142" />
  <row Id="11875" PostId="8283" Text="thank you! do you know if it is possible to buy it with the plastic part attached?" CreationDate="2010-12-25T15:05:25.767" UserId="2316" />
  <row Id="11876" PostId="8272" Text="Yes alot more than windows ;) " CreationDate="2010-12-25T15:09:06.217" UserId="1623" />
  <row Id="11878" PostId="8283" Score="1" Text="The encoder as sold is like a potmeter, i.e. with a plastic or metal 6mm axis. You'll have to purchase the knob separately. In the past I've had trouble finding knobs with greater than 40mm diameter, esp. ones with an index like in your picture may be hard to find." CreationDate="2010-12-25T15:11:40.677" UserId="2064" />
  <row Id="11879" PostId="8283" Text="ok, thank you again ;)" CreationDate="2010-12-25T15:19:07.420" UserId="2316" />
  <row Id="11880" PostId="8010" Text="@3mpty, I am getting read to buy something to play with these things, I will let you know what I find out." CreationDate="2010-12-25T16:43:10.910" UserId="230" />
  <row Id="11881" PostId="8279" Text="You've been using the TopR autorouter, haven't you? That program is crazy!" CreationDate="2010-12-25T16:43:47.180" UserId="2118" />
  <row Id="11882" PostId="8273" Text="@sskuce, Not everyone on the site celebrates Christmas, but there are significantly fewer people around right now. It may take a bit for you to get your answer, sorry for the delay." CreationDate="2010-12-25T16:46:56.100" UserId="230" />
  <row Id="11883" PostId="8282" Score="1" Text="It's also used in measurement equipment like scopes and logic analyzers, for instance." CreationDate="2010-12-25T16:56:09.773" UserId="2064" />
  <row Id="11884" PostId="8273" Text="@Kortuk, I expect that, but still better to get the question out there now so it's around when people get back.  I'll poke it with a meaningless edit if nobody's answered by Monday." CreationDate="2010-12-25T17:41:18.850" UserId="1555" />
  <row Id="11885" PostId="8258" Text="What kind of order, care to illustrate (more)?" CreationDate="2010-12-25T17:42:16.697" UserId="1200" />
  <row Id="11886" PostId="8273" Text="@sskuce, Just making sure you knew why people were not jumping on your question." CreationDate="2010-12-25T17:51:55.403" UserId="230" />
  <row Id="11887" PostId="8196" Score="1" Text="@andrejako, if it used to work, started popping fuses now, and you have replaced the fuse with a larger one, and it stops popping fuses, it means it is pulling larger current. Why it changed is not fixed by replacing the fuse." CreationDate="2010-12-25T17:53:49.443" UserId="230" />
  <row Id="11888" PostId="8281" Score="1" Text="@bt2, it can help you pass FCC cert to use it on places like pics, you want to use caps to filter first, as a ferrite does not do well against high power transients, it operates on absorbing low power transients. " CreationDate="2010-12-25T17:55:42.860" UserId="230" />
  <row Id="11889" PostId="6373" Text="http://www.lucidscience.com/pro-laser%20spy%20device-1.aspx" CreationDate="2010-12-25T18:05:32.070" UserId="2118" />
  <row Id="11890" PostId="8272" Score="1" Text="that looks similar to fritzing. http://fritzing.org/" CreationDate="2010-12-25T18:39:51.677" UserId="2060" />
  <row Id="11891" PostId="8285" Score="1" Text="I dont think any one will code it for you =, but you may want to try the 43oh.com forums for code examples using the ADC on the msp430 line of chips." CreationDate="2010-12-25T18:58:29.627" UserId="2060" />
  <row Id="11892" PostId="8278" Text="The clock is at the default, 8MHz divided by 8 to make 1 MHz." CreationDate="2010-12-25T19:10:54.753" UserId="2381" />
  <row Id="11893" PostId="8286" Text="I couldnt find the example code form the ones that ti gives you." CreationDate="2010-12-25T19:24:15.163" UserId="2386" />
  <row Id="11894" PostId="8285" Text="Thanks for the site, i actually have found some useful information." CreationDate="2010-12-25T19:27:27.563" UserId="2386" />
  <row Id="11895" PostId="8286" Text="try finding your chip here http://focus.ti.com/mcu/docs/mcuprodcodeexamples.tsp?sectionId=96&amp;tabId=1468" CreationDate="2010-12-25T20:11:50.043" UserId="2060" />
  <row Id="11896" PostId="8258" Score="1" Text="@Rick_2047, look at the diagram, they are in sequence." CreationDate="2010-12-25T20:42:36.783" UserId="1225" />
  <row Id="11898" PostId="8272" Text="@endolith: Actually yes. Especially for programming and stuff. How much of a hassle is it to read non ascii characters off a serial device in windows? I don't understand how an programmer can work on a windows device." CreationDate="2010-12-25T20:44:04.680" UserId="1360" />
  <row Id="11899" PostId="8263" Text="I'm not sure why you'd go to the expense and overhead of Ethernet; RS485 and ModBus is trivial to work with with any small microcontroller and even simpler with a PC. There are ModBus libraries freely available if you want to just plug and play, and there are many companies that make inexpensive (under $20) RS232-to-RS485 converters; you just read and write to the normal serial port." CreationDate="2010-12-25T21:25:48.087" UserId="974" />
  <row Id="11900" PostId="8288" Text="How much do the dsPIC's run for? Can you give me any suggestions?" CreationDate="2010-12-25T21:39:21.627" UserId="2386" />
  <row Id="11902" PostId="8286" Text="Ive tried looking though the example but have not found anything useful :(" CreationDate="2010-12-25T21:40:15.150" UserId="2386" />
  <row Id="11903" PostId="8288" Text="It depends on the chip, it could be &lt;$2. See the Microchip web site." CreationDate="2010-12-25T21:44:04.447" UserId="305" />
  <row Id="11904" PostId="8288" Text="What would i need in the way of an experimenters board so i can have a hook up to my computer?" CreationDate="2010-12-25T21:47:37.437" UserId="2386" />
  <row Id="11905" PostId="8196" Text="@Kortuk♦ &quot;if it used to work&quot; is itself strange. First fuse of 315 mA used to work for maybe 15 minutes and the rest of them died immediately, so I think that someone miscalculated fuse type, but I don't understand why first fuse worked for around 15 minutes and why it later died. I'm also thinking of putting 5 33µH coils on input and output to lower the inrush current next time I disassemble it. Would that work?" CreationDate="2010-12-25T21:54:52.053" UserId="1240" />
  <row Id="11906" PostId="8286" Score="1" Text="you will not find any out of the box code that will work for your project, but it should give you a good place to start coding. Try using msp430x54xA_adc12_05.c (ADC12, Using an External Reference) and msp430x54xA_adc12_07.c (ADC12, Repeated Single Channel Conversions) from slac375a.zip.  " CreationDate="2010-12-25T21:59:00.583" UserId="2060" />
  <row Id="11907" PostId="8288" Text="I'd design a small PCB." CreationDate="2010-12-25T22:08:27.290" UserId="305" />
  <row Id="11908" PostId="8286" Text="ok will look, and someone suggested this nyquist sampling code. http://programmers.stackexchange.com/questions/29991/help-how-would-i-sample-an-audio-tract-at-nyquist-frequency-using-c-c-and-a-mi your thoughts? look at answer 2." CreationDate="2010-12-25T22:08:57.050" UserId="2386" />
  <row Id="11909" PostId="8286" Text="That sampling code is a good start.  If you have specific code questions about your board, you may also want to check out www.43oh.com, there forums have a lot of msp430 related code and projects." CreationDate="2010-12-25T22:27:04.857" UserId="2060" />
  <row Id="11910" PostId="8288" Text="It would be great if you can give me a suggested link to a board that would be good for my project. i also hear you can simulate data in matlab eliminating the need for a board." CreationDate="2010-12-25T22:30:07.133" UserId="2386" />
  <row Id="11911" PostId="8286" Text="Yea i was linked to that site before, jsolarski is there anyway i can get in contact with you via e-mail you seem like you know a lot about this, would be great for future question i may have." CreationDate="2010-12-25T22:31:27.397" UserId="2386" />
  <row Id="11912" PostId="8286" Text="Absolutely, Use the contact form on my website http://justinstech.org/contact-me/ I will respond with my email address in the next 24 hours.  " CreationDate="2010-12-25T22:37:32.397" UserId="2060" />
  <row Id="11913" PostId="8272" Score="1" Text="I recommend using both linux and windows. Those restricted to one or the other miss out in great programs, and limit their program portability." CreationDate="2010-12-25T23:02:50.773" UserId="2118" />
  <row Id="11914" PostId="8289" Text="@Jay I would highly recommend you pick something that you are actually interested in doing. You also will want to find something your advisors are interested it (especially if they have funding). So, go talk to your advisor. Get ideas from them and then pick what you want. You are a masters student, this is one of the hurdles they make you go through but trust that you are fully capable of doing it." CreationDate="2010-12-25T23:03:15.663" UserId="319" />
  <row Id="11915" PostId="8288" Text="You could use one of the Microchip boards. See the web site." CreationDate="2010-12-25T23:04:45.243" UserId="305" />
  <row Id="11916" PostId="8286" Text="Thanks for all the help" CreationDate="2010-12-25T23:07:49.050" UserId="2386" />
  <row Id="11917" PostId="8288" Text="any recommendations though of which ones?" CreationDate="2010-12-25T23:08:19.473" UserId="2386" />
  <row Id="11918" PostId="8289" Score="4" Text="If you have to come to a site like this for ideas, you should ask yourself if you have chosen the correct course." CreationDate="2010-12-25T23:08:22.557" UserId="305" />
  <row Id="11919" PostId="8283" Score="2" Text="great answer!  sometime it seems like half the challenge is finding out the names of things." CreationDate="2010-12-25T23:13:32.123" UserId="1756" />
  <row Id="11920" PostId="8288" Text="It depends on your requirements. You should be able to find something suitable for yourself." CreationDate="2010-12-25T23:19:01.460" UserId="305" />
  <row Id="11921" PostId="8288" Text="ill go take a look." CreationDate="2010-12-25T23:23:25.083" UserId="2386" />
  <row Id="11922" PostId="8269" Text="pardon the noobness, What is a BGA?" CreationDate="2010-12-25T23:28:43.607" UserId="1756" />
  <row Id="11923" PostId="8290" Text="its not so much audio recording, my current board as a pre build recoding software, its sampling the data that im having trouble with." CreationDate="2010-12-25T23:43:35.173" UserId="2386" />
  <row Id="11924" PostId="8196" Text="@andrejako, I thought you said it worked for a long time then suddenly started having issues, I would not worry about it then." CreationDate="2010-12-25T23:51:00.810" UserId="230" />
  <row Id="11925" PostId="8270" Text="speaking as an old-time unix programmer, you will probably find a lot more embedded programming tools in the windows world.  Look for something that works well with WINE or with vmware.  A python-based environment would be great, though!" CreationDate="2010-12-26T00:09:14.400" UserId="1756" />
  <row Id="11926" PostId="8279" Score="1" Text="No autorouter here.  I did this by hand in Eagle and got a little carried away with the curved traces." CreationDate="2010-12-26T00:20:49.723" UserId="2377" />
  <row Id="11927" PostId="8290" Text="@martin I am not sure what part you are needing help with. The board I linked to had code given to sample. If you want to know how to do an A-D conversion just read what the command is in the datasheet." CreationDate="2010-12-26T00:38:21.173" UserId="319" />
  <row Id="11928" PostId="8290" Text="yea i saw it now after reading the examples more thoroughly, but i mainly need help with the sampling process using nyquist theorem in C." CreationDate="2010-12-26T00:46:57.853" UserId="2386" />
  <row Id="11929" PostId="8290" Text="What I would do is sample as fast as the hardware allows. I would then look for the highest frequency above a certain threshold. Double that and then use that for my sampling frequency." CreationDate="2010-12-26T00:53:36.257" UserId="319" />
  <row Id="11932" PostId="8296" Text="Are you sure it 1 Hz = 1 RPS? I'm measuring frequency and I'm getting around 50 Hz when I run the fan at 10 V. It's a 92x92x25 fan and they are usually rated between 1800 and 2200 RPM, so 3000 seems a bit high, especially on 10 V. Also, I just found out on the Internet that max RPM for my fan is 2000, so could it be 1 Hz = 1/2 RPS?" CreationDate="2010-12-26T02:21:56.070" UserId="1240" />
  <row Id="11933" PostId="8296" Text="@AndrejaKo, I suppose it could be - how many blades does it have? 4?" CreationDate="2010-12-26T02:37:04.360" UserId="1225" />
  <row Id="11934" PostId="8296" Text="@Thomas O It has 7 blades." CreationDate="2010-12-26T02:40:34.767" UserId="1240" />
  <row Id="11935" PostId="8296" Text="@AndrejaKo, well that's rather odd then, because there's no sane multiple that would get you that speed." CreationDate="2010-12-26T02:52:52.887" UserId="1225" />
  <row Id="11936" PostId="8296" Text="@Thomas O  How does number of blades affect speed reading?" CreationDate="2010-12-26T03:13:59.540" UserId="1240" />
  <row Id="11937" PostId="8295" Text="Related article: http://www.petervis.co.cc/cpu%20fan%20tacho/cpu%20fan%20tacho.html" CreationDate="2010-12-26T03:26:29.597" UserId="1240" />
  <row Id="11938" PostId="8290" Text="Thats what i think ill end up doing. http://programmers.stackexchange.com/questions/29991/help-how-would-i-sample-an-audio-tract-at-nyquist-frequency-using-c-c-and-a-mi that one answer of how to sample in nyquist frequency." CreationDate="2010-12-26T03:28:30.167" UserId="2386" />
  <row Id="11939" PostId="8258" Text="Seriously dude, I don't see the sequence. Your red line just shows they are all over the place, maybe I am being dense and would need some more explanation." CreationDate="2010-12-26T03:33:07.170" UserId="1200" />
  <row Id="11940" PostId="2105" Text="Or use a solder proto-board. breadboards are really only good if you're **really** cheap, and want to reuse ALL your components." CreationDate="2010-12-26T05:32:43.990" UserId="1374" />
  <row Id="11941" PostId="8281" Score="1" Text="Ferrites != Inductors : Ferrites are not inductors! Ferrites generally have very few turns, so interwinding capacitance is not important. Also, ferrites are dissipative, rather then inductive, so high frequency energy passing through a ferrite bead gets converted to heat, rather then simply reflected back. This is why they are commonly used for high frequency applications." CreationDate="2010-12-26T05:34:35.763" UserId="1374" />
  <row Id="11942" PostId="8281" Score="2" Text="Furthermore, if your dsPIC has separate digital and analog power connections, a ferrite between the digital and analog connections (With caps on both sides) is likely a good idea." CreationDate="2010-12-26T05:39:23.467" UserId="1374" />
  <row Id="11943" PostId="8300" Text="Kamal, please understand that this is a very broad question. Please give us more information, along the lines of what you want to accomplish with electronics, what are your interests, what requirements you have on the resources (cost, format, prior knowledge) so that we can give you answers relevant to your interests." CreationDate="2010-12-26T06:02:58.537" UserId="638" />
  <row Id="11945" PostId="8272" Text="Yes, Windows as your base OS for compatibility, and Linux in a virtual machine (for the same reason)." CreationDate="2010-12-26T07:58:12.373" UserId="142" />
  <row Id="11946" PostId="8289" Text="What simple technologies and applications do you find interesting an cool? Come up with a list of ingredients in your fridge, then we can come up with a list of recipes that fit! ;)" CreationDate="2010-12-26T08:45:06.187" UserId="2118" />
  <row Id="11947" PostId="8303" Score="1" Text="That's a little bit too clever. I'm on to you! ;)" CreationDate="2010-12-26T08:48:58.710" UserId="2118" />
  <row Id="11948" PostId="8294" Text="The beat way to use a breadboard is **DON'T**. If it's a simple circuit, use point-to-point wiring. Otherwise, PCBs are so cheap it's not worth the effort to breadboard." CreationDate="2010-12-26T08:54:47.693" UserId="1374" />
  <row Id="11949" PostId="2103" Score="1" Text="All of them. Breadboards are horrible." CreationDate="2010-12-26T08:55:15.273" UserId="1374" />
  <row Id="11950" PostId="8273" Text="Does `mainloop_cnt` toggle? Can you post complete code that shows this behaviour?" CreationDate="2010-12-26T09:45:57.507" UserId="2118" />
  <row Id="11952" PostId="8302" Text="Thanks for the information about Verilog:) " CreationDate="2010-12-26T11:26:07.413" UserId="2382" />
  <row Id="11953" PostId="8300" Text="Endolish the duplicated thread was useful, thx!" CreationDate="2010-12-26T11:33:52.027" UserId="2382" />
  <row Id="11954" PostId="8298" Text="That's not PWM (pulse width modulation)." CreationDate="2010-12-26T12:24:01.253" UserId="339" />
  <row Id="11955" PostId="8289" Text="@tyblu Thanks. I never thought of it in that direction but it makes more sense to think about the interesting technologies and list out the stuff that can be done with them instead of just mindlessly, thinking about something **cool**" CreationDate="2010-12-26T12:29:04.497" UserId="2385" />
  <row Id="11956" PostId="8309" Text="Thank you for your responses. I'll give you an idea of where this comes from. I'm from India – a price sensitive market. I'm part of a tech magazine and it's my interest to introduce a hobby platform that school kids will find easy to adapt to...any suggestion? I hope this helps... " CreationDate="2010-12-26T14:46:53.550" UserId="2392" />
  <row Id="11957" PostId="8310" Text="so is your leaning towards Arduino? Please refer to my comment below for more on the background of my question..." CreationDate="2010-12-26T14:48:06.667" UserId="2392" />
  <row Id="11958" PostId="8309" Text="India you say? Can you mail me? I am trying to bootstrap a company, the products are just what you want. But the product is not exactly on the shelf. Mail me. There is no finance, no business co founder and no business model. But if nothing you might get a good chat out of this." CreationDate="2010-12-26T14:59:47.673" UserId="1200" />
  <row Id="11959" PostId="8258" Score="1" Text="@Rick_2047, starting at pin #19 P0.0, pin #21 P0.1, (follow the red line, you'll see P0.x in order, except for a few special exceptions.) They are all over the place but the order isn't random." CreationDate="2010-12-26T15:00:11.570" UserId="1225" />
  <row Id="11960" PostId="8310" Text="I do lean towards the Arduino. For price sensitive markets you can make up your own Arduino [breadboard clones](http://itp.nyu.edu/physcomp/Tutorials/ArduinoBreadboard) using bare components on a breadboard. There are many other [examples](http://www.oomlout.co.uk/breadboard-arduino-compatible-kit-bbac-p-211.html?zenid=cc463ef0cb7c21c871abff66a73530cc) If you can source components locally at low cost - this might be a good way to get started. The advantage is that you can use the Arduino IDE, perhaps sharing a USB programming cable, and you can participate in the Arduino community." CreationDate="2010-12-26T15:09:44.480" UserId="2191" />
  <row Id="11961" PostId="8283" Score="2" Text="Another note, they sell these type of encoders as quadrature (as shown above) and pulse.  Pulse encoders pulse two lines every detent, with one trailing the other depending on direction.  I like the pulse better because you don't need a state machine to implement, just a couple interrupt inputs.  But it's important to know what you get or you could run into problems interfacing with them.  I'd also check out CUI, they have good encoder prices.  One other thing to look for, mechanical versus optical.  Mechanical is cheap, optical have long life." CreationDate="2010-12-26T15:57:54.097" UserId="2377" />
  <row Id="11962" PostId="8258" Text="Whats the use? I would need at least 8 pins to drive a data port or at least have all the peripheral pins in sequence to directly connect a connector. So the pins are random to me." CreationDate="2010-12-26T16:00:55.700" UserId="1200" />
  <row Id="11963" PostId="8304" Text="As much as I love hackaday, the projects aren't usually thesis level. He would have to have a great imagination to extend one to be good enough for a thesis and if he could do this I am sure he could come up with one on your own." CreationDate="2010-12-26T16:09:07.027" UserId="319" />
  <row Id="11964" PostId="8303" Text="You can set up a 555 in one-shot mode, and then you can actually get the strobe to be short enough to &quot;freeze&quot; the blades." CreationDate="2010-12-26T16:45:58.023" UserId="638" />
  <row Id="11965" PostId="8258" Text="@Rick_2047 Well P0.7 through P0.14 gives you 8 or so pins fairly close to each other to drive a data port. The pins are likely in that order because it makes it cheaper to produce." CreationDate="2010-12-26T17:03:12.420" UserId="1225" />
  <row Id="11966" PostId="8269" Text="@Mark Harrison, Ball Grid Array, no pins, just an array of solder balls, typically very high density (think 121+ pins on something which would have 44 or 64 pins) but a nightmare to layout and design around." CreationDate="2010-12-26T17:04:20.890" UserId="1225" />
  <row Id="11967" PostId="8290" Text="@Martin I was pretty sure that method doesn't work. I went ahead and checked with a friend of mine and confirmed that it doesn't work. You are trying to avoid aliasing and there is no way for a microcontroller to know if you have aliased or not. You always have to start by oversampling and watching it for a bit. Then you can make an assumption of what the bandwidth of your input is and sample based on that." CreationDate="2010-12-26T17:11:23.187" UserId="319" />
  <row Id="11968" PostId="5542" Text="Does the Persulfate turn the board substrate blue, or did your boards have a blue substrate from the beginning?" CreationDate="2010-12-26T17:16:29.153" UserId="746" />
  <row Id="11969" PostId="8258" Text="I cannot deny the fact that this design decision is most probably because of the manufacturing considerations. BTW, p0.7 is on the bottom row and others are on the right row. and between the other 7 pins there is p1.23 and p1.24. That doesn't look like a sequence to me." CreationDate="2010-12-26T18:17:04.353" UserId="1200" />
  <row Id="11970" PostId="8284" Text="A really cool way to do this is to make a rough PSD meter with an audio crossover, setting sampling frequency to the minimum frequency bin achieving a threshold. This is heavy hardware design, but that is what makes it cool! Note that it would still be inferior to oversampling." CreationDate="2010-12-26T19:32:54.477" UserId="2118" />
  <row Id="11971" PostId="8289" Text="Gravitating towards swarm robotics and evolution of control systems at the moment.. lets see" CreationDate="2010-12-26T20:31:49.013" UserId="2385" />
  <row Id="11972" PostId="8258" Text="@Rick_2047 it's in enough of a sequence for most connectors, just you need to route the traces so they are all facing the same direction." CreationDate="2010-12-26T20:41:00.227" UserId="1225" />
  <row Id="11973" PostId="8313" Text="Im planing on doing oversampling are my main experiment, then show the effects of undersampling on a 3 tone audio track. The reason i went with that board was 1) It was suggested 2) i can use it for multiple applications in the future.  " CreationDate="2010-12-26T21:32:05.100" UserId="2386" />
  <row Id="11974" PostId="8284" Text="Interesting thought of how to go about this. Ill look into it and see if its more work then just oversampling the data. " CreationDate="2010-12-26T21:34:32.727" UserId="2386" />
  <row Id="11975" PostId="8284" Text="@Martin, it is definitely more work! ;)" CreationDate="2010-12-26T21:52:40.377" UserId="2118" />
  <row Id="11976" PostId="8314" Score="1" Text="It is hard to understand what you mean by &quot;the frequency&quot; of an input.  Only a pure sine wave input is of a single frequency.  Any other signals are composed of several frequencies." CreationDate="2010-12-26T22:07:31.010" UserId="411" />
  <row Id="11977" PostId="8315" Text="Another way of measuring the frequency of a signal is to condition it then feed it into a PLL.  The PLL will attempt to keep the VCO (voltage-controlled oscillator) running at the same frequency as the input.  Therefore (with a linear VCO) the control voltage on the VCO is linearly related to the frequency.  This is how most FM radio demodulators work.  " CreationDate="2010-12-26T22:11:41.430" UserId="411" />
  <row Id="11978" PostId="8314" Text="@markrages Sorry, I mean max frequency. It was implied from the other posting, but should have be included in my question." CreationDate="2010-12-26T22:13:08.793" UserId="319" />
  <row Id="11979" PostId="8315" Text="Another, poorer method of FM demodulation is to make a filter with a wide slope in the stopband, so that the signal rides the slope.  The closer the signal gets to the passband, the greater its amplitude.  Follow with an amplitude detector.  This method won't reject noise like the PLL will." CreationDate="2010-12-26T22:14:02.693" UserId="411" />
  <row Id="11980" PostId="8316" Text="My first thought for the guys problem was to over-sample, but in an embedded environment I can see why a different method could be preferred." CreationDate="2010-12-26T22:15:44.063" UserId="319" />
  <row Id="11981" PostId="8316" Text="I think over-sampling and resampling in software is probably the best plan.  Otherwise, the sampling filter will need to be a &quot;brick wall&quot; of variable frequency, which is a tricky design in itself." CreationDate="2010-12-26T22:19:43.550" UserId="411" />
  <row Id="11982" PostId="8319" Score="1" Text="Is [this](http://goo.gl/kMIvl) it; or [this](http://goo.gl/fImdG) one?" CreationDate="2010-12-26T23:07:42.637" UserId="2118" />
  <row Id="11983" PostId="8319" Score="4" Text="Usually you want to consider physical considerations like mounting before layout, rather than after." CreationDate="2010-12-26T23:08:02.450" UserId="411" />
  <row Id="11984" PostId="8319" Text="What are you mounting to?" CreationDate="2010-12-26T23:08:41.980" UserId="411" />
  <row Id="11985" PostId="8319" Text="@tyblu, Second one, although that one will be replaced by a third soon." CreationDate="2010-12-26T23:12:19.157" UserId="1225" />
  <row Id="11986" PostId="8319" Text="@markrages, I am in the process of designing a third one and considering mounting before doing so." CreationDate="2010-12-26T23:12:44.320" UserId="1225" />
  <row Id="11987" PostId="8319" Text="Also, what environment is it in? Vibration suppression tablet or joyriding Humvee? Is it delicate?" CreationDate="2010-12-26T23:13:42.460" UserId="2118" />
  <row Id="11988" PostId="8319" Text="@markrages, That is a good question. The module may be left freely in the body of a model aircraft or may be fixed to something like the wing or on top of the plane. As I don't know how people will use it, I'm looking for a catch all best solution." CreationDate="2010-12-26T23:13:54.990" UserId="1225" />
  <row Id="11989" PostId="8319" Text="@tyblu, It has ceramic capacitors so microphonic effects might be observed, though it is fairly rugged, no moving parts." CreationDate="2010-12-26T23:14:32.650" UserId="1225" />
  <row Id="11990" PostId="8284" Text="How much work do you think a ADC, oversampling process, then DAC in c would take?" CreationDate="2010-12-27T00:13:21.670" UserId="2386" />
  <row Id="11991" PostId="8318" Text="How would i then use nyquist or oversample it? ADC isnt so much of a problem because they give example code, but chouldnt i just patch the sampling code into the already given ADC code?" CreationDate="2010-12-27T00:19:10.883" UserId="2386" />
  <row Id="11992" PostId="8284" Text="ADC and DAC can be hardware peripherals, leaving the micro to do nothing but wait for ADC interrupts to read values from the ADC registers or timer interrupts to write values to the DAC registers -- it's the FFT that can leave it breathless. It is worth learning where to optimize a FFT algorithm (including looking for alternatives) for cycles and memory while staying within your requirements." CreationDate="2010-12-27T00:20:03.573" UserId="2118" />
  <row Id="11993" PostId="8284" Text="How about this thought, only use the board for the ADC and DAC (since i already have the example code) and then doing the dsp process using my computer, This would work right?" CreationDate="2010-12-27T00:24:31.687" UserId="2386" />
  <row Id="11994" PostId="8318" Text="I don't know what you mean by &quot;use nyquist.&quot;  Please explain." CreationDate="2010-12-27T00:28:39.463" UserId="411" />
  <row Id="11995" PostId="8319" Text="Will you have connectors on it, or wires hanging out?  If it is wires hanging out, you can just shrink wrap the whole thing and let users mount it with wire ties into their harness.  If there are connectors on it, you will want a more rigid mount." CreationDate="2010-12-27T00:30:16.077" UserId="411" />
  <row Id="11996" PostId="8318" Text="sampling it at 2x the highest frequency; though i think just over sampling it would be best (so just say 20000hz instead of 2c highest of (unknown) frequency)..    But anyways what your saying is to download sample it first." CreationDate="2010-12-27T00:31:12.880" UserId="2386" />
  <row Id="11997" PostId="8319" Text="@markrages, There will be connectors on many parts of the board. I think this might impede putting it in heatshrink." CreationDate="2010-12-27T00:34:16.730" UserId="1225" />
  <row Id="11998" PostId="8318" Text="It's usually better to just decide *a priori* what the highest frequency you need to handle is.  For audio, you might choose 20 kHz, since that's around the top end of what people can hear.  Then design your system around that: for 20 kHz, you might sample at 48 kHz, so your sampling filter has 4kHz between passband and stopband, making it easier to design." CreationDate="2010-12-27T00:36:28.803" UserId="411" />
  <row Id="11999" PostId="8319" Text="ok, I think &quot;hole in each corner&quot; is probably the best you can do.  But maybe I lack imagination." CreationDate="2010-12-27T00:38:35.590" UserId="411" />
  <row Id="12000" PostId="8318" Text="Yea thats what i was saying, just to over sample it since the highest frequency is unknown in this situation. How should i go about making the sampling filter then in C? So it would be like this ADC -&gt; downsample -&gt; Re-resample using the new sampling filter -&gt; DAC ( reconstruction). And i suppose only to use the board for the ADC processes " CreationDate="2010-12-27T00:40:04.180" UserId="2386" />
  <row Id="12001" PostId="8318" Text="I was talking about the (analog) sampling filter before the ADC." CreationDate="2010-12-27T00:44:31.983" UserId="411" />
  <row Id="12002" PostId="8318" Text="oh, ok. just to make to put it in a flow chart, what would the process be for the whole process of downsampling to resampling to reconstruction?" CreationDate="2010-12-27T00:48:06.807" UserId="2386" />
  <row Id="12003" PostId="8318" Text="there's many ways to do it, but I would suggest ADC and DAC at 48kHz.  So the flow is analog signal -&gt; sampling analog filter -&gt; ADC -&gt; resample down -&gt; resample up -&gt; DAC -&gt; reconstruction analog filter.  If you sample with an audio codec it might include the reconstruction filter on the chip.  &quot;resample down&quot; and &quot;resample up&quot; will use a low-pass filter.  In fact this will be the *same* filter.   So if you don't need the downsampled stream for anything else, you could replace &quot;resample down-&gt; resample up&quot; with &quot;low pass filter&quot; and have the same output. " CreationDate="2010-12-27T00:52:10.247" UserId="411" />
  <row Id="12004" PostId="8318" Text="So i guess the tricky part will be making the sampling analog filters and the low pass filter(Down and up sampling). Would you suggest doing this in several steps rather then one large code." CreationDate="2010-12-27T00:54:56.330" UserId="2386" />
  <row Id="12005" PostId="8317" Text="AND they allow free samples! Up to 2 orders of up to 2 components per month = 4 micros per month (Note that you must have an e-mail at a different domain than common email providers like comcast or gmail. University emails might work, I've never tried)" CreationDate="2010-12-27T00:55:14.730" UserId="790" />
  <row Id="12006" PostId="8322" Text="if you can ssh, then you can use gdb for debugging code, or possibly foward the gdb traffic and use a graphical debugger on your computer" CreationDate="2010-12-27T00:55:42.450" UserId="708" />
  <row Id="12007" PostId="8273" Text="@tyblu, mainloop_cnt increments each time through the loop.  I've added the for-loop used as well." CreationDate="2010-12-27T00:59:51.600" UserId="1555" />
  <row Id="12008" PostId="8318" Text="@Martin, audio &gt; anti-aliasing &gt; ADC &gt; FFT &gt; digital LPF &gt; decimation &gt; DAC &gt; LPF" CreationDate="2010-12-27T01:00:26.410" UserId="2118" />
  <row Id="12009" PostId="8318" Text="If you use an audio codec, just follow the datasheet and you'll have the analog part covered.  If you use a devboard, make sure it is designed to process audio (it will have an input and output jack) and the board will have the analog stuff covered for you.  The low pass filter is to go from the full sampled bandwidth (24 kHz, if sampled @ 48 kHz) to whatever bandwidth is &quot;necessary&quot; for your signal.  There are good web resources to design a digital low pass filter." CreationDate="2010-12-27T01:00:41.617" UserId="411" />
  <row Id="12010" PostId="8318" Text="yea the dev board i have right now has all the required hardware for actual audio dsp processes i have the link im the main post to my board if you would i like to see it, and gives example DAC and ADC code for the microcontroller. So the main problem is the analog filter if i can find the digital low pass filter online." CreationDate="2010-12-27T01:04:34.663" UserId="2386" />
  <row Id="12011" PostId="8318" Text="Don't worry about the analog filter.  Your dev board will have it built in." CreationDate="2010-12-27T01:05:20.443" UserId="411" />
  <row Id="12012" PostId="8318" Text="i found this fft filer online http://pastebin.com/39zN9phE , is that heading in the right track" CreationDate="2010-12-27T01:08:18.137" UserId="2386" />
  <row Id="12013" PostId="8230" Text="Interesting... I actually wanted to do this with red LEDs only.  I also want something a little more predictable/controllable - thanks for the info though." CreationDate="2010-12-27T01:09:34.390" UserId="2366" />
  <row Id="12014" PostId="8323" Text="It currently looks like MCF5282_GPIO_PORTDD should be toggling between 0x10 and 0x00, every sixteen iterations. You're not getting any output?" CreationDate="2010-12-27T01:09:41.953" UserId="2344" />
  <row Id="12015" PostId="8318" Text="No, that's not helpful.  Frankly, I'm puzzled at the purpose of your project, since a successful result will mean the output is the same as the input.  But the same is also true of a piece of wire." CreationDate="2010-12-27T01:13:48.253" UserId="411" />
  <row Id="12016" PostId="8318" Text="Its just to show the effect of nyquist rate sampling, over and undersampling using a microconroller, but its turning out to be far more complicated then i had anticipated. " CreationDate="2010-12-27T01:16:27.067" UserId="2386" />
  <row Id="12017" PostId="8318" Score="1" Text="I suggest you do your DSP experimentation on your desktop with Octave or Matlab.  And start with &quot;blink the LED&quot; on the microcontroller.  Get good at both &quot;DSP&quot; and &quot;microcontroller&quot; before you attempt &quot;DSP on microcontroller&quot;." CreationDate="2010-12-27T01:33:40.493" UserId="411" />
  <row Id="12018" PostId="8284" Text="You would have to transmit and receive the data to and from your computer with a serial port or using an external USB chip (FTDI, etc.), which isn't a problem near 50 kHz, but seems overly complicated. If you can use a PC, why not get it to do it all, and just plug into the audio input and line out jacks?" CreationDate="2010-12-27T01:35:16.817" UserId="2118" />
  <row Id="12019" PostId="8318" Text="How hard would dsp on the computer be, forgetting the board entirely. The whole goal of my project is to study the effects of Nyquist, over-under sampling, and reconstruction of a audio track.  " CreationDate="2010-12-27T01:39:30.783" UserId="2386" />
  <row Id="12020" PostId="8318" Text="DSP on the computer is relatively easy.  Octave will have functions for loading an audio file and playing it back, and any kind of manipulation you can think of.  You will be free to concentrate on the math." CreationDate="2010-12-27T01:43:50.897" UserId="411" />
  <row Id="12021" PostId="8318" Text="So it will have the dsp functions for over and undersampling? Is there any specific dsp libraries for octave or is it all there?" CreationDate="2010-12-27T01:46:41.053" UserId="2386" />
  <row Id="12022" PostId="8318" Text="octave-forge has the user contributed libraries. There are probably functions to do the sampling, but if you are trying to learn, you should write your own." CreationDate="2010-12-27T01:59:01.937" UserId="411" />
  <row Id="12023" PostId="8318" Text="Hey, mark you have been a lot of help, but this is all the time i have for now. Is there any way i can contact you with further questions?" CreationDate="2010-12-27T02:01:20.443" UserId="2386" />
  <row Id="12024" PostId="8318" Text="@Martin, you should upvote his answer!" CreationDate="2010-12-27T02:54:17.447" UserId="2118" />
  <row Id="12025" PostId="8318" Text="Just registered " CreationDate="2010-12-27T02:58:50.310" UserId="2386" />
  <row Id="12026" PostId="8318" Text="Just post questions on here, you'll get lots of help.  In the meantime, poke around dspguru.com and read about sample rate conversion. http://www.dspguru.com/dsp/faqs/multirate/resampling" CreationDate="2010-12-27T03:07:10.737" UserId="411" />
  <row Id="12028" PostId="8309" Score="1" Text="I would not suggest MSP430 launchpad for starters, It is a great platform for the price but it may be to advanced for beginners." CreationDate="2010-12-27T08:48:41.760" UserId="2060" />
  <row Id="12029" PostId="8010" Text="looking forward to hear some news ;)" CreationDate="2010-12-27T11:16:43.550" UserId="2316" />
  <row Id="12031" PostId="8328" Text="I am not worried about circuit or battery protection. If i choose a Li-variation I will look into the circuits needed to charge and use those types of batteries. " CreationDate="2010-12-27T12:58:09.073" UserId="2060" />
  <row Id="12032" PostId="8334" Text="http://www.tkgate.org/" CreationDate="2010-12-27T14:13:27.570" UserId="2060" />
  <row Id="12033" PostId="8331" Text="In Belgium (where Peter is from) Blue=Neutral, Brown=Phase, Yellow/Green=Earth" CreationDate="2010-12-27T14:22:15.053" UserId="2064" />
  <row Id="12034" PostId="8332" Text="Thanks for your reply! I have updated my question to hopefully rectify the confusion in the answers. It can't be a cross switch however as I only have 3 wires on each and every switch. Must be magic? :-)" CreationDate="2010-12-27T14:22:21.060" UserId="2403" />
  <row Id="12035" PostId="8332" Text="You might be right though about a device that switches the yellow wire on/off on each pulse of the red. It would make so much sense but I can't seem to find such a device anywhere. Where would you put something like this? All my wiring is connected using PVC tubes in the attic." CreationDate="2010-12-27T14:24:32.807" UserId="2403" />
  <row Id="12036" PostId="8331" Text="Thanks for your answer, I've updated my question with additional info regarding the switch and wiring." CreationDate="2010-12-27T14:27:52.010" UserId="2403" />
  <row Id="12037" PostId="8328" Score="2" Text="Its more for protection of the battery." CreationDate="2010-12-27T14:49:20.020" UserId="1623" />
  <row Id="12038" PostId="8335" Text="Do you know what these switches are called so I can replace them with new ones? I can't find any info about them anywhere although it makes absolute sense what you're saying!" CreationDate="2010-12-27T14:54:22.807" UserId="2403" />
  <row Id="12039" PostId="8335" Text="On the [Niko site](http://www.niko.be/nlbe/consumers/producten/detail/je-basisinstallatie/schakelaars) they're called &quot;drukknop&quot;. You can have it as a single pushbutton, fourfold, or sixfold, with or without feedback LEDs." CreationDate="2010-12-27T14:57:26.973" UserId="2064" />
  <row Id="12040" PostId="8335" Text="I feel so stupid now :-) This must be it." CreationDate="2010-12-27T15:31:59.827" UserId="2403" />
  <row Id="12041" PostId="8309" Text="yes, msp430 is MUCH harder than arduino" CreationDate="2010-12-27T16:06:39.267" UserId="2006" />
  <row Id="12042" PostId="8337" Score="4" Text="&quot;PDF for sale&quot; should tell you all you need to know about this - its a scam. &quot;Threats from energy companies&quot; is also a classic telltale sign of prople who are either fraudsters or self-delusional. " CreationDate="2010-12-27T16:40:54.157" UserId="1681" />
  <row Id="12043" PostId="8337" Text="Virtually identical post as here: http://electronics.stackexchange.com/questions/4639/what-are-some-alternative-power-sources-for-wireless-sensors/8223#8223  This question may still be useful as a method to refute the bogus claims on the linked website, however." CreationDate="2010-12-27T16:42:56.803" UserId="1407" />
  <row Id="12044" PostId="8337" Text="It might be helpful, if someone can, to do a short analysis on this circuit.  I'm assuming the diodes form a sort of regulator?" CreationDate="2010-12-27T16:58:33.243" UserId="374" />
  <row Id="12045" PostId="8338" Text="I'd probably say *useable* energy, no.  More to the point, what antenna you use will largely determine what frequency you will capture, &quot;bulk capacitive&quot; perhaps being the most efficient for 50-60 Hz line power." CreationDate="2010-12-27T17:06:44.710" UserId="1407" />
  <row Id="12046" PostId="8338" Text="You are a serious coupler! I only get ~1Vpp ;)" CreationDate="2010-12-27T17:07:30.840" UserId="2118" />
  <row Id="12047" PostId="8338" Text="How much energy would 50 feet of copper tubing capture?" CreationDate="2010-12-27T17:14:06.780" UserId="794" />
  <row Id="12048" PostId="8340" Score="1" Text="It's a big-corp. conspiracy!" CreationDate="2010-12-27T17:19:40.300" UserId="2118" />
  <row Id="12049" PostId="8326" Text="Very well composed question. +1!" CreationDate="2010-12-27T17:22:00.373" UserId="2118" />
  <row Id="12050" PostId="8340" Score="5" Text="If it seems too good to be true, it probably is." CreationDate="2010-12-27T17:25:10.123" UserId="2064" />
  <row Id="12051" PostId="8337" Text="I bought their PDF, as I mentioned elsewhere. This PDF doesn't have a scrap of copyright anywhere in it. Does this mean I can freely distribute it?" CreationDate="2010-12-27T17:29:19.677" UserId="794" />
  <row Id="12052" PostId="8332" Text="@Peter: like I said, it's normally DIN-rail mounted in a cabinet (&quot;schakelkast&quot;). Don't you have such a cabinet where the yellow wire starts. You'll have to find this yellow wire to solve the mystery. " CreationDate="2010-12-27T17:45:30.010" UserId="2064" />
  <row Id="12053" PostId="8338" Text="@tyblu: you're not touching the ground wire at the same time, are you? 'cause I'm not." CreationDate="2010-12-27T17:47:27.060" UserId="2064" />
  <row Id="12054" PostId="8337" Text="@Arlen: it's not because it doesn't mention a copyright that a copyright isn't applicable. I guess you can't distribute it freely. Though I must say I'm curious what the document says. Not that I expect it to make much sense..." CreationDate="2010-12-27T17:50:50.693" UserId="2064" />
  <row Id="12055" PostId="8337" Score="3" Text="@Arlen: In most countries around the world, all works are copyrighted by the author by default unless mentioned otherwise.  In the US, the relevant law would be the [Berne Convention Implementation Act of 1988](http://en.wikipedia.org/wiki/Berne_Convention_Implementation_Act_of_1988), I believe." CreationDate="2010-12-27T17:55:03.670" UserId="1407" />
  <row Id="12056" PostId="8340" Text="@mark: ​​​​​​​​win." CreationDate="2010-12-27T18:02:08.810" UserId="1407" />
  <row Id="12058" PostId="8338" Text="@Arlen: I bet you could reach up to a power-co. kV line with 50' of copper, so potentially, lots.  You need to specify more details if you're talking wireless." CreationDate="2010-12-27T18:04:59.107" UserId="1407" />
  <row Id="12059" PostId="8338" Text="@steven: Never heard of a tin diode, can't find anything on Google either...some tin oxide composition?" CreationDate="2010-12-27T18:09:04.470" UserId="1407" />
  <row Id="12061" PostId="8337" Text="I googled a phrase in the document and found this: http://scribd.com/doc/41445605/TeslaSecret (I didn't post it, btw)" CreationDate="2010-12-27T18:17:32.757" UserId="794" />
  <row Id="12062" PostId="8260" Text="@tyblu - This is a question migrated from Superuser (Didn't know we could do that yet!).  Porramate Lim doesn't have an account here, so he probably can't answer your question." CreationDate="2010-12-27T18:28:25.483" UserId="857" />
  <row Id="12063" PostId="8337" Score="1" Text="I watched the ad video and I'm appalled. This is the biggest load of crap and lies I've seen since &quot;The Secret&quot;. Watch it at your own risk. You could write pages about what's wrong with it, which is more or less everything. It should be an incentive for more scientific education in high school, so that more people realize _why_ it's a load of crap, and won't be gullible enough to buy this kind of rubbish." CreationDate="2010-12-27T18:31:26.290" UserId="2064" />
  <row Id="12064" PostId="8340" Text="@markrages: sorry mark, I removed your picture because it completely alters Kellenjb's answer. Please post it as a separate answer." CreationDate="2010-12-27T18:37:20.700" UserId="2064" />
  <row Id="12065" PostId="8347" Score="4" Text="quick elaboration - the current draw of your circuit will dictate how much voltage drops over the 10 meters of wire (V = iR). You probably have some minimum operating voltage for your circuit..." CreationDate="2010-12-27T18:46:32.500" UserId="771" />
  <row Id="12066" PostId="8298" Text="it would be PFM (pulse frequency modulation)" CreationDate="2010-12-27T18:46:48.210" UserId="1407" />
  <row Id="12067" PostId="8343" Score="3" Text="Sorry Redburn, but I don't think [E&amp;R](http://electronics.stackexchange.com/) is the right forum to be asking this question. Please see the [FAQ here](http://electronics.stackexchange.com/faq)." CreationDate="2010-12-27T18:48:52.610" UserId="2118" />
  <row Id="12068" PostId="8344" Text="The circuit has an input; the antenna (or coil, plate of a cap, whatever).  You're interpreting it as a closed system (with some initial conditions)." CreationDate="2010-12-27T18:53:35.040" UserId="1407" />
  <row Id="12069" PostId="8349" Text="Thanks for answer. Yeah, I didn't know where the best place to ask was. I use StackOverflow all the time for software questions and thought this would be the best fit. " CreationDate="2010-12-27T18:54:37.967" UserId="2407" />
  <row Id="12070" PostId="8346" Score="1" Text="How could that possibly be stealing? Isn't it just wasted anyway?" CreationDate="2010-12-27T18:55:11.210" UserId="794" />
  <row Id="12071" PostId="8337" Text="The dumb thing about the video is that it makes very little sense (and is mostly VERY boring), whereas the PDF makes a lot of sense. I found it and linked to it above." CreationDate="2010-12-27T18:57:25.890" UserId="794" />
  <row Id="12072" PostId="8343" Text="As I mentioned to pingswept, thought this would be the best fit for any of the stack exchange sites go :)" CreationDate="2010-12-27T18:57:47.840" UserId="2407" />
  <row Id="12073" PostId="8344" Text="Yeah, that's true. The storage capacity is still limited as described. If the caps aren't storage, what are they?" CreationDate="2010-12-27T18:58:59.287" UserId="712" />
  <row Id="12074" PostId="4271" Text="http://stackoverflow.com/questions/3652233/arduino-bootloader/3655529#3655529 Was wondering where my answer went..." CreationDate="2010-12-27T19:01:08.153" UserId="1407" />
  <row Id="12075" PostId="8343" Text="Superuser would be better.  Possibly DIY.SE.  " CreationDate="2010-12-27T19:03:17.450" UserId="1407" />
  <row Id="12076" PostId="8343" Text="This question is best asked at an AV Forum." CreationDate="2010-12-27T19:17:24.803" UserId="374" />
  <row Id="12078" PostId="8346" Score="1" Text="What they would be constructing (in this almost assuredly apocryphal tale), is essentially a giant transformer with a half turn on the primary.  This would have an effect on the HV line, but the power company actually detecting it (electrically) is unlikely.  There might be a grain of truth in the tale where the power company saw something bizarre reaching towards their HV lines during maintenance, making them very nervous, so they tell whoever to stop." CreationDate="2010-12-27T19:24:46.307" UserId="1407" />
  <row Id="12079" PostId="8274" Text="Dave, signatures are discouraged here, as they are repetitive with your nameplate which is posted below your question/answer." CreationDate="2010-12-27T19:50:41.230" UserId="1407" />
  <row Id="12080" PostId="8351" Text="Yeah, but there is less demand for 4-channel oscilloscopes than 2-channel ones, so the prices are typically much higher. Don't forget for digital scopes you also need to take into account the extra ADCs if any, or the switching logic if no additional ADCs are used, and then complex things like noise/crosstalk between channels, etc. At least that's my experience - 4ch is often 2x-3x more expensive, there are exceptions of course." CreationDate="2010-12-27T20:08:26.090" UserId="1225" />
  <row Id="12081" PostId="8350" Text="DSO is Digital Storage Oscilloscope. I'm talking about digital sampling oscilloscopes (not DSO)." CreationDate="2010-12-27T20:46:39.387" UserId="2118" />
  <row Id="12082" PostId="8354" Text="Which spice program are you using on OSX?" CreationDate="2010-12-27T21:03:14.487" UserId="974" />
  <row Id="12083" PostId="8231" Text="The XC2064 is an ancient part.  I don't know if CY7C341B and CY39100V484B are still made.  You should consider that when making any comparison/decision." CreationDate="2010-12-27T21:11:51.453" UserId="206" />
  <row Id="12084" PostId="8354" Text="@AndrewKohlsmith, [MacSpice](http://www.macspice.com/); netlist- and command line-based. I'm not much of a SPICE guru, but it seems to work well." CreationDate="2010-12-27T21:17:03.713" UserId="2118" />
  <row Id="12085" PostId="8347" Text="@vicatu - Good point, the minimum operating voltage is what we're really looking for." CreationDate="2010-12-27T21:21:35.667" UserId="857" />
  <row Id="12087" PostId="8355" Text="What is the model of your function generator?" CreationDate="2010-12-27T21:33:09.770" UserId="2118" />
  <row Id="12088" PostId="8355" Text="The one I would be using would be the PI-8127 - http://store.pasco.com/pascostore/showdetl.cfm?&amp;DID=9&amp;Product_ID=57530&amp;groupID=264&amp;page=Experiments" CreationDate="2010-12-27T21:35:54.870" UserId="2409" />
  <row Id="12089" PostId="6091" Score="2" Text="Enough speculation; someone needs to go get the pricing information.  I visited [Tektronix](http://www.tek.com/products/oscilloscopes/) and [Agilent](http://www.home.agilent.com/agilent/product.jspx?cc=US&amp;lc=eng&amp;nid=-536902447.0&amp;&amp;cc=US&amp;lc=eng) and looked for US prices, choosing 3 semi-random scopes on the low, middle, and high-end lines for each manufacturer.  Aside from the cheapest Tek scopes (1.56x), **the 4 channel scopes were between 1.12 and 1.23 times as expensive.**  We need more data; price differences are all over the place." CreationDate="2010-12-27T21:42:39.820" UserId="857" />
  <row Id="12090" PostId="8351" Score="1" Text="@Thomas - Where are you getting this data?  Distributors?  Manufacturer web pages?  eBay?  I did a tiny amount of searching, and posted my findings - 4-ch is 1.12 to 1.23x more expensive - as a comment to the original question." CreationDate="2010-12-27T21:45:47.433" UserId="857" />
  <row Id="12091" PostId="6091" Score="3" Text="Additional findings: The multiplier is almost always less on more expensive scopes.  The &lt;$1000 Teks were 1.56x, while the $20,000 Agilents were 1.12.  This is not what I would have expected.  I thought I'd find that cheap scopes had very little money in the sampling electronics, and costs were mostly in the LCD, case, software etc., while expensive scopes would have most of the money in the sampling circuitry and the LCD, case, software etc. would be just a couple hundred dollars of overhead." CreationDate="2010-12-27T21:50:25.170" UserId="857" />
  <row Id="12092" PostId="8359" Text="Okay thanks, I assumed so, however I wasn't sure how the frequency affected the current. " CreationDate="2010-12-27T22:14:42.623" UserId="2409" />
  <row Id="12093" PostId="8358" Text="Okay thanks, that explains what I was missing, was the p-p part." CreationDate="2010-12-27T22:15:38.193" UserId="2409" />
  <row Id="12094" PostId="8360" Text="Okay, thanks, the R_load is this case would just be a helmholtz coil setup so it shouldn't be frequency dependent as you said." CreationDate="2010-12-27T22:16:31.763" UserId="2409" />
  <row Id="12095" PostId="8210" Text="Was after something I could make my self at what ever length" CreationDate="2010-12-27T22:21:01.960" UserId="665" />
  <row Id="12096" PostId="8134" Text="Leon's comment are the ones I will use" CreationDate="2010-12-27T22:21:42.927" UserId="665" />
  <row Id="12097" PostId="8134" Text="Oh and I am a Male not that it matters much" CreationDate="2010-12-27T22:22:17.513" UserId="665" />
  <row Id="12098" PostId="8359" Text="If you had a capacitor or inductor instead of just a resistor, the calculation gets trickier." CreationDate="2010-12-27T22:24:39.630" UserId="411" />
  <row Id="12099" PostId="8337" Text="Arlen, you are a spammer. I can see you trying to pretend like you are not involved on this other thread as well: http://electronics.stackexchange.com/questions/4639/what-are-some-alternative-power-sources-for-wireless-sensors/8223#8223" CreationDate="2010-12-27T22:29:34.320" UserId="2006" />
  <row Id="12100" PostId="8360" Text="A Helmholtz coil is definitely frequency dependent, but I wouldn't worry about it." CreationDate="2010-12-27T22:41:57.587" UserId="2118" />
  <row Id="12101" PostId="8337" Text="Look, I seriously am not." CreationDate="2010-12-27T22:46:38.513" UserId="794" />
  <row Id="12102" PostId="8118" Text="My particular application uses motors that I intend to run at 9v." CreationDate="2010-12-27T23:43:48.613" UserId="2172" />
  <row Id="12103" PostId="8114" Text="What would be the ground current for a 9v input with an LM7805?" CreationDate="2010-12-27T23:47:40.527" UserId="2172" />
  <row Id="12104" PostId="8175" Text="I'm running with this concept for now as it is the best fit with the hardware I have. Thanks!" CreationDate="2010-12-27T23:56:39.377" UserId="2172" />
  <row Id="12105" PostId="8360" Text="Oh okay then, thanks." CreationDate="2010-12-28T00:02:39.167" UserId="2409" />
  <row Id="12106" PostId="6091" Text="@reemrevnivek, you're probably correct, but prices are still more, and $560 extra is a lot more when $1000 is already a lot of money for me." CreationDate="2010-12-28T00:02:46.137" UserId="1225" />
  <row Id="12107" PostId="8346" Text="@Nick Mythbusters confirmed this story apparently; and this strange dude on youtube set them straight on how to &quot;do it right&quot; it seems: http://www.youtube.com/watch?v=6hs9Gz4JuhI ... wow, that could have been way more entertaining :)" CreationDate="2010-12-28T00:09:33.807" UserId="771" />
  <row Id="12108" PostId="8197" Text="Just thinking about this, what engineer on the planet earth would design a universal adapter that offers selections of 4.5, 6 and not 5!?  I'm guessing it's a switch based unit and they switch in and out a small set of resistors in the regulator feedback where some combination gives 4.5 and 6, and God forbid they spend 3 cents on a separate resistor for 5." CreationDate="2010-12-28T00:25:31.507" UserId="2377" />
  <row Id="12109" PostId="8175" Text="@Isaac, you may want to sketch several alternatives as well. Time spent on paper saves quite a bit more down the design path. This is only a quick sketch, and, as @NickT commented, it has flaws." CreationDate="2010-12-28T00:30:03.283" UserId="2118" />
  <row Id="12110" PostId="8363" Score="2" Text="I don't think this question fits E&amp;R. You'd be better off at [Stack Overflow](http://stackoverflow.com/)." CreationDate="2010-12-28T00:31:43.687" UserId="2118" />
  <row Id="12111" PostId="8363" Text="i posted it in all the forums hoping to get a wide spread of answers, as everyones help is wanted. Its funny i posted in stack overflow first and yet to get an answer were as both the other sites i have people have atleast looked at it." CreationDate="2010-12-28T00:36:39.403" UserId="2386" />
  <row Id="12112" PostId="8366" Text="Apreciate the polite way of putting it. You are right. I am very much over my head. But I can't really seem to find information about just how hard or simple such a project is. I hoped to find some sort of path on how to learn about how such projects are done." CreationDate="2010-12-28T00:54:55.207" UserId="941" />
  <row Id="12113" PostId="8363" Score="1" Text="This is a pure EE question. Better to present it here than to the mathematically illiterate programmers at SO." CreationDate="2010-12-28T01:31:29.103" UserId="411" />
  <row Id="12114" PostId="8363" Text="Im getting yelled at were ever i post this. mark is this what you were saying earlier about doing it in matlab first then reconstructing it for msp430?" CreationDate="2010-12-28T02:58:49.057" UserId="2386" />
  <row Id="12115" PostId="8197" Text="it's probably designed to replace an integral number of 1.5v cells" CreationDate="2010-12-28T04:26:28.287" UserId="2246" />
  <row Id="12116" PostId="8338" Text="Lots of metal oxides can have diode-behavior under the right conditions - often undesired ones, such as rectification in corroded antenna connections leading harmonic distortion and thus interference on other frequencies.  My great uncle claims to have made a crystal radio with a lump of coal instead of the usual galena crystal." CreationDate="2010-12-28T05:00:24.827" UserId="2246" />
  <row Id="12118" PostId="8363" Score="1" Text="@Martin Cross posting is not viewed nicely among the stack exchange communities. It especially seems fishy when you create different account (and names) for each site rather then using the same name and linking all sites together." CreationDate="2010-12-28T05:28:30.113" UserId="319" />
  <row Id="12119" PostId="8363" Text="@markrages E&amp;R is not a EE site, nor is SO a computer science site. It may so happen that EEs tend more toward E&amp;R, but that doesn't necessarily mean that all topics that EEs go over are appropriate for this site. However, with that said, I personally am fine with DSP questions being here." CreationDate="2010-12-28T05:31:19.660" UserId="319" />
  <row Id="12120" PostId="8371" Text="@Chris Stratton It might be helpful if you expand on why you can't just repeat the input values when he up-samples." CreationDate="2010-12-28T05:35:10.517" UserId="319" />
  <row Id="12121" PostId="8363" Score="2" Text="@Martin &quot;using nyquist&quot; is not really a proper use of the word. It almost sounds like nyquist could be a function that you call. Nyquist is the name of a guy when used by itself. It is more commonly said as Nyquist Frequency, or Nyquist–Shannon sampling theorem, or folding frequency. Either way, Nyquist isn't a process. Just some tips on how to word it better." CreationDate="2010-12-28T05:42:01.963" UserId="319" />
  <row Id="12122" PostId="8371" Text="Repeating samples is comparable to doing the right thing - alternating input samples and zeroes, and then feeding that through an FIR kernel consisting of a few ones.  That is to say, convolving it with a rectangular pulse in time, which is a sinc function in the frequency domain.  This gives the frequency response a sinc-function shape rather than flat passband up to the desired response frequency.  More intuitively, the repetition boosts the low frequencies but starts to destructively interfere with the higher ones.  Besides, it's cheaper to multiply by zero..." CreationDate="2010-12-28T05:57:50.493" UserId="2246" />
  <row Id="12123" PostId="8353" Text="With a cheap CPLD under a buck in small quantity, PAL/PLA/GAL are pretty much dead except for legacy applications." CreationDate="2010-12-28T06:15:15.087" UserId="2246" />
  <row Id="12124" PostId="8341" Score="1" Text="One reason for keeping a CPLD is that current low-cost CPLDs are still being made in single-supply voltage technologies, while most current FPGAs require several supply voltages.  So if you don't need to do a lot its cheaper to put a cpld on the board - but if you are talking about a large CPLD, a low-end fpga may be cheaper and give you more room for future enhancement, especially if you already have the core voltage supplies available for some other reason." CreationDate="2010-12-28T06:16:55.150" UserId="2246" />
  <row Id="12125" PostId="8231" Score="2" Text="FYI, with any of these parts, there's a huge difference between the variety of offerings that manufacturers put in their literature, and the much smaller assortment of gate count / package / speed and temperature combinations that you can actually expect to get your hands on in small quantities in less than half a year of leadtime.  So when designing with them, check real availability first.  Even if I know purchasing wants to get them from distribution, I prefer to choose devices where I know a more prototype oriented supplier actually has them on hand to overnight to me if needed." CreationDate="2010-12-28T06:21:12.527" UserId="2246" />
  <row Id="12126" PostId="8338" Text="@Chris well, coal is carbon as is graphite, and I've heard of plenty of people making a crystal radio using a long piece of wire, a jar, a piece of pencil lead(graphite), and a rusty razor blade. " CreationDate="2010-12-28T06:29:45.650" UserId="708" />
  <row Id="12127" PostId="8197" Text="@Tyblu I believe he can still comment on any threads he starts." CreationDate="2010-12-28T06:30:45.353" UserId="790" />
  <row Id="12129" PostId="8223" Score="2" Text="If it made sense to you, you don't understand what you are talking about." CreationDate="2010-12-28T06:45:49.360" UserId="1374" />
  <row Id="12130" PostId="8294" Text="@Fake PCBs are cheap? Where do you get your PCBs? Are you talking about protoboard?  (And also, desoldering is annoying at best)" CreationDate="2010-12-28T06:47:25.730" UserId="708" />
  <row Id="12131" PostId="8324" Text="I would have to buy a usb or parallel port tool for debugging over jtag, right? What would you recommend for that?" CreationDate="2010-12-28T06:49:11.763" UserId="444" />
  <row Id="12132" PostId="8356" Text="I have the BeagleBoard XM, ver A3 and it doesn't have a Nand on it, so I would have to go with the SD card option. Regarding the camera interface any idea what is the bandwidth limitation. I would like to interface a 5MP camera and acquire full res @ 15fps. Also how do I locate the drivers for the cam, does Angstrom have built-in cam drivers? The cam module that I has an omnivision image sensor on it." CreationDate="2010-12-28T06:53:52.730" UserId="444" />
  <row Id="12133" PostId="8324" Text="@Kevin: Í tried to use a affordable OpenOCD based jtag, but today that project has problem with internal caches on the Cortex A8 chip that the BeagleBoard is using.... However I know that the Expensive jtags from Lauterbach do work to debug the kernel. (They are good but expensive)..." CreationDate="2010-12-28T06:57:28.140" UserId="689" />
  <row Id="12134" PostId="8322" Text="I'm sorry but I'm new to this kind of development. Just to clarify would I be doing all my development on the BeagleBoard itself or would I need a PC + Beagleboard setup. I have a windows OS on the PC but I would mind setting up Linux if that's going to make development any easier." CreationDate="2010-12-28T06:59:14.707" UserId="444" />
  <row Id="12135" PostId="8374" Score="1" Text="What should trip the wire, and what shouldn't? Eg: fog, rain, pant leg, wheel hub? Also, can you install a mirror/shiny thing on the other side?" CreationDate="2010-12-28T07:50:42.413" UserId="2118" />
  <row Id="12136" PostId="8374" Text="@tybl Well I would want it to be half resistant to things like fog and rain. But basically I'd want for say a leg or animal or something like that to trigger it. And no a mirror can't be installed. It has to all be contained in one box basically. " CreationDate="2010-12-28T09:36:50.153" UserId="708" />
  <row Id="12137" PostId="8260" Text="@reemrevnivek, I'm hoping someone else knows. Anyway, I guessed CMOS buffer." CreationDate="2010-12-28T10:11:28.627" UserId="2118" />
  <row Id="12138" PostId="8324" Text="Thanks! Any idea how to get hold of cam drivers, if I have to interface to a cam module?" CreationDate="2010-12-28T10:29:29.163" UserId="444" />
  <row Id="12139" PostId="8376" Score="3" Text="I recommend the [$0.5M 1THz Agilent VNA](http://cp.literature.agilent.com/litweb/pdf/5989-7620EN.pdf). £1~$1070, right? :D" CreationDate="2010-12-28T11:27:06.207" UserId="2118" />
  <row Id="12140" PostId="8231" Text="Good advice, @ChrisStratton. This is usually the first thing I check with most parts, but it's still good to know that it's especially problematic with PLDs." CreationDate="2010-12-28T11:46:02.820" UserId="2118" />
  <row Id="12141" PostId="8376" Score="1" Text="@tyblu - What a bargain!" CreationDate="2010-12-28T11:53:36.550" UserId="1225" />
  <row Id="12142" PostId="8374" Text="Maybe something like a ultra sonic sonar may work better in the foggy or smokey conditions." CreationDate="2010-12-28T11:54:49.310" UserId="2060" />
  <row Id="12143" PostId="8339" Text="Do you have any suggestions on brand or manufacturer? I know most RC shops have Li-po kits of somesort, but they usually have so many companies to choose from." CreationDate="2010-12-28T11:58:39.183" UserId="2060" />
  <row Id="12144" PostId="8274" Text="Hey @Dave, I edited the question a bit for clarity." CreationDate="2010-12-28T12:19:35.180" UserId="2118" />
  <row Id="12145" PostId="8374" Text="Nah, a laser is a good idea. Will post about it tomorrow if [someone else doesn't](http://electronics.stackexchange.com/questions/6297/any-published-designs-for-time-of-flight-laser-distance-measurement)." CreationDate="2010-12-28T13:01:02.507" UserId="2118" />
  <row Id="12146" PostId="8363" Text="[Here](http://meta.electronics.stackexchange.com/questions/316/asking-questions-and-getting-answers) @Martin: [this](http://meta.electronics.stackexchange.com/questions/316/asking-questions-and-getting-answers) may be of use to get better answers." CreationDate="2010-12-28T13:03:00.523" UserId="2118" />
  <row Id="12147" PostId="8367" Text="Not complaining. Just want to understand. Thank you." CreationDate="2010-12-28T13:53:16.663" UserId="941" />
  <row Id="12148" PostId="8368" Score="1" Text="Very concise and informative answer. Thank you." CreationDate="2010-12-28T13:56:02.497" UserId="941" />
  <row Id="12149" PostId="8324" Text="@Kevin: No idea, but it can't hurt to ask the maker of the cam? And have a look a video 4 linux, http://en.wikipedia.org/wiki/Video4Linux" CreationDate="2010-12-28T15:11:43.270" UserId="689" />
  <row Id="12150" PostId="8376" Text="If you only have access to a sine wave source, run it through an op-amp with way too much gain. It will clip the signal to the point where it is a square wave. Bear in mind, though, that it will generate harmonics like crazy, probably out to 200 MHz or more. (I don't know if it's even-order or odd-order, or both. It's been a while.) You may want to run the signal through a low-pass filter to eliminate some of these harmonics. It'll distort your square wave a bit, but what's important -- the waveform or the spectrum?" CreationDate="2010-12-28T15:21:28.363" UserId="965" />
  <row Id="12151" PostId="8374" Score="2" Text="Mirrors are a pain to install; you'd use a retroreflector instead of them." CreationDate="2010-12-28T15:22:19.880" UserId="1407" />
  <row Id="12152" PostId="8339" Text="They're all probably the same, all made in China.  I don't have a ton of experience with them, if you want a better answer an RC forum will provide better experiential information." CreationDate="2010-12-28T15:24:11.687" UserId="1407" />
  <row Id="12153" PostId="8337" Text="@Matt, I axed the link to the terrible site he provided and he left it be, so I'll give him the benefit of the doubt.  @Fake, come on, be civil." CreationDate="2010-12-28T15:37:03.107" UserId="1407" />
  <row Id="12154" PostId="8322" Text="Sorry, I should have been more clear. The usual method is to use an SSH terminal on a local PC (could be Windows with Cygwin or Mingw, but Linux is a better fit). You SSH to the board and then run the editor on the board. You could also do the coding on your PC and copy the binaries over, but this means setting up an ARM compiler (&quot;cross-compiling&quot;) on your PC, which can be a bit tricky." CreationDate="2010-12-28T15:53:14.333" UserId="712" />
  <row Id="12155" PostId="8322" Text="Just to add: Earlz and Johan are correct to recommend gdb and JTAG. It's kind of hard to set up, and the hardware can be expensive, but it's great once you get it going. I wouldn't think it was necessary to get started." CreationDate="2010-12-28T15:54:56.983" UserId="712" />
  <row Id="12156" PostId="8356" Score="1" Text="Looks like someone just wrote a Linux driver: http://boundarydevices.com/blogs/omnivision-ov5642-camera-driver-for-linux That's good news, but it's very likely that it's not in the Beagleboard kernel yet. Looks like the XM is using 2.6.35 at present." CreationDate="2010-12-28T15:57:22.923" UserId="712" />
  <row Id="12157" PostId="8337" Text="@FakeName, keep it civil." CreationDate="2010-12-28T16:06:27.110" UserId="230" />
  <row Id="12158" PostId="8376" Text="So to simplify your question, you just want a variable frequency square-wave generator, 5-12MHz? Also, have you considered renting equipment?" CreationDate="2010-12-28T16:10:53.047" UserId="638" />
  <row Id="12159" PostId="8356" Text="@Kevin: well, I made some tests and the highest frequency I got for flipping a bit was about 4 MHz in a simple loop. If you put some logic then it goest to 1 MHz. That would mean that a QVGA frame would take 320x200/1M = 64ms. That'd give you a maximum frame rate of 15 fps, if you can use the processor time exclusively for it." CreationDate="2010-12-28T16:16:03.813" UserId="1078" />
  <row Id="12160" PostId="8356" Text="@Kevin #2: I should mention also that the tests I did were in C, and when I examined the generated assembly code I saw that it could be made a lot more efficient if written directly in assembly (for that particular case). I didn't try it, though, but maybe there's some hope to have better results. " CreationDate="2010-12-28T16:18:58.790" UserId="1078" />
  <row Id="12161" PostId="8376" Score="1" Text="@Jesse, many op-amps do not recover quickly from saturation, and at 10 MHz may not get a chance.  This is not always spec'd in the op-amp datasheet.  (An op-amp that recovers from overload quickly is called a &quot;comparator.&quot;)  For this purpose a Schmitt gate like the 74HC14 works and costs pennies." CreationDate="2010-12-28T17:07:19.217" UserId="411" />
  <row Id="12162" PostId="8353" Text="I won't argue that. I could only image that possibly where low (battery) power/small size is a constraint they might still be used as they might be more advantageous than a CPDL, but I'd still use the smallest/power-efficient CPLD if it were my design." CreationDate="2010-12-28T17:43:35.450" UserId="1571" />
  <row Id="12163" PostId="8378" Text="That's broadcast NTSC. I suspect most VTX's will be limited to 3-4 MHz, but I'm unsure. If you're dealing with composite video, I think there is no actual limitation on bandwidth, although 100 MHz is usually more than enough." CreationDate="2010-12-28T18:01:10.383" UserId="1225" />
  <row Id="12164" PostId="8378" Text="Thanks for the idea on the 4046, I've heard of that chip. I'll have to get some for myself at some point." CreationDate="2010-12-28T18:01:43.347" UserId="1225" />
  <row Id="12165" PostId="8371" Text="@chrisStratton, standard practice is just to edit the improved information into your answer. It is great to edit your answer, make it better, add section headings and such." CreationDate="2010-12-28T18:17:45.170" UserId="230" />
  <row Id="12166" PostId="8371" Text="@Kortuk, I intentionally left it out of the original answer, because I think it's a divergence that does not help with the base explanation.  I'm happy to have it as supplementary material though." CreationDate="2010-12-28T18:23:35.250" UserId="2246" />
  <row Id="12167" PostId="8382" Text="I can add holes, it's just they take up space. But it looks like I'll have to. The module is 35mm x 70mm." CreationDate="2010-12-28T18:43:06.417" UserId="1225" />
  <row Id="12168" PostId="8371" Text="@chrisStratton, Awesome, just trying to spread knowledge." CreationDate="2010-12-28T18:48:05.643" UserId="230" />
  <row Id="12169" PostId="8385" Text="I have been talking with someone in stack flow that has a similar point to yours. So first i would decimate the signal using matlab, then reconstruct the .wav file then take the new .wav file and sample it at nyquist rate?" CreationDate="2010-12-28T19:00:25.223" UserId="2386" />
  <row Id="12170" PostId="8319" Text="&quot;It's very space constrained&quot;  What are the space constraints?" CreationDate="2010-12-28T19:06:10.840" UserId="1407" />
  <row Id="12171" PostId="8319" Text="@Nick T, as small as possible. The smaller, the better, because it will be able to fit in small planes." CreationDate="2010-12-28T19:26:00.807" UserId="1225" />
  <row Id="12172" PostId="8380" Score="2" Text="This is not the proper site to ask this question. Try asking this at http://superuser.com/" CreationDate="2010-12-28T19:55:14.930" UserId="319" />
  <row Id="12173" PostId="8231" Text="@BrianCarlton, Hey Brian, Little tag discussion [here](http://meta.electronics.stackexchange.com/questions/188/tag-cleanup-tags-to-be-merged/318#318)." CreationDate="2010-12-28T20:58:50.740" UserId="2118" />
  <row Id="12174" PostId="8343" Text="Please do note that Superuser is not for question such as this. It's for **computer** hardware or software. " CreationDate="2010-12-28T21:07:47.653" UserId="1240" />
  <row Id="12175" PostId="8378" Text="Note that the original CD4046 is only good to about 1 MHz.  The 74HC one is faster.  The part is discussed a little bit in Don Lancaster's &quot;CMOS Cookbook&quot; (If you don't have it, buy an autographed copy from Don on eBay.)  A fuller treatment of the loop filter is found in &quot;PLLs: principles and practice&quot; but it's just another control system, more or less." CreationDate="2010-12-28T21:19:34.880" UserId="411" />
  <row Id="12176" PostId="8385" Score="1" Text="Martin, it is still unclear what your are trying to do.  Are you trying to determine the highest frequency component?  Look at the FFT of the original file.  Are you trying to subsample below Nyquist?  Are you trying to do everything &quot;by the book&quot;, or are you trying to undersample on purpose to see aliasing?" CreationDate="2010-12-28T21:20:34.893" UserId="411" />
  <row Id="12177" PostId="8387" Text="What is the power supply of the op-amp?" CreationDate="2010-12-28T21:24:24.000" UserId="411" />
  <row Id="12178" PostId="8387" Text="9 volts. Will it make a difference?" CreationDate="2010-12-28T21:25:21.237" UserId="1623" />
  <row Id="12179" PostId="8387" Score="1" Text="Is the negative supply pin of the op-amp connected to ground?" CreationDate="2010-12-28T21:28:46.677" UserId="411" />
  <row Id="12180" PostId="8387" Text="Yes let me find a better diagram. " CreationDate="2010-12-28T21:29:55.130" UserId="1623" />
  <row Id="12181" PostId="8385" Text="i want to sample at nyquist frequency to test the principle of it, and yes i want to undersample it on purpose. if you want heres my code as of now. http://pastebin.com/D0QzMkzy . and my audio clip http://www.4shared.com/audio/11xvNmkd/piano.html" CreationDate="2010-12-28T21:30:14.647" UserId="2386" />
  <row Id="12182" PostId="8389" Score="2" Text="This is not the proper site to ask this question. Try asking this at superuser.com" CreationDate="2010-12-28T22:24:17.220" UserId="319" />
  <row Id="12183" PostId="8389" Text="And also, be careful with how you tag questions. I don't see how this question has anything to do with audio or synthesizers." CreationDate="2010-12-28T22:28:23.240" UserId="319" />
  <row Id="12184" PostId="8389" Score="1" Text="thanks for the heads up, I wasn't sure where to ask or what to tag. The Roland MC-500 is a MIDI sequencer so I figured audio/synth heads might be in the know" CreationDate="2010-12-28T22:38:44.670" UserId="2418" />
  <row Id="12185" PostId="7794" Text="@Ian, Again, the onward transmissions (from the antenna to the receiver) will be assumed, by the receiver software, to be in divergent directions." CreationDate="2010-12-28T22:45:20.773" UserId="2257" />
  <row Id="12186" PostId="8381" Text="An OS on a USB 3.0 stick is going to be interesting." CreationDate="2010-12-28T22:59:43.633" UserId="2118" />
  <row Id="12187" PostId="8337" Text="@Nick, I'm good with that" CreationDate="2010-12-28T23:32:18.083" UserId="2006" />
  <row Id="12188" PostId="8392" Text="Best not to guess! ;) Welcome to the site. You may want to edit your answer as it is incorrect: SAs don't mix down their inputs prior to sampling [(source)](http://www.cbtricks.com/miscellaneous/tech_publications/scope/sampling.pdf)." CreationDate="2010-12-28T23:59:01.937" UserId="2118" />
  <row Id="12189" PostId="433" Score="2" Text="@Brian Carlton, Although the [`beginner`](http://electronics.stackexchange.com/questions/tagged/beginner) tag has been used many times and still exists, its use is discouraged due to its inability to stand alone -- it is a [meta-tag](http://blog.stackoverflow.com/2010/08/the-death-of-meta-tags/)." CreationDate="2010-12-29T00:17:33.573" UserId="2118" />
  <row Id="12192" PostId="8271" Text="one thing your missing here is that for a standard sampling scope to detect a signal at 30Ghz it needs to sample at twice that frequency (Nyquist) and accuracy can suffer if it can't sample even faster.  Also multiply by 10 to 20 the cost of the scope or SA for 30Ghz to include the cost of probes and additional equipment needed at those frequencies.  As to the cost, parasitics at these frequencies are dominant, 'resistors' and 'capacitors' are built with metal structures on RF substrate.  No offence but if your even asking this question your not ready to be working at those frequencies.  " CreationDate="2010-12-29T02:08:15.003" UserId="1438" />
  <row Id="12193" PostId="8271" Text="@Mark, I am not missing that - it is obvious enough not to include basic signal theory. I understand RF and sampling electronics. I am looking for *working differences* in the tools themselves when working at these frequencies." CreationDate="2010-12-29T02:19:40.943" UserId="2118" />
  <row Id="12194" PostId="8389" Text="@Ben My apologizes. I didn't realize that." CreationDate="2010-12-29T02:24:37.677" UserId="319" />
  <row Id="12195" PostId="8385" Text="@Martin, this was not clear in your question, I would have said, &quot;How do I go about intentionally aliasing a signal?&quot; I will add more later." CreationDate="2010-12-29T02:51:59.650" UserId="230" />
  <row Id="12196" PostId="8385" Text="Ok ill go update it. But its kinda of both, just showing the effects of undersampling which inturn will intentionally aliasing the signal." CreationDate="2010-12-29T03:11:31.087" UserId="2386" />
  <row Id="12197" PostId="8381" Text="@tyblu, I've run Ubuntu off a USB stick. It's not as fast as a hard disk, but it's still usable." CreationDate="2010-12-29T03:45:56.397" UserId="1225" />
  <row Id="12198" PostId="8381" Text="@ThomasO, Yes, me too, but I found it faster than my disk drive. I'm interested in USB3.0 because it is faster than SATA and SCSI (used for todays drives, incl. SSDs). Just need to wait a year or two for the price to come down!" CreationDate="2010-12-29T03:57:48.393" UserId="2118" />
  <row Id="12199" PostId="8381" Text="Just having a fast interface is not going to help unless the memory devices can keep up.  For reads maybe - but probably not for writes." CreationDate="2010-12-29T04:15:01.520" UserId="2246" />
  <row Id="12200" PostId="8356" Text="Did you try on the BB or the BBXM?, you see that BBXM has a dedicated camera interface port so it should have good throughput, shouldn't it? Also another point to note is Leopard imaging makes camera modules for the BBXM and these modules are upto 5MP in res, they also must have built the drivers for these, so I guess they might have got it working but I'm not sure what frame rate they support. " CreationDate="2010-12-29T04:39:39.903" UserId="444" />
  <row Id="12201" PostId="8274" Text="It's not clear to me what you're trying to measure. Could you clarify that a bit? " CreationDate="2010-12-29T04:40:34.470" UserId="2148" />
  <row Id="12202" PostId="8392" Text="Spectrum analyzers I've used do mix the input down before sampling. There's no ADC technology that can provide 90 to 100 dB of dynamic range across a 20MHz to 26GHz span in a single sweep, like the Agilent mxa on my bench can provide. " CreationDate="2010-12-29T04:43:35.310" UserId="2148" />
  <row Id="12203" PostId="436" Score="5" Text="While accurate in the idea that a serial bootloader isn't available on a new ATMEGA (though it is on many other microcontrollers), the claim that SPI or JTAG must be used is incorrect.  ATMEGAs also support a high voltage parallel programming mode, which has the ability to over-ride some fuse settings that would make the more popular in-circuit-programming methods unworkable.  JTAG was not designed for programming micros but for testing PC boards by clocking values into and out of IO pin registers.  Extending it for programming or debugging core functions was a later hack." CreationDate="2010-12-29T05:43:12.540" UserId="2246" />
  <row Id="12204" PostId="8392" Text="Whoops -- I meant sampling 'scopes!" CreationDate="2010-12-29T06:05:58.640" UserId="2118" />
  <row Id="12205" PostId="8370" Text="Thanks - a very informative answer - I'll go with the UBEC instead of the standard switching regulator." CreationDate="2010-12-29T09:38:51.860" UserId="2393" />
  <row Id="12206" PostId="8398" Score="2" Text="Maybe you can edit your starting post and give more information about what kind of serial device you're talking about? Is the communication via UART, SPI, I2C, or anything else? Component or module names come in handy." CreationDate="2010-12-29T09:56:19.287" UserId="1476" />
  <row Id="12207" PostId="8329" Text="Thank you for the answer, @Halst. It is appreciated." CreationDate="2010-12-29T10:12:15.593" UserId="2118" />
  <row Id="12208" PostId="8341" Text="Thanks for answering, @BrianCarlton, and the comments, @ChrisStratton. The given examples and current opinion are great info." CreationDate="2010-12-29T10:13:39.460" UserId="2118" />
  <row Id="12209" PostId="7925" Text="@zklapow, If one answer has helped you come to a decision more than others, perhaps you could consider accepting it." CreationDate="2010-12-29T10:19:50.390" UserId="2118" />
  <row Id="12210" PostId="8284" Text="@Martin, If one answer has helped you come to a decision more than others, perhaps you could consider accepting it." CreationDate="2010-12-29T10:21:34.710" UserId="2118" />
  <row Id="12211" PostId="8339" Text="Thanks for the info, I'm happy i can just walk to the RC shop lol to ask a few more questions about Li-po's" CreationDate="2010-12-29T12:18:44.827" UserId="2060" />
  <row Id="12212" PostId="8356" Text="@Kevin, mine is BB Rev C3. Indeed, if you have a dedicated port you could get rid of those limitations. The only thing is to check if the OV5642 you're using has a compatible interface. I suggested that approach not as a final one, but as a first try to test the device." CreationDate="2010-12-29T13:21:39.010" UserId="1078" />
  <row Id="12213" PostId="8403" Text="Well, with no load I do get around 5 V, so it should work." CreationDate="2010-12-29T14:07:06.307" UserId="1240" />
  <row Id="12214" PostId="8402" Text="Laptop USB ports can not always support the 100mA, I have had one laptop that could only source 50mA before giving out." CreationDate="2010-12-29T14:09:36.617" UserId="2060" />
  <row Id="12215" PostId="449" Text="@Kortuk, I've never heard of I2C being used as a native flash programming interface on a microcontroller, though there's no reason it couldn't be the entry point to a bootloader I suppose... " CreationDate="2010-12-29T14:46:47.290" UserId="771" />
  <row Id="12216" PostId="8402" Text="@jsolarski That's a good thing to know. Hopefully, my project won't take more than 50 mA." CreationDate="2010-12-29T14:48:23.663" UserId="1240" />
  <row Id="12217" PostId="8401" Text="The module is fit by users and may be removed regularly." CreationDate="2010-12-29T14:52:02.647" UserId="1225" />
  <row Id="12218" PostId="8354" Text="This answer is probably the one of the most helpful ones, along with the one I marked as the answer." CreationDate="2010-12-29T14:53:44.457" UserId="794" />
  <row Id="12219" PostId="8402" Score="2" Text="i wonder if you'd break anything if you were to wire the power lines of two USB ports in parallel?" CreationDate="2010-12-29T14:54:59.227" UserId="2344" />
  <row Id="12220" PostId="8402" Text="@Isaac I don't think so. I've seen special USB cables for external ODDs and HDDs which connect two ports in parallel." CreationDate="2010-12-29T14:59:31.927" UserId="1240" />
  <row Id="12221" PostId="8405" Score="1" Text="the amount of time you might end up spending trying to figure out a noisy power supply might offset the cost of picking up an adjustable power supply, or even a decent single voltage Meanwell (or similar) 5VDC power supply.  That said, maybe an LM6805 or LP2954 will do the trick?" CreationDate="2010-12-29T15:27:31.543" UserId="2288" />
  <row Id="12222" PostId="8405" Text="@Dave i want to be able to take this &quot;out of the lab&quot; and put it in my living room though :)" CreationDate="2010-12-29T15:29:15.163" UserId="771" />
  <row Id="12223" PostId="8398" Score="1" Text="@sheepel Tell us what connections you are making between the Arduino and the BT modem. Then tell us what serial device you are trying to connect additionally (datasheet ref would be good)." CreationDate="2010-12-29T15:38:59.600" UserId="771" />
  <row Id="12224" PostId="8405" Text="What are the characteristics of your &quot;headaches&quot;? Can you give us a better idea of what parts you're using?" CreationDate="2010-12-29T15:47:25.607" UserId="638" />
  <row Id="12225" PostId="8408" Text="I have tried all that, I also have a 4.7K at the SCK and SDA lines. But I get a NACK for 0x5A even for transmit." CreationDate="2010-12-29T16:06:01.760" UserId="1200" />
  <row Id="12226" PostId="8385" Text="@Martin, down-sampling and under-sampling are very different terms, they often happen together, but it is not implied that one happened when the other did." CreationDate="2010-12-29T16:11:31.477" UserId="230" />
  <row Id="12227" PostId="449" Text="@vicatcu, I was just adding it as a very common interface. " CreationDate="2010-12-29T16:13:49.120" UserId="230" />
  <row Id="12228" PostId="8408" Text="@Rick, please see additions I've made" CreationDate="2010-12-29T16:39:14.573" UserId="771" />
  <row Id="12229" PostId="8405" Text="@W5VO - I linked datasheets for the wall-wart and receiver I'm using. Headaches are basically terrible range performance when sourcing power from wall-wart" CreationDate="2010-12-29T16:44:51.087" UserId="771" />
  <row Id="12230" PostId="8407" Text="@lyndon I added a link to the datasheet for the wall-wart in the question. The datasheet *says* &quot;Regulated output&quot;, but also says you can expect a 200mV Pk-Pk ripple (if you use 10uF + 0.1uF filter caps)." CreationDate="2010-12-29T16:49:50.100" UserId="771" />
  <row Id="12231" PostId="8403" Score="1" Text="@Andrejako, you get 100mA automatically. http://electronics.stackexchange.com/questions/5498/how-to-get-more-than-100ma-from-a-usb-port/5581#5581 Has some more information about the spec." CreationDate="2010-12-29T16:53:25.713" UserId="230" />
  <row Id="12232" PostId="8363" Text="Discussion about relevance goes here: http://meta.electronics.stackexchange.com/questions/126/" CreationDate="2010-12-29T16:54:58.803" UserId="142" />
  <row Id="12233" PostId="8389" Text="Maybe http://audio.stackexchange.com/ ?" CreationDate="2010-12-29T17:19:50.030" UserId="142" />
  <row Id="12234" PostId="8410" Text="It actually says in the app note you linked to. Quote: &quot;the  resistance of a hot tungsten filament is 10 to 15 times greater than its resistance when it is cold&quot;" CreationDate="2010-12-29T17:30:24.993" UserId="638" />
  <row Id="12235" PostId="8410" Text="@W5V0 sometimes guesses are just memories in disguise :)" CreationDate="2010-12-29T17:32:50.440" UserId="771" />
  <row Id="12236" PostId="8413" Text="@tyblu get a different wallwart is a perfectly valid recommendation! Thanks for the detailed answer :)." CreationDate="2010-12-29T17:35:22.620" UserId="771" />
  <row Id="12237" PostId="8406" Text="in response to &quot;how can that be possible&quot; - it's a &quot;feature&quot; :)." CreationDate="2010-12-29T17:42:22.637" UserId="771" />
  <row Id="12238" PostId="8402" Score="3" Text="@jsolarski you must be buying cheap laptops. Everyone I have used can supply 100mA if not 500mA" CreationDate="2010-12-29T17:50:58.650" UserId="319" />
  <row Id="12239" PostId="8405" Text="what input filter capacitor are you using?" CreationDate="2010-12-29T18:07:38.327" UserId="411" />
  <row Id="12240" PostId="8405" Score="2" Text="That module will work down to 3.5V.  So maybe you try putting an LDO regulator in and making 4.0V." CreationDate="2010-12-29T18:09:49.793" UserId="411" />
  <row Id="12241" PostId="8405" Score="1" Text="Have you put probes on your power line to see what your actually voltage is as well as the noise on it? An unregulated 5v supply isn't usually actually 5v after you hook it up. It would probably be good to actually see whats going on. I realize you don't have a scope, but a DMM is better then nothing." CreationDate="2010-12-29T18:15:11.390" UserId="319" />
  <row Id="12242" PostId="8413" Text="&quot;the only way to get 5Vdc from less than 5V - is to use a switching regulator&quot;&#xA;&#xA;not precisely true, you could use a charge pump." CreationDate="2010-12-29T18:20:23.000" UserId="411" />
  <row Id="12243" PostId="8356" Text="@fceconel: How can the BB's processor that runs at 1000Mhz give you a maximum bit flipping speed of 4Mhz? Isn't that ironic? Is it because of the OS?" CreationDate="2010-12-29T18:27:03.373" UserId="444" />
  <row Id="12244" PostId="8413" Text="@markrages, I would call that a switcher, too..." CreationDate="2010-12-29T18:28:03.140" UserId="2118" />
  <row Id="12245" PostId="8413" Text="@tyblu how about a light bulb and solar cell arrangement, would you call that a switcher?" CreationDate="2010-12-29T18:32:03.870" UserId="411" />
  <row Id="12246" PostId="8413" Text="@markrages, ... I don't get it. Does that count as a charge pump?" CreationDate="2010-12-29T18:35:09.470" UserId="2118" />
  <row Id="12247" PostId="8413" Text="@tyblu, You can put the bulb across the supply and the solar cell in series with the supply, to increase the voltage.  So there's at least one other way to get 5V from less than 5V." CreationDate="2010-12-29T18:39:55.130" UserId="411" />
  <row Id="12248" PostId="8413" Text="@markrages, Well played, sir." CreationDate="2010-12-29T18:41:15.983" UserId="2118" />
  <row Id="12249" PostId="8413" Text="@tyblu, you didn't specify practicality." CreationDate="2010-12-29T18:42:44.723" UserId="411" />
  <row Id="12250" PostId="8413" Text="@markrages, Untrue, you can use a charge pump, which can double voltages." CreationDate="2010-12-29T19:03:21.587" UserId="1225" />
  <row Id="12251" PostId="8405" Text="@Kellenjb yes, I've done that, DMM consistently reads between 4.75 and 5.25V." CreationDate="2010-12-29T19:04:08.540" UserId="771" />
  <row Id="12252" PostId="8405" Text="@markrages, interesting thought on lowering operating voltage and using an LDO, might be worth a try - as for filtering caps; not using any right now (at least not upstream of the receiver), so I agree that is also something that's probably important to throw in." CreationDate="2010-12-29T19:06:11.500" UserId="771" />
  <row Id="12253" PostId="8412" Text="On the other hand, if you had 3 100W lightbulbs you should probably be using a relay rated for at least 13amps (Applying 10% derating, one 100W lightbulb should be good with about a 4A relay). Likewise you use conductors and breakers that are adequately rated to that load or you could have a fire hazard on your hands. I would also be cautious in suggesting that all relay failure modes are &quot;safe,&quot; as that has a lot to do with the context in which it's used." CreationDate="2010-12-29T19:18:33.457" UserId="771" />
  <row Id="12254" PostId="8356" Text="I don't think the OS is to blame very much; although the fact that it's multitasking and so there's some overhead involved, probably it's not really significant. I'd guess it's part the overhead in the generated code and part the maximum speed at which GPIO can operate. Also keep in mind that 1000 MHz (or, in my case, 600 MHz) is the processor internal clock only; That is made available inside the processor through a PLL that multiplies an external clock of 30 MHz." CreationDate="2010-12-29T20:04:24.370" UserId="1078" />
  <row Id="12255" PostId="8415" Text="My main concern was with the relay it melting on me. And im going to mount a plug on a pendant so i can keep my eye on whats happening to it during testing. " CreationDate="2010-12-29T20:16:00.653" UserId="1623" />
  <row Id="12256" PostId="8346" Text="http://electronics.stackexchange.com/questions/4664/stealing-energy-from-radio-towers-or-power-lines" CreationDate="2010-12-29T20:23:32.840" UserId="142" />
  <row Id="12257" PostId="8405" Text="@vicatcu 4.75 to 5.25 is a very large range, especially for a DMM to see. I wouldn't call that noise, in fact I am not sure what I would call it. Either way, I think you will be in a lot better shape by using a voltage regulator." CreationDate="2010-12-29T20:32:57.213" UserId="319" />
  <row Id="12258" PostId="8337" Score="1" Text="Any company that's developed a device for generating useful amounts of energy from thin air would not be selling plans for it.  They'd keep the design a secret, build a bunch of power plants, and sell the energy.  Free energy = free money!" CreationDate="2010-12-29T20:35:57.600" UserId="142" />
  <row Id="12259" PostId="8412" Text="@vicatcu - 400mA not 4A, the relay should be good for 3x100W." CreationDate="2010-12-29T22:13:58.183" UserId="1225" />
  <row Id="12260" PostId="8354" Text="What sense does it make to run AC analysis on a rectifier or voltage doubler circuit?" CreationDate="2010-12-29T22:29:02.080" UserId="1609" />
  <row Id="12261" PostId="7666" Text="What @JustJeff said. A lot of these conventions were already well-established by 1975, and are based on what was possible in early TTL logic families. TTL was *very* asymmetric in its sink/source capabilities. (Note that 7400 TTL dates from [1964!](http://www.computerhistory.org/semiconductor/timeline/1963-TTL.html))" CreationDate="2010-12-29T22:40:10.973" UserId="1494" />
  <row Id="12262" PostId="8356" Text="One thing I forgot to mention: I did the tests in user mode, so maybe the OS has indeed something to do with the performance penalty; a test in kernel mode would be helpful. I'm dealing with another task now, but I'll revisit these issues later. I'll post the results when I get them." CreationDate="2010-12-29T22:43:25.090" UserId="1078" />
  <row Id="12263" PostId="8322" Text="I don't think you need a JTAG unless you intend to debug the kernel and/or drivers. For standard apps, using gdbserver in the board accessed by a gdb-compatible IDE in a PC is far easier." CreationDate="2010-12-29T22:46:57.257" UserId="1078" />
  <row Id="12264" PostId="8415" Score="1" Text="@Dean, use a fuse rated for your maximum load + ~10%." CreationDate="2010-12-29T22:47:04.350" UserId="1225" />
  <row Id="12265" PostId="8416" Text="I have used multiple computers that managed per port. Acer and Dell were the two manufacturers I am sure of." CreationDate="2010-12-30T02:54:47.903" UserId="230" />
  <row Id="12266" PostId="8418" Score="1" Text="Copper thickness/weight?" CreationDate="2010-12-30T04:02:00.967" UserId="2118" />
  <row Id="12267" PostId="8402" Text="@Kellerjb It was a HP laptop from a few years back and i would suspect cheaper ones would be more prone to having low mA" CreationDate="2010-12-30T05:43:24.597" UserId="2060" />
  <row Id="12268" PostId="7841" Text="@Earlz my bad. like endolith says, swap the variable and photo resistors to achieve your aim. you might want to get a little theory on how transistors work, too (no offense intended). have fun" CreationDate="2010-12-30T07:11:12.337" UserId="2283" />
  <row Id="12269" PostId="8354" Text="@DarenW, About as much sense as any other analysis on a bogus circuit, but what do you mean? Rectifiers and doublers have frequency dependancies when modeled with non-idealities as I did." CreationDate="2010-12-30T07:13:13.203" UserId="2118" />
  <row Id="12270" PostId="8420" Text="140/1000 inch is often referred to as `140 mils`. I've never seen it as `thou` before." CreationDate="2010-12-30T08:44:21.177" UserId="2064" />
  <row Id="12271" PostId="8420" Text="Well, I am considered about skin effect during these pulses :-)" CreationDate="2010-12-30T09:43:45.767" UserId="2062" />
  <row Id="12272" PostId="8420" Score="1" Text="@stevenh, May be an old term or from across the ocean. A few old techs I've worked with use it. Hear it often in machine shops, too. Helps the uninitiated to not get mixed up with `mm`; I run across those who use `mil` as short for `mm` in speech often. Makes my brain skip a beat." CreationDate="2010-12-30T10:06:15.693" UserId="2118" />
  <row Id="12273" PostId="8405" Text="Unregulated != noisy! A common transformer-rectifier wall-wart is actually impressively quiet, provided you don't have a lot of garbage on your AC lines. It'll have some 120 hz ripple (assuming full-wave rectification), but that's about it." CreationDate="2010-12-30T11:45:34.193" UserId="1374" />
  <row Id="12274" PostId="8422" Text="If you want to get fancy, you can switch the HV after the ballast, which will let you flash them for however fast your power devices will go." CreationDate="2010-12-30T11:47:03.367" UserId="1374" />
  <row Id="12275" PostId="8422" Score="1" Text="Or better yet, with a very high-voltage pulse, you can start them with the filaments cold." CreationDate="2010-12-30T11:47:33.083" UserId="1374" />
  <row Id="12276" PostId="8338" Text="@Nick: they're not exactly commodity items. IIRC they only work near absolute zero. I don't have them in my box either" CreationDate="2010-12-30T12:17:26.873" UserId="2064" />
  <row Id="12277" PostId="8420" Text="@tyblu My old technology teacher used that, I went with it before I learnt that mil meant 1/1000th inch, then it confused me eternally." CreationDate="2010-12-30T12:27:44.873" UserId="1225" />
  <row Id="12278" PostId="8420" Text="If I want my product to work up to about 70°C ambient, what is the allowable temperature rise? What is the maximum temperature of any trace? Is 10°C too much?" CreationDate="2010-12-30T12:28:34.613" UserId="1225" />
  <row Id="12279" PostId="8422" Score="1" Text="With these nice very high-voltage pulses you surely can flash it, but doing so with cold electrodes will quickly evaporate them." CreationDate="2010-12-30T12:35:57.597" UserId="2062" />
  <row Id="12280" PostId="8429" Text="Many thanks to you my friend! the program works flawlessly!, anyway I have to open each port independently (with PuTTY) for it to capture. Now I'll look the captured data now." CreationDate="2010-12-30T15:36:09.527" UserId="1673" />
  <row Id="12281" PostId="8431" Text="I can't rely on an enclosure as it may be in any type of aircraft." CreationDate="2010-12-30T15:56:04.300" UserId="1225" />
  <row Id="12282" PostId="6679" Text="&quot;Read the datasheets&quot; is always good advice. However, how is it possible to deduce from the datasheet of a part whether it is a &quot;super-useful part that I should always keep a few on hand&quot; vs a &quot;specialized part to only buy as needed&quot; vs a &quot;completely obsolete part that there's no point buying -- instead part YYY is cheaper and better in every way&quot;?" CreationDate="2010-12-30T16:08:37.217" UserId="813" />
  <row Id="12283" PostId="8420" Text="@ThomasO, Some parts start to cut out at 85°C, but you can push trace temps quite high ( [`ref.`](http://electronics.stackexchange.com/questions/7692/maximum-trace-temperature-on-fr-4) )." CreationDate="2010-12-30T16:43:01.200" UserId="2118" />
  <row Id="12284" PostId="8425" Text="Do you mean &quot;to close the file and/or save data is very [in]consistent&quot;?" CreationDate="2010-12-30T16:48:33.303" UserId="2118" />
  <row Id="12285" PostId="8354" Text="I agree that you're not going to get worthwhile amounts of power out of this all by itself. But it's a bit misleading to say &quot;nothing&quot; when the graph clearly is non-zero with &quot;node 4 grounded&quot; -- it looks like a voltage doubler." CreationDate="2010-12-30T17:02:54.700" UserId="813" />
  <row Id="12286" PostId="8405" Text="@Kellenjb, I actually mis-spoke on my DMM range. It's reads pretty stable (+/- 10mV)... I might be barking up the wrong tree thinking the power is my problem based on what I'm reading here :-/" CreationDate="2010-12-30T17:05:56.850" UserId="771" />
  <row Id="12287" PostId="8434" Text="You could make your own. Bend some sheet metal and cut slits in them. then spray it." CreationDate="2010-12-30T17:07:13.087" UserId="1623" />
  <row Id="12288" PostId="8412" Text="@Thomas, derating by a factor of 10%, I believe, means you should divide current by 0.1 (i.e. multiply by 10). I got 4A from 400mA * 10..." CreationDate="2010-12-30T17:09:00.667" UserId="771" />
  <row Id="12289" PostId="8436" Score="1" Text="It would hold the memory of the PIC, but it has a 10uA max current rating. I don't think you could write to a SD card on that much current." CreationDate="2010-12-30T17:14:50.940" UserId="638" />
  <row Id="12290" PostId="8412" Text="@vicatcu, no, that is equivalent to derating by 90%. You should get around 400mA * 1.1 = 440mA for 10% extra (or you could derate the relay to 90%, to get 9A, either works.)" CreationDate="2010-12-30T18:47:17.267" UserId="1225" />
  <row Id="12291" PostId="8420" Text="@tyblu, That's why I'm stopping at 70°C ambient max - some parts are only rated for 85°C." CreationDate="2010-12-30T18:48:57.127" UserId="1225" />
  <row Id="12292" PostId="8441" Text="Thank you for the comment. This just tells us what an eFuse accomplishes. That is &quot; utilizing an eFUSE... a chip manufacturer can allow for the circuits on a chip to change while it is in operation&quot;. " CreationDate="2010-12-30T18:55:31.750" UserId="619" />
  <row Id="12293" PostId="8429" Text="great, I'm glad it's helping you.  PortMon has been my friend for a very long time.  :)" CreationDate="2010-12-30T18:58:07.333" UserId="2288" />
  <row Id="12294" PostId="8432" Text="Thanks for the info. Very helpful. I'll see what I can do with it..." CreationDate="2010-12-30T19:18:45.947" UserId="1235" />
  <row Id="12295" PostId="8444" Text="Also for anyone who hasn't seen [this neat trick](http://lifehacker.com/software/life-hacks/keep-headphone-wires-from-getting-tangled-152499.php), you can make devil orns, wind your headphone cable in a figure 8 around your fingers, and wrap the last couple inches around the middle to prevent tangles." CreationDate="2010-12-30T19:38:07.267" UserId="2344" />
  <row Id="12296" PostId="8413" Text="@Thomas, you just repeated my comment" CreationDate="2010-12-30T19:42:11.347" UserId="411" />
  <row Id="12297" PostId="8413" Text="@tyblu, I'll just leave here:     http://www.piclist.com/techref/postbot.asp?by=time&amp;id=piclist/2010/03/12/134908a" CreationDate="2010-12-30T19:42:39.287" UserId="411" />
  <row Id="12298" PostId="8443" Text="I use large Ziplocs too. They work pretty well." CreationDate="2010-12-30T20:08:56.013" UserId="712" />
  <row Id="12299" PostId="8423" Score="2" Text="Came here to say that" CreationDate="2010-12-30T21:11:58.900" UserId="1750" />
  <row Id="12300" PostId="8445" Text="Actually, I compared those 50 Ω speakers and they do sound much better than stock speakers. Also, I'm not planning to use 500 mA, because I don't want to go into microcontroller land at this time. I don't think I'm going to make more that 2-3 devices and I want to use components which I can easily obtain." CreationDate="2010-12-30T21:21:29.827" UserId="1240" />
  <row Id="12301" PostId="8420" Text="@ThomasO, That's probably closer to a function of your total system power dissipation, and your ability to remove heat from your system. " CreationDate="2010-12-30T21:28:53.603" UserId="638" />
  <row Id="12302" PostId="8442" Text="The non-paranoid view says that if a company like Microsoft started intentionally &quot;breaking&quot; xboxs, there would be a lot of backlash and lawsuits. They do have the right to prevent someone from modifying (aka hacking) the system and putting non-authorized code on the system." CreationDate="2010-12-30T21:47:13.587" UserId="319" />
  <row Id="12303" PostId="8423" Text="Why did you down-vote my answer?" CreationDate="2010-12-30T21:48:10.070" UserId="638" />
  <row Id="12304" PostId="8445" Text="You don't have to go into microcontroller land - As I said, a USB hub IC can do this for you just by soldering it down with the !BUSPWR pin pulled to ground." CreationDate="2010-12-30T21:51:06.287" UserId="857" />
  <row Id="12305" PostId="8427" Text="TV Cables, Stereo-cables, etc is more in the consumer electronics realm, but I think this question is more then relevant to all of us here." CreationDate="2010-12-30T21:51:24.643" UserId="319" />
  <row Id="12306" PostId="8423" Text="Wrong button ) Could you please edit anything in your answer? :-)" CreationDate="2010-12-30T22:00:02.250" UserId="2062" />
  <row Id="12307" PostId="8420" Text="OK, I've used the calculator, but it gives me two values - one internal value, and one external value. The external value is much smaller. Which one do I use?" CreationDate="2010-12-30T22:15:21.307" UserId="1225" />
  <row Id="12308" PostId="8442" Text="@Kellenjb, I don't like it either way - If I buy hardware, it belongs to ME, and not the company I bought it from. I can do whatever I like with it, as long as it's not actually illegal. (And even then, Microsoft shouldn't be involved.)" CreationDate="2010-12-30T22:30:24.533" UserId="1225" />
  <row Id="12309" PostId="8442" Text="@Thomas O Sure, you own the hardware, but you don't own the software or firmware, instead you just own a license to use it. If you don't like the terms of the license then don't buy it, end of story." CreationDate="2010-12-30T22:39:27.240" UserId="319" />
  <row Id="12310" PostId="8448" Text="http://electronics.stackexchange.com/questions/1404/low-cost-bluetooth" CreationDate="2010-12-30T22:42:42.307" UserId="319" />
  <row Id="12311" PostId="8448" Text="That post covers bluetooth modules to be integrated into your product at a low cost." CreationDate="2010-12-30T22:43:46.877" UserId="319" />
  <row Id="12312" PostId="8447" Score="2" Text="I think this question may be borderline of being too consumer electronics related; however, it may have some use here." CreationDate="2010-12-30T22:45:09.917" UserId="319" />
  <row Id="12313" PostId="8442" Text="@kellenjb, Yeah, that's where software licensing gets a bit dodgy... I mean, if you hack it to run homebrew games by physically modifying the hardware, have you invalidated the EULA, which really only applies to software/firmware?" CreationDate="2010-12-30T23:19:52.707" UserId="1225" />
  <row Id="12314" PostId="8451" Text="BTW, the reference would be the spec available at bluetooth.com; but as with any specification for a quite complex technology, you'll have to navigate through many pages to find what you want. http://www.bluetooth.com/English/Technology/Building/Pages/Specification.aspx" CreationDate="2010-12-30T23:38:09.323" UserId="1078" />
  <row Id="12315" PostId="8447" Text="I agree - this question, while interesting, is off-topic" CreationDate="2010-12-31T00:12:04.300" UserId="566" />
  <row Id="12316" PostId="8354" Text="Look at the multiplier on the Y-axis, @davidcary ;)" CreationDate="2010-12-31T00:40:56.027" UserId="2118" />
  <row Id="12317" PostId="8420" Score="1" Text="@ThomasO, That refers to internal or external traces, referring to their contact with ambient air. On a 2-layer, both layers are external." CreationDate="2010-12-31T00:42:54.853" UserId="2118" />
  <row Id="12318" PostId="8423" Text="@BarsMonster, NOP edit complete!" CreationDate="2010-12-31T00:44:48.863" UserId="2118" />
  <row Id="12319" PostId="8413" Text="@markrages, wtf. BE-junctions generate light? [cripes](http://dics.voicecontrol.ro/process_mails/arata_discutia/51478/Generating_small_negative_ref_voltage.html)." CreationDate="2010-12-31T00:54:23.910" UserId="2118" />
  <row Id="12320" PostId="8442" Text="@Thomas O, no, not in the USA (hardware only) anyways that was established in law quite some time ago. However it continues to be illegal(hardware AND software) in Australia and I believe parts of Europe. Of cause in Asia anything goes(hardware/software), which is probably why alot of the hack kits are made there. You example is generally the accepted one; i.e. homebrew/streaming is ok, but no licensed games or modification of firmware OS." CreationDate="2010-12-31T01:06:34.867" UserId="1457" />
  <row Id="12321" PostId="8413" Text="@tyblu I just tried it with a PN2222.  The BE voltage zenered at 7.5V, and the strongest collector output was -0.4V at a -10mA base current.  Epoxy case, so I didn't &quot;see the light.&quot;  750 mW in TO92 is toasty." CreationDate="2010-12-31T01:30:49.037" UserId="411" />
  <row Id="12322" PostId="8294" Text="Advanced Circuits (http://www.4pcb.com/) 33 each deal, $50 shipped, double sided copper, silk and sldermask, if you have a university address you can ship to. 2 Week turn." CreationDate="2010-12-31T01:41:29.630" UserId="1374" />
  <row Id="12323" PostId="8428" Score="1" Text="What you *really* want here is a logic analyzer. However, budget constraints seem to render that unavailable." CreationDate="2010-12-31T01:52:36.107" UserId="1374" />
  <row Id="12324" PostId="8412" Text="@Thomas, when switching incandescent loads, it is advisable to derate your relay to *10% of its resistive rating*. So if the relay is rated for 4A resistive loads, you should only use it for 0.4A = 400mA incandescent loads. If you've got a 1.2A incandescent load, you therefore need a relay rated for 12A resistive loads. Read the app note I linked in my answer, I think my reading of it is accurate." CreationDate="2010-12-31T05:17:49.143" UserId="771" />
  <row Id="12326" PostId="8454" Score="1" Text="Seems like you have a long, intense date with Google ahead of you!" CreationDate="2010-12-31T05:56:43.057" UserId="2118" />
  <row Id="12328" PostId="8455" Text="I have completed the layout for the board, only need two jumpers. I will add female headers for Vcc and the GND connections." CreationDate="2010-12-31T07:06:29.333" UserId="665" />
  <row Id="12329" PostId="8453" Text="Does anyone know how to judge if the Press-N-Peel is hot enough and ready to come off. I tried one sample of the above board design most of the tonner transfered alright but some of it came up (not hot enough/long enough???). Also how do I change the size of the autotrace route's to a slightly large width?" CreationDate="2010-12-31T07:09:00.190" UserId="665" />
  <row Id="12330" PostId="8453" Text="Go to *Tools* &gt; *DRC* &gt; *Sizes* and increase *Minimum Width*. &#xA;Or, in your schematic, click the *Info* button then a net, then set *Width* property. Recommend not using the autorouter." CreationDate="2010-12-31T07:26:42.673" UserId="2118" />
  <row Id="12331" PostId="8422" Text="So if the voltage is high enough, it's not necessary to heat the electrodes? What voltage do I need for this to work?" CreationDate="2010-12-31T09:34:06.763" UserId="2426" />
  <row Id="12332" PostId="8422" Text="I've heard you can put a copper strip around the tube near one of the electrodes and use this some how to trigger the tube to light up... has anyone else heard of this before?" CreationDate="2010-12-31T09:36:09.460" UserId="2426" />
  <row Id="12333" PostId="8450" Text="Yes.... but this will be way too expensive. Fluorescent tubes are cheap!" CreationDate="2010-12-31T09:37:23.157" UserId="2426" />
  <row Id="12334" PostId="8446" Text="This is great.... exactly what I was looking for. Thanks!" CreationDate="2010-12-31T09:38:19.817" UserId="2426" />
  <row Id="12335" PostId="8265" Score="1" Text="Do those PATA-&gt;SATA converters still support the &quot;old an slow&quot; protocols? My USB-&gt;PATA adapters only support UDMA and above, thats &gt;= 33MHz..." CreationDate="2010-12-31T10:16:43.980" UserId="1472" />
  <row Id="12336" PostId="8441" Text="To my untrained (relatively) mind, this looks suspiciously like a low complexity FPGA..." CreationDate="2010-12-31T13:00:39.080" UserId="1143" />
  <row Id="12337" PostId="8422" Text="@BG100: If you pulse high voltage on cold electrodes, top layer of metal just evaporates and tube dies soon. Using copper strip around - yes, that works. It ionize the gas, and in fact, if you put RF frequency on it, it will glow just because of this RF. " CreationDate="2010-12-31T13:23:12.133" UserId="2062" />
  <row Id="12338" PostId="8412" Text="@vicatcu, That makes some sense. I though incandescents were resistive only? Shows what I know." CreationDate="2010-12-31T14:59:59.150" UserId="1225" />
  <row Id="12339" PostId="8420" Score="1" Text="Thou for .001 inch is commonly used in the UK, although mil tends to be used much more often for PCB work, as in the USA." CreationDate="2010-12-31T15:22:03.393" UserId="305" />
  <row Id="12340" PostId="8465" Score="5" Text="The Altera and Xilinx software will estimate your power consumption, but you need to enter in your full design, clock frequencies, the I/O loads, and example waveforms." CreationDate="2010-12-31T16:02:19.490" UserId="638" />
  <row Id="12342" PostId="8466" Text="Can you supply some more information of what the Tamura Micro PL10-24 is. Such as a datasheet. " CreationDate="2010-12-31T16:51:43.790" UserId="1623" />
  <row Id="12343" PostId="8414" Score="1" Text="I feel compelled to reinforce the idea that incandescent lamps are NOT resistive loads from a relay standpoint. Given that this is the &quot;accepted&quot; answer, I feel like it shouldn't contain misinformation." CreationDate="2010-12-31T17:01:19.317" UserId="771" />
  <row Id="12344" PostId="8414" Text="Also, it's not *my* suggestion, I provided a reference for that factor, fwiw. I don't think an answer should be accepted on the basis that it tells you what you want to hear." CreationDate="2010-12-31T17:07:48.107" UserId="771" />
  <row Id="12345" PostId="8414" Text="@vicatcu: if incandescent lamps are not resistive, can you tell us whether they're capacitive or inductive? And what's their cos phi? My data says cos phi = 1." CreationDate="2010-12-31T17:11:29.987" UserId="2064" />
  <row Id="12346" PostId="8465" Score="1" Text="If you have a choice, you can usually reduce the power consumption of a given device by reducing operating voltage and slowing down clock frequencies." CreationDate="2010-12-31T17:24:23.513" UserId="771" />
  <row Id="12347" PostId="8414" Text="@stevenvh, they fall into their own category - as described in the appnote I linked to my answer (http://cp.literature.agilent.com/litweb/pdf/5988-6917EN.pdf). While they are generally speaking &quot;resistive&quot;, they have special temperature-based material properties that must be taken into account." CreationDate="2010-12-31T17:27:09.113" UserId="771" />
  <row Id="12348" PostId="8429" Text="Bear in mind that the USB conversion will affect timings, and teh relative ordering of bytes on each channel may even appear different. Reducing with latency timer and settings in the FTDI driver can make a big difference here (device manager-&gt;port settings-&gt;advanced). If timing is critical there is no substitute for real COM ports. " CreationDate="2010-12-31T17:29:14.803" UserId="1681" />
  <row Id="12349" PostId="8414" Text="@vicatcu: Exactly, inrush current, I'm not denying that. IMO the people at Agilent are overly cautious; they also recommend a series resistor for the bulb, don't they? Have you ever seen this in an actual installation? My point is that _in my experience_ a factor 4-5 will do.  And I take exception to your insinuation that I tell the OP what he wants to hear." CreationDate="2010-12-31T18:01:15.717" UserId="2064" />
  <row Id="12350" PostId="8442" Text="It is also worth remembering that Microsoft sells their hardware for a loss because they know they can make up the cost in media sales. If they left it as a completely open system we all would end up having to pay more up front." CreationDate="2010-12-31T18:59:49.490" UserId="319" />
  <row Id="12351" PostId="8454" Score="3" Text="It seems like you haven't read the answers on this post http://electronics.stackexchange.com/questions/8447/can-a-phone-be-paired-with-2-bluetooth-devices-at-the-same-time-closed There is a difference between pairing and connecting that you still are confusing." CreationDate="2010-12-31T19:04:45.087" UserId="319" />
  <row Id="12352" PostId="8434" Text="@Dean I had a lab manager that tried making his own. He didn't dull down the edges enough so our cables ended up getting shredded over time. Just something to keep in mind." CreationDate="2010-12-31T19:08:49.887" UserId="319" />
  <row Id="12353" PostId="8442" Text="@kellenjb. That's their business decision, but they aren't allowed to force me to do that, because I bought their hardware (actually, I got a Wii instead because I was sick of both Sony + Microsoft's crappy reliability, but that's beside the point...)" CreationDate="2010-12-31T19:23:49.967" UserId="1225" />
  <row Id="12354" PostId="8470" Text="What if I work with .txt files, just extracting the text and displaying it. How would I extract the text even from a .txt file." CreationDate="2010-12-31T19:46:01.023" UserId="2445" />
  <row Id="12355" PostId="8442" Text="@Thomas O Can you provide me some sources that say they aren't allowed to force you to do that once you buy from them?" CreationDate="2010-12-31T20:16:45.460" UserId="319" />
  <row Id="12356" PostId="8442" Text="@kellenjb. I'm not sure if they are or are not, but either way, I think, personally, it's wrong, because it's my hardware. If I own it personally the company can't take it off of me or change it without my permission. It's akin to a car manufacturer saying you can only drive their cars on roads that they own, or if you tweak the engine to make it go faster, you have to pay them the money they would get for the higher-end model with the faster engine. I just don't like it." CreationDate="2010-12-31T20:34:35.900" UserId="1225" />
  <row Id="12357" PostId="8370" Text="Just to follow this up, the Hobbywing UBEC arrived and works great - I've got it connected to a 7.2v NiMH battery outputting 5v and its powering the webcam fine." CreationDate="2010-12-31T22:22:56.647" UserId="2393" />
  <row Id="12358" PostId="8429" Text="absolutely!  You will see about a 16ms latency in round trip communication.  It's very noticeable when you compare reflashing a micro over a USB-&gt;serial adapter vs. a &quot;real&quot; COM port." CreationDate="2011-01-01T01:19:01.007" UserId="2288" />
  <row Id="12359" PostId="8439" Text="Docklight really shines when you want to work with mixed ascii/binary protocols.  In addition, I have found the macros feature really useful, where you can pre-program a series of bytes to automatically send.  The auto-respond feature is also very cool.  However, it can't log two ports simultaneously (as far as I can remember)." CreationDate="2011-01-01T01:24:33.027" UserId="2288" />
  <row Id="12360" PostId="8467" Text="com0com is awesome, plus it works on 64bit Windows.  I didn't know that it logged -- I've only used its super handy port simulator / internal null modem loopback / port mapping feature. " CreationDate="2011-01-01T01:25:35.973" UserId="2288" />
  <row Id="12361" PostId="8466" Text="Tamura makes transformers - see here: http://www.tamuracorp.com/index.php?src=directory&amp;view=2006products&amp;srctype=display&amp;id=129813&amp;category=Power%20Transformers&amp;PHPSESSID=655f4d7e5b9f249475557eab589220c3" CreationDate="2011-01-01T02:35:07.010" UserId="1374" />
  <row Id="12362" PostId="8434" Text="@Kellenjb I hadn't thought about that. D'oh. Happy New Year :)" CreationDate="2011-01-01T02:51:45.803" UserId="1623" />
  <row Id="12363" PostId="8465" Text="What @vicatcu suggests is supported in very few device families." CreationDate="2011-01-01T02:54:11.143" UserId="206" />
  <row Id="12364" PostId="8476" Text="This is not a forum. You should edit your question, not post additional info as an answer." CreationDate="2011-01-01T10:28:11.460" UserId="1374" />
  <row Id="12365" PostId="8157" Text="Stepper motors = No! Stepper motors are horribly low torque for their size, and are complex to drive. Basically, you need a high-torque DC brushmotor of some sort." CreationDate="2011-01-01T10:33:14.123" UserId="1374" />
  <row Id="12366" PostId="8476" Text="Having trouble getting into your account?" CreationDate="2011-01-01T10:34:26.327" UserId="2118" />
  <row Id="12367" PostId="8429" Score="1" Text="Another option is to use  FTDI's FT2232 or FT4323 dual/quad UART chips - these runs USB2 High Speed, so the latency from USB should be a lot lower." CreationDate="2011-01-01T12:38:16.760" UserId="1681" />
  <row Id="12368" PostId="8190" Text="hi jojo l'abricot,&#xA;&#xA;I have found the hex but I still don't understand about the avrdude..&#xA;&#xA;I have tried to program it using my external programmer, just the same way I program the chip to blink, but it doesn't give any visible result..&#xA;&#xA;maybe I still got the avrdude stuffs wrong..&#xA;&#xA;Any idea for that?&#xA;&#xA;Thanks " CreationDate="2011-01-01T12:57:08.657" UserId="2264" />
  <row Id="12370" PostId="8470" Text="That's much easier - you have a font bitmap and a RAM display buffer, both using the FPGA internal block RAM. Youadisplay the bitmap of each each  character on the appropriate part of the screen according to the content of the display buffer. A seperate section copies the text into the display buffer and formats.  You can initialise the RAM at compile time with known text while developing the display part.  This could readily be done without a CPU, especially if you avoid/simplify the FAT stiff to read the SD card. This is an entirely viable starter FPGA project. Way more so than PDF. " CreationDate="2011-01-01T15:37:05.787" UserId="1681" />
  <row Id="12371" PostId="8470" Text="Going to a character display buffer instead of a graphics bitmap brings the memory requirement down to what is available on-chip in a cheap FPGA" CreationDate="2011-01-01T15:45:08.490" UserId="1681" />
  <row Id="12372" PostId="8485" Score="1" Text="You might get more detailed answers from stackoverflow for this kind of question." CreationDate="2011-01-01T17:17:26.410" UserId="536" />
  <row Id="12373" PostId="4712" Score="1" Text="I asked a similar question [here](http://www.eevblog.com/forum/index.php?topic=1842.0), and got [a knowledgeable answer](http://www.eevblog.com/forum/index.php?topic=1842.msg25514#msg25514)." CreationDate="2011-01-01T17:48:42.037" UserId="2118" />
  <row Id="12374" PostId="8485" Text="I had thought about posting it there, but I thought as this would be more specific to embedded systems I should post it here." CreationDate="2011-01-01T19:23:35.510" UserId="1200" />
  <row Id="12375" PostId="621" Text="@Brian - The 'beginner' tag is known as a [meta tag](http://blog.stackoverflow.com/2010/08/the-death-of-meta-tags/) and should not be used.  This question probably doesn't need to be CW, so let's talk in the comments if you want to make any more revisions (which could push it to CW)." CreationDate="2011-01-01T19:46:32.633" UserId="857" />
  <row Id="12376" PostId="8489" Score="1" Text="A DVT is tailored to a design. What is the design?" CreationDate="2011-01-01T21:22:17.607" UserId="2118" />
  <row Id="12377" PostId="8344" Text="-1 irrelevant.&#xA;The capacitors in the PSU in my computer and in a Cockcroft-Walton voltage multiplier are connected with diodes in more or less the same circuit shown by the original poster -- a voltage doubler.&#xA;Those small capacitors connect the antenna -- the source of the power -- to the rest of the circuit.&#xA;&quot;Let's ignore the small [capacitors]&quot; is like saying &quot;let's ignore the power cable from my computer to that mysterious socket in the wall&quot;.&#xA;The small capacitors in those 3 circuits aren't used for storage; they are used to pass AC current and block DC current (aka &quot;voltage shifting&quot;)." CreationDate="2011-01-01T23:08:44.673" UserId="813" />
  <row Id="12378" PostId="8482" Text="Thanks, that helps a lot. I take it that most SPI communications are the same, in you shift op codes then the data length of each depends on the data sheet?" CreationDate="2011-01-01T23:48:38.993" UserId="665" />
  <row Id="12379" PostId="5651" Score="1" Text="Hmm... not sure about low voltage, you can get 2.5V, 2.7V and 5.5V supercaps, LiPos are 3.7V, Ni-MH 1.2V, they are all in the same ballpark." CreationDate="2011-01-02T01:27:57.853" UserId="1225" />
  <row Id="12380" PostId="7686" Text="BSF actually *does* affect all bits 0-7, even though we all wish it didn't. See http://techref.massmind.org/techref/readmodwrite.htm ." CreationDate="2011-01-02T04:21:52.603" UserId="813" />
  <row Id="12381" PostId="8492" Score="1" Text="If they are these, the proper way to connect to them is to directly solder a wire. " CreationDate="2011-01-02T05:00:55.000" UserId="1374" />
  <row Id="12382" PostId="8482" Text="I think it's more likely that they are all the same size (a byte in this case). The library is just badly written. Control commands (they're not really opcodes) should generally be written in hex, or whatever format the datasheet uses. Mixing bases is a recipe for disaster/unmaintainability." CreationDate="2011-01-02T05:05:16.743" UserId="1374" />
  <row Id="12383" PostId="6881" Text="I don't know why you bring up &quot;avoid damaged sections&quot;. We're talking about *detecting* permanently damaged RAM. if no damage is detected, then the code runs just as fast and has practically the same size as the original code. If even a single bit of damage is detected, then presumably the code would somehow indicate the problem and halt, and " CreationDate="2011-01-02T05:38:13.113" UserId="813" />
  <row Id="12384" PostId="6881" Text="I don't know why you bring up &quot;avoid damaged sections&quot;. We're talking about *detecting* permanently damaged RAM. If no damage is detected, then the MCU can be re-programmed with the original code with the original size and speed -- or perhaps the developer will make it a few lines longer to test the RAM every power-up; after that test, the rest of the code runs at the original speed. If even a single bit of damage is detected, then presumably the code would somehow indicate the problem and halt, and the developer would throw away that chip and get a replacement." CreationDate="2011-01-02T05:44:36.367" UserId="813" />
  <row Id="12385" PostId="8429" Text="My colleague had told me about a much better, newer FTDI chip that addresses this issue.  Must be the one you're talking about!  :)  I'll look into it -- thanks for sharing the part number." CreationDate="2011-01-02T05:57:49.563" UserId="2288" />
  <row Id="12386" PostId="8442" Text="Thomas O, your description of an &quot;eFuse&quot; sounds no different than the &quot;fuse bits&quot; in many MCUs and programmable array logic chips and some FPGA chips. So is an &quot;eFuse&quot; identical to a fuse bit, or is there some difference I&quot;m missing?" CreationDate="2011-01-02T06:06:02.050" UserId="813" />
  <row Id="12387" PostId="8482" Score="1" Text="Well my plan is to rewrite the library if for nothing else than the learning value. I will make sure that I use hex values instead of decimal values to keep with the datasheet" CreationDate="2011-01-02T09:46:08.670" UserId="665" />
  <row Id="12388" PostId="6755" Text="Might even use that might self in a different project; would work for 8*8 LED matrix's and not have to worry bout wether there common cathode or anode if I'm not mistaken. Will have to read more about them" CreationDate="2011-01-02T09:58:08.437" UserId="665" />
  <row Id="12389" PostId="8497" Score="1" Text="Apparently *&quot;post package trim&quot;* is used to adjust a bandgap reference that has been shifted by packaging. (See [1](http://goo.gl/KzZLm), [2](http://users.ece.gatech.edu/rincon-mora/research/gtac/gtac_f3b.pdf).) Thanks for the answer!" CreationDate="2011-01-02T10:42:19.563" UserId="2118" />
  <row Id="12390" PostId="8442" Text="@davidcary there are similarities, but I think an eFuse can be changed from software, whereas an MCU fuse can be changed only from a programmer. Also, MCU fuses are often EEPROM or FLASH, so they can be reset." CreationDate="2011-01-02T11:26:21.657" UserId="1225" />
  <row Id="12391" PostId="8497" Score="4" Text="Sometimes the &quot;NC&quot; pins have special diagnostic functions used at the factory. I think it's best to assume you cannot use the pins, rather than risk unspecified behavior." CreationDate="2011-01-02T11:52:35.987" UserId="1374" />
  <row Id="12392" PostId="8497" Score="1" Text="Additionally the NC pins may be bonded together to one common point. " CreationDate="2011-01-02T11:56:41.440" UserId="1225" />
  <row Id="12393" PostId="8497" Text="@FakeName, @ThomasO, Any datasheets that reference this?" CreationDate="2011-01-02T11:59:38.407" UserId="2118" />
  <row Id="12395" PostId="8497" Text="Sometimes, they might be reserved for a future version of the chip, although that is normally stated." CreationDate="2011-01-02T12:09:50.937" UserId="305" />
  <row Id="12397" PostId="8493" Score="5" Text="That's a pretty hardcore part! [Was that a pun? If so, it was intended.]" CreationDate="2011-01-02T12:24:49.477" UserId="2118" />
  <row Id="12398" PostId="8497" Text="@Leon: yes, the infamous RFE, a.k.a. `reserved for future enhancements`." CreationDate="2011-01-02T12:24:54.607" UserId="2064" />
  <row Id="12399" PostId="8498" Text="sparkfun sells a 5.2W solar panel: http://www.sparkfun.com/products/9241 , wouldn't this (ideally) need to be in the sun for &lt;1h to fully charge the battery ?" CreationDate="2011-01-02T13:06:11.870" UserId="417" />
  <row Id="12400" PostId="8474" Text="Would that help much? The antenna is only one wire. I know what you mean, though. The thing I don't like about wind generators is that they might slow down the wind and cause climate changes over a large area. My fear of that is slim, however, and easily overridden by practicality. ;)" CreationDate="2011-01-02T13:07:01.943" UserId="794" />
  <row Id="12401" PostId="8465" Text="Well, generally the FPGA core voltage will be set at something pretty low to begin with, such as 1.2V. You can't really mess with that too much. You can, however, change your I/O voltages, which can get you some savings. Also, your clock frequency is whatever you want it to be. Slowing the clock down can show significant power savings. " CreationDate="2011-01-02T13:10:43.690" UserId="638" />
  <row Id="12402" PostId="8498" Text="now that I re-read your post, a 3x3cm cell is tiny! I am willing to carry a much larger one if it means my battery will always still working (buying a new battery is expensive and much less fun)" CreationDate="2011-01-02T13:12:12.957" UserId="417" />
  <row Id="12403" PostId="8498" Text="I obviously made some mistakes in my original calculations. Could someone point out these ones in particular? I think I made an error in converting cm^2 to m^2." CreationDate="2011-01-02T13:14:02.367" UserId="1225" />
  <row Id="12404" PostId="8498" Text="@ThomasO, Nowadays I find myself trusting Google and brackets more than my head! You can type in `(3.4 W hour)/(4 hour)/((1321 W/m^2)*0.15) in cm^2` to get the conversion." CreationDate="2011-01-02T13:20:44.977" UserId="2118" />
  <row Id="12405" PostId="8498" Text="@penjuin, Fancy panel! It is 400cm^2, so I'd say yes, go for it! `(180 mm)*(220 mm)*(1321 W/m^2)*0.15=7.8W`, disclosing an efficiency of `5.2/7.8=66%`. There is, however, the small issue that I have zero experience with solar ;)" CreationDate="2011-01-02T13:27:23.770" UserId="2118" />
  <row Id="12406" PostId="8500" Score="2" Text="Also check continuity between individual NC pins." CreationDate="2011-01-02T13:39:43.487" UserId="1225" />
  <row Id="12407" PostId="8499" Score="4" Text="Modern processors can eat 145A? Wow." CreationDate="2011-01-02T15:45:50.803" UserId="1633" />
  <row Id="12408" PostId="8497" Text="@stevenvh, &quot;No Connect&quot; I have seen used meaning that the user should not connect. It still makes logical sense in that usage, but I understand the frustration." CreationDate="2011-01-02T16:43:30.823" UserId="230" />
  <row Id="12409" PostId="8499" Score="3" Text="Holy crap, I wouldn't have believed that myself, but there it is on page 23 of the linked datasheet (I_cc)." CreationDate="2011-01-02T17:07:42.340" UserId="771" />
  <row Id="12410" PostId="8497" Text="@Thomas O Do you know what the reason is for bonding together at some common point? It seems like a waste unless there's a good reason for it." CreationDate="2011-01-02T17:35:10.030" UserId="319" />
  <row Id="12411" PostId="8503" Score="2" Text="I've heard all of this as well. That's why cheap lipo chargers are like $17 (http://www.sparkfun.com/products/726)" CreationDate="2011-01-02T18:15:24.363" UserId="2006" />
  <row Id="12412" PostId="8505" Text="according to 320834.pdf, pointed by Thomas O, thanks!" CreationDate="2011-01-02T19:00:45.783" UserId="1994" />
  <row Id="12413" PostId="8508" Score="1" Text="hey, that's what I do with LEDs!" CreationDate="2011-01-02T19:51:11.357" UserId="2006" />
  <row Id="12414" PostId="8497" Text="@Leon @Stevenvh In other words, they got stuck with an extra pin and decided to claim it was an engineering decision for future (unknown) features." CreationDate="2011-01-02T20:08:43.753" UserId="319" />
  <row Id="12415" PostId="8506" Score="2" Text="I think you have misspoke. 1Vp-p and high frequency components isn't a reason to not use a DC blocking cap. What is a reason is a DC offset that changes slowly with time and is needed by the receiver to get some information." CreationDate="2011-01-02T20:12:36.120" UserId="319" />
  <row Id="12416" PostId="8482" Text="When you do rewrite it - please post it somewhere!" CreationDate="2011-01-03T00:35:01.607" UserId="1823" />
  <row Id="12418" PostId="1877" Text="I'm puzzled by the concern over not receiving SCSI commands.  IDE commands aren't all that complicated.  On a different subject, given that the minimal amount of memory in the ATMEGA makes throughput unimportant, transfer speed should be as slow as possible for convenience." CreationDate="2011-01-03T01:05:41.873" UserId="2246" />
  <row Id="12419" PostId="8464" Score="1" Text="Would suggest you try writing the HDL in simulation, and then buy and test it on an eval board (even if a bigger chip in the same family), before committing to a PCB.  The latest generation FPGAs will probably be lowest power, but will also require low core logic voltage supplies." CreationDate="2011-01-03T01:09:28.767" UserId="2246" />
  <row Id="12420" PostId="8511" Score="1" Text="On Alibaba.com:`Home &gt; Products &gt; Electronic Components &amp; Supplies &gt; Optoelectronic Displays &gt; LCD Modules`, then choose `Graphic` for &gt;2000 hits. Have fun browsing! :P" CreationDate="2011-01-03T01:39:32.100" UserId="2118" />
  <row Id="12421" PostId="8517" Text="i think he's thinking along the lines of maybe reversing the output (dpdt relay/h-bridge would do) in response to being able to determine which way the plug is. figuring out which way the plug is would be the harder part." CreationDate="2011-01-03T01:57:01.410" UserId="740" />
  <row Id="12422" PostId="8516" Text="Yes the third prong would help but you can't plug it upside down then under current designs.  :)" CreationDate="2011-01-03T02:01:18.843" UserId="2462" />
  <row Id="12423" PostId="8517" Text="I'm wondering if there's some other outlier that could be drawn in to make this &quot;magic&quot; adapter.  Something that interacts with the atmosphere to help discern true ground, I dunno... just imagining an inventors challenge to build such a device.  Sure, a radiotransmitter which lets you know the local power grid's phase... but... is there better?" CreationDate="2011-01-03T02:05:01.117" UserId="2462" />
  <row Id="12424" PostId="8517" Text="Although it might be fun to build something you plug in elsewhere in the house, that then gives an AC/DC adapter this property.  My friend would baffle for a bit, until he found it.  :)" CreationDate="2011-01-03T02:06:45.093" UserId="2462" />
  <row Id="12425" PostId="8517" Text="@Hostile Fork: elsewhere in the house, you could put a widget that puts a couple msec burst of 10kHz onto the mains at a selected phase point. Your Magic Supply could detect this. But then, many of your un-magic supplies might find this purposeful EMI objectionable." CreationDate="2011-01-03T02:21:33.320" UserId="740" />
  <row Id="12426" PostId="8516" Text="Isn't 1 of the prongs tied to the ground pin (at least in the US)? If this is the case then if you have reference to some other ground you could detect which line had AC on it and know which output polarity you wanted." CreationDate="2011-01-03T02:42:16.057" UserId="319" />
  <row Id="12427" PostId="8516" Text="Another though, take the ground pin on the plug and make it spring loaded. If you plug it in correctly the ground pin goes in correctly. If inverted the pin will be pressed in and could cause a switch to switch the output polarity. Might be odd, worthless, and wouldn't work in outlets with no ground, but could work." CreationDate="2011-01-03T02:44:46.177" UserId="319" />
  <row Id="12428" PostId="8510" Text="Hmm, so I'd end up powering the modulator and the camera from the power injected on the coax... not a bad idea..." CreationDate="2011-01-03T02:47:42.073" UserId="974" />
  <row Id="12429" PostId="8464" Score="2" Text="Yeah - buying an eval board isn't an option at the moment due to my low R&amp;D budget of about £0." CreationDate="2011-01-03T02:50:38.280" UserId="1225" />
  <row Id="12430" PostId="8519" Text="Link doesn't work for me." CreationDate="2011-01-03T02:52:24.377" UserId="319" />
  <row Id="12431" PostId="8519" Text="Should work now." CreationDate="2011-01-03T02:54:03.490" UserId="1179" />
  <row Id="12432" PostId="8344" Text="I agree with you that the small caps are used to pass AC and block DC, and I've added a note about that to my answer. My assumption, which is seems you disagree with, is that the circuit is intended for energy storage, as it is described as a replacement for a battery. Do you agree or disagree with my main point, which is that the circuit can store very little energy?" CreationDate="2011-01-03T03:07:58.823" UserId="712" />
  <row Id="12433" PostId="6755" Text="@AshleyHughes These chips only SINK current, so you can only hook them up to the cathodes of LEDs. You would need a common-anode LED array, or have the anodes driven by transistors." CreationDate="2011-01-03T05:11:35.373" UserId="638" />
  <row Id="12435" PostId="8526" Score="1" Text="What is [ADXL103](http://www.analog.com/static/imported-files/data_sheets/ADXL103_203.pdf), and where is my hossenfeffer?" CreationDate="2011-01-03T05:35:19.633" UserId="2118" />
  <row Id="12436" PostId="8519" Text="Have you actually ever used one of those? They can be very sensitive and pick up AC from over a foot away. It isn't really the best method for trying to find the neutral vs hot." CreationDate="2011-01-03T05:42:31.000" UserId="319" />
  <row Id="12437" PostId="8520" Text="Apparently the battery isn't switched into the circuit until power is applied. So... if they're pulls from used equipment, there's a very good chance the non-volatile property will be gone. It'll still work fine as SRAM though..." CreationDate="2011-01-03T06:00:23.963" UserId="638" />
  <row Id="12438" PostId="8519" Text="The existence of this thing raises the question of how such a thing works, as that is the issue here.  Antenna and op-amp, but how?" CreationDate="2011-01-03T06:23:30.890" UserId="2462" />
  <row Id="12439" PostId="8527" Text="[Some former NASA guy says he can get ~62% efficiency over 100km using microwave beams.](http://www.wired.com/wiredscience/2008/09/visionary-beams/)" CreationDate="2011-01-03T06:29:16.750" UserId="2118" />
  <row Id="12440" PostId="8526" Text="If you drew this and photographed it in response to my question, an admirable effort.  But if it's a sincere answer to the question, precisely what an accelerometer or &quot;hex inverting Schmitt trigger&quot; has to do with this requires further explanation.  :)" CreationDate="2011-01-03T06:29:26.560" UserId="2462" />
  <row Id="12441" PostId="8526" Score="2" Text="Hahahahahahaha - What this is doing is **literally** detecting if it is upside-down or not. The accelerometer detects if it is inverted, and changes the polarity by toggling a relay based on it's physical position." CreationDate="2011-01-03T08:09:39.790" UserId="1374" />
  <row Id="12442" PostId="8520" Text="It'll still work fine as SRAM!  That is good news, so maybe I won't have to throw them all away!" CreationDate="2011-01-03T08:16:02.750" UserId="2463" />
  <row Id="12443" PostId="8528" Score="1" Text="They don't provide any experimental evidence that it deters sharks, so I wouldn't trust their claims." CreationDate="2011-01-03T08:49:18.173" UserId="305" />
  <row Id="12444" PostId="8529" Text="more info on that kind of repellent - http://www.elasmo-research.org/education/white_shark/deterrents.htm" CreationDate="2011-01-03T09:36:13.687" UserId="2060" />
  <row Id="12445" PostId="5542" Text="My boards were blue from the beginning. The Natrium Persulfate solution turns blue after many uses but this does not affect the color if the board." CreationDate="2011-01-03T09:49:14.510" UserId="10" />
  <row Id="12446" PostId="8528" Score="1" Text="What the hell is a &quot;three dimensional electrical wave form&quot;?" CreationDate="2011-01-03T10:05:54.233" UserId="1374" />
  <row Id="12447" PostId="8528" Score="2" Text="@Fake Name  Well, sharks use, as far as I can see, [Ampullae of Lorenzini](http://en.wikipedia.org/wiki/Ampullae_of_Lorenzini) to detect electric field. Maybe the device would emit electric flied whose intensity is f(x,y,z). That would make it &quot;three dimensional&quot;, but it still sounds like technobabble to me." CreationDate="2011-01-03T11:01:05.847" UserId="1240" />
  <row Id="12448" PostId="8533" Text="+1, Well structured, clear and concise answer." CreationDate="2011-01-03T11:32:01.043" UserId="444" />
  <row Id="12449" PostId="8532" Score="2" Text="We usually test to the SPEC as well as a common standard that includes things like I/O protection, short circuit, over voltage conditions, etc., so that we don't have to include them in every spec for each product.  Every DC product must survive reversal of the power leads, for example, so that goes into the global requirements doc." CreationDate="2011-01-03T11:38:57.410" UserId="2377" />
  <row Id="12450" PostId="3951" Text="At the bottom of the page there are references to the original articles published in the Computer Music Journals. These discuss the trade-offs in S/N. " CreationDate="2011-01-03T11:58:58.893" UserId="424" />
  <row Id="12451" PostId="8528" Text="I think the 3d thing is a bunch of crap too, just another techno-babble used by salesmen and PR people  " CreationDate="2011-01-03T12:07:07.330" UserId="2060" />
  <row Id="12452" PostId="8534" Score="2" Text="it will also depend on the type of oscilloscope you have, could you please give us info on the one you are using?" CreationDate="2011-01-03T12:09:50.697" UserId="2060" />
  <row Id="12453" PostId="8519" Score="1" Text="@Kellenjb I've got a cheap one from Conrad.  It's not that sensitive, and sometimes it's even fooled by a thick layer of insulation. " CreationDate="2011-01-03T12:16:13.230" UserId="1179" />
  <row Id="12454" PostId="8534" Score="1" Text="it's an old Russian scope, it has 50Vpp and a high input impedance, i know the switches to change the time range and it's ok, but how do i connect it phisicaly to the 230V mains..." CreationDate="2011-01-03T12:23:36.247" UserId="2245" />
  <row Id="12455" PostId="8528" Score="6" Text="@Maltrap, Could you consider accepting some answers for your previous questions? You currently have *&quot;0% accept rate&quot;*, which can deter users from attempting to answer." CreationDate="2011-01-03T12:47:38.350" UserId="2118" />
  <row Id="12456" PostId="8425" Text="@ tyblu: Yup my bad. typing too fast." CreationDate="2011-01-03T13:01:31.717" UserId="1235" />
  <row Id="12457" PostId="8344" Text="@davidcary, A doubler is hooked up differently. What computer PSU do you have with a doubler in it? Would like to see that." CreationDate="2011-01-03T13:02:22.377" UserId="2118" />
  <row Id="12458" PostId="8432" Text="How long do you think it would take to write all zeros to a 4gb card? Seems like a long time. Also, do you have any code examples you could share for modifying the fswrite function to allow whole writes to whole sectors?" CreationDate="2011-01-03T13:04:40.140" UserId="1235" />
  <row Id="12459" PostId="8432" Text="Also, if you write all zero's to the file. How do you keep track of where the end of your actual data is? Do you just read all the data at the beginning and find the string of zeros?" CreationDate="2011-01-03T13:14:49.840" UserId="1235" />
  <row Id="12460" PostId="8536" Text="+1. Very thorough." CreationDate="2011-01-03T14:16:42.517" UserId="930" />
  <row Id="12462" PostId="8432" Text="If you're using FAT16, I believe you're limited to 2GB. I believe the SD/MMC card has an &quot;erase blocks&quot; function, which doesn't appear to be implemented in the MDDFS library. I used a proprietary code library for my SD card project, so I can't share any code examples. In order to find the last data, you would need to read until you found all 0's in a data record. If your data record can be all 0's, I'd advise adding in some non-zero data, or a delimiter of some sorts." CreationDate="2011-01-03T15:08:52.530" UserId="638" />
  <row Id="12463" PostId="8498" Text="@tyblu, 66% efficiency is *very* high for solar. The typical range is 15% to 40%, and you only get 40% with really expensive cells." CreationDate="2011-01-03T15:33:06.483" UserId="1225" />
  <row Id="12464" PostId="8505" Text="and here are some adapters for using JTAG on some older intel chips. http://www.arium.com/products/9/JTAG-Adapters-and-Interposers.html" CreationDate="2011-01-03T15:41:25.353" UserId="1994" />
  <row Id="12465" PostId="5564" Text="Surface-mount parts that dissipate heat have another failure mechanism: I've seen resistors unsolder themselves and slide off the board." CreationDate="2011-01-03T16:36:30.780" UserId="411" />
  <row Id="12466" PostId="8497" Score="1" Text="@steven, I'd emphasize the answer to this question by saying &quot;**No**, not unless *explicitly allowed* by the manufacturer.&quot; up front." CreationDate="2011-01-03T17:07:02.933" UserId="1407" />
  <row Id="12467" PostId="8528" Score="1" Text="@Fake Name @AndrejaKo @jsolarski I have 4d electrical waves, must mean I am awesome... (x,y,z,t)" CreationDate="2011-01-03T17:34:23.270" UserId="319" />
  <row Id="12468" PostId="8528" Score="1" Text="From the title, I thought this was some kind of Arduino accessory." CreationDate="2011-01-03T17:37:23.070" UserId="411" />
  <row Id="12469" PostId="8503" Text="Everything can be dangerous, just know and respect the hazards." CreationDate="2011-01-03T19:14:31.233" UserId="1407" />
  <row Id="12470" PostId="8440" Score="1" Text="The e obviously stands for Evil, which schemes like that are." CreationDate="2011-01-03T19:54:49.597" UserId="883" />
  <row Id="12471" PostId="8254" Text="I don't recall ever seeing a 741 in an actual production device that couldn't easily be labeled &quot;vintage&quot;. I have seen 741's as/in teaching tools and kits, though." CreationDate="2011-01-03T20:04:18.890" UserId="883" />
  <row Id="12472" PostId="8544" Text="Does Eagle or Kicad allow any kind of export-to-vendor for click and ship functionality? I'm totally lost on that front... some of the PCB design-n-ship companies seem to have basic software but no template for dropping in connection points for an arduino chip." CreationDate="2011-01-03T20:27:23.870" UserId="2469" />
  <row Id="12473" PostId="8544" Text="Many board suppliers accept Eagle files. Otherwise, you supply Gerber and Excellon files generated by your PCB software. If the library doesn't have the AVR part used in the Arduino, you will have to design your own." CreationDate="2011-01-03T21:07:02.637" UserId="305" />
  <row Id="12474" PostId="8498" Text="@ThomasO, That is the efficiency of the regulator, not the cell. Take a peek at the previous calculation: it has `*0.15` at the end." CreationDate="2011-01-03T22:44:32.130" UserId="2118" />
  <row Id="12475" PostId="8541" Text="How much time are you willing to invest, and what type of solar cell?" CreationDate="2011-01-03T22:53:16.257" UserId="2118" />
  <row Id="12476" PostId="8550" Text="ps... tell them Mini sent you ;)" CreationDate="2011-01-03T22:56:18.927" UserId="2433" />
  <row Id="12477" PostId="8548" Text="Which servos are you using?" CreationDate="2011-01-03T22:58:00.917" UserId="2118" />
  <row Id="12478" PostId="8552" Text="I can remember when Maplin was mail order only - my original customer number (still useable) is only 4 digits long!" CreationDate="2011-01-03T23:17:52.583" UserId="1750" />
  <row Id="12479" PostId="8526" Text="Why use an accelerometer - just use a mercury switch / or tilt switch to operate the relay from the supply..." CreationDate="2011-01-03T23:26:51.553" UserId="2192" />
  <row Id="12480" PostId="8519" Text="Abstractly I feel like one should be able to test for true ground reliably using some sort of gadget.  If this works for making a magic wall wart, then it is what I was looking for--and is the answer to this question.  If it doesn't work, then it's not.  What factors into the &quot;pretty reliably&quot;?" CreationDate="2011-01-03T23:36:09.080" UserId="2462" />
  <row Id="12481" PostId="8528" Text="@tyblu, Thanks for pointing that out.  Sorted.  Now let's see how many more answers come in. ;-)" CreationDate="2011-01-03T23:39:18.490" UserId="561" />
  <row Id="12482" PostId="8551" Text="RS have a trade counter in Bristol look here: http://uk.rs-online.com/web/generalDisplay.html?id=branchNetwork" CreationDate="2011-01-03T23:49:32.620" UserId="1623" />
  <row Id="12483" PostId="8558" Text="Are you talking about detecting whether the dishes in the machine are clean or dirty, or just logging their presence and dishwasher cycle?" CreationDate="2011-01-03T23:59:02.783" UserId="2118" />
  <row Id="12484" PostId="8551" Text="Good luck getting an account with RS unless you really are 'trade' (ie: a business with an estimated regular spend with RS)" CreationDate="2011-01-04T00:01:45.823" UserId="1750" />
  <row Id="12485" PostId="8558" Text="I was thinking more about calling the dishwasher state 'clean' until I detected an empty dishwasher after a wash cycle. That way, it accounts for the 'open it up to get one clean spoon but don't empty it' use case.   " CreationDate="2011-01-04T00:04:11.950" UserId="2258" />
  <row Id="12486" PostId="8551" Text="I have an account with RS and have used them before for orders. They do serve people with online accounts at the trade counters. " CreationDate="2011-01-04T00:19:40.867" UserId="1623" />
  <row Id="12487" PostId="8528" Text="@AndrejaKo -  Electrical **fields** are 3 dimensional, yes. But a 3D **wave form**?" CreationDate="2011-01-04T00:41:05.227" UserId="1374" />
  <row Id="12488" PostId="8526" Text="Mercury switches were hard to find even before RoHS.  And the rolling-ball tilt switches are really noisy and bouncy.  The ADXL 103 has +/- 1.7g, which means the voltage facing &quot;up&quot; is 2.5+2.5*1/1.7, or 4V, and the voltage facing down is 1V.  The Schmitt-trigger gives about 1V (or 0.7g) hysteresis.  This should remove false triggers caused by vibration, and even under zero-g conditions (being thrown across the room in frustration, say) the circuit will maintain its previous state.  A realistic circuit will use all six gates in parallel and a low-current relay, or add a transistor." CreationDate="2011-01-04T00:42:02.447" UserId="411" />
  <row Id="12489" PostId="8489" Score="1" Text="Don't just check at high and low temperatures and voltages, but sweep through them.  Not every temperature / voltage dependence is monotonic." CreationDate="2011-01-04T01:00:01.190" UserId="411" />
  <row Id="12491" PostId="8528" Text="@Fake Name I'm not electromagnetics expert, but what is wrong with 3D waveform? It is obvious that electrical fields are 3D, so why wouldn't we be able to use 3D waveforms with them if the actually make 3D waves. As far as I can see, if you use approximations liberally, you could create the need to describe field made by the device in question using 3D waveform.  As I said, if the field is a function of three spacial coordinates and time, why not use 3D waveform?" CreationDate="2011-01-04T01:43:23.827" UserId="1240" />
  <row Id="12492" PostId="8562" Text="20MHz is a good place to start as it is a common bandwidth on midrange (low end, nowadays) analog scopes (50MHz-60MHz is a common bandwidth on low end DSOs). As they were once common, they are now cheap. 20MHz allows you to capture rise times down to ~17ns. I my opinion, every enthusiast needs an analog 'scope as a *reality check*, as they display exactly what goes up the probes. DSOs are more versatile, in that you can capture and analyze data for FFT, computer logging (for custom display programs, screen capture, further analysis) and capture and/or trigger on *single-shot* events." CreationDate="2011-01-04T01:46:41.473" UserId="2118" />
  <row Id="12493" PostId="8561" Text="+1 for fun ideas" CreationDate="2011-01-04T01:52:10.067" UserId="319" />
  <row Id="12495" PostId="8563" Text="+1 for practical ideas" CreationDate="2011-01-04T01:54:49.503" UserId="2118" />
  <row Id="12496" PostId="8547" Text="The spartan 6 has DCM and PLL's, not found DLL yet. After searching forums I found that the Xilinx has a tool called Core Generator that can be configured to generate clock resources." CreationDate="2011-01-04T04:00:38.283" UserId="444" />
  <row Id="12497" PostId="8538" Text="Where did you get those numbers for skin depth in water?" CreationDate="2011-01-04T05:09:56.993" UserId="2118" />
  <row Id="12498" PostId="8560" Text="If I recall correctly, based on the PWM you give them they will go forwards/reverse; so they still have a controller of some sort left in them." CreationDate="2011-01-04T05:18:49.187" UserId="1407" />
  <row Id="12500" PostId="1455" Text="I second the DS1052E, it really is a nice scope, just be sure to mod it to 100 MHz bandwidth. However, if you can get a good Analog scope for cheap, then it's a good way to start and for some situations it can be really good supplement to the DSO. At my Hackerspace we have a stack of Tektronix scopes (2247A, 2246, TAS 250) and they are all quite usable and I can highly recommend either of them." CreationDate="2011-01-04T08:14:39.193" UserId="1675" />
  <row Id="12501" PostId="8567" Score="2" Text="10 MHz would be the point of 3dB attenuation, so 0.707x not 0.5x." CreationDate="2011-01-04T08:45:02.033" UserId="1225" />
  <row Id="12502" PostId="8566" Text="Note that some digital systems (CMOS in particular) define rise times from 20% to 80%." CreationDate="2011-01-04T09:05:51.737" UserId="2118" />
  <row Id="12503" PostId="8566" Text="Upvote!! quite technical and somethings that I don't understand!! ;)" CreationDate="2011-01-04T09:36:53.303" UserId="444" />
  <row Id="12504" PostId="8566" Text="The scope is here http://www.picotech.com/handheld-oscilloscope.html, model 2104" CreationDate="2011-01-04T09:39:25.987" UserId="444" />
  <row Id="12505" PostId="8567" Text="@dren.dk: This is a pc based oscilloscope. For measuring digital signals upto 100Mhz, what scope and probes would you recommend?" CreationDate="2011-01-04T09:41:02.163" UserId="444" />
  <row Id="12506" PostId="8567" Text=" 	&#xA;@dren.dk: I checked the Rigol ds1052e, it seems to be 50Mhz , how do you mod it to 100Mhz?" CreationDate="2011-01-04T09:48:54.890" UserId="444" />
  <row Id="12507" PostId="8566" Text="Any recommendations for 2 channel scope for 100Mhz?" CreationDate="2011-01-04T09:49:41.910" UserId="444" />
  <row Id="12508" PostId="8568" Text="What is direct measurement?" CreationDate="2011-01-04T09:50:27.960" UserId="444" />
  <row Id="12509" PostId="8568" Text="When you just connect the scope to your signal and want to see everything." CreationDate="2011-01-04T10:00:57.867" UserId="2062" />
  <row Id="12510" PostId="8566" Text="I checked the scope spec again and the Sample rate (single shot) = 50 MS/s and for repetitive signals is 1GS/s, not sure what these figures mean?" CreationDate="2011-01-04T10:02:43.177" UserId="444" />
  <row Id="12511" PostId="8567" Score="1" Text="@Kevin Boyd http://www.youtube.com/watch?v=LnhXfVYWYXE" CreationDate="2011-01-04T10:43:41.093" UserId="1225" />
  <row Id="12512" PostId="8523" Text="Cool... I'm gonna buy one of these! Thanks (+1)" CreationDate="2011-01-04T10:45:22.677" UserId="2426" />
  <row Id="12513" PostId="8566" Text="@KevinBoyd, The actual sample rate is always 50MS/s. 1GS/s can be claimed by combining samples from over 20 periods, a technique used by *sampling oscilloscopes* and some *digital spectrum analyzers* called [undersampling](http://en.wikipedia.org/wiki/Undersampling)." CreationDate="2011-01-04T10:50:50.330" UserId="2118" />
  <row Id="12514" PostId="8566" Score="1" Text="@KevinBoyd, Right now the Instek GDS-1062A looks quite nice with 2M memory and 60MHz. I have a Rigol DS1052E with 1M memory, and may bump it up to 100MHz, but that isn't as important to me as the word memory. For higher frequencies I got an old Tek 485: 4 channels, 200MHz. I think Rigol has changed their firmware recently to stop the hack. Info: [A](http://www.eevblog.com/forum/index.php?topic=553.0), [B](http://www.eevblog.com/forum/index.php?topic=1379.0)." CreationDate="2011-01-04T10:59:05.520" UserId="2118" />
  <row Id="12515" PostId="8566" Text="Also, I'll be updating [this question](http://electronics.stackexchange.com/questions/8271/what-are-the-functional-differences-between-a-digital-sampling-scope-and-a-digit) very soon to go into depth differentiating DSOs, sampling 'scopes and spectrum analyzers, if you're interested." CreationDate="2011-01-04T11:00:40.433" UserId="2118" />
  <row Id="12516" PostId="8463" Text="Did you find much in Microchip's selection? I've heard their analog offerings are quite good. Only rumours, though." CreationDate="2011-01-04T11:02:36.467" UserId="2118" />
  <row Id="12517" PostId="8567" Text="@Thomas O: Alas! as per tyblu Rigol seems to have changed their firmware!" CreationDate="2011-01-04T11:53:13.790" UserId="444" />
  <row Id="12518" PostId="7794" Text="@Eric - how can the receive antenna tell that the signals are radiating out from the retransmitting antenna in &quot;divergent directions&quot;.  It will only (ignoring reflections) receive the direct line signal between the two antennas.  It is exactly the same as having a remote antenna and a long coax" CreationDate="2011-01-04T12:08:34.233" UserId="400" />
  <row Id="12519" PostId="8567" Text="@Kevin: Sorry for the dB thinko there. " CreationDate="2011-01-04T12:58:44.507" UserId="1675" />
  <row Id="12520" PostId="8567" Score="1" Text="@Kevin: There is no problem modding the Rigol as you can still downgrade to the older firmware, do the mod, then upgrade to the latest and greatest. They will need to change the actual hardware to get rid of the mod." CreationDate="2011-01-04T12:59:48.377" UserId="1675" />
  <row Id="12521" PostId="8534" Score="1" Text="The way I actually do it is by not touching mains at all! I just stick the probe into my thumb and walk around 'til I get ~1Vpp noisy signal 60Hz signal. :)" CreationDate="2011-01-04T13:55:17.100" UserId="2118" />
  <row Id="12522" PostId="1454" Text="[Here](http://electronics.stackexchange.com/questions/8565/oscilloscope-bandwidth-whats-it-all-about) are some things to consider when looking at digital storage oscilloscopes." CreationDate="2011-01-04T14:01:10.573" UserId="2118" />
  <row Id="12523" PostId="1463" Text="Late +1 for old analog." CreationDate="2011-01-04T14:03:21.350" UserId="2118" />
  <row Id="12524" PostId="2039" Text="is sump.org outdated?  There haven't been any recent updates.  I'm wondering because I have the Spartan 3E starter board and would like to get some use out of it, and sump seems like a good option.  But the port for the 3E hasn't been updated in a couple of years.  EDIT -- ok, google is my friend: http://www.skippari.net/projects/?p=187" CreationDate="2011-01-04T14:31:39.950" UserId="2288" />
  <row Id="12525" PostId="8534" Text="230V is 50Hz back here in Europe" CreationDate="2011-01-04T15:46:32.807" UserId="2245" />
  <row Id="12526" PostId="8575" Text="I would add that the sampling rate (sub 10 Hz) may be low as the software could be using interpolation." CreationDate="2011-01-04T15:46:40.027" UserId="1225" />
  <row Id="12527" PostId="8538" Text="@tyblu bottom of this page: http://farside.ph.utexas.edu/teaching/em/lectures/node102.html" CreationDate="2011-01-04T16:32:31.863" UserId="771" />
  <row Id="12528" PostId="8580" Score="1" Text="Have you got a circuit diagram of what you normally do?" CreationDate="2011-01-04T16:41:21.440" UserId="1623" />
  <row Id="12529" PostId="8580" Score="1" Text="Are you sure it's due to your power management and not your software?  Infinite loops, illegal memory access, and illegal op-codes can cause resets and other bad behavior." CreationDate="2011-01-04T16:45:30.883" UserId="1407" />
  <row Id="12530" PostId="8566" Text="@tyblu: Do you design oscilloscopes?" CreationDate="2011-01-04T17:09:19.473" UserId="444" />
  <row Id="12531" PostId="8580" Text="@Dean, no but I'll draw one later and post it." CreationDate="2011-01-04T17:09:53.480" UserId="2426" />
  <row Id="12532" PostId="8580" Text="@Nick, I'm about 95% sure it's not the code. I have done a huge amount of testing by eliminating parts of the code and seeing if it fixes the problem... I know what I'm doing with code as I'm a programmer in my job, but my electronics knowledge is basic... so I'm guessing this is where my problem is." CreationDate="2011-01-04T17:15:04.520" UserId="2426" />
  <row Id="12533" PostId="8581" Text="Thanks, but this isn't too far off what I'm already using... Since I posted the question, I've found references on the internet about switched mode power supplies with a feedback circuit that produce a constant current, I can't find a circuit diag though! I'm wondering if this is more like what I need." CreationDate="2011-01-04T17:18:20.210" UserId="2426" />
  <row Id="12534" PostId="8581" Score="2" Text="You don't want constant current for most things microcontroller, you want constant voltage.  (On the other hand, current limit is extremely useful for preventing wiring mistakes from damaging components.)" CreationDate="2011-01-04T17:37:08.837" UserId="411" />
  <row Id="12535" PostId="8581" Text="If you are already using a linear regulator then it sounds like you either need more capacitors or you have an issue with your MCLR pull up or any number of other little things." CreationDate="2011-01-04T17:44:55.683" UserId="319" />
  <row Id="12536" PostId="593" Text="+1 This is a great link... a definitive list of everything you can do with an op amp. Thanks." CreationDate="2011-01-04T17:48:56.473" UserId="2426" />
  <row Id="12537" PostId="8582" Text="Should this be community wiki?  I've written it as a survey question, but if someone can come up with some documentation which describes the relevant information for a few popular styles then **that** would be the best answer, and deserve some rep and a check.    " CreationDate="2011-01-04T17:50:37.567" UserId="857" />
  <row Id="12538" PostId="5495" Text="@Mark - Funny, I'm usually really trying hard to get the pad under the QFP to make solid contact with the ground pad through the vias/holes..." CreationDate="2011-01-04T18:26:41.013" UserId="857" />
  <row Id="12539" PostId="8566" Text="@KevinBoyd, Heh - I wish! Thank you, but I am just a junior EE and hobbyist who has read an app note or two..." CreationDate="2011-01-04T18:33:16.190" UserId="2118" />
  <row Id="12540" PostId="8453" Text="I don't know about Press-N-Peel, but I know with toner that having the board very very clean is critical for adhesion. Also, when I switched to a hotter iron it was better." CreationDate="2011-01-04T18:43:34.777" UserId="1990" />
  <row Id="12541" PostId="8575" Text="@Thomas - The software is almost certainly doing a lot of work; the question is how low the sampling rate actually is." CreationDate="2011-01-04T18:53:21.157" UserId="857" />
  <row Id="12543" PostId="8589" Text="Aren't jumpers 0.1&quot; by 0.2&quot;, and DIP switches 0.1&quot; by 0.4&quot;?  The one advantage that DIP switches might have is that it's probably more convenient to use SMT versus TH." CreationDate="2011-01-04T19:16:52.720" UserId="1407" />
  <row Id="12544" PostId="8589" Text="With proper technique, you can change a part on a circuit board unlimited times.  With poor technique (iron too cold) you can't change it once without damage." CreationDate="2011-01-04T19:24:04.313" UserId="411" />
  <row Id="12545" PostId="8590" Text="This is a development board; it will be used by students and engineers.  That doesn't mean that they're all good with a soldering iron, though.  How many times can you flip that solder-blob SPDT switch before the pad comes up?" CreationDate="2011-01-04T19:26:01.910" UserId="857" />
  <row Id="12546" PostId="8589" Text="Unlimited times?  Hmm, maybe I have to turn my iron up.  Is 375C adequate for most jobs?" CreationDate="2011-01-04T19:28:33.000" UserId="857" />
  <row Id="12547" PostId="8567" Score="1" Text="@dren.dk, You are correct - I see the fix [here](http://goo.gl/ZrBtm). Software version 02.05 SP1 (00.02.05.01.00) [seems to have a trigger bug](http://goo.gl/1H4vV), so stay at 2.04 SP1." CreationDate="2011-01-04T19:29:21.450" UserId="2118" />
  <row Id="12548" PostId="8589" Text="I usually use ~350C with 63/37 solder (80W iron) and think it is a little hot. Not exactly sure what the right temp is!" CreationDate="2011-01-04T19:33:51.327" UserId="2118" />
  <row Id="12550" PostId="8589" Text="Eventually the solder will dissolve the copper on the board, so while not &quot;unlimited&quot;, dozens of times is still doable (unless you have 0.25 oz. copper or something crazy)" CreationDate="2011-01-04T19:36:16.820" UserId="1407" />
  <row Id="12551" PostId="8590" Text="@reem, I think you bring up the main point; if changing this is something that is going to be expected as part of normal use, a solder blob is inappropriate.  Updated my answer." CreationDate="2011-01-04T19:38:15.633" UserId="1407" />
  <row Id="12552" PostId="8582" Score="1" Text="Can always make it a wiki later if the answers warrant it." CreationDate="2011-01-04T19:39:43.947" UserId="2118" />
  <row Id="12553" PostId="8581" Text="[Here's a similar (clone?) item from SeeedStudio.](http://goo.gl/xQU5K)" CreationDate="2011-01-04T19:44:48.840" UserId="2118" />
  <row Id="12555" PostId="8590" Text="If it's for students purpose, leave it at jumpers. I think you can expect those people are qualified enough to figure out how to place the jumper, where, etc. I think a DIP switch is too fancy/expensive. Soldering is inpractical. If you want to change a setting you 'should' unplug the board and rework it in the solder lab. For me:&#xA;Solder for one time configuration, jumper settings for adjustment in a particular testcase, DIP switches if it requires some user interfacing." CreationDate="2011-01-04T19:51:42.853" UserId="1476" />
  <row Id="12557" PostId="8589" Text="What works for me is a hot iron, and short time.  When I have lifted tracks it is because my iron was too cold or my tip was too small, allowing the solder to freeze to the tip a little bit. @Nick T how does solder dissolve copper?" CreationDate="2011-01-04T20:31:32.517" UserId="411" />
  <row Id="12558" PostId="8589" Text="@Mark - The same way water dissolves sugar; it's just slower and only happens at high temperatures.  ENIG boards loose their gold coating after as little as 3-4 soldering/braid cycles." CreationDate="2011-01-04T20:38:27.430" UserId="857" />
  <row Id="12559" PostId="8591" Score="1" Text="It will be changed about one time for every project or breadboard job (assuming no mistakes are made). New source code has to be written, and new circuits built on the breadboard before you'd want a new design." CreationDate="2011-01-04T20:40:25.073" UserId="857" />
  <row Id="12562" PostId="8594" Text="No, they don't.  I haven't seen one yet that gives any of the dimensions listed in my diagram.  All of 3M's datasheets point [here](http://media.digikey.com/pdf/Data%20Sheets/3M%20PDFs/Solderless%20Breadboard%20Acces.pdf)[pdf], which only gives the outlines.   Twin Industries and Parallax, the other two suppliers, don't have datasheets at all." CreationDate="2011-01-04T22:39:25.313" UserId="857" />
  <row Id="12563" PostId="8593" Score="1" Text="Sorry, maybe I wasn't clear enough.  It is going to other engineers and developers, so changes are good.  " CreationDate="2011-01-04T22:42:08.510" UserId="857" />
  <row Id="12564" PostId="8593" Text="I like the EEPROM idea; maybe connect something like [this bus FET](http://focus.ti.com/lit/ds/symlink/sn74cbt3384a.pdf) switch from TI?  I've added it to my list, thanks for the idea!" CreationDate="2011-01-04T22:53:33.700" UserId="857" />
  <row Id="12565" PostId="8584" Score="2" Text="@user1498, please don't just dump a link, especially when linking to blogs.  Blogs are great at destroying links, so if someone comes along to your answer a few months later and if the link happens to be dead, your answer is *totally worthless*, and the site suffers as a result.  Links *aren't bad*, but at least offer a little description with it." CreationDate="2011-01-04T23:00:51.667" UserId="1407" />
  <row Id="12566" PostId="8589" Text="don't forget signal integrity.  You mentioned ethernet/USB so some signals may be high speed and the various options will impact the trace's characteristic impedance which may cause problems." CreationDate="2011-01-04T23:08:46.110" UserId="1438" />
  <row Id="12567" PostId="8589" Text="Are you going to electrically switch Ethernet/USB lines?  I was thinking this was for enable or config pins that weren't going to run at any real frequency.  Adding switches or other complexity to high speed lines must be done with care." CreationDate="2011-01-04T23:14:36.803" UserId="1407" />
  <row Id="12568" PostId="8589" Text="@Nick - Yes, I am.  It will only be 10Mb Ethernet, and USB 1.1.  The processor is running at 72MHz, so there's a good potential for some fast edges.  I plan to put some current limiting resistors on all the breadboard I/O to slow the edges down a little." CreationDate="2011-01-04T23:30:31.013" UserId="857" />
  <row Id="12569" PostId="8428" Text="You're absolutely right Fake Name, budget and lead-time is a bitch when you're in a company that's not in the electronics business and in the last country of the earth (Chile)." CreationDate="2011-01-04T23:45:08.290" UserId="1673" />
  <row Id="12570" PostId="8428" Text="Also, in the end the signals in the question's cables where not RS232@TTL :(" CreationDate="2011-01-04T23:46:34.047" UserId="1673" />
  <row Id="12571" PostId="2500" Text="IPA is commonly available (at least in the US) in drugstores. Look for the 99% type. Electronics stores often also carry anhydrous (99.9%), but it is a bit more expensive." CreationDate="2011-01-04T23:48:36.573" UserId="1990" />
  <row Id="12572" PostId="8596" Text="I normally put a 1000uF electolytic before and after the regulator, but not a small ceramic like you suggest. I'll give this a go and see if it helps. Do I solder it between Vdd and Vss? Also, if I have more than one PIC in my circuit, do I need a cap for each one? What does this do to the supply? How does it help?" CreationDate="2011-01-05T00:24:54.420" UserId="2426" />
  <row Id="12573" PostId="8596" Score="3" Text="Yes, you need tiny ceramic cap on each on your PICs. Yes, between Vdd and Vss. Large electrolytic cap far from chip cannot filter high freqency noise from the microcontroller (&gt;1Mhz range). So this tiny cap filters all digital noise from the micro. For better filtering some add 2 caps with different size in parralel (0.01 &amp; 1 uF for example) as single ceramic cap have a resonant frequency. Next improvement is ferite beads on Vdd, but this is usually used only for more complex chips like microprocessors &amp; FPGA's." CreationDate="2011-01-05T00:46:07.603" UserId="2062" />
  <row Id="12574" PostId="8566" Text="@tyblu: You say you have not been a big fan of PC based oscilloscopes, any drawbacks vs bench top oscilloscopes?" CreationDate="2011-01-05T02:51:32.460" UserId="444" />
  <row Id="12575" PostId="8575" Text="Does Apple's documentation cover anything about how fast drag events are captured and your respective selector (i.e. handler) is hit? I can't find anything. I figure it has to be in the 20ms range." CreationDate="2011-01-05T03:00:47.637" UserId="2484" />
  <row Id="12576" PostId="8576" Text="I don't think the msp430G22xx has enough memory or ram to be used as a web server, but I think some of the other msp430 chips can, I thought i saw an application note not too long ago, but could not find it recently " CreationDate="2011-01-05T03:07:55.183" UserId="2060" />
  <row Id="12577" PostId="8600" Score="1" Text="Huh...I have found 5 different breadboards, and they all have two-column power busses.  Do you have a link or dimensions?" CreationDate="2011-01-05T04:07:00.140" UserId="857" />
  <row Id="12578" PostId="8565" Text="Can you make a measurement on a sine wave rather than a square wave?  What you call a 50MHz square wave is really a combination of higher-frequency sine waves." CreationDate="2011-01-05T04:10:00.183" UserId="857" />
  <row Id="12580" PostId="8566" Text="@KevinBoyd, Just a general stereotype that paints them as hyped-up tools with cruddy analog inputs. What really matters is bandwidth, noise floor, trigger noise (w.r.t. jitter), and memory; excellent user interface is a personal requirement of mine. It would be difficult to match a DSO on all of these factors without matching the price, plus you tie up a computer. I imagine there are competitive PC-'scopes out there -- such is the nature of capitalism. [Here's something promising being developed right now. (PS: the open logic sniffer is great.)](http://goo.gl/kxISP)" CreationDate="2011-01-05T04:53:56.937" UserId="2118" />
  <row Id="12581" PostId="8603" Text="Can you provide part numbers? Is this CMOS?" CreationDate="2011-01-05T04:58:33.653" UserId="2118" />
  <row Id="12584" PostId="8602" Text="To clarify, you are using a serial monitor program (eg. Hyperterminal) on a PC to communicate over RS232 to the Arduino's USART (Tx and Rx) pins, correct?" CreationDate="2011-01-05T05:32:22.470" UserId="2118" />
  <row Id="12585" PostId="8603" Score="3" Text="Your question is very unclear. What does &quot;I have a metric&quot; mean? What does the value 18 represent? How many inputs on the NAND gate?Does the input load on the NAND matter?" CreationDate="2011-01-05T05:32:37.467" UserId="638" />
  <row Id="12588" PostId="8602" Text="Instead of a delay and an if, why not make it sit in a while until enough characters are available, or process and check the characters one by one as they come in?  This will also help as you can manually interact with it from the PC since there won't be a time limit for the response." CreationDate="2011-01-05T05:57:14.083" UserId="2246" />
  <row Id="12590" PostId="8566" Text="@tyblu - While nice scopes may do proper averaging when running at slower sample speeds, many crappy chinese DSOs don't bother, and just discard all the additional samples." CreationDate="2011-01-05T06:24:49.823" UserId="1374" />
  <row Id="12591" PostId="8566" Text="Also, if this is indeed a cheap, chinese model, don't count on it *even having* anti-aliasing filters. Many don't" CreationDate="2011-01-05T06:25:32.660" UserId="1374" />
  <row Id="12594" PostId="8609" Text="Ok, thanks for the clarification!  This opens up the possibilities for my LCD search quite a bit, I think." CreationDate="2011-01-05T06:58:52.167" UserId="2288" />
  <row Id="12595" PostId="8246" Text="Should be a different case. See here: http://www.repairfaq.org/REPAIR/cdkssp.gif (via Sam Goldwasser's very nice Repair FAQ, http://www.repairfaq.org/REPAIR/F_cdfaqa.html)&#xA;&#xA;Seems like the photo diode in the laser diode's case is just used to regulate the laser's power output." CreationDate="2011-01-05T07:52:18.530" UserId="930" />
  <row Id="12596" PostId="8565" Text="Nice idea! I don't have such a high frequency source though,  unless off course I build one?" CreationDate="2011-01-05T08:15:42.193" UserId="444" />
  <row Id="12597" PostId="8603" Text="I agree... please clarify." CreationDate="2011-01-05T10:43:27.190" UserId="2426" />
  <row Id="12598" PostId="7040" Text="Be careful when allowing &quot;Cathode&quot; to go lower than &quot;Ref&quot;: The diagram alone says that this might work, but remember that the internal reference needs at least 2.5 V (and 1 mA) to work, and both are supplied through the &quot;Cathode&quot; pin. Also remember that the internal opamp &quot;triangle&quot; will try to keep both of its inputs at the same voltage, i.e. 2.5 V. Therefore, the &quot;Cathode&quot; should, in a real application, remain at or above the voltage at the &quot;Ref&quot; pin, i.e. &gt;= 2.5 V. The LT1431 has separate pins for the supply and the open collector output and can go lower than &quot;Ref&quot; at &quot;Cathode&quot;." CreationDate="2011-01-05T11:05:39.203" UserId="930" />
  <row Id="12599" PostId="8576" Text="of course i'm not saying the MSP by it's self, with some PIC or Wiznet controler to do the hard work :D" CreationDate="2011-01-05T12:39:05.597" UserId="2245" />
  <row Id="12600" PostId="8474" Text="Besides, if you put them in the desert you won't have to worry about that anyway." CreationDate="2011-01-05T12:55:16.707" UserId="794" />
  <row Id="12601" PostId="8600" Text="This one only has a one-column power bus: http://www.sparkfun.com/products/137  It seems to me that most of the boards don't give dimensions on the inside (like you want) but only outside dimensions (like you found).  " CreationDate="2011-01-05T13:15:36.363" UserId="249" />
  <row Id="12602" PostId="8612" Text="If some of the above looks foreign, it's because I haven't programmed with the Arduino libraries or IDE before, and am not sure what nomenclature is used." CreationDate="2011-01-05T13:28:09.090" UserId="2118" />
  <row Id="12603" PostId="8612" Text="correct most of the code should be in the loop(), but you would not want to call the serial.write every loop." CreationDate="2011-01-05T13:49:19.397" UserId="2060" />
  <row Id="12604" PostId="8614" Text="There is RS485, but 30ft is easy in quiet env. Is it quiet?" CreationDate="2011-01-05T13:49:26.667" UserId="2118" />
  <row Id="12605" PostId="8616" Text="I have just been looking at the xbee and bluetooth products" CreationDate="2011-01-05T14:48:03.503" UserId="1235" />
  <row Id="12606" PostId="8616" Score="1" Text="xbee, from what i have heard work great, I probably will be picking a few up soon. " CreationDate="2011-01-05T15:17:56.157" UserId="2060" />
  <row Id="12607" PostId="8612" Text="@tyblu I believe the Arduino Serial library internally uses the UART receive interrupt and stores the received bytes in a managed circular buffer, so there's no need to implement the (polling/blocking) rx function you've described in at the end of your post." CreationDate="2011-01-05T15:36:06.663" UserId="771" />
  <row Id="12608" PostId="6498" Text="I love the sponsorship idea -- I'll have to look into that." CreationDate="2011-01-05T15:49:59.797" UserId="2288" />
  <row Id="12609" PostId="8622" Text="how about years?  I have thrown away breadboards because of this possible myth, since I've had stuff in them for 2 years or more.  :)" CreationDate="2011-01-05T16:01:19.440" UserId="2288" />
  <row Id="12610" PostId="8622" Text="Probably.... I can't remember exactly how long." CreationDate="2011-01-05T16:03:23.807" UserId="2426" />
  <row Id="12611" PostId="8623" Text="Yes it would, but from the given circuit on the webpage i don't unterstand &quot;how&quot; the duty cycle is held in a steady state. My thoughts are like this: The OTA compares Vo and Vref, when they are equal the current Ierr = 0, right? Then the positive input of the comparator is also 0 and when i compare that to the voltage ramp i get a different duty cycle. " CreationDate="2011-01-05T16:50:22.260" UserId="2277" />
  <row Id="12612" PostId="8622" Score="1" Text="@Dave And you didn't test to see if they are working!? " CreationDate="2011-01-05T17:01:20.927" UserId="1240" />
  <row Id="12613" PostId="8614" Text="Do you have a strong preference with respect to wired/wireless protocols?" CreationDate="2011-01-05T17:02:00.053" UserId="857" />
  <row Id="12614" PostId="8623" Text="Well i think i'm having an error in reasioning, because Vo = Vref can only be achieved, if the duty cycle is set correct." CreationDate="2011-01-05T17:09:50.660" UserId="2277" />
  <row Id="12615" PostId="8622" Text="I used a breadboard two weeks ago that had components left in it since August (4 months).  It wasn't anything super-sensitive to weak contacts, but it worked fine.  " CreationDate="2011-01-05T17:16:45.960" UserId="857" />
  <row Id="12616" PostId="8621" Score="2" Text="How much is your time worth?  If you're doing this for work, ask your manager if he'd rather have you spend an hour debugging bad contacts or just buy a new one. " CreationDate="2011-01-05T17:19:38.297" UserId="857" />
  <row Id="12617" PostId="8621" Text="@reemrevnivek  Good comment, but how can you determine if a breadboard is bad unless you provide a constant supply of new breadboards and assume that they themselves aren't damaged?" CreationDate="2011-01-05T17:27:15.300" UserId="1240" />
  <row Id="12618" PostId="7040" Text="An opamp doesn't try to keep its pins at the same voltage unless there is negative feedback." CreationDate="2011-01-05T17:37:49.383" UserId="411" />
  <row Id="12619" PostId="8599" Text="Why the negative vote?" CreationDate="2011-01-05T17:44:25.647" UserId="206" />
  <row Id="12620" PostId="8621" Score="1" Text="@Andreja - I should have said &quot;risk spending an hour&quot;.  The only way I know to determine if it's good or not is to build a circuit that should work.  If it doesn't work, there's either a problem with the circuit, your wiring, the components, or the breadboard itself.  If the circuit works, the wiring is correct, and the components are good, then you've got bad contacts.  Kinda labor-intensive." CreationDate="2011-01-05T17:49:59.390" UserId="857" />
  <row Id="12621" PostId="8596" Score="1" Text="Be careful with large caps on either side of the regulator. It's safer to put a big cap on the input and a much smaller one at the output. Reason being that when you unplug the transformer, the capacitors will discharge. If the voltage at the output of the regulator is higher than the voltage at the input, a lot of linear regulators will fail due to that reverse bias. An easy way around this is to make sure that the output capacitance is much less than at the input." CreationDate="2011-01-05T17:50:29.110" UserId="2255" />
  <row Id="12622" PostId="7697" Text="Be advised that liquid crystal switching speed can be very slow in low temperatures. A range of faster than the human eye can perceive at room temperature to a second for a black/white change at -15 degC is well possible." CreationDate="2011-01-05T18:58:09.187" UserId="2465" />
  <row Id="12623" PostId="8565" Text="@Kevin - Sure, you could build one with a narrow bandpass filter (opamp and some caps/resistors) centered at your desired frequency, and drive it with your square wave.  [National Semi](http://www.national.com/nationaledge/jun04/article.html) has an article on that, [here's a sine and cosine generator](http://www.play-hookey.com/analog/sine_wave_generator.html), and [here's the Falstad simulation of that generator.](http://www.falstad.com/circuit/e-sine.html)" CreationDate="2011-01-05T19:34:41.667" UserId="857" />
  <row Id="12624" PostId="8612" Text="@vicatu, Ah, that would make sense." CreationDate="2011-01-05T20:27:37.517" UserId="2118" />
  <row Id="12626" PostId="8634" Text="I want to use 1% for both divider resistors. I am using a voltage divider to read up to 40V signals. Does what you say still apply? And I will be looking around for a precision voltage reference, although ±0.05% is probably okay, and you can get DIP ICs which do that." CreationDate="2011-01-05T20:40:38.577" UserId="1225" />
  <row Id="12627" PostId="8634" Text="@Thomas OK, I misunderstood your question... you are using a voltage divider to step down a large voltage, not to measure an unknown resistance... I will change my answer accordingly." CreationDate="2011-01-05T20:47:20.930" UserId="771" />
  <row Id="12628" PostId="8635" Text="I figure temperature might influence a typical ±100ppm/°C resistor by -0.4% to +0.7% (or the reverse) over the -40°C to +70°C operating range of my device. If necessary, I could calibrate that too. It's more likely it will be exposed to high temperatures, and I can heat the board up to test this. " CreationDate="2011-01-05T20:47:21.147" UserId="1225" />
  <row Id="12629" PostId="8635" Score="3" Text="Sometimes with clever design you can get the resistor tempco's to cancel out.  If you identify such resistor pairs in your design, put them next to each other in the layout to maximize thermal coupling.  Or even use resistor arrays." CreationDate="2011-01-05T21:17:50.310" UserId="411" />
  <row Id="12630" PostId="8443" Score="1" Text="+1 ziplocks.  I have a box full of computer cables that are very easy to sort through since I did this.  They don't tangle, they stay clean, and everything is labeled on the bag.  I use it to store old wall-warts, and note the voltage/amperage as well." CreationDate="2011-01-05T21:25:08.400" UserId="1756" />
  <row Id="12631" PostId="8633" Text="What kind of production tools do you have access to?  Can you get/build anything like a bed-of-nails programmer/tester?" CreationDate="2011-01-05T21:36:19.550" UserId="857" />
  <row Id="12632" PostId="8633" Text="@reemrevnivek - Not currently. My PCB manufacturer E-tests each board, but it's not guaranteed that the soldering will work." CreationDate="2011-01-05T22:21:37.517" UserId="1225" />
  <row Id="12633" PostId="8634" Text="I'm not so sure the error won't be linear, ignoring for now resistor heating. It should be a fixed linear factor for each divider (there are four on the board), as the divider is just dividing by a fixed amount. With zero volts in, zero volts should be measured by the ADC, plus the offset error, which might cause it to read one count, so I don't really need to worry about the offset... Unless I'm missing something?" CreationDate="2011-01-05T22:24:50.477" UserId="1225" />
  <row Id="12634" PostId="8635" Text="@markrages, If both resistors are +100ppm/°C, will that minimise error, since both will be out by the same fraction? In theory, assuming both resistors drift by equal amounts, the output shouldn't change. In practice it probably would, especially since the voltage reference (LM4040) itself may drift." CreationDate="2011-01-05T22:26:25.613" UserId="1225" />
  <row Id="12635" PostId="8636" Text="If thick film are supposed to be cheaper, I am wondering why they are almost 5x as expensive on Farnell." CreationDate="2011-01-05T22:43:55.103" UserId="1225" />
  <row Id="12636" PostId="8636" Score="2" Text="@Thomas, A) Farnell's value add can add value in woefully opaque ways, B) Farnell lies, they are actually thin-film (read the datasheet), C) even if they were thick-film, getting ridiculous tolerances and Tc's with thick-film is asinine, so the volume is likely to be low and costs higher." CreationDate="2011-01-05T22:46:48.890" UserId="1407" />
  <row Id="12637" PostId="8625" Text="+1. That's it, in a nutshell." CreationDate="2011-01-05T23:24:01.307" UserId="930" />
  <row Id="12638" PostId="8621" Text="I know some people who build breadboarded circuits into enclosures, and just use them indefinitely, rather than make a PCB. 15 years later, they still work." CreationDate="2011-01-05T23:28:04.207" UserId="1374" />
  <row Id="12641" PostId="8630" Text="ah, yes, diodes are absolutely the worst.  I had some stuck in the breadboards that I tossed out.  :)" CreationDate="2011-01-05T23:52:53.187" UserId="2288" />
  <row Id="12642" PostId="8628" Score="2" Text="I think your comment about oxidation occurring more readily without components really depends upon the metals in question.  Back when I used to build PCs, they always said to avoid using gold-plated SIMMs in slots that are tin-plated.  I imagine the same thing goes for breadboards.  I assume they are tin-plated, so if you get a gold-plated SIP header and leave it in there, perhaps there is a risk there." CreationDate="2011-01-05T23:55:17.350" UserId="2288" />
  <row Id="12643" PostId="8629" Text="that's a great suggestion -- using Sharpie to designate keep-out zones.  I like it!" CreationDate="2011-01-05T23:55:56.727" UserId="2288" />
  <row Id="12644" PostId="8628" Text="@Dave As far as I know, that's correct. I just thought that metals would already be picked in such way that their contact won't cause oxidation. " CreationDate="2011-01-05T23:59:01.620" UserId="1240" />
  <row Id="12645" PostId="8499" Text="I think that this pins are very visible, so some hardware hacker could try to reverse engineer this pins, or just do some measurement of them." CreationDate="2011-01-06T00:08:48.247" UserId="1994" />
  <row Id="12646" PostId="8499" Text="@vicatcu Pretty mindblowing. That's why the components around the CPU VRM don't mess around. Also, don't forget the other components, like the PLL, and QPI." CreationDate="2011-01-06T00:14:49.817" UserId="1225" />
  <row Id="12647" PostId="8590" Text="@Nick - You had the best answer overall, so I gave you the check, but I actually am going to use Brian Carlton's answer for the configuration stuff and 5016 resistor networks for the configuration (since I want a few dozen ohms anyways to slow down the edges and stop ESD events)" CreationDate="2011-01-06T00:18:41.017" UserId="857" />
  <row Id="12648" PostId="8610" Text="How are the transistors balanced?  On an IC, you can get away with having pairs of transistors that need to have precisely matched parameters, but it sounds like you've got discrete parts, which would require some kind of load balancing circuitry which could damage something. " CreationDate="2011-01-06T00:22:13.840" UserId="857" />
  <row Id="12649" PostId="8603" Text="@Close voters - Please don't close this question as 'not a real question' because it's not something you're familiar with - that's for ambiguous/vague questions with no help from the poster.  osgx has tried to clarify the question, and I'm sure they'd be willing to provide further information." CreationDate="2011-01-06T00:27:08.767" UserId="857" />
  <row Id="12651" PostId="8635" Text="@Thomas.  Yes, that's the idea.  Let's see, the LM4040 claims 100ppm/C worst-case, 15ppm typical at 1mA or less.  The typical temperature response is plotted in the datasheet and doesn't look like something that could be easily canceled out.  I guess you could glue an NTC thermistor to it and &quot;ovenize&quot; it to keep it at a constant (elevated) temperature, but not if you're on a power budget." CreationDate="2011-01-06T04:08:45.527" UserId="411" />
  <row Id="12652" PostId="8603" Text="This appears to be homework.  Only tool and fab people need these numbers directly." CreationDate="2011-01-06T04:47:20.110" UserId="206" />
  <row Id="12654" PostId="8603" Text="@Brian Carlton, yes it looks _like_ a homework, but I have no one. Chip designers needs this too, not only physical designers, but also logic designers." CreationDate="2011-01-06T06:09:11.630" UserId="1994" />
  <row Id="12656" PostId="8642" Text="To add to the *RS232* answer: ensure you implement improved error checking on top of parity (CRC or whatever). You may be able to use CAT5e or CAT6 cable, depending on your environment, which is cheap." CreationDate="2011-01-06T06:55:25.260" UserId="2118" />
  <row Id="12657" PostId="8603" Score="1" Text="@Brian Carlton, Whether or not this question qualifies, [asking homework questions is ok](http://meta.stackoverflow.com/q/10811/154425). @osgx, Is it?" CreationDate="2011-01-06T07:03:19.467" UserId="2118" />
  <row Id="12659" PostId="8603" Text="It is not a homework. I have no teacher to ask him this question, and nobody asks me. It is a problem for my to convert NAND metric to FO4.  You can consider this q. as homework, but I will have no any mark for it. I will accept answer without full explanation and true answer." CreationDate="2011-01-06T08:10:51.330" UserId="1994" />
  <row Id="12660" PostId="8644" Text="Опа, и здесь барс. FO4 is a technology independent metric, isn't it? It is not my chip or my tech. process, so I can't resimulate. BUT! There is a standard NAND gate and NOT gate. We can estimate, how speed of NOT with FO4 correlates with NAND with FO3. В конце-то концов, в книжке есть формулы типа 4-25 да и многообещающие картинки на +-1 стр." CreationDate="2011-01-06T08:13:53.527" UserId="1994" />
  <row Id="12661" PostId="8616" Text="It's worth mentioning that I believe the linked RF modules have no error-checking or correction. It's entirely up to the user to check the transmitted data is valid. Any noise during the data transfer can cause errors, which will not be detectable unless you do parity or CRC checking." CreationDate="2011-01-06T10:04:59.407" UserId="1374" />
  <row Id="12662" PostId="8422" Text="Hmmm. It appears I'm confusing some research I did on xenon tubes with what I remember about fluorescents. Nevermind." CreationDate="2011-01-06T10:10:23.143" UserId="1374" />
  <row Id="12663" PostId="8422" Text="Oh, also, the breakdown voltage would be many kilovolts." CreationDate="2011-01-06T10:11:23.733" UserId="1374" />
  <row Id="12664" PostId="8647" Text="Do you have a link to this article?" CreationDate="2011-01-06T11:03:33.493" UserId="2118" />
  <row Id="12665" PostId="8613" Score="3" Text="Do you think you could elaborate?" CreationDate="2011-01-06T11:28:45.137" UserId="2118" />
  <row Id="12666" PostId="8648" Score="3" Text="120 W doesn't sound too bad as a guess, although I would assume it is a bit more, maybe around 200 W. The type of meter is important, though: The current waveform drawn by the switching power supplies is likely anything but sinusoidal and thus, only very good meters will yield accurate results." CreationDate="2011-01-06T11:39:22.013" UserId="930" />
  <row Id="12667" PostId="8446" Text="The article in your link is a very nice hack! I really like the circuit and its description! Just two notes: (i) Ideally, there should be dots on the primary and feedback (auxiliary) windings of the transformer: Top end (pri) and on the Left end (aux). The dot on the secondary could be anywhere because the load (fluo lamp) is non-polar. (ii) Even though I like using a ferrite rod from an AM radio for an experiment like this, I wouldn't take this circuit to a lab for testing electro-magnetic emissions. The screen of the frequency-domain diagram of test receiver would be very bright..." CreationDate="2011-01-06T12:40:33.770" UserId="930" />
  <row Id="12668" PostId="8613" Text="Well, I guess I get it: 1 npn/pnp pair is o.k., the bias circuit won't care if there is one path or if there are six parallel paths of big transistors, and 10...15 mA in each branch of power transistors is good. I actually like the answer: +1." CreationDate="2011-01-06T12:47:08.723" UserId="930" />
  <row Id="12669" PostId="8610" Text="There are the usual emitter resistors: 0R33, 4W for each transistor." CreationDate="2011-01-06T12:49:43.167" UserId="930" />
  <row Id="12670" PostId="8616" Text="@Fake Name Yes you are correct there is no error checking in the linked RF modules, they are very simple devices, so no bells and whistles." CreationDate="2011-01-06T13:21:17.717" UserId="2060" />
  <row Id="12671" PostId="8651" Text="+1 CAN is robust. However, I don't think it specifies hardware/physical layer. What voltage and cable scheme do you use?" CreationDate="2011-01-06T13:23:46.967" UserId="2118" />
  <row Id="12672" PostId="8634" Text="sorry, nonlinear was probably the wrong term in retrospect. What you'll effectively get from calibration is a scale factor, right? The deviation from predicted is going to be linear with respect to the input voltage. So given some &quot;predicted V based on the measurement&quot; the actual V is going to have to be multiplied by some factor. What *would* be non-linear is the error in assuming it was an offset voltage." CreationDate="2011-01-06T13:26:39.530" UserId="771" />
  <row Id="12673" PostId="8650" Text="[PS: Be excellent to each other](http://www.youtube.com/watch?v=WVXGC896Jdw)" CreationDate="2011-01-06T13:26:42.613" UserId="2118" />
  <row Id="12674" PostId="8647" Text="are you trying to calculate &quot;your&quot; computers power usage or general computer power usage?  if your trying to calculate your own what is the PSU rating? and on the monitor it should have a tag that has its electrical properties, I believe these are the maximum power usage characteristics." CreationDate="2011-01-06T13:32:29.710" UserId="2060" />
  <row Id="12675" PostId="8651" Text="We usually 5VDC along shielded twisted pair. This is uncommon, most automotive applications use 12 volts. For a 30 foot run in anything less noisy than a microwave I'd first try using CAT5 driven at 5VDC, because it's cheap and will probably work just fine. &#xA;&#xA;edit: I work in industrial lighting, not automotive" CreationDate="2011-01-06T13:51:47.877" UserId="2344" />
  <row Id="12676" PostId="8576" Text="@s.mihai I wish you luck, and if you succeed, let me know :)" CreationDate="2011-01-06T14:09:22.033" UserId="2060" />
  <row Id="12677" PostId="7659" Text="But that does not seem to be the pratice, check some out, it has been some time since I did." CreationDate="2011-01-06T15:08:23.910" UserId="1498" />
  <row Id="12678" PostId="8644" Text="@osgx Hehe :-) FO4 could not be technology independent. With process scaling some delays increase (namely RC ones), some delays decrease (switch time due to shorter channel). So FO4 changes greatly and quite unpredictable. One can think of a formula only if +-50% accuracy is acceptable." CreationDate="2011-01-06T15:27:12.733" UserId="2062" />
  <row Id="12679" PostId="8639" Score="1" Text="I'd think that you're going to want *some* spin on the ball when it's launched, otherwise it will drift all over." CreationDate="2011-01-06T15:36:22.243" UserId="1407" />
  <row Id="12680" PostId="8648" Text="@zebo: Good power supplies should have a PF close to unity, and shouldn't inject tons of noise onto the main's line, so I'd imagine their (steady-state) draw tracks very closely to a sinusoid." CreationDate="2011-01-06T15:40:54.423" UserId="1407" />
  <row Id="12681" PostId="2322" Score="1" Text="The main difference between the HCTL2020 and the other items is that the former's function can be easily performed by the microcontroller. It doesn't even cost much in terms of performance. Handling the rotary encoder in software also allows for variable resolution; count faster if the knob is turned faster. And! Where's the fun of programming if you have the work done by specialized ICs? As an intermediate solution you can create your own encoder by programming a microcontroller for it, including the variable resolution." CreationDate="2011-01-06T16:44:29.800" UserId="2064" />
  <row Id="12682" PostId="8650" Text="We had tAoE in the library at my last job. My only problem with the book is that Horowitz has in each chapter a number of good-and-bad examples without explaining why the latter are actually bad." CreationDate="2011-01-06T16:49:24.307" UserId="2064" />
  <row Id="12683" PostId="8655" Text="I notice both Bob Pease and Jim Williams have followup books to these.  Has anyone read them?  Impressions?" CreationDate="2011-01-06T16:52:21.160" UserId="411" />
  <row Id="12684" PostId="8656" Text="I though this was rather silly when I posted this: &quot;Oops! Your question couldn't be submitted because: users with less than 150 reputation can't create new tags. The tag 'emitter-follower' is new. Try using an existing tag instead.&quot;  So that is why it is posted under the ambiguous 'bjt' tag rather than something more helpful like 'emitter-follower'." CreationDate="2011-01-06T16:53:36.340" UserId="2059" />
  <row Id="12685" PostId="8650" Text="The bad examples are my favorite part!  Figuring out why they are wrong is more engaging (and more fun) than homework problems." CreationDate="2011-01-06T17:00:13.950" UserId="411" />
  <row Id="12686" PostId="2322" Score="2" Text="Totally agreed that programming a microcontroller to read an encoder is a worthy task. In the specific case of quadrature decoding, the HCTL2020's performance is extraordinary. I wrote a quadrature decoder in assembly for a PIC a few years ago. It takes at least 10 instructions to identify both pulses, determine direction, and set outputs accordingly. To match the HCTL2020 running at 14 Mhz with hardware logic, you'd have to be running around 140 MHz, which is faster than you can debug on a breadboard. In practice, I couldn't get my PIC to read an encoder above 20 kHz without dropping pulses." CreationDate="2011-01-06T17:00:50.197" UserId="712" />
  <row Id="12687" PostId="8658" Score="1" Text="Do you mean that Vin should be centered around a positive voltage larger than its amplitude, such as 7.5V (0.5 * Vcc)?" CreationDate="2011-01-06T17:09:49.820" UserId="2059" />
  <row Id="12688" PostId="2320" Text="Great question, great answers! I didn't know about most of these." CreationDate="2011-01-06T17:11:20.357" UserId="2344" />
  <row Id="12689" PostId="8656" Text="tag has been added!" CreationDate="2011-01-06T17:14:15.573" UserId="2064" />
  <row Id="12690" PostId="8647" Text="I think that this question is on-topic not because 'computers' is on topic (we're more interested in embedded stuff), but because it's about in the electrical topic of power.   Notice that BG100's answer and the comments are getting into issues of comparing actual measurements and ratings, power factors, and RMS values of non-sinusoidal signals.  I've submitted the first vote to reopen. " CreationDate="2011-01-06T17:20:23.893" UserId="857" />
  <row Id="12691" PostId="8647" Score="1" Text="The single [computers] tag is probably not the right thing for this question, and makes it look off-topic.  Any device which is plugged into AC power and has a power rating like an AC motor, light, or heater/air conditioner would have a very similar question.  A PC just has the issues of the switching power supply and varying load requirements to differentiate it. I'd add the [power], [power-supply], and [power-meter] tags to the question (but only if we want to reopen it)." CreationDate="2011-01-06T17:24:49.103" UserId="857" />
  <row Id="12692" PostId="2322" Text="@pingswept: I was thinking of rotary encoders as manually-operated, which obviously doesn't need 20k samples per second. Is your encoder mounted on a motor or so?" CreationDate="2011-01-06T17:32:18.133" UserId="2064" />
  <row Id="12693" PostId="8648" Text="@Nick T, most computer power supplies are not active PFC if output power is &lt;500W. It just isn't cost effective. I believe active PFC reduces the mains filter capacitor bill and bridge rectifier bill at higher output powers because the current through the capacitor is almost continuous rather than a surge every half cycle. But maybe I'm wrong?" CreationDate="2011-01-06T17:32:29.427" UserId="1225" />
  <row Id="12694" PostId="8656" Text="Thanks stevenvh!" CreationDate="2011-01-06T17:44:17.890" UserId="2059" />
  <row Id="12695" PostId="8656" Score="1" Text="@Dr. Watson If you're brave enough, you can use your computer as oscilloscope and function generator for low enough frequencies. I don't know if there's software for mac, but there is for windoze and GNU/Linux." CreationDate="2011-01-06T17:45:33.087" UserId="1240" />
  <row Id="12696" PostId="8647" Text="@reemrevnivek it is defiantly a boarder question. If he is wanting to know so he can spec out which type of UPS to buy then it is more of a super user question." CreationDate="2011-01-06T17:49:08.633" UserId="319" />
  <row Id="12697" PostId="8646" Score="1" Text="I'm sorry no one was able to answer your question, but I'm glad you figured it out!  Feel free to select your own answer as the answer to your question if you're confident in it, or leave it open for another day or two to see if other answers or corrections trickle in." CreationDate="2011-01-06T17:50:00.323" UserId="857" />
  <row Id="12698" PostId="8648" Text="Aah! thanks, feeling well now. I was thinking that all electricity bill comes just because of my computer." CreationDate="2011-01-06T17:54:44.433" UserId="2502" />
  <row Id="12699" PostId="8654" Text="+150 to 250W is too much. I must check it again with doing some processor intensive work." CreationDate="2011-01-06T17:56:00.860" UserId="2502" />
  <row Id="12700" PostId="8649" Text="Yes, gonna try that." CreationDate="2011-01-06T17:56:22.700" UserId="2502" />
  <row Id="12701" PostId="8659" Text="Thanks for the explanation, it all makes sense now.  In a &quot;real&quot; circuit, would I have two separate DC supplies for Vcc and Vee, or would I just be hooking up the &quot;red&quot; end of a 15V supply to Vcc and the &quot;black&quot; end to Vee?  I guess what I am asking is whether or not two supplies are required (like in the Spice model)." CreationDate="2011-01-06T17:58:30.387" UserId="2059" />
  <row Id="12702" PostId="8660" Text="Yes, the upper left is the circuit I was working with.  Thanks for sharing the diagrams, especially the NPN PNP chain.  When you say it wastes less power, where does the power go?  The resistor likely dissipates it as heat, but what happens with the PNP?" CreationDate="2011-01-06T18:01:33.100" UserId="2059" />
  <row Id="12703" PostId="8659" Text="When you need to have positive and negative supply voltages, I've really only seen a two-supply setup. Single supply operation is also common, but usually you adjust the signals to fall between the power supply rails." CreationDate="2011-01-06T18:10:58.057" UserId="638" />
  <row Id="12704" PostId="8660" Text="@DrW: The pnp (while npn is conducting) or npn (while pnp is conducting) stay off and just don't dissipate any power. The whole circuit will take less power from the +/- 15 V supply rails." CreationDate="2011-01-06T18:17:10.823" UserId="930" />
  <row Id="12705" PostId="8658" Score="1" Text="Yeah, that would be it. You could also use your original sine source (centered around GND), put its signal through a large enough capacitor and feed it tho the base from there, while setting the base to a positive voltage with a resistive divider. That would probably be the configuration that is most widely used because you can use just one supply voltage and you don't have to care about the DC part (offset) of the input voltage." CreationDate="2011-01-06T18:18:57.343" UserId="930" />
  <row Id="12706" PostId="8660" Text="Also, it's a bit odd that the base resistor is small and the emitter resistor is large. Usually, you use a transistor amplifier in this configuration to embiggen the input current, so you need a high input impedance (read: large base resistor) and a low output impedance (read: small emitter resistor)." CreationDate="2011-01-06T18:21:51.100" UserId="930" />
  <row Id="12707" PostId="8660" Score="1" Text="You really don't need a base resistor at all in this circuit" CreationDate="2011-01-06T18:25:04.643" UserId="411" />
  <row Id="12708" PostId="8655" Text="@markrages: I've read Jim Williams' &quot;The Art and Science of Analog Circuit Design&quot; and it is about as brilliant as the one above." CreationDate="2011-01-06T18:25:24.140" UserId="930" />
  <row Id="12709" PostId="8655" Text="I love (!) these books, and I am really glad someone mentioned them, but I have them on the part of my shelf that is not so much the learning person's collection and more the anecdotal corner of my library. Especially true for the text collections published by Jim Williams. However great these books are, I would say you enjoy them most if you already know how the circuits work..." CreationDate="2011-01-06T18:28:05.370" UserId="930" />
  <row Id="12710" PostId="8647" Text="@lifeH2O, if you are wanting to determine what components you have that are causing a different power draw, or why yours is different, take a trip to Superuser.com, they can help you. If you want to discuss how the wattmeter works, let us know." CreationDate="2011-01-06T18:28:31.193" UserId="230" />
  <row Id="12711" PostId="8102" Text="Wouldn't it be nice if every part of the world had the same power outlets in buildings, life shall continue, unless you mix up the outlets." CreationDate="2011-01-06T18:30:34.423" UserId="230" />
  <row Id="12712" PostId="8660" Text="Thanks for the info about the pnp and base resistor.  I don't think this circuit is meant to be a practical circuit, it is from the Lab 2 section of &quot;Student Manual for The Art of Electronics&quot;." CreationDate="2011-01-06T18:59:12.613" UserId="2059" />
  <row Id="12713" PostId="8663" Text="If you need to do a lot of multiplications per second, you would be wise to choose a PIC with a hardware multiplier." CreationDate="2011-01-06T19:03:02.380" UserId="411" />
  <row Id="12714" PostId="8655" Text="@zebonaut I would draw a distinction between learning and reference.  These books aren't reference material, but they are pretty good for learning.  Jim Williams' &quot;Zoo Circuit&quot; story for example, or Barrie Gilbert describing the Gilbert cell.  For sure, a rank beginner will need to learn a bit of circuit theory  first." CreationDate="2011-01-06T19:11:46.417" UserId="411" />
  <row Id="12715" PostId="8650" Text="Great book, the student manual for tAoe is fabulous for explaining circuits in a plain and simple way and offering supplementary circuits for furthering one's understanding.  The lack of explanations of the bad circuits is also frustrating to me!" CreationDate="2011-01-06T19:21:40.380" UserId="2059" />
  <row Id="12716" PostId="2333" Text="Yes, nice one on the MAX232." CreationDate="2011-01-06T19:30:12.743" UserId="2059" />
  <row Id="12717" PostId="8663" Text="Actually, the device does have an 8x8 hardware multiplicator. I agree with the 32bit choice, but I'm not the one who chose it.." CreationDate="2011-01-06T19:50:37.323" UserId="2285" />
  <row Id="12718" PostId="8656" Text="This online circuit simulator is easier to play with than Spice.  It has emitter follower built in as an example under circuits -&gt; transistors: http://www.falstad.com/circuit/" CreationDate="2011-01-06T20:31:48.140" UserId="142" />
  <row Id="12719" PostId="8655" Text="Your mentioning Bob's book elsewhere actually inspired this question - hoped you would answer!" CreationDate="2011-01-06T20:36:58.357" UserId="2118" />
  <row Id="12720" PostId="8655" Text="Heh, look at Bob's cover photo to see a *real* breadboard." CreationDate="2011-01-06T20:39:00.233" UserId="411" />
  <row Id="12721" PostId="8655" Score="1" Text="He must be projecting his awesome beardedness into his jumpers. Perhaps we all project personal traits into our circuitry." CreationDate="2011-01-06T20:47:22.213" UserId="2118" />
  <row Id="12722" PostId="8651" Text="+1 for CAN.  Hardware layer is defined esp. if you go for a protocol such as CANopen " CreationDate="2011-01-06T21:24:52.203" UserId="1827" />
  <row Id="12723" PostId="8644" Score="1" Text="@BarsMonster, Even if RC increases or channel decreases, will the chain of FO4 inverters (scaled) do job faster? Yes. But, if we take some CPU and downscale its netlist from 0.130 to 0.040, will FO4 change? No.   FO4 is measured in process-independent units. It is not a ps or ns. For finer technology 1 FO4 will be less when converted to ps, but it is not a technology metric, but a metric of design. " CreationDate="2011-01-06T21:25:46.243" UserId="1994" />
  <row Id="12724" PostId="8644" Text="You describe in this answer, that converting FO4 to ps is technology dependent. Yes, it is. But for the fixed technology we can estimate logical effort of different gate chains." CreationDate="2011-01-06T21:27:37.427" UserId="1994" />
  <row Id="12725" PostId="8675" Text="I've opened a question to clarify what is meant by &quot;trained&quot; in this context: http://electronics.stackexchange.com/questions/8678/basic-training-for-working-with-120v-ac" CreationDate="2011-01-06T23:20:53.323" UserId="2172" />
  <row Id="12726" PostId="8676" Text="Is this not a difficult question to answer as you will need different microcontrollers for different situations?" CreationDate="2011-01-06T23:21:23.613" UserId="1623" />
  <row Id="12727" PostId="8676" Score="1" Text="I'm looking for the cheapest of all microcontrollers - my requirements are minimal, 1 IO pin, any supply voltage, single chip (question updated)" CreationDate="2011-01-06T23:32:24.950" UserId="566" />
  <row Id="12728" PostId="8676" Text="see this piclist thread: http://comments.gmane.org/gmane.comp.hardware.microcontrollers.pic/177080" CreationDate="2011-01-06T23:38:28.800" UserId="411" />
  <row Id="12729" PostId="8679" Score="2" Text="Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/41239D.pdf" CreationDate="2011-01-06T23:43:08.313" UserId="566" />
  <row Id="12730" PostId="8676" Score="1" Text="It's a silly question, I voted to close it." CreationDate="2011-01-06T23:47:31.183" UserId="305" />
  <row Id="12731" PostId="8676" Score="1" Text="I would genuinely like an answer and I don't see how this question is different to http://electronics.stackexchange.com/questions/2641/cheapest-fpgas or http://electronics.stackexchange.com/questions/2704/cheapest-arm-with-an-mmu" CreationDate="2011-01-06T23:50:07.937" UserId="566" />
  <row Id="12732" PostId="8676" Score="1" Text="@Leon I was tempted but been edited now in two minds. " CreationDate="2011-01-06T23:50:44.713" UserId="1623" />
  <row Id="12733" PostId="8676" Text="It's a useful question. Some of these I didn't even know existed (PIC10 for example)." CreationDate="2011-01-07T00:09:02.067" UserId="1333" />
  <row Id="12734" PostId="8673" Text="Thanks for your answer! The datasheet of the transciever specifies the source impedance to be 15+j88 ohms. So does that mean this source impedance (balanced) gets transformed to 31+j7 ohms by the time it gets through the balun and past L3?" CreationDate="2011-01-07T00:40:37.203" UserId="1688" />
  <row Id="12736" PostId="8685" Score="2" Text="If I may be permitted to plug my own work, see [my answer to &quot;How can the Linux kernel compile itself?&quot; on Stack Overflow](http://stackoverflow.com/questions/494372/how-can-the-linux-kernel-compile-itself/494394#494394). The answer is not obvious until you understand the general principle, at which point you'll say *&quot;Well, of course...&quot;*" CreationDate="2011-01-07T01:21:30.513" UserId="1882" />
  <row Id="12737" PostId="8685" Text="@dmckee But it still doesn't answer the question how did it know what to do :) who told the computer with the switches what to do? I want a little more detail. " CreationDate="2011-01-07T01:24:16.423" UserId="1623" />
  <row Id="12738" PostId="8685" Score="2" Text="So the question is about *designing the boot sequence* of the first chip? Well, that is certainly a question that belongs on *this* site, but it proceeds like designing a digital logic built from components....get it to start in a known state, then feed it inputs that will do useful things. I'll leave it to other to provide the detailed answer, because I'm shaky on that, but you *do* know that the first computers were implemented in vacuum tubes, right? Then there was a generation in individual transistors, all before the first micro chip. The engineers already knew what they were doing." CreationDate="2011-01-07T01:26:53.570" UserId="1882" />
  <row Id="12739" PostId="8673" Text="What software is that?" CreationDate="2011-01-07T01:39:53.313" UserId="1374" />
  <row Id="12740" PostId="8690" Text="For speakers, I often heard term &quot;ultrasound capsules&quot; used to refer to speakers which emit sound above audible range." CreationDate="2011-01-07T03:17:00.330" UserId="1240" />
  <row Id="12741" PostId="8643" Text="How does larger wheels help? More time in contact with the ball?  I'm trying to visualize 4 wheels but I'm not sure what you mean, how would they be configured?" CreationDate="2011-01-07T04:00:44.203" UserId="2500" />
  <row Id="12742" PostId="8689" Text="Thanks that's worth looking at." CreationDate="2011-01-07T04:08:54.897" UserId="2500" />
  <row Id="12743" PostId="8640" Text="I'm trying to avoid that, but it is the simplest solution.  Just get an identical motor and turn it upside down..." CreationDate="2011-01-07T04:09:45.507" UserId="2500" />
  <row Id="12744" PostId="8674" Text="What are the specs for the transformer you're using here? What reasoning did you use to determine the values for R1 &amp; R2, and for the capacitors?" CreationDate="2011-01-07T04:18:55.467" UserId="2172" />
  <row Id="12745" PostId="8693" Text="Thanks for the phase shift tip. I was actually going to go with a square audio wave for simplicity, but I could get a much higher resolution with lower frequencies that could be picked up by typical mics if I use different wave forms and measure the phase shift instead!" CreationDate="2011-01-07T04:19:56.103" UserId="790" />
  <row Id="12746" PostId="8674" Text="Well I'm in the UK so my mains is 230v 50Hz, so my transformer would be different, I can't remember exactly but it would likely have been a 230v primary, 2 x 12v secondary 3VA transformer. The circuit will work just as well with your voltage / frequency though." CreationDate="2011-01-07T04:22:47.680" UserId="2426" />
  <row Id="12747" PostId="8693" Score="1" Text="Sorry, but you can only use sine wave. Other waveforms have unlimited spectrum and this means that you will always broadcast garbage which is kinda illigal. Also, you will never receive the same waveform you are transmitting. " CreationDate="2011-01-07T04:23:10.337" UserId="2062" />
  <row Id="12748" PostId="8674" Text="The capacitors don't have any bearing on the zero crossing circuit as they are just for smoothing the supply. I think the resistor values were chosen by trial and error to get them right, the other important components are the Zener diode and transistor. If you put a scope on the output of the zero cross circuit, you'll get a very short quick 5v pulse at exactly the zero cross time." CreationDate="2011-01-07T04:27:52.717" UserId="2426" />
  <row Id="12749" PostId="8674" Text="Also, I notice that your concerned about the safety of working with mains voltage, with this circuit as long as you have all the wires insulated properly up to the transformer before you plug it in and switch it on, then everything else is at a safe voltage... Apart from the triacs of course but they are out of the scope of this question." CreationDate="2011-01-07T04:39:27.093" UserId="2426" />
  <row Id="12750" PostId="8640" Text="reverse the polarity would be easier" CreationDate="2011-01-07T04:39:27.233" UserId="2060" />
  <row Id="12751" PostId="8673" Text="@cksa361, yes, I think that's correct.  Remember, there are a lot of limitations to this kind of analysis.  The schematic doesn't show all the stray capacitance and inductance, so that doesn't make it into the analysis." CreationDate="2011-01-07T04:51:43.670" UserId="411" />
  <row Id="12752" PostId="8673" Text="@Fake Name, the software is gsmc. http://www.qsl.net/ik5nax/ or &quot;apt-get install gsmc&quot;" CreationDate="2011-01-07T04:52:27.367" UserId="411" />
  <row Id="12753" PostId="8693" Text="@BarsMonster: If I will never receive the same waveform as I transmit, how can I calculate the phase shift? (Sorry for my lack of knowledge in this area...)" CreationDate="2011-01-07T05:02:17.957" UserId="790" />
  <row Id="12754" PostId="8693" Text="@BarsMonster - What's a coal microphone?" CreationDate="2011-01-07T05:02:24.260" UserId="2426" />
  <row Id="12755" PostId="8689" Text="@JK01 provided that the motion of one belt over the other doesn't involve contact.  If it does, they will wear, and you will get particulates in the mechanism.  But for your application the particulates bit probably doesn't matter." CreationDate="2011-01-07T05:08:08.330" UserId="2288" />
  <row Id="12757" PostId="8693" Score="1" Text="http://en.wikipedia.org/wiki/Carbon_microphone" CreationDate="2011-01-07T05:29:55.400" UserId="2062" />
  <row Id="12758" PostId="8693" Text="@wallacoloo That's why you need sine wave ) It will be the same." CreationDate="2011-01-07T05:30:51.983" UserId="2062" />
  <row Id="12759" PostId="8693" Text="@BarsMonster For each cycle of a sine wave, there are 2 x locations (time) that share the same height. Is it possible to do triangulation with sine waves by only sampling at one point in time? Or will I have to take multiple samples?" CreationDate="2011-01-07T05:37:54.650" UserId="790" />
  <row Id="12760" PostId="8695" Score="1" Text="In the extreme example of this, I know people who work on +10kV power electronics. The Device Under Test is hooked up, the oscilloscopes are set to trigger properly, everyone leaves and closes the metal fence around the equipment, everyone leaves the lab floor, gets into the control room, and THEN energizes the circuit." CreationDate="2011-01-07T05:53:31.300" UserId="638" />
  <row Id="12761" PostId="8688" Text="Great answer tcrosley! [Corrected a tidbit about EEPROM vs EPROM.](http://electronics.stackexchange.com/posts/8688/revisions) +1" CreationDate="2011-01-07T07:12:27.287" UserId="2118" />
  <row Id="12762" PostId="8696" Score="6" Text="Dammit, emacs.." CreationDate="2011-01-07T07:18:55.893" UserId="2118" />
  <row Id="12763" PostId="8675" Text="Why did you use a non-isolated solution?" CreationDate="2011-01-07T07:39:19.143" UserId="2118" />
  <row Id="12764" PostId="8693" Score="3" Text="Well, you'd better choose freq so that you are only in first quarter. But, I've just got even better idea: In such small scale you can just measure amplitude of detected(i.e. diode+capacitor) signal with precission low-frequency ADC. This is gonna be muuuuch easier &amp; more precise." CreationDate="2011-01-07T08:02:09.017" UserId="2062" />
  <row Id="12765" PostId="8683" Text="Wear shoes with rubber soles." CreationDate="2011-01-07T08:26:32.367" UserId="930" />
  <row Id="12766" PostId="8677" Text="i would also get a launchpad, ($5) because you get the programmer with 2 chips and order free samples from TI for more chips" CreationDate="2011-01-07T08:44:12.373" UserId="2060" />
  <row Id="12767" PostId="8690" Text="@AndrejaKo: or `ultrasonic transmitter/receiver`" CreationDate="2011-01-07T09:01:19.763" UserId="2064" />
  <row Id="12768" PostId="8675" Text="@tyblu, Targetting a very low cost price range. In future I would probably use a non-isolated ViPER-12A or similar buck converter due to higher efficiency." CreationDate="2011-01-07T09:22:29.407" UserId="1225" />
  <row Id="12769" PostId="8678" Text="Relevant E&amp;R questions: [un](http://electronics.stackexchange.com/q/8534/2118), [deux](http://electronics.stackexchange.com/q/7728/2118)." CreationDate="2011-01-07T11:04:45.460" UserId="2118" />
  <row Id="12770" PostId="8702" Text="Haha.... very funny! +1" CreationDate="2011-01-07T11:14:00.837" UserId="2426" />
  <row Id="12771" PostId="8678" Text="My tip - Don't be satisfied with what you've read on the internet, consult an expert in person" CreationDate="2011-01-07T11:23:39.740" UserId="566" />
  <row Id="12772" PostId="8704" Text="That's one reason why it's a silly question and should be closed!" CreationDate="2011-01-07T12:35:59.567" UserId="305" />
  <row Id="12773" PostId="5686" Text="Love the tongue test. Just tried it :D" CreationDate="2011-01-07T13:18:19.847" UserId="1333" />
  <row Id="12774" PostId="8682" Score="6" Text="Who buys anything locally anymore?" CreationDate="2011-01-07T13:22:03.293" UserId="2118" />
  <row Id="12775" PostId="5686" Score="1" Text="@Mr. Hedgehog, you can touch a new one, touch a dead one, and you are fully calibrated for determining the age of a battery. It is very easy, very effective." CreationDate="2011-01-07T14:16:32.503" UserId="230" />
  <row Id="12776" PostId="8690" Text="&quot;measure the difference in time between when each receiver gets the signal to triangulate it's source&quot;  That would be multilateration, not triangulation.  :)  http://en.wikipedia.org/wiki/Multilateration" CreationDate="2011-01-07T14:44:14.197" UserId="142" />
  <row Id="12777" PostId="8476" Text="@user2447, I can get you merged back into your original account, let me know if you need help." CreationDate="2011-01-07T14:58:31.063" UserId="230" />
  <row Id="12778" PostId="8697" Text="Can you elaborate a bit on the role of the 1:1 transformer? Naively, I would expect  electricity that has been transformed to the same voltage to be exactly as deadly as electricity that has not." CreationDate="2011-01-07T15:48:28.450" UserId="1802" />
  <row Id="12779" PostId="8707" Text="Why do you need to manually output pulses?  Can't you just use a couple timers/output-captures?" CreationDate="2011-01-07T16:13:57.573" UserId="1407" />
  <row Id="12780" PostId="8707" Text="What do you mean &quot;manually&quot;? I am using a timer interrupt to do it. I am just a little worried that the stepper motor interrupts will disrupt the TCP/IP communications. But maybe that's not the case. " CreationDate="2011-01-07T16:28:50.927" UserId="1235" />
  <row Id="12781" PostId="8697" Text="It's the same voltage between live and neutral as unisolated but not between live and earth." CreationDate="2011-01-07T16:33:34.403" UserId="2110" />
  <row Id="12782" PostId="8674" Text="While this will work to some extent, there's much more that could be done. You'll find that there's a lot of noise around the zero cross point in some buildings so you could get multiple transitions. Filtering will help but then you have a delay problem, the edge you see with micro is delayed from the actual zero crossing. The transformer is also adding a delay, which will be load dependent (load on the secondary side). This is actually a very hard problem to solve, search for Lutron's patents on RTISS." CreationDate="2011-01-07T16:41:14.333" UserId="2110" />
  <row Id="12784" PostId="8704" Score="3" Text="Or it makes the launchpad look even better for a $5 programmer" CreationDate="2011-01-07T16:51:16.550" UserId="2006" />
  <row Id="12785" PostId="8688" Score="1" Text="And if you really wanted to program a microcontroller without another computer (besides your brain) you could do so by building circuitry that fed the program into it directly.  If was programmed over jtag then you could flip switches to mimic the jtag commands needed to program the device.  If it used external ram then you could use a lot of demultiplexors and huge arrays of resistors tied high or low to represent the bits of the instructions (and probably use a low clock speed because your hardware will be slow)." CreationDate="2011-01-07T17:05:43.817" UserId="2517" />
  <row Id="12786" PostId="8674" Text="@Martin: I didn't have any such problems when I did this. The load on the transformer is very small and constant, and I ran it from a noisy diesel generator whos load was shared with motor inverters... it worked perfectly." CreationDate="2011-01-07T17:15:00.327" UserId="2426" />
  <row Id="12787" PostId="8688" Text="@tyblu, thanks for the edit." CreationDate="2011-01-07T18:26:43.663" UserId="1322" />
  <row Id="12788" PostId="8707" Text="&quot;manually&quot; = &quot;bit-banging&quot;, as opposed to just letting the module(s) do it's thing and output a pulse train (without interrupting you).  You may still need to count the pulses though, so it may be unavoidable unless you could get clever with using individual bytes of 16-bit timers--which may not even be possible on a PIC (I have poor knowledge of them)" CreationDate="2011-01-07T19:20:10.423" UserId="1407" />
  <row Id="12789" PostId="8643" Text="No, the 40mm number was so that your ball would fit between the wheels. The 4 wheel system would use two axles, and each would be configured big wheel-small wheel-big wheel.  If this was an electronics question, you'd get a beautiful schematic or PCB that would look great, but it's not, so prepare to be subjected to an MS Paint mechanical diagram. Sorry for that." CreationDate="2011-01-07T19:39:22.223" UserId="857" />
  <row Id="12790" PostId="8683" Text="Related, **do not** use ESD-safe equipment anywhere near energized circuits; especially clothing and boot-straps." CreationDate="2011-01-07T19:41:55.660" UserId="1407" />
  <row Id="12791" PostId="8706" Text="Wow. That's a lot of capacitance loss. The exact part is GRM21BR60J226ME39L - http://uk.farnell.com/murata/grm21br60j226me39l/capacitor-0805-22uf-6-3v/dp/1735531/." CreationDate="2011-01-07T19:44:09.740" UserId="1225" />
  <row Id="12792" PostId="8706" Text="I have footprint space for a 22u 10V 1206 cap - would it be advisable to place this instead of a 22u 6.3V 0805? I'm not currently placing it because of slightly higher cost of the 1206 cap vs. 0805 cap." CreationDate="2011-01-07T19:46:30.317" UserId="1225" />
  <row Id="12794" PostId="8697" Score="2" Text="This is commonly called an _isolation_  _transformer_ and many also include a circuit breaker.  They make it so that there is no circuit between the isolated side and the actual Earth ground, which keeps large amounts of current from flowing through you or your equipment into the ground.  Current can still flow between the two lines on the isolated side, and that is what the circuit breaker is for." CreationDate="2011-01-07T19:52:43.237" UserId="2517" />
  <row Id="12795" PostId="8713" Text="Yeah... I take that it's a bad thing, but how can it even measure at 100 MHz with such a capacitance?" CreationDate="2011-01-07T20:31:31.617" UserId="1225" />
  <row Id="12796" PostId="8682" Score="1" Text="@Tyblu - Depends on your definition of 'locally'.  I consider any US-based distributor or manufacturer to be local (greater North America only slightly less so), and Asian/European distributors to be non-local.  99% of my shopping is therefore local.&#xA;" CreationDate="2011-01-07T20:33:11.647" UserId="857" />
  <row Id="12797" PostId="8713" Text="It's an extreme example, but it does show why the capacitance is important. It wouldn't cause a problem at a low impedance point." CreationDate="2011-01-07T20:33:39.550" UserId="305" />
  <row Id="12798" PostId="8677" Score="3" Text="@Matt, @jsolarski - Samples are great for their intended purpose: to support new designs and to verify that a sample will work in existing designs.  Please don't abuse the program and ruin it for the rest of us; [read the TI FAQ](http://www.ti.com/sc/docs/sampfaq.htm) for more information." CreationDate="2011-01-07T20:37:27.010" UserId="857" />
  <row Id="12799" PostId="8713" Text="Okay, but my simulator says a 10pF cap draws ±1 amp at 100Vp-p. My scope is rated 250Vp-p. Does this mean, a higher frequency could actually damage it(?) It can measure up to 5Vp-p, giving ±20V, although it can move ±16 divisions, so it could measure 100V maximum... I must be missing something?!" CreationDate="2011-01-07T20:37:58.523" UserId="1225" />
  <row Id="12800" PostId="8697" Score="2" Text="You can get similar (but not as good) protection from a GFCI outlet.  It measures current leaving and entering the outlet.  If they don't sum to zero it shuts the power off.  I think I would trust the isolation transformer more.  Or both." CreationDate="2011-01-07T20:40:27.183" UserId="411" />
  <row Id="12801" PostId="8697" Text="@ Ranieri: Done. Answer is now longer." CreationDate="2011-01-07T20:53:11.830" UserId="930" />
  <row Id="12802" PostId="8714" Text="So the capacitor is in series with the input?" CreationDate="2011-01-07T20:55:13.773" UserId="1225" />
  <row Id="12803" PostId="8713" Text="@Thomas - Where is that 1A going to in your simulation?  In the real world, it's going to a high-impedance analog input, not directly to ground. " CreationDate="2011-01-07T20:55:52.620" UserId="857" />
  <row Id="12804" PostId="8714" Text="Yes, the cap is in series with the input just like the resistor is. You could say that at the input, the two resistors divide the DC voltage, and the two capacitors divide the AC part (up to very high frequencies). Remember that a (1/10) resistive divider has the big resistance on the upper part, and a (1/10) capacitive divider has the small cap on top." CreationDate="2011-01-07T20:59:04.227" UserId="930" />
  <row Id="12806" PostId="8713" Score="2" Text="Special secret trick for extreme low loading of the circuit under test (when you don't have an active FET probe): Use a 1:100 probe. They are designed primarily for high voltage probing, but they are also great when you want to insert an even lower capacitance into your circuit than you would using a 1:10 probe." CreationDate="2011-01-07T21:21:13.520" UserId="930" />
  <row Id="12807" PostId="8674" Text="Is there any particular reason your voltage regulators are in series? Is the 7805 more efficient when the input voltage is lower and more constant?" CreationDate="2011-01-07T21:24:09.157" UserId="2172" />
  <row Id="12808" PostId="8713" Text="@reemrevnivek, The cap is from the BNC to the earth ground, right? " CreationDate="2011-01-07T21:35:36.250" UserId="1225" />
  <row Id="12809" PostId="8597" Text="Isn't that what I said in the question?" CreationDate="2011-01-07T21:38:57.803" UserId="142" />
  <row Id="12810" PostId="8713" Text="@Thomas, there is capacitance from the probe tip to the earth ground, but it's not 10pF, it's 1.2pF.  See zebonaut's answer. What does that do to your simulation?" CreationDate="2011-01-07T21:40:09.307" UserId="857" />
  <row Id="12811" PostId="8674" Text="The reason was that I needed 12v to power a relay, and 5v for the PIC. Just part of the design of the circuit. If you don't need 12v then just omit the 7812 regulator." CreationDate="2011-01-07T22:11:59.057" UserId="2426" />
  <row Id="12812" PostId="8713" Text="@reemrevnivek It draws about 500mA, which is still pretty high! And at higher frequencies, it increases." CreationDate="2011-01-07T22:20:16.930" UserId="1225" />
  <row Id="12813" PostId="8681" Text="Looks like these are 1 to 2 dollars each" CreationDate="2011-01-07T22:23:38.153" UserId="142" />
  <row Id="12814" PostId="8681" Score="1" Text="To my knowledge, the ATtiny13 isn't very C-friendly (very limited stack space).  The ATtiny25/45/85 have a more useful amount of RAM." CreationDate="2011-01-07T23:21:49.407" UserId="1407" />
  <row Id="12815" PostId="8682" Text="@reem: My distributor has an office up the road.  They're based in another city.  The manufacturer in another state.  The manufacturing is done in another country..." CreationDate="2011-01-07T23:23:33.180" UserId="1407" />
  <row Id="12816" PostId="8107" Text="@tyblu, Many of the routing machines more than a year or two old still use 9600 baud serial lines.  I wrote a utility that converted Gerber files into a format used in a Fuji pick-n-place that is still in use at my old company and several others.  The machine's only link to the outside world was 9600 baud serial, on which sat an Irix-based PC with some proprietary software on it.  I guess a 10MB Gerber is fine for you, until you're the one who has to sit and wait a half hour for it to load between designs." CreationDate="2011-01-07T23:28:54.747" UserId="2257" />
  <row Id="12817" PostId="7270" Text="For some background theory, see the Computer Vision wiki: Tracking ( http://computervision.wikia.com/wiki/Tracking )" CreationDate="2011-01-08T00:02:47.813" UserId="813" />
  <row Id="12818" PostId="8718" Text="Yes, I have run into several old, killer app notes from the big players." CreationDate="2011-01-08T00:08:36.103" UserId="2118" />
  <row Id="12819" PostId="8107" Text="@Eric Cox, 10MB/9.6kbps is about 2.5 hours; I see your point! ;)" CreationDate="2011-01-08T00:10:14.620" UserId="2118" />
  <row Id="12820" PostId="8696" Score="4" Text="I program programmers. (And those programmers I program program programmers who program programmers.)" CreationDate="2011-01-08T00:27:54.333" UserId="1940" />
  <row Id="12821" PostId="8724" Text="@Joby: ah yes!!! I can't believe I didn't see that myself. Thanks." CreationDate="2011-01-08T00:38:05.650" UserId="2426" />
  <row Id="12822" PostId="3023" Text="You can use a stencil for a single board, but it takes about the same time to stencil and reflow a panel of several. Manual placing is also quicker as you can place all instances of each part, reducing time swapping between different tapes etc. The combination of tapes stuck down and a foot-operated vacuum pickup can save a lot of time (hint - it's hard to pick parts from tape with tweezers) - with  practice you can get down to a couple of secs per part for repetitive placements of the same part type." CreationDate="2011-01-08T01:33:49.557" UserId="1681" />
  <row Id="12823" PostId="8725" Text="I've always used a triac to switch mains voltage... I didn't realise a power MOSFET would do the same job... what are the differences?" CreationDate="2011-01-08T01:34:29.507" UserId="2426" />
  <row Id="12824" PostId="3023" Text="Just watched that video - this really isn't the way to do it efficiently. For a board that size you want to panelise them in a v-scored panel (v-score rather than routed so you can snap out easily) maybe 4x8 boards (hand reach when placing is the first limitation on size), and reflow the whole panel in a toaster oven. " CreationDate="2011-01-08T01:43:45.237" UserId="1681" />
  <row Id="12826" PostId="8725" Text="The main difference I'm going with is that Power MOSFETs can be switched off part of the way through a cycle, enabling reverse phase control (http://www.epanorama.net/documents/lights/lightdimmer.html). Apparently Gate Turn-Off Triacs will do the same thing, but I was having difficulty finding a vendor for GTO's." CreationDate="2011-01-08T01:55:12.930" UserId="2172" />
  <row Id="12828" PostId="8728" Text="He said that he &quot;want[s] to use reverse phase control&quot;, which is impossible with TRIACs." CreationDate="2011-01-08T02:24:22.457" UserId="1407" />
  <row Id="12829" PostId="8725" Text="Okay, I've read up on reverse phase control, is noise really a problem for you? Could you just use an input LC filter to eliminate the necessity of it? The extra cost of the filter will probably be made up for the savings in other components." CreationDate="2011-01-08T02:33:09.027" UserId="1225" />
  <row Id="12831" PostId="8728" Text="Thomas: if you could point me to a Gate Turn-Off thyristor or triac I could use with 120V AC mains, that would be helpful." CreationDate="2011-01-08T02:50:15.070" UserId="2172" />
  <row Id="12832" PostId="8728" Text="@Isaac Sutherland, I think the problem is that GTOs are high current devices. I couldn't find any rated below 400A continuous conduction current. There just isn't a market for them for fully switchable AC, it seems." CreationDate="2011-01-08T03:38:58.667" UserId="1225" />
  <row Id="12833" PostId="8731" Score="3" Text="How to build a cookie launcher? Best question evar!" CreationDate="2011-01-08T03:42:34.327" UserId="2118" />
  <row Id="12834" PostId="8731" Text="Can you use pneumatics?  (Probably not...but worth a shot `:P`)" CreationDate="2011-01-08T04:17:47.027" UserId="1407" />
  <row Id="12836" PostId="8696" Score="3" Text="I make my own programmers. " CreationDate="2011-01-08T05:31:36.073" UserId="638" />
  <row Id="12837" PostId="8713" Text="@Thomas O: Have you tried plugging the circuit in my link into your simulation (9 MOhm || 1.33 pF at the probe and 1 MOhm || 12 pF at the scope's input)? If I don't mess things up here, I think the impedace at 100 MHz is approx. Z = 1 / (2*pi*100MHz*1.2pF) = 1.3kOhm; The current at 100V_pkpk should then be something like I = 100V / 1.3kOhm = 75 mA. Significant, but better than 500 mA." CreationDate="2011-01-08T11:28:23.273" UserId="930" />
  <row Id="12838" PostId="4924" Score="1" Text="Do not break the ground connection of the scope's mains plug. Also, better don't use an isolation transformer to supply the scope. Instead, float the supply of the circuit under test; then, the protective earth of the scope can remain in place and do its job of providing user safety." CreationDate="2011-01-08T14:07:12.793" UserId="930" />
  <row Id="12839" PostId="8734" Text="http://electronics.stackexchange.com/questions/708/i2c-3-3-to-5-0-v-conversion http://electronics.stackexchange.com/questions/622/bi-directional-step-up-and-step-down-3-3v-5-etc" CreationDate="2011-01-08T14:24:27.823" UserId="566" />
  <row Id="12840" PostId="7665" Text="-1 -- It's just as easy to keep a level high regardless of Vcc. You use a pullup transistor or resistor, the same way you would use a pulldown transistor or resistor. Your argument says nothing special about the difference between the voltages at the power supply pins. On power-up, they move apart, and the valid logic levels are relative to the power supply voltage." CreationDate="2011-01-08T15:56:35.063" UserId="330" />
  <row Id="12841" PostId="7666" Text="+1. This is the primary correct answer. " CreationDate="2011-01-08T15:59:48.543" UserId="330" />
  <row Id="12842" PostId="6773" Text="please convert to community wiki" CreationDate="2011-01-08T16:03:39.740" UserId="330" />
  <row Id="12843" PostId="7665" Text="@Jason: it makes more sense to keep it at a level which is *always* clearly defined than rely on a level which is constantly changing." CreationDate="2011-01-08T16:06:27.933" UserId="2064" />
  <row Id="12844" PostId="8745" Text="Can you give a link describing exactly what you're thinking about? There are several related designs which do have some differences." CreationDate="2011-01-08T17:02:02.960" UserId="1240" />
  <row Id="12845" PostId="8674" Text="Why are the capacitors connected in parallel? I'm guessing it was some kind of protection for the electrolytic capacitors, but I can't find anything online that says a parallel ceramic capacitor is a good protective measure." CreationDate="2011-01-08T17:20:50.203" UserId="2172" />
  <row Id="12846" PostId="8674" Text="The small capacitors are to filter out noise from the microcontroller, I recently found out however that it's better to put them closer to the chip. The electrolytic caps are just to smooth the 5v." CreationDate="2011-01-08T17:43:57.650" UserId="2426" />
  <row Id="12847" PostId="8745" Text="Well, it's not particularily one of them, but on youtube I see a few (more or less powerful) that launch some metal sticks - usually  nails. Mainly what I'm asking is wether you need a single coil to build one or many, but also how it actually works, a-k-a how the energy is transfered  to make the nail go forward. Also I was wandering if it would be better to have high current or high voltage. I am obviously understanding that this is the opposite of an alternator, but I am in secondary and just started studying them. As you might understand, my physics teacher wouldn't tell me about coilguns." CreationDate="2011-01-08T17:46:05.307" UserId="2528" />
  <row Id="12848" PostId="8749" Text="I know, I think I've seen the same videos... He stands in a faraday cage and watches a huge spark hit it inches from his face." CreationDate="2011-01-08T17:46:54.140" UserId="2426" />
  <row Id="12849" PostId="8750" Text="Yes I know... But it's difficult to tell which ones are easier/harder to build... And I can only seem to find big ones... I wanna start off small, I'm not sure if it's as simple as scaling down everything... Maybe there is a reason they're all big." CreationDate="2011-01-08T17:52:44.103" UserId="2426" />
  <row Id="12850" PostId="8742" Text="I try to use 0.5oz copper for home-made small pitch features (&lt;15mil)." CreationDate="2011-01-08T18:03:53.740" UserId="2118" />
  <row Id="12851" PostId="8747" Score="2" Text="I suggest you try to make your question more specific. It requires a textbook-sized answer in its current form." CreationDate="2011-01-08T18:05:28.140" UserId="2118" />
  <row Id="12852" PostId="8742" Text="Why do you usually use 2oz copper? I know there are many valid reasons for using it, I'm just curious to your particular application." CreationDate="2011-01-08T18:05:37.780" UserId="638" />
  <row Id="12853" PostId="8751" Text="I've used 2oz copper several times for increased heat dissipation for components that sink heat to the ground plane.  Just as another reason (other than current) that one may need 2oz copper.  Never used it on a layer that wasn't a solid plane though." CreationDate="2011-01-08T18:33:13.320" UserId="1438" />
  <row Id="12854" PostId="8759" Text="All three answers look good, but this one helped me the most." CreationDate="2011-01-08T20:30:19.660" UserId="1240" />
  <row Id="12855" PostId="8761" Text="Where did yu get 15V from is that a rounded answer? As if you do 12*1.2 = 14.4V " CreationDate="2011-01-08T20:34:48.523" UserId="1623" />
  <row Id="12856" PostId="8761" Text="I use 1.25V for discharged - mostly because that's what the Roomba charging circuit uses as well." CreationDate="2011-01-08T20:44:38.133" UserId="249" />
  <row Id="12857" PostId="8762" Text="I want it to be controlled electronically, and with minimum cost. Do you have a better idea- I could use a switch, but it might be more expensive than a DPST relay." CreationDate="2011-01-08T21:04:57.977" UserId="1225" />
  <row Id="12859" PostId="8752" Score="2" Text="So...short answer = max cell voltage (1.78 V) × number of cells + LM317 dropout at your charging voltage (~2 V) + voltage across resistor (1.25 V, always)." CreationDate="2011-01-08T21:52:40.750" UserId="1407" />
  <row Id="12861" PostId="8763" Text="How is that? Aliasing won't happen until sample_rate/2, or 250MHz. A 10:1 oversampling ratio is used to improve signal resolution and some DSP algorithms." CreationDate="2011-01-08T22:00:40.757" UserId="2118" />
  <row Id="12862" PostId="8764" Text="What power supplies do you have available?" CreationDate="2011-01-08T22:15:37.787" UserId="411" />
  <row Id="12863" PostId="8764" Text="@markrages, 2.5V, -2.5V, 5V, -5V, GND and 1.8V." CreationDate="2011-01-08T22:30:44.940" UserId="1225" />
  <row Id="12864" PostId="8767" Score="2" Text="Great question! Would love to see some repository examples included in answers." CreationDate="2011-01-08T23:10:27.167" UserId="2118" />
  <row Id="12865" PostId="8768" Score="1" Text="Have you done this? Putting binaries into SVN or Mercurial has turned out terribly for me." CreationDate="2011-01-08T23:29:21.967" UserId="2118" />
  <row Id="12866" PostId="8768" Score="2" Text="No i haven't but i have used SVN for not just source code. Things Like PDFs and .txt files." CreationDate="2011-01-08T23:30:31.737" UserId="1623" />
  <row Id="12867" PostId="8752" Score="1" Text="@NickT, Aye! `[#cells]xI_chargex(120mΩ)+1.2V+1.25V+[#cells]x1.78V`. Complication is good for the soul, though (and the snowed-in weekend)." CreationDate="2011-01-08T23:34:27.190" UserId="2118" />
  <row Id="12868" PostId="8765" Text="As I understand it, the TL431 drops 2.495V, right? Could I use a 2.4V or 2.7V zener if accuracy wasn't critical?" CreationDate="2011-01-09T00:00:44.353" UserId="1225" />
  <row Id="12869" PostId="8768" Score="2" Text="@Tyblu what do you mean by terrible? I've done it with schematic and layout files and its worked great for me with subversion." CreationDate="2011-01-09T00:20:05.110" UserId="319" />
  <row Id="12870" PostId="8768" Text="I can't follow changes to EAGLE files with Mercurial. It looks like the entire file is different. Do you have a repository I can peek at?" CreationDate="2011-01-09T00:23:27.930" UserId="2118" />
  <row Id="12871" PostId="8731" Text="I wish, but no, no pneumatics haha" CreationDate="2011-01-09T01:00:57.930" UserId="2522" />
  <row Id="12872" PostId="8736" Text="this wouldnt work... It has to run continuous without human intervention which means no trigger mechanisms or anything like that" CreationDate="2011-01-09T01:01:46.370" UserId="2522" />
  <row Id="12873" PostId="8736" Text="So hold down the trigger? Set up something like a 555 driving a relay / microcontroller to periodically fire the trigger?" CreationDate="2011-01-09T02:17:16.753" UserId="638" />
  <row Id="12874" PostId="8770" Text="Did you use the integrated SVN GUI (with Altium) or something external?" CreationDate="2011-01-09T02:29:34.440" UserId="1407" />
  <row Id="12875" PostId="8770" Text="Newest Altium with SVN is great, although i'll add that PCB/schematic revisions aren't nearly as critical as they are in code.  If you're dealing with more than 3-4 max schematic / PCB release revisions something probably when very wrong in the design or requirements phases." CreationDate="2011-01-09T02:31:43.097" UserId="1438" />
  <row Id="12877" PostId="8770" Text="@Mark: Are you talking about the Release 10 beta, or Summer 09?" CreationDate="2011-01-09T02:51:32.370" UserId="1407" />
  <row Id="12879" PostId="8770" Text="I'm on summer 09 atm, i don't know exactly at what point the schematic/PCB diff tool was added, there was a several year period where i wasn't using altium so my use of 'newest' was probably inaccurate in terms of when this feature was added." CreationDate="2011-01-09T03:01:06.607" UserId="1438" />
  <row Id="12881" PostId="7665" Text="Vcc and Gnd are both changing relative to each other. It's just convention that we think of Gnd as &quot;constant&quot; when it's really the two relative to each other. Vcc is only changing relative to Gnd because we think of it that way, rather than Gnd increasing negatively relative to Vcc." CreationDate="2011-01-09T03:16:36.490" UserId="330" />
  <row Id="12882" PostId="8690" Text="@endolith: Ok. So is there a general term that encompasses all methods of pinpointing the origin of a signal?" CreationDate="2011-01-09T03:35:43.163" UserId="790" />
  <row Id="12883" PostId="8766" Text="I'm sorry - I must be missing something here. I thought the impedance on a scope was pretty much flat at 1 megohm to the rated BW, but you're saying it's not? How do 10X probes work then? I guess I need to do some more testing. Oscilloscopes are far more complicated than I expected - I should know by now!" CreationDate="2011-01-09T03:42:12.203" UserId="1225" />
  <row Id="12884" PostId="8776" Score="1" Text="To restate the obvious, this is a bad idea. Can you control the output voltage of the laptop power supply (keep it at 17V)? Can you measure current and voltage? Are the LED strips JUST LEDs (and maybe a resistor)?" CreationDate="2011-01-09T04:26:54.617" UserId="638" />
  <row Id="12885" PostId="8742" Text="I wish I had a good answer but basically because that's how we've always done it.  I've always been a schematic guy.  I'm just getting into actual layout side of things, and so am learning.  From the responses so far, it looks like using 2 ounce is not the norm, so I guess I should think about switching to 1 once unless there is a valid reason for 2, especially with small pitch SMDs." CreationDate="2011-01-09T04:31:51.583" UserId="2377" />
  <row Id="12886" PostId="8781" Score="2" Text="Please provide us with which PIC chip and programmer you are using." CreationDate="2011-01-09T05:52:55.467" UserId="638" />
  <row Id="12887" PostId="8766" Text="Yeah, 'scope impedances are fairly flat, and have less capacitance. I just put in values that would be typical using discrete parts, large'ish SMD packages (SOT, 0805), and a few cm of traces. Cs would be ~20-100pF without external caps, but would make numbers even worse. Just do the same calculations over again, or use SPICE sweeps (even MATLAB as the circuit is simple), with different cap values until you get about the same impedances (and attenuation) at all frequencies. Broadband matching is kind of difficult! May edit in more a bit later." CreationDate="2011-01-09T07:21:16.843" UserId="2118" />
  <row Id="12888" PostId="8765" Text="Since this is low-speed logic, you can probably get away with a two-resistor voltage divider, with the low side at -2.5v. Calculate the hih and low levels, but it should work for standard CMOS I/O at least. If the 0-5v sigal is coming from a micrcontroller, the divider will draw some current through the protection diodes when the micro is in reset and all it's pins are inputs.  Use high-value resistors in the divider so this current isn't a problem." CreationDate="2011-01-09T07:51:55.770" UserId="411" />
  <row Id="12889" PostId="8788" Text="Very little external light (noise) gets into photo-interruptor modules." CreationDate="2011-01-09T08:23:33.677" UserId="2118" />
  <row Id="12890" PostId="8787" Text="So wait, are you telling me that smoke alarms you buy off of the shelf measure light to determine how 'smoke' is in the air? Guess I am lost. Figured this would be a different type of sensor." CreationDate="2011-01-09T08:36:24.780" UserId="1575" />
  <row Id="12891" PostId="8781" Score="2" Text="Can you post your code?" CreationDate="2011-01-09T08:38:13.297" UserId="2426" />
  <row Id="12892" PostId="8788" Text="The problem is that there IR LED shines directly into photodiode, so difference with and without smoke is some 0.001% :-) When detecting diffused light, you need to differentiate between 0 and 0.001% which is much much easier :-)" CreationDate="2011-01-09T08:53:08.343" UserId="2062" />
  <row Id="12893" PostId="8787" Score="1" Text="Check here. http://en.wikipedia.org/wiki/Smoke_detector Optical ones are way easier to implement. Ionization probably a bit better, but they cannot be cheap, as they need some radioactive elements." CreationDate="2011-01-09T08:54:54.693" UserId="2062" />
  <row Id="12894" PostId="8788" Text="@BarsMonster, That is true." CreationDate="2011-01-09T09:15:53.950" UserId="2118" />
  <row Id="12895" PostId="8766" Text="Thomas O, please look again at my answer at http://electronics.stackexchange.com/questions/8712/what-does-input-capacitance-mean-on-an-oscilloscope. I've put more details there since my first reply." CreationDate="2011-01-09T11:05:17.827" UserId="930" />
  <row Id="12896" PostId="7873" Text="Turns out the motor needs about 300 mA to run so the driver was the only option." CreationDate="2011-01-09T11:11:05.207" UserId="1637" />
  <row Id="12897" PostId="8792" Score="1" Text="Why should something be simple when it can be complicated :)" CreationDate="2011-01-09T11:11:11.743" UserId="1240" />
  <row Id="12898" PostId="8793" Text="Do you have a link to the DC motor controller, or even the motor itself, datasheet?" CreationDate="2011-01-09T12:02:23.947" UserId="2118" />
  <row Id="12899" PostId="8752" Score="1" Text="Charging an 850mAh battery for 2 hours at 425mA may be arithmetically sound, but starts from the idea that charging is 100% efficient. It's not. I guess depending on your charging method efficiency is limited to about 80%. So if you charge at 425mA, you'll have to charge for 2.5 hours." CreationDate="2011-01-09T12:18:05.953" UserId="2064" />
  <row Id="12900" PostId="8752" Text="@stevenh, One of the listed sources claims 60%-70% efficiency." CreationDate="2011-01-09T12:34:01.500" UserId="2118" />
  <row Id="12901" PostId="8749" Text="yup - thats the one!" CreationDate="2011-01-09T13:15:01.660" UserId="1397" />
  <row Id="12902" PostId="8793" Text="No... It is just something I removed from an old mobile I had. It is drawing 300 mA with 5 V" CreationDate="2011-01-09T13:28:59.103" UserId="1637" />
  <row Id="12903" PostId="8752" Text="@tyblu: well, my point was that you can't just divide the capacity by current to find time." CreationDate="2011-01-09T13:38:13.217" UserId="2064" />
  <row Id="12904" PostId="8752" Text="@stevenh, yes, thank you. I believe Energizer's recommendation was in relation to charge rates, and charge termination logic is handled seperately. I'll fix it up for clarity." CreationDate="2011-01-09T13:41:32.480" UserId="2118" />
  <row Id="12905" PostId="8750" Text="I have to agree with mike, most people on the forum would probably need to google up instructions and repeat or link you to a sight with instructions - it is best if you research it first, find some interesting concepts/plans and then post links to them with more specific questions. It is not to fob you, just need to help others to help you :)" CreationDate="2011-01-09T14:50:31.640" UserId="1397" />
  <row Id="12906" PostId="8718" Text="Very true. Good App'notes are worth a lot, especially when you want to connect the missing link between formal (college/university) education and knowledge required for your first job(s) in industry." CreationDate="2011-01-09T15:56:53.643" UserId="930" />
  <row Id="12907" PostId="8768" Score="4" Text="@tyblu that's why you add comments when you check in files :)" CreationDate="2011-01-09T16:00:14.877" UserId="771" />
  <row Id="12908" PostId="8757" Text="It is also easy to talk to serial devices using processing." CreationDate="2011-01-09T16:44:18.533" UserId="1498" />
  <row Id="12909" PostId="8736" Text="How uniform are your cookies?  Oreo's or something easy like that?  Something like this would be a great method.  You could probably actually use a real one (though they are too big) if you came up with some insert for the clay holder and shim for the arm :P" CreationDate="2011-01-09T16:45:15.630" UserId="1407" />
  <row Id="12910" PostId="8800" Text="I'm surprised to see any measurable effect, but even these docs are showing minimal (&lt;10%) changes in leakage or capacitance. I imagine if the capacitor is in a circuit with minimal allowable tolerance it may be a problem, but for most applications I'm familiar with, this wouldn't even be noticeable." CreationDate="2011-01-09T16:56:17.893" UserId="2255" />
  <row Id="12911" PostId="8798" Score="1" Text="Could someone say what the acronym &quot;TVS&quot; stands for?" CreationDate="2011-01-09T17:24:34.460" UserId="638" />
  <row Id="12912" PostId="8792" Score="3" Text="@AndrejaKo: and to think that the answer could have been shorter, but E&amp;R insists on a minimum of 30 characters :-)" CreationDate="2011-01-09T17:41:13.233" UserId="2064" />
  <row Id="12913" PostId="8798" Score="1" Text="Transient Voltage Suppression or Suppressor" CreationDate="2011-01-09T17:53:00.117" UserId="2118" />
  <row Id="12914" PostId="8783" Text="If you still have the programmer connected when you try to run the program you will have to &quot;release from reset&quot; from mplab. If you don't do this it doesn't matter if you have a resistor pull-up for MCLR it will still be pulled down." CreationDate="2011-01-09T18:41:16.963" UserId="319" />
  <row Id="12915" PostId="8800" Text="Sure, this is just what the manufacturers tell you to make sure they don't get sued. My guess is as well that it would take much longer storage times and plenty of bad luck to have an electrolytic capacitor blow upon its first charging event after a long time. However, I know from experience that reputable manufacturers of switch-mode power supplies make sure that they don't store their capacitors too long before stuffing them into their products. When you use hundreds of thousands a year, you don't want any risk and you want your caps within spec." CreationDate="2011-01-09T19:14:21.537" UserId="930" />
  <row Id="12916" PostId="8807" Text="Development time is going to be 80-90% of the cost." CreationDate="2011-01-09T19:23:51.250" UserId="1407" />
  <row Id="12917" PostId="8807" Text="Are you wanting to estimate what it will costs to re-manufacture or the cost of development, redesign, and bug fixing? " CreationDate="2011-01-09T19:40:13.793" UserId="319" />
  <row Id="12918" PostId="8807" Text="I would like to calculate the price for remanufacturing the device using an existing developed construction. I need it to have a picture of how much this gadget would cost if manufactured in large amounts so that to know if its worth that." CreationDate="2011-01-09T19:48:00.140" UserId="2543" />
  <row Id="12919" PostId="8811" Score="1" Text="Disagree with point #2, I got a quantity of 10x 2-layer PCBs for $40 USD total and 10x 4-layer for $150 USD total." CreationDate="2011-01-09T20:08:11.737" UserId="1225" />
  <row Id="12920" PostId="8812" Text="How have you used this before, and why did you chose it instead of others?" CreationDate="2011-01-09T20:15:14.777" UserId="2118" />
  <row Id="12921" PostId="8812" Text="In a 12v automotive system, incidentally a system that passed all UK EMC requirements for fitment in emergency vehicles." CreationDate="2011-01-09T20:16:50.547" UserId="1827" />
  <row Id="12922" PostId="8807" Text="You already have a completed design, then? Seems the only thing left to do is add everything up and get quotes, then." CreationDate="2011-01-09T20:18:08.283" UserId="2118" />
  <row Id="12923" PostId="8811" Score="1" Text="@Thomas O Can you tell me where you got those prices? Did they include soldermask and silkscreen&quot;? Was there any student discount with that?" CreationDate="2011-01-09T21:20:11.570" UserId="319" />
  <row Id="12924" PostId="8774" Score="2" Text="I use CVS for all my projects (software and hardware, with PCB, firmware, tools, etc.) and have no problem. Sure, CVS is obsolete, but I have 20 years of project history and no converter worked to migrate my repositories to Mercurial, or SVN. " CreationDate="2011-01-09T21:29:01.687" UserId="244" />
  <row Id="12925" PostId="8257" Text="*Aside: I just incorporated a DIP uA741 into a new design specifically to get them out of my toolbox (I have ~100)! Maybe this is how it starts...*" CreationDate="2011-01-09T23:19:42.223" UserId="2118" />
  <row Id="12926" PostId="5050" Text="The simplest and most pre-fabricated solution.. is ususally the winner." CreationDate="2011-01-10T00:16:06.673" UserId="1457" />
  <row Id="12927" PostId="4924" Text="@zebonaut, I think nothing needs to be floated here, these are just a few peoples opinions on ways around it. In reality there are 18 different ways to get around this problem." CreationDate="2011-01-10T00:27:26.230" UserId="230" />
  <row Id="12928" PostId="8804" Text="OP wants to control current, not RPM.  To control current, you need to take feedback from the current." CreationDate="2011-01-10T00:28:56.153" UserId="411" />
  <row Id="12929" PostId="8805" Text="Hehe, I still have some caps I desoldered in my childhood, now I have an LCR meter to see how good are they. They are from some 1970s :-) That would be funny :-D" CreationDate="2011-01-10T00:30:39.690" UserId="2062" />
  <row Id="12930" PostId="8804" Text="You right, fixed." CreationDate="2011-01-10T00:32:02.527" UserId="2062" />
  <row Id="12931" PostId="8693" Text="@BarsMonster: How much interference am I likely to get with 100-200 MHz frequencies, or do I even need to worry about this?" CreationDate="2011-01-10T01:25:59.563" UserId="790" />
  <row Id="12932" PostId="8814" Text="What's the story behind concrete floor?" CreationDate="2011-01-10T01:37:21.877" UserId="1240" />
  <row Id="12933" PostId="8693" Text="You should not get much. With such close emitters &amp; receivers your signal will be 1000s of times stronger." CreationDate="2011-01-10T01:38:18.210" UserId="2062" />
  <row Id="12934" PostId="8783" Text="To W5VO:  Here's the code:&#xA;&#xA;#include &lt;p18f4550.h&gt;&#xA;#pragma config WDT = OFF&#xA;void delay (void)&#xA;{&#xA;unsigned int i;&#xA;for (i = 0; i &lt; 65535 ; i++)&#xA;;&#xA;}&#xA;void main (void)&#xA;{&#xA;TRISB = 0;&#xA;while (1)&#xA;{&#xA;&#xA;PORTB = 0;&#xA;&#xA;delay ();&#xA;&#xA;PORTB = 0xFF;&#xA;&#xA;delay ();&#xA;}&#xA;}" CreationDate="2011-01-10T01:48:17.423" UserId="2488" />
  <row Id="12935" PostId="8783" Text="Programmer is a MPLAB Compatible Mini USB PIC Programmer. MCLR is always low when ICSP cable connected. Gotta yank it out to run?" CreationDate="2011-01-10T01:51:45.377" UserId="2488" />
  <row Id="12937" PostId="8814" Text="@Andrejako, [Here's one version.](http://www.thebatteryterminal.com/TechTalk_Batteries_on_Concrete.htm)" CreationDate="2011-01-10T03:10:10.730" UserId="2118" />
  <row Id="12940" PostId="8822" Text="Are you just looking for something that can drive a 1080p monitor, or are you wanting video MPEG/h.264 processing too? What is your application?" CreationDate="2011-01-10T06:16:03.557" UserId="638" />
  <row Id="12941" PostId="8770" Score="1" Text="If the changes between board revs are substantial enough that it's not useful, you're not committing often enough.  Commit early, commit often!  Use tags to track board revs." CreationDate="2011-01-10T07:20:21.213" UserId="857" />
  <row Id="12942" PostId="8818" Text="If this is true, then why do appliances I own like an old CRT monitor, still continue to work after about 15 years? Surely something like that would be packed with electrolytic capacitors." CreationDate="2011-01-10T08:21:30.830" UserId="2426" />
  <row Id="12943" PostId="8811" Text="@Kellenjb, SeeedStudio and a few other places. 2-layer FR4, green soldermask (+$10 for red/blue/yellow soldermask), silkscreen on both sides, works with 6/6 mil rules. (8/8 for inner layers on 4-layer.)" CreationDate="2011-01-10T10:21:01.880" UserId="1225" />
  <row Id="12944" PostId="3211" Text="I would argue that solderless breadboards are crappy by definition." CreationDate="2011-01-10T11:35:24.010" UserId="1374" />
  <row Id="12945" PostId="8749" Score="1" Text="I don't understand why this gets an up-vote; it gives no information which comes even close to answering the question." CreationDate="2011-01-10T12:14:03.523" UserId="2064" />
  <row Id="12946" PostId="8822" Text="I think a lot of devices respect HDCP DRM, be sure to look that up to make sure it won't break everything." CreationDate="2011-01-10T12:46:51.607" UserId="2344" />
  <row Id="12947" PostId="8833" Text="especially on Bill's [main tesla page](http://amasci.com/tesla/tesla.html)" CreationDate="2011-01-10T12:51:48.243" UserId="2344" />
  <row Id="12948" PostId="8822" Text="Thank you for the quick responses.&#xA;I am not interested in mpeg, just driving a display in HD. My application for this is putting a lot of information on a display at once, hence wanting HD instead of sd. " CreationDate="2011-01-10T12:54:56.797" UserId="2050" />
  <row Id="12949" PostId="8710" Text="yes, I am using the ENC28J60." CreationDate="2011-01-10T13:10:22.873" UserId="1235" />
  <row Id="12950" PostId="7622" Text="Note: I have driven many steppers on breadboards without using diodes (usually because I forget!) and I've never fried my driving circuitry, BUT I ALWAYS include diodes in my final designs." CreationDate="2011-01-10T13:14:22.793" UserId="1235" />
  <row Id="12951" PostId="8747" Text="&quot;nearly every circuit I build fails to work the first time for one reason or another&quot;... perhaps because you are being careless? no offense intended, just sayin' that if you are careful to do everything right the first time you'll save time.  edit: that's not to say that my projects work the first time either :)" CreationDate="2011-01-10T13:23:24.803" UserId="2344" />
  <row Id="12952" PostId="8836" Text="I've tried Alibre too but I think solidworks is significantly better in terms of features available and support/tutorials. That said, Alibre is still the best value out of all of the common 3D packages that I've tried. (excluding Blender of course.)" CreationDate="2011-01-10T13:26:22.930" UserId="2344" />
  <row Id="12953" PostId="8783" Text="no, you should be able to run it with the ICSP cable still plugged in, IF you use Debug mode in MPLAB. Otherwise, if you build the project as Release, you will have to pull the cable out." CreationDate="2011-01-10T13:28:46.593" UserId="2344" />
  <row Id="12954" PostId="8834" Score="2" Text="This is a great question! Although I don't think a PIR sensor would work, as I believe it relies on differences between the average level of infrared light from when there is 'nothing' there, to when there is 'something' there. If your walking, then the average level will be continually changing, and so won't be able to get a point of reference for comparison." CreationDate="2011-01-10T13:53:00.307" UserId="2426" />
  <row Id="12955" PostId="8832" Text="Shouldn't this be a reply to BG100's comment on your other answer?" CreationDate="2011-01-10T14:07:50.307" UserId="2064" />
  <row Id="12956" PostId="8781" Text="Some PortB pins are shared with the ADC. They need to be configured for digital I/O." CreationDate="2011-01-10T14:12:18.380" UserId="305" />
  <row Id="12958" PostId="8834" Score="1" Text="I think this will help a little  http://en.wikipedia.org/wiki/Infrared_camera" CreationDate="2011-01-10T14:25:15.960" UserId="2060" />
  <row Id="12959" PostId="8830" Score="2" Text="What do you need help with?  You listed several questions: Charging a battery from mains, charging a battery with solar power, charging a battery with a diesel generator, switching between the three with a microcontroller, and displaying something on an LCD.  These could all be separate questions.  However, to get the best kinds of answers, you can't just ask &quot;How do I charge a battery from mains power&quot;.  Some description of what you've tried, your budget, and information on the battery chemistry would help you get a usable answer." CreationDate="2011-01-10T14:28:00.310" UserId="857" />
  <row Id="12960" PostId="8830" Score="2" Text="Also, it sounds like you want us to do this problem for you.  We'd love to help, but we're here to help if you get stuck, not to take the project from start to finish." CreationDate="2011-01-10T14:30:03.397" UserId="857" />
  <row Id="12961" PostId="8818" Text="Caps change over time in-circuit. Depending on how much they change (which depends on a lot of factors) and how critical their tolerance is, you may or may not see any failures in a given time frame. Give it long enough and you WILL see problems. For instance when dealing with old arcade machines, the first step with a 30 year old malfunctioning monitor is to replace all (or most) of the caps before trying anything else. That step fixes many problems and makes most other issues tractable. It's all a matter of time-frame." CreationDate="2011-01-10T14:30:38.990" UserId="259" />
  <row Id="12962" PostId="8839" Text="This looks awesome, nice find!" CreationDate="2011-01-10T14:34:59.113" UserId="2344" />
  <row Id="12964" PostId="8824" Score="1" Text="3 meters is not &quot;bulk&quot;. How important is it that it have the extra features on this sample? You could try looking for just simple box tubing.  2&quot;(50mm) by 4&quot;(100mm) rectangular tubing with a 1/8&quot;(3mm) wall is commonly available here." CreationDate="2011-01-10T14:42:18.353" UserId="857" />
  <row Id="12965" PostId="8821" Text="+1 for 'lawyer jibbajabba'.  Fixed formatting for you." CreationDate="2011-01-10T14:45:34.717" UserId="857" />
  <row Id="12966" PostId="8821" Text="Thanks @reemrevnivek! (Note: I sometimes use &lt;sub&gt;&lt;sup&gt;text&lt;/sup&gt;&lt;/sub&gt; to 'hack' in smaller text, but it does look like I messed this one up ;)" CreationDate="2011-01-10T14:54:01.780" UserId="2118" />
  <row Id="12968" PostId="8839" Text="It's used quite a bit in the open source 3D printing community.  Here is just one fantastic example of what it's capable of: http://www.thingiverse.com/thing:1570" CreationDate="2011-01-10T15:02:14.917" UserId="2288" />
  <row Id="12969" PostId="8770" Text="@reemrevnivek: When I wrote &quot;board revs,&quot; I mean releases sent out for fabrication. I can commit more often, but that won't change the differences between releases, though it would allow me to see them in small steps, which could be useful. What system are you using? Is it worthwhile?" CreationDate="2011-01-10T15:07:48.217" UserId="712" />
  <row Id="12970" PostId="8818" Text="... and the type of ageing will even be differet for caps on the shelf with no voltage applied and caps in a circuit that have to take voltage changes and resulting RMS current. I can strongly recommend reading the general applications information of all the major manufacturers as the put a lot of effort in explaining what happens inside of their products." CreationDate="2011-01-10T15:25:13.093" UserId="930" />
  <row Id="12971" PostId="8834" Text="Good! I didn't considered to use Infrared cameras. I'll update the question. Thanks!" CreationDate="2011-01-10T15:54:47.477" UserId="2557" />
  <row Id="12972" PostId="8838" Text="Really good point, also for the above comments!" CreationDate="2011-01-10T15:55:28.210" UserId="2557" />
  <row Id="12973" PostId="8770" Score="1" Text="I'm using SVN, and it is definitely worthwhile. My system is this: I hit the save button, I should proabably make a commit. I follow the changes by reading the commit messages like &quot;Added part X to library&quot; or &quot;Added test pads to I2C and SPI busses.&quot; Releases sent out for fabrication are entirely different, use `svn cp trunk/ tags/releaseX/` to take a snapshot of the release.  You can then diff releaseX/file and releaseY/file if you want to see changes between releases, or you can browse the commit logs and see individual changes.  Branches help modularize the flood of commits." CreationDate="2011-01-10T16:00:59.017" UserId="857" />
  <row Id="12974" PostId="8783" Text="@Isaac That contradicts my experience with MPLAB. If you build it as a release, there is a button in MPLAB that will allow you to release the programmer reset. No cable removal necessary." CreationDate="2011-01-10T16:04:14.713" UserId="638" />
  <row Id="12975" PostId="8808" Text="How does the Loc8tor work?" CreationDate="2011-01-10T16:04:40.077" UserId="2118" />
  <row Id="12976" PostId="8712" Text="I am not discouraging answers on this, but there is an excellent discussion of this in High Speed Digital Design(http://www.amazon.com/High-Speed-Digital-Design-Handbook/dp/0133957241/ref=sr_1_1?ie=UTF8&amp;qid=1294677352&amp;sr=8-1). I would suggest you read through it, it gives you a much better idea of what scope bandwidth also means." CreationDate="2011-01-10T16:37:08.860" UserId="230" />
  <row Id="12977" PostId="8220" Text="I got a decent flame going using an Arduino.  Still want to get a hardware solution going though.  I'll keep you guys posted." CreationDate="2011-01-10T17:00:55.633" UserId="2366" />
  <row Id="12978" PostId="8843" Text="About the thermistor, I doubt it would help with the spike when the motor shuts down? Also, your varistor/capacitor links are exchanged :)" CreationDate="2011-01-10T17:05:13.840" UserId="2560" />
  <row Id="12979" PostId="8843" Text="The varistor looks like a protection for exceptional surges, like lightning? I get a spike each time the fridge starts or stops…" CreationDate="2011-01-10T17:17:18.637" UserId="2560" />
  <row Id="12980" PostId="8220" Text="@Blankasaurus, What is your 'flicker algorithm'?" CreationDate="2011-01-10T17:18:52.537" UserId="2118" />
  <row Id="12981" PostId="8220" Text="Three LEDs with offset sinewaves.  The frequency of the waves gets changed randomly too.(This is also offset)" CreationDate="2011-01-10T17:24:08.680" UserId="2366" />
  <row Id="12982" PostId="8829" Score="1" Text="Various grades and package codes are present in virtually all ICs and can often blur together becoming near-impossible to parse...unless you consult the datasheet; usually sections like &quot;Ordering Information&quot;." CreationDate="2011-01-10T17:33:51.420" UserId="1407" />
  <row Id="12983" PostId="8690" Text="@wallacoloo: I don't know.  Geolocation?" CreationDate="2011-01-10T17:40:00.407" UserId="142" />
  <row Id="12984" PostId="8847" Text="Wouldn't that be a over kill?" CreationDate="2011-01-10T18:09:25.883" UserId="1200" />
  <row Id="12985" PostId="8847" Text="Also I don't have the monies or the xbox." CreationDate="2011-01-10T18:09:54.293" UserId="1200" />
  <row Id="12986" PostId="8847" Text="Maybe.... it's just an idea. I think shape recognition is pretty tricky stuff, and I thought that if the kinetic can do it for you then it will save you a lot of hassle!" CreationDate="2011-01-10T18:14:42.960" UserId="2426" />
  <row Id="12987" PostId="8846" Score="4" Text="This would probably be done on a PC, correct?  If so, it's probably better suited for Stack Overflow.  If you're working with a low-resource embedded device or FPGA and that's the way you want to learn, feel free to keep it here." CreationDate="2011-01-10T18:38:50.020" UserId="857" />
  <row Id="12988" PostId="8822" Text="@hak8or re: a lot of information: Text or images?  " CreationDate="2011-01-10T18:42:48.770" UserId="857" />
  <row Id="12989" PostId="8837" Text="The delays should avoid RMW problems. LATches should be used for output and PORTs should be used for input." CreationDate="2011-01-10T18:59:22.920" UserId="305" />
  <row Id="12990" PostId="8815" Text="I'm definitely open to other RF solutions. What I'm not understanding from your recommendation is how the simple RF receivers will determine the location. The robot is about 40 cm wide, if I have an RF receiver on each end, would they be sensitive enough to pick up different signal strengths? Do you have examples of RF receivers that could do that? " CreationDate="2011-01-10T19:05:36.463" UserId="2542" />
  <row Id="12991" PostId="8815" Text="And to be clear, I was able to get the direction from the loc8tor with a set up similar to http://www.youtube.com/watch?v=eJyDqn6rQKE. Now, I am trying to use two readers that don't move instead of a servo." CreationDate="2011-01-10T19:18:27.113" UserId="2542" />
  <row Id="12992" PostId="8822" Text="Just text at first, I would prefer to have the ability for putting in images later." CreationDate="2011-01-10T19:24:31.167" UserId="2050" />
  <row Id="12993" PostId="8808" Text="The Loc8tor is an active RFID reader running at the 2.45GHz ISM frequency. It comes with two powered RFID tags that you put on an object, like a cat's collar. When you turn the Loc8tor on, it gives you an idea of how close you are to the tag by lighting up LEDs and emitting a sound. When you face the direction of the tag, the sounds and lights get stronger." CreationDate="2011-01-10T19:27:17.313" UserId="2542" />
  <row Id="12994" PostId="8848" Text="Are you trying to log GPS data on some mobile device then upload that data via a wireless communications link like Bluetooth or WiFi when the device is within range of a server?" CreationDate="2011-01-10T19:31:30.663" UserId="529" />
  <row Id="12995" PostId="8849" Text="This can be done in a better schematic program and you can upload an image from your computer. This will automatically put it on imgur.com on the SO professional account." CreationDate="2011-01-10T19:37:44.967" UserId="230" />
  <row Id="12996" PostId="8846" Text="@reemrevnivek, This discussion has been had in the past, and in general people have argued that DSP should be on our site, as it does not have a good home anywhere else. " CreationDate="2011-01-10T20:15:06.087" UserId="230" />
  <row Id="12997" PostId="8847" Text="The Kinect is much better for depth perception and 3d modeling of a room. I am not sure it has much help for a problem like this." CreationDate="2011-01-10T20:23:27.547" UserId="319" />
  <row Id="12998" PostId="8846" Score="1" Text="@All of those who voted to close. Express your thoughts here: http://meta.electronics.stackexchange.com/questions/126/does-dsp-fall-into-our-realm-or-stack-overflows-realm" CreationDate="2011-01-10T20:39:43.680" UserId="319" />
  <row Id="12999" PostId="8843" Text="The NTC will limit inrush current when the compressor starts, yes. Once it's &quot;hot&quot; it drops to a low resistance and as you stated won't likely help much on turn-off." CreationDate="2011-01-10T20:47:48.317" UserId="1293" />
  <row Id="13000" PostId="8845" Text="I don't need a detailed view, but just to know if there are big (as a big dog) animals around. But I see the advantages of cameras. I found some howtos explain how to modify cameras to don't filter if. Do you think I can have acceptable results?" CreationDate="2011-01-10T21:12:04.203" UserId="2557" />
  <row Id="13003" PostId="8850" Text="*Holy freaking cool!* **+∞**" CreationDate="2011-01-10T21:49:37.823" UserId="2118" />
  <row Id="13004" PostId="8747" Score="1" Text="there are two quite different ways to go, it might help to decide whether you want to build a 'solid state tesla coil', or if you want to go with strictly 1890's tec." CreationDate="2011-01-10T22:20:14.283" UserId="740" />
  <row Id="13005" PostId="8853" Text="whoops, missed that one because I was searching for something more like a TSSOP, less like a res or cap." CreationDate="2011-01-10T22:41:59.250" UserId="1278" />
  <row Id="13006" PostId="8857" Text="Wait wait wait... 120A at 1000V?? That's a LOT of power... unless I'm misreading something." CreationDate="2011-01-10T23:51:31.603" UserId="1225" />
  <row Id="13007" PostId="8857" Text="There are two separate power supplies.  The voltage supply applies (up to) -1000V DC on the substrate.  The current through the substrate is ~2A when the plasma is on.  The current supply provides 120A to the target/plasma.  Typical voltage there is about 20V DC.  I'll update the post to clarify." CreationDate="2011-01-11T00:06:09.657" UserId="2524" />
  <row Id="13008" PostId="8848" Text="I think you'll find a number of modems with integrated GPS that can be configured this way from Sierra Wireless, Enfora, and others... I think you'll find a better approach a server that polls the modem though... I worked for a company with patents in this area...so beware." CreationDate="2011-01-11T00:38:53.437" UserId="2157" />
  <row Id="13009" PostId="8857" Text="Where do you work, @BASnappl? Love the question!" CreationDate="2011-01-11T00:44:24.727" UserId="2118" />
  <row Id="13010" PostId="8860" Text="Added what *I* remember from my IC manufacturing class ;)" CreationDate="2011-01-11T00:56:38.100" UserId="2118" />
  <row Id="13011" PostId="8850" Score="1" Text="Remember that you have to have a HAM radio license to use APRS.  It should be pretty obvious, but just making sure." CreationDate="2011-01-11T00:56:54.467" UserId="1477" />
  <row Id="13012" PostId="8857" Text="Acree Technologies Inc. in Concord, CA.  Lots of sputtering systems.  I'm just an ignorant intern :/" CreationDate="2011-01-11T01:11:21.787" UserId="2524" />
  <row Id="13013" PostId="8865" Text="Thanks for the detailed response.  I'm reading up on the suggestions.  I'll likely post a follow-up question since I'm unfamiliar a lot of this.  However, I'm trying hard to learn!" CreationDate="2011-01-11T01:14:54.480" UserId="2524" />
  <row Id="13014" PostId="8861" Text="The common-mode voltage is the problem with this solution, as far as I understand.  Since the chassis can be at a considerable voltage relative to earth ground, the concern is that breakdown through the meter might be preferable to going through the &quot;resistor&quot; (see image) to ground, thereby burning up the meter." CreationDate="2011-01-11T01:16:46.103" UserId="2524" />
  <row Id="13015" PostId="8863" Score="1" Text="Are you going to be using FSK with a 10 kHz carrier or sending data at 10 kbaud?  What do you mean by RS232-like; baseband or just 1 bit/symbol?" CreationDate="2011-01-11T01:37:30.180" UserId="1407" />
  <row Id="13016" PostId="8860" Score="1" Text="@tyblu: That graph means practically nothing to those of us who haven't taken an IC fab class (doesn't even seem familiar from VLSI)" CreationDate="2011-01-11T01:39:07.697" UserId="1407" />
  <row Id="13017" PostId="8858" Score="2" Text="500MHz analog spectrum analyzers start at about 3X that, which is pretty cheap..." CreationDate="2011-01-11T02:53:52.217" UserId="2118" />
  <row Id="13018" PostId="4121" Text="&quot;roxors soxors&quot;?" CreationDate="2011-01-11T03:10:49.563" UserId="1940" />
  <row Id="13019" PostId="8861" Text="Thats the reason to just use a simple pair of resistors as a voltage divider.  Given the minimal accuracy requirements a simple 1000:1 divider on each input terminal would allow him to use almost any type of earth grounded meter.  You can even get o-scope probes with such dividers built it that will function to very high voltages 25kV+, I would imagine many bench DMM supplies would offer similar probes." CreationDate="2011-01-11T04:31:26.790" UserId="1438" />
  <row Id="13020" PostId="8875" Text="LAMP = Linux, Apache, MySQL, PHP" CreationDate="2011-01-11T05:08:35.477" UserId="2060" />
  <row Id="13021" PostId="8850" Text="can you please name some GPS tracker device in which I can customize server?" CreationDate="2011-01-11T05:34:15.023" UserId="2563" />
  <row Id="13022" PostId="8865" Text="What's your take on high voltage probes? Are they unsuitable due to the potential for large common-mode voltage? What about isolation transformers for bench meters?" CreationDate="2011-01-11T05:38:52.047" UserId="638" />
  <row Id="13023" PostId="8852" Text="Umm.. that would be the process I think. But I am apprehensive about one thing though. My camera takes 640x480 resolution videos at 15 fps. Will my computer be able to step through that much of data in real time?" CreationDate="2011-01-11T05:43:59.127" UserId="1200" />
  <row Id="13024" PostId="8847" Text="Also I really want to learn all this stuff." CreationDate="2011-01-11T05:44:34.400" UserId="1200" />
  <row Id="13025" PostId="8860" Text="@NickT, A manufacturing window within which transistors fall. Variations in the (at least) 2 doping stages make the 2 types of transistors either 'fast' or 'slow'. Will clarify edit when brain is less fuzzy." CreationDate="2011-01-11T05:57:29.433" UserId="2118" />
  <row Id="13026" PostId="8852" Text="@Rick_2047 I do have to ask if you really need the 15 fps? How fast can the symbols be put on the white board? If 1-2 seconds of latency after the symbol is being drawn then you could easily just use 1 frame per second." CreationDate="2011-01-11T06:12:29.157" UserId="319" />
  <row Id="13027" PostId="8852" Text="@Rick_2047 However, you have to remember that the process I have described is mostly comparisons on integers, booleans, and longs. A computer is probably able to do this much faster then it can do some of the more complicated methods of edge detection." CreationDate="2011-01-11T06:13:53.620" UserId="319" />
  <row Id="13028" PostId="8852" Text="umm... maybe I can do some trial and error to guess what will be the optimal fps." CreationDate="2011-01-11T06:15:04.177" UserId="1200" />
  <row Id="13029" PostId="8879" Text="Range is not expected to be more than 1km at this point, so that shouldn't be a problem. The Arduino will be logging to a microSD card as well. So all data will be captured in a higher resolution than intended to be transmitted. I also have thought about two servo motors on a directional antenna, but that will be a second stage for the project. More interested to understand whether it's possible and whether the range will still at least be acceptable up to the 50mW versions transmit power. " CreationDate="2011-01-11T06:24:36.370" UserId="2568" />
  <row Id="13030" PostId="8706" Text="@ThomasO, [Here's an 0805 10V (21c/3000; $1.05/1).](http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=587-1958-2-ND) Not sure about pros &amp; cons of 0805 vs 1206, but 10V is definitely better than 6.3V. Are you going to be able to test the microphonics? Sounds interesting..." CreationDate="2011-01-11T06:30:37.787" UserId="2118" />
  <row Id="13031" PostId="8863" Text="Is it coax, or something else?" CreationDate="2011-01-11T07:05:35.493" UserId="2118" />
  <row Id="13032" PostId="8808" Text="I mean, how does it know the tag's direction? It must use either a directional antenna or two omni's with either phase or power comparison. Sounds very interesting." CreationDate="2011-01-11T07:30:06.853" UserId="2118" />
  <row Id="13033" PostId="8871" Text="There are green/yellow wires and the plug should have 3 prongs, but I have to get back behind it to measure anything. As for the speakers, they are near-field monitors each with their internal amp/alimentation so I'm not sure what I can do to them; the clack most probably comes from the signal wire because they only happen when they are plugged to my laptop; the desktop computer must have a better ground connexion than the laptop's power brick." CreationDate="2011-01-11T08:30:38.200" UserId="2560" />
  <row Id="13034" PostId="8824" Text="Well, 3 or 6 m are common lengths of stock around here, the main point was that I didn't want 100 mm pieces. The main features needed are: rails for PCBs and holes to screw the ends on." CreationDate="2011-01-11T09:07:06.030" UserId="1675" />
  <row Id="13035" PostId="8885" Text="Shit, that is exactly like one of my ideas (haven't started working on it). Are you blogging about it or releasing something?" CreationDate="2011-01-11T10:47:41.707" UserId="1200" />
  <row Id="13036" PostId="8885" Score="1" Text="I did something similar with photo diodes, and you are on the right track I think. you may also want to check out LMR (http://letsmakerobots.com) they have lots of good info about your sharp IR." CreationDate="2011-01-11T11:20:15.373" UserId="2060" />
  <row Id="13037" PostId="8848" Text="@coure06 I don't think there is enough info for a complete answer, what are you looking for? are you looking  to make your own tracker or do you want an out of the box solution? Your question is still very vague." CreationDate="2011-01-11T11:29:21.250" UserId="2060" />
  <row Id="13038" PostId="8885" Score="2" Text="Exact sensor model please + link to datasheet." CreationDate="2011-01-11T12:07:07.183" UserId="2062" />
  <row Id="13039" PostId="8706" Text="@tyblu, It's nice, but quite expensive (twice the price) and it seems I need to order min. 3000. Also, it would be bad to depend on a single capacitor manufacturer. There are several suppliers for 22u/6.3V caps." CreationDate="2011-01-11T13:22:57.013" UserId="1225" />
  <row Id="13040" PostId="8706" Text="@ThomasO, Are you designing for the military or Apple? Replacing this part would be trivial if the original manufacturer went kaput." CreationDate="2011-01-11T13:46:39.967" UserId="2118" />
  <row Id="13041" PostId="8706" Text="@tyblu, It's for a product which may sell thousands or just 10. But it's not military rated in any way, only -40 to +70 degrees C, maximum." CreationDate="2011-01-11T13:49:00.433" UserId="1225" />
  <row Id="13042" PostId="8886" Text="Thermographic cameras exists and are widely used: http://en.wikipedia.org/wiki/Thermographic_camera . I found a solution here http://www.embedds.com/interactive-diy-infrared-and-ultrasonic-scanner/ , but the range is really little (21 inches = 0.5 meters)" CreationDate="2011-01-11T13:57:27.653" UserId="2557" />
  <row Id="13043" PostId="8886" Text="@tmow - yes, but that's a camera, not a radar." CreationDate="2011-01-11T14:19:25.337" UserId="2575" />
  <row Id="13044" PostId="8881" Text="@Joby neat I'll have to try this out sometime, but those \ should probably be \\ through right? or does puts actually recognize those entire strings as individual escape codes? I'm used to think of escape codes as a backslash followed by one character..." CreationDate="2011-01-11T14:59:51.437" UserId="771" />
  <row Id="13046" PostId="8881" Score="1" Text="actually, never mind, I see you are using the octal flavor of escape codes and the emitting the escape &lt;ESC&gt; character (0x1B = 033 = 27) as a prefix" CreationDate="2011-01-11T15:06:22.927" UserId="771" />
  <row Id="13047" PostId="8867" Text="I've been trying to determine if this lumped model is adequate for this, vs. a distributed model (where you divide the RLGC network into much smaller serialized sections).  G is supposedly hundreds of megaohms even at 10km (over 5 mm of insulation)" CreationDate="2011-01-11T15:12:23.300" UserId="1270" />
  <row Id="13048" PostId="8886" Text="@Vilx the second it's a radar/sonar and it's not a camera. Here there is another potentially good idea http://hackaday.com/2009/07/01/poor-mans-thermographic-camera/ , but I cannot find much details about it." CreationDate="2011-01-11T15:14:35.293" UserId="2557" />
  <row Id="13049" PostId="8891" Score="1" Text="He says that the iron has flaked off, which if is the case, a file isn't going to harm it much more, and should help for short durations.  True, using a file near any tip that still has it's iron coating is flatly wrong, but in this case..." CreationDate="2011-01-11T15:19:00.290" UserId="1407" />
  <row Id="13050" PostId="8867" Text="My main concern at this point is the square wave shape of the ASK signal. I'm not sure if I can just ignore those relatively fast transitions or not. I remember horrible ringing from observing this stuff years ago... but I'm guessing that was more likely due to very poor impedance matching." CreationDate="2011-01-11T15:19:14.627" UserId="1270" />
  <row Id="13051" PostId="8886" Text="@tmow - OK then. :) I just thought that you wanted something with a 360 degree view, and realistically mountable on your backpack or something. :P As for the second idea - looks like it just measures lots of points for temperature by moving the thermometer around, so it's not a real-time solution." CreationDate="2011-01-11T15:22:40.357" UserId="2575" />
  <row Id="13052" PostId="8886" Text="@Vilx you are right, I'm agree, but indeed I'm looking for a real and realistic solution if any :-) to re-invent the wheel there is time... In fact it's why I came here to post the question." CreationDate="2011-01-11T15:30:39.403" UserId="2557" />
  <row Id="13053" PostId="8885" Text="@Bars - Most all of the Sharp IR sensors have nearly the same datasheets, just different numbers throughout. The lessons learned should be the same." CreationDate="2011-01-11T15:31:43.303" UserId="857" />
  <row Id="13054" PostId="8886" Text="@tmow - the thermometer gave me an idea - check update." CreationDate="2011-01-11T15:36:56.137" UserId="2575" />
  <row Id="13055" PostId="8891" Score="2" Text="Nope, he says that it's flaked off next to the catalyst, so the tip is probably just covered in oxide. For the record I've had exactly the same problem with exactly the same iron (from the looks of it) and I fixed it by scrubbing the tip with a brass wire brush. If I'm reading it wrong and the coating on the tip is flaking off, then file away and get a new tip that you don't abuse." CreationDate="2011-01-11T15:37:41.520" UserId="1675" />
  <row Id="13056" PostId="8891" Score="1" Text="Never use a file? or Never use a file on a decent tip?" CreationDate="2011-01-11T15:41:20.783" UserId="2426" />
  <row Id="13057" PostId="8834" Score="1" Text="Will there be a third question for sensing undead creatures like zombies?  That should probably be #1 on the priority list." CreationDate="2011-01-11T15:50:25.713" UserId="857" />
  <row Id="13058" PostId="8834" Text="It will be very hard to detect moving creatures if the camera itself is moving (ie, you're walking).  Would you be interested in a stationary system that you can permanently locate in the wood to know if there are things in there before you enter? " CreationDate="2011-01-11T15:53:43.013" UserId="857" />
  <row Id="13059" PostId="8580" Text="Have you tried using a regulated (lab) PSU or batteries instead of your &quot;normal&quot; PSU on otherwise identical hardware? Divide and conquer." CreationDate="2011-01-11T15:55:42.963" UserId="883" />
  <row Id="13060" PostId="8808" Text="I would like to know too, tyblu. I had assumed it was a directional antenna. " CreationDate="2011-01-11T15:56:37.287" UserId="2542" />
  <row Id="13061" PostId="8845" Text="@tmow - Depends on how you define 'acceptable' and 'modify'.  If the results were excellent and the process was easy, there would be no market for the expensive equipment Nick mentioned.  The only way to know whether your camera and modifications will be acceptable is to try it." CreationDate="2011-01-11T15:56:40.420" UserId="857" />
  <row Id="13062" PostId="8891" Score="2" Text="@dren.dk FTFQ: &quot;it seems the iron coating on the tip has flaked off completely&quot;" CreationDate="2011-01-11T16:14:14.560" UserId="1407" />
  <row Id="13063" PostId="8867" Text="@darron, I think the lumped model is fine as long as all you care about is what's coming out the other side of the line and not what's going on at points along the way. The infinite series is a useful model for solving the space-time field within the line." CreationDate="2011-01-11T17:06:21.580" UserId="771" />
  <row Id="13064" PostId="8867" Text="@darron, you should be able to comfortably ignore G if it's &gt;&gt; than R in the model. In that case, your losses are going to be primarily due to the effective R-L-C filter evident in the model, at the operating point of your frequency. This will end up looking like a low-pass filter for all intents and purposes. So expect to see some softening of your edges." CreationDate="2011-01-11T17:07:43.030" UserId="771" />
  <row Id="13065" PostId="8867" Text="@darron, check out http://sim.okawa-denshi.jp/en/RLClowkeisan.htm" CreationDate="2011-01-11T17:13:34.677" UserId="771" />
  <row Id="13066" PostId="8888" Score="1" Text="Good catch on the Oreos, I would have missed that.  Basically, with the Sharp sensors, you get what you pay for.  I have found that oversampling then averaging is the best approach.  If you are trying to generate a map, then you may want to step up to some higher-quality sensors as your budget allows." CreationDate="2011-01-11T17:16:41.853" UserId="1477" />
  <row Id="13067" PostId="8899" Text="What is the chip?" CreationDate="2011-01-11T17:51:49.963" UserId="305" />
  <row Id="13068" PostId="8891" Score="1" Text="What is file? :-D" CreationDate="2011-01-11T18:03:34.467" UserId="2062" />
  <row Id="13069" PostId="8630" Score="1" Text="Some other candidates are power ICs, transistors, pots and switches. The latter two also cause stress when they're turned or pushed. I have a few boards where I've marked &quot;dead&quot; tracks that are probably caused by some of these.." CreationDate="2011-01-11T18:10:19.390" UserId="883" />
  <row Id="13070" PostId="8621" Score="1" Text="This sounds like something that ought to be submitted to Mythbusters :)" CreationDate="2011-01-11T18:11:22.337" UserId="883" />
  <row Id="13071" PostId="8891" Text="@BarsMonster Here's the wikipedia page for a file: http://en.wikipedia.org/wiki/File_%28tool%29" CreationDate="2011-01-11T18:22:26.873" UserId="638" />
  <row Id="13072" PostId="8899" Text="@Leon Heller - the Chipcon CC1110" CreationDate="2011-01-11T18:41:24.820" UserId="566" />
  <row Id="13073" PostId="8902" Text="Why does he need higher efficiency?" CreationDate="2011-01-11T19:11:15.697" UserId="857" />
  <row Id="13074" PostId="8885" Text="@Rick_2047 I've considered blogging about my experiences with the Sharp IR - I might do a post here once I get to the bottom of it.  @BarsMonster I'm using the 2Y0A21." CreationDate="2011-01-11T19:15:14.010" UserId="2573" />
  <row Id="13075" PostId="8888" Text="Not sure what you mean about FFT and DSO, I assume something to do with oscilloscopes? I'm definitely within my sensors range, and I opted for the lookup table over the linearization, as my poor maths let me down with the linearize function. I've just ordered a pack of Oreos, so I'll let you know how I get on!" CreationDate="2011-01-11T19:19:45.893" UserId="2573" />
  <row Id="13076" PostId="8888" Text="@mjcarroll What other sensors would you recommend, I haven't come across any other than the Sharps." CreationDate="2011-01-11T19:20:32.973" UserId="2573" />
  <row Id="13077" PostId="8893" Text="It's the 2Y0A21 that I'm using, and I built a lookup table rather than use a function.  I'm also ignoring values towards the far end of the range. I'm an electronics newb, so don't have a lot of capacitors knocking about; I bought a mixed bag from Maplin, but most of the ceramic ones don't have a value printed on, just some random numbers. I've got some 10uF electrolytic (I think? They look like tiny cans of pop?) caps, so I'll try soldering one of those on, and if it makes no difference I'll try to source some of the other ones you mention.  I'll also try twisting the cables together. Thanks!" CreationDate="2011-01-11T19:27:22.543" UserId="2573" />
  <row Id="13078" PostId="8905" Text="I am using a lithium polymer pack, no chance of them sticking a battery in that.  Also part you linked to seems to boost to 3.3v I am trying to get to 15v from 3v-4v" CreationDate="2011-01-11T19:58:22.473" UserId="2115" />
  <row Id="13079" PostId="8902" Text="erm figure 12 refers to the test setup where Vcc is targeted at 5v, this is a configurable boost regulator." CreationDate="2011-01-11T20:03:04.077" UserId="2115" />
  <row Id="13080" PostId="8885" Text="@littlecharva I am not just interested in sharp IR, I am interested in the project as a whole. As I said this is exactly what I had written in my wish list of projects." CreationDate="2011-01-11T20:13:26.103" UserId="1200" />
  <row Id="13081" PostId="8905" Text="I think the maximum voltage boost you could get out of the LT1307 is about 4x; as the SW duty cycle tops out at about 75%." CreationDate="2011-01-11T20:21:06.733" UserId="1407" />
  <row Id="13082" PostId="8898" Text="Out of curiosity, what's your 15 V rail power?" CreationDate="2011-01-11T20:21:46.297" UserId="1407" />
  <row Id="13083" PostId="8893" Text="The ceramic caps in a mixed bag will probably be less than 1uF.  Electrolytics and other through-holes aren't as good at filtering high frequency signals as ceramic surface-mount caps, the inductance of the leads starts to make a difference at high frequencies.   " CreationDate="2011-01-11T20:23:16.720" UserId="857" />
  <row Id="13084" PostId="8893" Text="By the way, make sure that you get the polarity right; the negative terminal (often has a stripe) should be connected to ground.  If you keep the cap reverse biased for too long, it can overheat and even explode." CreationDate="2011-01-11T20:24:08.030" UserId="857" />
  <row Id="13085" PostId="8905" Text="A pack?  Sorry, I misread your question - my brain said 'coin'.  However, you're incorrect about the 3V3 output- The part is configured with a resistor divider connected to the FB pin, the voltage is Vout = 1.22*(1+R1/R2).  The example circuit shows the use of a 1.02M and 604k resistor to get 3.3V, you could set these values to, for example, 920k and 87k to get 15.6V." CreationDate="2011-01-11T20:32:51.833" UserId="857" />
  <row Id="13086" PostId="8741" Text="It lasts until the fan is so clogged up with dust and hair it can't turn anymore?  Also, I read that fans should always be used to blow cool air into a chassis rather than suck hot air out, so that the fan itself is operating at a lower temperature, for longer life." CreationDate="2011-01-11T20:45:34.890" UserId="142" />
  <row Id="13087" PostId="8747" Text="I built one, but we eventually decided to condemn it because it was arcing and blowing breakers." CreationDate="2011-01-11T20:49:18.613" UserId="142" />
  <row Id="13088" PostId="8731" Text="Maybe this could inspire you? http://www.youtube.com/watch?v=Q0OTX4IwSOo" CreationDate="2011-01-11T20:59:10.493" UserId="142" />
  <row Id="13089" PostId="4121" Text="It's a US computer enthusiast idiom.  It means &quot;this is great.&quot;" CreationDate="2011-01-11T21:18:22.377" UserId="374" />
  <row Id="13090" PostId="8824" Text="Why can't you just call up the company and ask how much X' of  extrusion costs?" CreationDate="2011-01-11T21:51:34.253" UserId="1407" />
  <row Id="13091" PostId="8905" Text="@reem: Am I reading the maximum duty cycle wrong?  I don't think you can endlessly increase the voltage by just adjusting the feedback divider; there's a maximum multiplication you can get out of it.  The max SW current * input voltage will also limit the power you can kick out." CreationDate="2011-01-11T21:56:59.727" UserId="1407" />
  <row Id="13092" PostId="8814" Text="You say, &quot;wait a while, then test&quot;. Every 5 minutes? Every 30? Also, do I need to unplug from the charger, plug into the system, load it, and then test? If I over-charge it is a problem after roughly ____ minutes?" CreationDate="2011-01-11T22:07:39.187" UserId="1774" />
  <row Id="13094" PostId="8905" Text="@Nick - With respect to the maximum power, the OP was working with a 3-4V battery, and the switch current has a normal maximum of 600mA.  If the battery was discharged, 3V*.6A*(3/15 current division)*75% efficiency is about 270mA, which is about what the OP wanted.  600mA is probably more than the battery pack can sustain anyways.  If they need more, they'll need to move away from the single-cell oriented supplies to something more powerful, possibly with an external switch. " CreationDate="2011-01-11T22:44:53.860" UserId="857" />
  <row Id="13095" PostId="8814" Text="@mankoff, Wait 'til it's supposed to be done under ideal conditions (1Ah in = 1Ah stored), test then and every 15 minutes thereafter until it's finished. How are you testing it? I use a 30W bulb at work, but make mistakes pretty often due to the variety of brands, ages, and electrolyte concentrations (not the sealed type)." CreationDate="2011-01-11T22:49:01.363" UserId="2118" />
  <row Id="13096" PostId="8814" Text="I'll test it by hooking it up to the motor it drives and turning the motor on, then checking the V. Also, I got the manual charger because it was cheap and I'm on a budget... Perhaps not worth the savings if it'll be problematic." CreationDate="2011-01-11T22:57:09.627" UserId="1774" />
  <row Id="13097" PostId="8908" Text="Why would you want to roll your own?  We need to know your design goals (size, cost, educational value, precision, reliability, simplicity) to help you make a decision." CreationDate="2011-01-11T23:04:11.077" UserId="857" />
  <row Id="13098" PostId="8814" Text="@mankoff, Decent size motor will certainly do the job. Ensure feedback from the motor doesn't artificially boost the measured terminal voltages (use protection diodes)." CreationDate="2011-01-11T23:04:24.990" UserId="2118" />
  <row Id="13099" PostId="8905" Text="@Nick - With respect to the current, you're right, for a simple converter the output voltage is limited by the duty cycle to Vo/Vin = 1/(1-D), or about 12V in this case. However, other topologies can increase the voltage further.  The datasheet has schematics for converters with Vout=16-24V, Vout up to 85V (!), and capacitor doublers and tripplers that extend the maximum voltage even higher.  These will all decrease the current available, so I've edited my part number from the LT1307 to the LT1308 :)" CreationDate="2011-01-11T23:13:04.130" UserId="857" />
  <row Id="13101" PostId="8897" Text="No problem with a simple protocol. As the data will all be logged to an SD card, the radio link is to provide some information to people on the ground as to what's happening. As such, losing some data isn't critical. It will also help with having a simplified GPS lat/long being sent to know last locations the rocket transmitted from and aid with its recovery. I'm more interested in whether the Zigbee will provide the range of a one way high to a low power receiver and that the two devices will communicate this way." CreationDate="2011-01-11T23:20:56.860" UserId="2568" />
  <row Id="13103" PostId="8908" Text="I thought it'd be simple enough that rolling your own would actually be cheaper..." CreationDate="2011-01-11T23:26:40.660" UserId="1688" />
  <row Id="13104" PostId="8881" Text="So.. what redraws the screen, in this case? Does the shell just do intelligent echoing?" CreationDate="2011-01-11T23:29:52.687" UserId="2118" />
  <row Id="13105" PostId="8811" Text="your not tossing a 2.4Ghz RF transceiver (bluetooth) on a 2 layer FR-4 board and getting an operational device, at least not unless you really know what your doing and using specific types of antennas " CreationDate="2011-01-11T23:41:52.447" UserId="1438" />
  <row Id="13106" PostId="8881" Text="A real VT100 display would have a framebuffer being continuously redrawn. On a PC, terminal emulators emulate terminals and do the same thing" CreationDate="2011-01-11T23:43:42.757" UserId="566" />
  <row Id="13107" PostId="8807" Text="What is &quot;large amounts&quot; unless you talking 10,000+ the NRE costs will be significant.  You need FCC/CE certification, your doing RF design at 2.4Ghz, etc.  You could drop $100,000 pretty fast if you had an engineering firm do the design work." CreationDate="2011-01-11T23:44:42.180" UserId="1438" />
  <row Id="13108" PostId="8919" Text="10nF?  That's new for me - I use .1uF/100nF 0603s everywhere, and parallel two where that's not enough.  What kind of clock speeds are you designing for?  " CreationDate="2011-01-11T23:49:00.587" UserId="857" />
  <row Id="13109" PostId="8811" Text="@Mark I use a bluetooth module that has the antenna on board. In a situation like that a 2 layer is just fine. But yes, a bluetooth ic with your own antenna is a bit more difficult to do on 2 layers." CreationDate="2011-01-11T23:53:01.887" UserId="319" />
  <row Id="13110" PostId="8910" Text="Thanks for you answers." CreationDate="2011-01-11T23:57:41.053" UserId="2571" />
  <row Id="13111" PostId="8834" Text="True infrared cameras, actually called bolometers, are very expensive, companies like RedShift and FLIR build modules.  The only even moderately cheap ($x00) modules are also quite low resolution, 80x60 ish.  All the cheap consumer cameras that are sold are just CMOS cameras which are sensitive to near-IR which isn't really heat and needs illumination from IR diodes to see very far/well.  Just take a marshal arts class and buy some pepper spray." CreationDate="2011-01-11T23:58:39.257" UserId="1438" />
  <row Id="13112" PostId="8919" Text="Often system clocks of 24-25Mhz (digital audio) with USB/Ethernet interfaces (higher clocks).  0.1uF ceramic caps have fairly high impedance over 100Mhz or so and to limit emissions to pass FCC you'd need cover to 250-300Mhz or so.  I've had to use 10nF caps even with PIC microcontollers with Ethernet on board though." CreationDate="2011-01-12T00:05:19.060" UserId="1438" />
  <row Id="13114" PostId="8897" Text="Problem with simple protocol: After further reading, the XBee doesn't appear to allow it." CreationDate="2011-01-12T00:13:45.807" UserId="857" />
  <row Id="13115" PostId="8811" Text="@kellenjb Yes obviously if your using a module thats fine.  If your just plopping a device on the board, thats the issue.  One of the reasons many use things like bluetooth in a module form is that RF PCB substrate is expensive and so they only want to use it for sections of the circuit that require it.  You may be able to get away with in with FR-4 if your were very careful in your PCB stack up and had the manufacturer impedance match the traces in post processing.  Doing that with a 2 layer board would be near impossible unless the PCB fab could make strange board thicknesses." CreationDate="2011-01-12T00:16:36.103" UserId="1438" />
  <row Id="13116" PostId="8811" Text="I should probably add that FR4 is just a designation, and there are many materials that fall under that designation.  You can get substrates that are still &quot;FR4&quot; that will operate up to 10-15Ghz but the stuff cheap PCB fabs use by default (what i'm referring to in this context) and call FR4 is generally good up to about 1Ghz depending on trace length.  The dielectric losses and propagation delays for frequencies past that get unmanageable.  " CreationDate="2011-01-12T00:24:04.697" UserId="1438" />
  <row Id="13119" PostId="8910" Text="@Joby - No, you can program in custom firmware; see section 8.5 of the [manual](http://www.sparkfun.com/datasheets/Wireless/Zigbee/XBee-2.5-Manual.pdf).  The XBee modules actually have some GPIO and A/D functionality on them.  However, I think you're pretty much on your own when it comes to putting together this firmware." CreationDate="2011-01-12T00:35:15.860" UserId="857" />
  <row Id="13122" PostId="8811" Text="@Thomas O Places like SeeedStudio, batchpcb, etc. are not really designed for the production stage of a product." CreationDate="2011-01-12T00:39:27.700" UserId="319" />
  <row Id="13123" PostId="8811" Text="@Kellenjb - I also disagree with the $300-$400 number, but only because it implies that prototyping will be this expensive.  To get a few boards for testing will probably be much less. (&lt;100, or much less if you're willing to wait for BatchPCB/Dorkbot/Seeedstudio etc.), but I'd agree that several panels will probably run about that much.   Try 4PCB's $33 each (2 layer) or $66 (4 layer) deals as well." CreationDate="2011-01-12T00:42:10.927" UserId="857" />
  <row Id="13124" PostId="8811" Text="@reemrevnivek he said he is specifically looking for a price for manufacturing in large quantities. If anything I should have given numbers for larger quantities." CreationDate="2011-01-12T00:46:15.463" UserId="319" />
  <row Id="13125" PostId="8811" Text="@Kellenjb - My thoughts exactly!  In my opinion/line of work, &lt;100 is not 'large quantities'.   If you can estimate the cost as being always $300-$400, what you're getting is the setup costs, and that's not a useful metric.  I'd go with a number closer to $0.15 per square inch for large quantities of 2-layer boards, which seems to be fairly consistent from manufacturer to manufacturer.  You'll need to buy &gt;$1,000 worth of PCB for prices in that range, i.e. the setup/shipping costs will have to be removed from the equation." CreationDate="2011-01-12T00:52:45.117" UserId="857" />
  <row Id="13126" PostId="8807" Text="How much is &quot;large amounts&quot;? This could be interpreted as 50, 500, 5,000, or 50,000+, depending on who you talk to." CreationDate="2011-01-12T00:55:03.837" UserId="857" />
  <row Id="13127" PostId="8919" Text="@Mark, from what I've seen, package inductance pretty much dominates high frequency response, making the capacitor value almost meaningless.  I've also seen studies showing the LC resonance from using multiple different cap values leads to overall worse bypassing over the entire frequency range, which is why some EMC guys recommend just sticking to one value, 0.1 or 0.01 all over the board (other than bulk) and that mixing caps (such as 0.01 with 0.1 should actually be avoided) - see Henry Ott's book.  But, have you failed EMC testing before, and then passed after changing a cap to a 10nF?" CreationDate="2011-01-12T01:10:35.583" UserId="2377" />
  <row Id="13128" PostId="8908" Score="1" Text="If you have all the required components onboard already (maybe you've got a quad opamp with an unused quadrant?), it *might* be cheaper.  The cost you just spent by thinking about it probably exceeded the savings, though. " CreationDate="2011-01-12T01:26:34.633" UserId="857" />
  <row Id="13129" PostId="8919" Text="@bt2 I've failed FCC testing using just 0.1uF 0603 capacitors and then passed it adding 0402 10nF caps to all IC power pins.  This was a PIC18F97J60 which has a current mode ethernet transceiver, same operation at enc28j60 which is known to have EMI issues at ~200Mhz.  This particular board also had a DSP and 2 stereo class D amplifiers that were rated at 18W a channel (72W total) among other analog audio ins and outs.  You are correct that package is critically important but capacitance is not irrelevant.  There would have to be able evidence to discount years of use of decade capacitors.    " CreationDate="2011-01-12T01:38:30.010" UserId="1438" />
  <row Id="13130" PostId="8910" Text="for firmware help, TI would be the resource to check out http://focus.ti.com/analog/docs/rfifcomponentshome.tsp?familyId=367&amp;contentType=4" CreationDate="2011-01-12T02:23:40.817" UserId="2060" />
  <row Id="13131" PostId="8811" Text="Eh? Is it really that hard to do RF on FR-4? 63 mil microstrip into an inverted f antenna, easy peasy?" CreationDate="2011-01-12T02:40:04.287" UserId="2183" />
  <row Id="13132" PostId="8718" Text="@lyndon, Thoughts on Jung's newest edition, [Op Amp Applications Handbook ](http://www.amazon.com/Amp-Applications-Handbook-Analog-Devices/dp/0750678445/ref=lh_ni_t_)?" CreationDate="2011-01-12T02:52:17.963" UserId="2118" />
  <row Id="13134" PostId="8902" Text="@reemrevnivek He might not needed, but as efficiency is not stated anywhere, it might be quite horrible." CreationDate="2011-01-12T03:11:54.713" UserId="2062" />
  <row Id="13135" PostId="8919" Text="@Mark, interesting, thanks for letting me know.  I'm actually working with that exact PIC at the moment, though most likely won't be going through FCC testing. Years past, decade capacitance worked for low frequency design, but in high speed digital designs using it can be like playing Russian roulette.  The resonances between the different value caps produce impedance spikes.  If some clock harmonics should fall on or near the frequency of these spikes, the power to ground noise can actually increase.  Please check out this study, or at least the summary  " CreationDate="2011-01-12T03:12:21.407" UserId="2377" />
  <row Id="13136" PostId="8919" Text="http://www.interferencetechnology.com/uploads/media/ITEM_01.pdf" CreationDate="2011-01-12T03:12:42.857" UserId="2377" />
  <row Id="13137" PostId="8888" Text="@littlecharva Aside from the advice given in reemrevnivek's answer, I would say try some of the ultrasonic rangefinders as well.  You may find that they work better, depending on the application.  If you can afford it, a laser range finder is always a good option (1.1k cost, though).  There has also been a lot of cool research into the Microsoft Kinect, but that would exclude a pure-Arduino solution." CreationDate="2011-01-12T04:09:14.133" UserId="1477" />
  <row Id="13138" PostId="8925" Text="lol I had code for a 16bit shift register for MSP430, but cant find it as well" CreationDate="2011-01-12T04:57:16.140" UserId="2060" />
  <row Id="13139" PostId="8811" Text="@krapht yep that would work, assuming that a PCB antenna works for the application and the chip to antenna distance can be minimized.  Given that we have no idea if those requirement can be met we don't really know.  And again, we don't know what 'FR-4' material we're talking about..." CreationDate="2011-01-12T05:23:45.363" UserId="1438" />
  <row Id="13140" PostId="8919" Text="@bt2 I read the study but frankly it seems that a LOT of variables in real PCB designs were left out, i mean we don't even know what package the capacitors were in or the impedance characteristics of the SMA connectors.  Vias were mentioned multiple times, how many were on the test board? where? what size?  Honestly, I'll continue to be safe rather than sorry, the costs of repeat FCC testing, re-spins, and increased time to market continue to be more important driving forces for the areas i work in than sprinkling a few more $0.01 10nF caps around the board is. " CreationDate="2011-01-12T05:46:50.533" UserId="1438" />
  <row Id="13141" PostId="8922" Text="They won't release much info the system because they want us to buy the parts from them at a high price.  They are mostly from Coin op redemption games. I see the same sized motor used on a few different games. If I understand you correctly, I will try one that is a .9 degree six wire the same size and try and get as close as I can with the other specs and give that a try. Thanks" CreationDate="2011-01-12T05:56:07.863" UserId="2579" />
  <row Id="13142" PostId="8824" Text="Because I can't find anyone who has it as raw stock." CreationDate="2011-01-12T07:41:04.300" UserId="1675" />
  <row Id="13143" PostId="8910" Text="@jsolarski so far as I know, the chip in Digi's XBee is a Freescale part running Ember ZNet, not TI" CreationDate="2011-01-12T07:50:38.443" UserId="566" />
  <row Id="13144" PostId="8919" Text="@Mark, he was using 0805 caps for all values.  There are certainly many variables in PCB design, but the only variables Archambeault was changing was the value and number of capacitors.  I think the study, at a minimum, shows inter cap resonance is real, and does cause impedance spikes.  In any case, if something works for you, don't fix what aint broken.  I only wish I had access to unlimited EMC testing resources to test things like this.  I wonder how much your PIC design was improved by the 10nF value or the lower inductance 0402 package, for example.  In any case, good talking to you." CreationDate="2011-01-12T10:22:57.777" UserId="2377" />
  <row Id="13145" PostId="8910" Text="My mistake i thought the Xbee's had CCxxxx chips in them not ember." CreationDate="2011-01-12T10:56:43.120" UserId="2060" />
  <row Id="13146" PostId="8888" Text="I'd read that the ultrasonics weren't as accurate as the Sharps, which is why I avoided them at first.  Laser range finder would be awesome, but out of my budget - although I have read some articles suggesting there might be a &lt;£100 due on the market soon, so I'm keeping me eyes open." CreationDate="2011-01-12T11:13:48.887" UserId="2573" />
  <row Id="13147" PostId="8933" Score="2" Text="I can remember electric kettles that didn't have a switch, they didn't even have a thermostat!" CreationDate="2011-01-12T11:28:00.693" UserId="305" />
  <row Id="13148" PostId="8757" Text="+1 for Python, I use it on the Mac to receive data from my Arduino app and display it in various graphs using TKinter for the user interface." CreationDate="2011-01-12T11:42:15.060" UserId="2573" />
  <row Id="13149" PostId="8937" Text="Not really sure, but you might get a better answer on [electronics.se](http://electronics.stackexchange.com/)." CreationDate="2011-01-12T12:47:14.190" UserId="898" />
  <row Id="13150" PostId="8933" Text="Whoa thanks for the awesome answer, seems this might be out of my league for a little while unless I can find a way to do this mechanically." CreationDate="2011-01-12T13:38:17.567" UserId="2333" />
  <row Id="13151" PostId="8934" Text="Thanks that is great as well but I dont have the parts etc readily available atm. Will keep it in mind though" CreationDate="2011-01-12T13:41:25.363" UserId="2333" />
  <row Id="13152" PostId="8928" Text="Do you specialize in VHDL? Regarding the UCF why would it be important for working with the Digilent board?" CreationDate="2011-01-12T13:55:16.577" UserId="444" />
  <row Id="13153" PostId="6101" Text="Is it that easy to find microcontrollers supporting Java? I'd think this would limit the choices considerably. And what are your experiences about performance penalty (since in uCs you usually wouldn't have JIT)? What about the impact of GC unpredictability in realtime systems?" CreationDate="2011-01-12T14:39:23.263" UserId="1078" />
  <row Id="13154" PostId="8942" Text="except that I would really prefer a method for doing this with analog components.  Perhaps my question should be retitled to ask for a tutorial, rather than open-source, which implies code to some extent." CreationDate="2011-01-12T14:53:34.340" UserId="2288" />
  <row Id="13155" PostId="8940" Text="What kinds of sounds do you want to make?  Simple tones are fairly easy, complex tones (Like I imagine a laser gun sound effect to sound like) slightly more difficult, but speech or music will be next to impossible.  Can you provide a link to a laser gun sound?" CreationDate="2011-01-12T15:23:45.347" UserId="857" />
  <row Id="13156" PostId="8942" Text="@Dave: ok, I've added an option using analog components..." CreationDate="2011-01-12T15:23:55.487" UserId="2426" />
  <row Id="13157" PostId="8940" Text="Also, do you have access to function generators?  That would make prototyping this much easier." CreationDate="2011-01-12T15:24:45.317" UserId="857" />
  <row Id="13158" PostId="8942" Text="@BG100 what are my options for getting the frequencies?  Do I need to find a sample and then do an FFT or something (I have never done one before) on the sound to figure out what the composition of the sound is?  Any tips?" CreationDate="2011-01-12T15:25:55.860" UserId="2288" />
  <row Id="13159" PostId="8940" Text="I believe my Saelig USB scope has a function generator, but then I only have one.  I'll look into it.  I'll see if I can find a laser gun sound, but pretty much &quot;Star Wars Clone Trooper&quot; sums it up.  :)" CreationDate="2011-01-12T15:27:21.317" UserId="2288" />
  <row Id="13160" PostId="8942" Text="I think the easiest thing to do is build your circuit using potentiometers instead of resistors, so that you can easily adjust the frequencies of your circuit... and then you can play around with it and see if you can get something that sounds good." CreationDate="2011-01-12T15:30:40.937" UserId="2426" />
  <row Id="13161" PostId="8941" Text="@fceconel, I have to disagree here, the is no sudden point where C++ becomes acceptable due to system resources, good design practice can keep C++'s footprint where C's footprint is. This results in code with OOP designs that take the same space. Poorly written C can be just as bad." CreationDate="2011-01-12T15:35:50.507" UserId="230" />
  <row Id="13162" PostId="8942" Score="1" Text="When I was younger I had one of these: http://www.quasarelectronics.com/maxitronix/epl300-300-in-1-electronic-project-lab-kit-mx-908.htm and the manual that came with it had some great schematics of circuits that created sound effects with analog components... I can't find a copy of the manual on google though... if you can then it might be worth a look!" CreationDate="2011-01-12T15:37:03.630" UserId="2426" />
  <row Id="13163" PostId="8942" Text="@BG100 I will look around!  thanks for the tip." CreationDate="2011-01-12T15:51:56.823" UserId="2288" />
  <row Id="13164" PostId="8891" Text="I warmed the iron up and doused the tip in flux-cored solder until I was tired of making little solder balls (it just wouldn't wet.) I then tried rubbing the tip with some copper desoldering braid, but it didn't do a thing. So I got out the file, got myself a nice shiny surface, tinned it and made a few joints. With a tinned tip and low heat I had a much easier time of it. I left the tip with a blob of solder on it; but ten minutes later the tip had all but corroded away. +1 for &quot;turn it all the way down so the catalyst is only just glowing.&quot; Now I know." CreationDate="2011-01-12T16:01:02.570" UserId="1633" />
  <row Id="13165" PostId="8903" Score="1" Text="It's an Iroda SolderPro 50, the tips are replaceable, but SGD$15 each. I now know why—if I don't abuse them like I have been, they should last for a couple of years." CreationDate="2011-01-12T16:04:43.703" UserId="1633" />
  <row Id="13166" PostId="8933" Text="You could also consider replacing the boiling sensor (which is probably just a simple mechanical thing) with a sensor set for a temperature just above that of boiling water. Since you can't heat liquid water above boiling (at pressures you'll encounter in the home), and steam will depart the kettle, once the temperature exceeds that of boiling water you know the water is all gone, and you're just burning the kettle. That would keep you mostly safe in the event the arduino did something dumb." CreationDate="2011-01-12T17:15:32.320" UserId="1213" />
  <row Id="13167" PostId="2875" Text="@0x2A31: Then maybe accepting some answers?" CreationDate="2011-01-12T17:24:11.923" UserId="689" />
  <row Id="13168" PostId="6101" Text="@Tim Williscroft - What MCUs are out there that support embedded Java?" CreationDate="2011-01-12T17:36:12.653" UserId="374" />
  <row Id="13169" PostId="8939" Text="I agree. I think the Bus Pirate would be an excellent choice. It is a lot more versatile." CreationDate="2011-01-12T18:09:31.527" UserId="2489" />
  <row Id="13170" PostId="8941" Text="Well, it depends on how big your application is and how much you use certain features that require more space (like templates and exceptions). But personally I'd rather use C than have to limit myself to a restrained C++. But even then you'll have the overhead of a bigger RTL, virtual method thunks, constructor/destructor chain invocation... these effects may be mitigated with careful coding, but then you're losing the main reason for C++ use, abstraction and high level perspective." CreationDate="2011-01-12T18:12:13.037" UserId="1078" />
  <row Id="13171" PostId="8943" Text="thanks for the tip, I'll consider it as I go through my options!" CreationDate="2011-01-12T18:25:28.740" UserId="2288" />
  <row Id="13173" PostId="8925" Score="1" Text="You forgot to include '1' and '0', the two numbers I will need to learn to program a binary computer." CreationDate="2011-01-12T18:41:52.170" UserId="1363" />
  <row Id="13174" PostId="8925" Text="@joeforker, Fortunately we have [mnemonics](http://www.atmel.com/dyn/resources/prod_documents/doc0856.pdf) for even long sequences of 1's and 0's, and furthermore [advanced techniques](http://www.avrfreaks.net/index.php?name=PNphpBB2&amp;file=viewtopic&amp;t=101529) for stringing these mnemonics together! I doesn't get [any better](http://www.atmel.com/dyn/resources/prod_documents/doc1497.pdf) than that. ;)" CreationDate="2011-01-12T18:55:18.760" UserId="2118" />
  <row Id="13175" PostId="8945" Text="[DDS](http://en.wikipedia.org/wiki/Direct_digital_synthesizer) is a standard method of generating various tones. The dsPIC series is suitable for this method with a built-in DAC. Two DDS examples [here](http://webspace.webring.com/people/jl/leon_heller/)." CreationDate="2011-01-12T19:07:33.623" UserId="2118" />
  <row Id="13176" PostId="8120" Text="Just wanted to say that I flew in both directions (with the NXT in my checked luggage) without a hitch." CreationDate="2011-01-12T19:19:45.203" UserId="106" />
  <row Id="13178" PostId="8943" Text="Do check out the TI data sheet (via Wikipedia) - there's a number of example circuits. Ooh, it took me back looking at all that. I think I have one of the chips still - somewhere!" CreationDate="2011-01-12T19:48:04.557" UserId="1750" />
  <row Id="13179" PostId="8928" Score="1" Text="I don't specialize as such - just haven̈́'t studied Verilog. The UCF is the file that describes which pins your ports connect to, as well as clocking demands. Without it, pins are assigned randomly, which won't match the existing board." CreationDate="2011-01-12T20:15:35.163" UserId="1181" />
  <row Id="13180" PostId="8880" Text="Thank you Eric. Do you have any examples of components/projects - preferably for distances ranging from 0.5 to 3 meters - you could point me in the direction on?" CreationDate="2011-01-12T20:30:06.110" UserId="2542" />
  <row Id="13181" PostId="8945" Text="@tyblu thanks!  I'll check it out.  dsPICs are pretty cost effective." CreationDate="2011-01-12T20:31:51.007" UserId="2288" />
  <row Id="13182" PostId="8924" Text="Before I answer, what I'm hearing is that you want to receive input from an SNES controller using an ATTiny2313, is that right? I believe this is an &quot;active&quot; process in that you need to &quot;sample&quot; the controller..." CreationDate="2011-01-12T20:55:39.377" UserId="771" />
  <row Id="13183" PostId="8949" Score="3" Text="Absolutely agree about source control. Commit early, commit often" CreationDate="2011-01-12T21:18:28.320" UserId="566" />
  <row Id="13184" PostId="8947" Text="Unfortunately my project must include the 12 filters." CreationDate="2011-01-12T21:46:33.537" UserId="638" />
  <row Id="13186" PostId="8757" Text="I'll give a second vote to processing, www.processing.org, it's arduino's companion on the computer.  There are lots of examples on the processing website about connecting with an arduino.  you should go check it out.&#xD;&#xA;Jim" CreationDate="2011-01-12T22:51:52.267" UserId="2581" />
  <row Id="13187" PostId="8895" Text="One Explorer dongle amd 1 more XBee to come. &#xD;&#xA;Thanks for your help.&#xD;&#xA;&#xD;&#xA;" CreationDate="2011-01-12T22:55:16.760" UserId="2571" />
  <row Id="13189" PostId="4283" Text="Your software should have a modular design, separating the high-level AI from the low-level motion control, regardless of whether those software components run on separate micros or a single micro. I suppose using separate micros would force that good design principle on the weak-minded. ;)" CreationDate="2011-01-12T23:05:35.230" UserId="1025" />
  <row Id="13190" PostId="8929" Text="Kinda dangerous for reasons mentioned below. Why do you want to do this anyway? What problem are you trying to solve? " CreationDate="2011-01-12T23:30:34.630" UserId="814" />
  <row Id="13191" PostId="8955" Text="I have a negative supply, generated by a buck-boost converter. I want to measure the current through an LED connected to this, which means I'll have to use a current shunt resistor which gives me a negative voltage. I have a potentiometer which outputs a positive voltage. I want to compare the two, without signs." CreationDate="2011-01-12T23:32:42.000" UserId="1225" />
  <row Id="13192" PostId="8955" Text="@Thomas - You can't just connect the potentiometer to the negative supply?" CreationDate="2011-01-12T23:49:31.103" UserId="857" />
  <row Id="13193" PostId="8956" Text="Size is an issue; I'm trying to fit this onto a 1&quot; diameter board, which is realllly small, so I'm not sure about the full wave rectifier. Small signal means low level to me, less than 100mV typically, which makes it difficult to offset." CreationDate="2011-01-12T23:50:28.950" UserId="1225" />
  <row Id="13194" PostId="8955" Text="@reemrevnivek, The negative supply will have a lot of ripple, and it will only be -2V to -3V (any where between the two.) It drives an LED. Either way, I've now got two negative voltages to compare against each other. How do I do that with a +5V and GND supply only?" CreationDate="2011-01-12T23:52:15.327" UserId="1225" />
  <row Id="13195" PostId="8864" Score="1" Text="3um?  I read that the newest Intel process is 32nm - Yes, nanometers!  I understand they probably have a lot of scrap, and at $300 a pop (or $1000 for the extreme series) they can afford to work slow, but I'm not understanding your point here." CreationDate="2011-01-12T23:53:26.780" UserId="857" />
  <row Id="13196" PostId="8954" Text="Without some evidence, I'd be hard pressed to believe that manufacturers would design in adjusting circuitry and take the time to blow fuses. I'd be much more inclined to blame plain old process variation than some sort of chip-hobbling conspiracy.  Also, reducing bias currents is usually a good thing." CreationDate="2011-01-12T23:55:26.373" UserId="857" />
  <row Id="13197" PostId="8957" Text="This is a good and interesting idea... however I'm not sure if a ground-referenced comparator will be able to distinguish between, say, -50mV and 0V (it might even produce an incorrect result.) It should handle +50mV and 0V, though. " CreationDate="2011-01-12T23:58:16.743" UserId="1225" />
  <row Id="13198" PostId="8953" Text="I wrote [quick question guide](http://meta.electronics.stackexchange.com/q/316/2118) that includes a link to common issues in questions, and I think one applies to this: [The XY Problem](http://meta.stackoverflow.com/q/66377/154425)." CreationDate="2011-01-12T23:59:03.983" UserId="2118" />
  <row Id="13200" PostId="8954" Text="It's quick enough to blow a fuse in final test. As for using the same hardware for different performance grades intentionally, this happens, and not just with chips: http://technabob.com/blog/2010/12/27/amd-radeon-hd-6950-upgrade-bios-hack/" CreationDate="2011-01-13T00:24:19.077" UserId="814" />
  <row Id="13201" PostId="8940" Text="The MK113 sound generator seems easier to get than the HT2884: http://store.qkits.com/moreinfo.cfm/MK113  http://www.maplin.co.uk/module.aspx?moduleno=25238 " CreationDate="2011-01-13T00:41:47.517" UserId="1750" />
  <row Id="13202" PostId="8865" Text="@W5VO, High voltage probes sound like a good idea to me, especially for only 5% accuracy specs. Bench meters are generally expensive and are for more accurate readings than handheld DMMs. I'm not familiar with 1kV+ isolation transformers." CreationDate="2011-01-13T00:57:12.723" UserId="2118" />
  <row Id="13203" PostId="8933" Text="Electric kettles are for wimps.  Real kettles sit on a stove top." CreationDate="2011-01-13T00:58:04.180" UserId="1285" />
  <row Id="13205" PostId="8956" Text="You can't fit those circuits onto a board of that size?  If you use one with the resistors all the same value and one other, a DFN op-amp and resistor array is all you need" CreationDate="2011-01-13T01:01:04.603" UserId="1407" />
  <row Id="13206" PostId="8953" Text="What are you trying to do in mathematical terms?  abs(abs(X) - Y)?" CreationDate="2011-01-13T01:02:35.117" UserId="1407" />
  <row Id="13207" PostId="8925" Text="@joe: I *have* programmed using machine code, and in addition to 1's and 0's I use 2-9 and A-F." CreationDate="2011-01-13T01:12:00.207" UserId="1407" />
  <row Id="13208" PostId="8947" Text="@W5VO - Ah, I'd read &quot;non-negotiable&quot; to mean you didn't want to implement the filters due to design/cost/space constraints. Can you take the input to your bar graph part before the filtering?" CreationDate="2011-01-13T01:13:44.930" UserId="857" />
  <row Id="13209" PostId="8940" Text="@Linker3000 thanks for the link!  That looks like an option.  Pretty freakin' huge, but perhaps I can shrink it all down if I can get the IC separately.  promising!" CreationDate="2011-01-13T02:14:51.673" UserId="2288" />
  <row Id="13210" PostId="8951" Text="Nice, TQFP on 0.100&quot; perf board.  Most people would just QQ about that." CreationDate="2011-01-13T04:15:03.890" UserId="1407" />
  <row Id="13211" PostId="8951" Text="@Nick Yeah that guy's a bit crazy: http://elm-chan.org/docs/wire/wiring_e.html . Here's another guy: http://www.flickr.com/photos/oohshiny/3309808873/" CreationDate="2011-01-13T05:36:28.817" UserId="131" />
  <row Id="13212" PostId="8844" Text="*&quot;quick summary&quot;!? Cripes! Nice work!*" CreationDate="2011-01-13T06:31:24.210" UserId="2118" />
  <row Id="13214" PostId="8957" Text="so bias the resistive divider and comparator to some nominal positive voltage so a reading of -50mV difference is really read as (bias - 50mV)(actual math may be a bit more complicated based on the resistive divider), choose the bias such that for expected values the reading will remain positive.  " CreationDate="2011-01-13T07:03:05.223" UserId="1438" />
  <row Id="13215" PostId="8933" Text="Heh i am sure its going to work out easier controlling my stove " CreationDate="2011-01-13T07:12:37.307" UserId="2333" />
  <row Id="13216" PostId="8953" Text="@Nick T: |x| &lt; |y|" CreationDate="2011-01-13T07:53:40.270" UserId="1225" />
  <row Id="13217" PostId="6101" Text="www.ajile.com for starters." CreationDate="2011-01-13T09:41:28.870" UserId="1481" />
  <row Id="13218" PostId="8965" Text="Do you have any idea what you want to use it for, and what language you want to use to program it?" CreationDate="2011-01-13T09:42:32.190" UserId="2426" />
  <row Id="13219" PostId="8968" Text="Yeah, I know what you mean.... do you know what this stuff is called?" CreationDate="2011-01-13T10:21:45.403" UserId="2426" />
  <row Id="13220" PostId="8968" Text="Unfortunately I don't know the name. Or, better, I know the name, but I'm italian, and &quot;our&quot; name can't help you to find it. :-) A colleague suggest to start from http://solutions.3m.com/wps/portal/3M/en_US/Window_Film/Solutions/" CreationDate="2011-01-13T10:46:16.883" UserId="244" />
  <row Id="13221" PostId="8968" Text="Thank you for this... I think this would be a really good solution, but the only problem is that I need a tiny amount of it, and I expect I would have to but lots of it. Thanks for the suggestion though." CreationDate="2011-01-13T11:01:34.870" UserId="2426" />
  <row Id="13222" PostId="8970" Text="ummmm... maybe. I don't think I really want a mirror finish though... just dark." CreationDate="2011-01-13T11:08:49.697" UserId="2426" />
  <row Id="13223" PostId="8967" Text="You could add MSP430 from TI using mspgcc and mspdebug , but just learning I would go with PIC or Arduino." CreationDate="2011-01-13T11:17:26.850" UserId="2060" />
  <row Id="13224" PostId="8968" Score="2" Text="Try to ask to a car shop that installs those films. I usually can get small pieces for free as they are installation waste." CreationDate="2011-01-13T11:21:49.303" UserId="244" />
  <row Id="13225" PostId="8968" Text="Ok... that's a great idea. Thanks." CreationDate="2011-01-13T11:33:54.330" UserId="2426" />
  <row Id="13226" PostId="8969" Score="4" Text="Don't fear surface mount soldering. It's probably much easier than you think. http://electronics.stackexchange.com/questions/4678/what-tools-equipments-and-techniques-do-you-use-to-solder-microminiature-smd-par " CreationDate="2011-01-13T12:12:47.823" UserId="566" />
  <row Id="13227" PostId="8967" Text="Wow I had not heard of mplabx until right now. I'm downloading their linux IDE/compiler. Lack of Linux support has been one of the biggest reasons that I've stopped using them in my designs.  Thanks!" CreationDate="2011-01-13T12:51:00.210" UserId="974" />
  <row Id="13228" PostId="8965" Score="5" Text="If you are just starting out, and want the easiest entry into electronics without messing around with figuring out how to interface with a bare MCU, it is very hard to recommend anything but Arduino.  The editor isn't very good, but you can get up and running very quickly, and this will enable you to have lights blinking and switch states read in minutes.  Although I haven't tried very hard, I have still not gotten my Launchpad kit up and running since I had issues with the toolchain.  Arduino was a piece of cake." CreationDate="2011-01-13T13:52:20.237" UserId="2288" />
  <row Id="13229" PostId="8965" Score="1" Text="Define support: tools you can run on X OS for chip Y or being able to run X OS on chip Y?" CreationDate="2011-01-13T14:35:19.960" UserId="1407" />
  <row Id="13230" PostId="8965" Score="2" Text="By &quot;good linux support&quot; do you mean you want to use Linux for development or run Linux on the chip?" CreationDate="2011-01-13T14:59:17.943" UserId="857" />
  <row Id="13231" PostId="8957" Text="Go shopping. Some comparators include 0v in the common-mode range.  Or power the low side of the comparator with a negative rail.  Use a split pullup resistor on the comparator's open-collector output to get the logic swing you want." CreationDate="2011-01-13T15:01:22.490" UserId="411" />
  <row Id="13232" PostId="8969" Text="I don't doubt that! But it's part of a series of projects for beginners and therefore we want to stick to DIP packaged parts." CreationDate="2011-01-13T15:02:06.803" UserId="2587" />
  <row Id="13233" PostId="8971" Text="As mentioned above the circuit is intended for beginners and we would like to stick to DIP packaged parts. " CreationDate="2011-01-13T15:06:47.473" UserId="2587" />
  <row Id="13234" PostId="8279" Text="Check the footprint and pin out of the Ethernet connector.  Pins 1&amp;2 are TX, 3&amp;6 are RX.  Something looks odd." CreationDate="2011-01-13T15:08:19.137" UserId="204" />
  <row Id="13235" PostId="8971" Text="FTDI chips are deadly simple. You just solder it and it works fine.  No debugging." CreationDate="2011-01-13T15:20:21.233" UserId="2062" />
  <row Id="13236" PostId="8974" Text="It´s difficult to me imagine something out of ecuations or whatever mathematical expressions. Well, at the end you have mathematical expressions and how do you implement it? That´s the questions.I suposse neural networks are interesting because they can be implemented on electronics (I don´t know imagine any signal processing application that it not based on mathematical expressions). Anyway, I have to use a Fuzzy Neural Networks and as I am concerned, Fuzzy Neural Networks are described by mathematical expressions. " CreationDate="2011-01-13T15:25:09.070" UserId="2597" />
  <row Id="13237" PostId="8974" Text="Besides, I use the 'if then rule' form proposed by Takagi and Sugeno. This form is described by mathematical expressions." CreationDate="2011-01-13T15:27:31.847" UserId="2597" />
  <row Id="13238" PostId="8974" Text="Please, can you show me any reference about ANN techniques that don't require floating-point?" CreationDate="2011-01-13T15:28:13.250" UserId="2597" />
  <row Id="13239" PostId="8976" Text="That would work, but even under ideal conditions I think this would need at least a 85x85 sensor array to read a minimal (15x15) QR code.  I was hoping I could do it with a smaller array (and correspondingly less processing power.)" CreationDate="2011-01-13T15:36:31.750" UserId="1285" />
  <row Id="13240" PostId="8976" Text="you don't need 15x15. for 10 bit coordinates, you need just 20 bits of data + ECC ~10 bit -&gt; 6x6 pixels or so. " CreationDate="2011-01-13T15:40:57.323" UserId="2062" />
  <row Id="13241" PostId="8957" Text="@thomasO, you say you are not sure, but seem to imply that you are correct. This does work, you are correct that you would have to choose your components carefully, but how often do you not have to choose components carefully." CreationDate="2011-01-13T15:49:09.747" UserId="230" />
  <row Id="13242" PostId="8969" Text="Note that there is also [LUFA](http://www.fourwalledcubicle.com/LUFA.php), though I not sure whether or not it has the same speed limits." CreationDate="2011-01-13T15:51:31.057" UserId="2118" />
  <row Id="13243" PostId="8957" Text="@Kortuk, I have seen some expensive comparators which can work to -300mV or more below ground, but - they're expensive and/or single source." CreationDate="2011-01-13T15:52:27.793" UserId="1225" />
  <row Id="13244" PostId="8957" Text="@thomasO, I have used a rail to rail op-amp and made a comparator that worked perfectly for this." CreationDate="2011-01-13T15:54:35.297" UserId="230" />
  <row Id="13245" PostId="4728" Text="For BGAs, when you can't avoid them at all, there's schmartboard: http://www.schmartboard.com/index.asp?page=products_bga" CreationDate="2011-01-13T16:16:13.570" UserId="1078" />
  <row Id="13247" PostId="4283" Text="In the context of the question the seperation is valid. There is no point in trying to write high level AI code on simple 8bit controllers, yet they are perfect as sensor interfaces and sensor data aggregators. If your robot is running on a single processor (and I've built a few based on ARM7/9) then it makes good sense anyway to have a modular design but I'm not trying to 'force' people to design things in a particular way." CreationDate="2011-01-13T16:39:47.793" UserId="611" />
  <row Id="13248" PostId="8596" Text="a) Follow the linear regulator's datasheet recommendations for input and output capacitor values. Typically a moderately large value near the input (100uF), and a smaller value on the output (0.1 - 1.0uF) b) Short piece on decoupling capacitors: http://www.edn.com/archives/1997/091297/19col.htm c) The input/output capacitors are _not_ the same as the power supply filtering capacitors that are located after the bridge rectifier, where 1000uF is a reasonable value. " CreationDate="2011-01-13T16:52:35.020" UserId="2598" />
  <row Id="13249" PostId="8581" Text="@BG100, no you do not necessarily need a switch mode power supply. There are more advanced design, which have far more potential for causing problems (namely RFI/EMC). The _efficiency_ improvement won't solve your problems. " CreationDate="2011-01-13T16:55:47.183" UserId="2598" />
  <row Id="13250" PostId="8969" Text="If it's for absolute beginners, 38kbit should be plenty. When they want more speed, they can graduate to the slightly more complex setups -- eg using USB AVR's with built in USB hardware. I believe LUFA has a theoretical limit of around 8000kbit via CDC, but that's only if you're just sending a constant stream of data from RAM. It requires USB AVR though, I don't think any come in DIP." CreationDate="2011-01-13T17:25:51.820" UserId="131" />
  <row Id="13251" PostId="8976" Text="Added few more ideas." CreationDate="2011-01-13T17:31:43.960" UserId="2062" />
  <row Id="13252" PostId="8975" Text="The optical mouse sensor is a really good idea. They pack a lot of DSP punch nowadays, and can track on a variety of surfaces (as we all know). It gives relative motion, so integrating for position would be up to you." CreationDate="2011-01-13T17:35:26.513" UserId="2118" />
  <row Id="13253" PostId="8957" Text="@Kortuk, For a switching power supply, an op-amp is not feasible, as they do not have suitable speeds except in high cost chips." CreationDate="2011-01-13T18:12:48.117" UserId="1225" />
  <row Id="13254" PostId="8983" Text="Is expected to use only for reprogramming of parameters, so simply simulate a few keys, arrow, up, down, enter." CreationDate="2011-01-13T18:36:07.543" UserId="1888" />
  <row Id="13255" PostId="8957" Text="@thomasO, so you have a speed requirement, but in the question do not mention it? This is something that influences an answer. And yes, an op-amp can run at 100 or 400 kHz." CreationDate="2011-01-13T18:49:07.587" UserId="230" />
  <row Id="13256" PostId="8985" Score="1" Text="Community Wiki..." CreationDate="2011-01-13T18:58:02.947" UserId="771" />
  <row Id="13257" PostId="8985" Text="@vicatcu I agree." CreationDate="2011-01-13T18:59:40.670" UserId="1240" />
  <row Id="13258" PostId="8985" Text="Agreed ... but I can't see the Community Wiki checkbox.  http://english.stackexchange.com/privileges/community-wiki" CreationDate="2011-01-13T19:01:54.113" UserId="106" />
  <row Id="13259" PostId="8985" Text="@vicatcu, @andrejako, @clintonBlackmore, you have to flag a moderator. People were using CW to try to sneak in bad questions often on SO, so now it takes a moderator. Just flag for moderator attention and request CW, and as long as the question is good, we will take care of it." CreationDate="2011-01-13T19:16:24.390" UserId="230" />
  <row Id="13261" PostId="8958" Text="[Alternative diagram here, showing zener or diode drop alternatives to LED.](http://i.imgur.com/X7VDE.png)" CreationDate="2011-01-13T19:43:06.327" UserId="2118" />
  <row Id="13262" PostId="8983" Text="@lsalamon - In that case, if you're committed to the touchscreen plan, I'd use the TSC2200's integrated keypad. Otherwise, a simple 4-button (physical buttons) interface is a common sight: You navigate up and down menus, and enter/backup with the left/right buttons." CreationDate="2011-01-13T19:47:16.293" UserId="857" />
  <row Id="13263" PostId="8985" Text="Thanks, Kortuk." CreationDate="2011-01-13T20:12:02.573" UserId="106" />
  <row Id="13264" PostId="8957" Text="@kortuk, I figured for a comparator it would not be critical. An op-amp can run at 100kHz or 400kHz, but slew rates are poor and response time is long." CreationDate="2011-01-13T20:48:56.593" UserId="1225" />
  <row Id="13265" PostId="8957" Text="@thomasO, it is critical to give operator defining details, like frequency. I have already pointed that out though. I will say that yes, an op-amp can operate at that, and well." CreationDate="2011-01-13T20:56:02.657" UserId="230" />
  <row Id="13266" PostId="8989" Score="1" Text="May I refer you to a type of DNA sequencing called *&quot;shotgun sequencing&quot;*. To characterize the DNA of certain organism, it is blasted into millions of pieces, then sequenced in parallel. I suggest the same with a CD player, using a big hammer and a room full of people. :D (I kid..)" CreationDate="2011-01-13T21:27:14.640" UserId="2118" />
  <row Id="13267" PostId="8949" Text="Along with the commit, is to check it out to a fresh directory and rebuild it.  Nothing worse than forgetting to add a file to the source control." CreationDate="2011-01-13T21:38:01.280" UserId="204" />
  <row Id="13268" PostId="8957" Text="@Kortuk, I would be surprised. Op-amps are not comparators, which is why they are distinct devices. If you can name an op-amp for a reasonable price which outperforms the LM311/LM393 then by all means do." CreationDate="2011-01-13T21:43:42.427" UserId="1225" />
  <row Id="13269" PostId="8985" Text="Here's quite a list of different events: http://robogames.net/events.php" CreationDate="2011-01-13T22:04:30.063" UserId="106" />
  <row Id="13270" PostId="8990" Text="and the lasers in these are IR, aren't they?" CreationDate="2011-01-13T22:20:24.533" UserId="740" />
  <row Id="13271" PostId="8990" Score="2" Text="@JustJeff, yes IR, 780 nm" CreationDate="2011-01-13T22:40:05.600" UserId="2598" />
  <row Id="13272" PostId="8989" Score="3" Text="The general process you are asking about is often called a _teardown_, which is used by engineers to examine a product. Searching for CD player teardown will find one at iFixit, that can give you a general idea even if you do not have the same model. http://www.ifixit.com/Teardown/Sony-CD-Walkman-D-NF430-Teardown/1249/2" CreationDate="2011-01-13T22:41:42.713" UserId="2598" />
  <row Id="13273" PostId="8957" Text="@ThomasO, this is a waste of time to discuss in comments, it is not basic operation, you will need compensation. No worries. I would suggest you place any frequency requirements in your question." CreationDate="2011-01-13T22:43:10.873" UserId="230" />
  <row Id="13274" PostId="4122" Text="@Mark, running your CPU at increased temperature will reduce the expected life of the CPU. Just as a side note, thought I would add it. I still find that in general my computer will be outdated before my CPU fails, so not a major risk." CreationDate="2011-01-13T22:45:17.330" UserId="230" />
  <row Id="13276" PostId="8989" Text="@ tyblu, lol, this was my favourite thing when I was a kid. Electronics are just made to be smashed to smithereens" CreationDate="2011-01-13T22:53:45.623" UserId="1457" />
  <row Id="13277" PostId="616" Text="Great question, very characteristic of the SO question along the same lines. " CreationDate="2011-01-13T22:54:35.967" UserId="1457" />
  <row Id="13278" PostId="8854" Score="1" Text="Seems to me that the specific configuration would be pretty important since you're asking if that specific configuration is common." CreationDate="2011-01-13T22:59:40.710" UserId="2495" />
  <row Id="13279" PostId="8854" Text="very true. ok I will edit and reword the question. I really just want to know which is standard and if one is better than the other. cheers." CreationDate="2011-01-13T22:59:40.803" UserId="1457" />
  <row Id="13280" PostId="4121" Text="muntoo - The direct translation from l33t (Leet) would be &quot;rocks [my] socks&quot;, and the translation from that slang to normal English is &quot;This is great.&quot;" CreationDate="2011-01-13T23:03:23.750" UserId="857" />
  <row Id="13281" PostId="8973" Score="1" Text="What's your skill level?  Do you need an intro to FPGAs and VHDL, or a reference for implementing floating-point operations with some recipes in VHDL?  " CreationDate="2011-01-13T23:06:25.793" UserId="857" />
  <row Id="13282" PostId="8999" Score="1" Text="yeah, logitech and kingston already have it figured out!  You don't want a mouse, you want to take the pattern used in their trackballs to get X and Y.  See the special pattern on the ball:   http://www.logitech.com/assets/14756/14756.png" CreationDate="2011-01-13T23:19:34.260" UserId="2288" />
  <row Id="13283" PostId="618" Text="@All, very cool, wiki and other sources mention a new version (3rd edition) is going to be available later in the year (2011). updated to include current digital circuits" CreationDate="2011-01-13T23:47:01.680" UserId="1457" />
  <row Id="13284" PostId="9002" Text="You might have some luck searching for a &quot;reference design&quot;" CreationDate="2011-01-14T00:04:18.260" UserId="566" />
  <row Id="13285" PostId="9002" Text="@Joby Taffey - Tried your recommendation, still no luck; will look around some more with the term though before giving up." CreationDate="2011-01-14T00:23:52.980" UserId="2466" />
  <row Id="13286" PostId="9004" Text="Thank you. Part of the problem is that I am doing this on behalf of a friend, and do not know much about electronics myself. Any chance you have a url to a promising site/resource?" CreationDate="2011-01-14T00:39:47.623" UserId="2466" />
  <row Id="13287" PostId="9005" Score="1" Text="Are there any obvious pads on the board for production programming?" CreationDate="2011-01-14T00:59:06.070" UserId="1407" />
  <row Id="13288" PostId="9005" Text="@Nick Yes, there are 6 marked pads, GND, RESET, SI, SO, SCLK and VPP - hence I know where reset and a SPI bus are" CreationDate="2011-01-14T01:01:08.950" UserId="566" />
  <row Id="13289" PostId="9005" Text="More modern MCUs aren't programmed through the SPI though, but some proprietary interface (sometimes parallel for high-speed)" CreationDate="2011-01-14T01:04:39.073" UserId="1407" />
  <row Id="13290" PostId="9005" Text="Good point, it could just as easily be a SPI debug port, or test interface" CreationDate="2011-01-14T01:09:08.853" UserId="566" />
  <row Id="13291" PostId="9003" Text="It looks like this is what cksa361 is already doing. This doesn't eliminate contact resistance." CreationDate="2011-01-14T01:17:20.253" UserId="2118" />
  <row Id="13293" PostId="9003" Text="@tyblu, I'm not sure. They seem to be using an ammeter and a fixed voltage, not measuring the voltage across the resistor directly, which is pretty much identical to 2-wire measurement, and includes the ~10mOhm shunt of the meter." CreationDate="2011-01-14T01:22:22.700" UserId="1225" />
  <row Id="13294" PostId="9001" Score="1" Text="What is the ammeter accuracy in the 20mΩ range?" CreationDate="2011-01-14T01:51:44.013" UserId="2118" />
  <row Id="13295" PostId="7843" Text="Did you find a solution, @rics?" CreationDate="2011-01-14T02:07:37.780" UserId="2118" />
  <row Id="13296" PostId="9003" Text="sorry gtg lunch, but i put different CPU loads on the dev board... and measured the current via the input jack...against the measured current via the I2C Current monitor" CreationDate="2011-01-14T02:17:13.843" UserId="1688" />
  <row Id="13297" PostId="8978" Score="3" Text="Indeed. I was going to answer this with &quot;a credit card&quot;." CreationDate="2011-01-14T02:22:23.293" UserId="222" />
  <row Id="13298" PostId="8991" Text="There are really 2 versions of overclocking, the first being running the device faster than it was ever designed to run.  The second being running a part that was binned at a lower speed grade that its family can run.  The former certainly has much more danger involved, the latter, especially in later steppings of the die, is really quite safe.  I get the impression the linked article was discussing primarily the former." CreationDate="2011-01-14T02:46:53.707" UserId="1438" />
  <row Id="13299" PostId="9005" Score="2" Text="those 6 pads sound a lot like a PIC ICSP programming interface.  You could try connecting a PIC programmer to read out the chip ID." CreationDate="2011-01-14T04:05:11.703" UserId="411" />
  <row Id="13300" PostId="9009" Text="Just so I'm clear:  By &quot;connect a 5k resistor from your pin to your ground&quot; you mean to the device I'm measuring's ground? I know there's 12V on the signal line because when I connect my volt meter to the line and the a ground point on the component.  " CreationDate="2011-01-14T04:13:34.990" UserId="2604" />
  <row Id="13301" PostId="8965" Text="@Dave what toolchain are you trying to get working? i have installed mspgcc on pclinux and ubuntu 8.4 through 10.10 and it worked with out a problem, minus looking up a few dev files" CreationDate="2011-01-14T04:47:05.800" UserId="2060" />
  <row Id="13302" PostId="8928" Text="I understood the pin assignment part what's about the clocking demands?" CreationDate="2011-01-14T05:03:47.697" UserId="444" />
  <row Id="13304" PostId="9008" Text="Is this an automotive environment?" CreationDate="2011-01-14T06:13:38.677" UserId="2118" />
  <row Id="13305" PostId="8965" Text="@jsolarski I was on Windows, just following the quickstart guide.  Actually, now that I think of it, the problem was that I didn't want to install it because NAV said that one of the archives had a Trojan!" CreationDate="2011-01-14T06:27:31.573" UserId="2288" />
  <row Id="13306" PostId="8928" Score="1" Text="Timing constraints cover things like clock frequency, setup and hold times. You'll still get the information in the timing analysis, but specifying the requirements in the constraints file lets the tools detect when they fail, and possibly try harder to satisfy your needs when it's borderline." CreationDate="2011-01-14T07:27:16.207" UserId="1181" />
  <row Id="13307" PostId="8988" Score="2" Text="I usually use `-Os` for size optimization, and `-fwhole-program` when building everything at once. It saves some space and usually speeds things up. To accurately match the controller, you want to accept latch at any time (which is why SNES controllers work on NES, which only reads 8 bits). &#xA;For typos: hi is read from `PORTD` instead of `PORTB`, and you should use `PINB` and `PIND` anyway to read the inputs. Possibly want to mask away D7 using `PIND&amp;0x7f` too." CreationDate="2011-01-14T07:35:58.267" UserId="1181" />
  <row Id="13308" PostId="8762" Text="Before looking too deeply into the idea of using a relay, you might want to check its parasitic properties. I have no experience with using relays at high frequencies, but as far as I've heard, RF relays are way expensive and pretty special. It must be possible to use relays, however, because that is what expensive scopes do when switching the input between 1 MOhm and 50 Ohm. CMOS switches might work, too." CreationDate="2011-01-14T07:42:09.560" UserId="930" />
  <row Id="13309" PostId="9008" Text="Nope, it is not automotive. It has to do with home automation. Why?" CreationDate="2011-01-14T08:51:04.650" UserId="2604" />
  <row Id="13310" PostId="8969" Text="Yeah you're probably right that 38kbit is enough. " CreationDate="2011-01-14T10:08:49.770" UserId="2587" />
  <row Id="13311" PostId="9017" Text="then i'd also get the quiescent current draw of the regulator supply power to the micro right?" CreationDate="2011-01-14T10:50:24.780" UserId="1688" />
  <row Id="13312" PostId="8967" Text="Simulator, the component asked for in the question, is not addressed." CreationDate="2011-01-14T10:52:09.190" UserId="1181" />
  <row Id="13313" PostId="9017" Text="Yes. You would." CreationDate="2011-01-14T11:20:20.323" UserId="566" />
  <row Id="13314" PostId="8967" Text="@Yann I'm not convinced that the OP really meant simulator, perhaps he/she can confirm" CreationDate="2011-01-14T11:21:17.530" UserId="566" />
  <row Id="13315" PostId="8973" Text="@reemrevnivek: I´ve studied VHDL before, but I haven´t had a formal intro to FPGAs.Do you know any reference I should read about FPGAs? I have the feeling FPGAs is a wide world in the sense, every FPGA manufacturer has a different technology. Of course theres is something in common between all manufacturers..." CreationDate="2011-01-14T11:34:53.427" UserId="2597" />
  <row Id="13316" PostId="8999" Text="@Dave, that pattern ensures there is always a dot in range of the sensor, but I don't think it is designed to determine the position statically (because otherwise it would not be possible to swap in a ball from another model with different dot density, but you can) but it may be possible to design a similar pattern that does uniquely identify the position, e.g. avoid repetition of the quadrilaterals formed by neighbouring dots.  Maybe they already did that (but the sensor does not take advantage of it.)" CreationDate="2011-01-14T13:01:39.053" UserId="1285" />
  <row Id="13317" PostId="9001" Score="1" Text="In light of a comment on ThomasO's answer, I think you should explain exactly how you are measuring these values." CreationDate="2011-01-14T13:28:40.423" UserId="2118" />
  <row Id="13318" PostId="9008" Score="1" Text="12V is common in auto electronics, and that environment comes with a whole bag o' trouble." CreationDate="2011-01-14T13:33:18.893" UserId="2118" />
  <row Id="13319" PostId="9019" Score="1" Text="When a battery is disconnected, a regulator may go through a period when its output is at higher potential than its input. Many of them require external protection (reverse bypass fast diode) for these events, but not a TVS." CreationDate="2011-01-14T13:40:11.727" UserId="2118" />
  <row Id="13320" PostId="8999" Text="@finnw the pattern isn't for determining absolute position, it's used to determine relative position.  You would need to keep track of all of the relative changes to get your absolute position.  In the end, I think that's &quot;all&quot; you need.  :)  Now as far as sourcing the sensors and the pattern on the ball goes, I can't comment." CreationDate="2011-01-14T13:42:25.903" UserId="2288" />
  <row Id="13321" PostId="8988" Text="Originally I was worried about not having enough time to check the latch pin in an interrupt. According to http://www.repairfaq.org/REPAIR/F_SNES.html#SNES_005 , the clock is a 12 microseconds per cycle square wave and the gamepads are polled at about 60Hz. That should be plenty of time to do what needs to be done." CreationDate="2011-01-14T13:59:08.987" UserId="1363" />
  <row Id="13322" PostId="9004" Text="I'd find a motherboard that meets your specs, buy it and start identifying chips.  Look up the chip on the manufacturers site and look for datasheets.  Reference designs are sometimes there, sometimes separate.  If you're lucky they'll be PDF, if not, altium or some other schematic capture program." CreationDate="2011-01-14T14:22:34.817" UserId="249" />
  <row Id="13323" PostId="9008" Text="@tyblu, I have actually done some auto-electronics and the signal quality was not as bad as promised." CreationDate="2011-01-14T14:54:00.990" UserId="230" />
  <row Id="13324" PostId="9009" Text="@cek, Your chip that is detecting this and your chip that is generating the signal need to have the same ground. If this is absolutely not an option, and I am not sure why it would not be, then we can discuss other options. Yes, it should connect from the pin you are measuring on to the chips ground. But This ground should be connected to your controllers ground also." CreationDate="2011-01-14T14:58:10.100" UserId="230" />
  <row Id="13325" PostId="8959" Text="@joeforker, I'd be curious to know if this works for you - please let us know your findings... I think you have to be in master mode in order for the ATTiny2313 to generate the clock signal (as the SNES would otherwise do)." CreationDate="2011-01-14T15:08:42.013" UserId="771" />
  <row Id="13326" PostId="8959" Text="@vicatcu again, thanks for this, but the ATtiny2313 is pretending to be the gamepad. The role of master will be fulfilled by a real SNES console." CreationDate="2011-01-14T15:32:35.803" UserId="1363" />
  <row Id="13327" PostId="8924" Text="I want the ATtiny2313 to act as the slave device, attached to a real SNES console." CreationDate="2011-01-14T15:33:37.407" UserId="1363" />
  <row Id="13328" PostId="9023" Score="1" Text="Very important, I would think, is debouncing that switch." CreationDate="2011-01-14T15:39:06.883" UserId="230" />
  <row Id="13329" PostId="9029" Text="I know about microcontrollers (I use AVRs) but not microprocessors which is what i want to learn about. " CreationDate="2011-01-14T16:01:38.477" UserId="1623" />
  <row Id="13330" PostId="9029" Score="1" Text="@Dean, OK - so you're thinking along the lines of ARMs then... I don't think you're going to find 8-bit cores that are in the realm of &quot;microprocessors&quot; as compared to what you are terming &quot;microcontrollers.&quot;" CreationDate="2011-01-14T16:05:14.200" UserId="771" />
  <row Id="13331" PostId="9029" Text="It doesn't have to be 8-bit but thats what i'm reading about so would help with understanding." CreationDate="2011-01-14T16:11:53.207" UserId="1623" />
  <row Id="13332" PostId="9009" Text="My &quot;chip that is detecting&quot; is an Adicon SECU16 digital IO controller that is connected to my home control system via RS-485.  It sits in one room.  The device I am monitoring the voltage of sits in another room. It's all the same Earth, so ground is ground, but..." CreationDate="2011-01-14T16:21:58.167" UserId="2604" />
  <row Id="13333" PostId="9009" Text="@cek, when you run a wire from one room to the other, the one that carries the signal, also run a ground reference. You can do the divide to 5V on either side. If you are going to run a long wire, I would suggest keeping a high voltage on the line for noise reasons." CreationDate="2011-01-14T16:24:11.243" UserId="230" />
  <row Id="13334" PostId="8465" Text="I'd strongly recommend against deviating from the nominal core voltage specified for the device; it's playing with fire. The FPGA vendors guarantee that the device will operate at that voltage (+/- 5--10%). The tolerances/fluctuations of your power supply, and variability of the FPGA's characteristics, will lead to failures over large amounts of manufactured systems if you're operating at or close to the absolute min or max." CreationDate="2011-01-14T16:35:04.443" UserId="2531" />
  <row Id="13335" PostId="9023" Score="2" Text="@Kortuk, good point.  I was assuming the micro would turn on fast enough that it could override the switch before the first bounce, assuming driving the pin high was the first thing the micro did.  If that isn't the case, one could add a capacitor on the -SHDN lead to create a time constant for the turn on (although this would also introduce a slight delay in turn off).  The 10 nF one probably needs to be left in for noise suppression (it was included in a datasheet sample schematic).  Or one could add additional RC circuit for just the switch." CreationDate="2011-01-14T16:36:44.687" UserId="1322" />
  <row Id="13336" PostId="8959" Text="@joeforker, got it I misunderstood - thought you were trying to control the Tiny2313 with a gamepad. " CreationDate="2011-01-14T16:52:09.700" UserId="771" />
  <row Id="13337" PostId="9030" Text="agreed, the 22A rating is the maximum current the power supply can source at 5V." CreationDate="2011-01-14T16:55:49.543" UserId="771" />
  <row Id="13338" PostId="9023" Text="@tcrosley, I have seen some crazy bounce on switches before." CreationDate="2011-01-14T17:03:19.320" UserId="230" />
  <row Id="13339" PostId="9017" Text="@cksa361, some micros this is nano or micro amps. I use the MSP430 and we keep it around 3-5 microamps." CreationDate="2011-01-14T17:03:58.120" UserId="230" />
  <row Id="13341" PostId="8464" Text="Make friends with your local distributor sales reps, many times you can get a loan or free sample of a part or eval board off of them - especially if the hardware has been around a while." CreationDate="2011-01-14T17:47:30.340" UserId="960" />
  <row Id="13342" PostId="9034" Text="Thanks for this, but I'm in the UK, so I need to find somewhere that sells this stuff over here. I liked your first answer though, before you edited... I might try that!" CreationDate="2011-01-14T17:55:18.267" UserId="2426" />
  <row Id="13343" PostId="9029" Text="@vicatu, ARMs are microcontrollers. --&gt; [What's the difference between a microcontroller and a microprocessor?](http://electronics.stackexchange.com/q/1092/2118)" CreationDate="2011-01-14T18:32:31.070" UserId="2118" />
  <row Id="13344" PostId="9036" Text="I didn't know they were called a single board computer. " CreationDate="2011-01-14T18:59:41.320" UserId="1623" />
  <row Id="13345" PostId="9038" Text="Can you recommend me a new title then please struggled to find something newer. " CreationDate="2011-01-14T19:05:12.717" UserId="1623" />
  <row Id="13346" PostId="1011" Text="Do you you mean &quot;Professional Engineer&quot; to mean someone with a P.E. license from the state (province, etc.)?  Or an engineer who gets paid, rather than a hobbyist?" CreationDate="2011-01-14T19:06:02.620" UserId="206" />
  <row Id="13348" PostId="9027" Score="2" Text="Simple microprocessors with external RAM, ROM and I/O are no longer made. If you want that sort of thing you will have to design your own using an FPGA." CreationDate="2011-01-14T20:03:00.613" UserId="305" />
  <row Id="13349" PostId="9007" Score="1" Text="Thanks, I didn't know there were companies who could do this for you." CreationDate="2011-01-14T20:04:19.903" UserId="566" />
  <row Id="13350" PostId="9027" Text=":( thats not very good. I guess I will have to just carry on play with my AVRs. " CreationDate="2011-01-14T20:09:06.707" UserId="1623" />
  <row Id="13351" PostId="4728" Text="Re: BGAs - I etch a stencil and reflow on a hot plate. You can probably get a local arts store to laser cut mylar for the stencil, and buy a toaster oven for the reflow if you can't find a hot plate." CreationDate="2011-01-14T20:09:52.260" UserId="2183" />
  <row Id="13352" PostId="8991" Text="@Mark, my (incomplete) understanding is that binning (small die, graded for different speeds) is based on statistical analysis of yields, not purely market economics (cost vs. supply). You would need to compare sunk (NRE) costs to material costs per unit to give you a clue to whether binning was being used to maximize profit." CreationDate="2011-01-14T20:14:55.623" UserId="2598" />
  <row Id="13353" PostId="8996" Text="There are many manufacturers and suppliers. It is commonly used in mocking up industrial fixtures and even on production machinery." CreationDate="2011-01-14T20:30:04.443" UserId="1810" />
  <row Id="13354" PostId="4728" Text="OK, so it is possible to do BGAs.  However, you can't inspect them without X-Ray equipment.  I figured that anyone who has the equipment and know-how to do BGAs would be unlikely to read this post, and those who were reading this post would be unlikely to have that equipment and know-how.  Turns out I was wrong twice." CreationDate="2011-01-14T20:41:09.030" UserId="857" />
  <row Id="13355" PostId="8991" Text="...same die, graded for different speeds..." CreationDate="2011-01-14T20:41:40.503" UserId="2598" />
  <row Id="13356" PostId="9030" Text="Ok guys, done it. It works :) Thanks very much for the reassurance." CreationDate="2011-01-14T20:54:48.183" UserId="2178" />
  <row Id="13357" PostId="9029" Text="@tyblu, I believe ARM are available both as microprocessors (external RAM/ROM, etc., e.g. TI ARM Cortex AM3517) and microcontrollers (NXP LPC series). " CreationDate="2011-01-14T21:00:23.617" UserId="2598" />
  <row Id="13358" PostId="9041" Score="1" Text="This looks like homework." CreationDate="2011-01-14T21:27:58.247" UserId="305" />
  <row Id="13359" PostId="9041" Text="@LeonHeller, Nope. Besides, it's way too fun to be homework." CreationDate="2011-01-14T21:29:22.983" UserId="2118" />
  <row Id="13360" PostId="9040" Text="I'm afraid shopping questions like this are not permitted on E&amp;R. There are several questions related to your query, though..." CreationDate="2011-01-14T21:34:50.593" UserId="2118" />
  <row Id="13361" PostId="9027" Text="http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=2556260 DigiKey's microprocessor section" CreationDate="2011-01-14T21:44:20.077" UserId="566" />
  <row Id="13362" PostId="8464" Text="@digikata - It's hard to make friends with your distributor sales reps when your R&amp;D budget is one of $0 or £0." CreationDate="2011-01-14T21:45:50.947" UserId="857" />
  <row Id="13363" PostId="9043" Text="Thanks for that. I like the look of the z80 microcomputer thing. Going to luck round some used bookshops to see if i can find it. So can have a hard copy." CreationDate="2011-01-14T22:38:11.437" UserId="1623" />
  <row Id="13364" PostId="9043" Text="if you want to play around with an 8 bit cpu, the z80 and 6502 are probably electrically the least complicated, as they present non-multiplexed buses, operate from a single 5V supply, and don't require multi-phase clocks." CreationDate="2011-01-14T23:30:17.450" UserId="740" />
  <row Id="13365" PostId="9002" Text="&quot;478&quot;? Do you mean Socket 478, or Intel Pentium 4 X86 Motherboards? If so , I am interested in the answer to this question as well." CreationDate="2011-01-14T23:35:58.887" UserId="1374" />
  <row Id="13366" PostId="8975" Text="@tyblu - If you look at the link (de Bruijn Torus), it seems he's interested in absolute positioning." CreationDate="2011-01-14T23:37:49.353" UserId="1374" />
  <row Id="13367" PostId="8981" Text="I'm not sure what kind of keyboard you are trying to mimic, but resistive touch screens/film is not multitouch, unless the type you are using deviates significantly from common resistive position sensors." CreationDate="2011-01-14T23:40:09.397" UserId="1374" />
  <row Id="13368" PostId="9047" Text="It is really for the fun of it. " CreationDate="2011-01-15T00:03:44.467" UserId="1623" />
  <row Id="13369" PostId="9046" Score="2" Text="PFC (power factor correction) is an independent issue from the voltage range." CreationDate="2011-01-15T00:15:01.660" UserId="206" />
  <row Id="13370" PostId="9046" Score="2" Text="@Brian Carlton, True, but 95% of all PFC adapters support international input range because the PFC circuit is just a special type of boost converter. There are a few exceptions, of course, but it's a general rule." CreationDate="2011-01-15T01:12:09.907" UserId="1225" />
  <row Id="13371" PostId="9050" Text="Related question: http://electronics.stackexchange.com/q/8447/1240" CreationDate="2011-01-15T05:28:57.520" UserId="1240" />
  <row Id="13372" PostId="9051" Text="Other way around: she needs a 220V device, and has a 100V one." CreationDate="2011-01-15T05:31:25.740" UserId="2118" />
  <row Id="13373" PostId="8820" Text="Now to combine power harvesting and bidirectional data connection... :)" CreationDate="2011-01-15T05:34:04.883" UserId="2118" />
  <row Id="13374" PostId="9049" Text="Oh man! Where did I put the torch?" CreationDate="2011-01-15T07:38:42.540" UserId="2466" />
  <row Id="13375" PostId="9056" Text="http://www.youtube.com/watch?v=aLwaPP9cxT4 &lt;-- example of melting ice with metal particles in it. " CreationDate="2011-01-15T07:47:19.830" UserId="2625" />
  <row Id="13376" PostId="9056" Text="Just realized a fast, way of going about it would be to pass a wire through the pipe, and to put the induction coils over the pipeline." CreationDate="2011-01-15T07:51:20.760" UserId="2625" />
  <row Id="13377" PostId="9056" Text="In response, if you do go the microwave route, please wear metal protection over your eyes, some kind of screen. Microwaves cause instant blindness even with your eyes closed, they cause cataracts to form. Please be careful." CreationDate="2011-01-15T07:54:39.180" UserId="2625" />
  <row Id="13378" PostId="8974" Text="@Leon Heller: The link you have put it isn´t usefull, that web page don´t contain any link to documentation or libraries. May be I can access if I were a member of York University but I am not." CreationDate="2011-01-15T08:26:07.940" UserId="2597" />
  <row Id="13379" PostId="9044" Score="2" Text="Might have been easier if we had a clue what cellphone it is. Plenty of them charge with a standard USB cable, for instance." CreationDate="2011-01-15T09:03:33.430" UserId="1181" />
  <row Id="13380" PostId="9056" Text="@Allan Ball - Unfortunately passing a wire through the pipe is not practical. Also, the microwave method, as you and tyblu say, is a safety hazard." CreationDate="2011-01-15T09:14:19.590" UserId="2466" />
  <row Id="13382" PostId="9060" Text="+1 Good suggestion. Off to [instructables.com](http://www.instructables.com/pages/search/search.jsp?cx=partner-pub-1783560022203827:npr2q7v5m6t&amp;cof=FORID:11&amp;ie=ISO-8859-1&amp;q=heating+blanket) to find something on same lines as a heating blanket." CreationDate="2011-01-15T12:15:07.467" UserId="2466" />
  <row Id="13383" PostId="8967" Text="I'm convinced enough by OP adding &quot;simulator&quot; twice in their edit (including in the title). Whether that's a need is another question, but I wouldn't ignore it." CreationDate="2011-01-15T12:28:18.957" UserId="1181" />
  <row Id="13384" PostId="9048" Score="3" Text="This isn't an electronics based solution, but it sounds like you have problems with your building envelope.  The cheapest and easiest solution is usually to fix the problem at the source...   Better insulation is clutch! Sometimes just shooting some expanding foam in the right place will take care of it)." CreationDate="2011-01-15T12:36:33.247" UserId="1823" />
  <row Id="13385" PostId="9048" Text="@RQDQ - Completely agree." CreationDate="2011-01-15T12:42:21.327" UserId="2466" />
  <row Id="13386" PostId="9050" Text="Duplicate of an off-topic question. hmm." CreationDate="2011-01-15T16:35:31.970" UserId="319" />
  <row Id="13387" PostId="8999" Text="@Dave, The joint's position is not known when the sensor is first powered on, and it may have been moved while the system was powered off, so I don't think I can use this solution." CreationDate="2011-01-15T18:01:03.707" UserId="1285" />
  <row Id="13388" PostId="9048" Text="Note: the use of [meta-tags](http://meta.electronics.stackexchange.com/q/115/2118) such as `[practical]` is discouraged." CreationDate="2011-01-15T19:05:46.597" UserId="2118" />
  <row Id="13389" PostId="9046" Score="1" Text="Even if the charger's input has no PFC stage (and I doubt it has one), it might work from 90...264V. Flyback converters often work over a wide range of rectified AC input voltages." CreationDate="2011-01-15T19:48:15.670" UserId="930" />
  <row Id="13390" PostId="9050" Text="Although the questions are different, [the answer given in the other thread](http://electronics.stackexchange.com/questions/8447/can-a-phone-be-paired-with-2-bluetooth-devices-at-the-same-time/8451#8451) also answers this one. Borderline OT, too... not sure, myself." CreationDate="2011-01-15T19:53:46.933" UserId="2118" />
  <row Id="13391" PostId="9071" Score="1" Text="The Metcals use 13.560MHz (square wave) RF heating, so I would imagine the sheath is a shield and should be grounded..." CreationDate="2011-01-15T20:03:14.370" UserId="2118" />
  <row Id="13392" PostId="9071" Text="This question prompted me to take apart my 80W Weller pen. There's a circuit board and resistor in there, along with 4 wires! Now to see if it actually goes back together... :\" CreationDate="2011-01-15T20:15:15.253" UserId="2118" />
  <row Id="13393" PostId="9071" Score="1" Text="With no tip fitted it should measure open" CreationDate="2011-01-15T20:58:06.827" UserId="1681" />
  <row Id="13394" PostId="9066" Score="1" Text="are you sure you've got the polarity of all your LEDs right?" CreationDate="2011-01-15T21:23:15.657" UserId="771" />
  <row Id="13395" PostId="9066" Score="2" Text="do you have the requisite pin modes set to output? e.g. pinMode(8, OUTPUT); pinMode(9, OUTPUT); pinMode(10, OUTPUT); pinMode(0, OUTPUT); pinMode(1, OUTPUT); pinMode(2, OUTPUT); " CreationDate="2011-01-15T21:24:56.810" UserId="771" />
  <row Id="13396" PostId="8999" Text="@finnw fair enough -- if you cannot force the user to home the joint upon powerup, then your only solution lies within the realm of absolute encoding / position sensing." CreationDate="2011-01-15T21:25:55.890" UserId="2288" />
  <row Id="13397" PostId="8975" Text="@finnw if you're using a ball joint, I assume something protrudes from a spot on the ball.  If that is true, can you go away from sensing features on the ball, to sensing based off of the position of the link?  What are the ranges of motion that you have to support with this ball joint?  Do you have a basic sketch?" CreationDate="2011-01-15T21:28:04.683" UserId="2288" />
  <row Id="13398" PostId="6002" Text="Excellent answer, Nick. In my experience as well, I've never seen a SMT resistor break off, even in high-vibration environments. (Although honestly, we never used through-hole resistors in that environment, so I don't know if those would break off or not). I've seen lots of relatively big SMT electrolytic caps and through-hole electrolytic caps and crystal oscillators that would fail in the field until they started adding epoxy to anchor them to the board more securely." CreationDate="2011-01-15T21:48:42.523" UserId="813" />
  <row Id="13399" PostId="9066" Text="@vicatu, I'd upvote that as an answer. (Er, in 2 hours, when my daily limit clears.)" CreationDate="2011-01-15T21:50:08.577" UserId="2118" />
  <row Id="13400" PostId="9064" Text="I`ve used exclusively Keil for 10 years and found the compiler, hardware and support to be very good.  However they are the most expensive of the 3 you mention!" CreationDate="2011-01-15T22:12:53.480" UserId="1827" />
  <row Id="13401" PostId="7633" Text="So, did you get this working?" CreationDate="2011-01-15T22:18:09.610" UserId="1827" />
  <row Id="13403" PostId="8453" Text="I had my 1st successful transfer, only a small bit didn't transfer fully but when i etch'ed the board the copper stayed. The only thing i found was that I didn't leave the board in the Ferric Chloride long enough as there are some copper dots left around some of the more dense areas. Although I have done a small test and found no shorts just waiting on my Drill press from mytoolstore to come and I will drill out the bad boy and populate it." CreationDate="2011-01-15T23:54:46.023" UserId="665" />
  <row Id="13404" PostId="6755" Text="@W5VO I order a heap of common anode displays by mistake and can't use them the MAX7219's that I have due to the max being common cathode. So should work for what I want I will have to look at how I am going to do it another time." CreationDate="2011-01-15T23:57:39.267" UserId="665" />
  <row Id="13406" PostId="7548" Text="Grounding one side of a cable provides electric field shielding (but not magnetic).  Grounding both sides provides electric and magnetic protection by &quot;closing the loop&quot; and allowing current flow in the shield (to cancel the magnetically induced noise.  It also introduces the possibility of ground loops, which can increase noise.  This probably isn't a problem for home audio equipment though." CreationDate="2011-01-16T00:29:44.133" UserId="2377" />
  <row Id="13407" PostId="9074" Text="I feel exactly the same way about the modern tendency to [route PCBs on a square grid](http://electronics.stackexchange.com/questions/7913/why-is-there-such-a-strong-preference-for-45-degree-angles-in-pcb-routing), although the benefits of migration are much less significant." CreationDate="2011-01-16T00:30:49.073" UserId="1951" />
  <row Id="13409" PostId="7913" Text="@romkyns, The given example is the result of an [autorouter](http://www.eremex.com/products/topor/competitiveadvantages/autorouting.html), not manual routing. Many of the answers given apply only to manual routing (re: design efficiency)." CreationDate="2011-01-16T00:35:17.313" UserId="2118" />
  <row Id="13411" PostId="7913" Text="@tyblu I know. I still don't see any logic in claims that manual routing on the grid can be better quality than manual routing without a grid." CreationDate="2011-01-16T00:38:27.083" UserId="1951" />
  <row Id="13412" PostId="7913" Text="@romkyns, It's really just design time &amp; effort -- you don't have to *tweak* tracks when routing on a grid, because you know they're following the minimum spacing you setup beforehand. When going for minimum spacing without a grid you have to check spacing, or rely on a real-time DRC to tell you that you screwed up." CreationDate="2011-01-16T00:42:07.327" UserId="2118" />
  <row Id="13417" PostId="7231" Text="&quot;Linux host&quot; -- do you want to do development on your Linux PC? Or do want a chip capable of running Linux?" CreationDate="2011-01-16T01:19:15.987" UserId="813" />
  <row Id="13418" PostId="8991" Text="To clarify perhaps, the failure rate for a individual die is not the same across the surface of a wafer, but I believe in most cases it is lowest at the center, and increases for dies at the outer edge of the wafer. So binning of seemingly identical die cores, is done due to probability of failure, which can be mitigated through speed reductions, or potentially disabling a subset of features (i.e. if L2 cache or FPU is common spots for failure to appear due to density or parallel-ness), a binned version can have the feature disabled, reducing chance of failure for these outermost dies." CreationDate="2011-01-16T02:08:12.347" UserId="2598" />
  <row Id="13419" PostId="7913" Text="@tyblu with crappy tools - maybe. I don't see why a good tool wouldn't let your tracks &quot;snap&quot; to minimum spacing you've set in your design rules. Seriously, I understand the argument that current tools suck at that, but not that this is an inherent property of no-grid design." CreationDate="2011-01-16T02:26:45.497" UserId="1951" />
  <row Id="13420" PostId="4999" Text="Brad, a balanced transformer would be feasible, but a inductor (i.e. single wire, no coupling) would be useless. The phone line side needs a very high impedance though, at least 5 Megaohm." CreationDate="2011-01-16T02:28:51.113" UserId="2598" />
  <row Id="13421" PostId="4994" Text="Stefan, wire tapping laws are pretty much universal. I'm sure SA does have such laws and regulations." CreationDate="2011-01-16T02:32:14.090" UserId="2598" />
  <row Id="13423" PostId="8694" Text="Sounds like possibly the KIM-1 or Cosmac ELF, both of which included a microprocessor (MOS 6502 and RCA [CD]1802). KIM: http://oldcomputers.net/kim1.html  ELF: http://www.cosmacelf.com/" CreationDate="2011-01-16T02:57:49.320" UserId="2598" />
  <row Id="13424" PostId="9091" Text="Which datasheet? The FRM for UART, the PIC24F datasheet itself, or something else? The PIC24F datasheet has some timer documentation on 129, and the FRM only has 38 pages, am I missing something? Also, I thought that all inputs were by default digital but I will try turning them off anyway, thanks for the suggestion." CreationDate="2011-01-16T03:48:50.283" UserId="1225" />
  <row Id="13425" PostId="9091" Text="Datasheet for the PIC24FJ64GA002 (39881D.PDF) Should be page 110. The analogue function is mentioned there." CreationDate="2011-01-16T03:59:18.317" UserId="305" />
  <row Id="13426" PostId="9057" Score="1" Text="Can you link us to these examples?" CreationDate="2011-01-16T04:07:58.670" UserId="230" />
  <row Id="13427" PostId="9063" Text="Give us links! They help users dive right in." CreationDate="2011-01-16T04:08:13.850" UserId="230" />
  <row Id="13433" PostId="9058" Text="why the 1 vote for close?" CreationDate="2011-01-16T05:35:17.737" UserId="1688" />
  <row Id="13435" PostId="9085" Text="I just did this on the 24FJ, yesterday, as well :) .. And for your setup you will see a 115200/(8+1+1)=11.5kHz tone." CreationDate="2011-01-16T06:23:52.050" UserId="2118" />
  <row Id="13436" PostId="9095" Text="Any idea what this peak is for some standard cells? The closest indictor I've seen for this is Energizer's *&quot; [Battery Selection Indicator](http://data.energizer.com/PDFs/E91.pdf) &quot;* in all their datasheets, and they are qualitative." CreationDate="2011-01-16T06:33:11.887" UserId="2118" />
  <row Id="13437" PostId="4728" Text="@ fceconel: Have you used schmartboard? what are you reviews of it?" CreationDate="2011-01-16T06:35:08.000" UserId="444" />
  <row Id="13438" PostId="9093" Text="@AnswerToThePoint If you think this is a bad answer, vote it down. It is very much on-topic for your question, as it is good safety/legal advice. However, your previous question was clearly off-topic for the site as a whole. If you have an issue with it, please raise it on meta." CreationDate="2011-01-16T08:49:24.107" UserId="566" />
  <row Id="13442" PostId="9085" Text="@tyblu Ah yeah... because you've got 8 bits of data, 1 start bit and 1 stop bit." CreationDate="2011-01-16T11:47:30.977" UserId="1225" />
  <row Id="13443" PostId="9071" Score="1" Text="@mikeselectricstuff - That depends on what you mean by tip. My metcal iron has a &quot;Tip&quot; and a &quot;Heater Cartridge&quot;. The tip is actually completely isolated from the heater leads (well, it is grounded), and is heated inductively by a coil in the &quot;Heater Cartridge&quot;. Therefore, removing the tip will not affect the resistance, but removing the heater cartridge will." CreationDate="2011-01-16T11:49:10.523" UserId="1374" />
  <row Id="13444" PostId="9089" Text="I am curious about this. I have several phones which work off the telephone line. One digital one too. If you unplug the AC adapter the display goes very faint, but it is still usable. I think it is some kind of legal requirement that you can still dial emergency services without power but I could be wrong." CreationDate="2011-01-16T13:17:06.127" UserId="1225" />
  <row Id="13446" PostId="9093" Text="@Joby I can't voted down yet... Thanks for the advice." CreationDate="2011-01-16T14:43:05.473" UserId="2634" />
  <row Id="13448" PostId="9089" Text="@Thomas do these phones (that you mentioned) have a caller ID feature?" CreationDate="2011-01-16T14:52:25.957" UserId="2634" />
  <row Id="13452" PostId="9089" Text="@Answer To The Point. I don't think so - but the additional current consumption of such a feature should be minimal. I live in the UK though, so requirements are probably different." CreationDate="2011-01-16T15:18:28.377" UserId="1225" />
  <row Id="13453" PostId="9097" Score="1" Text="Take a look at http://www.shieldlist.org/ and see if you can find your shields in the list. 1) The shield list shows the pins used by each shield, so you can see if the shields are using the same pins. 2) If you are still stuck, you can point the rest of us to the shields you are using to better help you out." CreationDate="2011-01-16T16:19:29.923" UserId="2489" />
  <row Id="13454" PostId="9099" Text="Read into 4-wire measurement. There are 2 pairs of wires of which one does the measurement, and the other wires are for the measurement (voltage). Wire resistance on thin wires can become significant in 100 ohm range, of thicker wire at several ohm's." CreationDate="2011-01-16T16:20:45.657" UserId="1476" />
  <row Id="13455" PostId="9091" Text="Ah, turns out the problem wasn't analog inputs, but JTAG on the pins being enabled (the same as for I2C.) But it got me thinking about it being some peripheral conflict. Thanks! :)" CreationDate="2011-01-16T16:24:21.660" UserId="1225" />
  <row Id="13456" PostId="9099" Text="possible duplicate of [Resistance Measurement](http://electronics.stackexchange.com/questions/8021/resistance-measurement)" CreationDate="2011-01-16T16:25:23.757" UserId="2118" />
  <row Id="13457" PostId="9100" Text="What is the secondary load?" CreationDate="2011-01-16T16:33:13.733" UserId="2118" />
  <row Id="13458" PostId="9099" Text="Its borderline duplicate as I'm asking about whether or not I should ignore the resistance of the wires when taking my readings. But your answer is very good." CreationDate="2011-01-16T16:34:51.783" UserId="1623" />
  <row Id="13459" PostId="9099" Text="I agree: it is borderline, and I like it. I'll try to answer later." CreationDate="2011-01-16T16:40:10.277" UserId="2118" />
  <row Id="13460" PostId="9100" Text="I got a good answer on why you need the grounds connected when using two supplies here:  http://electronics.stackexchange.com/questions/7018/why-do-0v-have-to-be-connected-when-using-two-power-supplies-and-uln2803a" CreationDate="2011-01-16T16:43:50.793" UserId="1623" />
  <row Id="13462" PostId="9097" Text="i don't know what pins are used by the libelium shield yet :(" CreationDate="2011-01-16T16:54:58.113" UserId="2245" />
  <row Id="13463" PostId="9089" Text="@Thomas Thanks. In my answer below I provided a link to an REN article which confirms that requirements vary among countries. It seems that **as long as you meet the REN requirement**, there is not difference whether you power a ringer or any other circuit." CreationDate="2011-01-16T16:57:56.907" UserId="2634" />
  <row Id="13464" PostId="8973" Text="@Peterstone, Do you have a project or class page link? This sounds very interesting." CreationDate="2011-01-16T18:23:27.787" UserId="2118" />
  <row Id="13465" PostId="9085" Text="I like to debug UARTs by sending `UUUU...`, which translates to `1010101010*...`, giving a baud/2 square wave. (`0*` is stop bit, and should be slightly longer than other `0` s.)" CreationDate="2011-01-16T18:42:01.643" UserId="2118" />
  <row Id="13466" PostId="9102" Text="I don't understand your answer. Could you clarify?" CreationDate="2011-01-16T19:23:58.973" UserId="2118" />
  <row Id="13467" PostId="2854" Text="Starting bounty! Am interested the comparison between RTOS's." CreationDate="2011-01-16T19:28:03.117" UserId="2118" />
  <row Id="13468" PostId="2854" Score="3" Text="Why is there a vote to close on this question? RTOS's are used in electronics and robotics all of the time." CreationDate="2011-01-16T19:34:47.330" UserId="319" />
  <row Id="13469" PostId="9101" Text="Thanks zebonaut. Back supplying was something I was worried about. When looking for the supply should I think of the two devices as in series or parallel? Do you know of any links that help explain this." CreationDate="2011-01-16T19:37:55.013" UserId="2617" />
  <row Id="13470" PostId="9086" Text="Getting closer... It seems that this is very doable as there already at least one product that does this: http://www.phonesonsale.com/fc-7627.html" CreationDate="2011-01-16T20:10:22.653" UserId="2634" />
  <row Id="13471" PostId="9104" Text="Yes, microwaves would work. The issue is that without shielding, high power microwaves are dangerous. It would be difficult to shield a device that beamed into a pipe, but I don't think it would be impossible." CreationDate="2011-01-16T21:01:22.177" UserId="2118" />
  <row Id="13472" PostId="9107" Text="Im using NiMH batteries. So will take this in to consideration now. " CreationDate="2011-01-16T21:41:41.950" UserId="1623" />
  <row Id="13473" PostId="9089" Text="@Answer To The Point, while REN is a requirement, you also **must** have your device certified to be legal (as per part 68), and this is expensive (upwards of thousands of dollars.) " CreationDate="2011-01-16T21:42:50.240" UserId="1225" />
  <row Id="13474" PostId="9085" Text="@tyblu, Good idea. I did that too. You have to be aware though when working at high frequencies as the processor latency between loading the next byte can become a deciding factor. For example, I found at 115,200 baud my MCU could adequately produce a square wave with only a tiny bit of jitter. At 2 Mbaud, it had considerable delay between each byte and no longer resembled a square wave." CreationDate="2011-01-16T21:44:48.317" UserId="1225" />
  <row Id="13475" PostId="9109" Text="I was thinking of combining the two into some kind of message format which used both parity and CRC8 or CRC16. The PIC24F I'm using has a built in CRC generator which is very useful for me." CreationDate="2011-01-16T22:06:33.973" UserId="1225" />
  <row Id="13476" PostId="8643" Text="A variation on this would be to do away with the wider-diameter pieces, and spring-load the undriven wheel against the one with the motor, so that the undriven wheel spins up by contact, but when a ball enters the gap, it can 'swing out of the way' a little bit. The energy for the kick from the undriven wheel comes from its inertia, so you'd probably want to weight it a little. " CreationDate="2011-01-16T22:58:07.013" UserId="740" />
  <row Id="13477" PostId="8639" Text="@Nick T - with a *ping pong ball* it's probably going to drift all over no matter what =P" CreationDate="2011-01-16T22:59:40.080" UserId="740" />
  <row Id="13479" PostId="9089" Score="1" Text="@Anwer To The Point: I have answered the question as best I can given the lack of technical details." CreationDate="2011-01-16T23:50:47.103" UserId="2598" />
  <row Id="13480" PostId="9065" Score="1" Text="For just below freezing ambient temperatures, constantly flowing cold water (e.g. 4-10 C [40-50F]) will actually work too. That is why cold water pipes most often burst while people are away, the cold water is still long enough to cool to freezing." CreationDate="2011-01-17T00:43:20.347" UserId="2598" />
  <row Id="13481" PostId="9058" Text="I didn't down-vote, but it may of been because the question may be considered _too local_ as it is about buying of a non-electronic (i.e. pieces of machines metal - which may be _off-topic_) parts." CreationDate="2011-01-17T00:52:27.713" UserId="2598" />
  <row Id="13482" PostId="9047" Text="@Dean: right on, go for it." CreationDate="2011-01-17T01:29:51.520" UserId="740" />
  <row Id="13483" PostId="8689" Text="i agree with the figure 8 pulley-belt thing." CreationDate="2011-01-17T01:53:38.220" UserId="2643" />
  <row Id="13484" PostId="9111" Score="2" Text="+1 on the timeouts.  On an application like this, you need to enable your watchdog and test to make sure it is working properly." CreationDate="2011-01-17T03:40:39.693" UserId="411" />
  <row Id="13485" PostId="9109" Score="2" Text="It is very rare, almost impossible, to have an error that the parity will catch and the CRC won't catch." CreationDate="2011-01-17T03:41:22.953" UserId="411" />
  <row Id="13486" PostId="9101" Text="@JustSmith One way of thinking about the whole series-parallel issue, it may be useful to keep this in mind: parts/devices in series share the same current, and parts in parallel share the same voltage. For IC's with the same voltage requirement, you want to share the same power supply VOLTAGE, so they will be in parallel." CreationDate="2011-01-17T03:51:09.800" UserId="638" />
  <row Id="13488" PostId="9116" Score="1" Text="Note: You should **never** assume the wire colors are correct. My house is largely wired with orange and yellow wire, and the ground is carried through the flexible metal conduit through which all the wires run." CreationDate="2011-01-17T07:19:09.620" UserId="1374" />
  <row Id="13490" PostId="9117" Score="1" Text="I think this is a duplicate of http://electronics.stackexchange.com/questions/616/basic-electronics-book. Take a look at the answers here, and you might find something useful." CreationDate="2011-01-17T07:47:09.063" UserId="2426" />
  <row Id="13491" PostId="9109" Score="1" Text="@markrages, for 32-bit CRC, you have 1/8 billion chance to have same crc &amp; parity, provided that you have multi-bit errors." CreationDate="2011-01-17T08:47:28.543" UserId="2062" />
  <row Id="13492" PostId="8689" Text="With a flat-belt, the system is surprisingly low-wear, with belts often failing from age before mechanical wear. With other belt types, it varies, depending on the belt tension, sheave spacing, and bely shape and material. In all cases, however, the rubbing force is fairly low, so the wear is pretty minor." CreationDate="2011-01-17T10:05:04.270" UserId="1374" />
  <row Id="13493" PostId="8981" Text="Good observation. Thanks." CreationDate="2011-01-17T10:09:54.220" UserId="1888" />
  <row Id="13494" PostId="9123" Text="Ugh. My college blocks &quot;hackaday.com&quot; as &quot;Hacking/Cracking/Computer Crime&quot;... :(" CreationDate="2011-01-17T10:51:33.623" UserId="1225" />
  <row Id="13495" PostId="6102" Text="And for the software side, look in the excellent AVR32 Software Framework available from Atmel which has drivers and examples for the USARTs." CreationDate="2011-01-17T11:42:20.120" UserId="2308" />
  <row Id="13496" PostId="9130" Score="2" Text="The rightmost cap in the top row looks more like &quot;221&quot; to me, so I'd vote for 220pF - I concur with the rest of your statements." CreationDate="2011-01-17T13:22:45.213" UserId="1293" />
  <row Id="13497" PostId="9127" Text="Actually, the cap is X5R." CreationDate="2011-01-17T13:23:42.713" UserId="1225" />
  <row Id="13498" PostId="9129" Score="1" Text="Do you have a DMM with a capacitance setting, or an oscilloscope to do the measurement manually?" CreationDate="2011-01-17T13:24:57.673" UserId="857" />
  <row Id="13499" PostId="9124" Text="+1 for the chamfer.  That's the method that I've seen most often.  Should we put up a diagram?" CreationDate="2011-01-17T13:26:24.037" UserId="857" />
  <row Id="13500" PostId="9120" Text="Related: http://electronics.stackexchange.com/q/8705" CreationDate="2011-01-17T13:28:37.670" UserId="2118" />
  <row Id="13501" PostId="9127" Text="X5R is good for -55 to +85 with +/- 15% variation. I would stick with AVX's recommendations for derating. See http://www.avx.com/tantalum/data/tech/voltage_deraing.pdf" CreationDate="2011-01-17T13:30:57.697" UserId="1293" />
  <row Id="13503" PostId="9130" Text="I think you are right. I've changed it." CreationDate="2011-01-17T14:33:44.697" UserId="305" />
  <row Id="13504" PostId="9106" Score="1" Text="Helical does decrease the polarization issue by sacrificing a little bit of gain all the way around to avoid massive loss of gain in certain polarization scenarios.  However, you do still have right hand vs. left hand to deal with if the GPS satellites use circular polarization.  Not sure about that at the moment..." CreationDate="2011-01-17T14:41:59.777" UserId="1678" />
  <row Id="13506" PostId="8893" Text="I'm struggling to find any 10uF ceramic SMDs like you suggested.  I'm not really sure what the '1206' and 'SMD' references mean to be honest.  I've been looking at this site here: http://uk.farnell.com/capacitors_ceramic but don't know what dielectric or voltage rating I need, so can't figure out which caps are suitable.  Could you suggest something?" CreationDate="2011-01-17T14:56:49.340" UserId="2573" />
  <row Id="13507" PostId="8893" Score="1" Text="Caps in 600 chars:  SMD/SMT/SMC are acronyms for Surface Mount Device/Technology/Component. 1206 is a package ID, just like DIP-8 or TO-220. 1206 is the size of the component-a 1206 cap is approximately [0.12&quot; by 0.06&quot;](http://en.wikipedia.org/wiki/Surface-mount_technology#Package_sizes). The first character of the dielectric is the minimum temperature (X&lt;Y&lt;Z; X is best) is the maximum temperature (2&lt;3&lt;...&lt;8, 8 is best), and the last number is the temperature dependence (V is -20/+80, R is +/-15%, there are others). X7R and X5R are good. Derate the voltage by 50-100%, so use a 10V cap on 5V.  " CreationDate="2011-01-17T15:46:55.213" UserId="857" />
  <row Id="13508" PostId="8893" Score="1" Text="To find it on Farnell, select 'Capacitance&gt;10uF' and 'Capacitor Case Style&gt;1206' to narrow it down to 96 possibilities.  Then, select the voltage rating to be 50% to 100% greater than your expected voltage, so pick the 10V rating, and choose X5R and X7R dielectrics for [these 15 possibilities](http://bit.ly/etkZMg).  Pick the cheapest in stock one; looks like [this £0.099 one: 1650933](http://uk.farnell.com/taiyo-yuden/lmk316bj106kl-t/capacitor-ceramic-multilayer/dp/1650933) is the best right now." CreationDate="2011-01-17T15:53:27.327" UserId="857" />
  <row Id="13509" PostId="8893" Score="1" Text="Note: it looks like they're also available in 0805 for similar (or even lower!) prices, last I checked 10uF at 10V was hard to get in 0805.  Guess I'm a little out of date." CreationDate="2011-01-17T15:55:32.690" UserId="857" />
  <row Id="13510" PostId="9125" Text="I heard that people had success using convection ovens and PCBs for temperature testing." CreationDate="2011-01-17T16:11:48.457" UserId="1240" />
  <row Id="13511" PostId="9139" Score="3" Text="This is exactly what I needed! Searching for &quot;chip-on-board&quot; yielded a wealth of information, including a page that shows the various stages of assembly before the &quot;blob&quot; is added.  http://www.empf.org/empfasis/dec04/improve1204.htm" CreationDate="2011-01-17T16:25:52.900" UserId="1802" />
  <row Id="13512" PostId="2417" Text="@DoxaLogos, for those who haven't seen it, the original Write Only Memory story and datasheet. http://www.national.com/rap/Story/WOMorigin.html" CreationDate="2011-01-17T16:43:43.850" UserId="2110" />
  <row Id="13513" PostId="8977" Text="Thanks for the pic, what brand is it, what is your feedback regarding this device?" CreationDate="2011-01-17T16:50:31.920" UserId="444" />
  <row Id="13514" PostId="8893" Text="Thanks, that's been a great help - trouble is, those things look tiny, am I going to be able to solder them onto the Sharp IR with a normal bog-standard soldering iron?" CreationDate="2011-01-17T16:59:40.387" UserId="2573" />
  <row Id="13516" PostId="9034" Text="Spray paint &amp; masking tape? Do it up!" CreationDate="2011-01-17T17:31:14.137" UserId="2006" />
  <row Id="13517" PostId="9137" Score="1" Text="If you really want to know more, you can dissolve the epoxy and have a look http://travisgoodspeed.blogspot.com/2009/06/cold-labless-hno3-decapping-procedure.html" CreationDate="2011-01-17T17:40:18.823" UserId="566" />
  <row Id="13518" PostId="9139" Text="Also called glob-top or blob-top http://en.wikipedia.org/wiki/Blob_top ." CreationDate="2011-01-17T17:44:15.263" UserId="813" />
  <row Id="13519" PostId="8215" Text="'XC' is definitely a Xilinx IC designator; they had an XC3000 series in the late 80s early 90s, long obsolete." CreationDate="2011-01-17T18:08:46.997" UserId="2531" />
  <row Id="13520" PostId="9089" Text="@mctylr You were one of the very few who answered my questions to the point. Thank you for that and I am sorry if my initial reply to your very useful answer didn't reflect that (I was still shocked by the &quot;welcome&quot; I received here). Because I was new, I wasn't able to give you the upvotes you deserve. Now I can. :)" CreationDate="2011-01-17T18:27:38.087" UserId="2634" />
  <row Id="13521" PostId="9089" Text="Also, the initial phrasing was suggested @tyblu, not realizing this would prompt legal advice instead of general technical information that helps focus on the problem at hand. I don't really have any invention, I was just looking to see if a caller ID phone **without** batteries is at all possible. It turns out that there already are quite a few products like that, which implies that this is perfectly possible within the law(s). " CreationDate="2011-01-17T18:35:10.297" UserId="2634" />
  <row Id="13522" PostId="9119" Text="Can you explain what you mean by &quot;free&quot;." CreationDate="2011-01-17T19:42:54.350" UserId="319" />
  <row Id="13523" PostId="9130" Text="An LC meter that outputs in Morse code...right.  I figured with the FCC no longer requiring hams to know Morse meant it could be pronounced dead once and for all :P" CreationDate="2011-01-17T20:45:44.200" UserId="1407" />
  <row Id="13524" PostId="9119" Text="@Kellenjb - I imagine that Bars is referring to a hardware-based parity check, as opposed to software.  A parity bit will, however, require an additional bit in the data stream, so it's not really free.  " CreationDate="2011-01-17T21:11:35.280" UserId="857" />
  <row Id="13526" PostId="9137" Text="@Joby - I've never tried it, but I imagined that the epoxy is a different sort of component from the plastic cases.  Now I need to get myself some acid and try it out...." CreationDate="2011-01-17T21:19:54.363" UserId="857" />
  <row Id="13527" PostId="9113" Text="+1 Good. More preventive actions." CreationDate="2011-01-17T21:29:45.817" UserId="2466" />
  <row Id="13528" PostId="9142" Text="Thanks a lot for the feedback. I'm aware of the GS407 from Sparkfun, but it seems a bit pricey. The update rates are no problem, even 1 Hz would be no problem for my applications. Thanks for the tip on runners' watches, although my project is a single-build hobby project (for fun) not meant for production so my budget won't allow such things. I'll probably end up with a Sarantel SL1300 attached to some reasonably priced module." CreationDate="2011-01-17T22:58:43.930" UserId="2642" />
  <row Id="13531" PostId="9146" Score="2" Text="http://electronics.stackexchange.com/questions/6283/learning-about-electronics-stuff http://electronics.stackexchange.com/questions/724/what-are-the-best-beginner-project-using-an-arduino http://electronics.stackexchange.com/questions/8082/what-are-some-simple-and-informative-beginners-projects http://electronics.stackexchange.com/questions/3641/good-easy-soldering-projects-like-bristlebots" CreationDate="2011-01-17T23:24:00.090" UserId="566" />
  <row Id="13532" PostId="9146" Score="1" Text="@Carlos Your question is very broad. You will get better answers from several small questions on specific topics." CreationDate="2011-01-17T23:25:34.440" UserId="566" />
  <row Id="13534" PostId="9123" Text="My work blocks it as well. However, I've never had anything so urgent or valuable to reference on it that I've felt that it would be acceptable to report the misclassification.  It usually comes up when I'm browsing before clocking in, during lunch, or after clocking out (like now.)" CreationDate="2011-01-17T23:27:59.867" UserId="857" />
  <row Id="13535" PostId="9132" Score="1" Text="...And you've never generated any flames?" CreationDate="2011-01-17T23:28:27.870" UserId="857" />
  <row Id="13536" PostId="9147" Text="Your first link is broken." CreationDate="2011-01-17T23:36:55.317" UserId="857" />
  <row Id="13538" PostId="9151" Score="1" Text="Aha, pre-tinning both the SIL socket's pin and the pad could be the secret. I'll try it and report back." CreationDate="2011-01-17T23:42:44.420" UserId="1633" />
  <row Id="13539" PostId="9151" Text="I'm assuming the above advice applies to SIL-socket-to-pad, also?" CreationDate="2011-01-17T23:44:37.490" UserId="1633" />
  <row Id="13540" PostId="9139" Score="1" Text="You may also want to look into &quot;potting&quot; (http://en.wikipedia.org/wiki/Potting_%28electronics%29). Encapsulating the die in resin may also have security advantages -- the chip(s) under it require quite a procedure to expose and identify." CreationDate="2011-01-17T23:45:43.717" UserId="2531" />
  <row Id="13541" PostId="9151" Text="Indeed it does. If you have a longer strip of sockets to solder on adjacent pads, you'll only want pre-solder one pad. Once the part is attached to the PCB with a single joint, it will stay in place - you then feed fresh solder with the freed-up hand, just like soldering through-hole mounts." CreationDate="2011-01-17T23:59:19.090" UserId="2545" />
  <row Id="13542" PostId="9150" Text="Fixed the spelling of &quot;Arduino&quot; for you, not that I recommend it as the starting point for a project like this." CreationDate="2011-01-18T00:09:02.210" UserId="857" />
  <row Id="13543" PostId="9152" Text="Actually, I was planning on using E6000 under the heatshrink, as it says, &quot;hot-melt glue does exactly that&quot;: http://wiki.orbswarm.com/index.php?title=Building_Electronics_and_Robots_for_the_Desert" CreationDate="2011-01-18T00:09:29.637" UserId="1633" />
  <row Id="13544" PostId="9147" Text="Fixed, thanks. Sidenote: it took me a bit of random googling to work out these were called &quot;SIL sockets&quot; :-P" CreationDate="2011-01-18T00:12:29.923" UserId="1633" />
  <row Id="13545" PostId="9152" Text="@Robert - Good point!  I've also used superglue for really small stuff, but a limited flexibility epoxy like E6000 is probably better for larger wires like you're working with." CreationDate="2011-01-18T00:32:39.670" UserId="857" />
  <row Id="13546" PostId="9153" Score="2" Text="Connecting a (different) 3.3V I2C sensor to Arduino http://electronics.stackexchange.com/questions/708/i2c-3-3-to-5-0-v-conversion" CreationDate="2011-01-18T00:32:53.010" UserId="566" />
  <row Id="13547" PostId="9155" Text="CAN-Pirate http://dangerousprototypes.com/forum/index.php?topic=464.msg4045#msg4045" CreationDate="2011-01-18T00:38:18.557" UserId="566" />
  <row Id="13549" PostId="9139" Score="1" Text="@Davidcary very interesting. I am sure @Ranieri had no ideal that &quot;blob&quot; was actually the technical word for it when asking the question." CreationDate="2011-01-18T02:43:23.053" UserId="319" />
  <row Id="13550" PostId="9109" Text="@BarsMonster, How did you get that figure?" CreationDate="2011-01-18T02:46:04.327" UserId="2118" />
  <row Id="13551" PostId="1324" Text="I just had this exact same question! " CreationDate="2011-01-18T03:07:22.613" UserId="771" />
  <row Id="13552" PostId="9155" Text="@Joby - Yeah, but that's still pretty experimental, is hard to get, and requires assembly/soldering.  I didn't want to recommend it for a first time back to electronics." CreationDate="2011-01-18T03:10:48.360" UserId="857" />
  <row Id="13553" PostId="8462" Text="This guy likes using OPA2134: http://sound.westhost.com/projects-2.htm" CreationDate="2011-01-18T03:27:52.423" UserId="2545" />
  <row Id="13554" PostId="9119" Text="Yes, free = it's already implemented in hardware on both sides." CreationDate="2011-01-18T04:01:51.433" UserId="2062" />
  <row Id="13555" PostId="9109" Score="1" Text="For multibit errors, probability to get same CRC - 1/2^32. Probability to get same parity = 1/2. Multiply and here we go." CreationDate="2011-01-18T04:02:26.723" UserId="2062" />
  <row Id="13556" PostId="9159" Text="That Phillips appnote is practically a classic." CreationDate="2011-01-18T04:08:27.977" UserId="857" />
  <row Id="13557" PostId="9160" Text="Addtionally, I'd appreciate it if someone would embed the schematic in the question. I do not yet have sufficient rep." CreationDate="2011-01-18T04:29:08.520" UserId="2656" />
  <row Id="13558" PostId="9160" Text="It is not yet possible to use TeX, but [we're working on it.](http://meta.electronics.stackexchange.com/q/192/2118)" CreationDate="2011-01-18T04:45:21.233" UserId="2118" />
  <row Id="13559" PostId="9154" Text="Fantastic info, Mark! I also thought a stable passband from 3-30GHz would be unmanageable (and not useful), but would like to try out some in that range. My *5-year plan* is to build a ~3GHz spectrum analyzer with external mixers, so BPFs couldn't have more than a ~2.4GHz passband. I will definitely look into everything you've mentioned." CreationDate="2011-01-18T05:56:06.367" UserId="2118" />
  <row Id="13562" PostId="9109" Text="Ah, I see, so `&lt;#bits/packet&gt;[bits/packet]*2^33[packets/error]/1Mbaud[bps]=&lt;#bits/packet&gt;*2.4hours/error`, or about 2.4hours per error per bit, or ~102 days for 1kB packets." CreationDate="2011-01-18T06:47:22.187" UserId="2118" />
  <row Id="13563" PostId="7231" Text="@stevenvh, in Wavecom's case it made it impossible to find anything (datasheets, forum posts, docs etc) using a search engine as everything required registration. Downloading old version of the IDE is also a pain now that they have been acquired." CreationDate="2011-01-18T07:08:18.407" UserId="554" />
  <row Id="13564" PostId="9155" Text="@reemrevnivek I agree, just thought I'd mention it" CreationDate="2011-01-18T08:20:54.813" UserId="566" />
  <row Id="13565" PostId="8416" Text="@Kortuk, I should probably edit to weaken the implication of my observation that I've never met a PC shedding load per port. It is certainly allowed (and encouraged) by the spec, and is probably the correct answer so that a limited energy budget is allocate to things that must be powered for the PC to remain useful." CreationDate="2011-01-18T09:27:34.710" UserId="1494" />
  <row Id="13566" PostId="9165" Text="uh... 20 m/s is 72 km/h" CreationDate="2011-01-18T11:04:05.527" UserId="1240" />
  <row Id="13567" PostId="9162" Text="Yes, I know about PICMG, but that is a for a two-segment pcie backplane. I need one with only one pcie slot, as you find in the regular computer industry, not on servers &amp; co." CreationDate="2011-01-18T11:24:58.730" UserId="2645" />
  <row Id="13568" PostId="9166" Text="There is also commercial equipment, like this: http://www.bennettavionics.com/radaraltimeter.html" CreationDate="2011-01-18T11:28:25.183" UserId="2636" />
  <row Id="13569" PostId="9165" Text="Vmax is 100 kph. Vaverage is 20m/s. Thanks for pointing it out. :)" CreationDate="2011-01-18T12:38:49.490" UserId="2659" />
  <row Id="13570" PostId="8416" Text="@RBerteig, I would agree. I know some computers do not enforce power limits, but designing a product for that is bad." CreationDate="2011-01-18T12:47:16.350" UserId="230" />
  <row Id="13571" PostId="9166" Text="We have considered this. It's not quite a &quot;homebrew&quot;-project, so I think we have the means to build, perhaps even buy a radar-altimeter. Thanks!" CreationDate="2011-01-18T12:54:48.730" UserId="2659" />
  <row Id="13572" PostId="9167" Text="Unfortunately we can't implement a vision-based solution due to weight-limitations. The core-CPU of the drone is already used for sensor-input and other image-processing and we have reached the maximum amount of payload." CreationDate="2011-01-18T12:58:00.193" UserId="2659" />
  <row Id="13573" PostId="9159" Text="@reemrevnivek yes, and very clever indeed" CreationDate="2011-01-18T14:10:35.823" UserId="771" />
  <row Id="13574" PostId="9119" Text="@BarsMonster I am using a hardware module on a PIC24F which supports odd, even and no parity." CreationDate="2011-01-18T14:24:35.823" UserId="1225" />
  <row Id="13575" PostId="9155" Text="Thanks, I appreciate the answer. Have a look at Caterham 7 online. They make car kits. No idea what one could build for ones car however." CreationDate="2011-01-18T14:55:23.273" UserId="2655" />
  <row Id="13576" PostId="9166" Score="1" Text="make sure whatever you do is in compliance with emission regulations for your region" CreationDate="2011-01-18T15:11:00.717" UserId="771" />
  <row Id="13577" PostId="9160" Text="it's j * omega... i is for mathematicians not engineers :)" CreationDate="2011-01-18T15:13:50.700" UserId="771" />
  <row Id="13578" PostId="9161" Text="@tyblu gives an excellent answer. The key point here is that the resistors determine the DC bias (as a plain old voltage divider) that gets added to the AC signal at V_in. The size of the capacitor should be such that it has a negligible impedance in the frequency range of interest (so it's generally a very small valued capacitor)" CreationDate="2011-01-18T15:32:34.037" UserId="771" />
  <row Id="13579" PostId="9168" Text="Yup, I saw that on the mailing list. Thanks for the update!" CreationDate="2011-01-18T15:46:03.490" UserId="857" />
  <row Id="13580" PostId="9155" Text="@Carlos - Also have a look at http://www.wikispeed.com/, I talked to one of their engineers at NAIAS this weekend, and it (their modular, carbon-fiber body, 100mpg, Honda engine car) looks promising.  " CreationDate="2011-01-18T15:49:52.800" UserId="857" />
  <row Id="13581" PostId="8416" Text="@Kortuk - Certainly, but modding your own laptop with no intentions of going to production (or even transferring the design to a different computer) is not bad." CreationDate="2011-01-18T15:53:36.507" UserId="857" />
  <row Id="13582" PostId="8416" Text="@reemrevnivek, your warranty and your time, that is your decision. I design with intent to follow standards and layout with intent of FCC validation (CE Mark), I have never sent a personal project to FCC validation, but I would feel comfortable sending one. Just like to old adage, &quot;To write beautiful code you must have already written beautiful code for 20 years,&quot; always following good design methodology is good practice." CreationDate="2011-01-18T16:02:40.007" UserId="230" />
  <row Id="13583" PostId="9165" Text="@fakemustache - You can click the 'edit' text beneath the tags to fix any errors or clarify your question.  Other users with enough rep can also do this, so I'll fix that for you." CreationDate="2011-01-18T17:11:55.770" UserId="857" />
  <row Id="13584" PostId="9173" Text="I know about the site, but I am looking for a much more concise way to learn. " CreationDate="2011-01-18T17:14:02.523" UserId="1200" />
  <row Id="13586" PostId="9161" Text="Thank you tyblu for mentioning superposition! Superposition makes sense because the voltage-current relation of all of the elements in the network are linear. (In the case of the capacitor, exciting the voltage as a sinusoid, the current is a sinusoid with the same frequency) &#xA;&#xA;I am not sure I understand the small correction. I agree that the impedance of the capacitor is 1/sC, but in node current sum (Kirchoff's law) equation, I am adding all of the currents, so I'm dividing the voltage across the device by the impedance of the device." CreationDate="2011-01-18T17:23:33.640" UserId="2656" />
  <row Id="13587" PostId="9165" Text="@reemrevnikev, thx!" CreationDate="2011-01-18T18:32:52.647" UserId="2659" />
  <row Id="13588" PostId="9171" Text="Or for more general coarse/fine sensors you could use GPS for a coarse sensor and below some height use radar/ultrasonic/IR/whatever." CreationDate="2011-01-18T18:49:15.153" UserId="1407" />
  <row Id="13589" PostId="9159" Text="I count 2 more pull-ups than normal.  Not quite exact :P" CreationDate="2011-01-18T18:53:16.867" UserId="1407" />
  <row Id="13590" PostId="9171" Text="@Nick, agreed though for GPS altitude is by far the least accurate dimension. I've seen variations on some GPS receivers on the order of +/-30 meters for a stationary receiver." CreationDate="2011-01-18T19:12:16.197" UserId="771" />
  <row Id="13591" PostId="9161" Text="@Gus, You're quite right! Thanks for not taking what people say at face value!" CreationDate="2011-01-18T19:38:08.560" UserId="2118" />
  <row Id="13592" PostId="9178" Text="@hongyi - Do you expect the surrounding devices to run a program to identify themselves and broadcast their identity via Bluetooth or 802.11 wifi, or are you trying to detect them without modification?  The former seems doable, the later will be extremely difficult to generalize.  Are you sure you meant to group 'remote' in there, and are you looking for an iPod touch (which has bluetooth/wifi)?" CreationDate="2011-01-18T19:58:54.493" UserId="857" />
  <row Id="13593" PostId="9177" Text="Interesting technique! The OP did post a comment to [this answer](http://electronics.stackexchange.com/questions/9165/how-do-i-implement-accurate-distance-measuring-to-ground-on-a-plane-like-uav-fo/9167#9167) stating that &quot;Unfortunately we can't implement a vision-based solution due to weight limitations.&quot;  Still, it would be interesting to see if this technique could be used to control horizontal attitude as well." CreationDate="2011-01-18T20:03:49.993" UserId="857" />
  <row Id="13594" PostId="9005" Text="You could post a picture and maybe get lucky and someone identifies it, or has informed leads. Bunnie Huang may be interested in detective work as well ;) http://www.bunniestudios.com/" CreationDate="2011-01-18T20:32:13.753" UserId="2531" />
  <row Id="13595" PostId="9171" Text="I tend to agree with vicatcu, GPS is way to inaccurate. Unfortunately, since GPS is implemented one way or the other. " CreationDate="2011-01-18T20:35:10.847" UserId="2659" />
  <row Id="13596" PostId="9179" Text="It might help if you ask a specific question - let people know where you're stuck.   Sometimes experience from other devices can be applied, or it may be related to a more general IMU issue not specific to the Invensense." CreationDate="2011-01-18T20:35:49.470" UserId="249" />
  <row Id="13597" PostId="9170" Text="The thing with the radio emitters is very interesting, but too complex." CreationDate="2011-01-18T20:36:32.153" UserId="2659" />
  <row Id="13598" PostId="9180" Text="Very good points. Thank you. We have had the idea with the GPS ground station, I don't know why we didn't pursue it, I will mention it once more on our next meeting. " CreationDate="2011-01-18T20:41:13.507" UserId="2659" />
  <row Id="13599" PostId="9175" Text="We had that idea, too, and for now it is our favorite. As accurate height measurement is for autopilot landing only it doesn't matter that the height is for a point only.. I hope the landing area is at ground. :)) The main problem I see with this technique is that the result varies with the angle of the UAV which is especially difficult for landing procedures. Or am I not thinking this through?" CreationDate="2011-01-18T20:49:39.840" UserId="2659" />
  <row Id="13600" PostId="9178" Score="2" Text="@reemrevnivek It almost sounds like he is making a spectrum analyzer that could be used for regulatory validation, but I could be reading it wrong." CreationDate="2011-01-18T20:51:18.543" UserId="319" />
  <row Id="13601" PostId="9179" Text="That IMU comes with a pretty large library, some functions of which must be rewritten for the specific platform you're using.. I'm stuck at various levels within that library, I just would like to know whether anyone had to deal with it specifically.." CreationDate="2011-01-18T20:51:56.687" UserId="2285" />
  <row Id="13602" PostId="9179" Text="@Stefano Salatie So in other words you are re-asking http://electronics.stackexchange.com/questions/7844/invensense-imu3000-with-pic that question, but with less detail?" CreationDate="2011-01-18T20:53:55.527" UserId="319" />
  <row Id="13603" PostId="9177" Text="This really sounds beautiful. :D I will make sure to mention it. " CreationDate="2011-01-18T21:00:10.550" UserId="2659" />
  <row Id="13604" PostId="7177" Score="1" Text="This seems incomplete because it doesn't mention anything about the motor generating a back-emf, which would reduce the input energy (power) until it balances the losses." CreationDate="2011-01-18T21:06:04.193" UserId="1407" />
  <row Id="13605" PostId="9179" Text="@Kellenjb Indeed, hoping in the meanwhile somebody adopted this technology!" CreationDate="2011-01-18T21:30:00.693" UserId="2285" />
  <row Id="13606" PostId="9180" Score="1" Text="A possible lower-cost approach to the ground station and rover may be RTKlib.  It is an open-source RTK (differential) solution.  I believe that the creator of the library has also ported the solution to a Beagleboard, with some pointers on how to do the same.  I believe that his implementation uses a uBlox sensor (on the order of 300 dollars) coupled with a more expensive base station, capable of generating RTK corrections.  This would drive down the cost from purchasing two RTK-capable units (multiple thousands of dollars)." CreationDate="2011-01-18T21:33:44.353" UserId="1477" />
  <row Id="13607" PostId="9132" Text="Not so far :) Mind you, I usually work on stuff in chassis, and push the temps up to 60C." CreationDate="2011-01-18T21:55:24.037" UserId="1293" />
  <row Id="13608" PostId="9179" Text="Do you have a particular question about the IMU3000?  What do you want experiential knowledge about?  Ease?  Capabilities?  Performance?  Compatibility?" CreationDate="2011-01-18T21:59:05.567" UserId="1407" />
  <row Id="13609" PostId="9139" Text="@Kellenjb: I certainly did not! But it is very descriptive and engineers have a way of calling a spade a spade. Or a TLA ;)" CreationDate="2011-01-18T22:34:03.303" UserId="1802" />
  <row Id="13610" PostId="9154" Text="at frequencies under 3ghz constraints are much easier, you can use simpler/cheaper substrate.  You'll still be designing mostly with micro-strip structures for filters but there are a lot more off the shelf parts like PA/LNA etc as well as design information due to the high use of the 2.4Ghz spectrum." CreationDate="2011-01-18T23:21:05.897" UserId="1438" />
  <row Id="13611" PostId="9184" Text="I thought it was something to do with the internal resistance and could be shown with ohms law. Wasn't completely sure on the details." CreationDate="2011-01-18T23:37:32.083" UserId="1623" />
  <row Id="13612" PostId="9166" Text="that design is a good example but you could easily get to 3000m with a higher power PA (200mW maybe) and a more sensitive receiving circuit as well as improved post processing.  Controlling the sweep in an intelligent manor and bringing the output of the LPF into a DSP for post processing will help a lot.  At that point you've really built an FMCW radar and can get a fair bit of additional information out of it (weather conditions, type of ground cover, other planes under you, etc).  The antenna used will greatly influence performance and what kind of information you can determine.  " CreationDate="2011-01-18T23:46:52.573" UserId="1438" />
  <row Id="13613" PostId="9166" Text="SiverIMA (http://www.siversima.com/) makes some front ends you could probably use to save yourself from the RF development, but they aren't cheap and likely overkill for this application.  I've used the 10Ghz FMCW front end for prototype testing." CreationDate="2011-01-18T23:47:52.663" UserId="1438" />
  <row Id="13614" PostId="9166" Text="err, meant 3000ft in that first comment, oops" CreationDate="2011-01-18T23:53:06.887" UserId="1438" />
  <row Id="13615" PostId="9178" Text="you'd need either an array of antennas, probably well spaced out or a directional antenna on a motorized gimble to get direction.  Distance...you can kind of get with an array of antennas, but without knowing whats in the beam path it won't be very accurate.  Basically what you get on your cell phone when you let it figure out your position based on cell tower information.  Accuracy could obviously vary based on the positions of the antennas in relation to the source your trying to detect." CreationDate="2011-01-19T00:04:59.787" UserId="1438" />
  <row Id="13616" PostId="9154" Text="@Mark, Good to know. I'm hoping to make external mixers to mix RF down to &lt;3GHz IF from a few fixed frequencies. 30GHz is the top of the range." CreationDate="2011-01-19T00:27:21.883" UserId="2118" />
  <row Id="13617" PostId="9156" Text="@Craig I have one of those at home, just not sure on how to hook it up as I2C has more than one line. and is bi-directional" CreationDate="2011-01-19T00:46:11.297" UserId="665" />
  <row Id="13618" PostId="9187" Text="Can you determine the frequency of the ripple?" CreationDate="2011-01-19T00:54:44.140" UserId="2118" />
  <row Id="13620" PostId="9187" Text="@tyblu I've since moved it away from the scope... I'm guessing 50 Hz or 100 Hz (because I live in the UK) - I suspect the transformer is producing a magnetic field of some kind, but I'm not entirely sure on the operation of that." CreationDate="2011-01-19T00:56:08.033" UserId="1225" />
  <row Id="13621" PostId="9190" Text="You can buy solenoid motors, is that what you are talking about here?  I would think it much easier to buy a solenoid motor than create your own.  You can search by stroke and power.  I'm guessing you don't need much of either." CreationDate="2011-01-19T05:32:14.160" UserId="2377" />
  <row Id="13622" PostId="9190" Score="2" Text="How quickly does it have to open and close?" CreationDate="2011-01-19T05:34:32.707" UserId="2118" />
  <row Id="13623" PostId="9190" Score="2" Text="Shutter != Aperture. A shutter has two states - Open and Closed, and cycles between the two very fast. An aperture, (which is what you linked), often will never fully close, and has degrees of openness, related to the size of the opening. If you want to control a *shutter*, an single electromagnet will suffice. If you want to control an *aperture*, more is involved." CreationDate="2011-01-19T06:10:30.587" UserId="1374" />
  <row Id="13624" PostId="9177" Text="If you can fit a GPS, you can fit a camera. It may take a bit of effort, but cell-phone cameras are **tiny**." CreationDate="2011-01-19T06:27:02.693" UserId="1374" />
  <row Id="13625" PostId="9194" Text="Links aren't getting me anywhere...." CreationDate="2011-01-19T06:40:40.863" UserId="857" />
  <row Id="13626" PostId="9194" Text="hmm, double-checked the links, they're working for me.  Perhaps its the https://?  It seems to work with plain http://, let me change to that." CreationDate="2011-01-19T07:04:47.690" UserId="1756" />
  <row Id="13627" PostId="9191" Score="1" Text="Do all PCs have the same hardware from the same manufacturer, or there is a specification or compatibility that many are trying to achieve? ;-)))" CreationDate="2011-01-19T08:33:41.190" UserId="1129" />
  <row Id="13628" PostId="9196" Text="just what I needed... thanks!!!" CreationDate="2011-01-19T10:25:34.207" UserId="1756" />
  <row Id="13629" PostId="9170" Text="Not really complex. It would be complex to try to measure propagation delay, but power level is easy to measure with simple detector receiver, capacitor &amp; ADC." CreationDate="2011-01-19T10:31:59.530" UserId="2062" />
  <row Id="13630" PostId="9196" Score="1" Text="IMO, being able to stack multple shields is a bit of a myth. Every shield is going to use different pins for different functions, sometimes can share same pins, sometime not. Fortuantely there's the &quot;Arduino Shield List&quot; site (http://shieldlist.org/) to help with comparing pin usage of different popular shields." CreationDate="2011-01-19T11:54:24.933" UserId="2654" />
  <row Id="13631" PostId="9156" Text="According to some of the user comments on that page, the 'TX' lines are supposed to be bi-directional. So I assume you'd connect SDA to TX1 and SCL to TX2, for example." CreationDate="2011-01-19T12:01:58.137" UserId="2654" />
  <row Id="13632" PostId="7014" Score="1" Text="I've had a few boards made from the DorkbotPDX PCB Order (http://dorkbotpdx.org/wiki/pcb_order) they batch up orders similar to BatchPCB and send full panels to fab. Costs $5/sq inch (for 2-sided) and you get 3 copies of your board." CreationDate="2011-01-19T12:29:25.767" UserId="2654" />
  <row Id="13633" PostId="9195" Score="1" Text="Perhaps in an enclosed chamber made of iron or mu-metal?" CreationDate="2011-01-19T13:58:00.223" UserId="771" />
  <row Id="13634" PostId="9203" Score="1" Text="There is a major note you should add to the different class of Bluetooth, you pay an increased fee to register a higher class, but you do NOT have to radiate that much power. Some people radiate class 3 and then license class 1 so they can say class 1 while only having hardware for class 3. You need to check the radiated power. 20dBm is highest possible and should be your target for the best range." CreationDate="2011-01-19T14:06:15.937" UserId="230" />
  <row Id="13635" PostId="9177" Text="The problem isn't the camera, we have that. The problem is the cost (complexity) of the image-processing as the core-CPU has to handle it and we don't have the ability to change it.  " CreationDate="2011-01-19T14:19:51.893" UserId="2659" />
  <row Id="13636" PostId="9194" Text="@Mark - Dur, I should have tried that." CreationDate="2011-01-19T14:22:46.667" UserId="857" />
  <row Id="13637" PostId="9187" Text="Sounds like a perfect excuse to get a shiny new digital LCD scope!" CreationDate="2011-01-19T14:27:38.813" UserId="857" />
  <row Id="13638" PostId="9145" Text="I would like to mention that some systems, when they calculate parity bits they look at what the logic is and not the actual voltage. My answer still holds true, just make sure that how ever the parity works out, it requires a change in voltage for the idle state." CreationDate="2011-01-19T14:52:04.243" UserId="319" />
  <row Id="13639" PostId="9208" Text="link to datasheet?" CreationDate="2011-01-19T14:53:46.847" UserId="771" />
  <row Id="13640" PostId="8774" Score="4" Text="Then a pragmatic way is simply too leave the old stuff in CVS, and then put new stuff in the new system..." CreationDate="2011-01-19T15:14:56.547" UserId="689" />
  <row Id="13641" PostId="9187" Text="@reemrevnivek Why? This one works perfectly well. It is a digital oscilloscope." CreationDate="2011-01-19T17:48:27.107" UserId="1225" />
  <row Id="13642" PostId="9211" Text="The option which worked for me was to move the power supply to the other side of the bench away from the scope. No rippling now." CreationDate="2011-01-19T17:49:41.393" UserId="1225" />
  <row Id="13643" PostId="9211" Text="Glad that the easy way out worked for you." CreationDate="2011-01-19T18:41:40.073" UserId="857" />
  <row Id="13644" PostId="9187" Text="@Thomas - Because you need more tools?  It was a joke." CreationDate="2011-01-19T18:43:08.930" UserId="857" />
  <row Id="13645" PostId="9215" Text="@gregory Nutt, would you like me to edit this information into your other answer, it does seem they go together." CreationDate="2011-01-19T18:52:51.667" UserId="230" />
  <row Id="13646" PostId="9216" Score="4" Text="If you have the time and the interest, it may be of use to go through some of the early lecture material for electrical and computer engineering found at MIT's opencourseware site: http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/ ." CreationDate="2011-01-19T19:47:00.973" UserId="536" />
  <row Id="13647" PostId="9208" Text="How have you verified that you are transmitting and receiving correctly from one? You would need atleast two working nodes. If you can give me a bit more detail I can help." CreationDate="2011-01-19T19:48:20.613" UserId="230" />
  <row Id="13648" PostId="9216" Score="1" Text="There's also http://www.allaboutcircuits.com/  which is interesting." CreationDate="2011-01-19T19:49:40.423" UserId="1240" />
  <row Id="13649" PostId="9208" Text="Agreed, Kortuk; there is not enough information here for us to even begin to help. I've done a lot of CAN work (not specifically with this part) and without a testcase and a comparison of what happens with CAN1 and CAN2 we can only speculate." CreationDate="2011-01-19T20:13:26.897" UserId="974" />
  <row Id="13650" PostId="9186" Score="3" Text="Could you provide some links to those application notes?" CreationDate="2011-01-19T21:22:20.333" UserId="142" />
  <row Id="13651" PostId="9187" Text="@reemrevnivek It is very difficult to express emotions over the internet." CreationDate="2011-01-19T21:31:06.593" UserId="1225" />
  <row Id="13652" PostId="9216" Text="+1 - This is a really good question..." CreationDate="2011-01-19T21:44:19.603" UserId="2426" />
  <row Id="13653" PostId="9216" Score="2" Text="Since you are starting, I'd also recommend getting familiar with a SPICE program like the free LTSpiceIV, which will allow you to simulate circuits and experiment, without having to go through all the effort of wiring and unwiring." CreationDate="2011-01-19T21:47:33.417" UserId="2578" />
  <row Id="13654" PostId="9219" Score="3" Text="electronics should be used for good and not evil" CreationDate="2011-01-19T22:05:29.513" UserId="771" />
  <row Id="13655" PostId="9215" Text="Sure, feel free.  Rant about 8051 and 80c52 and hc12 also seems out of context here." CreationDate="2011-01-19T23:03:12.130" UserId="2680" />
  <row Id="13656" PostId="9222" Score="1" Text="[Here](http://en.wikipedia.org/wiki/Electrical_safety)'s a start. It's a huge filed and there are countless books written about electrical safety and human contact. Basically, there is no &quot;casual&quot; contact. In short: current kills, voltage hurts. Frequency is also very important!" CreationDate="2011-01-19T23:41:26.183" UserId="1240" />
  <row Id="13658" PostId="9225" Text="Y1 and C1 are given by the manufacturer, but different manufacturers give slightly different values for each. I'm trying to decide between the various styles (mostly, does the back of the pad line up with the back of the pin).  I'm really trying to get the best heel fillet." CreationDate="2011-01-20T00:12:42.557" UserId="857" />
  <row Id="13659" PostId="9225" Text="Oh I see, I missed that. Are the devices really identical? Their manufacturing processes could very well account for the differences in L and L1. I wouldn't worry too much about centering, to be honest." CreationDate="2011-01-20T00:17:29.230" UserId="974" />
  <row Id="13660" PostId="9225" Text="I'm just curious.  I tried to import a generic 0.5mm pitch 100-pin footprint to my PCB library, and when it didn't line up with the recommendations, I looked around and noticed some variation." CreationDate="2011-01-20T00:22:49.127" UserId="857" />
  <row Id="13661" PostId="9222" Score="3" Text="It also varies from person to person. Someone with cardiac arrhythmia is much more susceptible to being driven into fibrillation then someone with a health heart." CreationDate="2011-01-20T01:06:54.323" UserId="1374" />
  <row Id="13662" PostId="9219" Text="no schematic but i think this is more of what your looking for? http://planetstephanie.net/2010/12/07/owbox/ you should be able to figure out how it works, but pretty much just a 555 timer 9v battery and a few other components." CreationDate="2011-01-20T02:04:56.443" UserId="2060" />
  <row Id="13663" PostId="9227" Score="1" Text="What topology are you using?" CreationDate="2011-01-20T02:22:49.097" UserId="857" />
  <row Id="13665" PostId="9208" Text="@Kortuk and @Andrew Kohlsmith Yeah.... I am transmitting and Receiving correctcly from CAN 1. If I just my connector from CAN 1 to CAN 2, It receives data being broadcasted on the bus.... Means it is receiving correctly. But I can't spot any frame coming out of CAN 2 (i.e. Transmission is not Working!).... Sorry for inadequate information!!" CreationDate="2011-01-20T04:28:43.110" UserId="2574" />
  <row Id="13666" PostId="9226" Text="Is the unedited demo working properly?" CreationDate="2011-01-20T04:38:37.497" UserId="2118" />
  <row Id="13667" PostId="9196" Text="Yeah, that's definitely something that someone will have to worry about if they think they can blindly stack shields.  Thanks for pointing that out." CreationDate="2011-01-20T04:43:13.727" UserId="2288" />
  <row Id="13668" PostId="74" Score="1" Text="Have you tried WINE?" CreationDate="2011-01-20T05:11:56.980" UserId="1374" />
  <row Id="13669" PostId="9216" Text="Thanks guys, I'll try those sites, and give a Spice program a whirl." CreationDate="2011-01-20T09:03:41.393" UserId="2573" />
  <row Id="13670" PostId="9218" Text="Ah, I think I get this now.  The closed switch and the first resistor act like a voltage divider, and as the switch has almost no resistance, the resistor consumes most of the voltage, so there isn't enough to trigger the LED - correct?&#xA;So replacing the switch with a suitable resistor divides the voltage differently, so there is enough to trigger the LED, but because the voltage is still divided, the LED is receiving less voltage and so doesn't glow as brightly?" CreationDate="2011-01-20T09:04:20.313" UserId="2573" />
  <row Id="13671" PostId="9218" Text="So if I were to replace the LED with a bulb, and leave the switch in place, some of the current would flow through the bulb (unlike the LED), but the voltage would still be too low to make it glow?" CreationDate="2011-01-20T09:04:52.420" UserId="2573" />
  <row Id="13672" PostId="9220" Text="How do you calculate how much of the current goes through each part of the circuit?  I know how to work out the total resistance of the paralell resistors, and then from there how much current is flowing through the whole circuit, but not how much is going through each resistor." CreationDate="2011-01-20T09:05:27.957" UserId="2573" />
  <row Id="13673" PostId="9226" Text="yep, I got it to work. but two buttons is not enough for me :)" CreationDate="2011-01-20T09:37:55.777" UserId="2040" />
  <row Id="13674" PostId="84" Text="SDCC can compile for PIC. However, you'll still need a programmer and software to drive it. XCode is just an IDE/editor, it won't easily integrate with SDCC" CreationDate="2011-01-20T11:27:26.590" UserId="566" />
  <row Id="13675" PostId="9218" Text="@littlecharva I think that's right, but the &quot;some current&quot; part is going to be really really small. For example, I've seen a light bulb which has working resistance of 1000 Ω, while one of the switches I have shows resistance of around 0.1 Ω. So if we put for example, 9 V across the closed switch and bulb connected in parallel, we'd get 90 A through the switch and 9 mA through the bulb, assuming the bulb manages to get into high resistance state." CreationDate="2011-01-20T11:38:06.467" UserId="1240" />
  <row Id="13676" PostId="9227" Text="@reemrevnivek A simple SMPS boost converter. Is there a specific topology?" CreationDate="2011-01-20T13:23:38.257" UserId="1225" />
  <row Id="13677" PostId="9234" Text="For such a circuit, what would you suggest? I was thinking of a polyswitch/resettable fuse (suggested by bt2) as the supply may be occasionally short circuited. It is for surge testing a device against a 60V transient which could be continuous." CreationDate="2011-01-20T14:27:26.677" UserId="1225" />
  <row Id="13678" PostId="9238" Score="2" Text="Oh, duh about your last comment, I didn't even think about that! Thanks!" CreationDate="2011-01-20T15:05:00.483" UserId="876" />
  <row Id="13679" PostId="9239" Text="Are there any DIP switches with built-in resistors? I'm pretty sure they exist, but my google-fu has failed me." CreationDate="2011-01-20T15:18:45.240" UserId="876" />
  <row Id="13680" PostId="9239" Score="1" Text="Not DIP, AFAIK. Some BCD thumbwheel switches have them, IIRC." CreationDate="2011-01-20T15:37:57.727" UserId="305" />
  <row Id="13681" PostId="9201" Text="i posted in the forum but still... no answer from anyone... i thought libelium was better as customer support than this." CreationDate="2011-01-20T15:46:31.813" UserId="2245" />
  <row Id="13682" PostId="9220" Text="First, look at just the voltage divider - if there is not sufficient voltage across the bottom resistor to forward-bias the LED, the LED will not be drawing current and the circuit simplifies to just the divider. Otherwise, the resistor will be 'clamped' to the forward-bias voltage of the diode (i.e. 1.5V - check the datasheet) and by KVL you can determine the voltage drop across the series resistor, its current, and subtract the series resistor current (1.5V / resistor value) to see how much is going through the LED. (The actual forward voltage varies with the current.)" CreationDate="2011-01-20T15:49:17.797" UserId="1293" />
  <row Id="13683" PostId="9220" Text="@littlcharva, i added more theoretical detail on parallel current distribution in passive circuits" CreationDate="2011-01-20T15:55:18.280" UserId="771" />
  <row Id="13684" PostId="9220" Text="@Madmanguruman, the OP's follow here is not wrt diodes in circuit, only passive elements" CreationDate="2011-01-20T15:57:30.577" UserId="771" />
  <row Id="13685" PostId="7419" Text="Look at microchip MPLAB X that all.&#xD;&#xA;" CreationDate="2011-01-20T15:58:28.237" UserId="2688" />
  <row Id="13686" PostId="9238" Text="@samoz: That will turn your switches into a logic gate (e.g. NOR or similar depending on how you have it wired), and you won't be able to get 8 independent signals out of them." CreationDate="2011-01-20T16:24:32.977" UserId="1407" />
  <row Id="13687" PostId="9226" Score="1" Text="The LUFA keyboard sample shows how to detect buttons on IO pins and generate keyboard events. Using this, you have easy access to scancodes for the entire keyboard" CreationDate="2011-01-20T16:26:57.410" UserId="566" />
  <row Id="13688" PostId="9224" Text="I'm curious why you think you need to improve on their recommended footprint?  Depending on their packaging machine or what plant they come out of, they might change radically (and they probably won't tell you unless you buy &gt;100k-1M or so), but they all should fit on the standard footprint." CreationDate="2011-01-20T16:35:40.907" UserId="1407" />
  <row Id="13689" PostId="9219" Score="2" Text="@vicatcu, evil and good are often determined by whom you use the tool on, not the tool. For example, if I were to shock @tyblu, that would be good, but @pingswept and I get scolded. " CreationDate="2011-01-20T18:07:07.310" UserId="230" />
  <row Id="13690" PostId="9215" Text="@patacongo, I was just ensuring that you realized you could edit more in. Since you knew it and did it intentionally we can just leave it here. Normally you can just edit in another section and use titles. Let me know if I can help if you change your mind." CreationDate="2011-01-20T18:25:35.600" UserId="230" />
  <row Id="13691" PostId="9234" Text="You need to evaluate worst-case conditions, and in particular how much power your supply can provide. Semiconductors often fail before a polyfuse trips,  unless they are suitably over-rated and have enough thermal mass to  tough it out until the fuse trips." CreationDate="2011-01-20T18:51:30.540" UserId="1681" />
  <row Id="13692" PostId="9208" Text="Microchip CAN products shut off transmission if they detect more than n errors. I think this is part of the CAN spec. These could be anything from bit timing errors on up, so the maximum allowed number of errors can be reached really quickly. While debugging, make sure that you are re-initializing everything each time you perform a test, to minimize the chances that the chip is locking out transmissions. (Of course, you may be able to simply read the status registers to determine if that's happening.)" CreationDate="2011-01-20T19:43:52.367" UserId="2344" />
  <row Id="13693" PostId="9221" Text="god I love stack exchange" CreationDate="2011-01-20T19:45:06.203" UserId="2344" />
  <row Id="13695" PostId="8804" Score="1" Text="I´m using PWM to control the RPM actually. I just wanted to know if I could assume the current is halved if I use 50% cycle because there is some report writing involved and I didn´t want to look stupid when I presented it :)" CreationDate="2011-01-20T20:19:49.700" UserId="1637" />
  <row Id="13696" PostId="9228" Score="1" Text="It's not current that kills, it's the fibrillation.  The path the current takes through your body and the presence of vibrations that interfere with the heart are important. Saying &quot;voltage doesn't matter; it's the current that kills&quot; will only encourage people to look at the current *rating* of a power supply and think that somehow has something to do with the danger of it.  Power supplies are almost always voltage supplies.  They don't force a specific current.  The amount of current that goes through your heart depends on your resistance *and the supply's voltage*." CreationDate="2011-01-20T20:52:42.667" UserId="142" />
  <row Id="13697" PostId="9228" Score="1" Text="@endolith &quot;It's not current that kills, it's the fibrillation.&quot; Considering that its current that causes the fibrillation i don't get what your point is.  Thats like saying &quot;It's not the lack of breathing that killed you, its the lack of O2 in your blood&quot;.  I get what your saying on the voltage vs current issue, but honestly if someone is daft enough to look at a supply's current rating and grab on to it there isn't much you could say that would save them.  Also, I don't often see a supply thats limited to currents below what i stated are dangerous that outputs enough V to pass through skin." CreationDate="2011-01-20T21:42:27.540" UserId="1438" />
  <row Id="13698" PostId="9199" Text="I am interested in knowing if there are chips that will detect if its plugged into a usb charger and increase the charge current limit." CreationDate="2011-01-20T21:53:29.890" UserId="319" />
  <row Id="13699" PostId="9244" Text="Good article.  I would add that the discussed in your answer is a very much worst case analysis.  Very large contact areas, thin/wet skin, long duration exposure, abrasions, etc.  Skin resistance can change considerably in response to such situations.  For instance the article lists dry unbroken to have resistance of 100k-2M ohms and that under 12V little to no skin resistance breakdown occurs.  This meshes with my experience doing electrical work when younger, 50-75V was not noticeable work work on live (hand to hand contact) unless your hands were sweating a lot. 120V hurts though." CreationDate="2011-01-20T22:07:43.950" UserId="1438" />
  <row Id="13700" PostId="9247" Text="The one in the picture looks like it's sealed and you push the tracks against the dark material (probably something resistive), rather than using human skin, which has terrible manufacturing tolerances and temperature coefficients." CreationDate="2011-01-20T22:14:07.217" UserId="1407" />
  <row Id="13701" PostId="9219" Text="@Kortuk... wow, never thought of it that way lol" CreationDate="2011-01-20T22:15:12.477" UserId="771" />
  <row Id="13702" PostId="9247" Text="I think you are right. It's more like my second suggestion, then. I've amended my answer." CreationDate="2011-01-20T22:16:56.650" UserId="305" />
  <row Id="13703" PostId="9249" Text="Answering with a question is normally not productive, as noone can answer you." CreationDate="2011-01-20T22:18:13.720" UserId="230" />
  <row Id="13704" PostId="4258" Text="http://www.allnewsmac.com/2010/08/20/replace-magic-trackpad-batteries-with-a-diy-usb-cable/" CreationDate="2011-01-20T22:18:34.123" UserId="142" />
  <row Id="13705" PostId="9228" Text="@Mark Meaning that 1 mA of DC has a different effect from 1 mA of 60 Hz AC, which has a different effect from large spikes at 2 Hz that average out to 1 mA.  There isn't a magical voltage that kills people, and there's not a magical current, either." CreationDate="2011-01-20T22:23:05.023" UserId="142" />
  <row Id="13706" PostId="9210" Text="So it seems it will work for applications like helicopter &quot;heading hold&quot;, since those applications only care about relative changes and not absolute compass-like directions.  We will be able to hover our magnetometer-controlled UAV's right over either magnetic pole!" CreationDate="2011-01-20T22:27:51.570" UserId="1756" />
  <row Id="13707" PostId="9242" Text="@Dean I've edited in your changes and deleted the second response" CreationDate="2011-01-20T22:29:16.497" UserId="566" />
  <row Id="13708" PostId="9083" Text="Buy a pack of batteries and test it.  :)  Build a circuit that draws a spiky current and then connect a resistor across another battery to use the same average power." CreationDate="2011-01-20T22:30:49.573" UserId="142" />
  <row Id="13709" PostId="9195" Text="@vicatcu, it should still work perfectly there.  I'd think it might not do so well in a volcanic region though." CreationDate="2011-01-20T22:36:01.283" UserId="1407" />
  <row Id="13710" PostId="9019" Text="You probably need ESD protection.  Shocks from human beings can be thousands of volts.  I'm not sure of the difference between TVS diodes and ESD protection diodes." CreationDate="2011-01-20T22:38:27.163" UserId="142" />
  <row Id="13711" PostId="9246" Text="One possible method for a home built FSR can be found here: http://www.instructables.com/id/Pressure-Sensor-Matrix/&#xA;This makes use of 2 strips semi-conductive foam. The harder you press, the more contact area is made between the two pads, lowering the resistance. I didn't post this as an answer because I don't know if that's a commonly used method, or just one for DIY FSRs." CreationDate="2011-01-20T22:43:26.567" UserId="790" />
  <row Id="13712" PostId="9221" Text="When I was a kid some 50 years ago I built something like this using a Model T spark coil -- then attached the output to a doorknob handle." CreationDate="2011-01-21T00:10:32.767" UserId="1322" />
  <row Id="13713" PostId="9228" Score="2" Text="Current won't pass through your body without voltage.  I've worked with continuity test equipment capable of flowing massive amounts of current and could safely hold the anode and cathode in my hands, due to the low voltage.  So, saying it's the current that kills you, is like saying &quot;It's not the lack of breathing that killed you, its the lack of O2 in your blood.&quot;  Without a difference in potential, you aren't going to get any current." CreationDate="2011-01-21T00:30:05.150" UserId="2377" />
  <row Id="13714" PostId="9222" Text="Try experimenting." CreationDate="2011-01-21T00:31:54.527" UserId="1940" />
  <row Id="13715" PostId="9249" Text="@Kortuk... you'll rue the day you met me Trebek!" CreationDate="2011-01-21T01:31:33.383" UserId="771" />
  <row Id="13716" PostId="9009" Text="I must not be understanding something. I built this: http://www.kindel.com/misc/12v%20to%205v%20circuit.png.  If I apply the 12V signal I measure ~5V across the analog input leads...as expected. but as soon as I connect the analog IO sensor I read 1.3V (and the sensor reads 1.3V).  Where is the additional resistance coming from?" CreationDate="2011-01-21T03:07:41.710" UserId="2604" />
  <row Id="13717" PostId="9009" Text="Never mind. I'm an idiot. I previously had the input configured for digital which meant I had a 1K ohm resistor across it. We're good.  Now to take the components off the proto board and solder it up for good..." CreationDate="2011-01-21T03:12:47.193" UserId="2604" />
  <row Id="13718" PostId="9219" Text="@Kortuk: Wait, why do I get scolded just because you're testing your &quot;Touch of God&quot; machine on @tyblu? I'm innocent!" CreationDate="2011-01-21T03:28:40.177" UserId="712" />
  <row Id="13719" PostId="9228" Text="while true, voltage is just a potential, that is voltage can do no work, only current can." CreationDate="2011-01-21T05:04:24.663" UserId="1438" />
  <row Id="13720" PostId="9256" Text="This is what some cell phones do, with MEMS switches." CreationDate="2011-01-21T05:59:50.240" UserId="2118" />
  <row Id="13721" PostId="9009" Text="And we're done. My home control system now knows when the house is on normal power or when it's on emergency power. Thanks for you help folks!" CreationDate="2011-01-21T06:37:30.243" UserId="2604" />
  <row Id="13722" PostId="9242" Text="Is the second code block supposed to have &quot;Report Size (5)&quot; instead of ..&quot;(6)&quot;? (The corresponding code is the same.)" CreationDate="2011-01-21T08:25:24.757" UserId="1859" />
  <row Id="13723" PostId="9259" Score="2" Text="You can't expect anyone to help unless you give enough information, like what processor it is for a start..." CreationDate="2011-01-21T09:38:38.360" UserId="1681" />
  <row Id="13724" PostId="9256" Text="Doesn't usual MOSFET work? Even at 1.8Ghz it should be fine..." CreationDate="2011-01-21T10:02:04.543" UserId="2062" />
  <row Id="13725" PostId="9256" Text="So you could have two antennas. Say A1 and A2, Once you read from A1 only A2 would be active and then once you have read from A2 only A1 will go on? " CreationDate="2011-01-21T10:59:16.793" UserId="2703" />
  <row Id="13726" PostId="9256" Text="Yes. That would be the idea." CreationDate="2011-01-21T11:02:49.067" UserId="2062" />
  <row Id="13727" PostId="9257" Text="Can you explain how it is more efficient.  If we consider the number of math operations required to calculate the output, I don't see much of a difference between the two.  In fact, the Z-transform derived equation looks to have a greater number of operations, which would seem to place a greater burden on a processor." CreationDate="2011-01-21T11:33:42.880" UserId="2377" />
  <row Id="13728" PostId="9263" Text="Looks like you may have posted too early. Might want to check your post." CreationDate="2011-01-21T12:14:20.990" UserId="319" />
  <row Id="13729" PostId="9259" Text="@mikeselectricstuff :I am using MFC5253 processor with WindRiver Debugger! " CreationDate="2011-01-21T12:19:38.783" UserId="2574" />
  <row Id="13730" PostId="9263" Text="@Kellenjb Blame Internet Exploder, which I have to use here at college :(. It appears to abort transactions randomly." CreationDate="2011-01-21T13:11:43.913" UserId="1225" />
  <row Id="13731" PostId="9210" Text="@Mark Harrison - Maybe close to the magnetic pole, but not &quot;right over&quot;, since even the relative changes would start to be huge (in the horizontal plane, at least).  What would you expect to happen if you told it to head straight north as it approached the north magnetic pole?  But for all practical purposes, it should be fine (would it really work in the weather of the north pole anyway?)." CreationDate="2011-01-21T13:45:26.510" UserId="2677" />
  <row Id="13736" PostId="8940" Text="Use your computer as a function generator for prototyping." CreationDate="2011-01-21T15:26:02.113" UserId="142" />
  <row Id="13737" PostId="9242" Text="yes it does, and works ! thanks, I missed that input part. I understand now that it simply comlete a byte. " CreationDate="2011-01-21T15:38:33.980" UserId="2040" />
  <row Id="13738" PostId="9228" Text="@Mark: Current in a superconducting loop isn't doing any work, either. :)" CreationDate="2011-01-21T15:46:59.363" UserId="142" />
  <row Id="13739" PostId="9009" Text="@cek, Glad to hear it works." CreationDate="2011-01-21T15:57:57.637" UserId="230" />
  <row Id="13740" PostId="9257" Text="Same number of math operations, different representation of numbers.  Doubles are a much more complex representation of numbers than the fixed-point method used in the case study.  Less complex means fewer operations (on the silicon)." CreationDate="2011-01-21T16:04:11.500" UserId="249" />
  <row Id="13741" PostId="9220" Text="+1 for the cool text circuit diagrams!" CreationDate="2011-01-21T16:44:15.293" UserId="529" />
  <row Id="13742" PostId="8977" Text="@Kevin Boyd, it is from [modelcraftcollection.com](http://www.modelcraftcollection.com/).  The magnifier is very convenient, allowing you to see the components from any angle (unlike a helping hand magnifier whose position is fixed.)  The lamp is less important as you generally have a desk lamp pointed ad the object anyway." CreationDate="2011-01-21T17:33:44.197" UserId="1285" />
  <row Id="13743" PostId="8051" Text="I think that the statement &quot;there is no law which makes UL certification mandatory&quot; is meant to imply that you are not required to use UL to do the certification, not that certification is not required." CreationDate="2011-01-21T17:49:11.070" UserId="1293" />
  <row Id="13744" PostId="9276" Score="2" Text="Fun fact - none of the standards are free, you have to pay money to find out what the rules are that you have to play by!" CreationDate="2011-01-21T18:43:58.823" UserId="2344" />
  <row Id="13745" PostId="9228" Text="@Endolith There are no losses in the loop, and the current in the loop doesn't perform work, but measuring that current requires work to be performed.  Such loops are usually coupled to 'standard' circuits where losses are measured to determine the current in the loop.  The loop pretty much useless without the ability to measure either its operation or its effect, measurement requires work." CreationDate="2011-01-21T19:07:16.500" UserId="1438" />
  <row Id="13746" PostId="9228" Text="@bt2 This is just a chicken and egg debate.  My point is quite simply: 1) Current is the physical action that causes damage.  2) X00,000+V at 1mA isn't dangerous, 500mA at 100V is dangerous.  You need some voltage to induce current flow but the functions of skin resistance breakdown means that body resistance can change massively.  Ultimately the voltage that is applied to your body doesn't matter when it comes to damage, its the current that needs to be controlled to prevent damage.  Again hundreds of thousands of volts current limited is not dangerous.  100V without a current limit is." CreationDate="2011-01-21T19:15:54.170" UserId="1438" />
  <row Id="13747" PostId="9228" Text="@bt2 If you wanted to build a safe &quot;shock&quot; device.  You don't do so by limiting the voltage because we can't account for wide fluctuations in body resistance.  We'd build it with a high voltage and a current limit as limiting the current is how we can guarantee limiting possible damage.  As mentioned there may be a frequency component in the mix as well, depending on what you want to achieve.  I doubt it matters much in a hand-shake shock device, matters more in something like a tazer if you want to lock muscles. " CreationDate="2011-01-21T19:21:57.807" UserId="1438" />
  <row Id="13748" PostId="9281" Text="Thanks, for some reason I wasn't see the diode as being reverse-biased, my mistake.  So when V &lt; Vz(breakdown), there is no regulation, but when V == Vz(breakdown), the zener diode then holds the output voltage at Vz(breakdown)?" CreationDate="2011-01-21T19:35:25.673" UserId="2059" />
  <row Id="13749" PostId="9228" Text="&quot;2) X00,000+V at 1mA isn't dangerous, 500mA at 100V is dangerous.&quot; One of those is a resistance of 100,000,000 ohm, the other is a resistance of 200 ohm.  You can't have both with the same human body.  And a &quot;current limiter&quot; is just going to reduce the voltage." CreationDate="2011-01-21T20:42:20.200" UserId="142" />
  <row Id="13750" PostId="9281" Text="Yes, similar to a forward-biased ideal diode with Vz voltage source at the cathode." CreationDate="2011-01-21T21:00:13.163" UserId="2118" />
  <row Id="13751" PostId="9271" Text="The use of [meta-tags](http://meta.electronics.stackexchange.com/questions/115/what-meta-tags-on-er-should-be-axed) such as [best-practices] is discouraged." CreationDate="2011-01-21T21:05:03.537" UserId="1623" />
  <row Id="13752" PostId="9228" Text="@endolith I'm really not going to argue about what a current limiting circuit is, obviously it lowers the voltage, its monitoring and reacting to current, i'm not going to call it a voltage limiter just because thats how it operates.  As for the resistance, yes actually you can.  Your body doesn't have a fixed resistance, your skin is the major source of resistance but its resistance tends to break down in response to application of voltage/current.  Your skin may start out at 2M ohm and drop to maybe few hundred ohms in response to applied voltage/currents levels and duration of application." CreationDate="2011-01-21T21:20:05.480" UserId="1438" />
  <row Id="13753" PostId="9244" Text="What's the ring voltage on phone lines?  48v?  Or is it 96v?  Either way, it gives a nice sharp poke if a phone call happens to come in while you're working on live wiring...  :-)" CreationDate="2011-01-21T21:20:07.423" UserId="1678" />
  <row Id="13754" PostId="9228" Text="@endolith for instance a Tazor may have an initial operating voltage of 600,000 volts, which will be applied for a split second to break down skin resistance before the current limiter kicks in and lowers the current (obviously by limiting voltage) by that time your body resistance has changed significantly as a result of the skin resistance break down.  Again the body resistance is changing, you wouldn't build this as a fixed voltage limiter, but as a fixed current limiter to handle the change in body resistance." CreationDate="2011-01-21T21:23:57.177" UserId="1438" />
  <row Id="13755" PostId="9244" Text="@Brian -- ringing voltage is around 90v AC at 20 Hz" CreationDate="2011-01-21T21:47:30.733" UserId="1322" />
  <row Id="13756" PostId="9244" Score="1" Text="In the US the ring is theoretically 90VAC at 20Hz, but i've seen it vary quite a lot, especially in rural areas I'd see 100-110V routinely.  When ideal there is supposed to be -48VDC on the line, but again it can vary especially in rural areas where i worked.  The ring voltage(90VAC) is imposed on the supervisory voltage (-48VDC) as well.  When current is drawn the Tip goes down from ground and Ring rises, the current limit is roughly 20mA as a result of the system resistance.  I've been zapped by ring pulses a couple times, it hurts but the current drops the voltage quickly." CreationDate="2011-01-21T21:53:28.917" UserId="1438" />
  <row Id="13757" PostId="9286" Score="1" Text="Not to be pedantic, but the program can only support what speeds the hardware allows.  It may not even bother asking and just list off the standard speeds.  Asking my hardware, `zip(*serial.Serial('COM10').getSupportedBaudrates())`, it replies: `(50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200)`" CreationDate="2011-01-21T22:44:38.240" UserId="1407" />
  <row Id="13758" PostId="9254" Text="Ah, sorry for confusing the &quot;length&quot; and &quot;width&quot; measurements. This was quite helpful. Thank you!" CreationDate="2011-01-21T22:50:46.677" UserId="1021" />
  <row Id="13761" PostId="9257" Text="@AngryEE, my question is more related to the general equations.  There is no reason fixed point math couldn't be used with the basic, PID without a PHD type implementation, in fact I've done it before." CreationDate="2011-01-21T23:38:32.813" UserId="2377" />
  <row Id="13762" PostId="8918" Text="One follow up to this, If I am using a 1 amp Stepper motor and replace it with a 3 amp. Will the 3 amp draw that much current and therefore stress the driver circuit or will the 1amp circuit only draw one amp from the 3 amp motor?  Or is it OK to replace a 1amp with a 3amp motor?  Thank you for the help." CreationDate="2011-01-21T23:43:05.270" UserId="2579" />
  <row Id="13763" PostId="8918" Text="Yes if you are using a 3A stepper motor you need something that can handle that current. For my project involving stepper motors I'm using a ULN2803A to drive them and each darlington pair can handle about 1/2 an Amp so double up if you need more current. As for swapping the 1 amp with a 3 I'm unsure on that. Can your power supply handle that?" CreationDate="2011-01-21T23:46:43.617" UserId="1623" />
  <row Id="13764" PostId="9161" Text="@vicatcu, I think you mean a large value cap, and were thrown off by my juvenile math mistake :)" CreationDate="2011-01-22T00:02:27.040" UserId="2118" />
  <row Id="13766" PostId="9270" Text="The PID without a PHD article is just an example of the simpler implementation, which uses a running sum for the integral and the difference between consecutive samples for the derivative.  The article states that sample time should be consistent.  Sampling time could easily be added to the I and D calculations, but in most instances it isn't done in the actual calculation.  The controller's GUI (or other interface) will present the I and D terms to the user in terms of seconds based off the loop time." CreationDate="2011-01-22T00:33:16.843" UserId="2377" />
  <row Id="13767" PostId="9227" Text="There are several.  You can have the basic design (not sure what it's called but I'm 90% sure it's what you're referring to), but there's also SEPIC, Ćuk, inverting buck/boost, isolated (noniverting) buck/boost, switched capacitor, and there are probably more.  There's definitely more than one way to do the job.  See dren.dk's answer." CreationDate="2011-01-22T00:53:24.217" UserId="857" />
  <row Id="13768" PostId="9224" Text="I don't need to improve, I'm just curious as to why they would have variation, and wanted to choose the best variation." CreationDate="2011-01-22T00:54:56.680" UserId="857" />
  <row Id="13769" PostId="9272" Text="Does it broadcast RF energy in significant amounts?  " CreationDate="2011-01-22T00:58:21.933" UserId="857" />
  <row Id="13770" PostId="9288" Score="2" Text="That board might be a bad example, it's bad because double banana jacks have a standard spacing of 0.75&quot;, and this board doesn't follow that.  It would be like designing a board with 0.08&quot; headers; it's just not done without a good reason." CreationDate="2011-01-22T01:01:02.990" UserId="857" />
  <row Id="13771" PostId="9292" Score="1" Text="Cough *Arduino* cough." CreationDate="2011-01-22T01:02:21.990" UserId="857" />
  <row Id="13772" PostId="9257" Text="Well the general equations are the same.  Some people are just more comfortable with the Z-transform approach.  " CreationDate="2011-01-22T01:04:44.483" UserId="249" />
  <row Id="13773" PostId="9271" Score="1" Text="Does your schematic capture program allow you (possibly through an export or import) to run a simulation?  gEDA has a lot of tools which could be easily automated to run Spice or Verilog simulations.  " CreationDate="2011-01-22T01:06:25.290" UserId="857" />
  <row Id="13774" PostId="9271" Score="1" Text="Also, are you referring to the schematic or the PCB layout?  Building the PCB (even if it was feasible) is rather detached from errors I'd expect to see on a schematic.  PCBs have their own problems." CreationDate="2011-01-22T01:07:22.763" UserId="857" />
  <row Id="13775" PostId="9295" Text="There are a few bit-bang serial libraries: [SoftSerial](http://www.arduino.cc/en/Tutorial/SoftwareSerial), [NewSoftSerial](http://arduiniana.org/libraries/NewSoftSerial/)." CreationDate="2011-01-22T01:20:26.820" UserId="2118" />
  <row Id="13776" PostId="7826" Text="good answer, only thing i could think of to add is to work with a PCB fab that you like and trust, the pre-fab engineer has caught minor things in rev 1 designs i've done a few times and that was well worth paying a bit more for the PCB run." CreationDate="2011-01-22T02:14:51.383" UserId="1438" />
  <row Id="13777" PostId="9288" Score="4" Text="&quot;its low current (5 amps) which shouldn't be enough to spark across the terminals at those voltages&quot;  This is shenanigans, current level doesn't even matter in this context, voltage will cause &quot;sparking&quot; not current." CreationDate="2011-01-22T02:17:50.397" UserId="1438" />
  <row Id="13778" PostId="9257" Score="2" Text="@bt2, I would say more efficient in the sense that DSP chips are set up for SIMD (Single Instruction, Multiple Data) instruction sets.  While it is the same number of math operations, the Z transform allows you to do all of the multiplies in one instruction cycle, then sum all of the elements of the resultant vector in one cycle (platform dependent).  So while the math is the same, the time complexity is significantly lower, yielding higher speedups." CreationDate="2011-01-22T02:21:48.037" UserId="1477" />
  <row Id="13779" PostId="9170" Text="Could you give a little more info on how one would measure power level; my googling skills have proven lacking." CreationDate="2011-01-22T02:55:37.703" UserId="1773" />
  <row Id="13780" PostId="9161" Text="@tyblu, ah yes right larger the capacitance, lower the impedence..." CreationDate="2011-01-22T02:55:51.667" UserId="771" />
  <row Id="13781" PostId="9257" Text="@mjcarroll, I guess I fail to see why you can't vectorize either implementation." CreationDate="2011-01-22T03:11:00.900" UserId="2377" />
  <row Id="13782" PostId="6351" Text="I prefer a hot air tool and a good pair of tweezers. A fine-tipped iron helps with after-the-fact touch-up." CreationDate="2011-01-22T04:02:05.367" UserId="1293" />
  <row Id="13783" PostId="9294" Score="2" Text="n00b question: what is the IPC? (and... why do their standards in particular matter?)" CreationDate="2011-01-22T07:58:15.297" UserId="1021" />
  <row Id="13784" PostId="9170" Text="Well, check out simplest RF receiver - LC circuit, diode detector, capacitor to smooth the signal. Then you can measure this with precision ADC." CreationDate="2011-01-22T08:06:58.993" UserId="2062" />
  <row Id="13785" PostId="9279" Text="Take a look at my emitter-follower answer - it shows the assumptions made for that circuit.  http://electronics.stackexchange.com/questions/8656/emitter-follower-output/8659#8659" CreationDate="2011-01-22T08:41:27.300" UserId="638" />
  <row Id="13786" PostId="9151" Text="Well, despite the good advice, I still managed to f%#k it up spectacularly: http://frabjousdei.net/post/2871704888/i-cant-solder-to-save-my-life-ive-just-proven" CreationDate="2011-01-22T10:37:02.057" UserId="1633" />
  <row Id="13787" PostId="9300" Text="I take it this comes with the normal limitations associated with using the USB-&gt;Serial interfaces (ie many PIC boards etc don't play well with them)." CreationDate="2011-01-22T11:02:10.497" UserId="2326" />
  <row Id="13788" PostId="9286" Text="I used a 600 bit/s half duplex acoustic coupler in the eighties. 75 bit/s was used in the german BTX system in the upload direction for a long time, download was at 1200 bit/s." CreationDate="2011-01-22T11:04:48.947" UserId="339" />
  <row Id="13789" PostId="9294" Score="1" Text="http://landpatterns.ipc.org/" CreationDate="2011-01-22T11:21:39.357" UserId="339" />
  <row Id="13790" PostId="9306" Text="What is the RAKE Receiver? Is this EDA software or hardware? More details, please." CreationDate="2011-01-22T12:41:15.810" UserId="1374" />
  <row Id="13791" PostId="9307" Score="1" Text="50 uF across the USB 5V should not be an issue. PTCs have a time constant, so a short duration current spike will not trip it. Anyways, I have some project with several hundred uF across the USB rails, to no ill effect." CreationDate="2011-01-22T12:43:09.427" UserId="1374" />
  <row Id="13792" PostId="9308" Text="Agreed. An RC circuit will limit the current going to the capacitor. Care must be taken to ensure that minimum rise times on the devices connected to the rail are met, else there may be weird start-up logic glitches which are hard to diagnose. Also, a fast turn-off diode across the resistor may be needed (to quickly shut off the MOSFET)." CreationDate="2011-01-22T12:47:40.953" UserId="1293" />
  <row Id="13793" PostId="9303" Text="Just noticed you have questions in the topic and expansion that are opposite senses. Makes the &quot;yes&quot; answer quite ambiguous. Good thing I wrote more than that..." CreationDate="2011-01-22T13:21:27.770" UserId="1181" />
  <row Id="13794" PostId="5782" Text="I find this slightly odd I would almost take &quot;Once you have gotten your feet wet, by all means branch out &quot; as a suggestion to go with the Netduino to start because the *programming* element should be so much less of an issue - allowing one to develop the &quot;other&quot; skills needed." CreationDate="2011-01-22T14:04:33.100" UserId="2716" />
  <row Id="13795" PostId="9304" Text="This question is localized in both time and location." CreationDate="2011-01-22T14:17:07.367" UserId="230" />
  <row Id="13796" PostId="9312" Text="This is localized in time and in location. E&amp;R is not a good place for shopping advice." CreationDate="2011-01-22T14:17:53.183" UserId="230" />
  <row Id="13797" PostId="9308" Score="3" Text="@mikeselectricstuff. This seems the best solution. Indeed MOSFET based soft-start circuit is shown in FTDI guidelines http://www.ftdichip.com/Documents/AppNotes/AN_146_USB_Hardware_Design_Guidelines_for_FTDI_ICs.pdf. Thank you." CreationDate="2011-01-22T14:21:21.917" UserId="1932" />
  <row Id="13799" PostId="9307" Score="1" Text="@Fake Name. PTCs are slow and, agreed, they do not trip because of short duration spike. However, such a spike can create a sufficient drop on voltage rail, which I would like to avoid. The USB spec says the inrush equivalent load should not exceed 10uF paralleled with 44 Ohms." CreationDate="2011-01-22T14:32:14.150" UserId="1932" />
  <row Id="13800" PostId="9306" Score="1" Text="@FakeName, it is actually a [known device](http://en.wikipedia.org/wiki/Rake_receiver) Wikipedia was the first result of a google." CreationDate="2011-01-22T14:33:19.560" UserId="230" />
  <row Id="13801" PostId="9317" Text="Thanks, these look good :)." CreationDate="2011-01-22T15:01:55.663" UserId="2251" />
  <row Id="13802" PostId="9312" Text="It is extremely hard for newbies to find suppliers for uncommon parts online, anyone with experince finds things by brand name. I (and probably many others) have no clue about where to buy microelectronics. Therefore I believe that this question is perfectly relevant. " CreationDate="2011-01-22T15:03:32.320" UserId="2251" />
  <row Id="13804" PostId="9266" Text="@tryskele, this seems like it could be community wiki, as no one answer will ever be correct and having people constantly posting and updating methods might fit it." CreationDate="2011-01-22T15:13:57.530" UserId="230" />
  <row Id="13805" PostId="9295" Text="But why add the complexity?  The cable I linked to will work for any voltage level and you can connect it directly to a computer.  There's no real reason to include an Arduino unless you don't want to buy the cable.  And if you use the Arduino you have to ensure that voltage levels are correct.  I just think the cable is a simpler solution." CreationDate="2011-01-22T16:18:06.380" UserId="249" />
  <row Id="13806" PostId="9304" Text="@kortuk - this is true, but the best answer I was able to find. Google searching produced only online order sites." CreationDate="2011-01-22T16:24:59.220" UserId="2326" />
  <row Id="13807" PostId="9269" Score="1" Text="I'd add extra emphasis to 2.  Agile methods don't work as well with hardware as they do with software, so time spent on a solid specification up front can save boatloads of time later.  For novel products, there might also be some R&amp;D steps toward the beginning to evaluate new technology or methods." CreationDate="2011-01-22T16:37:51.497" UserId="2377" />
  <row Id="13808" PostId="9304" Text="@DannyStaple, I am not doubting the communities ability to answer questions that are too localized. I am enforcing SO rules. I could ask this question another 100 times for just location in the UK without a problem. And in a month, RS may shutdown, you will need to come unaccept the answer and have new answers written. Wait, you already received your board, this would just stay up giving people poor advice, think in 2 years how much value this question might have. What is sparkfun opens up storefronts in London? I understand why the question was asked, I hope you understand why it was closed." CreationDate="2011-01-22T17:02:38.407" UserId="230" />
  <row Id="13809" PostId="9315" Text="Hmm - I've now found this link http://www.electro-tech-online.com/microcontrollers/29943-help-pic-01-development-board.html - where some helpful chappy has posted a schematic. Handy - since the loginway documentation is a bit sparse." CreationDate="2011-01-22T17:28:25.957" UserId="2326" />
  <row Id="13810" PostId="2854" Text="Another review here: http://www.fiberdownload.com/Download/26542/NuttX" CreationDate="2011-01-22T17:57:44.303" UserId="2680" />
  <row Id="13811" PostId="9179" Text="I see nobody who read this question has expertise with this piece of hw, otherwise some answer would have popped up, apart from comments.. I'm sorry, next questions will be more specific!" CreationDate="2011-01-22T18:02:03.637" UserId="2285" />
  <row Id="13812" PostId="9271" Score="2" Text="There are real-time DRCs... close enough?" CreationDate="2011-01-22T18:13:31.207" UserId="2118" />
  <row Id="13813" PostId="9324" Text="I'm gonna guess a few thermionic valves got involved too, especially in the video transmitting parts." CreationDate="2011-01-22T18:16:22.043" UserId="1225" />
  <row Id="13814" PostId="9324" Text="Are you including things that don't directly manipulate the video, for example, the power station's electronics for the TV station?" CreationDate="2011-01-22T18:18:04.977" UserId="1225" />
  <row Id="13815" PostId="9324" Text="Please add much more information about the intended system. Basically, everything you've got. I suspect [an XY problem...](http://meta.stackoverflow.com/q/66377/154425)" CreationDate="2011-01-22T18:18:52.807" UserId="2118" />
  <row Id="13816" PostId="9306" Text="Does [this help](http://www.freescale.com/files/dsp/doc/app_note/AN2252.pdf)? Out of my league!" CreationDate="2011-01-22T18:25:01.300" UserId="2118" />
  <row Id="13817" PostId="9324" Score="5" Text="Without a lot more details the only answer is &quot;Billions of transistors&quot;" CreationDate="2011-01-22T18:52:51.483" UserId="1438" />
  <row Id="13818" PostId="9192" Text="IMHO it is worth noting that digipots tend to be on the expensive side. :)" CreationDate="2011-01-22T19:18:02.890" UserId="659" />
  <row Id="13819" PostId="9325" Text="Which laser are you using? I'm also interested in this." CreationDate="2011-01-22T19:38:07.183" UserId="2118" />
  <row Id="13820" PostId="6373" Text="Wow, that lucid science link has the theory of operation completely wrong. the window pane *is* modulating the reflected laser light. It's pretty much just a photophone but with a laser instead of the sun. The movement of the window glass is amplitude-modulating the received laser light." CreationDate="2011-01-22T20:34:26.063" UserId="974" />
  <row Id="13821" PostId="9323" Text="Thanks Leon! very clear." CreationDate="2011-01-22T21:22:24.107" UserId="2719" />
  <row Id="13822" PostId="9327" Text="Thanks Kellenjb for the answered parts! Good to get a positive push in my headings. the remaining 9more secialistic questions remain unanswered byt that Q nr. 3 needs an expert, indeed!" CreationDate="2011-01-22T21:23:35.867" UserId="2719" />
  <row Id="13823" PostId="9300" Score="1" Text="It worked like a charm! I was able to connect it to my BD player and make it region free. Thank you for the tip!" CreationDate="2011-01-22T22:10:07.710" UserId="2712" />
  <row Id="13824" PostId="9328" Score="2" Text="How can you have -2628% error? That would be −13,976,786,195,591,899,169,808 transistors..." CreationDate="2011-01-22T22:29:12.880" UserId="1225" />
  <row Id="13825" PostId="9328" Score="1" Text="@ThomasO, Yep, which goes along well with my theory of negative resistance resistors." CreationDate="2011-01-22T22:47:11.323" UserId="2118" />
  <row Id="13826" PostId="9328" Text="@tyblu They exist! It's just a conspiracy by the NWO, and the CIA, and big oil!!!" CreationDate="2011-01-22T22:59:48.407" UserId="1225" />
  <row Id="13827" PostId="9329" Text="@Ismar, You don't appear to have asked a question. What are you having trouble with?" CreationDate="2011-01-22T23:14:22.617" UserId="2118" />
  <row Id="13828" PostId="9329" Text="the question is, how to make this..it is a school project, and I have no clue how to write this program..any help ?" CreationDate="2011-01-22T23:21:01.027" UserId="2721" />
  <row Id="13829" PostId="9329" Text="You'll find much more success in asking specific questions. Try writing the program and, if part of it doesn't work, post your code and ask about that part. If it's purely software, it belongs on [StackOverflow.com](http://stackoverflow.com/). If I were you, I'd Google &quot;How to turn on LED with STK500&quot;." CreationDate="2011-01-22T23:36:10.843" UserId="2118" />
  <row Id="13830" PostId="9329" Text="thanks for the link..i would ask specific questions if I had a clue where to start..actually, I am kind of sure that this is an example program that I can find somewhere on the internet" CreationDate="2011-01-22T23:42:52.317" UserId="2721" />
  <row Id="13831" PostId="8730" Text="So: we have 2 separate DC regulators: one to give us +5V for microcontroller logic, and between +12V and +30V to drive the MOSFETs. The optoisolator protects the microcontroller circuit from the +12V non-isolated supply." CreationDate="2011-01-23T00:06:37.997" UserId="2172" />
  <row Id="13832" PostId="8725" Text="It's possible that adding an LC filter will do the trick in terms of reducing noise. However, I don't have the experience to know instinctively if this is the case. (See http://electronics.stackexchange.com/questions/8733/lc-filter-for-phase-control)" CreationDate="2011-01-23T00:08:17.993" UserId="2172" />
  <row Id="13833" PostId="8715" Text="My original question mentions that I'd like to know what constitutes &quot;training&quot;. Do I have to go through a 2-year college program? or are there organizations which offer in-person basic training by people who know what they're doing?" CreationDate="2011-01-23T00:20:56.217" UserId="2172" />
  <row Id="13834" PostId="9332" Text="Wauw, thats very interesing BarsMonster! So, if I understand correctly, then its a matter of give or take: you can have bit higher Volt 3.7, but give bit away in capacity of current. And vise versa the 3.6 V might hold bit more amp? I guesse the main question then would be: `Can i rate/charge a 3.6V batt as 3.7 V batt and input a bit lower Amps in the smart charger?`" CreationDate="2011-01-23T01:02:35.070" UserId="2719" />
  <row Id="13835" PostId="9307" Score="1" Text="My laptop has flashed overcurrent errors and not worked with devices with 47 uF across VBUS.  Stick with the USB spec of &lt;10 uF." CreationDate="2011-01-23T02:28:09.583" UserId="142" />
  <row Id="13836" PostId="9279" Text="How poor my memory is!  Thanks for pointing that out." CreationDate="2011-01-23T03:04:12.067" UserId="2059" />
  <row Id="13837" PostId="9257" Score="1" Text="@bt2 the z-form lends itself to implementation as a difference equation, which depends only on past outputs and the current input, without requiring a running sum which will at some point overflow (or underflow). DSPs are designed to allow efficient implementation of digital filters via the differences equation approach. See http://en.wikipedia.org/wiki/Digital_filter esp. direct forms - that's what DSPs are optimised for." CreationDate="2011-01-23T03:26:56.273" UserId="2340" />
  <row Id="13838" PostId="9257" Text="@freespace managed to put what I wanted to say a bit more eloquently." CreationDate="2011-01-23T04:29:12.457" UserId="1477" />
  <row Id="13839" PostId="9328" Text="@ThomasO if you made vacuum tubes negative numbers... Personally I like the idea of big oil keeping the practical implementation of negative resistors from coming to a product." CreationDate="2011-01-23T05:32:31.980" UserId="638" />
  <row Id="13841" PostId="9326" Text="Um... freaking cool!?" CreationDate="2011-01-23T06:25:02.877" UserId="2118" />
  <row Id="13843" PostId="8711" Text="-1: sorry, but the question was about main safty training, not about dimming lights." CreationDate="2011-01-23T08:08:42.230" UserId="2426" />
  <row Id="13844" PostId="9324" Text="Why? - - - - - -" CreationDate="2011-01-23T09:26:32.387" UserId="339" />
  <row Id="13845" PostId="9329" Text="@starblue, The use of [meta-tags](http://meta.electronics.stackexchange.com/q/115/2118) such as `[homework]` is discouraged." CreationDate="2011-01-23T09:54:06.833" UserId="2118" />
  <row Id="13846" PostId="9332" Text="No, you sacrifice battery life, not current. (But in long term yes, max current will decline). If you charge 3.6 battery to 3.7v it will die sooner, but probably not instantly. Extra stored charge is too little. It's more important when undercharging 4.2v one :-)" CreationDate="2011-01-23T10:27:55.407" UserId="2062" />
  <row Id="13847" PostId="9334" Text="Good info. Found a page mentioning this, and that they changed to PC: http://www.cpu-world.com/CPUs/6800/Motorola-XC6800B.html" CreationDate="2011-01-23T10:32:14.213" UserId="1181" />
  <row Id="13848" PostId="9312" Text="It is relevant to you, but not to the audience at large now or in the future, when the answers may no longer apply due to companies moving, failing, and otherwise changing. When Farnell and RS get bought out by Renesas, this question will be outdated." CreationDate="2011-01-23T10:33:01.263" UserId="2118" />
  <row Id="13849" PostId="9307" Score="1" Text="I guess USB current sensing is pretty implementation/motherboard specific. If you want to be safe, put a powered USB hub in series with your device. That way it's much harder to blow anything on your computer, even if something does go wrong." CreationDate="2011-01-23T10:49:13.590" UserId="1374" />
  <row Id="13850" PostId="2871" Text="@0x2A31 - I don't think the issue is the 5V, the 5A is a very high current for measuring resistors. That current will fry many resistors (or other components for that matter.)" CreationDate="2011-01-23T12:22:50.337" UserId="718" />
  <row Id="13851" PostId="9257" Text="I think you are missing something.  The running sum will never overflow under normal circumstances.  IIR filters won't always saturate, and in the case of a PID control, that normally won't be the case.  Saying it will with one algorithm but won't with another is false.  The running sum is likewise based on previous outputs.  If one causes overflow, they both will.  Think of it this way, the 2nd implantation IS the first, with some math factored out...u(k-1) - kp(e(k-1) - kd/Ti(e(k-1) - e(k-2) == (running sum)." CreationDate="2011-01-23T13:44:49.703" UserId="2377" />
  <row Id="13852" PostId="9257" Text="The remaining math is also a difference equation which can be vectorized." CreationDate="2011-01-23T14:00:22.377" UserId="2377" />
  <row Id="13853" PostId="9341" Text="@Jim - thanks for the great idea. Do you know anything even simpler? I need to transfer about 4-8 bits of data each time, with some possible pause between them. (data bursts).&#xA;" CreationDate="2011-01-23T15:45:06.507" UserId="2737" />
  <row Id="13854" PostId="9340" Score="2" Text="http://electronics.stackexchange.com/questions/7715/best-method-for-sending-data-over-a-mono-audio-channel" CreationDate="2011-01-23T15:45:51.420" UserId="566" />
  <row Id="13855" PostId="9342" Text="Perfect! thanks :)" CreationDate="2011-01-23T15:53:04.733" UserId="2737" />
  <row Id="13856" PostId="9275" Score="3" Text="@semaj, I actually have had one friend that was payed decently by the FCC to drive around his city with alot of electronics in the back of his car. If a light turned on up front, he went and recorded the readings from the back and sent them to the FCC. This is how the FCC would get the location of violators, random chance of if you radiate while he drives by. Frequencies that you are allowed to radiate on you should be okay as long as you stay below the maximum allowed power, and small spurious emissions will just be background noise at a distance." CreationDate="2011-01-23T16:04:25.313" UserId="230" />
  <row Id="13859" PostId="3145" Text="You might believe it if you knew it was only 180sps." CreationDate="2011-01-23T16:42:09.003" UserId="1024" />
  <row Id="13860" PostId="7451" Text="Sugar + Air?  Why not, say, C4 + air?" CreationDate="2011-01-23T19:40:36.470" UserId="857" />
  <row Id="13861" PostId="9340" Score="1" Text="I'm just getting a kick out of this question - it makes me feel so old.  Back when I was a kid computers came with cassette drives to store data in an audio format.  So yes, it is possible to transfer data over an audio cable and in fact it was one of the first ways to do so :)" CreationDate="2011-01-23T19:52:20.837" UserId="249" />
  <row Id="13862" PostId="9326" Text="This technique also works for single shot ranging." CreationDate="2011-01-23T21:35:40.983" UserId="1481" />
  <row Id="13863" PostId="2871" Text="You better may use a multimeter 0X2A31 to measure the resistance straight away. If the equipment you're using is capable of going to 0.1V (which sounds a lot to me), your multimeter is going to have a far greater accuracy in measuring. Especially if you know that current measurements on multimeters can be way off, and that multimeters have a considerable resistance as well. " CreationDate="2011-01-23T22:05:27.463" UserId="1476" />
  <row Id="13864" PostId="9346" Text="It looks like you're measuring currents larger than ~50mA, but still good to know: meter burden voltage makes low current measurements inaccurate in most multimeters, even really good ones. This can be fixed by using [a low burden current shunt](http://goo.gl/jMnAc) and calculating I=V/R." CreationDate="2011-01-23T22:23:53.247" UserId="2118" />
  <row Id="13867" PostId="9350" Text="Of course, thank you for any answer :)" CreationDate="2011-01-23T22:52:13.023" UserId="2653" />
  <row Id="13868" PostId="1474" Text="@Jim Be careful when you look at micro-controllers that &quot;have 12 ADCs&quot;  I've never seen one that actually does, they almost always have 1 ADC, maybe 2, with 12 or however many pins that are just hooked to the ADC through a MUX.  That is you can only measure one pin at a time (as there is really only 1 ADC!).  You can achieve the same thing with about any micro-controller and whatever sized external multiplexer you need.  I looked through the pSoC catalog(quickly), most actual ADCs i found was 4, plenty of parts with 12 'analog blocks' but reading the data sheet shows only 4 ADC's." CreationDate="2011-01-23T23:17:16.723" UserId="1438" />
  <row Id="13869" PostId="9356" Text="Thank you for the answer, Kellenjb! If I used the Arduino for the 5V and 3.3V sources, I would thus connect the two GND to the GND of the Arduino, right ?" CreationDate="2011-01-23T23:38:07.210" UserId="2653" />
  <row Id="13870" PostId="1096" Text="Probably best to just zap it." CreationDate="2011-01-23T23:49:34.287" UserId="2742" />
  <row Id="13871" PostId="9351" Text="Related: http://electronics.stackexchange.com/q/7728/2118" CreationDate="2011-01-23T23:50:15.043" UserId="2118" />
  <row Id="13872" PostId="9357" Text="Interesting. Then you just write an app that listens on that port? Would I need a resistor in serial of the 120v side?" CreationDate="2011-01-24T00:18:52.970" UserId="2741" />
  <row Id="13874" PostId="9356" Score="1" Text="You need to connect the ground of the phone to your system. This is what ties the systems together to have a standard ground to reference against. If you look at the sparkfun board you will find that the grounds of both high and low are just tied together." CreationDate="2011-01-24T01:16:00.407" UserId="319" />
  <row Id="13877" PostId="9355" Text="In my experience with 5-band 1/8 Watt blue colored (through hold) resistors, and any SMT resistors this is what I end up doing as a sanity check." CreationDate="2011-01-24T02:53:36.513" UserId="2598" />
  <row Id="13878" PostId="2869" Score="1" Text="Any reason not to empirically find the solution using test equipment such a multi-meter or DMM?" CreationDate="2011-01-24T02:55:26.743" UserId="2598" />
  <row Id="13879" PostId="9219" Text="@pingswept no, you would scold Kortuk if he were to test it on you." CreationDate="2011-01-24T03:02:13.293" UserId="319" />
  <row Id="13880" PostId="9358" Text="@jluciani, Where are you seeing a cap on RTS? There is a not populated resistor on RTS. The capacitor (C13) is wired between DTR (FT232L pin 2) and the MCU's reset pin..." CreationDate="2011-01-24T03:27:13.213" UserId="771" />
  <row Id="13881" PostId="9362" Text="This is categorically off topic for E&amp;R.SE.  You are better off asking at a site like [SuperUser](http://superuser.com/), or possibly a hardware specific site, like [Apple.SE](http://apple.stackexchange.com/)." CreationDate="2011-01-24T03:29:08.890" UserId="1407" />
  <row Id="13882" PostId="4056" Text="CMOS gates use much more than kT ln(2), though, don't they?  That's like 10^-21 J per bit, or picowatts at 3 GHz." CreationDate="2011-01-24T03:55:48.650" UserId="142" />
  <row Id="13883" PostId="9358" Text="@jluciani, Your explanation makes good sense. I like your explanation regarding no instantaneous change in voltage across capacitors. That's a handy base principle to keep in mind. Part of me wonders why both sides should drop to zero then one side recharge, rather than the DTR side simply discharging through the internal resistance of the DTR pin? Also why did you use a PWL source instead of a PULSE source in the sim?" CreationDate="2011-01-24T04:13:13.223" UserId="771" />
  <row Id="13884" PostId="9363" Score="1" Text="Desktops are useful to design E&amp;R stuff and sometimes directly for E&amp;R, but that doesn't mean questions tangentially related to them are on-topic. " CreationDate="2011-01-24T04:18:21.173" UserId="1407" />
  <row Id="13885" PostId="9362" Score="2" Text="Question is off topic. But just to help you out, look around for media center keyboards. There are several out there that include a pointing device. They are designed for Windows Media Center, but will work with OS X, just may not be able to use every feature." CreationDate="2011-01-24T04:18:51.670" UserId="319" />
  <row Id="13886" PostId="9362" Text="Fair enough re: the off-topic. Cheers for suggesting alternatives, Nick." CreationDate="2011-01-24T04:24:39.740" UserId="2743" />
  <row Id="13887" PostId="9358" Text="@vicatu, I do not know the period or duty cycle of the pulse, and a simple drop to 0V verifies all assumptions nicely." CreationDate="2011-01-24T04:32:22.253" UserId="2118" />
  <row Id="13888" PostId="9265" Text="@Robert That was the Reason!! Thank you!!" CreationDate="2011-01-24T04:44:04.393" UserId="2574" />
  <row Id="13889" PostId="4264" Text="@Pingswept: Any idea of a chip having an Arm9 core with 12bit adc and 12bit stereo dac?" CreationDate="2011-01-24T09:23:52.843" UserId="444" />
  <row Id="13890" PostId="9369" Score="1" Text="What did you say BarsMonster? A temperature controlled room? :) Allow me the idea for a `temperature controlled country` 22 C degrees throughout the year with a constant sound of beach waves and daily Mango juces served at a `controlled 5 C degrees chilled temps`. Back to topic: Funny you use UniT too, apparently more famous brand than i ghought. looking forward to your Uni-T  specs. I heard the Fluke's are the best on this planet. true?" CreationDate="2011-01-24T09:42:27.187" UserId="2719" />
  <row Id="13891" PostId="9369" Score="1" Text="Fluke are great, but a &quot;little&quot; bit expensive. For temperature controlled room you just need conditioner. If you will have 22C+-2C you will have much higher accuracy after calibration." CreationDate="2011-01-24T10:29:17.397" UserId="2062" />
  <row Id="13892" PostId="9356" Text="Do you mean `HV &lt;-&gt; 5V Arduino`, `HV GND &lt;-&gt; Arduino GND`, `LV &lt;-&gt; 2.8V source` and `LV GND &lt;-&gt; Phone GND` ? So grounds for &quot;lows references&quot; and power sources for &quot;highs references&quot;." CreationDate="2011-01-24T11:36:36.543" UserId="2653" />
  <row Id="13893" PostId="9365" Score="1" Text="Your certainty seems a bit odd to me. As if you were present when it was *decided* not to use a logical system..." CreationDate="2011-01-24T12:00:29.443" UserId="2064" />
  <row Id="13894" PostId="9341" Score="1" Text="@roman - For that amount of data I would just pick two easily distinguished tones to play and then apply a notch filter at each frequency and test the energy level.  You could use two other frequencies that switch back and forth and use them as a clock.  A quick search should get you a notch filter in nearly any language you want." CreationDate="2011-01-24T12:14:17.883" UserId="2738" />
  <row Id="13895" PostId="9365" Score="1" Text="Also, if there isn't any logic in it, why didn't they name them AAA001, AAA002, etc?" CreationDate="2011-01-24T13:15:08.977" UserId="2064" />
  <row Id="13896" PostId="9356" Text="Pretty much, yes." CreationDate="2011-01-24T13:30:03.250" UserId="319" />
  <row Id="13897" PostId="9369" Score="1" Text="Unless you need better than 0.05% drift (most people don't) then temperature control is not critical. A temperature from 15-25 degrees can usually be maintained by the thermostat in the house." CreationDate="2011-01-24T13:46:08.430" UserId="1225" />
  <row Id="13898" PostId="9368" Score="2" Text="[$50](http://www.eevblog.com/2010/06/04/eevblog-91-50-multimeter-shootout/), [$100](http://www.eevblog.com/2010/07/11/eevblog-99-100-multimeter-shootout-extech-amprobe-bk-precision-ideal-uei-uni-t-part-1of2/), and the [continued $100](http://www.eevblog.com/2010/07/11/eevblog-99-100-multimeter-shootout-extech-amprobe-bk-precision-ideal-uei-uni-t-part-2of2/) meter comparison." CreationDate="2011-01-24T14:22:37.820" UserId="2118" />
  <row Id="13899" PostId="9325" Score="2" Text="tyblu: My research is into underwater freespace optical communication, as such we're using blue/green lasers. Currently the cheapest way to get a blue/violet diode laser is to salvage them from BlueRay DVD players. A 6x burner diode will give you about 200 - 300 mW optical power. 12x burners are closer to 600 mW. Now that the pico projectors are coming down in price 445 nm (1 W) are more available. A good place for info is http://laserpointerforums.com/, though if you just want to buy straight up diodes, this guy is quite good: http://hightechdealz.com" CreationDate="2011-01-24T15:08:37.297" UserId="2454" />
  <row Id="13900" PostId="9219" Text="@kellenjb: Ah, I misunderstood. That's a relief. I was worried I was complicit in shocking @tyblu." CreationDate="2011-01-24T15:10:35.690" UserId="712" />
  <row Id="13901" PostId="9368" Text="Thanks very much for that good sidebyside link tyblu ! I already saw the videos from that crazy Australian guru, very funny! BUT that is a one mans review. He likes meters with color white and blue and doesnt like lcd's with green background etc!!  He complained about strange things of which I am SURE other users will not find an issue at all. Thats why I want to hear from `real life owners themselves` what they think after long time use, who, preferably, discriminate less on the colors the device came in but put more value to the overall persomance of the device as the age naturally :)" CreationDate="2011-01-24T15:11:00.990" UserId="2719" />
  <row Id="13902" PostId="4264" Text="@Kevin Boyd: I don't know of any ARM9's with on-chip DACs. They might exist, but I've not seen one. The Freescale i.MX233 might be your best bet-- 12-bit ADC plus dual serial audio interfaces on chip. " CreationDate="2011-01-24T15:23:50.607" UserId="712" />
  <row Id="13903" PostId="9358" Text="@tyblu, yes I fully intend to accept this answer, I'm just hoping for some elaboration in response to my comments above." CreationDate="2011-01-24T16:20:04.820" UserId="771" />
  <row Id="13904" PostId="9221" Text="And this is safe to zap people with, right? Causing no permanent or serious damage? Thanks, that is very helpful! I always like to seek advice for potentially dangerous projects" CreationDate="2011-01-24T17:13:02.597" UserId="2681" />
  <row Id="13905" PostId="9360" Text="I've used 300bps AFSK over a pair of FRS radios before.  Works great!" CreationDate="2011-01-24T17:18:45.760" UserId="1554" />
  <row Id="13906" PostId="9282" Text="@dren.dk, daily builds are less important now that a build can be done in under 30 seconds normally. A once a day master build as a double check does not hurt though." CreationDate="2011-01-24T17:36:42.400" UserId="230" />
  <row Id="13907" PostId="9338" Text="Can you post or link to high-res photos of the PCB?  Flatbed scanners work well for this if there are no tall components." CreationDate="2011-01-24T17:46:15.133" UserId="857" />
  <row Id="13908" PostId="9376" Text="tricky. I've never seen quad resistors before. tnx" CreationDate="2011-01-24T19:08:12.683" UserId="1514" />
  <row Id="13909" PostId="9369" Text="Updated info of my meters." CreationDate="2011-01-24T19:12:34.933" UserId="2062" />
  <row Id="13910" PostId="9376" Text="They are used alot on motherboards in our computers. There are also octal ones. " CreationDate="2011-01-24T19:14:57.803" UserId="2062" />
  <row Id="13911" PostId="9377" Text="It looks like a heat sink of some wort to me." CreationDate="2011-01-24T19:47:15.067" UserId="319" />
  <row Id="13912" PostId="9377" Text="That shiny plate on the top is paper. So I don't think it's a heatsink" CreationDate="2011-01-24T19:53:42.130" UserId="1514" />
  <row Id="13913" PostId="9374" Text="That does not improve the model, just reduces the inductance." CreationDate="2011-01-24T20:28:45.013" UserId="230" />
  <row Id="13914" PostId="9376" Score="2" Text="Specifically, it's an isolated resistor array.  Some resistors that appear similar can be bussed to provide X (usually 9 or 15) pull-ups in a small space with a minimal number of vias." CreationDate="2011-01-24T20:33:53.717" UserId="1407" />
  <row Id="13915" PostId="9380" Score="1" Text="Every time I see words 'impedance' and 'imaginary part' in the same sentence, I feel so dumb...." CreationDate="2011-01-24T21:04:21.447" UserId="2062" />
  <row Id="13916" PostId="9380" Text="homework much? :)" CreationDate="2011-01-24T21:24:05.943" UserId="1438" />
  <row Id="13917" PostId="9271" Score="1" Text="simulation from the actual schematic is not really feasable for most real-world designs of any complexity.  it is better to spin the board early and plan to throw the first one away. http://c2.com/cgi/wiki?PlanToThrowOneAway" CreationDate="2011-01-24T21:26:04.567" UserId="411" />
  <row Id="13918" PostId="9368" Score="1" Text="That multimeter shootout excludes bench meters, which I prefer.  Bench meters don't have power supply or bulk/weight restrictions, which allows them to achieve higher accuracy." CreationDate="2011-01-24T21:28:30.507" UserId="411" />
  <row Id="13919" PostId="9380" Text="ok so i'll give you a hint, if the question is being posed exactly as it is presented here, its a trick question(kinda).  They are asking for power _dissipated_ in the load, aka true power which is a separate concept from reactive power or apparent power and that should both influence and simplify(a bit) your calculation.   " CreationDate="2011-01-24T21:49:48.937" UserId="1438" />
  <row Id="13920" PostId="9388" Text="What have you looked at so far?  Does the cheapest Fluke do that?" CreationDate="2011-01-24T22:22:12.220" UserId="206" />
  <row Id="13921" PostId="9391" Text="So OP had the right answer, because 1/40 W == 25 mW." CreationDate="2011-01-24T22:24:03.230" UserId="411" />
  <row Id="13922" PostId="9388" Text="@Brian Carlton I think a Fluke will be too expensive for me. £80 doesn't buy much in the world of high end meters." CreationDate="2011-01-24T22:32:39.663" UserId="1225" />
  <row Id="13923" PostId="3564" Text="Here's a similar question on stack overflow http://stackoverflow.com/questions/1524244/tool-for-drawing-timing-diagrams" CreationDate="2011-01-24T22:36:49.837" UserId="1708" />
  <row Id="13924" PostId="9391" Text="yep OP had the right answer, but given the nature of the question i don't think OP knew why it was right, so i figured I'd show it in a way more connected to the electronics concepts." CreationDate="2011-01-24T22:37:20.373" UserId="1438" />
  <row Id="13925" PostId="3591" Score="1" Text="I've used Drawtiming for auto-generated timing diagrams in a parallelized build-flow to great effect.  I  recommend it." CreationDate="2011-01-24T22:39:01.677" UserId="1708" />
  <row Id="13926" PostId="9394" Text="I've seen those and I'm leaning towards the BK, but I'm still not certain." CreationDate="2011-01-24T22:44:03.987" UserId="1225" />
  <row Id="13927" PostId="9395" Text="Maybe move this Q to electronics.stackexchange.com" CreationDate="2011-01-24T20:52:01.450" UserId="1750" />
  <row Id="13928" PostId="9393" Text="@RocketMagnet, I understand other methods, but am wanting to expand to an RTOS. I will be running multiple tasks and having a hard real time system, but am willing to start without the requirements of hard real time. Thank you for taking the time to answer, but I am wanting to learn an RTOS so that I can use it in a high demand situation." CreationDate="2011-01-24T22:52:13.117" UserId="230" />
  <row Id="13929" PostId="9395" Text="possible duplicate of [Circuit Simulation Software](http://electronics.stackexchange.com/questions/7022/circuit-simulation-software)" CreationDate="2011-01-24T22:56:49.647" UserId="1623" />
  <row Id="13930" PostId="9368" Text="Interesting throw to this topic Markrages! Hadn't thought of that myself. By `don't have power supply` you mean probably they have a more stable power supply? Any suggestions? Which meter do you use/are you fond of?" CreationDate="2011-01-24T22:59:48.817" UserId="2719" />
  <row Id="13931" PostId="9387" Score="1" Text="More to OP's question, there isn't really going to be a tremendous difference between solid and stranded unless you're using Litz wire." CreationDate="2011-01-24T22:59:54.513" UserId="1407" />
  <row Id="13932" PostId="9399" Text="The error rate seems to be a direct function of the GND voltage difference. I can make the error rate increase or decrease right before my eyes, simply by decreasing or increasing the amount of copper connecting the grounds." CreationDate="2011-01-24T23:16:23.000" UserId="1024" />
  <row Id="13933" PostId="9399" Text="yep thats not surprising, if there is current flowing through the ground loops, which it sounds like there definitely is, decreasing the resistance reduces the voltage drop on the ground...have you tried just removing this ground between all the nodes and just leaving the CAN H/L ?  As mentioned, its not needed for CAN and it doesn't sound like its part of the power supply so its really not doing anything but creating a current loop that is causing problems." CreationDate="2011-01-24T23:40:30.123" UserId="1438" />
  <row Id="13934" PostId="9399" Text="lets put it another way, If you've connected the grounds of all the nodes and are using 6 feet of 18 guage copper to do so.  If you measure 150mV between the two end nodes there could well be 3.32 AMPS of current flowing between those nodes on the ground wire.  That is a major problem and can cause all sorts of issues with the entire circuit." CreationDate="2011-01-24T23:57:54.737" UserId="1438" />
  <row Id="13935" PostId="9387" Text="@NickT, I missed that part somewhat, rectified." CreationDate="2011-01-25T00:29:57.550" UserId="230" />
  <row Id="13936" PostId="9368" Score="1" Text="@Sam, Bench meters can get up to around 6.5 digits. What accuracy do you need? I personally prefer handheld battery meters." CreationDate="2011-01-25T01:36:45.267" UserId="2118" />
  <row Id="13937" PostId="9389" Score="1" Text="[I'm linking this Aussie everywhere...](http://www.eevblog.com/2011/01/23/eevblog-140-battery-capacity-tutorial/)" CreationDate="2011-01-25T01:38:55.140" UserId="2118" />
  <row Id="13938" PostId="9388" Text="Related: http://electronics.stackexchange.com/q/9368/2118" CreationDate="2011-01-25T01:40:33.267" UserId="2118" />
  <row Id="13939" PostId="9368" Text="Thanks for nailing my problem.. I guesse I have been too obsessed with _more is better_ but at some point, `there is just no more accuracy, only higher resolution`. So, lets say I just need another decent multimeter which has a beautifully clear display!" CreationDate="2011-01-25T02:04:49.243" UserId="2719" />
  <row Id="13940" PostId="9369" Text="How interesting that the model UT61E performs in accuracy seemingly better than UT70A! Or at least their specs say." CreationDate="2011-01-25T02:06:33.530" UserId="2719" />
  <row Id="13941" PostId="9388" Text="A DMM that does everything will do everything badly. You really want a LC meter, a DMM, and a temperature probe, not a single unit." CreationDate="2011-01-25T02:20:51.553" UserId="1374" />
  <row Id="13942" PostId="9369" Text="@Sam: Flukes are generally the gold-standard in portable, rugged meters, but some other companies: Agilent, etc, have excellent bench meters." CreationDate="2011-01-25T02:45:40.310" UserId="1407" />
  <row Id="13943" PostId="9407" Text="Feel free to tick your own answer as the accepted one; you don't get points for it but it's probably the most helpful; remind everyone to make sure you are using the right parts :P" CreationDate="2011-01-25T02:48:08.293" UserId="1407" />
  <row Id="13944" PostId="9382" Score="1" Text="Jeez...and I thought DCM was &quot;bad&quot;...RFNA can certainly oxidize almost anything, but I'd be worried that the only thing it would leave would be the more resistant plastics, glass, and maybe silicon die (and lead wires if they're made out of gold).  Copper will disappear, and I don't even know if the soldermask would survive, so you couldn't even tell what traces were where." CreationDate="2011-01-25T02:52:34.437" UserId="1407" />
  <row Id="13945" PostId="9368" Score="2" Text="I mean, handheld meters are limited to low-current circuits because they are powered by batteries.  The designer of the bench meter doesn't have that limitation.  My favorite meter is the Agilent (née HP) 34401a.  Four-wire sensing, beautiful VFD display, RS-232 interface.   Exceeds your budget by about 6dB." CreationDate="2011-01-25T03:30:48.247" UserId="411" />
  <row Id="13946" PostId="9395" Score="1" Text="not a duplicate of that (it's not about simulation), more a duplicate of http://electronics.stackexchange.com/questions/1024/" CreationDate="2011-01-25T03:33:35.467" UserId="411" />
  <row Id="13949" PostId="9395" Text="This answer fits better here: http://electronics.stackexchange.com/questions/1024/good-tools-for-drawing-schematics/3035#3035" CreationDate="2011-01-25T03:36:48.677" UserId="411" />
  <row Id="13950" PostId="9406" Text="Your answer sounds impressive, but I have pretty much no idea what you said.  What is quantization stability, for example, and how is it superior for one form of the equation than the other?" CreationDate="2011-01-25T04:15:21.113" UserId="2377" />
  <row Id="13951" PostId="9406" Score="1" Text="The transfer function H(z) is a rational function B(z)/A(z). Each polynomial in z is a factor of N zeros for an Nth order system. The zeros of A(z), the ones in the denominator, are called the poles (this is the feedback path). To a constant scaling factor, a Linear Time Invariant (LTI) system is described by its zeros and poles. " CreationDate="2011-01-25T04:23:29.880" UserId="721" />
  <row Id="13952" PostId="9406" Score="1" Text="A discrete-time LTI system is stable if all of its poles are inside the unit circle on the z-plane. But quantization with finite digital precision introduces noise that can cause a system to be marginally stable, unstable or drift into instability over time. By factoring H(z) into a product biquadratics (biquads), this kind of error is minimized." CreationDate="2011-01-25T04:29:01.043" UserId="721" />
  <row Id="13953" PostId="9406" Score="1" Text="A biquad is the preferred minimum partition since the zeros of a polynomial with real coefficients are either real or in pairs of complex conjugates. The biquad B(z)/A(z) is (b0 + b1z^-1 + b2z^-2)/(a0 + a1z^-1 + a2z^-2)." CreationDate="2011-01-25T04:34:29.103" UserId="721" />
  <row Id="13954" PostId="9406" Score="1" Text="upvote for shit I don't understand!!" CreationDate="2011-01-25T05:55:26.640" UserId="2118" />
  <row Id="13955" PostId="9368" Text="@Sam, After [some discussion in Meta-E&amp;R](http://meta.electronics.stackexchange.com/q/375/2118), conclusion is that asking for specific multimeters without qualifications is not useful for future internet audiences. Could you instead ask for what to look for in a multimeter; or some other qualities?" CreationDate="2011-01-25T06:00:29.630" UserId="2118" />
  <row Id="13956" PostId="9398" Text="I haven't, didn't know they supported electronic circuit designs. I'll have a look." CreationDate="2011-01-25T06:37:29.743" UserId="2761" />
  <row Id="13957" PostId="9404" Score="1" Text="Visio is great for general use but it doesn't have a big library of symbols." CreationDate="2011-01-25T06:38:35.890" UserId="2761" />
  <row Id="13958" PostId="9406" Text="I added and then removed an example for the quantization noise comparing a cascaded quadratic to a direct 4th order poly. But it was too much. I need to get some sleep. Sorry, tyblu." CreationDate="2011-01-25T06:47:50.973" UserId="721" />
  <row Id="13959" PostId="9257" Text="To chime in with bt2 here, a running sum is a 1st order difference equation, sum[n] = sum[n-1] + x[n]. Also, SUM(z) = 1 / (1 - z^-1). The Z-transform has a pole at z = 1, i.e. 0 radians/sample. Any other frequency will sum to zero over a period; it's just the presence of a constant value that makes the sum increase without bound." CreationDate="2011-01-25T06:59:37.387" UserId="721" />
  <row Id="13962" PostId="9410" Text="How far, how fast, and over what medium are you communicating?" CreationDate="2011-01-25T07:59:39.263" UserId="2118" />
  <row Id="13963" PostId="9399" Text="Mark, if I remove the GND connection between nodes, then the difference goes up, and so does the error rate. The problem is that each group of nodes is powered from its own isolated power supply, so there is nothing much preventing the GND difference going beyond the spec 7v maximum." CreationDate="2011-01-25T08:28:07.573" UserId="1024" />
  <row Id="13964" PostId="9410" Score="1" Text="It's probably far wiser to extract the video from the NTSC modulation, encode it using something like h.264 or another streaming codec, and transmit it that way, converting back to NTSC at the other end." CreationDate="2011-01-25T08:33:14.763" UserId="1374" />
  <row Id="13965" PostId="9392" Score="1" Text="+1.  Rate of discharge is often overlooked.  &quot;Deep-cycle&quot; batteries are batteries that, relatively speaking, can't put out too many amps, but they have more Ah (i.e. higher capacity) than batteries that can put out a lot of amps very quickly." CreationDate="2011-01-25T08:36:32.513" UserId="2764" />
  <row Id="13966" PostId="9369" Text="@Nick : Yeah, but for 1 Fluke or Agilent multimeter you may buy like 5-10 decent UNI-T ones :-D Of course that does not matter if company buys it :-D" CreationDate="2011-01-25T08:38:58.640" UserId="2062" />
  <row Id="13967" PostId="9399" Score="1" Text="@rocketmagnet Where are you getting 7V?  The datasheet for that transceiver lists +- 42V for common mode DC voltage limit on CANH/CANL.  As long as your using similar isolated supplies and they are plugged into even remotely the same power system you shouldn't see much different in the board ground potential, maybe a couple volts.  Board ground level differences have no effect on differential signaling, thats one big reason to use differential signaling.  If you remove all connections between nodes except the CANH/CANL and still have problems there is another issue in the design." CreationDate="2011-01-25T08:47:44.710" UserId="1438" />
  <row Id="13968" PostId="9399" Text="According to the Microchip application note &quot;A CAN Physical Layer Discussion&quot; http://ww1.microchip.com/downloads/en/AppNotes/00228a.pdf " CreationDate="2011-01-25T10:32:53.157" UserId="1024" />
  <row Id="13969" PostId="9399" Text="&quot;While the MCP2551 is specified to handle ground&#xA;offsets from -12V to +12V, the ISO-11898 specification&#xA;only requires -2V to +7V.&quot;" CreationDate="2011-01-25T10:33:38.820" UserId="1024" />
  <row Id="13970" PostId="1222" Text="It looks like you're looking for free as in 'free beer', not free as in 'free speech'.  Is this correct?" CreationDate="2011-01-25T10:50:56.130" UserId="857" />
  <row Id="13971" PostId="9374" Text="and resistance (voltage drop)" CreationDate="2011-01-25T12:25:23.807" UserId="2471" />
  <row Id="13972" PostId="9390" Score="1" Text="With your scope on, do you get errors still? Effectively this will ground CAN 0v through your scope earth clip" CreationDate="2011-01-25T12:43:37.230" UserId="1827" />
  <row Id="13973" PostId="9405" Text="possible duplicate?  http://electronics.stackexchange.com/questions/5507/how-to-calibrate-multimeters" CreationDate="2011-01-25T13:11:40.503" UserId="1514" />
  <row Id="13974" PostId="9368" Text="@Tyblu, point taken! revised the entire post. Think this is ACTUALLY my question!" CreationDate="2011-01-25T13:13:37.903" UserId="2719" />
  <row Id="13975" PostId="9390" Text="Plugging the 'scope into the ground can help. But the correlation still holds. If I it reduces the GND voltage difference, then the error rate decreases." CreationDate="2011-01-25T14:08:20.783" UserId="1024" />
  <row Id="13976" PostId="9398" Text="AutoCAD Electrical 2011 - Seems geared towards PLC users more than embedded controllers." CreationDate="2011-01-25T14:16:15.303" UserId="588" />
  <row Id="13977" PostId="9417" Text="but if he is building a model the inductance of the wire is probably what he needs to build it." CreationDate="2011-01-25T15:39:21.777" UserId="230" />
  <row Id="13978" PostId="9406" Text="@bt2 He pretty much went into depth on my 2nd and 3rd paragraph." CreationDate="2011-01-25T18:34:52.747" UserId="319" />
  <row Id="13979" PostId="9406" Text="@eryksun I think your example is very good. Even if it is not understood by everyone it at least can help others." CreationDate="2011-01-25T18:37:30.823" UserId="319" />
  <row Id="13980" PostId="9270" Text="@bt2 it sounds like you have a very specific case where the PID w/o a PhD is the best approach. Most systems don't have a display of I and D terms in any way. It is the result of the PID controller that has some change on the system as a whole that is then looped back on itself. If you are just displaying to a user then there isn't really any reason to worry about stability." CreationDate="2011-01-25T18:44:20.623" UserId="319" />
  <row Id="13981" PostId="9179" Text="@stef it is not appropriate to double post on this site hoping to get more attention." CreationDate="2011-01-25T18:47:18.170" UserId="319" />
  <row Id="13982" PostId="9406" Text="stupid question, would PID by definition mean single pole and zero transfer function (proportional, integral, differential) ?" CreationDate="2011-01-25T19:04:35.007" UserId="1471" />
  <row Id="13983" PostId="5627" Score="1" Text="The part about why increased voltage decrease switching time is not correct. The threshold of the CMOS gate will change with supply voltage too (and within reasonable supply range will be more or less equal to constant fraction of the supply - for example 50%). As percentage change of the voltage do not depend on the supply (one RC will always be ~63% regardless supply) this is not the reason why supply does meter. With increased supply drive capability of the MOS transistor also increases (bigger Vgs). That means that actual R from RC decreases and that is why gate is faster." CreationDate="2011-01-25T19:36:53.503" UserId="1471" />
  <row Id="13984" PostId="9410" Text="@Fake Name: Are you aware of a piece of hardware which will let me pull the video from the NTSC signal in real time?" CreationDate="2011-01-25T20:39:27.957" UserId="2762" />
  <row Id="13985" PostId="9412" Text="Great, that's the first step. As I recall, the blanking interval makes up about 7% of the total transmission time. Perhaps I can use that to buffer the data transmission somewhat and improve the channel utilization. Thoughts?" CreationDate="2011-01-25T20:41:25.503" UserId="2762" />
  <row Id="13986" PostId="9412" Text="Any buffering would complicate your job alot (currently you can make it even without processor/FPGA). 7% loss is not much in fact. " CreationDate="2011-01-25T21:00:12.603" UserId="2062" />
  <row Id="13987" PostId="9424" Text="Why do you spec 16-bit?  This is going to be a rather high spec 16-bit processor to handle an I/O byte every 3 microseconds." CreationDate="2011-01-25T21:20:02.833" UserId="411" />
  <row Id="13988" PostId="9427" Text="So you are proposing one bit clock == one instruction.  That means you have ten instructions to deal with each incoming byte when they are arriving back-to-back.  This is not impossible, but  requires very tight coding and a deeper FIFO than the one-byte one common on small micros or a DMA engine like the high-end MSP430s have." CreationDate="2011-01-25T22:24:25.717" UserId="411" />
  <row Id="13989" PostId="9427" Text="@markrages. Investigate the dsPIC33F and PIC32, which have 8 channel DMA controllers and can do 1KB block transfers. I am currently using 1.8432 Mbaud between a PIC24F and a dsPIC33F and it has almost zero latency between each byte. You have 8x the baud clock to load each byte which is plenty. PIC24F/dsPIC33F have 4-deep FIFOs." CreationDate="2011-01-25T22:27:05.963" UserId="1225" />
  <row Id="13990" PostId="9427" Text="Sending is not such a problem, you can send the bytes when you get around to it.  You feel the pinch on incoming bytes.  Assuming start, 8 bits, stop, the baudrate is 10x the byte rate.  So your system needs to handle receiving 184320 bytes/sec.  And you have (14.7456/4)/18430 cycles (about 20) per byte to handle it." CreationDate="2011-01-25T22:34:31.637" UserId="411" />
  <row Id="13991" PostId="9424" Text="The MCU has to do some math on inertial data (gyros and accel), so a 16 bit solution is required" CreationDate="2011-01-25T22:54:08.173" UserId="2285" />
  <row Id="13992" PostId="9427" Text="@markrages, That's what DMA is for on the 33F's. And with the 4-deep receive FIFO, it gives you almost 80 cycles per byte. Interrupt latency is maybe 5 cycles and you can interrupt on each FIFO 3/4 full event (giving you time to empty it before it overflows.)" CreationDate="2011-01-25T23:01:04.707" UserId="1225" />
  <row Id="13993" PostId="9428" Text="Are you here to make your own circuit or are you wanting to buy one off the shelf?" CreationDate="2011-01-25T23:04:25.107" UserId="2744" />
  <row Id="13994" PostId="9426" Text="It doesn't need to do it entirely in software, because of the bit shifters in the IO ports. That's going to matter since power is a factor. I like the XS1, but there's no particular reason to choose it for this case, and lack of on-chip flash is a point against." CreationDate="2011-01-25T23:18:37.700" UserId="1181" />
  <row Id="13996" PostId="9429" Text="From the datasheets I sampled, the USCI supports up to 1Mbaud." CreationDate="2011-01-25T23:38:37.447" UserId="1181" />
  <row Id="13997" PostId="8699" Text="Or better yet, use a Kinect to track the object." CreationDate="2011-01-26T00:13:07.017" UserId="2454" />
  <row Id="13998" PostId="9428" Text="I'm cool with either.  I would need some guidance on what parts to buy either way.  I just need to make sure I cover both the detection and reporting issues.  I actually would prefer to build something." CreationDate="2011-01-26T00:26:19.060" UserId="2772" />
  <row Id="13999" PostId="9430" Text="They are small, but I do worry about having a powered element hanging from the roof." CreationDate="2011-01-26T00:30:10.257" UserId="2772" />
  <row Id="14000" PostId="9433" Score="1" Text="I was thinking of a strip, but I was reading about the fatigue and wondering if being constantly bent would be a problem.  As to the reporting, I actually need to have something that can tie into a computer (serial, usb) or send e-mail itself.  I am generally not here when it all goes bad (2 and 3 in the morning last time)." CreationDate="2011-01-26T00:31:14.827" UserId="2772" />
  <row Id="14001" PostId="9406" Text="@mazurnification The PID has `Gc(s) = (Kd*s^2 + Kp*s + Ki)/s; there could also be a pre-filter Gp(s) to control overshoot, and finally the device under control G(s). The transfer function is `T(s) = Gp(s)*Gc(s)*G(s)/(1 + Gc(s)*G(s))`. Also, higher orders than 1 might be used (though not typically) to approximate the derivative and integral in the discrete-time system since no finite-order rational function B(z)/A(z) can represent s = Fs*ln(z)." CreationDate="2011-01-26T00:53:28.277" UserId="721" />
  <row Id="14002" PostId="9406" Text="@mazurnification So in other words you're right about the PID, unless the derivative and integral are more finely approximated. However, analyzing the stability of the system is best done with the Z-transform." CreationDate="2011-01-26T01:31:13.737" UserId="721" />
  <row Id="14003" PostId="9427" Text="@Thomas, you are missing my point.  If I send you a stream of bytes at 184320 bytes/sec, and you are executing 14.75M/4 instructions per second, you only have 20 instructions per byte to do something with the data.  Buffering helps lose some interrupt overhead, but with zero overhead you are still stuck at 20 instructions per byte.  You can fix this with a faster processor clock or slowing down the data with flow control.  But if you are slowing down the data, what is the point of choosing such a baudrate in the first place?" CreationDate="2011-01-26T02:25:04.090" UserId="411" />
  <row Id="14004" PostId="9424" Text="Why not 32-bit?" CreationDate="2011-01-26T02:29:36.253" UserId="411" />
  <row Id="14005" PostId="9424" Text="3 M = 3 250 000?" CreationDate="2011-01-26T02:30:12.197" UserId="1407" />
  <row Id="14006" PostId="9426" Text="How is XMOS at low-power applications? " CreationDate="2011-01-26T02:31:23.833" UserId="411" />
  <row Id="14007" PostId="9430" Text="Why are you worried about it?" CreationDate="2011-01-26T02:56:17.213" UserId="305" />
  <row Id="14009" PostId="9426" Text="Not all that good. They are very high-performance devices." CreationDate="2011-01-26T03:07:39.403" UserId="305" />
  <row Id="14010" PostId="9429" Text="They don't run at anything like 40 Mhz." CreationDate="2011-01-26T03:13:27.997" UserId="305" />
  <row Id="14012" PostId="9430" Score="1" Text="I've heard of using a diode junction (actually an abused transistor) as an anemometer; jam some current through it to heat it up, then measure the voltage which will vary with temperature.  The accuracy pales in comparision to a hot-wire anemometer, but if you're looking for a binary flow/no-flow should work." CreationDate="2011-01-26T03:48:45.797" UserId="1407" />
  <row Id="14013" PostId="3566" Text="With effort, time and imagination, Excel can draw much of what one needs." CreationDate="2011-01-26T04:00:18.003" UserId="2059" />
  <row Id="14014" PostId="9429" Text="@Leon, my mistake - it looks like 25MHz is about the high end, thanks for the correction I updated my answer accordingly" CreationDate="2011-01-26T04:06:52.100" UserId="771" />
  <row Id="14015" PostId="9441" Text="You might be better off asking this question on http://electronics.stackexchange.com/" CreationDate="2011-01-26T04:00:58.190" />
  <row Id="14016" PostId="9433" Text="@mccoma Why would something like that break when you were around, that would just be too convenient. " CreationDate="2011-01-26T05:56:48.453" UserId="319" />
  <row Id="14017" PostId="9432" Text="I went with #4. I'm currently waiting for my materials to arrive :-)    My project is actually to create a re-sizable pen-based input system. I want to be able to use it on a table or attach it to an LCD of any (reasonable) size without having to do any major modifications." CreationDate="2011-01-26T05:57:07.860" UserId="790" />
  <row Id="14018" PostId="9427" Text="@markrages. That's what U1CTS/U1RTS are for, right? If you're expecting a continuous stream of data then no microcontroller is really suitable. " CreationDate="2011-01-26T07:30:55.923" UserId="1225" />
  <row Id="14019" PostId="9424" Text="@markrages 32 would be perfect as well" CreationDate="2011-01-26T13:00:44.367" UserId="2285" />
  <row Id="14020" PostId="9429" Text="TI was my original choice as well, no way I could increase the freq with an embedded PLL?" CreationDate="2011-01-26T13:02:41.573" UserId="2285" />
  <row Id="14021" PostId="9444" Text="have you tried using the reset button before you sending your code to the board? and have you looked at reinstalling the FTDI driver or updating it?" CreationDate="2011-01-26T13:21:14.883" UserId="2060" />
  <row Id="14022" PostId="9444" Score="1" Text="Yes, no positive result.  These boards don't use FTDI, the ATMega 8U2 is used for USB-to-serial communications.  The driver is a .inf file that modifies the standard USB serial driver." CreationDate="2011-01-26T13:45:44.960" UserId="2775" />
  <row Id="14023" PostId="9428" Text="Sending an email is a very different problem from detecting airflow or temperature.  The sensors can be monitored with a $0.25 microcontroller, but email requires a much, much, much more complex system.  Do you have a computer that could run a program to continuously monitor a serial, USB, or Ethernet connection and do the email sending from there?  Serial is cheap and easy, USB is in the middle, and Ethernet is the hardest and most expensive.  (That's probably a silly question in a server room, but I don't know)." CreationDate="2011-01-26T14:12:36.037" UserId="857" />
  <row Id="14024" PostId="7901" Text="In spite of my skepticism towards embedded Java, I just found out that the AVR32 has a partially hardware-based JVM and felt compelled to add it to this question - See their [Java Technical Reference](http://www.atmel.com/dyn/resources/prod_documents/doc32049.pdf)" CreationDate="2011-01-26T14:34:54.137" UserId="857" />
  <row Id="14025" PostId="9443" Text="It is beyond question that I use a combination of big aluminium and ceramic, staggered by ESR and that I have a voltage regulator with good line regulation and low ripple. But the capacitors will probably do their job better when I provide them with an L or R. I'd like to avoid noise that I don't yet see on the lab bench, eg. from SMPSs in the neighbourhood." CreationDate="2011-01-26T14:58:23.203" UserId="1950" />
  <row Id="14026" PostId="9433" Text="@mccoma good point about fatigue. Maybe having it oscillate would then be a good idea. You'll just need to measure the oscillation and determine if/when it stops to detect an airflow problem." CreationDate="2011-01-26T15:27:51.840" UserId="2454" />
  <row Id="14027" PostId="9448" Text="You might also check out the XPort or WiPort from Lantronix. They do serial&lt;-&gt;ethernet and also have GPIO built in." CreationDate="2011-01-26T15:28:59.590" UserId="2454" />
  <row Id="14028" PostId="9428" Text="yeah, I've got an OpenBSD box and an OS X 10.6 box that could do the heavy lifting and poll a sensor.  The OpenBSD box has serial and USB.  The OS X has USB." CreationDate="2011-01-26T15:59:56.717" UserId="2772" />
  <row Id="14029" PostId="9444" Score="1" Text="It is probably related to the USBSER.SYS driver in Win2K. A preliminary search on Google found several results where people have experienced problems with the Win2K version of the driver vs. the XP version. Some people have mentioned using the XP version of the driver on Win2K, but the information is spotty." CreationDate="2011-01-26T16:01:36.727" UserId="2489" />
  <row Id="14030" PostId="9430" Text="I've built hot-wire anemometers using transistors. I used sot23-6 devices (dual transistors) but you could use two bigger ones with a little less accuracy. The idea is to use one as a temperature sensor and the other " CreationDate="2011-01-26T16:17:28.900" UserId="974" />
  <row Id="14031" PostId="9430" Text="I've built hot-wire anemometers using diode-connected transistors. I used sot23-6 devices (dual transistors) but you could use two bigger ones with a little less accuracy. The idea is to use one as a temperature sensor and the other as a heater. You have a DAC or PWM to vary a current to one of the transistors and a simple PI loop. The amount of current to keep the transistor at temp is proportional to the airflow over the pair. You will need to calibrate for air density (humidity) but I'm guessing in your application this doesn't change much." CreationDate="2011-01-26T16:23:09.287" UserId="974" />
  <row Id="14032" PostId="734" Text="This one seems to work http://www.lulu.com/items/volume_63/1108000/1108699/4/print/ARDUINO_NOTEBOOKv6.pdf" CreationDate="2011-01-26T18:11:53.220" UserId="2782" />
  <row Id="14033" PostId="9429" Text="@stef it seems like the 5xx series of MSP430's is capable of sourcing the baud rate clock from an external clock source. See http://www.ti.com/lit/pdf/slau208, section 26.3.9:  &quot;The baud-rate is generate using the BRCLK that can be sourced by the external clock UCAxCLK, or the internal clocks ACLK or&#xA;SMCLK depending on the UCSSELx settings.&quot; I haven't ever tried this or researched the limitations on the external clock, but at face value it seems viable." CreationDate="2011-01-26T20:12:50.850" UserId="771" />
  <row Id="14035" PostId="9431" Text="Why must it be an NXP branded chip?  Other vendors sell equally capable ARM7 and Cortex parts." CreationDate="2011-01-26T20:26:12.383" UserId="857" />
  <row Id="14036" PostId="9449" Text="Better use an LM358, it can go down to the lower rail. Add a resistor to limit the base current." CreationDate="2011-01-26T20:30:58.157" UserId="339" />
  <row Id="14037" PostId="9449" Text="LM324 also can go down to the lower rail." CreationDate="2011-01-26T20:33:03.683" UserId="411" />
  <row Id="14038" PostId="9427" Text="@mark - How many instructions do you need per byte?  Assuming you have a suitable FIFO/DMA system, you're going to have some multiplier (like 1/4 in this case), a clock speed, and a bit rate.  The math gives you some number of instructions (like 20 in this case), and you have to increase your clock to deal with it." CreationDate="2011-01-26T20:34:46.023" UserId="857" />
  <row Id="14039" PostId="9425" Text="As I said to Mike, any Cortex-M3 will have similar functionality to the SAM3S.  There's no need to hawk specific vendors unless yours provides a compelling additional feature (like a faster UART)." CreationDate="2011-01-26T20:36:43.260" UserId="857" />
  <row Id="14040" PostId="9427" Text="You can do actually some useful things at 20 instructions/byte." CreationDate="2011-01-26T20:44:24.530" UserId="411" />
  <row Id="14041" PostId="9456" Score="1" Text="I looked at that briefly a while ago, can you generate Gerbers or other netlists/BOMs for export, or are you locked into ExpressPCB forever? " CreationDate="2011-01-26T20:45:32.843" UserId="857" />
  <row Id="14042" PostId="9427" Text="@markrages, I imagine it would be fast enough to execute `mov U1RXREG, [W0++]` where W0 is a pointer to a character array. Extra instructions could be utilised to check overflow and load `W0` with the pointer." CreationDate="2011-01-26T21:15:19.247" UserId="1225" />
  <row Id="14043" PostId="9424" Text="@stef - Any reason the Bluetooth module needs to talk over UART? This will give you clock synchronization headaches and a minimum 4x clock delay, you can do better with a synchronous, possibly parallel interface.  " CreationDate="2011-01-26T21:19:48.290" UserId="857" />
  <row Id="14044" PostId="9458" Text="Am I correct in assuming the 9, 10 and 12 pins are used for other things? They don't seem to affect the sensor circuit." CreationDate="2011-01-26T21:24:11.390" UserId="1802" />
  <row Id="14046" PostId="9463" Text="Ha!  I uploaded that description.  Good to know someone else read it." CreationDate="2011-01-26T21:25:36.053" UserId="857" />
  <row Id="14047" PostId="9463" Text="Yes haha, I noticed you linked to imgur, so I searched for your name on reddit, then googled your name. Apologies for stalking but I found this site which may help quite a bit. These lights are ridiculous!" CreationDate="2011-01-26T21:28:56.603" UserId="2785" />
  <row Id="14048" PostId="9461" Text="There are built-in USARTs in a lot of the devices (UC3B is the only one I'm halfway familiar with). You'll have to clock it at 26MHz (top baudrate clock/8 for asynchronous mode). Should be no problem with the built in PLLs." CreationDate="2011-01-26T21:36:10.937" UserId="1181" />
  <row Id="14049" PostId="9464" Text="I agree, just cover them over" CreationDate="2011-01-26T21:36:47.007" UserId="566" />
  <row Id="14050" PostId="9464" Text="No, Joe, you don't understand. These things are INCREDIBLY BRIGHT.  They're also in a tight spot in a translucent case, so you'd likely overheat something if you put electrical tape or glue on them." CreationDate="2011-01-26T21:37:47.083" UserId="857" />
  <row Id="14051" PostId="9458" Text="Yes, it looks like 9 &amp; 10 are just controlling LEDs and 12 is a switch" CreationDate="2011-01-26T21:38:26.800" UserId="566" />
  <row Id="14052" PostId="9464" Text="They definitely won't overheat if covered, and if the LED breaks because it has overheated -- problem solved! The tape might not fit in the case however." CreationDate="2011-01-26T21:39:56.423" UserId="1363" />
  <row Id="14053" PostId="9464" Text="I'm glad you said NOT to do the tape thing, I was unsure.. Last night I used electrical tape on them.. I knew it wasn't the best idea.. And, there was still enough light leak to cast a big blue glow in my room. They are just very hard to cover thoroughly.  SO you're saying this is not the type of LED I can just yank off with pliers? " CreationDate="2011-01-26T21:40:44.223" UserId="2785" />
  <row Id="14054" PostId="9464" Text="How many people have this silly hub?" CreationDate="2011-01-26T21:41:42.877" UserId="1363" />
  <row Id="14055" PostId="9464" Text="@user2785 - The solder blob on the back of the PCB will never pull through the hole.  It's fairly thick wire, a metal-to-metal bond, and a copper-clad hole in a fiberglass board.  Cutting them will be much easier." CreationDate="2011-01-26T21:53:35.673" UserId="857" />
  <row Id="14056" PostId="9464" Score="1" Text="@Joe - It was the cheapest one in stock at my local Best Buy.  I presume this means a LOT of people." CreationDate="2011-01-26T21:54:17.797" UserId="857" />
  <row Id="14057" PostId="9463" Text="@user2785 - No problem.  I have a unique username because some other &quot;Kevin Vermeer&quot;s seem to have taken all the other reasonable permutations of my name: kevin.vermeer, kvermeer, vermeerk, kevinv, etc." CreationDate="2011-01-26T21:58:18.040" UserId="857" />
  <row Id="14058" PostId="9460" Text="I tried setting the pin to output a low, the the ADC is still reading mid-range values." CreationDate="2011-01-26T22:00:33.810" UserId="204" />
  <row Id="14059" PostId="9460" Text="Perhaps then when the output is low make a note in the program to ignore ADC readings?" CreationDate="2011-01-26T22:05:00.277" UserId="1225" />
  <row Id="14060" PostId="9467" Score="1" Text="YES!!! I DID IT. Thanks a ton man. I actually used your original pocketknife method (number 2), but your posts here helped clairfy a bit. I was unsure what to do from the original post. So happy. I was picking at all differnt angles, but when that first resister popped off and I figured it out, it was like winning the olympics.  YES. YESSSSSSSSSSSSSSSSSSSSSSSSSSSSS.    I wish you all the best of luck with future tinkering and thank everyone for their comments. " CreationDate="2011-01-26T22:10:02.373" UserId="2785" />
  <row Id="14061" PostId="9461" Text="@Yann - The OP specified UART (Asynchronous), which requires multiple clocks per bit.  They may have meant USART.  Yes, this is also available in hardware.  However, it means you have to have multiple samples per clock cycle, because the incoming data isn't synchronized with your clock.  That's why I suggested an external transceiver." CreationDate="2011-01-26T22:10:39.350" UserId="857" />
  <row Id="14062" PostId="9427" Text="@Thomas, putting bytes into RAM isn't useful by itself.  That's what I am calling &quot;overhead&quot;.  Presumably you are doing something else with the data stream?" CreationDate="2011-01-26T22:10:55.030" UserId="411" />
  <row Id="14063" PostId="9456" Text="Yes, you are locked in. No, it doesn't even support netlists/BOMs or anything. It's purely a layout package, you have to manage all your netlists yourself." CreationDate="2011-01-26T22:10:55.663" UserId="1374" />
  <row Id="14064" PostId="9467" Text="An epic tale of desperate, on the spot hacking if I ever heard one." CreationDate="2011-01-26T22:12:11.160" UserId="1363" />
  <row Id="14065" PostId="9463" Text="..and I was just thinking about changing my username to something more professional.  " CreationDate="2011-01-26T22:13:16.367" UserId="857" />
  <row Id="14066" PostId="9456" Text="Just had a look, you can export a DXF mechanical drawing (not too sure what that is), and import a netlist. The schematic program allows you to copy a BOM to the clipboard." CreationDate="2011-01-26T22:30:59.467" UserId="2426" />
  <row Id="14067" PostId="9464" Text="...or paint the LEDs with black paint." CreationDate="2011-01-26T22:43:30.497" UserId="2426" />
  <row Id="14068" PostId="9449" Text="Thanks, that's very useful!" CreationDate="2011-01-26T22:58:34.860" UserId="1756" />
  <row Id="14069" PostId="9438" Text="Thanks, it's very helpful to see this worked out!" CreationDate="2011-01-26T22:59:53.237" UserId="1756" />
  <row Id="14070" PostId="9427" Text="What if you're just buffering it for future processing? How about sending it directly to the DAC on some chips? What about sending it over SPI, or another UART, or writing it to flash? There are many almost zero-overhead things you can do - I should know, I'm using one of these chips at a high data rate. I think we will just have to disagree on it. Isn't your &quot;problem&quot; the same problem most network connections suffer from? You can transfer at super fast 1 Gbit/s, but it's unlikely your computer or OS can store the data that fast. Latency is not the same as transfer speed." CreationDate="2011-01-26T23:11:50.727" UserId="1225" />
  <row Id="14071" PostId="9461" Text="8 cycles per bit is multiple clocks. The USART has both Synchronous and Asynchronous modes, and does multisampling in asynchronous mode. " CreationDate="2011-01-26T23:30:52.177" UserId="1181" />
  <row Id="14072" PostId="9447" Text="The unit I need to monitor is a Sanyo KS1872 which is enclosed so I can't attach anything to the actual fans. (If I total missed on what you meant, sorry)" CreationDate="2011-01-26T23:37:44.480" UserId="2772" />
  <row Id="14073" PostId="9465" Score="1" Text="http://electronics.stackexchange.com/questions/2012/start-off-with-embedded-c-with-atmega32-atmega-avr-series http://electronics.stackexchange.com/questions/8909/good-resources-for-learning-about-my-stk500 http://electronics.stackexchange.com/questions/9172/resources-to-learn-about-the-avr-risc-architecture " CreationDate="2011-01-26T23:50:58.663" UserId="566" />
  <row Id="14074" PostId="1682" Score="1" Text="You are wrong where you say &quot;see signals much faster than the rated 50MHz&quot;.  If the analog chain isn't up to passing faster than that, it doesn't matter how fast you sample it." CreationDate="2011-01-26T23:54:55.260" UserId="206" />
  <row Id="14075" PostId="1682" Score="1" Text="@Brian - I didn't say that you'd be able to measure them, or see their exact representation, but the analog chain doesn't simply cut off everything above 50MHz.  It's designed to be able to accurately render and measure signals at 50MHz, and the accuracy degrades beyond that as the analog filters attenuate higher frequency signals.  So while it won't be a great representation, you would, in fact, be able to see if your 60MHz oscillator is at least oscillating, for instance." CreationDate="2011-01-27T00:18:13.233" UserId="161" />
  <row Id="14076" PostId="9458" Score="1" Text="Let's see if i get this. I would drive 8 high, establishing a (small) current through the probe. This current is amplified by the BJT and I would measure the voltage drop of this current over a known resistor of 100 Ohm. What would this buy me over the voltage divider design?" CreationDate="2011-01-27T01:05:30.490" UserId="1802" />
  <row Id="14078" PostId="9427" Text="@Thomas An embedded microprocessor is not a PC.  In a micro, it's wasteful of memory to choose a baudrate where you have to buffer lots of data before you can act on it.  PCs have a whole different set of constraints, like the hierarchy of access times." CreationDate="2011-01-27T02:43:33.513" UserId="411" />
  <row Id="14080" PostId="9449" Text="Can you link to your answer to the other question that you drew this diag for?" CreationDate="2011-01-27T07:29:06.023" UserId="2426" />
  <row Id="14081" PostId="9457" Score="1" Text="Could you please elaborate a bit more on the concept of a Wenner bridge? A search yields mostly journal papers, and I do not have access to those without physically going to the university library. The titles (salinity measurements etc) seem promising!" CreationDate="2011-01-27T08:25:06.957" UserId="1802" />
  <row Id="14082" PostId="9331" Text="Yes, but any microcontroller has direct instrucctions that manage directly the floating point arithmetic? For Instance: plus,3.678,2.45" CreationDate="2011-01-27T08:36:55.073" UserId="2597" />
  <row Id="14083" PostId="1635" Text="Also look at the [DSO Nano v2](http://www.seeedstudio.com/depot/dso-nano-v2-p-681.html) and the DSO Quad (it's [currently in beta](http://www.seeedstudio.com/depot/preorder-dso-quad-beta-test-p-736.html?cPath=174))" CreationDate="2011-01-27T08:46:01.743" UserId="1802" />
  <row Id="14084" PostId="9316" Text="The Floating point instructions pages start at page 133." CreationDate="2011-01-27T08:50:55.157" UserId="2597" />
  <row Id="14085" PostId="9331" Text="A xilinx microblaze controller has a latency of 30. (See the page 136 of this document http://www.xilinx.com/support/documentation/sw_manuals/mb_ref_guide.pdf )" CreationDate="2011-01-27T08:55:39.003" UserId="2597" />
  <row Id="14087" PostId="7843" Text="Not yet, the board is not mine and now I cannot test it. I am thinking about buying a separate bluetooth module and connecting it to my Arduino Duemilanove board." CreationDate="2011-01-27T15:17:31.773" UserId="1649" />
  <row Id="14088" PostId="9477" Score="2" Text="-1: I don't really agree with this answer. Although your right about Assembly being close to machine language, C and C++ are very different high level languages." CreationDate="2011-01-27T17:37:15.333" UserId="2426" />
  <row Id="14089" PostId="1635" Text="@Ranieri - v2 is now [in stock at Sparkfun](http://www.sparkfun.com/products/10244) as well, admittedly for $10 more than seeedstudio.  BTW, you can make better links with `[text](http:\\link)`  (edited your comment for you)" CreationDate="2011-01-27T17:38:17.867" UserId="857" />
  <row Id="14090" PostId="9475" Text="If your question is &quot;Isn't it worth it to program *any* machine with the most powerful programming language you can get your hands on,&quot; the [C++](http://electronics.stackexchange.com/q/3027/857) and [Java](http://electronics.stackexchange.com/q/7901/857) questions are recommended reading (about OOP rather than functional programming).  " CreationDate="2011-01-27T17:45:49.590" UserId="857" />
  <row Id="14091" PostId="9475" Text="Your first paragraph comes across as argumentative, which has netted you a few close votes. Consider rewording to something more passive (&quot;I'm interested in using functional programming for machine control, what examples are there of Haskell/LISP/Scheme implementations for embedded systems&quot;) or removing it entirely." CreationDate="2011-01-27T17:46:43.160" UserId="857" />
  <row Id="14092" PostId="9475" Score="1" Text="I don't buy your &quot;inefficient&quot; statement.  You seem to exhibit extreme bias towards the hobbyist/prototype side--low volume (aka: 1).  C/C++/asm results in smaller, faster code that is amplified thousands or millions of times when you can use processors with just enough speed and space.  Embedded is embedded.  You are not programming on a general-purpose OS." CreationDate="2011-01-27T17:51:04.887" UserId="1407" />
  <row Id="14093" PostId="9471" Text="It would be a much cheaper idea to screw the power components to the case (e.g. TO-220's) then use some arbitrary potting compound and not worry about it having excellent thermal properties." CreationDate="2011-01-27T17:53:07.973" UserId="1407" />
  <row Id="14094" PostId="9331" Text="@Peterstone, you can code in assembly, but if you are using C the compiler will handle it for you. I was making this point so that people do not make microcontroller decisions based on a floating point operation they must compute every 3 days." CreationDate="2011-01-27T18:44:55.553" UserId="230" />
  <row Id="14095" PostId="9475" Text="@sheepsimulator, this question is very much argumentative and their is never a clear cut correct answer. This is not what they expect SO to be used for." CreationDate="2011-01-27T18:49:47.327" UserId="230" />
  <row Id="14096" PostId="1635" Text="@reemrevnivek - Thanks, I had no idea that worked in comments too." CreationDate="2011-01-27T20:52:56.037" UserId="1802" />
  <row Id="14097" PostId="2015" Text="if you have the ability to program the chip, then you can load the Arduino firmware on it, then use the serial link + bootloader for subsequent work." CreationDate="2011-01-27T21:09:03.070" UserId="2454" />
  <row Id="14098" PostId="9475" Text="@Kortuk - Let's make it not argumentative, then, rather than getting rid of it.  I'm going to go ahead and edit it and vote for a reopen, there are already 2 reopen votes and it's received constructive answers like Joby's (which will now need to be edited) and Pingswept's.  Not trying to usurp your ♦ authority, just trying to help." CreationDate="2011-01-27T21:12:57.280" UserId="857" />
  <row Id="14099" PostId="9475" Text="@reemrevnivek, I make a call knowing it can be reopened if the community feels differently, but programming language discussions are inherently emotional." CreationDate="2011-01-27T21:17:49.910" UserId="230" />
  <row Id="14100" PostId="9475" Text="@Kortuk, reemrvnivek - the main reason I asked it like this is because I see little discussion of using things beyond C/C++ for programming MCUs.  I found Joby's answer helpful.  That was the only way I could think of saying it; if someone can find a way that seems less inflammatory, go for it." CreationDate="2011-01-27T21:18:41.657" UserId="374" />
  <row Id="14101" PostId="9475" Text="@sheepsimulator - Done!  " CreationDate="2011-01-27T21:22:45.503" UserId="857" />
  <row Id="14102" PostId="9475" Text="@Kortuk - Of course they are.  However, this isn't (or at least, this shouldn't be) a discussion of the merits of various programming languages.  It's (now) a question about implementations of functional programming languages." CreationDate="2011-01-27T21:24:21.243" UserId="857" />
  <row Id="14103" PostId="9475" Score="2" Text="@Nick T - &quot;C/C++/asm results in smaller, faster code that is amplified thousands or millions of times when you can use processors with just enough speed and space&quot; - what about maintenance?  A functional language can frequently do in a single line what a C-program requires 10s to do, meaning less room for bugs.  In addition, they can be complied (ie Haskell), and made to run on the target, which is faster than interpreters.  I wanted to explore this topic a bit because a compiled-Haskell might be just as fast, but quicker to develop than say a C app.  Wanted to question the status quo a bit." CreationDate="2011-01-27T21:28:10.773" UserId="374" />
  <row Id="14104" PostId="9483" Text="Thanks for the heads up. Unfortunately I'm stuck with existing equipment that uses the MDR system, and I need to (1) break out a few of the channels, and (2) interface it with a [MillMax .050&quot;][1] connector on the other end. I don't know of a distributor that can accomodate that... [1][http://www.alliedelec.com/search/productdetail.aspx?SKU=9002055]" CreationDate="2011-01-27T21:36:50.613" UserId="2796" />
  <row Id="14105" PostId="9475" Score="1" Text="@Sheepsimulator Unfortunately, comments like your last one make questions like this argumentative." CreationDate="2011-01-27T21:39:19.563" UserId="319" />
  <row Id="14106" PostId="9475" Text="@Sheepsimulator, I can easily start to argue that just because it is less code doesn't mean it is less bugs. I have had many times where knowing less about what is actually happens caused me to create a bug that I wouldn't have if I had to write more lines of code." CreationDate="2011-01-27T21:40:54.973" UserId="319" />
  <row Id="14107" PostId="9475" Score="1" Text="@Sheepsimulator and not to pick on you. But a 33% accept rate really isn't that great. Either you aren't asking good questions in order to get good answers or you are just not every accepting answers. Either way it doesn't look great on you as a user." CreationDate="2011-01-27T21:42:33.410" UserId="319" />
  <row Id="14108" PostId="9477" Score="1" Text="@BG100, I'd actually draw the &quot;high level/low level&quot; line somewhere within C rather then just call it a high-level language.  When performing arithmetic, pointer (string) operations, and other common basic tasks, the instructions that compilers generally produce have the CPU directly manipulating the data without any layers of abstraction." CreationDate="2011-01-27T21:58:08.690" UserId="1407" />
  <row Id="14109" PostId="1585" Text="What are you guys meaning by H-bridge drivers? Is it not ok to just plug the leads of the motor up to a potentiometer and battery?" CreationDate="2011-01-27T22:02:18.420" UserId="2769" />
  <row Id="14110" PostId="9483" Score="3" Text="I'd design a little PCB for that sort of thing." CreationDate="2011-01-27T22:02:45.003" UserId="305" />
  <row Id="14111" PostId="9484" Score="1" Text="I think what this person is asking for is a much quicker alert. If your just measuring temperature, then the room takes time to get to the alert threshold level. If your measuring airflow, then you'll get the alert as soon as the aircon cuts out." CreationDate="2011-01-27T22:04:01.927" UserId="2426" />
  <row Id="14112" PostId="9471" Text="@mikeselectricstuff: This is a better kind of link for that message: http://lmgtfy.com/?q=heatsink+box :)" CreationDate="2011-01-27T22:21:43.863" UserId="718" />
  <row Id="14113" PostId="9477" Text="@Nick T: I see your point, but consider this: if you write an interrupt routine that generally needs to execute as quickly as possible, in C you would have no idea how long it would take to run, but in assembler you would can just count the instructions. I think low level is knowing EXACTLY was is going on in your program, you don't know this for sure if your using C." CreationDate="2011-01-27T22:33:14.980" UserId="2426" />
  <row Id="14114" PostId="9487" Text="+1 for EX330 for being a good 'all-around' $50-ish meter." CreationDate="2011-01-27T23:23:17.193" UserId="2654" />
  <row Id="14115" PostId="9483" Text="i'll second making a breakout board..." CreationDate="2011-01-27T23:45:34.493" UserId="771" />
  <row Id="14116" PostId="9410" Text="@codeMonk - Probably a really fast ADC and a FPGA? It's not trivial." CreationDate="2011-01-28T01:16:47.893" UserId="1374" />
  <row Id="14117" PostId="9410" Text="@Fake Name: It certainly isn't. I'm reading up on my CCDs; I may just build the camera myself. Thanks for your help!" CreationDate="2011-01-28T02:43:44.950" UserId="2762" />
  <row Id="14118" PostId="9477" Text="@BG100: the same assembler instruction can take different numbers of cycles to execute based on operands and their addressing modes.  Though in C, once you compile you get static code that does not (can not) change.  True, this is a somewhat tenuous argument, but if we're going to argue the minutiae to try to draw a big red line..." CreationDate="2011-01-28T03:29:01.587" UserId="1407" />
  <row Id="14119" PostId="9489" Text="Is soldering wire leads to the connector not an option?" CreationDate="2011-01-28T05:58:57.393" UserId="2118" />
  <row Id="14120" PostId="9490" Score="1" Text="@Community. Does this fit on the site? http://meta.electronics.stackexchange.com/questions/156/lego-mindstorms-robotics-on-topic" CreationDate="2011-01-28T06:11:46.160" UserId="319" />
  <row Id="14121" PostId="9490" Text="I think you mean &quot;RXE&quot;, not &quot;NXE&quot;. Also, I just wanted to let you know about this brilliant place called [the Mindboards Forums](https://sourceforge.net/apps/phpbb/mindboards/index.php) (in case you haven't heard of it already). But of course, asking questions here should be fine... I hope. As @Kellenjb mentioned, there's currently a debate about Mindstorms [which is clearly *Robotics*] questions here. You can find more info on [my blog](http://muntoo.wordpress.com/2010/11/14/electronics-stackexchange-website-for-mindstorms/)." CreationDate="2011-01-28T06:14:04.843" UserId="1940" />
  <row Id="14122" PostId="9490" Text="Yes, I intended RXE.  Thanks for the the tip on the Mindboards Forums--I'll check it out.  I've had my kit &lt; 1 week." CreationDate="2011-01-28T06:34:51.033" UserId="2260" />
  <row Id="14123" PostId="9483" Text="Yeah, but the linked connector is a *solder cup* connector. It may not be possible to terminate it to a PCB." CreationDate="2011-01-28T07:19:14.740" UserId="1374" />
  <row Id="14124" PostId="9458" Text="Thanks for pointing me to Botanicalls! I have examined their schematics and code and I have made some interesting discoveries, aside the difference in measuring circuits above. They use galvanized steel electrodes that are only energized during measurement (no delay at all, not even a ms) and they still have problems with degradation due to electrolysis. They also keep a moving average of the moisture sensor readings, by default 10 samples over 2 minutes. I'll experiment a bit and report back." CreationDate="2011-01-28T09:22:59.297" UserId="1802" />
  <row Id="14125" PostId="6757" Text="Your price estimate for the AVR DSO seems way off to me. The author quotes EUR 50-60, which is about USD 70-80." CreationDate="2011-01-28T10:00:31.107" UserId="1802" />
  <row Id="14126" PostId="9494" Text="Very interesting! I had heard of probes measuring the dielectric constant by basically building a capacitor, but I had seen any for sale. Since it's a hobby project I prefer &quot;build&quot; to &quot;buy&quot;, but i do prefer &quot;buy&quot; to &quot;nothing&quot; ;)" CreationDate="2011-01-28T13:40:27.713" UserId="1802" />
  <row Id="14127" PostId="9494" Text="On that note, &quot;Because our probe measures the dielectric constant of the soil using transmission line techniques, it is insensitive to water salinity, and will not corrode over time as does conductivity based probes.&quot; - it sounds like exactly the technology i need." CreationDate="2011-01-28T13:41:59.940" UserId="1802" />
  <row Id="14128" PostId="9420" Text="Thanks for the detailed reply. I'm still confused as to how powerful of a servo I actually need. I don't need micro precision - probably 3 degrees to a step would be enough - but how much torque do you think I'll need to swing a 2x4 around? Or move a fairly heavy cart on a linear track? How much torque is lot?" CreationDate="2011-01-28T14:06:52.463" UserId="2769" />
  <row Id="14129" PostId="9499" Score="3" Text="http://electronics.stackexchange.com/questions/1404/low-cost-bluetooth http://electronics.stackexchange.com/questions/514/cheapest-simplest-way-to-implement-a-bluetooth-keyboard-mouse" CreationDate="2011-01-28T14:18:46.330" UserId="566" />
  <row Id="14130" PostId="9489" Text="Not unless I was an inch tall. They're much too small." CreationDate="2011-01-28T14:23:13.267" UserId="2799" />
  <row Id="14131" PostId="9496" Text="I also like my ChipMax.  But the OP needs to keep in mind that it requires a parallel port.  It works in XP just fine, but I haven't tried Windows 7 yet." CreationDate="2011-01-28T14:24:18.320" UserId="2288" />
  <row Id="14132" PostId="9498" Text="is it suited also for MCUs with no operating system?" CreationDate="2011-01-28T14:36:13.303" UserId="2285" />
  <row Id="14133" PostId="9498" Text="It looks like it's primarily targetted at iPhone, but is very portable." CreationDate="2011-01-28T14:43:41.253" UserId="566" />
  <row Id="14134" PostId="9400" Text="Of those, I liked pst-circ best: http://pstcirc.free.fr. Its named nodes are like a netlist layout." CreationDate="2011-01-28T15:16:23.633" UserId="721" />
  <row Id="14135" PostId="3209" Text="@wallacoloo do you have any links to these kinds of devices?  I searched ebay for IR emitters and couldn't find anything close to what you describe.  Thanks!" CreationDate="2011-01-28T15:50:24.217" UserId="2288" />
  <row Id="14136" PostId="3205" Text="@davr your SeeedStudio link doesn't point to a product, but I assume this is what you're referring to?  It looks very cool, and I might have to pick up a pair to play with!  http://www.seeedstudio.com/depot/433mhz-rf-link-kit-p-127.html?cPath=139_140" CreationDate="2011-01-28T15:52:15.853" UserId="2288" />
  <row Id="14137" PostId="9481" Score="1" Text="I think you need to revisit your definition of microcontroller.  Many microcontrollers now have 128kB or more of Flash, and 64kB or more of RAM, plenty of space to run an interpreter for some smallish languages.  It looks like you're giving specs for an embedded Linux device; I think the OP was asking for a dedicated port." CreationDate="2011-01-28T15:52:27.677" UserId="857" />
  <row Id="14138" PostId="9499" Text="I see... I can't belive I can order USB bluetooth dongles for 1.5$, but can't buy some uart&lt;&gt;bluetooth chip for 5$ :-(" CreationDate="2011-01-28T15:54:00.200" UserId="2062" />
  <row Id="14139" PostId="9497" Text="What is HCI in this context?  Human–computer interaction?" CreationDate="2011-01-28T16:00:11.820" UserId="206" />
  <row Id="14140" PostId="9457" Text="http://www.corrosion-doctors.org/Corrosion-Kinetics/Ohmic-drop-soil.htm" CreationDate="2011-01-28T16:20:56.703" UserId="1438" />
  <row Id="14141" PostId="9271" Text="@markrages: Throwing one away is politically infeasible anywhere I have worked.  Doing a respin, perhaps, but not starting over." CreationDate="2011-01-28T16:34:40.697" UserId="206" />
  <row Id="14142" PostId="9497" Text="USB Host Controller Interface" CreationDate="2011-01-28T16:37:08.120" UserId="305" />
  <row Id="14143" PostId="9497" Text="HCI = Host Controller Interface, but it is not tied to USB.  It can be accessed via an type of serial bus (UART, SPI, etc.) -- http://www.bluetooth.com/English/Technology/Works/Pages/Architecture__Host_Controller_Interface_HCI.aspx" CreationDate="2011-01-28T18:21:47.473" UserId="1322" />
  <row Id="14144" PostId="9456" Text="@BG100 - [DXF](http://en.wikipedia.org/wiki/AutoCAD_DXF) is a fairly well supported, ASCII-based format (it's short for Document Exchange Format) which is most prominently used by AutoCad software.  It suffers from versioning and standardization problems (everyone has their own little subtle changes), but many other PCB programs have an import/export option for DXF.  So, no schematic export, but at least you can get your board.  I'd say DXF is not quite as good as Gerbers, but it looks like they weren't aiming for lock-in as a software feature." CreationDate="2011-01-28T18:56:50.270" UserId="857" />
  <row Id="14145" PostId="7113" Text="@Joby - CC1110 is a popular chip, but I think we should steer away from creating new tags for a single part number, that could get out of hand really fast.  Plus, it wasn't even the problem, but you didn't know that when you asked.  I'll let you decide whether you want to delete the tag entirely, or replace it with [wireless], which is a used tag which seems to convey the meaning you want." CreationDate="2011-01-28T19:01:49.513" UserId="857" />
  <row Id="14146" PostId="9379" Score="1" Text="If you really want to know what's under there, asking the manufacturer would probably be a better idea.  They might even be able to send you one without the potting compound so you can do your testing or whatever you need to do." CreationDate="2011-01-28T19:09:31.207" UserId="857" />
  <row Id="14147" PostId="5627" Text="@mazurnification, I honestly could not remember why, and took what someone said they knew. I figured it someone knew better they would come drop it. Your explanation makes sense to me and I have edited it in." CreationDate="2011-01-28T19:17:55.110" UserId="230" />
  <row Id="14148" PostId="6759" Text="I love eevblog-- it's really informative for the beginner" CreationDate="2011-01-28T19:59:53.920" UserId="2006" />
  <row Id="14149" PostId="6440" Text="I'm a software engineer with lots of programming experience and I started hardware on the arduino. The msp430 is wayyy harder to work with, but definitely closer to what most hardware engineers would be using for scale projects." CreationDate="2011-01-28T20:01:00.817" UserId="2006" />
  <row Id="14150" PostId="8699" Score="1" Text="One thing to worry about: opencv takes a lot of cpu power and you'd need two cameras for depth perception" CreationDate="2011-01-28T20:06:02.793" UserId="2006" />
  <row Id="14151" PostId="7113" Text="@reemrevnivek you're right, done." CreationDate="2011-01-28T20:21:42.207" UserId="566" />
  <row Id="14152" PostId="9496" Text="I've googled on this ChipMax but unfortunately it's around $300 " CreationDate="2011-01-28T20:21:59.473" UserId="1514" />
  <row Id="14153" PostId="7113" Text="@Joby: What did you use for your omega symbol? It shows up as a square on my iPhone safari." CreationDate="2011-01-28T20:41:14.757" UserId="2426" />
  <row Id="14154" PostId="7113" Text="@BG100 - It shows up as a square for me as well, tested on FF 3.6, Opera 11, on a Windows XP machine.  Therefore, I'm going to replace it with the [HTML entity](http://meta.electronics.stackexchange.com/questions/136/138#138)  `&amp;Omega;`, which should render properly everywhere (unlike whatever Unicode symbol was used for the original copied from the datasheet).  Unfortunately, this will push this question into 'Community wiki' status." CreationDate="2011-01-28T21:33:25.380" UserId="857" />
  <row Id="14155" PostId="9507" Score="1" Text="When you say sink, should it burn the power as heat, or return it to the low-voltage rail?  How much power should it handle?" CreationDate="2011-01-29T01:31:14.153" UserId="411" />
  <row Id="14156" PostId="9508" Text="my gut feeling is - it sounds like you would be taking on a lot of liability doing this project... but I applaud your enthusiasm" CreationDate="2011-01-29T02:02:52.023" UserId="771" />
  <row Id="14157" PostId="9508" Text="@vicatcu: I know, but I've been thinking about how to do this for several years, spent many hours googling and reading up on the theory that I want to at least have a go. If it doesn't work, or it turns out to be too dangerous then maybe I can finally give up this silly idea!" CreationDate="2011-01-29T02:10:59.067" UserId="2426" />
  <row Id="14158" PostId="8344" Text="http://en.wikipedia.org/wiki/Voltage_doubler" CreationDate="2011-01-29T05:40:41.520" UserId="813" />
  <row Id="14159" PostId="8344" Text="@tyblu, To me, the diagram in the original question looks almost identical to the &quot;Voltage quadrupler&quot; schematic in the Wikipedia &quot;voltage doubler&quot; article, lacking 1 component and 1 connection wire. http://en.wikipedia.org/wiki/Voltage_doubler " CreationDate="2011-01-29T05:57:55.513" UserId="813" />
  <row Id="14160" PostId="8344" Text="@tyblu, most older PSUs had a 115/230 switch: http://www.sherline.com/images/VoltageSw.jpg . (More modern &quot;wide ranging&quot; PSUs don't have that switch). My understanding is that every PSU with such a switch has a voltage doubler circuit in it, such as http://www.aprs.org/prius/swer/SWER-115-caps.GIF . There's a brief discussion at The Straight Dope http://boards.straightdope.com/sdmb/showthread.php?t=34679 ." CreationDate="2011-01-29T06:11:41.617" UserId="813" />
  <row Id="14161" PostId="8344" Text="@pingswept I agree with your main point: the circuit can store very little energy. But I find it irrelevant. The same calculation would indicate that my computer's PSU can likewise store very little energy -- surely you aren't claiming that my computer's PSU can't possibly work?" CreationDate="2011-01-29T06:26:51.493" UserId="813" />
  <row Id="14162" PostId="9517" Text="Does anyone create the tags 'System Generator' and 'cordic'?" CreationDate="2011-01-29T08:17:34.850" UserId="2597" />
  <row Id="14163" PostId="9326" Text="Thanks - eventually got this doc from Maxim. It's based around their MAX3806 chip. Still pretty complex, and uses very short 5 watt (!) IR laser pulses. I was mostly interested in the Rx front-end, so this is a useful starting point. As  I'm only interested in shorter ranges I'm wondering if a simpler approach is possible by putting the TOF path in the loop of an amplifier, to make it oscillate at a TOF-proportional frequency." CreationDate="2011-01-29T10:08:47.713" UserId="1681" />
  <row Id="14164" PostId="9326" Text=" The Maxim doc also references this academic paper which looks interesting: http://herkules.oulu.fi/isbn9514269667/isbn9514269667.pdf" CreationDate="2011-01-29T10:14:24.247" UserId="1681" />
  <row Id="14165" PostId="8988" Text="Good progress! The next bit you want to look at is how you clear the status bits. You've noted interrupt flags are cleared by setting them, but the reason is to avoid read-modify-write cycles like |= does. In addition, there's more you want to change. Write the entire USISR to reset the shift counter, so the next overflow interrupt comes after 8 bits (it counts both edges, so 0 is probably right). You may also want to make the pin change interrupt ignore one of the edges by checking the pin level." CreationDate="2011-01-29T12:00:13.343" UserId="1181" />
  <row Id="14166" PostId="9520" Score="1" Text="+1 for fixed point alg. " CreationDate="2011-01-29T12:20:09.603" UserId="689" />
  <row Id="14167" PostId="9522" Text="I know it, but the version of System Generator that I am using (9.2.01) don´t have any MicroBlaze block." CreationDate="2011-01-29T12:45:08.337" UserId="2597" />
  <row Id="14168" PostId="9521" Text="Coregen is available from the version 10.x, isn´t it? My version of System Generator is 9.2.01 : (" CreationDate="2011-01-29T12:47:30.753" UserId="2597" />
  <row Id="14169" PostId="9521" Text="coregen has been available from before 9.2 as far as I recall... but then you don't get new cores that were developed since the version you're using, of course. Why don't you upgrade to a newer version? Can you use WebPack at all?" CreationDate="2011-01-29T12:52:13.370" UserId="2531" />
  <row Id="14170" PostId="9523" Text="I suppose you have already read the Wikipedia article? https://secure.wikimedia.org/wikipedia/en/wiki/Cordic" CreationDate="2011-01-29T13:11:29.033" UserId="339" />
  <row Id="14171" PostId="9521" Text="@saar drimer: upgrade my current version will cost montey, won´t it? " CreationDate="2011-01-29T13:28:57.860" UserId="2597" />
  <row Id="14172" PostId="9523" Text="offcourse, but that article use trigonometric function to explain how it works." CreationDate="2011-01-29T13:32:26.047" UserId="2597" />
  <row Id="14173" PostId="8988" Text="Thanks Yann. I did realize I had to set the counter, but I haven't quite tested the new code yet. In gcc, `|` does emit the `sbi` instruction when possible. According to the datasheet, unlike most interrupt flags, `USIOIF` is only cleared by a `1` and not automatically cleared when the interrupt handler returns." CreationDate="2011-01-29T13:41:41.590" UserId="1363" />
  <row Id="14175" PostId="8973" Text="@peterstone, this has been converted to community wiki by your request." CreationDate="2011-01-29T15:50:27.310" UserId="230" />
  <row Id="14176" PostId="2879" Text="Your local thrift store carries these, usually $1 each. Assuming you have time to dig through the box." CreationDate="2011-01-29T17:09:01.300" UserId="906" />
  <row Id="14177" PostId="2877" Text="There's also an Instructable on DIY'ing this. You have to be competent enough to open the PS and fiddle with the insides, of course. 115VAC and big capacitors." CreationDate="2011-01-29T17:11:54.447" UserId="906" />
  <row Id="14179" PostId="9490" Text="@muntoo If I thought the question needed to be closed I would have voted to close. I thought it might be worth a revisit to that meta question now that the site has grown." CreationDate="2011-01-29T18:09:46.180" UserId="319" />
  <row Id="14180" PostId="8344" Text="@davidcary, clearly, your PSU works. It has switching elements, a clock signal in the kHz range, and feedback control. Take those out, and the caps would discharge in a couple of seconds, like the circuit we've been discussing. I suspect that this circuit is similar, i.e. maybe it could supply nanowatts continuously. But, I don't see that as a success. Do you think it could supply, say, 1 watt continously? If so, how?" CreationDate="2011-01-29T18:58:04.497" UserId="712" />
  <row Id="14181" PostId="9533" Text="There are a few switchers with everything inside. I've used the [V7805](http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&amp;lang=en&amp;site=ca&amp;keywords=102-1709-ND&amp;x=0&amp;y=0). They're never *cheap*, and often not *good*. *(Pick &quot;fast&quot;...)*" CreationDate="2011-01-29T19:02:40.460" UserId="2118" />
  <row Id="14182" PostId="3209" Text="@Dave: On eBay, you can do a search for &quot;IR LED pack&quot; or &quot;IR LED&quot; of something similar. Here's [20/$1][http://cgi.ebay.com/5mm-IR-LED-Emitters-20-Pack-/110639821407?pt=US_Flashlights&amp;hash=item19c2a5b25f#ht_3379wt_1139] (but no data sheet) Searching for &quot;IR receiver diode&quot; or something similar can yield a couple results, like this [100/$15][http://cgi.ebay.com/100-pcs-5MM-Infrared-receiver-diode-IR-LED-/320552252146?pt=LH_DefaultDomain_0&amp;hash=item4aa26732f2#ht_1886wt_905]. [Futurelec.com][http://www.futurlec.com/LEDInfrared.shtml] sells matching 3mm/5mm emitters and detectors for $.16 each." CreationDate="2011-01-29T19:03:34.750" UserId="790" />
  <row Id="14183" PostId="9517" Text="Perhaps you could describe the options available in the CORDIC divider block." CreationDate="2011-01-29T19:10:45.193" UserId="2118" />
  <row Id="14184" PostId="9521" Text="@Peterstone, not if you can make do with the free Xilinx tools, which are fully functions except that they limit the devices you can target. See more here: xilinx.com/tools/webpack.htm (look at the &quot;product table&quot; to see if the device you're targeting is available through WebPack)." CreationDate="2011-01-29T19:12:22.660" UserId="2531" />
  <row Id="14187" PostId="4982" Text="I mean this as a user, your post is lacking anything technical. This guys is great, here is another reason, now go to his website." CreationDate="2011-01-29T19:22:00.013" UserId="230" />
  <row Id="14189" PostId="9358" Text="@vicatcu the input resistance of any digital input is very high. Not much current will flow. The charging current can only come from the digital output or the 10K." CreationDate="2011-01-29T19:36:21.463" UserId="424" />
  <row Id="14190" PostId="9358" Text="@vicatcu I believe I saw the RTS on an Arduino schematic. On all of my boards I wire the RTS to the reset capacitor." CreationDate="2011-01-29T19:37:39.730" UserId="424" />
  <row Id="14193" PostId="9358" Text="@vicatcu On the Arduino schematic I have both the DTR and RTS are connected to the reset with series capacitors. Boards that use an FTDI cable need to use RTS because the DTR line is not brought out on the header connector. Since the boards I sell can be built with either the FTDI IC or the header the RTS made the most sense." CreationDate="2011-01-29T19:48:29.077" UserId="424" />
  <row Id="14194" PostId="9537" Text="So in other words you are telling me to take it one step at a time? :-) I have been trying to figure out the easiest way to collect that much data for Matlab analysis. Guess that might be worth a second question If I can't find any other questions about it." CreationDate="2011-01-29T22:19:00.157" UserId="319" />
  <row Id="14195" PostId="9516" Text="Thank you, this is really helpful... but are you serious about this being a 500-1000 hour job with costly materials? Looking at the datasheet, and the microchip appnotes 00843a that bt2 mentioned in his answer, this actually doesn't seem too complex." CreationDate="2011-01-30T00:27:27.467" UserId="2426" />
  <row Id="14196" PostId="9514" Text="Thanks for these datasheets, looking at these and the datasheet that pingswept provided in his answer, I think I can actually work out how to do this." CreationDate="2011-01-30T00:29:32.533" UserId="2426" />
  <row Id="14197" PostId="9534" Text="Not necessarily -one advantage of integration is frequency can go up, sometimes to a few MHz, allowing smaller inductors in the single digit uH's. For example http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1042,C1032,C1787,P112171  and this teeny one from Murata :http://www.murata.com/new/news_release/2010/1005/index.html" CreationDate="2011-01-30T00:31:38.217" UserId="1681" />
  <row Id="14198" PostId="8988" Text="Right. `sbi` is limited to the lower 32 I/O registers, but the USI is in that range on the tiny2313. Which leads to an odd quirk - `PORTA|=1; PORTA|=2;` is faster than `PORTA|=3;`, as the latter compiles to 3 instructions (but does set both bits the same cycle). Not your problem, just a quirk." CreationDate="2011-01-30T01:08:58.823" UserId="1181" />
  <row Id="14199" PostId="9507" Text="When I say sink, I mean an electron (negative current) sink. The application I am working on floats a collector plate to a high negative voltage. ( - 80 V to - 100V) range.  " CreationDate="2011-01-30T01:25:49.903" UserId="1581" />
  <row Id="14200" PostId="9507" Text="I should have mentioned that with my question, sorry" CreationDate="2011-01-30T01:26:07.643" UserId="1581" />
  <row Id="14201" PostId="5927" Text="There's quite a bit of example programs on the net involving the 16f690 too (probably because it used to be shipped with the pickit2). That's always a good thing for beginning." CreationDate="2011-01-30T03:14:47.577" UserId="790" />
  <row Id="14202" PostId="9358" Text="@jluciani, interesting, can you provide a link to a reference Arduino schematic that uses the RTS line from the FTDI chip? I think you would agree that the link I provided in my question does not have any such connection right?" CreationDate="2011-01-30T05:37:13.697" UserId="771" />
  <row Id="14203" PostId="8711" Text="@BG100: My answer told a novel way to electrically isolate the high voltage and/or AC circuit from the control circuit, which is the _safest_ way I know if to do this type of design." CreationDate="2011-01-30T06:04:21.567" UserId="2517" />
  <row Id="14204" PostId="9537" Score="1" Text="you could start of with a data aqusition card for the PC to acquire the data, then as suggested use matlab to develop your algorithm on real data and so on." CreationDate="2011-01-30T08:12:46.290" UserId="1397" />
  <row Id="14205" PostId="9534" Text="@mike: you're right about the higher frequency. The links you provide are in fact hybrid (mixed integrated and discrete) solutions, albeit that the Murata is really damn small!" CreationDate="2011-01-30T11:59:53.123" UserId="2064" />
  <row Id="14206" PostId="9515" Score="1" Text="Actually, VJ is used to calculate the junction capacitance based on the applied voltage. Modifying this and the reverse breakdown voltage won't really set the gross DC characteristics. The final result should be almost identical to the default diode model." CreationDate="2011-01-30T14:52:56.787" UserId="638" />
  <row Id="14207" PostId="4903" Text="You can find a datasheet for a compatible LM565 at [National's site](http://www.national.com/opf/LM/LM565.html#Overview). Note that it's marked obsolete." CreationDate="2011-01-30T17:05:06.167" UserId="2064" />
  <row Id="14209" PostId="9550" Text="I'm glad you got an answer but this isn't the place for questions on home electronics." CreationDate="2011-01-30T17:31:52.000" UserId="249" />
  <row Id="14210" PostId="9550" Text="If the OP said &quot;oscilloscope&quot; in place of &quot;42 inch plasma TV&quot; it would have been very much on topic. I think the basic problem is relevant to this site. And it isn't like he wouldn't be downvoted into oblivion if he asks how to hook up his DVR..." CreationDate="2011-01-30T17:37:30.607" UserId="906" />
  <row Id="14211" PostId="8078" Text="Have you found solution? I am facing similar problem with ATMega32. Serial communication works perfect on 6V DC Power supplied through LM7805 regulator. But it only transmits junk characters when powerd from AC Adaptor. I tried 6/7.5 and 9 V AC Adapters, but no luck." CreationDate="2011-01-30T17:48:04.723" UserId="2822" />
  <row Id="14212" PostId="8078" Score="1" Text="The trick is in the timing of switching between transmit and receive modes. This solved the problem when we also added a large capacitance between ground and power. But my advice would be to abandon this IC is possible, its just a mean IC." CreationDate="2011-01-30T17:48:04.770" UserId="1200" />
  <row Id="14213" PostId="9550" Text="@JohnLopez, If you just change things in any question you can make it a good question. This does not make it something that fits. &quot;If I buy a DVI switcher will my video lose quality?&quot; is off topic, you could change it to, &quot;I am building a dvi switcher, what do I need to ensure to avoid loss of audio quality?&quot; which is on topic. This does not meant hat is what I asked or that it should be left open because it is related." CreationDate="2011-01-30T17:51:26.217" UserId="230" />
  <row Id="14214" PostId="9550" Text="@JohnLopez, The issue is almost any consumer electronics question could be changed slightly and be a technical question, but someone asking a consumer electronics question does not want that technical answer, if they did, they probably would have asked it." CreationDate="2011-01-30T17:51:53.860" UserId="230" />
  <row Id="14215" PostId="9540" Text="Why the negative vote.  The post didn't say he had to do it himself." CreationDate="2011-01-30T17:54:51.827" UserId="206" />
  <row Id="14216" PostId="8448" Score="1" Text="You don't say 1) what you found 2) how cheap what you found is and 3) how much you wish it to be." CreationDate="2011-01-30T17:56:15.210" UserId="206" />
  <row Id="14217" PostId="9534" Text="Mike, you should add those links to your other answer.  All very helpful." CreationDate="2011-01-30T18:17:11.160" UserId="1819" />
  <row Id="14218" PostId="9484" Score="1" Text="I have a room temp sensor.  I am looking for something to specifically monitor the airflow because it would give me more time and allow me to page additional people / groups who deal specifically with the air conditioner." CreationDate="2011-01-30T18:55:33.363" UserId="2772" />
  <row Id="14219" PostId="8988" Text="Congrats on the Hackaday post. http://hackaday.com/2011/01/30/snes-arcade-controller/ Also, nice to see the build!" CreationDate="2011-01-30T20:09:57.303" UserId="1181" />
  <row Id="14220" PostId="9555" Score="1" Text="Wow, the sentence &quot;my wife and I are planning a robot&quot; definitely caught my attention. :) Then I noticed the sentence continues, so the level of awesomeness dropped a little (but the idea is still awesome enough!)." CreationDate="2011-01-30T20:16:49.357" UserId="1850" />
  <row Id="14221" PostId="8924" Text="Nicely done! http://hackaday.com/2011/01/30/snes-arcade-controller/" CreationDate="2011-01-30T21:56:54.890" UserId="566" />
  <row Id="14222" PostId="9543" Score="1" Text="This is an awesome answer. **+∞**" CreationDate="2011-01-31T02:37:27.677" UserId="2118" />
  <row Id="14223" PostId="9561" Text="Ensure current limiting.." CreationDate="2011-01-31T04:44:28.097" UserId="2118" />
  <row Id="14224" PostId="2232" Text="Just a heads up: These parts are not mechanically equivalent to injection molded plastics, and you should check the environmental requirements of your application before deciding on the process." CreationDate="2011-01-31T06:14:37.047" UserId="2762" />
  <row Id="14225" PostId="9565" Text="@CoderTao I liked 2nd trick! That is pure logical and awesome! " CreationDate="2011-01-31T08:45:01.237" UserId="2574" />
  <row Id="14226" PostId="9520" Text="Can you justify your opinion by mention any article or documentation reference?" CreationDate="2011-01-31T08:50:27.260" UserId="2597" />
  <row Id="14227" PostId="9565" Text="You're missing the major point of bus arbitration - that the very first thing in a CAN packet is the address. " CreationDate="2011-01-31T12:41:21.660" UserId="638" />
  <row Id="14228" PostId="9566" Score="1" Text="Good answer! If I remember correctly, sending a '0' is dominant over a '1', which results in the lowest address winning arbitration. A neat feature of this is that if the losing node stops when it's supposed to stop, there will be no data corruption on the bus." CreationDate="2011-01-31T12:44:35.103" UserId="638" />
  <row Id="14229" PostId="9561" Text="Oh crap, maybe I wasn't clear enough. The diode is 2 pins, and the detector is 4 pins, making for a total of 6 pins." CreationDate="2011-01-31T12:51:54.407" UserId="2813" />
  <row Id="14230" PostId="9564" Text="Swanand, you may get better answers to your questions if you wait a little bit longer to accept the answer. This is an international community, and some experts may not be able to respond instantly." CreationDate="2011-01-31T12:52:34.187" UserId="638" />
  <row Id="14231" PostId="9564" Text="@W5VO I will remember it next time! Thanks for suggestion! :)" CreationDate="2011-01-31T13:13:26.703" UserId="2574" />
  <row Id="14233" PostId="9570" Text="@Jim C I already know this.... My Question was not about Arbitration at Start.... It was about in between transmission...." CreationDate="2011-01-31T14:18:30.477" UserId="2574" />
  <row Id="14234" PostId="9503" Text="btw, this would be a perfect question for this area 51 proposal: http://area51.stackexchange.com/proposals/20632/programmable-logic-and-fpga-design?referrer=YmxhQ2OJUo-FAaI1gMp5oQ2 consider supporting it" CreationDate="2011-01-31T14:20:00.543" UserId="2531" />
  <row Id="14235" PostId="9516" Score="1" Text="I am serious about that estimate. While it's true that the control components are cheap the switching elements and and large filters you'll need will be expensive. Also, you'll need to pay for circuit boards, which are at least $100 per run for something this size. I guess an experienced electrical engineer could maybe do it in 250 hours and maybe $1500, but that seems very optimistic." CreationDate="2011-01-31T15:14:45.987" UserId="712" />
  <row Id="14236" PostId="9516" Score="1" Text="I should also add that part of what makes all this hard is the high voltage. Everything would be cheaper and easier if you were running at 48 V. As power goes up, you have to start worrying about more details." CreationDate="2011-01-31T15:16:50.557" UserId="712" />
  <row Id="14237" PostId="9503" Text="But, could you take content from this site to that FPGA site?" CreationDate="2011-01-31T16:21:07.403" UserId="2597" />
  <row Id="14238" PostId="9503" Text="@Peterstone, the proposal needs more committers in order to be created, to eventually become just like an stack exchange site, but with many FPGA experts. Currently it's only at the commit phase, so questions cannot be asked there yet. " CreationDate="2011-01-31T16:51:55.137" UserId="2531" />
  <row Id="14239" PostId="9577" Text="but this method, is bad right? as it charges when car running discharges when car at stand still (assuming that all components of car are in a running state). so battery charge and discharge, charge and discharge, bad bad?" CreationDate="2011-01-31T17:10:11.567" UserId="2830" />
  <row Id="14240" PostId="9575" Text="but this method, is bad right? as it charges when car running discharges when car at stand still (assuming that all components of car are in a running state). so battery charge and discharge, charge and discharge, bad bad?" CreationDate="2011-01-31T17:11:15.497" UserId="2830" />
  <row Id="14241" PostId="9577" Score="3" Text="Ancedotal Evidence: If it was seriously detrimental to the performance of the battery, your car wouldn't be using lead acid batteries. Different chemistries of batteries behave differently." CreationDate="2011-01-31T18:38:18.527" UserId="638" />
  <row Id="14242" PostId="9578" Text="Good thinking Joe, I'll look into that. By the sounds of it, if it's an RS232 device, I *should* be able to talk to it as per the original question too." CreationDate="2011-01-31T19:19:55.550" UserId="2782" />
  <row Id="14243" PostId="9580" Score="4" Text="Just as a heads up, make sure you follow all legal regulations. Now that I have gotten that out of the way, people shouldn't need to include it in their answers." CreationDate="2011-01-31T19:22:22.443" UserId="319" />
  <row Id="14244" PostId="9581" Text="So, can I use it with my micro, `Mega32` , or I have to use Computer system like a laptop?" CreationDate="2011-01-31T19:37:26.430" UserId="2832" />
  <row Id="14245" PostId="9583" Text="Could you post a reference about the `XBee Pro`?" CreationDate="2011-01-31T19:57:18.160" UserId="2832" />
  <row Id="14246" PostId="9577" Score="2" Text="If the battery is *completely* discharged repeatedly, that can  eventually damage it. But in normal use, it is only partially discharged  (unless you leave your headlights on all day with the engine off, or keep trying to crank an engine that won't start). " CreationDate="2011-01-31T20:01:48.023" UserId="222" />
  <row Id="14247" PostId="9583" Score="1" Text="http://www.digi.com/products/wireless/point-multipoint/xbee-pro-series1-module.jsp According to that, up to 1 mile range." CreationDate="2011-01-31T20:12:47.757" UserId="536" />
  <row Id="14248" PostId="9583" Score="2" Text="You probably want to look at the 900mhz line for that range:   http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/point-multipoint-rfmodules/xbee-pro-xsc.jsp#overview" CreationDate="2011-01-31T20:13:36.060" UserId="1438" />
  <row Id="14249" PostId="9483" Text="There are also PCB mount versions of the connector. That would be the neat way of doing it; sounds like something I need to learn how to do. Thanks for the suggestions." CreationDate="2011-01-31T20:26:10.967" UserId="2796" />
  <row Id="14250" PostId="9583" Text="@Mark, nice, I had not seen the range at that frequency." CreationDate="2011-01-31T20:30:34.373" UserId="536" />
  <row Id="14251" PostId="9583" Text="don't get too excited by Digi's quoted range, they are...optimistic...at best.  The module I linked is only a 100mW transmitter.  It may get to 15 miles, in a vacuum and thats at 9.6kbps.  Something like the LSR module i mentioned below can run zigbee stacks but is a 250mW transmitter and operates at up to 1Mbps." CreationDate="2011-01-31T20:46:12.570" UserId="1438" />
  <row Id="14252" PostId="9516" Text="Ok, well I don't care how long it takes as I can use my spare time over a year or two if needed. The cost is a problem though as I may as well just buy one! For the filtering, I take it you're talking about the smoothing capacitors for the rectified DC? Given that this doesn't have to be perfect as it will only power the motors on the carnival float for 20 hours in any one year, unlike an industrial grade unit, how little filtering can I get away with? e.g. from DigiKey, I can get 2 x 10000uF 450v caps for $178, giving my 5000uF in series. Can I get away with just this?" CreationDate="2011-01-31T20:55:21.030" UserId="2426" />
  <row Id="14253" PostId="9580" Score="1" Text="On the legal front using a module can actually mitigate some issues.  Under FCC at least there is a separate certification process that can grant a &quot;Module Certification&quot;.  Meaning that your final device wouldn't need to be certified as a transmitter if the module has been tested as such.  That wouldn't get you out of the requirement to be certified as an incidental radiator if the rest of the device requires it but that usually isn't an issue unless selling the final product.  Building a transmitter that breaks the rules can get you in trouble even if not selling it.  " CreationDate="2011-01-31T21:26:11.117" UserId="1438" />
  <row Id="14254" PostId="9579" Score="1" Text="That's usually the case... During peak electrical loads (staring up a large fan motor or similar) at low engine idle (therefore, low alternator output) power is pulled from battery.  As soon as the load goes down and or the RPM's come back up, the alternator then produces enough to meet the car's electrical needs and the battery starts getting charged again." CreationDate="2011-01-31T21:30:21.047" UserId="1823" />
  <row Id="14255" PostId="9516" Text="You won't build a 3-phase AC drive capable of driving IGBTs large enough to safely control a 50-75HP motor in 250 hours, I don't care how good your engineer is. There's a LOT of control software to write if you're after something reliable and safe. See my answer below for more detail." CreationDate="2011-01-31T23:04:27.907" UserId="974" />
  <row Id="14256" PostId="9483" Text="Many solder cup connectors are spaced so that you can actually slide a double-sided circuit board between the rows. With the right trace patterns you should just be able to solder it up and go. Almost every USB serial port dongle I have ever seen uses this kind of construction, and long ago when dinosaurs roamed the earth we soldered PCMCIA connectors to boards using the same method. It beats the crap out of trying to hand-crimp or solder each connection individually!" CreationDate="2011-01-31T23:36:10.297" UserId="974" />
  <row Id="14257" PostId="9591" Score="1" Text="Maybe i'm reading this wrong but &quot;A device is able to pull the lines low. It has to supply current that gets dissipated by the pull up resistors. &quot; I think you mean 'It' ( the device ) has to sink whatever current is required to pull the output pin to ~0V rather than supply it." CreationDate="2011-01-31T23:41:05.427" UserId="1438" />
  <row Id="14258" PostId="9591" Text="Its all sorta relative. Sure it is sinking current, but I could also argue that it is supplying negative current." CreationDate="2011-01-31T23:43:57.967" UserId="319" />
  <row Id="14259" PostId="9589" Text="Thanks for your very detailed answer, I appreciate information from an expert in the subject! To answer your first question, after ramp-up, the speed doesn't vary however the speed won't be 50Hz, it could be anything between 25 and 60Hz and as the generator supplies AC at 50Hz I need something to change the frequency. So I might be wrong but I don't think I can get away with a reduced voltage soft starter." CreationDate="2011-01-31T23:53:24.710" UserId="2426" />
  <row Id="14260" PostId="9589" Text="If your generator is not able to meet its rated speed and you are relying on the VFD's ability to adjust the motor speed to compensate I think that your generator is either woefully undersized or the governor is in need of some repair! Some surge and sag is expected with any engine-driven generator but they should be able to stay within 5% of their rated output frequency under load." CreationDate="2011-01-31T23:56:39.827" UserId="974" />
  <row Id="14261" PostId="9575" Score="1" Text="Cars have alternators.  Alternators need an electrical field to start making electricity (can't charge a completely dead battery) but how much power they provide doesn't vary a lot with rpm.  Because of their relatively stable power output they work well in cars.  Also, when you stop a car, the engine is still rotating (unless it's a hybrid) and you still generate electricity." CreationDate="2011-02-01T00:00:38.790" UserId="1819" />
  <row Id="14262" PostId="9590" Score="2" Text="http://electronics.stackexchange.com/questions/7423/what-is-a-pull-up-and-pull-down" CreationDate="2011-02-01T00:07:17.407" UserId="566" />
  <row Id="14263" PostId="9589" Text="I think I'll certainly try contacting some manufacturers as you suggest. The generator we use is an 800KVA, and we normally load it up to around 70%, so I don't think brownouts (although we ran out of fuel once). Also, I don't know if it makes a difference to anything you can suggest, but the load that I'm powering has a lot of momentum, but the gearboxes we use have worm gears that prevent free-wheeling. If you want to see it in action, take a look at this youtube video: http://www.youtube.com/watch?v=sL2i0SxpKIY" CreationDate="2011-02-01T00:07:33.427" UserId="2426" />
  <row Id="14264" PostId="9589" Text="To reply to your comment about the generator speed, I think you misunderstood... the generator runs at 50Hz, but I need the motor to run at a fixed frequency say 30Hz which is the speed that I want to configure the motor to run at for the duration it's switched on." CreationDate="2011-02-01T00:09:51.147" UserId="2426" />
  <row Id="14265" PostId="9589" Text="yeah I'm aware of the general mechanical concept (and have ridden a few of the rides &lt;g&gt;) -- the generator should be able to keep up with the load... Might be worthwhile getting the generator technician out and explaining to him that the thing can't keep a reasonably steady frequency. The electronic governors are pretty painless but I've adjusted a few oldschool mechanical ones... it's like a Rube Goldberg machine in them, I swear. :-)" CreationDate="2011-02-01T00:10:11.533" UserId="974" />
  <row Id="14266" PostId="9589" Text="Ahh okay so the motor does not run at its rated speed (1500 or 3000RPM are the common ones in 50Hz land) -- you're adjusting the drive speed to run them at under their rated speed... yes in that case you definitely need a VFD or perhaps a change in gearing, which is not always so easy. " CreationDate="2011-02-01T00:11:45.790" UserId="974" />
  <row Id="14267" PostId="9589" Text="I'm pretty sure the generator is good... we hire it from aggreko." CreationDate="2011-02-01T00:13:05.387" UserId="2426" />
  <row Id="14268" PostId="9589" Text="Exactly, that's my problem... it's very difficult to plan the mechanical gearing ahead of time, because the design kind of evolves over the few months it takes to build it, then when they hand it over to the electricians to fire it up, we discover that it goes way too fast or way too slow, and the gearing it already built into the system." CreationDate="2011-02-01T00:16:19.110" UserId="2426" />
  <row Id="14269" PostId="1633" Text="You suggested the MAX1555 Li-ion charger. Does this means that **all** Li-ion chargers can charge LiPo batteries?" CreationDate="2011-02-01T00:17:36.737" UserId="790" />
  <row Id="14270" PostId="9589" Text="So if I write to VFD manufactures and explain what I'm doing, and why I need the drive units, and that we are a non-profit carnival club, do you think they are likely to help out and offer a cheap reconditioned unit? I guess it won't hurt to try!" CreationDate="2011-02-01T00:18:12.243" UserId="2426" />
  <row Id="14271" PostId="5691" Score="1" Text="I don't have much trouble with blind or buried vias with Eagle; the interface works as well as any other system I've used, although I think you might have to have some German blood in you in order to really &quot;grok&quot; the way Eagle does some things. :-)   I will admit that working with boards dense enough to require them makes me go cross-eyed. :-)" CreationDate="2011-02-01T02:24:11.213" UserId="974" />
  <row Id="14272" PostId="9507" Text="@EnderWiggins, You can [edit](http://electronics.stackexchange.com/posts/9507/edit) your question." CreationDate="2011-02-01T02:44:53.357" UserId="2118" />
  <row Id="14273" PostId="8110" Text="Power requirements (i.e., how often you need to change the battery) increase with frequency. Electromagnetic interference also generally increases with clock frequency. " CreationDate="2011-02-01T03:27:59.230" UserId="813" />
  <row Id="14274" PostId="1390" Text="@davr - No, I think metcal irons are just that nice." CreationDate="2011-02-01T03:30:42.037" UserId="1374" />
  <row Id="14275" PostId="9597" Text="+1 for FT2232...I've used several dev boards that have that chip as their JTAG host, and my next PCB will have one on it.  FTDI support in MacOSX is present but hard to configure; I got an EK-LM3S6965 dev board with FT2232 JTAG tester to work with OpenOCD a while ago.  A generic version from Olimex would be worth $70 to me, I'll have to check that out." CreationDate="2011-02-01T03:43:15.887" UserId="857" />
  <row Id="14276" PostId="9574" Score="1" Text="A piezoelectric tuner is basically a contact microphone coupled to a normal tuner." CreationDate="2011-02-01T03:46:26.880" UserId="1374" />
  <row Id="14277" PostId="9599" Score="1" Text="This is a shopping question *(&quot;Where can I buy X? Which of Y should I buy?&quot;)* Please try making the question applicable to an audience years down the road, when product X or Y are obsolete or no unavailable." CreationDate="2011-02-01T03:48:04.480" UserId="2118" />
  <row Id="14278" PostId="9599" Score="1" Text="@tyblu, he could change the question to a completely different question and it would fit, but that is a completely different question, so let us close this one and let him open a new one when he writes a new one." CreationDate="2011-02-01T03:54:31.007" UserId="230" />
  <row Id="14279" PostId="9601" Text="I am currently working on a project that uses a SAW filter. We are having to fab it ourselves. Not much help for you, but could be an option. They aren't overly difficult to make, but does take some thought." CreationDate="2011-02-01T04:14:05.550" UserId="319" />
  <row Id="14280" PostId="3209" Text="@wallacoloo ah ok, thanks, you're talking about the LEDs themselves, and not something that comes on a PCB.  Thanks!" CreationDate="2011-02-01T06:10:35.987" UserId="2288" />
  <row Id="14281" PostId="5694" Text="+1, the tour video shows the guys adding an rj45 right on the breadboard http://mbed.org/handbook/Tour" CreationDate="2011-02-01T06:39:09.027" UserId="2006" />
  <row Id="14282" PostId="7117" Text="@steven - You can register for free with the [JEDEC standards body](http://www.jedec.org/); their motto is &quot;Leading developer of standards for the solid-state industry, all being available online, free of charge.&quot; Not applicable here, but useful in many other cases like memory and layout design!" CreationDate="2011-02-01T06:49:43.570" UserId="857" />
  <row Id="14283" PostId="9601" Text="What about trying to find other companies that are using the components in a mass produced product, they may be able to help out?" CreationDate="2011-02-01T07:33:56.837" UserId="2841" />
  <row Id="14284" PostId="6020" Text="I really like the plug computers." CreationDate="2011-02-01T07:57:34.400" UserId="2183" />
  <row Id="14285" PostId="9520" Text="Which part, float-to-fixed point conversion?" CreationDate="2011-02-01T10:22:10.733" UserId="1938" />
  <row Id="14286" PostId="9520" Text="sybreon is correct to mention fixed-point when floating-point isn't available. I know for a fact that in smaller, older or less powerful gaming consoles, where there is no FPU (Floating-Point Unit), fixed-point math is commonly used." CreationDate="2011-02-01T10:30:43.260" UserId="1333" />
  <row Id="14287" PostId="9006" Text="Depends on if your inverter needs a minimum load, the work around would be to use multiple inverters (I.E one inverter per channel) with a dummy load to meet the minimum" CreationDate="2011-02-01T12:01:09.070" UserId="2060" />
  <row Id="14288" PostId="9612" Score="6" Text="Why a PIC? Just a battery a DC motor and an on/off switch. :)" CreationDate="2011-02-01T13:33:42.947" UserId="2157" />
  <row Id="14289" PostId="9583" Text="Yeah, I haven't very good experiences with XBees in the past. They tend to be overpriced for the performance, imo." CreationDate="2011-02-01T13:37:19.433" UserId="536" />
  <row Id="14290" PostId="9615" Text="agreed on arduino and lm35, was just typing basically the same answer. ," CreationDate="2011-02-01T13:38:04.797" UserId="1381" />
  <row Id="14291" PostId="9604" Text="Technically, on the pictured 'LCD' (the evalbot), it's an OLED display ;)" CreationDate="2011-02-01T13:38:39.213" UserId="536" />
  <row Id="14292" PostId="9504" Text="I've looked at the website and I've noticed they have both capacitative sensors and resistive sensors embedded in gypsum. Which are you using? Are they any good?" CreationDate="2011-02-01T13:45:58.603" UserId="1802" />
  <row Id="14293" PostId="9520" Text="I've done a lot of fixed point work over the years. Between that and simple scaling (taking all your numbers and *16 so you have 4 bits of fractional data at the expense of 1/16th the range) I have never had to use floating point numbers in embedded systems in over 13 years of work in the field." CreationDate="2011-02-01T14:10:44.523" UserId="974" />
  <row Id="14294" PostId="9604" Text="@pyfon - Yeah, sure, and the same with the LM3S6965, but it's the same mounting system (I think). " CreationDate="2011-02-01T14:14:38.793" UserId="857" />
  <row Id="14295" PostId="9616" Score="2" Text="You'll want some hysteresis on that comparator or your relay will chatter at the setpoint. This is an excellent solution though. It's cheap, it's effective and it works." CreationDate="2011-02-01T14:39:50.723" UserId="974" />
  <row Id="14296" PostId="9614" Text="@SWEngineer, this is not the type of question that goes well here, this answer will be invalid in 6 months, it is completely opinionated, and we honestly cannot be 100% sure of what you are looking for. I chose too localized, but there were other options." CreationDate="2011-02-01T15:51:17.533" UserId="230" />
  <row Id="14297" PostId="9612" Score="1" Text="@kenny, no need to deter someone from learning microcontrollers." CreationDate="2011-02-01T16:02:29.440" UserId="230" />
  <row Id="14298" PostId="9616" Score="1" Text="thanks for the answer. How would I design that hysteresis (it should be more than 2 C)?" CreationDate="2011-02-01T16:10:39.727" UserId="2843" />
  <row Id="14299" PostId="9616" Text="I think you'll need to add a schmitt trigger to it, which will basically set the 'on' threshold lower than the 'off' threshold." CreationDate="2011-02-01T16:18:55.830" UserId="2426" />
  <row Id="14300" PostId="9618" Text="Pointer to the specific $200 switch you mention would help." CreationDate="2011-02-01T16:25:48.760" UserId="206" />
  <row Id="14301" PostId="9619" Text="&lt;_&lt;  Somehow, I assumed that I couldn't put Flash and RAM on the same bus at the same time.  This is probably what I'll do, but I'll leave the question here because I still want to know what AxB:C means." CreationDate="2011-02-01T16:35:33.780" UserId="857" />
  <row Id="14302" PostId="9618" Text="@Brian - [Here's the datasheet](http://www.national.com/ds/LM/LMH6584.pdf), and [here's the product page on Digikey](http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=LMH6585VV/NOPB-ND)." CreationDate="2011-02-01T16:38:16.617" UserId="857" />
  <row Id="14303" PostId="9588" Text="I started working through your suggestions last night. I tested every pair of pins in both directions, and did find a pair of pins that dropped a different amount of voltage depending on if the LED was lit, so hurray! It's a very small amount, about .14 volts. The datasheet seems helpful but I'm struggling to understand it. Any idea what 'Output Phototransister: Collector-Emitter Voltage: 30 V, Emitter-Collector Voltage: 5 V&quot; is all about?" CreationDate="2011-02-01T16:47:50.240" UserId="2813" />
  <row Id="14304" PostId="9616" Text="I'm pretty sure the way to do that is to add a resistor between the output of the op amp and the non-inverting input. I'm not sure of the value of the resistor though, it might be a good idea to use a variable resistor here so you can adjust the difference between the on and off thresholds." CreationDate="2011-02-01T16:49:11.410" UserId="2426" />
  <row Id="14305" PostId="9588" Text="This website has a pretty good explanation of Collector-Emitter voltage: http://www.johnloomis.org/ece445/topics/egginc/pt_char.html" CreationDate="2011-02-01T16:58:55.267" UserId="2426" />
  <row Id="14306" PostId="9620" Text="If the displays I am looking at don't come with this cage, do I have to make my own, or is there a place I can buy these in various (possibly custom) sizes?" CreationDate="2011-02-01T17:03:43.183" UserId="857" />
  <row Id="14307" PostId="9624" Text="I knew about that adapter, but like you said, it's way too expensive (and I don't want to know how much more here in Argentina). I tried to google for technical specs about it, but there is a endless list of pages to sell the product and no pages showing info (not even the output voltage!)." CreationDate="2011-02-01T17:14:06.527" UserId="1613" />
  <row Id="14308" PostId="9620" Text="I don't think that you'll find it easily in the market, they are usually manufactured in conjunction with the display. If they're available, the same site that sells the display will show it as an option/accessory. One option is to make in acrylic, you can find easily anywhere workshops that can cut/bend/punch acrylic sheets to your needs at a reasonable price." CreationDate="2011-02-01T17:22:24.183" UserId="1078" />
  <row Id="14309" PostId="9620" Text="BTW, the link to the document is www.displaytech.com.hk/pdf/LCDConnectionMethods.pdf . Unfortunately I tried to access it and the site says it's temporarily unavailable; BUT Google cache still has it, do a search for the doc name and click on the 'cached' link." CreationDate="2011-02-01T17:24:01.623" UserId="1078" />
  <row Id="14310" PostId="9604" Text="If the board is going to be abused and you'll need to rework them, then the plastic cage fceconel sounds like a good approach, though you might have to find someone local to print them for you.  I'd post in the Makerbot / Thingiverse google group to see if anyone can help you out.  I can help but I'm not local.  Otherwise, if you have access to a laser cutter, I would consider laser cutting some acrylic bread and sticking your LCD and PCB meat inside.  Cut holes where the buttons and screen are, just big enough to capture the LCD.  The MeggyRGB is a good example for buttons." CreationDate="2011-02-01T17:28:15.623" UserId="2288" />
  <row Id="14311" PostId="9604" Text="Actually, you can completely sandwich it since you're not using a touchscreen.  A little double-stick would be nice to keep the LCD from shifting too much." CreationDate="2011-02-01T17:29:01.567" UserId="2288" />
  <row Id="14312" PostId="9624" Text="@Tomas - I found some specs and added a link." CreationDate="2011-02-01T17:37:08.087" UserId="1823" />
  <row Id="14313" PostId="9624" Text="There is no DC jack! If you see the product, they give you a fake battery body with a female plug in its back, where you can connect the plug. Because of that, I have to figure out how to connect some wires inside the camera." CreationDate="2011-02-01T17:53:19.537" UserId="1613" />
  <row Id="14314" PostId="9624" Text="Page 32 of the manual you gave me. Anyway, that info is good and should allow me to use the 7805 voltage regulator and a diode in serial." CreationDate="2011-02-01T17:56:05.637" UserId="1613" />
  <row Id="14315" PostId="9620" Text="@fceconel - Great, thanks!  I put a copy of the cached version in your answer, hope you don't mind." CreationDate="2011-02-01T17:56:26.207" UserId="857" />
  <row Id="14316" PostId="9604" Text="@Dave - I have access to CNC machines, commercial rapid prototyping machines, and laser engravers (not cutters - it chokes on anything much thicker than mylar) at school, but thanks for the offer!  What is acrylic bread?  A google search returns plastic boxes for holding loaves of bread." CreationDate="2011-02-01T18:03:52.970" UserId="857" />
  <row Id="14317" PostId="9604" Text="@Dave - I'd worry that it would get scratched, hazy, or smudged if it covered the display.  I love the clarity of the screens without acrylic on top (especially machined acrylic, it's pretty clear but not great).  Maybe I'll just capture a small glass square underneath it.  This could make for a nice case!" CreationDate="2011-02-01T18:06:27.443" UserId="857" />
  <row Id="14318" PostId="9620" Text="Not at all, glad you found it." CreationDate="2011-02-01T18:13:20.627" UserId="1078" />
  <row Id="14319" PostId="9624" Text="@Tomas - sorry about the power jack... I saw one of the cameras had a picture of a jack and that stuck in my head.  Good luck!" CreationDate="2011-02-01T18:33:25.257" UserId="1823" />
  <row Id="14320" PostId="9627" Text="If it's bidirectional, why do we need a concept of inputs and outputs?  Or, what's the difference between an AxB:C chip and an AxC:B chip?" CreationDate="2011-02-01T18:33:50.263" UserId="857" />
  <row Id="14321" PostId="9623" Score="1" Text="Any chance you could accept some answers?  It looks like you've asked 4 answers but haven't accepted any." CreationDate="2011-02-01T18:34:22.760" UserId="1823" />
  <row Id="14322" PostId="9627" Text="Ah, I was looking in 'Interface - Switches, Multiplexers, Demultiplexers' when I wanted 'Logic - Signal Switches, Multiplexers, Decoders'" CreationDate="2011-02-01T18:36:01.760" UserId="857" />
  <row Id="14323" PostId="9627" Text="Not all MUX topologies are bidirectional. The MOSFET switch ones are, because the switch behaves that same in both directions. Only if a topology is bidirectional can B and C be interchangeable. Normally, a 1:2 circuit is considered a de-mux." CreationDate="2011-02-01T18:42:04.077" UserId="638" />
  <row Id="14324" PostId="9624" Text="This is super weird. I've connected my laptop charger to the regulator and the output shows 5 V right? But when I put the diode in serial, the voltage after the diode is 14 V. Why?" CreationDate="2011-02-01T18:43:43.473" UserId="1613" />
  <row Id="14325" PostId="9624" Text="That sounds like another question to me (I can't help you with that one)." CreationDate="2011-02-01T18:46:03.120" UserId="1823" />
  <row Id="14326" PostId="9630" Text="So, if I understand what you wrote corectly, the potential of the com port is potential of the - side of the battery plus 2.8 V. Now, if I connect the power supply as the meter's power source, the supply's - side is meter's - side. Since the voltge between ends of the power supply is around 9 volts, and the voltage between the com port and the - of the supply is 2.8 volts, I should be getting around 6.2 volts reading for supply's voltage, since the reference point is same for both com and supply voltage. I get zero at one meter and out of range for **all** scales on the second meter." CreationDate="2011-02-01T19:10:47.857" UserId="1240" />
  <row Id="14327" PostId="9630" Text="Also, while this would make an impact on voltage measurement, why would it afect current measurement?" CreationDate="2011-02-01T19:11:42.230" UserId="1240" />
  <row Id="14328" PostId="9630" Text="@AndrejaKo, it would affect current measurement as that is just measuring a voltage dropped across a shunt resistor." CreationDate="2011-02-01T19:22:08.990" UserId="1225" />
  <row Id="14329" PostId="9630" Text="@AndrejaKo, am I understanding you correctly that you cannot measure the voltage across a power supply? It would be helpful to see a schematic/diagram as I am confused by your description." CreationDate="2011-02-01T19:24:02.983" UserId="1225" />
  <row Id="14330" PostId="9630" Text="@Thomas O OK. But that still doesn't explain zero reading on both meters. Since the reference is 2.8V, I'd expect current readings to be decreased proportionally. " CreationDate="2011-02-01T19:24:47.677" UserId="1240" />
  <row Id="14331" PostId="9629" Text="Agreed - as I mentioned, this is really the preferred way to do multiple memory banks." CreationDate="2011-02-01T19:25:15.463" UserId="638" />
  <row Id="14332" PostId="9630" Text="@AndrejaKo. Overrange is usually indicated by exceeding the smallest range, probably 200mV-400mV, and is often clamped by diodes. If you are applying 2.8V to the ADC input of the main ASIC, who knows what it will read?" CreationDate="2011-02-01T19:28:22.137" UserId="1225" />
  <row Id="14333" PostId="9630" Text="@Thomas O I addded images. The meter which is showing overrange has manual ranging. " CreationDate="2011-02-01T19:38:38.347" UserId="1240" />
  <row Id="14334" PostId="9630" Text="@AndrejaKo I am confused about the second schematic. How is XMM2 measuring current?" CreationDate="2011-02-01T19:39:53.823" UserId="1225" />
  <row Id="14335" PostId="9630" Text="@Thomas O Well, here's how I intended it to measure current: Current goes from the supply to the current input of the meter and the to the current output of the meter. After that, it goe into the meter's 9 V jack, goes out and then back into the supply. XMM1 is just measuring voltage and should be making minimal impact on the current measured." CreationDate="2011-02-01T19:42:00.077" UserId="1240" />
  <row Id="14336" PostId="9630" Text="@AndrejaKo, but it's just measuring the current through a 10k resistor." CreationDate="2011-02-01T19:44:20.040" UserId="1225" />
  <row Id="14337" PostId="9630" Text="@Thomas O On the image, I used the 10k resistor to represent the meter's 9 V jack (I just found out that it's called PP3 clip), because of the program's limitations. There is no 10k resistor in reality." CreationDate="2011-02-01T19:46:16.840" UserId="1240" />
  <row Id="14338" PostId="9630" Text="@AndrejaKo, so the 10k resistor is the battery connection for the other meter?" CreationDate="2011-02-01T19:47:12.130" UserId="1225" />
  <row Id="14339" PostId="9630" Text="@Thomas O The 10k resistor is the battery connector of XMM2 on both pictures." CreationDate="2011-02-01T19:48:18.587" UserId="1240" />
  <row Id="14340" PostId="9630" Text="@AndrejaKo in which case that would put COM at 2.8V shorting that to V+ and that would essentially measure 0 as it is the difference between COM and V+ which the meter measures, which explains your zero reading." CreationDate="2011-02-01T19:51:16.383" UserId="1225" />
  <row Id="14341" PostId="9630" Text="@Thomas O OK, I think I understand and by the way, my mind is now officially blown. " CreationDate="2011-02-01T19:55:42.803" UserId="1240" />
  <row Id="14342" PostId="9633" Text="1600 MIPS!?!?!!?" CreationDate="2011-02-01T20:57:19.357" UserId="857" />
  <row Id="14343" PostId="9634" Text="The cable is about 1.5m long. Is it possible to fix it?" CreationDate="2011-02-01T21:15:25.043" UserId="1225" />
  <row Id="14344" PostId="9634" Text="@Thomas - Is it possible to fix the cable or the video card?  I don't know about the condition of either, but I know that my Macbook Pro can drive a projector over a 20m cable, so this isn't normal.  &#xA;Is your cable integrated into the monitor (allowing you to test a different cable), do you have a different monitor, and/or do you have a laptop or other computer you can test the monitor and cable with?" CreationDate="2011-02-01T21:31:28.690" UserId="857" />
  <row Id="14345" PostId="9634" Score="3" Text="it's possible that the suspect video card has poor or missing termination. " CreationDate="2011-02-01T21:33:11.220" UserId="974" />
  <row Id="14346" PostId="9612" Text="@Kortuk, that's not my intention. But just trying to say how simple a DC motor is." CreationDate="2011-02-01T21:46:12.417" UserId="2157" />
  <row Id="14347" PostId="9634" Score="1" Text="If you only see it on one video card then I would guess its not the cable and would go with Andrew's suggestion of it having poor or missing termination. Sure it is possible to fix it. First thing that comes to mind is buying a new video card." CreationDate="2011-02-01T22:23:34.377" UserId="319" />
  <row Id="14348" PostId="9635" Text="The only way I know how is to capture the color image in a frame grabber and process it with tools like opencv." CreationDate="2011-02-01T22:23:59.810" UserId="2157" />
  <row Id="14349" PostId="9634" Score="1" Text="+1 to buying a new vga card....cheap too." CreationDate="2011-02-01T22:26:03.180" UserId="2157" />
  <row Id="14350" PostId="9633" Text="I've read about this device some more now but I haven't yet found a really compelling story or article about it which verifies the claims they have. I know the AmigaOne's got one in it as a coprocessor as well, and I've poked around their community site a bit... Have you benchmarked this thing? Are there some &quot;big deal&quot; articles or demonstrations for it? I'm a little skeptical about the device." CreationDate="2011-02-01T22:56:19.683" UserId="974" />
  <row Id="14351" PostId="9633" Text="You'll find lots of applications on the XMOS web site. For instance, it's being used in high-end audio systems, because of its unique features." CreationDate="2011-02-01T23:13:00.340" UserId="305" />
  <row Id="14352" PostId="9612" Text="@kenny, can we use that for a BLDC motor?" CreationDate="2011-02-01T23:30:59.993" UserId="230" />
  <row Id="14353" PostId="9613" Text="A car that's powered from a wall wart would have a somewhat limited range..." CreationDate="2011-02-01T23:46:55.453" UserId="222" />
  <row Id="14354" PostId="9549" Text="Thank you for this! But: I can't find anything on Mouser or Digikey which have 100 mm x 80 mm boxes. Digikey has one which is 100 mm x 160 mm - but that is $30. I'm looking at their &quot;enclosure&quot; section; am I searching for the wrong thing? Or are there other vendors I should be aware of?" CreationDate="2011-02-02T00:20:11.787" UserId="1021" />
  <row Id="14355" PostId="9634" Text="@kenny Depends how cheap, if you're talking about a 9800 GT (which in my case was free from someone who upgraded their PC) then it's around £100 for a new one." CreationDate="2011-02-02T00:21:54.983" UserId="1225" />
  <row Id="14356" PostId="9634" Score="1" Text="@Thomas O They still really that expensive? I bought a 9800 GT a long time ago(over 2 years) for less the $150USD. I do have a question about your DVI-VGA converter, are you using it on your other setups also?" CreationDate="2011-02-02T00:30:28.040" UserId="319" />
  <row Id="14357" PostId="9634" Text="@Kellenjb, I dunno, maybe PC World are just ripping me off. I'm using the same converter with the other card with no problems." CreationDate="2011-02-02T00:40:12.590" UserId="1225" />
  <row Id="14358" PostId="9593" Text="@Andrew: I like how you've answered the question above and beyond what Dean is looking for (with your explanation on I2C)." CreationDate="2011-02-02T00:40:42.260" UserId="1944" />
  <row Id="14359" PostId="9632" Text="Woah. That is a pricey dev-kit." CreationDate="2011-02-02T02:19:53.423" UserId="790" />
  <row Id="14360" PostId="8978" Text="Why the down votes?  Not everyone here is a hobbyist, just building one and a good solder." CreationDate="2011-02-02T04:29:27.953" UserId="206" />
  <row Id="14361" PostId="9604" Text="@reemrevnivek sorry, I was totally speaking metaphorically there.  I was referring to your project as a &quot;sandwich&quot; where the acrylic is the &quot;bread&quot; and the PCB/LCD is the &quot;meat&quot;.  :)" CreationDate="2011-02-02T05:07:08.047" UserId="2288" />
  <row Id="14362" PostId="9639" Text="The torque is milliNewton meters, mNm, not mN per meter!" CreationDate="2011-02-02T06:15:18.280" UserId="305" />
  <row Id="14363" PostId="9639" Text="How will it actuate the shutter, exactly?" CreationDate="2011-02-02T07:38:32.077" UserId="2118" />
  <row Id="14364" PostId="9559" Text="@gallamine: I´ve just read and I agree with you, is an excellent and very clear article." CreationDate="2011-02-02T08:02:57.600" UserId="2597" />
  <row Id="14365" PostId="9642" Text="Does anyone creates a tag called &quot;System Generator&quot;? Thank you." CreationDate="2011-02-02T08:59:01.853" UserId="2597" />
  <row Id="14366" PostId="9517" Text="@tyblu: That´s done." CreationDate="2011-02-02T09:04:25.293" UserId="2597" />
  <row Id="14367" PostId="9568" Text="Yeeaah!!, I´ve put as 'Number of Proccessing Elements:' 10; and I´ve put a Latency for each Processing Element: [0 0 0 0 0 0 0 0 0 0 1] and I´ve gotten 0.498." CreationDate="2011-02-02T09:50:49.823" UserId="2597" />
  <row Id="14368" PostId="9568" Score="1" Text="Excellent! Just for future readers -  &quot;[zeros (1,9) 1]&quot; isn't (just) shorthand, you really can type that in the box.  Any legal matlab commands can go in the box and as long as they evaluate to a vector, it'll get used by the underlying scripts." CreationDate="2011-02-02T13:46:20.683" UserId="763" />
  <row Id="14369" PostId="9654" Text="Got an example of a low-cost enclosure? I wouldn't mind paying for a decent backboard just for not having to spend timing designing *another* part and make sure it'll fit in the enclosure." CreationDate="2011-02-02T13:55:16.800" UserId="2395" />
  <row Id="14370" PostId="9612" Text="@Kortuk, I never tried but I'm pretty sure you can get it to move. Typically those are used with a higher end controller to drive. See http://en.wikipedia.org/wiki/Brushless_dc_motor" CreationDate="2011-02-02T14:11:13.897" UserId="2157" />
  <row Id="14371" PostId="9653" Score="1" Text="I'm having a hard time picturing your different boards, because it sounds like they'd all have different form factors, but you also mention a backplane.  Can you update your post with a pic?" CreationDate="2011-02-02T15:08:48.500" UserId="2288" />
  <row Id="14372" PostId="9655" Text="I figured I need to do this, but electricity doesn't travel at the speed of light through copper (it's slower.) Anyway, I think it should be okay, I just need a little reassurance." CreationDate="2011-02-02T15:12:35.787" UserId="1225" />
  <row Id="14373" PostId="9646" Text="Consumer electronics is outside the domain of this site, please ask on [gaming.stackexchange.com](http://gaming.stackexchange.com)" CreationDate="2011-02-02T15:29:45.877" UserId="1407" />
  <row Id="14374" PostId="9646" Text="Apparently you did: http://gaming.stackexchange.com/questions/15810/charging-nintendo-dsi-xl-from-usb-5v" CreationDate="2011-02-02T15:37:05.933" UserId="1407" />
  <row Id="14375" PostId="9612" Text="@kenny, I do not think they work with just a switch, they need a higher end controller because you need feedback to control it, it is not a simple on/off. I think learning motor control algorithms is worth it, even if right now he has a simple brushed motor." CreationDate="2011-02-02T15:39:04.083" UserId="230" />
  <row Id="14376" PostId="9646" Text="@Nick T - thanks for your comment. I agree that it is somewhat edgy here, however, the FAQ states that *&quot;Electronics and Robotics - Stack Exchange is for electronics and robotics hardware hacking enthusiasts&quot;*. In a broad sense, using USB to charge a DSi can be considered as hardware hacking. For now, I'll leave the question here. I have, however, posted it on Gaming as well." CreationDate="2011-02-02T15:39:10.703" UserId="2422" />
  <row Id="14377" PostId="9646" Score="1" Text="@ysap, I understand your issue, if you are trying to build your own charger or such, then it might be a good fit here, but this problem is 100% consumer electronics. " CreationDate="2011-02-02T15:40:58.683" UserId="230" />
  <row Id="14379" PostId="9650" Text="@Martin Thompson: ok, I am understand the matlab notation of a vector, but for the cordic block, what means [0 0 0 0 0 0 0 0 0 0 1]? this represent a bunch of 11 PE?Other example...[1 1 1] This represents a bunch of 3 PE? Thank you for your help." CreationDate="2011-02-02T16:16:40.697" UserId="2597" />
  <row Id="14381" PostId="9661" Text="Actually, there is no evidence that the card is in fact made by nVidia or that the manufacturer decided to use the reference design. Further more you're talking about nVidia who made the 8000 series of self destructing cards. Also, stupid problems do happen to computer components and it is unsafe to assume that manufacturers do pay attention to what they are doing. For example, the newest Intel fiasco, silent withdrawal of several motherboard models by Asus few years ago and so on. " CreationDate="2011-02-02T16:21:41.503" UserId="1240" />
  <row Id="14382" PostId="9503" Text="@saar drimer: I´ve joined to your proposal." CreationDate="2011-02-02T16:23:19.490" UserId="2597" />
  <row Id="14383" PostId="9663" Text="Could anyone create a tag called how-to or suggest me one synonymous?" CreationDate="2011-02-02T16:49:55.040" UserId="2597" />
  <row Id="14384" PostId="9661" Text="The card is not made by Nvidia: that is just the chipset/GPU, in fact the card was made by PNY. The card was given to me free, so I have no option of returning it. And it's certainly not a driver issue, as the problem occurs during POST too - it's entirely independent display resolution or mode." CreationDate="2011-02-02T17:03:56.973" UserId="1225" />
  <row Id="14385" PostId="9652" Text="I was going to mark this as a duplicate, but I decided that this one is different enough (faster and parallel) to not mark your [question about skew on 400kHz I2C](http://electronics.stackexchange.com/q/5526/8) as a dupe." CreationDate="2011-02-02T17:04:45.770" UserId="857" />
  <row Id="14386" PostId="9662" Score="1" Text="Are you planning on running these at very high speed in an FPGA or the like?  Barring some extreme performance requirement or if you are already using an FPGA (or have very high volume), using an appropriate MCU and doing it in software would likely be cheaper in both component and development cost." CreationDate="2011-02-02T17:23:27.043" UserId="1407" />
  <row Id="14387" PostId="9663" Text="@Peter, meta tags are bad.  Anyone that knows [fpga]'s or  specifically about [xilinx] products and keeps track of those tags might be able to help." CreationDate="2011-02-02T17:25:53.793" UserId="1407" />
  <row Id="14388" PostId="9648" Text="@thomas O check out this question: http://electronics.stackexchange.com/questions/7535/what-precautions-should-i-take-when-mixing-analog-audio-and-digital-on-the-same-b#7550 " CreationDate="2011-02-02T18:29:23.327" UserId="1438" />
  <row Id="14389" PostId="9634" Text="Well, as I am sure you know, it is pretty clear by this point that there is something wrong with the video card. If it is an impedance mismatching issue then I would guess the video card was damaged and had a capacitor, inductor, or resistor break off. You might be lucky enough to be able to visibly see an issue like this, but then you are still left with figuring out what value needs to be put back on." CreationDate="2011-02-02T19:04:34.223" UserId="319" />
  <row Id="14390" PostId="9648" Score="2" Text="@Leon Heller, &quot;I wouldn't bother unless you have a lot of PCB design experience.&quot; I disagree. I would bother because he will never learn if he never has the chance to try to do something like that and possibly fail at it. " CreationDate="2011-02-02T19:09:13.830" UserId="319" />
  <row Id="14391" PostId="9608" Text="I've had good luck with this series.  I haven't used them at any distances over 5 feet, though." CreationDate="2011-02-02T19:21:41.437" UserId="1477" />
  <row Id="14392" PostId="9667" Text="If I recall correctly, getting equal-length traces (even with differential pairs) is a few clicks in Altium Designer." CreationDate="2011-02-02T20:05:27.167" UserId="1407" />
  <row Id="14393" PostId="9639" Text="nMm?  nanomegameters (a millimeter)?" CreationDate="2011-02-02T20:11:30.703" UserId="1407" />
  <row Id="14396" PostId="9671" Text="Why the down vote on this question? Seems like a good question to me." CreationDate="2011-02-02T21:09:56.380" UserId="319" />
  <row Id="14398" PostId="9666" Text="+1 Good question. If it were me I would do the &quot;Oh look, it works better now&quot; method." CreationDate="2011-02-02T21:21:53.653" UserId="319" />
  <row Id="14399" PostId="9668" Text="@Mark: I will be passing by Shenzhen. " CreationDate="2011-02-02T21:22:53.753" UserId="1944" />
  <row Id="14400" PostId="9671" Text="Signal level should be specified." CreationDate="2011-02-02T21:23:04.433" UserId="305" />
  <row Id="14401" PostId="9660" Score="1" Text="The companies that I'm thinking of visit is in the area I'll be visiting, and I'm going to visit several cities. " CreationDate="2011-02-02T21:24:07.620" UserId="1944" />
  <row Id="14402" PostId="9671" Score="4" Text="@Leon Heller, that is no reason for down voting. That is worthy of a comment instead of just a blind down vote." CreationDate="2011-02-02T21:25:24.400" UserId="319" />
  <row Id="14403" PostId="1696" Score="2" Text="@seidleroni, make your edit that says your solution an answer, it should not be part of the question." CreationDate="2011-02-02T21:38:51.170" UserId="230" />
  <row Id="14404" PostId="9675" Text="headphone cables are high-level analog." CreationDate="2011-02-02T22:15:58.770" UserId="411" />
  <row Id="14405" PostId="3205" Text="@Dave looks like they re-organized their website, breaking links in the process." CreationDate="2011-02-02T22:45:29.560" UserId="131" />
  <row Id="14406" PostId="3205" Score="1" Text="Hrm, sparkfun ALSO broke their links as well. I fixed both of them. Does nobody understand the importance of long-lived links any more?" CreationDate="2011-02-02T22:46:41.773" UserId="131" />
  <row Id="14407" PostId="9682" Text="Any technical reason for why it is a wast of money?" CreationDate="2011-02-02T23:24:20.773" UserId="319" />
  <row Id="14409" PostId="9682" Score="3" Text="It won't make any difference to the sound quality. Double-blind testing comparing expensive speaker cables to ordinary cables has showed that listeners couldn't distinguish between them." CreationDate="2011-02-02T23:35:09.077" UserId="305" />
  <row Id="14410" PostId="9680" Score="1" Text="I would recommend this over the mbed if you're there for learning ARM. As for getting quick prototypes up and running, mbed would be preferable.&#xA;&#xA;" CreationDate="2011-02-03T00:25:43.210" UserId="1688" />
  <row Id="14411" PostId="9682" Score="1" Text="i wouldn't call it a waste of money, last time i looked 100ft of 12 AWG speaker wire from monoprice is cheaper than 100ft of 12/2 NM.  Not to mention that 12/2 NM isn't all that likely to slide under your baseboards or bend around 90 degree corners so its not visible." CreationDate="2011-02-03T00:42:53.627" UserId="1438" />
  <row Id="14412" PostId="9655" Text="Travels at `v=c/sqrt(permittivity)`, or around 0.4c." CreationDate="2011-02-03T00:51:17.407" UserId="2118" />
  <row Id="14413" PostId="8048" Text="-1: Wheatstone bridges give very good relative accuracy (and in strain gauges can multiply the signal x 4 if all resistors are strain-dependent), but don't provide any advantage in absolute accuracy unless you know the reference resistors in the bridge. They also provide no help with low-ohm resistance measurements, where connection resistance can be signification." CreationDate="2011-02-03T01:21:36.493" UserId="330" />
  <row Id="14414" PostId="3209" Text="Ah. I tried naming the links, but it didn't work. There's a trailing &quot;]&quot; at the end of each of the links that needs to be removed. Sorry. I'd edit the comment if I could." CreationDate="2011-02-03T01:21:59.030" UserId="790" />
  <row Id="14415" PostId="9665" Text="Separation of ground planes is a topic of holy wars... let's just say there are different reasons whether or not to just use one ground plane or have separate planes joined at one point." CreationDate="2011-02-03T01:23:56.290" UserId="330" />
  <row Id="14416" PostId="9661" Text="@hak8or, Video cards are actually not that complicated, although they may seem that way, they just demand the highest end ram and GPU to keep up." CreationDate="2011-02-03T01:39:25.083" UserId="230" />
  <row Id="14417" PostId="8608" Text="there is the chumby screen/psp screen from sparkfun.&#xD;&#xA;(both are 24bit parallel.)&#xD;&#xA;ps: what is you controller? i cannot seem to find one." CreationDate="2011-02-03T01:39:52.570" UserId="2864" />
  <row Id="14418" PostId="9667" Text="And Mentor Graphics Expedition PCB, which this board was designed in.  " CreationDate="2011-02-03T02:09:03.353" UserId="857" />
  <row Id="14419" PostId="9682" Score="1" Text="Isn't mains cable usually solid (by code?); that could be fairly impractical." CreationDate="2011-02-03T02:11:23.640" UserId="1407" />
  <row Id="14420" PostId="9664" Text="It is possible, because floating point ALUs exist in many processors.  Whether it's been made open source and is achievable on an FPGA of reasonable size is up for debate." CreationDate="2011-02-03T02:30:28.733" UserId="857" />
  <row Id="14421" PostId="9670" Text="@Mark, I thought it boiled down to, as you increase twist rate you are effectively reducing distance between the wires and decreases cross-sectional area." CreationDate="2011-02-03T02:32:43.287" UserId="230" />
  <row Id="14422" PostId="6691" Text="There are a number of power units on ebay.  Where can I find out which ones are compatible with later handpieces and cartridges?" CreationDate="2011-02-03T02:39:45.097" UserId="857" />
  <row Id="14424" PostId="8608" Text="@dave, since your other question was deleted, noone but moderators can see it." CreationDate="2011-02-03T03:53:04.357" UserId="230" />
  <row Id="14425" PostId="8608" Text="@Kortuk oops!  :)  thanks for letting me know." CreationDate="2011-02-03T05:23:02.897" UserId="2288" />
  <row Id="14426" PostId="9670" Score="3" Text="and the more twists the longer the wire resulting in more attenuation" CreationDate="2011-02-03T05:43:49.447" UserId="2006" />
  <row Id="14427" PostId="9679" Text="This question is too localized.  Another user with three different boards will not benefit from this question.  Therefore, I'm voting to close. If you want to know what qualities to look for in a dev kit, feel free to ask that (as a different question, this one's too far down the tubes)." CreationDate="2011-02-03T07:06:31.223" UserId="857" />
  <row Id="14429" PostId="9682" Score="1" Text="Stranded mains cable, of course. Not the stuff that is used for household wiring." CreationDate="2011-02-03T07:27:11.760" UserId="305" />
  <row Id="14431" PostId="9686" Text="Well I was mainly looking for something to which I would add more stuff, seeing as anything with added peripherals generally exist out of my circa $50 price range. Furthermore, this seems to be more flexible with adding random other things.&#xA;&#xA;I actually happened to be tinkering with QEMU a bit earlier. I was trying to use it to see if the binaries compiled by my toolchain would work properly... I was using the CodeSourcery toolchain to compile by the way. Speaking of which, am I correct in thinking that the code needs to be a plain binary file with no formatting (such as ELF, etc?)" CreationDate="2011-02-03T08:15:07.303" UserId="2701" />
  <row Id="14433" PostId="9686" Text="Also, the stellaris does seem quite nice, and seems like a nice choice if I do decide I want to spend an amount similar to the cost of the mbed.&#xA;&#xA;But what about the ET STM32? It seemed to be in the league of the mbed, and is likely even cheaper than the Armmite Pro." CreationDate="2011-02-03T08:31:27.510" UserId="2701" />
  <row Id="14434" PostId="9690" Text="Software part of screen capture depends on a few variables, but there are ways, [C#](http://msdn.microsoft.com/en-us/library/fw1kt6f9.aspx) providing some of the easiest. Using the linked method I got between 1 and ~100 FPS capture rate, depending on monitor settings (16 bit color sped it up a lot)" CreationDate="2011-02-03T09:08:06.997" UserId="1507" />
  <row Id="14435" PostId="9690" Text="I do agree that a prebuilt solution would be most ideal" CreationDate="2011-02-03T09:09:07.370" UserId="1507" />
  <row Id="14436" PostId="9526" Text="your diagram looks correct, but i would connect all gnd pins to ground, and also connect a backup battery to keep the RTC going. all the pin connections start on page 11 of the datasheet you linked... it looks like a lot of pins need to be left floating (not connected).....other then that it looks good :)" CreationDate="2011-02-03T09:10:55.590" UserId="2060" />
  <row Id="14437" PostId="9682" Text="I use 6A mains cable for a PA with no problems at all. And it's the perfect diameter for use with Speakon connectors." CreationDate="2011-02-03T10:15:03.643" UserId="2234" />
  <row Id="14438" PostId="9692" Text="Wow! Same case here, except I got me an ATMega 162." CreationDate="2011-02-03T10:27:23.170" UserId="1240" />
  <row Id="14439" PostId="9668" Text="You might be in luck then... try this place: http://www.new-shenzhen-business.com/electronics.html  If you can, bring somebody to help you talk to everybody.  Happy Shopping!" CreationDate="2011-02-03T10:30:29.390" UserId="1756" />
  <row Id="14441" PostId="9653" Text="When I'm making my own boards I only use 160mm x 100mm prototyping boards. I can also get boards of the same size that I can etch myself. This is one possible board https://www.elfa.se/elfa3~no_no/elfa/init.do?item=48-504-20&amp;toc=20548, it even has place for a connector at the end." CreationDate="2011-02-03T11:32:05.507" UserId="2395" />
  <row Id="14442" PostId="9653" Text="The other boards I'm buying are usually smaller than 160x100 so I can just mount them on a board and use the bigger board to connect the back plane and connections on the smaller board." CreationDate="2011-02-03T11:32:59.563" UserId="2395" />
  <row Id="14443" PostId="9693" Score="2" Text="you may also want to check out Hackadays AVR tutorial http://hackaday.com/2010/10/23/avr-programming-introduction/" CreationDate="2011-02-03T12:08:19.313" UserId="2060" />
  <row Id="14444" PostId="9644" Text="What format floating point?  IEEE754 single or double?  Or can you use funky  custom formats (as you are targetting an FPGA)?" CreationDate="2011-02-03T13:26:21.823" UserId="763" />
  <row Id="14446" PostId="9682" Text="I totally agree, but thats not the question. Whats best from a scientific point of view.." CreationDate="2011-02-03T13:57:57.820" UserId="2860" />
  <row Id="14448" PostId="9676" Text="I'll give you an up vote, but I'm not sure if its the right answer. How I read it, it doesn't matter as long as the cable is thick enough? But still, in a world of HiFi and magic shielding would still be better? " CreationDate="2011-02-03T14:10:06.973" UserId="2860" />
  <row Id="14449" PostId="9670" Text="It's not just ethernet; the 50-pair telephone trunk cables did this exact same thing (slightly different twists on the pairs) well before ethernet was even a concept." CreationDate="2011-02-03T15:37:28.833" UserId="974" />
  <row Id="14451" PostId="9686" Text="I am not familiar with the ET STM32, I have multiples of all the boards I mentioned but not this one nor the leaflabs one you mentioned.  Both look interesting, I may have to get one of these ET STM32s.  Am I just not seeing a link to the schematic?  It seems like it has rs232 line drivers, I would want to not have the rs232 level shifters and use something like this http://www.sparkfun.com/products/718 to both power it and talk to it.  I may have to just order one of these" CreationDate="2011-02-03T16:24:16.093" UserId="985" />
  <row Id="14452" PostId="9686" Text="I dont know of qemu can read elf files, I would hope/assume, but usually a raw binary will work  arm-something-something-objcopy myfile.elf -O binary myfile.bin works if you have .text and .data and everything compiled for one base memory area and the entry point is the beginning of the .bin file, the base address.  If it can read elfs then you dont have to worry about spreading the program out across memory regions.  When I have used qemu I let it think it is loading/branching to a linux kernel at some address like 0x10000 or whatever and gain access that way." CreationDate="2011-02-03T16:29:52.657" UserId="985" />
  <row Id="14453" PostId="9686" Text="hmmm, I could easily add elf support to thumbulator...perhaps I should..." CreationDate="2011-02-03T16:30:26.840" UserId="985" />
  <row Id="14454" PostId="9686" Text="I think when you add serial and power to the ET STM32 you are going to get back up into that $35-$50+ price range.  Sorry that I dont have hands on experience with that board to be able to tell you more.  I am probably going to buy one.  Debating about the leaflabs card as well.  futurelec has an ET arm stamp, arm7 based that looks interesting." CreationDate="2011-02-03T16:38:00.870" UserId="985" />
  <row Id="14456" PostId="9699" Text="Sounds very promising. Do you have any canonical source for those for a hobbyist? Like max 10 of them?" CreationDate="2011-02-03T16:59:10.020" UserId="1877" />
  <row Id="14457" PostId="6413" Text="It works!   But the problem was silly - blown fuses." CreationDate="2011-02-03T17:00:06.057" UserId="1877" />
  <row Id="14458" PostId="9697" Text="What is the question?" CreationDate="2011-02-03T17:04:53.400" UserId="1240" />
  <row Id="14459" PostId="9699" Text="I've bought them from Clere Electronics, the UK distributor, in small quantities, and they are also available from Farnell. Sparkfun sells modules using them that I have used, as well." CreationDate="2011-02-03T17:07:55.883" UserId="305" />
  <row Id="14460" PostId="9702" Text="Ok, it's weird though, I bought an arduino kit and it came with the motors, but did not provide a motor shield. It is safe to run a servo without a shield though, correct?" CreationDate="2011-02-03T17:11:05.040" UserId="2873" />
  <row Id="14461" PostId="9695" Score="1" Text="I'd give you an upvote if you posted the code here, or to somewhere I don't need an account..." CreationDate="2011-02-03T17:12:36.287" UserId="566" />
  <row Id="14462" PostId="9702" Score="1" Text="If your kit came with a transistor - http://electronics.stackexchange.com/questions/7235/motor-driver-using-only-a-2n2222-transistor" CreationDate="2011-02-03T17:18:27.633" UserId="566" />
  <row Id="14463" PostId="9702" Text="Yes it did. I guess that explains it." CreationDate="2011-02-03T17:19:31.300" UserId="2873" />
  <row Id="14464" PostId="6413" Text="@Amigable Clark Kant, good to hear!" CreationDate="2011-02-03T17:53:27.553" UserId="1225" />
  <row Id="14465" PostId="9698" Text="On the software side, there are tons of radio modem programs for GNU/Linux. As far as I can see, they make the sound card act as a modem and send data to output which is then sent over radio. I don't know of there anything similar for other operating systems, becasue I only saw them in repositories. It seems that there are established standards for transmitting data over radio using PC sound cards." CreationDate="2011-02-03T18:06:52.060" UserId="1240" />
  <row Id="14466" PostId="9706" Text="I2C also has a 3.4Mhz high speed mode but i don't know of any micro-controllers in the MSP430 or cortex-M3 market segments that support it." CreationDate="2011-02-03T18:10:11.727" UserId="1438" />
  <row Id="14467" PostId="9686" Text="Ahh, more painful than it needed to be, but the leaflabs schematic is in the github project.  I like what leaflabs is doing in principle, compared to the ET STM32.  I am more interested in the maple mini and the oak than the maple but neither of those are out yet." CreationDate="2011-02-03T18:20:53.697" UserId="985" />
  <row Id="14468" PostId="9421" Text="And they include the microcontroller, if you like AVR." CreationDate="2011-02-03T18:35:46.820" UserId="1363" />
  <row Id="14469" PostId="9670" Text="@kortuk I think that is certainly a consideration also, reduced cross-sectional area = smaller loop area = less inductive coupling.  But of course pulling the conductors closer together changes the characteristic impedance also which has to be adjusted for.  Ultimately i think there is a lot that goes into the final specification but its not something we'd often hear about as for the most part, UTP/STP is bought to a specification (Cat1 through Cat7) and the twist rate is part of the specification so all we ever see is the final performance of the twist rate chosen." CreationDate="2011-02-03T19:09:01.437" UserId="1438" />
  <row Id="14471" PostId="2057" Text="Have a look at the chipophone. No source code, but it is designed similar to the synthesizer in the NES. None of this crappy 2-voice garbage. 38khz 12-bit 8-channel polyphony from an AVR. http://www.linusakesson.net/chipophone/index.php" CreationDate="2011-02-03T19:43:27.523" UserId="1363" />
  <row Id="14472" PostId="9710" Text="Your correlation vs causation is off.  For instance gigabit Ethernet operates at the same frequency that 100mbit Ethernet does but the required specifications for gigabit operation are much tighter in several regards including cross-talk.  One of the ways used to meet the specification is to use a higher twist rate.  As a byproduct this does improve performance at higher frequencies but thats not why it was done as higher signaling frequencies were not needed to operate gigabit Ethernet." CreationDate="2011-02-03T19:45:25.540" UserId="1438" />
  <row Id="14473" PostId="9709" Score="1" Text="Any chance you could post a pic of the header pins to make sure we point you in the right direction?" CreationDate="2011-02-03T20:07:30.007" UserId="1823" />
  <row Id="14474" PostId="9709" Text="@RQDQ: Added pic of jaguar" CreationDate="2011-02-03T22:05:08.977" UserId="1217" />
  <row Id="14475" PostId="9686" Text="I was also quite interested in LeafLab's other unreleased products, particularly, the Maple Native. I don't care so much for the arduino form factor necessarily since I don't have a large array of shields in that form anyway...Furthermore it seems a bit of a shame to restrict the potential of the ARM Processor due to form factor constraints.&#xA;&#xA;Thank you for your continued assistance by the way!" CreationDate="2011-02-03T22:31:26.323" UserId="2701" />
  <row Id="14476" PostId="9686" Text="The thing about the closed JTAG port on the Cortex-M3 concerns me a bit.&#xA;&#xA;I am not exactly sure what to do for QEMU, But I'll try to figure that out next week when I have a bit more time. I'll probably make a purchasing decision next week also. At first I was mostly deciding with the ET-STM32, but now I am a bit more undecided as to what to choose. The closed source Cortex-M3 JTAG kind of annoys me, but i'm not sure if it bothers me enough for me to try to go for a different chip." CreationDate="2011-02-03T22:34:09.910" UserId="2701" />
  <row Id="14477" PostId="9716" Text="Good decoupling should help with this, but it never hurts if one device is pulling very high current compared to the others to avoid this." CreationDate="2011-02-03T23:32:02.777" UserId="230" />
  <row Id="14478" PostId="2591" Text="I'm pretty sure you won't be able to do recording over RS232, as would be required for answering machine functionality. If you want it to take messages, you need to be certain to get a modem which can also make voice calls. Some can, some cant." CreationDate="2011-02-04T00:32:43.740" UserId="1374" />
  <row Id="14479" PostId="9717" Score="2" Text="Is there a control switch for the water pump, possibly one controlled by 5ish volts, or is it simply apply 110vac or 220vac and it turns on?" CreationDate="2011-02-04T01:37:07.373" UserId="319" />
  <row Id="14482" PostId="9702" Score="1" Text="Although I use H-Bridges nowadays, when I first started, I plugged brushed motors in directly to outputs and it didn't damage anything as far as I can tell. This was a few years back and it's the only arduino I have. I think these ATmegas are pretty dang tough." CreationDate="2011-02-04T01:44:53.020" UserId="2006" />
  <row Id="14483" PostId="9686" Text="Hmm Another thought, Even if the price of the ET STM32 eventually goes up due to the added cost of serial breakout board and powering it. . . At least those things are re-usable for other purposes. But it is also a bit inconvenient to have it separately in a way." CreationDate="2011-02-04T01:47:32.253" UserId="2701" />
  <row Id="14484" PostId="9719" Text="It's a thought, but why is it needed for charging outside the vehicle but not inside it? You'd think it'd be more useful *inside* the vehicle -- not the other way around!" CreationDate="2011-02-04T01:52:12.873" UserId="2879" />
  <row Id="14485" PostId="9686" Text="openocd has some cortex-m3 support, stellaris and some others.  Just looked up swd again and this page http://www.arm.com/products/system-ip/debug-trace/coresight-soc-components/serial-wire-debug.php looks to have a whitepaper, perhaps it is now a published.  will have to play with this some day.  Was half the reason I ditched the lpcxpresso, first code red locks you in, second couldnt get info on the swd interface. " CreationDate="2011-02-04T03:42:20.377" UserId="985" />
  <row Id="14486" PostId="9725" Text="Should connect to both battery posts when boosting, though, as a lot of current will surge through." CreationDate="2011-02-04T03:48:31.217" UserId="2118" />
  <row Id="14487" PostId="9725" Text="That makes sense. Thanks! Also, @tyblu -- I'm not sure that's correct. The booster cables I have specifically say to ground to the car body when boosting a negatively-grounded vehicle." CreationDate="2011-02-04T04:58:51.700" UserId="2879" />
  <row Id="14488" PostId="9724" Text="it is a 9v battery.  The whole setup needs to be portable. The pump is intended to circulate ice water.  I get hot inside my costume and the ice water inside a tube across my forehead should help. Obviously I need to move around and constant running will cause brain freeze.  I have considered a 555 timer and am researching it now." CreationDate="2011-02-04T05:18:38.983" UserId="2880" />
  <row Id="14489" PostId="9686" Text="try this http://dwelch.s3.amazonaws.com/integrator.tar.gz I dont know how long ago I wrote it.  Use the latest codesourcery if you like dont have to use the old one.  Is basically a small embedded binary that you can run on qemu-system-arm, it is a uart echo program so when you go to the serial console window, what you type echos back." CreationDate="2011-02-04T05:26:05.000" UserId="985" />
  <row Id="14490" PostId="9686" Text="Too cool, I figured it out... http://dwelch.s3.amazonaws.com/qemu-stellaris.tar.gz  if you give qemu-system-arm a .elf file then it loads the program where the elf file says.  So by specifying a stellaris eval board it knows to use the cortex-m3 emulation, being an emulation the uart just works without clocks or anything being initialized properly you can simply throw bytes at it." CreationDate="2011-02-04T06:21:53.110" UserId="985" />
  <row Id="14491" PostId="9652" Text="I'd also be looking at terminating these lines correctly to minimize reflections." CreationDate="2011-02-04T07:31:57.857" UserId="1688" />
  <row Id="14492" PostId="9724" Text="Second the 555 timer idea, as it doesn't sound like you need it to be very precise. You might want to reduce the period as to maintain a better temperature, e.g. not 3 minutes too hot and 3 minutes too cold. You might consider putting a simple temperature dependent resistor in there to increase/decrease the flow rate depending on your costume temperature. Would also love to see this costume :D" CreationDate="2011-02-04T08:09:42.537" UserId="2340" />
  <row Id="14493" PostId="9653" Text="A case + backplane like this is something like what I'm after: http://www.s100computers.com/My%20System%20Index%20Page.htm" CreationDate="2011-02-04T09:15:09.200" UserId="2395" />
  <row Id="14494" PostId="9725" Score="1" Text="Also, when charging outside the vehicle, always switch the charger on at the mains *after* connecting the battery and switch off the charger *before* disconnecting the battery. The sparks produced when disconnecting a powered charger can ignite the hydrogen gas produced by the charging battery with *very* unpleasant results." CreationDate="2011-02-04T09:25:26.627" UserId="2234" />
  <row Id="14495" PostId="6413" Text="At least it has modern regulators now with thermal protection. It might need that protection after all since I fixed the fuses with aluminum foil... :-P" CreationDate="2011-02-04T09:29:24.933" UserId="1877" />
  <row Id="14496" PostId="9699" Text="Ok thanks. What do you mean using a suitable MCU?  That I don't get... can't you hook the sound card up almost directly to the Nordic Semi chip? With MCU, do you mean micro controller?" CreationDate="2011-02-04T09:32:39.190" UserId="1877" />
  <row Id="14497" PostId="9698" Text="@AndrejaKo, yes, I know there are, and I am comfortable with dreaming up all kinds of solutions within the computer. It's the little physical widgets that I want help with. :-)" CreationDate="2011-02-04T09:34:05.443" UserId="1877" />
  <row Id="14498" PostId="6413" Text="@Amigable Clark Kant, your fault if the &quot;fuses&quot; need to blow. The older regulators have thermal protection, too. " CreationDate="2011-02-04T10:14:16.570" UserId="1225" />
  <row Id="14499" PostId="9706" Text="I stand corrected. I confused it with the spec of another micro I was evaluating. The msp430 can go up to 400MH. Still a bit too low though." CreationDate="2011-02-04T10:42:19.103" UserId="941" />
  <row Id="14500" PostId="6413" Text="Yes, it was my fault." CreationDate="2011-02-04T11:34:22.907" UserId="1877" />
  <row Id="14501" PostId="7117" Text="@meemrevnivek - thanks for the link!" CreationDate="2011-02-04T11:47:49.803" UserId="2064" />
  <row Id="14502" PostId="6413" Text="@Amigable Clark Kant Just warning you of the possible consequences, a fried PCB that is, or worst a fire, if you replace fuses with non-fuses." CreationDate="2011-02-04T12:26:23.723" UserId="1225" />
  <row Id="14503" PostId="9726" Text="...or solder them correctly to begin with" CreationDate="2011-02-04T13:04:58.820" UserId="1571" />
  <row Id="14504" PostId="9731" Score="1" Text="+1 on using a diode to drop the voltage. A lot of AVRs will run all the way down to 1.6V, too, and all of them will run at 3.6 volts, so it may not matter if he drops even more. The servos' voltage range would be the limitation. I like using 4 1.2V NiMH batteries to get about 5V but a gift would have to be more robust." CreationDate="2011-02-04T13:12:37.917" UserId="1363" />
  <row Id="14505" PostId="9733" Text="Is it any comparison to QFN?" CreationDate="2011-02-04T13:23:06.073" UserId="1225" />
  <row Id="14506" PostId="9719" Text="in the vehicle you connect the negative to a ground point on the vehicle, not directly to the battery terminal." CreationDate="2011-02-04T13:57:28.313" UserId="1810" />
  <row Id="14507" PostId="9733" Score="1" Text="Quite different. I can solder QFN parts with a soldering station, quite easily." CreationDate="2011-02-04T13:59:15.403" UserId="305" />
  <row Id="14509" PostId="9725" Score="1" Text="Aendrew - I suspect that the reasoning is the same - They want you to not be standing over the battery.  Tyblu is pointing out that whatever you connect to might limit the current, either through a poor connection to the metal through paint or corrosion, or by a poor conduction path through more corrosion-the solid lead battery post won't do that.  Plus, when boosting, you can connect to a known good battery on the boosting car and be much less likely to cause an explosion or boil-over." CreationDate="2011-02-04T14:12:12.813" UserId="857" />
  <row Id="14510" PostId="9737" Text="...and sparks + hydrogen gas = fire." CreationDate="2011-02-04T14:13:31.343" UserId="857" />
  <row Id="14511" PostId="9736" Text="I haven't used that, but a quick read reveals that it requires specific drawing methods, which the author of your PDF isn't likely to have used.  Is your PDF encrypted and/or compressed, as most datasheets and appnotes are?  If so, it's not going to work." CreationDate="2011-02-04T14:17:32.183" UserId="857" />
  <row Id="14512" PostId="9736" Text="Also, how large/complex is your design?  The PDF should use a vector drawing, which will be crisp and precise at any size.  Most EDA layout programs have some method of importing an image (for, say, a silkscreen logo).  You could blow it up to a high resolution in your PDF viewer (See [these](http://superuser.com/q/120266) [Superuser](http://superuser.com/q/38101) [questions](http://superuser.com/q/203490/) for methods) and import that to a CAD program.  That will work great for simple/small layouts, but you'll have to watch your scaling carefully!" CreationDate="2011-02-04T14:27:06.973" UserId="857" />
  <row Id="14513" PostId="9724" Text="To expand on the temperature dependent resistor idea-- you could make a voltage divider with such a resistor, and then run the voltage into a LM339 comparator with the threshold set so it toggles at the right temperature. Then connect the comparator to a relay that controls the pump." CreationDate="2011-02-04T14:27:17.360" UserId="712" />
  <row Id="14514" PostId="9644" Text="Well, whatever... I´m using a virtex 4." CreationDate="2011-02-04T14:31:27.750" UserId="2597" />
  <row Id="14515" PostId="9715" Text="Yes, those are jumpers. What I want to know how to do is turn attach the 5 loose wires that come out of the encoder onto a set of jumper cable ends, preferably without cannibalizing jumper cables." CreationDate="2011-02-04T15:27:43.140" UserId="1217" />
  <row Id="14517" PostId="9709" Text="Picture updated to show where cables go" CreationDate="2011-02-04T15:47:17.687" UserId="1217" />
  <row Id="14518" PostId="9715" Text="I'm having difficulty finding multi-wire jumper cables that aren't polarized. Can you point me to some? Or is it not the done thing to use one large connector at each end?" CreationDate="2011-02-04T15:48:32.427" UserId="1217" />
  <row Id="14520" PostId="9742" Text="Thanks. That's kind of what I thought from my experiments. Fortunately, the design is simple enough that it's not THAT big a deal to simply copy the LED array designs onto separate sheets and renumber. I had just been hoping that I was missing something." CreationDate="2011-02-04T16:13:28.077" UserId="259" />
  <row Id="14522" PostId="9733" Text="It's LGA pads/balls/whatever around the edges only though, which makes me draw a comparison to QFN. It's an LSM303 accelerometer / magnetometer." CreationDate="2011-02-04T17:15:31.633" UserId="1225" />
  <row Id="14523" PostId="9715" Score="1" Text="If you don't want to crimp them yourself (tool needed), you can get http://www.pololu.com/catalog/product/1904 and put http://www.pololu.com/catalog/category/71 inside them." CreationDate="2011-02-04T17:18:57.850" UserId="1950" />
  <row Id="14524" PostId="9746" Text="A PDF file can include drill holes, if they are supported in the PCB software." CreationDate="2011-02-04T17:22:28.427" UserId="305" />
  <row Id="14525" PostId="9746" Text="@Leon Heller, I have never heard of that? The PDF file may contain polygons representing the holes (if that's what you mean), but the fabs need actual information about how the holes are drilled (like what drill size to cut, or the thickness of the plating.)" CreationDate="2011-02-04T17:26:50.603" UserId="1225" />
  <row Id="14526" PostId="9746" Text="Not if the holes are drilled manually. I can get round holes in PDFs from the PCB software I use." CreationDate="2011-02-04T17:46:40.377" UserId="305" />
  <row Id="14527" PostId="9746" Text="@Leon Heller, I suppose so, but if you were doing it manually why wouldn't you just expose the images on the PDF?" CreationDate="2011-02-04T17:51:57.953" UserId="1225" />
  <row Id="14528" PostId="9746" Text="That's what I was suggesting." CreationDate="2011-02-04T18:08:30.060" UserId="305" />
  <row Id="14529" PostId="9733" Text="that package looks like a cross between a QFN and a LGA.  Basically its a QFN with leads that don't wrap around and are pushed in from the package edge just slightly.  You won't be soldering that with an iron but i don't think it would be too difficult with a board heater and a hot air soldering unit. Or paste and a hot plate / baker.  You shouldn't have the settling issues that would normally occur with a 'regular' LGA." CreationDate="2011-02-04T18:55:32.033" UserId="1438" />
  <row Id="14530" PostId="3732" Text="Just to clarify that what an ADC outputs as digital data is independent of the implementation of the analog circuitry. For example the TI ADS8519 is a differential ADC that allows the user to choose either a straight binary or two's complement output. " CreationDate="2011-02-04T19:20:18.967" UserId="1614" />
  <row Id="14532" PostId="9578" Text="It seems Joe inadvertently answered my question with the statement &quot;It's an RS232 device&quot;. The code and wiring examples I was using won't work at all because the TW523 X10 device uses TTL. At least I know what to solve next... RS232&lt;-&gt;TTL!" CreationDate="2011-02-04T19:31:13.523" UserId="2782" />
  <row Id="14535" PostId="9747" Text="Where do you get (or how do you make) your stencils?  I imagine that you're not doing huge quantities if you're using a hot plate." CreationDate="2011-02-04T20:00:25.877" UserId="857" />
  <row Id="14536" PostId="9749" Text="hey dude, i did what you said and it worked! its all working now thw new socket has 1 less pin i think mby its earth but who cares it sounds good !!" CreationDate="2011-02-04T20:06:05.647" UserId="2889" />
  <row Id="14537" PostId="9748" Text="I cleaned up your question a bit.  &quot;Socket&quot; in this context usually refers to a connector into which an IC is inserted on the PCB, while &quot;Connector&quot; refers to something you'd plug a wire into.  Stack Exchange has an account with imgur; we prefer to host images there rather than ImageShack (where someone else could delete it)." CreationDate="2011-02-04T20:09:01.047" UserId="857" />
  <row Id="14538" PostId="9749" Text="Just as a note, it might be difficult to heat up a joint when there is remaining solder in it (like you can't use the pump to get it out). In that case you might add more solder so it stays liquid for a little bit longer. Same goes for wick, you may need to add a bit of new fresh solder so it reflows better. " CreationDate="2011-02-04T20:09:20.003" UserId="1476" />
  <row Id="14539" PostId="9745" Text="hmm...never tried this!  Will have to send out a few emails..." CreationDate="2011-02-04T20:15:24.333" UserId="857" />
  <row Id="14540" PostId="9749" Score="1" Text="@brux It could be something like a detect switch, to tell the unit that a cable is plugged in." CreationDate="2011-02-04T20:17:14.710" UserId="1225" />
  <row Id="14541" PostId="9746" Text="You can get drill sizes, but I agree that you're unlikely to get silkscreen/soldermask/paste layers or parameters like copper thickness. Also, I'm not sure how you'd handle multiple layers - Does the PDF really draw lines that pass under other lines/polygons?" CreationDate="2011-02-04T20:18:01.323" UserId="857" />
  <row Id="14542" PostId="9744" Text="How would you deal with conflicts on the bus, such as if two devices start to talk at the same time? " CreationDate="2011-02-04T20:24:26.200" UserId="857" />
  <row Id="14543" PostId="9703" Text="When you say that you could have more Stellaris nodes, do you mean that you'd have multiple masters?  This is much easier (see AngryEE's answer) if you only have one master." CreationDate="2011-02-04T20:25:51.647" UserId="857" />
  <row Id="14544" PostId="9715" Text="Damn. I just ordered a bunch from [farnell](http://uk.farnell.com/). I would have much preferred to buy them from polulu. Thanks anyway. Those are exactly what I was looking for." CreationDate="2011-02-04T21:49:48.973" UserId="1217" />
  <row Id="14545" PostId="9507" Text="@Ender - I'm confused by your description of a sink and your circuit topology.  A schematic might help - To me, a regulator that can sink is one that could be connected to a battery or capacitor (through a resistor) on the output, and regulate its output down (unlike a conventional linear regulator, which would turn its pass transistor off, exacerbating the problem).  Also, input voltage and current requirements would help narrow the field a little." CreationDate="2011-02-04T22:06:35.593" UserId="857" />
  <row Id="14546" PostId="9754" Score="2" Text="I'm not sure that will help... grass, sand and tarmac can all have bumps." CreationDate="2011-02-04T22:32:31.893" UserId="2426" />
  <row Id="14547" PostId="9754" Text="That's the thing - you'll never know until you try. And even if you can't identify every type of terrain, this can be included as part of a bigger system later on.  " CreationDate="2011-02-04T22:44:36.293" UserId="249" />
  <row Id="14548" PostId="9746" Text="My PCB software will output a separate PDF for each layer. They can be combined, of course." CreationDate="2011-02-04T23:03:23.767" UserId="305" />
  <row Id="14549" PostId="9752" Text="Thanks Mark for clear answer." CreationDate="2011-02-04T23:12:47.730" UserId="2891" />
  <row Id="14550" PostId="3630" Text="And on July 21, 2010 someone turned the book upside down..." CreationDate="2011-02-05T05:59:42.920" UserId="1246" />
  <row Id="14551" PostId="9687" Text="fixed my loader to work with the uno and pro." CreationDate="2011-02-05T06:50:53.087" UserId="985" />
  <row Id="14552" PostId="9757" Text="To clarify, are you are talking about a T flip-flop? Are you looking for the smallest physical footprint? Is there a specific reason why you are interested in a discrete transistor implementation, and is that a requirement?" CreationDate="2011-02-05T08:42:52.467" UserId="638" />
  <row Id="14553" PostId="9687" Text="added a C programming example to the bottom of the web page.  Are you looking to learn the C programming language, or do you mean just not programming C in their sandbox/environment but good old command line linux.  The examples and loader program on the page I linked were compiled and loaded from a linux host." CreationDate="2011-02-05T08:43:03.723" UserId="985" />
  <row Id="14554" PostId="9764" Score="4" Text="Please pay attention to case for SI units: ampere is upper case A, lower case a is year (from latin annum); hour is lower case h, upper case H is Henry, the unit for inductance." CreationDate="2011-02-05T09:31:03.907" UserId="339" />
  <row Id="14555" PostId="9754" Text="i dont see this working" CreationDate="2011-02-05T09:44:33.380" UserId="2791" />
  <row Id="14556" PostId="9767" Score="2" Text="Thanks for the answer but what you are describing is &quot;bandgap circuit&quot;, my question was regarding &quot;_half_ bandgap circuit&quot;. (Note: I am linking to the same Wikipedia article in question)" CreationDate="2011-02-05T09:49:30.207" UserId="1471" />
  <row Id="14557" PostId="9756" Text="i was thinking something like a sonar that measures distance. if you had it set at a fixed hight from the ground you should be able to measure the different signals coming back" CreationDate="2011-02-05T09:58:25.777" UserId="2791" />
  <row Id="14558" PostId="9768" Text="it will have a petrol engine so that will not work " CreationDate="2011-02-05T09:59:00.517" UserId="2791" />
  <row Id="14559" PostId="9764" Text="How long does it need to last in standby mode?" CreationDate="2011-02-05T11:28:57.127" UserId="857" />
  <row Id="14560" PostId="9771" Text="@leonHeller, kellenjb has that answer." CreationDate="2011-02-05T14:21:16.180" UserId="230" />
  <row Id="14561" PostId="9771" Text="It's different, he didn't mention colour." CreationDate="2011-02-05T14:43:52.683" UserId="305" />
  <row Id="14562" PostId="7913" Text="&quot;Liquid PCB&quot; https://sourceforge.net/projects/liquidpcb/ makes some interesting-looking traces with lots of graceful curves." CreationDate="2011-02-05T15:31:14.933" UserId="813" />
  <row Id="14563" PostId="9757" Text="Yes, T flip-flop. No, it's not smallest physical footprint. Transistor implementation is the whole idea of the project, so it's the core requirement :-)" CreationDate="2011-02-05T17:56:11.173" UserId="2062" />
  <row Id="14565" PostId="9754" Score="1" Text="This type of approach is used a lot in neural networks where you take data from many different sensors and train a system to predict what type of ground it is. In general the more sensors and types of sensors you have the better results you can get, but will also require more training data." CreationDate="2011-02-05T19:03:29.680" UserId="319" />
  <row Id="14566" PostId="9756" Text="Most sonar setups are designed to measure distances that are longer then this. I would be worried about not getting a great accuracy with them at close range." CreationDate="2011-02-05T19:07:17.723" UserId="319" />
  <row Id="14568" PostId="9758" Text="Thanks Andre. I did not know PIR sensors work this way. " CreationDate="2011-02-05T23:28:56.613" UserId="2891" />
  <row Id="14569" PostId="9754" Score="2" Text="having 32k for programming and 1k for storing does not lend its self well to that tough... i see the idea, but that approach might just be out of the arduino's league " CreationDate="2011-02-06T00:42:43.053" UserId="2791" />
  <row Id="14570" PostId="9771" Score="1" Text="that is good till there is a dead patch of grass that is the color of light sand, or dirty tarmac that is brownish." CreationDate="2011-02-06T00:44:25.890" UserId="2791" />
  <row Id="14571" PostId="9747" Text="I etch my own stencils at home with a kit from Rena Electronics." CreationDate="2011-02-06T00:53:43.890" UserId="2183" />
  <row Id="14572" PostId="9771" Text="You seem to have accepted this technique, though, in your edited question!" CreationDate="2011-02-06T01:42:52.113" UserId="305" />
  <row Id="14573" PostId="9769" Text="Dumb question, but could you get away with using the +/-5V part in the family? One man's 0V is another man's -5V..." CreationDate="2011-02-06T07:15:11.197" UserId="638" />
  <row Id="14574" PostId="9788" Text="Thank you. Is it safe to work with it powered since it is a laser product ? I have a 25mhz oscilloscope, is it ok to work with it -I have no idea about the bandwidth of internals in cd- ?" CreationDate="2011-02-06T08:25:27.500" UserId="2891" />
  <row Id="14575" PostId="9792" Score="1" Text="+1 for excellent photos." CreationDate="2011-02-06T08:51:35.037" UserId="1374" />
  <row Id="14576" PostId="9751" Text="I edited the question title a bit, since the first thing I thought when reading it was that you were trying to do some sort of ground-testing in an electrical system." CreationDate="2011-02-06T08:53:56.330" UserId="1374" />
  <row Id="14577" PostId="9796" Text="Keep in mind that computers often have ±5% tolerance on the input line, so that could be a problem for input from alternator. Also, [here](http://en.wikipedia.org/wiki/Cigarette_lighter_receptacle)'s a nice article pointing to some problems which could occur." CreationDate="2011-02-06T11:48:11.717" UserId="1240" />
  <row Id="14578" PostId="9792" Score="6" Text="-1 for absent photos" CreationDate="2011-02-06T12:27:52.887" UserId="1217" />
  <row Id="14579" PostId="9768" Text="@dogmatic69, But the sound of the petrol engine is predictable (at least if you know the current load and RPM) so you might be able to filter that out." CreationDate="2011-02-06T14:28:41.740" UserId="1285" />
  <row Id="14581" PostId="9800" Text="Thanks for your answer, but that solution does not satisfy 2. " CreationDate="2011-02-06T16:11:54.637" UserId="2883" />
  <row Id="14582" PostId="9768" Text="no it wont be, when there is more load it slows down, and more gas speeds up. that would make it really complicated. also talking about a petrol engine like 200cc from a generator type size, not from a rc car something like http://tinyurl.com/6ds4e9u" CreationDate="2011-02-06T16:18:11.870" UserId="2791" />
  <row Id="14583" PostId="9779" Text="Does the 192/200 divider work for low values of Vin? Say, Vin=0.1V?" CreationDate="2011-02-06T17:03:37.090" UserId="2893" />
  <row Id="14584" PostId="3066" Text="I've seen zeners in all sorts of packages" CreationDate="2011-02-06T17:38:23.287" UserId="2770" />
  <row Id="14585" PostId="9779" Score="1" Text="Yes, resistors are linear all the way down to 0V and beyond." CreationDate="2011-02-06T18:24:49.410" UserId="411" />
  <row Id="14586" PostId="9788" Text="The laser beam is focused on the CD and reflected light shouldn't be harmful during reading. So it should be safe with a CD in. To be sure, don't put your head into the imaginary beam. The nominal data rate 2,1 Mbit plus a litte bit for FEC, you should be able to see that on your oscilloscope. For a thorough understanding of the system you are interested in other signals than the data stream, anyway. Give it a try. :)" CreationDate="2011-02-06T18:30:40.100" UserId="1950" />
  <row Id="14587" PostId="9686" Text="got a leaflabs maple and the non pro version of the armmite.  the armmite is nice in that power and communication comes through the usb connector, but it is on par with the price of the armmite pro plus power/serial ftdi board. AND, similar to an arduino, unlike the pro, you can pull dtr to reset to program it." CreationDate="2011-02-06T18:43:33.337" UserId="985" />
  <row Id="14588" PostId="9686" Text="the maple, I sorta bricked it already with dfu-util.  Acording to the forums if you use one of the sparkfun ftdi breakout boards you can hook up to usart1, hold the BUT button while pressing reset. release BUT, and run their script from the git maple-bootloader repo.  Basically, the stm32 supposedly has a built in programming protocol through usar1, so you dont have to mess with jtag or worry about bricking." CreationDate="2011-02-06T18:46:26.767" UserId="985" />
  <row Id="14589" PostId="9703" Text="CAN will work at 1Mbps at over 20 metres. Not sure if any of the others will. The Stellaris microcontrollers also have very good support. Make sure you check out the errata as there are some sticking points. Their driver library is pretty good at circumventing the many errata!" CreationDate="2011-02-06T18:54:09.603" UserId="2770" />
  <row Id="14590" PostId="9795" Score="1" Text="I thought the ideas of thin clients is that they didn't have hard drives and only a simple OS to load network capabilities, which means no data is stored on the client. So are you going to have a very long network cable attached to you car as well? " CreationDate="2011-02-06T19:01:56.783" UserId="1623" />
  <row Id="14591" PostId="9638" Text="I'm not sure this is on-topic. And I don't know why the _circuit_ tag was added, as there is no references to any circuits, only a product purchasing recommendations request." CreationDate="2011-02-06T19:34:25.603" UserId="2598" />
  <row Id="14592" PostId="9686" Text="actually the dfu-util appears to be working.  no need for usart1 serial loading stuff.  it appears I am getting an exception.  Note that you may need to run the dfu-util right after a reset before the usb disconnects." CreationDate="2011-02-06T19:38:16.287" UserId="985" />
  <row Id="14593" PostId="9803" Text="Were you using solder paste?  That seems very slow.  I've assembled boards approximately five times more complex, at about that same rate." CreationDate="2011-02-06T19:46:19.443" UserId="411" />
  <row Id="14594" PostId="9792" Score="1" Text="Unless your pictures are on a *good* server, please download and re-upload them to StackExchange's image hosting service." CreationDate="2011-02-06T19:53:24.260" UserId="1407" />
  <row Id="14595" PostId="3732" Text="@spade78 i presume by &quot;straight binary&quot; you mean &quot;unsigned binary&quot;, right?" CreationDate="2011-02-06T20:11:55.210" UserId="771" />
  <row Id="14596" PostId="9773" Text="&quot;Is there additional error checking or other important logic that my NXC version might be missing?&quot; No. The NXC version is smaller because the compiler's smarter. The reason that the NXT-G version is so big is because it's poorly designed [IMHO]. If you look at Robolab (another Visual Programming Language), it's compile size is a lot smaller. [Here's an entire chart of NXT Programming Languages by Steve Hassenplug.](http://www.teamhassenplug.org/NXT/NXTSoftware.html)" CreationDate="2011-02-06T20:29:58.190" UserId="1940" />
  <row Id="14597" PostId="9808" Text="What is a wrist mounted button pusher?" CreationDate="2011-02-06T20:49:47.427" UserId="566" />
  <row Id="14598" PostId="9686" Text="http://stm32stuff.blogspot.com/" CreationDate="2011-02-06T21:03:00.410" UserId="985" />
  <row Id="14599" PostId="3732" Text="Not so much signed or unsigned, more like how the bit codes are mapped to the voltages. Straight binary is defined in the ADS8519 as binary 0 being mapped to the negative rail, binary 32768 represents 0V, and binary 65535 (its a 16-bit device) is mapped to the positive rail." CreationDate="2011-02-06T21:04:26.180" UserId="1614" />
  <row Id="14600" PostId="9808" Text="Well, from your description, it's going to be very complicated device. Can you provide a sketch of what you want? Also, what kind of buttons you need to push? DO you have exact specifications of the numpad? Also, on millisecond range, installation of the device is going to be a major problem. I doubt that it could be easily made to operate while wrist mounted with such precision. You'd need to exactly calculate distances when the device is connected to target and I doubt that a human could easily mate the wrist mounted device precisely enough to the target." CreationDate="2011-02-06T21:24:48.753" UserId="1240" />
  <row Id="14601" PostId="9808" Text="Also, how important is the size? Since it's going to be wrist mounted, I expect that it needs to be small. On the other hand, as far as I know servos are mostly used to control rotation and you'd need mechanical rig to get translation from rotation. It can get pretty big and could be heavy. Also, is there any chance of you telling us what you exactly want to do with it? There could be an easier way to accomplish same thing." CreationDate="2011-02-06T21:28:26.333" UserId="1240" />
  <row Id="14602" PostId="9808" Text="If you can modify the target device, it would be extremely helpful if you could get an output jack for the keypad. This way you could bypass mechanical connection and get electical connection to the target. It would then be very easy to simulate keypad operation with a microcontroller and there would be no problems in mounting the device in watch sized chassis." CreationDate="2011-02-06T21:31:14.847" UserId="1240" />
  <row Id="14603" PostId="9808" Text="Also since you can't even pick a microcontroller, I'd say that the chances of you making an electromechanical button pushing device of millisecond resolution are slim. Once again, check if you really really really need to have such a device and if it can be replaced with something which could make similar results." CreationDate="2011-02-06T21:34:06.857" UserId="1240" />
  <row Id="14605" PostId="9703" Text="Just one master. Updated question" CreationDate="2011-02-06T22:33:02.633" UserId="941" />
  <row Id="14606" PostId="9744" Text="Interesting. I'll have to investigate this too." CreationDate="2011-02-06T22:36:45.127" UserId="941" />
  <row Id="14607" PostId="9799" Text="I am using macros (which have previously worked in correctly setting up ports) to modify the port settings. For example, DISABLE_RA0_PULLUP(); sets the _CN2PUE register bit to 0. Then I set _TRISA0 = 1 and _PCFG0 = 1. Does that seem correct? Are the PIC's pull-ups notoriously weak? I was unaware of that." CreationDate="2011-02-06T22:38:11.430" UserId="2895" />
  <row Id="14608" PostId="9638" Text="Edited the tags. Have no idea what tags to add yet have people check out my question." CreationDate="2011-02-06T23:22:36.237" UserId="1944" />
  <row Id="14609" PostId="9808" Score="1" Text="What I have in mind is a small motor that can move something (the button pushing part) less than an inch or so forward and back. It's movement would be determined by a routine on the micro contorller that can be turned on or off. The routine, once set, should set off the motor at specific times specific to the millisecond. The wristmounted part is not necessary, I figure I'll work around that once everything else is figured out, but the point is to keep it small. I want something to program and use on arcade games that depend on matching moving lights on a target to win. " CreationDate="2011-02-06T23:39:25.250" UserId="2905" />
  <row Id="14610" PostId="9811" Text="I fixed your formatting." CreationDate="2011-02-07T00:06:18.270" UserId="1225" />
  <row Id="14611" PostId="9811" Text="For your LEDs, how bright is &quot;bright&quot;?" CreationDate="2011-02-07T00:06:34.633" UserId="1225" />
  <row Id="14612" PostId="9803" Text="Thanks sharing your experiences " CreationDate="2011-02-07T00:07:24.523" UserId="2896" />
  <row Id="14613" PostId="9802" Text="You raise some good points, starting to think that outsourcing is the right answer" CreationDate="2011-02-07T00:08:10.623" UserId="2896" />
  <row Id="14614" PostId="9808" Text="To clarify the button part, it only needs to be able to push one button at a time. This button will typically be 2-3 inches in length, width, and height." CreationDate="2011-02-07T00:15:49.430" UserId="2905" />
  <row Id="14615" PostId="9795" Text="That's the base idea. But did you already have a look at the specs? 1 GHz i686 arch cpu, 512/1024 MB RAM, same for storage. Audio in/output, serial &amp; parallel ports, us, vga. Low power consumption... Tell me if I'm wrong, but that's far enough for a carpc or an embedded system. Why spend more money?" CreationDate="2011-02-07T00:29:14.397" UserId="2900" />
  <row Id="14616" PostId="9636" Text="Ugh! I hate companies who don't publish datasheets. They can be sure I won't design in their part. Thanks for this, I'm leaning towards the TI or the Maxim part, more towards TI at the moment." CreationDate="2011-02-07T01:27:26.797" UserId="1225" />
  <row Id="14617" PostId="9793" Text="Hehe, I wrote an article about MT15 too :-D http://3.14.by/en/read/homemade-cpus  " CreationDate="2011-02-07T01:55:09.960" UserId="2062" />
  <row Id="14618" PostId="9793" Text="I see, this transistor clock is using 2T flipflops, similar to ones I am already investigating... I was wondering is there any fancy 1T circuits...." CreationDate="2011-02-07T02:01:42.697" UserId="2062" />
  <row Id="14619" PostId="3336" Text="Wow, that sucks" CreationDate="2011-02-07T02:42:25.920" UserId="1650" />
  <row Id="14620" PostId="9811" Text="http://www.sparkfun.com/products/9738 &quot;Luxeon rebel RGB&quot; plus a driver board is another option." CreationDate="2011-02-07T02:48:27.580" UserId="1363" />
  <row Id="14621" PostId="9768" Text="I agree with your initial assessment, but I wonder if you could feed a tachometer input to remove noises at the harmonics of the engine RPM... interesting..." CreationDate="2011-02-07T03:02:20.413" UserId="638" />
  <row Id="14622" PostId="9808" Score="1" Text="would a solenoid work better instead of a motor or a servo? i think you could get better timing out of them " CreationDate="2011-02-07T03:34:04.900" UserId="2060" />
  <row Id="14623" PostId="9808" Text="Jsolarski - I don't know, but I'm willing to try either." CreationDate="2011-02-07T05:38:32.400" UserId="2905" />
  <row Id="14624" PostId="9816" Text="Wouldn't stranded be a bit better?" CreationDate="2011-02-07T06:31:26.087" UserId="2118" />
  <row Id="14625" PostId="9792" Text="The photos are up, @Eric." CreationDate="2011-02-07T06:37:58.533" UserId="2118" />
  <row Id="14626" PostId="9817" Score="2" Text="This is off topic in E&amp;R. Try the [math SE](http://math.stackexchange.com/), or [your textbook](http://en.wikipedia.org/wiki/Canonical_form_(Boolean_algebra))." CreationDate="2011-02-07T06:57:33.713" UserId="2118" />
  <row Id="14627" PostId="9779" Text="@markrages: Yes, I know, but when you workout the eqns, it doesn't seem like for low voltages, divide by 2 works, due to the 0.9V bias that's connected to R2. So the eqn is: (Vin/Rdivider1) = ((Vin/2)/Rdivider2) + (Vin/2-0.9)/8.3k. The Rdivider values are dependent on the input voltage, due to the bias. Or am I missing something entirely? --regards" CreationDate="2011-02-07T07:12:13.920" UserId="2893" />
  <row Id="14628" PostId="9817" Score="6" Text="Actually this is very much on topic to digital logic.  It's equivalent to saying how do I change a circuit that consists of a bunch of and gates feeding an or gate to one consisting of a bunch of or gates feeding an and gate. " CreationDate="2011-02-07T07:44:58.763" UserId="2246" />
  <row Id="14629" PostId="9815" Score="1" Text="Actually, EMC often was used with the parallel port hooked directly to chopper stepper amplifiers, with no &quot;control module&quot;.  It's not actually trivial to get things to work right with a micro controller and USB or whatever latency in there, unless you offload the task at a higher level and have the embedded system do all the realtime work." CreationDate="2011-02-07T07:57:46.663" UserId="2246" />
  <row Id="14630" PostId="9784" Text="Some of the things to think about are providing the reels of parts to the assembler or loading them on the machine, visual que-carding the reference designators if doing it by hand, number of same value parts, if they can work on a whole panel at once, do all the 10k resistors on all of them, then the next part, etc." CreationDate="2011-02-07T08:02:21.573" UserId="2246" />
  <row Id="14631" PostId="752" Text="Actually IDE *is* pretty trivial to communicate over.  It's only slightly more complicated than talking to your typical parallel interface microprocessor peripheral chip.  Sure there are all sorts of options and speedups and legacy modes, but you don't have to get into those." CreationDate="2011-02-07T08:05:50.697" UserId="2246" />
  <row Id="14632" PostId="8392" Text="The complaint that this answer is incorrect is itself ultimately incorrect. **Sampling is itself a type of mixing** and undersampling is thus a form of downmixing, one is simply multiplying by an impulse train rather than a sinusoidal local oscillator." CreationDate="2011-02-07T08:22:07.093" UserId="2246" />
  <row Id="14633" PostId="9815" Score="1" Text="@Chris Stratton, I think the chopper stepper amplifier is considered the control unit, and yes you can just use a parallel interface to hook up a few L297/8 to it to get some steppers up and running. source here http://pminmo.com/PMinMOwiki/index.php5?title=L297-8" CreationDate="2011-02-07T08:57:10.103" UserId="2060" />
  <row Id="14634" PostId="9815" Text="Great advice from you both, thanks. I've looked at those two sites before, but I'll revisit them now I'm getting a better feel for what's required. I'll keep an eye on this thread, too, for any more input." CreationDate="2011-02-07T09:16:42.597" UserId="2894" />
  <row Id="14635" PostId="9817" Text="What's SOP and POS?" CreationDate="2011-02-07T09:25:01.887" UserId="1240" />
  <row Id="14636" PostId="9817" Score="2" Text="SOP = sum of products. POS = product of sums, e.g. (x + y)(~x + ~y). Logical &quot;OR&quot; is a sum, while &quot;AND&quot; is a product. " CreationDate="2011-02-07T11:03:32.843" UserId="721" />
  <row Id="14637" PostId="9820" Text="In future, please use full names for links, including http://, ftp:// etc. for links which have them." CreationDate="2011-02-07T11:06:09.020" UserId="1240" />
  <row Id="14638" PostId="9820" Text="I tried to do that, but it would only let me enter two links as I'm still a newbie here. " CreationDate="2011-02-07T11:23:05.510" UserId="2914" />
  <row Id="14639" PostId="9820" Text="Thanks for inserting the image btw, I wasn't permitted to do that either :-)" CreationDate="2011-02-07T11:24:36.223" UserId="2914" />
  <row Id="14640" PostId="9820" Text="I might end up going with a 1/4&quot; version as they are more readily available: http://www.futurlec.com/Audio-65mm.shtml (Part Code P065STSCK02). Any leads on 3.5mm versions would be great though." CreationDate="2011-02-07T12:15:41.773" UserId="2914" />
  <row Id="14641" PostId="9769" Text="@W5V0: A good point indeed. Will look into it. Thanks" CreationDate="2011-02-07T12:16:50.303" UserId="2893" />
  <row Id="14642" PostId="9770" Text="Yes, maybe for the next spin of the pcb." CreationDate="2011-02-07T12:17:15.983" UserId="2893" />
  <row Id="14643" PostId="9794" Text="@bt2: Thanks for the response. The signal is quite fast, which is why we selected a ~400ksps ADC. Unfortunately, mid-project, the input requirements changed." CreationDate="2011-02-07T12:19:39.897" UserId="2893" />
  <row Id="14644" PostId="9817" Text="This is certainly taught in undergrad digital logic courses, but tyblu is right that this belongs in math SE. @TheLameProgrammer, Look up Karnaugh maps (K maps) and DeMorgan's theorem.&#xA;" CreationDate="2011-02-07T12:50:24.983" UserId="721" />
  <row Id="14645" PostId="9650" Text="[0 0 0 0 0 0 0 0 0 0 1] represents the additional latencies of the 11PE if (and only if) you ask for 11 PEs.  You have to specify both parts correctly." CreationDate="2011-02-07T13:14:45.260" UserId="763" />
  <row Id="14646" PostId="9810" Text="I'm using an Amulet Technologies controller." CreationDate="2011-02-07T14:22:03.843" UserId="2288" />
  <row Id="14647" PostId="9488" Text="Thanks, I tried 57600 and it did not make a difference.  If I run realterm on the machine I can see characters go down to the Uno.  If I jumper the connection from pin 1 to pin 0 I don't see the echo from the Uno. " CreationDate="2011-02-07T14:32:08.967" UserId="2775" />
  <row Id="14648" PostId="9444" Text="I'm not able to get the XP version to work on W2K.  I go into safemode, move the XP usbser.sys into the /dllcache directory and into the /driver directory.  When I reboot the windows critical file manager has put the W2K version back.  I've googled how to do it, but there is no real guide.  " CreationDate="2011-02-07T14:34:54.050" UserId="2775" />
  <row Id="14649" PostId="9825" Score="1" Text="This is what I use as well.  Easy to parse into or out of, a lot easier to hand-edit than XML, and easy to import/export from Excel or other spreadsheet software.  " CreationDate="2011-02-07T14:51:20.200" UserId="857" />
  <row Id="14650" PostId="8732" Score="2" Text="I tried to edit a typo, but couldn't because of the length restriction.  Anyhow, the product is **8846A**, not 8864A." CreationDate="2011-02-07T14:53:19.590" UserId="2288" />
  <row Id="14651" PostId="9820" Text="I can't imagine why you'd need double-throw switches. That will give you a connection to the un-sprung contact inside the jack when nothing's inserted, which is equivalent to the single-throw switch.  Or am I missing something? Type D should, by my logic, be equivalent to Type C.  The subtlety of the difference, if there is one, is probably why the DPDT are so hard to get.  They could be just a misprint." CreationDate="2011-02-07T14:57:03.817" UserId="857" />
  <row Id="14652" PostId="9792" Text="@tyblu, @Nick T, @Eric - I uploaded them to the SE imgur account." CreationDate="2011-02-07T15:06:37.380" UserId="857" />
  <row Id="14653" PostId="9638" Text="Generally you evaluate if something could be a good buy by figuring out if it will solve your problem.  Then you see if there seems to be any evidence of cheaper solutions, and guess if you are likely to find something enough cheaper (at applicable quantity) to justify the time spent continuing to look.  You might also do some research on the manufacturer and see if their products are viewed as reliable, reasonable to work with, etc." CreationDate="2011-02-07T15:07:13.590" UserId="2246" />
  <row Id="14654" PostId="9615" Text="An advantage of this route is that you can set it up to output the temperature over a serial port and during development connect a PC to take data which you can plot to evaluate its performance." CreationDate="2011-02-07T15:10:37.330" UserId="2246" />
  <row Id="14655" PostId="9827" Score="1" Text="I was going to link in Atmel's microcontroller tables, but they seem to have reorganized their website to do away with those.  Can anyone find them?" CreationDate="2011-02-07T15:16:08.637" UserId="857" />
  <row Id="14657" PostId="7051" Text="*Some* design software used to design and verify ICs is free. MAGIC, SPICE, IRsim, etc. See http://david.carybros.com/html/vlsi.html#design" CreationDate="2011-02-07T15:19:18.333" UserId="813" />
  <row Id="14658" PostId="9799" Text="You want the pull-ups to be weak if you're not disabling them.  The problem is that you're trying to bring the SCK and MOSI lines higher than their (0V) VCC, so there's a current path from VCC, through the internal pullups, and out through the diodes internal to the SD card." CreationDate="2011-02-07T15:26:10.263" UserId="857" />
  <row Id="14659" PostId="9826" Text="Supply could be an issue, but at least the designs for *duino are open source." CreationDate="2011-02-07T15:45:16.753" UserId="2288" />
  <row Id="14660" PostId="9779" Text="Eek, I didn't notice the 0.9V bias." CreationDate="2011-02-07T16:32:30.673" UserId="411" />
  <row Id="14661" PostId="9779" Text="So with a 0V input, and the 192/200 Ω divider, the voltage at Vdiv will be 108 uV.  This about 10% of one bit. (5.0 / (1&lt;&lt;12) = 1220 uV).  I wouldn't worry about it too much." CreationDate="2011-02-07T16:36:52.073" UserId="411" />
  <row Id="14662" PostId="9817" Text="@eryksun Thanks a lot! I couldn't figure out abbreviations. " CreationDate="2011-02-07T16:37:44.973" UserId="1240" />
  <row Id="14663" PostId="9803" Text="Do they really use manual soldering for fine SMD work in China? The errors introduced in manual soldering must make it more efficient to use pick-and-place?" CreationDate="2011-02-07T16:47:57.027" UserId="2770" />
  <row Id="14664" PostId="9751" Text="A robot with a petrol engine? Sounds like a fun project." CreationDate="2011-02-07T17:12:43.977" UserId="813" />
  <row Id="14665" PostId="9817" Score="2" Text="... use DeMorgan's Laws? also, the example provided in the question is not a canonical SOP because all variables should be present in all terms right?" CreationDate="2011-02-07T17:17:45.133" UserId="771" />
  <row Id="14666" PostId="7278" Text="cheap ARM JTAG dongle == OpenOCD" CreationDate="2011-02-07T17:34:39.567" UserId="689" />
  <row Id="14667" PostId="9821" Score="1" Text="The clock frequency doesn't really matter.  Its the rise-time and fall-time of the edges that will determine signal integrity and EMC concerns.  If not using slew rate control and using a transceiver that can operate much faster than 8Mhz, say maybe 50Mhz you can have all the signal integrity and EMC issues that you would have at 50Mhz even though the buses clock rate is much lower.  A common way to deal with this is to use a transceiver with some level of slew rate control or use external components to slow down the rise/fall times." CreationDate="2011-02-07T18:05:49.403" UserId="1438" />
  <row Id="14668" PostId="9831" Text="The arduino (and even arm-powered) designs are simple enough that if you are going to be making a PCB suitable for digital logic to accessorize them, you might as well just include the processor too.  They'd be more tempting if you were not going to be making a PCB at all, or were doing it single sided or in a special analog or RF technology where you didn't want digital parts on that board, and having to do a controller board too would be more expense than buying (and even reworking) them." CreationDate="2011-02-07T18:45:08.277" UserId="2246" />
  <row Id="14669" PostId="9826" Text="@Dave - You missed the point.  Chris (I think) was talking mostly about problems with .NET, not with the hardware.  " CreationDate="2011-02-07T18:55:19.593" UserId="857" />
  <row Id="14670" PostId="9833" Text="I've seen &lt;http://electronics.stackexchange.com/q/6151/1571&gt;, but it is not the same as what I'm asking. These are two different diodes and this parallel configuration is not for current handling capacity" CreationDate="2011-02-07T19:15:10.793" UserId="1571" />
  <row Id="14671" PostId="9808" Text="1 millisecond resolution is going to be hard to achieve with any mechanical or electromechanical device. Even electronic switches will be difficult to control at that rate. Most input / output circuits can have a time delay of up to 10 milliseconds. hardware like solenoids and motors will often have delays measured in 100's of milliseconds. " CreationDate="2011-02-07T19:26:26.453" UserId="1810" />
  <row Id="14673" PostId="9803" Score="1" Text="Manual soldering. We don't have any machinery involved other than our hands and a pincet. Yes it may seem long and slow, but it were very small boards. I just want to make clear that if you're doing manual production, it's a very tedious job and something to seriously doubt if you really want to go through it. If you lose a few days on it, it could have spent making money instead." CreationDate="2011-02-07T19:43:44.387" UserId="1476" />
  <row Id="14674" PostId="9833" Score="1" Text="Please post schematic of what you're trying to do.  Where do you plan for the energy to be dissipated?  Are these zeners?" CreationDate="2011-02-07T19:48:22.917" UserId="411" />
  <row Id="14675" PostId="9836" Text="Production does not have to mean thousands.  There's a lot of engineering in highly specialized equipment that may sell in orders of a few dozen to a few hundred pieces - and obviously it sells for rather high prices or no one would make money doing it.  Such industries are focused on meeting the need rapidly, not on spending months getting every last dollar out of the BOM." CreationDate="2011-02-07T19:57:58.640" UserId="2246" />
  <row Id="14676" PostId="9826" Score="1" Text="@reemrevnivek - hmm... sure sounded like hardware issues to me.  Why would supply issues, firmware loading, and mfg. quality have anything to do with .NET?" CreationDate="2011-02-07T20:00:37.930" UserId="2288" />
  <row Id="14677" PostId="9836" Score="1" Text="@reemrevnivek - I think you and I are working in completely different worlds.  When I refer to a production part, it's anything that gets released to a customer, and it can be in quantities from 1 to 20, not tens of thousands, thousands, or even hundreds.  I could care less if I could reduce a part from $50 to 5 dollars, if that means I'll have to spend an extra 3 months on development.  I also don't mind if someone copies the code." CreationDate="2011-02-07T20:06:01.593" UserId="2288" />
  <row Id="14678" PostId="9837" Text="Yes, this would certainly work and it is my current line of inquiry. The main trouble I'm having is designing the probe such that is has a capacitance swing that is large enough to measure. This is my main source of inspiration: http://mechanical.poly.edu/faculty/vkapila/ME3484/Readings/NV27-Measuring%20Water%20Level.pdf" CreationDate="2011-02-07T20:06:06.750" UserId="1802" />
  <row Id="14679" PostId="9836" Score="1" Text="You've brought up really good points, though, and I value your input.  I think your answer was a little extreme and you are clearly opinionated on this subject, but I can distill the key points from it." CreationDate="2011-02-07T20:08:26.800" UserId="2288" />
  <row Id="14680" PostId="9826" Score="1" Text="You may or may not be able to get a license to load a particular runtime on an alternate sourced board.  The various issues I was suggesting are an assortment not necessarily related to each other." CreationDate="2011-02-07T20:09:13.430" UserId="2246" />
  <row Id="14681" PostId="9779" Text="For Vin=0.5, Vdiv comes out to be 0.262, if I worked out the math right. That's a lot of bits I think. In any case, I think this is as good as it gets with a resistive divider. We really should use an amp. Thanks..." CreationDate="2011-02-07T20:10:01.760" UserId="2893" />
  <row Id="14682" PostId="9830" Text="that is exactly the idea, keeping it either on / off a particular surface. also using wheels, not legs" CreationDate="2011-02-07T20:26:15.850" UserId="2791" />
  <row Id="14683" PostId="9831" Text="Chris-definitely.  Everyone should know that if you're making a PCB yourself there's little point in adding an Arduino board as opposed to just recreating one on your PCB." CreationDate="2011-02-07T20:35:28.467" UserId="249" />
  <row Id="14684" PostId="9836" Text="@Dave - Sorry, I consciously tried to make it not opinionated or extreme.  This is what it looks like after a few re-readings and edits :P.  However, I stand by my statement that the word 'production' means (in every context I've operated in, which is mainly as an automotive OEM supplier) thousands of parts.  Can you imagine opening your hood and seeing an Arduino hacked into your fan controller?  No, and for good reason.  I tried to give a few of those reasons." CreationDate="2011-02-07T20:50:15.490" UserId="857" />
  <row Id="14685" PostId="9836" Text="@reemrevinek - haha! no offense taken.  I was hoping to get a lot of viewpoints with this question.  My environment is totally different.  We sell a few customized products that are quite expensive, so a part like an embedded board is okay if it costs more, and offsets the development time.  I'm using the Netduino right now only for prototyping concepts, but then it occurred to me that we could probably put it into the product, since it's just used with a display controller anyway.  I certainly agree that it is better / more professional to have a custom board, but wanted to hear opinions." CreationDate="2011-02-07T20:53:04.250" UserId="2288" />
  <row Id="14686" PostId="9833" Text="Might this be a job for a MOV?  Hard to advise w/o a schematic to show just where this clamping is to be done." CreationDate="2011-02-07T21:29:26.480" UserId="1609" />
  <row Id="14687" PostId="9833" Score="2" Text="It is hard to make suggestions without more of a few numbers to help understand the problem. &quot;beefy&quot;, &quot;pretty big spikes&quot;, mean very different things to a digital designer used to 5V or less at _fairly_ low amperage ( &lt; 20A), than to a neon sign power supply designer, or an automotive _safe_ design." CreationDate="2011-02-07T21:33:09.057" UserId="2598" />
  <row Id="14688" PostId="9833" Text="Also is this for the input or for feedback protection on the output?" CreationDate="2011-02-07T21:34:16.480" UserId="2598" />
  <row Id="14689" PostId="7051" Text="@davidcary I'm not seeing any mention about Design Rule Checking or Layout vs. Schematic tools. I'm somewhat skeptical that anyone does deep submicron design using those tools." CreationDate="2011-02-07T21:59:41.213" UserId="638" />
  <row Id="14692" PostId="9801" Text="How fast will the signals be varying?  What kinds of noise do you expect?   What is the impedance of the source of the signals?  A simple resistor voltage divider is probably fine for the 0-30V, but good results depend on knowing these things to pick the right resistors." CreationDate="2011-02-07T22:21:17.247" UserId="1609" />
  <row Id="14693" PostId="9840" Text="I thought about that.  Once the GDT breaks down it becomes a short.  Under what conditions will that short become an open circuit again?" CreationDate="2011-02-07T22:40:50.190" UserId="1571" />
  <row Id="14694" PostId="9817" Text="@vicatu Yes, it's in minimal SoP form. Canonical form would be F = xyz' + xy'z + xy'z' + x'yz'." CreationDate="2011-02-07T23:37:09.773" UserId="721" />
  <row Id="14695" PostId="9821" Score="1" Text="@Mark, The rise time drives EMC issues, but not necessarily integrity issues.  The timing budget is so large at 8Mhz that you can have all types of EMC issues without any signal integrity issues because the signals will steady before the clock latches the data.  My guess is he has near 20ns of margin here.  Of course, if the problem is so bad that the clock is getting double latched or something, he may  have issues, but baring a horrible layout, not likely.  At higher frequencies termination and layout become much more important for integrity, but most people don't even think about it for SPI" CreationDate="2011-02-08T00:03:06.890" UserId="2377" />
  <row Id="14696" PostId="9793" Text="Well, looks like this transistor clock PDf was quite detailed :-) It's T-trigger is much better than mine, and I easily modded it for my requirements - it is so great, works over such a wide range of params... THanks alot :-D" CreationDate="2011-02-08T00:14:23.223" UserId="2062" />
  <row Id="14697" PostId="9842" Text="868MHz is right at around 900-915MHz in the US. Just as a side note if you are in a different area. 434MHz in the US requires a backoff time between transmits of at least 10 seconds in the US." CreationDate="2011-02-08T00:43:31.400" UserId="230" />
  <row Id="14698" PostId="9840" Score="1" Text="@JoelB, by memory, you need a power off event and a cooldown for it to turn off." CreationDate="2011-02-08T00:45:05.720" UserId="230" />
  <row Id="14699" PostId="9833" Text="To summarize @mctylr: **numbers/context please.**" CreationDate="2011-02-08T00:54:51.017" UserId="1407" />
  <row Id="14700" PostId="9840" Text="When the surge is over. However, I wonder if the GDT will even reach ignition voltage when the TVS diode is already conducting?" CreationDate="2011-02-08T01:00:10.773" UserId="1950" />
  <row Id="14701" PostId="9766" Score="2" Text="Maybe you should mention where you &quot;came across&quot; that term." CreationDate="2011-02-08T01:11:28.603" UserId="1950" />
  <row Id="14702" PostId="9842" Text="@Kortuk If you want to get technical it is actually 902-928 MHz and 433.05–434.79 MHz" CreationDate="2011-02-08T01:54:07.330" UserId="319" />
  <row Id="14703" PostId="9779" Text="Yes, use an amp." CreationDate="2011-02-08T02:27:51.270" UserId="411" />
  <row Id="14704" PostId="9843" Score="1" Text="+1 for typing up a K-map." CreationDate="2011-02-08T02:55:15.920" UserId="721" />
  <row Id="14706" PostId="9843" Text="But it should be F = (x + y)(y' + z')." CreationDate="2011-02-08T03:20:54.570" UserId="721" />
  <row Id="14707" PostId="9836" Text="@reemrevnivek I could easily imagine seeing an arduino in an enclosure under the hood of a race car.  " CreationDate="2011-02-08T05:13:58.400" UserId="2246" />
  <row Id="14708" PostId="9381" Text="Somewhat a nitpick, but the skin effect does not mean that thick wires are useless at high frequencies, rather it means that the interior of the wire is not useful.  There's still more conductor in the skin deep circumferential ring of a large wire than that of a small one.  Tubing is sometimes used in high power transmitters." CreationDate="2011-02-08T05:19:36.743" UserId="2246" />
  <row Id="14709" PostId="8267" Text="And don't forget 'earth'" CreationDate="2011-02-08T05:25:29.967" UserId="2246" />
  <row Id="14710" PostId="9766" Text="@AndreKR That was informal conversation with engineer from other company. He work on this type of circuits (design them). From conversation I got impression that it is standard industry name for such device but I did not get a chance to ask for details as we had to do other things." CreationDate="2011-02-08T05:50:27.740" UserId="1471" />
  <row Id="14711" PostId="9816" Text="If it's Litz wire (which has each strand insulated), yes.  But for regular stranded wire it's worse for a given (overall) wire diameter because the stranded wire still has some gaps between the wires, meaning you have less overall copper.  The strands all short to each other, so its effectively a big wire with some holes in it as far as skin effect is concerned." CreationDate="2011-02-08T07:33:14.460" UserId="2909" />
  <row Id="14712" PostId="9850" Score="1" Text="What is an IO shield?" CreationDate="2011-02-08T08:27:05.630" UserId="305" />
  <row Id="14713" PostId="9850" Score="1" Text="Computers have IO shields (like, from an arduino?)? ...... What?" CreationDate="2011-02-08T08:27:13.180" UserId="1374" />
  <row Id="14714" PostId="9849" Text="This is for a real product, so rolling my own LDO isn't feasible." CreationDate="2011-02-08T08:28:43.990" UserId="411" />
  <row Id="14716" PostId="9850" Text="I can't believe that so many respected people here didn't know what IO shield is.... :(" CreationDate="2011-02-08T09:50:09.563" UserId="1240" />
  <row Id="14717" PostId="9850" Score="2" Text="I would call it a RFI/EMI cover plate, not an &quot;IO Shield&quot;. &quot;IO Shield&quot; is dangerously unspecific, particularly considering the proliferation of the use of the term &quot;Shield&quot; for boards that plug on to arduinos." CreationDate="2011-02-08T11:50:39.793" UserId="1374" />
  <row Id="14718" PostId="9850" Text="If he'd said I/O connector screening hardware I'd have known immediately what he meant." CreationDate="2011-02-08T12:15:44.433" UserId="305" />
  <row Id="14719" PostId="9850" Score="2" Text="@Fake Name The IO shield is already established name which you will find in motherboard manuals and other computer literature. It's been in use for much longer than Arduino and similar devices. [Here](http://en.wikipedia.org/wiki/ATX#Connectors)'s an article about it." CreationDate="2011-02-08T12:17:30.463" UserId="1240" />
  <row Id="14720" PostId="9850" Score="2" Text="I agree, the term is somewhat strange. Many terms in the field of computing hardware are strange and misleading. But it still seems to be popular and used by many, so I guess arguing makes little sense. (I also don't get &quot;form factor&quot;, for example. Board outline would be so much better, imho. I have never multiplied an ATX with anything, so I really don't know what a factor does in this context.)" CreationDate="2011-02-08T12:24:06.007" UserId="930" />
  <row Id="14721" PostId="9664" Text="obviously FPUs exist, but designing one that can do the kind of operations that the OP wants, is not trivial." CreationDate="2011-02-08T12:38:34.673" UserId="1938" />
  <row Id="14722" PostId="9853" Score="1" Text="you may want to re-phrase your question, it looks like a shopping question as it is right now, maybe ask for recommendation for a good embedded camera module." CreationDate="2011-02-08T13:13:00.837" UserId="2060" />
  <row Id="14723" PostId="9850" Score="1" Text="@FakeName, I get annoyed when I am interacting with someone and I tell them we need to get a shield for something and they think of arduino parts. Shields was used long before, and will be used long after, to refer to components that protect against unwanted effects. I understand that naming convention, and I do not mean to start a holy war, but an RF shield is very important." CreationDate="2011-02-08T14:28:15.663" UserId="230" />
  <row Id="14724" PostId="9766" Text="Maybe he just didn't finish his work on a bandgap circuit, so it was only half. ;)" CreationDate="2011-02-08T14:39:17.587" UserId="1950" />
  <row Id="14726" PostId="9840" Text="@Kortuk - That's what I remembered too, but I can't find it in writing anywhere, can you?" CreationDate="2011-02-08T15:20:19.477" UserId="1571" />
  <row Id="14728" PostId="9766" Text="I got info what it is - it is synonym of sub-bandgap voltage reference. This is easily &quot;googlable&quot; term and several circuit solutions are posted on the net." CreationDate="2011-02-08T15:40:02.297" UserId="1471" />
  <row Id="14729" PostId="9858" Score="1" Text="Here's a cheap spectrum analyser for sub-1ghz http://ossmann.blogspot.com/2010/03/16-pocket-spectrum-analyzer.html" CreationDate="2011-02-08T15:45:28.497" UserId="566" />
  <row Id="14730" PostId="9839" Text="Thanks, that was good hint, but it turned out this was synonym for sub-bandgap voltage reference." CreationDate="2011-02-08T15:59:12.703" UserId="1471" />
  <row Id="14731" PostId="9859" Text="you guidelines are right but i am happy, its just another task, but please provide some links to circuit diagrams, site with walk throughs" CreationDate="2011-02-08T16:01:09.020" UserId="2830" />
  <row Id="14732" PostId="9858" Text="k, thnks will check it out" CreationDate="2011-02-08T16:02:23.400" UserId="2830" />
  <row Id="14733" PostId="9856" Text="please refer this link also:  http://electronics.stackexchange.com/questions/9861/cannot-i-use-a-radio-receiver-type-deivce-built-in-cassete-players-to-scan-for-r" CreationDate="2011-02-08T16:38:55.290" UserId="2830" />
  <row Id="14734" PostId="9858" Text="please rfer this link also:  thns" CreationDate="2011-02-08T16:39:15.743" UserId="2830" />
  <row Id="14735" PostId="9863" Text="I don't get your problem; you pair one device, then pair the other.  Bluetooth supports up to 7 devices (e.g. headset, whatever your thing is) being paired with a host (cellphone)." CreationDate="2011-02-08T16:41:01.210" UserId="1407" />
  <row Id="14736" PostId="9859" Score="1" Text="I've updated my answer to include a couple of examples of the sort of circuit I would attempt to build as a hobbyist." CreationDate="2011-02-08T17:05:36.230" UserId="2191" />
  <row Id="14737" PostId="9853" Score="1" Text="@jsolarski - Changed, hope this is better." CreationDate="2011-02-08T17:06:29.520" UserId="2861" />
  <row Id="14738" PostId="9859" Score="2" Text="+1 for the commercial bug detector and security consultant." CreationDate="2011-02-08T17:09:06.203" UserId="857" />
  <row Id="14739" PostId="9863" Text="How is this much different than http://electronics.stackexchange.com/questions/8454/bluetooth-capabilities-by-cell-phone and  http://electronics.stackexchange.com/questions/8447/can-a-phone-be-paired-with-2-bluetooth-devices-at-the-same-time and http://electronics.stackexchange.com/questions/9050/2-bluetooth-connections-concurrently" CreationDate="2011-02-08T17:24:04.483" UserId="319" />
  <row Id="14740" PostId="9853" Text="to give you an idea of whats out there check out sparkfun's selection http://www.sparkfun.com/search/results?term=camera&amp;what=products (sorry no experience with these)" CreationDate="2011-02-08T17:33:28.210" UserId="2060" />
  <row Id="14741" PostId="9856" Score="6" Text="I think it may be time to start looking for a new boss." CreationDate="2011-02-08T17:37:03.200" UserId="2096" />
  <row Id="14742" PostId="9863" Text="Those questions deal with &quot;pairing&quot; at the same time, while mine deals with &quot;simultaneously connecting&quot; with each at the same time.  But they were good reading material for me" CreationDate="2011-02-08T17:54:53.247" UserId="2931" />
  <row Id="14743" PostId="9867" Text="A bit of an aside, but yes indeed, there is provision in the FCC regulations for legal low-power FM operation in certain parts of the band." CreationDate="2011-02-08T18:11:46.610" UserId="1678" />
  <row Id="14744" PostId="9852" Text="As per keeping electro-magnetic radiation inside.  What are the consequences if this is leaked?  Could it interfere Wi-Fi or something..or with other electronics :S" CreationDate="2011-02-08T18:14:34.330" UserId="2924" />
  <row Id="14745" PostId="9849" Text="O.K., then I suggest using an LDO with an enable pin. There are plenty... Hmmm. Should I feel bad because I've rolled my own LDO for a real product? Maybe not -- as long as I don't get field returns which have a root cause that can be attributed to this part of the board." CreationDate="2011-02-08T18:25:49.180" UserId="930" />
  <row Id="14746" PostId="9864" Text="I might be wrong, but if you only have 2 8-bit ports, then you can only control 64 individual LEDs... (unless you control them in groups of 4)" CreationDate="2011-02-08T18:26:10.723" UserId="2426" />
  <row Id="14747" PostId="9871" Text="The fact that this might actually happen scares me." CreationDate="2011-02-08T18:40:39.853" UserId="857" />
  <row Id="14748" PostId="9868" Text="Another key word is &quot;undesired operation&quot;.  The speakers are not designed to accept the interference they're receiving without undesired operation." CreationDate="2011-02-08T18:42:38.510" UserId="857" />
  <row Id="14749" PostId="9853" Score="1" Text="What resolution and framerate do you want?  What is your price range?  What interface do you require? How much time, effort, and money are you willing to expend designing this device?  There's so many variables." CreationDate="2011-02-08T18:45:50.020" UserId="857" />
  <row Id="14750" PostId="8453" Score="1" Text="@Ashley - Care to re-upload the files to the E&amp;R imgur account?" CreationDate="2011-02-08T18:48:44.730" UserId="857" />
  <row Id="14751" PostId="9872" Text="Look for different panels. You'd need at least 15 or so panels for the router to start plus few more for control electronics." CreationDate="2011-02-08T19:00:04.470" UserId="1240" />
  <row Id="14752" PostId="9852" Text="Could be anything, really, but for instance, the pixel clock of a VGA card is exactly where FM radio is. Interference with Wi-Fi is likely as well. You never know. As an indicator: PC hardware is very (!) cost-sensitive. Manufacturers don't spend an exta 0.3 Ct. on something that would not be absolutely required to pass certification measurements." CreationDate="2011-02-08T19:01:26.530" UserId="930" />
  <row Id="14753" PostId="9852" Text="ok cool, thanks :)" CreationDate="2011-02-08T19:06:47.607" UserId="2924" />
  <row Id="14754" PostId="9874" Text="Well, my supply can give up to 0.2 V of AC voltage. I don't know how big problem would that be. You mentioned 10 µF on the right. The right of what? Should I put 10 µF and after it 4.7 µF? This is my first µC circuit, so I don't really know what to expect. Also, in one document the used 47 nH coil. Would that be a problem? It's written in the datasheet that the coil can be of any inductance as long as it makes an insignificant voltage drop." CreationDate="2011-02-08T19:31:15.770" UserId="1240" />
  <row Id="14755" PostId="9874" Text="Supply -&gt; L -&gt; 10µF -&gt; 100nF -&gt; Controller. For the inductor I'd prefer a ferrite which actually has insignificant resistance." CreationDate="2011-02-08T19:35:17.130" UserId="1950" />
  <row Id="14756" PostId="9836" Text="@Chris I am thinking about putting one in mine, but only for displaying sensor data, not something like engine management.  :)" CreationDate="2011-02-08T19:35:19.673" UserId="2288" />
  <row Id="14757" PostId="9856" Score="1" Text="Turn off fluorescent bulbs (&amp; ballasts). Check for sound. ???. Profit." CreationDate="2011-02-08T19:37:04.040" UserId="2118" />
  <row Id="14758" PostId="9877" Score="1" Text="What's the duty cycle of your application?  If you're just pulsing the trigger for 100ms every 5 minutes, you don't need to worry much about wire heating, which will be an issue with higher (or continuous) duty cycles." CreationDate="2011-02-08T19:48:13.650" UserId="857" />
  <row Id="14760" PostId="9877" Text="There's a possibility for continuous operation for probably no more than 3 seconds at a time. The user could potentially hold the trigger down indefinitely. (they _should_ know better) I added this information to paragraph 2 in the OP." CreationDate="2011-02-08T20:15:53.890" UserId="2932" />
  <row Id="14762" PostId="1180" Score="1" Text="&quot;Logic design&quot; was in use long before programmable logic was developed. It was commonly used to describe the process of developing digital circuits based on TTL and other logic families." CreationDate="2011-02-08T20:57:38.010" UserId="305" />
  <row Id="14763" PostId="9881" Text="@Jim - He specified an 18&quot; run.  That might be doubled (out and back) to the battery, but it probably wasn't going to be 6'." CreationDate="2011-02-08T20:59:12.277" UserId="857" />
  <row Id="14764" PostId="9855" Text="Which package fries? Does it have pull-ups/downs?" CreationDate="2011-02-08T21:11:54.360" UserId="2118" />
  <row Id="14765" PostId="9869" Text="I am not sure what you are trying to get at here. The GSM bands are mostly below 1GHz and 2.4GHz has nothing to do with his question. The interference he is having is in the audible range which you surely know is also sub 1GHz." CreationDate="2011-02-08T21:12:23.303" UserId="319" />
  <row Id="14766" PostId="9868" Text="I think you addressed the fact that his stereo meets spec, but his question was around why his phone is causing his stereo to do that in the first place." CreationDate="2011-02-08T21:13:41.337" UserId="319" />
  <row Id="14767" PostId="9870" Text="Am I missing something in his question? It seems to me that he is asking about why his cell phone causes that noise in the first place. Having everyone else answer differently is making me wonder if I have miss read the question." CreationDate="2011-02-08T21:15:25.453" UserId="319" />
  <row Id="14769" PostId="9881" Text="I specified 18&quot; from + to - on the battery. That is all-inclusive of the entire circuit. Granted, there's a motor in the middle adding resistance. The trigger switch is a sliding plastic plate with copper on the end which makes contact with another copper plate. I'm not sure if that would add significant resistance or not. (I assume motors add significant resistance)" CreationDate="2011-02-08T21:22:45.683" UserId="2932" />
  <row Id="14770" PostId="6958" Text="@Thomas O This question is now being linked to by other questions. It would really be nice if you could come back to it and let us know what fixed your issue." CreationDate="2011-02-08T21:24:11.217" UserId="319" />
  <row Id="14771" PostId="9881" Text="I read that you can use a smaller wire if it is plated with silver as it has a slightly lower resistance than copper, is that true?" CreationDate="2011-02-08T21:25:21.050" UserId="2932" />
  <row Id="14772" PostId="8613" Score="1" Text="@rarque: Thanks again. The repair work on this monster (http://www.dynacord.com/downloads/pm2600_datenblatt.pdf) with its four massive banks of TO-3 transistors is almost done and it already looks good enough that I can confirm your advice was really valuable and is much appreciated." CreationDate="2011-02-08T21:26:31.110" UserId="930" />
  <row Id="14773" PostId="9881" Text="@sholsinger Make sure your taking appropriate precautions in handling the inductive backlash from that motor.  You don't want your battery pack exploding. " CreationDate="2011-02-08T21:28:06.257" UserId="1438" />
  <row Id="14774" PostId="9881" Text="@Mark Is it sufficient to place a resistor in the circuit between the battery &amp; motor to prevent the backlash? If so, how do I calculate the R value? Also, @Jim C your answer doesn't mention whether I should use solid or stranded wire. Is there little difference in this application?" CreationDate="2011-02-08T21:33:24.147" UserId="2932" />
  <row Id="14775" PostId="9881" Score="1" Text="Why does current matter with respect to safety? Isn't it just voltage (electrical risk, not thermal)?" CreationDate="2011-02-08T21:40:00.787" UserId="2118" />
  <row Id="14777" PostId="9843" Text="Whoops you're right. It's been a while since I've done k-maps so I read it wrong. I've fixed the answer." CreationDate="2011-02-08T22:30:10.990" UserId="2922" />
  <row Id="14778" PostId="9884" Score="1" Text="An *&quot;IC&quot;* is an *[&quot;Integrated Circuit&quot;](http://en.wikipedia.org/wiki/Integrated_circuit)*. I don't understand what your question is looking for." CreationDate="2011-02-08T22:30:25.143" UserId="2118" />
  <row Id="14779" PostId="6958" Text="@kellenjb, Done." CreationDate="2011-02-08T22:36:05.680" UserId="1225" />
  <row Id="14780" PostId="9864" Text="@BG100, yeah, that's right, I was calculating 8**2 as 256 for some reason..." CreationDate="2011-02-08T23:02:49.153" UserId="1407" />
  <row Id="14781" PostId="9856" Text="haha, I thought this was actually referring to real bugs, not eavesdropping bugs." CreationDate="2011-02-08T23:13:30.907" UserId="2288" />
  <row Id="14782" PostId="9878" Text="I no longer believe this is a duplicate of [Audio coupling capacitors](http://electronics.stackexchange.com/questions/6958/audio-coupling-capacitors), as one is for line-level and the other for low-level &amp; high impedance (electret mic), which are quite different applications." CreationDate="2011-02-08T23:40:07.860" UserId="2118" />
  <row Id="14783" PostId="9873" Text="I say don't fix what ain't broke! Use 1 bigger (1uF-100uF) regulator output electrolytic, then 1 smaller (10nF-100nF) ceramic decoupler near each supply and reference. If there are issues, patch in fixes." CreationDate="2011-02-08T23:47:11.427" UserId="2118" />
  <row Id="14785" PostId="9888" Text="Breadboard or PCB?" CreationDate="2011-02-09T01:07:53.287" UserId="1225" />
  <row Id="14786" PostId="9890" Text=".. short version of what I wrote, and earlier! +1 for getting to the point!" CreationDate="2011-02-09T01:11:46.657" UserId="2118" />
  <row Id="14787" PostId="9761" Text="When you say *&quot;serial&quot;*, do you mean by UART/RS232 or over USB?" CreationDate="2011-02-09T01:26:14.633" UserId="2118" />
  <row Id="14788" PostId="9803" Text="But how much money could it cost you if there is a design fault and you moved into high volume production before it was discovered?   I have had this happen to me before and hand soldered 2k units, not only did it take along time and cost more in additional parts but the product looked like crap and I had to deal with a recall issue. " CreationDate="2011-02-09T03:26:57.160" UserId="2896" />
  <row Id="14789" PostId="9892" Text="I didn't know this - thanks! What is [the book](http://www.amazon.com/Electromagnetic-Compatibility-Engineering-Henry-Ott/dp/0470189304) like?" CreationDate="2011-02-09T03:27:01.660" UserId="2118" />
  <row Id="14790" PostId="9892" Text="I attended a Henry Ott seminar and it blew my mind.  There are a lot of conventional practices out there today that may be ineffective or even make things worse that he covers with down to earth explanations and studies or data to back it up.  If you can't get work to send you to one of his seminars (or even if you can) I'd highly recommend the book.  It's my EMC bible.  It may be my favorite engineering book of all time.  It covers almost everything and is written in a very understandable manner.  It's also packed with great sources for further reading on almost every subject." CreationDate="2011-02-09T03:35:32.470" UserId="2377" />
  <row Id="14791" PostId="7889" Score="1" Text="High / Low refer to the physical voltage levels.  1/0 refer to the logical states.  In positive logic, 1==High.  In negative logic 1==Low.  A complex logic design will probably have some positive and some negative logic.  (You can use the bubbles on logic gates to keep track.)  Maybe not so important, but assuming that 1==High is a pet peeve of mine." CreationDate="2011-02-09T05:28:20.947" UserId="411" />
  <row Id="14792" PostId="9860" Text="just an alternate way to drive the LEDs http://focus.ti.com/docs/prod/folders/print/tlc5921.html instead of the 74xx595" CreationDate="2011-02-09T05:42:31.980" UserId="2060" />
  <row Id="14793" PostId="9894" Text="**+1** *for a very interesting question! I love this type of DSP...*" CreationDate="2011-02-09T06:00:55.490" UserId="2118" />
  <row Id="14794" PostId="9856" Score="1" Text="It's worth noting that there is **NO** way to reliably detect passive (e.g. recording) bugs, short of a exhaustive physical search. All the answers so far deal *exclusively* with detecting bugs which **transmit** the audio they pick-up. Something which simply records to a SD card or similar for later retrieval it pretty much impossible to passively detect, (except when someone comes to retrieve it, anyways)." CreationDate="2011-02-09T07:07:06.310" UserId="1374" />
  <row Id="14795" PostId="9856" Text="Furthermore, if you want to get really cutting edge, a modern FHSS (Frequency-hopping spread spectrum) device is very hard to detect even with a spectrum analyzer, provided the transmit duty cycle is kept low." CreationDate="2011-02-09T07:10:30.770" UserId="1374" />
  <row Id="14796" PostId="9888" Text="@Thomas O Actually, I'll be using a prototyping board which has an individual solder pad for each pin and the pins are later manually connected together. I think that they're called Perfboard in English, but I'm not 100% sure." CreationDate="2011-02-09T07:53:02.130" UserId="1240" />
  <row Id="14797" PostId="9832" Text="very helpfull. Will look into it" CreationDate="2011-02-09T08:46:18.420" UserId="2843" />
  <row Id="14798" PostId="6692" Text="A radio? It's a good project, but I'm not sure it's suited for parent-child bonding. It's not something that captures the imagination of anyone born after 1960, and we want to close the generational gap, not shine a searchlight at it." CreationDate="2011-02-09T09:41:48.673" UserId="1802" />
  <row Id="14799" PostId="9892" Text="@bt2 Can you provide a sketch of the capacitor arrangement?" CreationDate="2011-02-09T11:56:29.743" UserId="1240" />
  <row Id="14800" PostId="9897" Text="@markrages I really like this answer. I hope I'll be able correctly solder the capacitor." CreationDate="2011-02-09T11:57:05.093" UserId="1240" />
  <row Id="14801" PostId="9877" Text="&lt;deleted - put comment in wrong thread&gt;" CreationDate="2011-02-09T12:39:16.957" UserId="1681" />
  <row Id="14802" PostId="9881" Score="2" Text="Silver plating won't help noticeably at DC as it's too thin - it's only useful at RF where more of the current flows near the surface." CreationDate="2011-02-09T12:40:25.427" UserId="1681" />
  <row Id="14803" PostId="7923" Text="alcohol will also help get some of the water out places it likes to stick. basically, the alcohol just displaces the water, and the little bits of alcohol left in the nooks and crannies will evaporate much more quickly than water would." CreationDate="2011-02-09T12:47:22.880" UserId="740" />
  <row Id="14804" PostId="9894" Text="@Imelza - Do you need help with the hardware or the math?" CreationDate="2011-02-09T14:27:09.377" UserId="857" />
  <row Id="14805" PostId="9897" Score="2" Text="Check digikey... I think some sockets actually come with that cap installed..." CreationDate="2011-02-09T14:28:06.297" UserId="1363" />
  <row Id="14806" PostId="9891" Text="@tyblu - He said in a comment that he was using perfboard." CreationDate="2011-02-09T14:33:42.943" UserId="857" />
  <row Id="14807" PostId="7926" Score="1" Text="@BarsMonster I just got a great deal on these keyboards at Amazon.  And now it's even lower than before!  $90 for 5 of them.  I'm thinking about getting another box because I've yet to find a keyboard as good as this one.  http://amzn.to/fbF5r3" CreationDate="2011-02-09T14:50:43.727" UserId="2288" />
  <row Id="14808" PostId="9903" Text="Is there anywhere that you know of that I can get it in lower quantities than 100ft spools?" CreationDate="2011-02-09T14:54:16.017" UserId="2932" />
  <row Id="14809" PostId="9870" Text="That was the question I answered - the problem with the noise he is picking up is caused by the poor design of consumer equipment, and is nothing to do with the phone." CreationDate="2011-02-09T15:21:16.900" UserId="305" />
  <row Id="14810" PostId="9901" Text="This module, also from SparkFun, supports Mifare and is able to read and write: http://www.sparkfun.com/products/10126" CreationDate="2011-02-09T15:45:01.707" UserId="2489" />
  <row Id="14811" PostId="6554" Text="All very helpful comments. However, We've got a 2 layer board (most of one layer is gnd) with Ethernet, PoE and RFID showering the board, and it sailed through EMC and is very reliable." CreationDate="2011-02-09T16:49:42.943" UserId="2770" />
  <row Id="14812" PostId="7926" Text="Good for you :-)" CreationDate="2011-02-09T17:07:28.333" UserId="2062" />
  <row Id="14813" PostId="9897" Text="Yes, they come with capacitor installed.  They are also crazy expensive, over $10.   Ant I tink a ground plane would have less series inductance than those long capacitor leads." CreationDate="2011-02-09T18:15:45.173" UserId="411" />
  <row Id="14814" PostId="6962" Text="Put bleeder resistors from your inputs and outputs to ground so you have a known bias." CreationDate="2011-02-09T19:26:02.723" UserId="142" />
  <row Id="14815" PostId="9878" Text="They're the same application, just different load impedances.  The accepted answer on that page explains how to figure it out for any impedance." CreationDate="2011-02-09T19:29:09.070" UserId="142" />
  <row Id="14816" PostId="9848" Text="Related: http://electronics.stackexchange.com/questions/4967/circuit-to-protect-against-undervoltage" CreationDate="2011-02-09T19:31:42.580" UserId="142" />
  <row Id="14817" PostId="9782" Text="a &quot;current-sensing resistor&quot; placed inline with the power supply" CreationDate="2011-02-09T19:50:26.247" UserId="142" />
  <row Id="14818" PostId="9771" Text="Remember that we see with three colors, but objects reflect an infinite number of colors.  You might be able to look at the spectra and choose LEDs at wavelengths that only occur with certain materials, and then figure out the material by comparing the relative reflectance of the light from each LED.  Turn the LEDs on and off in a pattern to reject fluctuations in light level from other sources?" CreationDate="2011-02-09T20:01:15.723" UserId="142" />
  <row Id="14819" PostId="9912" Text="Should this question be community wiki? Nothing is actually asked and I don't see how there can be one correct answer. " CreationDate="2011-02-09T20:02:04.163" UserId="1240" />
  <row Id="14820" PostId="9855" Text="It's the MAX232 chip that fries. It a DIP16 package" CreationDate="2011-02-09T20:17:07.467" UserId="1235" />
  <row Id="14821" PostId="9922" Text="What temperature?" CreationDate="2011-02-09T20:20:57.720" UserId="305" />
  <row Id="14822" PostId="9922" Text="about 200C. I want to heat up a thin rectangle of aluminum about 3&quot; x 5&quot; and .25&quot; thick." CreationDate="2011-02-09T20:51:58.763" UserId="1235" />
  <row Id="14824" PostId="9915" Score="1" Text="There is no doubt that discrete MOSFETs are **very** sensitive to ESD. However, an interesting question if *big* MOSFETs are a lot less sensitive. I'd guess yes, but I have no figures to prove it." CreationDate="2011-02-09T21:21:03.207" UserId="1950" />
  <row Id="14826" PostId="9925" Text="Where can you get resistance wire?" CreationDate="2011-02-09T22:14:57.363" UserId="1235" />
  <row Id="14827" PostId="9926" Score="1" Text="I can't seem to find one that can go hotter than 200F, I need 200C" CreationDate="2011-02-09T22:24:35.873" UserId="1235" />
  <row Id="14828" PostId="8747" Text="@endolith - despite having the parts, i've avoided building one for a long time, for just the reasons you cite. however, lately i've been wondering how much harm a *small* one could cause. Which leads me to ask, what were the specs of your machine? Even just approximate values are of interest." CreationDate="2011-02-09T22:58:26.733" UserId="740" />
  <row Id="14830" PostId="9897" Text="Clever! Where did you come across this technique?" CreationDate="2011-02-09T23:09:46.083" UserId="638" />
  <row Id="14831" PostId="9920" Score="1" Text="I still believe it all depends on the cost of your product.  Let's say that it's possible to create something really compelling with the *duino, and it's a small part of a 1M USD project, and you're only ever going to sell 3 of them.  Why wouldn't that be economically viable?  Would you prefer to spend thousands on development for something that's going to be used twice?" CreationDate="2011-02-09T23:11:40.840" UserId="2288" />
  <row Id="14832" PostId="9920" Score="1" Text="Regarding the .NET comment, I frequently run into people that don't like to use Visual Studio and / or .NET just because.  I personally don't get it.  Visual Studio is by far one of the best IDEs I have ever used.  I am admittedly biased towards Microsoft tools because they let me get my work done quickly, and 99% of the time, they just work.  Although I should really learn to use development boards with an ICE, I definitely appreciate the ease of using a familiar environment that lets me set breakpoints during debugging.  AFAIK you can't do that with Arduino." CreationDate="2011-02-09T23:15:14.763" UserId="2288" />
  <row Id="14834" PostId="9925" Text="Look for something like Nichrome 60" CreationDate="2011-02-10T00:42:07.040" UserId="2288" />
  <row Id="14835" PostId="9926" Score="2" Text="also don't forget that with peltiers, you could end up with a condensation issue on the cold side, which might be an undesirable effect.  I've encountered unpleasant situations like this before." CreationDate="2011-02-10T00:43:10.800" UserId="2288" />
  <row Id="14836" PostId="9922" Score="2" Text="is that temperature for the heating element or the heating target?  And what is the allowable variance for the temperature of the target? I think you'll find that this will have a massive influence on your design as heating up a block the size your talking around to a uniform temperature, even maybe +-10 degC is a more difficult task than getting the heating element to a particular temperature.  Although a heating element of that size is likely going to have to be segmented with independent monitoring of segments to approach uniform heating over that area." CreationDate="2011-02-10T00:44:55.690" UserId="1438" />
  <row Id="14837" PostId="9897" Text="digikey ED2108-ND" CreationDate="2011-02-10T01:06:17.767" UserId="411" />
  <row Id="14838" PostId="5265" Text="there is also octave which free/open source and is (mostly) compatible with matlab code for filter design: http://www.gnu.org/software/octave/" CreationDate="2011-02-10T06:15:03.523" UserId="1438" />
  <row Id="14839" PostId="9854" Text="LT1120 looks interesting, but the voltage range is wrong for a single Li-Ion cell. And the comparator output needs to be inverted to drive the shutdown pin, necessitating at least an external transistor." CreationDate="2011-02-10T07:40:07.787" UserId="411" />
  <row Id="14840" PostId="9854" Text="So far the front-runner is an TC54VC2902 and TC1014-3.3 combo. This is a two part solution, $0.30 + $0.24 in 1k. (LT1120 is $2.55 in 1k.)" CreationDate="2011-02-10T07:48:00.870" UserId="411" />
  <row Id="14841" PostId="9900" Text="What do you refer about IMO? What means IMO?" CreationDate="2011-02-10T07:59:03.770" UserId="2597" />
  <row Id="14842" PostId="9900" Text="I´m using a small form factor board of Software Define Radio to perform my design." CreationDate="2011-02-10T08:00:37.780" UserId="2597" />
  <row Id="14843" PostId="9938" Text="Can anyone create a tag called 'howto'?" CreationDate="2011-02-10T09:03:07.630" UserId="2597" />
  <row Id="14844" PostId="9920" Text="WRT your first comment, I did say relatively small runs. I would see a run of three large budget developments as ongoing prototypes. I imagine the client would, too. In that situation, I would happily use an Arduino." CreationDate="2011-02-10T09:06:30.303" UserId="2894" />
  <row Id="14845" PostId="9920" Score="1" Text="The MS/.net thing is based on personal experience. Over the last twenty or so years I've used almost every platform out there. The biggest headaches have invariably come from MS products. MS seem to assume that their way is the only proper way. Currently I'm using OS X, Ubuntu and Windows 7, all in a development environment. Guess which one I have to reboot (at all)?" CreationDate="2011-02-10T09:11:07.707" UserId="2894" />
  <row Id="14846" PostId="9831" Text="If Arduino environment becomes a limiting factor, you can always use any other AVR compiler like GCC, BASCOM, AvrCo and produce firmware that will live on the same Arduino board..." CreationDate="2011-02-10T09:15:35.910" UserId="1129" />
  <row Id="14847" PostId="9940" Text="yes you can get a WiFi repeater off the shelf or use a directional antenna , but i dont think this is the right place to ask this question" CreationDate="2011-02-10T09:32:06.583" UserId="2060" />
  <row Id="14848" PostId="9940" Text="seemed to be the closest, though i could be wrong.. any more suiting stack exchange site?" CreationDate="2011-02-10T09:34:57.017" UserId="2948" />
  <row Id="14849" PostId="9940" Text="You can try to rephrase your question, for instance: &quot;a easy circuit to perform a wifi extender&quot; or &quot;any board to develop mutiple transmision signal applications like a wifi extender&quot;. I think could be a very interesting question." CreationDate="2011-02-10T09:38:40.800" UserId="2597" />
  <row Id="14850" PostId="9940" Score="1" Text="I believe 'super user' is the one to go." CreationDate="2011-02-10T09:39:18.200" UserId="2062" />
  <row Id="14851" PostId="9940" Text="I think superuser would be a better fit" CreationDate="2011-02-10T09:41:39.367" UserId="2060" />
  <row Id="14852" PostId="9940" Text="@Peterstone I think it would be too " CreationDate="2011-02-10T09:49:07.333" UserId="2060" />
  <row Id="14853" PostId="9940" Text="Ok after learning a couple of terms I wasn't familiar with earlier on, I changed the question to something more specific... It might not have been what you guys were hoping for but honestly I have no idea what is an easy circuit or a multiple transmission signal :I" CreationDate="2011-02-10T09:52:41.933" UserId="2948" />
  <row Id="14854" PostId="9870" Score="1" Text="The cell phone causes this noise in the first place because it is designed to be an RF transmitter with high modulated/pulsed RF power output. It's a fact of life that this will be demodulated by analogue electronics, and if the modulation is in the audio range, it will be noticable on audio equipment." CreationDate="2011-02-10T10:34:27.017" UserId="2110" />
  <row Id="14855" PostId="9940" Text="@Asaf: I mean a circuit less complex as possible." CreationDate="2011-02-10T10:46:00.677" UserId="2597" />
  <row Id="14856" PostId="9941" Score="3" Text="Do you mean bitwise NOT? &quot;Bitwise&quot; encompasses many operations. Which one in particular are you referring to?" CreationDate="2011-02-10T11:01:45.313" UserId="1374" />
  <row Id="14857" PostId="9938" Text="You have some &quot;Dudes&quot;? ..... What? Do you mean &quot;doubts&quot;?" CreationDate="2011-02-10T11:03:20.227" UserId="1374" />
  <row Id="14861" PostId="9920" Text="@Dave - You can do on-chip debugging if you have JTAG support with OpenOCD and GDB.  You're right, the Arduino doesn't support this.  You'll need a processor with JTAG: Most ARM variants work with OpenOCD. The Netduino does have this, but that's because it's leveraging the JTAG support in the ARM processor it's using." CreationDate="2011-02-10T14:24:11.490" UserId="857" />
  <row Id="14862" PostId="9949" Score="2" Text="No, negating a floating point number involves swapping the sign bit. The mantissa is always unsigned.  As Peterstone said, the only thing that needs to be done is change one bit." CreationDate="2011-02-10T14:26:18.323" UserId="857" />
  <row Id="14863" PostId="9938" Text="@Fake Name - Fixed." CreationDate="2011-02-10T14:28:55.323" UserId="857" />
  <row Id="14864" PostId="9946" Text="I definitely agree with you, but at some point you still need a PCB.  I have enough skill to make one for *duino and others to create a simple PCB for breaking out signals and power, so at least that's still pretty cheap." CreationDate="2011-02-10T14:35:58.407" UserId="2288" />
  <row Id="14865" PostId="9920" Text="@reemrevnivek: I definitely need to learn how to use JTAG.  Do you know of any micros that support it with a relatively cheap interface and a gcc/gdb toolchain that's easy to set up?  I know you mentioned ARM, but I don't know if those JTAG tools are inexpensive or not.  Any recommendations are welcome as I like to keep up with the latest options." CreationDate="2011-02-10T14:37:53.740" UserId="2288" />
  <row Id="14866" PostId="9920" Score="2" Text="The ATMegas used on Arduino support debugging via debugwire- not sure if the Arduino reset pin hardware is compatible but if not wouldn't take much to hack as it's only one pin. Another potentially major issue about using other people's boards is if you care about stuff lie EMC, FCC cretification etc. " CreationDate="2011-02-10T15:01:58.243" UserId="1681" />
  <row Id="14867" PostId="9939" Text="Interesting that this question came within hours of http://electronics.stackexchange.com/questions/9941/the-bitwise-of-a-floating-point-binary-representation.  Homework, perhaps?" CreationDate="2011-02-10T15:49:33.710" UserId="206" />
  <row Id="14868" PostId="9920" Text="+1 for cretification. Good word." CreationDate="2011-02-10T16:13:51.037" UserId="2894" />
  <row Id="14869" PostId="9953" Text="You can make the caps bigger or you can make the resistors bigger" CreationDate="2011-02-10T16:53:56.307" UserId="142" />
  <row Id="14870" PostId="9955" Text="How do you attach the female socket with its pins sticking in the air?  Most of these aren't bottom-entry.  The linked one has a 2.1mm stacking height.  I do know that you can get through-board SMD male headers, though." CreationDate="2011-02-10T17:09:09.507" UserId="857" />
  <row Id="14871" PostId="9682" Score="1" Text="What do you mean by &quot;best&quot;?  An audio amplifier is a system for presenting information to a human, and it's been proved scientifically that there's no human-distinguishable difference between lamp cord and any other type of large-diameter cable.  So the only differences would be things like convenience (stranded vs solid), longevity (corrosion resistance), etc." CreationDate="2011-02-10T17:18:07.987" UserId="142" />
  <row Id="14872" PostId="9675" Text="&quot;For the most part it either works or it doesn't work and the quality doesn't change at all&quot;  One exception is when the clock for the DAC is extracted directly from the digital signal.  The digital information may get there with 100% purity in the presence of noise, but the clock does not." CreationDate="2011-02-10T17:20:27.860" UserId="142" />
  <row Id="14873" PostId="9912" Text="The question appears to be, &quot;are there alternatives to the MAX6675 and AD597 for thermocouple reading&quot;. " CreationDate="2011-02-10T17:35:08.190" UserId="1293" />
  <row Id="14874" PostId="9953" Score="1" Text="Not sure where the output of your filter leads, but could you use a digital filter?" CreationDate="2011-02-10T18:21:00.193" UserId="1407" />
  <row Id="14875" PostId="9941" Text="I´m refering to change the ones by zeros, and the zeros by ones." CreationDate="2011-02-10T18:36:24.487" UserId="2597" />
  <row Id="14876" PostId="9938" Text="Sorry, that what I wanted to say &quot;doubts&quot;. Thank you to fixed." CreationDate="2011-02-10T18:40:28.650" UserId="2597" />
  <row Id="14878" PostId="9888" Score="1" Text="Use a better package?  The TQFP/MLF packages have more power inputs, plus with all the space you save you could fit all the decoupling caps you like." CreationDate="2011-02-10T18:47:55.350" UserId="1407" />
  <row Id="14879" PostId="9965" Text="Do you have an amateur radio license? What you propose is illegal, otherwise. 73 from G1HSM." CreationDate="2011-02-10T18:50:13.380" UserId="305" />
  <row Id="14880" PostId="2564" Text="if there is anything ferromagnetic in the club, you could wrap the wire around a magnet and hold it nearby.  This is commercially available as a guitar pickup. http://www.guitarpartssite.com/Allparts-PU-6432-023-p/pu-6432-023-ap.htm" CreationDate="2011-02-10T18:55:20.463" UserId="411" />
  <row Id="14881" PostId="9577" Text="If you ever have an alternator die, you'll find out that the battery isn't capable of supplying everything for very long..." CreationDate="2011-02-10T18:59:42.563" UserId="142" />
  <row Id="14882" PostId="9955" Text="Most i've run into, are actually top or bottom entry, including the one one i linked as an example." CreationDate="2011-02-10T19:23:57.147" UserId="1438" />
  <row Id="14883" PostId="9965" Text="Yes, actually as I was editing my question I must have accidentally removed that info. I'll re-edit the question to include it =)" CreationDate="2011-02-10T19:25:49.890" UserId="1033" />
  <row Id="14884" PostId="7453" Text="@pfyon - I might guess that though rain makes some noise it also drowns out much more ambient noise such as rustling leaves or tall grass by weighing down and suppressing otherwise noisy things.  A sound of a bunch of dry leaves can integrate into one loud ambient noise.  I go hiking on the Appalachian Trail and there is always one spot that we go under power lines and I can hear them even when it's not raining.  Also, when it rains, the air is more saturated with water vapor (making it less of an empty vacuum) and can most likely carry sound further." CreationDate="2011-02-10T19:51:10.157" UserId="1571" />
  <row Id="14885" PostId="9833" Text="@mctylr - This is more of a conceptual question, and as such I don't really want part numbers, just want to know if the theory is correct" CreationDate="2011-02-10T19:53:55.613" UserId="1571" />
  <row Id="14886" PostId="9928" Text="Hmm, now let's work out how we can make an 8K2 wirewound resistor very hot....!!" CreationDate="2011-02-10T20:10:34.010" UserId="1750" />
  <row Id="14888" PostId="9838" Score="1" Text="If the two have the same breakdown rating, they will likely share the current pretty well.  This is because there is some equivalent series resistance: the I/V characteristic is not completely vertical." CreationDate="2011-02-10T20:20:34.273" UserId="411" />
  <row Id="14889" PostId="9970" Text="I didn't know there was a standard!  Good link." CreationDate="2011-02-10T20:21:46.643" UserId="857" />
  <row Id="14890" PostId="9838" Text="@JP314159 - A single component won't do what I want to do as the turn on time for high energy handling parts is slower compared to that of lower energy handling parts.  That is why I'm attempting to split the work between the two and gain both responsiveness and current handling." CreationDate="2011-02-10T20:29:54.747" UserId="1571" />
  <row Id="14891" PostId="9967" Score="4" Text="While I mostly agree that you don't need fancy equipment to do this, I disagree on two points. First, tons of flux doesn't do a job better than a proper amount, it just makes the work area messy and gives you a bigger cleanup job.  Second: I prefer a smaller soldering iron tip (I think the one I use for most of my soldering is a Weller 1.2mm conical tip) and I do use very thin solder. No, you don't need super fancy stuff, but it's helpful to have tools that are about the right size for the job. :-)" CreationDate="2011-02-10T20:32:59.107" UserId="974" />
  <row Id="14892" PostId="9962" Score="1" Text="There are very, very few things that require hot air. This really isn't one of them." CreationDate="2011-02-10T20:33:37.217" UserId="974" />
  <row Id="14893" PostId="9954" Text="Slimstack looks very interesting. One thing that is of concern with it is the durability rating. It has maximum 30 mating cycles durability." CreationDate="2011-02-10T20:52:00.087" UserId="2893" />
  <row Id="14894" PostId="9916" Text="Very true. I've seen many BSS84, BSS123 and the like fail. They are much more sensitive than ICs are because ICs usually have protective diodes at the I/Os and discrete MOSFETs don't. Also, damaged small signal MOSFETs often don't fail in an obvious way but get degraded just a bit (although enough to cause trouble later on). I have no doubt the same is true for big MOSFETs since their structure looks like many small MOSFETs in parallel. However, big MOSFETs have higher parasitic capacitance that acts as a somewhat better protection: More (dis-) charge is required to raise the voltage." CreationDate="2011-02-10T20:53:17.267" UserId="930" />
  <row Id="14895" PostId="9888" Text="@Nick T Good suggestion (it's in Atmel's documentation as well), but I haven't advanced enough to be able to make my own PCB and to solder such packages. " CreationDate="2011-02-10T20:56:37.457" UserId="1240" />
  <row Id="14896" PostId="9944" Text="I disagree with this comment but was not able to down vote" CreationDate="2011-02-10T21:04:12.393" UserId="1827" />
  <row Id="14897" PostId="9949" Text="Doh!  You're quite right - not sure what I was thinking then! All that needs inverting is the sign bit.  But not the whole bit pattern!" CreationDate="2011-02-10T21:30:59.367" UserId="763" />
  <row Id="14898" PostId="9962" Text="I'm used to air-soldering 0603, 0402 and MSOP parts. I find that the solder joints are more reliable with the hot air tool than with an iron. " CreationDate="2011-02-10T21:36:32.973" UserId="1293" />
  <row Id="14899" PostId="9944" Text="@Eddie Hitler To downvote you need a reputation of 125+ http://electronics.stackexchange.com/faq" CreationDate="2011-02-10T23:41:39.113" UserId="566" />
  <row Id="14900" PostId="9395" Text="I've found this wiki page which includes some programs that are specifically used for drawing circuits: http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Electronics/Programs" CreationDate="2011-02-11T00:12:33.423" UserId="2761" />
  <row Id="14901" PostId="9901" Text="+1 and the answer. Thanks very much!" CreationDate="2011-02-11T01:43:37.013" UserId="2940" />
  <row Id="14902" PostId="9907" Text="+1 thanks; I will also check that one out" CreationDate="2011-02-11T01:44:07.073" UserId="2940" />
  <row Id="14903" PostId="9904" Text="+1 thanks. I'll check that out &amp; get back to you" CreationDate="2011-02-11T01:49:27.220" UserId="2940" />
  <row Id="14904" PostId="9902" Text="+1 Wow! some really good links there. Thanks" CreationDate="2011-02-11T01:50:27.657" UserId="2940" />
  <row Id="14905" PostId="9977" Score="1" Text="See Joby Taffey's answer for an explanation why." CreationDate="2011-02-11T01:57:04.193" UserId="1950" />
  <row Id="14906" PostId="9965" Text="When you say &quot;feed it Morse Code audio&quot; are you talking about Modulated CW (e.g. an audio side-tone) or a binary on/off signal? How many external components are acceptable? Would a 7MHz/14MHz/28MHz oscillator outside the chip be acceptable? Is it on all three bands simultaneously, or is each band selectable, or does it just have to be for one band? How tunable do you need it to be? " CreationDate="2011-02-11T02:32:32.400" UserId="638" />
  <row Id="14907" PostId="9947" Text="Unlike two's complement integers, IEEE 754 floating point has a positive and a negative! zero." CreationDate="2011-02-11T02:38:20.340" UserId="1363" />
  <row Id="14908" PostId="9941" Text="The Binary inversion of a number (what you describe) is called the &quot;logical NOT&quot; operation." CreationDate="2011-02-11T03:29:15.017" UserId="1374" />
  <row Id="14909" PostId="9849" Text="I don't want to roll my own LDO because an integrated one costs less than a quarter and (more importantly) 6 mm^2 real estate." CreationDate="2011-02-11T03:58:41.653" UserId="411" />
  <row Id="14910" PostId="8747" Text="I really don't remember, it was more than 10 years ago.  Capacitor was maybe a foot wide, with 10 layers?  Coil was 2 or 3 feet tall, professionally wound with hundreds of turns.  Neon sign transformer that I think put out 5 kV?" CreationDate="2011-02-11T04:15:04.853" UserId="142" />
  <row Id="14911" PostId="9941" Text="i believe the operation in question is also referred to as the &quot;ones complement&quot; :)" CreationDate="2011-02-11T04:34:58.303" UserId="771" />
  <row Id="14912" PostId="9936" Text="thanks. Upto what speed can i get with 1 WiFi 11n transceiver in 5Ghz band?" CreationDate="2011-02-11T05:02:26.133" UserId="2947" />
  <row Id="14913" PostId="9939" Text="More or less, is part the reflexions I have doing a undergraduate thesis project." CreationDate="2011-02-11T06:17:08.897" UserId="2597" />
  <row Id="14914" PostId="9949" Text="Yeah, &quot;not the whole bit pattern&quot; you are right...Sorry I´ve done that and it works more or less, even the reason it´s not clear...I take it as a provisional solution.If anybody could tell me how can acess to just one bit, the sign bit..." CreationDate="2011-02-11T06:21:01.623" UserId="2597" />
  <row Id="14915" PostId="9948" Text="FGPAOptim is free?" CreationDate="2011-02-11T06:25:38.157" UserId="2597" />
  <row Id="14916" PostId="9979" Score="1" Text="This is not really the place to ask this question, try serverfault.com." CreationDate="2011-02-11T06:38:57.163" UserId="2426" />
  <row Id="14917" PostId="9894" Text="Hi I would like to find some alternative way to compute very accurate orientation. The idea is that compass readings are inaccurate in most indoor environments (because of the metal interferences from walls, surfaces etc) I will be moving the compass through a room and I need to have very accurate movement in a fixed direction so that I can measure the inaccuracy of the compass readings and then use the gyro to correct them. But to prove anything, I need to have a measure of that very accurate direction, and I don't know how :(" CreationDate="2011-02-11T06:48:36.453" UserId="2939" />
  <row Id="14918" PostId="9979" Text="Sounds like power issues to me, make sure all of your equipment you are having issues with are plugged into a stable power source(eg UPS), but i do agree this is the wrong place for this question" CreationDate="2011-02-11T06:51:19.803" UserId="2060" />
  <row Id="14919" PostId="9948" Text="Yes, FPGAOptim is free" CreationDate="2011-02-11T08:25:14.603" UserId="763" />
  <row Id="14920" PostId="9922" Text="Just so we're clear, you are going to run this off a relay right?" CreationDate="2011-02-11T09:38:54.773" UserId="1802" />
  <row Id="14921" PostId="9984" Text="While they are not exact duplicates, I do not think there is much to be gained by asking a number of closely related questions at the same time, such as this question and a similar question for the Xilinx system generator. See also the questions about floating point formats/negation." CreationDate="2011-02-11T09:43:35.533" UserId="1802" />
  <row Id="14922" PostId="9987" Text="Well, I am using the xilinx ISE 8.2. Do you know if 'Data2Mem' is compatible with my ISE version?" CreationDate="2011-02-11T09:56:47.953" UserId="2597" />
  <row Id="14923" PostId="9958" Text="Thanks, I'll view the videos." CreationDate="2011-02-11T09:57:48.903" UserId="2395" />
  <row Id="14924" PostId="9977" Text="You only invert the MSB, hence in your example 0x3E20 0000 becomes 0xBE20 0000 which is infact the correct answer" CreationDate="2011-02-11T10:40:21.007" UserId="1827" />
  <row Id="14925" PostId="9961" Text="There is bound to be someone at the hackspace who can show you how to do this. " CreationDate="2011-02-11T10:49:45.773" UserId="1681" />
  <row Id="14926" PostId="9984" Text="@Ranieri: I do that because there is always several ways to do one thing." CreationDate="2011-02-11T10:52:32.117" UserId="2597" />
  <row Id="14927" PostId="9989" Text="I don´t understand why there are so large words between quotes like:&quot;00000000002002F803BA059E03CC03E60654007800700030001C00F800F80020&quot; any port of signa in your example code has so many bits." CreationDate="2011-02-11T10:56:15.373" UserId="2597" />
  <row Id="14930" PostId="9902" Text="You're welcome ;-)" CreationDate="2011-02-11T11:28:00.057" UserId="1129" />
  <row Id="14931" PostId="9946" Text="It is cheap if you don't need thousands, and if you need more power then modules like the one from above link is nice, too. Beware that you will probably have to deal your self with brown out detection, power disturbance if writing to eeprom, reliable power supply, and many other things that depend on your specific application." CreationDate="2011-02-11T11:34:59.567" UserId="1129" />
  <row Id="14932" PostId="9992" Text="It has been so easy that is difficult to believe." CreationDate="2011-02-11T11:41:26.397" UserId="2597" />
  <row Id="14933" PostId="9977" Text="You'll need a XOR operation for that." CreationDate="2011-02-11T12:35:58.613" UserId="1950" />
  <row Id="14934" PostId="10000" Score="1" Text="This looks OK for the first phase of the charging cycle - the constant current phase - but once the cell voltage gets to ~4.2V (see manufacturers data sheet for the precise voltage) you have to go into constant voltage mode.  When the current in this mode has dropped to a threshold value (again see data sheet) then you must switch the charging supply off.  Improper charging is very dangerous." CreationDate="2011-02-11T13:02:32.673" UserId="400" />
  <row Id="14935" PostId="9965" Text="One band at a time, Tunability not critical, for example swapping crystals is fine. Once I find a good frequency I'll stick to it. I'd like to feed it a sine wave at most, so the CW modulation needs to happen in the circuit. I also would be happy feeding it an &quot;on off&quot; to modulate its own tone etc. " CreationDate="2011-02-11T13:45:33.950" UserId="1033" />
  <row Id="14936" PostId="9965" Text="You'll need different filters on the output for each band, if nothing else, to ensure a clean signal." CreationDate="2011-02-11T13:59:11.853" UserId="305" />
  <row Id="14937" PostId="9922" Text="@Ranieri: Yes an SSR Triac" CreationDate="2011-02-11T14:05:46.380" UserId="1235" />
  <row Id="14938" PostId="9922" Text="@Mark: Thanks for the heads up. Ideally I want to heat the target to 200ish °C. Perfect uniformity is not necessary but the closer the better, as always! I don't have any quantitative numbers yet but some testing will prove if it's good enough or not. " CreationDate="2011-02-11T14:08:11.730" UserId="1235" />
  <row Id="14939" PostId="9928" Text="Lol. Right now, my most viable option is using these resistors. I found some 50Watt, 20 ohm-ers for a couple bucks each. If I run 120VAC through four of them that should give me some pretty good heat. We'll see....." CreationDate="2011-02-11T14:09:38.343" UserId="1235" />
  <row Id="14940" PostId="10000" Text="Yeah, my bad - stop your charge when your current hits around c/20.&#xA;Best to MAKE SURE you stay below the 4.2V threshold tho and closer to 4.1 where possible and you should be sweet.&#xA;Be fully sure they're li-ion or lipo before you charge them like this because different cells take different voltages, lifepo4 (although wouldnt be in laptop packs) does its stuff at lower voltages." CreationDate="2011-02-11T14:18:34.967" UserId="2963" />
  <row Id="14941" PostId="9965" Text="I don't have access to the site due to a work filter at the moment, but [this Hackaday article](http://hackaday.com/2011/02/11/launchpad-serial-morse-code-transmitter/) came up in my email this morning, and might be of use." CreationDate="2011-02-11T14:38:15.400" UserId="857" />
  <row Id="14942" PostId="10000" Text="Thank you very much also Ian thanks for the warning :) I don't have 15 rep points here or i would up vote both of your answers. :)" CreationDate="2011-02-11T14:47:26.993" UserId="2962" />
  <row Id="14943" PostId="9971" Score="1" Text="Hi reemrevnivek: I would love to see the photo of the deconstructed scale." CreationDate="2011-02-11T15:08:21.210" UserId="1288" />
  <row Id="14944" PostId="10004" Text="Your second link is broken." CreationDate="2011-02-11T15:20:25.390" UserId="712" />
  <row Id="14945" PostId="9572" Text="the piezo measures pressure or bending, so it would need to be between the object and something else.  otherwise you're modifying the resonant frequency with the weight of the piezo" CreationDate="2011-02-11T15:35:48.683" UserId="142" />
  <row Id="14946" PostId="10005" Score="2" Text="@Brux - Am I understanding correctly that you cut the wire off of a wall wart or desk-style power adapter on the side of the block closer to the amp (which would be DC), and plugged it into AC?  Watch out - you're working with high voltage, and it sounds like you don't know what you're doing." CreationDate="2011-02-11T15:39:40.527" UserId="857" />
  <row Id="14947" PostId="9971" Text="@miles - No, it's not a deconstructed scale.  It would be a scan of a page from The Way Things Work by David Macaulay." CreationDate="2011-02-11T15:41:11.663" UserId="857" />
  <row Id="14948" PostId="10004" Text="Thanks for point me to that. Its now corrected." CreationDate="2011-02-11T16:16:27.063" UserId="1074" />
  <row Id="14949" PostId="10014" Text="Please, Can anyone create a tag called 'integer'?" CreationDate="2011-02-11T16:30:29.843" UserId="2597" />
  <row Id="14950" PostId="10015" Text="can i just bypass the fuse?" CreationDate="2011-02-11T17:25:59.417" UserId="2889" />
  <row Id="14951" PostId="10014" Score="1" Text="Integer seems a little broad to me an not tag worthy." CreationDate="2011-02-11T17:31:42.140" UserId="319" />
  <row Id="14952" PostId="10015" Score="3" Text="Bypassing fuses is almost never a good idea. As long as the root cause (short or bad component deeper down in the circuit) is not found and repaired, powering with a bypassed fuse will cause more trouble than you already have (i.e. break lots more things). Once the root cause is found, the fuse must be replaced with the same type and rating. Imagine something else breaks later on: You want the proper fuse to protect the circuit from big damage and your house from fire." CreationDate="2011-02-11T17:53:31.447" UserId="930" />
  <row Id="14953" PostId="10015" Score="3" Text="Do NOT bypass the fuse. Full stop. No debate or questioning will be accepted." CreationDate="2011-02-11T19:26:13.287" UserId="1293" />
  <row Id="14954" PostId="10019" Score="1" Text="Honestly, the warranty is the best shot in my opinion unless they flat out refuse. Or, if DVI isn't that important, most graphics cards support legacy VGA through a DVI to VGA converter." CreationDate="2011-02-11T20:25:04.313" UserId="1225" />
  <row Id="14955" PostId="10019" Text="@Thomas O: so it'd be tough repair? :(" CreationDate="2011-02-11T20:27:26.713" UserId="2967" />
  <row Id="14956" PostId="9186" Text="The open-source pickit2 uses a PIC to control a switching regulator. See http://augroups.blogspot.com/2009/05/understanding-microchip-pickit-2-rev.html for a brief explanation (it's &quot;the VPP signal generation circuit&quot;). Some people, such as myself, like to see the complete circuit in context -- see http://www.microchip.com/pickit2 for the complete schematics. &quot;AN1086 - Switching Power Supply Design&quot; http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&amp;nodeId=1824&amp;appnote=en529838 &quot;Lighting Design Center&quot; http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&amp;nodeId=2541" CreationDate="2011-02-11T20:28:06.420" UserId="813" />
  <row Id="14957" PostId="4956" Score="1" Text="It sounds like you want your PIC to act as a slave I2C device. Perhaps the tips on the Massmind on that subject might be useful. http://techref.massmind.org/techref/microchip/i2c.htm" CreationDate="2011-02-11T20:33:46.290" UserId="813" />
  <row Id="14958" PostId="8747" Text="@endolith - well, i've seen hand-made ones ranging from just a few inches high to more than 6 feet, so even just '2 or 3 feet' is good info. Also, neon sign xfmr's are about on par, wattage-wise, with oil burner ignition xfmrs, which is what i was thinking of using. Guess i'd better proceed with caution! Thanks for the info." CreationDate="2011-02-11T21:49:04.740" UserId="740" />
  <row Id="14959" PostId="10014" Text="It makes sense to me, as much as floating point does." CreationDate="2011-02-11T22:01:50.783" UserId="206" />
  <row Id="14960" PostId="10025" Text="Ok. What would happend if I tried to run it on the shield? Even if I used an external power supply such as a double a battery?" CreationDate="2011-02-11T22:14:28.323" UserId="2873" />
  <row Id="14961" PostId="10019" Text="@evan, It might not be difficult for someone who is experienced, but you might damage more trying to repair it. Just get one of these (http://shop.ebay.com/i.html?_trkparms=65%253A12%257C66%253A2%257C39%253A1%257C72%253A4837&amp;rt=nc&amp;_nkw=dvi+to+vga&amp;_sticky=1&amp;_trksid=p3286.c0.m14&amp;_sop=15&amp;_sc=1), stick it on the back of the graphics card and use the VGA interface, unless you have some reason not to. Most graphics cards still support it." CreationDate="2011-02-11T22:25:55.823" UserId="1225" />
  <row Id="14962" PostId="10025" Text="The Adafruit shield won't drive a 3V motor (I've tried it), so it isn't likely to work." CreationDate="2011-02-11T22:27:21.137" UserId="305" />
  <row Id="14963" PostId="10025" Text="What happened when you tried? Did anything fry or did it just not work?" CreationDate="2011-02-11T22:30:36.457" UserId="2873" />
  <row Id="14964" PostId="9796" Text="Thanks for your reply. What kind of filter comes in your mind? As I said, I don't know the electronic-stuff very well, therefore I'd appreciate for example a link to an article, if you have one..." CreationDate="2011-02-11T22:46:14.403" UserId="2900" />
  <row Id="14965" PostId="9798" Text="&quot;It should not be hard to find a 12V/5A power supply for the thin client.&quot; Do you mean as output? I already have one. But what input specs would this one need?" CreationDate="2011-02-11T22:47:13.980" UserId="2900" />
  <row Id="14966" PostId="9798" Text="&quot;...to bring the automotive DC up to 120VAC&quot; - Does that mean the voltage is 120V? Does this cause any energy &quot;loss&quot;? Doesn't this mean that there's any type of inefficiency?" CreationDate="2011-02-11T22:50:37.360" UserId="2900" />
  <row Id="14967" PostId="10025" Text="Nothing much. It tried to turn but there just wasn't enough voltage." CreationDate="2011-02-11T22:59:12.787" UserId="305" />
  <row Id="14968" PostId="10025" Text="Enough? I was thinking it would overvolt it. Hmm." CreationDate="2011-02-11T23:04:58.117" UserId="2873" />
  <row Id="14969" PostId="10025" Text="I used a 3V supply for the motor, of course." CreationDate="2011-02-11T23:10:24.387" UserId="305" />
  <row Id="14970" PostId="10025" Text="Ok. I have another motor that is rated at 3v but can easily handle 5 volts and an unsafe max at 9. Would I be able to use it with the shield?" CreationDate="2011-02-11T23:25:11.873" UserId="2873" />
  <row Id="14971" PostId="10025" Text="It should work OK if you run it at 5V. 4.5V is the minimum for the drivers on that shield." CreationDate="2011-02-11T23:32:02.027" UserId="305" />
  <row Id="14972" PostId="10025" Text="And I would achieve that by attaching an external power supply with 5v and configuring it to draw from the external power, correct?     " CreationDate="2011-02-11T23:34:59.627" UserId="2873" />
  <row Id="14973" PostId="9948" Text="I like this approach. If I went to an architect to design a house on a budget, I wouldn't accept a cost estimate of &quot;build it and see&quot;. However, I wouldn't expect the estimate to be perfect, either. As its being built the plan gets optimized to stay within budget. But avoid premature optimization. Build up your design in sections and only optimize if profiling shows a section is taking significantly more resources than you estimated. If one section goes a little over budget, on the other hand, it might balance with a section that's under budget." CreationDate="2011-02-11T23:48:19.633" UserId="721" />
  <row Id="14974" PostId="10022" Text="I found the BusPirate too slow and buggy to be a useful SPI converter, even in binary mode. I moved on to programming a TI launchpad with the logic to control the device and sending out the results via serial." CreationDate="2011-02-11T23:58:03.860" UserId="1950" />
  <row Id="14975" PostId="10025" Text="Yes. That's what I did." CreationDate="2011-02-11T23:59:50.957" UserId="305" />
  <row Id="14976" PostId="10026" Text="Couldn't you limit currentThrottle and/or use a negative Kd to reduce overshoot?" CreationDate="2011-02-12T00:07:08.190" UserId="1950" />
  <row Id="14977" PostId="10019" Text="@evan When you return something like that the manufactures will usually run some very quick diagnostics in order to tell what subsystem has an issue and then will usually just replace that whole subsystem and then sell it as a refurb. " CreationDate="2011-02-12T00:07:49.430" UserId="319" />
  <row Id="14978" PostId="5773" Text="VMs are what Smalltalk, Java, Python, etc...  run on.  It means any abstracted machine, running an instruction set different from the &quot;bare metal&quot;.  Not just a virtualized PC. " CreationDate="2011-02-12T00:20:49.537" UserId="2235" />
  <row Id="14979" PostId="10019" Text="@Thomas O: I actually had a vga-dvi converter laying around and have already done that for the moment but I don't think (no actually proof of this, just opinion) that I'm getting the same quality I was over dvi which is what led me hopping it wouldn't be to hard to just repair the monitor myself. I appreciate your advice and Keyllenjb's though, I'll only attempt the repair if they definitively deny the warranty :). Thanks!" CreationDate="2011-02-12T00:43:34.120" UserId="2967" />
  <row Id="14980" PostId="10019" Text="@evan, You'll get a bit more noise, but generally, using well shielded VGA cables (not cheap, thin ones) you'll notice little difference." CreationDate="2011-02-12T00:57:40.587" UserId="1225" />
  <row Id="14981" PostId="10033" Text="tkgate also looks nice. Are there any commercial alternatives with fancier UI and more horsepower?" CreationDate="2011-02-12T01:46:53.860" UserId="2062" />
  <row Id="14982" PostId="10033" Score="1" Text="@BarsMonster, no idea. I only use these free software packages, and rarely at that, as I'm more of an analog person." CreationDate="2011-02-12T01:47:38.977" UserId="1225" />
  <row Id="14984" PostId="9798" Text="The inverter is converting 12VDC to 120VAC, usually a stepped approximation to a sine wave. This is switching conversion, so yes indeed there is some power lost in the process. And yes, the 12V/5A power supply I was talking about would be one that takes 120V input (from the inverter)." CreationDate="2011-02-12T02:18:51.750" UserId="1293" />
  <row Id="14985" PostId="9947" Text="It also has NaN, Infinity, and 'subnormals' (the little deviants)... oh my! This number format is designed to make life simpler for numerical methods accelerated by hardware. IEEE 754 even supports decimals! (base 10): http://en.wikipedia.org/wiki/Decimal32_floating-point_format." CreationDate="2011-02-12T02:23:43.657" UserId="721" />
  <row Id="14986" PostId="10035" Text="It seems odd because I used hacky mode: switch is set between &quot;22V&quot; and &quot;24V&quot; =&gt; both 22V and 24V LEDs are on and output is 34V. (BTW this power adaptor is in general considered unsafe). Currently powering my laptop from it having connected additional large capacitor in parallel to laptop, but the voltage seems falling and falling." CreationDate="2011-02-12T02:39:41.787" UserId="2898" />
  <row Id="14987" PostId="10034" Text="It seems to work worse and worse. Stopped using it in favour of old and big one." CreationDate="2011-02-12T03:05:40.960" UserId="2898" />
  <row Id="14988" PostId="10031" Text="What do you mean by &quot;filtering large frequencies&quot;? I was talking about filtering the power supply, that's DC." CreationDate="2011-02-12T03:10:33.260" UserId="1950" />
  <row Id="14989" PostId="10035" Text="Is the blown capacitor the only one on the output? Most converters that I know of won't work at all without a capacitor." CreationDate="2011-02-12T03:17:11.217" UserId="1293" />
  <row Id="14990" PostId="10035" Text="I expect that blown capacitor still works (reduced). For example, adaptor's LED fade out slowly (not abruptly) when it is plugged off from mains. (There are also other, smaller 25V capacitors in other parts of circuit)." CreationDate="2011-02-12T03:51:54.960" UserId="2898" />
  <row Id="14991" PostId="8197" Text="In my Universal Laptop adaptor if I put switch between two modes I get undocumented/buggy mode with voltage much greater than official maximum. Have just burned the adaptor because of this." CreationDate="2011-02-12T03:56:13.350" UserId="2898" />
  <row Id="14992" PostId="10031" Score="1" Text="You're trying to filter high frequency noise from the micro (10+Mhz), switching regulator and such from the analog supply rails, no?  If you have a perfect DC supply with no noise then there is no need to filter.  Usually, ferrites (with ceramic capacitors) are used to filter analog rails from digital rails because at high digital frequencies inductors are ineffective. " CreationDate="2011-02-12T05:03:33.430" UserId="2377" />
  <row Id="14993" PostId="10033" Text="@barsmonster, why would you insist on a commercial alternative? The Qucs works fine" CreationDate="2011-02-12T05:18:51.750" UserId="1200" />
  <row Id="14994" PostId="9443" Text="@AndreKR, Why is it beyond question? What is your noise budget/target?" CreationDate="2011-02-12T05:56:51.530" UserId="2118" />
  <row Id="14995" PostId="10015" Text="its ok i wont kill myself, thanks for the help" CreationDate="2011-02-12T11:13:28.323" UserId="2889" />
  <row Id="14996" PostId="10049" Text="could anyone create a tag called 'whatis'?" CreationDate="2011-02-12T12:03:58.720" UserId="2597" />
  <row Id="14997" PostId="10047" Score="2" Text="I think this belongs on [http://math.stackexchange.com/](http://math.stackexchange.com/)" CreationDate="2011-02-12T12:33:05.833" UserId="2064" />
  <row Id="14999" PostId="10045" Text="Where can I find the bit patterns for the cases fo NaN, signed, zeros, infitinity?" CreationDate="2011-02-12T14:06:33.093" UserId="2597" />
  <row Id="15000" PostId="10045" Text="@peterstone http://en.wikipedia.org/wiki/Single_precision_floating-point_format#IEEE_754_single_precision_binary_floating-point_format:_binary32" CreationDate="2011-02-12T14:14:49.303" UserId="1225" />
  <row Id="15001" PostId="10018" Text="Thanks! I ended up using this." CreationDate="2011-02-12T14:17:29.330" UserId="1225" />
  <row Id="15002" PostId="10006" Text="I tried using such a circuit but I found it had two problems; it offset the output by about 0.7V, and it was difficult to modify the limit to less than about 500mA, but thanks for the suggestion anyway." CreationDate="2011-02-12T14:18:58.473" UserId="1225" />
  <row Id="15003" PostId="10051" Score="1" Text="Measuring component values in circuit can be difficult, especially if you don't have the schematics to study, more so if you aren't really sure of what you are looking for. You might have better luck if this question is moved to electronics.stackexchange.com" CreationDate="2011-02-12T13:46:55.777" UserId="1750" />
  <row Id="15004" PostId="9981" Text="Most undergraduate texts in circuits focus on working with linear differential and difference equations. Beyond a 2nd order system, they'll usually switch to the frequency domain using Laplace or Z transforms. College texts can be expensive, though. Are you looking for free online books/tutorials?" CreationDate="2011-02-12T15:02:42.320" UserId="721" />
  <row Id="15006" PostId="10047" Text="a quaternion is essentially a direction vector with a rotation around that vector. But, what stevenvh said - this is probably too abstract for this site." CreationDate="2011-02-12T15:32:09.937" UserId="740" />
  <row Id="15007" PostId="7695" Text="Oh my god! Thank you for this great answer! So much time was wasted because of not knowing this ) Thank you once more!" CreationDate="2011-02-12T15:34:11.540" UserId="2977" />
  <row Id="15008" PostId="8152" Text="I'm sorry, this is a question, not an answer, but i'm struggling with the same problem here, i was wondering if you succeeded using this chip with a pic18 device?" CreationDate="2011-02-12T15:35:47.497" UserId="2974" />
  <row Id="15009" PostId="9965" Text="nice, those hackaday articles rock! I ordered one of those all-in-one dealio's and I'm looking forward to trying it. " CreationDate="2011-02-12T15:38:46.780" UserId="1033" />
  <row Id="15010" PostId="10056" Score="1" Text="@fms : Here is a link to a white paper that explains how they work: http://www.avagotech.com/docs/AV02-1649EN" CreationDate="2011-02-12T15:49:48.800" UserId="2489" />
  <row Id="15011" PostId="10030" Text="What do you base the +-2C number on?" CreationDate="2011-02-12T16:30:10.487" UserId="857" />
  <row Id="15012" PostId="10047" Text="Quaternions are the set of 2x2 complex matrices I, J, and K, plus the 2x2 identity matrix U, that satisfy the equations I^2 = J^2 = K^2 = -U, IJ = K, JK = I, KI = J, JI = -K, KJ = -I, and IK = -J. They're commonly used in mechanical analysis, so I think it's relevant to implementing an internal measurement unit to track orientation in space. I guess there should be a separate stack for mechanical engineering questions." CreationDate="2011-02-12T16:35:53.097" UserId="721" />
  <row Id="15013" PostId="10053" Text="Interesting, the board is from Lattice Semiconductor.  I could easily remove the cap, but what type of adverse affect will it have on the clock signal?  Will it cause delays or deform the clock waveform?" CreationDate="2011-02-12T16:49:22.903" UserId="2059" />
  <row Id="15014" PostId="10055" Score="4" Text="We try to avoid pure wikipedia linking here. It is helpful for this community to build our own knowledge set instead of just liking to other peoples." CreationDate="2011-02-12T16:50:44.120" UserId="319" />
  <row Id="15015" PostId="10053" Score="1" Text="It would increase the rise and fall times. Perhaps that is the reason for including it." CreationDate="2011-02-12T16:54:46.780" UserId="305" />
  <row Id="15016" PostId="9798" Text="Okay thanks. The supply takes from 100-240V as input. As the voltage here is aroud 230V, therefore it's anyway better to take an inverter for 100-120V than one with output 230V?" CreationDate="2011-02-12T17:09:34.837" UserId="2900" />
  <row Id="15017" PostId="7675" Text="Tut tut Joel, you should really accept an answer! ;)" CreationDate="2011-02-12T17:21:45.847" UserId="1333" />
  <row Id="15018" PostId="10059" Text="Nice find!  Thank you." CreationDate="2011-02-12T17:29:19.423" UserId="2059" />
  <row Id="15020" PostId="10014" Score="1" Text="@Brian, [meta discussion on tag.](http://meta.electronics.stackexchange.com/questions/388/asking-for-a-system-generator-tag)" CreationDate="2011-02-12T18:27:16.947" UserId="2118" />
  <row Id="15022" PostId="10049" Score="1" Text="@Peterstone, That would be a [meta-tag](http://meta.electronics.stackexchange.com/q/115/2118), the use of which is discouraged." CreationDate="2011-02-12T18:36:02.853" UserId="2118" />
  <row Id="15025" PostId="10065" Text="If there's only a 0.2V drop, then that's ~300mW per output -- still too much for DIL?" CreationDate="2011-02-12T18:46:08.240" UserId="2118" />
  <row Id="15026" PostId="10065" Text="That means very low saturation voltage devices, I don't think that they are available in DIL packages." CreationDate="2011-02-12T18:52:33.007" UserId="305" />
  <row Id="15027" PostId="10065" Text="Ok have you got any ideas then? " CreationDate="2011-02-12T18:59:19.270" UserId="1623" />
  <row Id="15028" PostId="10063" Text="How do you plan to feed data into your pic? This question is difficult to answer without knowing that." CreationDate="2011-02-12T18:59:46.990" UserId="2426" />
  <row Id="15029" PostId="10065" Text="If you need a through hole package but not necessarily DIP, there are some higher power packages and hybrid chips. Don't know Darlington arrays off the top of my head, though." CreationDate="2011-02-12T19:26:00.887" UserId="883" />
  <row Id="15030" PostId="10030" Score="1" Text="Just an estimation. In fact it will be better - it's all connected to same PCB and I don't see why uC will be constantly way hotter (given 0.1-0.5W power consumption)" CreationDate="2011-02-12T19:31:46.690" UserId="2062" />
  <row Id="15031" PostId="10065" Text="Any thing that could do the job doesn't need to be a DIP. If you know of transistors that could do the job then I would use those. " CreationDate="2011-02-12T19:44:09.340" UserId="1623" />
  <row Id="15032" PostId="10063" Text="Which LCD do you have? (Is it SPI, I2C, other?) And are you sure you want the *compiled* software? Kinda useless, as such." CreationDate="2011-02-12T19:56:52.600" UserId="2118" />
  <row Id="15033" PostId="10068" Score="3" Text="LOL @ &quot;I might actually run the DRC&quot;! Hard lessons are the best teachers, though!" CreationDate="2011-02-12T20:27:47.553" UserId="2118" />
  <row Id="15034" PostId="10068" Text="@tyblu, Thing is, I did, and it passed. However, this was a last-minute change before sending it off to production, and I didn't run the DRC after making that change. Stupid, I know." CreationDate="2011-02-12T20:30:06.830" UserId="1225" />
  <row Id="15035" PostId="10068" Score="1" Text="I can't say I have every had a situation where I was able to get a gerber file sent in for a board fab and have not be forced to go through a DRC and a DFM. It is always nice to be forced to." CreationDate="2011-02-12T20:37:44.267" UserId="319" />
  <row Id="15036" PostId="10070" Text="I have a 3A (CC/CV, short circuit protected) power supply, would this be able to do it? Unfortunately, trace resistance is going to be &lt;0.1 ohms, and I^2*R tells us that even this would only just heat up the trace (0.9W.) Would 0.9W do it? " CreationDate="2011-02-12T20:41:48.047" UserId="1225" />
  <row Id="15037" PostId="10068" Text="@Kellenjb, the PCBs were cheap (about £28 for 10, including shipping), so they probably skimped on doing their own DRC. No big deal for me unless I forget to do it myself." CreationDate="2011-02-12T20:43:40.010" UserId="1225" />
  <row Id="15038" PostId="10070" Text="Heck if I know, @Thomas! S/C protection usually means voltage will drop upon short, though. AA batteries can surge quite a bit (use Alkaline so it doesn't wreck a rechargeable). I've never done this for such a tightly-spaced, small trace application." CreationDate="2011-02-12T20:46:55.863" UserId="2118" />
  <row Id="15039" PostId="10071" Text="This should probably be solution #1..." CreationDate="2011-02-12T20:48:09.903" UserId="2118" />
  <row Id="15040" PostId="10070" Text="@tyblu, Yep, it drops to almost zero if it's shorted. As it's constant current, voltage drops if current increases beyond the set CC limit." CreationDate="2011-02-12T20:54:09.563" UserId="1225" />
  <row Id="15041" PostId="10070" Text="+1 for most exciting fix" CreationDate="2011-02-12T20:58:07.687" UserId="638" />
  <row Id="15043" PostId="10046" Text="@starblue, Could you contribute to [this meta discussion on the `xilinx-system-generator` tag](http://meta.electronics.stackexchange.com/q/388/2118) ?" CreationDate="2011-02-12T21:10:21.317" UserId="2118" />
  <row Id="15044" PostId="10071" Text="Nothing you can use that won't melt/contaminate the joint. Better to solder the parts in place and then mechanically remove the resulting short (ie, cut away some of the solder). You can coat the repaired area with a conformal coating pen or ersatz coating (glue, etc) afterwards." CreationDate="2011-02-12T21:25:47.780" UserId="906" />
  <row Id="15045" PostId="10073" Text="Wheres the datasheet?" CreationDate="2011-02-12T21:56:32.773" UserId="1623" />
  <row Id="15046" PostId="10074" Text="Note [their recommendation to upgrade.](http://www.microchip.com/wwwproducts/ProductCompare.aspx?product1=PIC16F873A&amp;product2=PIC16F883)" CreationDate="2011-02-12T22:00:28.837" UserId="2118" />
  <row Id="15047" PostId="10074" Text="I saw that, but I have some example programs to serve as a basis for this chip... as bad as this may sound, I dont want to deal with the slight changes they may have introduced in dealing with both." CreationDate="2011-02-12T22:05:26.007" UserId="2985" />
  <row Id="15048" PostId="10073" Text="@Dean For some reason, it wouldn't let me link directly to file. I linked now to the list of the datasheets for their displays. " CreationDate="2011-02-12T22:05:49.600" UserId="1240" />
  <row Id="15049" PostId="10076" Text="Is that it? I've seen the same notation elsewhere, I thought the E, I and SP might have some special meaning." CreationDate="2011-02-12T22:06:11.313" UserId="2985" />
  <row Id="15050" PostId="10075" Text="OK. I'll try with that, once I obtain suitable potentiometer." CreationDate="2011-02-12T22:06:22.470" UserId="1240" />
  <row Id="15051" PostId="10076" Text="@Cenoc, *&quot;SP&quot;* for *SPDIP* in *&quot;Skinny Dual In-line Package&quot;*; *&quot;I&quot;* for *&quot;industrial grade&quot;*." CreationDate="2011-02-12T22:13:42.823" UserId="2118" />
  <row Id="15052" PostId="10076" Text="@Cenoc *&quot;E&quot;* is likely *&quot;military grade&quot;*, though it may be something else, as I usually see this go to -55C." CreationDate="2011-02-12T22:20:01.197" UserId="2118" />
  <row Id="15053" PostId="9928" Text="That's the other nice thing - they are available for pretty much any supply voltage and output power you need! Just don't be tempted to thinking that as they are metal you can very grossly overload them - I've seen taser-like failure modes where the end blows off pulling a trail of live wire behind it!" CreationDate="2011-02-12T23:50:09.870" UserId="1681" />
  <row Id="15054" PostId="10069" Text="Thanks kellenjb - that explains why I had no luck in finding any. Would have only wanted open source if available. I'll dig in." CreationDate="2011-02-13T00:26:04.070" UserId="2319" />
  <row Id="15055" PostId="10071" Text="I was thinking more about shorts that were under parts." CreationDate="2011-02-13T00:27:47.267" UserId="319" />
  <row Id="15056" PostId="10063" Text="I planned to send serial data like in the Sparkfun SerLCD_V2 spec. I don't know the brand of the LCD, it is a 4 x 20 with the parallel 16 pin header HD44780 type controller. I have it working on Arduino using the liquidcrystal library, but wanted to mount it remotely, since I had some 16f648 chips laying around, thought that would work. Thanks for your input." CreationDate="2011-02-13T00:31:23.817" UserId="2319" />
  <row Id="15057" PostId="10081" Text="I guess price is significant, but most expensive ($500+) bench multimeters seem to use dual-slope converters too. " CreationDate="2011-02-13T00:51:15.760" UserId="1225" />
  <row Id="15058" PostId="10081" Text="I don't honestly know I've seen a bench multimeter that has been designed recently enough to use sigma-delta ADCs.  They may add tweaks and changes but i would bet the measurement circuits in most haven't been touched in 10+ years." CreationDate="2011-02-13T00:56:03.030" UserId="1438" />
  <row Id="15059" PostId="7675" Text="I'll do something better... add a bounty!" CreationDate="2011-02-13T00:59:18.223" UserId="2233" />
  <row Id="15060" PostId="10082" Score="2" Text="You'd have to provide more information on a specific laser diode as there are various types.  Also &quot;stabilizing&quot; current in 50ns pulses isn't easy." CreationDate="2011-02-13T01:16:47.443" UserId="1438" />
  <row Id="15061" PostId="10082" Text="These are simple ones salvaged from DVD-RW's." CreationDate="2011-02-13T02:08:17.407" UserId="2062" />
  <row Id="15062" PostId="10071" Text="Um, don't do that? Seriously though, this is a hard one to solve. You can kludge air gaps under SMT parts by first putting a solder bump on the pad, then holding the part touching them and soldering. Still you're talking about sub-10 mil gaps in most cases. You can also 'billboard' chip components (mount them on edge) to reduce their X/Y coverage area." CreationDate="2011-02-13T03:44:44.250" UserId="906" />
  <row Id="15063" PostId="10071" Score="1" Text="You can add solder mask by painting on a bit of enamel paint.  You can find small jars of red brush-on enamel paint in the cosmetics aisle. " CreationDate="2011-02-13T04:02:47.497" UserId="411" />
  <row Id="15064" PostId="10070" Text="This is a useful fix when the short is underneath a component.  I have used this when Vcc was shorted to ground.  A standard ATX power supply puts out enough current on the +5V and +3.3V buses to clear some big shorts.  And the voltage is limited so no components are damaged.  Hopefully." CreationDate="2011-02-13T04:04:49.400" UserId="411" />
  <row Id="15065" PostId="10085" Score="3" Text="It is the same difference as between a CD and DVD. A CD uses 780nm laser and 1.6µm bumps; a DVD uses 650nm laser and 0.74µm bumps; BluRay uses 405nm laser." CreationDate="2011-02-13T04:37:10.923" UserId="2118" />
  <row Id="15066" PostId="5894" Text="Also a nice book would be The Elements of Computing systems." CreationDate="2011-02-13T06:51:53.567" UserId="1200" />
  <row Id="15067" PostId="5871" Text="deleted message felt bad" CreationDate="2011-02-13T06:53:13.800" UserId="1200" />
  <row Id="15068" PostId="10080" Score="2" Text="high resolution doesn't matter?  (6.5 digit DMM is about 20 bits of resolution.)  And dual-slope converters can have very high resolution, It's the time constant * the clock used to measure the slope time, both under the control of the system designer." CreationDate="2011-02-13T08:27:26.570" UserId="411" />
  <row Id="15069" PostId="10088" Text="I doubt you need tremendous update rates; the relatively slow speed of a quadrotor and its reaction time doesn't really make it a good fit." CreationDate="2011-02-13T08:44:25.100" UserId="1407" />
  <row Id="15070" PostId="10089" Text="no autorouter. no superfluous traces. =\" CreationDate="2011-02-13T09:24:37.280" UserId="1688" />
  <row Id="15071" PostId="10088" Text="Thanks for the alternative solution Choscura. I'll definitely look into using an optical mouse - I don't need the camera part of a camera either ;-) The only problem I can see is that if the image is out of focus, the difference algorithm might not work as well. Am I right?" CreationDate="2011-02-13T10:22:53.607" UserId="2212" />
  <row Id="15072" PostId="10091" Text="The use of meta tags is discouraged. http://meta.electronics.stackexchange.com/q/115/2118" CreationDate="2011-02-13T12:49:53.507" UserId="1623" />
  <row Id="15073" PostId="10039" Text="Hey! so we are both using a pic18, that could make things easier.. I believe the idea of compiling as a library makes no sense, as I dunno how such a thing can be done for a PIC. I started by looking at the code (which wasn't fitting my PIC) and commenting stuff which wasn't needed and trying to write equivalent functions for those functions which aren't available on a PIC (such as all the stuff in aio.c/h) and expecially by rewriting the MLSL functions (I'm having some problem with the WriteBurst one). Maybe when u'll have started digging a bit we can compare our result!" CreationDate="2011-02-13T12:51:53.320" UserId="2285" />
  <row Id="15074" PostId="10091" Text="Fair enough - that makes sense." CreationDate="2011-02-13T12:55:13.503" UserId="2991" />
  <row Id="15075" PostId="10039" Text="One thing is that what you compiled was compiled for windows, no way that library can be used on a PIC.. I tried to contact Invensense several times about thata bu I got no answer... let me know if you manage to get some info.." CreationDate="2011-02-13T13:04:51.670" UserId="2285" />
  <row Id="15076" PostId="10047" Score="1" Text="@eryksun - if the question was specifically about a robotics problem, that involved quaternions, i think that'd be fine here. but as stated, the question is overly broad and not really specific to any electronics/robotics problem." CreationDate="2011-02-13T13:23:55.810" UserId="740" />
  <row Id="15077" PostId="10092" Text="To your comment about the contacts wear out. Developments have been made in solid state relays. " CreationDate="2011-02-13T13:34:36.593" UserId="1623" />
  <row Id="15078" PostId="10109" Score="2" Text="perhaps much more depending on the required edge rise/fall times." CreationDate="2011-02-13T17:29:03.607" UserId="1438" />
  <row Id="15079" PostId="10105" Text="How much have you got to spend? Bandwidth?" CreationDate="2011-02-13T17:34:45.053" UserId="305" />
  <row Id="15080" PostId="10111" Score="2" Text="You can try this yourself here: http://www.falstad.com/fourier/" CreationDate="2011-02-13T17:52:52.820" UserId="1950" />
  <row Id="15081" PostId="10094" Text="thank you! i can imagine how hearing it would be useful :)" CreationDate="2011-02-13T17:53:00.043" UserId="2992" />
  <row Id="15082" PostId="10095" Text="thank you! i've always preferred transistors, they seem.. neater :)" CreationDate="2011-02-13T17:54:08.560" UserId="2992" />
  <row Id="15083" PostId="10096" Text="thank you! hadn't even considered solid state components till now..." CreationDate="2011-02-13T17:59:46.997" UserId="2992" />
  <row Id="15084" PostId="10105" Score="4" Text="If you're a student, can you use one at your college?  Buying one is an extreme investment just to learn with it." CreationDate="2011-02-13T18:35:07.213" UserId="1407" />
  <row Id="15085" PostId="7675" Text="What are you looking for?  A logic diagram?" CreationDate="2011-02-13T18:36:45.790" UserId="1407" />
  <row Id="15086" PostId="10096" Score="1" Text="The Rds(on) of power N-ch MOSFETs can easily be better than the contact resistance in a relay of comparable size." CreationDate="2011-02-13T18:41:55.940" UserId="1407" />
  <row Id="15087" PostId="10103" Text="You can't transmit or receive electromagnetic radiation with transistors?" CreationDate="2011-02-13T18:43:19.043" UserId="1407" />
  <row Id="15088" PostId="10111" Score="3" Text="also consider the slew rate of the op-amp as that may be the limiting factor in reproduction of square waves with a required edge rise/fall time." CreationDate="2011-02-13T18:51:46.607" UserId="1438" />
  <row Id="15089" PostId="10103" Text="@Nick T, they are not very sensitive. I should clarify." CreationDate="2011-02-13T19:56:06.230" UserId="1225" />
  <row Id="15090" PostId="7675" Text="I've always wondered how an electro-mechanical (pre-computer) elevator control system worked. What happens when you press a floor number? How does it decide which car to send? How are doors, indicator lights, etc. controlled? Why doesn't the DOOR CLOSE button do anything?" CreationDate="2011-02-13T20:26:35.903" UserId="2233" />
  <row Id="15091" PostId="10115" Text="For a signal generator, the purer the better really." CreationDate="2011-02-13T20:51:04.973" UserId="1225" />
  <row Id="15092" PostId="10107" Score="3" Text="Just an FYI, the battery terminals on your car are *not* 12V DC like you'll get from your laptop power supply.  They're more like 13.8 when the alternator is running, they dip down to 10.5V or lower when starting the car, and they have all sorts of noise from the spark plugs, alternator, and various motors.  PSU design for automobiles is tricky business." CreationDate="2011-02-13T20:52:40.887" UserId="857" />
  <row Id="15093" PostId="10100" Text="+1 for proper grounding of the tip." CreationDate="2011-02-13T20:53:27.063" UserId="857" />
  <row Id="15094" PostId="10115" Text="OK, good luck finding that infinite-bandwidth op-amp then." CreationDate="2011-02-13T21:35:29.863" UserId="411" />
  <row Id="15095" PostId="9949" Text="@Martin - I corrected your answer as we discussed in the comments - You can use the &quot;edit&quot; link if you can add some more information or make a correction to your answer." CreationDate="2011-02-13T21:47:52.113" UserId="857" />
  <row Id="15096" PostId="7676" Text="When I was younger I worked doing security/fire systems and I tore out several old fire alarm panels that were just massive cases with 100+ relays in them hand wired to build all the alarm logic.  Pretty crazy what they used to do with a box full of relays and a spool of wire.  We'd replace a 6' x 4' x 2' enclosure filled with relays with a 12&quot; x 8&quot; x 3&quot; modern panel, and the only reason new panels that big is for all the screw terminals and wire management." CreationDate="2011-02-13T22:05:38.010" UserId="1438" />
  <row Id="15097" PostId="10101" Text="BTW, http://en.wikipedia.org/wiki/Charlieplexing. I did not know about it, so I figured I'd save people like me the typing by posting a link." CreationDate="2011-02-13T22:32:24.837" UserId="1802" />
  <row Id="15098" PostId="10068" Text="Now that is an interesting price. Do they ship to mainland Europe? :P" CreationDate="2011-02-13T22:35:54.520" UserId="1802" />
  <row Id="15099" PostId="10068" Text="@Ranieri, Yes. For £3 on top of the £25. (I live in the UK.) It takes about three weeks though (2.5 of those being shipping.)" CreationDate="2011-02-13T22:47:35.640" UserId="1225" />
  <row Id="15100" PostId="10097" Text="It fixed the problem. Great answer!" CreationDate="2011-02-13T22:53:22.897" UserId="1688" />
  <row Id="15101" PostId="4542" Text="What did you end up going with? I'm solving a similar problem right now." CreationDate="2011-02-14T00:02:10.930" UserId="207" />
  <row Id="15102" PostId="10070" Text="I actually used this with success, so it gets the accepted answer. 3A is more than enough to vaporise a trace." CreationDate="2011-02-14T00:12:55.830" UserId="1225" />
  <row Id="15103" PostId="10070" Text="@Thomas, Congratulations on entering the world of seat-of-your-pants repairs! ;)" CreationDate="2011-02-14T00:21:42.540" UserId="2118" />
  <row Id="15104" PostId="9939" Text="Really? I was starting to get the impression *we* were doing your undergraduate thesis project ;)" CreationDate="2011-02-14T00:23:51.557" UserId="1802" />
  <row Id="15105" PostId="9808" Text="@Harry this may not be your application but you can see what you can do with solenoids http://www.youtube.com/watch?v=g_hiz-Kx0kM" CreationDate="2011-02-14T00:49:17.557" UserId="2060" />
  <row Id="15106" PostId="9686" Text="Oh! I didn't realize stack overflow didn't alert you when new comments were added. I've ended up buying the ET STM32, So we'll see how that goes once it gets shipped to me. I'll keep an eye on your blog and thanks for all the help thus far!" CreationDate="2011-02-14T01:15:19.597" UserId="2701" />
  <row Id="15107" PostId="10117" Text="Oh yeah, I forgot about this project! One of my friends also suggested that I just use an oscilloscope for low frequency stuff. If I build a transmitter that operates around like 1 MHz, then even if I'm off by a factor of 10, I can still see it. And simulating it is also a good idea. Thanks guys! " CreationDate="2011-02-14T04:20:47.457" UserId="2993" />
  <row Id="15108" PostId="10083" Score="1" Text="Millisecond precision (or at least 5-10 ms) is easily doable and valid.  If the actuator is fast enough, you should be able to get millisecond repeatability on snap-action switches.  It's not like you would (or could) run it at a kHz." CreationDate="2011-02-14T05:03:38.460" UserId="1407" />
  <row Id="15109" PostId="9932" Text="only thing is, these run on DC" CreationDate="2011-02-14T05:22:08.437" UserId="2006" />
  <row Id="15110" PostId="5883" Text="You could also use a PNP to do a NOT in the same fashion as the AND with the NPN" CreationDate="2011-02-14T05:45:35.803" UserId="2006" />
  <row Id="15111" PostId="10118" Text="+1. Thank you. Can you add this url to your answer? Lego NXT kit: http://www.amazon.com/LEGO-4544091-Mindstorms-NXT-2-0/dp/B001USHRYI/ref=cm_cr_pr_product_top and When I got confused to go with NXT or Vex kit. This http://www.vexforum.com/showthread.php?t=6551 says, NXT is for beginners &amp; Vex is for advanced users because Vex is more flexible than NXT." CreationDate="2011-02-14T06:01:27.617" UserId="1433" />
  <row Id="15112" PostId="4542" Text="@msutherl: I didn't. One of the digital pots mentioned by endolith looked to be the best but the whole project including other parts ended up being to expensive (IIRC $400 to several grand depending on how exactly I did it)." CreationDate="2011-02-14T06:19:23.460" UserId="1182" />
  <row Id="15113" PostId="10038" Text="Thank you for the reply. I have looked at two of those papers before. They don't really provide a method to actually compute the weights. " CreationDate="2011-02-14T06:48:54.207" UserId="2939" />
  <row Id="15114" PostId="10038" Text="Let me explain my problem a little further. I am working on the basis that the electronic compass alone is subjected to magnetic interferences in the indoor environment and hence the gyro should be used along with it to improve the accuracy of orientation. " CreationDate="2011-02-14T06:49:30.353" UserId="2939" />
  <row Id="15115" PostId="10038" Text="Now, these magnetic interferences will form the external/environment noise of the process and will definitely be non-Gaussian, since they are bound to be biased towards the side of the metallic structure. That is why I chose the Particle filter over say, the Kalman filter although it is the most preferred method. So when I really don't know the pdf of the noise, then how do I estimate the likelihood that a predicted value is equal to a real value (which would be its weight, right?) " CreationDate="2011-02-14T06:49:49.433" UserId="2939" />
  <row Id="15116" PostId="9958" Text="I found this tool+blog that combines Eagle with SketchUp: http://eagleup.wordpress.com/, I'm going to try that too." CreationDate="2011-02-14T09:15:44.190" UserId="2395" />
  <row Id="15117" PostId="10065" Text="You'll never get anywhere near 0.2v for a darlington - the darlington configuration inherently adds at least a full b-e drop, so it will be droppping 0.7-1v" CreationDate="2011-02-14T09:47:01.137" UserId="1681" />
  <row Id="15118" PostId="10124" Text="So are the internal diodes in the l293d strong enough to handle any of the loads I am dealing with? Or are they cheap things added just incase you decide to risk it?" CreationDate="2011-02-14T12:36:57.397" UserId="2873" />
  <row Id="15119" PostId="10107" Text="Thanks for the tip. Actually I'm more interested in using car batteries with solar cells." CreationDate="2011-02-14T14:15:51.337" UserId="2994" />
  <row Id="15120" PostId="9932" Text="@Matt that's true if you click on the DC silicone pad link.  But if you click on every other link on the page, you'll see that they take 120VAC." CreationDate="2011-02-14T14:28:10.347" UserId="2288" />
  <row Id="15121" PostId="9932" Text="sorry, I clicked the first one. good heads-up for the op then" CreationDate="2011-02-14T14:42:16.587" UserId="2006" />
  <row Id="15122" PostId="10038" Text="To address the first comment regarding &quot;how&quot;: p.122 of the book &quot;Probabilistic Robotics&quot; by Thrun, Burgard, and Fox, 2005 gives a good example of sampling. " CreationDate="2011-02-14T14:50:51.787" UserId="2632" />
  <row Id="15123" PostId="10128" Text="Interesting, one of my friends is looking for the answer to exactly this question. " CreationDate="2011-02-14T14:55:16.257" UserId="1200" />
  <row Id="15124" PostId="9101" Text="@W5VO thanks that clears up my understanding of of the answer." CreationDate="2011-02-14T15:03:36.223" UserId="2617" />
  <row Id="15125" PostId="10118" Score="1" Text="I'd agree that Vex is probably a bit more advanced. NXT is also easier to program. If he already has some Legos, then NXT is probably a better choice. After he gets comfortable making stuff with NXT, then the next step is Vex or maybe an Arduino kit like Throwback1986 mentioned." CreationDate="2011-02-14T15:11:22.033" UserId="2993" />
  <row Id="15126" PostId="10128" Score="2" Text="@shitake83: Your question is very broad, and difficult to answer. If you can break your question down into smaller more specific questions I think you'll get a much better response." CreationDate="2011-02-14T15:28:36.777" UserId="2426" />
  <row Id="15128" PostId="10132" Text="using 328 with arduino bootloader.ive succesfully created the 8* rgb led.its out there to copy on the internet ;) the thing is,what i would have to consider if the stuff wasnt out there.thats what im interested in.more to say &quot;where can i get the expertise to create whatever i want&quot;.i think you didnt get my question right.&#xA;&#xA;for example,what do i consider if i add a temperature sensor, does it need a resistor etc.&#xA;&#xA;its not the 74hc595 itself but more about what knowledge i have to acquire.&#xA;&#xA;for example its unnecessary if you know how to tie the shoelaces if you dont know how to score a goal." CreationDate="2011-02-14T16:11:12.777" UserId="2995" />
  <row Id="15129" PostId="10132" Text="But thanks for pointing out the other projects, i maybe can take some information off of that." CreationDate="2011-02-14T16:11:48.347" UserId="2995" />
  <row Id="15130" PostId="10136" Text="As a bonus, if you have 2 batteries in series, you can use the middle terminal as ground and have a positive and negative supply from the 2 other battery terminals." CreationDate="2011-02-14T16:38:17.153" UserId="204" />
  <row Id="15131" PostId="10129" Score="1" Text="FYI, in case you ever need a split supply (e.g. +/- 4.5V supply for an op-amp powered by a 9V battery), here are some circuits for a buffered, low-impedance VGND at half the battery voltage: http://tangentsoft.net/elec/vgrounds.html" CreationDate="2011-02-14T17:06:55.833" UserId="721" />
  <row Id="15132" PostId="10127" Text="I'd already thought of these as an alternative. " CreationDate="2011-02-14T17:12:46.337" UserId="1623" />
  <row Id="15133" PostId="10144" Score="5" Text="could also be an electrolytic capacitor with a small leak, they tend to make roughly the same sound." CreationDate="2011-02-14T17:21:28.723" UserId="1438" />
  <row Id="15134" PostId="10128" Text="@BG100: ok youre right.Its a very broad question.let me put it this way.I already know how to wire up the atmel 8*8 rgb etc cause its all over the internet.ok.So now i want to custom add parts to the setup and im not sure how to find the specific information about certain parts,for example an ethernet chip (w5100 in this case) i printed out the whole datasheet and read it.I have a basic understanding of what each pin does.Does this one need a pullup? This one a diode in front because xy? do i have to reduce voltage to pin xx??  I want to solve such questions. Thx :)" CreationDate="2011-02-14T17:37:51.360" UserId="2995" />
  <row Id="15135" PostId="9948" Text="@eryksun: except the difference is it costs a fortune to build it and see with a house... Not so with software.  Take advantage of that" CreationDate="2011-02-14T18:13:20.363" UserId="763" />
  <row Id="15136" PostId="4542" Text="@BCS: So did you go with a DSP in the end?  :)" CreationDate="2011-02-14T19:26:18.357" UserId="142" />
  <row Id="15137" PostId="9958" Text="Ooh, excellent find!  I'll check that out as well. Thanks!" CreationDate="2011-02-14T19:28:14.073" UserId="2928" />
  <row Id="15138" PostId="10109" Text="If you don't have at least 3x it will look like a slightly bumpy sine wave." CreationDate="2011-02-14T19:54:16.517" UserId="339" />
  <row Id="15139" PostId="10148" Text="From what I know: The syntax in Eagle to avoid confusing a pin is to name it, for example, GND@1 and GND@2, and then (I forget how) these pins are linked.  Eagle does not use automatic loop removal.  Eagle does not allow exploding package footprints, though vias are allowed in the package design." CreationDate="2011-02-14T20:10:15.633" UserId="857" />
  <row Id="15140" PostId="10146" Text="See this similar [question](http://electronics.stackexchange.com/questions/6956/how-do-i-define-a-tented-via-in-pad-in-eagle/7261#7261) on QFN packages. You could follow the same procedure without messing with the stop mask." CreationDate="2011-02-14T20:10:42.760" UserId="638" />
  <row Id="15141" PostId="10133" Text="Agreed. Start with something big, and then if necessary pare down to the smallest part that meets your final requirements." CreationDate="2011-02-14T20:13:34.037" UserId="638" />
  <row Id="15142" PostId="10157" Text="Does it work if you connect it directly to 5V?" CreationDate="2011-02-14T21:05:16.943" UserId="857" />
  <row Id="15143" PostId="10157" Text="@reemrevnivek Yes." CreationDate="2011-02-14T21:07:00.640" UserId="1240" />
  <row Id="15144" PostId="10152" Score="2" Text="Do you need twisted pairs or shielding?  Microvolt levels, small diameters, and independent signals grouped in a cable are a perfect recipe for crosstalk, distortion, and interference." CreationDate="2011-02-14T21:10:40.293" UserId="857" />
  <row Id="15145" PostId="10157" Text="Double check the pin out of the transistor.  Post a schematic if it still doesn't work." CreationDate="2011-02-14T21:11:32.800" UserId="204" />
  <row Id="15146" PostId="10155" Text="thanks, I thought I heard of the stripboard stuff before, but I didn't know the exact name. I'll look into getting some of that, some more components, and a station. I'm not sure where to look online for those pieces, I know theres not many brick stores selling components near me, but I don't know good sites either, I've just pretty much gotten a few bags of random stuff for my own projects and borrowed ones from my school's lab for assignments." CreationDate="2011-02-14T21:13:37.353" UserId="3012" />
  <row Id="15147" PostId="10157" Text="@Robert  I've added a schematic." CreationDate="2011-02-14T21:22:56.197" UserId="1240" />
  <row Id="15148" PostId="10154" Text="Thanks for the suggestion, I hadn't come across them before. Looking at the spec sheets for those cables, though, they reach 7mm OD for 16 cores. So it's thicker by a fair amount than what I need." CreationDate="2011-02-14T21:32:21.753" UserId="2796" />
  <row Id="15149" PostId="10152" Text="Yes, twisted pairs and shielding -- a screen with drain wire, perhaps -- would be nice. For this particular application it hasn't been essential, though: I have made a such a cable from individual, untwisted PTFE-insulated wires myself (but I don't want to do it again, hence the question)." CreationDate="2011-02-14T21:44:14.673" UserId="2796" />
  <row Id="15150" PostId="10157" Text="Try using a different transistor and limit the base current with a resistor per the datasheet." CreationDate="2011-02-14T21:57:12.433" UserId="1363" />
  <row Id="15151" PostId="10154" Text="Try searching google images for [cat5 UTP &quot;100 pair&quot;](http://tinyurl.com/6bxjk8o), there are loads of examples, but I'm having trouble finding the specs for it at the moment!" CreationDate="2011-02-14T22:02:23.713" UserId="2426" />
  <row Id="15152" PostId="10154" Text="This is another possibility: [IO cable](http://www.okidensen.co.jp/en/prod/cable/tashin/saikei_io_cable.html), although the data at the bottom indicates it may still be too thick." CreationDate="2011-02-14T22:05:07.767" UserId="2426" />
  <row Id="15153" PostId="10157" Text="Can you measure the voltage between the emitter and collector while you have the transistor on? Are you sure you don't have the emitter and collector swapped on your board? Are you sure you haven't killed your transistor (Vbe max = 5V)? This should work and the transistor has plenty of power to drive a 50mA load." CreationDate="2011-02-14T22:05:19.590" UserId="638" />
  <row Id="15154" PostId="10157" Text="use a mosfet then you wont need a series R" CreationDate="2011-02-14T22:33:37.413" UserId="1827" />
  <row Id="15155" PostId="10155" Score="1" Text="@nocley Some of the popular shops seem to be [SparkFun](http://www.sparkfun.com/), [Farnell](http://www.farnell.com/), [Adafruit](http://adafruit.com/), [Mouser](http://mouser.com) and [Digikey](http://www.digikey.com/). There are countless others, but these come to my mind right now." CreationDate="2011-02-14T22:37:26.740" UserId="1240" />
  <row Id="15156" PostId="10157" Text="Doesn't the microcontroller have a resistor inside on the pin?" CreationDate="2011-02-14T22:42:43.770" UserId="1240" />
  <row Id="15157" PostId="10157" Text="As for the resistor, would 250 ohm be good enough?" CreationDate="2011-02-14T22:47:58.213" UserId="1240" />
  <row Id="15158" PostId="10157" Score="2" Text="@AndrejaKo The micro does not have a resistor inside the pin. It only has a maximum specified output current which, when exceeded, may release magic smoke. Use Ohm's law to specify the resistor. " CreationDate="2011-02-14T22:59:39.040" UserId="1363" />
  <row Id="15159" PostId="10157" Text="@joeforker OK. Thanks! I definitely don't want to let the magic smoke go!" CreationDate="2011-02-14T23:02:09.527" UserId="1240" />
  <row Id="15160" PostId="4542" Text="@endolith. Nope, I canned/shelved the project. (See my second comment to your answer.)" CreationDate="2011-02-14T23:25:24.310" UserId="1182" />
  <row Id="15161" PostId="10136" Text="@Robert wouldn't that put the ground at non-zero potential? Is that ok?" CreationDate="2011-02-14T23:58:45.080" UserId="3022" />
  <row Id="15162" PostId="10132" Score="1" Text="youre analogy of tying your shoe and scoring a goal, you have to learn to tie your shoe before even walking onto the field....You have to start somewhere, start with the data sheets and start asking specific questions about what you dont understand or cant get to work. search for reference circuits or tutorials to get a better understanding of how component A works or part B. " CreationDate="2011-02-15T00:10:58.050" UserId="2060" />
  <row Id="15163" PostId="10158" Text="Thanks for the link, I found a protection circuit that you may be interested in http://www.all-battery.com/protectioncircuitmodulepcbfor37vli-polymerbattery85alimit-pcb1s.aspx" CreationDate="2011-02-15T00:26:47.470" UserId="2060" />
  <row Id="15164" PostId="10185" Text="Your spec link doesn't work..." CreationDate="2011-02-15T01:07:00.790" UserId="2426" />
  <row Id="15165" PostId="10124" Text="The internal diodes are likely matched to the drivers power capacity, e.g. if the power devices in the L293 can handle the load, the internal clamp diodes should be able to handle the inductive kickback. I would imagine it is *possible* to get a big enough inductor that you could blow the clamp diodes, but you'd likely have to specifically search for it. Basically, assuming you're using the L293 to drive a normal motor, rather then a GIANT inductor, you should be fine." CreationDate="2011-02-15T01:59:42.840" UserId="1374" />
  <row Id="15166" PostId="10185" Score="1" Text="remove the / at the end of the url and it will bring it up till he can fix it" CreationDate="2011-02-15T02:23:27.697" UserId="2060" />
  <row Id="15167" PostId="10139" Text="do you have RS and R/W hooked up and have selected the correct settings for these pins? Edit- never mind its there " CreationDate="2011-02-15T02:44:35.760" UserId="2060" />
  <row Id="15168" PostId="10160" Text="just curios if your using PWM?" CreationDate="2011-02-15T03:22:52.840" UserId="2060" />
  <row Id="15169" PostId="10183" Text="Is it safe to put 400mA ?? in any case if the current in one of the battery goes less then the 2nd battery would me getting above its max charge voltage and might damage it ?&#xA;&#xA;Or do we need to put some sort of cutt-off circuit to each of these batteries ?" CreationDate="2011-02-15T03:57:11.323" UserId="1839" />
  <row Id="15170" PostId="10158" Text="This might turn up to be useful but here in the link it says &quot;from discharging current more than 14A&quot; but in my case the the max discharge current is only 240mA so shouldn't I have a circuit which prevents it from drawing more than 240mA..? If yes then how can I build/buy one of those ??" CreationDate="2011-02-15T04:04:44.437" UserId="1839" />
  <row Id="15171" PostId="10136" Score="1" Text="@Agos - The potential is relative. Ground is an arbitrary designation. In a situation with split rails, as long as the voltage between the rails is fixed, the overall potential of the entire circuit can move up and down without any negative effects." CreationDate="2011-02-15T04:52:30.487" UserId="1374" />
  <row Id="15172" PostId="10189" Text="do you have the datasheet or link for your motor? " CreationDate="2011-02-15T05:44:43.763" UserId="2060" />
  <row Id="15173" PostId="10144" Score="1" Text="And finally, it might be ceramic caps which sound pretty loud in 10Khz range (on some dielectrics) :-)" CreationDate="2011-02-15T05:55:21.317" UserId="2062" />
  <row Id="15175" PostId="10160" Text="@jsolarski No, I'm not using PWM." CreationDate="2011-02-15T08:35:19.373" UserId="1240" />
  <row Id="15176" PostId="10139" Text="@jsolarski Yes, all lines are connected and I can output text, but it starts writing on random position." CreationDate="2011-02-15T08:36:22.007" UserId="1240" />
  <row Id="15177" PostId="9895" Score="1" Text="Any specific reason this was downmodded? Surveying landmarks is a tried-and-true technique to establish absolute direction." CreationDate="2011-02-15T09:21:52.247" UserId="1802" />
  <row Id="15178" PostId="10082" Text="You *should* be able to use a simple constant-current supply to power them. What issues have you been having?" CreationDate="2011-02-15T10:34:30.563" UserId="1374" />
  <row Id="15180" PostId="9949" Text="@reemrevnivek: Many thanks - I've added a small tweak" CreationDate="2011-02-15T12:21:17.670" UserId="763" />
  <row Id="15181" PostId="10147" Text="Thanks for the suggestion, but the DRC errors are exactly what I'm trying to remove." CreationDate="2011-02-15T12:27:43.497" UserId="2960" />
  <row Id="15182" PostId="10146" Text="@W5VO thanks, that's an interesting question. Unfortunately part of the advice is &quot;ignore the DRC errors&quot;." CreationDate="2011-02-15T12:28:25.150" UserId="2960" />
  <row Id="15183" PostId="10148" Text="@Mark - Thanks but I'm afraid your reply doesn't really address my problem. I've already got the bits you suggest down pat :)" CreationDate="2011-02-15T12:30:23.290" UserId="2960" />
  <row Id="15184" PostId="1783" Text="the link is broken..." CreationDate="2011-02-15T13:09:11.320" UserId="689" />
  <row Id="15185" PostId="10146" Text="The best way to handle the problem is very carefully approve the DRC &quot;error&quot;. It is a limitation of the software." CreationDate="2011-02-15T13:24:44.267" UserId="638" />
  <row Id="15187" PostId="10082" Text="I don't have issues yet, just want to understand what is the proper way of driving laser diodes close to their power limit without killing them." CreationDate="2011-02-15T13:42:06.273" UserId="2062" />
  <row Id="15188" PostId="10147" Score="1" Text="You don't seem to have any other option, it looks like an Eagle limitation." CreationDate="2011-02-15T13:58:39.137" UserId="305" />
  <row Id="15189" PostId="10139" Text="@Andrejako have you tried setting the cursor to the return home command after it initializes? It sounds like it starts at a random address in the memory. And could you point me to which page has the initialization info?" CreationDate="2011-02-15T14:11:16.100" UserId="2060" />
  <row Id="15190" PostId="10189" Score="3" Text="Mmmm, sounds like homework.  It's not wrong to ask homework questions usually - provided you tag them and don't ask everyone to just give you the answer." CreationDate="2011-02-15T14:26:00.657" UserId="249" />
  <row Id="15191" PostId="10195" Text="That is a great link." CreationDate="2011-02-15T14:38:37.713" UserId="2060" />
  <row Id="15193" PostId="10082" Text="from my research for the laser cutter i would love to make, constant current or current monitoring is what you will need in the power supply. It depends on your application but both will work with laser diodes." CreationDate="2011-02-15T15:05:11.247" UserId="2060" />
  <row Id="15195" PostId="10142" Text="http://en.wikipedia.org/wiki/Magnetostriction" CreationDate="2011-02-15T15:44:51.363" UserId="142" />
  <row Id="15196" PostId="10129" Score="1" Text="You can pick *any* point in a circuit and call it ground.  It's just a label.  Did someone else design the circuit?  Did they label a point ground?  Did they show how the battery or batteries are connected to it?" CreationDate="2011-02-15T15:48:25.337" UserId="142" />
  <row Id="15197" PostId="10158" Score="1" Text="are you sure it isnt 240mAh? and yes that is the protection circuit needed, I am still looking for a protection circuit diagram myself, but from what i can tell its cheaper to buy a pre-built one(not my favorite choice)" CreationDate="2011-02-15T15:49:09.213" UserId="2060" />
  <row Id="15198" PostId="10198" Text="I'd guess that the different sound is due to the decreased voltage which would change the oscillation frequency." CreationDate="2011-02-15T15:49:45.000" UserId="857" />
  <row Id="15199" PostId="10111" Text="&quot;Both of these waveforms are the sum of *an infinite number of* sine waves&quot;.  You need to decide how many you need in your output." CreationDate="2011-02-15T15:49:46.863" UserId="142" />
  <row Id="15200" PostId="2199" Text="Why the down vote?" CreationDate="2011-02-15T15:59:05.323" UserId="206" />
  <row Id="15201" PostId="4791" Text="@Boyd: The Linistepper, like all stepper motor drivers, puts out a constant voltage on its 4 output wires at some positions. Let's call this &quot;A&quot; at position number 18 (where it puts out AAAAAAAAAAAA...), and &quot;B&quot; at position number 21 (" CreationDate="2011-02-15T16:01:38.237" UserId="813" />
  <row Id="15202" PostId="10158" Text="Yeah its cut-off is at 14A but I did some with 5A but thats still high.. I need something that matches 240mA. Even I would prefer making one myself If i could get the circuit diagram but couldn't find any so far. " CreationDate="2011-02-15T16:03:13.133" UserId="1839" />
  <row Id="15203" PostId="4791" Text="@Boyd: ... &quot;B&quot; at position number 21, where it puts out BBBBBBBBBBBBBBBB... . When you command the Linistepper to hold at position 19, it oscillates AABAABAABAABAAB... . You might imagine that the motor moves to position 18, then moves to position 21, then moves back to 18, but oscillation is so fast that there isn't time for the motor to move more than a tiny fraction of that distance -- that the mechanical inertia of the motor and the electrical low-pass filtering inside the Linistepper keep the motor very close to a fixed location in-between position 18 and position 21." CreationDate="2011-02-15T16:12:52.593" UserId="813" />
  <row Id="15204" PostId="10159" Text="Good point and note blow tourch is useful for taking things apart, but not putting them together. http://www.opencircuits.com/Salvage_Parts_and_Sources" CreationDate="2011-02-15T16:17:16.860" UserId="1498" />
  <row Id="15205" PostId="3210" Text="I've used some of these. The documentation I could get hold of was rubbish!" CreationDate="2011-02-15T18:28:09.313" UserId="2770" />
  <row Id="15206" PostId="10049" Text="The answer to this question is given by Martin Thompson in his answer to http://electronics.stackexchange.com/questions/10050/system-generator-how-to-make-a-channel-selector/10110#10110. I really wish you would keep strongly related topics like these in one question." CreationDate="2011-02-15T19:23:56.497" UserId="1802" />
  <row Id="15207" PostId="10224" Text="Thanks for the quick reply. So if I wanted to run the geared motor just forward or reverse, no speed control, would I be able to just hook it directly to a power supply? Or do I need a resistor or diode inline with it?" CreationDate="2011-02-15T19:47:00.177" UserId="2769" />
  <row Id="15208" PostId="10224" Text="Yes, as long as your powering it with the rated voltage or lower." CreationDate="2011-02-15T19:57:45.687" UserId="2426" />
  <row Id="15209" PostId="10226" Text="Wow, this is exactly what I was hoping for. I am actually planning on mounting this on the back of a large picture frame. It will be a world more pleasing to the eye, not to mention a conversation starter of why my picture frame is plugged into the TV." CreationDate="2011-02-15T20:12:58.803" UserId="3034" />
  <row Id="15210" PostId="3247" Text="I know this is an old thread, but as a follow-up, could I control a large(high torque) servo with the arduino, or would I need to wire it differently?" CreationDate="2011-02-15T20:34:29.353" UserId="2769" />
  <row Id="15211" PostId="3446" Text="+1 for &quot;Make sure that each of the other outputs has the min load&quot;.  Min load is a royal pain when debugging ATX supplies.  Better invest in a supply of high-power resistors." CreationDate="2011-02-15T20:41:33.653" UserId="857" />
  <row Id="15212" PostId="10139" Score="1" Text="@jsolarski Looks like they removed the page with the links, but the documents are [instruction initialization](http://www.display-elektronik.de/INSTRUCTION_INITIALIZATION.PDF), [INITIALIZATION](http://www.display-elektronik.de/INITIALIZATION.PDF), [TIMING](http://www.display-elektronik.de/TIMING.PDF), [SOFTWARE_EXAMPLE](http://www.display-elektronik.de/SOFTWARE-EXAMPLE.PDF)." CreationDate="2011-02-15T20:43:49.737" UserId="1240" />
  <row Id="15213" PostId="10015" Text="It's not a matter of killing yourself, it's a matter of killing things in your amplifier that haven't been killed yet." CreationDate="2011-02-15T21:04:57.723" UserId="142" />
  <row Id="15214" PostId="9557" Text="Then you'll use a full-wave rectifier and smoothing circuit to drive the actual meter" CreationDate="2011-02-15T21:14:47.947" UserId="142" />
  <row Id="15215" PostId="10183" Text="charge in parallel. charger voltage limited to 4.2V. 2nd cell cannot see more than charger voltage. Cells in our application are 8x parallel and work fine.  Cell with lowest resistance charges first, comes up to 4.2V and charges no further." CreationDate="2011-02-15T21:24:40.153" UserId="1481" />
  <row Id="15216" PostId="10198" Text="@davidcary  I just tested the buzzer on voltages form 2.7 V to 5.5 V and it doesn't make the sound I can hear from the microcontroller on any of those voltages. The sound does change with voltage, but it's very different to what I'm getting. On direct power supply, it sounds like speaker on a new computer case or a fax modem, while on controller, it sounds like a whine of a SMPS mixed with ticking sound. I'll try measuring voltage on the buzzer when I'm running it form the microcontroller and report back." CreationDate="2011-02-15T21:43:36.017" UserId="1240" />
  <row Id="15217" PostId="10198" Text="@davidcary Alo, I never used FETs before, so could I use IRF9540N (P-type, 100V, 23A, 140W, Rds:0.117Ω) or IRFZ44N (N-type, 55V, 49A, 94W, Rds:0.0175Ω) instead? They have the advantage of being easily obtainable here." CreationDate="2011-02-15T21:49:25.530" UserId="1240" />
  <row Id="15218" PostId="9451" Text="I was going to suggest the same thing.  They won't make a continuous connection, but if air is moving, they'll connect intermittently, so you'd be looking for them to stop making contact for a long period of time or make continuous contact (stuck together).  Neither of these states should last for long if air is moving.  Use several pairs of strips for redundancy, connected to digital inputs of a micro.  If all the inputs remain unchanged for a few minutes, the air is still." CreationDate="2011-02-15T21:59:42.103" UserId="142" />
  <row Id="15219" PostId="10198" Text="I'm getting 4.97 V on the buzzer terminals. For the transistor, I get Emitter-Collector -0.064 V, Collector-Base -0.502 V (sound changes when measuring), Emitter-Base -0.0569. I don't have a real scope available, but the current theory is probably correct. At first, I connected the buzzer to the decoupling capacitors and ATmega kept resetting. Now I connected it directly to the power pins on the board and I don't have power problems with ATmega.&#xA; " CreationDate="2011-02-15T22:12:21.407" UserId="1240" />
  <row Id="15220" PostId="10229" Score="1" Text="Not to put you down, but probably very few, if any, unless maybe if you had a prior job in the same area." CreationDate="2011-02-15T22:28:29.493" UserId="1225" />
  <row Id="15221" PostId="10229" Score="1" Text="I suppose if you have that entrepreneurial streak, the best way would be to start your own (fabless, of course) design company." CreationDate="2011-02-15T22:39:09.963" UserId="1802" />
  <row Id="15222" PostId="10229" Score="1" Text="A new fab is only a few hundred million $... What a bargain!" CreationDate="2011-02-15T22:46:20.860" UserId="1225" />
  <row Id="15223" PostId="10229" Text="Really *that* cheap?  And I thought it would take a billion...." CreationDate="2011-02-16T00:22:33.780" UserId="1609" />
  <row Id="15224" PostId="10220" Text="Thanks! This might turn out to be very helpful..." CreationDate="2011-02-16T01:03:34.273" UserId="1839" />
  <row Id="15225" PostId="10237" Text="So for each component that I want to put on the board, I have to use a socket for it?" CreationDate="2011-02-16T01:18:54.973" UserId="1657" />
  <row Id="15226" PostId="10235" Score="1" Text="There are these little carrier plugs that fit in 14 pin or 16 pin sockets, that will accommodate 7 or 8 small components, like 1/8W resistors or disc ceramic caps or 1n400x, etc. For example with the 16 pin kind, you'd have a resistor (or cap, etc) between pins 1 and 16, another between pins 2 and 15, etc. I believe this is what Leon Heller's referring to." CreationDate="2011-02-16T02:37:40.477" UserId="740" />
  <row Id="15227" PostId="10240" Text="So you're saying make 1,2,3 into 00, 01, 10, then cycle through the password press by press, testing each press against the stored code in the shift register?" CreationDate="2011-02-16T03:38:19.020" UserId="3037" />
  <row Id="15228" PostId="10242" Text="What if I'm just putting in something like a voltage regulator?" CreationDate="2011-02-16T03:57:08.457" UserId="1657" />
  <row Id="15229" PostId="10247" Text="Maybe my question misleading, I want to know more about the circuit can do in automation" CreationDate="2011-02-16T04:02:01.633" UserId="2596" />
  <row Id="15230" PostId="10038" Text="The weighting is used to focus or shape the particle distribution.  You can still use a particle filter without weighted resampling, but this implies a larger number of particles are needed.  As for the noise affect, take some data to determine the influence of metallic structures.  A Weibull distribution or a gaussian distribution with a non-zero mean might fit the data well enough to proceed." CreationDate="2011-02-16T04:04:04.113" UserId="2632" />
  <row Id="15231" PostId="10247" Text="your question is not so much misleading as *vague*. Depending on the nature of what is automated, a microcontroller is quite often the best option. " CreationDate="2011-02-16T04:06:52.907" UserId="3039" />
  <row Id="15232" PostId="10250" Score="4" Text="+1 for using ASCII. Most apps have processing and bandwidth to spare for this. It's also more immediately apparent when you're getting garbage." CreationDate="2011-02-16T04:38:39.480" UserId="906" />
  <row Id="15233" PostId="10238" Text="Depending on your experience, you may be able to jump straight into a masters program. Otherwise there's a high barrier of entry to IC manufacturing." CreationDate="2011-02-16T04:38:43.993" UserId="638" />
  <row Id="15234" PostId="10237" Score="1" Text="That's how I did everything in school, but I totally understand that that seems like overkill.  They even sell plastic holders with pins that stick into IC wirewrap sockets, and then you solder your resistors and diodes to it.  I looked at Jameco's website but couldn't think of the right search keyword.  I had bought them there, but back in the day I was ordering from the catalog.  :)" CreationDate="2011-02-16T04:40:25.220" UserId="2288" />
  <row Id="15235" PostId="9249" Text="I can answer him. The answer is no, it's not a piezo-resistive effect. It's completely different. Piezo-resistance is a quantum effect related to the change in the inter-atomic distances and the related band-gap. The effect that is questioned here is a mechanical effect, causing particles to touch by squeezing a film with a higher-than-the-particles resistance." CreationDate="2011-02-16T05:28:00.623" UserId="2122" />
  <row Id="15236" PostId="10158" Score="2" Text=" instead of using the 240mAh 1C you should be looking for a higher C rating and mAh, you will get a longer run between charges. some things that you will need to consider are...the runtime of the bot, total current (400mA), so lets say you need to run your bot for 1Hour @ 400mA you would need a 400mAh 1C battery, or a 200mAh 2C for the same hour. but your Battery datasheet should give you a better idea of runtime - reference http://www.allaboutcircuits.com/vol_1/chpt_11/3.html" CreationDate="2011-02-16T05:49:52.167" UserId="2060" />
  <row Id="15237" PostId="10158" Text="As for the protection circuit, I wouldn't worry about over current so much, I would worry if you are pulling more current then what the battery is rated for(causes heat and expansion, and possible fire). as long as you are within the limits you will not have to worry about it." CreationDate="2011-02-16T05:58:57.043" UserId="2060" />
  <row Id="15238" PostId="10229" Score="1" Text="@Thomas, @Ranieri specifically said &quot;fabless&quot;." CreationDate="2011-02-16T06:33:09.913" UserId="2118" />
  <row Id="15239" PostId="6347" Text="RS-232 is inverted (low=1) from the logic level.  A noninverting clamp like this will keep the RS-232 from damaging the UART, but communication won't work." CreationDate="2011-02-16T07:13:07.070" UserId="411" />
  <row Id="15240" PostId="8974" Text="@Peterstone: it contains links to all the publications by that research group. That is the normal way for scientists to share their knowledge." CreationDate="2011-02-16T09:20:18.040" UserId="1802" />
  <row Id="15241" PostId="10239" Text="Tangential comment: You can most likely implement the whole thing in a CPLD quicker, easier and cheaper than using discrete logic components. Added benefit is that the attacker cannot see how the components are wired together. The question is still very relevant though, as you have to construct the whole thing out of logic gates one way or the other." CreationDate="2011-02-16T09:24:11.357" UserId="1802" />
  <row Id="15242" PostId="10244" Text="Excellent question!" CreationDate="2011-02-16T09:30:32.333" UserId="1802" />
  <row Id="15243" PostId="10250" Score="2" Text="+1 for mentioning that it will not automatically synchronize. Many experienced engineers don't seem to get this." CreationDate="2011-02-16T10:49:13.030" UserId="2234" />
  <row Id="15244" PostId="10102" Score="1" Text="+1. This is exactly why laser diodes for communications have integral photo-diodes so that the optical power can be controlled in a feedback loop. They also often have integral thermistors so that the temperature can be regulated with the addition of a Peltier cooler" CreationDate="2011-02-16T10:57:02.383" UserId="2234" />
  <row Id="15245" PostId="10240" Text="not exactly- first press would enter a pair of bits to the 1st stage of the shift register. 2nd press would shift the 1st code to the 2nd stage, and enter the new code in the 1st stage, and so on, so that at any point in time, if you have say 5 stages of shift register, you have the last 5 button presses represented. This 'latest-5' would be checked against the key value *all the time*. I.e., the key is not stored in the shift register, the key is just hardwired inputs to the XORs, or some hidden switch inputs to them; the shift reg stores the user input." CreationDate="2011-02-16T11:53:14.040" UserId="740" />
  <row Id="15246" PostId="10242" Text="@awakeFromNib - use the single pins he mentions. They're just a wire-wrap post, but at one end there's a wider bit that press-fits into the hole, and then the very end is a little fork that you cram the component lead into. A touch of solder will bond the component into the pin. Biggest advantage - you can set the pins anywhere, and accommodate any sort of discrete you want." CreationDate="2011-02-16T11:57:10.743" UserId="740" />
  <row Id="15247" PostId="10237" Text="@Dave - try 'header plug'" CreationDate="2011-02-16T11:57:35.783" UserId="740" />
  <row Id="15248" PostId="10254" Score="3" Text="Not an answer as to whether invertors or uCs are better but beware that multiple crystals can, through EMI coupling, end up in phase and so will drift together. Are you looking for absolute accuracy or low tempco or low long term drift or low immunity to other external factors? What about the effect of voltage, vibration, loading, external fields? If you use a passive component to calibrate, that could drift." CreationDate="2011-02-16T12:52:23.437" UserId="2110" />
  <row Id="15249" PostId="10254" Text="long term drift is the main goal. Temperature &amp; voltage will be very stable (+-0.1C, +-0.01V). Also, temperature controlled box will be EMI-shielded. So possible coupling might be a problem..." CreationDate="2011-02-16T13:19:10.910" UserId="2062" />
  <row Id="15250" PostId="10243" Text="For an application this slow, the ADCs on most microcontrollers will be adequate.  The absolute accuracy may be lackign, but you're not likely to get more than 10 bits of linearity out of your potentiometer, unless you use a very pricey one, or use a stereo pot and average the two signals." CreationDate="2011-02-16T13:43:48.940" UserId="857" />
  <row Id="15251" PostId="10237" Text="@JustJeff thanks!  That's exactly what I was referring to." CreationDate="2011-02-16T14:31:26.310" UserId="2288" />
  <row Id="15252" PostId="10198" Text="I used IRFZ44N and buzzer sounds normal now." CreationDate="2011-02-16T15:01:08.483" UserId="1240" />
  <row Id="15253" PostId="10254" Text="Sounds like a fun statistics problem to me." CreationDate="2011-02-16T16:08:47.887" UserId="319" />
  <row Id="15254" PostId="10238" Text="I'd be going straight into a Master's. Already have a BS Physics and real world experience in electronics (not IC design though)." CreationDate="2011-02-16T16:17:30.933" UserId="1609" />
  <row Id="15255" PostId="10251" Text="Well, that's a fairly dismal picture!  Is this the same experience others have?  So maybe another career path then..." CreationDate="2011-02-16T16:20:06.143" UserId="1609" />
  <row Id="15256" PostId="10260" Text="Well, in fact I am building OCXO, but using multiple crystals to filter out failing ones, and averaging the rest. I don't trust TXCO factory calibration, i need to be better than that :-)" CreationDate="2011-02-16T16:58:20.373" UserId="2062" />
  <row Id="15257" PostId="10262" Text="This would not work for Russia. Anyway, I can use GPS/Glonass clock which is even better, but I need to have independent clock. It will be calibrated by GPS." CreationDate="2011-02-16T17:01:48.203" UserId="2062" />
  <row Id="15258" PostId="10110" Text="A visual diagram of this perform could be perfect to put this answer as a accepted. By the way thank you so much for your answer." CreationDate="2011-02-16T17:16:36.167" UserId="2597" />
  <row Id="15259" PostId="10262" Text="You should be able to receive that transmission in Russia." CreationDate="2011-02-16T17:21:53.633" UserId="305" />
  <row Id="15260" PostId="10265" Text="This belongs on http://electronics.stackexchange.com/" CreationDate="2011-02-16T17:55:10.700" UserId="1229" />
  <row Id="15262" PostId="10265" Text="For current, you the input rating is the minimum. If you can get stronger, there should be no problems." CreationDate="2011-02-16T18:28:47.057" UserId="1240" />
  <row Id="15263" PostId="10263" Text="How do you suggest getting NTP to a device like this? I've had a hard time figuring out how to get the signal with that high of accuracy." CreationDate="2011-02-16T18:28:52.423" UserId="319" />
  <row Id="15264" PostId="10240" Text="Makes sense, thanks a lot! The shift register is the component I needed." CreationDate="2011-02-16T18:38:02.913" UserId="3037" />
  <row Id="15265" PostId="10281" Text="Just about to post this, but you saved me the typing." CreationDate="2011-02-16T18:52:14.650" UserId="857" />
  <row Id="15267" PostId="10188" Text="I've used PSPICE for simulations, but I didn't know about the PCB export abilities on that. I'll see what I can do with that, but I do need to get a bit more components before I even bother doing PCB stuff." CreationDate="2011-02-16T19:10:33.130" UserId="3012" />
  <row Id="15268" PostId="10266" Text="Both answers were superb, thank you SO MUCH.  I ticked this one since it was earlier, it seemed fair!  Thank you so much Olli!" CreationDate="2011-02-16T20:31:44.907" UserId="3048" />
  <row Id="15269" PostId="10229" Text="I don't want to depress you, but if I may add a simple comparison:&#xA;I think it's like applying for a job as a bus driver or truck driver. You may say you have a lot of experience in driving vans as a post deliverer and that you also drove 'large vehicles'. Whilst a van can be big, it isn't completely the same and they would probably tell you to show your driving license for truck/bus. If you don't have that, why should they hire you? You may be familiar with driving, but not with the exact vehicle.&#xA;This isn't answering your question I know, but my personal opinion is that it's going to be hard." CreationDate="2011-02-16T20:32:11.867" UserId="1476" />
  <row Id="15270" PostId="10281" Text="Thank you so much Pyfon!!!  Thank you, thank you for that clear explanation." CreationDate="2011-02-16T20:32:12.910" UserId="3048" />
  <row Id="15271" PostId="10265" Text="PS, for anyone looking for an answer, I also found this QA: http://electronics.stackexchange.com/questions/5759/is-it-normal-for-dc-wall-adapter-power-supplies-to-provide-voltages-above-the-nom" CreationDate="2011-02-16T20:35:13.343" UserId="3048" />
  <row Id="15272" PostId="10286" Text="Does an ARM soft core not give you hardware floating-point operations? " CreationDate="2011-02-16T20:37:05.387" UserId="857" />
  <row Id="15273" PostId="10287" Text="An oscilloscope would not only give you a known impedance, it would show &quot;All over the place&quot; for signals which oscillate quickly.  I don't think that an unstable signal would be &quot;all over the place&quot; so much that a DMM would pick it up, nor would it have a period in seconds.  Of course, it's out of specification, so it could do both of those things." CreationDate="2011-02-16T20:53:40.253" UserId="857" />
  <row Id="15274" PostId="10263" Text="depends on the processor, the NTP protocol is very simple, I've implemented it on PIC18's before, I think its included in microchip's stack now.  The processing required is fairly low you would have to include processing time in the clock setting on something like a PIC to get higher accuracy.   " CreationDate="2011-02-16T20:57:13.107" UserId="1438" />
  <row Id="15275" PostId="10290" Text="Wow, didn't know that! So no dropping resistors, just the load resistor across the loop? That's pretty simple. The LEDs I have are 30 ma but maybe that won't make much difference, worth trying anyway. What effect does the resistor have then? If say I just connected the LEDs in series across the loop without it the resistor, what would that do?? Or do loops HAVE to have a certain resistance??" CreationDate="2011-02-16T21:07:19.457" UserId="3047" />
  <row Id="15276" PostId="10261" Text="Depending on how much you already know, another free resource is Hans Camenzind's book on the subject http://www.designinganalogchips.com/_count/designinganalogchips.pdf" CreationDate="2011-02-16T21:09:39.040" UserId="404" />
  <row Id="15277" PostId="10290" Text="No sorry, everything needs to be in series in the loop including the resistor. " CreationDate="2011-02-16T21:19:42.380" UserId="2612" />
  <row Id="15278" PostId="10290" Text="Excellent, I'll try that out. Thanks" CreationDate="2011-02-16T21:28:44.717" UserId="3047" />
  <row Id="15279" PostId="10283" Text="That font is awesome in the datasheet..." CreationDate="2011-02-16T21:50:41.413" UserId="638" />
  <row Id="15280" PostId="10286" Text="A Cortex-M3 won't!" CreationDate="2011-02-16T21:59:52.703" UserId="305" />
  <row Id="15282" PostId="10250" Text="@MikeJ-UK - indeed. i've seen it happen where someone thinks that just because there are breaks between messsages, that his application's read() calls are automatically going to get the correct message framing." CreationDate="2011-02-16T22:44:49.637" UserId="740" />
  <row Id="15283" PostId="10292" Text="We need to discuss what tag this should get." CreationDate="2011-02-16T22:59:10.570" UserId="230" />
  <row Id="15285" PostId="10292" Text="@cksa361, 4-20mA is still often used in industrial." CreationDate="2011-02-16T23:05:53.823" UserId="230" />
  <row Id="15286" PostId="10009" Text="The tutorial videos are pretty good, and they do not take up an ungodly amount of time either. Excellent recommendation!" CreationDate="2011-02-16T23:09:58.337" UserId="1802" />
  <row Id="15287" PostId="10251" Score="1" Text="I didn't realize you already have a degree in physics.  Technically, you do not have to have a EE degree to do analog IC design.  Physics definitely helps of course since most analog design involves in-depth knowledge of device physics.  Your best chance is doing an MS degree at a school that has co-op programs with technical companies that you are interested in working for.  That's how most entry level jobs (if there are any) are filled in this industry." CreationDate="2011-02-16T23:27:18.943" UserId="3040" />
  <row Id="15288" PostId="10250" Score="1" Text="@JustJeff - And I've seen people send a stream of 0x55 bytes with no gaps as a 'synchronization pattern' without realizing that if connected 'mid-stream', the receiver could take any of the zero bits as a start bit and get valid bit-framing, only to fall-over when the first real data byte arrives." CreationDate="2011-02-16T23:34:24.377" UserId="2234" />
  <row Id="15289" PostId="10250" Text="that's probably why, given the option, i like a couple of 0xFF bytes for the start-of-message marker. " CreationDate="2011-02-16T23:45:04.423" UserId="740" />
  <row Id="15290" PostId="10298" Text="1V across 1Gohm is 1nA of current rather than 1pA.  I think you'd have to be very careful with your buffer design and make sure it has strong high frequency rejection.  Its not hard to generate currents on the level of 1nA from stray EMI especially with probe leads in the mix." CreationDate="2011-02-16T23:46:12.470" UserId="1438" />
  <row Id="15291" PostId="10067" Text="plus one for the interesting idea! I doubt it would be able to handle the power though... " CreationDate="2011-02-17T00:21:38.547" UserId="1235" />
  <row Id="15292" PostId="10077" Text="Well this is going to be a prototype for something that will hopefully be sellable some day!" CreationDate="2011-02-17T00:22:15.160" UserId="1235" />
  <row Id="15293" PostId="9925" Text="I think I am going to use this approach. It seems to be the most cost effective way of getting a lot of heat." CreationDate="2011-02-17T00:24:06.300" UserId="1235" />
  <row Id="15294" PostId="10311" Text="damn, you got the full answer in before I could finish mine. +1. :-)" CreationDate="2011-02-17T00:27:24.200" UserId="974" />
  <row Id="15295" PostId="10307" Text="I've never used such a thing. Are you talking about something like this [TPS61015](http://focus.ti.com/docs/prod/folders/print/tps61015.html)? It looks a bit complicated to me, for example why does it have 10 pins? Why isn't it just Vin, Vout, GND?" CreationDate="2011-02-17T00:40:56.480" UserId="3049" />
  <row Id="15296" PostId="10312" Text="The first couple fans that I have looked at require about 250mA @12VDC" CreationDate="2011-02-17T00:48:06.917" UserId="1235" />
  <row Id="15297" PostId="10298" Text="Higher voltage will definitely help in that case. You need to go lower than 1 pA though. Check out http://www.national.com/pf/LM/LMP7721.html, especially some of the application circuits. You will have to be VERY careful about contamination on your board, any kind of flux will create a leakage path.&#xA;&#xA;Also, you'd be much better off with an alternate circuit than a voltage divider. Noise will dominate your measurement. Check out a transimpedance amplifier." CreationDate="2011-02-17T01:01:33.850" UserId="404" />
  <row Id="15298" PostId="10313" Score="1" Text="instead of diodes you could use a Rectifier http://www.radioshack.com/product/index.jsp?productId=2062580 " CreationDate="2011-02-17T01:03:21.750" UserId="2060" />
  <row Id="15299" PostId="10307" Text="That's the sort of thing. Because it's boosting the voltage it requires an inductor as well as other parts. You don't actually have much choice!" CreationDate="2011-02-17T01:07:16.287" UserId="305" />
  <row Id="15300" PostId="10286" Text="Would it be too complicated to provide a bus to an FPGA multiplier?" CreationDate="2011-02-17T01:39:22.560" UserId="2118" />
  <row Id="15301" PostId="10308" Text="I've tried connecting it directly to the AA battery and it resulted in 1.380 V - 110 mA. Do you think it's dangerous?" CreationDate="2011-02-17T01:49:24.977" UserId="3049" />
  <row Id="15302" PostId="10307" Text="I would really like to keep it super simple. I'll need to make a couple of them and use them for active markers for an IR camera. I think I'll stay with resistors." CreationDate="2011-02-17T01:50:41.947" UserId="3049" />
  <row Id="15303" PostId="10310" Text="I have a dozen of those LEDs. I've checked them with my cheap multimeter and in the diode testing mode, it said 1537-1540 for all of them. And the one sample I've measured is precisely 0.10 A @ 1.35V, like in the specification. Do you think I really need that complexity? I'd need to make a dozen of them." CreationDate="2011-02-17T02:01:07.847" UserId="3049" />
  <row Id="15304" PostId="10318" Text="Uhm, my AA battery is capable of supplying 4A, so it's not really a useful limit in my case. But I tried it connecting directly to the battery and it resulted in 1.380 V - 110 mA. Do you think it's too much?" CreationDate="2011-02-17T02:03:08.813" UserId="3049" />
  <row Id="15305" PostId="10298" Text="@Chris - Thanks for the advice! My answer was just a first shot at solving the problem, and unfortunately I didn't know anything about transimpedance amplifiers before tonight.  Want to throw an answer up?" CreationDate="2011-02-17T02:47:19.560" UserId="857" />
  <row Id="15306" PostId="10307" Score="1" Text="@zsero, You will still need current-limiting resistors, even with a boost regulator. You can use two batteries instead." CreationDate="2011-02-17T02:56:11.153" UserId="2118" />
  <row Id="15307" PostId="10296" Score="1" Text="A AA battery's capacity is between about 1V and 1.4V. You need a higher voltage to get any battery life and maintain 100mA. Two AA's will drop from 2.8V to ~2V: 2.8V/110mA=25ohm; 2.0V/90mA=22ohm -- so about 20ohms, in series with battery ESR, will do it, and actually use the whole battery." CreationDate="2011-02-17T03:02:27.857" UserId="2118" />
  <row Id="15308" PostId="10290" Text="@davek, test your LEDs with a battery and resistor (or a variable-current supply if you have one) to see if their brightness is sufficient for you." CreationDate="2011-02-17T03:29:24.117" UserId="411" />
  <row Id="15309" PostId="10290" Text="Do you want the LEDs to extinguish at 4 mA?" CreationDate="2011-02-17T03:30:10.280" UserId="411" />
  <row Id="15310" PostId="10290" Text="If so, then you will need to add a resistor across the LEDs to take 4 mA current at something less than their forward voltage.  But this will steal some current at full brightness too, leaving maybe 15 mA for the LED." CreationDate="2011-02-17T03:30:27.113" UserId="411" />
  <row Id="15311" PostId="10290" Text="You can get higher current with a switching step-down power supply, but I would suggest you avoid it if 20mA is bright enough for you." CreationDate="2011-02-17T03:32:48.060" UserId="411" />
  <row Id="15312" PostId="10322" Score="8" Text="You will do better to think about electronics as a kind of applied math, and forget about the electrons entirely." CreationDate="2011-02-17T03:34:44.360" UserId="411" />
  <row Id="15313" PostId="10318" Text="according to the datasheet, it should work, I would still use a resistor for longer life and better battery performance   http://electronics.stackexchange.com/questions/8182/will-these-leds-work-for-throwies/8187#8187" CreationDate="2011-02-17T04:44:56.537" UserId="2060" />
  <row Id="15316" PostId="10328" Text="What makes that scheme canonical?" CreationDate="2011-02-17T05:02:01.490" UserId="857" />
  <row Id="15317" PostId="10328" Text="Sounds about the same as what I've seen." CreationDate="2011-02-17T05:02:39.040" UserId="1407" />
  <row Id="15318" PostId="10318" Text="@zsero sorry, I should have boldfaced and italicized the ***if*** when I was talking about the output current limit.  :)  I would definitely use a resistor.  LEDs will not last long if constantly driven with 100mA.  You really need to PWM the LED in such a situation." CreationDate="2011-02-17T05:08:04.883" UserId="2288" />
  <row Id="15319" PostId="10323" Score="1" Text="Thanks. Just wondering though: Why would devices &quot;choose&quot; to require -5 Volt instead of +5 Volt? If I have a device that's powered by a &quot;normal&quot; Power Supply, why wouldn't the manufacturer just require +5 Volt? (Some LC Screens requite negative voltage)" CreationDate="2011-02-17T05:17:13.810" UserId="3051" />
  <row Id="15320" PostId="10323" Text="It's specific to the device. Read up on how LCD's work at a technical level and I bet it'll explain it." CreationDate="2011-02-17T05:43:12.157" UserId="131" />
  <row Id="15321" PostId="10323" Text="@michael, LCD screen contrast provides the reference for each of the cells. It may be rated for common 3.3V or 5V for easy integration, but the cells may need more of a drop in order to read them (molecules need to be twisted). Often 5V LCDs can use 0V contrast, even without an integrated (-ve) charge pump." CreationDate="2011-02-17T05:51:57.413" UserId="2118" />
  <row Id="15322" PostId="9325" Text="What's the frequency of the RF signal?" CreationDate="2011-02-17T06:45:23.800" UserId="638" />
  <row Id="15323" PostId="10286" Text="The ARM has a multiplier. There is a lot more to floating-point than that." CreationDate="2011-02-17T07:07:39.467" UserId="305" />
  <row Id="15324" PostId="10335" Text="Hmmm...I think I need to figure out what my brother-in-law is using to connect to the Prius. If he's just plugging in his USB cable directly into the Prius, then I think the 7805 is not going to work...don't they take a higher input voltage?  USB is at 5V already no?" CreationDate="2011-02-17T07:43:22.557" UserId="1288" />
  <row Id="15325" PostId="10335" Text="i was stating to bypass the prius usb and connect to the electrical system(12v) I really dont know of anyway to prevent it from browning out like that from the usb, unless you want to hack a Ipod Cable and put something to prevent that brownout/spike. " CreationDate="2011-02-17T08:14:19.037" UserId="2060" />
  <row Id="15326" PostId="10250" Text="How exactly does the synchronization pattern work? Could somebody elaborate on this? If the bytes themselves aren't lined up, how could it get re-sync'd?&#xA;Is this: http://en.wikipedia.org/wiki/Asynchronous_serial_communication&#xA;a good description of how it works? If so, I can see that ASCII will do the job fine. " CreationDate="2011-02-17T10:49:37.767" UserId="3039" />
  <row Id="15327" PostId="10310" Score="1" Text="@zsero - It could be that the LEDs' characteristics are very tightly controlled at manufacture and that the datasheeet is over-cautious. What you have done is a &quot;select-on-test&quot; process which used to be common in industry but is too labour intensive these days. It's still perfectly valid though. If you have tested a bunch of LEDs and they work in your circuit, use them.&#xA;My answer was based on experience. I have seen circuits where insufficient voltage has caused wide variations in brightness." CreationDate="2011-02-17T11:14:20.803" UserId="2234" />
  <row Id="15328" PostId="10250" Score="2" Text="It doesn't necessarily work - that was my point. I think we were over-complicating the issue from your point of view. Just be aware that if you need very reliable communications, your receiver should check the data against some expected pattern. If the pattern doesn't match, throw the data away and wait until it does. The more complicated you make the pattern, the less likely it will be to be erroneously detected in corrupted data." CreationDate="2011-02-17T11:27:32.150" UserId="2234" />
  <row Id="15329" PostId="1770" Text="There is a lot of strange and silly things that can be done with a Arduino, and hackaday is filled with strange example. Take the &quot;fart o metet&quot; as example: http://hackaday.com/2011/02/16/arduino-fart-o-meter/" CreationDate="2011-02-17T11:53:43.750" UserId="689" />
  <row Id="15330" PostId="10341" Score="1" Text="You just described the entirety of my debugging process:  Plug it in, if it burns up - something is wrong!" CreationDate="2011-02-17T13:22:38.623" UserId="1823" />
  <row Id="15331" PostId="10349" Score="1" Text="how are car lighter converts a little light for the job? " CreationDate="2011-02-17T13:37:04.967" UserId="2060" />
  <row Id="15332" PostId="10343" Score="1" Text="I wonder if you could just take the one male and one female USB connector and take the power and ground, add the caps to smooth the power and connect the corresponding data lines together, and the circuitry that is needed for the charging is built into the cable." CreationDate="2011-02-17T13:44:48.313" UserId="2060" />
  <row Id="15333" PostId="10341" Text="just try not to go over the Power rating of the inverter. you should have a tag saying how many watts its rated for. But dont worry if it gets slightly hot(can still touch it and not get burned) " CreationDate="2011-02-17T13:49:15.707" UserId="2060" />
  <row Id="15334" PostId="10313" Text="&quot;a little higher than 12VDC&quot;? More like 40% higher at least. You're smoothing the peak of the ac, not the rms, so it has the 1.414 factor for a start. Then add on the fact that transformers are specified for the output voltage at the full load, so if you don't fully load them, the output voltage is higher (see the regulation part of their spec). Then subtract the diode drops. " CreationDate="2011-02-17T13:53:26.790" UserId="2110" />
  <row Id="15335" PostId="1834" Text="how you connect qtr senzor to your microcontroler ? " CreationDate="2011-02-17T13:55:28.117" UserId="3058" />
  <row Id="15336" PostId="10349" Text="if the convertor is passing through a surge that is resetting the device, then it's too light/weak or not up for the job." CreationDate="2011-02-17T13:58:58.167" UserId="2157" />
  <row Id="15337" PostId="10341" Text="@RQDQ: Well, not burnup, but heating above 50C :-)" CreationDate="2011-02-17T14:07:45.227" UserId="2062" />
  <row Id="15338" PostId="10285" Text="My priorities are:&#xA;1) Performance, using less logic cells is better&#xA;2) Community, What I'm trying to do is hard enough without support from a community.&#xA;3) Flexability, the ease at which new &quot;instructions&quot; can be added.&#xA;&#xA;I'm using a Spartan 3E with 500K gates (10K cells)." CreationDate="2011-02-17T14:22:18.223" UserId="3045" />
  <row Id="15339" PostId="10351" Score="2" Text="Yes. I am looking for a way to detect symbol rate for a general received signal, not just for standard serial ports. In addition, there is no START or any other kind of flag symbols to help the receiver. " CreationDate="2011-02-17T14:43:00.137" UserId="3061" />
  <row Id="15340" PostId="10343" Text="@jsolarski That's what I meant." CreationDate="2011-02-17T14:59:17.970" UserId="1240" />
  <row Id="15341" PostId="10322" Score="1" Text="Yeah, don't think about electrons.  Engineers use conventional current instead (&quot;just a convention&quot;), since charge can flow in both directions at the same time.  http://amasci.com/amateur/elecdir.html  And power is not &quot;generated&quot; by electrons.  Energy is carried in electric and magnetic fields.  http://amasci.com/elect/poynt/poynt.html" CreationDate="2011-02-17T15:13:44.483" UserId="142" />
  <row Id="15342" PostId="10324" Text="Ground is just a convention, too.  You can pick any single point in a circuit and label it ground, but we choose specific points out of convention." CreationDate="2011-02-17T15:16:59.657" UserId="142" />
  <row Id="15343" PostId="10350" Text="What is your signal look like at baseband? Is it a square wave?" CreationDate="2011-02-17T15:59:00.633" UserId="319" />
  <row Id="15344" PostId="10350" Text="It is a baseband signal. It is filtered raised cosine filter. And it has some white Gaussian noise. " CreationDate="2011-02-17T16:03:35.933" UserId="3061" />
  <row Id="15348" PostId="10323" Score="2" Text="+1 for the ASCII art." CreationDate="2011-02-17T16:34:37.030" UserId="204" />
  <row Id="15351" PostId="10350" Text="Sounds nasty to me. What type of system is using this?" CreationDate="2011-02-17T17:01:01.727" UserId="319" />
  <row Id="15352" PostId="10266" Text="If this answered your question, you should mark it as an answer (http://meta.stackoverflow.com/questions/5234/how-does-accepting-an-answer-work)" CreationDate="2011-02-17T17:11:07.423" UserId="3064" />
  <row Id="15353" PostId="10350" Text="As a note, I have been talking through this with my coworker. At least from the theory that we remember being taught we thought that you don't get any benefit from using shapes other then square." CreationDate="2011-02-17T17:18:05.137" UserId="319" />
  <row Id="15354" PostId="10350" Text="What kind of modulation is used?&#xA;BTW: I thought that in general baseband signal is down covered by mixer but not yet demodulated. Is this a case?" CreationDate="2011-02-17T17:21:31.450" UserId="1471" />
  <row Id="15355" PostId="10350" Text="It is a signal a from a radio communication system. &#xA;&#xA;Using square shape signal minimizes the probability of misdetection of symbol, But square shapes needs a wide bandwidth to send. The raised cosine shape provides a good trade-off between bandwidth and symbol detection. &#xA;&#xA;Signals would be modulated with BPSK, QPSK, etc. The modulation does not have direct impact on symbol rate detection because the given signal is demodulated already." CreationDate="2011-02-17T17:29:53.890" UserId="3061" />
  <row Id="15356" PostId="10328" Score="1" Text="I suppose since the overwhelming majority of books, schematics, etc. that I've seen use this scheme." CreationDate="2011-02-17T17:30:28.697" UserId="1293" />
  <row Id="15357" PostId="10282" Text="From what I gathered from the responses: Microblaze is a better soft cpu than it's ARM counterparts. Therefore it is better for FPGA use. Thanks all." CreationDate="2011-02-17T17:35:20.810" UserId="3045" />
  <row Id="15358" PostId="10350" Text="@mazurnification: It is actually the plot of phase of demodulated baseband signal. " CreationDate="2011-02-17T17:40:47.933" UserId="3061" />
  <row Id="15359" PostId="10261" Text="That PDF is a great read!   Now I will get none of the work I'm paid to do done today..." CreationDate="2011-02-17T18:40:46.143" UserId="1609" />
  <row Id="15360" PostId="10347" Text="The Wikipedia article has both a table and a list.  The table says &quot;The table below lists designators commonly used, and does not comply with the standard.&quot;  The list says &quot;Component name abbreviations widely used in industry.&quot;  But, upvoted for the list standards and the Wikipedia references to those standards (and others)." CreationDate="2011-02-17T19:31:43.897" UserId="857" />
  <row Id="15361" PostId="9799" Text="Well, I am definitely disabling the pull-ups, but it is not correcting the issue. There is still a significant amount of current leakage through the SCK and MOSI lines." CreationDate="2011-02-17T20:18:55.567" UserId="2895" />
  <row Id="15362" PostId="175" Text="not only do you have to be signed up for the MFI (Made for iPhone) program, but your hardware has to include an Apple authentication chip -- that's actually the hard part." CreationDate="2011-02-17T20:23:42.697" UserId="1322" />
  <row Id="15364" PostId="10350" Text="Do you have any examples of what each symbol looks like? I am having a hard time seeing what something like that would decode to." CreationDate="2011-02-17T20:47:01.757" UserId="319" />
  <row Id="15367" PostId="10356" Text="@heckruler, I like your approach, but if you only connect one side of a circuit to 10V and leave the other floating(both relative ground) you will find that the entire device should measure 10V, as you have just charged it to 10V, if it only went to 8V on the fare side you have a 2V drop and current is flowing. This would only happen if your measurement device was loading it." CreationDate="2011-02-17T23:10:27.163" UserId="230" />
  <row Id="15368" PostId="10324" Text="@michaelStum, @pingswept, I always like to remind people that there is potential energy from height if you take physics. (mgh) is potential energy, if I pick the atmosphere as my reference we all suddenly have negative potential energy." CreationDate="2011-02-17T23:11:56.070" UserId="230" />
  <row Id="15369" PostId="10324" Text="Good points, the both of you." CreationDate="2011-02-17T23:30:47.870" UserId="712" />
  <row Id="15370" PostId="10350" Score="1" Text="I am almost positive you are overflowing and wrapping somewhere in your data acquisition system. I think you need to take a closer look at your filter, and maybe change the topology." CreationDate="2011-02-17T23:53:17.767" UserId="1374" />
  <row Id="15371" PostId="10350" Text="So, let me condense your description a bit... Basically you are trying to do clock rate recovery from a binary (or is it more heavily encoded, such as [PAM](http://en.wikipedia.org/wiki/Pulse_amplitude_modulation) ) bitstream, which lacks any fixed features (e.g. stop bits). It sounds like you just need to schmitt trigger filter it, and then just fft the resulting edges." CreationDate="2011-02-17T23:55:37.267" UserId="1374" />
  <row Id="15373" PostId="10350" Text="@FakeName:  The phase counter may be wrapping, but just imagine that the Y axis is wrapped around a circle.... 0 and MAX are the same value.   If he is taking the difference between successive samples in, say, 2's-complement signed integers, it can work. " CreationDate="2011-02-18T00:09:24.660" UserId="2235" />
  <row Id="15374" PostId="10360" Text="Whoops, thanks for getting the correct information. I'll dabble more carefully next time." CreationDate="2011-02-18T00:39:41.800" UserId="638" />
  <row Id="15375" PostId="10350" Text="@Joe - potentially yes, but I think if we could see a more continuous-looking waveform we might be able to eyeball something and think up a heuristic algorithm for finding the baud rate.  Man that was a lot of big words." CreationDate="2011-02-18T00:41:05.720" UserId="249" />
  <row Id="15376" PostId="8619" Text="Getting stuff done is a lesson that is best learnt the hard way" CreationDate="2011-02-18T00:52:17.650" UserId="3045" />
  <row Id="15377" PostId="6461" Text="C and C++ aren't good enough for video. You'll need Verilog for that :)" CreationDate="2011-02-18T00:53:19.240" UserId="3045" />
  <row Id="15378" PostId="10076" Score="1" Text="I think of &quot;E&quot; as &quot;Extended Temperature&quot;" CreationDate="2011-02-18T00:53:44.950" UserId="2235" />
  <row Id="15379" PostId="10346" Text="What kind of protective insulation?" CreationDate="2011-02-18T02:09:08.080" UserId="142" />
  <row Id="15380" PostId="10366" Text="Thanks for this idea, in terms of size and complexity this is the closest one to what I'm thinking! But I still don't understand if this has any kind of limit for either voltage or current. I mean it looks like a nice device for saving the batteries, but I would still need to use something to limit the voltage to 1.35 V no matter how the battery is changing, do I not?" CreationDate="2011-02-18T03:06:45.237" UserId="3049" />
  <row Id="15382" PostId="6366" Text="That is a fracking good answer." CreationDate="2011-02-18T03:18:42.180" UserId="3045" />
  <row Id="15383" PostId="9799" Text="Is the leakage equal between SCK and MOSI, or more so one than the other?" CreationDate="2011-02-18T03:44:29.510" UserId="1293" />
  <row Id="15384" PostId="7335" Text="Yes, FFT is the way to go. To get exactly 2 Hz wide frequency bins, you'll need to pass a window of data exactly 0.5 seconds long to the FFT." CreationDate="2011-02-18T04:32:09.140" UserId="813" />
  <row Id="15385" PostId="10374" Text="Yes! That looks like what I need. What audio input component would you recommend for this?" CreationDate="2011-02-18T04:33:24.973" UserId="3065" />
  <row Id="15386" PostId="8619" Text="@kurtnelle it sounds like you're advocating not using the .NET MF? " CreationDate="2011-02-18T04:38:33.053" UserId="2288" />
  <row Id="15388" PostId="10377" Text="Hey, if I connected the MAX232 chip, it would still be a COM port but over serial right? I was thinking of using an FTDI but where I live it isn't available easily. " CreationDate="2011-02-18T05:30:20.750" UserId="1200" />
  <row Id="15389" PostId="10335" Text="Oh I see. Ok...if we want to purely power up the iPod then this will work. We also want the iPod to communicate with the car's audio system...so your suggestion won't work in our situation." CreationDate="2011-02-18T08:03:07.753" UserId="1288" />
  <row Id="15390" PostId="10332" Text="You should have edited your original topic with new conclusions, instead of providing an answer to your own question. This was probably the reason why some users have down voted your answer and didn't bother explaining the reasons. Read the rules, if you want to avoid this in the future." CreationDate="2011-02-18T08:14:03.840" UserId="1129" />
  <row Id="15391" PostId="6461" Text="There are at least 10 projects that create video with just software. Most are B/W or gray, but there are even color ones and game systems with just AVR software generated video. OSD projects also exist. There are also few examples of capturing low res video frames with AVR without FPGA. Just google around..." CreationDate="2011-02-18T08:29:55.137" UserId="1129" />
  <row Id="15392" PostId="10379" Text="Here's the datasheet www.analog.com/static/imported-files/data_sheets/AD676.pdf. It's a good place to start." CreationDate="2011-02-18T08:47:08.507" UserId="1240" />
  <row Id="15393" PostId="10381" Text="How would it reach middle position? By only a spring?" CreationDate="2011-02-18T08:54:25.643" UserId="1950" />
  <row Id="15394" PostId="10381" Score="1" Text="@AndreKR &amp; Dave - Correct, but it not a brushed motor. It is basically an solenoid with a magnetic plunger, and spring centering. You drive current through it in one direction, and it repels the plunger, the other and it attracts it, turning toe other direction. When no power is applied, it is centered by the spring. Technically, it's really not a servo, per-se." CreationDate="2011-02-18T09:02:43.557" UserId="1374" />
  <row Id="15396" PostId="10387" Text="I understand more now from asking 1 question than from reading all that documentation. " CreationDate="2011-02-18T10:12:43.457" UserId="3045" />
  <row Id="15397" PostId="10384" Text="Would that be the output of the the board or just the IC?" CreationDate="2011-02-18T10:13:51.723" UserId="3045" />
  <row Id="15398" PostId="10392" Score="1" Text="I really don't understand this question at all. Is it making a distinction between &quot;electronic&quot; and &quot;electrical&quot;? Is it about software or hardware?" CreationDate="2011-02-18T07:46:43.497" />
  <row Id="15399" PostId="10392" Text="electrical tends to be associated with interconnection of motors, high voltage switch gear, three-phase transformers, etc. Most electronic circuit makers don't model these components." CreationDate="2011-02-18T09:22:32.370" />
  <row Id="15400" PostId="10392" Text="@keenan, Johs has described me well :) Thanks @John. &#xA;And its about software." CreationDate="2011-02-18T09:27:46.430" />
  <row Id="15405" PostId="10395" Text="Any way I can avoid those diodes and resistors? MAX232 does what this is trying to achieve right? BTW, what are the arrows on the left indicating?" CreationDate="2011-02-18T12:29:35.897" UserId="1200" />
  <row Id="15406" PostId="10372" Text="Side question: I'm using an LT1933. In the datasheet, for 34V in and 3.3V out, they recommend a 40V catch diode. If I'm not mistaken, isn't the catch diode exposed to full brunt of the supply's 34V about 550,000 times per second?" CreationDate="2011-02-18T12:30:07.153" UserId="1225" />
  <row Id="15407" PostId="10395" Text="Yes, it is possible to do that using max232, but I don't have scheme nearby. This particular scheme does very rough voltage level conversion, max232 is much better. " CreationDate="2011-02-18T12:31:58.837" UserId="2062" />
  <row Id="15408" PostId="10395" Text="Also, what is uniprof? Couldn't find anything about it. See the schematic I posted in my update. That good enough?" CreationDate="2011-02-18T12:35:45.533" UserId="1200" />
  <row Id="15409" PostId="10110" Text="Diagram of what particular part?" CreationDate="2011-02-18T12:48:06.437" UserId="763" />
  <row Id="15410" PostId="10395" Text="http://www.getchip.net/wp-content/plugins/download-monitor/download.php?id=14" CreationDate="2011-02-18T13:15:12.097" UserId="2062" />
  <row Id="15411" PostId="10394" Text="Here is another good source of information about different ways to program AVRs: http://elm-chan.org/works/avrx/report_e.html" CreationDate="2011-02-18T13:15:17.147" UserId="2489" />
  <row Id="15412" PostId="10398" Text="Of course, splitting the voltage would dissipate a lot of power, unless some kind of switch-mode splitter (if such a thing even exists) was used." CreationDate="2011-02-18T13:28:14.157" UserId="1225" />
  <row Id="15413" PostId="10398" Text="See my edit about half-wave rectification, that should be less wasteful." CreationDate="2011-02-18T13:37:44.513" UserId="1802" />
  <row Id="15414" PostId="10370" Text="Software Defined Radio is a technique, and there are many ways to implement it before and after the digital break. I can certainly understand using a voltage controlled oscillator, but it isn't a requirement for a SDR." CreationDate="2011-02-18T13:45:11.303" UserId="638" />
  <row Id="15415" PostId="10350" Text="@Fake Name: Actually I just have access to such signals. I cannot change the properties of sender or demodulation units of receive. All we have is a binary file that contains samples of this signal." CreationDate="2011-02-18T13:51:13.763" UserId="3061" />
  <row Id="15416" PostId="10381" Score="1" Text="@Fake Out of curiosity, how can you tell that it's a solenoid? I haven't seen any models use that, but I also haven't gotten one in a while." CreationDate="2011-02-18T13:52:52.917" UserId="638" />
  <row Id="15417" PostId="10350" Text="@FakeName: Approximately yes. I am doing &quot;symbol clock recovery&quot; from a binary or PAM encoded signal. This signal does not have any hints (e.g. stop bits). The receiver is faced with two problems: *Symbol Rate Estimation* and *Symbol Timing Synchronization*. I am seeking for a solution for the former." CreationDate="2011-02-18T13:55:53.367" UserId="3061" />
  <row Id="15418" PostId="10384" Text="Hopefully both.  I've never seen the output of a voltage regulator be different than the output of the pins that the powered-device is connected to on the board." CreationDate="2011-02-18T13:56:34.700" UserId="2288" />
  <row Id="15419" PostId="10381" Score="1" Text="@Fake oh duh, I totally forgot about the cars I've seen in the past.  It's really obvious when you see the wheels flick back and forth.  Definitely a solenoid." CreationDate="2011-02-18T13:58:11.187" UserId="2288" />
  <row Id="15420" PostId="10381" Text="...and I just threw that little car away about a month ago.  Rats!  I could have pulled it apart." CreationDate="2011-02-18T13:58:57.300" UserId="2288" />
  <row Id="15421" PostId="10393" Text="@Onur it sounds like he wants something that handles electrician-type work, not electronics work." CreationDate="2011-02-18T14:01:13.133" UserId="2288" />
  <row Id="15422" PostId="10350" Text="@AngryEE: I would be really happy if a good heuristic is suggested for this problem. But I think this problem is discussed in the academic and there ARE some methods for it (look at the cyclostationary paper I cited in the question). I am looking for an implementation of these kind of methods" CreationDate="2011-02-18T14:03:18.910" UserId="3061" />
  <row Id="15423" PostId="10364" Text="Thanks. But the clock recovery is done in another module which I don't have access to it. `PLL`s is for *carrier clock recovery* while I am seeking for a method for *symbol clock (rate) recovery*" CreationDate="2011-02-18T14:06:33.680" UserId="3061" />
  <row Id="15424" PostId="10373" Text="Thanks. Not sure about `FFT` because the noise would create high  frequencies in the spectral domain. The auto-correlation would be the right solution for this problem. There is no *burst transmits* and no **stop-bits**/**stop-symbols**. The first option you suggested in *autocorrelation* section is what is called cyclostationary properties of signal. Based on the cited paper in the question, this method is not robust when the sender uses raised-cosine shape filter with a small roll-off (a&lt;0.3). The paper suggest an improved method. I hope i can find an implementation of that method." CreationDate="2011-02-18T14:19:34.023" UserId="3061" />
  <row Id="15425" PostId="10390" Text="Epic, thanks dude" CreationDate="2011-02-18T14:23:24.783" UserId="3045" />
  <row Id="15426" PostId="10374" Text="Note that the IC combines all the outputs into a single pin.  Looks like you have to hit it with a clock signal to get a DC value for each band?  Then you'd feed that DC value into your arduino ADCs?  Kinda convoluted for something you can just do for free inside the Arduino with an FFT." CreationDate="2011-02-18T14:56:41.073" UserId="142" />
  <row Id="15427" PostId="9146" Text="Dupe? http://electronics.stackexchange.com/questions/4795/books-for-basic-electronics http://electronics.stackexchange.com/questions/616/basic-electronics-book" CreationDate="2011-02-18T14:59:12.850" UserId="142" />
  <row Id="15428" PostId="10374" Text="I disagree.  Toggling a pin and taking an ADC reading is MUCH easier than doing an FFT." CreationDate="2011-02-18T15:06:16.677" UserId="857" />
  <row Id="15429" PostId="10374" Text="Also this is limited to 7 bands, and it's a peak reading instead of an RMS reading.  An FFT can do as many bands as you want, in whatever way you want." CreationDate="2011-02-18T15:09:18.863" UserId="142" />
  <row Id="15430" PostId="9799" Text="Well, I tested them simultaneously with 2 different types of ammeters and I'm afraid that they may have had slightly different impedances. I was getting ~80mA on one line and ~120mA on the other. However, I can't remember which is which. I assumed they are very close to equal." CreationDate="2011-02-18T15:13:19.900" UserId="2895" />
  <row Id="15431" PostId="10386" Text="I don't know about ATmega, but many PIC UARTs can invert the output.  Read the datasheet." CreationDate="2011-02-18T15:36:12.773" UserId="411" />
  <row Id="15432" PostId="10402" Text="That is exactly what the RC car we tore down as part of our engineering project last year looked like. Definitely just a motor, gears, and spring." CreationDate="2011-02-18T15:37:33.037" UserId="536" />
  <row Id="15434" PostId="10388" Text="This seems to have more information available and is closer to what I'm trying to do. Found this and it's extremely similar to what I'm trying to do: http://blog.makezine.com/archive/2010/10/circuit-skills-led-color-organ-spon.html" CreationDate="2011-02-18T16:12:55.253" UserId="3065" />
  <row Id="15436" PostId="10409" Text="My desire for wanting to go embedded is cost and size. Guess I will need to weigh development time in there." CreationDate="2011-02-18T17:41:46.580" UserId="319" />
  <row Id="15439" PostId="10412" Text="Interesting idea.... but maybe a magnet and reed switch would work better and be less prone to wear." CreationDate="2011-02-18T18:00:56.120" UserId="2426" />
  <row Id="15440" PostId="10426" Score="2" Text="I don't prefer them. They are all I have right now. So just wanting to use parts at hand to solve problem at hand." CreationDate="2011-02-18T18:32:01.323" UserId="1200" />
  <row Id="15441" PostId="10405" Text="If you haven't seen this, you may consider it for it's small size, powerful capabilities, but not cheap price: http://www.phidgets.com/products.php?product_id=1072" CreationDate="2011-02-18T18:33:12.697" UserId="2457" />
  <row Id="15442" PostId="10405" Text="@gahooa that is interesting. I am looking for a cheap option though. My market would be buying 10's or 100's of my device so every cent I can cut costs can help make the item more marketable." CreationDate="2011-02-18T19:00:39.927" UserId="319" />
  <row Id="15443" PostId="10421" Text="What are the downsides of the MAX202? If you can just replace the MAX232 with it and use 100n caps then why is everyone still using the MAX232?" CreationDate="2011-02-18T19:04:23.900" UserId="319" />
  <row Id="15444" PostId="10407" Text="Leon's link is for BC859 / BC860.  Not sure how trustworthy deep links to NXP.com are." CreationDate="2011-02-18T19:06:24.090" UserId="411" />
  <row Id="15445" PostId="7675" Text="People that say the &quot;Door Close&quot; button does nothing are only sometimes correct.  For one, it depends on the elevator system, and two, it depends on the context in which you're pressing it.  For example, in my office's elevator, the door close button will immediately close the door if it stopped at a floor because someone *inside* requested it.  In some override mode, I've seen it used to keep the door open despite the cab moving (used when we needed to transport something that was ~3 inches too long for the elevator)" CreationDate="2011-02-18T19:43:43.160" UserId="1407" />
  <row Id="15446" PostId="10421" Text="There are no downsides. I think it's caused by people looking at old designs, they just don't know that the much better MAX202 exists. It's slightly cheaper." CreationDate="2011-02-18T19:44:34.990" UserId="305" />
  <row Id="15447" PostId="10412" Text="@BG100 - I hadn't though about wearing out the pot.  I thought of this as a temporary test fixture and hoped you would be able to characterize the acceleration/deceleration timing before the pot wore out but maybe you're right." CreationDate="2011-02-18T19:53:01.033" UserId="529" />
  <row Id="15448" PostId="10421" Text="Also, the MAX232 data sheet states that the MAX202 is a better device! ESD performance is improved. There isn't any point in using the MAX232." CreationDate="2011-02-18T19:54:55.183" UserId="305" />
  <row Id="15449" PostId="10412" Text="Is this a situation for motor shaft encoders? I thought those were for turning steppers into servos. Hum... so the solution is to use an encoder. Sounds good." CreationDate="2011-02-18T19:55:23.180" UserId="3045" />
  <row Id="15450" PostId="10421" Text="&quot;It's slightly cheaper.&quot;  It is? MAX202 in 16 pin DIP qty 1: $3.86 ( http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=MAX202CPE%2B-ND )  MAX232 in 16 pin DIP qty 1: $1.16 ( http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=296-1402-5-ND )" CreationDate="2011-02-18T19:56:04.247" UserId="1322" />
  <row Id="15452" PostId="10421" Text="The MAX202CDR costs $0.48 and the MAX232ECDR costs $0.65 from TI for 1 ku. That's the SOIC package device. It's a big difference!" CreationDate="2011-02-18T20:09:01.817" UserId="305" />
  <row Id="15453" PostId="10432" Text="Is that anything different from the usual 0.1&quot; connectors you can find on every PC mainboard?" CreationDate="2011-02-18T20:57:02.137" UserId="1950" />
  <row Id="15454" PostId="10408" Text="Not free, but only $5." CreationDate="2011-02-18T21:42:56.540" UserId="204" />
  <row Id="15455" PostId="10417" Text="It should always be OK to use larger sized caps but they are required. The caps are part of charge pumps that produce and store +/- ~7 volts for RS-232 (I measured mine). I understand higher frequencies are required for smaller caps since the storage capacitor will drain more quickly - so your big-caps build will oscillate more slowly than if you had built it with those 1uF caps you don't have." CreationDate="2011-02-18T21:52:17.983" UserId="1363" />
  <row Id="15456" PostId="10429" Score="1" Text="The patent system is broken, the only guys that benefit from patents today are layers. A bit sad since the idea was to help and protect the small inventors... " CreationDate="2011-02-18T22:04:19.750" UserId="689" />
  <row Id="15457" PostId="10432" Text="They are the same.  These are the extremely common &quot;headers&quot;.  0.1&quot; centers, 0.025&quot; square.  Lots of vendors sell them, but prices vary by about 10dB." CreationDate="2011-02-18T22:24:54.133" UserId="411" />
  <row Id="15458" PostId="517" Text="So like this? http://www.sparkfun.com/products/10253" CreationDate="2011-02-18T22:55:07.540" UserId="142" />
  <row Id="15459" PostId="10430" Text="Brooke Clarke maintains a fascinating page about time and frequency measurements: http://www.prc68.com/I/timefreq.shtml" CreationDate="2011-02-18T23:16:16.460" UserId="411" />
  <row Id="15461" PostId="10417" Text="Note that there's a variant of the MAX232 called the MAX232A that can use 0.1uF capacitors. Make sure you read the exact datasheet for your particular part! Pay particular attention to datasheets for cross-referenced parts like the ST232 which is basically ST Microelectronics' MAX232A drop-in equivalent." CreationDate="2011-02-18T23:50:20.817" UserId="2622" />
  <row Id="15462" PostId="10431" Score="1" Text="Berg are a manufacturers of header strips, so it was probably &quot;Berg Strip&quot;" CreationDate="2011-02-19T00:24:16.940" UserId="1681" />
  <row Id="15463" PostId="10433" Text="Use popular electronics distributors' parametric search tools to learn more: [DigiKey](http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_homepage_link=hp_ProductIndex&amp;lang=en&amp;site=CA&amp;keywords=)." CreationDate="2011-02-19T02:04:31.323" UserId="2118" />
  <row Id="15464" PostId="10437" Text="The knife slowly comes into it, but not far. It is not very hard. The knife needs a bit of strain to remove after attempt." CreationDate="2011-02-19T02:37:18.163" UserId="2898" />
  <row Id="15465" PostId="10436" Text="This is popped capacitor I want to replace. There is other part nearby, so rolling it from side to side is not that easy." CreationDate="2011-02-19T02:38:47.497" UserId="2898" />
  <row Id="15466" PostId="10404" Score="1" Text="I've considered this as a possible alternative, my only issue with requesting data from the PIC is that I want it to have the ability to be easily accessible if on the other side of a router and this becomes problematic because then I would need port forwarding." CreationDate="2011-02-19T03:16:07.643" UserId="3054" />
  <row Id="15467" PostId="10439" Text="Yes, that definitely seems like the guy I was looking for.  Thanks!" CreationDate="2011-02-19T04:03:53.770" UserId="3083" />
  <row Id="15468" PostId="10439" Text="Its a shame that the BEAM movement never got too big. It definitely looked interesting." CreationDate="2011-02-19T04:23:48.250" UserId="1200" />
  <row Id="15469" PostId="9249" Text="@bev cool thanks for clarifying" CreationDate="2011-02-19T05:05:45.863" UserId="771" />
  <row Id="15470" PostId="10377" Text="@Rick, yes it would still be a COM port, very likely COM1 or COM2" CreationDate="2011-02-19T05:07:24.413" UserId="771" />
  <row Id="15471" PostId="10377" Score="1" Text="@Rick also a word of caution - beware of getting pins 2+3 (rx+tx) backwards :)" CreationDate="2011-02-19T05:10:50.507" UserId="771" />
  <row Id="15472" PostId="10437" Text="@Vi0, I think you need a bigger knife! (My buddy Dundee can hook you up.)" CreationDate="2011-02-19T06:10:32.740" UserId="2118" />
  <row Id="15473" PostId="10441" Score="3" Text="I use acetone on everything. Toothpaste? No need! Deodorant? Nay, sir!" CreationDate="2011-02-19T06:27:12.717" UserId="2118" />
  <row Id="15474" PostId="10364" Text="Nothing stopping you from using another PLL on the symbols.  If they aren't bilevel, you really need to expand the question with more information about the encoding.  You seem to know what's going on - so why make us poke at answers?" CreationDate="2011-02-19T06:37:21.430" UserId="2235" />
  <row Id="15475" PostId="10381" Text="@W5VO - I took apart a bunch of RC cars when I was young." CreationDate="2011-02-19T06:48:42.120" UserId="1374" />
  <row Id="15476" PostId="10350" Score="1" Text="So your system is PAM based. ok, I don't really see why clock recovery is so hard, unless you have a LOT of noise, or a lot of possible amplitude levels. Basically, you just iteratively try baudrates in descending order, until you hit one  where none of the sample points are at an intermediate state. Since you are just trying to estimate the datarate, if you sample a bunch of times, and average down, you should get pretty accurate results." CreationDate="2011-02-19T06:53:12.003" UserId="1374" />
  <row Id="15477" PostId="10387" Text="I don't mind the question about how stepper motors behave, I'm just pointing out that it seems you have order some unneeded parts, since you haven't really read the documentation." CreationDate="2011-02-19T06:54:42.720" UserId="1374" />
  <row Id="15478" PostId="10436" Text="^This. Just grab it and yank." CreationDate="2011-02-19T06:56:06.853" UserId="1374" />
  <row Id="15479" PostId="10405" Text="I hope you have a BIG micro. SSL Is pretty heavy, computationally." CreationDate="2011-02-19T06:58:45.520" UserId="1374" />
  <row Id="15480" PostId="10442" Text="Errr... The type of hacking that can be seen in the picture on the right... is that what we hackers do? ;-)" CreationDate="2011-02-19T09:23:20.077" UserId="930" />
  <row Id="15481" PostId="10430" Text="Hmm... When I probed crystal connected to Atmel uC, I've seen a sine wave, not square..." CreationDate="2011-02-19T10:05:37.040" UserId="2062" />
  <row Id="15482" PostId="8661" Text="This looks like it might work. Bonus points for linking a place that might provide a free sample." CreationDate="2011-02-19T10:57:42.357" UserId="2240" />
  <row Id="15483" PostId="10440" Text="$10 is my weekly allowance." CreationDate="2011-02-19T10:57:45.850" UserId="1200" />
  <row Id="15484" PostId="10308" Text="@zsero It will be dangerous when youtry and put an alkaline, lithium, or NiZn battery in your circuit, or maybe even with freshly charged NiMHs. With diodes, small changes in voltage can result in large changes in current, which is why they need to be driven with a medium- to high-resistance source. Your 110mA at 1.38V might become 400mA at 1.6 volts." CreationDate="2011-02-19T11:07:58.397" UserId="2240" />
  <row Id="15485" PostId="10446" Score="1" Text="Why don't you want to use a microcontroller? That would probably be the best and cheapest option." CreationDate="2011-02-19T11:10:16.320" UserId="339" />
  <row Id="15486" PostId="10449" Score="1" Text="A fixed line telephone, or a mobile phone?" CreationDate="2011-02-19T11:26:51.077" UserId="2426" />
  <row Id="15487" PostId="10449" Text="@BG100- a fixed one!!" CreationDate="2011-02-19T11:38:08.887" UserId="2074" />
  <row Id="15488" PostId="10441" Text="Used CCl4 and it became softer." CreationDate="2011-02-19T11:44:38.123" UserId="2898" />
  <row Id="15489" PostId="10451" Text="@BG100- I want to use a computer like a telephone so that I'll be able to make and receive calls. I think the modem's close enough to what I'm wanting- please elaborate on that." CreationDate="2011-02-19T11:54:42.020" UserId="2074" />
  <row Id="15490" PostId="10451" Text="Are you going to be talking, or sending/receiving data?" CreationDate="2011-02-19T12:25:08.667" UserId="2426" />
  <row Id="15491" PostId="10451" Text="Talking and/or sending data. I want to be able to record conversations, and play an mp3 file so the other person on a handset hears the mp3." CreationDate="2011-02-19T12:36:10.113" UserId="2074" />
  <row Id="15492" PostId="10440" Text="fair enough, so you have something to save up for!" CreationDate="2011-02-19T13:30:00.260" UserId="771" />
  <row Id="15493" PostId="10448" Text="+1 for pointing out that the source data is binary, not binary coded decimal, which makes logic-based conversions complicated.  But any type of ROM chip for a lookup table is an easy solution." CreationDate="2011-02-19T15:22:05.843" UserId="2246" />
  <row Id="15494" PostId="10450" Text="A ROM-based lookup table is the traditional solution, using whatever programmable ROM technology is cheapest and easiest for you to deal with.  Though it will probably be more expensive and require more work to build a device programmer than modern micro controllers.  Multi-digit displays are often multiplexed - easy with a micro, though with a ROM you could have a two-bit &quot;digit&quot; address input driven by an oscillator and counter and use that to alternately lookup one of the three digits during its turn to be displayed.  Otherwise you'll need a fairly wide ROM." CreationDate="2011-02-19T15:24:08.397" UserId="2246" />
  <row Id="15495" PostId="10396" Score="2" Text="This is not a data rate that is likely to cause you difficulty for moderately intelligent routing within typically sized PCBs, especially if you series terminate with a resistor at the driving pin.  But this is a data rate that is is starting to get into the territory where cabling between boards or devices may need impedance-matched termination (probably resistive) to prevent reflections from causing errors." CreationDate="2011-02-19T15:49:49.680" UserId="2246" />
  <row Id="15496" PostId="10380" Text="It's an open loop actuator based either on a motor that stalls at a limit or a solenoid.  Controlling it proportionally will probably not work, as it will be too dependent on mechanical load variation.  PWM hobby servos are dirt cheap now, well under $10, just get one and rig it in there.  Get a spare too for when the gears in the first die." CreationDate="2011-02-19T15:57:32.727" UserId="2246" />
  <row Id="15497" PostId="10381" Text="@Fake I had only seen the simple DC motor steering like jsolarski has in his answer. Obviously I haven't taken apart enough cars :)" CreationDate="2011-02-19T16:36:43.013" UserId="638" />
  <row Id="15498" PostId="10451" Score="2" Text="http://en.wikipedia.org/wiki/Voice_modem ?" CreationDate="2011-02-19T16:43:34.650" UserId="142" />
  <row Id="15499" PostId="10405" Text="@Fake Name I was thinking a dsPIC. The way I understand it is the initial handshaking can be pretty heavy, but everything else is not too bad." CreationDate="2011-02-19T16:48:34.247" UserId="319" />
  <row Id="15501" PostId="10381" Text="I found another car, I'm going to pull it apart today sometime and will post my findings.  :)" CreationDate="2011-02-19T21:43:32.190" UserId="2288" />
  <row Id="15502" PostId="10442" Text="I couldn't help but +1 this answer.  haha" CreationDate="2011-02-19T21:44:31.703" UserId="2288" />
  <row Id="15503" PostId="10466" Text="Yes, I only need those three wires. However, how do I figure out which wire is what?" CreationDate="2011-02-19T22:11:19.543" UserId="1657" />
  <row Id="15504" PostId="10466" Text="You will have to check against the hardware documentation." CreationDate="2011-02-19T22:12:47.530" UserId="305" />
  <row Id="15505" PostId="10465" Score="1" Text="Duplicate question! I vote to close it." CreationDate="2011-02-19T22:14:21.400" UserId="305" />
  <row Id="15508" PostId="10465" Text="It's related but it's not a duplicate. This is asking about a certain method of figuring something out. Also the other question hasn't been answered." CreationDate="2011-02-19T22:16:54.300" UserId="1657" />
  <row Id="15509" PostId="10466" Text="I don't think you understand the question. I just want to know which wires in the cable are connected to which pins in the connector." CreationDate="2011-02-19T22:21:32.287" UserId="1657" />
  <row Id="15510" PostId="10466" Text="It depends on the hardware details of the system that the RJ45 is plugged into. You need the documentation." CreationDate="2011-02-19T22:50:51.803" UserId="305" />
  <row Id="15511" PostId="10466" Score="1" Text="@200ok404notfound - not sure there is any color standard. &quot;when in doubt, ohm it out&quot;. in other words, it's easy enough to use the continuity-check setting of a dvm to match wire ends to pins, and then you know 100% for sure." CreationDate="2011-02-19T22:51:22.410" UserId="740" />
  <row Id="15512" PostId="10465" Text="It's too similar. You should have edited the other question!" CreationDate="2011-02-19T22:52:40.290" UserId="305" />
  <row Id="15513" PostId="10462" Score="3" Text="Question is too vague!" CreationDate="2011-02-19T22:54:35.373" UserId="305" />
  <row Id="15514" PostId="10465" Text="it's similar, but not *identical*.. but man, it is close, isn't it." CreationDate="2011-02-19T22:59:55.903" UserId="740" />
  <row Id="15516" PostId="10467" Text="For a system to be considered only digital, does the output need to be deterministic? These systems output a 1 or 0, but for any input vector, you are not always seeing the same output." CreationDate="2011-02-19T23:40:43.863" UserId="3085" />
  <row Id="15517" PostId="10465" Text="@Leon Heller Why the hostility? Be yeah, similar enough to me that I don't think it deserves a new question." CreationDate="2011-02-19T23:43:17.993" UserId="319" />
  <row Id="15518" PostId="10465" Text="What I see is the originally question had 3 parts to it. This is a subset of one of those questions." CreationDate="2011-02-19T23:45:52.327" UserId="319" />
  <row Id="15519" PostId="10471" Text="Yes, that is what I was looking for." CreationDate="2011-02-19T23:46:48.620" UserId="1657" />
  <row Id="15520" PostId="10467" Text="@user3085, No, it does not need to be deterministic. In fact, randomness is often desired. Digital denotes the use of a limited number of discrete states, and that is all." CreationDate="2011-02-20T00:10:13.350" UserId="2118" />
  <row Id="15521" PostId="726" Text="@NeedTungsten - That would only be if he was trying to interface *two* cameras..." CreationDate="2011-02-20T00:15:57.807" UserId="1374" />
  <row Id="15522" PostId="10474" Score="4" Text="Picture or bust." CreationDate="2011-02-20T02:46:07.307" UserId="2118" />
  <row Id="15524" PostId="10479" Text="Thats a really great idea Theran. The status would change 4 times a day (maximum). I would worry about the reliability of the mechanism though. Im new to electronics are there specific low power motors that you had in mind?" CreationDate="2011-02-20T04:31:01.287" UserId="3089" />
  <row Id="15525" PostId="10462" Text="@Leon Heller, the question is about taxonomy. Similar one would be &quot;would opamp be classified as analog technology or something else?&quot;. And this question is specific and has an answer." CreationDate="2011-02-20T04:49:02.983" UserId="1471" />
  <row Id="15526" PostId="10474" Score="1" Text="That's a stock picture (or you watermarked it).  Are there any letters or other marks on it, e.g. underline or overbar on either of the characters?" CreationDate="2011-02-20T05:37:52.980" UserId="1407" />
  <row Id="15527" PostId="10479" Text="what a neat e-ink like idea!" CreationDate="2011-02-20T05:41:07.873" UserId="2288" />
  <row Id="15528" PostId="10474" Text="Get ahold of a multimeter. Many will check capacitance." CreationDate="2011-02-20T05:42:58.143" UserId="1990" />
  <row Id="15529" PostId="10480" Score="2" Text="Yes, very *un*likely to be 10uF. " CreationDate="2011-02-20T05:54:43.543" UserId="411" />
  <row Id="15530" PostId="10481" Text="I doubt your monitor runs on serial cable." CreationDate="2011-02-20T05:58:02.233" UserId="411" />
  <row Id="15531" PostId="10480" Score="2" Text="yea theres no chance that is 10uF as pictured unless its rated for like 1V, which its not likely.  10pF or 10nF at best." CreationDate="2011-02-20T06:04:05.877" UserId="1438" />
  <row Id="15532" PostId="10481" Text="@markrages See the update" CreationDate="2011-02-20T06:15:26.000" UserId="1200" />
  <row Id="15533" PostId="10481" Text="That's a VGA plug, not serial." CreationDate="2011-02-20T06:27:54.170" UserId="411" />
  <row Id="15534" PostId="10481" Text="Just opened it and realized how wrong I am." CreationDate="2011-02-20T06:36:18.830" UserId="1200" />
  <row Id="15535" PostId="10481" Text="Most common and supported response to homemade programmer troubles on AVRFreaks is to buy a cheap serial programmer, like the [AVRISP](http://goo.gl/P1qU2) for $35. If on a budget and want something more versatile go for [the Dragon](http://goo.gl/4c0NO) for ~$50." CreationDate="2011-02-20T07:34:20.567" UserId="2118" />
  <row Id="15536" PostId="10481" Score="2" Text="I do not have access to those things, I do not live in USA or somewhere this can be shiped with reasonable price. AND I WANT TO LEARN ALL THIS STUFF." CreationDate="2011-02-20T07:48:38.873" UserId="1200" />
  <row Id="15537" PostId="10456" Text="Will take a look at those books!! " CreationDate="2011-02-20T09:15:58.910" UserId="2074" />
  <row Id="15538" PostId="10481" Text="You should add a 100nF capacitor on the power supply close to the AVR." CreationDate="2011-02-20T09:33:14.637" UserId="339" />
  <row Id="15539" PostId="10481" Text="-c ponyuser seems correct." CreationDate="2011-02-20T09:45:08.253" UserId="339" />
  <row Id="15540" PostId="10474" Score="2" Text="@Peter: Getting one that can measure pF accurately can be difficult." CreationDate="2011-02-20T09:56:00.297" UserId="1407" />
  <row Id="15541" PostId="10443" Text="This a good idea that can be done programatically; I'll keep that in mind." CreationDate="2011-02-20T14:26:15.450" UserId="3045" />
  <row Id="15542" PostId="10455" Text="Actually, I'm doing a design that is intented to be repeatable; so I'll have to do that math you spoke of. Would the Gecko drive be an example of a well engineered and adjusted high voltage chopping driver amplifier?" CreationDate="2011-02-20T14:30:46.300" UserId="3045" />
  <row Id="15543" PostId="10482" Score="1" Text="You don't need to connect Vs+ and Vs- (V+ and V- in my data sheet) to anything other than the capacitors indicated in the data sheet and the circuit of the OP. The MAX232 actually generates the higher voltages on these pins, and you can use them if you don't draw too much current (a few mA)." CreationDate="2011-02-20T14:34:42.363" UserId="339" />
  <row Id="15544" PostId="5581" Text="The &quot;termination resistance&quot; of a dumb charger is really just a short." CreationDate="2011-02-20T15:12:27.393" UserId="1950" />
  <row Id="15546" PostId="10482" Text="@starblue I can't believe that I haven't seen the capacitors there in the schematic! And I checked several times! I definitely shouldn't answer questions when tired... " CreationDate="2011-02-20T17:24:17.783" UserId="1240" />
  <row Id="15547" PostId="10034" Text="Repaired it with a pair of capacitors soldered from old defunct laptop adaptor. Now it works." CreationDate="2011-02-20T18:08:49.447" UserId="2898" />
  <row Id="15548" PostId="10462" Score="1" Text="@user3085, I'm not sure I deserve the correct answer checkmark at this point. If you remove it, others may try to answer and/or challenge my own. I think there's a good argument for classifying it as something other than digital, but can't really play my own devil's advocate..." CreationDate="2011-02-20T18:08:53.770" UserId="2118" />
  <row Id="15549" PostId="5581" Text="@andreKR, this is not always true, but yes, often people hard short it." CreationDate="2011-02-20T21:28:53.790" UserId="230" />
  <row Id="15550" PostId="10490" Text="The original hack : http://frontiernerds.com/brain-hack&#xA;" CreationDate="2011-02-20T23:30:44.543" UserId="3097" />
  <row Id="15551" PostId="10455" Text="Repeatable implies reliable, but not necessarily optimized for needed performance at minimum price - so overbuying on motors might be possible.  Alternatively, if you don't have a hard performance requirement, you can just run it at whatever ramp/speed is reliable.  The Gecko modules I had years ago seemed a big improvement on what they replaced, but the surplus motors I had for that project were fairly high impedance, so performance wasn't going to be spectacular anyway." CreationDate="2011-02-21T00:17:12.077" UserId="2246" />
  <row Id="15552" PostId="10485" Text="Controllers usually incorporate diodes to protect the FET's and provide a path for the induced currents." CreationDate="2011-02-21T00:19:29.940" UserId="2246" />
  <row Id="15554" PostId="10491" Text="Thahks for the advice. I'll be sure to read that enter &quot;Jones on Steppers&quot; blog." CreationDate="2011-02-21T00:34:58.393" UserId="3045" />
  <row Id="15555" PostId="10250" Text="So to clarify, the only synchronization issues that could arise are byte-wise ones. i.e. first byte received may not be the first byte of the packet. Therefore, drop all packets that didn't begin with the &quot;sync byte&quot; or some similar packet-starting magic number, etc. " CreationDate="2011-02-21T01:13:51.230" UserId="3039" />
  <row Id="15556" PostId="10494" Text="This would allow addressing any single solenoid. But the OP wants to control all the solenoids at the same time." CreationDate="2011-02-21T02:39:08.517" UserId="411" />
  <row Id="15557" PostId="10250" Score="1" Text="You can have bitwise synchronization problems too, if the receiver see a low bit and thinks it is a start bit. Then you have a 50-50 chance of the &quot;stop&quot; bit being valid too, so the UART thinks it has a valid byte. The checksum will save you from this." CreationDate="2011-02-21T02:43:22.573" UserId="411" />
  <row Id="15558" PostId="8619" Text="@Dave, Yes I am. This is only because I tried the old c based 8 bit microcontroller thingy and got very little done for a lot of effort." CreationDate="2011-02-21T03:19:32.540" UserId="3045" />
  <row Id="15559" PostId="10494" Text="@markrages would a solenoid notice the difference ?" CreationDate="2011-02-21T03:27:34.570" UserId="1481" />
  <row Id="15560" PostId="10492" Text="Awesome. I'm ordering the parts tonight! Also, the timestamp is mostly for logging purposes, but I figured it would help. Thanks!" CreationDate="2011-02-21T05:52:17.483" UserId="3097" />
  <row Id="15561" PostId="8619" Text="@kurtnelle but with the .NET MF I'm actually getting a lot done with very little effort." CreationDate="2011-02-21T06:37:00.500" UserId="2288" />
  <row Id="15562" PostId="8344" Text="I agree that when a voltage multiplier is disconnected from its source of power, the amount of energy stored in its capacitors is economically insignificant. That is true for both the voltage doubler in my PSU, and also the one illustrated by the original poster which the Wikipedia &quot;voltage doubler&quot; article identifies as a &quot;voltage quadrupler&quot;. How does assuming that zero power comes from the antenna -- or assuming that only insignificant power comes from the antenna -- answer the original poster's question, or have any relevance to whether a device is &quot;useful&quot; or &quot;a success&quot;?" CreationDate="2011-02-21T08:47:45.063" UserId="813" />
  <row Id="15563" PostId="5581" Text="The document you linked to specifies a resistance of &quot;maximum 200 Ohms&quot;, which is basically a description of a short." CreationDate="2011-02-21T08:53:56.380" UserId="1950" />
  <row Id="15564" PostId="10198" Text="I'm happy it's working for you now -- yay! Yes, N-type should work with the schematic you posted +5V -- buzzer -- NFET -- GND. P-type should work if you shuffle the order so you have +5V -- PFET -- buzzer -- GND. Using what is easily available is smart -- but if you go into production, FETs that have 1/10 the cost will probably work just as well." CreationDate="2011-02-21T09:36:05.877" UserId="813" />
  <row Id="15565" PostId="5581" Text="@AndreKR, I believe it has to be a measurable resistance if you want an IPhone to use it, that is how iPhones originally had their own separate chargers." CreationDate="2011-02-21T12:47:51.807" UserId="230" />
  <row Id="15566" PostId="8619" Text="@Dave, sorry for the dyslectic response previously; I'm advocating for .NET MF" CreationDate="2011-02-21T13:06:31.540" UserId="3045" />
  <row Id="15567" PostId="10499" Text="Good thinking, using Serial.available() function is a good indirect approach... Do you know how deep the hardware Serial library rx buffer is? It might suffice for me to track whether the queue is growing over time since I have a continuous flow of bytes coming in... flow control wouldn't help in my case either because I essentially have a streaming source." CreationDate="2011-02-21T13:12:12.820" UserId="771" />
  <row Id="15568" PostId="10408" Text="Very cheap! I didn't know that." CreationDate="2011-02-21T14:18:45.990" UserId="938" />
  <row Id="15569" PostId="10499" Text="@vicatcu the docs I read said 128 bytes, but it could also be hardware-dependent." CreationDate="2011-02-21T14:38:12.893" UserId="2288" />
  <row Id="15570" PostId="10499" Text="@vicatcu so perhaps in your case you'll need to simulate threading with a round-robin state machine approach.  One such &quot;thread&quot; could monitor the buffer, and you'd have a &quot;low buffer&quot; threshold as well as a &quot;high buffer&quot; threshold.  This could adjust the streaming rate, which could throttle up or down depending upon where you are in the buffer.  This assumes that you have a communication protocol with the client that allows for such speed adjustments." CreationDate="2011-02-21T14:41:32.907" UserId="2288" />
  <row Id="15571" PostId="8619" Text="@kurtnelle  :) np!" CreationDate="2011-02-21T14:42:01.237" UserId="2288" />
  <row Id="15572" PostId="10507" Score="1" Text="Any specific reason you need high-voltage programming? If you just mis-set some fuse bits, it is probably cheaper (not to mention easier!) to get a replacement micro than to build a high-voltage programmer." CreationDate="2011-02-21T14:51:05.870" UserId="1802" />
  <row Id="15573" PostId="10447" Text="Thanks. Indeed the general bandwidths were in the range of 300MHz, and the prices often topped $100, the one I mentioned was the cheapest one I found in Analog Devices' catalog.&#xA;&#xA;Anyway, thinking of a discrete solution, I could probably implement it on a double-sided PCB, and I would probably only need about 120 FETs for a 16 x 16 matrix - but what kind? Wouldn't JFETs color the sound?" CreationDate="2011-02-21T14:56:40.343" UserId="3075" />
  <row Id="15574" PostId="10505" Text="I concur, 9W worth of solar panels is quite a bit." CreationDate="2011-02-21T15:00:05.430" UserId="1802" />
  <row Id="15575" PostId="9872" Text="Also, 70mA is the rating at 1kW/m2 incident sunlight. You will only get that at the tropic at the solstice at noon, and even then under the best conditions. You should expect quite a bit less in normal usage. I have no idea where the poster is geographically, but 10% of the rated current is not uncommon. Under realistic condition, the asker is looking at 150 panels." CreationDate="2011-02-21T15:01:38.157" UserId="1802" />
  <row Id="15576" PostId="10509" Text="I agree with the ice water bath, but he said the circuit was limited to 90 degree C which leaves out the boiling water. Ideally he should try to find two other reading for a good measure of the circuits accuracy.   " CreationDate="2011-02-21T15:37:56.770" UserId="1810" />
  <row Id="15577" PostId="10509" Score="3" Text="Don't forget to calibrate your barometer." CreationDate="2011-02-21T15:38:20.187" UserId="1927" />
  <row Id="15578" PostId="10509" Text="Excellent point doc." CreationDate="2011-02-21T15:59:10.813" UserId="1802" />
  <row Id="15579" PostId="8344" Text="I think that the antenna will produce nanowatts at most, which I think makes it useless for powering a cellphone, which was the original application described, and hence not a success. I'll ask again: do you think it could supply, say, 1 watt continously? If so, how?" CreationDate="2011-02-21T16:07:35.387" UserId="712" />
  <row Id="15580" PostId="10509" Text="Also, precision thermometer is much more accurate for this. With ice water you have to cover it to get more accurate reading. For boiling water, it must be very slowly boiling to be 100C. If you need it to be really accurate (like +-0.1C), that's not good enough." CreationDate="2011-02-21T17:12:37.303" UserId="3064" />
  <row Id="15581" PostId="10447" Text="I don't like JFETs :-) There are 4-wire FET's - they might be more appropriate. It's all depends on price. Also, as guys suggest - there are 8-&gt;1 analog multiplexors for about 0.2$, so you can build what you need from them." CreationDate="2011-02-21T17:16:10.820" UserId="2062" />
  <row Id="15582" PostId="10345" Text="Awesome explaination, W5VO. Is the 100:1 ratio a rule-of-thumb, or are you just picking some reasonable? My design needs to supply ~200 mA to the diode. It's a 405 nm diode, so the operating voltage is ~4-5v. I have a wide bandwidth, so anywhere from a Fc of 5 Mhz to 50 MHz will probably work. My transmit bandwidth is about 2 MHz." CreationDate="2011-02-21T17:40:13.933" UserId="2454" />
  <row Id="15584" PostId="10513" Text="Sorry, I misunderstood the question. I deleted my answer." CreationDate="2011-02-21T18:05:46.707" UserId="938" />
  <row Id="15585" PostId="10513" Text="@Daniel No worries, I've attempted to clarify the question." CreationDate="2011-02-21T18:07:23.640" UserId="2096" />
  <row Id="15586" PostId="10308" Text="The biggest danger or a small resistance is that a little change in voltage will influence the current. If your resistor drops only 0.1V, it means that a 0.1V increase in supply voltage means double the current (a resistor is liniear, 2x the voltage = 2x the current, assuming the LED stays about the same voltage, which is a safe assumption). A 0.5 ohm obviously takes almost no voltage at all, so a fractional voltage means a dead LED." CreationDate="2011-02-21T18:16:29.953" UserId="1476" />
  <row Id="15587" PostId="10513" Score="1" Text="+1: This is an excellent question... I'm looking forward to reading the answers. I'd love to know how people store their resistors in an organised way. Having to search through I pile of them looking for specific coloured bands is a pain!" CreationDate="2011-02-21T18:31:22.270" UserId="2426" />
  <row Id="15588" PostId="10487" Score="1" Text="I saw a project somewhere where someone just implemented a SMPS with a microcontroller in place of a dedicated chip. If you were up to it the result would be adjustable completely in software." CreationDate="2011-02-21T18:40:14.273" UserId="1363" />
  <row Id="15589" PostId="10501" Text="Remember, even with the best-chosen start bits, if the receiver starts listening during the data bytes, it can be out-of-sync until the next message. Hence, checksums." CreationDate="2011-02-21T18:42:38.560" UserId="411" />
  <row Id="15590" PostId="10345" Text="At 100:1, your loss from the components is going to be about 1%, or mostly negligible. You may need to adjust your rule for the inductor to maybe 10:1, or whatever you can get. It should just impact your efficiency, and maybe your matching with the amplifier." CreationDate="2011-02-21T18:46:36.330" UserId="638" />
  <row Id="15591" PostId="10514" Text="Ooh, RazorLab looks just the ticket." CreationDate="2011-02-21T19:43:20.003" UserId="255" />
  <row Id="15592" PostId="487" Text="Ponoko is merely a front for a number of manufacturing companies. There's one in the UK, one in Germany, Italy... etc." CreationDate="2011-02-21T19:59:56.830" UserId="1802" />
  <row Id="15593" PostId="10307" Score="2" Text="If you're going to build a switcher, build a constant-current one and don't worry about the voltage." CreationDate="2011-02-21T20:03:42.920" UserId="411" />
  <row Id="15594" PostId="10494" Text="Let's see, let's say you have a 9x8 multiplex and drive the solenoid 1/9th of the time.  With a catch diode on the solenoid, current can flow for a while, keeping the solenoid closed.  Assume zero losses, then we want to put the equivalent energy into the solenoid as the solenoid's DC rating.  So drive it with rated voltage * 9.  (to get rated current, di/dt = v/L).  So 24V solenoids would need 216V drivers.  If you stay below the voltage where the coil arcs over this might work." CreationDate="2011-02-21T20:12:57.383" UserId="411" />
  <row Id="15595" PostId="10494" Text="LEDs are easily multiplexed because they are open circuit when reverse-biased.  For solenoids, each will need a series resistor for this reason." CreationDate="2011-02-21T20:13:38.783" UserId="411" />
  <row Id="15596" PostId="10518" Score="2" Text="This brings out the OCD in all of us!" CreationDate="2011-02-21T20:31:36.440" UserId="2118" />
  <row Id="15597" PostId="10522" Score="1" Text="I like your thinking with the sigfigs." CreationDate="2011-02-21T20:42:11.457" UserId="2288" />
  <row Id="15599" PostId="10523" Score="1" Text="This should go back to superuser - it's asking about MS Windows." CreationDate="2011-02-21T20:52:03.417" UserId="3106" />
  <row Id="15600" PostId="10523" Text="@joelCoehoorn, It was just migrated from SU." CreationDate="2011-02-21T20:55:46.087" UserId="230" />
  <row Id="15601" PostId="10522" Score="3" Text="While you're at it with the resistors I can help you out with the color-coded labels I made for a similar cabinet.  It's meant to be used with Avery 6150 address labels (pretty standard) and cut into thirds for use on the dividers and front of each drawer: https://spreadsheets.google.com/pub?hl=en&amp;hl=en&amp;key=0AlW3tzPu0DsLdHVtZHBmc1pKajdfSUtoSG8ySjI5dVE&amp;single=true&amp;gid=0&amp;output=html" CreationDate="2011-02-21T21:02:37.580" UserId="249" />
  <row Id="15602" PostId="10517" Text="Put the feedback resistors down first and route (but don't populate) a series resistor in line with the DAC output.  Measured the desired/steady state feedback voltage.  Then remove the feedback resistors and populate the series DAC resistor with a 0 Ohm, setting the DAC voltage equal to the measured voltage.  To change the output voltage, simply add or subtract from the DAC voltage according to the change you want to see." CreationDate="2011-02-21T21:40:39.190" UserId="1571" />
  <row Id="15603" PostId="4168" Score="2" Text="It's there to draw attention away from the two mistakenly-routed, yellow wires on the top of the board." CreationDate="2011-02-21T21:45:07.310" UserId="1571" />
  <row Id="15604" PostId="10516" Text="@watson, Can you provide links." CreationDate="2011-02-21T21:51:09.397" UserId="230" />
  <row Id="15605" PostId="10417" Text="@joeforker, _always_ is too strong. In many cases it may be okay, depending on how / why the capacitor is used. For example in any frequency or resonant circuit, then the value can often be altered, depending on the interdependence of other components. For example in an analog RC filter. You can change the C, but that requires adjusting the R to compensate. " CreationDate="2011-02-21T22:35:57.240" UserId="2598" />
  <row Id="15606" PostId="10416" Text="Did you read the manufacturer's datasheet? You do not specify if it is a Maxim MAX232 or Texas Instructment MAX232(N). For starters they will tell you why the capacitors are needed. I don't know if it will work, because I prefer to follow the recommended usage so that my circuits are reliable, and ceramic 1.0uF capacitors are cheap enough I keep plenty of spares on-hand." CreationDate="2011-02-21T22:47:08.560" UserId="2598" />
  <row Id="15607" PostId="10493" Text="+1 for mentioning high pass filter on the input" CreationDate="2011-02-21T22:47:15.793" UserId="813" />
  <row Id="15608" PostId="10479" Text="@Dave that's a nice idea. Similar to what's in this device http://www.eink.com/customer_showcase_jumpdrive.html and here's the source http://www.eink.com/display_products_surf.html" CreationDate="2011-02-21T22:48:05.737" UserId="2157" />
  <row Id="15609" PostId="10430" Text="Actaully the inflection point of the quartz crystal (e.g. AT or SC, etc.) determines the best temperature to operate the crystal at, if you want to minimize drift due to temperature variations. 25-35 °C for AT, and roughly 90 °C for SC-cut. So an &quot;oven&quot; (resistive heater) is normally used rather than a Peltier cooler" CreationDate="2011-02-22T00:26:41.643" UserId="2598" />
  <row Id="15610" PostId="10513" Score="2" Text="One cabinet? First off, you need a dedicated room... :)" CreationDate="2011-02-22T00:50:09.167" UserId="2598" />
  <row Id="15611" PostId="10034" Text="BTW the popped capacitor still works (although internal resistance is much higher)" CreationDate="2011-02-22T01:14:21.153" UserId="2898" />
  <row Id="15614" PostId="10499" Text="@Dave I can confirm available maxes out at 127, experimentally. I have no means of throttling the stream. On the bright side, it looks like I don't have a buffer overflow problem after all... I'm not showing an increasing queue size operationally. Back to the drawing board..." CreationDate="2011-02-22T01:59:59.087" UserId="771" />
  <row Id="15615" PostId="10499" Text="I'm accepting this answer anyway based on good feedback." CreationDate="2011-02-22T02:00:24.220" UserId="771" />
  <row Id="15616" PostId="10521" Text="Wow, thank you for this answer. I understand it so much better from this. My question is that is it actually boosing to 14.4V in this example? From a 1V battery source? Does it work in theory the same as what I do when I'd start raising the voltage with a current meter in my hand and stop when the current reached my goal? What are parts C1, L1, D1, C2 doing? Do I need them for it to work?" CreationDate="2011-02-22T02:02:22.553" UserId="3049" />
  <row Id="15617" PostId="10517" Score="4" Text="This is a bad idea.  The FB pin voltage won't be precisely 1.23V, and there's a good chance that you won't be able to keep it stable.  A digital pot is a much better choice for this application." CreationDate="2011-02-22T02:03:35.250" UserId="857" />
  <row Id="15618" PostId="10534" Text="That deals with bounce. But with each key press the key is only activated for a short period of time (depending on how long the key takes to get from the actuation point to the reset point) and if the scanner doesn't check the key during this time period then the key press will be missed, using my method will I be able to check it sufficiently fast enough that a user tapping the key very lightly? (the key activates and resets halfway down, so if tapped lightly it could quickly fluctuate on and off)" CreationDate="2011-02-22T02:26:47.920" UserId="3108" />
  <row Id="15619" PostId="10533" Text="Nick, i agree with you that using GPS indoors is a terrible idea. Do u know of an algorithm that will help the rc car or a robot to move from point A to point B autonomously?" CreationDate="2011-02-22T02:54:32.150" UserId="3109" />
  <row Id="15620" PostId="10535" Score="2" Text="I assume you have the ability to turn off the fence to make modifications?  It could be... difficult otherwise." CreationDate="2011-02-22T02:59:09.463" UserId="249" />
  <row Id="15621" PostId="10517" Text="He asked, I answered.  I don't disagree with you - it'd be a fair bit of work to make this happen practically but I don't see any major issues with it theoretically.  The only hitch is how they implement the feedback control system in the SMPS.  Without being sure what its bandwidth, gain, etc is I imagine it wouldn't be straightforward to do this. " CreationDate="2011-02-22T03:06:17.270" UserId="249" />
  <row Id="15622" PostId="10533" Score="1" Text="@Praveen: 1. Determine vehicle orientation, 2. Determine angle and range to target, 3. Travel to target." CreationDate="2011-02-22T03:09:07.527" UserId="1407" />
  <row Id="15623" PostId="10534" Score="5" Text="People don't type nearly as fast as you think.  Think of it this way - 20ms pressed and 20ms released would give a key press a period of 25Hz.  Can you hit a key 25 times in one second?  I can get 5 or 7 presses in a second here.  That key is down for at least 50ms.  Even light presses will be down for longer than you think." CreationDate="2011-02-22T03:12:39.660" UserId="249" />
  <row Id="15624" PostId="10538" Score="5" Text="What input voltage?" CreationDate="2011-02-22T03:56:45.643" UserId="206" />
  <row Id="15625" PostId="10536" Score="3" Text="It's a cattle fence, not cattle killer.  " CreationDate="2011-02-22T03:57:51.880" UserId="857" />
  <row Id="15626" PostId="10535" Score="5" Text="100V and 120KV are very different numbers.  You should probably narrow that range down a bit.   I think that the voltage on these is usually between 2.5kV and 10kV, with pulse durations as short as 10 microseconds.  An interesting problem!" CreationDate="2011-02-22T04:00:56.057" UserId="857" />
  <row Id="15627" PostId="10501" Text="This is really great. Thanks for further clarifying!" CreationDate="2011-02-22T04:05:05.583" UserId="3039" />
  <row Id="15628" PostId="10499" Text="@vicatcu thanks, and feel free to keep posting comments as you progress through your project, and maybe I can give more feedback." CreationDate="2011-02-22T05:43:26.140" UserId="2288" />
  <row Id="15629" PostId="10543" Text="I've used it for a prototype.  Your going to have to be more specific as i don't know what your really asking.  Are you using their dev board for testing or did you build your own controller?" CreationDate="2011-02-22T06:13:38.453" UserId="1438" />
  <row Id="15630" PostId="10533" Score="2" Text="@Praveen 1. Put GPS module on Roomba. 2. Tell Roomba to clean your indoor room. 3. Have microcontroller read GPS and kill Roomba power when within X feet of target. 4. Profit!" CreationDate="2011-02-22T06:18:54.043" UserId="638" />
  <row Id="15631" PostId="10506" Text="Is this relying on the accuracy of the thermocouple to check the LM35? If so then I guess any source of reasonably stable temperature would do (I don't think my oven understands sub 100C)" CreationDate="2011-02-22T07:24:41.340" UserId="1497" />
  <row Id="15632" PostId="10509" Text="How much difference does the weather make? I see the boiling point reduces by 1C every 285M, so I could factor for that, but would the weather make a more significant difference?" CreationDate="2011-02-22T07:33:03.153" UserId="1497" />
  <row Id="15633" PostId="10549" Text="another page that may help http://mbed.org/handbook/SerialPC" CreationDate="2011-02-22T07:47:48.673" UserId="2060" />
  <row Id="15634" PostId="10533" Text="@Nick T: Assuming that there are no obstacles of course!" CreationDate="2011-02-22T07:56:18.263" UserId="2426" />
  <row Id="15635" PostId="10381" Text="Some higher end RC cars use Servos, RCs from retail stores will only have a DC motor. an example of a high end RC steering..http://www.beginningrc.com/components/car-truck-rc-steering-servo.php" CreationDate="2011-02-22T08:36:51.373" UserId="2060" />
  <row Id="15636" PostId="10041" Text="Does it really have to be base-10?" CreationDate="2011-02-22T09:04:11.850" UserId="1802" />
  <row Id="15637" PostId="10532" Score="1" Text="What are the typical length-scales we're talking about? Indoor-as-in-small-living-room or indoor-as-in-aircraft-hangar?" CreationDate="2011-02-22T09:18:28.790" UserId="1802" />
  <row Id="15638" PostId="10532" Score="1" Text="Are there any obstacles? Do you know where they are?" CreationDate="2011-02-22T09:18:50.100" UserId="1802" />
  <row Id="15639" PostId="10513" Score="1" Text="@mctylr Well, one's got to start *somewhere* :)" CreationDate="2011-02-22T09:23:40.970" UserId="2096" />
  <row Id="15640" PostId="10532" Score="1" Text="Do you have a time-limit? Do you have any incentive to be quick?" CreationDate="2011-02-22T09:23:43.057" UserId="1802" />
  <row Id="15641" PostId="10550" Text="For a linear regulator, something like this is probably the best way to do it. An alternative, with no short-circuit protetcion, however, is using a TL431 with an external pass transistor. Cf. fig. 24 or fig. 19 in the TL431's data sheet (http://focus.ti.com/lit/ds/symlink/tl431.pdf). What is ist input voltage (range?) for your application? Remember that the linar regulator has to be big enough to get rid of the dissipated power P_V (surface area or heat sink!). P_V,max = (V_in,max - V_out) * I_out,max." CreationDate="2011-02-22T10:23:11.217" UserId="930" />
  <row Id="15642" PostId="10523" Text="He is asking about electronic device and software for Windows, so I think this deserves an answer. Take a look at Girder control software at http://www.promixis.com (you can still find older free version) and use IR device like this one: http://www.cesko.host.sk/IgorPlugUSB/IgorPlug-USB%20%28AVR%29_eng.htm." CreationDate="2011-02-22T10:39:12.360" UserId="1129" />
  <row Id="15643" PostId="10523" Text="There is also bluetooth only solution: http://www.softpedia.com/get/Internet/Telephony-SMS-GSM/Bluetooth-Remote-Control.shtml" CreationDate="2011-02-22T11:01:20.367" UserId="1129" />
  <row Id="15644" PostId="10513" Score="1" Text="possible duplicate of [What's the best way to store and categorise resistors/capacitors/ICs/etc?](http://electronics.stackexchange.com/questions/3578/whats-the-best-way-to-store-and-categorise-resistors-capacitors-ics-etc)" CreationDate="2011-02-22T11:14:12.693" UserId="244" />
  <row Id="15645" PostId="10536" Score="1" Text="That can be fixed if you charge up a big enough array of capacitors ... :P (edit: for the record, I am not advocating cattle murder)" CreationDate="2011-02-22T11:41:29.483" UserId="1802" />
  <row Id="15647" PostId="10555" Score="1" Text="possible duplicate of [Using a laptop to communicate with an MBED module](http://electronics.stackexchange.com/questions/10546/using-a-laptop-to-communicate-with-an-mbed-module)" CreationDate="2011-02-22T11:59:36.627" UserId="305" />
  <row Id="15648" PostId="10513" Score="1" Text="Let me suggest you an handy (free) windows application: http://cidadao.uni.cc/comporg Maybe it helps too." CreationDate="2011-02-22T12:13:02.377" UserId="1074" />
  <row Id="15649" PostId="3124" Text="What about using a bootloader? " CreationDate="2011-02-22T12:23:26.637" UserId="1074" />
  <row Id="15650" PostId="10447" Text="I know those mux chips - some quad CMOS switches would be more up my alley. And those 4-wire FET's, maybe you could give me a part/model number to look up? (:" CreationDate="2011-02-22T12:23:33.520" UserId="3075" />
  <row Id="15651" PostId="10555" Score="1" Text="are you selecting the correct speed for your serial, and the correct port(hyperterm settings)? What is the code you are using on the mbed(similar to what i posted)? have you tried just the serial port and not a usb to serial converter? I would also suggest trying what Joby Taffey has suggested as well." CreationDate="2011-02-22T12:25:41.607" UserId="2060" />
  <row Id="15652" PostId="10560" Score="2" Text="In some parts of the world, such as Serbia, 3-phase power is standard even for small households. For single phase devices, load is distributed over 3 phases." CreationDate="2011-02-22T13:21:51.533" UserId="1240" />
  <row Id="15653" PostId="10560" Text="@AndrejaKo: Thanks... that would explain the need for 3 clamps then. I'm not as familiar with things like this outside my own country." CreationDate="2011-02-22T13:28:26.303" UserId="2426" />
  <row Id="15654" PostId="10560" Score="1" Text="A single clamp meter around all three phase conductors at once is also no good, because they are seperated in phase so they won't be summed correctly. The question implied that a single clamp would be used around 3 phase plus neural, and that also won't work because the neutral field should cancel the live fields." CreationDate="2011-02-22T13:36:10.137" UserId="2110" />
  <row Id="15655" PostId="10559" Score="1" Text="Be especially careful when working on 3 phase, it is usually a higher voltage than single phase mains (eg 415V instead of 230V)." CreationDate="2011-02-22T13:37:42.037" UserId="2110" />
  <row Id="15656" PostId="10560" Score="1" Text="Yes Andreja, I live in Serbia ;-) Жив био и хвала на учешћу!" CreationDate="2011-02-22T13:40:17.750" UserId="1129" />
  <row Id="15657" PostId="5581" Text="For Apple products, things are a bit more complicated: http://www.ladyada.net/make/mintyboost/icharge.html" CreationDate="2011-02-22T14:10:54.930" UserId="1950" />
  <row Id="15658" PostId="10417" Text="@mctylr clearly a 1F supercap would be too big. Of course I meant the remark just for this particular circuit." CreationDate="2011-02-22T14:43:04.223" UserId="1363" />
  <row Id="15659" PostId="10447" Text="Havan't quickly found any modern ones, I've seen only 'made in USSR' in such form. 4rth pin is connected to 'body' so that you can make sure that diode does not conduct." CreationDate="2011-02-22T14:46:16.790" UserId="2062" />
  <row Id="15660" PostId="5581" Text="@andreKR, yeah, apple does make your life easy..." CreationDate="2011-02-22T15:08:32.857" UserId="230" />
  <row Id="15661" PostId="726" Text="wow I thought when ever you connect a VGA camera to a FPGA it runs by itself.&#xD;&#xA;and you should plug it in the 220V AC.&#xD;&#xA;&#xD;&#xA;so may I was wrong.&#xD;&#xA;" CreationDate="2011-02-22T15:11:29.480" UserId="3084" />
  <row Id="15663" PostId="10449" Text="@gomek, This is really just looking for hardware for your computer, this might be a better fit for a site like superuser.com" CreationDate="2011-02-22T15:49:16.877" UserId="230" />
  <row Id="15664" PostId="10532" Text="@Ranieri- I don't have a time limit or obstacles to worry about. The typical length scale is a small living room or hallway." CreationDate="2011-02-22T16:10:01.053" UserId="3109" />
  <row Id="15665" PostId="10404" Text="While I haven't tried implementing a generic TCP client if you review the Microchip TCP/IP stack help file under TCP you can see the API that would need to be used to implement a TCP client." CreationDate="2011-02-22T16:12:12.390" UserId="588" />
  <row Id="15666" PostId="10563" Score="1" Text="Have you modeled / measured the system response?  Does &quot;P-only&quot; control work?  Adding another pole to the loop seems like a recipe for more instability." CreationDate="2011-02-22T16:28:09.113" UserId="411" />
  <row Id="15667" PostId="10563" Text="Have you measured the linearity of the LDR/LED combination?  If this is nonlinear, it will reduce your control system performance." CreationDate="2011-02-22T16:36:26.400" UserId="411" />
  <row Id="15668" PostId="10563" Text="Is your LDR is a CDS cell?" CreationDate="2011-02-22T16:37:12.813" UserId="411" />
  <row Id="15669" PostId="10527" Text="These are great - if you only have a few components/values/whatever they don't take up much space, but there's no problem with growing as you add more. I started out with just a few values and I put holes in the envelopes and had them on a ring. Now I'm up to keeping them in a shoebox, and it still works great." CreationDate="2011-02-22T16:58:36.507" UserId="259" />
  <row Id="15670" PostId="10564" Score="2" Text="You may have checked for continuity, but have you checked for shorts? Check at each end, between each pin and all the other pins. Cables have been known to be crushed which causes shorts." CreationDate="2011-02-22T17:52:51.177" UserId="2110" />
  <row Id="15671" PostId="10564" Text="@Martin I would imagine that 1:1 means that 1 pin goes to 1 pin and not more then that." CreationDate="2011-02-22T18:05:22.190" UserId="319" />
  <row Id="15672" PostId="9524" Text="What cost did you have in mind?" CreationDate="2011-02-22T18:22:21.297" UserId="206" />
  <row Id="15673" PostId="10566" Text="Most likely not twisted far enough up to the connector.  I've not seen hardly any issues from the connectors themselves.  In nearly every case it's been untwisting too far back.  Second most likely is not having all the wires pushed in far enough.  It's common for people to only get the wire pushed far enough for the first half of the vampire tap to make a connection, leaving the second half unconnected." CreationDate="2011-02-22T18:29:39.160" UserId="1678" />
  <row Id="15674" PostId="10518" Text="if you have just one decade per drawer then you just have to sort out the right one." CreationDate="2011-02-22T18:51:34.410" UserId="1498" />
  <row Id="15675" PostId="10563" Text="Yes it's a CDS cell." CreationDate="2011-02-22T19:23:16.743" UserId="3118" />
  <row Id="15676" PostId="10535" Text="That's useful info, thanks. I wasn't sure what voltage they actually used, so took the 100V and 12kV numbers from the range of a meter used to test the fences." CreationDate="2011-02-22T19:28:17.487" UserId="3112" />
  <row Id="15677" PostId="10563" Score="1" Text="CDS cells have a memory effect, where it takes some time for them to return to resistance after seeing some light.  This nonlinearity will make your control system difficult." CreationDate="2011-02-22T20:26:24.153" UserId="411" />
  <row Id="15678" PostId="10568" Text="Stability can't be much worse than it is now. I'm trying to figure out what an integrator would to my signal, seems a common circuit. Also seems to invert so that would need addressing." CreationDate="2011-02-22T20:26:56.757" UserId="3118" />
  <row Id="15679" PostId="10563" Text="To check your isolator linearity, vary the current through the LED and look at the output current.  Plot one against the other.  Is it a straight line over the range of temperatures you encounter?" CreationDate="2011-02-22T20:41:51.887" UserId="411" />
  <row Id="15680" PostId="10563" Text="I will check the linearity asap. I have an led in series in the current loop and you can clearly see the rapid rise in brightness, the main lamps correspond to this also. Is there a better way of obtaining a variable resistance from a current loop? It must be isolated of course." CreationDate="2011-02-22T20:52:10.227" UserId="3118" />
  <row Id="15681" PostId="10532" Score="1" Text="You might as well just move randomly (e.g. get a Roomba as @W5VO suggests) and leave the required GPS module unpowered.  It will be equally useful on or off as the accuracy will be insufficient to know that you've arrived at any given point with ~5-10m indoors." CreationDate="2011-02-22T21:49:09.527" UserId="1407" />
  <row Id="15682" PostId="10068" Text="@Thomas O: Ok, I'm biting. Can you tell me who these guys are?" CreationDate="2011-02-22T21:55:20.337" UserId="1802" />
  <row Id="15683" PostId="9165" Text="Why do you need heights over 10m? When you are landing anyway you are within the 7 or so meters an ultrasonic sensor can do." CreationDate="2011-02-22T21:57:28.627" UserId="1950" />
  <row Id="15684" PostId="10564" Text="@Martin: If there was a short, the I doubt he would even get 10/100Mbps, and even a cheap tester would pick that up." CreationDate="2011-02-22T22:39:39.690" UserId="2426" />
  <row Id="15685" PostId="10564" Score="1" Text="@BG100 - 10/100 only uses two of the four wire pairs, so a short may not affect the behavior at 10/100." CreationDate="2011-02-22T22:51:02.257" UserId="1374" />
  <row Id="15688" PostId="10523" Text="It is a border question in my opinion. &quot;Do you know of something I can buy or build myself to serve this purpose?&quot; If this only said &quot;build my self&quot; then if would be for us, if it only said &quot;can buy&quot; then it would be for superuser. Superuser clearly doesn't want it, but I don't think it is a bad question for us from the building perspective." CreationDate="2011-02-23T01:10:41.360" UserId="319" />
  <row Id="15689" PostId="10555" Text="I think this question has enough of a different question posed that people searching from google may come to this question when they would have never found the other, from that perspective it should remain open." CreationDate="2011-02-23T01:16:30.117" UserId="319" />
  <row Id="15690" PostId="10558" Text="@Immad the problem with this question is that it is all about Linux and compiling. Beagle board sorta falls into our realm, but you are going to get better results by looking at other stack exchange communities and finding one that has a strong Linux. Sorry, I don't know the communities well enough to help." CreationDate="2011-02-23T01:20:17.397" UserId="319" />
  <row Id="15691" PostId="10492" Text="I just tested it out using two Arduinos and a modified blink sketch and it worked! Assuming I can get the radio modules to work as well as wire, I'm set. " CreationDate="2011-02-23T01:21:32.543" UserId="3097" />
  <row Id="15692" PostId="10563" Text="Can you slow down the loop time of your PID controller?  Or does the PID controller have an adjustable filter?  It sounds like your PID controller is much to fast.  Temperature control can usually be accomplished with extremely slow loop times." CreationDate="2011-02-23T01:47:47.367" UserId="2377" />
  <row Id="15693" PostId="10068" Text="@Ranieri, http://www.seeedstudio.com and http://www.seeedstudio.com/depot/fusion-pcb-2-layer-10cm10cm-max-10pcs-p-396.html?cPath=185  - I just bought some about 10 minutes ago and some others are currently in the post. Brilliant service but can only recommend it once as that's all I've got so far; I've got another week or so before I receive my next project boards." CreationDate="2011-02-23T02:13:33.157" UserId="1225" />
  <row Id="15694" PostId="10068" Text="@Ranieri, Also - remember in your email to ask them for 10 or they'll only ship you one." CreationDate="2011-02-23T02:14:35.707" UserId="1225" />
  <row Id="15695" PostId="9961" Text="What about hot air soldering? http://www.youtube.com/watch?v=s49dIm0LX5I" CreationDate="2011-02-23T02:26:25.090" UserId="2956" />
  <row Id="15696" PostId="10576" Text="Always be aware that when using non-isolated equipment, unexpected things may happen; especially ground loops which can at best be annoying and at worst cause extreme damage and fire." CreationDate="2011-02-23T02:40:33.447" UserId="1407" />
  <row Id="15697" PostId="10580" Score="5" Text="[Yep.](http://focus.ti.com/mcu/docs/mcuprodmsptoolsw.tsp?sectionId=95&amp;tabId=1203&amp;familyId=342&amp;toolTypeId=1)" CreationDate="2011-02-23T02:46:46.830" UserId="2118" />
  <row Id="15698" PostId="10577" Text="I have used a Prolific cable (like the one linked) with the 22-812 meter.  And it worked fine.  I wrote my own Python script, available on request.  There are lots of scripts and software out there if you Google &quot;22-812&quot;." CreationDate="2011-02-23T04:15:47.503" UserId="411" />
  <row Id="15699" PostId="10576" Text="The interface *is* isolated.  It uses an IR LED / phototransistor pair.  The LED is powered by the meter's battery and the phototransistor is powered by the RS232 line.  Communication is one-way.  And the LED current will kill the battery after a few days of continuous use.  But it makes a handy data logger." CreationDate="2011-02-23T04:18:35.133" UserId="411" />
  <row Id="15700" PostId="10577" Text="Here is the exact adapter I used:  http://www.dealextreme.com/p/usb-to-rs232-db9-serial-port-adapter-22407  Notice that it uses a real charge pump IC to make the RS232 voltages.  This is good, because the 22-812 needs the proper voltage to power the phototransistor inside." CreationDate="2011-02-23T04:23:55.113" UserId="411" />
  <row Id="15701" PostId="10557" Text="Yes, there was something wrong there." CreationDate="2011-02-23T05:45:52.533" UserId="1657" />
  <row Id="15702" PostId="10563" Text="Have you any idea what that setting might be called? The instructions are 'vague' at best i'm afraid :(" CreationDate="2011-02-23T07:06:01.133" UserId="3118" />
  <row Id="15703" PostId="10586" Text="I am also curious on how this is done. " CreationDate="2011-02-23T07:34:10.327" UserId="2060" />
  <row Id="15704" PostId="10564" Text="@Fake Name: Ok, my mistake." CreationDate="2011-02-23T08:04:46.053" UserId="2426" />
  <row Id="15705" PostId="10068" Text="Oh yeah I know those guys! I had no idea they did PCBs too!" CreationDate="2011-02-23T09:03:00.940" UserId="1802" />
  <row Id="15706" PostId="10570" Score="1" Text="&quot;ambiguous AC adapters&quot; - do you mean ubiquitous or anonymous?" CreationDate="2011-02-23T09:24:06.657" UserId="2110" />
  <row Id="15707" PostId="10590" Text="Ohh that makes sense! I'm retracting my answer." CreationDate="2011-02-23T09:37:24.067" UserId="1802" />
  <row Id="15708" PostId="10588" Text="Where have you seen the third pin? Im interested in it." CreationDate="2011-02-23T10:14:56.780" UserId="1623" />
  <row Id="15709" PostId="10409" Text="http://mbed.org/users/toddouska/libraries/CyaSSL/lm43pv" CreationDate="2011-02-23T11:14:44.393" UserId="566" />
  <row Id="15710" PostId="10590" Text="Yep. The &quot;T&quot; stands for &quot;Temperature&quot; (Or &quot;Thermistor&quot;). Normally, it's a thermistor." CreationDate="2011-02-23T11:26:38.087" UserId="1374" />
  <row Id="15711" PostId="10592" Text="@JustJeff: Nice answer!" CreationDate="2011-02-23T12:06:26.263" UserId="2426" />
  <row Id="15712" PostId="10566" Text="That sounds like it could be the problem -- although I'm still puzzled that all cables I made seem to have the same issue, regardless of length." CreationDate="2011-02-23T12:52:02.280" UserId="3119" />
  <row Id="15714" PostId="10588" Text="Canon NB-4L for example" CreationDate="2011-02-23T13:20:56.027" UserId="2110" />
  <row Id="15715" PostId="10408" Text="@Robert and @Daniel Grillo I believe it is $5 for the starter package and then once you go retail its about $2,500 for 5000 units. At least that is what it is for this: http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&amp;nodeId=1406&amp;dDocName=en020159" CreationDate="2011-02-23T13:46:42.983" UserId="319" />
  <row Id="15716" PostId="10408" Text="However, the ENCx24J600 is the part that interests me a lot." CreationDate="2011-02-23T13:48:24.013" UserId="319" />
  <row Id="15717" PostId="10586" Score="3" Text="possible duplicate of [How to determine position from gyroscope and accelerometer input?](http://electronics.stackexchange.com/questions/4983/how-to-determine-position-from-gyroscope-and-accelerometer-input)" CreationDate="2011-02-23T13:59:24.570" UserId="319" />
  <row Id="15718" PostId="10572" Score="1" Text="@JYelton Thanks for the suggestion. I think there's a lot to be said for this system. What is unclear to me is how easy is it to find exactly the right part in a drawer of colour-coded resistors. What's your experience?" CreationDate="2011-02-23T14:00:37.797" UserId="2096" />
  <row Id="15719" PostId="10522" Text="@AngryEE Thanks!" CreationDate="2011-02-23T14:01:35.177" UserId="2096" />
  <row Id="15720" PostId="10592" Text="Also the clock drift will start to really show up after a long time of use. This is typically fixed by having a GPS resync every so often, but as @srinathhs said, theres no power for a GPS on this system." CreationDate="2011-02-23T14:02:32.773" UserId="319" />
  <row Id="15721" PostId="10521" Text="14.4V might be a bit too high for it, but theoratically it will try to act as a current source (not a voltage source).&#xA;C1 and C2 are added for stability of the regulator. L1 and D1 are there because it is a switching regulator (a DC-DC converter). To understand more about a boost (step-up) converter, read on wikipedia: http://en.wikipedia.org/wiki/Boost_converter&#xA;It's quite a 'complex/long' story about how they work." CreationDate="2011-02-23T14:34:28.820" UserId="1476" />
  <row Id="15722" PostId="10509" Text="Good point about also calibrating the barometer. Notice though that air preassure will not make any noticable difference for the melting point of water since the triple point (http://en.wikipedia.org/wiki/Triple_point) only is 0.01 °C at 0.6117kPa (6.117mbar) which is quite far off from 1013mbar. But for the boiling point you will probably get noticable differenses." CreationDate="2011-02-23T14:43:25.503" UserId="568" />
  <row Id="15723" PostId="10588" Text="Roomba batteries too.  Can't gut them and replace the internals without making sure you hook that third contact back up." CreationDate="2011-02-23T14:51:01.083" UserId="249" />
  <row Id="15724" PostId="10578" Text="If it rains or your grass starts to approach the bottom wire, you can to turn up the voltage on the fence so it kills the grass. There is a significant amount of current available.  But yes, if you let your grass get very tall and then it rains, you'll probably have to bring out the string trimmer and cut it manually." CreationDate="2011-02-23T15:48:55.300" UserId="857" />
  <row Id="15726" PostId="10563" Text="Ok, i think this one is solved, some seriously odd PID tuning seems to be helping so i think thats job done. Thanks to all." CreationDate="2011-02-23T15:55:21.187" UserId="3118" />
  <row Id="15728" PostId="7772" Text="Microsoft's may be the only battery holder which compensates for reverse polarity, but many devices use the shape of the battery ends to ensure that the positive terminal will only make contact with the positive end of a stack, and vice versa.  Devices with five or more batteries in a stack could be reverse-biased if one connected the end batteries in one polarity and the inner batteries the other way, but that's probably not a terribly common a scenario, and the properly-polarized batteries would help to impede the errant current." CreationDate="2011-02-23T16:07:16.880" UserId="3123" />
  <row Id="15729" PostId="10592" Text="If i use kalman filtering , will it be accurate enough?" CreationDate="2011-02-23T16:14:32.197" UserId="1705" />
  <row Id="15730" PostId="10572" Text="@aix To be honest it's still a hassle sometimes, especially if you have a full drawer of many different values. To mitigate this I've taken to putting very common values in another drawer, with less often used values in the original drawer. (So I have a drawer with 1k, 10k, and 100k resistors which I use a lot.) That said, I still like having a range of values together because finding substitutions is easier." CreationDate="2011-02-23T16:26:22.443" UserId="2028" />
  <row Id="15731" PostId="10598" Text="excellent!  A mite pricey, but I guess small things usually are.  Thanks for the help!" CreationDate="2011-02-23T16:27:25.967" UserId="3077" />
  <row Id="15732" PostId="10570" Text="@Martin - good question. I called them ambiguous because they all seem to look alike and unless they are labeled (pet peeve) it's very difficult to tell what they are powering. So, at least in MHO, they are &quot;ambiguous - their meaning/use is not well defined. Probably not the best use of the word, but it seemed to fit with my experience. Ubiquitous would certainly fit too, but for a different reason. Thanks for reading closely enough to question that! :)" CreationDate="2011-02-23T16:52:05.347" UserId="2904" />
  <row Id="15733" PostId="10606" Score="3" Text="This question is subjective, localised in time and place, and is a shopping question. I can't see how there can be an objective, right answer. It would be better reworded to ask the difference between dielectric materials or how much to overrate the voltage by, if those hadn't been already asked." CreationDate="2011-02-23T17:36:05.413" UserId="2110" />
  <row Id="15734" PostId="10606" Text="@Martin:  The prices of such capacitors don't change as dramatically over time as, for example, DRAM.  And I don't think there are huge differences between US, EU or Asian prices.  I suspect that if X7R is only 10% more than X5R today in the US, it won't be 100% more next year or in Asia." CreationDate="2011-02-23T17:41:32.800" UserId="206" />
  <row Id="15735" PostId="10607" Score="1" Text="@Daniel nice edit!  I didn't know about that feature.  :)" CreationDate="2011-02-23T18:18:09.057" UserId="2288" />
  <row Id="15736" PostId="10602" Score="1" Text="@Richard the only thing that sounds wrong here is that my balancing LiPo battery charger uses *four* pins, not one.  How can they do the balancing with only one pin in cell phones?" CreationDate="2011-02-23T18:19:43.783" UserId="2288" />
  <row Id="15737" PostId="10607" Score="1" Text="@Dave not at all. If you want to learn more see the [editing help](http://electronics.stackexchange.com/editing-help)" CreationDate="2011-02-23T19:01:05.243" UserId="938" />
  <row Id="15738" PostId="10610" Score="1" Text="If you could draw a schematic on paper, scan it, and have it automatically converted to a netlist, then it would be appropriate to call it &quot;schematic capture&quot;, in my opinion" CreationDate="2011-02-23T19:02:18.943" UserId="142" />
  <row Id="15739" PostId="10609" Text="The 3.3 V is a signal or a power rail?  What is it used for?  What are your source and load impedances?  Can you draw your circuit?  You can enter it in http://www.falstad.com/circuit/ and then export link from the file menu" CreationDate="2011-02-23T19:02:43.827" UserId="142" />
  <row Id="15740" PostId="10610" Score="5" Text="I would buy such a program..." CreationDate="2011-02-23T19:04:38.093" UserId="411" />
  <row Id="15741" PostId="10609" Text="@endolith, Yes, it's a power rail. As the micro could execute various code and enter sleep modes, power consumption may vary - is it still possible to use an LC filter?" CreationDate="2011-02-23T19:08:08.620" UserId="1225" />
  <row Id="15742" PostId="10593" Text="Thank you Martin. Please help me on this: if the TVS was defective shouldn't it be short-circuited, and couldn't I verify this by measuring the resistance? I don't care about the hdd, I just want the data back and I don't think I have the appropriate tools to weld such small components, so my idea was to find out if this component is defective and extract it or short-circuit it (depending on what is going to make the hdd work, I don't know) just to get the data." CreationDate="2011-02-23T19:59:01.607" UserId="3133" />
  <row Id="15743" PostId="10194" Text="Is this for a one-off?  It will probably cost more and be less capable than a cheap Behringer control surface: http://www.bhphotovideo.com/c/product/321871-REG/" CreationDate="2011-02-23T19:59:04.430" UserId="411" />
  <row Id="15744" PostId="10609" Text="Cascaded RC filters are simpler, but will waste energy in the resistors, so it's only good for signals where the energy is not important.  For a power rail, you don't want to waste energy (voltage drop), so either use small value Rs, or use LC filter.  But LC filters can resonate, which produces the peak you're seeing." CreationDate="2011-02-23T20:25:58.060" UserId="142" />
  <row Id="15745" PostId="10613" Text="You first need to load a reel into the pick and place machine, which involves buying some caps.  I think this question is about what caps to buy and keep on the pick and place machine, not so much about what caps to use in a specific situation." CreationDate="2011-02-23T20:34:12.857" UserId="857" />
  <row Id="15746" PostId="10609" Score="5" Text="if your having 30khz noise on a power rail you should consider the cause of that noise.  It shouldn't be there and you should solve the problem at the source of the noise rather than bandaiding it with a filter." CreationDate="2011-02-23T20:34:15.370" UserId="1438" />
  <row Id="15747" PostId="10606" Text="@Brian Carlton, Read @martin's response. This is all of those things. I know this was asked with the best intentions, but I must agree." CreationDate="2011-02-23T20:41:36.837" UserId="230" />
  <row Id="15750" PostId="10566" Text="any kinks or sharp bends (90 degree) in cat 5E will also be a major problem at gigabit speeds.  You mentioned jacks, if you mean wall jacks make sure you haven't coiled/kinked up extra wire behind the jack and that you didn't use a staple gun directly on the wire, pinching it.  In generally cat-5e is quite sensitive when running at gigabit speeds.  " CreationDate="2011-02-23T21:20:11.733" UserId="1438" />
  <row Id="15751" PostId="10617" Text="I just looked it up to be safe :) http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1138892708" CreationDate="2011-02-23T21:23:04.360" UserId="2288" />
  <row Id="15752" PostId="10616" Text="I've done something similar for a device that had a few slightly different firmwares and purposes: Write all of the files to external SPI flash (which is available in sizes much larger than most microcontrollers), and reflash the controller with one of the images with the bootloader if a button is held down during reset." CreationDate="2011-02-23T21:40:29.883" UserId="857" />
  <row Id="15753" PostId="10602" Text="Cell phones normally use single cell batteries, so it can't be for balancing purposes." CreationDate="2011-02-23T21:58:20.057" UserId="1374" />
  <row Id="15754" PostId="10620" Score="2" Text="This will just burn up the excess charge in the batteries until it no longer conducts, and then you'll have a series resistor in your supply line that will cause the input voltage to be less than the battery voltage.  This is not a good idea." CreationDate="2011-02-23T22:48:23.940" UserId="857" />
  <row Id="15755" PostId="6854" Text="I thought older amplifiers tended to have very high output impedances (since vacuum tubes modulate current rather than voltage), and a failure of the speaker to absorb the current that was being sent in its direction would result in the amp outputting a higher-than-expected voltage.  I'll readily admit I don't understand vacuum tubes circuits very well, so tell me if I'm wrong." CreationDate="2011-02-23T23:05:01.283" UserId="3123" />
  <row Id="15756" PostId="6851" Text="One thing I've wondered about is how the output impedance of loudspeakers varies with frequency, and how the impedance-versus-frequency response tracks with sound-output-versus-frequency (at uniform voltage) response, and whether an amplifier could make use of such variations in trying to produce a flat frequency response for a speaker in a room.  Any idea if that's been looked into?" CreationDate="2011-02-23T23:08:08.643" UserId="3123" />
  <row Id="15757" PostId="6851" Text="@supercat Well, the impedance to SPL level is a complicated function and is definitely impacted by the speaker enclosure, driver mechanic features, and t-s parameters among other things.  An average '8ohm' speaker will have impedance swings from ~3ohm to 50+ohms yet can achieve very close to flat frequency response.  You wouldn't generally adapt a speaker to fit an acoustical environment as all rooms are different (especially at low frequencies).  Room correction is done with EQ.   Google Audyssey for the most popular automatic room correction system." CreationDate="2011-02-23T23:19:08.353" UserId="1438" />
  <row Id="15758" PostId="5561" Score="2" Text="I believe that if you add a bit of H2O2, it works again. Try it!" CreationDate="2011-02-23T23:32:56.960" UserId="1374" />
  <row Id="15759" PostId="10622" Text="The etchant can be safely dumped down the drain, but it is *very bad* to dump dissolved heavy metals (like copper) down the drain." CreationDate="2011-02-23T23:47:48.013" UserId="411" />
  <row Id="15760" PostId="10592" Text="@srinathhs - depends on your accuracy requirements, of course. i know kalman filters are supposed to improve this kind of system, but i don't have enough experience with them to be able to tell you. fwiw, it's not inconceivable that you could get what need without it." CreationDate="2011-02-24T00:44:18.673" UserId="740" />
  <row Id="15761" PostId="10586" Text="@Kellenjb - significant overlap, to be sure." CreationDate="2011-02-24T00:45:20.997" UserId="740" />
  <row Id="15762" PostId="10623" Text="Hey unixbigot, thanks for your answer. Regarding (2), I actually tried one that delivered 1A but apparently that wasn't enough to power it. 2-3A would probably be ideal, but I can't find a ready-made charger that offers that combination of voltage and current. If you know any or find any, I'd be glad to accept your contribution in the [Battery-powering up a Beagleboard XM](http://electronics.stackexchange.com/questions/9772/battery-powering-up-a-beagleboard-xm) question." CreationDate="2011-02-24T01:12:17.007" UserId="2883" />
  <row Id="15763" PostId="10578" Text="Better fence chargers use current monitoring to compensate for this." CreationDate="2011-02-24T01:16:32.180" UserId="2255" />
  <row Id="15764" PostId="10621" Text="If the dev board will function with less than 5 V (e.g. 3.3-5.0 V), then you could just as well power it with the 4 cells and an LDO.  That said, however, the archaic 7805 may misbehave (draw an abnormal amount of quiescent current) if you are operating near the regulation point.  Modern LDOs should not have this problem, but as always, check the datasheet." CreationDate="2011-02-24T01:55:15.207" UserId="1407" />
  <row Id="15765" PostId="10625" Text="Ok so reading a register value will result in 0x0E 0x03 (hexadecimal E3) in the 2 bytes that is returned?" CreationDate="2011-02-24T02:06:54.067" UserId="3045" />
  <row Id="15766" PostId="10625" Text=" It depends on the register, as I said. You might get different values. You seem confused about hex representation, 0x03 is a hex value: one byte." CreationDate="2011-02-24T02:42:28.040" UserId="305" />
  <row Id="15767" PostId="10625" Text="Yea, but I'm getting 2 bytes back each time." CreationDate="2011-02-24T02:51:11.720" UserId="3045" />
  <row Id="15768" PostId="10623" Text="The beagleboard xm manual specifies the power consumption on page 26, it says it uses 750mA.   Maybe you have more stuff plugged into the expansion port?" CreationDate="2011-02-24T03:17:05.377" UserId="389" />
  <row Id="15769" PostId="10629" Score="1" Text="and not 6.22, either, 5.0 was the last best DOS! =P" CreationDate="2011-02-24T03:32:10.497" UserId="740" />
  <row Id="15770" PostId="10620" Text="I could have sworn that H&amp;H showed that as a solution when I was in school.  :)  Thank you for the clarification!" CreationDate="2011-02-24T03:53:10.263" UserId="2288" />
  <row Id="15773" PostId="6854" Text="@supercat: I don't know tube amps, but if they have a high output impedance, and you're driving a low speaker impedance, you can use a transformer to make the amp see a larger load impedance, and the speaker see a smaller source impedance.  I still don't think they'd be identical (&quot;matched&quot;); the virtual source would still be made smaller than the load. But I don't know tube amps." CreationDate="2011-02-24T04:51:02.413" UserId="142" />
  <row Id="15774" PostId="10625" Text="You must be sending two bytes, then. Here is my code for reading/writing a byte:&#xA;&#xA;unsigned char spi_Send_Read(unsigned char byte)&#xA;{&#xA;	SSPBUF = byte;	&#xA;	while(!DataRdySPI())&#xA;		;	&#xA;	return SSPBUF;&#xA;}	" CreationDate="2011-02-24T05:38:02.367" UserId="305" />
  <row Id="15775" PostId="10630" Text="Thanks a ton, I'll try the 14500 batteries. One question: I used a USB-to-5/2.1mm cable adapter when I powered the Beagleboard with the made-for-mobiles charger. I don't have a multimeter easily available to measure the current used, but do you think that the adapter may have decreased the current? AFAIK, it is USB ports that have the 500mA-max limitation, not USB cables, correct? " CreationDate="2011-02-24T05:47:38.240" UserId="2883" />
  <row Id="15777" PostId="10630" Score="1" Text="The cable is unlikely to have had much of an effect (although using too-light cable can melt it, DAMHIKT).   The phone charger circuit probably had a current limit set too low.   I've found the circuits in phone chargers stick pretty close to the example circuit in the regulator chip's datasheet, so it is possible to reverse engineer the charger and figure out which resistor is the current limiting resistor, and change it out for a different value." CreationDate="2011-02-24T07:07:07.183" UserId="389" />
  <row Id="15778" PostId="1156" Text="Presuming the OP is in Sydney, check out the local surplus store Oatley Electronics for gearhead motors.   Jaycar has 'em too." CreationDate="2011-02-24T07:10:23.837" UserId="389" />
  <row Id="15779" PostId="10632" Score="4" Text="I would try on [math](http://math.stackexchange.com/) or [stats](http://stats.stackexchange.com/). Perhaps even quant, as I understand econometricians use this technique a lot." CreationDate="2011-02-24T08:09:35.800" UserId="1802" />
  <row Id="15781" PostId="10609" Text="@Mark, it's mainly to attenuate noise from a noisy battery line  which also powers a motor, so lots of current is drawn and this causes glitches in the power line. But I'm not certain I will still need it after doing a scope of the power line." CreationDate="2011-02-24T09:47:09.833" UserId="1225" />
  <row Id="15782" PostId="10633" Text="Nice project! Thank you." CreationDate="2011-02-24T10:45:14.000" UserId="938" />
  <row Id="15783" PostId="10608" Text="+! to capture the ideas of the mind" CreationDate="2011-02-24T11:35:25.367" UserId="2157" />
  <row Id="15784" PostId="5402" Text="+1 for the PC. There are so many good software tools for electronics hobbyists and pros alike. It's a valuable piece of equipment I always want to have on hand.  " CreationDate="2011-02-24T12:53:28.950" UserId="2904" />
  <row Id="15785" PostId="10632" Score="1" Text="@Imelza, give it time, someone will come through and be helpful, I would like to run your code, but I am absent matlab on my current computer." CreationDate="2011-02-24T13:07:10.707" UserId="230" />
  <row Id="15786" PostId="6646" Text="Yes, once you've seen the logic analyser show you the values in a serial (RS232), SPI or I2C signal, you'll never want to try to read it off a scope again. Especially a two channel scope." CreationDate="2011-02-24T13:18:51.220" UserId="2110" />
  <row Id="15787" PostId="10625" Text="I am sending 2 bytes. The example code that I'm using always sends 2 bytes minimum; I'll have to find out from the author why that is. Thanks for the assist. " CreationDate="2011-02-24T13:34:23.603" UserId="3045" />
  <row Id="15788" PostId="10593" Text="If the TVS is defective, the melted silicon could produce any resistance; I wouldn't say it must measure as a short. You need to remove it rather than short it out. You'd need access to a soldering iron to heat the junctions with the board. Solder goes underneath the component so you can't use a knife to cut the solder away at the ends, and in any case you risk cutting the tracks, they are only a thin layer." CreationDate="2011-02-24T13:34:51.573" UserId="2110" />
  <row Id="15789" PostId="10637" Text="How many mW are required to get 5km of range out of your WiFi antenna?  Martin was correct; low frequency gets you more range for an equivalent power if the antenna size is not constrained, but limits bandwidth.  " CreationDate="2011-02-24T14:13:52.093" UserId="857" />
  <row Id="15790" PostId="10637" Text="With directional antenna - standard power (10mW)" CreationDate="2011-02-24T14:15:18.793" UserId="2062" />
  <row Id="15791" PostId="10637" Text="Well, we need then to talk the same bandwidth. How much range would we get with 25kHz band @ 2.4Ghz? :-) That's 800 times more power/bandwidth. If we would have same power per kHz difference would be much much smaller." CreationDate="2011-02-24T14:17:14.323" UserId="2062" />
  <row Id="15792" PostId="10638" Text="*In **general**, lower carrier frequencies mean lower bandwidth for data on them.* No, this is a mathematical certainty: Read up on the [Shannon-Hartley Theorems](http://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theorem#Statement_of_the_theorem)" CreationDate="2011-02-24T14:18:01.313" UserId="857" />
  <row Id="15793" PostId="10636" Text="http://en.wikipedia.org/wiki/IEEE_802.11s ?  http://www.wired.com/dangerroom/2011/02/secret-tools-force-net/" CreationDate="2011-02-24T14:40:33.053" UserId="142" />
  <row Id="15794" PostId="10637" Text="@barsmonster I don't really about 3G 4G networks, because those networks are freaking expensive, and require subscription etc. I'm just just wondering if I can have *P2P* freely, knowing that a significantly slower bandwidth is acceptable, since I want to create my own protocol for data transport. By P2P I really mean NOT having an hotspot, I really mean cellphone TO cellphone, by radiowaves. Hotspots amplify signals and receives weak signals, but I'm interested in full P2P." CreationDate="2011-02-24T15:09:10.870" UserId="3141" />
  <row Id="15795" PostId="10638" Text="Thanks, I did know about that. I suppose I meant &quot;in principle&quot; rather than &quot;in general&quot; to avoid the charge that protocol X uses a lower carrier frequency that protocol Y but is specified as a higher data rate, which can occur when the Shannon limit isn't being reached by protocol Y. In other words, you can send 1 bit per second using a 2.4GHz carrier and 9600 bps using a 433MHz carrier, so someone could argue the bandwidth of a given implementation is not higher, but of course the maximum possible bandwidth is higher even if it is not used." CreationDate="2011-02-24T15:14:15.113" UserId="2110" />
  <row Id="15796" PostId="10636" Text="I'm not sure since I think in meshed networks, a node can forward a flow of packets to an other device. That's not what I want to do. I want to litteraly transpose the CB concept to the data concept." CreationDate="2011-02-24T15:17:17.340" UserId="3141" />
  <row Id="15797" PostId="6854" Text="@endolith: All the tube amps I've seen have had output transformers.  If tubes are inherently high-impedance, one could use a transformer to adjust the output impedance of the amp to be nearer that of the speaker, but trying to lower the output impedance would also cut the gain.  Consequently, with a tube amp, I don't think one would normally want to try for near-zero output impedance.  I wonder if output impedance might be part of the reason tube amps are reputed to sound different from transistor amps, since output impedance would change the accoustical response of a speaker." CreationDate="2011-02-24T15:32:58.067" UserId="3123" />
  <row Id="15798" PostId="10625" Text="Just a guess, but he might be sending the second byte so that he can check that it was received correctly. I just check with the debugger when I'm developing the code." CreationDate="2011-02-24T15:58:28.303" UserId="305" />
  <row Id="15801" PostId="6854" Text="@supercat: From what I'm reading, they *do* try to match impedances in tube amps.  Since the source impedance is high and fixed, you need to match the load to it to get maximum power.  &quot;there are two sweet spots, one for highest power, one for lowest distortion; the two spots are not the same for any known tube&quot;  So a 30:1 transformer connected to a 8 ohm speaker would show the amplifier a 30^2*8 = 7200 ohm load, which would be optimal for a tube with 7000 ohm output impedance.  http://www.radioremembered.org/outimp.htm http://www.geofex.com/tubeampfaq/TUBEFAQ.htm#XformImped" CreationDate="2011-02-24T16:32:17.150" UserId="142" />
  <row Id="15802" PostId="5849" Text="Another distinction between a PLA and a ROM: if e.g. a 16x1 ROM with a 50ns access time has a &quot;1&quot; at addresses 1100 and 1101, then it will output high within 50ns of either of those patterns appearing, but if address 1100 is selected and the LSB of the address goes high, then for the next 50ns the output may go low and high in any arbitrary pattern (it must end up high).  By contrast, a PLA which is configured to output a high whenever the first three inputs are 110 will not have any glitches induced on the output when the fourth input changes." CreationDate="2011-02-24T17:35:05.793" UserId="3123" />
  <row Id="15804" PostId="10072" Text="Uh oh - I was about to build a board with one of these on it! Looks like some advice is in order.  The [Microchip PIC32 Ethernet Starter Kit](http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&amp;nodeId=2615&amp;dDocName=en545713) has one on it, if you're interested in an application circuit.  " CreationDate="2011-02-24T19:11:05.933" UserId="857" />
  <row Id="15805" PostId="10610" Text="I like the netlist reason.  After all, it is that net list that you have to feed into so many other tools." CreationDate="2011-02-24T21:00:27.300" UserId="2059" />
  <row Id="15806" PostId="10657" Score="1" Text="I changed the crystal, this is two crystals showing the same behaviour." CreationDate="2011-02-24T21:33:28.327" UserId="1225" />
  <row Id="15807" PostId="10655" Score="2" Text="Any clue as to the physics/chemistry of this effect?" CreationDate="2011-02-24T21:43:56.970" UserId="1802" />
  <row Id="15808" PostId="10658" Text="Would this also cause it to be really unstable?" CreationDate="2011-02-24T22:13:56.527" UserId="1225" />
  <row Id="15809" PostId="10072" Score="1" Text="We used a NatSemi development module that provided the crystal and magnetics and all, we'll copy that circuit when we flatten it onto our board.  We actually ran into lots of trouble making this chip work at all, but every problem we had was related to the driver for the MAC (it was a nios2 softprocessor in an Altera FGPA)... except for this one.  DP83848J works quite nicely in 100Base-T mode.  I'm wondering if anyone at all has gotten in working in 10Base-T, but my project doesn't actually NEED 10Mbps, using a slower speed was mainly a troubleshooting idea for our other problems." CreationDate="2011-02-24T22:14:02.000" UserId="1743" />
  <row Id="15810" PostId="10072" Text="@reemrevnivek: But naturally we'd like to have 10Base-T compatibility also if possible.  Thanks for placing the bounty.  If you ever want a bounty on a problem over at stackoverflow, just let me know.  Over there I've got plenty of rep to spare." CreationDate="2011-02-24T22:15:27.643" UserId="1743" />
  <row Id="15811" PostId="10072" Text="@Ben - No problem!  You asked a good question, and it was going unanswered.  " CreationDate="2011-02-24T22:18:58.560" UserId="857" />
  <row Id="15812" PostId="10658" Score="1" Text="@Thomas - Yes. You might get better luck if you bend the OSC pins of the micro up and out of the breadboard, and solder your crystal and caps directly to those pins and the neighboring ground pin. " CreationDate="2011-02-24T22:34:26.367" UserId="857" />
  <row Id="15813" PostId="10650" Text="Why not use a line receiver instead? Like the MAX4444/MAX4445, it has a BW of 90MHz 0.1dB or 550MHz -3dB bandwidth." CreationDate="2011-02-24T22:35:48.400" UserId="1476" />
  <row Id="15814" PostId="10654" Text="+1 Nice Question" CreationDate="2011-02-24T22:47:17.963" UserId="3045" />
  <row Id="15815" PostId="10659" Score="1" Text="I'd like to note that this is far more common with NiMH and NiCd batteries than other types. Lithium ion/polymer batteries do not like it one bit and will probably be ruined - if they don't burst or explode first." CreationDate="2011-02-25T00:00:34.453" UserId="1225" />
  <row Id="15816" PostId="10655" Text="Wikipedia: &quot;If the battery drain current is high enough, the weak cell's internal resistance can experience a reverse voltage that is greater than the cell's remaining internal forward voltage.&quot; Seems that it has something to do with the chemistry still being at 1.2V, but the ESR creates the negative voltage somehow. And no, I don't understand either..." CreationDate="2011-02-25T00:01:31.910" UserId="1225" />
  <row Id="15817" PostId="10662" Text="It varies widely depending on how you use the micro, too.  I remember they have actual charts of idle current consumption for different clock speeds, etc." CreationDate="2011-02-25T00:02:26.707" UserId="142" />
  <row Id="15818" PostId="7529" Text="What about using triacs to control the solenoids?" CreationDate="2011-02-25T00:04:27.740" UserId="1225" />
  <row Id="15819" PostId="10660" Text="An example would be interesting" CreationDate="2011-02-25T00:11:12.200" UserId="206" />
  <row Id="15820" PostId="10650" Text="Isn't there an example schematic in the datasheet?" CreationDate="2011-02-25T00:14:07.933" UserId="142" />
  <row Id="15821" PostId="10664" Text="i'd like to try that. where can i get a supply like that?" CreationDate="2011-02-25T00:42:03.723" UserId="740" />
  <row Id="15822" PostId="10667" Text="@tyblu, Nope, I have a digital scope - always had it, although it is nearly 19 years old. I don't think this is causing the problem since the oscillator is erratic anyway, I can see this from a UART output." CreationDate="2011-02-25T00:49:24.737" UserId="1225" />
  <row Id="15823" PostId="10669" Text="Perhaps a comparitor chip could be allowed, or a simple current regulator.  But I'm aiming for zero chips as much as can be reasonable." CreationDate="2011-02-25T01:49:16.450" UserId="1609" />
  <row Id="15824" PostId="10658" Text="@reemrevnivek, That's unfortunately not an option given that this is one of few chips I have and I can't ruin it. I've run an 8 MHz oscillator on a breadboard before - heck, I've run a 20 MHz one too - so I'm thinking it's more likely my construction than the breadboard." CreationDate="2011-02-25T01:53:23.963" UserId="1225" />
  <row Id="15826" PostId="10664" Score="3" Text="Just finish your dyson sphere, and line it with solar panels." CreationDate="2011-02-25T02:06:21.213" UserId="1374" />
  <row Id="15828" PostId="10668" Score="1" Text="I think getting rid of ICs completely conflicts with your goal of &quot;illustrates nicely the operation of class D amplifiers&quot;." CreationDate="2011-02-25T02:37:34.463" UserId="142" />
  <row Id="15829" PostId="10664" Score="2" Text="&quot;commercial solar cell have short-circuit currents between about 28 mA/cm2 and 35 mA/cm2.&quot;  If we assume this is at typical solar irradiation at Earth distance from the sun, the surface area of the Dyson sphere would be http://www.wolframalpha.com/input/?i=area+of+sphere%2C+radius+1+AU and the short circuit current would be http://www.wolframalpha.com/input/?i=30+mA%2Fcm2+12.57+square+astronomical+units+to+gigaamperes  10^16 billion amps" CreationDate="2011-02-25T03:23:01.947" UserId="142" />
  <row Id="15830" PostId="10660" Text="I think I finally understand this. As for a real world example: If I have a stepper motor rated at 1.2 amps per phase and I try to run it off of a powersupply rated at 650mili amps... The powersupply will fry." CreationDate="2011-02-25T04:28:07.620" UserId="3045" />
  <row Id="15831" PostId="10662" Text="So then a regulated wall wart producing 7V at 1 amp should cover most situations?" CreationDate="2011-02-25T04:38:46.890" UserId="3045" />
  <row Id="15832" PostId="10670" Score="1" Text="+1 Because I had to do research to understand it." CreationDate="2011-02-25T04:40:35.343" UserId="3045" />
  <row Id="15833" PostId="7379" Text="the armmite pro, like the maple is an ARM with an arduino footprint.  " CreationDate="2011-02-25T04:56:58.567" UserId="985" />
  <row Id="15834" PostId="10673" Text="hmmm, if the question was how do pros choose the size of the flash.  sometimes write some code that resembles the solution, compile and see how big it is.  If an rtos is going to be used, take some samples and size them and add a fudge factor for the code you will add.  A lot of it has to do with personal experience at estimating.  Often you may choose to estimate then double it just in case and your boss may double your estimate so he/she doesnt get in trouble and so on.  And that can help because once implemented you may switch to the smaller part and be a hero with the savings." CreationDate="2011-02-25T06:10:55.433" UserId="985" />
  <row Id="15835" PostId="7529" Text="@Thomas, you would still need an optoisolator to drive the triac.  In other words, you would be rolling your own solid-state relay.  I've done this before and it works, but prepackaged SSRs are really competitive now: http://www.futurlec.com/RelSS.shtml" CreationDate="2011-02-25T06:34:03.103" UserId="411" />
  <row Id="15837" PostId="3843" Text="I have some sympathy with the first paragraph, as a hobbyist I can't afford the quality components and test equipment that would make some of my many headaches disappear. But the second paragraph is just plain wrong" CreationDate="2011-02-25T07:14:34.297" UserId="1497" />
  <row Id="15838" PostId="10657" Text="Are there decoupling ceramic cap right on pins of your uC?" CreationDate="2011-02-25T08:51:18.703" UserId="2062" />
  <row Id="15839" PostId="10663" Text="How exactly is it dangerous if the current is too low. Say a device needs 350mA and I have an adapter at 300mA what would happen?" CreationDate="2011-02-25T10:02:37.430" UserId="1623" />
  <row Id="15840" PostId="10663" Score="1" Text="A device doesn't 'need' 350 mA. It will *let through* 350 mA at a specified supply voltage. Ohm's law: I = U / R. With a constant resistance device, it will let a current directly proportional to the voltage applied on its ends. So, if a device takes 350 mA at 10 V, it will let through 700 mA if 20 V supplied through it. " CreationDate="2011-02-25T10:12:26.730" UserId="1036" />
  <row Id="15841" PostId="10663" Score="2" Text="Of course, the above is only true for purely resistive circuits (incadescent lamps, LEDs etc.). If you only get 300 mA of current through the same circuit, chances are that you're supplying only a fraction of the voltage needed. It's not dangerous in terms of safety, but it's dangerous in terms of device's functionality, especially if the device is not just a light bulb, but a microcontroller, for example. " CreationDate="2011-02-25T10:21:36.033" UserId="1036" />
  <row Id="15842" PostId="10663" Text="@Dean: Maybe I should rephrase that to &quot;possible dangerous situations&quot;. I was more thinking of something like powering a 2.5A kettle with a piece of cable rated at 0.5A... it would get hot, possibly melt and catch fire... hence dangerous." CreationDate="2011-02-25T10:35:14.523" UserId="2426" />
  <row Id="15843" PostId="10584" Text="Can you tell what the Hyperterminal is and what do you connect to your mbed to send text through it?" CreationDate="2011-02-25T10:59:29.933" UserId="1036" />
  <row Id="15844" PostId="10663" Text="@BG100 ok I now understand. " CreationDate="2011-02-25T11:12:44.300" UserId="1623" />
  <row Id="15845" PostId="10677" Text="Some of the PIC24F series have 16-bit CRC generators. I imagine it would be possible to combine these in some  manner to get 32-bit CRCs." CreationDate="2011-02-25T12:45:31.757" UserId="1225" />
  <row Id="15846" PostId="10650" Score="1" Text="Hans, never heard of a line receiver - thanks!" CreationDate="2011-02-25T12:57:17.623" UserId="2454" />
  <row Id="15847" PostId="10665" Text="Brian, thanks for the answer. Since this is a communications signal, there's no DC component." CreationDate="2011-02-25T12:57:34.453" UserId="2454" />
  <row Id="15848" PostId="10667" Text="Can you have a look at the trace and tell me if it is this problem or something else." CreationDate="2011-02-25T13:01:58.017" UserId="1225" />
  <row Id="15849" PostId="10657" Text="@barsmonster, Yes." CreationDate="2011-02-25T13:21:41.713" UserId="1225" />
  <row Id="15850" PostId="10677" Text="In fact CRC-16 is needed here, so it looks much better." CreationDate="2011-02-25T13:37:21.233" UserId="2062" />
  <row Id="15851" PostId="10646" Text="Also won't protect you from electrocution (common misconception of &quot;safety&quot;). A fuse is a deliberately weak point in the circuit designed to blow first, before the wiring. If you don't have one the wiring will blow, in an uncontrolled location and probably slowly, melting its insulation and causing a fire." CreationDate="2011-02-25T13:51:50.047" UserId="2110" />
  <row Id="15852" PostId="10652" Score="1" Text="&quot;The load capacitance is correct it seems - well within the specified 12pF to 32pF.&quot; - How do you know this? The inductance of the breadboard, even the leads of the crystal, pic, and caps can cancel out a lot of your capacitance." CreationDate="2011-02-25T14:29:59.687" UserId="319" />
  <row Id="15853" PostId="10323" Text="@kellenjb Very helpful description! I never really fully grasped this before, but this helps a lot." CreationDate="2011-02-25T14:59:39.903" UserId="3122" />
  <row Id="15854" PostId="10652" Text="@Kellenjb - you could be correct, but I have no means to measure this. I've done this before on a breadboard which is why I'm suspicious that it  is the breadboard. I'm tempted to try another crystal - will report back." CreationDate="2011-02-25T15:18:05.290" UserId="1225" />
  <row Id="15855" PostId="10654" Score="1" Text="I have also seen and wondered about this phenomenon. I have seen it occur in alkaline batteries that have experienced a deep discharge." CreationDate="2011-02-25T15:47:05.190" UserId="588" />
  <row Id="15856" PostId="10660" Text="Not necessarily. It should be protected against an over-current situation, if it has been properly designed." CreationDate="2011-02-25T15:52:46.333" UserId="305" />
  <row Id="15857" PostId="10615" Text="take an ohmmeter and measure between something clearly marked as ground on the board (if anything).  Perhaps large mounting holes if they have a metal ring.  " CreationDate="2011-02-25T16:01:59.977" UserId="985" />
  <row Id="15858" PostId="10677" Score="1" Text="A bit-banged four-bit SD interface will not be faster than a hardware-assisted SPI interface.  (According to Wikipedia, an SD card can be clocked at 208MHz.  That speed will be difficult for a PIC microprocessor.)" CreationDate="2011-02-25T16:10:02.867" UserId="411" />
  <row Id="15859" PostId="10685" Score="1" Text="What camera did you buy?" CreationDate="2011-02-25T16:40:31.880" UserId="938" />
  <row Id="15860" PostId="10682" Text="Is the Active PFC on computer supplies an example of current limiting?" CreationDate="2011-02-25T16:59:19.797" UserId="3045" />
  <row Id="15861" PostId="10685" Text="Have you tested your Spark Fun shield?" CreationDate="2011-02-25T16:59:24.290" UserId="938" />
  <row Id="15862" PostId="10652" Text="MS/a = megasamples per annum (year)?" CreationDate="2011-02-25T17:01:44.580" UserId="1407" />
  <row Id="15863" PostId="10663" Text="@BG100: Is Andrei Sosnin's comment about the device letting 350mA pass?" CreationDate="2011-02-25T17:02:57.390" UserId="3045" />
  <row Id="15864" PostId="10663" Text="@kurtnelle: I don't really understand what Andrei means by that comment." CreationDate="2011-02-25T17:09:23.960" UserId="2426" />
  <row Id="15865" PostId="6854" Text="@endolith: I'm surprised I haven't seen the output impedance of tube amps mentioned as a factor in &quot;tube sound&quot;, nor have I seen any discussion of designing amplifiers with higher &quot;effective&quot; output impedance to mimic the sound of tube amps.  One wouldn't have to use power-wasting resistors to adjust the output impedance; I would think current-sensing feedback could to a pretty good job." CreationDate="2011-02-25T17:36:50.177" UserId="3123" />
  <row Id="15866" PostId="8344" Text="As mjh2007 already mentioned, the [WiTricity](http://en.wikipedia.org/wiki/Witricity) team [press release photo](http://web.mit.edu/newsoffice/2007/wireless-0607.html) that shows team members in the direct line of sight between the antennas while powering a 60 W lightbulb. By attaching the WiTricity receive antenna to the above circuit rather than a lightbulb, the above circuit could convert the high frequency AC at the antenna to more than 1 W of DC power continuously. Early [crystal radio receiver](http://en.wikipedia.org/wiki/crystal_radio) also work on the power received by an antenna." CreationDate="2011-02-25T17:39:10.733" UserId="813" />
  <row Id="15867" PostId="10417" Text="@joeforker, Sorry, I mistook that as a &quot;general rule of thumb&quot; for any usage of capacitor values. My concern would be, I'm guessing, but I assume the MAX232 charge pump uses a simplistic fixed frequency oscillator for the switching frequency, thus larger values capacitors could/may produce _higher_ output voltages outside EIA-232C specs." CreationDate="2011-02-25T17:40:17.530" UserId="2598" />
  <row Id="15868" PostId="10417" Text="@BG100, assuming what you read on the Internet is correct, can be a big assumption. :) Heck, they let me write things on the Internet." CreationDate="2011-02-25T17:41:55.940" UserId="2598" />
  <row Id="15869" PostId="6829" Text="A PSU with a voltage doubler switch may work with DC, but only with the [switch in the &quot;230&quot; position](http://www.aprs.org/prius/swer/SWER-115-caps.GIF)." CreationDate="2011-02-25T17:44:43.647" UserId="813" />
  <row Id="15870" PostId="10417" Text="@mctylr: I know, I understand that, and I think I made that clear in my answer..." CreationDate="2011-02-25T17:52:09.297" UserId="2426" />
  <row Id="15871" PostId="10652" Text="@Nick T, megasamples per second. It's written on the case and in the manual. MS/a. I think it differentiates from the real time sample rate of 10 G/S." CreationDate="2011-02-25T17:53:01.540" UserId="1225" />
  <row Id="15872" PostId="10689" Score="5" Text="Have you considered asking the software company directly.  If you are a paying customer, I am sure they will be happy to inform you." CreationDate="2011-02-25T18:02:33.357" UserId="3077" />
  <row Id="15873" PostId="10689" Score="5" Text="Take one of your designs, unroute the entire board, open the CPU usage window, and autoroute the PCB.  If you CPU stays at 100%, then all the cores are used.  If it only hits 50% (for a 2 core CPU), then it does not take advantage of multiple CPUs." CreationDate="2011-02-25T18:50:23.933" UserId="204" />
  <row Id="15874" PostId="10695" Text="Why? has the general &quot;Robots/Electronics&quot; group kinda moved away from using Assembly and stuck more with &quot;more&quot; reliable C code?" CreationDate="2011-02-25T18:50:39.103" UserId="3073" />
  <row Id="15875" PostId="10695" Text="reliable != accessible" CreationDate="2011-02-25T18:54:22.717" UserId="3161" />
  <row Id="15876" PostId="10682" Text="No, PFC is correcting for a reactive load (where the current draw changes over time).  It's closer to current 'smoothing'. A current limit circuit will effectively dynamically alter it's resistance to keep the current from rising above a set point. (INTERNAL_RESISTANCE_OF_POWER_SUPPLY mentioned above goes up)" CreationDate="2011-02-25T18:56:12.433" UserId="1270" />
  <row Id="15877" PostId="10692" Text="No one really programs in Assembly anymore because its easier to debug, quicker to develop and porting to different version uControllers like from AVR mega to AVR Tiny, is easier. " CreationDate="2011-02-25T19:10:06.707" UserId="1623" />
  <row Id="15879" PostId="10697" Score="1" Text="According to the datasheet page 76, RMII uses two data bits.  But `RXD[1]` is not toggling.  So it's not RMII mode.  Or is the datasheet missing some information (I can't find any waveforms for RMII 10 Mbps mode)?" CreationDate="2011-02-25T19:18:50.330" UserId="1743" />
  <row Id="15880" PostId="7710" Text="other [discussions of using series resistors to reduce noise](http://techref.massmind.org/techref/electips.htm#series_resistor)." CreationDate="2011-02-25T19:19:12.263" UserId="813" />
  <row Id="15881" PostId="10685" Text="@Daniel: I bought this camera in the link below:http://www.robotshop.com/seeedstudio-electronic-brick-serial-cmos-camera-2.html. Yes I did test my Spark fun shield. It is getting enumerated as a Virtual Com Port" CreationDate="2011-02-25T20:11:41.483" UserId="3159" />
  <row Id="15882" PostId="6854" Text="&quot;This variable loading affects the amplifier's performance both because the amplifier has finite output impedance (it cannot keep its output voltage perfectly constant when the speaker load varies) ... The influence of the speaker impedance is different between tube amplifiers and transistor amplifiers, principally because tube amplifiers normally use output transformers and they tend to use low feedback.&quot; - [Wikipedia - &quot;Tube Sound&quot;](http://en.wikipedia.org/wiki/Tube_sound#Harmonic_content_and_distortion) Also: http://www.diyaudio.com/forums/solid-state/100799-current-mode-amp-speakers.html" CreationDate="2011-02-25T20:26:28.090" UserId="142" />
  <row Id="15883" PostId="4155" Text="At 5 pins or more, you cant draw a full charlieplexing circuit without crossing lines. Topology problem. " CreationDate="2011-02-25T20:27:31.100" UserId="3161" />
  <row Id="15884" PostId="10706" Text="The devil is in the details.  Please post your circuit.  What thermistor are you using?  Did you calculate the power (and self-heating) at maximum resistance?" CreationDate="2011-02-25T21:11:06.750" UserId="411" />
  <row Id="15885" PostId="10700" Text="The intended laptop to purchase is faster than these requirements in both cases. But still this doesn't quite address the question of whether multiple cores are useful for autorouting." CreationDate="2011-02-25T21:34:36.697" UserId="2028" />
  <row Id="15886" PostId="10581" Text="Specifically, MSP430F2122." CreationDate="2011-02-25T22:05:07.627" UserId="2520" />
  <row Id="15887" PostId="10696" Text="Can whoever downvoted give some feedback to what @Shauron can do better next time?" CreationDate="2011-02-25T22:06:03.273" UserId="319" />
  <row Id="15888" PostId="10708" Text="Try contacting Microchip support. I've always found them very helpful." CreationDate="2011-02-25T22:25:43.017" UserId="305" />
  <row Id="15889" PostId="8344" Score="1" Text="Sure, but in the WiTricity case, they're irradiating the antenna from a short distance at a tuned frequency. The crystal radio example is perfect-- that's a very similar case to what we've been discussing. I think that a crystal radio antenna captures much less than 1 W and thus would be useless for powering a cellphone." CreationDate="2011-02-25T23:05:03.683" UserId="712" />
  <row Id="15890" PostId="10696" Text="Ya Im curious about that myself?" CreationDate="2011-02-25T23:09:12.397" UserId="3073" />
  <row Id="15891" PostId="9252" Score="1" Text="Thanks, and don't feel obliged to gather any more data points on my account!" CreationDate="2011-02-25T23:24:06.337" UserId="1756" />
  <row Id="15892" PostId="9222" Text="Thanks to all for these great answers, I wish I could &quot;accept&quot; all of them!" CreationDate="2011-02-25T23:25:23.213" UserId="1756" />
  <row Id="15893" PostId="10701" Score="3" Text="Soldermask is useful for several other reasons than making it easier to &quot;machine solder&quot; (I assume you mean wave): including but not limited to reducing corrosion, controlling impedance, and reducing bridging between fine pitch pads." CreationDate="2011-02-26T00:20:02.090" UserId="1407" />
  <row Id="15894" PostId="10715" Text="Certainly one can add handshaking by adding I/O's, but normal SPI devices already require a somewhat excessive number of pins (4), when three wires are plenty to produce a master-slave bus with handshaking.  I would have rather used a microcontroller than a CPLD for my SPI slave, but the device has to consume minimal power when idle, and I wanted to use three wires rather than five.  Thus my desire for a microcontroller with features that would allow nice handshaking." CreationDate="2011-02-26T00:20:34.430" UserId="3123" />
  <row Id="15895" PostId="10715" Text="I'm not sure if a **hardcoded** handshaking in a bus would lead to less power consumption. After all, that extra feature requires Driving or Sinking a signal, no matter where that extra control comes from (your own or hardcoded) or goes into (as in: it may go into an extra line, or into an existing line as in your example). I think the Handshaking's algorithm itself would mean more in terms of time and power optimization." CreationDate="2011-02-26T00:44:47.957" UserId="3078" />
  <row Id="15896" PostId="10706" Text="The current I'm running is less than 10uA.  I don't care exactly what the value is, so long as I can measure what it is, which I can.  What I'm not confident about is how stable that will be, as BarsMonster mentioned, over temperature and time." CreationDate="2011-02-26T01:45:21.173" UserId="3164" />
  <row Id="15897" PostId="10711" Text="Am I worried about ambient temp (which I can measure and use a look up table to correct for) or die temp which would be much harder.  I'm running this very low current, so I don't expect power dissipation by the opamp itself to be a driving factor in heat buildup." CreationDate="2011-02-26T01:46:35.400" UserId="3164" />
  <row Id="15898" PostId="10700" Text="I use Altium 9 on a 2 Ghz Pentium M (When Traveling), so their &quot;requirements&quot; are really more recommendations. You do wait a bit when opening big board files, but it works well enough." CreationDate="2011-02-26T02:50:38.820" UserId="1374" />
  <row Id="15899" PostId="10700" Text="@Fake: Do you use autoroute though?  Autoroute has HIGH demands on CPU." CreationDate="2011-02-26T04:12:42.243" UserId="1743" />
  <row Id="15900" PostId="10718" Text="With Intel Turbo Boost, and I think AMD came out with something similar on their last set of chips, there isn't a dichotomy between quad-core and faster dual core.  The quad-core chip BECOMES a faster dual core and even faster single core when the workload calls for that." CreationDate="2011-02-26T04:14:17.793" UserId="1743" />
  <row Id="15901" PostId="8971" Text="Also, FTDI chips are available pre-soldered to DIP modules for a reasonable price." CreationDate="2011-02-26T04:22:43.383" UserId="1743" />
  <row Id="15903" PostId="10700" Text="Which one? I never use the full-board autorouter, because I've never seen it produce results that aren't rubbish. The real-time single-trace router I have dialed pretty far back, because I've found it to not be particularly useful. So.... Not really. As soon as they produce an autorouter that isn't crap, I probably will start." CreationDate="2011-02-26T04:39:50.290" UserId="1374" />
  <row Id="15904" PostId="9809" Text="Thanks for the response, I ended up getting a spade connector of the given width and this did indeed fit and works well.  It seems the weirdness of this connector was simply to make it easy to connect and disconnect - you can push in on the middle part to slide it off with no effort at all, and indeed the plastic cover does this for you when you try to pull it away from the connector." CreationDate="2011-02-26T05:03:18.043" UserId="548" />
  <row Id="15905" PostId="10714" Text="@brianCarlton, I have to disagree on the supercap note. Supercaps have very high self discharge rates, this means that if you need a long term battery source without recharge you cannot use a supercap. If you need only a day or so, you will still have to significantly over-spec your supercap, the cost will normally be a deterrent for this to be a feasible solution." CreationDate="2011-02-26T06:57:04.400" UserId="230" />
  <row Id="15906" PostId="10714" Text="@BrianCarlton, If you mean use a supercap as short term power for the power bursts and a battery to give a trickle charge, this is a great solution, but the complexity of circuitry and cost can be a deterrent in low complexity/low cost systems." CreationDate="2011-02-26T06:58:05.507" UserId="230" />
  <row Id="15909" PostId="10041" Text="I would prefer a solution for base-10 numbers." CreationDate="2011-02-26T09:58:04.153" UserId="2597" />
  <row Id="15910" PostId="10696" Score="1" Text="I didn't downvote this question but agree that it's not a good question in the spirit of the Stack Exchange community. It is not a specific question with a specific answer, rather than &quot;how do I design a circuit to do X?&quot; its more &quot;how do I find out more about electronics?&quot;. To which I would answer: education - courses (evening class through to degree/doctorate level), books, websites, magazines, experimentation - to show how broadly this can be answered. If anyone disagrees, tell us what the one right answer is." CreationDate="2011-02-26T11:40:15.133" UserId="2110" />
  <row Id="15911" PostId="10705" Text="Ah, thank you! I didn't think about the voltage difference problem. You saved me a lot of trouble there. Regarding the circuit: Yeah, sorry, you're right. The circuit shown above was meant as a simple diagram of what I meant, not a real circuit (consider it as sort of a flowchart). Sorry about the confusion." CreationDate="2011-02-26T12:28:03.767" UserId="2642" />
  <row Id="15912" PostId="10685" Score="1" Text="@Sai Ok. Now you can do another test. Make a short with TX and RX pins of your Spark Fun Shield. Send any data using a software like Hyperterminal. Everything you send, you have to receive. If you remove the short and try send a character again, and you won't receive nothing." CreationDate="2011-02-26T13:03:55.637" UserId="938" />
  <row Id="15915" PostId="10737" Text="Thankyou for the informative reply. As I have no battery in my circuit I just wired up 1 and 2 and that did the trick." CreationDate="2011-02-26T16:49:19.693" UserId="2739" />
  <row Id="15916" PostId="10699" Text="@BrianCarlton, I think Art of Electronics is a standard and fantastic book, but when I am learning things in it I really think you need to have some training to understand what they are writing. It is very to the point, which if a complete amateur could read it the book would have to be very large with very extended explanation." CreationDate="2011-02-26T18:17:57.740" UserId="230" />
  <row Id="15917" PostId="10737" Text="I'd much rather use a Diode-OR or something to that effect rather than a mechanical switch to provide continuity of power." CreationDate="2011-02-26T18:27:02.600" UserId="1407" />
  <row Id="15918" PostId="10706" Text="A bridge is good at canceling resistor tempco, where a current source is effectively comparing the varing resistor to the one in the current source.  But with a good thin-film resistor that may not be a problem.  Details are important. Please post your circuit." CreationDate="2011-02-26T18:44:02.213" UserId="411" />
  <row Id="15919" PostId="10647" Text="Have you heard of the Free Charge Controller project?&#xA;http://freechargecontroller.org/" CreationDate="2011-02-26T20:30:19.797" UserId="813" />
  <row Id="15920" PostId="10715" Text="@Arturo: In my application, when clock and MOSI are both low, the CPLD will drive MISO high if it has something it wants to say, and low otherwise.  Since there are no passive pull-ups, there is no static current drain.  There are a variety of approaches that can be used to trade off half- vs full duplex, stateless idle behavior (when MOSI and CLK are both low, MISO will be high when the CPLD requires attention, regardless of what state the CPLD is in), in-line receipt of data without having to send anything, etc." CreationDate="2011-02-26T21:29:02.550" UserId="3123" />
  <row Id="15921" PostId="10715" Text="@Arturo: If nothing like what I describe already exists, I'd be more than happy to write up a specific proposal if anyone would be interested.  If such a thing does already exist, however, why reinvent the wheel?" CreationDate="2011-02-26T21:34:23.873" UserId="3123" />
  <row Id="15922" PostId="10646" Text="@Martin - Good point!  I've added it to my answer." CreationDate="2011-02-26T21:38:33.670" UserId="857" />
  <row Id="15923" PostId="10723" Text="The &quot;second reason&quot; is usually called a bootloader." CreationDate="2011-02-26T21:52:20.130" UserId="857" />
  <row Id="15924" PostId="10710" Score="1" Text="Kapton tape is a good idea for this project. I think I'll try cutting some on my laser engraver to see how this works!  Do you know where you can get broader sheets of the stuff?" CreationDate="2011-02-26T21:56:43.590" UserId="857" />
  <row Id="15925" PostId="10744" Text="+1. Very good! You can take it wherever you want." CreationDate="2011-02-26T21:57:12.530" UserId="938" />
  <row Id="15926" PostId="10416" Text="If you did try this. I would like to know the results you had with using 10uF caps with a MAX232 (which manufacturer if known please). " CreationDate="2011-02-26T23:00:41.007" UserId="2598" />
  <row Id="15927" PostId="10710" Text="Unfortunately no :-|" CreationDate="2011-02-26T23:19:09.207" UserId="2062" />
  <row Id="15928" PostId="10711" Text="Well, if you can digitally correct it you must be fine. Selfheating on such currents shouldn't cause much problems (as long as you are not shooting for 0.001C accuracy :-) )" CreationDate="2011-02-26T23:24:07.840" UserId="2062" />
  <row Id="15929" PostId="10710" Text="You have a laser engraver?  Then, problem solved! Engravers will remove solder mask and leave the copper/tinplate untouched. Just spray-paint the board and laser away the paint on the pads.  " CreationDate="2011-02-27T00:00:07.310" UserId="411" />
  <row Id="15930" PostId="10753" Text="I considered making them at home but I came unstuck when I realised how much time it would take. There are 80 x 0603 components, 2 x TQFP, 8 x SOT23, as well as many others. I'll be producing prototypes myself, but production simply has to be done by machine to be viable." CreationDate="2011-02-27T01:49:16.313" UserId="1225" />
  <row Id="15931" PostId="10753" Text="Well, 1 minute per tqfp, 5 seconds per sot&amp;0603, 10 minutes per board (worst case). Making this board using toner transfer method would require some 1-2 minutes of human time, so 12 minutes per board in total. Maybe you can just hire a student to do that. Also, if you use resistors on parallel buses you can get quad &amp; octal resistors to save time." CreationDate="2011-02-27T02:09:42.513" UserId="2062" />
  <row Id="15932" PostId="10753" Text="1 guy = 40 boards per day, 800 per month :-) Hehe :-)" CreationDate="2011-02-27T02:10:19.907" UserId="2062" />
  <row Id="15933" PostId="10753" Text="@BarsMonster, maybe if I live in Russia, but in the UK labour is expensive; min wage £5.80/hr IIRC. Future possibility of considering hand assembly but I think machine assembly is best." CreationDate="2011-02-27T02:56:16.787" UserId="1225" />
  <row Id="15934" PostId="10752" Score="3" Text="You tell us. Go get some quotes for your board and find out what is cheaper. There is just so many variables for us to be able to tell you one way or another. Price will depended on size, components, minimum spacing, etc." CreationDate="2011-02-27T03:23:38.173" UserId="319" />
  <row Id="15935" PostId="3578" Text="I think the question you need to ask yourself first is this: ** Is sorting the resistors worth your time**. Resistors are so dirt cheap that whenever I drop a few, or mix up my bins, I typically toss them, because I can replace all the lost resistors for ~$2.50, and it would take me more than an hour or two to sort them. Are you only worth $1.25 an hour?" CreationDate="2011-02-27T04:12:52.013" UserId="1374" />
  <row Id="15936" PostId="10756" Text="This is a shopping question, and off topic: a user is looking for a product that may not be available in the near future or be geographically limited. I suggest looking at parametric searches provided by DigiKey, Mouser, and other electronics distributors." CreationDate="2011-02-27T04:13:06.233" UserId="2118" />
  <row Id="15937" PostId="10755" Text="The stiffness of a two-resistor voltage divider is the resistance of the two resistors in parallel.  To get 300 mV drop when 100 mA is drawn, this parallel resistance must be 3 ohms.  If R1 is the top resistor and R2 the bottom, then R1=Rp / k, where k=3.3/5.0.  And R2 = k*r1/(1-k). So the divider would be 4.55 and 8.82 ohms.  Quiescent current 374 mA, burning off 1.87 watts.  A voltage regulator seems like a better idea." CreationDate="2011-02-27T04:44:00.263" UserId="411" />
  <row Id="15938" PostId="10755" Text="@markrages - Yeah, I just didn't remember the formula off the top of my head." CreationDate="2011-02-27T04:58:56.180" UserId="1374" />
  <row Id="15939" PostId="10752" Text="I imagine China will have better prices in high volumes as well.  If the small batch works out well, I suggest you use the same company for the larger production.  The risk and hassle of switching companies will negate any price difference." CreationDate="2011-02-27T04:59:21.607" UserId="411" />
  <row Id="15940" PostId="10755" Text="@fake to be honest, I didn't either and had to write it down." CreationDate="2011-02-27T05:00:31.310" UserId="411" />
  <row Id="15941" PostId="4405" Text="The emitter-followers have an output impedance of 10k || (50k / beta).  10k is huge, so let's call it 50k/beta.  If the transistors have a beta of 200, then the output impedance is 250 ohms.  So maximum attenuation is about 250/50k, or -46dB.  This is OK but not great performance.  Use op-amp buffers instead of the emitter-followers if fidelity is important." CreationDate="2011-02-27T05:09:52.877" UserId="411" />
  <row Id="15942" PostId="10714" Text="Assuming capacitor across battery: To limit the battery drain to 15mA, limit the voltage droop to 150 mV. (assuming 10 ohms internal resistance.)  So we need enough capacitance to drop 150 mV in 10 seconds of 60 mA.  That's 10mV/second.  I=C * dv/dt, so C = 60 mA / 10 mV, or 6 farads.  Moral: Put a resistor in series with the battery, so that heavy currents are drawn from the capacitor.  " CreationDate="2011-02-27T05:24:55.750" UserId="411" />
  <row Id="15943" PostId="10714" Text="@Kortuk, what complexity of circuitry?  Wouldn't a 100 ohm resistor fromt the coin cell to the supercap be sufficient?  (and power the circuit from the supercap.)" CreationDate="2011-02-27T05:29:39.320" UserId="411" />
  <row Id="15944" PostId="10762" Text="@markrages So then as long as the junction temperature is less than the max recommended in the TI datashet (125°C), I should be OK?" CreationDate="2011-02-27T06:24:32.237" UserId="2654" />
  <row Id="15945" PostId="10753" Score="2" Text="In Czech Republic the minimal wage is £1.7/hr (e.g. 3.5 times less than in UK) and I can get &quot;hand pick&amp;place&quot; assembly from £9/hour plus some tiny fee per component. Trained worker can do between 500-1000 components per hour. So I don't see any particular reason why this could not be done in any European country or in U.S. for less than 7 quids per board in your case, and possibly for half of that. It's obviously possible in Italy, so look harder. These are often small companies that do only small series or prototypes and do not advertise much." CreationDate="2011-02-27T06:43:58.803" UserId="2636" />
  <row Id="15946" PostId="10762" Score="2" Text="Yep. You should be fine.  If the heat bothers you, and you are re-laying-out the board try putting a big plane of copper on the tab of the SOT223, and vias to connect to a plane on the other side.  This forms a heat sink and reduces the junction-&gt;ambient resistance." CreationDate="2011-02-27T07:15:49.300" UserId="411" />
  <row Id="15947" PostId="10714" Text="@markrages, have you seen the size/cost of a 6 farad supercap? I think if a coin cell battery is on the order of acceptable cost a 6Farad cap is adding quite a bit. I am not saying one solution is correct for all cases, I just find that when a coin cell battery is on the order of acceptable cost for your power an extra 6Farad supercap is probably not an option. 6F superap I will say is 2 dollars, looking up they are more, but rounding down for very very large order. 6 coin cells for about 20 cents. We got them for 2 cents a piece(only buying a couple thousand), but you can add a little." CreationDate="2011-02-27T07:23:14.060" UserId="230" />
  <row Id="15948" PostId="10543" Text="@MartinHernandez, please try to edit all of your information about what you are doing and what is not working into your question. Currently this is not a question. I could see a few things that you could be asking about. When you have updated this question to be a question just flag for moderator attention and I can come and open it for answers." CreationDate="2011-02-27T07:26:44.440" UserId="230" />
  <row Id="15950" PostId="10714" Text="@Kortuk, with the 100 ohms resistor in series, you need about 0.5F.  Still big, but more manageable." CreationDate="2011-02-27T07:36:49.833" UserId="411" />
  <row Id="15951" PostId="10755" Text="@markrages - well, that makes me feel better." CreationDate="2011-02-27T07:41:28.087" UserId="1374" />
  <row Id="15952" PostId="10714" Text="@markrages, for .47F I am still seeing $2.50 in large quantities. They have such potential but cost so much and for many low cost sensor network application they just do not fit. There are many other things that they are just perfect for though. We shall see, as I think we both know this has a large amount to do with their specific needs. I was adding a disclaimer to help others in the future whom see this and wonder." CreationDate="2011-02-27T07:45:57.830" UserId="230" />
  <row Id="15953" PostId="10714" Text="to the original poster:  If you can break up the 10 seconds of 60 mA into briefer pulses, you will greatly increase your power options. " CreationDate="2011-02-27T07:58:09.100" UserId="411" />
  <row Id="15954" PostId="10762" Score="1" Text="It's important to remember that the datasheet's rated values are generally for a situation with an ideal heatsink." CreationDate="2011-02-27T08:22:15.720" UserId="1374" />
  <row Id="15955" PostId="10752" Text="@kellenjb. I've asked many suppliers. In my question, I say they won't talk to me or give me outrageous prices. One quoted me $100/board for just assembly, excluding components! The product only sells for $85!" CreationDate="2011-02-27T10:38:13.833" UserId="1225" />
  <row Id="15956" PostId="10753" Text="@Jaroslav Cmunt, any idea where I can find these companies?" CreationDate="2011-02-27T10:38:48.857" UserId="1225" />
  <row Id="15957" PostId="10753" Text="Well, no, I only searched until I found one, which is enough for me. They don't have web pages in English, so I can't really help you with this in some specific way, sorry. But I remember that I had to sift through quite a few pages of search results on Google and that it was not easy to find. Many of these companies don't publish prices on web, so you have to ask etc. However I think there may be quite a few of them here, because I can even get PCB prototypes cheaper and faster than in China from at least two companies etc." CreationDate="2011-02-27T11:41:47.860" UserId="2636" />
  <row Id="15958" PostId="10753" Text="You may want to ask national trade associations to check if they can find something for you, though I am not sure if they promote these small companies." CreationDate="2011-02-27T11:45:15.160" UserId="2636" />
  <row Id="15959" PostId="10753" Text="@Thomas I've just checked local salaries of guys who do smd soldering - it's about £3.8/hour, so labor is not cheap anywhere. Even at 5.8 it's still £1-2 per board :-D" CreationDate="2011-02-27T12:04:10.890" UserId="2062" />
  <row Id="15960" PostId="10753" Text="@BarsMonster. Thanks! It's definitely something to check out. Hand assembly. Will have to keep it in mind. I'd appreciate if anyone can hint towards a place to look as I'm otherwise stuck." CreationDate="2011-02-27T12:41:55.210" UserId="1225" />
  <row Id="15961" PostId="10324" Text="Gravitational potential energy is referenced negative by setting it to zero at infinity. Electrical potential energy is negative between two charges of opposite sign and positive between charges of the same sign. Say there's an electrical potential drop from 5V to 3V. A positive test charge q would add -2q to its potential energy (becoming less positive), while a negative test charge -q would accelerate in the other direction (+2V, from 3V to 5V), but also adding -2q to its potential energy (becoming more negative). In both cases potential energy decreases." CreationDate="2011-02-27T13:06:19.150" UserId="721" />
  <row Id="15963" PostId="10604" Text="Maybe it makes engineers feel like conquerors: today we capture the schematic; tomorrow the world! Muwah ha ha ha ha!" CreationDate="2011-02-27T14:29:27.737" UserId="721" />
  <row Id="15964" PostId="10629" Text="We've still got Windows 98 on some of the computers at work.  :)  I don't think the software even runs on anything modern." CreationDate="2011-02-27T14:36:30.663" UserId="142" />
  <row Id="15965" PostId="10759" Text="That's a single chip which can act like both, not a single chip that *contains* both." CreationDate="2011-02-27T14:37:14.623" UserId="142" />
  <row Id="15968" PostId="10773" Text="Why?..........." CreationDate="2011-02-27T15:30:29.743" UserId="2062" />
  <row Id="15969" PostId="10759" Text="The cd4052 then." CreationDate="2011-02-27T15:57:33.090" UserId="411" />
  <row Id="15970" PostId="10774" Text="Yes but what about the losses as no transformer is 100% efficient. Also the health risks associated with living next to substations(the transformers, we call them substations in the UK)." CreationDate="2011-02-27T16:11:55.763" UserId="1623" />
  <row Id="15971" PostId="10774" Text="Yes, but these days we also have thyristors and transistors which able to do DCDC very efficiently with no moving parts too up to some 2kV..." CreationDate="2011-02-27T16:19:13.913" UserId="2062" />
  <row Id="15972" PostId="10752" Text="@Thomas O If they wont talk to you what makes you think that they would be willing to talk to any of us for an equal order." CreationDate="2011-02-27T16:32:01.460" UserId="319" />
  <row Id="15973" PostId="10773" Score="8" Text="@Leon Heller I am really starting to get annoyed with how short you are with things on this site. It really is not needed. If you don't like something you need to explain yourself." CreationDate="2011-02-27T16:36:11.927" UserId="319" />
  <row Id="15974" PostId="10777" Text="I don't understand both 'Not so fast Longer' and what is say in the second part... Both solid state converters &amp; transformers are good???? :-|" CreationDate="2011-02-27T16:44:52.940" UserId="2062" />
  <row Id="15975" PostId="10774" Score="1" Text="you also have to look at the power plants themselves. Most power plants create some sort of AC through mechanical means. Are there ways of converting That to DC efficiently, for DC power transmission at such high levels?" CreationDate="2011-02-27T16:57:19.113" UserId="2060" />
  <row Id="15976" PostId="10696" Text="Before you get into active circuits, find a good intro to linear circuits with ideal sources, resistors, capacitors, and inductors (i.e. ask a more narrow question). Move on to diodes and ideal op-amps, and eventually small signal modeling of non-linear circuit elements such as bipolar transistors: http://en.wikipedia.org/wiki/Small_signal_model. &quot;The Art of Electronics&quot; would be a good book for your &quot;what to use&quot; question, but I wouldn't use it as an intro to circuits." CreationDate="2011-02-27T17:03:58.387" UserId="721" />
  <row Id="15977" PostId="10752" Text="@Kellenjb, I'm asking for others' experience on this matter - perhaps people have managed it before? Some will talk to me, they just give me stupid prices." CreationDate="2011-02-27T17:08:28.163" UserId="1225" />
  <row Id="15979" PostId="10779" Text="I wonder if it's feasible to have 380 at homes, must be too dangerous..." CreationDate="2011-02-27T18:05:36.643" UserId="2062" />
  <row Id="15980" PostId="10779" Score="2" Text="Well, we have 400 V AC 3-phase in just about all homes around here (Denmark), so it's certainly not any more dangerous than what we're already doing." CreationDate="2011-02-27T18:27:10.330" UserId="1675" />
  <row Id="15981" PostId="10774" Score="1" Text="@Dean, There are health risks with being near a substation? Do you mean getting electrocuted? " CreationDate="2011-02-27T19:01:44.263" UserId="230" />
  <row Id="15982" PostId="10774" Text="By switching long chains of semiconductors synchronously you can get up to hundreds of kV these days.  But it's very new and not cheap, so it is only done for very long distance transmission, to reduce losses." CreationDate="2011-02-27T19:06:53.680" UserId="339" />
  <row Id="15983" PostId="10774" Text="@Kortuk♦ Some people believe that among other things ЕМ field can cause cancer and similar &quot;bad stuff&quot;. Unfortunately, I was unable to find any serious research data backing the claims. There appears to be a [Wikipedia article](http://en.wikipedia.org/wiki/Electromagnetic_radiation_and_health), but I haven't analyzed it in detail." CreationDate="2011-02-27T20:24:19.530" UserId="1240" />
  <row Id="15984" PostId="10774" Score="3" Text="@Andrejako, people believe alot of things, lets stick to science &lt;3" CreationDate="2011-02-27T20:25:25.283" UserId="230" />
  <row Id="15985" PostId="10750" Text="Thanks. I thought I'd need 100% of Vcc due to a signaling problem in the past. After mysteriously fixing it with a a relay in between, I assumed the small differences in Vcc gave the problem. But you're right, I doesn't make sense at all." CreationDate="2011-02-27T20:31:02.753" UserId="941" />
  <row Id="15986" PostId="10743" Text="What if the uC voltage on the 3.3V is derived from the 24V supply? You still get any protection out of a opto coupler?" CreationDate="2011-02-27T20:36:16.493" UserId="941" />
  <row Id="15987" PostId="10774" Score="1" Text="@Kortuk the possibility of the magnetic fields causing damage to human health. I personally think its a load of rubbish. " CreationDate="2011-02-27T20:37:09.460" UserId="1623" />
  <row Id="15988" PostId="10780" Text="Use a flyback diode." CreationDate="2011-02-27T21:04:19.897" UserId="721" />
  <row Id="15989" PostId="10745" Text="If you can link us to the different parts you are using you will normally get a much improved set of answers." CreationDate="2011-02-27T21:11:47.390" UserId="230" />
  <row Id="15990" PostId="10780" Text="Just like in AC - if you pull the plug in the right time, you will be cutting 380v..." CreationDate="2011-02-27T21:14:06.637" UserId="2062" />
  <row Id="15991" PostId="10780" Score="2" Text="AC self extinguishes to zero 50/60 times a second though.  You CANNOT switch HVDC in the same manner as AC." CreationDate="2011-02-27T21:39:15.577" UserId="1827" />
  <row Id="15992" PostId="10745" Text="Thanks, updated." CreationDate="2011-02-27T21:49:36.927" UserId="1603" />
  <row Id="15993" PostId="10774" Text="@Kortuk♦ That's true!" CreationDate="2011-02-27T21:59:13.140" UserId="1240" />
  <row Id="15997" PostId="10773" Score="3" Text="Another idea is to have a centralized, well-designed SMPS for each house, and supply a few standardized DC voltages to special outlets, so you aren't wasting copper and energy on tons of inefficient wall warts and brick adapters." CreationDate="2011-02-27T23:43:52.177" UserId="142" />
  <row Id="15998" PostId="10795" Score="2" Text="I would upvote you 1000 times for FTDI if I could." CreationDate="2011-02-28T01:52:09.353" UserId="1477" />
  <row Id="15999" PostId="10795" Score="2" Text="I have never had any issues with FTDI drivers on any OS, I would suggest it very much." CreationDate="2011-02-28T01:57:20.987" UserId="319" />
  <row Id="16000" PostId="10773" Score="2" Text="@endolith that is the idea that I have always loved. The logistics of changing a grid to DC are difficult regardless of technical difficulties. Keeping our existing infrastructure and just distributing the SMPS will be the cheapest route. No reason houses can't implement this now." CreationDate="2011-02-28T02:01:14.730" UserId="319" />
  <row Id="16001" PostId="10767" Text="Hi BG100, thanks for your answer. I definitely go through the links provided." CreationDate="2011-02-28T03:34:57.383" UserId="3173" />
  <row Id="16003" PostId="10775" Text="Hi jsolarski, thanks for your answer. I definitely go through the links provided." CreationDate="2011-02-28T03:37:58.567" UserId="3173" />
  <row Id="16004" PostId="10769" Text="Hi BarsMonster, thanks for your answer. I definitely go through the links provided." CreationDate="2011-02-28T03:38:58.210" UserId="3173" />
  <row Id="16005" PostId="10772" Text="Hi Ryan, thanks for your answer. I definitely go through the links provided." CreationDate="2011-02-28T03:40:36.570" UserId="3173" />
  <row Id="16006" PostId="10769" Text="Great copy&amp;paste ;-)" CreationDate="2011-02-28T04:31:18.127" UserId="2062" />
  <row Id="16007" PostId="10800" Score="7" Text="http://www.wolframalpha.com/input/?i=.02+mA+8+years+to+mAh" CreationDate="2011-02-28T05:45:34.610" UserId="142" />
  <row Id="16008" PostId="10790" Text="Some toy train sets use magnets in the tracks and reed relais in the engine to do simple toggling. They have a simple trigger switch to turn the engine on. Seen at a 80's Lego Duplo Train. This should be fairly easy to make, and have low power consumption. Think about a Flipflop or retriggerable Monoflop. " CreationDate="2011-02-28T05:55:01.390" UserId="3161" />
  <row Id="16009" PostId="10123" Score="4" Text="well, obviously big brother injected you with a tracking tag the last time you went to the doctors and thats what your reading! :p" CreationDate="2011-02-28T06:33:03.387" UserId="1438" />
  <row Id="16010" PostId="10779" Text="Presumably he means 380VDC as the feeder to home.  I wonder what his plans are for actual transmission/distribution.  He certainly can do high voltage DC (probably 3k-200k V depending on the distance/load of the run) but has to come up with a cheap and efficient alternative for a pole transformer which would have to convert something on the order of 3k-30k VDC to 380VDC (assuming similar current levels as AC systems)." CreationDate="2011-02-28T06:47:12.610" UserId="1438" />
  <row Id="16011" PostId="10800" Score="1" Text="@endolith, you are awesome! So is wolframalpha." CreationDate="2011-02-28T06:48:08.587" UserId="230" />
  <row Id="16012" PostId="10800" Score="2" Text="At some point in the 240mAh capacity discharge, the voltage will fall below the operating voltage for the flip flop, so it will go to an indeterminate or reset state. You need to examine the discharge curve to see what this is, so it's unlikely that you will get the full 240mAh because your circuit will not work all the way down to 0V." CreationDate="2011-02-28T08:25:38.370" UserId="2110" />
  <row Id="16013" PostId="10784" Text="What kind of customization you want? Why not just taking standard ones?" CreationDate="2011-02-28T08:59:21.307" UserId="2062" />
  <row Id="16014" PostId="10783" Score="1" Text="Thanks, but I'm not looking for SPI-to-UART. The question is not about picking the alternative, but rather about how to interconnect these two parts :-)" CreationDate="2011-02-28T09:03:43.500" UserId="1603" />
  <row Id="16015" PostId="9837" Text="I'm making good progress with a capacitive sensor. The main challenge is making sure the moisture does not come into direct contact with the electrodes, as that turns it into a resistive load. But I think i have the electronics part of it worked out." CreationDate="2011-02-28T09:26:24.953" UserId="1802" />
  <row Id="16016" PostId="10800" Score="1" Text="@Martin, this is a good point, but I was mostly focused on showing that the current draw from his gate would be too much to last 8 years." CreationDate="2011-02-28T10:56:55.453" UserId="230" />
  <row Id="16017" PostId="4203" Text="Provided a C++ compiler even exists for PIC, I see nothing wrong with using the language in an embedded device.  There are some great benefits to be had using an object-oriented language, even in constrained environments." CreationDate="2011-02-28T11:05:23.683" UserId="51" />
  <row Id="16018" PostId="10708" Score="1" Text="You'd be better off on the Microchip specialist forum at http://www.microchip.com/forums/f49.aspx" CreationDate="2011-02-28T11:29:19.880" UserId="2110" />
  <row Id="16019" PostId="10123" Score="1" Text="Search in your code for &quot;2E31204D&quot; maybe its a debug setting anywhere?" CreationDate="2011-02-28T11:55:48.997" UserId="3130" />
  <row Id="16020" PostId="10779" Text="Yes, it's a local grid of +/- 190V (with, e.g., 24V outlets in data centers). Here's a Wikipedia list of high voltage DC projects: http://en.wikipedia.org/wiki/List_of_HVDC_projects" CreationDate="2011-02-28T12:15:47.803" UserId="721" />
  <row Id="16021" PostId="10765" Text="Dimmers for mains powered incandescent lights normally use a TRIAC to turn the power on for a fraction of the mains cycle.  Using a potentiometer to dim a lamp directly will get very hot." CreationDate="2011-02-28T12:24:45.427" UserId="400" />
  <row Id="16022" PostId="10815" Text="Hi gallamine, Thank you very much for your lengthy answer. I definitely will follow the links you've provided. Thanks again." CreationDate="2011-02-28T12:55:59.873" UserId="3173" />
  <row Id="16023" PostId="10766" Text="Thanks for the advice. It looks as though my driver is not designed for dimming as it does infact flicker and humm probably best if I disconnect it from the mains dimmer!" CreationDate="2011-02-28T13:13:13.143" UserId="3178" />
  <row Id="16024" PostId="10806" Text="A nettop may not be suitable in a greenhouse environment, but it is a simple solution." CreationDate="2011-02-28T13:18:04.320" UserId="2060" />
  <row Id="16025" PostId="10804" Text="How many devices do you plan on controlling or monitoring?" CreationDate="2011-02-28T13:24:05.797" UserId="2060" />
  <row Id="16026" PostId="10806" Text="Modern ones consume just about 10W when little load. You can go down to 1W by going for slower uC, but it will triple time expenses, I am not really sure it's worth it. " CreationDate="2011-02-28T13:46:04.747" UserId="2062" />
  <row Id="16027" PostId="10708" Text="I've been in touch with Microchip support. They haven't resolved the issue yet. I figured I'd check here to see if anyone has had similar problems with the ICD3." CreationDate="2011-02-28T13:49:49.710" UserId="588" />
  <row Id="16028" PostId="4203" Text="@blalor - For a beginner, I didn't want to get into those issues.  See [&quot;Is C++ suitable for embedded systems&quot;](http://electronics.stackexchange.com/questions/3027/is-c-suitable-for-embedded-systems) for more discussion of the issue." CreationDate="2011-02-28T13:56:28.607" UserId="857" />
  <row Id="16029" PostId="10721" Text="It's important to note that you will *ALWAYS* store constants, and the rest of the program, in flash. Whether you /additionally/ store the data in RAM is up to you." CreationDate="2011-02-28T14:21:53.280" UserId="1363" />
  <row Id="16030" PostId="10820" Score="3" Text="Just a question. If the device automatically adjusts it's physical position, why do you need to remember the last temperature? When you power on the device again, it will not update the temperature and adjust its position?" CreationDate="2011-02-28T14:24:22.847" UserId="938" />
  <row Id="16031" PostId="10821" Score="2" Text="Microchip App note on endurance: &#xA;http://ww1.microchip.com/downloads/en/AppNotes/01019A.pdf&#xA;&#xA;From the Appnote, you can also increase the endurance by about 2x by decreasing the operating voltage from 5v to 3.5v.  &#xA;&#xA;&#xA;&#xA;" CreationDate="2011-02-28T14:57:05.357" UserId="2909" />
  <row Id="16032" PostId="10800" Text="And you need still MORE margin if the product can ever get warmer than room temp (77F).  In this class of device (CD4000), quiescent current increases by 2x if the temp rises ~20degF." CreationDate="2011-02-28T15:12:16.283" UserId="2909" />
  <row Id="16033" PostId="10820" Text="I agree with Daniel.  What if you power down and the ambient temperature changes drastically?  Upon powerup, if you used the last saved temp/position, you'd be in the wrong spot anyway, and the device would end up moving regardless.  Is there another requirement that isn't listed in your question?" CreationDate="2011-02-28T15:18:27.123" UserId="2288" />
  <row Id="16034" PostId="10790" Text="They already make a remote controlled Thomas engine that's the same size as the standard Trackmasters trains.  Perhaps someone has already posted the disassembly online and you can glean some info from it?  I have one at home and if I can find it, I'll try to snap pictures for you." CreationDate="2011-02-28T15:22:57.510" UserId="2288" />
  <row Id="16035" PostId="10790" Text="@Dave I'm really attached to the wooden tracks, but that's just me and a little superfluous to the solution." CreationDate="2011-02-28T15:25:20.890" UserId="1227" />
  <row Id="16036" PostId="10790" Text="@posipiet I hadn't considered that." CreationDate="2011-02-28T15:26:12.433" UserId="1227" />
  <row Id="16037" PostId="10819" Text="Hi, I didn't know about FriendlyARM, it looks quite nice and i like the screen :)" CreationDate="2011-02-28T15:38:18.463" UserId="2030" />
  <row Id="16038" PostId="10804" Text="Hi, mainly 3 or 4 fans and one humidifier in the hi-voltage side, and some sensors and small actuators in the logic side." CreationDate="2011-02-28T15:39:22.567" UserId="2030" />
  <row Id="16039" PostId="10123" Text="You've got a whole 50m reel of wire for the antenna?" CreationDate="2011-02-28T15:42:04.090" UserId="2770" />
  <row Id="16040" PostId="10781" Text="For a protocol to support bit-banging a slave with no timing requirements would require both master and slave to have two outputs (two wires that were open-collector at both ends would probably suffice in practice, though speed would not be wonderful and I'm not sure one could arrange a protocol that wouldn't have trouble if master+slave timing lined up precisely 'wrong', though one could use a random retry pattern to minimize the harm therefrom)." CreationDate="2011-02-28T16:11:32.770" UserId="3123" />
  <row Id="16041" PostId="10781" Text="One of the things I'd like in a handshaked SPI slave, though, would be the ability to work with a normal SPI master; ehnahced SPI master hardware could offer improved capabilities (e.g. DMA with handshake) but even a normal device could be useful.  Further, it would be desirable to have a slave MCU that could share the bus with other peripherals (e.g. if a slave receives a certain command, it would enable some other device and ignore the bus until it receives the next start sequence)." CreationDate="2011-02-28T16:14:35.513" UserId="3123" />
  <row Id="16042" PostId="10819" Text="@SubniC, the photo was taken by a friend of mine here in Brazil. http://www.sergioprado.org/2010/09/12/mini2440-instalando-o-android/ " CreationDate="2011-02-28T16:24:32.823" UserId="938" />
  <row Id="16043" PostId="10816" Text="http://opencores.org/ is cool too." CreationDate="2011-02-28T16:32:16.840" UserId="3045" />
  <row Id="16044" PostId="10825" Text="You mean &quot;the Android isn't suitable for that&quot;?" CreationDate="2011-02-28T16:32:44.500" UserId="142" />
  <row Id="16045" PostId="10685" Score="1" Text="Are you level shifting to rs232 levels? " CreationDate="2011-02-28T15:54:31.317" UserId="3193" />
  <row Id="16047" PostId="10765" Text="@Ian Using a potentiometer directly is a bad idea, of course, but form what I've seen many dimmers have a potentiometer as a control element. I was thinking about replacing that potentiometer with one which has a switch. " CreationDate="2011-02-28T16:40:23.263" UserId="1240" />
  <row Id="16048" PostId="10823" Score="3" Text="I might disappoint you, but when you flash a bit, entire sector is overwritten. Your solution will make 'bitmask' sector dead really soon." CreationDate="2011-02-28T16:50:18.843" UserId="1603" />
  <row Id="16049" PostId="10825" Text="No. The Arduino won't be suitable as it doesn't have host mode and won't be able to communicate with the phone." CreationDate="2011-02-28T16:54:54.020" UserId="305" />
  <row Id="16050" PostId="10808" Text="@ Taniwha: Thank you for your reply.&#xD;&#xA;&#xD;&#xA;Yes, I've tried with simple design before the big one. I just generated a sign signal and did DAC. Those all were able to be done with 100MHz clock and got the output from FPGA and tested in an oscilloscope. " CreationDate="2011-02-28T16:04:06.333" UserId="3194" />
  <row Id="16052" PostId="10823" Score="1" Text="If you don't erase the flash, you don't use up one of the 10K erase cycles for the sector.  If you have the value 0x7F and you write the value 0x3F, the result will be 0x3F.  This keeps the bitmask up-to-date, but does not erase the flash.  The erase only happens once the entire bitmask is 0." CreationDate="2011-02-28T17:03:38.173" UserId="204" />
  <row Id="16054" PostId="10823" Text="If I'm wrong, let's discuss.  I don't want bad answers here and I really don't want a bad design in my project." CreationDate="2011-02-28T17:04:35.753" UserId="204" />
  <row Id="16055" PostId="10770" Text="@akilan, this is not a forum; keep the Answers box for answers. Please read the [FAQ](http://electronics.stackexchange.com/faq). Edit your question for better explanation." CreationDate="2011-02-28T17:10:39.320" UserId="938" />
  <row Id="16056" PostId="10710" Text="@Mark - It sounds like you've done this before.  What sort of paint should be used?  It would have to be high-temperature and non-conductive, right?" CreationDate="2011-02-28T17:31:37.323" UserId="857" />
  <row Id="16057" PostId="9629" Text="The 74HC138 is unlikely to work at the 72MHz desired by the original poster. Still, +1 this answer is perfect, because all the processors I've worked with either (a) run slow enough that many people use a 74HC138 and it works fine, or (b) have dedicated chip select pins." CreationDate="2011-02-28T17:40:39.607" UserId="813" />
  <row Id="16058" PostId="10821" Text="If you use your first method, make sure that writing to the nonvolatile memory is the highest priority in your system once it starts, ie. that interrupts can't cause your values to change mid write or the micro to start some other processing which makes you run out of time. It is most important that you do not write corrupt values as you power down. Additionally, a CRC on the values would help you confirm that corruption did not occur, but you'd have to decide what to do if it did, such as using defaults." CreationDate="2011-02-28T17:49:12.173" UserId="2110" />
  <row Id="16059" PostId="9619" Text="Yes, good digital logic teachers tell the students &quot;don't short output pins, or they will fight each other and cause permanent damage!&quot; dozens of times. And yet there are a few devices seem to contradict that -- they are designed to have outputs shorted together in a &quot;tri-state bus&quot; or &quot;open-collector bus&quot; or &quot;matrix&quot; -- tri-state data buses, tri-state shared-memory multiprocessor address buses, I2C communication bus, multi-drop RS485 bus, LED charlieplexing, keyboard matrix, etc." CreationDate="2011-02-28T17:57:41.760" UserId="813" />
  <row Id="16060" PostId="10701" Text="But those thing can be done with conformal coating as mentioned?" CreationDate="2011-02-28T18:14:03.167" UserId="883" />
  <row Id="16061" PostId="10674" Text="GCC 4 was released in 2005, and &quot;default&quot; msp430 port sticking to v3 is a disgrace. Then again, the mspgcc4 project doesn't seem to be providing a very complete kit by itself. :(" CreationDate="2011-02-28T18:22:38.090" UserId="883" />
  <row Id="16062" PostId="10710" Text="Just regular enamel spray paint.  You should probably measure conductance yourself, just to be sure." CreationDate="2011-02-28T18:42:46.217" UserId="411" />
  <row Id="16063" PostId="10806" Text="@jsolarski Why would a nettop be any less suitable for a greenhouse environment than any other offered options?" CreationDate="2011-02-28T18:56:09.417" UserId="1240" />
  <row Id="16064" PostId="10373" Text="FFT: Yes, noise will create a bunch of spurious peaks at higher and lower frequencies -- but if you are lucky, your SNR ratio is good enough that all those peaks falls below -3dB below the peak level, and you can ignore them. Do the FFT, pick a cutlevel of half of the peak amplitude of all the bins, zero out all the FFT bins with an amplitude below the cutlevel, and count how many (hopefully consecutive) nonzero bins remain. With reasonable amounts of white noise, there's not enough noise to push the high and low frequencies above the cutlevel and so they will still be zeroed out and ignored" CreationDate="2011-02-28T18:57:29.080" UserId="813" />
  <row Id="16065" PostId="5561" Text="I did, and that just seems to water it down. :-(" CreationDate="2011-02-28T20:18:12.297" UserId="51" />
  <row Id="16066" PostId="10710" Text="so where can one find this soldermask?" CreationDate="2011-02-28T20:21:24.260" UserId="3077" />
  <row Id="16067" PostId="10823" Text="I think Robert is right. On my microcontroller, you can only write 4 bytes at a time, but the required bits are set to zero. The only way to get them back to 1's is to blank the 1k block. Its only the erase cycles that wear the flash..." CreationDate="2011-02-28T20:43:45.003" UserId="2770" />
  <row Id="16068" PostId="10844" Text="+1 for stating sentimentality as the definitive choice for the processor. " CreationDate="2011-02-28T21:10:35.103" UserId="857" />
  <row Id="16070" PostId="10800" Text="@Vandee, the long and the short of it is that you need a much much heftier battery." CreationDate="2011-02-28T22:32:33.240" UserId="230" />
  <row Id="16072" PostId="5531" Text="Be careful.  The voltages can hurt." CreationDate="2011-02-28T23:02:34.047" UserId="206" />
  <row Id="16074" PostId="10770" Text="@ sybreon:&#xD;&#xA;I really understand the pipelining very well from your explanation. Thank you so much.&#xD;&#xA;&#xD;&#xA;&#xD;&#xA;@ saar drimer and Martin Thompson:  thank you so much for your replies too.&#xD;&#xA;Regarding my Question 2, I add more detail here below (I'm sorry for not explaining it earlier):&#xD;&#xA;&#xD;&#xA;Note that, I wanted to upload pictures for all explantions but couldn't as I'm still new comer for this forum. &#xD;&#xA;&#xD;&#xA;*Finally, I really appreciate all your helps. In fact I'm getting more knowledge on digital designs from all your replies.* &#xD;&#xA;" CreationDate="2011-02-28T23:24:46.393" UserId="3194" />
  <row Id="16075" PostId="10770" Text="@akilan, if you give me the links to your information in a comment the users will often edit in your pictures for you, I understand the issue, maybe in a few upvotes you can do it yourself." CreationDate="2011-02-28T23:29:41.147" UserId="230" />
  <row Id="16077" PostId="10852" Text="Alternatively: `((X1 XNOR Y1) AND (X2 XNOR Y2) AND (X3 XNOR Y3) AND (X4 XNOR Y4))`" CreationDate="2011-02-28T23:38:00.797" UserId="1374" />
  <row Id="16078" PostId="9074" Text="@romkyns - That's more down to the fact that writing PCB software that uses non-rectilinear grids is *hard*." CreationDate="2011-02-28T23:39:27.300" UserId="1374" />
  <row Id="16080" PostId="10855" Score="2" Text="Aha!  The corrosion prevention sounds like the real motivation for it.  Thanks!" CreationDate="2011-03-01T00:06:24.510" UserId="2773" />
  <row Id="16081" PostId="10849" Score="3" Text="That has to be homework." CreationDate="2011-03-01T02:44:57.447" UserId="206" />
  <row Id="16082" PostId="10806" Text="@AndrejaKo From my experience, fan-less PCs (nettops/thin clients) only last for a few years in that kind of environment." CreationDate="2011-03-01T03:04:17.990" UserId="2060" />
  <row Id="16083" PostId="10765" Text="@AndrejaKo You make a good point.  Some dimmers use a pot to control a 10Vdc signal, but these seem to be fairly rare.  However, if that's the system you have then a pot with a switch may work for you.  The only caveat would be that the switch operation would likely be inverted and it probably wouldn't be rated for the power and voltage.  " CreationDate="2011-03-01T03:58:45.023" UserId="2051" />
  <row Id="16085" PostId="10856" Text="@carlRaymond, nice tool, it should have just been a few audio muxes, as 56k modems and voice just operate in the audio frequencies." CreationDate="2011-03-01T04:11:50.210" UserId="230" />
  <row Id="16087" PostId="10784" Text="What do you mean when you're talking&#xA;about a customized graphic LCD? &#xA;Specifically, what displays have you&#xA;looked at already that you have&#xA;rejected?  Why did you reject&#xA;them--what are your unique&#xA;requirements?" CreationDate="2011-03-01T04:44:05.233" UserId="1407" />
  <row Id="16088" PostId="10784" Text="Nobody fabricates their own graphic&#xA;LCDs; even the highest volume&#xA;customers buy from one of a handful of&#xA;manufacturers; Sharp, NEC, Toshiba,&#xA;Hitachi, LG Display, etc." CreationDate="2011-03-01T04:44:45.123" UserId="1407" />
  <row Id="16089" PostId="10806" Text="@jsolarski I still see no reason why that should be so, but I'll take your experience into account if I ever come into similar situation as OP." CreationDate="2011-03-01T04:44:49.790" UserId="1240" />
  <row Id="16090" PostId="10806" Text="@AndrejaKo It may be the case design and placement that caused those failures, but it is something to consider if its supposed to be a permanent installation. I would not want to choose a nettop that doesn't have a suitable case for the environment. " CreationDate="2011-03-01T04:57:32.027" UserId="2060" />
  <row Id="16091" PostId="10848" Text="I can personally vouch for Newhaven, they're a good US-based distributor with excellent support and good prices. I was going to post an answer naming them specifically, but I'll just leave it as a comment to your answer." CreationDate="2011-03-01T04:58:27.767" UserId="857" />
  <row Id="16092" PostId="8114" Text="@IsaacSutherland, input current = output current on a linear regulator(minus a small leakage). This means that if you are pulling 30mA at 5V you will see at 30mA at 9V as your input. This should explain the inefficiency as your efficiency is approximately Vout/Vin. " CreationDate="2011-03-01T06:03:11.190" UserId="230" />
  <row Id="16093" PostId="10861" Score="1" Text="Before getting into it too much, how good are your measurements--what did you make them with?  Most multimeters won't read 47 kHz signals (yours being a triangle wave has even higher frequency components) accurately.  A better measure for Pin/Pout could be performed with resistive loads and shunts and very large capacitors." CreationDate="2011-03-01T06:10:22.803" UserId="1407" />
  <row Id="16094" PostId="10863" Text="I do not have any source except knowing people whom have made choices like this before so I am only writing a comment. Often you take a 1k and say 1.8mA cannot hurt my input so lets just use this 1k, it will protect me and I can measure. I am not sure it is always the best choice, but it works 99/100 times." CreationDate="2011-03-01T07:15:56.120" UserId="230" />
  <row Id="16095" PostId="8114" Score="1" Text="@Kortuk, ground current is related to power wasted irrespective of load.  According to the Fairchild LM7805 datasheet, graound current for lm7805 is 5mA typ, 8mA max, and doesn't change much with load or input voltage.  This current will drain a standard 9V Energizer 522 flat in about 100 hours, so if the circuit will be on standby it would be better to use a more modern regulator with lower ground current." CreationDate="2011-03-01T07:40:08.767" UserId="411" />
  <row Id="16097" PostId="8114" Score="1" Text="@markrages, I did not know the term ground current and took a shot at answering since he asked a while ago. Thank you for taking the time to clear that up!" CreationDate="2011-03-01T07:54:58.410" UserId="230" />
  <row Id="16105" PostId="10602" Text="@Dave/@Fake Name - good points. I stand corrected :)" CreationDate="2011-03-01T09:33:26.760" UserId="3101" />
  <row Id="16106" PostId="10876" Text="What sort of &quot;protection&quot; do you need?" CreationDate="2011-03-01T10:32:20.397" UserId="566" />
  <row Id="16107" PostId="10876" Text="Cooling, electrical protection, loop isolation. (i'm no electronics engineer, but a web dev) so i'm just passing on requests from the engineers" CreationDate="2011-03-01T10:35:11.843" UserId="3205" />
  <row Id="16108" PostId="10876" Text="Keep in mind that the arduino is actually a very simple circuit. All it *really* does is power the AVR and break out the pins to standard connectors. You can make a custom PCB with a similar AVR chip that suits your physical needs." CreationDate="2011-03-01T11:00:36.563" UserId="1802" />
  <row Id="16109" PostId="10827" Text="Interesting idea, but is that a wired solution? Are we talking about cutting into the droid's speaker wires? Or just emitting the sound and using the wave shield on the arduino?" CreationDate="2011-03-01T13:24:48.603" UserId="2769" />
  <row Id="16110" PostId="10823" Text="It may be different for each type of memory and maybe even the memory vendor. I've seen EEPROMs must erase the page then re-write it for every write. I've seen flash memory you can write bits that are still 1's without erasing the page." CreationDate="2011-03-01T13:31:22.420" UserId="588" />
  <row Id="16111" PostId="10827" Text="Plug a headphone jack into the Droid and wire the audio outputs to servos (possibly via an amp)" CreationDate="2011-03-01T13:47:42.083" UserId="566" />
  <row Id="16113" PostId="10887" Text="Self healing fuses? never heard of those? how do they work!" CreationDate="2011-03-01T14:43:26.643" UserId="3073" />
  <row Id="16114" PostId="10887" Score="1" Text="http://en.wikipedia.org/wiki/Resettable_fuse" CreationDate="2011-03-01T14:44:12.887" UserId="2062" />
  <row Id="16115" PostId="2508" Text="FYI, the 6502 (mid 1970's) fetches the second byte of each instruction while decoding of the first one (if the second byte isn't needed, it's discarded), and overlaps the register write-back (if necessary) with the fetch of the first byte of the next instruction." CreationDate="2011-03-01T15:35:50.143" UserId="3123" />
  <row Id="16116" PostId="10887" Text="I've never heard of them called &quot;self healing fuses&quot;; &quot;resettable fuse&quot; is more common, or what you're specifically referring to is a PPTC resistor/fuse." CreationDate="2011-03-01T15:47:46.203" UserId="1407" />
  <row Id="16117" PostId="10887" Text="Any advantage/disadvantage of using a resettable over the traditional ones?" CreationDate="2011-03-01T16:13:31.590" UserId="3073" />
  <row Id="16118" PostId="10885" Text="what are the required rise and fall times for the signal?  And does it just go from 1 pin on the FPGA to 1 pin on the memory or will each signal make multiple stops?" CreationDate="2011-03-01T16:21:49.883" UserId="1438" />
  <row Id="16119" PostId="10879" Score="3" Text="You can take a closer look at those conditions specified on the data sheet and still be operating the part safely for your application.  For instance, if the part is spec'd run at 80 MHz up to 125°C and you plan on running inside where the temperature may never exceed 30°C you'll be fine running at 81 MHz.  There is an [interesting article](http://www.eetimes.com/design/signal-processing-dsp/4209479/Go-beyond-the-datasheet--Part-2--Understand-the-considerations) on this subject." CreationDate="2011-03-01T16:59:58.803" UserId="529" />
  <row Id="16122" PostId="10538" Text="The input will be 9v" CreationDate="2011-03-01T17:32:52.943" UserId="2617" />
  <row Id="16124" PostId="10899" Score="2" Text="You don't know how to bake things?  You could put them in at 115°C/240°F for a few days in a standard consumer oven (the lower temp to account for the relatively terrible temperature control)." CreationDate="2011-03-01T17:59:55.153" UserId="1407" />
  <row Id="16125" PostId="10900" Score="3" Text="It's not really the thermal gradient that will cause damage in moisture sensitive parts, but the vaporization of said moisture causing mechanical problems (e.g. popcorning).  Good article link" CreationDate="2011-03-01T18:02:47.240" UserId="1407" />
  <row Id="16126" PostId="10900" Score="1" Text="Clarified, for clarity. :)" CreationDate="2011-03-01T18:06:19.260" UserId="1293" />
  <row Id="16127" PostId="10904" Text="It does look similar to that one! I did try manually powering the LCD using a single 1.5v battery with a 1M pot, but it seems that when I touched my leads to certain regions, a section on the display would appear then dim out, reappearing when I reverse polarity of the leads. Would PWM (which I know the arduino I have can provide) do this? I thought PWM just generated between 0v and full voltage." CreationDate="2011-03-01T18:17:22.107" UserId="3122" />
  <row Id="16129" PostId="10866" Text="Could just as well be on [English.SE](http://english.stackexchange.com/)." CreationDate="2011-03-01T18:25:44.163" UserId="1407" />
  <row Id="16130" PostId="10884" Text="The general solution to the telegrapher's differential equations -- which are derived from the equivalent RLC circuit of a differential length of a two-conductor transmission line -- yields both forward and backward propagating waves. From the fact that the impedance of the load is ZL = VL/IL, you can derive that V- = [(ZL - Z0)/(ZL + Z0)]V+, where Z0 is the transmission line's characteristic impedance and V- and V+ are the voltage amplitudes of the reflected and incident waves respectively. Thus if ZL = Z0, the amplitude of the reflection is 0 and there are no standing waves." CreationDate="2011-03-01T18:28:42.900" UserId="721" />
  <row Id="16131" PostId="10899" Text="@Nick T, I have to eat too, using the same cooker. Otherwise I would have." CreationDate="2011-03-01T18:30:33.300" UserId="1225" />
  <row Id="16132" PostId="10886" Text="possible duplicate of [Designing with fuses...when to use?](http://electronics.stackexchange.com/questions/10643/designing-with-fuses-when-to-use)" CreationDate="2011-03-01T18:35:43.920" UserId="857" />
  <row Id="16134" PostId="10905" Text="That is a useful PDF also, thanks @NickT. Is there any easy way to produce this AC voltage without the AVR340 from DC input?" CreationDate="2011-03-01T18:40:13.073" UserId="3122" />
  <row Id="16135" PostId="10905" Text="@Will, I believe you are interpreting your measurements poorly, I expanded the answer to help I hope." CreationDate="2011-03-01T19:00:32.400" UserId="1407" />
  <row Id="16136" PostId="10905" Text="That does help, but I am still a little confused. To clarify: you are saying if I have, hypothetically, pin 1 on the LCD to pin 1 on my Arduino, and pin 2 of the LCD to ground on the Arduino and, at a particular frequency, switch on &amp; off pin 1 that it would produce a signal which could drive the LCD (assuming arbitrary pin 1 and 2 on the LCD)? The Arduino Uno (my only microcontroller), when pins set to high, puts out 5V, so I would have to somehow regulate this down, correct (maybe PWM, as recommended by @Madmanguruman)?" CreationDate="2011-03-01T19:19:58.850" UserId="3122" />
  <row Id="16137" PostId="10908" Score="1" Text="LDR == Light dependent resistor?" CreationDate="2011-03-01T19:50:22.303" UserId="857" />
  <row Id="16138" PostId="10795" Text="I'm going to give you an update not for FTDI (Which everyone knows) but for Prolific, which is new to me." CreationDate="2011-03-01T19:55:14.857" UserId="857" />
  <row Id="16139" PostId="10908" Score="3" Text="It's what I would expect to find on the LDR's data sheet ..." CreationDate="2011-03-01T19:58:48.177" UserId="1802" />
  <row Id="16140" PostId="10895" Text="DDR2 is controlled by JEDEC, which has gratis standards, right?  What is the number of the relevant standard?" CreationDate="2011-03-01T20:00:28.503" UserId="857" />
  <row Id="16141" PostId="10905" Text="@Will, In order to switch on or off an LCD segment, it must be charged like a capacitor.  However, you should not apply a static DC voltage lest the (small) current that flows will damage the LCD.  Hence, the suggested method to drive the LCD requires that you apply an in-phase pulse (effectively 0 V) to discharge the segment, or out-of-phase pulses (so the segment sees no DC bias) to charge it.  All this info is from the PDF, so read it for more, and look at Figure 2-2 in it." CreationDate="2011-03-01T20:29:33.870" UserId="1407" />
  <row Id="16142" PostId="10885" Text="1 to 1, no other devices or multi-chip memory configuration." CreationDate="2011-03-01T20:30:40.513" UserId="2062" />
  <row Id="16143" PostId="10905" Text="I did read that, but it was a little over my head. I'll do a bit of reading on in/out-of-phase pulses so that the PDF will make more sense. I guess I assumed this would be easier than it is :) Thanks for hanging in there and helping." CreationDate="2011-03-01T20:38:06.007" UserId="3122" />
  <row Id="16144" PostId="10906" Text="The better language is C++ ( with some quibbles )" CreationDate="2011-03-01T20:43:41.720" UserId="1498" />
  <row Id="16145" PostId="10911" Score="1" Text="BTW, the missing link is the voltage. A volt means that one coulomb carries one joule of energy. A battery operates at 12V, and lighting is in the tens of thousands or more ..." CreationDate="2011-03-01T20:46:46.407" UserId="1802" />
  <row Id="16146" PostId="10902" Text="Unfortunately, DDR2 have a lower speed limit 150-200Mhz, that means 300-400Mhz data transmission. The crazy thing is that I want to use just 2 layers." CreationDate="2011-03-01T20:55:00.507" UserId="2062" />
  <row Id="16147" PostId="10887" Text="No need to replace :-) They have higher resistance in normal operation. Might trigger at lower current at high temperature. " CreationDate="2011-03-01T20:56:25.780" UserId="2062" />
  <row Id="16148" PostId="10913" Score="3" Text="I think milliwatts would be a very optimistic amount." CreationDate="2011-03-01T21:31:02.427" UserId="1407" />
  <row Id="16149" PostId="10917" Score="8" Text="Only if the total power output of the Sun is coupled to the Enlightened Cat" CreationDate="2011-03-01T22:00:42.363" UserId="566" />
  <row Id="16150" PostId="10902" Text="@AndrejsCainikovs, I always try to remember, it is the rising edge that will kill you, not the clock frequency. Often as you increase one you are increasing the other also, but with a high rising edge speed you could easily false trigger something that you were only planning to use at 10MHz." CreationDate="2011-03-01T22:12:46.377" UserId="230" />
  <row Id="16151" PostId="10918" Score="2" Text="I don't get it, what else would you expect the marking &quot;220&quot; to mean?  In most electronics contexts it means 22." CreationDate="2011-03-01T22:26:47.387" UserId="1407" />
  <row Id="16152" PostId="8336" Text="We never figured this out (we ended up using another pin for the GPIO), but your explanation is the only one I've heard that makes sense.  " CreationDate="2011-03-01T22:27:38.113" UserId="1555" />
  <row Id="16153" PostId="10918" Text="@Nick T, given that the other one was &quot;3R3&quot; I'd expect &quot;220&quot; to mean &quot;220R&quot; or 220µH." CreationDate="2011-03-01T22:28:17.197" UserId="1225" />
  <row Id="16154" PostId="10922" Score="1" Text="I think &quot;R&quot; can be used on inductors too, but I have no idea why they use that convention. Maybe &quot;L&quot; wouldn't be clear enough; suppose it could be read as a 7 upside down..." CreationDate="2011-03-01T22:34:04.947" UserId="1225" />
  <row Id="16155" PostId="10912" Score="5" Text="-1 for not including at least 2 Maxwell equations. (+1)" CreationDate="2011-03-01T23:03:15.887" UserId="2118" />
  <row Id="16156" PostId="10905" Text="Here's another one: http://www.zilog.com/docs/z8encore/appnotes/an0162.pdf" CreationDate="2011-03-01T23:16:44.227" UserId="1950" />
  <row Id="16157" PostId="10912" Score="2" Text="Interesting... I liked the hand grenade analogy... Thanks." CreationDate="2011-03-01T23:28:08.123" UserId="2426" />
  <row Id="16159" PostId="10911" Text="Well, they're different but linked. Potential energy exists between charges. And the thousands of amps in a lightning strike is significant as well. It's just so brief that only a few coulombs gets transferred." CreationDate="2011-03-01T23:44:05.130" UserId="721" />
  <row Id="16160" PostId="10856" Text="I found the web site for this: http://www.digitalproductsco.com/partyln.htm.  It's more expensive than I remember, but it looks like it has new features.  This may be way more than you care to spend, and not as much fun as building something yourself." CreationDate="2011-03-01T23:50:16.990" UserId="2773" />
  <row Id="16161" PostId="4516" Text="USB uses a 4 conductor cable, one of them being ground, so you're not going to avoid ground loops by leaving the shield unconnected." CreationDate="2011-03-02T00:18:30.750" UserId="2377" />
  <row Id="16162" PostId="10906" Score="3" Text="@russ, that's a minority view, especially in small microcontrollers. I'm sure there's a relevant stackoverflow question..." CreationDate="2011-03-02T01:03:59.433" UserId="411" />
  <row Id="16163" PostId="10923" Text="A resistive divider is fine.  Use 1.5kΩ + 3kΩ in series, take the output across the 3k resistor.&#xA;&#xA;Ohms's law works! Nothing sketchy about it.&#xA;" CreationDate="2011-03-02T01:40:32.037" UserId="411" />
  <row Id="16164" PostId="10863" Text="See also http://electronics.stackexchange.com/questions/9153" CreationDate="2011-03-02T01:41:38.900" UserId="411" />
  <row Id="16165" PostId="10918" Score="5" Text="Maybe it's 22 Henries.  Were the inductors delivered with a forklift?" CreationDate="2011-03-02T01:44:28.947" UserId="411" />
  <row Id="16166" PostId="10924" Text="Another analogy, is that the receiver will cast a &quot;shadow&quot;.  " CreationDate="2011-03-02T02:00:17.380" UserId="411" />
  <row Id="16168" PostId="10918" Score="1" Text="With +/-5% components, all you need are 2 digits plus one for order-of-magnitude.  Just like on resistors and capacitors, there are 2 mantissa digits and one for radix." CreationDate="2011-03-02T03:10:31.760" UserId="1407" />
  <row Id="16169" PostId="10927" Score="3" Text="Is this not it? http://db.sanyodenki.co.jp/stepping_e/two/pdf/2step_e_069-073.pdf" CreationDate="2011-03-02T03:20:29.120" UserId="2873" />
  <row Id="16170" PostId="10861" Text="lots of [information on switching regulator design](http://opencircuits.com/switching_regulator) at the Open Circuits wiki." CreationDate="2011-03-02T04:20:45.880" UserId="813" />
  <row Id="16171" PostId="10923" Text="Heh, diodes are definitely *not* &quot;fixed-drop&quot; devices when operating at some unknown current (driving into an unknown receiver).  A resistor divider is a much better solution unless we're operating at high speeds (not sure even then) or low power." CreationDate="2011-03-02T04:47:08.727" UserId="1407" />
  <row Id="16172" PostId="10910" Score="1" Text="Would a geared stepper motor work? And most hobby servos are fairly accurate, What kind of precision do you need?" CreationDate="2011-03-02T05:55:07.653" UserId="2060" />
  <row Id="16173" PostId="10873" Text="One thing I noticed now: [ethernet over twisted pair](http://en.wikipedia.org/wiki/Ethernet_over_twisted_pair) transmits on pin 1,2 and receives on 3,6. So the circuit interconnects send1/recv1 send2/recv2... I'm not really understanding how this works.&#xA;&#xA;And: did I get that right that each diode pair is basically only acting as a resistor?" CreationDate="2011-03-02T06:28:24.210" UserId="3203" />
  <row Id="16174" PostId="10883" Text="A DDR2 Chip - As in a Dram IC, or a DDR *Card*, as in the kind of memory module you see in a desktop computer (which are not, and will never really be &quot;chips&quot;, even if some uneducated people like to call them so)?" CreationDate="2011-03-02T07:25:46.857" UserId="1374" />
  <row Id="16175" PostId="1693" Text="@community, @starblue just used a technique called &quot;sarcasm&quot;. Sortof." CreationDate="2011-03-02T07:30:29.567" UserId="230" />
  <row Id="16176" PostId="10907" Score="1" Text="I have to say that in several years of being cavalier about prototype IC storage, I have yet to see a a single failure could definitely trace to, or even suspect, moisture issues." CreationDate="2011-03-02T07:30:46.260" UserId="1374" />
  <row Id="16177" PostId="8112" Text="Is 9v dc converted into 5v dc using 7805 ,0.33microF cap &amp; 0.1 microF cap? pl answer me fast.. " CreationDate="2011-03-02T04:38:41.213" UserId="3209" />
  <row Id="16178" PostId="8112" Text="@Rajesh, yes, this does get the job done." CreationDate="2011-03-02T07:31:28.117" UserId="230" />
  <row Id="16179" PostId="10918" Score="2" Text="MEasure them. It's the only way to know." CreationDate="2011-03-02T07:32:18.397" UserId="1374" />
  <row Id="16180" PostId="10918" Text="@Fake Name, LCR meter is on my list but my poor student budget can't afford it - just spend £80 on a new multimeter." CreationDate="2011-03-02T08:13:45.343" UserId="1225" />
  <row Id="16181" PostId="10924" Text="Brilliant answer, thanks!" CreationDate="2011-03-02T08:21:49.080" UserId="1225" />
  <row Id="16182" PostId="10918" Text="@Thomas O - Do you have oscilloscope, a signal generator, and a resistor?" CreationDate="2011-03-02T08:28:46.617" UserId="1374" />
  <row Id="16183" PostId="10915" Text="Thanks Nick. In response to the comments on my OP, yeah, I should have thought of that. :-(" CreationDate="2011-03-02T09:01:43.733" UserId="2212" />
  <row Id="16184" PostId="10883" Text="Single DDR2 IC. Interfacing to whole DIMM is pretty hardcore for beginners :-)" CreationDate="2011-03-02T09:02:56.290" UserId="2062" />
  <row Id="16185" PostId="10882" Text="@barsmonster, when I used their dsPIC a while back it said its maximum was an absolute maximum, and when trying to go higher my actual clock frequency(effective to the chip) decreased." CreationDate="2011-03-02T09:21:19.427" UserId="230" />
  <row Id="16186" PostId="10935" Score="3" Text="I don't understand how do you get from &quot;display water usage&quot; to &quot;linux&quot;. Can you please elaborate a bit more?" CreationDate="2011-03-02T09:57:30.200" UserId="1802" />
  <row Id="16187" PostId="10935" Score="1" Text="You need to be more specific. Which part are you having problems with? Interfacing to your water sensor? Building a linux kernel? Building a linux root filesystem? Writing a graphical application? Please edit your question to add more detail." CreationDate="2011-03-02T09:57:48.373" UserId="566" />
  <row Id="16188" PostId="10879" Text="Also note that you cannot generalize. If that particular chip works at 81 MHz, there's no guarantee the next one will too." CreationDate="2011-03-02T10:01:26.467" UserId="1802" />
  <row Id="16189" PostId="10906" Text="The linker generally produces some proprietary binary file - for example my (rather old) version of the Keil toolchain produces a file with no extension. A separate step is to convert this to a text file which contains the code in one of several standard hexadecimal formats, eg IntelHex or Motorola S, which is recognisable by the device programmer. It is this file which usually has the .hex extension. Some development systems that support in-system-programming via bootloaders bypass this last step and load the binary image directly using a standard or proprietary interface." CreationDate="2011-03-02T10:04:00.693" UserId="2234" />
  <row Id="16190" PostId="10927" Text="@a swandwich +1 1st google result searching for 'Sanyo Denki 103H5208'" CreationDate="2011-03-02T10:12:04.250" UserId="2157" />
  <row Id="16191" PostId="10935" Score="1" Text="look into LFS or linux from scratch to build your own Linux.....http://www.linuxfromscratch.org/ I also agree that you need to elaborate on your question a bit more." CreationDate="2011-03-02T11:09:40.703" UserId="2060" />
  <row Id="16192" PostId="10882" Text="Well, you should have tried feeding raw clock into it without any PLLs and stuff, it would have no chance to avoid overclocking :-D" CreationDate="2011-03-02T11:28:24.337" UserId="2062" />
  <row Id="16194" PostId="10882" Text="@BarsMonster, it had built in PLL on the extern clock lines. There was no way around that." CreationDate="2011-03-02T11:29:51.670" UserId="230" />
  <row Id="16195" PostId="10882" Text="Ok, then we have artificial obstacle here :-)" CreationDate="2011-03-02T11:30:44.610" UserId="2062" />
  <row Id="16196" PostId="10913" Text="Think pico and nano watts." CreationDate="2011-03-02T11:31:12.417" UserId="230" />
  <row Id="16197" PostId="10924" Text="@davidcary, forgive me if I am wrong on this, but -90 dBm correlates to 1pW. Just adding this for those that do not do dBm conversions well." CreationDate="2011-03-02T11:33:46.283" UserId="230" />
  <row Id="16198" PostId="10917" Text="@JobyTaffey, well written. @Thomas, there is actually an important point in what Joby wrote, more than an excellent joke, in that if your receiver causes a change in output impedance for the transmitter you can change how much power the tower has to radiate. In reality any device at any range does give a feedback(a perfect antenna system radiates as much power as it receives) and this could couple back to the original tower causing mismatch issues. The theory can get very complicated, but related to building a metal wall nearby that uses power from 1/4 of the field, this would change things." CreationDate="2011-03-02T11:37:18.123" UserId="230" />
  <row Id="16199" PostId="10924" Text="@davidcary, on the note of the wall of receivers, in this case I think the antenna would start having near fields effects and reflected power effects, but that is above the scope of the OP, just want to note it." CreationDate="2011-03-02T11:38:09.400" UserId="230" />
  <row Id="16201" PostId="10902" Text="@Kortuk: Thanks, good point." CreationDate="2011-03-02T12:42:52.490" UserId="1603" />
  <row Id="16202" PostId="10918" Text="@Fake Name, have scope and resistor, no signal generator yet either... that's on the list too." CreationDate="2011-03-02T12:56:25.777" UserId="1225" />
  <row Id="16204" PostId="10827" Score="1" Text="That, my friend, is genius. If only there were a +5 button on here. I'm only irritated I didn't think of it first." CreationDate="2011-03-02T13:46:42.497" UserId="2769" />
  <row Id="16205" PostId="10906" Text="@Mark - I think Russ was referring to the version of Wiring (which is similar to C++) that the Arduino uses - I called it a 'beginner' language since it hides some of the details behind the Arduino framework, and I think he called it 'better'.  Anyways, the relevant E&amp;R question is [here](http://electronics.stackexchange.com/q/3027/857).  " CreationDate="2011-03-02T13:52:33.157" UserId="857" />
  <row Id="16206" PostId="10935" Score="1" Text="It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form." CreationDate="2011-03-02T14:18:13.213" UserId="319" />
  <row Id="16207" PostId="10912" Score="1" Text="+1 Very simple and clearly answered" CreationDate="2011-03-02T14:22:36.017" UserId="319" />
  <row Id="16208" PostId="10902" Text="@barsmonster make sure you have a very good ground plane under all of that! In applications like this it is very bad to have a trace cut across your plane. This is usually a big reason why people go to 4+ layers (because they just cant get a good plane otherwise)" CreationDate="2011-03-02T14:27:54.283" UserId="319" />
  <row Id="16209" PostId="10902" Text="@Kellenjb: Yes, plus small addition: for high speed pcb's, if you have the ground plane, you should also have the power plane too, which will compensate and lower down EMI." CreationDate="2011-03-02T14:55:17.200" UserId="1603" />
  <row Id="16210" PostId="10902" Text="@BarsMonster: IMO, it will be really tricky to accomplish this on 2 layer PCB. Perhaps it's worth to move to 4 layer PCB? I mean.. headache vs pcb price? :)" CreationDate="2011-03-02T14:57:05.640" UserId="1603" />
  <row Id="16212" PostId="10940" Text="In this case, they were talking about BIOS chip, so I don't think that it would be directly written by the OS. " CreationDate="2011-03-02T16:09:03.087" UserId="1240" />
  <row Id="16213" PostId="10922" Text="Why couldn't they just write 22 µH as &quot;22&quot;?" CreationDate="2011-03-02T16:11:37.087" UserId="142" />
  <row Id="16214" PostId="10940" Score="2" Text="In that case... the answer is definitely NO :-)  The age is the only factor that can &quot;damage&quot; the memory, if you only read it.  " CreationDate="2011-03-02T16:13:00.260" UserId="244" />
  <row Id="16215" PostId="10913" Text="It's not &quot;dissipated in the air&quot;.  We specifically choose radio frequencies because the air is transparent for them. http://en.wikipedia.org/wiki/Absorption_%28electromagnetic_radiation%29  http://en.wikipedia.org/wiki/File:Atmospheric_electromagnetic_opacity.svg Related: http://electronics.stackexchange.com/questions/4664/stealing-energy-from-radio-towers-or-power-lines" CreationDate="2011-03-02T16:13:57.180" UserId="142" />
  <row Id="16216" PostId="10922" Text="@Wonko The Sane: You say the minimum for this coding is 100 (meaning 10 x 10^0 = 10)... but why can't you have 010 (meaning 01 x 10^0 = 1)?" CreationDate="2011-03-02T16:14:00.883" UserId="2426" />
  <row Id="16217" PostId="10931" Score="2" Text="Indeed. Some batches of chips may even overclock better than other. Me and my brother have bought a PC a couple of years back with both a Intel Q6600 CPU. We bought from different shops, and we got different batches (shown on the box).&#xA;My batch overclocks to 3.2GHz (from 2.4GHz) on a boxed cooler, without adjusting any voltages. My brothers version has to increase voltage above 3GHz.&#xA;It heavily depends on the batch, fabrication plant, etc. There is no fixed point to hold on to if you're designing with overclocked parts. " CreationDate="2011-03-02T16:16:39.733" UserId="1476" />
  <row Id="16218" PostId="10311" Text="In choosing the maximum and minimum current values, there are three objectives: (1) the higher the minimum current, the more power will be available to a transducer that needs to send out a &quot;minimum&quot; signal; (2) the lower the maximum current, the less power will be required to power everything; (3) the greater the difference between maximum and minimum current, the greater the signal-to-noise ratio.  I suspect 4mA and 20mA were simply an arbitrary compromise." CreationDate="2011-03-02T16:16:54.977" UserId="3123" />
  <row Id="16219" PostId="10924" Text="@markrages: I don't think that's a very good analogy, since radio waves will diffract around any human-sized objects." CreationDate="2011-03-02T16:19:27.187" UserId="142" />
  <row Id="16220" PostId="10895" Text="I don't have the standard; check Micron's web site for DDR2 data sheets and application notes." CreationDate="2011-03-02T16:31:06.413" UserId="206" />
  <row Id="16221" PostId="10718" Text="I am still waiting for an official answer from Altium directly, after nearly a week... Your answer seems to be the most accurate for this particular case thus far. Thanks." CreationDate="2011-03-02T16:37:22.493" UserId="2028" />
  <row Id="16222" PostId="10922" Text="@BG100: If you did that then you lose significant digits as you're putting useless leading zeros in your mantissa (significand).  How would you express 1.5, or 3.3 as in the OP question?" CreationDate="2011-03-02T16:40:37.203" UserId="1407" />
  <row Id="16224" PostId="10922" Text="@endolith: Because part values are really logarithmic, it's better to use a consistent method that is exponential in some respect.  Using only three digits, we can cover 10 to 99 billion--10 orders of magnitude--with 5% precision.  To be somewhat consistent with that useful method, a decimal character is massaged in to go down to 0.10, 2 orders lower.  For 1% resistors, this doesn't work, so I think I've seen some with 4 characters, but others (smaller ones that can't fit 4 chars) use a code, usually [EIA-96](http://www.hobby-hour.com/electronics/eia96-smd-resistors.php)." CreationDate="2011-03-02T16:54:06.770" UserId="1407" />
  <row Id="16225" PostId="10941" Text="Agreed, @Vinod, I *strongly* suggest beginning with a Linux distro and build that works on the BeagleBoard before trying to roll your own." CreationDate="2011-03-02T17:01:16.700" UserId="1407" />
  <row Id="16226" PostId="4265" Text="One caveat with this approach is that the Dataflash only allows (i.e. specifies the behavior of) programming operations on completely blank pages.  The approach I used in my application was to maintain a count of how many flash writes had been performed in the application's lifetime, and store in each flash page the value that counter had when the page was written." CreationDate="2011-03-02T17:25:19.207" UserId="3123" />
  <row Id="16227" PostId="1093" Text="Many microcontrollers make a memory bus available for external code and data; those pins may or may not usable for other purposes if external memory is not used.  To my mind, the defining distinction is whether a device would typically(*) be capable of running at least somewhat usefully without an external memory bus. (*) The 8051 is certainly capable, so it's clearly &quot;microcontroller&quot;. An 8031 is the same chip as an 8051, but with the ROM contents unspecified. The lack of useful ROM would make it a microprocessor, but since it's the same chip as the 8051, it could be called a microcontroller." CreationDate="2011-03-02T17:31:36.847" UserId="3123" />
  <row Id="16228" PostId="10904" Text="If you AC couple a PWM waveform with 50% duty cycle, you get positive and negative-referenced AC..." CreationDate="2011-03-02T17:51:10.970" UserId="1293" />
  <row Id="16229" PostId="10944" Score="1" Text="How many kinds of heat are there?  This question is far too vague in it's current form." CreationDate="2011-03-02T17:53:23.817" UserId="1407" />
  <row Id="16230" PostId="10944" Text="@Nick T well, there is the hot heat and then the cold heat. :-) My guess is he is asking how much heat will be created from it. But still it means nothing to say &quot;5W chip&quot;." CreationDate="2011-03-02T17:57:37.633" UserId="319" />
  <row Id="16231" PostId="10944" Score="1" Text="Impossible to say without specific circuit details." CreationDate="2011-03-02T17:58:21.870" UserId="1293" />
  <row Id="16232" PostId="10944" Score="2" Text="'5 watts' is the amount of energy per second that's being dissipated by the chip - if your question is really &quot;what TEMPERATURE will it reach?&quot; then you have to look at the thermal characteristics of its package" CreationDate="2011-03-02T18:08:02.907" UserId="3190" />
  <row Id="16234" PostId="10902" Text="@Andrejs ,it's about doing something with my hands :-) And doing 4-layer board manually is tricky a little. Without that I would just buy finished product :-) Anyway, I can still do some kind of ground planes by glueing grounded foil on top of these DDR2 traces." CreationDate="2011-03-02T18:16:05.123" UserId="2062" />
  <row Id="16235" PostId="10944" Score="3" Text="@Taniwha not necessarily. '5W Chip' doesn't have to mean the energy per second that is being dissipated. Example, it could be a buck boost that is about to output 5W of power, doesn't mean that chip is dissipating that power." CreationDate="2011-03-02T18:26:52.803" UserId="319" />
  <row Id="16236" PostId="3760" Text="Another list of PCB fabs: http://electronics.stackexchange.com/questions/1893/cheap-pcb-manufacture-100-units-at-a-time" CreationDate="2011-03-02T19:37:34.210" UserId="813" />
  <row Id="16237" PostId="1893" Text="Another list of PCB fabs: http://electronics.stackexchange.com/questions/3760/moderately-priced-6-layer-pcb-fab" CreationDate="2011-03-02T19:37:59.547" UserId="813" />
  <row Id="16238" PostId="10940" Score="2" Text="@Axeman is right.  However some older parts do have data retention issue, e.g. only for 10 or 20 years." CreationDate="2011-03-02T16:32:34.137" UserId="206" />
  <row Id="16239" PostId="10902" Text="@BarsMonster, you are just going to need a large board and try to avoid embedded traces in your ground plane." CreationDate="2011-03-02T19:53:46.030" UserId="230" />
  <row Id="16240" PostId="10948" Text="@blutrane0, can you expand, what has changed?&#xA;" CreationDate="2011-03-02T19:56:06.557" UserId="230" />
  <row Id="16241" PostId="10950" Text="Question, why do it convert the 44 pin plcc to a 40 pin dip ? " CreationDate="2011-03-02T20:15:18.500" UserId="3186" />
  <row Id="16242" PostId="10922" Text="@Nick: Are 22 µH and 220 µH both common values in this logarithmic system?  Yes.  Does a plain &quot;220&quot; confuse everyone who sees it for the first time?  Yes.  So why not write it in a different way that represents the same value without confusion, like &quot;22_&quot; or &quot;22R&quot; instead of &quot;220&quot;?" CreationDate="2011-03-02T20:22:23.067" UserId="142" />
  <row Id="16243" PostId="4760" Text="One consequence of the lower reliability of NAND flash is that while NAND flash devices allow random reads of individual bytes (with a little setup time), it's not really possible to read less than a page unless one includes error-correcting information in smaller chunks (e.g. one could write each byte as 16 bits and be able to detect all single- and double-bit errors, at the cost of only being able to store half as much information)." CreationDate="2011-03-02T20:29:38.690" UserId="3123" />
  <row Id="16244" PostId="10950" Score="1" Text="Perhaps there are several power and ground pins" CreationDate="2011-03-02T21:54:10.503" UserId="566" />
  <row Id="16245" PostId="10953" Text="http://electronics.stackexchange.com/questions/7022/circuit-simulation-software" CreationDate="2011-03-02T22:20:14.913" UserId="142" />
  <row Id="16246" PostId="10935" Text="@vinod, please let us know more detail when you come back and we can edit it in and reopen this." CreationDate="2011-03-02T22:47:36.940" UserId="230" />
  <row Id="16247" PostId="7049" Text="What is a &quot;crash&quot; on a microcontroller anyway?" CreationDate="2011-03-02T23:08:45.297" UserId="1950" />
  <row Id="16248" PostId="10943" Text="Thanks for your reply.&#xA;I have not considered the problem more generally, and as you suggest, it may be time to survey modern alternatives. The TA7279AP is used as 1) a voltage doubler using a capacitor and diode, and 2) as a polarity reversible pulse generator for a DC irrigation solenoid. The first circuit powers the second. Pulse is 200ms at about 20V, power supply is 12volt solar charged sealed lead acid. Intelligence is PIC controller.&#xA;I love the low component count, and the small number of solder joins. Do not need high voltage or high current, would CMOS control lines to reduce power." CreationDate="2011-03-02T23:10:00.307" UserId="3212" />
  <row Id="16249" PostId="10943" Text="Last sentence should read ' would PREFER CMOS control lines (rather than TTL) to reduce power consumption.' But given that power is off most of the time ( while controller sleeps) this is not a big issue all things considered." CreationDate="2011-03-02T23:14:42.830" UserId="3212" />
  <row Id="16250" PostId="10962" Score="1" Text="LED means Light Emitting Diode. " CreationDate="2011-03-02T23:16:03.117" UserId="1623" />
  <row Id="16251" PostId="10960" Text="I was unaware I could program a Mindstorms kit in C. I thought it had to be their proprietary language... or Java. Last time I used a Mindstorms kit was 10 years ago though..." CreationDate="2011-03-02T23:21:11.640" UserId="3221" />
  <row Id="16252" PostId="10969" Score="1" Text="For integrating SPICE into an overall simulation, a quick Google search came up with eispice and MyHDL (if you know Python, but it's an easy language). For example, you can do mixed-mode simulation in Python using MyHDL and eispice: http://myhdl.org/doku.php/projects:mixedmodesimulation" CreationDate="2011-03-02T23:29:55.220" UserId="721" />
  <row Id="16253" PostId="10968" Score="1" Text="@JYelton, if you exclude zener diodes, most every diode you use will conduct when it has a &quot;forward&quot; voltage, and will cutoff when the reverse voltage is met." CreationDate="2011-03-02T23:36:06.493" UserId="230" />
  <row Id="16254" PostId="3925" Text="Hm, I think this may be difficult to achieve because many &lt;a href=&quot;http://www.proxynetworks.com/products/remote-access-software.html&quot;&gt;remote access&lt;/a&gt; systems use internet and computers. Phone based systems are going to be few and far between." CreationDate="2011-03-02T23:17:31.377" UserId="3224" />
  <row Id="16255" PostId="10962" Score="1" Text="I added &quot;and LED's&quot; as a way of capturing search queries that don't spell out the &quot;D&quot; :)" CreationDate="2011-03-03T00:26:53.337" UserId="2028" />
  <row Id="16256" PostId="10902" Text="@Kortuk, sorry I don't understand what you said here :-) COuld you please give a bit more explanations for the stupid?" CreationDate="2011-03-03T00:29:20.637" UserId="2062" />
  <row Id="16257" PostId="7049" Text="@AndreKR, on most microcontrollers a &quot;crash&quot; is defined as an unexpected reset. MCUs rarely freeze, they just go into a reset or shutdown mode in case of a disallowed condition. In my case, it was resetting every so often, seemingly randomly." CreationDate="2011-03-03T00:49:50.523" UserId="1225" />
  <row Id="16258" PostId="10967" Text="@Taniwha - &quot;Above&quot; is relative; answers are first sorted by vote count and then randomized.  I think you meant &quot;As mentioned by Leon&quot;." CreationDate="2011-03-03T01:12:32.307" UserId="857" />
  <row Id="16259" PostId="10907" Text="@Fake: I haven't either, but unless you/your company does protoduction (a dubious blend of prototyping and production) on an even bigger scale than I've seen at mine, the low frequency of failures in the relatively few moisture-sensitive parts on the BOM probably won't manifest." CreationDate="2011-03-03T01:44:41.857" UserId="1407" />
  <row Id="16260" PostId="10902" Score="2" Text="@BarsMonster, you are not stupid, these are terms you must be taught. An embedded trace is a point where you do not have a continuous ground plane so that you can route one of your other traces. A perfect ground place is just a solid sheet. There will be small gaps where vias are used, but excluding that, your target should be a solid ground plane." CreationDate="2011-03-03T02:20:11.127" UserId="230" />
  <row Id="16261" PostId="10973" Text="It's the only way to be sure." CreationDate="2011-03-03T03:06:36.247" UserId="1407" />
  <row Id="16262" PostId="10974" Score="1" Text="@Nick T - one of my past employers did the same stair-step thing. It made it easy to tell how many layers were on the board and (I suppose) if a layer was left off, that would have been obvious as well. Don't know what else it was good for." CreationDate="2011-03-03T03:15:59.853" UserId="259" />
  <row Id="16263" PostId="10973" Text="@kellenJB, When I saw the question I was coming to write this answer." CreationDate="2011-03-03T03:39:10.700" UserId="230" />
  <row Id="16264" PostId="10973" Score="1" Text="Couldn't you just take a notch off the corner?" CreationDate="2011-03-03T04:15:55.673" UserId="142" />
  <row Id="16266" PostId="10716" Text="Thanks for your experience.  Out of curiosity, were those standard CR2450-type cells (basic consumer lithium), or a rechargeable variant?" CreationDate="2011-03-03T06:40:54.420" UserId="3163" />
  <row Id="16267" PostId="10716" Text="@JohnLaxson, ours did not need to be recharged. They were the standard consumer type. During our testing we testing other variants and sizes, our final choice was a CR2032. We were better off with multiple of these than a higher capacity option with only one! We only needed to pull 20mA also, but two batteries just beat everything else out of the water to stay below the 10mA threshold per battery." CreationDate="2011-03-03T06:42:49.323" UserId="230" />
  <row Id="16268" PostId="9694" Text="@farshad, direct email is not what this site is for. You may ask questions on this site and get answers, but direct contact is not the goal, if he helps you in private no-one else learns. If it is something that only benefits you, well, you should probably hire someone." CreationDate="2011-03-03T06:59:06.530" UserId="230" />
  <row Id="16269" PostId="10975" Text="I dont think you will find any thing that will just plug in, but you always can hack an old MicroSD, rip out the internals and attach a flat conductors to break out the pins. " CreationDate="2011-03-03T07:20:33.797" UserId="2060" />
  <row Id="16273" PostId="10975" Text="@jsolarski: I tried that, and ruined it.  I'd love to find something like a flex molded to a uSD shell." CreationDate="2011-03-03T07:48:50.463" UserId="3225" />
  <row Id="16274" PostId="10975" Score="1" Text="Though I did find this **[uSD Extender](http://www.hwtools.net/ExtenderBoard/TFEX.html)**." CreationDate="2011-03-03T07:54:55.543" UserId="3225" />
  <row Id="16278" PostId="10960" Text="RCX had its own linux distribution, with toolchain and whatever. LegOS was its name, IIRC. Something similar exists for NXT, but I have not yet tried it: http://lejos-osek.sourceforge.net/" CreationDate="2011-03-03T09:00:29.063" UserId="244" />
  <row Id="16279" PostId="10973" Text="@endolith, yes, the concept is the same, I think kellenjb is just making a point that you can cut into it and know for sure." CreationDate="2011-03-03T09:22:34.253" UserId="230" />
  <row Id="16282" PostId="10975" Score="1" Text="And **[this](http://www.dealextreme.com/p/sd-to-microsd-transflash-card-converter-module-27001)** for only $5.71!" CreationDate="2011-03-03T09:35:37.190" UserId="3225" />
  <row Id="16283" PostId="10975" Text="@BobC that first link to the uSD extender looks promising except its a bit pricey for just being a fancy break out board. That second one is worth a try for the price :) " CreationDate="2011-03-03T10:31:37.517" UserId="2060" />
  <row Id="16284" PostId="10975" Text="@jsolarski: The next question is what to connect to the other end to emulate a pause-free FAT-formatted uSD card." CreationDate="2011-03-03T11:52:10.490" UserId="3225" />
  <row Id="16288" PostId="10987" Score="1" Text="What about use directional antennas?" CreationDate="2011-03-03T13:29:59.653" UserId="938" />
  <row Id="16289" PostId="10987" Text="Yes, Antenna will Definitely increase the range but my experience is Obstacles reduce range considerably. " CreationDate="2011-03-03T13:33:46.470" UserId="2574" />
  <row Id="16291" PostId="10975" Text="@BobC - How about [this Sparkfun microSD sniffer](http://www.sparkfun.com/products/9419) ($10)?  Since the SD card as currently mounted won't work for you, you might just want to use the Eagle files as reference for your device." CreationDate="2011-03-03T13:57:17.633" UserId="857" />
  <row Id="16292" PostId="10975" Score="2" Text="@BobC - Reading the product page, it appears to claim that the device buffers the data to internal Flash.  In any case, you should probably contact the manufacturer and complain that it's missing.  A uSD card should write more than fast enough to capture the 512 Hz data.  There's no reason for gaps at those write speeds." CreationDate="2011-03-03T14:17:05.590" UserId="857" />
  <row Id="16294" PostId="10647" Text="@davidcary: That looks like a wonderful project. Thanks for informing me. However, they seem to focus on charging 12 V batteries, and from what I can tell, the firmware is still incomplete." CreationDate="2011-03-03T14:51:46.703" UserId="2642" />
  <row Id="16295" PostId="10868" Text="Cool. I didn't knew that rats make nests." CreationDate="2011-03-03T15:17:05.897" UserId="1311" />
  <row Id="16296" PostId="10995" Text="How much do you think the total current draw would be for a PWM controlled RGB LED from a 1.5V battery?" CreationDate="2011-03-03T15:46:37.680" UserId="2395" />
  <row Id="16297" PostId="10999" Text="So &quot;Atmel AVR&quot; is a specification for Microcontrollers?" CreationDate="2011-03-03T15:50:29.140" UserId="3130" />
  <row Id="16298" PostId="10997" Text="Also see http://electronics.stackexchange.com/questions/8676/what-are-the-cheapest-microcontrollers" CreationDate="2011-03-03T15:50:40.387" UserId="566" />
  <row Id="16299" PostId="10998" Text="This is the link to Atmel AVR 8 bit: http://www.atmel.com/dyn/products/devices.asp?category_id=163&amp;family_id=607&amp;subfamily_id=760" CreationDate="2011-03-03T15:53:35.097" UserId="3130" />
  <row Id="16300" PostId="10995" Text="It would depend on the microcontroller and LED, you'd have to consult the datasheets" CreationDate="2011-03-03T15:53:38.467" UserId="566" />
  <row Id="16301" PostId="10999" Score="1" Text="Yes, Atmel are a semiconductor company who make a range of microcontrollers. Their AVR microcontrollers use their proprietary AVR core. The AVR's have a different instruction set to other processors. http://en.wikipedia.org/wiki/Instruction_set" CreationDate="2011-03-03T15:56:20.277" UserId="566" />
  <row Id="16302" PostId="10974" Score="1" Text="The stairstep also makes sure the layers are in their proper order.  If you are not using blind/buried vias, the connectivity will be the same regardless of the layer order.  But there may be subtle problems like high-frequency traces with the wrong characteristic impedance if the layer stack is messed-up.  Still, this is an unlikely thing for the board house to get wrong.  Sometimes board designers just add features because they look cool.  I know I do." CreationDate="2011-03-03T16:07:54.407" UserId="411" />
  <row Id="16303" PostId="11002" Text="And you can sniff Microsoft wireless keyboards... http://travisgoodspeed.blogspot.com/2011/02/promiscuity-is-nrf24l01s-duty.html" CreationDate="2011-03-03T16:16:16.477" UserId="566" />
  <row Id="16304" PostId="10995" Text="You'd need to step up the voltage from a 1.5V battery.  See Vf in the table: http://www.kpsec.freeuk.com/components/led.htm#data . 3V is a better choice." CreationDate="2011-03-03T16:17:33.480" UserId="411" />
  <row Id="16305" PostId="11004" Score="7" Text="You are wrong about &quot;wasted as heat.&quot;" CreationDate="2011-03-03T16:46:49.120" UserId="411" />
  <row Id="16306" PostId="11004" Text="It doesn’t matter where it goes, the point is ending with less makes sense, but ending with more requires drawing the excess from *somewhere*, and that’s what I cannot find." CreationDate="2011-03-03T16:50:53.987" UserId="2042" />
  <row Id="16307" PostId="11004" Score="7" Text="Yes, it does matter where it goes.  You are confusing voltage with power, which is why your question is wrong." CreationDate="2011-03-03T16:55:21.173" UserId="411" />
  <row Id="16308" PostId="10985" Text="I'd like to use SMD parts but I don't have access to a reflow station.  Is there some hackish method to solder on SMD parts onto PCB without using a frying pan?" CreationDate="2011-03-03T17:02:44.553" UserId="954" />
  <row Id="16309" PostId="11005" Text="Aha, that makes sense. The explanations I could find all made it seem like a step-up was giving something for nothing without explaining where it comes from. Adding current to the query, finds a proper explanation much easier now: http://www.powertransformer.us/stepuptransformers.htm Thank you!" CreationDate="2011-03-03T17:02:54.680" UserId="2042" />
  <row Id="16310" PostId="11005" Text="@Joby: Thanks... I was going to tidy it up later anyway!" CreationDate="2011-03-03T17:10:55.607" UserId="2426" />
  <row Id="16311" PostId="11005" Text="@Synetech inc.: No problem." CreationDate="2011-03-03T17:11:14.357" UserId="2426" />
  <row Id="16312" PostId="10982" Score="1" Text="How reliable does the system need to be? Do you have access to a lot of power? Are you cost constrained? " CreationDate="2011-03-03T17:12:55.120" UserId="2454" />
  <row Id="16313" PostId="10975" Text="The manufacturer knows all about the problem, and is unable to fix it with the available hardware resources (it's only an 8051 that's breathing really hard).  All pauses seem to be due to a) FAT overhead, and/or b) flash erase cycles.  I want to create a system that has NO PAUSES, and plugs into a microSD slot.&#xA;&#xA;Presently:  X250-2 --&gt; microSD slot --&gt; microSD card&#xA;&#xA;Goal:  X250-2 --&gt; microSD slot --&gt; extender cable --&gt; SPI port on microcontroller --&gt; microcontroller RAM --&gt; SDHC card" CreationDate="2011-03-03T17:49:30.923" UserId="3225" />
  <row Id="16314" PostId="11004" Text="The heat in a transformer is due to copper loss and core loss, neither of which is due to voltage. Copper loss is the I^2R loss due to the current and resistance, and core loss is due to the magnetic material and magnetic field which is also current derived." CreationDate="2011-03-03T17:50:13.530" UserId="2110" />
  <row Id="16315" PostId="10995" Text="@Joby Taffey: A nice variation on binary code modulation, which I'm surprised I haven't often seen implemented in hardware, is to output the MSB on every other sample, the next bit on every other sample among those remaining, etc.  This gives a cleaner steady-state signal than PWM, though updating the output value smoothly can be tricky.  As with BCM, many bits can be handled in parallel." CreationDate="2011-03-03T18:05:15.017" UserId="3123" />
  <row Id="16316" PostId="11008" Text="@supercat: nice analogy!" CreationDate="2011-03-03T18:15:22.943" UserId="2426" />
  <row Id="16319" PostId="9686" Text="Looks like ST now has an STM32VLDISCOVERY for about $12.  I accidentally ordered the STM8S discover thinking it was an ARM, there is an STM32 on it that can be repurposed but supposedly you need jtag.  I have a copule STM32VLDISCOVERY boards on order, hopefully here next week.  You get your ET STM32?" CreationDate="2011-03-03T19:34:34.703" UserId="985" />
  <row Id="16321" PostId="11004" Score="2" Text="@synetech, think of voltage as potential energy, just like gravitational. you can get higher voltage by using one mass(current) on one side to counterweight your mass(current) on the other. As long as P in on the left side is equal to the P out on the right you are golden." CreationDate="2011-03-03T19:53:03.080" UserId="230" />
  <row Id="16322" PostId="11002" Text="We have used RFID cards for many years, and while fun they're more expensive. This year each visitor will get its own [QR code](http://en.wikipedia.org/wiki/QR_Code) which we'll scan on entrance and for participation in the different quizzes." CreationDate="2011-03-03T20:05:41.983" UserId="2395" />
  <row Id="16323" PostId="10948" Text="Octopart shows search results from digi-key now." CreationDate="2011-03-03T20:29:17.833" UserId="3218" />
  <row Id="16324" PostId="11002" Text="Depending on the type of tech conference, you might get parts donated for PR value.  That's how the Next HOPE badge was funded." CreationDate="2011-03-03T20:35:59.517" UserId="411" />
  <row Id="16325" PostId="10973" Text="@endolith, @Kortuk, if you only notch a corner, you might miss signal planes that don't have traces there." CreationDate="2011-03-03T20:48:53.853" UserId="1407" />
  <row Id="16326" PostId="10996" Text="This should apply to most touch-screen phones as well." CreationDate="2011-03-03T22:55:44.837" UserId="1407" />
  <row Id="16327" PostId="4320" Text="@davidcary, I think this is similar to the LED as a diode problem, as long as you stay at 5V or lower you are fine, at my job we use 24V(industrial) and my coworker did not listen. Those 8 LED boards cost a lot to replace if they are certified for medical applications." CreationDate="2011-03-03T22:58:30.533" UserId="230" />
  <row Id="16328" PostId="10927" Text="There are three 103H5208 models listed in that sheet, none of which are the 1241. The models that are listed vary from 0.25-1A/Phase and 66-1.4 Ohm/Phase. The back-plate of this model indicates a resistance of 1.6 Ohm (it has that and 1.8 degrees per steps) which doesn't match any of those. That is the catalog I mentioned btw." CreationDate="2011-03-03T23:52:22.197" UserId="3208" />
  <row Id="16329" PostId="10932" Text="Thanks, that is good advice and I'm fairly sure I can trust the wiring diagrams from the other 103H5208 datasheets I've found. But I can't figure out what the maximum current rating is, I've found three supposed max current ratings in forums, ebay, and such. (I'd like the power curves and such as well, but a reliable max current would be enough.)" CreationDate="2011-03-04T00:01:51.003" UserId="3208" />
  <row Id="16330" PostId="10932" Text="@Jagerkin, [&quot;Sanyo Denki 103H5208-0842 or -1241 NEMA 17 1.8 deg 200 steps/rev when full-stepping 2.0 ohm motors, Current per Phase: 1.2A unipolar, 1A bipolar&quot;](http://www.edaboard.com/thread194845.html#post816719)" CreationDate="2011-03-04T00:26:16.287" UserId="1407" />
  <row Id="16331" PostId="10994" Text="Sounds like a budget (read: boring) [DEFCON badge](http://www.google.com/search?q=DEFCON+badges)." CreationDate="2011-03-04T01:09:36.360" UserId="1407" />
  <row Id="16332" PostId="10973" Text="@Nick: You should still be able to tell how many layers there are. Aren't they always equally spaced?" CreationDate="2011-03-04T01:53:13.763" UserId="142" />
  <row Id="16333" PostId="10973" Text="@endo, they don't have to be, it's however it's manufactured with whatever thicknesses of prepeg and core material.  Plus, the power planes may be spaced out in such a way that misleads." CreationDate="2011-03-04T02:18:41.230" UserId="1407" />
  <row Id="16334" PostId="10988" Score="1" Text="I would ask your Actel FAE or their support email." CreationDate="2011-03-04T02:54:55.923" UserId="206" />
  <row Id="16335" PostId="10550" Text="I think the diagram is exactly what I am looking for. Could you provide some information on how to set up the equations under it? My input will be between 9-5v and my max draw will be 2.5a" CreationDate="2011-03-04T03:03:29.070" UserId="2617" />
  <row Id="16336" PostId="10982" Text="@Gallamine - My setup should be cost effective." CreationDate="2011-03-04T03:23:54.420" UserId="1731" />
  <row Id="16337" PostId="6767" Text="The [&quot;custom notebook&quot; page on the Computer Component wiki](http://www.communitywiki.org/odd/ComputerComponent/CustomNotebook) lists a few first steps towards customizable laptops and &quot;open hardware laptops&quot;." CreationDate="2011-03-04T05:19:13.520" UserId="813" />
  <row Id="16338" PostId="10430" Text="@mctylr: Yes, the minimum frequency offset per degree is at those temperatures. However, it is not at all obvious to me: What is the best trade-off between frequency error due to small unavoidable temperature variations (best at the special temperatures you mentioned) vs. frequency error due to thermal noise (better at lower temperatures)?" CreationDate="2011-03-04T06:26:23.433" UserId="813" />
  <row Id="16339" PostId="10975" Score="2" Text="If you're gonna bother with everything involved in buffering the writes, just finish the job and build your own datalogger. It'll probably be easier." CreationDate="2011-03-04T08:08:15.327" UserId="1374" />
  <row Id="16340" PostId="10902" Text="@BarsMonster: After you will get it to work, I would like to hear the results :)" CreationDate="2011-03-04T08:49:03.793" UserId="1603" />
  <row Id="16341" PostId="11018" Score="2" Text="Your question is tagged `switching-regulator` but the LM340 is a linear regulator. As BarsMonster says, you probably really do need a switching regulator." CreationDate="2011-03-04T09:07:16.467" UserId="2234" />
  <row Id="16342" PostId="11018" Score="1" Text="Your tags and title don't match the content. The LM340/78XX series are linear not switching regulators, and the arduino isn't relevant even if that is your application for this supply." CreationDate="2011-03-04T09:15:23.957" UserId="2110" />
  <row Id="16343" PostId="11023" Text="The datasheet says Vin: 0 V to Vdd, so you need to clamp the audio signal to some voltage in the middle." CreationDate="2011-03-04T10:06:38.327" UserId="1950" />
  <row Id="16344" PostId="10447" Text="TEA6422 is a chip designed for audio switching." CreationDate="2011-03-04T10:09:27.077" UserId="1950" />
  <row Id="16345" PostId="10994" Text="Hm, didn't know of those. I'll see if I can learn something from those." CreationDate="2011-03-04T10:27:13.920" UserId="2395" />
  <row Id="16346" PostId="11019" Text="Thanks for that, I don't believe the data to be encrypted as another person on avrfreaks managed to find the bit that is set when the alarm is armed and unset when it isn't (hrm i can't put in newlines in this comment) www.baranharper.com/pdfs/dsc/pc5401-dev_guide.pdf &lt;-- I believe this is the data that is being sent back and forth. So I know what I'm looking for just not exactly how to read it.  Thanks for your comment again, hopefully I can spend some time on this project this weekend." CreationDate="2011-03-04T11:46:22.063" UserId="3239" />
  <row Id="16347" PostId="11026" Text="Thanks @Joby, please can you explain little bit more how can i do that?" CreationDate="2011-03-04T12:26:32.093" UserId="2037" />
  <row Id="16348" PostId="11028" Score="1" Text="I put some images to help clarify better." CreationDate="2011-03-04T12:27:56.053" UserId="938" />
  <row Id="16349" PostId="11026" Text="Also can you please explain that why the controller is returning 0x000012 this weird signature. If i did not provided the proper clock it should not return any signature at all.  " CreationDate="2011-03-04T12:28:46.723" UserId="2037" />
  <row Id="16350" PostId="10985" Text="There is a way to use a little oven like this. http://www.real-onlineshop.de/medias/sys_master/products/000_099/010/011/0118891_001_001_xtralarge_1.jpg i dont know if you have access to such a device in the country where you live. in germany theyre sold in almost every shop. there is a tutorial to hack the device and control the temperature in a way that will melt the solder, but not harm the components. so yeah there is a way. i can point you to the tutorials if you like." CreationDate="2011-03-04T12:42:22.327" UserId="2995" />
  <row Id="16351" PostId="11029" Text="What was wrong with that? I thought I'd answered the question about the pad size." CreationDate="2011-03-04T12:44:59.530" UserId="305" />
  <row Id="16352" PostId="10984" Text="@kortuk: yeah its a cool move for you to add a link. but i think any decent person with a functioning brain, is able to take a phrase and find something after it ;).i will not say what to use, since its OBVIOUS . no insult ^^" CreationDate="2011-03-04T12:45:24.993" UserId="2995" />
  <row Id="16353" PostId="10132" Text="presume: i can walk. and i know how to walk :)&#xA;sorry the question is indeed very broad asked. sorry for that. i mean something like &quot;i want to use this or that chip, how do i find out if i need pullup/down or a diode in front of it or or or&quot; these type of questions. &#xA;&#xA;and the only thing i am afraid of is. that im forced to read every datasheet everytime i want to use x. i was looking for some (minimal) universal guide on what is, necessary basics for circuit x. but i think however i state the question and how often i will ask. the answer will be. READ THE DATASHEET ^^ . thanks." CreationDate="2011-03-04T12:48:44.037" UserId="2995" />
  <row Id="16354" PostId="11029" Text="I misclicked the minus button, could you make a null edit so I can upvote you?" CreationDate="2011-03-04T12:49:39.093" UserId="1225" />
  <row Id="16355" PostId="11029" Text="@Leon There's nothing wrong with your answer. I've edited it." CreationDate="2011-03-04T12:57:06.840" UserId="938" />
  <row Id="16356" PostId="11029" Text="Thomas, you should be able to undo your vote by clicking the button again." CreationDate="2011-03-04T12:59:21.707" UserId="2064" />
  <row Id="16357" PostId="11029" Text="@stevenh I have done so. It appears someone else voted down too." CreationDate="2011-03-04T13:19:02.297" UserId="1225" />
  <row Id="16358" PostId="10999" Text="@Joby - That thread points to [this page](http://www.avr-developers.com/cputable.html), which lists a number of Atmel micros that have been made to compile/work under the Arduino software, including AT90CAN, AT90USB, ATtiny models, and, of course, ATmega - 40 different micros in all (59 when you differentiate -p part numbers).  It might be good to incorporate some of the info from that thread in your answer." CreationDate="2011-03-04T13:59:03.947" UserId="857" />
  <row Id="16359" PostId="11022" Text="Thanks, that the exact kind of oversight on my part I was worried about." CreationDate="2011-03-04T14:15:20.173" UserId="2617" />
  <row Id="16360" PostId="11026" Score="1" Text="I'm afraid, I've never done it before. I'd try a fresh microcontroller and more care with the fuse settings. You could ask on avrfreaks, they're a good specialist resource for AVR questions" CreationDate="2011-03-04T14:21:45.613" UserId="566" />
  <row Id="16361" PostId="10999" Text="@reemrevnivek I took the question to mean &quot;what chips can I put in my Uno&quot;. If you include everything with some level of Arduino compatability, you could go as far as the Maple and other ARM based boards... Maybe even the Papilio AVR soft core..." CreationDate="2011-03-04T14:27:24.253" UserId="566" />
  <row Id="16362" PostId="8679" Text="This seems to be the cheapest one available, from my research." CreationDate="2011-03-04T15:05:00.503" UserId="857" />
  <row Id="16363" PostId="8681" Text="The Attiny13 isn't the cheapest in the ATtiny line.  I think that status belongs to the ATtiny4." CreationDate="2011-03-04T15:10:33.043" UserId="857" />
  <row Id="16364" PostId="10988" Text="I sent an email late yesterday and will post the response as soon as I have it." CreationDate="2011-03-04T15:37:50.180" UserId="923" />
  <row Id="16365" PostId="10687" Text="@Supercat - Good points, but I wanted to add that you can use the format &lt;number&gt;&lt;period&gt;&lt;space&gt; to define better formatted lists. See the &quot;Simple Lists&quot; and &quot;Advanced Lists - Nesting&quot; sections of the [Markdown editing help](http://electronics.stackexchange.com/editing-help) page." CreationDate="2011-03-04T16:11:06.357" UserId="857" />
  <row Id="16366" PostId="11013" Text="Thanks for this, but I think these are a little too professional for a beginner hobbyist like me, I suppose I should have made that clearer in my question." CreationDate="2011-03-04T16:15:23.533" UserId="2681" />
  <row Id="16367" PostId="11033" Score="2" Text="Are you basing this 5-6 Hour life off of actually running the battery down or the software power meter?" CreationDate="2011-03-04T16:17:50.100" UserId="319" />
  <row Id="16368" PostId="11016" Text="Okay thanks for this, it has made me realize that I have allot more to learn than I first thought. I'l do some reading because I don't even know what an encoder is :S" CreationDate="2011-03-04T16:18:02.703" UserId="2681" />
  <row Id="16369" PostId="11033" Text="actuall usage. How long I can play music until I need to charge (which I let the battery bar get to 25% before plugging in)" CreationDate="2011-03-04T16:20:51.267" UserId="3242" />
  <row Id="16371" PostId="8676" Text="I think this question should be closed as &quot;too localized&quot;" CreationDate="2011-03-04T16:28:14.993" UserId="938" />
  <row Id="16372" PostId="11035" Text="@supercat +1 because I assume that since much of what you are saying is over my head, it must be correct." CreationDate="2011-03-04T16:35:43.623" UserId="3122" />
  <row Id="16374" PostId="11037" Text="Ok @Dean, now it's a community wiki" CreationDate="2011-03-04T17:28:40.090" UserId="938" />
  <row Id="16375" PostId="11033" Text="I can say from personal experience that (for whatever unknown reason) USB charged devices charge about 2x as fast when plugged into the SunRay on my desk as the PC...  A real headscratcher as it should be identical..." CreationDate="2011-03-04T17:56:51.870" UserId="1678" />
  <row Id="16376" PostId="11040" Score="2" Text="Not enough information!" CreationDate="2011-03-04T18:34:36.350" UserId="305" />
  <row Id="16377" PostId="11040" Text="Edited if you need to know anything else i will add. " CreationDate="2011-03-04T18:42:13.667" UserId="1623" />
  <row Id="16378" PostId="11042" Score="1" Text="This is true, unless you're using lead-free solder ... all joints good and bad tend to look dull with it, making visual inspection much more difficult." CreationDate="2011-03-04T18:54:00.603" UserId="1293" />
  <row Id="16379" PostId="11042" Text="Yeah i'm using lead free solder. :/" CreationDate="2011-03-04T18:54:50.583" UserId="1623" />
  <row Id="16380" PostId="9294" Text="IPC is an industry association of manufacturers that do work with printed circuit boards and electronic assembly in general. Their standards represent 'best practices' and are de facto requirements. You'll find that their procedures are almost universally followed by professional electronics manufacturers." CreationDate="2011-03-04T18:59:25.127" UserId="1293" />
  <row Id="16381" PostId="11018" Text="I retagged the original question as per these comments." CreationDate="2011-03-04T19:01:54.283" UserId="1293" />
  <row Id="16382" PostId="10250" Text="IF one sends an FF character, one can be certain that even if a framing error prevents it from being received correctly, the byte that follows it will be received correctly.  If bandwidth allows, it may be helpful to follow each packet with an FF; this will assure that even if one packet gets garbled by a framing error, the next packet will not." CreationDate="2011-03-04T19:06:18.593" UserId="3123" />
  <row Id="16383" PostId="11043" Score="1" Text="@community probably needs tag help" CreationDate="2011-03-04T19:06:26.167" UserId="319" />
  <row Id="16384" PostId="11043" Text="Yeah i didn't know what to tag it as so feel free to edit them. " CreationDate="2011-03-04T19:10:27.187" UserId="1623" />
  <row Id="16385" PostId="11043" Text="The object needs to be reflective, what is it in your case?" CreationDate="2011-03-04T19:16:04.883" UserId="305" />
  <row Id="16386" PostId="11043" Text="Its in a Micromouse maze to the UK standards. They say: &#xA;1.2. The side of the micromouse maze walls shall be white, and the top of the walls shall normally be red. The floor of the micromouse maze shall be made of MDF and finished with a matt variety of black paint (blackboard paint). The coating on the top and side of the wall shall be selected to reflect, and the coating on the floor shall be selected to absorb, visible and infra-red light." CreationDate="2011-03-04T19:17:53.577" UserId="1623" />
  <row Id="16387" PostId="11049" Text="Can you elaborate on what I/O expanders would be?" CreationDate="2011-03-04T19:26:03.273" UserId="2028" />
  <row Id="16389" PostId="11049" Score="2" Text="An I/O expander is external chip that contains I/O pins and registers. You can use standard communication bus like I2C or SPI to communicate with them." CreationDate="2011-03-04T19:32:00.023" UserId="588" />
  <row Id="16390" PostId="8677" Text="Samples are also often more trouble than they're worth. If you are going to buy 1k of something, chances are you can buy one from DigiKey and pay for a predictable delivery date." CreationDate="2011-03-04T19:34:10.443" UserId="1363" />
  <row Id="16391" PostId="11046" Text="I had not seen. Possibly duplicated: http://electronics.stackexchange.com/questions/9860/what-is-needed-to-control-200-leds-from-an-arduino" CreationDate="2011-03-04T19:36:19.583" UserId="938" />
  <row Id="16392" PostId="11040" Score="1" Text="@Dean - Your steps to reproduce are &quot;plug something into the board&quot; and the result is &quot;it stops being recognized by the programming software&quot;.  There is an enormous number of potential sources for this problem - Software, hardware, cables, power supply, solder connections, PCB traces...the list goes on, and on, and on. " CreationDate="2011-03-04T19:41:57.090" UserId="857" />
  <row Id="16393" PostId="11040" Score="2" Text=" Copyright law prevents me from posting the entire text of *[Debugging: The 9 Indispensable Rules for Finding Even the Most Elusive Software and Hardware Problems* by David Agans](http://www.amazon.com/Debugging-David-J-Agans/dp/0814474578/) as an answer, but I'll recommend it. " CreationDate="2011-03-04T19:43:04.610" UserId="857" />
  <row Id="16394" PostId="11043" Text="@Dean - Requests for clarification: What is the input impedance of your voltage sensing circuit, what is the power supply current (and voltage), what are you using as a reflective object, what distances are you trying to measure, and does an IR sensitive camera (any unfiltered camera/cell phone will work) pick up anything from the sensor's IR LED?" CreationDate="2011-03-04T19:47:34.903" UserId="857" />
  <row Id="16395" PostId="11043" Text="BTW, Micromouse is sweet!  I've always wanted to try that." CreationDate="2011-03-04T19:48:34.560" UserId="857" />
  <row Id="16396" PostId="11052" Score="2" Text="O-scopes are not useful for high precision measurements.  Maybe some of the high-dollar ones will do the job, but if you need a precision voltage measurement, use a voltmeter.  If you need a precision frequency measurement, use a frequency counter, and so on.  (Both of my digital scopes use 8-bit converters.)  If your scope agrees with your voltmeter, and you see power-line frequency when your finger touches the probe, I'd consider it good enough. " CreationDate="2011-03-04T19:49:29.897" UserId="411" />
  <row Id="16397" PostId="7125" Text="In particular, http://reprap.org/wiki/Automated_Circuitry_Making shows a PCB that was milled by a RepRap." CreationDate="2011-03-04T19:52:36.657" UserId="813" />
  <row Id="16398" PostId="11043" Text="@reemrevnivek I have an iPhone which does as do the rest of my family so it won't detect the IR. How would I find out the input impedance? I have the output from the distance sensor going straight in to an ADC in a PIC. " CreationDate="2011-03-04T20:10:07.063" UserId="1623" />
  <row Id="16399" PostId="11043" Text="@reemrevnivek its Alevel project to create a micromouse its nearly finished :D jsut getting the software developed on the PIC then its ready to roll.:D" CreationDate="2011-03-04T20:11:20.060" UserId="1623" />
  <row Id="16400" PostId="11043" Text="I also have a test maze so it is a maze wall that im reflected the IR at for testing. " CreationDate="2011-03-04T20:12:10.577" UserId="1623" />
  <row Id="16401" PostId="11052" Text="Yeah, I don't use scopes for measurement, even at work.  They're for looking at the wave, generally, not measuring it." CreationDate="2011-03-04T20:22:30.357" UserId="142" />
  <row Id="16402" PostId="8681" Text="32 bytes of RAM!" CreationDate="2011-03-04T20:24:50.947" UserId="142" />
  <row Id="16403" PostId="11046" Score="1" Text="Don't forget to compare your options against the cost of buying a slightly pinnier microcontroller. Also pay attention to the per-port and total current limits." CreationDate="2011-03-04T20:39:34.533" UserId="1363" />
  <row Id="16404" PostId="11043" Text="@Dean re: input impedance - Straight into an ADC input should be a very high impedance (you can get it from the datasheet), I was wondering if you were using a resistive divider that was too high, or a mis-configured filter circuit or something. (You may want some filtering for this)" CreationDate="2011-03-04T20:42:38.900" UserId="857" />
  <row Id="16405" PostId="11043" Text="@reemrevnivek it says this: &#xA;The maximum recommended impedance for analog sources is 10 kΩ. &#xA;Is that what your talking about with input impedance? Here is the datasheet for the PIC im using:&#xA;http://ww1.microchip.com/downloads/en/DeviceDoc/41291F.pdf" CreationDate="2011-03-04T20:57:17.923" UserId="1623" />
  <row Id="16406" PostId="11049" Text="+1 You can drive a lot of LEDs with TI's TLC594 (http://focus.ti.com/lit/ds/symlink/tlc5940.pdf), but it may be overkill for many jobs. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=TLC5940NTG4-ND" CreationDate="2011-03-04T21:15:44.920" UserId="2157" />
  <row Id="16407" PostId="11043" Text="I might have wired it up wrong just going to check and will report back. This might explain why its not working :/ " CreationDate="2011-03-04T21:23:44.487" UserId="1623" />
  <row Id="16408" PostId="11051" Text="In the event the slider loses contact with the track, wouldn't the resistance from the terminal in use to the slider terminal be the same as an open connection (air)? Assuming a 10K pot, is this safer than having a sudden 10K resistance? Just curious about this point. Thanks for the excellent answer." CreationDate="2011-03-04T21:40:04.013" UserId="2028" />
  <row Id="16409" PostId="11052" Text="This clears up some things - I recently was testing an automotive ABS module where I should have expected an 11 volt square wave. The scope showed only a constant DC 8V whereas a voltmeter showed 11.9V. (As it turns out, the module was broken, no square wave at all was present.) But the voltage difference between the two measurement devices made me question the scope's accuracy." CreationDate="2011-03-04T21:44:04.790" UserId="2028" />
  <row Id="16410" PostId="11046" Text="When I began working with micros a while ago, this is a question I wished had been easy to find with clear answers. I managed to learn about charlieplexing and successfully implement it, but I wanted to recreate the question here with the excellent quality of SE-community answers." CreationDate="2011-03-04T21:47:29.297" UserId="2028" />
  <row Id="16411" PostId="11049" Text="@mjh Thanks - I should design a project that makes use of I/O expanders to force my learning of their usage." CreationDate="2011-03-04T21:48:35.880" UserId="2028" />
  <row Id="16412" PostId="11056" Text="+1 for explaining a bit about the duty cycle aspect. In the second sentence about Charlieplexing, did you mean &quot;drive *n^2-n* **LED's** with *n* IO pins?" CreationDate="2011-03-04T21:52:09.933" UserId="2028" />
  <row Id="16413" PostId="11046" Text="@joeforker You're right, the cost for a micro with more pins was pretty minimal, considering my project was a one-off. I thought at one point about using a micro with about 20 IO pins to accomplish the job, but one of my goals was a very small circuitboard footprint. Also, awesome adjective ***pinnier***!" CreationDate="2011-03-04T21:54:23.817" UserId="2028" />
  <row Id="16414" PostId="11059" Text="Oops... lapse in concentration!  I'm *using* the WinAVR toochain with eclipse ;-)" CreationDate="2011-03-04T22:07:16.987" UserId="3247" />
  <row Id="16415" PostId="10861" Text="@Nick T,  I am measuring the frequency with an oscilloscope. So, it is accurate. But for measuring Pin and Pout I am using a DC multimeter to measure avg. current through the inductor (Pin = Vin * IL) and voltage output (Pout = V^2/R)" CreationDate="2011-03-04T22:24:18.033" UserId="3199" />
  <row Id="16416" PostId="11052" Score="4" Text="That's a pretty severe difference.  I bet the module was in a high-impedance state, such that the impedance difference between the scope and voltmeter influenced the reading.  If you measure low impedance, a battery or something, they should read about the same." CreationDate="2011-03-04T22:29:48.973" UserId="411" />
  <row Id="16417" PostId="2178" Text="One of the simplest functioning inductive chargers I've seen (with a wacky sense of humor): http://www.afrotechmods.com/cheap/arnoldpad/arnold.htm" CreationDate="2011-03-04T22:37:13.263" UserId="813" />
  <row Id="16418" PostId="11016" Text="read up on quadrature encoders, since they are ubiquitous.  Basically, you have slits in a round disc, and an emitter-detector pair.  The slits are aligned 90 degrees out of phase so that you can tell which direction the disc is spinning.  You'll then have an IC that can decode these pulses into discrete &quot;ticks&quot;, where each tick represents a fraction of a rotation.  Depending upon your gearing / lead, you can convert this directly into an amount of motion." CreationDate="2011-03-04T22:53:44.607" UserId="2288" />
  <row Id="16419" PostId="11019" Text="@User3239, I was sidetracked by work, if you save the data you pulled off of the data lines as an image on your computer it can be easily uploaded to the question, then users like myself whom cannot install non-work related software can look at it." CreationDate="2011-03-04T23:04:24.420" UserId="230" />
  <row Id="16420" PostId="10984" Text="@Shitake83, anyone with a functioning brain can also link to a product they know the name of. The value in this site is that you give a detailed and functional explanation. I know xbee, every time someone asks a wireless question I could just post your answer, but that does not tell them WHY it is a good choice." CreationDate="2011-03-04T23:06:10.613" UserId="230" />
  <row Id="16421" PostId="10987" Text="@DanielGrillo, remember, you have to reduce your output power to meet maximum radiated power guidelines if you go directional. Most guidelines are written as a maximum field intensity. This means that radiating power in all directions or only just one, your range in that direction does not change. " CreationDate="2011-03-04T23:07:42.827" UserId="230" />
  <row Id="16422" PostId="1248" Score="1" Text="And because what davr says it true, never drive an led from a constant voltage source ( without a current limiting resistor )" CreationDate="2009-12-23T01:53:57.497" UserId="1498" />
  <row Id="16423" PostId="10948" Score="1" Text="@blutrane0, edit your answer and expand upon what you mean here." CreationDate="2011-03-04T23:10:05.290" UserId="230" />
  <row Id="16425" PostId="11059" Score="1" Text="I will confess...it never occurred to me that in either system that there would be a debugger, aside from pin 13. That definitely necessitates a second look at Netduino..." CreationDate="2011-03-04T23:18:23.803" UserId="989" />
  <row Id="16426" PostId="11051" Text="Sometimes rheostats are used to set the gain of a system; a circuit may be designed so the highest resistance setting will produce e.g. a gain of ten, but an open circuit might produce a gain of 1,000.  In such cases, having the contact momentarily open to expose the full resistance of the element would produce an excessive level of gain, but not the super-excessive level that would be caused if the element weren't connected as a &quot;backup&quot;." CreationDate="2011-03-04T23:47:45.377" UserId="3123" />
  <row Id="16427" PostId="4056" Score="1" Text="Can could reversible computer be Turing-complete, being able to solve any problem with a bounded function of the amount of memory that would be required for a non-reversible Turing machine&gt;?" CreationDate="2011-03-04T23:53:31.877" UserId="3123" />
  <row Id="16428" PostId="11065" Text="Is this the thing you mean? http://www.maplin.co.uk/spiral-cable-wrap-26849 BTW i live in the UK and have a maplin local. " CreationDate="2011-03-05T00:05:59.947" UserId="1623" />
  <row Id="16429" PostId="11018" Text="How about an achieveable min input voltage.  Do you really need down to 5 V input to 5 V output?" CreationDate="2011-03-05T00:08:31.647" UserId="206" />
  <row Id="16430" PostId="11018" Text="possible duplicate of [Regulator solution for 5 volts at +2ish amps](http://electronics.stackexchange.com/questions/10538/regulator-solution-for-5-volts-at-2ish-amps)" CreationDate="2011-03-05T00:09:23.627" UserId="206" />
  <row Id="16431" PostId="11052" Text="My scope has a rated DC gain accuracy of ±1.5% in the manual, and it cost $3,300 US new in '93. However, I've heard that a newer scope from Rhode+Schwartz may have a 14-bit ADC, and presumably with that kind of ADC they'd compliment it with high gain accuracy. However, if you have to ask the price - you can't afford it..." CreationDate="2011-03-05T00:27:00.133" UserId="1225" />
  <row Id="16432" PostId="11065" Text="@Dean - yes, if that isn't the actual same stuff, it is certainly the same concept." CreationDate="2011-03-05T01:15:24.193" UserId="740" />
  <row Id="16433" PostId="11054" Text="Did you mean to say &quot;external *power* source&quot; in your first sentence?" CreationDate="2011-03-05T01:35:31.810" UserId="1407" />
  <row Id="16434" PostId="11059" Text="Yep; you can use DebugWire on the smaller ATMegas, and JTAG on the larger chips (1280 and above I think) to do on-chip debigging of Arduino apps via the two environments mentioned above.  You have to have hardware to do this, though, and for me the Dragon at around $50USD was a good buy" CreationDate="2011-03-05T01:35:49.503" UserId="3247" />
  <row Id="16435" PostId="11059" Text="But, as I mentioned both options seemed to be average at best experiences.  I'm looking forward to doing the debugging comparison with the netduino i have coming." CreationDate="2011-03-05T01:38:16.817" UserId="3247" />
  <row Id="16436" PostId="11047" Text="Thank you for the output pin dataset as well as a helpful schematic." CreationDate="2011-03-05T02:15:11.180" UserId="2028" />
  <row Id="16437" PostId="10891" Text="@supercat, many people use parity to just know that the byte is bad, not because they need to correct it. That is an ECC problem." CreationDate="2011-03-05T03:12:35.623" UserId="230" />
  <row Id="16438" PostId="10891" Text="@supercat, but causing spacing so that every data word has an even number of transitions you have implemented parity, it will take at least a bit of wasted space to implement this. Barcodes are the end all of redundancy though, using a very large portion of their space for redundancy." CreationDate="2011-03-05T03:18:48.223" UserId="230" />
  <row Id="16439" PostId="11019" Text="ah, sorry bout that. I can't embed a picture (10 rep limit) but i can link to one." CreationDate="2011-03-05T04:15:23.573" UserId="3239" />
  <row Id="16440" PostId="11023" Text="@AndreKR, you could also run the 4066 from a dual supply to ensure that the signal is between the two power rails, but you'd have to shift the levels of the control inputs as well." CreationDate="2011-03-05T08:49:07.473" UserId="1409" />
  <row Id="16441" PostId="11043" Text="@Dean, if you want the question deleted you should be able to. I see no harm in keeping this question, it may have been a basic solution, but it is something someone can pull off of their search results and find our site to ask more detailed questions." CreationDate="2011-03-05T12:13:21.830" UserId="230" />
  <row Id="16444" PostId="11031" Text="I'm running bleeding-edge firmware (I'm testing pre-release candidates), and am pushing GCDC hard to let me into their source tree.  The 8051 processor is from Silicon Labs, which is powerful but has very little RAM.  Unfortunately it is a uBGA package, and is well beyond my home soldering capabilities.  This work is for a hobby project that may eventually yield revenue, but is presently budget-limited, so new hardware isn't planned." CreationDate="2011-03-05T15:26:21.443" UserId="3225" />
  <row Id="16445" PostId="11077" Text="Both supplies ive tried it with have a 5A output. " CreationDate="2011-03-05T15:37:44.697" UserId="1623" />
  <row Id="16446" PostId="11077" Text="I think there causeing some interference with it as its getting a little bit further now just verification error. " CreationDate="2011-03-05T15:54:52.817" UserId="1623" />
  <row Id="16447" PostId="11077" Text="But there not on the programming pins. " CreationDate="2011-03-05T15:55:42.173" UserId="1623" />
  <row Id="16448" PostId="9221" Text="@tcrosley - didn't those make inch long sparks? that must have been quite a surprise for someone." CreationDate="2011-03-05T17:05:20.777" UserId="740" />
  <row Id="16449" PostId="6439" Text="Fig 4. is unipolar, with output below ground.  So if Vref is 5V, output is -5V..0.  How does the circuit deal with this?" CreationDate="2011-03-05T17:47:42.473" UserId="411" />
  <row Id="16450" PostId="8303" Text="You can use the pulse to [fire a gun through the blades](http://en.wikipedia.org/wiki/Interrupter_gear) without damage.  Should you be inclined to do so." CreationDate="2011-03-05T19:25:00.877" UserId="411" />
  <row Id="16452" PostId="9221" Score="1" Text="@Eli - Yes, it's safe because you only have *E = 1/2 * C * V^2* ~= 0.1 millijoules of energy stored in the cap." CreationDate="2011-03-05T20:01:43.717" UserId="857" />
  <row Id="16453" PostId="11054" Text="@Nick T: Yes, thanks, I've fixed that." CreationDate="2011-03-05T20:04:15.880" UserId="3246" />
  <row Id="16455" PostId="11073" Score="1" Text="This is a possible duplicate of [Which equipment for electronics should I always have on hand?](http://electronics.stackexchange.com/questions/3382/which-equipment-for-electronics-should-i-always-have-on-hand) and it's probably related to [What tools, equipment, and techniques do you use to solder fine-pitch SMT parts?](http://electronics.stackexchange.com/questions/4678/what-tools-equipment-and-techniques-do-you-use-to-solder-fine-pitch-smt-parts)" CreationDate="2011-03-05T20:28:55.883" UserId="857" />
  <row Id="16456" PostId="11082" Score="2" Text="Using the noninverting input for feedback won't work as a unity gain buffer, at best you'll get a Schmitt-Trigger." CreationDate="2011-03-05T21:26:07.667" UserId="339" />
  <row Id="16457" PostId="9221" Text="@JustJeff -- yes, about that and very visible.  Yes, it was a quite a &quot;shock&quot; for someone." CreationDate="2011-03-05T21:27:33.407" UserId="1322" />
  <row Id="16458" PostId="11082" Text="@starblue It will, try it ;)." CreationDate="2011-03-05T21:31:13.780" UserId="1225" />
  <row Id="16459" PostId="10891" Text="@Kortuk: What advantage is there to knowing that e.g. the sixth byte in a message is bad, as opposed to merely knowing that something is bad, if one isn't going to attempt error correction?  Sometimes it can be useful to have a protocol where each packet has a short checksum, and each group of packets has a long one.  If a bad packet is caught, just that packet needs retransmission.  If a bad packet gets through without a checksum error, the longer group checksum will show something's wrong, but it will be necessary to retransmit the whole group." CreationDate="2011-03-05T21:53:16.583" UserId="3123" />
  <row Id="16460" PostId="10891" Text="@Kortuk: I'm not sure that principle would apply to parity-checking individual bytes, though, unless one had a means of requesting that only specific bytes needed retransmission.  There would be ways of handling that, but I can't think of any communications contexts where it would really help." CreationDate="2011-03-05T21:54:30.670" UserId="3123" />
  <row Id="16461" PostId="11040" Text="That looks an awsome book" CreationDate="2011-03-05T22:31:33.497" UserId="1623" />
  <row Id="16462" PostId="9156" Text="If you look at the Data sheet It is almost the same as the Schematic that vicatcu posted in his answer. And as experience goes they are bi-directional. " CreationDate="2011-03-05T23:01:26.413" UserId="2060" />
  <row Id="16463" PostId="7080" Text="@tyblu: What are the &quot;best tools&quot; that only run on Linux?  What's wrong with running it in a virtual machine?" CreationDate="2011-03-05T23:25:38.703" UserId="142" />
  <row Id="16464" PostId="7080" Text="@endolith, There is nothing wrong with VM's. In fact, I consider it to be a superior option to dual-booting or having separate PCs, and is what I do (Linux, running Win in VM). I love easy access to scripting libraries (UNIX), machine customizability (incl. security), and possibility for low overhead (satisfies my OCD). For some reason I like ext3/4 more than NTFS, too, though my reasons are likely outdated." CreationDate="2011-03-06T00:26:16.113" UserId="2118" />
  <row Id="16465" PostId="10891" Text="@supercat, an easy example, you put parity on the output from a keypad. if you get a bad byte you ignore it instead of using that number. I think there would be many many situations where dropping a bad byte does not harm it. All of them completely transparent to the user. You could even have a byte by byte acknowledgment. I can understand why this seems pointless to you, but if a byte coming in is a command, you might be better off without the command then flushing the buffer of data or whatever other possible command was falsely called." CreationDate="2011-03-06T00:30:42.753" UserId="230" />
  <row Id="16466" PostId="11082" Text="@Thomas, have you tried it?" CreationDate="2011-03-06T00:42:08.143" UserId="411" />
  <row Id="16467" PostId="3579" Text="I bought a 1000-piece resistor kit that came with each value in a little bag with no labels.  &gt;:(  I just spent a long time writing the value on each bag and sorting them by first digit.  There are more 1s than 9s, though, so my meta-grouping ended up being 1.0-1.2, 1.3-1.9, 2_, 3_, 4_-5_, and 6_-9_." CreationDate="2011-03-06T00:42:48.443" UserId="142" />
  <row Id="16468" PostId="11082" Text="@markrages, in a circuit simulator it worked. Maybe the simulator was broken?" CreationDate="2011-03-06T00:53:56.627" UserId="1225" />
  <row Id="16469" PostId="11082" Text="@markrages: http://falstad.com/circuit/#%24+1+5.0E-6+1.3804574186067096+50+5.0+50%0Aa+256+192+384+192+0+15.0+-15.0+1000000.0%0AO+384+192+432+192+1%0Aw+384+192+384+128+0%0Aw+256+128+256+176+0%0Aw+256+128+384+128+0%0AR+256+208+224+208+0+1+40.0+5.0+0.0+0.0+0.5%0AR+256+320+224+320+0+1+40.0+5.0+0.0+0.0+0.5%0Aw+256+240+384+240+0%0Aw+256+240+256+288+0%0Aw+384+304+384+240+0%0AO+384+304+432+304+1%0Aa+256+304+384+304+1+15.0+-15.0+1000000.0%0A" CreationDate="2011-03-06T00:55:40.947" UserId="1225" />
  <row Id="16470" PostId="11082" Score="1" Text="@thomasO, build it, it will not work with positive feedback." CreationDate="2011-03-06T01:51:02.200" UserId="230" />
  <row Id="16471" PostId="11082" Score="3" Text="If your computer persists in lying to you—junk that digital piece of disaster—throw it off the roof. You’ll feel much better about it—and the computer will never lie to you again.&#xA;&#xA;— Robert A. Pease, Troubleshooting Analog Circuits&#xA;" CreationDate="2011-03-06T02:02:46.793" UserId="411" />
  <row Id="16472" PostId="11082" Score="1" Text="If you disconnect and reconnect the feedback in Falstad sim, then it does the right thing." CreationDate="2011-03-06T02:10:10.750" UserId="411" />
  <row Id="16473" PostId="7025" Text="Falstad sim is broken, see http://electronics.stackexchange.com/questions/11082" CreationDate="2011-03-06T02:11:21.810" UserId="411" />
  <row Id="16475" PostId="11092" Text="Is there any reason why we couldn't just connect DS18S20's data pin to a MAX232 or similar and have the computer do all the decoding? Couple of transistors could be used to switch the data pin between RX and TX pins of the port and other two pins could be used to control transistors. After that one of the USB to serial chips could be used or a prefabricated USB based serial port." CreationDate="2011-03-06T03:18:39.490" UserId="1240" />
  <row Id="16476" PostId="11073" Text="@reemrevnivek  Actually, other questions don't discuss software list for beginners, so this could be a nice list of software. " CreationDate="2011-03-06T03:27:17.720" UserId="1240" />
  <row Id="16477" PostId="11094" Text="Thanks for the reply. I've already given up on the module - I've sent explicit RF On commands and I verify with an SSB receiver that the field was on, and yet, it kept giving me the same reply. I've returned the module for RMA on the suspicion that it's faulty. I was using the SMRFID software that was provided by SonMicro (the guys who made the module) so I would presume they should have got the commands and sequencing right." CreationDate="2011-03-06T04:04:42.657" UserId="2998" />
  <row Id="16478" PostId="10123" Text="The code I'm using is the sample application from SonMicro called SMRFID - I don't have the sources for it, but as far as I can tell, it's what the module is sending back over the RS232-TTL link." CreationDate="2011-03-06T04:07:49.207" UserId="2998" />
  <row Id="16479" PostId="10123" Text="And yes, I tried a 50m reel of solid core wire just because it's a lot of wire and it gives a very strong field with it when judged with my SSB receiver. Anyway, I have given up on this module and RMA'd it on suspicion that it is faulty. Thanks for all your replies!" CreationDate="2011-03-06T04:08:46.010" UserId="2998" />
  <row Id="16480" PostId="11094" Text="@GoughLui, Yes, I would assume they were doing it properly, but knowing at which specific command they are receiving the 55 can change what the error means. I am not completely impressed by the design, but it does seem to be better than some I have seen. " CreationDate="2011-03-06T04:12:41.800" UserId="230" />
  <row Id="16481" PostId="11094" Text="@GoughLui, does it use the RTS and CTS signals during comm? I would like to note that I would consider you one of the question askers here whom actually gave solid work before asking." CreationDate="2011-03-06T04:13:23.080" UserId="230" />
  <row Id="16482" PostId="11092" Text="@AndrejaKo: possibly yes, that's a good idea, it it can be done quick enough to talk to the DS18S20. I think you need at least 15us. You should add this as your own answer!" CreationDate="2011-03-06T06:16:14.333" UserId="2426" />
  <row Id="16483" PostId="11095" Text="Turns out I could just watch the voltage drop across my power supply go from 5.09V unloaded to 5.19V when it was charging the battery. Still looking for an answer though =)" CreationDate="2011-03-06T06:39:34.750" UserId="3261" />
  <row Id="16484" PostId="11094" Text="@GhoughLui, it is possible that the software you are using is running so quickly that it energizes the RF field and before it has fully reached steady state attempts to read. This would result in the tag being read as state 0x55, or RF field is off. There is not good information on the datasheet about this, but if you were to send the 0x90 to start it and wait and then try a select tag it may work." CreationDate="2011-03-06T07:50:28.433" UserId="230" />
  <row Id="16485" PostId="11096" Text="@W5VO, really, you need to use a third meter to check to make sure that the second is not causing the problem." CreationDate="2011-03-06T09:57:41.340" UserId="230" />
  <row Id="16486" PostId="11095" Text="@nvuono,measure the resistance between the two ports for current while your multimeter is in resistance measurement. The resistance measurement normally uses the voltage prong and that will have the current side &quot;off&quot;. The resistance on that side should still measure as a short. This is not a perfect test, but a quick one that can give 95% confidence." CreationDate="2011-03-06T10:00:23.693" UserId="230" />
  <row Id="16487" PostId="11083" Score="1" Text="@BarsMonster, be careful of electrolytic on a &quot;motor&quot;. This can easily have voltage reverse and make fireworks out of your cap." CreationDate="2011-03-06T10:03:41.850" UserId="230" />
  <row Id="16488" PostId="11092" Score="1" Text="@Andrejako, @BG100, one of you make a schematic and add it in. show using RTS or the like to switch the transistors and an FT232 chip to do it. The user is not in heavy electronics so a &quot;how you do it&quot; schematic could be in order here." CreationDate="2011-03-06T10:11:26.397" UserId="230" />
  <row Id="16489" PostId="11082" Text="Gah, now I need to fix my project which can't possibly work. I chose one of the configurations - the wrong one." CreationDate="2011-03-06T10:14:31.790" UserId="1225" />
  <row Id="16490" PostId="11091" Text="Little question: the device driver is for Windows it says. I don't have a Windows machine ^^. Are there also drivers available for Linux or Mac OS X?" CreationDate="2011-03-06T10:36:56.373" UserId="3087" />
  <row Id="16491" PostId="11092" Text="@Kortuk♦ Since I was considering making a thermometer connected to serial port one of these days, I'll probably make a schematic soon. " CreationDate="2011-03-06T10:42:36.480" UserId="1240" />
  <row Id="16492" PostId="11083" Score="2" Text="Inductive loads should always have a reversed &gt;fast&lt; diode added parallel to it." CreationDate="2011-03-06T10:46:52.160" UserId="1476" />
  <row Id="16494" PostId="11091" Text="@Radek S It looks as if the software needs to be compiled using MinGW. If that's the case, then it could probably be easily ported to GNU/Linux or MacOS X." CreationDate="2011-03-06T11:05:25.493" UserId="1240" />
  <row Id="16496" PostId="11091" Text="That should work for Linux, at any rate." CreationDate="2011-03-06T11:19:43.133" UserId="305" />
  <row Id="16497" PostId="11098" Text="+1 for an explanation of why the circuit simulator does this. Thanks." CreationDate="2011-03-06T11:37:13.373" UserId="1225" />
  <row Id="16498" PostId="11092" Text="@AndrejaKo, Sounds great, make an answer." CreationDate="2011-03-06T12:25:25.127" UserId="230" />
  <row Id="16499" PostId="11098" Score="1" Text="so the short version of this is, &quot;only simulate with real component models, even if the ideal ones seem to work better&quot;. well done!" CreationDate="2011-03-06T13:07:17.270" UserId="740" />
  <row Id="16500" PostId="10984" Text="ok youre right. i should have explained it a little more and point to something." CreationDate="2011-03-06T13:41:58.033" UserId="2995" />
  <row Id="16501" PostId="10891" Text="@Kortuk: It may be useful to use parity with a keypad, granted, though preferred behavior would be to request a retransmission rather than ignoring a keystroke, and single-bit parity is a little wimpy (too much likelihood of undetected error)." CreationDate="2011-03-06T14:21:48.177" UserId="3123" />
  <row Id="16502" PostId="11083" Text="I've just did that on my scheme - PWM with PC FAN. 555 goes into 220 uH inductor, then to 10'000 uF cap. On cap I see beautiful line, with no spikes higher than 20-50mV, and absolutely no audiable noise. So, no danger for electrolyte on usual FAN's. But you indeed need a diode to protect a PWM controller, there are negative spikes up to -12 on that side." CreationDate="2011-03-06T16:10:31.770" UserId="2062" />
  <row Id="16503" PostId="4352" Score="1" Text="Chumby hacker board is like $90 [http://www.adafruit.com/index.php?main_page=product_info&amp;cPath=46&amp;products_id=278]" CreationDate="2011-03-06T17:11:28.690" UserId="2654" />
  <row Id="16504" PostId="3745" Text="&quot;Specific kits&quot; would be a shopping question, which is not allowed.  I'm getting kind of sick of all the &quot;I don't know anything, where should I start?&quot; questions.  Think about what you want to accomplish first, do some research, and then ask specific questions." CreationDate="2011-03-06T17:51:55.540" UserId="142" />
  <row Id="16505" PostId="11073" Text="@AndrejaKo - Good point, but the examples in the question and both answers refer to hardware." CreationDate="2011-03-06T19:22:31.120" UserId="857" />
  <row Id="16507" PostId="11109" Score="2" Text="Bare FETs, baby! Make your own input conditioning, level shifting, and output drivers, not to mention custom logic! :) I kid, I kid..." CreationDate="2011-03-06T20:46:52.217" UserId="2118" />
  <row Id="16508" PostId="10386" Text="It's actually +25V maximum, with +15V being a *typical* limit." CreationDate="2011-03-06T21:31:46.703" UserId="1225" />
  <row Id="16509" PostId="11114" Text="What? I don't understand this? Are you saying its easier to swap it from being pulled up to being pulled down?" CreationDate="2011-03-06T22:08:37.617" UserId="1623" />
  <row Id="16510" PostId="11114" Text="Just one connection has to be made, instead of one having to rewire the input. It  applies to both pull-up and pull-down resistors on inputs." CreationDate="2011-03-06T22:22:07.457" UserId="305" />
  <row Id="16511" PostId="11067" Text="I've used this for a variety of projects and it looks good and is easy to use." CreationDate="2011-03-06T22:33:10.280" UserId="1823" />
  <row Id="16512" PostId="11098" Score="1" Text="No, the moral of this is, don't trust simulator output.  This is a convergence problem, where the positive feedback opamp is in a  metastable state.  Different simulators have different tricks to get circuits like this to converge.  But if you don't know what a circuit does before you simulate it, the simulation will lead you astray.  (And the Falstad sim is a worse liar than most.)" CreationDate="2011-03-06T22:49:19.080" UserId="411" />
  <row Id="16513" PostId="11113" Score="2" Text="If the board is exposed to environmental conditions that severe, the value of your pull-up isn't what you should be worried about." CreationDate="2011-03-06T23:13:51.467" UserId="1407" />
  <row Id="16514" PostId="11114" Text="The edit makes it alot clearer." CreationDate="2011-03-06T23:26:21.170" UserId="1623" />
  <row Id="16515" PostId="11103" Text="Finding a hackerspace is a very good suggestion." CreationDate="2011-03-06T23:49:58.973" UserId="2395" />
  <row Id="16516" PostId="11111" Text="There must also be a downside, or HCT would be the only thing that exists." CreationDate="2011-03-07T00:50:11.380" UserId="142" />
  <row Id="16518" PostId="11108" Score="2" Text="@Paulo I don't encourage you to give your email because corresponding by email makes the communication private. So nobody else can benefit. But if you really wants to provide your email for private communications, the best place to do that is in your profile." CreationDate="2011-03-07T01:18:49.077" UserId="938" />
  <row Id="16521" PostId="10891" Text="@supercat, I am not saying that your logic is not solid, I am trying to say that you are thinking of cases where single bit parity makes sense. In high error situations you may want a hamming code. How useful is a CRC in a higher error rate channel? It is not because you will end up having an error every time and just get stuck in a retransmit loop. ECC and error detection need to be chosen on a case by case basis." CreationDate="2011-03-07T02:29:02.463" UserId="230" />
  <row Id="16522" PostId="11104" Text="@mikeselectricstuff, I think this may have been a better comment, as it is really not answering the question, just a side note." CreationDate="2011-03-07T02:30:47.800" UserId="230" />
  <row Id="16524" PostId="11098" Text="@Hans, very well done, I wanted to take time to make simulations and just did not have it. Your answer is concise and well done!" CreationDate="2011-03-07T02:49:23.243" UserId="230" />
  <row Id="16525" PostId="11109" Text="What voltage do you need?" CreationDate="2011-03-07T03:14:48.857" UserId="206" />
  <row Id="16526" PostId="11111" Text="HCT is 5 V (4.5-5.5 V).  HC is roughly 2-5 V. http://focus.ti.com/lit/ds/symlink/sn74hct244.pdf http://focus.ti.com/lit/ds/symlink/sn74hc244.pdf" CreationDate="2011-03-07T03:15:31.680" UserId="206" />
  <row Id="16527" PostId="10781" Text="@supercat: I'm quite sure that people *have* implemented a protocol that can handle *any* master or slave timing -- the 4-cycle protocol. See Davis and Nowick for details. These people did it, therefore it must be possible." CreationDate="2011-03-07T03:45:46.930" UserId="813" />
  <row Id="16528" PostId="11093" Text="But before doing suspicious-looking things at a dumpster, ask your friends, neighbors, coworkers, etc if any have broken printers and such they don't know what to do with." CreationDate="2011-03-07T04:11:52.857" UserId="1609" />
  <row Id="16529" PostId="11004" Text="A transformer could be made with superconductors, and careful choice of surrounding materials, and you could a zero loss transformer (or close to it). It could be a step up or a step down transformer." CreationDate="2011-03-07T04:18:50.477" UserId="1609" />
  <row Id="16530" PostId="562" Text="I'm disappointed that I don't see any answers that say *how many* lumens a LED needs to be visible in sunlight. How do you get the 2,000 cd/m² you need to be sunlight-visible? I'm also disappointed that none of the answers mention what to put around a LED to increase on/off contrast in sunlight -- things like the visor that casts shade on a standard traffic light, or various colored filters and light traps." CreationDate="2011-03-07T04:29:00.060" UserId="813" />
  <row Id="16531" PostId="10987" Text="@Swanand:What about the expected cost of this one ?" CreationDate="2011-03-07T06:19:07.947" UserId="1731" />
  <row Id="16532" PostId="11111" Score="1" Text="... Then again... Powered at 5 V, HCT will accept logic levels provided by other ICs that use 3.3 V, i.e.: It can be used for interfacing between parts of your circuit that run at different supply voltages. You cant't use the output of 3.3 V logic at the inputs of HC gates that run on 5 V rails." CreationDate="2011-03-07T06:58:26.380" UserId="930" />
  <row Id="16533" PostId="11122" Score="1" Text="IR probably will not work very well, water absorbs red light. Ultrasonic sounds good, but i have no idea how well it works underwater. " CreationDate="2011-03-07T07:59:14.083" UserId="2060" />
  <row Id="16534" PostId="11123" Score="7" Text="Why do you want to use the watch dog instead of a normal timer/interrupt?  " CreationDate="2011-03-07T08:10:43.230" UserId="2060" />
  <row Id="16535" PostId="11113" Text="Often have boards subjected to high humidity and hydrocarbon mist (exhaust, etc.), @NickT, but you are right: salts would be a killer." CreationDate="2011-03-07T08:25:54.527" UserId="2118" />
  <row Id="16536" PostId="11122" Text="I have a feeling you should be able to waterproof piezo elements rather easily for underwater operation, both as a speaker and a mic. I have never tried through, so don't hook up anything expensive to it if you do ;)" CreationDate="2011-03-07T10:12:09.973" UserId="1802" />
  <row Id="16537" PostId="11125" Text="That was my thought on how the watchdog worked on most chips." CreationDate="2011-03-07T10:56:22.383" UserId="2060" />
  <row Id="16538" PostId="11123" Score="3" Text="Why can't you use a UART?" CreationDate="2011-03-07T11:12:50.887" UserId="305" />
  <row Id="16539" PostId="4056" Score="1" Text="@endolith: Yes, *today*, gates use much more than kT ln(2) -- both destructive and non-destructive CMOS gates. However, if [current trends continue](http://www.cise.ufl.edu/research/revcomp/RevComp-trend.jpg), the energy used by non-destructive CMOS gates will drop below kT ln(2) around 2025. Destructive gates, whether CMOS or anything else, cannot use less than the theoretical minimum of kT ln(2)." CreationDate="2011-03-07T13:19:12.477" UserId="813" />
  <row Id="16540" PostId="11126" Text="...but understand that the transducer will output data which can be turned into something you'd see on a fish finder LCD. It will not be trivial to parse!  " CreationDate="2011-03-07T13:35:58.410" UserId="857" />
  <row Id="16541" PostId="11016" Text="For quadrature decoding, you might find the HCTL-2020 to be a simple solution. It's a relatively antiquated chip, but it works well." CreationDate="2011-03-07T13:46:00.743" UserId="712" />
  <row Id="16543" PostId="11126" Score="1" Text="The transducer simply emits a pulse and receives the echo. The processing is done by the main unit." CreationDate="2011-03-07T13:54:45.927" UserId="305" />
  <row Id="16544" PostId="11125" Text="At least on the AVR reset on watchdog and interrupt on watchdog can be toggles using a control register. So you can use the watchdog timer purely for interrupts. The benefit is that the watchdog can have interrupt periods of up to 8s, whereas the regular timers are limited to much less." CreationDate="2011-03-07T14:06:37.447" UserId="1802" />
  <row Id="16545" PostId="11126" Text="@Leon - Precisely!  But the signal processing required to transform that echo into &quot;the nearest solid object is x feet away&quot; is going to be very difficult." CreationDate="2011-03-07T14:29:04.760" UserId="857" />
  <row Id="16546" PostId="11126" Score="1" Text="It just involves measuring the time for the reflected pulse to arrive back at the transducer." CreationDate="2011-03-07T14:31:47.923" UserId="305" />
  <row Id="16547" PostId="11128" Text="I recently came across a switch that was powered by the motion on switching it. It was able to transmit a signal using that power. Idea was it could be used in a home automation environment. Can't find the link to it now though, and it wasn't all that small." CreationDate="2011-03-07T14:34:07.593" UserId="319" />
  <row Id="16548" PostId="11130" Text="By the way, it might make your code more simple if you WIRE the steppers backwards instead of CODING them backwards.  Swap the B and B' wires to reverse the direction of rotation on a stepper." CreationDate="2011-03-07T14:48:52.783" UserId="1824" />
  <row Id="16549" PostId="11117" Score="1" Text="Could you explain what you are trying to accomplish a little clearer? If you are trying to transmit the combined signal over a wire, then you could search for DSL-modems which use QAM at baseband." CreationDate="2011-03-07T14:56:21.200" UserId="1627" />
  <row Id="16550" PostId="11113" Text="@tyblu, if they are, a sealed enclosure and/or conformal coating is a must.  The only reason that you should up the strength of a pull-up is for manufacturing reasons (flux residue left on the board) or for part tolerances, especially IC and transistor leakage at higher temperatures." CreationDate="2011-03-07T15:50:14.727" UserId="1407" />
  <row Id="16551" PostId="10948" Text="@Kortuk - This is really a response to Pingswept's answer.  " CreationDate="2011-03-07T16:05:47.890" UserId="857" />
  <row Id="16552" PostId="11109" Text="@Brian: I don't know.  The point is to be compatible with a wide range of common voltages for usefulness in future projects." CreationDate="2011-03-07T16:21:21.877" UserId="142" />
  <row Id="16553" PostId="11112" Text="If it were connected directly to V+, then it would *always* be V+.  You couldn't pull it down." CreationDate="2011-03-07T16:36:54.080" UserId="142" />
  <row Id="16554" PostId="10781" Text="@davidcary: For a protocol to be timing-independent with general-purpose I/O, the party sending data must have two wires over which it can transmit (a 'ready' signal as well as a signal for the data itself).  A small amount of hardware can eliminate software timing requirements, but in general slave software is hard." CreationDate="2011-03-07T16:40:06.770" UserId="3123" />
  <row Id="16555" PostId="11128" Text="That would be EnOcean." CreationDate="2011-03-07T16:48:20.537" UserId="2110" />
  <row Id="16556" PostId="11123" Text="i don't have the UART port free in my board. There is just one UART port which is already used. i don't have any problem using normal timer interrupt either" CreationDate="2011-03-07T16:55:33.787" UserId="3276" />
  <row Id="16557" PostId="11125" Text="okie thanks for the reply. i have a 4800 bps 8N1 signal coming from the GPS device. i need to store the information in the buffer of the board. So for my purpose i need to use some way to interrupt in (1/4800 bps) =  .2 ms i need to check if the device support such a small value " CreationDate="2011-03-07T17:01:38.740" UserId="3276" />
  <row Id="16558" PostId="11123" Text="i have a 4800 bps 8N1 signal coming from the GPS device.  So for my purpose i need to use some way to interrupt in (1/4800 bps) =  .2 ms i need to check if the device support such a small value for normal interrupts." CreationDate="2011-03-07T17:02:29.163" UserId="3276" />
  <row Id="16559" PostId="8646" Score="1" Text="Thank you for posting your results. I get the same results -- they both have identical stage effort g*h = 4, so 18 FI2FO3 NANDs is very roughly 18 FO4 inverters. The FO4 inverter has total normalized delay d= 5, the FI2FO3 NAND has a total normalized delay d= 6. So a normalized delay of 18 FI2FO3 NANDs equals a normalized delay of about 22 FO4 inverters. (I avoid answering to 3 significant figures when we're using such a rough -- but useful! -- approximation.)" CreationDate="2011-03-07T17:10:17.450" UserId="813" />
  <row Id="16560" PostId="11128" Score="2" Text="The link would be [enocean.com](http://www.enocean.com/en/), or read the [Wikipedia article](https://secure.wikimedia.org/wikipedia/en/wiki/EnOcean) and follow to [wireless light switch](https://secure.wikimedia.org/wikipedia/en/wiki/Wireless_light_switch), where you'll also read about products from [Lightning Switch](https://secure.wikimedia.org/wikipedia/en/wiki/Lightning_Switch) and [Ad hoc Electronics](http://www.illumra.com/)" CreationDate="2011-03-07T17:19:07.293" UserId="857" />
  <row Id="16561" PostId="11117" Text="@trondd I'm trying to convert YCbCr 720p to a composite video stream for transmission over a radio." CreationDate="2011-03-07T17:24:54.373" UserId="1225" />
  <row Id="16562" PostId="4265" Text="Oops, it looks like you are right. Most of the other flash chips I've used or read about -- such as the Atmel Block Erase Flash -- allow partial writes: I can arbitrarily change bit(s) from 1 to 0, without an erase cycle, even if I've already changed some bits in that block from 1 to 0. Since the Dataflash datasheet doesn't specifically say what happens when I write more 0 bits to a page that already has some 0 bits, it's an undefined operation." CreationDate="2011-03-07T17:26:41.050" UserId="813" />
  <row Id="16563" PostId="11032" Text="Yeah, I mean, had it hooked up without a resistor for a while, too, and nothing fried either... " CreationDate="2011-03-07T17:43:23.983" UserId="3039" />
  <row Id="16564" PostId="10923" Text="Yeah I think at this point I won't even be bothered to put together a divider circuit, but I do know from what circuit analysis i know that that will get the job done. If i did have a convenient IC that did 5v-&gt;3v I'd use that too i suppose. I think the actual question I was looking for when I asked this question was, how come a 1kOhm resistor in series was sufficient; why didn't I need a divider? The answer is kinda wishy-washy so I'll just accept it as &quot;use the divider but the resistor in series seems to work fine so might as well use that for now&quot;" CreationDate="2011-03-07T17:48:25.133" UserId="3039" />
  <row Id="16565" PostId="11123" Score="1" Text="You need to sample more often than 1/4800 seconds.  How are you synchronizing to the start bit so that you can sample in the center of the data bits?" CreationDate="2011-03-07T19:22:24.303" UserId="411" />
  <row Id="16567" PostId="3986" Text="&quot;The yellow RCA input should be a high-impedance input.&quot; Incorrect, baseband video is impedance-matched at 75 ohms." CreationDate="2011-03-07T19:33:38.600" UserId="411" />
  <row Id="16568" PostId="11135" Text="You mean [this tool](http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0040d/Chddefih.html) for which the documentation is marked as &quot;Withdrawn&quot; on infocenter.arm.com?  That's worrisome. " CreationDate="2011-03-07T19:54:32.590" UserId="857" />
  <row Id="16569" PostId="11135" Text="Also, why don't you inspect the value of the pin with an oscilloscope or DMM - Is it a BGA or QFN with inaccessible tracks?  The basic idea (which I've used in gdb) is to read the value at the memory address which stores the pin status." CreationDate="2011-03-07T19:56:55.817" UserId="857" />
  <row Id="16570" PostId="11135" Text="Yes exactly. I don't get much help how to do debug in hardware with JTAG port using APM" CreationDate="2011-03-07T19:57:55.260" UserId="3283" />
  <row Id="16571" PostId="11135" Text="when you use gdb to inspect the values, how do you do live debugging. how do you stop your processor at certain moment to inspect some value. In brief can you please describe me the debugging flow?" CreationDate="2011-03-07T20:01:35.507" UserId="3283" />
  <row Id="16572" PostId="11136" Text="@Leon - Your link was broken, and mine pointed to a broken site.  For now, the PDF of the docs (see Ch. 3 for the debugger) is at [this URL](http://infocenter.arm.com/help/topic/com.arm.doc.dui0040d/DUI0040D.pdf)" CreationDate="2011-03-07T20:03:56.263" UserId="857" />
  <row Id="16573" PostId="11136" Text="i am novice in doing real time debugging in embedded. can you please point me to some pointers to get started. or please let me know the standard process used." CreationDate="2011-03-07T20:04:06.393" UserId="3283" />
  <row Id="16574" PostId="11136" Text="Thanks you for your help. This link is great." CreationDate="2011-03-07T20:05:56.343" UserId="3283" />
  <row Id="16575" PostId="5302" Text="Try the From-Scratch AVR Tutorial on [this](http://www.avrfreaks.net/index.php?name=PNphpBB2&amp;file=viewtopic&amp;t=70673) AVR Freaks page. You'll find lots more stuff there." CreationDate="2010-10-17T15:40:14.090" UserId="305" />
  <row Id="16576" PostId="11135" Text="@David - Briefly, `monitor reset halt`, `b main`(or other function), `continue`, `s` to desired point in program, `x addr` where addr is the desired location. Use OpenOCD to connect remotely.  I started learning with [this lab](http://claymore.engineer.gvsu.edu/~steriana/courses/424/lab2.pdf).  However, this is really a different question." CreationDate="2011-03-07T20:24:52.253" UserId="857" />
  <row Id="16577" PostId="11130" Text="Great answer but to my delight i had blown a ULN2803A. Because it was only missing certain steps which showed me that certain darlington arrays were broken. As the one stepper motor was working fine" CreationDate="2011-03-07T21:16:41.810" UserId="1623" />
  <row Id="16578" PostId="11139" Score="1" Text="ICs almost certainly have the same die.  Those things are expensive, and it would be senseless to design a new one for a different package. " CreationDate="2011-03-07T21:38:08.740" UserId="857" />
  <row Id="16579" PostId="11140" Score="3" Text="Woah!  I was going to say the opposite.  Surface mount components can be connected to large areas of copper on the PCB through a die pad, and thus have lower effective Θja. " CreationDate="2011-03-07T22:35:18.817" UserId="857" />
  <row Id="16580" PostId="11140" Score="3" Text="@reemrevnivek - And through-hole components can be mounted to a heatsink. External heatsinking does not change the fact that, *without heatsinking*, through-hole components can generally handle more power." CreationDate="2011-03-07T23:02:03.643" UserId="1374" />
  <row Id="16581" PostId="11140" Score="1" Text="It's not a hard and fast rule, I've just noticed when reading the datasheet of a part available in both packages, the SMT package will have a lower power rating." CreationDate="2011-03-08T00:17:39.757" UserId="411" />
  <row Id="16582" PostId="11133" Score="1" Text="If the required range is fairly small, it would be better to use a single resistor chain so you could be guaranteed that the ref voltage to your low comparator will be less than the other ref voltage" CreationDate="2011-03-08T00:54:17.540" UserId="1407" />
  <row Id="16584" PostId="11113" Text="Well, conformal coatings have measurable conductance, too..." CreationDate="2011-03-08T01:05:04.757" UserId="2118" />
  <row Id="16585" PostId="10748" Text="This is too strange a LCD.  Please provide a link to a data sheet or expect it to be closed." CreationDate="2011-03-08T01:50:20.167" UserId="206" />
  <row Id="16586" PostId="10781" Text="@supercat: I expected a response something like either &quot;Yes, the 4-cycle protocol sounds like it meets my requirements&quot;, or &quot;Sorry, I absolutely need backwards compatibility with off-the-shelf SPI hardware, so the 4-cycle protocol won't work for me, no matter how 'pervasive' or 'superior' it may be&quot;, or else &quot;Sorry, that won't work for me because (something)&quot;. The SPI-like protocol the original question describes sounds very clever, and I wish you great success using and tweaking it." CreationDate="2011-03-08T03:58:26.687" UserId="813" />
  <row Id="16587" PostId="11141" Text="This is probably more of a problem in RF and high frequency components, where the switching speed of the signal causes losses due to the inductance and capacitance of the leads.  More energy is required to maintain signal integrity. " CreationDate="2011-03-08T04:39:27.380" UserId="857" />
  <row Id="16588" PostId="11140" Text="SMD components can be mounted to a heatsink as well." CreationDate="2011-03-08T04:43:36.627" UserId="857" />
  <row Id="16589" PostId="11140" Score="1" Text="Assuming no heatsink, Through hole is regularly higher-power. Heatsinks are an additional option, and not mentioned anywhere in the question." CreationDate="2011-03-08T08:27:52.730" UserId="1374" />
  <row Id="16590" PostId="11083" Text="Where would the ceramic go? And to what end?" CreationDate="2011-03-08T09:11:05.077" UserId="1124" />
  <row Id="16591" PostId="11141" Text="@reemrevnivek, I wasn't being serious, if you've got a 50mohm MOSFET, what's &lt;1 mohm of wire gonna do?" CreationDate="2011-03-08T10:14:24.220" UserId="1225" />
  <row Id="16592" PostId="10987" Text="@iRobot : I got it from SparkFun. [link]http://www.sparkfun.com/categories/111   I am not sure about the range you require but here are few models to which you can connect the antenna! Have a look at it. Go for XBEE **PRO**!" CreationDate="2011-03-08T12:35:05.463" UserId="2574" />
  <row Id="16593" PostId="11141" Text="@Thomas - I understand that you weren't being completely serious on the resistance front, but there are plenty of situations where through-hole and SMD packages have significantly different inductance and/or capacitance." CreationDate="2011-03-08T13:10:24.217" UserId="857" />
  <row Id="16594" PostId="11128" Text="We're closing this question because it's a brainstorming session, which is [disallowed in our FAQ](http://electronics.stackexchange.com/faq#dontask) and we've also had a [question on Meta](http://meta.electronics.stackexchange.com/q/428/857) about it.  Feel free to brainstorm [in chat](http://chat.stackexchange.com/rooms/15), but keep future questions about actual problems that you face, not discussions about potential projects you haven't started.  Thanks!&#xA;" CreationDate="2011-03-08T13:14:48.610" UserId="857" />
  <row Id="16595" PostId="11093" Text="+1 for dumpster diving!" CreationDate="2011-03-08T13:14:55.630" UserId="1823" />
  <row Id="16596" PostId="11152" Score="1" Text="14 bits is 0.006%" CreationDate="2011-03-08T13:35:50.943" UserId="1407" />
  <row Id="16597" PostId="10781" Text="@davidcary: In my particular implementation, one of the requirements is to minimize the number of connections; another requirement is to achieve good speed.  The ability to use SPI master hardware means I can get a peak data rate of 10mbps for graphical data using a 40MHz PIC; any sort of bit-bang protocol would be limited to at most a quarter of that." CreationDate="2011-03-08T14:38:20.367" UserId="3123" />
  <row Id="16598" PostId="10748" Text="@Brian Carlton: My first prototype drove an off-the-shelf 4.5-digit LCD from Digi-Key with 15 pins: 3 common wires, and four groups of three segment wires controlling nine segments each.  In each group of nine segments, seven segments formed a digit, one was the left-side decimal point, and the other was either a leading minus, a leading &quot;1&quot;, &quot;BATTERY&quot;, or &quot;CONTINUITY&quot;.  I drove the LCD using a PIC 16C84 and two 74HC595 shift registers.  The drive technique is one I invented back around 1996 or 1997.  My question is whether anyone else has ever done anything similar." CreationDate="2011-03-08T14:43:04.153" UserId="3123" />
  <row Id="16599" PostId="11133" Text="yeah you are right... :)" CreationDate="2011-03-08T14:56:42.393" UserId="1839" />
  <row Id="16600" PostId="11155" Text="of course about the decoupling cap. The arrows in the circuit diagram made me question there purpose. what other purpose would those lines serve other then completing the charge pump?" CreationDate="2011-03-08T15:18:44.527" UserId="2060" />
  <row Id="16601" PostId="11156" Text="Where are you looking?  What would you call &quot;Reasonable&quot;?" CreationDate="2011-03-08T15:46:45.627" UserId="857" />
  <row Id="16602" PostId="11156" Text="Sorry, this isn't going to get a good answer on a Stack Exchange site. The answer depends too much on geographic location, exchange rates, quantity and year (suppliers change prices regularly, and may go into administration). Not to mention what you think is unreasonable may be fine for another person (hobbyist who only needs one), and what you think is reasonable is no use when you need to shave pennies off and are sourcing millions." CreationDate="2011-03-08T15:53:58.340" UserId="2110" />
  <row Id="16603" PostId="11152" Score="3" Text="Can you define &quot;Affordable&quot;? I'm working with some Agilent data aquisition modules (34970A) that are 22-bit (you said precision - 14 bits is a nice microcontroller ADC, not &quot;precision&quot; in my industry) that are $1500 for RS232/GPIB, or $1800 for USB/Ethernet.  Figure $500 or so for each (up to 3) mux or switch (20 channels or so) you want to add.  Is that &quot;Affordable&quot;?" CreationDate="2011-03-08T15:54:18.067" UserId="857" />
  <row Id="16604" PostId="11157" Text="The specific use is a one off serial programmer that i need in a rush, and power on time is  not a consideration. I like your idea of using those points to power a device, when I'm done I may look into that." CreationDate="2011-03-08T15:56:26.180" UserId="2060" />
  <row Id="16605" PostId="11047" Score="1" Text="Another way of drawing the schematic is as an NxN grid, but driving columns only, and replacing the primary diagonal with row-column shorts." CreationDate="2011-03-08T16:10:44.870" UserId="3123" />
  <row Id="16606" PostId="6804" Text="Actually, it's possible in some cases to extend Charlieplexing to provide N*(N+1) LEDs with N pins, if the supply voltage is less than twice the LED voltage drop, and one has the right combination of LED voltage drops available.  Let's assume for simplicity that the goal is to control 12 LEDs with three pins; six LEDs have a 2.5 volt drop, and six have a 1.7-volt drop, and supply voltage is 3.0 volts.  Goal is 5mA for the 2.5 volt diodes and 6.5mA for the 1.7-volt diodes.  Put a 100ohm resistor in series with each output.  Three of the 2.5-volt LEDs connect the outputs to VDD, three to VSS..." CreationDate="2011-03-08T16:23:28.113" UserId="3123" />
  <row Id="16607" PostId="6804" Text="...and the 1.7-volt LEDs connect the outputs to each other in &quot;normal&quot; Charlieplex form.  To turn on a 1.7-volt LED, drive one output high and one low.  The resistors will drop 0.65 volts, leaving 1.7 volts for the LED, and insufficient voltage for the 2.5-volt LED.  To turn on a 2.5-volt led, drive one output high or low and none of the others at all.  Then a 2.5-volt LED will have enough current to light." CreationDate="2011-03-08T16:26:15.303" UserId="3123" />
  <row Id="16608" PostId="6804" Text="One could add more resistors or silicon diodes to deal with different voltage scenarios if necessary, but that would add some complexity.  @tcrosley: The above generalizes to using one pin to control two LED's." CreationDate="2011-03-08T16:28:00.963" UserId="3123" />
  <row Id="16609" PostId="11158" Text="yes, including $6 switches." CreationDate="2011-03-08T16:33:21.717" UserId="3077" />
  <row Id="16610" PostId="11156" Text="I would consider reasonable, anything that is at or below RadioShack prices.  They gouge pretty hard, but their selection is obviously limited.  I can get a SPST switch there for $3." CreationDate="2011-03-08T16:35:11.887" UserId="3077" />
  <row Id="16611" PostId="11156" Text="@Martin:  Yes, clearly I am a hobbyist looking for one or two units.  If I needed millions, this is the last place I would look." CreationDate="2011-03-08T16:37:14.757" UserId="3077" />
  <row Id="16612" PostId="11149" Score="1" Text="Will the clockwise sequence be LH, HH, HL, LL (briefly), LH; or will it be LH, HH (for awhile), HL, HH (briefly), LH; or could it be either?  One should never rely upon two asynchronous signals to switch and precisely the same time; if one expects them simultaneously, one must be prepared for either to actually happen first." CreationDate="2011-03-08T16:45:30.163" UserId="3123" />
  <row Id="16613" PostId="11149" Score="1" Text="Instead of &quot;LH-HH-HL-LH&quot; I think you mean &quot;LH-HH-HL-LL&quot; and instead of &quot;LH-HL-HH-LH&quot; I think you mean &quot;LL-HL-HH-LH&quot;.   You never want two bits to be changing at the same time, because they are never at *exactly* the same time, so there is a glitch when one has changed but not the other.  AS code with one bit changing at a time is called a Gray code." CreationDate="2011-03-08T16:46:19.117" UserId="411" />
  <row Id="16614" PostId="11156" Text="www.allelectronics.com --&gt; This appears to be a good source for the parts I mentioned.  Under a dollar for a DIN5 female is a reasonable price.  Good thing the thread got closed!" CreationDate="2011-03-08T17:29:59.213" UserId="3077" />
  <row Id="16615" PostId="11128" Text="I'm really not sure why this is posted as a brainstorm.  It would be a decent question if asked simply as &quot;Is there an unpowered  switch technology which can have its state querried via a nearby RF device in the way an RFID tag can be?&quot;" CreationDate="2011-03-08T17:59:10.270" UserId="2246" />
  <row Id="16616" PostId="11087" Text="Good link for now, but more important for future readers is how you got here.  What process brought you to that link?  I think we can assume that the process will work in the future, but the link is likely to go bad." CreationDate="2011-03-08T18:06:36.160" UserId="857" />
  <row Id="16617" PostId="11125" Score="1" Text="Most processors don't clear data memory on reset.  Though startup code might wipe out some portion of it, or potentially leave a DRAM controller misprogrammed long enough to make memory contents unreliable.  Nonetheless, resetting the processor would be a roundabout way to solve the problem." CreationDate="2011-03-08T18:06:41.213" UserId="2246" />
  <row Id="16618" PostId="11093" Text="The list of surplus suppliers *might* be helpful, but dumpster diving and reusing discarded inject printers are not acceptable solutions for any purpose except a one-off hobbyist project." CreationDate="2011-03-08T18:08:32.367" UserId="857" />
  <row Id="16619" PostId="11114" Text="Yes - and you could even manually hold a powered or grounded jumper wire on a configuration pin's pull up/down resistor to over-ride the resistor while tripping the reset." CreationDate="2011-03-08T18:24:12.883" UserId="2246" />
  <row Id="16620" PostId="11119" Text="Yes, though this could be done with a 0-ohm SMT part too.  " CreationDate="2011-03-08T18:24:55.880" UserId="2246" />
  <row Id="16621" PostId="11156" Text="@A.R. The issue is that StackExchange is looking to provide to a global audience, and although you may have found a place, it doesn't mean that place is the proper recommendation for the entire world. On the other hand, things like coding methods and hardware construction methods are universal." CreationDate="2011-03-08T18:29:06.783" UserId="319" />
  <row Id="16622" PostId="11123" Text="@David - What other hardware do you have available?  You could use something like the NXP SC16IS7X chips, which translates UART to I2C or SPI." CreationDate="2011-03-08T18:40:37.910" UserId="857" />
  <row Id="16623" PostId="11168" Score="2" Text="Can you draw a brief schematic of how you hooked everything up? It's impossible to tell from your description." CreationDate="2011-03-08T19:54:24.233" UserId="1802" />
  <row Id="16625" PostId="11170" Text="Oh yeah, current limitations on what the PWM can supply is a great point. Older circuits may very possibly want more than you can give directly (without op amps, etc)." CreationDate="2011-03-08T20:23:58.733" UserId="1270" />
  <row Id="16626" PostId="11168" Text="No, PWM is not the same thing as a potentiometer." CreationDate="2011-03-08T20:23:59.637" UserId="142" />
  <row Id="16627" PostId="11168" Text="Pong uses a potentiometer?  It doesn't have a continuously turning encoder?" CreationDate="2011-03-08T20:28:06.310" UserId="142" />
  <row Id="16628" PostId="11152" Text="This is an odd ose of the word &quot;calibration&quot;.  Normally a calibration standard is a fixed voltage or current or resistance.  When you buy a precision scale, for example, it will come with a 5.00 gram weight to calibrate it." CreationDate="2011-03-08T20:38:38.793" UserId="411" />
  <row Id="16629" PostId="11152" Text="Initially forgot to define affordable. 1500 is a bit too expensive as I don't really need 22 bits samples. I guess I was a bit generous calling it precision though. It's just that so many DAQs are rated with a rather high error percentage (even though the bit per sample resolution is high)." CreationDate="2011-03-08T20:40:18.603" UserId="941" />
  <row Id="16630" PostId="11119" Text="@Chris Stratton: Indeed it could, but usually there will be some other resistor value that's already used elsewhere on the board that would work just as well.  The rare possibility that a port pin might accidentally get configured as an output might not justify using a part where none would otherwise be needed, but if one is going to use a part, it may as well be a resistor." CreationDate="2011-03-08T20:41:12.753" UserId="3123" />
  <row Id="16631" PostId="11171" Text="Here's a 48b power supply for $8 =) http://cgi.ebay.com/NEW-Original-CISCO-Power-Supply-AC-ADAPTER-48V-ADP-18FB-/390294921664?pt=LH_DefaultDomain_0&amp;hash=item5adf63e1c0" CreationDate="2011-03-08T20:44:03.077" UserId="1033" />
  <row Id="16632" PostId="11111" Text="Seems like this is mainly intended as a replacement for TTL?  &quot;These devices only work with a 5V power supply. They form a replacement for TTL, although HCT is slower than original TTL (HC logic has about the same speed as original TTL).&quot;" CreationDate="2011-03-08T20:55:59.113" UserId="142" />
  <row Id="16633" PostId="11152" Text="Looks like my comment was messed up due to [the new LaTeX support](http://meta.electronics.stackexchange.com/questions/192/tex-should-be-supported-on-er-like-on-math-se-et-al/431#431).  But that's a good thing!  Just need to escape `$` signs in the future." CreationDate="2011-03-08T21:07:50.343" UserId="857" />
  <row Id="16634" PostId="11110" Text="Doesn't the CD4000 series have a wider supply range?  CPLDs make more sense than 1 or 2 logic ICs?" CreationDate="2011-03-08T21:12:26.583" UserId="142" />
  <row Id="16637" PostId="11170" Text="Here's an example of using the RC filter hack to smooth the PWM output to simulate a resisitve voltage divider: http://dangerousprototypes.com/2011/03/07/arduino-varies-lcd-contrast-using-pwm/" CreationDate="2011-03-08T22:42:25.290" UserId="389" />
  <row Id="16638" PostId="11093" Text="&quot;I have a project in mind&quot; sounds like a one-off hobbyist project to me." CreationDate="2011-03-08T22:44:19.483" UserId="389" />
  <row Id="16639" PostId="11093" Text="DarenW: in Brisbane we have a thing called &quot;large item collection&quot; where once a year you put dead or unwanted appliances on the footpath and the city collects them and recycles.   Everyone helps themselves to things they can reuse." CreationDate="2011-03-08T22:45:32.883" UserId="389" />
  <row Id="16640" PostId="9399" Text="Fascinating problem. You've exposed that CAN might be balanced, but is little better than RS485 in a ground potential difference condition. " CreationDate="2011-03-08T22:48:08.153" UserId="1481" />
  <row Id="16641" PostId="11156" Text="I can understand that, but SOME information is better than NO information, right?" CreationDate="2011-03-08T23:18:47.453" UserId="3077" />
  <row Id="16643" PostId="10861" Text="This is a too specific question.  Please rephrase to be more general or it will likely be closed." CreationDate="2011-03-09T01:48:17.397" UserId="206" />
  <row Id="16645" PostId="10923" Text="@Steve, my guess (all I can do given a black box) would be that if you put 5 V into the iPhone through a resistor, clamping diodes on the input would limit it to 3.3 V.  You could test this by measuring the voltage on the iPhone side of the resistor when you're giving it 5 V on the other end." CreationDate="2011-03-09T02:16:13.410" UserId="1407" />
  <row Id="16646" PostId="11176" Score="1" Text="Battlebots? What better way to attract kids and still teach about electronics. You can build them pretty cheaply with a couple motors and a microcontroller. I've made one for under $20." CreationDate="2011-03-09T02:54:10.920" UserId="2873" />
  <row Id="16649" PostId="10861" Text="How do you measure Pin from average inductor current?" CreationDate="2011-03-09T03:49:10.730" UserId="411" />
  <row Id="16650" PostId="11178" Text="Hey Russell, welcome to E&amp;R.  The usual pattern here is: 1) questioner asks ambiguous question, 2) comments on question ask for more information, 3) Answerers answer as best they can.  Also, you can post images here.  I sometimes sketch a circuit on paper and take a picture with my webcam.  It's easier than following a text-only description.  Anyway, hope you stick around." CreationDate="2011-03-09T03:54:10.553" UserId="411" />
  <row Id="16653" PostId="11189" Text="Kortuk, Thank you very much for the reply. I guess what I'm looking for is kind of a pre-built circuit, a schematic, or something simple I can create that I can connect to an Arduino development board and power it from 24 volts. I've read that the minimum voltage that the development board will accept is 7 volts. So do you know of anything like this: http://www.sparkfun.com/products/9948 that will output above 7 volts? I know that the development board has it's own voltage regulator on it it, and I'm sure it's not the best practice to step-down from 24 volts...continued..." CreationDate="2011-03-09T05:19:03.950" UserId="3301" />
  <row Id="16654" PostId="11189" Text="and then let the development board step down again to 5 volts and 3.3 volts. But I just need something simple and reliable." CreationDate="2011-03-09T05:20:12.183" UserId="3301" />
  <row Id="16655" PostId="10987" Text="@Swanand: Thanks man." CreationDate="2011-03-09T05:33:24.290" UserId="1731" />
  <row Id="16656" PostId="11190" Text="You're lucky! People on the Internet keep telling me to buy stuff from Digikey, but their minimum shipping charge for my region is $120!" CreationDate="2011-03-09T06:07:54.370" UserId="1240" />
  <row Id="16657" PostId="11190" Text="My god where do you live? (...and I though digikey was expensive for me) The thing that sucks is that 3 was only what they could (and would) fit in an envelope. If I ordered anything bigger it when to like.. 8 or 9." CreationDate="2011-03-09T06:23:40.233" UserId="3210" />
  <row Id="16658" PostId="11190" Text="radio shack is your best bet for local easy find parts, yes they are over priced but you dont have to wait for shipping....personally I use http://www.newark.com or element14.also check out http://sparkfun.com . really Small orders (under $10) shipping will be expensive. " CreationDate="2011-03-09T06:45:22.963" UserId="2060" />
  <row Id="16659" PostId="11189" Score="1" Text="I found a good tutorial (http://www.ladyada.net/library/equipt/diypsupp.html) on creating a variable voltage regulator using this http://www.sparkfun.com/products/527 as well as some caps, a trim pot, and two diodes. I picked up a heatsink as well to be safe. Thanks again Kortuk. Btw, I chose an adjustable one, since I wanted to learn how to create it (for future projects). Also I'm going to ditch the dev board and create my own breadboard Arduino." CreationDate="2011-03-09T06:46:14.870" UserId="3301" />
  <row Id="16660" PostId="11189" Text="@DylanVester, I am glad my advice helped you, but it sounds like you found your own very specific solution. I may have guided you, but it seems like you could write your own answer about how you accomplished it and explain how to go about it. This could be very helpful to others." CreationDate="2011-03-09T07:15:20.707" UserId="230" />
  <row Id="16661" PostId="11193" Score="2" Text="@Nak, give us some figures and links!" CreationDate="2011-03-09T07:15:43.903" UserId="230" />
  <row Id="16662" PostId="11180" Text="I totally agree. The sandwich-container line-follower (it's a BEAM project in spirit) is an excellent beginning project, and I am very in favor of starting with analog components. I have no affiliation with this book or the author, I just think it's an excellent reference for beginners. [Robot Building for Beginners (Technology in Action) by David Coook](http://www.amazon.com/gp/product/1430227486/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&amp;pf_rd_s=lpo-top-stripe-1&amp;pf_rd_t=201&amp;pf_rd_i=1893115445&amp;pf_rd_m=ATVPDKIKX0DER&amp;pf_rd_r=112ZB3NSJMYHJT3HK6JW)" CreationDate="2011-03-09T08:04:46.093" UserId="1269" />
  <row Id="16663" PostId="11083" Text="ceramic - in parralel to electrolythic cap, just before FAN. That is just to filter high-frequency EM noise and lower heat dissipation of electrolythic cap(but on such low power it's neglible anyway), so it is optional." CreationDate="2011-03-09T08:48:29.247" UserId="2062" />
  <row Id="16664" PostId="11110" Text="low-range CPLD are indeed might be more useful than 1-2 complex/rare logic ICs, as availability &amp; price is very stable. " CreationDate="2011-03-09T08:56:36.677" UserId="2062" />
  <row Id="16665" PostId="11188" Text="&quot;You are supposed&quot;? Is it homework? " CreationDate="2011-03-09T09:32:27.580" UserId="1802" />
  <row Id="16666" PostId="11195" Text="what OS are you using?" CreationDate="2011-03-09T10:19:55.213" UserId="2060" />
  <row Id="16668" PostId="11195" Text="I'm using Window 7" CreationDate="2011-03-09T10:47:19.437" UserId="3130" />
  <row Id="16669" PostId="11195" Text="can you post the code from instrucables, some people do not have accounts and cannot access those files, it would help greatly " CreationDate="2011-03-09T11:04:33.317" UserId="2060" />
  <row Id="16670" PostId="11117" Text="So basically you are looking for a solution for sending component video signal over the air? If so then I suggest you update the title of the question to better reflect this." CreationDate="2011-03-09T11:12:56.550" UserId="1627" />
  <row Id="16672" PostId="11200" Text="You are right, I mixed up something! The code is java and is interpreted by Processing and not Arduino, updated the description." CreationDate="2011-03-09T12:22:28.117" UserId="3130" />
  <row Id="16673" PostId="11200" Text="kein ding, läuft ;)" CreationDate="2011-03-09T12:28:01.077" UserId="2995" />
  <row Id="16674" PostId="11200" Text="Ja, es funkt! ;)" CreationDate="2011-03-09T12:29:39.810" UserId="3130" />
  <row Id="16675" PostId="11117" Text="@trondd, Not just over the air; also over single cables, and for storage on an analog data recorder. I've asked before about transmitting YCbCr, with little success." CreationDate="2011-03-09T12:45:38.677" UserId="1225" />
  <row Id="16676" PostId="11205" Score="1" Text="+1 for honestly trying to help" CreationDate="2011-03-09T13:02:09.110" UserId="3311" />
  <row Id="16677" PostId="11193" Score="1" Text="95 cents qty 1 at digikey http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=LM386N-4-ND" CreationDate="2011-03-09T13:04:24.953" UserId="2157" />
  <row Id="16678" PostId="2458" Text="ajs410, I still don't get it with your example. You said that B- and A+ are the same potential because they are hooked up by a wire. If you think about it B+ and A- are hooked up by a wire which should make them the same potential but why do you have current flow in that case and not the case when B- is hooked to A+?&#xD;&#xA;&#xD;&#xA;I have always wondered about this issue but noone has been able to explain it to me. I guess I am slow. LOL." CreationDate="2011-01-10T07:07:11.457" UserId="2552" />
  <row Id="16679" PostId="112" Text="@Jason S, I disagree. They aren't the best, but they are good enough for me." CreationDate="2011-03-09T13:33:03.797" UserId="1225" />
  <row Id="16680" PostId="11190" Score="1" Text="I always thought paying a couple bucks for shipping was cheaper than my time and gas getting to where I was going, and paying for the inevitable latte on the way..." CreationDate="2011-03-09T13:40:34.073" UserId="1266" />
  <row Id="16681" PostId="112" Text="They may be good enough for you, but I've wasted more hours than I can count on my fingers trying to set up watch windows and breakpoints to debug something, only to have the debugger flake out on me somehow, and half the time my program works fine and the debugger leads me on a red herring. When they get it working well under Eclipse, then I'll use PICs. Otherwise I won't touch them. (and for the record, I'm even a MCHP shareholder! :-? )" CreationDate="2011-03-09T13:41:50.327" UserId="330" />
  <row Id="16682" PostId="168" Score="2" Text="We figured this out from the last comment you left. :)" CreationDate="2011-03-09T14:13:41.927" UserId="1293" />
  <row Id="16683" PostId="3579" Text="The point is to sort resistors by the first two bands (the first two digits). So each value in the same drawer differs only by the third band (that is the &quot;number of zeroes&quot; after first two digits) and it's easy to discriminate between values. " CreationDate="2011-03-09T14:38:52.087" UserId="244" />
  <row Id="16684" PostId="10744" Text="I use many of these Raaco for Lego Technic pieces... they're great. " CreationDate="2011-03-09T14:39:58.607" UserId="244" />
  <row Id="16685" PostId="11188" Text="@Ranieri - It certainly looks like homework to me, but it's not very well asked.  The Wikipedia link looks like it took about as much effort to answer as this user has put into solving the problem.  Voting to close as too localized." CreationDate="2011-03-09T14:45:41.953" UserId="857" />
  <row Id="16686" PostId="11188" Text="Touche, I did take the easy way out on that answer. I was hoping it would prod the asker into specifying his problem a bit more." CreationDate="2011-03-09T14:53:56.873" UserId="1802" />
  <row Id="16687" PostId="11206" Text="Is this to drive headphones?  speakers?  What is your power source?" CreationDate="2011-03-09T15:19:51.777" UserId="411" />
  <row Id="16688" PostId="11087" Text="That assortment doesn't look like it contains light duty springs, though.  And there aren't any spring constants so you don't even know what you're getting until you buy it." CreationDate="2011-03-09T15:23:41.567" UserId="2288" />
  <row Id="16689" PostId="11084" Text="I'm liking this more and more as I look for springs.  If the OP needs them in quantity, then there is no shortage of overseas suppliers on Alibaba." CreationDate="2011-03-09T15:27:06.197" UserId="2288" />
  <row Id="16690" PostId="11163" Text="Oversampling at 3x baud is better than 4x.  At N*baud rate, with N odd, the allowable margin is 1/2N.  If N is even, the allowable margin is 1/N." CreationDate="2011-03-09T15:41:15.877" UserId="3123" />
  <row Id="16691" PostId="11059" Text="An update on this - received a netduino plus a couple of days ago and have been playing with it.  I have to say the out of the box experience is amazing compared to the current state of play in Arduino.  Nothing fancy required - just visual studio (you can use the free 'express' version) and a usb cable and you're up and running with on-board debugging in a jiffy.  All the intellisense stuff works in the IDE, and I have to say - even though I've done a bunch of c/c++ work on other platforms, using .NET makes buildnig embedded code criminally easy ;-)" CreationDate="2011-03-09T15:53:27.583" UserId="3247" />
  <row Id="16692" PostId="11059" Text="Also - my project involves a bunch of network coding.  I can't begin to describe the amount of pain I've had getting my freetronics ethernet shield to work reliably with any of the mega boards I have.  The netduino plus has an onboard ethernet port, which out of the box supports DHCP, and works with .NET MF with no dramas whatsoever.  Lovely!  My XBee is also happily sending and receiving data via the .NET MF serial classes, which took all of 10mins to figure out and get running.  I think I'm in love ;-)" CreationDate="2011-03-09T15:59:19.657" UserId="3247" />
  <row Id="16693" PostId="11212" Text="But this is bit-banging, how will a converter do bitbaning. Is there a way to check if the bitbanging is working?" CreationDate="2011-03-09T16:11:26.493" UserId="1200" />
  <row Id="16694" PostId="11212" Text="You need some custom software at the PC end to use the RTS/DTS lines as general purpose IOs" CreationDate="2011-03-09T16:19:30.743" UserId="566" />
  <row Id="16695" PostId="11212" Text="I did an lsusb from ubuntu and I can confirm it is a PL2303 from inside. This is pin compatible with FT232R. So the connections inside have to be exactly like a normal connection. Can I achieve bitbanging through that? i.e without editing the circuit inside" CreationDate="2011-03-09T16:23:07.407" UserId="1200" />
  <row Id="16696" PostId="11207" Text="you meant &quot;half a minute&quot;, right? " CreationDate="2011-03-09T16:27:04.900" UserId="2288" />
  <row Id="16697" PostId="11206" Text="Just headphones (32 Ohm, up to some 100 mW), no speakers. Also I want to (optionally) be able to drive some 250 Ohm(also some 100-200 mW). Power source - LiIon+DCDC to get required voltages. " CreationDate="2011-03-09T17:11:52.180" UserId="2062" />
  <row Id="16698" PostId="1715" Score="1" Text="+1, excellent answer... thanks." CreationDate="2011-03-09T18:03:59.433" UserId="2426" />
  <row Id="16699" PostId="11219" Score="6" Text="&quot;Variable soldering iron intensities&quot; != temperature-controlled soldering iron.  What you'll get from this is an adjustable-wattage iron, not one with adjustable temperature.  You can buy variable-wattage irons at electronics stores, but they're not much better than the bargain barrel, uncontrolled models.  You need to just pony up for the temperature-controlled iron." CreationDate="2011-03-09T18:30:26.647" UserId="857" />
  <row Id="16700" PostId="11221" Score="1" Text="I was halfway through an identical answer." CreationDate="2011-03-09T18:33:41.793" UserId="857" />
  <row Id="16701" PostId="11087" Text="and this thread is not too localized?" CreationDate="2011-03-09T18:35:52.710" UserId="3077" />
  <row Id="16702" PostId="778" Text="Your image link is broken. Can you try to find new image and link to that?" CreationDate="2011-03-09T18:38:16.153" UserId="3064" />
  <row Id="16703" PostId="11217" Text="Well, while MP3 decoding would take about 30-70mW, I don't want to spend 300mW to get 100mW of output via opamp-based headphones driver. I do have 24-bit output of decoder, so while one can get decent 16-bit sound, this would require special handling of quantization errors. Power budget - the less the better, but not strictly limited :-)" CreationDate="2011-03-09T18:38:24.107" UserId="2062" />
  <row Id="16704" PostId="11222" Text="I see, ok, I officially ditch 250 Ohm support, only 32-50 Ohm range is left. I agree about 100mW, 200 were for some of the bigger &amp; high-Ohm ones." CreationDate="2011-03-09T18:40:48.210" UserId="2062" />
  <row Id="16705" PostId="11217" Text="Also, D-class chips I've seen does not require any analog circuit on output, so it can't be any simpler..." CreationDate="2011-03-09T18:44:42.557" UserId="2062" />
  <row Id="16706" PostId="11217" Text="In my experience, class D requires more careful layout and design than an op-amp.  Just like linear regulators are easier than switchers." CreationDate="2011-03-09T19:13:32.690" UserId="411" />
  <row Id="16707" PostId="11224" Text="@Richard - Dean said &quot;Then the part at the bottom is the same Row A 1-30 are connected and so on to F 1-30.&quot; I interpreted that to mean the busses run perpendicular to your drawing.  But, I don't own it, so I can't verify it.  Perhaps we should add something to the answer to help determine how to verify the layout of a breadboard?  " CreationDate="2011-03-09T19:16:54.603" UserId="857" />
  <row Id="16708" PostId="11225" Text="@Patrick Please, put your resume on your profile and indicate it in your question. Please, read the [FAQ](http://electronics.stackexchange.com/faq) for more information" CreationDate="2011-03-09T19:51:35.720" UserId="938" />
  <row Id="16709" PostId="11222" Text="keep in mind when looking at headphones or speakers that the rated power is the thermal limit of the driver's voice coil, i.e. how much continuous power it takes to melt the voicecoil.  Most of the time the driver reaches XMAX ( basically the drivers linear excursion range, i.e. its 'clean' excursion ) or XMECH (actual mechanical limits of cone excursion, 'bottoming out') well before it reaches its power handling limit.  This is especially true when the driver is playing low frequencies(high excursion). the power needed to reach XMAX/XMECH is also dependent on the enclosure design." CreationDate="2011-03-09T19:52:41.193" UserId="1438" />
  <row Id="16710" PostId="11217" Text="At low power levels most modern class D amps are of the &quot;filterless&quot; variety.  No external filtering is required and layout isn't critical for such devices.  Class D does require more attention to the power rail(s) as gain is directly tied to the rail level, any dip reduces amp gain and thus impacts frequency response.  You have to also be aware of bus pumping.  For such low power these issues are pretty easy to handle though.  Class D is more complicated to design for when your talking about 10's or 100's of watts." CreationDate="2011-03-09T20:00:12.793" UserId="1438" />
  <row Id="16711" PostId="8881" Text="I'm pretty sure the upper-left corner of the screen is 1;1 rather than 0;0, but omitted parameters or those specified as zero will be regarded as 1 before the A, B, C, D, or H commands." CreationDate="2011-03-09T20:06:43.573" UserId="3123" />
  <row Id="16712" PostId="11222" Score="1" Text="so unless your blasting a test tone in an SPL contest your limiter will usually be cone excursion.  The driver will mechanically tear itself apart before the voice coil melts.  This means that in most cases the power handling number should be a safety check in your design rather than treating it as a goal to reach for your amplifier design. " CreationDate="2011-03-09T20:09:02.810" UserId="1438" />
  <row Id="16713" PostId="961" Text="@Kortuk: If the error was known to be in a certain direction, one could arrange for a remote-end tolerance of e.g. 0-10% fast, but if one does that communications may fail if the remote end is 0.01% slow.  Many UART designs have nearly symmetrical error ranges, though some 4x-oversampled ones are asymmetric; I've never seen one that allowed to user to adjust the start-bit timing to favor a faster or slower remote, though." CreationDate="2011-03-09T20:27:57.673" UserId="3123" />
  <row Id="16714" PostId="11216" Text="Yes; but have a look a the tips of the waveform; they show microinstability (is that a word?) Maybe the circuit just isn't correct..." CreationDate="2011-03-09T20:32:04.117" UserId="1225" />
  <row Id="16715" PostId="11228" Text="+1 for mentioning MIDI" CreationDate="2011-03-09T20:50:59.203" UserId="857" />
  <row Id="16716" PostId="11219" Text="Damn. Well, good to know. So I can't adjust temperature through changing the wattage?" CreationDate="2011-03-09T21:25:16.130" UserId="3315" />
  <row Id="16717" PostId="11225" Text="Hah, I thought &quot;modelling resume&quot; would be something completely different ;)" CreationDate="2011-03-09T21:25:30.350" UserId="1802" />
  <row Id="16718" PostId="11222" Text="Yeah, I am not going to listen 32 Ohm ones at 100mW, I bet comfort level is way way less :-)" CreationDate="2011-03-09T21:28:08.670" UserId="2062" />
  <row Id="16719" PostId="11216" Score="1" Text="You're fretting over pretty minor things in a simulation. Is this circuit so complex and expensive you can't just build it and see if it works?" CreationDate="2011-03-09T21:31:31.077" UserId="249" />
  <row Id="16720" PostId="11226" Text="Are you sure you are talking about the same thing? A 'long' pulse in Manchester code would mean it's switching from 1's to 0's or vice-versa?" CreationDate="2011-03-09T21:32:10.757" UserId="1363" />
  <row Id="16721" PostId="11227" Text="Why is AVR out?  There is an established tool chain (including debugger) and some pretty powerful chips.  You might have to hook some components together to get more external memory, and EPROM, but that's part of the fun, no?" CreationDate="2011-03-09T21:49:24.297" UserId="1823" />
  <row Id="16722" PostId="11219" Text="Temperature is adjusted indirectly through wattage.  A temperature-controlled iron controls the output (temperature) directly and will adjust for the thermal mass of the iron and any cooling caused by using it (ie, transferring heat away from the iron to the solder). " CreationDate="2011-03-09T22:17:05.020" UserId="249" />
  <row Id="16723" PostId="11236" Text="Any more details you could provide, remember I'm a total newbie when it comes to building electronics, and I want to take this challenge as my first.  With the information you provided above, it's a great start, however I don't know what microcontroller I would need.  Also, how to develop a firmware?  Do you write the firmware in C and the upload it to the firmware, or do you have to write it in ASM?" CreationDate="2011-03-09T22:30:32.590" UserId="3249" />
  <row Id="16724" PostId="11236" Text="@Ryan, also could you provide a good website that sells electronics equipment at a very inexpensive rate for hobbyists?  Appreciate your support!" CreationDate="2011-03-09T22:31:31.747" UserId="3249" />
  <row Id="16725" PostId="11221" Text="Looks like I win! :)" CreationDate="2011-03-09T22:36:35.940" UserId="1293" />
  <row Id="16726" PostId="11236" Text="The two main hobbyist microcontrollers are the PIC, and the AVR. There are C compilers for both of these devices. A simple microcontroller will work for your project, as long as it has enough Input/Output pins to interface with your keypad and LCD. A good website for hobbyist electronics would be [SparkFun](http://www.sparkfun.com)" CreationDate="2011-03-09T22:39:19.763" UserId="2857" />
  <row Id="16727" PostId="11193" Score="2" Text="The input impedance is only 50k (or 10k if you leave that pot in).  A piezo needs to see a lot more than that, or all you'll hear is treble." CreationDate="2011-03-09T22:43:56.687" UserId="142" />
  <row Id="16728" PostId="11229" Text="What preamp did you build?" CreationDate="2011-03-09T22:52:30.063" UserId="142" />
  <row Id="16729" PostId="11230" Text="@Supercat - I was familiar with the multiply-accumulate, but modulo addressing and repeated fetch-free code execution were features I wasn't familiar with.  " CreationDate="2011-03-09T23:25:14.130" UserId="857" />
  <row Id="16730" PostId="11230" Text="@Supercat - You have a lot of great answers, and it's cool that you work on both old and new questions. I would go through and upvote all of your answers if it weren't for the [fraud detection](http://blog.stackoverflow.com/2008/12/vote-fraud-and-you/) algorithms and [daily rep cap](http://meta.stackoverflow.com/q/22447/146495).  Expect a few a day, though!  Keep up the awesome work!" CreationDate="2011-03-09T23:26:07.267" UserId="857" />
  <row Id="16731" PostId="11009" Text="@Supercat - Did you forget your footnote?" CreationDate="2011-03-09T23:28:47.390" UserId="857" />
  <row Id="16732" PostId="11241" Score="2" Text="Do you need floating point math, or can you make do with fixed point algorithms?  The former will be significantly more expensive and hard to find than the latter." CreationDate="2011-03-09T23:29:53.253" UserId="857" />
  <row Id="16733" PostId="11240" Text="I'm sure it makes a good physical connection, but how's the electrical connection?  I'll bet if you plug it into a scope and move it around, you'd see a lot of noise." CreationDate="2011-03-09T23:31:17.917" UserId="857" />
  <row Id="16734" PostId="11219" Score="1" Text="Well, just for the sake of curiosity, can anybody still answer the original question, which is how to wire a dimmer into an appliance?" CreationDate="2011-03-09T23:33:44.920" UserId="3315" />
  <row Id="16736" PostId="961" Text="@supercat, I think the MSP430 we used to use we could use &quot;modulation&quot; which gave high error on the first bit but improved over bits." CreationDate="2011-03-09T23:52:22.953" UserId="230" />
  <row Id="16737" PostId="11240" Text="I make the physical connection by forming the hooks, and then I solder to make the electrical connection." CreationDate="2011-03-10T00:08:08.430" UserId="2857" />
  <row Id="16738" PostId="11220" Text="By any chance are you trying to Decode UNI/O protocol? " CreationDate="2011-03-10T00:15:52.657" UserId="2060" />
  <row Id="16739" PostId="10927" Text="Looks like the best I can do is forum posts and experimenting to see. The accepted answer is good, but the overall lesson is, &quot;if you want detailed specifications find the data sheet *before* you buy something. Thanks for the efforts on my behalf." CreationDate="2011-03-10T01:16:28.223" UserId="3208" />
  <row Id="16740" PostId="11193" Text="Can the LM386 handle a 40kHz input signal?" CreationDate="2011-03-10T01:21:41.543" UserId="790" />
  <row Id="16741" PostId="9925" Text="@PICyourBrain, The main reason it was such a commonly used product, cheap and effective!" CreationDate="2011-03-10T01:24:28.870" UserId="230" />
  <row Id="16742" PostId="9926" Text="@RichardMarier, the system supports adding a link to text so that someone can click on what the link relates to and get more information rather than just knowing the links are related." CreationDate="2011-03-10T01:26:30.413" UserId="230" />
  <row Id="16743" PostId="11223" Text="@manju, the reason you see bluetooth so often because it is significantly more cost effective. If you need wifi that is understandable, but just letting you know your cost is going up." CreationDate="2011-03-10T01:27:37.340" UserId="230" />
  <row Id="16744" PostId="11246" Text="Oh, good point about testing the resistance. Thanks for the answer!" CreationDate="2011-03-10T01:33:52.750" UserId="3080" />
  <row Id="16745" PostId="11241" Score="1" Text="Please provide some more information about your project. Why do you need a board and not just a PC? Will the board measure anything or only simulate and drive the scope?" CreationDate="2011-03-10T01:47:06.653" UserId="659" />
  <row Id="16746" PostId="11220" Text="No protocol, just self-clocked serial data." CreationDate="2011-03-10T01:52:58.647" UserId="1363" />
  <row Id="16747" PostId="11242" Text="@LeonHeller, my friends doing computer vision and other heavily simulation based work often find that controlling a graphics card and using it can be 5 or more orders of magnitude faster then matlab. This can mean the difference between days and seconds." CreationDate="2011-03-10T02:12:49.940" UserId="230" />
  <row Id="16748" PostId="11238" Text="I have a parallel port programmer but the problem is there are only usb ports on newer computers" CreationDate="2011-03-10T02:32:13.247" UserId="1200" />
  <row Id="16749" PostId="11230" Text="@reemrevnivek: Glad you find my responses useful.  As I noted, the design for double-fetch multiply-accumulate is a feature I've not seen on non-DSP processors.  The ARM does a good job with operations requiring multiply-accumulate and modulo addressing (using an effective address of e.g. (R0 + (R1 &gt;&gt; 24)) for a 256-byte table) but a typical ARM would require four instructions to do what a DSP does in one cycle." CreationDate="2011-03-10T02:32:48.380" UserId="3123" />
  <row Id="16750" PostId="7687" Score="1" Text="@Leon Heller: The separate latch registers were a feature of later General Instruments PIC parts which unfortunately didn't get incorporated into Microchip's PIC parts until the 18F series; odd that GI noted the problem with read/write PORTx registers in the 1980's, but Microchip didn't deal with it for decades." CreationDate="2011-03-10T02:36:59.867" UserId="3123" />
  <row Id="16751" PostId="11220" Text="just as a reference, Microchips UNI/O does Manchester-encoding, the application notes will give some great info and sample c code, http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&amp;nodeId=1824&amp;appnote=en535411 I know you are not using a protocol but it will give you a good start on how to decode your signal" CreationDate="2011-03-10T03:03:25.867" UserId="2060" />
  <row Id="16752" PostId="11254" Score="4" Text="do you mean a tone generator? or a function generation? do you need a square wave, sine wave or saw tooth?" CreationDate="2011-03-10T03:09:33.663" UserId="2060" />
  <row Id="16753" PostId="10654" Text="I've noticed it too with an alkaline AA.  I tested the battery with a 50mA load and it was actually able to supply significant reverse current." CreationDate="2011-03-10T03:55:35.653" UserId="3123" />
  <row Id="16754" PostId="11258" Text="How old is &quot;old&quot;?  Do you know the date of production?" CreationDate="2011-03-10T02:38:50.397" />
  <row Id="16755" PostId="11258" Text="The pcb says 1995. July, I think." CreationDate="2011-03-10T02:42:49.730" UserId="2873" />
  <row Id="16756" PostId="11258" Score="1" Text="This belongs on [Electronics and Robotics](http://electronics.stackexchange.com/)." CreationDate="2011-03-10T02:44:50.920" />
  <row Id="16757" PostId="11258" Text="Ooh. Sorry. I guess i should have posted there." CreationDate="2011-03-10T02:46:11.960" UserId="2873" />
  <row Id="16758" PostId="11258" Text="@a sandwhich:  That's okay.  A mod should move it for you in a little bit." CreationDate="2011-03-10T02:47:05.350" />
  <row Id="16759" PostId="11258" Text="You can click the flag link and ask a moderator to move the question for you." CreationDate="2011-03-10T04:16:49.273" UserId="1229" />
  <row Id="16760" PostId="11259" Score="1" Text="Batteries haven't been in it since 2001, and there were not any corrosion traces. I just ate some popcorn, but I washed my hands first, so I think I should be ok. What type of heavy metals might be in there?" CreationDate="2011-03-10T02:54:32.837" UserId="2873" />
  <row Id="16761" PostId="11259" Text="Printed circuit boards can contain traces of Cd, Co, Cr, Cu, Ni, Pb, and Zn as noted in research on the human impacts of e-waste recycling operations." CreationDate="2011-03-10T03:07:13.997" UserId="3321" />
  <row Id="16762" PostId="11259" Score="2" Text="Some very old batteries contained mercury.  The EPA has clean-up procedures documented for mercury.  Although I couldn't find anything directly for remote control units or batteries, this document may be of interest to you if you ever run into anything like this again and you just want to take precautions for additional safety:  http://www.epa.gov/cfl/cflcleanup.html" CreationDate="2011-03-10T03:15:22.337" />
  <row Id="16763" PostId="11260" Text="I am on ubuntu so I do not require a driver for the chip. I was just hoping that I could make these drivers work with libftdi as both are pin compatible. Maybe I will get it to work someday." CreationDate="2011-03-10T04:53:16.747" UserId="1200" />
  <row Id="16766" PostId="11241" Text="I know that it could be done much more easily on a PC (and I have done something similar on the PC), but I want to build a standalone device for the purpose(to create something similar to an analog computer, but implemented digitally). I do need floating point functionality.It wouldn't have to measure any inputs from sensors, the only inputs I need are just to toggle between types of and changing several parameters(so several push buttons and one or two potentiometers." CreationDate="2011-03-10T05:46:35.747" UserId="3319" />
  <row Id="16767" PostId="11262" Text="lol. What is that?  I think I've seen it before, though I'm not sure.  Very curious to see if I can get my hand on one of those.  Do you have a name or a link to one of those?" CreationDate="2011-03-10T05:52:16.217" UserId="3249" />
  <row Id="16768" PostId="11262" Score="2" Text="http://en.wikipedia.org/wiki/Slide_rule" CreationDate="2011-03-10T06:03:59.430" UserId="1950" />
  <row Id="16769" PostId="11262" Text="this inspired my question: http://electronics.stackexchange.com/questions/11263" CreationDate="2011-03-10T06:28:13.623" UserId="411" />
  <row Id="16770" PostId="11264" Text="Alternatively, add a little bit of positive feedback to the comparators" CreationDate="2011-03-10T06:29:03.870" UserId="1374" />
  <row Id="16771" PostId="11262" Text="@KerxPhilo - Hahahahahahahahahahah...... oh how times change." CreationDate="2011-03-10T06:30:11.653" UserId="1374" />
  <row Id="16772" PostId="11264" Text="Agreed - some additional hysteresis in the comparators would improve the original circuit. I still maintain that the SR latch is a &quot;stable&quot; solution." CreationDate="2011-03-10T06:33:23.650" UserId="638" />
  <row Id="16773" PostId="11238" Text="@Rick_2407 with your parallel programmer, a borrowed computer and a blank AVR, you could burn the firmware (http://arduino.cc/playground/Code/MegaISP) for a serial-port programmer onto an AVR.  You can then use that AVR and a USB-serial dongle to program other AVRs." CreationDate="2011-03-10T06:49:19.770" UserId="389" />
  <row Id="16774" PostId="11248" Text="I second the idea of using a borrowed programmer (or a borrowed computer that works with the programmer you have) to make a USBasp or other avr-based programmer.  Here's the one I built, complete kit was only €20 - http://shop.tuxgraphics.org/electronic/detail_avrusb500.html.  Heck you can get a USBasp for $13 on ebay now." CreationDate="2011-03-10T07:06:18.897" UserId="389" />
  <row Id="16775" PostId="11264" Text="It would definitely be stable. However, it is not very efficient in terms of parts. " CreationDate="2011-03-10T07:06:36.723" UserId="1374" />
  <row Id="16776" PostId="11265" Score="1" Text="the last one is no longer a triangle wave, because the &quot;current source&quot; has such a low output impedance." CreationDate="2011-03-10T07:07:04.510" UserId="411" />
  <row Id="16777" PostId="11257" Text="Looks like something I saw at the UFO exhibit in Minneapolis circa 1979 or thereabouts, but I remember that as being somewhere around 4096 miniature light bulbs.  Does anyone else remember seeing something like that?" CreationDate="2011-03-10T07:35:38.757" UserId="3123" />
  <row Id="16779" PostId="11219" Text="To amplify AngryEE's point, a variable-wattage control might be useful if you could turn it up by just the right amount as you were soldering a component, and down by just the right amount when you were done, but in practice managing to perform the proper adjustments at the proper times would be rather difficult; it's much more effective to simply use a temperature-controlled iron which will adjust the power automatically." CreationDate="2011-03-10T07:38:28.380" UserId="3123" />
  <row Id="16780" PostId="11214" Text="Usually the difficulty with oscillator simulations is getting them started. Typically simulations don't have any noise, so there's nothing that can be amplified and filtered. Also, startup may take hundreds to thousands of cycles to simulate. This is just an unstable oscillator." CreationDate="2011-03-10T07:42:22.743" UserId="638" />
  <row Id="16781" PostId="11216" Text="@AngryEE, well, it's nice to have a pure wave. Look at the op-amp output during those periods, it's oscillating rapidly." CreationDate="2011-03-10T07:43:41.827" UserId="1225" />
  <row Id="16782" PostId="11264" Text="Of course, you could always just use a 555... I was just answering towards the question. The window function is a bit pricey, although the current sink/source would be easy on an IC without opamps." CreationDate="2011-03-10T07:50:57.323" UserId="638" />
  <row Id="16783" PostId="11241" Text="@reemrevnivek I was hoping to use the RK method to solve the ODEs and I don't know of any algorithms for integration that only uses integers that can be run in realtime.  " CreationDate="2011-03-10T08:03:56.720" UserId="3319" />
  <row Id="16785" PostId="11262" Text="@markrages, kudos to your question, very interesting :)" CreationDate="2011-03-10T09:32:06.543" UserId="3249" />
  <row Id="16786" PostId="11263" Text="@mark, just searching around I found that futurlec.com is selling the lm394 at a very affordable rate, check http://www.futurlec.com/cgi-bin/search/search.cgi?search=lm394. scratch that, i just realized you said &quot;obsolete&quot;, darn I need sleep." CreationDate="2011-03-10T09:37:11.420" UserId="3249" />
  <row Id="16787" PostId="11219" Text="@Supercat, but you can adjust your iron to what you need with a dimmer and a soldering iron if that is all you have and cannot afford a nice iron?" CreationDate="2011-03-10T09:52:56.217" UserId="230" />
  <row Id="16788" PostId="11253" Text="The OP does not say where in the world they are.  The output current capability for any mains power outlet will be dependant upon local specifications.  In the UK the max is 240V(nominal) 13A.  The European plug is rated at 16A, Australian/ZZ at 10A and the North American at 15A.  What standard gives 20A?" CreationDate="2011-03-10T10:08:42.223" UserId="400" />
  <row Id="16789" PostId="10695" Text="@Sauron: I think &quot;Robots/Electronics group&quot; has moved away from Assembly for better long time ago. Assembly is not more reliable, unless you can write perfect code. And that's pretty hard task." CreationDate="2011-03-10T10:26:47.520" UserId="3064" />
  <row Id="16792" PostId="11253" Text="@Ian, I will edit to 15, I must have mixed it up. Honestly, I thought they often wired houses to go in excess of 20 here but are required 15A. I do forget, and I have only been told, never verified." CreationDate="2011-03-10T10:45:27.597" UserId="230" />
  <row Id="16793" PostId="9050" Text="@the6e, This is an off topic question. I am closing it." CreationDate="2011-03-10T10:47:23.117" UserId="230" />
  <row Id="16794" PostId="11254" Score="1" Text="They are usually called [oscillator circuits](http://en.wikipedia.org/wiki/Electronic_oscillator), so try searching for that term." CreationDate="2011-03-10T10:50:16.007" UserId="2110" />
  <row Id="16795" PostId="11227" Text="I havnt found any AVR part that have address lines nor datalines so I was under the assumption that it only had onchip memory (?)" CreationDate="2011-03-10T11:02:39.157" UserId="3318" />
  <row Id="16796" PostId="11232" Text="Planing to build the board myself as a learning project, but thanks for the tips, maybe for some other project !" CreationDate="2011-03-10T11:03:15.397" UserId="3318" />
  <row Id="16797" PostId="11270" Score="3" Text="Everything you need can be found [here](http://www.arduino.cc/en/Tutorial/X10). Have you a real problem about it? You should only ask practical, answerable questions based on actual problems that you face. Please, read [FAQ](http://electronics.stackexchange.com/faq)" CreationDate="2011-03-10T11:19:34.407" UserId="938" />
  <row Id="16799" PostId="11227" Text="External memory interface is not very common in low-end MCUs. If you really want want, maybe have a look at the higher-end STM32 or LM3S, or LPC24xx. You can also always bitbang using GPIOs, especially if you don't need high speeds." CreationDate="2011-03-10T11:27:19.250" UserId="1082" />
  <row Id="16800" PostId="11009" Text="@supercat, this goes back to what I was trying to explain in as laymen terms as possible, it is technically possible to pull off, but in all reality the complexity is so much higher with no payoff that no one would do it." CreationDate="2011-03-10T12:50:44.863" UserId="230" />
  <row Id="16801" PostId="2763" Text="No, he's cheating by using a an arduino mega. :)  The mega has many more IO pins than a normal arduino." CreationDate="2011-03-10T12:56:32.800" UserId="389" />
  <row Id="16802" PostId="11274" Score="5" Text="@ImranNaqvi, This site is really good for getting technical advice. This is not a great place to come to get someone to do a complete project for you. Try starting on your own and come back if you have issues." CreationDate="2011-03-10T13:14:30.677" UserId="230" />
  <row Id="16803" PostId="11273" Text="Wow.  In the age of System-on-Chip, you want him to wire up twenty gates per digit [just to add](http://en.wikipedia.org/wiki/Adder_(electronics)#Full_adder)?  Even the [first handheld calculator](http://www.vintagecalculators.com/html/ti_cal-tech.html) didn't do that.  Single chip calculators have been around for thirty years." CreationDate="2011-03-10T13:40:59.633" UserId="1824" />
  <row Id="16804" PostId="11227" Text="Thats a shame, I've looked a bit on Zilogs classic range, but I do not know how the development environment situation looks like, otherwise the z80182 looks like a contender ...." CreationDate="2011-03-10T14:33:16.040" UserId="3318" />
  <row Id="16805" PostId="11274" Text="So, really you just want to connect the devices directly to the battery, and then have an intelligent charger on the battery?" CreationDate="2011-03-10T14:34:43.690" UserId="1678" />
  <row Id="16806" PostId="11277" Score="1" Text="MAT12 is still in production, but octopart.com shows 13 pieces available worldwide, for $22 each.  So no cheaper than the LOG101." CreationDate="2011-03-10T15:23:22.853" UserId="411" />
  <row Id="16807" PostId="11280" Text="BTW, I tried putting too many volts into a HDD using a modified ATX PSU. They will run up to around 14V - but past that point, the disk goes too fast and the drive keeps resetting. About 18V was when some magic smoke was released... (It was an old 5 GB ATA drive. I didn't verify functionality because I didn't want to blow up a motherboard.)" CreationDate="2011-03-10T15:38:57.067" UserId="1225" />
  <row Id="16808" PostId="11275" Text="There is no such LPCXpresso board! The only processors are LPC1114, LPC1343 and LPC1769." CreationDate="2011-03-10T16:00:22.523" UserId="305" />
  <row Id="16809" PostId="11219" Score="2" Text="@Kortuk: In theory, yes, if you knew exactly how much to adjust the iron.  In practice, not really.  The problem is that the temperature of the iron is very greatly dependent upon the rate it which it is losing heat, and that in turn will depend upon many other factors having to do with the item being soldered.  Actually, there's another problem not yet mentioned: thermal mass." CreationDate="2011-03-10T16:06:22.050" UserId="3123" />
  <row Id="16810" PostId="11219" Text="@Kortuk: Irons without temperature controls are usually built with a rather large thermal mass, to minimize the amount by which their temperature will go up and down in normal use.  One can try to regulate the temperature of this thermal mass, but during use the tip will be cooler than the mass.  By contrast, temperature-controlled irons have much lower thermal mass and can warm up and cool down much more quickly (10 seconds versus 10 minutes).  There's just no comparison between working with a good iron versus a $5 thing." CreationDate="2011-03-10T16:12:40.777" UserId="3123" />
  <row Id="16811" PostId="11275" Text="Well, LPC3154 is on each of these, on the host part. :-) That's what I want to reprogram. I have 2 LPCxpresso boards, and It would be so nice to reuse such a juicy 192kb SRAM chip..." CreationDate="2011-03-10T16:17:40.317" UserId="2062" />
  <row Id="16812" PostId="11284" Text="falstad links don't work for me.  I just get the default circuit.  please post a screenshot." CreationDate="2011-03-10T16:32:57.787" UserId="411" />
  <row Id="16813" PostId="11285" Text="That's an interesting forum thread, especially the story about MAT12." CreationDate="2011-03-10T16:35:39.623" UserId="411" />
  <row Id="16814" PostId="11288" Score="1" Text="@Brian Carlton: Can you please explain how that saves power? Also, is it not possible to get a clean output form a switching regulator? Isn't that what the additional components are for at the output?" CreationDate="2011-03-10T16:38:31.477" UserId="1235" />
  <row Id="16815" PostId="11288" Text="6V outputs are much harder to find. I don't want to add $5 to my board cost..." CreationDate="2011-03-10T16:42:52.363" UserId="1235" />
  <row Id="16816" PostId="11275" Text="I'd ask the question on the LPCXpresso forum." CreationDate="2011-03-10T16:43:39.680" UserId="305" />
  <row Id="16817" PostId="11242" Text="The simulation that Alexdagre8 wants to do is much less demanding than that, MATLAB and Scilab on a PC should be quite adequate." CreationDate="2011-03-10T16:47:27.007" UserId="305" />
  <row Id="16818" PostId="11275" Text="I will, but officials would not be happy about that question - price of 3154 is comparable to price of this devboard :-)" CreationDate="2011-03-10T16:55:11.097" UserId="2062" />
  <row Id="16819" PostId="11274" Text="@Imran Naqvi: you might consider accepting some of the answers to the questions you have asked..." CreationDate="2011-03-10T17:09:59.090" UserId="1337" />
  <row Id="16820" PostId="11234" Score="2" Text="The [uWatch](http://opencircuits.com/UWatch) (aka calcwatch) is a scientific calculator. All the firmware is open-source, and you can see the [complete calculator schematic online](http://www.calcwatch.com/construction.htm). Total overkill for your goals, but perhaps it will give you a few ideas." CreationDate="2011-03-10T17:16:17.447" UserId="813" />
  <row Id="16821" PostId="11273" Text="Well, you could use a 74181 for a 4-bit slice. That would be easier, if nothing else." CreationDate="2011-03-10T17:23:00.340" UserId="638" />
  <row Id="16822" PostId="11288" Score="1" Text="@Brian - How will converting to 6V and then using linear regulator below that save power?  That's only the case if your switcher is less than 80% efficient, which is probably not the case." CreationDate="2011-03-10T17:34:58.973" UserId="857" />
  <row Id="16823" PostId="11284" Text="@markrages, see screenshot. The circuit is also under Circuits &gt; Op-Amps &gt; Amplifiers &gt; Log Amplifier." CreationDate="2011-03-10T17:37:48.643" UserId="1225" />
  <row Id="16824" PostId="11236" Text="@KerxPhilo: Yes, the majority of embedded system people write the firmware in C. Ladyada has good [tutorials on how to write firmware in C and upload it to a microcontroller](http://www.ladyada.net/learn/arduino/lesson3.html) as well as [tutorials on connecting a LCD and displaying stuff on it](http://www.ladyada.net/learn/lcd/index.html)." CreationDate="2011-03-10T17:48:29.430" UserId="813" />
  <row Id="16825" PostId="11193" Text="@wallacoloo: Bandwidth (BW) VS = 6V, Pins 1 and 8 Open 300 kHz&#xA;http://www.biltek.tubitak.gov.tr/gelisim/elektronik/dosyalar/6/LM386.pdf" CreationDate="2011-03-10T17:58:36.973" UserId="3304" />
  <row Id="16826" PostId="11293" Score="4" Text="possible duplicate of [What's the difference between a microcontroller and a microprocessor?](http://electronics.stackexchange.com/questions/1092/whats-the-difference-between-a-microcontroller-and-a-microprocessor)" CreationDate="2011-03-10T18:33:04.197" UserId="319" />
  <row Id="16827" PostId="11294" Text="Oh ok that makes more sense, but the ASM for each one is basically the same?" CreationDate="2011-03-10T18:39:08.907" UserId="3073" />
  <row Id="16828" PostId="11293" Score="1" Text="@Kellenjb: It would be if it wasn't asking about the programming differences. I think this is different enough not to close." CreationDate="2011-03-10T18:49:42.250" UserId="2426" />
  <row Id="16829" PostId="11295" Text="Well what I meant was yea ASM will be different for each one.....but are the commands/etc generally the same (or done the same way) between a MC and a MP...I mean a MC has an MP so i would assume so.. (minus the memory)" CreationDate="2011-03-10T18:53:31.717" UserId="3073" />
  <row Id="16830" PostId="11295" Text="@Sauron: No, not really.. while some commands may be similar between devices, like add, mov, sub, etc, they are probably implemented differently, and will not port between devices." CreationDate="2011-03-10T18:57:11.993" UserId="2426" />
  <row Id="16831" PostId="11295" Text="Excellent reply, and one that probably could have helped me when I was starting my microprocessors class." CreationDate="2011-03-10T19:19:32.737" UserId="536" />
  <row Id="16832" PostId="11249" Text="I plan on giving it to my school as a present so I want to keep the budget to a minimum, so are there cheaper dev boards than a beagleboard(suitable for this purpose)? If not would an old 1G iPod touch work." CreationDate="2011-03-10T19:22:20.130" UserId="3319" />
  <row Id="16833" PostId="11295" Text="@BG100 , well what I meant was......Like since a Microcontroller has a CPU inside of it...the Assembly instructions are more aimed at the actual CPU rather than the components around it. " CreationDate="2011-03-10T19:42:25.340" UserId="3073" />
  <row Id="16834" PostId="11295" Text="@Sauron: Yes, that's correct." CreationDate="2011-03-10T20:03:36.807" UserId="2426" />
  <row Id="16835" PostId="11247" Text="Excellent.  Thanks!" CreationDate="2011-03-10T20:10:34.630" UserId="1264" />
  <row Id="16836" PostId="11227" Text="A lot of the AVR's have hardware support for SPI which can be used to access external memory (not as fast as other methods, obviously)." CreationDate="2011-03-10T20:43:35.567" UserId="1823" />
  <row Id="16837" PostId="11046" Text="Duplicate: http://electronics.stackexchange.com/questions/1609/how-many-individual-lights-can-an-arduino-control" CreationDate="2011-03-10T21:01:43.960" UserId="588" />
  <row Id="16838" PostId="11298" Text="A relay may indeed do it I guess. But as you pointed out, the switching speed is an issue. This would be a serious bottleneck in my design, so I will only consider it if I have really no other choice..." CreationDate="2011-03-10T21:01:47.937" UserId="2740" />
  <row Id="16839" PostId="11273" Text="Yes, this could be done with one or two chips (using a microprocessor like [this example](http://www.instructables.com/id/LED-Binary-Calculator/)), if he wants to create the calculator in software.  Perhaps building the whole calculator using discrete components would take too much time, but if he wants to get into hardware, a binary calculator might be a good starting point." CreationDate="2011-03-10T22:28:00.193" UserId="3323" />
  <row Id="16843" PostId="10397" Text="So, what did you end up doing?" CreationDate="2011-03-10T22:49:54.080" UserId="1802" />
  <row Id="16845" PostId="11302" Text="What is a Nexsys2 board?" CreationDate="2011-03-10T23:04:01.370" UserId="305" />
  <row Id="16847" PostId="11302" Text="Betting it should have been Nexys2?" CreationDate="2011-03-10T23:08:31.470" UserId="319" />
  <row Id="16848" PostId="11302" Text="http://www.digilentinc.com/Products/Detail.cfm?Prod=NEXYS2" CreationDate="2011-03-10T23:15:29.190" UserId="305" />
  <row Id="16850" PostId="11302" Text="What error do you get?" CreationDate="2011-03-10T23:26:01.307" UserId="1407" />
  <row Id="16851" PostId="11046" Text="@mjh: I wanted to post a question worded in this way because at one time I would have found it immensely helpful. The question you reference is specific to an Arduino though certainly the principle is identical." CreationDate="2011-03-10T23:30:17.293" UserId="2028" />
  <row Id="16852" PostId="11271" Text="I marked this one as correct, but I'll probably never buy these. I like the cheap tubing solution and the free Wester Union. " CreationDate="2011-03-11T00:15:53.603" UserId="1742" />
  <row Id="16853" PostId="11253" Text="I think new/renovated homes in the US (or MI at least) require 20 A circuits to outlets (or it may be that they require 12 AWG, which is rated for 20 A anyways)" CreationDate="2011-03-11T03:20:56.960" UserId="1407" />
  <row Id="16854" PostId="11189" Text="Thank you Kortuk, you did help spur me to do a little research on linear vs. switching regulators, that is why I chose you. Also, you made me consider whether I wanted a squealing or heat. My parts should arive in a day or two, and once I put it together, I'll post my findings. Thanks again! " CreationDate="2011-03-11T04:18:31.263" UserId="3301" />
  <row Id="16855" PostId="11309" Text="What microcontroler are you talking about?" CreationDate="2011-03-11T04:34:34.213" UserId="938" />
  <row Id="16856" PostId="10944" Text="In response to comments on the closed question: Your question is bad because it doesn't provide any specifics. What you need to do is to ask a teacher or another student what exactly those 5.2 W are. You are also confusing efficiency and power dissipation. Let's say we have a 5 W device which is 80% efficient. That means that it spends 4 W doing what it's supposed to do and 1 W on all other things, including emitting heat. On the other hand if you have a device which dissipates 5 W as heat, that (probably) means that it converts X watts at Y% efficiency and that 5 W are wasted as heat." CreationDate="2011-03-11T04:56:20.590" UserId="1240" />
  <row Id="16857" PostId="10944" Text="Next problem is to determine how theoretical solution you want. We can't help you there either because we don't know what type of solution you need, so you need to figure out that part yourself. A real component usually has its junction which generates heat and has thermal resistances to different parts of the case. Your component may have thermal resistance (or conductance) or it may be considered perfect component with zero resistance. That is important because it directly impacts temperature. " CreationDate="2011-03-11T05:01:18.387" UserId="1240" />
  <row Id="16858" PostId="10944" Text="So basically you have resistance between junction and case and resistance between case and air. If component has cooler, then you'd have resistance between junction and case and between case and thermal compound and between thermal compound and cooler and between cooler and air. We can't tell if those thing will make an impact on your assignment or not, so we can't help you there. " CreationDate="2011-03-11T05:05:58.180" UserId="1240" />
  <row Id="16859" PostId="10944" Text="To cut the long story short, your question assumes that we know how you do such problems in your school. We don't, so you could provide us with similar solved problem or more information so that we could determine what you are expected to do. Then we may give you ideas on how to do it. In question such as this one, hard part is often in understanding what is being asked and finding the list of things which can be disregarded." CreationDate="2011-03-11T05:08:16.620" UserId="1240" />
  <row Id="16860" PostId="11309" Text="@Daniel An Atmel Atmega 328P" CreationDate="2011-03-11T05:23:31.177" UserId="1729" />
  <row Id="16862" PostId="11284" Text="@markrages Why don't they work for you?  What browser/platform?" CreationDate="2011-03-11T05:57:19.417" UserId="142" />
  <row Id="16863" PostId="11284" Text="Chromium on Ubuntu 10.04.  Nothing fancy, just the supplied browser and Java.  The simulator works fine, it's just the hyperlinking that's broken." CreationDate="2011-03-11T06:22:09.003" UserId="411" />
  <row Id="16864" PostId="11274" Text="@Kortuk, Thanks for your response, i am new to electronics but i don't want that someone should do it for me, it can't be. I just want some directions." CreationDate="2011-03-11T06:37:20.800" UserId="2037" />
  <row Id="16865" PostId="11274" Text="@Brian Knoblauch, yes you are right." CreationDate="2011-03-11T06:37:48.163" UserId="2037" />
  <row Id="16866" PostId="11274" Text="@Richard, ofcourse i will if i get one." CreationDate="2011-03-11T06:38:19.783" UserId="2037" />
  <row Id="16867" PostId="11280" Text="@dren.dk Thanks your answer have been most helpful for me." CreationDate="2011-03-11T06:46:33.023" UserId="2037" />
  <row Id="16868" PostId="11284" Text="@markrages, Firefox on Ubuntu 10.04 seems to work." CreationDate="2011-03-11T07:47:11.450" UserId="1225" />
  <row Id="16869" PostId="11189" Text="@DyalnVester, My switching regulators have never ever made a sound. I have never designed past 5A though. At my work our 1kA rectifier does make a nice little sound, but it is actually generating an audible range output frequency, our higher power supplies do not generate a sound." CreationDate="2011-03-11T09:03:58.217" UserId="230" />
  <row Id="16870" PostId="11253" Text="@NickT, thank you for letting me feel a little more sane, I have been told 20A by more than one person and over years. I tried to easily find a simple document to link to for standards, that was not a simple task." CreationDate="2011-03-11T09:04:53.083" UserId="230" />
  <row Id="16872" PostId="11291" Text="@Seth this was already posted as a comment by Daniel up above." CreationDate="2011-03-11T09:10:02.827" UserId="230" />
  <row Id="16874" PostId="11314" Text="That was my impression if I tried to use the micro directly, seems unnecessarily dangerous. Is there some equivalent to the isolator I can throw together from standard parts? " CreationDate="2011-03-11T09:29:47.147" UserId="1729" />
  <row Id="16875" PostId="11219" Score="1" Text="@supercat, this sounds like answer material. Write an answer! If you also know how to wire it, why not let them know so they can learn themselves. It seems like someone could use a dimmer to reduce heating while they are not using it and turn it back up to full when they are about to use it again." CreationDate="2011-03-11T09:34:54.820" UserId="230" />
  <row Id="16876" PostId="11314" Text="Isolation requires an opto transistor/led pair or a transformer (not autotransformer). It's possible to make an optocoupler from an opto transistor (usually IR sensitive) and an IR LED, but hardly worthwhile. It's also possible to wind your own transformers." CreationDate="2011-03-11T09:39:35.120" UserId="2110" />
  <row Id="16877" PostId="11284" Score="1" Text="@ThomasO, as previously noted, does falstad simulator use real components, because, like most things, they can very easy to build accurately if you get a 100% match to spec on every component." CreationDate="2011-03-11T09:40:36.967" UserId="230" />
  <row Id="16878" PostId="11310" Text="I have, but I failed to find a reasonable development environment for the Z80182 MCU that I was thinking of using. Programing Eproms and debugging with led:s are not an option nowdays, to little time left after all daily chores." CreationDate="2011-03-11T09:54:06.170" UserId="3318" />
  <row Id="16879" PostId="11253" Text="I do not believe that you 2nd point about communication protocols is true. I disassembled a Macbook charger once and while I did find funky stuff inside (like a CoolMOS! never seen them in practice before) there was nothing suggesting any serious logic on the output end (and the cable has only 2 wires)." CreationDate="2011-03-11T10:53:29.167" UserId="659" />
  <row Id="16880" PostId="11253" Text="@JPC, both my Lenovo brand and my Dell brand laptops have, my dell is not 7 years old and was able to tell what wattage charger I attached. My friends HP could detect it. I am not saying that you should go connecting random chargers, but if the voltage matches and the current limit is higher you should be fine. communication over power lines has become more and more common." CreationDate="2011-03-11T10:55:20.133" UserId="230" />
  <row Id="16881" PostId="11306" Text="I'm sure there are a lot more though. I had hoped someone had already done the research put a list of valid pragmas together." CreationDate="2011-03-11T10:59:56.557" UserId="3145" />
  <row Id="16882" PostId="11288" Text="As far as sensitive analog parts are concerned you may still not get clean output because of RF coupling of the noise." CreationDate="2011-03-11T11:00:28.770" UserId="659" />
  <row Id="16883" PostId="11301" Text="But beware of gate capacitance (especially during switching) and package inductance (it's 1GHz after all)." CreationDate="2011-03-11T11:05:02.933" UserId="659" />
  <row Id="16884" PostId="11298" Text="Reed switches (http://en.wikipedia.org/wiki/Reed_switch) may be especially useful." CreationDate="2011-03-11T11:12:37.637" UserId="659" />
  <row Id="16885" PostId="11321" Text="So the solution is to toggle the pullup on D+?" CreationDate="2011-03-11T11:50:20.997" UserId="230" />
  <row Id="16886" PostId="11302" Score="2" Text="Load the self test program, it lets you switch all LEDs on and off via the corresponding slide switches. If you can switch on the LEDs that way, then nothing is wrong with your board." CreationDate="2011-03-11T11:59:01.083" UserId="2340" />
  <row Id="16887" PostId="11304" Score="1" Text="This isn't true. The UCF at first glance appears to say this, but it doesn't: for s3e500 led4 is connected to E17, otherwise E16. This is true for led4-led7. You need to comment out definition line that doesn't match the chip you have on the board." CreationDate="2011-03-11T12:05:07.943" UserId="2340" />
  <row Id="16888" PostId="11318" Text="Pb is not a notation I am used to, it may be very common and I have not seen it, I am much more used to Lead acid, but Pb is shorter, which people seem to prefer the shortest name." CreationDate="2011-03-11T12:07:21.123" UserId="230" />
  <row Id="16889" PostId="11327" Text="Axially (I updated the question to reflect that). I thought about something like a large ball bearing but I was having trouble finding the right sizes and cost was getting up there for those as well. I don't have direct access to a lathe, but I might be able to work something out (my wife went to the local engineering college)... still open for other ideas but I'll look into that a bit." CreationDate="2011-03-11T12:23:08.693" UserId="3339" />
  <row Id="16890" PostId="11318" Score="1" Text="Just to clarify this, pb is the symbol for lead in the list of chemical elements. its not a preferred short name, its actually a defined symbol and not something people use because of preference." CreationDate="2011-03-11T13:07:14.067" UserId="2995" />
  <row Id="16891" PostId="11321" Text="Thanks for the tip, I will try it and report back." CreationDate="2011-03-11T13:10:18.530" UserId="1802" />
  <row Id="16892" PostId="11315" Text="@mad_z, glad to see you asking questions again!" CreationDate="2011-03-11T13:12:50.677" UserId="230" />
  <row Id="16893" PostId="11318" Text="@Shitake83, Yes, Pb is the chemical symbol, I asked because I am not used to seeing Pb battery. It threw me for just a second." CreationDate="2011-03-11T13:55:28.753" UserId="230" />
  <row Id="16894" PostId="11207" Text="Nope.  Half a second.  When you get into industrial sizes and drives, steppers get hot.  There is no way you're going to leave your hand on 120F for half a minute." CreationDate="2011-03-11T14:15:02.933" UserId="1824" />
  <row Id="16895" PostId="11333" Score="2" Text="http://electronics.stackexchange.com/questions/9824/what-makes-a-particular-platform-suitable-or-unsuitable-for-production-use" CreationDate="2011-03-11T14:58:29.447" UserId="566" />
  <row Id="16897" PostId="11318" Text="no prob. :) if you own a car, i think youve been using your Pb &quot;battery&quot; kinda frequently. eventhough its not the battery it are the electrodes/cathodes which are out of Pb. " CreationDate="2011-03-11T15:05:22.797" UserId="2995" />
  <row Id="16898" PostId="11304" Text="I was going off the schematic, it should have a note against those connections about the PCB being suitable for two versions of the FPGA." CreationDate="2011-03-11T15:09:55.537" UserId="305" />
  <row Id="16899" PostId="11117" Text="I started a bounty." CreationDate="2011-03-11T15:48:08.157" UserId="1225" />
  <row Id="16900" PostId="11335" Text="Why would have an optoisolated solid state relay a higher bandwidth than a standard analog switch? Besides, it would certainly have a lower switching speed." CreationDate="2011-03-11T16:05:14.100" UserId="2740" />
  <row Id="16901" PostId="11335" Text="@Olvier - Two reasons: a) usually higher voltage range, b) switching speed is still fairly fast (though not as fast as a discrete FET), c) doesn't require the input to referenced to the control signal (driving a FET could be difficult with a varying signal on the output.)" CreationDate="2011-03-11T16:14:48.543" UserId="1225" />
  <row Id="16902" PostId="11336" Text="I've considered them too, but I suspect they will be limited to conventional SD video bandwidth and wouldn't cope with 720p or even (as a future upgrade) 1080p..." CreationDate="2011-03-11T16:15:42.257" UserId="1225" />
  <row Id="16903" PostId="11286" Text="Thanks so much!" CreationDate="2011-03-11T16:23:31.970" UserId="3322" />
  <row Id="16904" PostId="11286" Text="Im trying to build an ultrasonic pest repeller. Would this circuit work for an applicaion like that? I don't know why my science professor wants me to make it up to 80 KHz though..." CreationDate="2011-03-11T16:24:51.127" UserId="3322" />
  <row Id="16905" PostId="11276" Text="Im trying to build an ultrasonic pest repeller. Would this circuit work for that? This is for a science project at school. Thanks for your help!" CreationDate="2011-03-11T16:26:05.290" UserId="3322" />
  <row Id="16906" PostId="8089" Text="Early Macintosh programmers used malloc() and free() (or their Pascal equivalents) quite often, despite the fact that early Macintosh computers had no MMU. The idea that &quot;correctly&quot; using malloc() requires a MMU seems incorrect to me." CreationDate="2011-03-11T16:27:37.980" UserId="813" />
  <row Id="16907" PostId="11254" Text="Im trying to build an ultrasonic pest repeller.Im assuming that it will generate a tone at 80 KHz constantly. Im not sure if the shape of the wave matters." CreationDate="2011-03-11T16:28:05.867" UserId="3322" />
  <row Id="16908" PostId="11314" Score="1" Text="Martin is absolutely correct. I have (had) a HC16 BDM module and a BP6 motherboard that did not survive me plugging the BDM into a variable frequency drive; it converts three-phase AC to DC and then back to AC in order to speed-control an induction motor.  The drive survived just fine but the 900VDC bus presented enough of a challenge to the BDM and PC such that a lot of copper was removed from both. I was fine, after the big flash and bang and a  change of underwear. :-)" CreationDate="2011-03-11T16:35:41.617" UserId="974" />
  <row Id="16909" PostId="11227" Text="The problem is that as I understand it, these new kind of MCU's cant use the external memory, so you have to &quot;swap&quot; it into the internal ram before you can use it (?)" CreationDate="2011-03-11T17:11:10.040" UserId="3318" />
  <row Id="16912" PostId="6879" Text="@Nick T: Over the last couple years, I've seen &quot;color-changing&quot; LED lights which have anti-parallel LED strings in different colors.  The supply selects one or other polarity to light a particular string.  I've been thinking it would be fun to have some processor-controlled TRIAC outputs so I could nicely sequence the lights in different colors, but I don't know of any off-the-shelf controllers that would allow one to dim the hot-positive and hot-negative phases separately." CreationDate="2011-03-11T18:15:52.053" UserId="3123" />
  <row Id="16913" PostId="11322" Text="No external memory bus on that chip family either (?)" CreationDate="2011-03-11T18:59:09.493" UserId="3318" />
  <row Id="16914" PostId="8688" Score="2" Text="@tyblu: I'm pretty certain fuse-PROMs predated EPROMs.  The simplest form of ROM is essentially a selectively-populated diode array (in early days, diodes would literally be soldered onto a grid to represent one polarity of bit; a missing diode represented the other polarity).  A fuse-PROM puts a diode array on a chip, but has row transistors which are much beefier than the diodes at the intersections.  One could selectively remove diodes by setting the address wires and then hitting really hard the data wires connected to the diodes one wanted to remove." CreationDate="2011-03-11T19:17:39.317" UserId="3123" />
  <row Id="16915" PostId="8688" Text="@tyblu: Note that fuse-PROMs are electrically nothing like modern OTPROMs, which are simply EPROM chips in non-windowed packages.  EPROM/OTP devices are programmed by electrically charging the gates of certain transistors (which have enough capacitance, and little enough leakage, to hold a charge essentially indefinitely).  By contrast, fuse-PROM chips are programmed by physically destroying the connections to the unwanted diodes." CreationDate="2011-03-11T19:18:15.633" UserId="3123" />
  <row Id="16916" PostId="11307" Text="A picture or sketch would be enormously helpful!" CreationDate="2011-03-11T19:18:55.563" UserId="1823" />
  <row Id="16917" PostId="11340" Text="The reason is that I'm not using prebuilt library is that the main goal of my device is to learn how to control an LCD. I'll check the code and report back with results." CreationDate="2011-03-11T19:32:59.933" UserId="1240" />
  <row Id="16918" PostId="9836" Text="@Chris &amp; Dave: Same here. I'm restoring an old Corvette and in the process of putting additional sensors and analyzers in. I'm using FEZ Panda (Arduino compatible) test equipment and I'm considering using a mini version of one of the dev boards &quot;in production&quot;. I see nothing wrong with that application and wouldnt even see anything wrong in selling them. Of course, mass quantity production would be limited due to the reasons reemrevnivek listed." CreationDate="2011-03-11T19:33:48.967" UserId="3344" />
  <row Id="16919" PostId="9836" Text="@reemrevnivek: I can't say I agree with your disdain for tools and development environment. Paranoia of Microsoft going out of business or not supporting the .Net framework in the future is undue." CreationDate="2011-03-11T19:35:04.270" UserId="3344" />
  <row Id="16920" PostId="11207" Text="Ok, I was just wondering if the rule of thumb was meant to be like ICs, and thought maybe steppers shouldn't get that hot.  But if their nominal temp can get up to 120, then I understand.  I've not run large industrial steppers before." CreationDate="2011-03-11T19:38:41.570" UserId="2288" />
  <row Id="16921" PostId="9836" Text="BTW...the .Net Micro Framework 4 is open source" CreationDate="2011-03-11T19:53:21.337" UserId="3344" />
  <row Id="16922" PostId="11339" Text="LGPL does not in any way imply that hardware design needs to be released to the public or that any other part of the non-free code needs to be released to the public as long as it is not derivative work. The whole point of LGPL is to have a license which will work with non-free components. To be 100% sure, check [LGPL](http://www.gnu.org/licenses/lgpl.html) website and ask Arduino team which version of LGPL they are using, as there are 3 versions. There is also a large amount of information on GNU's website about licenses, so be sure to read it." CreationDate="2011-03-11T19:54:54.050" UserId="1240" />
  <row Id="16923" PostId="11339" Text="@AnrekaKo - thanks for your feedback (and insight).  I've updated my answer." CreationDate="2011-03-11T20:35:38.813" UserId="1823" />
  <row Id="16924" PostId="11333" Text="nice link @Joby Taffey, thanks" CreationDate="2011-03-11T21:01:03.587" UserId="3343" />
  <row Id="16925" PostId="11337" Text="What have you tried?" CreationDate="2011-03-11T21:26:32.030" UserId="206" />
  <row Id="16926" PostId="11290" Text="@Oliver - It looks to me like your Analog parts are a better answer than the ones you've been given thus far.  You're welcome to post that as an answer, and accept it, if it works for you.  However, the 50 ohm vs. 1kohm question probably deserves its own problem entirely. Short answer: Yes, the bandwidth depends heavily on the load.  You want everything to match at 50 or 75 ohm, typically." CreationDate="2011-03-11T21:29:58.910" UserId="857" />
  <row Id="16927" PostId="8681" Score="1" Text="... should be enough for anyone?" CreationDate="2011-03-11T21:39:06.840" UserId="3240" />
  <row Id="16928" PostId="11290" Text="Alright, I also posted a separate question regarding the bandwidth vs. load issue: [How the bandwidth is impacted by the load?](http://electronics.stackexchange.com/questions/11343/how-the-bandwidth-is-impacted-by-the-load)" CreationDate="2011-03-11T21:51:45.080" UserId="2740" />
  <row Id="16929" PostId="10430" Text="@davidcary, I haven't looked at the numbers, but I assume that the long-term stability drift swamps (much larger) the short-term noise from thermal, and noise has the benefit of being typically unbiased randomness - thus cancelling itself out over time, whereas long-term stability can be due to properties such as aging, which are likely to distort in a biased fashion.  " CreationDate="2011-03-11T23:33:24.153" UserId="2598" />
  <row Id="16930" PostId="11348" Text="+1 I always wondered this myself. I never had problems using batteries in water, but I really don't know what washing could have done." CreationDate="2011-03-11T23:58:39.140" UserId="1240" />
  <row Id="16931" PostId="11117" Text="What frequencies do you imagine this to work at? To do 720p I imagine the frequencies would start getting up there and when you start talking about RF types of frequencies board layout can be very difficult unless you have significant experience doing this. This does not sound like a side project this sounds like a job! :)" CreationDate="2011-03-12T00:19:49.887" UserId="3348" />
  <row Id="16932" PostId="11117" Text="@Stephenmm, DC to about 100 MHz. " CreationDate="2011-03-12T00:55:24.197" UserId="1225" />
  <row Id="16933" PostId="11348" Text="Don't dry them with hot air or anything -- just some desiccant." CreationDate="2011-03-12T02:56:14.620" UserId="2118" />
  <row Id="16934" PostId="11353" Text="Yeah, this was a schematic I got from another site, it just showed the right resistors in the right places :)" CreationDate="2011-03-12T04:03:46.813" UserId="3240" />
  <row Id="16935" PostId="11284" Score="1" Text="Especially in this circuit, which lives and dies by transistor matching, the simulator is going to give a very optimistic performance estimate.  Those &quot;transistors&quot; are identical." CreationDate="2011-03-12T04:17:30.467" UserId="411" />
  <row Id="16936" PostId="2151" Text="I doubt there is a relationship.  I'd like to know why there are two different sizes, though.  Anyone have a picture of one of these opened up?" CreationDate="2011-03-12T04:43:27.040" UserId="142" />
  <row Id="16937" PostId="11355" Text="not a direct answer to your question, but multimeters often show lower voltages when their batteries are weak. i'd check the multimeter against a known good power source to be sure." CreationDate="2011-03-12T05:31:47.110" UserId="1870" />
  <row Id="16938" PostId="11265" Text="@markrages - True, but the original drawing isn't a perfect triangle wave generator either. Anyways, I added a true triangle wave generator." CreationDate="2011-03-12T05:51:56.937" UserId="1374" />
  <row Id="16940" PostId="9836" Text="@Kihoffer - are the ports to a given target board all required to be open source, or only the upstream distribution from Microsoft? " CreationDate="2011-03-12T06:44:45.040" UserId="2246" />
  <row Id="16941" PostId="11359" Text="Please explain the line  then you would get a build-up of electrical charge on the on the floating node that would violate energy conservation principles.How the violate energy conservation principle will voilate.thanks!" CreationDate="2011-03-12T06:49:20.753" UserId="2951" />
  <row Id="16942" PostId="9920" Text="@Dave - breakpoint target debugging is hardly unique to Visual Studio, it's really a feature of most IDE's and embedded tools once you get away from the smallest and most resource-constrained target processors, for example any platform that can handle gdb/gdbserver will work with any IDE that can speak GDB's command language." CreationDate="2011-03-12T06:52:29.727" UserId="2246" />
  <row Id="16943" PostId="11338" Text="What is or isn't commercially viable depends on the requirements of a given project.  Quantity and time frame for example." CreationDate="2011-03-12T06:54:46.090" UserId="2246" />
  <row Id="16944" PostId="11352" Text="Your blanket 'totally unsuitable' claim reflects severe ignorance of the diverse reality of engineering applications.  While you raise a variety of points which can be important in some applications, in many others they are irrelevant, and there are ultimately many situations where a simple ready-to-go solution is the right answer.  As always, one must be aware of the factors when making a decision.  Note also that an arduino is likely easier to source than a loose atmel part, and that using the arduino board does not necessarily imply using their software." CreationDate="2011-03-12T06:59:46.600" UserId="2246" />
  <row Id="16945" PostId="6238" Text="If chips are cheap, use a cpld to make a cpld programmer... posted as a joke, but that's actually what you will find inside a lot of them.  Often the USB ones are an FT245 and the same CPLD previously used in the parallel version." CreationDate="2011-03-12T07:15:18.210" UserId="2246" />
  <row Id="16947" PostId="11284" Text="@markrages. I tried adjusting the Hfe of the transistors and unless it was something like 20-100 it kept a very clean log output. I'm not sure to what extent other parameters would matter, though." CreationDate="2011-03-12T08:31:50.077" UserId="1225" />
  <row Id="16948" PostId="11363" Score="4" Text="Yep, it's possible." CreationDate="2011-03-12T08:41:27.863" UserId="2118" />
  <row Id="16949" PostId="11362" Text="Honestly this is your homework right? you ought to figure it out for yourself - I'll give you a simple hint - you shouldn't be 'activating' a block to choose the function that appears on the outputs" CreationDate="2011-03-12T08:41:31.233" UserId="3190" />
  <row Id="16950" PostId="11355" Text="Normally laptop chargers have voltages in range of 15 V to 24 V, so it could be that charger is expecting some sort of signal before it switches to higher voltage. This could have been implemented as a failsafe, in case it gets connected to a laptop with lower voltage requirement. " CreationDate="2011-03-12T09:20:57.737" UserId="1240" />
  <row Id="16951" PostId="11362" Text="OK well thanks for your comment, for one I'm only asking here as I'm stuck, and the other is that, 'activating' a block was the starting point that I was told to go on??." CreationDate="2011-03-12T10:22:27.090" UserId="2322" />
  <row Id="16952" PostId="11358" Score="2" Text="I'm.... not entirely sure this is even a valid question. Please, work on your grammar." CreationDate="2011-03-12T13:31:03.040" UserId="1374" />
  <row Id="16953" PostId="11334" Text="Are you sure it's not your scope? Have you checked for bad connections, etc...?" CreationDate="2011-03-12T13:32:30.513" UserId="1374" />
  <row Id="16954" PostId="11369" Score="1" Text="It's effectively a stepper motor (you drive it with the same waveform). As for cheap ones, surplus is your only bet, I think. I've *never* seen them go for less than a few hundred dollars." CreationDate="2011-03-12T13:34:29.543" UserId="1374" />
  <row Id="16955" PostId="11371" Score="1" Text="@Olli The results needn't be that accurate it is just for demonstration of various types of motion graphically on an oscilloscope.From simple bouncing balls to those involving springs and pendulums. Like those listed at http://www.myphysicslab.com/ I want the unit to run standalone so what what you recommend for the microcontroller." CreationDate="2011-03-12T14:31:47.293" UserId="3319" />
  <row Id="16958" PostId="11371" Text="@Alexdagre8 Make your question more specific, then." CreationDate="2011-03-12T15:19:04.013" UserId="142" />
  <row Id="16959" PostId="11362" Score="1" Text="Are you allowed to use 3-state logic?  http://en.wikipedia.org/wiki/Three-state_logic" CreationDate="2011-03-12T15:20:58.503" UserId="142" />
  <row Id="16960" PostId="11334" Text="@Fake Name, certain, because an output from a comparator at 300mV also has the same problem." CreationDate="2011-03-12T15:58:15.750" UserId="1225" />
  <row Id="16961" PostId="11352" Text="@Chris, on the latter point, that's why I separated them.  If you're open to spending 20-30 USD on what's essentially a single chip, sourcing is a little easier; e.g. Digi-Key.  I don't quite understand your &quot;ready-to-go&quot; point; as I mention in my post, most applications would require additional circuitry anyways, which may be on a PCB, so you save very little (more likely lose) if you end up using an Arduino as a daughterboard." CreationDate="2011-03-12T17:01:31.970" UserId="1407" />
  <row Id="16962" PostId="11373" Text="Wouldn't that still a complete circuit, just with some large capacitors?" CreationDate="2011-03-12T17:05:57.597" UserId="1407" />
  <row Id="16963" PostId="11377" Score="1" Text="Sensor API http://developer.android.com/reference/android/hardware/Sensor.html" CreationDate="2011-03-12T17:27:00.070" UserId="2060" />
  <row Id="16964" PostId="11345" Text="Seems like questions 1-3 would all be answered in a datasheet." CreationDate="2011-03-12T18:14:17.530" UserId="319" />
  <row Id="16965" PostId="11334" Text="IC bigger then the discrete components required to do the same stuff? I find that hard to believe. Must be a bunch of features you are stripping out." CreationDate="2011-03-12T18:17:46.247" UserId="319" />
  <row Id="16966" PostId="11382" Text="A dedicated controller is going to offer a great mix of performance and features, likely at a price that's hard to match with discretes, and board area that's impossible." CreationDate="2011-03-12T18:18:31.910" UserId="1407" />
  <row Id="16968" PostId="11383" Text="Ah ok, that's neat! But do the three different colors need a different voltage (and can this be done), or am I misunderstanding the current/voltage relation?" CreationDate="2011-03-12T19:51:15.000" UserId="3362" />
  <row Id="16969" PostId="11371" Text="@Alexdagre8, the integration isn't a big deal; note that there are other faster methods than Runge Kutta. Concentrate on your display requirements, which will take up the bulk of the micro's resources." CreationDate="2011-03-12T19:57:02.517" UserId="2118" />
  <row Id="16970" PostId="11334" Text="@Kellenjb, AFAIK, a SOT363 diode+0603 components would be smaller than a SO8 or MSOP10. Besides; it's not just the IC's surface area you have to compare against. The LMH1980 requires three caps (ac coupler, plus two filter caps and a resistor - all of these take space up on top of the small surface area." CreationDate="2011-03-12T20:10:20.447" UserId="1225" />
  <row Id="16971" PostId="11383" Score="2" Text="@Rengers All you need to do is make sure that you have enough voltage applied to the anode of the device so that your highest voltage LED will turn on. Looking at the datasheet, your anode voltage should be at least 3.6V. If you apply 20mA to your LED, then you will have your forward voltage drop - they are related." CreationDate="2011-03-12T20:25:16.983" UserId="638" />
  <row Id="16972" PostId="11373" Text="I don't think most people would consider it a circuit, since the spheres are not near each other or connected in any obvious way.  The spheres could be charged in isolated rooms and then brought together, for instance." CreationDate="2011-03-12T20:59:09.680" UserId="142" />
  <row Id="16973" PostId="11380" Text="Is there anything wrong with this answer? Except that 0.1 A would be specific to the type of capacitor used?" CreationDate="2011-03-12T21:03:23.300" UserId="1240" />
  <row Id="16974" PostId="11386" Text="Your problem is that unlike 80186 or 80386, 8086 was discontinued early in the 90s and it wasn't as popular at the time." CreationDate="2011-03-12T21:39:49.933" UserId="1240" />
  <row Id="16976" PostId="11355" Text="I'm not experienced enough to say for sure, but if the laptop power is a switching power supply, wouldn't it not supply full voltage until an amount of current flow is met?" CreationDate="2011-03-12T21:51:59.670" UserId="708" />
  <row Id="16977" PostId="11388" Text="That's probably a full PC emulation, not just the CPU. Interesting nonetheless because I have an FPGA sitting on my desk. The gate count is probably too low for such a thing though" CreationDate="2011-03-12T21:53:18.157" UserId="708" />
  <row Id="16978" PostId="11322" Text="@RA01 well, it provides 512k ROM and 64k RAM. I'd say that more than enough for most of the things I do. And most (early) 80s computers didn't have a lot more than 64k of RAM" CreationDate="2011-03-12T22:20:09.273" UserId="708" />
  <row Id="16979" PostId="11374" Text="When you say &quot;power supply&quot;, I'm interpreting that as the dedicated power management you have on your board, not some bench PSU as some of the answers do.  Which is it?" CreationDate="2011-03-12T22:28:58.170" UserId="1407" />
  <row Id="16980" PostId="11369" Text="They are driven with with same driver as a stepper motor, really? Would that include microstep capability?" CreationDate="2011-03-12T22:32:38.807" UserId="3045" />
  <row Id="16981" PostId="11375" Text="Yes it would but I need 9 feet." CreationDate="2011-03-12T22:33:16.747" UserId="3045" />
  <row Id="16982" PostId="11390" Text="The funny thing is that I believe KP1810 &amp; KP580 are still being produced here in exUSSR. My home signalization is using one of them, and it is brand new :-) Crazy things :-)" CreationDate="2011-03-12T23:14:58.053" UserId="2062" />
  <row Id="16983" PostId="11390" Text="@BarsMonster  I've been looking in stocks of some sellers and I've seen them with date codes of year 2000." CreationDate="2011-03-12T23:19:59.877" UserId="1240" />
  <row Id="16984" PostId="11334" Text="@Thomas O, I don't know anything about those chips, my point is just that it seems odd for them to put a diode + some 0603 components on a chip, too basic of thing, they must have more they are doing. If they require 2 filters caps and a resistor then when don't you?" CreationDate="2011-03-12T23:24:47.987" UserId="319" />
  <row Id="16985" PostId="11334" Text="@Kellenjb, because the chip does sync separation - far more than DC restore. I'll be moving the sync sep to a software routine using a comparator on my MCU, which already has decoupling caps, but they're necessary anyway." CreationDate="2011-03-12T23:50:58.537" UserId="1225" />
  <row Id="16986" PostId="11374" Text="In my case, I'm referring to a bench power supply which has adjustable voltage, current limiting and should have short-circuit protection. Still, I'd like not to depend too much on the capabilities of the power supply. Instead, I'd like to limit intake current on the board side, so I could later switch to a simpler power supply." CreationDate="2011-03-13T00:07:29.870" UserId="1240" />
  <row Id="16987" PostId="11345" Text="@Kellenjb I wouldn't ask here if I hadn't already read the datasheet in detail." CreationDate="2011-03-13T00:08:55.410" UserId="1225" />
  <row Id="16988" PostId="11362" Text="@endolith : oh cheers, I'm not able to use that, but thanks for the info:)." CreationDate="2011-03-13T00:31:48.033" UserId="2322" />
  <row Id="16989" PostId="11383" Score="2" Text="The TLC5940 forces the correct current through the LEDs. As long as the correct current goes through the LEDs, the LEDs will set their own voltage -- there's nothing you can do about that voltage, even if you wanted to." CreationDate="2011-03-13T01:04:37.507" UserId="813" />
  <row Id="16990" PostId="11383" Text="Thanks, I think I get it now. Since my LEDs require 20mA current, I would need a 1.92k Ohm reference resistor (as stated in the datasheet)." CreationDate="2011-03-13T01:22:36.320" UserId="3362" />
  <row Id="16991" PostId="11395" Text="Oh yeah, and you might want to look at the xcore from xmos, a good looking product in general." CreationDate="2011-03-13T01:38:43.263" UserId="985" />
  <row Id="16992" PostId="11396" Text="Thanks for the reply. The board is an embedded single board computer. The datasheet for the board is here: http://support.advantech.com.tw/support/DownloadDatasheet.aspx?Literature_ID=2fcec812-9336-4818-bbc1-a94fc49f8856&amp;utm_source=www.advantech.com&amp;utm_medium=Download&amp;utm_campaign=PCM-9361+Data+Sheet" CreationDate="2011-03-13T01:39:02.250" UserId="3367" />
  <row Id="16993" PostId="11227" Text="Are you not looking for a Microprocessor instead of a microcontroller?" CreationDate="2011-03-13T02:20:12.043" UserId="1623" />
  <row Id="16994" PostId="11396" Score="3" Text="It looks like the board uses both 5V and 12V at the same time. The board uses 2.38 A at 5V to power the board, and .09 A at 12V to power an LCD or optional add-on card." CreationDate="2011-03-13T03:27:46.100" UserId="2857" />
  <row Id="16995" PostId="11397" Text="Did a little more research.  Would a large capacitor inline between the panel and the fan do the job?  I imagine it would charge up and then blow the fan for however long it can, provided the capacitor is above the voltage the fan requires (12v)?  " CreationDate="2011-03-13T03:33:02.537" UserId="3368" />
  <row Id="16996" PostId="11363" Text="Your question belongs on a programming site. This is a question about computation, and not about sensors or I/O or actuators (in which case this site would be OK)" CreationDate="2011-03-13T04:28:02.310" UserId="330" />
  <row Id="16997" PostId="11381" Text="-1: Your discussion about inductance is correct from a theoretical standpoint, but useless from a practical standpoint, as any 1H inductors rated for 5A are huge custom magnetics." CreationDate="2011-03-13T04:31:16.363" UserId="330" />
  <row Id="16998" PostId="11402" Text="Can you give us a direct source of that information? This will help us to put it into correct context." CreationDate="2011-03-13T04:46:30.167" UserId="1240" />
  <row Id="16999" PostId="11399" Text="Thank you, but sadly we don't have any of these :(" CreationDate="2011-03-13T05:23:29.610" UserId="3365" />
  <row Id="17000" PostId="11369" Text="@kurtnelle - Sure, I don't see why you couldn't microstep it." CreationDate="2011-03-13T05:36:25.637" UserId="1374" />
  <row Id="17001" PostId="11364" Text="My charger does in fact have an outer ground and inner connector, which is what I tested with the multimeter. I also am fairly sure that my multimeter is correct--it reads 9V and AA batteries fine. To remove all doubt, I called up a few relatives and found one with the same charger and took a trip to test it. My charger worked on their computer and theirs still did not work on mine. Additionally, I used my multimeter to test their charger and got a different value less than 15, so I assume it does in fact have to do with not having power drawn. Thanks for the lengthy explanation." CreationDate="2011-03-13T06:34:36.743" UserId="3352" />
  <row Id="17002" PostId="9920" Text="@Chris Yes, I realize that.  I think it's just that I've never experienced anything this easy before.  You just have to understand that my background is not embedded programming (and setting up gcc / gdb toolchains), and getting the embedded tools in the past (on linux, for example) has really gotten the best of me.  But in the PC s/w development world, Visual Studio will spoil you.  " CreationDate="2011-03-13T06:48:29.477" UserId="2288" />
  <row Id="17003" PostId="11293" Text="@BG100 the accepted answer only really explained the difference, not a programming difference." CreationDate="2011-03-13T06:53:02.473" UserId="230" />
  <row Id="17004" PostId="11399" Text="If it's really 1pF it will be hard to measure." CreationDate="2011-03-13T08:12:27.257" UserId="339" />
  <row Id="17005" PostId="11394" Score="1" Text="You need to work on your understanding of units. A (Ampere) is the unit of current, W (Watt) is the unit of power, and watts per hour doesn't make sense." CreationDate="2011-03-13T08:52:15.643" UserId="339" />
  <row Id="17007" PostId="11398" Text="@TomWij, yes, in general comments like &quot;thanks&quot; are removed, but only if there is another reason to edit. Editing to just remove thanks is a bit ridiculous." CreationDate="2011-03-13T10:12:38.157" UserId="230" />
  <row Id="17008" PostId="11396" Text="@Ryan, you should make an answer with explanation and links, that is what I expected the case to be also." CreationDate="2011-03-13T10:14:49.903" UserId="230" />
  <row Id="17010" PostId="11398" Score="1" Text="@TomWij, I saw your other changes, so I approved it, but since your edit comment had a question this seemed to be the best way to respond. Glad to see you visiting our neck of the woods." CreationDate="2011-03-13T10:17:08.667" UserId="230" />
  <row Id="17011" PostId="11377" Text="API dosen't allow to change them. I think that i can find this data in the api source, but it is not simple. Now i'll try." CreationDate="2011-03-13T10:36:15.660" UserId="3360" />
  <row Id="17012" PostId="11377" Text="For the drift i need only the standard deviation at costant tempereture. I cannot determine it from the datasheet?" CreationDate="2011-03-13T10:47:41.063" UserId="3360" />
  <row Id="17013" PostId="11411" Text="@zain, take the time to format your code, it is not easily readable right now." CreationDate="2011-03-13T11:54:15.287" UserId="230" />
  <row Id="17014" PostId="11411" Score="5" Text="That isn't valid C code. I'm not surprised that you get errors." CreationDate="2011-03-13T14:37:23.757" UserId="305" />
  <row Id="17015" PostId="11381" Text="Even from the theoretical stand point it means that when a circuit is pulling power, the inductor will want to provide constant current, which is not what the circuit will want. If the circuit is suddenly turned off, the inductor will want to keep delivering that current, which will cause the voltage to spike on the cap." CreationDate="2011-03-13T14:47:51.483" UserId="319" />
  <row Id="17016" PostId="11413" Score="1" Text="Magnetic fields won't affect the inputs!" CreationDate="2011-03-13T15:28:20.010" UserId="305" />
  <row Id="17017" PostId="11411" Text="I have write a small part of code and if you are talking about # before define then i did it and if bout sbit declaration then in sdcc we define  &lt;br&gt;sbit rs = cmdport^0; as&lt;br&gt;sbit at  cmdport^0  rs ;" CreationDate="2011-03-13T15:58:30.080" UserId="2951" />
  <row Id="17018" PostId="6378" Text="Actually the &quot;simplified language&quot; is just C++ with yet another preprocessing step and some extra libraries (known as libWiring.a)." CreationDate="2011-03-13T16:34:39.350" UserId="708" />
  <row Id="17019" PostId="6235" Text="I've found myself frequently wiring controller pins together, wondering all the while why the designers insisted on segregating functionality as they did.  For example, is there any reason why one wouldn't want a processor to be able to query the state of an interrupt-request pin?" CreationDate="2011-03-13T17:48:54.757" UserId="3123" />
  <row Id="17020" PostId="4912" Score="1" Text="@endolith: If both devices transmit the same thing, they will be unaware of each other's existence.  If they transmit different things, the first device that transmits a &quot;1&quot; while the other was transmitting a &quot;0&quot; should detect that it has lost arbitration, immediately cease transmitting, and most likely expect to retransmit its entire command from the beginning." CreationDate="2011-03-13T17:52:19.230" UserId="3123" />
  <row Id="17021" PostId="2461" Text="I have a voltmeter which uses 60Hz Nixie-tube flicker to avoid the need for latching circuits.  During one half of each line cycle, the display shows a reading; during the other half, a new reading is acquired.  I certainly haven't found the 60Hz flicker objectionable." CreationDate="2011-03-13T18:13:11.257" UserId="3123" />
  <row Id="17022" PostId="2461" Score="1" Text="@supercat To each his/her own. I notice flickering, and it bothers me. I don't like the LED car tail lights that are pulsed either. Making the display not flicker is a (usually low) price I'm willing to pay." CreationDate="2011-03-13T18:42:13.930" UserId="638" />
  <row Id="17023" PostId="2461" Text="I suppose if there's no reason to have the displays flicker, it would be advantageous to have a regulated supply (how noticeable would 120Hz flicker be, btw?)  In the case of the meter I have, the flicker is there for a reason.  Of course, if one is multiplexing a display, it may be necessary to have a filter cap on the supply to ensure all rows or digits are uniformly lit (sometimes I see display that look like they're being scanned rather slowly; I suspect the real scan rate is close to 60Hz or 120Hz, a filter cap failed, and I'm seeing a beat frequency)." CreationDate="2011-03-13T19:08:01.210" UserId="3123" />
  <row Id="17024" PostId="11336" Text="I think that part of the confusion here might be that digital QAM modulation is commonly used for TV (especially cable) - QAM64 and QAM256 are common standards used for HDTV - they have nothing to do with YIQ from NTSC (or YUV for PAL) - in modern systems we mpeg encode a video stream (mpeg2, or in some more advanced systems, mpeg4) and then multiplex it into a transport stream, FEC is added and then the result is QAM modulated 6 or 8 bits at a time" CreationDate="2011-03-13T19:19:07.283" UserId="3190" />
  <row Id="17025" PostId="11430" Score="5" Text="It would be much safer to look in the datasheet and get it right" CreationDate="2011-03-13T20:56:47.227" UserId="566" />
  <row Id="17026" PostId="11430" Text="That's not helpful because the chip is on a board where the connections are not known. http://electronics.stackexchange.com/questions/11426/how-is-the-board-connected-to-this-chip" CreationDate="2011-03-13T20:59:03.727" UserId="1657" />
  <row Id="17028" PostId="11429" Text="I'm not using the AT45 I'm using the W25Q80, which is similar. The legs are numbered in the same way, but the pin assignments are different. Is finding VCC and GND sufficient to know where everything else is?" CreationDate="2011-03-13T21:18:00.833" UserId="1657" />
  <row Id="17029" PostId="11427" Text="Correct me if I'm wrong but doesn't the development board, already have the level shifter built onto it? Even if I did try to transmit without the level shifter, I would still be getting some data right? Garbage as though it might be?" CreationDate="2011-03-13T21:18:54.613" UserId="3375" />
  <row Id="17030" PostId="11429" Text="Yes, three points define a plane. So, you need to know which way up the chip is too ;)" CreationDate="2011-03-13T21:20:06.480" UserId="566" />
  <row Id="17033" PostId="11429" Text="I did a continuity test directly on the chip and found continuity between pins 5 and 8. That would be data input and Vcc. How is that possible?" CreationDate="2011-03-13T21:32:37.603" UserId="1657" />
  <row Id="17035" PostId="3849" Text="related: http://stackoverflow.com/questions/5162673/how-to-read-two-32bit-counters-as-a-64bit-integer-without-race-condition" CreationDate="2011-03-13T21:38:40.720" UserId="813" />
  <row Id="17036" PostId="11429" Text="Use a continuity checker to check which pins on the IC match to which pins on the board. Checking the pins of the package itself is less useful. I do not know why pins 5 and 8 conduct." CreationDate="2011-03-13T21:38:40.857" UserId="566" />
  <row Id="17038" PostId="11429" Text="Actually I made a mistake. It was touching something else. I was able to verify the pin connections to the board by putting one probe on a pin from the chip and the other probe on a pin from the board. I verified seven connections but it seems that pin 8, which is Vcc, is not connected. What kind of tool do I need to fix this?" CreationDate="2011-03-13T21:46:56.600" UserId="1657" />
  <row Id="17039" PostId="11431" Text="Hi Leon : Please see the updated first post ..." CreationDate="2011-03-13T22:00:06.030" UserId="3375" />
  <row Id="17040" PostId="11391" Text="@AndrejaKo My original plan was to build an analogue computer but I couldn't find any information on how to build one from scratch using modern components, so this is an attempt to mimic such a system digitally. A hybrid design where the analogue circuit (or at least the parameters) could be altered with a microcontroller/FPGA would be ideal, but it's just a dream for now." CreationDate="2011-03-13T22:39:41.877" UserId="3319" />
  <row Id="17041" PostId="11363" Text="@Jason S Sorry about asking it in the wrong site, this is related to another question I asked about hardware on this site and I forgot that this site doesn't cover programming (then again this doesn't belong at Stackoverflow either). Do you want me to delete it?" CreationDate="2011-03-13T22:47:51.760" UserId="3319" />
  <row Id="17042" PostId="11394" Text="&quot;The output of the power plant increased by 1000 W per hour.&quot;" CreationDate="2011-03-13T23:08:33.397" UserId="142" />
  <row Id="17043" PostId="11403" Text="Sadly, noone on ebay seems to have a 9 foot acme leadscrew, and some of the suppliers I've talked to consider that a special request. The intended purpose is for CNC Milling. Yes I know that lead screws are the dominat drive system, however I have encountred difficulties in obtaining them, and have not been successful thus far. &#xA;&#xA;Btw FakeName, what's ya real name? lol" CreationDate="2011-03-13T23:34:51.220" UserId="3045" />
  <row Id="17044" PostId="11128" Text="I named it &quot;brainstorm&quot; because a) that was the title of the original email message I sent out, and b) I was open to different solutions to my problem (ie. both recommendations for products I could buy, OR suggestions for techniques I could try to build myself OR possibilities I haven't even thought of). I can't think why this kind of &quot;open&quot; question should be banned here. " CreationDate="2011-03-14T01:12:03.510" UserId="3279" />
  <row Id="17045" PostId="11363" Text="Hmm. well, now that I think about it, maybe I was a bit harsh. if you provided some quantitative information (e.g. how many state variables, max. frequencies) and wanted to know if your CPU could meet computational throughput, that might be appropriate here... but I don't think you'd get an answer here, and even maybe not on SO. Math.stackexchange.com maybe? (but if so, leave out the hardware requirements, and ask how to figure out how much CPU power you need) Don't delete the question." CreationDate="2011-03-14T01:14:11.773" UserId="330" />
  <row Id="17046" PostId="6167" Text="If your app works, that's great! &quot;If it's stupid but it works, it's not stupid.&quot; -- Murphy's Law of Combat #6" CreationDate="2011-03-14T01:20:23.237" UserId="813" />
  <row Id="17047" PostId="11430" Text="why don't you just post a picture of the breakout board (both sides) its likely very obvious what the connections are.  If not just check for continuity." CreationDate="2011-03-14T01:36:55.770" UserId="1438" />
  <row Id="17048" PostId="11389" Text="Another clue: somebody at the lab told me those were bought for a button debounce circuit." CreationDate="2011-03-14T01:56:38.853" UserId="3365" />
  <row Id="17049" PostId="11438" Text="Thanks for your answer. Could you please point me one, or at least what I must look for? For example, in http://en.wikipedia.org/wiki/Operational_amplifier_applications I can see a lot of things that can be done with a Op-Amp, but which one could be usefull for what I'm trying to do?" CreationDate="2011-03-14T04:09:38.520" UserId="3365" />
  <row Id="17050" PostId="11439" Text="So if I wanted to get the device ID would this work?      pc.printf(&quot;ID = %d\r\n&quot;, spi.write(0x9f));&#xA;     pc.printf(&quot;memory type = %d\r\n&quot;, spi.write(0x00));&#xA;     pc.printf(&quot;capacity = %d\r\n&quot;, spi.write(0x00));" CreationDate="2011-03-14T04:42:32.550" UserId="1657" />
  <row Id="17051" PostId="11439" Text="I don't know specifically if that would work, since i am not familiar with that language but sending 9F should return the info on that register." CreationDate="2011-03-14T04:49:50.950" UserId="2060" />
  <row Id="17052" PostId="11443" Text="yes that should work. use this for reference http://mbed.org/projects/libraries/api/mbed/trunk/SPI#SPI.Functions " CreationDate="2011-03-14T04:56:23.640" UserId="2060" />
  <row Id="17053" PostId="11442" Text="Why does is there an FI in between those letters?" CreationDate="2011-03-14T04:58:16.633" UserId="1657" />
  <row Id="17054" PostId="11443" Text="Why does the figure show an EFh for the manufacturer ID? Am I supposed to send that instead of 0x00?" CreationDate="2011-03-14T05:02:07.110" UserId="1657" />
  <row Id="17055" PostId="11443" Text="No you should not send EFh , that is the manufacture ID that is should return" CreationDate="2011-03-14T05:05:31.477" UserId="2060" />
  <row Id="17056" PostId="11443" Text="the comms flow should be - send 9F -&gt; memory(chip) should send back EF -&gt;then ID15-ID0 should also be sent to your MBED" CreationDate="2011-03-14T05:20:25.403" UserId="2060" />
  <row Id="17057" PostId="11443" Text="I'm just reading 0s. I updated my question to show the code." CreationDate="2011-03-14T05:29:52.333" UserId="1657" />
  <row Id="17058" PostId="11442" Score="1" Text="it all depends on what the chip was used for or who it was manufactured for." CreationDate="2011-03-14T05:37:05.507" UserId="2060" />
  <row Id="17059" PostId="11404" Text="@A.R., you should be able to accept your own answer." CreationDate="2011-03-14T05:37:26.100" UserId="230" />
  <row Id="17060" PostId="11443" Text="Do you ever send the spi.write(0x9F) command as shown in the datasheet?" CreationDate="2011-03-14T05:45:06.830" UserId="813" />
  <row Id="17061" PostId="11443" Text="Yes ......make sure you are using the correct SPI pins and serial pins (5, 6, 7) or (11, 12, 13)" CreationDate="2011-03-14T05:47:18.240" UserId="2060" />
  <row Id="17062" PostId="11444" Text="http://electronics.stackexchange.com/questions/11440/are-there-datasheets-for-this-dataflash-memory" CreationDate="2011-03-14T06:22:09.633" UserId="2060" />
  <row Id="17063" PostId="11415" Score="1" Text="A problem I would have with using FETs is that it is harder to use them when the switched signal can be either +15V or -15V (an output enable switch for example). I guess I could work with FETs in other circuits where only positive voltages are amplified or used." CreationDate="2011-03-14T07:40:36.920" UserId="1476" />
  <row Id="17064" PostId="11438" Text="&quot;Differential amplifier&quot;. You put some reference voltage on one of inputs, fed your signal into second, and tune resistors to get output range you want." CreationDate="2011-03-14T08:03:54.140" UserId="2062" />
  <row Id="17065" PostId="11415" Text="No, this is not a problem. If you need to work with -15, you can use 2 FET's connected face-to-face or use 4-pin ones, where die is 4rth pin (these are rare)." CreationDate="2011-03-14T08:05:03.903" UserId="2062" />
  <row Id="17066" PostId="11441" Text="how far away do you want to detect people in front of the Project?" CreationDate="2011-03-14T09:30:48.367" UserId="2060" />
  <row Id="17067" PostId="11447" Score="2" Text="How much data do you need to capture at a time or is this constant, real-time?" CreationDate="2011-03-14T12:13:47.230" UserId="1407" />
  <row Id="17068" PostId="11446" Score="1" Text="...for some definitions of &quot;Cheap&quot;.  What would a Kinect do for this project that a webcam on the ceiling wouldn't do?" CreationDate="2011-03-14T13:26:48.877" UserId="857" />
  <row Id="17069" PostId="11446" Text="Depth perception" CreationDate="2011-03-14T13:29:41.907" UserId="566" />
  <row Id="17070" PostId="11453" Score="4" Text="+1! Just what I was about to post. Also, why megajoules PER HOUR?  Electricity is usually charged per energy consumed (so joules with no hours), per installed power (so watts or VAs) or per peak power (again W or VA). Also, it's not watt/hour, it's watt*hour." CreationDate="2011-03-14T13:31:50.807" UserId="1240" />
  <row Id="17071" PostId="11453" Text="quite right, wasn't thinking straight" CreationDate="2011-03-14T13:42:05.840" UserId="566" />
  <row Id="17072" PostId="11360" Text="Over the weekend I came up with an idea of using two bolts on the outside of the pipes going along the entire length. On the back end of the pipe (doesn't rotate), it would go through two holes. On the front end, it would go through slotted holes, allowing the pipe to rotate on the rods. This morning I got to thinking about your suggestion of Moglice and then Delrin. Now I'm thinking of using two PVC tubes coupled together. Do you know if any of these compounds bond to PVC? (don't want them to). Is it possible to melt down Delrin and pour it into a gap? (Such that it creates a bushing?)" CreationDate="2011-03-14T13:48:12.267" UserId="3339" />
  <row Id="17073" PostId="11451" Text="Assuming you can get it in a state suitable for an FPGA, the opal kelly PCIe FPGA board might be of use http://www.opalkelly.com/products/xem6110/" CreationDate="2011-03-14T13:52:03.090" UserId="2960" />
  <row Id="17074" PostId="11446" Score="1" Text="@Joby but if you mount the webcam on the ceiling, you've got proximity detection for the wall." CreationDate="2011-03-14T13:57:09.467" UserId="2288" />
  <row Id="17075" PostId="11446" Text="True, I guess it depends on what kind of effects you want. A PIR sensor would do for something, a Kinect for others" CreationDate="2011-03-14T14:04:13.497" UserId="566" />
  <row Id="17076" PostId="11453" Score="2" Text="I've just eaten a Caramel Wafer - 134 kCal it says on the wrapper. I just worked out that this is 0.156 kWh. I feel much healthier now :)" CreationDate="2011-03-14T14:21:58.723" UserId="2234" />
  <row Id="17077" PostId="11457" Text="http://electronics.stackexchange.com/questions/5998/smd-vs-through-hole-components-in-high-vibration-environments" CreationDate="2011-03-14T14:52:03.863" UserId="566" />
  <row Id="17078" PostId="11456" Text="I have clones of these http://www.sparkfun.com/products/105, so I think as the tri-state logic is used in Charlie plexing,so it will work." CreationDate="2011-03-14T14:56:39.913" UserId="1200" />
  <row Id="17079" PostId="11457" Text="@Joby, I saw that before I posted, and it was informative. " CreationDate="2011-03-14T15:00:09.493" UserId="638" />
  <row Id="17080" PostId="11449" Text="what makes you think so? it is not an easy task as illumination changes, even the one coming from the wall itself." CreationDate="2011-03-14T15:07:52.490" UserId="3377" />
  <row Id="17081" PostId="11448" Text="what is the minimum distance to trigger a PIR sensor, how does it work? is it sensitive to abrupt changes in illumination?&#xA;&#xA;Thanks" CreationDate="2011-03-14T15:12:45.653" UserId="3377" />
  <row Id="17082" PostId="11425" Text="+1 for pointing out the nicer-looking generic includes." CreationDate="2011-03-14T15:13:38.527" UserId="813" />
  <row Id="17083" PostId="11441" Text="I'd say 50 cm is enough" CreationDate="2011-03-14T15:15:40.643" UserId="3377" />
  <row Id="17084" PostId="11411" Text="@Leon Heller: while this technically isn't ANSI C code, the original poster clearly stated he is using SDCC. The [__sbit __at language extension is clearly documented in the SDCC manual](http://sdcc.sourceforge.net/doc/sdccman.html/node59.html#SECTION00441700000000000000)." CreationDate="2011-03-14T15:17:13.157" UserId="813" />
  <row Id="17085" PostId="11456" Score="1" Text="@joby: There are also rgb leds with no common anode and no common cathode. They actually have six connectors. 3 single anode + the 3 RGB contacts. i have them lying around my house, since i wrongly ordered them instead of common anode :)" CreationDate="2011-03-14T15:19:45.680" UserId="2995" />
  <row Id="17087" PostId="11448" Text="PIR sensors detect IR And can be sensitive to abrupt light changes but it can be filtered out. Miniumum distance is dependent on the PIR sensor, but most will work right up to the lens(E.G. moving your hand past the lens). " CreationDate="2011-03-14T15:28:12.503" UserId="2060" />
  <row Id="17088" PostId="11447" Text="In the end, I would like to send these bits to remote clients via the PCs network card. The RAM is used to store the bits while they await a request. If client demand is high, RAM storing is not really necessary (I think). If there is no client demand, the RAM is full and new incoming bits from the comparator are simply discarded." CreationDate="2011-03-14T15:31:45.710" UserId="3378" />
  <row Id="17089" PostId="11448" Score="1" Text="maybe an array of these or similar would be better? http://www.sparkfun.com/products/242 10cm  to 80cm range" CreationDate="2011-03-14T15:34:29.763" UserId="2060" />
  <row Id="17090" PostId="11451" Text="BarsMonster, ralight, thanks for the input. FPGA is def something I am looking at. I would need to outsource since I have no experience with FPGAs." CreationDate="2011-03-14T15:43:21.033" UserId="3378" />
  <row Id="17091" PostId="11448" Text="True, but they are not very cheap and I'd have to use a lesser amount of them." CreationDate="2011-03-14T16:08:15.997" UserId="3377" />
  <row Id="17092" PostId="11422" Text="When I bought a new bench supply 2 years ago I was looking for the same thing.  The cheapest capable 3 output (2 0-32V, 1 5V fixed) supply that I could find at the time was the BK Precision 1672 for $330.  It has worked perfectly for the time that i've had it.  I do wish it was network controllable but otherwise its been great.  I know its higher than your price range but i really don't think your going to find a dual or triple output commercial grade bench supply for &lt; $200 unless you go used.  " CreationDate="2011-03-14T16:17:39.587" UserId="1438" />
  <row Id="17093" PostId="11458" Text="What software did you use to make this schematic? I couldn't get it to work in eagle." CreationDate="2011-03-14T16:22:55.867" UserId="1200" />
  <row Id="17094" PostId="11422" Score="1" Text="apparently that comment got eaten but the dollar sign mathjax delimiters....do we even really need latex in comments?" CreationDate="2011-03-14T16:24:32.837" UserId="1438" />
  <row Id="17095" PostId="11438" Text="Great! Thank you very much, that's what I was looking for." CreationDate="2011-03-14T16:29:32.650" UserId="3365" />
  <row Id="17096" PostId="11462" Text="Computer power supplies do not have adjustable current limiting, so they are not suitable for powering prototype circuits." CreationDate="2011-03-14T16:36:28.643" UserId="411" />
  <row Id="17097" PostId="11425" Text="i was including like you but i could not add # in question.I also tried __ before sbit and at as they were warned by sdcc as depriciated.i just copy your code nd now my code is working fine.but still i can,t figure out the cause f problem.please let me to know. " CreationDate="2011-03-14T16:46:27.803" UserId="2951" />
  <row Id="17098" PostId="11462" Text="For sure. Adjustable current limit is essential for a bench supply. Also, operation at light or zero load while maintaining regulation is important - most PC supplies don't like zero load at all." CreationDate="2011-03-14T16:50:34.630" UserId="1293" />
  <row Id="17099" PostId="11458" Text="I didnt make the pic, Someone offered to replace one of my olds ones from my blog and this was the replacement. It was created with CAD software and the one that you see is a PNG." CreationDate="2011-03-14T16:54:55.717" UserId="2060" />
  <row Id="17100" PostId="11448" Text="that was an example IR sensor, and yes for $10 a piece it can get pricey, but that doesn't stop you from making your own with an IR photo-transistor and an IR emitter." CreationDate="2011-03-14T17:02:15.707" UserId="2060" />
  <row Id="17101" PostId="11425" Text="@Zain Try the SDCC mailing list. That's a much better forum for detailed back and forth discussion" CreationDate="2011-03-14T17:27:51.030" UserId="566" />
  <row Id="17102" PostId="11404" Score="1" Text="Yeah, I still have to wait another day.  =)" CreationDate="2011-03-14T17:47:01.183" UserId="3077" />
  <row Id="17103" PostId="10132" Text="I print every datasheet for all the ICs I use, They are my goto guide if I have any question about my circuit, no you don't have to read every detail in it, I skip about 1/2 of it, but it gives you most of the data that you need to get it to work.most datasheets contain a example circuit(where to put that diode) and logic tables for pins(pullup or pulldown). Maybe starting a minimal universal guide would be a good idea(note to self). I am sure not all your questions will be answered by read the datasheet." CreationDate="2011-03-14T17:54:04.880" UserId="2060" />
  <row Id="17104" PostId="11449" Text="@dnul It's the way certain effects are centered on the head of passers by. It could just be that they chose to use an average human height for those effects, but I didn't get that sense from it. Could also be wrong, but a video feed would be the cheapest/easiest way of tracking folk. " CreationDate="2011-03-14T17:59:08.493" UserId="1507" />
  <row Id="17105" PostId="11393" Score="1" Text="Voted in support, 1pf seems the most likely. " CreationDate="2011-03-14T18:20:42.163" UserId="1729" />
  <row Id="17106" PostId="11449" Text="I was not aware of the height sensitivity,thanks.&#xA;I was assuming there were some kind of proximity sensors placed on the same wall, maybe one every certain number leds. Also, I wonder, if you were true , where the camera/s would be placed?." CreationDate="2011-03-14T18:31:47.917" UserId="3377" />
  <row Id="17107" PostId="11469" Text="Mmm that's a really interesting option, because we do have a DSO Nano v2 in the lab :D. I'll try that!" CreationDate="2011-03-14T19:46:15.910" UserId="3365" />
  <row Id="17108" PostId="11467" Text="Lots of excellent suggetstions - Thanks! Unfortunately I don't have any benchmark for the applied forces - this would be the first attempt to measure it as far as I know." CreationDate="2011-03-14T19:57:59.507" UserId="638" />
  <row Id="17109" PostId="11461" Score="1" Text="The high vibration stuff I've seen is almost always potted." CreationDate="2011-03-14T20:26:46.063" UserId="1270" />
  <row Id="17110" PostId="11427" Text="What processor and package are you using? I looked at the datasheet for the PIC24F16KA102, which is the default processor for the development board. Page 14 of the datasheet shows the pin numbers for U1TX and pin 3 is not one of them. Make sure you are using the correct pin." CreationDate="2011-03-14T23:21:17.943" UserId="2489" />
  <row Id="17111" PostId="11411" Text="@Zain, would you mind if I edit your original question so that it's valid C? You have a good question here about sbit with SDCC, but it's being overshadowed by confusion around the code" CreationDate="2011-03-15T01:28:43.927" UserId="566" />
  <row Id="17112" PostId="11404" Text="@A.R., I knew there was a delay, but I thought I would check to make sure you knew you could." CreationDate="2011-03-15T02:06:33.647" UserId="230" />
  <row Id="17113" PostId="11470" Score="1" Text="Forward current meaning the current into or out of the gate must match the direction of the current going into or out of MT2." CreationDate="2011-03-15T02:24:55.940" UserId="1407" />
  <row Id="17115" PostId="11373" Text="@endolith, you are effectively charging the spheres as a capacitor in a complete circuit(taking charge from one and depositing on the other). You are then shorting it. Noone may consider it a circuit because it has no value. It is still a case of applying potential to the two elements as a capacitor, even if they are both capacitors in reference to the &quot;ground potential. " CreationDate="2011-03-15T06:04:25.423" UserId="230" />
  <row Id="17116" PostId="11452" Score="1" Text="You are right kWh is more proper in this case ;)" CreationDate="2011-03-15T07:37:43.600" UserId="689" />
  <row Id="17118" PostId="10194" Text="rofl, I actually ended up buying this two wees ago." CreationDate="2011-03-15T08:36:28.630" UserId="3385" />
  <row Id="17119" PostId="11486" Text="How would I read that data back?" CreationDate="2011-03-15T08:37:33.123" UserId="1657" />
  <row Id="17120" PostId="11486" Text="Read Data - 9.2.6 opcode 03h and a 24 bit address  or fast read (0Bh- 24 bit address 1byte of dummy code) 9.2.7" CreationDate="2011-03-15T08:43:46.407" UserId="2060" />
  <row Id="17121" PostId="11467" Text="+1 for the &quot;out of the box idea&quot; (2 boards)!" CreationDate="2011-03-15T11:00:53.160" UserId="1757" />
  <row Id="17123" PostId="11373" Text="@Kortuk: You don't have to take charge from one and add it to the other.  You can take charge from another object and add it to one.  They don't have to be equal and opposite.  And there can be zero capacitance between the two spheres, as long as they have self-capacitance?  If infinity is considered part of a complete circuit, then I'm not sure what to say..." CreationDate="2011-03-15T11:41:20.260" UserId="142" />
  <row Id="17124" PostId="11473" Score="2" Text="Oh the wonders of having questions written in American.  When I saw this I thought that by stoplight you meant the brake light on a car, not making what would be called a &quot;Traffic Light&quot; in English.  As Winston Churchill said &quot;Two nations divided by a common language.&quot;" CreationDate="2011-03-15T11:58:03.700" UserId="400" />
  <row Id="17125" PostId="11453" Score="1" Text="Please note that when measuring the total energy used, you are measuring WattHours, not Watts per Hour" CreationDate="2011-03-15T12:05:15.313" UserId="1728" />
  <row Id="17129" PostId="11404" Text="Thanks for the tip.  Looks like jsolarski really does have the best answer though.  I mean, that is a very good resource that he pointed out. =)" CreationDate="2011-03-15T12:45:39.137" UserId="3077" />
  <row Id="17130" PostId="11400" Text="solid core wires are great, but when there are a lot of them their inflexibility can be bothersome.  Also, if the ends get little bends in them they become even more trouble.  I like to stay focused on the task at hand and not have to fiddle with little details all of the time." CreationDate="2011-03-15T12:48:07.263" UserId="3077" />
  <row Id="17131" PostId="11458" Score="1" Text="your single resistor combination above will give differing levels of brightness when more than 1 LED is on - use 3 resistors?" CreationDate="2011-03-15T13:01:26.083" UserId="1827" />
  <row Id="17133" PostId="11458" Text="to even out the brightness you would use 3 on the anode side, but use a potentiometer to find the best value for each line. Or just correct it in the pwm signal " CreationDate="2011-03-15T13:20:40.710" UserId="2060" />
  <row Id="17134" PostId="11219" Text="A final problem is temperature is not linear to voltage. V^2/R." CreationDate="2011-03-15T13:33:58.293" UserId="1225" />
  <row Id="17136" PostId="11400" Score="1" Text="ok, cool -- I learned something new :-)" CreationDate="2011-03-15T13:51:51.863" UserId="330" />
  <row Id="17138" PostId="11492" Score="1" Text="Is this a programming problem? It sounds like you just need a resistor, which is clearly a hardware issue." CreationDate="2011-03-13T07:40:04.233" />
  <row Id="17139" PostId="11492" Text="It is programming issue. I know that I can use PWM in some way. Let's say that I want to achieve a fading LED effect via change the output voltage level (using timer modlue)." CreationDate="2011-03-13T07:45:49.220" />
  <row Id="17140" PostId="11492" Score="1" Text="So you need software control over the voltage output. Are you asking *how* to do PWM? Or do you know how to do PWM and are asking for other solutions?" CreationDate="2011-03-13T07:49:07.350" />
  <row Id="17141" PostId="11473" Score="2" Text="@Ian, I'm always surprised at the difficulty the British have with our language. ;)" CreationDate="2011-03-15T14:12:41.893" UserId="2157" />
  <row Id="17143" PostId="11473" Text="@kenny, It is a wonder that we let you have anything when you look at the way that you have broken the language that we lent you :-)" CreationDate="2011-03-15T15:07:59.547" UserId="400" />
  <row Id="17144" PostId="11496" Text="The holes in the blades are just over 3mm in diameter. There's no way you can put your finger in either! " CreationDate="2011-03-15T15:12:48.700" UserId="1293" />
  <row Id="17145" PostId="11496" Text="+1 for being a good sport. :)" CreationDate="2011-03-15T15:19:13.123" UserId="1293" />
  <row Id="17146" PostId="11473" Text="@Ian, we followed the rules of the English language, as they are codified in `[document not found]`." CreationDate="2011-03-15T15:35:28.670" UserId="1407" />
  <row Id="17147" PostId="11496" Text="Some other speculation: http://www.straightdope.com/columns/read/579/why-are-there-holes-in-the-prongs-of-electrical-plugs" CreationDate="2011-03-15T15:39:50.320" UserId="712" />
  <row Id="17148" PostId="11496" Score="1" Text="I don't see how adding holes to anything improves the manufacturing process. I see it as being an extra step or an extra tooling requirement. Unfortunately, that article is mostly hearsay. I'm hoping for an authoritative answer." CreationDate="2011-03-15T15:45:43.307" UserId="1293" />
  <row Id="17149" PostId="11466" Text="A worthwhile thing to note about multi-output supplies: some are designed so that a fault condition or failure on one output will not affect others, while others are designed so that a failure or fault condition on one output will not only shut down the faulted output, but others as well.  The former style of design may allow for better overall system reliability (if the part that faults isn't needed for all operations), while the latter style may help protect downstream components from damage (e.g. if +12 leaks onto +5)." CreationDate="2011-03-15T15:57:46.420" UserId="3123" />
  <row Id="17150" PostId="11495" Text="I've always wondered this, too, thinking maybe it's a way to allow wires to be attached directly to the blades." CreationDate="2011-03-15T16:15:52.053" UserId="142" />
  <row Id="17151" PostId="815" Text="I want to inform also that QP the famous state machine framework is now available for arduino http://arduino.cc/playground/Code/QP" CreationDate="2011-03-15T16:54:36.257" UserId="199" />
  <row Id="17152" PostId="11503" Text="By &quot;pulldown resistor after the switch&quot; I assume you mean that I need to connect the inputs to ground through a high-value resistor (5k or more)? Remember, it's been 20 years since my limited education on the subject..." CreationDate="2011-03-15T17:28:05.237" UserId="3240" />
  <row Id="17153" PostId="11421" Text="That seems like a digital solution, not an analog solution. But FPGAs may be the way forwards. It would just be insanely expensive - high speed ADCs and high speed DACs would be required." CreationDate="2011-03-15T17:28:31.473" UserId="1225" />
  <row Id="17154" PostId="11483" Text="What do you mean that I'm connecting power and iron to runners? Can you explain the iron and the runners a little better to me? Is there a way to make a three-way dimmer work on a household appliance?" CreationDate="2011-03-15T17:38:32.113" UserId="3315" />
  <row Id="17155" PostId="11503" Text="http://www.seattlerobotics.org/encoder/mar97/basics.html was extremely helpful. I'll set it up like that." CreationDate="2011-03-15T17:57:08.580" UserId="3240" />
  <row Id="17156" PostId="11504" Score="1" Text="You left out one important constraint: How long you plan on wearing your project between recharge cycles / new batteries" CreationDate="2011-03-15T18:09:39.173" UserId="638" />
  <row Id="17157" PostId="11503" Text="Also, I can debounce the switch with something like a simple 100nF ceramic cap?" CreationDate="2011-03-15T18:18:12.243" UserId="3240" />
  <row Id="17158" PostId="11504" Score="1" Text="@Robert the ebay page cites 2.2W consumption at 12V, which corresponds to  ~200mA per 5m." CreationDate="2011-03-15T18:34:06.430" UserId="1729" />
  <row Id="17159" PostId="11505" Score="3" Text="The potential to be shocked does not entirely depend on the voltage of the supply. Its true that the conductivity of *dry* skin is low enough to act as an insulator at low voltages, however given wet skin or a wet wound and the chance for shock goes way up even at 12 volts. You can in fact be *killed* by a 9v battery if you wire it up properly (like sticking a probe directly into the blood stream). " CreationDate="2011-03-15T18:52:09.167" UserId="1729" />
  <row Id="17160" PostId="11504" Score="1" Text="even if you want a constant color you don't need to drive the LED &quot;full on&quot; just choose your PWM frequency &gt; 60hz (flicker as this speed isn't detectable to the human eye) and control the duty cycle to determine brightness.  What you'll find that the brightness difference is small between &quot;full on&quot; and PWM with maybe a 50% duty cycle but your current usage goes way down.  To put it another way, the light output vs current relationship for most LEDs is logarithmic.  " CreationDate="2011-03-15T19:20:45.763" UserId="1438" />
  <row Id="17161" PostId="11503" Text="A 100nF will help, but a capacitor is not a great debouncer.  Would be better to follow it with a 74hc14 or similar." CreationDate="2011-03-15T19:31:07.720" UserId="411" />
  <row Id="17162" PostId="11503" Text="Note you only need to debounce the clock line.  The other lines aren't edge-sensitive." CreationDate="2011-03-15T19:31:36.237" UserId="411" />
  <row Id="17163" PostId="11503" Text="Look at the datasheet to see if a minimum clock rise/fall time is specified.  If so, the capacitor may slow you down too much.  Then the 74hc14 is essential." CreationDate="2011-03-15T19:32:38.107" UserId="411" />
  <row Id="17164" PostId="11321" Text="Wow, this works like a charm. Thanks! Also, thanks a lot for pointing me to the USB libraries. They seem like a more fruitful route for the future." CreationDate="2011-03-15T19:56:51.583" UserId="1802" />
  <row Id="17165" PostId="3256" Text="image link is broken" CreationDate="2011-03-15T20:10:16.327" UserId="1227" />
  <row Id="17166" PostId="11505" Score="2" Text="I'd suggest that if there are people trying to stab DMM probes into your blood vessels to either side of your heart, you have other problems. :)" CreationDate="2011-03-15T20:22:03.353" UserId="2523" />
  <row Id="17167" PostId="11505" Score="5" Text="Doesn't anyone lick 9Vs to see if they're fresh anymore?" CreationDate="2011-03-15T21:02:51.440" UserId="1269" />
  <row Id="17168" PostId="11496" Text="Yeah, agreed. It's at least true, judging by the outlets I've checked, there are no longer bumps interfacing with the holes, if ever there were." CreationDate="2011-03-15T22:00:09.383" UserId="712" />
  <row Id="17169" PostId="11511" Text="Thanks! Much better solution." CreationDate="2011-03-15T22:06:10.703" UserId="1078" />
  <row Id="17170" PostId="11516" Text="The original correspondent specified power consumption as a factor in the design." CreationDate="2011-03-15T22:20:08.727" UserId="411" />
  <row Id="17172" PostId="11421" Score="1" Text="@Thomas O I have a guy in my lab doing research on software defined radios. I think they are the way of the future. the ADCs used right now are very expensive, but as they become used more they will drop in price. It adds a lot of flexibility for firmware changes. Especially nice in cell phones where they can just switch frequencies at will instead of a set few frequencies that can be used on each phone. " CreationDate="2011-03-15T22:27:29.347" UserId="319" />
  <row Id="17173" PostId="11516" Score="3" Text="Why couldn't you replace the resistor with a P-channel and have a full totem-pole?" CreationDate="2011-03-15T22:48:12.167" UserId="411" />
  <row Id="17174" PostId="11520" Text="The power is coming from a voltage regulator which is powering something else. If I take power straight from the power supply, then I get 5.1V. I'm thinking of maybe doing that and using resistors to get the right voltage. I tried some resistors but the voltage is too low. What kind of resistance do I need?" CreationDate="2011-03-15T23:16:21.927" UserId="1657" />
  <row Id="17175" PostId="11520" Score="1" Text="@200ok404notfound - resistors are an inefficient way to go, and unless your chip takes the same current under all operating conditions, you could have a difficult time finding a single specific resistor that would work in all cases." CreationDate="2011-03-15T23:28:08.480" UserId="740" />
  <row Id="17176" PostId="11520" Text="You should use a second voltage regulator of 3 or 3.3v. You wont be able to get what you want with just resistors. ICs hardly ever pull a constant current, this means that the voltage will always be changing, which is not what you want." CreationDate="2011-03-15T23:35:37.620" UserId="319" />
  <row Id="17177" PostId="11504" Text="It it was 12V/9A, that's half again the wattage of a fairly powerful heated jacket, so unless you were planning on wearing it in a blizzard you would get quite hot fast. But as crasic states, it's only a tenth that." CreationDate="2011-03-15T23:42:17.660" UserId="1158" />
  <row Id="17178" PostId="11404" Text="@AR, more importantly, there was a picture." CreationDate="2011-03-15T23:42:56.777" UserId="230" />
  <row Id="17179" PostId="11373" Text="@Endolith, there is no such thing as self capacitance, you are just referencing ground. There always must be two sides. Yes, this is a charge pump, but yes, it is just a capacitor." CreationDate="2011-03-15T23:44:12.657" UserId="230" />
  <row Id="17180" PostId="11520" Text="I have a 5V voltage regulator. What if I uses this in combination with resistors?" CreationDate="2011-03-15T23:53:56.453" UserId="1657" />
  <row Id="17181" PostId="11522" Score="3" Text="In your last example, without packing enabled and a default 32-bit alignment, some compilers might instead add extra bytes to the structure, so that it would appear in memory as a, x, x, x, b0, b1, b2, b3, c, x, x, x, d where x is a padding byte.  Other variations are possible." CreationDate="2011-03-16T00:04:05.533" UserId="1322" />
  <row Id="17182" PostId="11520" Text="A resistor divider is a poor choice for a voltage supply if what is being supplied draws current, because the voltage at the divided node will change with the current. A simple solution that may get you where you want to go is to use a 3V Zener diode." CreationDate="2011-03-16T00:09:07.900" UserId="3382" />
  <row Id="17183" PostId="11527" Score="3" Text="You really should put the part number and link to the data sheet." CreationDate="2011-03-16T00:39:06.140" UserId="206" />
  <row Id="17184" PostId="11528" Text="For the supply voltage it says -0.6 to +4.0. So how likely is it?" CreationDate="2011-03-16T00:39:56.723" UserId="1657" />
  <row Id="17185" PostId="11528" Score="1" Text="The longer you exceed the maximum ratings for and by what degree determine the damage caused. Each chip is different." CreationDate="2011-03-16T00:41:04.843" UserId="566" />
  <row Id="17186" PostId="11409" Text="Put in enough for us to help you or expect this to be closed." CreationDate="2011-03-16T00:42:22.050" UserId="206" />
  <row Id="17187" PostId="11524" Text="Thanks a lot - makes sense to me now!" CreationDate="2011-03-16T00:46:35.637" UserId="1785" />
  <row Id="17188" PostId="11522" Text="Thank you for your explanation Joby and tcrosley. I finally get it!" CreationDate="2011-03-16T00:47:26.760" UserId="1785" />
  <row Id="17189" PostId="11489" Text="I saw a similar &quot;toy&quot; 12-volt implementation made exactly as you describe, except that it used an old can with tape providing the insulated parts.  It impressed me when I first saw it as a kid, and I remember it to this day as one of the first &quot;engineering&quot; projects I ever saw." CreationDate="2011-03-16T00:51:48.643" UserId="1756" />
  <row Id="17190" PostId="11525" Score="1" Text="Can I get a link to the datasheet?" CreationDate="2011-03-16T00:53:16.977" UserId="1240" />
  <row Id="17191" PostId="11527" Score="1" Text="Alright, I edited my post." CreationDate="2011-03-16T00:56:21.563" UserId="1657" />
  <row Id="17192" PostId="11527" Text="Why the downvote?" CreationDate="2011-03-16T00:57:11.343" UserId="1657" />
  <row Id="17193" PostId="11525" Text="Alright, I posted a link to it." CreationDate="2011-03-16T00:57:32.437" UserId="1657" />
  <row Id="17194" PostId="11365" Text="@Kortuk heh. I was just saying that a question that may seem obvious to most electronics experts, can have answers that are very enlightening. I meant no offense" CreationDate="2011-03-16T01:12:56.820" UserId="708" />
  <row Id="17195" PostId="11530" Text="Is that the same thing as the SPI frequency?" CreationDate="2011-03-16T01:37:12.640" UserId="1657" />
  <row Id="17196" PostId="11530" Text="Yes. It's the clock frequency for the SPI signal." CreationDate="2011-03-16T01:45:05.290" UserId="3382" />
  <row Id="17197" PostId="11526" Text="I'm told that they can be joined to acheive virtually and unlimited length." CreationDate="2011-03-16T04:01:36.030" UserId="3045" />
  <row Id="17198" PostId="8938" Text="Does it write? The entire card, not just directory &amp; SMS?" CreationDate="2011-03-16T06:23:30.223" UserId="3396" />
  <row Id="17199" PostId="11536" Text="@supercat, Awesome answer. I think it would be interesting to get some links on resources on approaching my own RTOS. My focus here really was getting a high quality RTOS from a vendor whom has done the work of ensuring hard real time, but this might be a fun hobbyist project for myself." CreationDate="2011-03-16T07:03:17.723" UserId="230" />
  <row Id="17200" PostId="11497" Text="In my OP I mentioned that certain IC names, including prefixes, are used by different manufacturers" CreationDate="2011-03-16T07:21:47.260" UserId="2064" />
  <row Id="17201" PostId="11545" Score="1" Text="@shane, edit in what you have already figured out and what you have going on. Right now someone has to do the project for you for them to really answer this question. I think you will get more answers as the size of the answer required goes down." CreationDate="2011-03-16T08:33:06.863" UserId="230" />
  <row Id="17202" PostId="11543" Score="1" Text="@Mawg, I am glad you dropped by, but in the past Lego-mindstorms has not received the most answers from this site." CreationDate="2011-03-16T08:34:42.900" UserId="230" />
  <row Id="17203" PostId="11545" Text="Hi,&#xA;I have some initialsation code, as follows:&#xA;&#xA;Serial.print(“\r\n+STWMOD=1\r\n”);   Serial.print(“\r\n+STNA=modem”);   Serial.print(“\r\n+RTPIN=0000\r\n”);   Serial.print(“\r\n+INQ=1\r\n”);   &#xA;Serial.print(“\r\n+STBD=9600″);&#xA;&#xA;In this, I'm following the lead of the Seeedstudio material, but I'm unsure of whether it'll allow me to pair the phone with it. In fact, the only thing I understand is the 9600 baud setting... I'll look up some AT commands now." CreationDate="2011-03-16T08:38:45.623" UserId="3397" />
  <row Id="17204" PostId="11547" Text="So do i need an extra microcontroller to control the two MOSFETs And programme it to pull the gate inputs of desire MOSFETs (By connecting the mosfet gates to tri-state output ports on a microcontroller, it can it can choose which power supply to use once)" CreationDate="2011-03-16T08:54:20.707" UserId="2951" />
  <row Id="17205" PostId="11545" Text="I guess, what I'm asking for is the process of connection - on Seeedstudios forum once the +INQ=1 command is issued, then the phone (or computer) can find the Bee. As you can see, I have an RTPIN of &quot;0000&quot; (secure, I know...) so inputing that into the phone will pair the phone and Bee? Or am I way off the mark?" CreationDate="2011-03-16T08:58:40.433" UserId="3397" />
  <row Id="17207" PostId="11545" Score="1" Text="@Shane, edit the new information into your original question. This improves the question and will improve your number of answers." CreationDate="2011-03-16T09:21:46.193" UserId="230" />
  <row Id="17208" PostId="11549" Text="Can you make your questions less personal in future? For example, this question would be more widely appreciated if phrased more like &quot;How to get past the limitations of the graphical programming language MindStorms NXT?&quot; or &quot;Alternatives to MindStorms NXT&quot;. Everybody has a different level of experience, so their version of &quot;for me&quot; is different." CreationDate="2011-03-16T10:44:31.227" UserId="2110" />
  <row Id="17209" PostId="11544" Text="Are you sure you want to use the battery even if the USB is connected? It would make more sense to me to primarily use USB and then fall back to battery." CreationDate="2011-03-16T11:33:28.697" UserId="2395" />
  <row Id="17210" PostId="11544" Text="What ever the sequence may be i just want to know how to use FETs in this scenario." CreationDate="2011-03-16T11:40:20.327" UserId="2951" />
  <row Id="17211" PostId="11318" Text="@shitake83, I am just used to lead acid, even Pb acid would have done the job, just clearing it up, the question was answered." CreationDate="2011-03-16T11:53:22.120" UserId="230" />
  <row Id="17212" PostId="11318" Text="@kortuk: sorry to be a smart ass again, but Pb = lead. And there is no lead (or pb) acid, since the battery is a Pb+acid battery. Not Pb acid battery." CreationDate="2011-03-16T12:09:44.610" UserId="2995" />
  <row Id="17213" PostId="11318" Text="@shitake83, are you used to hearing them called Lead batteries? I have only every heard or read lead acid. I am not implying it is an acid solution of lead, I do not pretend to be a good chemist, I am saying that if I just see Pb I assume that I may not know this batter technology. " CreationDate="2011-03-16T12:18:12.213" UserId="230" />
  <row Id="17214" PostId="11535" Text="Which processor?" CreationDate="2011-03-16T12:18:59.350" UserId="339" />
  <row Id="17215" PostId="11318" Text="Yes in germany we call them &quot;Autobatterie&quot; &quot;Bleiakkumulator&quot; or &quot;Blei-Säure&quot; Batterie which means Lead/Acid-Battery. If you write &quot;lead acid&quot; it comes off as one word and someone with minor knowledge might just put that in his head as something that is existent ;). Did i mention its 13:37 over here xD. And just to show you that other people are aware of the fact. http://electronics.stackexchange.com/questions/78/charging-lead-acid-batteries" CreationDate="2011-03-16T12:34:23.037" UserId="2995" />
  <row Id="17216" PostId="11360" Text="After doing more research I realized that PVC can have a lower melting point than Acetal/Delrin. I ended up purchasing a sintered bronze bushing from McMaster Carr - hopefully it will work well :-) Thanks for the input." CreationDate="2011-03-16T12:37:26.650" UserId="3339" />
  <row Id="17217" PostId="11558" Text="Indeed. You can overlay a struct onto an incoming packet (or use it to construct an outgoing one), onto a set of memory-mapped registers, or build log packet, all cases where the packing could potentially differ from the CPU's optimal alignment for memory accesses." CreationDate="2011-03-16T12:41:31.450" UserId="3361" />
  <row Id="17218" PostId="11549" Text="@Mawg, which programming language to use would fit better on Stackoverflow.com They will close it though as an opinion question, there is not perfect answer to this, but their site will offer help for this." CreationDate="2011-03-16T12:42:17.737" UserId="230" />
  <row Id="17222" PostId="11373" Text="@Kortuk: I guess it's just a matter of interpretation?  http://en.wikipedia.org/wiki/Capacitance#Self-capacitance  http://www.iue.tuwien.ac.at/phd/wasshuber/node74.html If there are two spheres floating in space, with nothing else around, and one is charged via the photoelectric effect, and a current flows when they are connected together due to the charge equalizing, I would not consider that current part of a &quot;complete circuit&quot;." CreationDate="2011-03-16T14:18:06.200" UserId="142" />
  <row Id="17223" PostId="11560" Text="my bad. fixed the links" CreationDate="2011-03-16T14:19:48.210" UserId="1293" />
  <row Id="17224" PostId="11539" Text="Yeah, a buffer chip with eight resistors would be a ready off-the-shelf approach.  Practically any buffer chip would work, but having to use eight resistors seems a bit icky.  It would seem curious that a bus-keeper feature would be almost a standard feature on CPLDs, but not a convenient function in discrete logic.  Even though it would end up needing more pins than would otherwise be necessary, a tri-state driver chip with 'weak' outputs would be handy." CreationDate="2011-03-16T14:25:07.027" UserId="3123" />
  <row Id="17225" PostId="11373" Score="1" Text="@endolith, the photoelectric effect was using high enough frequency electric energy to be able to use the free space to couple energy. I am not saying you are wrong, but I think this explanation may give the wrong idea to someone new in the field trying to understand it. You are not a slouch, you know you theory, and I think you are able to use this to explain an open and not have any loss of the fact that for standard operation you are going to have a solid conductor connecting the circuit in a complete loop." CreationDate="2011-03-16T14:25:15.957" UserId="230" />
  <row Id="17226" PostId="11373" Text="@endloith, I did enjoy the link to self-capacitance though." CreationDate="2011-03-16T14:26:13.893" UserId="230" />
  <row Id="17227" PostId="11539" Text="Actually, I also find it curious that I've never seen a micro or CPLD which conveniently allows a pin to be configured as a &quot;weak&quot; output for both high- and low-side drive.  Many micros and CPLDs have weak pull-ups, and some have weak pull-downs as well, but I've never seen one where an output could be configured to use a weak high and low side drive without reconfiguration." CreationDate="2011-03-16T14:26:57.960" UserId="3123" />
  <row Id="17228" PostId="11539" Score="1" Text="MSP430 processors, and probably others, have individual pullup/pulldown resistors that pull towards the output latch.  Doesn't this accomplish what you want?" CreationDate="2011-03-16T14:32:24.337" UserId="411" />
  <row Id="17229" PostId="11373" Score="1" Text="@Kortuk: Actually, I answered like this because I think this explanation *increases* understanding for someone new to the field.  Current is just flows of charge, and it's important to have a gut feeling for how charge works in the absence of complete circuits in order to understand better how it works *in* circuits.  https://webcache.googleusercontent.com/search?q=cache%3Aamasci.com%2Femotor%2Fcap1.html#eng" CreationDate="2011-03-16T14:41:19.570" UserId="142" />
  <row Id="17230" PostId="11559" Text="What part are you replacing?" CreationDate="2011-03-16T14:46:49.003" UserId="411" />
  <row Id="17231" PostId="11560" Text="@Teal will need a custom PCB to get the pinout he describes." CreationDate="2011-03-16T14:48:13.200" UserId="411" />
  <row Id="17232" PostId="11560" Text="Or, he can use wires instead of pins when installing the PCB into his kit, making the connections as he needs them." CreationDate="2011-03-16T14:53:42.067" UserId="1293" />
  <row Id="17233" PostId="11373" Text="@endolith, hmm. I will have to note this down to different learning styles. I have never tutored anyone whom this type of approach helped. But I have also only had to tutor those that did not learn it the first time it was taught in class." CreationDate="2011-03-16T14:56:46.370" UserId="230" />
  <row Id="17234" PostId="11537" Text="In fact, I'm not aware of any processor where indianness is selectable." CreationDate="2011-03-16T15:00:06.903" UserId="1802" />
  <row Id="17235" PostId="11559" Text="Why are you giving us pin locations?" CreationDate="2011-03-16T15:08:46.490" UserId="638" />
  <row Id="17236" PostId="11537" Score="1" Text="Actually, quite a few are selectable http://en.wikipedia.org/wiki/Endianness#Bi-endian_hardware" CreationDate="2011-03-16T15:20:10.257" UserId="1938" />
  <row Id="17237" PostId="11557" Text="Thanks ! i'll go have a look !!! " CreationDate="2011-03-16T15:26:11.777" UserId="3398" />
  <row Id="17238" PostId="11547" Score="1" Text="Watch the body diodes on the MOSFETs.  It's easy to accidentally make a battery charger that way." CreationDate="2011-03-16T15:33:08.900" UserId="411" />
  <row Id="17239" PostId="11539" Text="@markrages: I'll have to look at those; who makes them?  Can those weak drivers be used with I/O features like UARTs, etc.?  In any case, current-limited driver chips would be useful for cases where signals go through some discrete logic before joining together; depending upon the limit current, they could also be useful for bus interfaces in cases where contention would not be expected, but could possibly occur (e.g. during certain device startup or reset situations)." CreationDate="2011-03-16T15:33:41.990" UserId="3123" />
  <row Id="17240" PostId="11537" Text="That's actually quite cool!" CreationDate="2011-03-16T15:34:35.610" UserId="1802" />
  <row Id="17241" PostId="9365" Text="The sequence AAA001,AAA002 has a certain logic.  There is certainly no INDUSTRY WIDE naming convention.  Individual companies may have a convention while they survive." CreationDate="2011-03-16T15:36:13.730" UserId="400" />
  <row Id="17242" PostId="4270" Text="It would be nice if this answer was marked as a community wiki answer." CreationDate="2011-03-16T15:50:04.347" UserId="2395" />
  <row Id="17243" PostId="11571" Score="1" Text="Do you have a separate voltage that you can use as a reference?" CreationDate="2011-03-16T15:51:37.967" UserId="319" />
  <row Id="17244" PostId="11572" Text="A photograph or circuit diagram of the board would help us. Can you see the names of any of the chips?" CreationDate="2011-03-16T16:08:06.877" UserId="566" />
  <row Id="17245" PostId="11487" Text="Thanks! I'll do the loopback method, and see how it goes." CreationDate="2011-03-16T16:17:03.403" UserId="3383" />
  <row Id="17246" PostId="11571" Text="This sounds VERY cool ill def be following this question." CreationDate="2011-03-16T16:19:15.947" UserId="3073" />
  <row Id="17247" PostId="11542" Score="1" Text="I think you has not read the question carefully.I was asking what will be possibility of loading operating system in memory with out BIOS." CreationDate="2011-03-16T16:31:10.117" UserId="2951" />
  <row Id="17248" PostId="11571" Score="2" Text="Here's a start: http://www.national.com/mpf/LM/LM3916.html" CreationDate="2011-03-16T16:36:31.017" UserId="142" />
  <row Id="17249" PostId="8223" Text="more discussion of this circuit: http://electronics.stackexchange.com/questions/8337/can-you-harvest-electrical-energy-from-the-air" CreationDate="2011-03-16T16:37:10.220" UserId="813" />
  <row Id="17250" PostId="11563" Text="Thanks for the quick reply, I appreciate it.&#xA;&#xA;I am trying to build an analog guitar effect pedal, replacing out the standard potentiometers with ones that can be controlled by a computer.  It is my goal to preserve the sound of the circuit and to change the original tone as little possible.  And I would hope to do this with the an amount of precision that could not be discerned by the ear.&#xA;&#xA;Are there motorized analog pots that can be digitally controlled?  Just another thought..." CreationDate="2011-03-16T16:38:16.320" UserId="3394" />
  <row Id="17251" PostId="9634" Text="I wanted to let everyone know that I fixed the problem - I got another adapter. It's still got ghosting, but it's very faint and shorter, which I can live with. I'm not entirely sure what was up with the last adapter which made it work with only one card. Anyone want me to disassemble it? I suspect it's just wire-to-wire, but there could be components in it..." CreationDate="2011-03-16T16:52:27.910" UserId="1225" />
  <row Id="17252" PostId="11572" Score="1" Text="@Joby - Help us do what?  I'm not sure this is a real question. Part numbers/manufacturers of the boards would at least give us a clue on where to help and what's really being asked." CreationDate="2011-03-16T17:09:07.233" UserId="857" />
  <row Id="17254" PostId="11572" Text="Help us identify the purpose of the board" CreationDate="2011-03-16T17:17:26.800" UserId="566" />
  <row Id="17255" PostId="11563" Text="Digital pots won't be much more out of tolerance than the original pots in the pedal." CreationDate="2011-03-16T17:35:51.817" UserId="142" />
  <row Id="17256" PostId="11306" Text="Oh, I thought you meant ways to turn off synthesis only. My bad." CreationDate="2011-03-16T17:42:29.877" UserId="3078" />
  <row Id="17257" PostId="10795" Text="@Kellenjb: I've had considerable problems with FTDI if a device is plugged in while a connection is open; in my application, that's unavoidable (the software needs to be ready to receive data from a device at any time, so the connection has to stay open; it would be unacceptable to require users of the system to indicate in advance when they were going to unplug a device)." CreationDate="2011-03-16T18:49:26.750" UserId="3123" />
  <row Id="17258" PostId="11585" Text="Could i plug the other end in to the ground of my PSU and turn it on?" CreationDate="2011-03-16T19:50:55.683" UserId="1623" />
  <row Id="17259" PostId="11584" Text="http://opencircuits.com is interesting" CreationDate="2011-03-16T20:14:22.357" UserId="1298" />
  <row Id="17260" PostId="11518" Text="I see.  This is assuming the system's power supply is voltage controlled I guess?  Thanks for the explanation!" CreationDate="2011-03-16T20:14:27.833" UserId="2524" />
  <row Id="17261" PostId="11586" Text="Ask a single question, please.  Otherwise expect it to be closed." CreationDate="2011-03-16T20:49:07.257" UserId="206" />
  <row Id="17263" PostId="5879" Text="Are you talking about [diode-resistor logic](http://en.wikipedia.org/wiki/Diode_logic)?" CreationDate="2011-03-16T21:09:01.560" UserId="813" />
  <row Id="17264" PostId="11542" Score="4" Text="I explained as much as I could given the limited information you state in the question. For instance, what architecture you are using,is this a PC or an embedded system, things like that." CreationDate="2011-03-16T21:13:18.220" UserId="3068" />
  <row Id="17265" PostId="11589" Text="@msutherl Thanks for your response, I am sorry about changing the question. " CreationDate="2011-03-16T21:19:09.070" UserId="3319" />
  <row Id="17266" PostId="11539" Text="@supercat, MSP430 is made by TI (Texas Instruments.)" CreationDate="2011-03-16T21:28:29.643" UserId="1225" />
  <row Id="17267" PostId="11561" Text="I would rather go with the asynclabs solutions which are cheaper and don't require me to buy additional stackable headers... I suppose this is my only option now, though. It just doesnt look like its worth $90. " CreationDate="2011-03-16T21:33:06.097" UserId="3039" />
  <row Id="17268" PostId="11595" Score="1" Text="To have your question answered you should provide some context so that others may understand what are you talking about. Also pay attention to spelling. You ask about solving a problem but we don't know what problem you are talking about." CreationDate="2011-03-14T17:56:45.263" />
  <row Id="17269" PostId="11595" Score="1" Text="Agree with Jakub. From the context I assume you're working with an embedded system? It would help to know what exactly this demo board is (can you provide a link?) and what operating system it will be running. Right now it's not clear that your question is a programming question (are you implementing IPv6 yourself or are you trying to enable some RTOS vendor's IPv6 support?), so there's a good chance it could be closed if you can't explain what the programming problem is." CreationDate="2011-03-14T19:56:44.437" />
  <row Id="17270" PostId="11593" Text="The TI parts look like what I'm after, though the I/V behavior looks more like a resistor than like a current source/sink (which I would think would be preferable).  They look a bit expensive, but maybe there's not enough demand to justify someone making them cheaper?" CreationDate="2011-03-16T22:23:17.527" UserId="3123" />
  <row Id="17271" PostId="11584" Text="+1 for OpenCircuits.  " CreationDate="2011-03-16T22:24:03.053" UserId="857" />
  <row Id="17272" PostId="11589" Text="Now my answer doesn't answer the question anymore. Might be useful anyway, so I suggest keeping it." CreationDate="2011-03-16T22:24:44.490" UserId="207" />
  <row Id="17273" PostId="11585" Score="2" Text="@Dean - The earth ground of your PCB should be directly connected to the ground pin in the wall; you shouldn't have to turn it on.  Remember that your PCB is still floating!  It's probably not as bad as the tip of your soldering iron, but you could still develop a potential difference." CreationDate="2011-03-16T22:26:18.277" UserId="857" />
  <row Id="17275" PostId="11535" Text="We are using an ARM Cortex M series chip from ST and using an IAR compiler." CreationDate="2011-03-16T22:45:05.303" UserId="1785" />
  <row Id="17278" PostId="11596" Text="@reem, well I didn't mean fuse then. I disagree that this question is a duplicate. " CreationDate="2011-03-17T00:05:17.000" UserId="708" />
  <row Id="17279" PostId="11597" Score="2" Text="600V is the marketing spec, you need to go to the datasheet where it says 400V continuous or 4kV burst." CreationDate="2011-03-17T00:16:16.610" UserId="857" />
  <row Id="17280" PostId="11521" Text="Just something to keep in mind: pragmas are by definition non-standard and the available pragmas and their usage differ based on what compiler you're using.  Lessons learned for this particular application will NOT necessarily transfer to another situation." CreationDate="2011-03-17T00:34:34.410" UserId="249" />
  <row Id="17281" PostId="11549" Text="Sorry, but past experience has shown that questions such as this have to be personal, else they get kiskced as subjective (this oen got kicked anyway, so I will repost &amp; rephrase). I really do mean &quot;which is best for me&quot; (objective, if I explain my experience better in the next question), as opposed to 'which is  &quot;best&quot;?' (subjective &amp; likely to start a religios war)   +++" CreationDate="2011-03-17T00:45:38.210" UserId="3396" />
  <row Id="17282" PostId="11549" Text="I considered stack overflow, which is where I normally post, but can't see why it would get me a better response than a lego-minstorms tag here" CreationDate="2011-03-17T00:47:02.580" UserId="3396" />
  <row Id="17284" PostId="11553" Text="+1 thanks. That sounds good. I will look into it. But it's enough to know that it can be done in pronciple." CreationDate="2011-03-17T00:52:45.927" UserId="3396" />
  <row Id="17285" PostId="8939" Text="Does it write? The entire card, not just directory &amp; SMS?" CreationDate="2011-03-17T00:53:56.177" UserId="3396" />
  <row Id="17286" PostId="11596" Text="@reemrevnivek, Close Votes go away with time. If the &quot;issue&quot; that causes a close vote resolves then no one else will vote and it will resolve itself." CreationDate="2011-03-17T01:50:22.187" UserId="230" />
  <row Id="17289" PostId="11596" Text="I made some minor edits to remove the reference to fuses, which was already covered in a different question (and is inappropriate in this case).  I had previously voted to close as a duplicate do to these references, but I think it can now stay open.  If the close vote is still there when you read this, just give it a few days, and, as Kortuk said, it will disappear." CreationDate="2011-03-17T02:06:05.427" UserId="857" />
  <row Id="17290" PostId="11602" Score="1" Text="Your question is very similar to this one on StackOverflow: http://stackoverflow.com/questions/664615/lego-mindstorms-programming-which-language-ide-do-you-use-recommend" CreationDate="2011-03-17T03:20:06.863" UserId="2489" />
  <row Id="17291" PostId="11360" Text="Probably you don't want to run a bushing on the threads of a bolt, but if there isn't much mechanical load you will get away with it.  " CreationDate="2011-03-17T04:55:07.373" UserId="2246" />
  <row Id="17292" PostId="10683" Text="Hi,thanks for the reply. I guess I missed out the extra end when I copied it from MATLAB. Do you know if there is a separate approach to deal with time-correlated measurement/process noise? I haven't taken that into account and I wonder if it is the problem. Even in the case when the state is very close to the observation, I don't get satisfactory results.&#xA;" CreationDate="2011-03-17T04:56:21.007" UserId="2939" />
  <row Id="17293" PostId="9920" Text="@Dave - until you want to do something it can't do, or run on or develop for a platform it can't handle.  But I agree the OSS tools can be a real pain to set up perfectly." CreationDate="2011-03-17T05:00:30.847" UserId="2246" />
  <row Id="17294" PostId="11352" Text="Actually lots of applications do not involve a PCB - for example, there may not be time to have one made.  Or it may require an analog or RF process that's not suitable for the ATMEGA chip.  Obviously if you are doing a PCB with digital chips on it, folding in the ATMEGA makes a lot of sense provided you can source them." CreationDate="2011-03-17T05:05:54.507" UserId="2246" />
  <row Id="17295" PostId="11572" Text="hi, Joby, thanks for the reply. it is a Marvell Prestera for switch." CreationDate="2011-03-17T08:01:44.363" UserId="3402" />
  <row Id="17296" PostId="11547" Score="1" Text="When the microcontroller is in reset, the gates will be tristated and the pullups/pulldowns will control the behaviour (say, always use the battery during reset).   When the microcontroller has booted it can configure two pins as outputs and &quot;override&quot; the resistor biasing." CreationDate="2011-03-17T10:02:33.933" UserId="389" />
  <row Id="17297" PostId="11443" Text="Did you get this to work, @200ok404notfound ?" CreationDate="2011-03-17T13:07:16.220" UserId="2118" />
  <row Id="17298" PostId="11275" Text="Any luck with this, @BarsMonster ?" CreationDate="2011-03-17T13:08:27.873" UserId="2118" />
  <row Id="17299" PostId="11275" Score="1" Text="Not yet, the only reply I've got on official forum was 'That would be cool' :-)" CreationDate="2011-03-17T13:10:07.503" UserId="2062" />
  <row Id="17301" PostId="11615" Text="Thanks! My board takes 12V, but the problem is that car battery is never 12V exactly, even detached and fully charged." CreationDate="2011-03-17T14:09:13.440" UserId="3412" />
  <row Id="17302" PostId="11571" Score="1" Text="Kellenjb, The reference voltage I was going to use would be the power supply voltage charging the capacitor." CreationDate="2011-03-17T14:30:31.003" UserId="2781" />
  <row Id="17303" PostId="11591" Text="During charging wouldn't the LM3916 show a 100% full" CreationDate="2011-03-17T14:30:56.743" UserId="2781" />
  <row Id="17304" PostId="11615" Text="They you need to consider that in the range, for example 8-14 V should be easy to " CreationDate="2011-03-17T14:39:13.943" UserId="206" />
  <row Id="17305" PostId="11614" Text="You need to specify if you need the 12V, 5V, 3.3V and -5V/-12V rails, and also how much power (on each rail) it will consume in the worst case." CreationDate="2011-03-17T15:03:33.667" UserId="1225" />
  <row Id="17308" PostId="11591" Text="No, capacitors don't charge like batteries.  The voltage on the capacitor is proportional to the energy it is storing, so it will work for both charging and discharging." CreationDate="2011-03-17T18:11:49.100" UserId="142" />
  <row Id="17309" PostId="10622" Text="@markrages: If I remember my chemistry right, I would expect that adding sodium carbonate to a solution containing CuCl2 should cause CuCO3 to precipitate (leaving harmless NaCl in solution)." CreationDate="2011-03-17T19:30:23.180" UserId="3123" />
  <row Id="17310" PostId="5561" Text="You want to let some of the water evaporate off, so you are not diluting the strength." CreationDate="2011-03-17T20:01:23.717" UserId="1374" />
  <row Id="17311" PostId="11621" Score="1" Text="The only way to achieve high precision is to use assembly. Your C compiler may optimise in non-obvious ways" CreationDate="2011-03-17T20:05:16.177" UserId="566" />
  <row Id="17312" PostId="11427" Text="Again can you tell us the full part number of the PIC24, Just that some of the PIC24s have PPS which allowes you to map the internal UART or other stuff to diffent pins on the chip. We can help more if you can link the Dev board also. Ta" CreationDate="2011-03-17T20:30:38.080" UserId="2649" />
  <row Id="17313" PostId="11481" Text="thanks, sounds of interest!" CreationDate="2011-03-17T20:36:36.123" UserId="3381" />
  <row Id="17314" PostId="11489" Text="hmm good idea for &quot;simple&quot;" CreationDate="2011-03-17T20:40:17.040" UserId="3381" />
  <row Id="17315" PostId="11628" Text="@Leon: I've never used a switching regulator before, is it just a single component? Can I use it as a direct replacement for the linear reg?" CreationDate="2011-03-17T22:12:02.577" UserId="2426" />
  <row Id="17316" PostId="11596" Text="@reem thanks that makes it a bit more clear" CreationDate="2011-03-17T22:26:51.750" UserId="708" />
  <row Id="17317" PostId="2567" Text="...I thought it was illegal to wear headphones while driving? (In the USA)" CreationDate="2011-03-17T22:34:29.513" UserId="708" />
  <row Id="17318" PostId="11538" Score="1" Text="One more thing to add: If you're say developing an operating system, or any code which will run on both your ARM processor and some other type of processor(such as x86), almost all modern processors now use little endian. Usually, it's nothing to worry about. But when doing very many bitwise operations, even subtle &quot;simple&quot; things can break. " CreationDate="2011-03-17T22:49:25.720" UserId="708" />
  <row Id="17319" PostId="11628" Text="You can get them as single components, as a drop-in replacement for a linear regulator, made by TI. They are usually built from a chip, an inductor and a few other parts. Nat Semi makes a large range." CreationDate="2011-03-17T23:01:50.733" UserId="305" />
  <row Id="17320" PostId="11626" Score="1" Text="Please note that you will be having problems finding such resistors as they are not standard. Since your driver is the problem, go for resistors with a bit higher resistance." CreationDate="2011-03-17T23:02:17.937" UserId="1240" />
  <row Id="17321" PostId="11617" Text="Some TI dsp's come from the factory with a boot loader in hardware. they'll boot load from a serial port." CreationDate="2011-03-17T23:20:44.777" UserId="1481" />
  <row Id="17322" PostId="11617" Text="lots of microcontrollers do that, they just open up the spi port and read from some fixed address in an external SPI memory device and execute the code there (or receive code from the spi port).  I wouldn't call that a bootloader though, really the first few instructions it fetches are the bootloader as its that code that setups up the environment and hands over control to the 'real code' be it an OS kernel or a bare metal app.  This function is more 'BIOS-like' rather than a bootloader." CreationDate="2011-03-17T23:33:30.470" UserId="1438" />
  <row Id="17323" PostId="11630" Text="So then it would work?" CreationDate="2011-03-18T00:17:33.960" UserId="3045" />
  <row Id="17324" PostId="11567" Text="That basically just means you're making the BIOS your OS :P" CreationDate="2011-03-18T00:25:09.517" UserId="708" />
  <row Id="17325" PostId="11575" Text="I accepted this answer because it was the most helpful. I think I'm going to get the Wifly shield from Sparkfun since it's my only option at the moment. I can't wait an indefinite amount of time to see what happened to asynclabs' wifi solutions just to save $30..." CreationDate="2011-03-18T01:22:57.213" UserId="3039" />
  <row Id="17326" PostId="11617" Text="Correction: booting from an asynchronous serial port." CreationDate="2011-03-18T01:42:44.397" UserId="1481" />
  <row Id="17327" PostId="11619" Text="This is a theory question.Just for concept building." CreationDate="2011-03-18T01:55:58.853" UserId="2951" />
  <row Id="17328" PostId="11547" Text="@unixbigot nice comment.But plese you will explain this line      When the microcontroller has booted it can configure two pins as outputs and &quot;override&quot; the resistor biasing." CreationDate="2011-03-18T02:11:02.480" UserId="2951" />
  <row Id="17329" PostId="11632" Score="1" Text="I've never seen a value on an 0402 resistor." CreationDate="2011-03-18T02:20:50.407" UserId="411" />
  <row Id="17330" PostId="11636" Score="5" Text="Also, SMT resistors have a top and a bottom (e.g. resistive film is on only one side), while caps do not (top and bottom are interchangeable)" CreationDate="2011-03-18T02:26:31.437" UserId="1374" />
  <row Id="17331" PostId="11606" Text="+1 thanks, that sounds promising. I will follow it up &amp; get back to you" CreationDate="2011-03-18T02:29:24.777" UserId="3396" />
  <row Id="17332" PostId="11602" Text="+1 thankjs, that helped. I didn't expect and answer on S.O, thought the midstorms forum here would be more helpful" CreationDate="2011-03-18T02:30:09.550" UserId="3396" />
  <row Id="17333" PostId="11636" Text="I've seen an example of ceramic SMD caps with printing - 0805 size or so. As I recall it wasn't readily decodable." CreationDate="2011-03-18T02:51:36.963" UserId="906" />
  <row Id="17334" PostId="11628" Text="[National Semi's SIMPLE SWITCHER](http://www.national.com/simple_switcher) modules are switching regulators packaged with an inductor, so all you need are 6 additional components, including 2 caps for input/output, and 2 resistors for setting the output voltage.  They're somewhat pricey compared to a plain controller and associated passives, but they have a niche." CreationDate="2011-03-18T02:52:16.983" UserId="1407" />
  <row Id="17335" PostId="11547" Text="@unixbigot, if you can sketch the schematic it will be helpful.  Make sure to show the body diodes on the MOSFET." CreationDate="2011-03-18T03:29:12.923" UserId="411" />
  <row Id="17336" PostId="11637" Text="http://meta.electronics.stackexchange.com/questions/440" CreationDate="2011-03-18T03:34:16.130" UserId="411" />
  <row Id="17337" PostId="11621" Score="1" Text="An example of using assembly for precision delays is included in the avr-libc util/delay.h file which may be a good starting point." CreationDate="2011-03-18T05:06:33.643" UserId="2308" />
  <row Id="17338" PostId="11504" Text="@W5VO, that's the lower bound I'm trying to get a handle on. Even though the eBay page does say 2.2W @ 12V, the seller said in an email I'd need one 3A power supply per 5m length. Similar strips whose published specs I trust more (http://bliptronics.com/item.aspx?ItemID=84) say 1-3W/m which sounds more sensible to me." CreationDate="2011-03-18T05:10:39.473" UserId="1633" />
  <row Id="17339" PostId="11588" Text="@BASnappl, We had actually planned to not seed questions. I appreciate the question and information. The issue is that when you already know the answer most people will not take the time to answer it. This could also mean that we do not get better solutions for the answer. In general the process of seeding is not a great way to go about generating site content. HOWEVER, sharing your knowledge with us now and again is not harmful. Thank you for taking the time" CreationDate="2011-03-18T05:15:17.300" UserId="230" />
  <row Id="17340" PostId="11573" Score="2" Text="@endolith, at 200-500KHz a half wavelength dipole and such are gigantic. The difference is that the &quot;near-field&quot; of such an antenna is gigantic. This is where inductive and capacitive coupling take place. For this case it means that you do not need a radiator, you just want to promote capacitive and inductive coupling." CreationDate="2011-03-18T06:15:10.220" UserId="230" />
  <row Id="17341" PostId="11598" Text="@earlz, power dissipated is Voltage times Current. This means that a 1k resistor will reduce your possible output current to be very small, this resistor is a &quot;power limiting&quot; resistor as markrages notes." CreationDate="2011-03-18T06:18:17.110" UserId="230" />
  <row Id="17342" PostId="11164" Text="@reemrevnivek, I have seen the light of subversion, and it is amazing. It makes releases very easy for us. Good comments make tracking bugs and such a breeze also." CreationDate="2011-03-18T07:14:31.850" UserId="230" />
  <row Id="17343" PostId="11318" Text="@Shitake83, it is a name of the technology to most whom use it I believe. Honestly, for an electronics guy, does it hurt anything if he thinks it is an acid based on lead? This seems to be more nit picking then important to me. Most people call it lead acid and identifying it in a standard way seems more important." CreationDate="2011-03-18T07:18:21.883" UserId="230" />
  <row Id="17344" PostId="11632" Text="@markrages On some older 0402's, I have. Perhaps they have stopped doing it. I use 0603 in most of my designs." CreationDate="2011-03-18T08:02:16.153" UserId="1225" />
  <row Id="17345" PostId="11164" Text="The answer is good (exactly what I would write myself), but I would recommend Git over Subversion any day. See http://stackoverflow.com/questions/871/why-is-git-better-than-subversion" CreationDate="2011-03-18T08:31:27.240" UserId="2395" />
  <row Id="17346" PostId="11606" Text="-1 It's Atmel, not Altera. Sensor and motor handling is shared between the ATmega48 and the ARM. &quot;RCX with an ARM slapped on top&quot; is nonsense." CreationDate="2011-03-18T09:13:59.183" UserId="339" />
  <row Id="17347" PostId="11166" Text="No wonder embedded products are expensive if you do all the work by hand. Not that I like the work flow, but event if you did your answer could *easily* be automated." CreationDate="2011-03-18T09:25:09.500" UserId="2395" />
  <row Id="17348" PostId="11630" Text="probably - but you're only talking about DC issues here - you may see some LR issues slowing down edges " CreationDate="2011-03-18T09:38:01.323" UserId="3190" />
  <row Id="17349" PostId="11563" Text="@Patrick Hogan I've seen motorized analog potentiometers controlled by microcontroller in a speaker system. I'll try to find out how exactly it was connected." CreationDate="2011-03-18T09:44:38.797" UserId="1240" />
  <row Id="17352" PostId="11645" Text="+1 You made some very good points. Welcome to the site! I love the PPS, I have used it on the dsPIC and have almost got to the point of favoring it even for simple projects. I do want people to be aware that if they ever do want to market their product every penny counts and in large quantities the lower end PICs will be cheaper. It can be difficult to switch PIC lines down the road, so if you do start trying to make products, try to start with an 18f or lower unless you need something in the higher line. But 24f and dsPICs are still great for learning." CreationDate="2011-03-18T12:47:05.590" UserId="319" />
  <row Id="17357" PostId="11645" Text="Thanks Kellenjb.  &#xA;I totally right with you about production scales.  For &quot;real&quot; products you'd take the time to find a the cheapest pic that meets just the requirements you need.  There are some many of them!  " CreationDate="2011-03-18T13:19:16.227" UserId="3419" />
  <row Id="17360" PostId="11645" Text="**Sorry**. This was meant to be 1 comment. I wasn't aware of the edit time limit which explains the bad spelling! &#xA;&#xA;For hobby use I think ease of use outweighs a cost variance of a dollor or two. It's also nice to start with a &quot;big&quot; chip to gain experience from without having to worry too much about capabilities. Once you have more confidence you can make moves in other directions. For me that's the 24f family. Nothing I have attempted has really stretched it's capabilities.  &#xA;Mind you it is a bit sad to think of the 24f sitting there twiddling it's thumbs whilst I ask it to blink a few LEDs." CreationDate="2011-03-18T13:37:05.347" UserId="3419" />
  <row Id="17361" PostId="11653" Score="1" Text="I can add support to gputils is someone could shed some light on how to do it. But if not I'll have to use MPLAB X for now, I have it set up and running at home. I would like to use gputils+pk2cmd though as it's free, available and I haven't gotten the PICkit to work with MPLAB." CreationDate="2011-03-18T13:57:06.710" UserId="2395" />
  <row Id="17363" PostId="11655" Text="Thanks for the answer! I know 75mA is way to much for an Arduino pin. I planned on using a transistor and flyback diode to overcome this (exactly like in your circuit). I was just trying to figure out how to drop the 5V output pin to 3V. So you are saying I should use 3 diodes in series? What are the advantages of multiple diodes vs a resistor?" CreationDate="2011-03-18T14:15:18.207" UserId="3362" />
  <row Id="17364" PostId="11164" Text="@trygvis - I agree as well, but (1) when we picked a VCS, Git wasn't available, and (2) Subversion is centralized, and we have a great company LAN that's super-fast, always up, and has lots of storage that's backed up by professionals, letting me focus on working.  We *want* centralized control over the data, and Git is distributed." CreationDate="2011-03-18T14:19:18.603" UserId="857" />
  <row Id="17365" PostId="11606" Text="@starblue it is an Atmel,I'm sorry. I had Altera on my mind from an fpga discussion on another board and messed the two up. The main CPU talks with intelligent sensors (over i2c) but all the analog sensors are controlled by the 8bit micro. Although i understand how my analogy might sound facetious, it was never intended as an exact description of the device." CreationDate="2011-03-18T14:24:54.180" UserId="1729" />
  <row Id="17366" PostId="11473" Text="@Ian I was unaware that &quot;American&quot; was a language. But this does pose an interesting question: If in British English &quot;Traffic Light&quot; is the equivalent of American English &quot;Stop Light,&quot; and British &quot;Stop Light&quot; is American &quot;Brake Light,&quot; then is there a usage or meaning of &quot;Brake Light&quot; in the UK?" CreationDate="2011-03-18T14:26:58.477" UserId="2028" />
  <row Id="17367" PostId="11516" Text="@reemrevnivek: transistor+resistor is tiny and cheap, and functions fine. 2 discrete transistors is almost as small, and I think it functions fine -- or am I overlooking something? Is there something magic about transistors inside an IC that can't be duplicated by individual discrete transistors?" CreationDate="2011-03-18T14:30:01.377" UserId="813" />
  <row Id="17368" PostId="11658" Text="Thanks, nice overview! But I already knew I needed a flyback/snubber diode to prevent back EMF from doing any damage. I was just wondering what would be the best way to get the 5V output down to 3V :)." CreationDate="2011-03-18T14:35:48.717" UserId="3362" />
  <row Id="17369" PostId="11655" Text="You could use a resistor. I make it 2V/75mA = 27R." CreationDate="2011-03-18T14:36:53.387" UserId="305" />
  <row Id="17371" PostId="11636" Text="+1 can you provide a link to the reference(s) you found?" CreationDate="2011-03-18T15:05:26.837" UserId="2157" />
  <row Id="17372" PostId="11633" Text="+1 cool project." CreationDate="2011-03-18T15:11:00.467" UserId="813" />
  <row Id="17373" PostId="11516" Text="After further consideration, I've come to the conclusion that yes, you can use discrete transistors to duplicate an inverter.  You can't, however, duplicate more complex logic, because your transistor has the source tied to the substrate.  You need to connect the substrate (but not the sources) together for other logic circuits. Edited." CreationDate="2011-03-18T15:17:32.757" UserId="857" />
  <row Id="17374" PostId="11558" Text="Quite right, but beware of endianness. When multi-byte entities are mapped onto a struct, they may need endian swapping. For example, IP packets are packed big endian, but x86 and (usually) ARM are little endian" CreationDate="2011-03-18T15:21:39.263" UserId="566" />
  <row Id="17375" PostId="11056" Text="Charlieplexing can be done very similarly to multiplexing, if one simply omits one light from each row.  Actually, it may be possible to &quot;regain&quot; that light by adding a diode, though unless column drivers are constant-current outputs, making it match the brightness of the others may be difficult." CreationDate="2011-03-18T15:40:50.720" UserId="3123" />
  <row Id="17376" PostId="11665" Text="So Chopper Driving is better than current driving?" CreationDate="2011-03-18T16:01:00.313" UserId="3045" />
  <row Id="17377" PostId="11664" Score="1" Text="I'll second this. This family of LED drivers is really nice - it eliminates the need for current limiting resistors and makes using separate supplies very easy. The 24 output part would line up nicely with your LEDs. Maybe consider a chip with multiple SPI I/O." CreationDate="2011-03-18T16:05:35.927" UserId="638" />
  <row Id="17378" PostId="11667" Text="(2) Are you saying that a capacitor scheme will likely NOT work with a slow-rise of power?&#xA;(3) Can you explain or link to an explanation of &quot;BOD&quot;?&#xA;(4) Are you saying that 0V is the default state when powering up?" CreationDate="2011-03-18T16:09:33.590" UserId="3424" />
  <row Id="17379" PostId="11164" Text="You will still have a single authoritative repository with a distributed model, it just give you much more flexibility and *much* faster local operations." CreationDate="2011-03-18T16:23:26.463" UserId="2395" />
  <row Id="17380" PostId="640" Text="@Kortuk - probably because your &quot;answer&quot; did not answer anything. Your text would be perfectly suited for a comment to the question." CreationDate="2011-03-18T16:25:35.883" UserId="2395" />
  <row Id="17381" PostId="11667" Text="I think he's talking about brown-out detection. The initial state(s) would be held until the supply voltage reaches a minimum level (or is above a level for a certain period of time) then the initial state(s) are released." CreationDate="2011-03-18T16:25:42.927" UserId="1293" />
  <row Id="17382" PostId="11658" Text="Ok, good. Always best to check to avoid explosions :)" CreationDate="2011-03-18T16:32:21.207" UserId="2960" />
  <row Id="17383" PostId="11667" Text="Implementing a detection scheme like that seems to be a little too complicated for my purposes.  Maybe I'll just take the pullup resistor power hit." CreationDate="2011-03-18T16:59:11.860" UserId="3424" />
  <row Id="17384" PostId="11633" Text="@davidcary are you the same David Carrie that I met at Vancouver Hack space (VHS) last year?" CreationDate="2011-03-18T17:05:00.483" UserId="592" />
  <row Id="17385" PostId="11605" Text="&quot;making things modular&quot; sounds good. Could you give some specific examples of how to do that?" CreationDate="2011-03-18T17:11:02.967" UserId="813" />
  <row Id="17386" PostId="11606" Text="No, on each sensor port the ARM also has an analog input. Though there are not many sensors that use it, maybe the sound sensor. The motor encoders also go to inputs on the ARM." CreationDate="2011-03-18T17:16:18.290" UserId="339" />
  <row Id="17387" PostId="11653" Text="Actually, MPLABX's assembler doesn't support my device. It has a linker file for it, but no .INC file. I guess I'll have to write it myself. :(" CreationDate="2011-03-18T17:26:27.657" UserId="2395" />
  <row Id="17388" PostId="10474" Text="@Nick: True, although if one is going to spend time trying to use unmarked (grab bag) parts, having a good DMM and, ideally, an LCR meter is a requirement." CreationDate="2011-03-18T17:53:42.657" UserId="1990" />
  <row Id="17389" PostId="11667" Text="Yes, BOD =  brown-out detection. With slowly rising power (microseconds) pulse after capacitor would not be powerful enough to trigger your circuit." CreationDate="2011-03-18T18:18:53.707" UserId="2062" />
  <row Id="17393" PostId="11673" Score="7" Text="1. It's not the inductance in the resistor that is the problem. 2. Even if it were, that wouldn't be at 200 kHz, more like 200 MHz." CreationDate="2011-03-18T18:41:15.573" UserId="206" />
  <row Id="17394" PostId="11483" Text="Sorry I used the wrong term for the travelers (I mistakenly called them runners), they are just the two (or more) wires that connect the hot wires when the switches are in matching positions. I edited my answer to show how they work, and what to avoid when using them as single switches." CreationDate="2011-03-18T18:46:51.457" UserId="3384" />
  <row Id="17395" PostId="11653" Text="There is a P12F1822.INC MPLAB X include file! LF devices use the standard include files." CreationDate="2011-03-18T18:56:32.977" UserId="305" />
  <row Id="17396" PostId="11653" Text="Where? find /opt/microchip -name P12F1822.INC returns zero hits for me. Which version and OS are you using? I'm at alpha 4 on Linux." CreationDate="2011-03-18T19:00:20.073" UserId="2395" />
  <row Id="17397" PostId="11665" Text="Yes, the stepper motor can't tell the difference between chopper drives and constant-current drives, and chopper drives pull less power from the power supply." CreationDate="2011-03-18T19:13:57.213" UserId="813" />
  <row Id="17398" PostId="11673" Text="I remove the resistor and the signal looks much better. When I look at the oscilloscope, the clock signal is rectangular shaped. With the resistor, at high frequencies the clock signal looks triangular shaped. Thus I concluded that it was the inductance in the resistor filtering out the high frequency components. " CreationDate="2011-03-18T19:34:25.617" UserId="2968" />
  <row Id="17399" PostId="11675" Score="2" Text="DIO = digital I/O? (sorry, I'm a total noob).  This looks pretty neat, I'll have to try it out, but I am still looking for a chip-based solution as I plan on moving to more advanced techniques later on." CreationDate="2011-03-18T19:56:43.440" UserId="3077" />
  <row Id="17400" PostId="11672" Text="I'll have to check this out too..." CreationDate="2011-03-18T19:59:32.750" UserId="3077" />
  <row Id="17401" PostId="11605" Text="Some examples would be arduino with its shields, modular synthesizers, a personal project would be my helicopter,Modules include motor driver, power supply, uC, and sensors. I couldn't find any Commercial Electronic examples." CreationDate="2011-03-18T20:40:07.733" UserId="2060" />
  <row Id="17402" PostId="11670" Text="Beagle Board does have PWM through the expansion port, I couldn't find the exact number of ports tho. more info here http://elinux.org/BeagleBoardPWM" CreationDate="2011-03-18T20:56:15.437" UserId="2060" />
  <row Id="17403" PostId="11664" Score="1" Text="Does PWM work on a spinning POV display?" CreationDate="2011-03-18T21:34:11.273" UserId="813" />
  <row Id="17404" PostId="11633" Text="@Funvill , I wish I was -- photos of that space I see on the internet look awesome. I would like to start such a space in Tulsa. Alas, I haven't been in Canada in years." CreationDate="2011-03-18T21:40:25.747" UserId="813" />
  <row Id="17405" PostId="11665" Text="There fore I don't need the resistors, just a chopper driver. Will the power suppply be able to tell that a chopper driver is in use, or do I need to get one that can supply more amperage than the motor can consume?" CreationDate="2011-03-18T22:18:47.397" UserId="3045" />
  <row Id="17406" PostId="11673" Text="@umps - No, it's the capacitance in your scope probe.  See [MikeJ's answer](http://electronics.stackexchange.com/questions/11673/types-of-resistors-and-inductance/11684#11684)." CreationDate="2011-03-18T22:30:20.513" UserId="857" />
  <row Id="17407" PostId="640" Text="@trygvis, this is from a SE 1.0 site and when I was just getting involved in the site. I did not know better at the time. I hope you got a laugh out of it." CreationDate="2011-03-18T23:07:33.993" UserId="230" />
  <row Id="17408" PostId="11628" Text="@Leon: Thanks for the answer... I don't really want to change anything at this stage as the circuit is built and working. I think I'm just going to stick a bigger heat sink on it and let it heat up... you've put my mind at rest about the thermal limiting. I guess if it gets too hot it will just switch off for a bit, which is not a big problem for this application." CreationDate="2011-03-19T00:20:27.117" UserId="2426" />
  <row Id="17409" PostId="11637" Text="@Fake Name: Thanks for the answer. I don't think I'll use a switching regulator in this case, but I'll certainly keep it in mind for my next project." CreationDate="2011-03-19T00:21:52.887" UserId="2426" />
  <row Id="17410" PostId="11255" Text="Can you clarify on what sort of circuit you are suggesting here?  Emitter follower is a BJT topology." CreationDate="2011-03-19T01:51:05.910" UserId="857" />
  <row Id="17411" PostId="11358" Text="@Fake Name - Not everyone is a native English speaker!  Zain's profile says they're from Pakistan.  Fixing little things like this is what the &quot;edit&quot; button is for." CreationDate="2011-03-19T01:54:43.427" UserId="857" />
  <row Id="17412" PostId="11691" Score="1" Text="Something i'll add about the SD card issue is that SD isn't just SD when it comes to these small embedded devices.  SD cards can be accessed in multiple ways.  SPI, 1-bit SD, 4-bit SD, UHS-I and UHS-II in order of speed.  The SPI interface is the easiest to implement and almost any microcontroller can do it very easily but its also by far the slowest.  So when looking at this platforms don't just look for an SD slot but look at what transfer modes it actually implements to get an idea of how fast it will be.  " CreationDate="2011-03-19T03:13:16.157" UserId="1438" />
  <row Id="17413" PostId="11673" Text="I guess the scope probe can make it worse. Still the circuit does not work at high frequencies even without the probe so I will try replacing the resistor with a higher quality one (I have been using radio shack components of unknown origin so this may also be the problem).  " CreationDate="2011-03-19T03:17:37.560" UserId="2968" />
  <row Id="17414" PostId="11255" Text="@reemrevnivek: See edit above.  I'd been mentally tossing around a few variations, and they got muddled together.  If one is adding transistors to boost the high-side drive but not the low-side drive, they need to be BJT's.  If one were using transistors for both, mosfets might be better." CreationDate="2011-03-19T03:17:46.623" UserId="3123" />
  <row Id="17415" PostId="11692" Score="1" Text="Are you looking for an embedded PC that is capable of running Windows or Linux? Or, are you looking for an embedded platform that has all the interfaces and capabilities you mentioned?" CreationDate="2011-03-19T03:23:11.400" UserId="2489" />
  <row Id="17416" PostId="11694" Text="this dont solves my problem... must be really small...&#xA;Dont want to stole files, just protect in an secure place..." CreationDate="2011-03-19T03:36:27.107" UserId="1539" />
  <row Id="17417" PostId="11699" Text="Oh, and KiCAD is another option, but in my experience it has a similar learning curve to gEDA, and [Zuph already posted it](http://electronics.stackexchange.com/questions/11690/making-etchable-pdfs-in-linux/11698#11698)." CreationDate="2011-03-19T04:25:59.850" UserId="857" />
  <row Id="17418" PostId="11694" Text="How is a mouse secure?" CreationDate="2011-03-19T04:26:48.787" UserId="857" />
  <row Id="17419" PostId="11697" Score="1" Text="[Here's one example](http://hackaday.com/2010/10/02/usb-ports-hidden-inside-gaming-mouse/) of such a hack." CreationDate="2011-03-19T04:29:33.090" UserId="857" />
  <row Id="17420" PostId="11694" Text="nobody searchs a pen drive inside an mouse..." CreationDate="2011-03-19T04:32:34.143" UserId="1539" />
  <row Id="17421" PostId="2763" Text="@unixbigot - Sad, I had hoped to see a cool hack involving reuse of the reset pin for LED driving, or diode drop use.." CreationDate="2011-03-19T04:32:49.360" UserId="857" />
  <row Id="17422" PostId="2763" Score="1" Text="@Davidcary - Your link is dead, and you should probably link to [Windell Oskay's answer](http://electronics.stackexchange.com/questions/1609/1651#1651).  It may not seem important when you post, but as more answers appear, your post becomes distant from the other." CreationDate="2011-03-19T04:33:09.920" UserId="857" />
  <row Id="17423" PostId="11429" Text="@200ok - You may be able to revive it with a bit of flux on the offending pin, and then reflowing that pin with a soldering iron.  If that fails, use a hot air gun or soldering iron and wick to remove the chip and inspect the PCB." CreationDate="2011-03-19T04:47:14.807" UserId="857" />
  <row Id="17424" PostId="11695" Text="@AdamDavis, the chips I have with ESD diodes often will result in the same result on any pin and ground, so atleast you found ground." CreationDate="2011-03-19T04:51:45.020" UserId="230" />
  <row Id="17425" PostId="11692" Score="1" Text="@Mawg - Expanding on what Louis said, RS232 and ModBus (the serial version; Ethernet is a bit harder) can be bit-banged on a microcontroller costing less than a dollar.  WiFi is hard and expensive.  For a software analogy, it's like you want a programming language that will let you allocate some memory and write some lines to a file (thinking C or assembly here...) and have support for regular expressions and maybe GUI programming (oops, now we're into Python or Java)." CreationDate="2011-03-19T04:54:46.237" UserId="857" />
  <row Id="17426" PostId="9352" Text="@Fletcher - Those pages do have good information right now (two months after you posted), but it will be better if you can summarize/quote (use the `&quot;` button) the relevant parts of those pages.  If that link goes dead, your answer is pretty useless as is..." CreationDate="2011-03-19T05:01:06.463" UserId="857" />
  <row Id="17428" PostId="11697" Text="this can help =]" CreationDate="2011-03-19T05:26:26.240" UserId="1539" />
  <row Id="17429" PostId="11672" Text="Is this different from PWM?" CreationDate="2011-03-19T05:27:28.173" UserId="142" />
  <row Id="17430" PostId="11680" Text="A 12-bit ADC should be able to reproduce any old music waveforms, just with more background hiss than a CD." CreationDate="2011-03-19T05:29:39.807" UserId="142" />
  <row Id="17431" PostId="11358" Text="@reemrevnivek - I would have tried to fix it if I could figure out what the question was about." CreationDate="2011-03-19T07:05:05.283" UserId="1374" />
  <row Id="17432" PostId="11694" Score="1" Text="@Andrew Except it will show up on device manager or lsusb or whatever, so don't forget to include a way to power down the hub and use mouse directly when the computer is being searched. Also make sure you have a hub handy at all times. Otherwise, you won't be able to explain how you connected mouse to the computer." CreationDate="2011-03-19T07:05:46.537" UserId="1240" />
  <row Id="17433" PostId="11358" Score="1" Text="This question was about basic circuit theory." CreationDate="2011-03-19T07:12:30.937" UserId="2951" />
  <row Id="17434" PostId="640" Text="@Kortuk, hehe. I just wanted to answer the question for future reference as the question is good (and popular!)." CreationDate="2011-03-19T08:43:41.000" UserId="2395" />
  <row Id="17435" PostId="11607" Text="BarsMonsters: Thanks for your reply,I asked as I have seen some abstracts of research papers on use of FPAAs in solving diff eqns. I suppose should look at more conventional designs." CreationDate="2011-03-19T09:14:09.447" UserId="3319" />
  <row Id="17436" PostId="640" Text="@trygvis, No worries. A moderator gets used to being told his is wrong, when I am wrong, everyone tells me." CreationDate="2011-03-19T09:45:28.147" UserId="230" />
  <row Id="17437" PostId="11689" Score="1" Text="@Andrew, this is really not enough information. Do you want chips, do you want to know whom sells these hubs? What is your target here? making one, making 1000?" CreationDate="2011-03-19T09:47:54.587" UserId="230" />
  <row Id="17438" PostId="11698" Text="Use plot to postscript to get a decent output." CreationDate="2011-03-19T10:28:21.010" UserId="339" />
  <row Id="17439" PostId="11653" Text="When I downloaded it on OSX I got beta 5 which has support for the chip, yay." CreationDate="2011-03-19T11:19:47.357" UserId="2395" />
  <row Id="17440" PostId="11636" Text="So why are tantalums frequently printed with useless nonsense ?" CreationDate="2011-03-19T11:49:32.213" UserId="1024" />
  <row Id="17441" PostId="11422" Text="The BK 1672 is nice looking, I'm not sure I want to pay that much (Looks like ~350USD) but it's tempting." CreationDate="2011-03-19T12:52:08.193" UserId="3208" />
  <row Id="17442" PostId="11465" Text="Thanks for the Apogee info, I think I'll be combing e-bay to see if I can find something before I go for it though." CreationDate="2011-03-19T12:53:22.360" UserId="3208" />
  <row Id="17443" PostId="1610" Text="Keep in mind with this method it is only possible to have N-1 LEDs on at a time." CreationDate="2011-03-19T13:37:15.327" UserId="249" />
  <row Id="17444" PostId="11668" Text="Hmmm....  Can you draw an equivalent circuit?" CreationDate="2011-03-19T14:22:44.680" UserId="142" />
  <row Id="17445" PostId="11691" Text="An excellent point, Mark. I suspect that few, if any, embedded boards implement UHS-I or UHS-II yet. I just looked at some schematics, and both the TS-7500 and the Beagleboard use the 4-bit bus. (I had said I used a TS-7550 previously, but now I think it's a TS-7500. Will now update answer.)" CreationDate="2011-03-19T15:31:27.153" UserId="712" />
  <row Id="17446" PostId="11143" Text="Any progress with this, @Imelza ?" CreationDate="2011-03-19T15:59:39.553" UserId="2118" />
  <row Id="17447" PostId="11577" Text="Are you able to provide any more details as to your current setup? ie: type of ADCs used, which touch sensor, which touch controller." CreationDate="2011-03-19T16:03:42.573" UserId="2118" />
  <row Id="17448" PostId="11275" Score="1" Text="[Was about to add a small bounty](http://chat.stackexchange.com/transcript/message/697459#697459) as I think this is a great question, but you have no shortage of rep yourself ;) ... maybe offer a bit for an answer?" CreationDate="2011-03-19T16:05:30.230" UserId="2118" />
  <row Id="17449" PostId="11691" Text="+1 for technologic. Also http://en.wikipedia.org/wiki/SheevaPlug" CreationDate="2011-03-19T16:27:01.153" UserId="2157" />
  <row Id="17450" PostId="11275" Score="1" Text="@tyblu : done, had to end another bounty earlier ;-)" CreationDate="2011-03-19T16:58:58.637" UserId="2062" />
  <row Id="17451" PostId="11664" Text="@davidcary Yes you can use PWM's on a POV display " CreationDate="2011-03-19T18:26:56.370" UserId="592" />
  <row Id="17452" PostId="11708" Text="This does not explain one we cannot load 3rd party firmware." CreationDate="2011-03-19T18:27:07.843" UserId="2062" />
  <row Id="17453" PostId="11633" Text="@davidcary here is one in Tulsa, it looks more software then hardware but it would be a good start.  http://hackerspaces.org/wiki/Free_Information_Exchange_Foundation" CreationDate="2011-03-19T18:34:54.930" UserId="592" />
  <row Id="17454" PostId="11647" Text="You are absolutely right. In the latest Android version 2.3.3 Google delivered all the neccecary tools for card emulation. At the time I researched and wrote that article however Android 2.3 only posessed reading capabilities and Google had stated that they **might** implement full NFC functionality in future Android releases. As this has now happend I change my original post the be kind of up to date once again." CreationDate="2011-03-19T18:39:57.310" UserId="2510" />
  <row Id="17455" PostId="11360" Text="I just did a rough assembly last night and it seems to be working. The setup is 2&quot; PVC-&gt;2&quot; PVC coupling-&gt;Bushing-&gt;1.5&quot; PVC. There is a little bit of slop, but not enough to concern me - I might see what other techniques I can utilize to reduce the slop later on in the project." CreationDate="2011-03-19T19:04:31.897" UserId="3339" />
  <row Id="17456" PostId="11689" Text="need to hide an pen drive inside an mouse... to boot an Operation System on it" CreationDate="2011-03-19T19:28:32.143" UserId="1539" />
  <row Id="17457" PostId="11577" Text="@tyblu thanks, I added some more info" CreationDate="2011-03-19T20:14:52.750" UserId="207" />
  <row Id="17458" PostId="11607" Text="Analog computation has a rich history and potential, but it's fallen out of favor due to the relative difficulty of constructing such systems vs. digital &quot;equivalents&quot;. This is what I've gathered from casual research over the past few years. @BarsMonster exaggerates a bit – analog computation is useful for many kinds of systems as is chemical computation, but he's right, don't expect to be doing anything useful anytime soon." CreationDate="2011-03-19T20:22:13.633" UserId="207" />
  <row Id="17459" PostId="11607" Text="Well, I am not against analog computations. I am just saying that FPAA would not do the same for analog computations, as FPGA does for digital." CreationDate="2011-03-19T20:28:17.117" UserId="2062" />
  <row Id="17460" PostId="11712" Text="I finally used a broken Jack wire : and it worked!" CreationDate="2011-03-19T20:54:33.747" UserId="3442" />
  <row Id="17461" PostId="11709" Text="Look around for &quot;serial to USB&quot; converter, we have several questions that address them from varying point of views." CreationDate="2011-03-19T21:04:15.843" UserId="319" />
  <row Id="17463" PostId="11607" Text="Agreed, though theoretically it could ^_^" CreationDate="2011-03-19T21:24:18.180" UserId="207" />
  <row Id="17464" PostId="11560" Text="This seems like a roundabout way connecting a DIP or, rather, a DIP socket to the kit with wires, which is what I eventually did. The result looks about as awful as expected, but it'll work until someone decides to use lethal force against the chip for the second time. A PCB would probably made the soldering job cleaner and easier and the result simply better as a whole, but that would've been way too easy." CreationDate="2011-03-19T21:40:02.693" UserId="3400" />
  <row Id="17465" PostId="11708" Text="@Leon - That post links to another thread, which has, at the bottom, an authoritative post from NXP.  I'm going to give you a hand, and drop the links in for ya... " CreationDate="2011-03-19T21:53:47.937" UserId="857" />
  <row Id="17466" PostId="11715" Text="No, not gold plated, but most of them have a gold look to them." CreationDate="2011-03-19T22:00:38.237" UserId="1225" />
  <row Id="17467" PostId="11716" Text="5/10 are tested by fab according to netlist (generated from gerber), but who knows, they were dirt cheap, they could have skimped." CreationDate="2011-03-19T22:01:23.870" UserId="1225" />
  <row Id="17468" PostId="11714" Text="Wait - Your fab can do 12 mil vias, but you used 15 mil?  That should be *easier*.  Also, can you upload a picture?  If the holes aren't plated through, you won't have continuity.  Are you saying that they're missing an annular ring?  Confused..." CreationDate="2011-03-19T22:10:45.020" UserId="857" />
  <row Id="17471" PostId="11714" Text="@reemrevnivek. I'll upload a pic later, my camera sucks for macro. I think the problem is the lack of annual ring on both sides of the board - the vias look otherwise identical to any other copper." CreationDate="2011-03-19T22:32:22.923" UserId="1225" />
  <row Id="17472" PostId="11607" Score="1" Text="@msutherl My aim is to build an analog system capable of simulating simple physical systems like damped oscillations,similar to the bouncing ball system shown here. http://www.youtube.com/watch?v=qt6RVrmvh-o " CreationDate="2011-03-19T22:37:45.367" UserId="3319" />
  <row Id="17474" PostId="4082" Text="I ended up going with mbed. It's online compiler concept is a bit weird, but working right out of the box is something I'm very fond of. Also, the specs of mbed are a good step up from Arduino along with letting me explore the ARM architecture.(which I've been wanting to do for a while) " CreationDate="2011-03-19T23:50:18.567" UserId="708" />
  <row Id="17475" PostId="11689" Text="@Andrew, I think this is a better fit for superuser.com" CreationDate="2011-03-19T23:54:08.873" UserId="230" />
  <row Id="17476" PostId="11142" Text="Sadly this is not an option. We need all the bandwidth we can get." CreationDate="2011-03-20T00:00:55.537" UserId="1024" />
  <row Id="17477" PostId="11722" Text="My stepper is rated at 1.4A while my chopper driver is rated at 750mA. The driver does have thermal shutdown however." CreationDate="2011-03-20T01:57:04.767" UserId="3045" />
  <row Id="17478" PostId="11538" Text="As mentioned above the world is little endian, the processor market embedded and desktop are owned by little endian and they network just fine.  Doing your system engineering solves all of those problems anyway.  As far as an ARM or any platform you are best by going with native mode, in this case little endian.  The tools will work better, operating systems, etc.  With arm you are either BE8 or BE32 they dont have both on the same core.  The cortex-m's are BE8, which is that much more complicated and risky, go little endian with an ARM, make your life easier." CreationDate="2011-03-20T03:25:51.617" UserId="985" />
  <row Id="17479" PostId="11365" Text="@Earlz, it came off differently, no harm done." CreationDate="2011-03-20T03:53:37.093" UserId="230" />
  <row Id="17480" PostId="11727" Text="Ah, guess I should've checked major suppliers before a general google. " CreationDate="2011-03-20T07:24:56.297" UserId="708" />
  <row Id="17481" PostId="11726" Text="@Earlz, this site is not good for shopping advice." CreationDate="2011-03-20T07:26:31.007" UserId="230" />
  <row Id="17482" PostId="11692" Score="1" Text="@Mawg Please define &quot;cheap&quot;. As cheap as possible regardless of the amount of work involved?" CreationDate="2011-03-20T07:47:01.433" UserId="2096" />
  <row Id="17483" PostId="11720" Text="@vicatcu, the first question is a shopping question. SE sites do not allow this. If you would like to ask how you should go about the problem, that would make a great question." CreationDate="2011-03-20T08:18:36.683" UserId="230" />
  <row Id="17484" PostId="11724" Text="@fani, we need more information to help with this type of question." CreationDate="2011-03-20T08:22:14.260" UserId="230" />
  <row Id="17485" PostId="11718" Text="@ralight, You are writing an answer, if the question is not clear ask. It might be important to ask how much light is needed, but your answer could be much better then asking the OP(Original Poster) another question." CreationDate="2011-03-20T08:47:27.473" UserId="230" />
  <row Id="17486" PostId="11728" Score="1" Text="@kodamapixel, Reading your question it looks like you have an issue, maybe &quot;what is the easiest way to power this device where children cannot reach it?&quot; and now have done some research. After research you found something that might work. Your question is geared to your solution, if you were instead interested in some original question asking it directly often give very very good answer, sometimes informing you of something you would need to be in the field to easily learn about." CreationDate="2011-03-20T09:42:07.453" UserId="230" />
  <row Id="17488" PostId="11729" Text="Thanks for the speedy reply! I'm planning on using very simple and limited sensory inputs: perhaps a pressure sensor, or accelerometer. These would possibly trigger something like a small motor, or LEDs. So battery power could be an alternative option, but I would still like to be able to communicate data with the local network, meaning cabling or a transmitter of some description." CreationDate="2011-03-20T11:27:47.227" UserId="1855" />
  <row Id="17489" PostId="11728" Text="You're absolutely right - it was very much a leading question. From the research I've done PoE looks to be a good solution, but because of my limited knowledge, I'm definitely open to any suggestions." CreationDate="2011-03-20T11:29:56.710" UserId="1855" />
  <row Id="17490" PostId="11728" Score="1" Text="@kodampixel, if you edit your question to include what you need, all of your specs and let us decide we can help, but we really need all of your requirements. It may take a bit of time to type it up, but your question was well written and I am sure you will like the result of telling us what you need and experts weighing in." CreationDate="2011-03-20T11:52:57.883" UserId="230" />
  <row Id="17491" PostId="11720" Text="@Kortuk, ok I've modified the question to remove the shopping aspect" CreationDate="2011-03-20T14:09:22.553" UserId="771" />
  <row Id="17492" PostId="11720" Text="@vicatcu, I meant to tell you to just open a new one, only one answer so far, so no serious harm." CreationDate="2011-03-20T16:08:41.930" UserId="230" />
  <row Id="17493" PostId="11726" Text="@Kortuk are you sure? http://electronics.stackexchange.com/search?q=buy the majority of questions about buying things are open." CreationDate="2011-03-20T16:10:32.643" UserId="708" />
  <row Id="17494" PostId="10399" Score="1" Text="@BarsMonster, people regularly use the clock rate as the measure of their signal speed. It is not, you need to use the knee frequency which is related to the rise time." CreationDate="2011-03-20T16:11:06.933" UserId="230" />
  <row Id="17495" PostId="5084" Text="@Andrew LOL only thing I've done slightly dangerous with electronics(oh I've burned my fair share of LEDs though) is I wired a transistor wrong when connected to a 9V battery. Ended up it shorted through the transistor with an unrestricted 9V. I went to pick up the transistor off the breadboard and burned my thumb and index finger pretty bad lol" CreationDate="2011-03-20T16:33:31.540" UserId="708" />
  <row Id="17496" PostId="11726" Score="1" Text="@earlz, yes, I am sorry if you feel singled out. The mods are going to start cracking down on it. If we wanted to make a single meta post about suppliers, I think that makes sense, and as the community we can discuss doing this. SO is not a good place for shopping questions and the number has been increasing. You just asked a question today as I was discussing it with other moderators." CreationDate="2011-03-20T17:01:57.137" UserId="230" />
  <row Id="17498" PostId="11734" Text="@reemrevnivek, the argument could be made that holes are still a flow of current." CreationDate="2011-03-20T17:07:35.007" UserId="230" />
  <row Id="17499" PostId="11731" Text="@iamgopal - This is dangerously close to being a [shopping question](http://blog.stackoverflow.com/2010/11/qa-is-hard-lets-go-shopping/).  I suggest you read that link, and try to make sure it's a 'good shopping' question." CreationDate="2011-03-20T17:11:59.577" UserId="857" />
  <row Id="17500" PostId="11731" Text="Also, the website linked in your profile: http://www.inqzin.com/ (which I assume is the &quot;We&quot; in your question) gives me `Error: Forbidden\nYour client does not have permission to get URL / from this server.`  I had hoped that page would help me make a better answer for your situation (though that shouldn't be necessary), but I had to use the Google cache (which is lacking).  Just a heads up!" CreationDate="2011-03-20T17:15:17.563" UserId="857" />
  <row Id="17501" PostId="11731" Text="@reemrevnivek, Thanks for stepping in. @iamgopal, we can help if you have technical issues and need help." CreationDate="2011-03-20T17:22:43.910" UserId="230" />
  <row Id="17502" PostId="10392" Text="@umer we need more information on what you are looking for." CreationDate="2011-03-20T17:28:54.963" UserId="230" />
  <row Id="17503" PostId="11717" Text="@wcmartin, you have gone down the bulb source as research to a question and then asked about it. This is common, but I think you will get the best help if you ask about what you technical problem is." CreationDate="2011-03-20T17:37:31.117" UserId="230" />
  <row Id="17504" PostId="3901" Text="@Reemrevnivek, I would disable single file optimizations which has effect and overall timing but then use the file to benchmark and test other systems. With all optimizations I would use LED blinking and such measured with an oscope to measure timings." CreationDate="2011-03-20T17:39:49.913" UserId="230" />
  <row Id="17505" PostId="3901" Text="@OEngenheiro, Take a look at some of the books [Jack Ganslle recommends](http://www.ganssle.com/bkreviews.htm) if you want applied to embedded systems. Otherwise I would assume asking SO would be a great way to get the CS books on this practice." CreationDate="2011-03-20T17:43:35.667" UserId="230" />
  <row Id="17506" PostId="11726" Text="@Earlz, please also take a look at http://blog.stackoverflow.com/2010/11/qa-is-hard-lets-go-shopping/" CreationDate="2011-03-20T17:48:19.610" UserId="230" />
  <row Id="17507" PostId="11731" Text="inqzin.com does not have outside access at the moment...and i should have removed it from my profile. thanks for the pointer.  " CreationDate="2011-03-20T17:50:37.807" UserId="1312" />
  <row Id="17508" PostId="11734" Text="The only way you can get positive charges to move (instead of the absence of negative charges, if we're going to differentiate that) is through transporting atom nuclei.  In a solid or crystal structure this will be *extremely* slow, and possibly damaging." CreationDate="2011-03-20T18:06:41.183" UserId="1407" />
  <row Id="17509" PostId="11734" Text="Er, current in fluorescent bulbs is indeed the flow of electrons ;)" CreationDate="2011-03-20T18:13:14.877" UserId="2118" />
  <row Id="17510" PostId="11735" Score="3" Text="I give your answer +2 anti-negatronic votes." CreationDate="2011-03-20T18:35:17.800" UserId="2118" />
  <row Id="17511" PostId="11717" Text="By &quot;IR bulb&quot; do you mean a heat lamp, or something else?  Most heat lamps have the vast majority of their radiation output at wavelengths much longer than IR LED's." CreationDate="2011-03-20T18:51:37.120" UserId="3123" />
  <row Id="17512" PostId="11712" Text="Is this question now closed? If so, please mark it as closed." CreationDate="2011-03-20T19:22:13.060" UserId="566" />
  <row Id="17513" PostId="11736" Score="1" Text="This sounds like a shopping question, which is off-topic. Are you able to edit it to instead ask about how to reduce heat dissipation?" CreationDate="2011-03-20T20:00:04.603" UserId="2118" />
  <row Id="17514" PostId="3904" Text="But single stepping the code can be almost impossible with optimisations turned on. Debug with optimisations off, and run your unit tests with release code." CreationDate="2011-03-20T20:32:19.247" UserId="1024" />
  <row Id="17515" PostId="11728" Text="Thanks for the suggestion, Kortuk. I've updated the post, which hopefully makes things a bit clearer now." CreationDate="2011-03-20T20:46:16.600" UserId="1855" />
  <row Id="17516" PostId="11746" Text="Well, there are also monitors :-) Universal &amp; non-orthodoxal solution would be much more interesting." CreationDate="2011-03-20T21:34:20.893" UserId="2062" />
  <row Id="17520" PostId="11747" Text="Here's an example of doing the inversion with transistors (its for L293 but will work for 298 with the right pin assignments): http://www.tigoe.net/pcomp/code/circuits/motors/stepper-motors" CreationDate="2011-03-20T23:29:49.590" UserId="389" />
  <row Id="17521" PostId="10584" Text="I think the mbed forums would be a suitable place to ask this question  as well http://mbed.org/forum/" CreationDate="2011-03-20T23:47:37.033" UserId="2060" />
  <row Id="17523" PostId="11748" Text="i think having it be visible adds to the coolness-factor somehow though :)" CreationDate="2011-03-20T23:54:33.677" UserId="771" />
  <row Id="17525" PostId="11742" Text="Where's the current flow in water pipes coming from?  Chlorine and fluorine in the water is more oft discussed because that's the &quot;active&quot; part in the additives, but those negative ions usually come attached with some positive ones to make it neutral; sodium, potassium, hydronium (acid), etc." CreationDate="2011-03-21T00:16:54.343" UserId="1407" />
  <row Id="17526" PostId="11750" Score="1" Text="I seem to remember all the poles being in the left half plane being a necessary condition for stability of a control system - and the punchline to a joke to that affect" CreationDate="2011-03-21T00:20:41.657" UserId="771" />
  <row Id="17527" PostId="11756" Text="+10 rep to get you on the way. A very informative post. " CreationDate="2011-03-21T01:13:10.780" UserId="1225" />
  <row Id="17528" PostId="11714" Score="1" Text="It's a bad picture, but it looks to me like you've accidentally tented your Vias.  Check your gerbers, I bet your solder mask layer covers the vias.  Your boards are fine." CreationDate="2011-03-21T01:31:12.107" UserId="3395" />
  <row Id="17529" PostId="3210" Text="I used these a couple of times and I am in the middle of making a product with of them. The docs suck but take a look at [JeeLabs](http://jeelabs.com/) - the guy is using these modules for all his radio comms)" CreationDate="2011-03-21T01:45:13.127" UserId="659" />
  <row Id="17530" PostId="11321" Text="Kortuk: Yes. Ranieri: I am glad I could help. And thanks for accepting the answer." CreationDate="2011-03-21T02:11:49.100" UserId="659" />
  <row Id="17531" PostId="9770" Text="Driving it with a op amp as a voltage follower is probably the best idea (just watch out for output oscillation because the ADC is probably quite capacitive and op amps generally don't like this)." CreationDate="2011-03-21T02:14:48.317" UserId="659" />
  <row Id="17532" PostId="11742" Text="@tyblu, I am not sure I would count photons, but I always forget electroplating. +1 for finding a way to add electromagnetic spectrum to your post." CreationDate="2011-03-21T02:45:21.713" UserId="230" />
  <row Id="17533" PostId="11728" Text="@kodamapixel, it is what they don't pay me for : )" CreationDate="2011-03-21T02:46:31.167" UserId="230" />
  <row Id="17534" PostId="11768" Text="@Juank, Unix! As noted below." CreationDate="2011-03-21T02:47:29.340" UserId="230" />
  <row Id="17536" PostId="11692" Text="goiod points, all. Maybe I should ask for 2 recommendations, based on o/s. For one, somplething simple &amp; compact like FreeRTOS or EeCos would do, for the other, Winodws or Linux would be nice. That's porbably the biggest price difference and I have a slight preferance for the former. The only real use for  windows is to use existing device drivers if needed ... hmmm, that's quite a biggy ... " CreationDate="2011-03-21T02:58:23.543" UserId="3396" />
  <row Id="17537" PostId="2280" Text="It was really cheaper when I bought it. I guess they realized they are getting paid less then they could be." CreationDate="2011-03-21T02:59:51.770" UserId="659" />
  <row Id="17538" PostId="11692" Text="@aix, I guess I am thinking off the shelf - I don't want to develop drivers or an o/s, if that's what you mean. Generally, I just want some input from a h/w measurement device on a serial port or Etehrnet if it doesn't add &gt; $100. I will then write code to massage the input and output it on a 2nd port. I am a coder, not an h/w guy, in case that isn't obvious ;-)" CreationDate="2011-03-21T03:00:47.597" UserId="3396" />
  <row Id="17539" PostId="1500" Text="In fact even AVRs use this - they do not have an add immediate instruction (only substract immediate) since you can convert easily one into another. If both values are coming from registers then both sub and add are nice and fast but one is still not strictly necessary." CreationDate="2011-03-21T03:03:38.817" UserId="659" />
  <row Id="17540" PostId="5593" Text="Alan Kay calculated that since he was working on Smalltalk in Xerox PARC we have lost 18 years of transistor doubling because of wrong architectures and software inefficiency because computers are certainly not as fast as transistor doubling would suggest." CreationDate="2011-03-21T03:21:02.117" UserId="659" />
  <row Id="17541" PostId="11577" Text="How big are the variation you expect to get from environment changes?" CreationDate="2011-03-21T03:33:57.767" UserId="659" />
  <row Id="17542" PostId="11772" Score="1" Text="@jpc, I have built CWFM radar before, it was very fun. We down-convetered to signals that mostly stayed below 100kHZ." CreationDate="2011-03-21T03:36:46.333" UserId="230" />
  <row Id="17543" PostId="11714" Text="@Zuph, if the etch mask registration is bad enough (looks borderline in the picture) and not covering the via entirely, the enchant can work its way into the via and eat it out." CreationDate="2011-03-21T05:31:52.277" UserId="1407" />
  <row Id="17544" PostId="11714" Text="@Thomas, vias are *always* plated.  When you take a copper clad board and drill holes in it, they won't conduct between the sides.  Plating is used to put metal into them, forming a conductive path between both sides of the board.  Later, depending on the process that is specified, the fab house will put some finish on the exposed copper, ENIG, HASL, etc." CreationDate="2011-03-21T05:36:48.467" UserId="1407" />
  <row Id="17545" PostId="11750" Score="1" Text="@vicatcu, yes. And it is an excellent joke." CreationDate="2011-03-21T05:58:27.930" UserId="230" />
  <row Id="17546" PostId="11758" Text="@jpc, when you tell someone to check wikipedia and such you can embed a link to it. As future users find this link with google they will have all the links they could ever want in one place." CreationDate="2011-03-21T06:28:17.763" UserId="230" />
  <row Id="17548" PostId="11759" Text="It was only $40 for 10 boards. Registration error specified as 0.09mm. http://www.seeedstudio.com/depot/fusion-pcb-2-layer-10cm10cm-max-10pcs-p-396.html?cPath=185" CreationDate="2011-03-21T07:51:30.953" UserId="1225" />
  <row Id="17549" PostId="11759" Text="Self-evidently, it sounds like the chinese PCB house is fudging their numbers." CreationDate="2011-03-21T08:26:43.280" UserId="1374" />
  <row Id="17550" PostId="11774" Text="Good question. I've been wondering that myself. I started with using integer, positive and other types all over the place but it turned out to be very hairy to get synthesized properly. I'm hoping someone can explain why everyone ends up using std_logic in a highly typed language." CreationDate="2011-03-21T08:55:13.797" UserId="2395" />
  <row Id="17552" PostId="11749" Text="What does the 2937 chip refer to in their schematic? I can't seem to find it from the number alone..." CreationDate="2011-03-21T09:29:50.853" UserId="1217" />
  <row Id="17553" PostId="11772" Text="Thanks for the reassurance. :)" CreationDate="2011-03-21T09:59:09.490" UserId="659" />
  <row Id="17554" PostId="11758" Text="I added some links, thanks." CreationDate="2011-03-21T10:18:23.867" UserId="659" />
  <row Id="17555" PostId="11734" Text="I think you can have holes allowing for flow, without an equal number of electrons.  The material is ptype, doped for having holes without (many) electrons. So (not that you necessarily would) but if you doped Si with As or P, you would get a material with extra holes relative to electrons." CreationDate="2011-03-21T12:41:00.753" UserId="1266" />
  <row Id="17556" PostId="1500" Text="Yes, see http://stackoverflow.com/questions/1337831/why-is-this-code-being-generated-by-avr-gcc-and-how-does-it-work" CreationDate="2011-03-21T13:09:18.497" UserId="339" />
  <row Id="17557" PostId="11780" Score="1" Text="I think you mean interface rather than portability - you are not going to write the code for the microcontroller and then port it to run on the Android phone; you want it to interface to the Android phone." CreationDate="2011-03-21T13:45:57.970" UserId="2110" />
  <row Id="17558" PostId="11780" Text="In the Microchip range, I would say the PIC18 is unsuitable, you need at least the dsPIC. And for Wifi you'd be better off with a 32 bit micro - doing an ethernet stack on 16 bit or lower is hard." CreationDate="2011-03-21T13:48:17.063" UserId="2110" />
  <row Id="17559" PostId="11777" Text="This is a really good product and works great on the Mac." CreationDate="2011-03-21T14:04:53.333" UserId="659" />
  <row Id="17560" PostId="2038" Text="The device is *not* RS232 level compatible. It uses 3.3V internally, but is 5V compatible so it'll work with most digital circuits. Not sure how far down it can go though, it would be nice to use it with 2.5V or even 1.8V stuff too." CreationDate="2011-03-21T14:26:34.383" UserId="2395" />
  <row Id="17561" PostId="11780" Text="Thanks Martin for clearing my misconception. Your correct, I should be looking at interfacing instead of portablity, I should probably look into Android emulators initially to help with debugging." CreationDate="2011-03-21T14:46:44.467" UserId="3458" />
  <row Id="17562" PostId="11781" Text="Thanks Kellen, I'll take a look at the link you posted. Although, it basically just seems like a solution to allow Bluetooth communication and not more information on interfacing with an Android Platform." CreationDate="2011-03-21T14:47:43.340" UserId="3458" />
  <row Id="17563" PostId="11734" Text="@Nick: I don't think that's necessarily true.  The moveable charges don't need to be the same material as the solid.  The link describes proton flow in water ice, for instance.  Most flows of current are &quot;extremely slow&quot;." CreationDate="2011-03-21T15:10:18.157" UserId="142" />
  <row Id="17564" PostId="11734" Text="@tyblu: In fluorescent tubes, there is a flow of positive ions.  They are operated with AC because DC would cause all the mercury ions to accumulate at one end of the tube." CreationDate="2011-03-21T15:18:51.630" UserId="142" />
  <row Id="17565" PostId="11781" Text="@microSense if you are looking at how to program an Android App then you will probably need to look else where. We will help all you want with the micro and bluetooth module you pick. It just seemed like you didn't know what path to take at all and I was trying to point you to bluetooth." CreationDate="2011-03-21T15:25:32.783" UserId="319" />
  <row Id="17566" PostId="11734" Text="ArielP: But holes places where electrons would be but gone missing. So to have hole current you have to have electrons hopping between these holes." CreationDate="2011-03-21T15:40:23.307" UserId="659" />
  <row Id="17567" PostId="11776" Text="Yes, I use numeric_std. I guess I'm mostly worried about Xilinx tools... they still generate std_logic_vector for everything and &quot;UNSIGNED&quot; isn't even in the syntax highlighting." CreationDate="2011-03-21T15:54:20.527" UserId="1270" />
  <row Id="17568" PostId="3209" Text="If you *really* want low component count, you can use the same LED as emitter and sensor.  Simply add a method of reverse biasing the same LED, and it now becomes an inefficient light *sensor*.  See this app note: http://www.altera.com/literature/wp/wp-01076-led-driver-reduces-power-adjusting-intensity-ambient-light.pdf" CreationDate="2011-03-21T16:18:41.823" UserId="3395" />
  <row Id="17569" PostId="11664" Text="All the mechanically spinning displays I've seen so far&#xA;give at most the 8 colors: the CMYK + RGB + W that you mentioned.&#xA;The ~ 7000 kbits/second to get full color&#xA;(rather than ~ 600 kbits/second to get 8 colors)&#xA;seems difficult for an Arduino,&#xA;but it might be a cool additional feature." CreationDate="2011-03-21T16:22:36.757" UserId="813" />
  <row Id="17570" PostId="11780" Text="@microSense check out http://developer.android.com/sdk/index.html it has pretty much everything that you need to know for getting started. They even have a software based emulator. However, for interfacing with the outside world you will have to use a physical device." CreationDate="2011-03-21T16:27:18.283" UserId="319" />
  <row Id="17571" PostId="11585" Text="I was somewhat dubious that a dead short to ground would be best, but apparently some [Hakko Irons](http://www.all-spec.com/products/FX951-66.html) have &quot;&lt;2 ohm tip-to-ground resistance&quot; in their specs" CreationDate="2011-03-21T17:57:21.857" UserId="1407" />
  <row Id="17572" PostId="11768" Score="1" Text="@Juank, what are you asking?  (1) Is there professional electronics design software for the Mac? [Answer: Yes] (2) Are Mac electronics designed on PCs? [Answer: Probably, a lot of components/subcircuits are likely to be contracted out.]" CreationDate="2011-03-21T18:03:44.073" UserId="857" />
  <row Id="17573" PostId="11735" Text="I was really asking about electrical components, though, not the human body.  The human body is already covered in the linked article.  Batteries, fluorescent tubes, ..." CreationDate="2011-03-21T18:18:00.137" UserId="142" />
  <row Id="17576" PostId="11781" Text="Understand. Thank you :). Will definitely post here for hardware based questions. I do agree, I was unclear on how to accomplish this." CreationDate="2011-03-21T18:26:24.013" UserId="3458" />
  <row Id="17577" PostId="11784" Text="Thanks Nick, this is very interesting!" CreationDate="2011-03-21T18:26:59.177" UserId="3458" />
  <row Id="17578" PostId="11749" Text="It's a 5 Volt linear regulator." CreationDate="2011-03-21T18:54:37.360" UserId="1477" />
  <row Id="17579" PostId="11749" Text="Never mind, found it. Needed to search for the LM2973. Looks like a voltage regulator, which I already have elsewhere.  **EDIT:** whoops, late post" CreationDate="2011-03-21T18:55:47.797" UserId="1217" />
  <row Id="17581" PostId="11737" Text="To elaborate, the reason there's no good way around the problem without going to a switching supply is because with any other solution you have to dissipate (24V-3.3V) * 250mA = 5.175W worth of power somehow. " CreationDate="2011-03-21T19:21:36.480" UserId="3382" />
  <row Id="17582" PostId="11577" Text="What kind of bit-resolution do you need? I ask because I think it would be simpler to increase the spec on your ADCs by 4 bits (x16), and do the adaptation in software. That should be sufficient to capture a single order of magnitude variation. Of course, if you need 16 or 20 bits of resolution already, then that's going to be very expensive." CreationDate="2011-03-21T19:27:40.810" UserId="3382" />
  <row Id="17583" PostId="10912" Score="4" Text="I would still rather someone chuck me a Snickers bar than a grenade." CreationDate="2011-03-21T19:36:38.603" UserId="3469" />
  <row Id="17584" PostId="11734" Score="1" Text="@reemrevnivek : AFAIk, hole flow in semiconductors is not actually flow of positive charges -- it's still electron flow but it's not due to the free electrons (which is also why holes generally  have lower mobility)" CreationDate="2011-03-21T18:40:41.897" UserId="3460" />
  <row Id="17585" PostId="11785" Text="AFAIR microsoft.com used load balancing hardware which run on Linux. Nothing is known about the actual servers but I doubt they used anything but ASP. Also some high-exec from Microsoft said that he would use a MacBook if company policy wasn't not to. :)" CreationDate="2011-03-21T19:44:40.560" UserId="659" />
  <row Id="17586" PostId="6778" Text="@barsMonster, Can you please let us know how this worked out in the end?" CreationDate="2011-03-21T19:52:09.350" UserId="1240" />
  <row Id="17587" PostId="11791" Text="Interesting question. What expectation do you have of the meter? How accurate should it be and what's your budget? I know some people did it using current measuring clamps on wires. Do you have each power wire exposed near the breakout box so you can measure it? Do you have single or three phase power supply? Please provide as much information as you can." CreationDate="2011-03-21T19:56:36.147" UserId="1240" />
  <row Id="17589" PostId="11792" Text="Very Hackerish, interesting." CreationDate="2011-03-21T19:59:32.953" UserId="319" />
  <row Id="17590" PostId="11784" Text="This is really nice." CreationDate="2011-03-21T20:10:53.743" UserId="659" />
  <row Id="17591" PostId="11735" Text="@endolith, your electrical cicuits we use every day use electronics. The metals we use are electron flow. There is no way around this, protons form part of the lattice, electrons may move freely." CreationDate="2011-03-21T20:11:23.957" UserId="230" />
  <row Id="17592" PostId="6829" Text="The &quot;isolation&quot; transformer is the main DC/DC converter transformer, which is expecting DC input and is chopping it as required. Even though it's stepping down the voltage, it is providing isolation from primary to secondary." CreationDate="2011-03-21T20:47:03.760" UserId="1293" />
  <row Id="17593" PostId="11798" Score="1" Text="Point #2 is incorrect. The AC is rectified. 230V is rectified to 325V dc with some ripple. Therefore you should feed it 325V dc. It may not work with a lower voltage." CreationDate="2011-03-21T21:09:26.150" UserId="1225" />
  <row Id="17594" PostId="11742" Text="@NickT, group charge does indeed tend to neutralize over time, but is usually non-neutral in water pipes -- at least locally. Personal experience was an undergrad project to map magnetic field over a ~km^2 to get an idea as to what kind of shielding and pipe relocation was needed for some new, fancy nanotech equipment at [NINT](http://www.nrc-cnrc.gc.ca/eng/ibp/nint.html)." CreationDate="2011-03-21T21:14:09.247" UserId="2118" />
  <row Id="17595" PostId="11735" Text="@Kortuk A battery is an electrical component, and part of the circuit.  In a battery, current consists of positive and negative ions, not electrons.  Lone protons and ionized atoms are certainly capable of moving in electric circuits." CreationDate="2011-03-21T21:30:10.290" UserId="142" />
  <row Id="17596" PostId="5330" Text="The Yaler project (http://yaler.org/) enables you to run an embedded IPv4 Web server from behind a NAT/firewall. A single Yaler relay server instance with a public IP address supports 1000's of embedded devices. (Disclosure: I work for the company developing Yaler)" CreationDate="2011-03-21T21:33:29.843" UserId="3088" />
  <row Id="17597" PostId="11799" Score="3" Text="+1 for it being longer then I want to read with pretty headings and image" CreationDate="2011-03-21T21:36:59.237" UserId="319" />
  <row Id="17598" PostId="11799" Text="@Kellenjb - Not the reasons that I hoped it would earn upvotes, but I'll take it. :P" CreationDate="2011-03-21T21:40:20.480" UserId="857" />
  <row Id="17599" PostId="11760" Text="@Jpc - You said in words: *Rectification is a non-linear process so it can change the spectrum of a signal* what endolith said in a picture. Unfortunate that he's got more upvotes...." CreationDate="2011-03-21T21:42:17.153" UserId="857" />
  <row Id="17600" PostId="11792" Text=" +1: Already gets the job 99% done." CreationDate="2011-03-21T21:47:13.497" UserId="857" />
  <row Id="17601" PostId="11798" Text="&quot;Some ripple&quot; is undefined. The average voltage on the caps will be less than 325V, especially if you're doubling 110VAC input. If the converter will work at the lower, stiffer DC input, why push it?" CreationDate="2011-03-21T22:04:17.843" UserId="1293" />
  <row Id="17602" PostId="11798" Text="@Madmanguruman, the ripple will be almost zero with no load on the PSU, so you can't say that the average voltage will be less than 325V. Also, don't forget higher AC inputs like 250V which gives you ~350V. I'd imagine that due to the wide input range, ripple is going to be around 50Vp-p." CreationDate="2011-03-21T22:06:41.040" UserId="1225" />
  <row Id="17603" PostId="11547" Text="@zain when the micro is in reset its output pins will be tri-stated and the logic level will be 1 due to a pull up resistor.  When the micro enables output on the pin, if it outputs a 0 this will be a lower resistance connection to ground than the &quot;weak 1&quot; via the pullup, so will be an effective logic 0.  (See http://en.wikipedia.org/wiki/Open_collector)." CreationDate="2011-03-21T22:45:20.220" UserId="389" />
  <row Id="17604" PostId="11547" Text="@markrages I said it'd be tricky :)  I'm going to test this and see if I can make it work." CreationDate="2011-03-21T22:47:57.427" UserId="389" />
  <row Id="17605" PostId="11799" Text="Note that you can diffuse your own LEDs just by lightly sanding the outside of the case.  More of the light will bounce back into the LED and out through other walls when the walls are of a rough texture.  Just a tip for if you accidentally get stuck with water-clear LEDs when you wanted diffused ones." CreationDate="2011-03-21T23:01:35.047" UserId="3424" />
  <row Id="17606" PostId="11799" Text="@Joe Mac - For large quantities (anything greater than 1, really) ou'll be much better off doing this chemically (either with an acid, like the original manufacturer would use) or by spraying with a clear paint or adhesive.  Both methods are hacks, and both will reduce the light output.  " CreationDate="2011-03-21T23:13:18.383" UserId="857" />
  <row Id="17607" PostId="11799" Text="@Joe Mac - Really, any modification of individual components is probably best left to the manufacturer, who already has them on an assembly line.  There's no reason that you should accidentally get stuck with a component: if your supplier screws up, a phone call should fix the situation.  " CreationDate="2011-03-21T23:15:30.453" UserId="857" />
  <row Id="17608" PostId="11760" Text="@reemrevnivek: His picture is nice and his remark about even and odd functions is better than my hand-waving (despite both having their uses) so I don't envy him. :) But thank you for your support." CreationDate="2011-03-21T23:40:19.457" UserId="659" />
  <row Id="17609" PostId="6778" Text="Sure  thing    )............" CreationDate="2011-03-22T00:53:05.087" UserId="2062" />
  <row Id="17610" PostId="11735" Text="@endolith, you knew the battery case, and I thought it was the first example your article gave. I put in a few other example of flow." CreationDate="2011-03-22T01:52:19.080" UserId="230" />
  <row Id="17611" PostId="11805" Score="1" Text="You need some more details; are you talking about 32-bit processors?  Parallel addressed RAM?  8 bits/address?" CreationDate="2011-03-22T01:55:22.753" UserId="1407" />
  <row Id="17612" PostId="11792" Text="Because why do what's already been done?  It provides a clear path to learn how to do it, and if you learn more, how to do it better/do more." CreationDate="2011-03-22T01:57:38.230" UserId="1407" />
  <row Id="17613" PostId="11567" Text="well, the line is a blur one..." CreationDate="2011-03-22T02:50:39.650" UserId="1938" />
  <row Id="17614" PostId="11809" Text="Thanks alot...:)" CreationDate="2011-03-22T03:01:33.707" UserId="3140" />
  <row Id="17615" PostId="11806" Text="The PIC16F84A is a dinosaur.  Why start by learning an obsolete chip? http://www.finitesite.com/d3jsys/16F628.html" CreationDate="2011-03-22T04:15:04.210" UserId="411" />
  <row Id="17616" PostId="11790" Text="After reemrevnivek's answer, there is nothing left to say. Funny that you should post it here, I made a propeller display using 8-RGB LEDs just last week (my first experience http://www.youtube.com/watch?v=4RWoWv-n_pQ) These are fun and easy to work with. I think these are fun to work with and maybe you are overthinking." CreationDate="2011-03-22T04:18:29.647" UserId="1200" />
  <row Id="17617" PostId="7163" Text="VHDL, like C, is pretty much static. Logic gates have not really changed, though new chips have more of them. There may be chip-specific extensions from the device manufacturers, but the underlying structure does not need to change." CreationDate="2011-03-22T05:37:36.137" UserId="1374" />
  <row Id="17618" PostId="11798" Score="1" Text="#6 is also debatable - DC will not drive your heart into fibrillation. The main risk from DC are burns. AC On the other hand also causes tetanus, or *extended* involuntary muscle contraction, while DC just causes an initial jerk." CreationDate="2011-03-22T05:52:30.027" UserId="1374" />
  <row Id="17619" PostId="11813" Text="Putting this in a comment because I'm not sure, but you should be fine. AFAIK most houses get one of these split phase lines, and all 120V circuits are powered in this way (one of the legs)." CreationDate="2011-03-22T06:00:27.727" UserId="2467" />
  <row Id="17621" PostId="11799" Text="Thank you thank you, that was way more then I expected to get and made my choice a lot easier. " CreationDate="2011-03-22T06:40:49.450" UserId="592" />
  <row Id="17622" PostId="11143" Text="It turned out that the default settings pointed to simulatedcompass for the GPS and it didn't let me change it in VPL. So I used a compass sensor instead! But I found some code online which changed some properties in C# to make the SimulatedGPS work. I didn't try it though, since my project is strictly limited to VPL. " CreationDate="2011-03-22T06:41:45.017" UserId="2939" />
  <row Id="17623" PostId="11790" Text="@rick_2047 You are probably right, but I am investing a lot of money in to this project and if I can save my self any failed tests it will be worth it. " CreationDate="2011-03-22T06:42:47.590" UserId="592" />
  <row Id="17624" PostId="11768" Text="Thank you everyone! All answers have been enlightening  " CreationDate="2011-03-22T07:26:29.467" UserId="3455" />
  <row Id="17625" PostId="11803" Text="Thanks, that was a really helpful response - loads of new ideas for me to look at. Fortunately, I don't need to contend with attaching anything physically to participants in the study, so I think I will try PoE to start with (as you say, it also ticks the box of being network aware). I hadn't thought of the Arduino being capable of acting as shock protection for low currents though - that will also being really helpful." CreationDate="2011-03-22T07:37:59.890" UserId="1855" />
  <row Id="17626" PostId="11806" Text="@markrages ahahaahaha...thanks man...I will be sure to try it out :)" CreationDate="2011-03-22T07:58:48.727" UserId="3140" />
  <row Id="17628" PostId="11814" Text="@FakeName, it would be great if you had links to back things up. I know that sometimes adds hours to writing an answer, but thought I would just note how valuable they are." CreationDate="2011-03-22T08:11:41.710" UserId="230" />
  <row Id="17629" PostId="11817" Score="1" Text="Perfect sense... I was actually using the 4 batteries in series and a lawnmower spark plug to decrease the energy requirement. If you ever take a 9v battery apart it's nothing but 6 AAAA (yes, there is a AAAA battery classification) batteries hooked up in series. If needed, I could add 2 (or 4) more AA or AAA batteries in the series to up the voltage requirement. Any idea of how long it takes to let the caps charge, is there any easy way to tell (like, will an led hooked on the supply side lite up when the cap quits drawing power)?" CreationDate="2011-03-22T08:19:52.263" UserId="1866" />
  <row Id="17630" PostId="11817" Text="Well originally I use disposable camera circuits which generally come with a LED which turns on or brightens to its fullest when charged but you can check it with the resistance. I will have a look for you and see if there are any circuits on the net for you :)" CreationDate="2011-03-22T08:34:27.487" UserId="3140" />
  <row Id="17631" PostId="11790" Text="BTW, failure is part of the process.&#xA;&#xA;And secondly, these are really expensive from these distributors. I can get them for .13USD in India and that is if I buy them in retail. And all of them are high quality. I don't know why are these so overpriced from the major vendors.&#xA;" CreationDate="2011-03-22T09:02:59.480" UserId="1200" />
  <row Id="17632" PostId="11817" Score="1" Text="@EvanPlaice, if you use something designed for this like a 12V lead-acid battery you may have better results." CreationDate="2011-03-22T09:18:00.073" UserId="230" />
  <row Id="17633" PostId="11817" Text="Well the time to charge depends on your capacitor and your battery. If for instance I had a AAA battery and a average camera capacitor it would take about 5 seconds to charge. You can generally &quot;hear&quot; a capacitor charge as it makes a whining sound going higher and higher in pitch and when it stops going higher in pitch then it has stop charging. There is another way as I told you before which you find here: http://www.physicsforums.com/showthread.php?t=326150 which uses resistance...:) Hope I make sense" CreationDate="2011-03-22T09:26:01.703" UserId="3140" />
  <row Id="17634" PostId="11817" Text="@Kortuk Very true!" CreationDate="2011-03-22T09:27:49.563" UserId="3140" />
  <row Id="17635" PostId="11814" Text="I've been trying to find something concise. I'm not done with the answer. However, there does not seem to be much information on making stepper motors movement very smooth, since most serious motion control systems use servo motors." CreationDate="2011-03-22T09:29:59.787" UserId="1374" />
  <row Id="17636" PostId="11814" Text="@FakeName, I had a feeling you would have a hard time finding good sources, I added the note a little for you, but I have been trying to leave these regularly around now so that the community slowly moves towards finding references." CreationDate="2011-03-22T10:13:49.523" UserId="230" />
  <row Id="17637" PostId="1802" Text="I use RealTerm, as well. It's very good." CreationDate="2010-03-09T19:20:59.090" UserId="305" />
  <row Id="17638" PostId="11817" Score="1" Text="@James 5 seconds is perfect. It's a spud gun not a gatling spud gun :). I'm trying to stick with 12v pack to keep it portable (ie, fit in a small project box). The LED design is interesting. I was thinking of a LED on the supply side to make it turn on when the cap is charged. IE, bridge a resistor in series with the led to ground so before the capacitor. So, the cap would be the path of least resistance while charging and become an open circuit when charged thus lighting the LED. I'm probably missing something here though." CreationDate="2011-03-22T11:11:07.217" UserId="1866" />
  <row Id="17639" PostId="11817" Text="I'm guessing I'm going to need a beefier relay or something like a high voltage power FET to trigger the spark. Initially I could do without one so it'll spark as soon as the cap is sufficiently charged but I'd like to be able to open the circuit to the spark plug for a push button ignition." CreationDate="2011-03-22T11:15:03.127" UserId="1866" />
  <row Id="17640" PostId="11817" Text="@James Are you registered on that forum. I can't download the attached schematic without signing in and I'd rather not have to register on a site that I'll probably never visit again." CreationDate="2011-03-22T11:17:19.817" UserId="1866" />
  <row Id="17641" PostId="9713" Text="@cbrulak, We love to help with technical questions but shopping advice does not work well on SE." CreationDate="2011-03-22T11:21:42.940" UserId="230" />
  <row Id="17642" PostId="11825" Text="@fatai, maybe it is because I rarely use HDL, but your question is not very clear." CreationDate="2011-03-22T11:34:57.917" UserId="230" />
  <row Id="17644" PostId="11823" Text="You probably wont find a &quot;sensors&quot; like command for what you are looking for, you may be able to write a quick script that will poll your USB/I2C adapter or serial port and print it to the CLI" CreationDate="2011-03-22T11:44:20.983" UserId="2060" />
  <row Id="17645" PostId="9820" Text="@reemrevnivek - C and D are entirely different electrically. C does not connect to the unsprung jack, instead it provides a connection between pins 2 and 3 and 6 and 7 (reading from the top) when no jack inserted, and connections between 1 and 2 , and between 7 and 8 when a jack is inserted." CreationDate="2011-03-22T12:06:53.403" UserId="3525" />
  <row Id="17646" PostId="11829" Text="Yeah, so I can use the circuit in conjunction with a 100k expression pedal. Isn't there a way to use arbitrary values?" CreationDate="2011-03-22T12:19:47.633" UserId="3075" />
  <row Id="17647" PostId="11829" Score="1" Text="Unfortunately using arbitrary values will change the way the rest of the circuit behaves. You could recalculate all the values to ensure voltage/current are still in the right ranges. Or you could be better off altering the resistance of the expression pedal - bring it down to 10k, that way the circuit remains as planned." CreationDate="2011-03-22T12:41:30.443" UserId="3525" />
  <row Id="17648" PostId="11825" Text="@Fatai - I added the sequence `1 0 0 1` in the left to right portion.  I think that your 'insect' was performing a two-step 'jump' previously.  Is the current version correct?" CreationDate="2011-03-22T12:43:00.567" UserId="857" />
  <row Id="17649" PostId="11813" Text="@Tig - what's your location?  Since you referenced NEMA, I'm guessing that you're in the US, right?" CreationDate="2011-03-22T12:44:32.127" UserId="857" />
  <row Id="17650" PostId="5483" Text="It does; I've used it before.  It's available through Macports, but you'll want to build from source as the official packages tend to lag behind development quite a bit." CreationDate="2011-03-22T13:24:32.077" UserId="857" />
  <row Id="17651" PostId="11817" Score="1" Text="@James: What you're hearing is a switching boost converter that steps up the voltage to give the capacitor a high voltage charge.  For a spark plug, you don't want to store lots of energy at high voltage, you just want to produce a high voltage momentarily.  An ignition coil would be a better choice." CreationDate="2011-03-22T13:46:52.033" UserId="142" />
  <row Id="17652" PostId="11799" Text="Great answer, I enjoyed it thoroughly!" CreationDate="2011-03-22T13:52:57.407" UserId="2288" />
  <row Id="17653" PostId="11829" Text="A 11k resistor in parallel to the expression pedal wouldn't work, would it? Otherwise, any hints on modifying the circuit?" CreationDate="2011-03-22T14:11:19.120" UserId="3075" />
  <row Id="17654" PostId="11831" Text="What about BarsMonster's concern that the capacitor charging will not work if the powerup curve is too slow?  Also, how is a D-type flip-flop an example of a device with a reset state?  In all my tests, the Ds I have always have started up in the last state they were in when the device was last shut down, rather than in one particular state or the other.  If they did start in one particular state, they would be fit to provide a reset signal but this is not the case." CreationDate="2011-03-22T14:12:20.803" UserId="3424" />
  <row Id="17655" PostId="11835" Text="It looks like this is designed for 3.3V systems.  Would it still work correctly on powerup for a 5V system?" CreationDate="2011-03-22T14:19:44.583" UserId="3424" />
  <row Id="17656" PostId="11774" Text="Yeah. Isn't that crazy? Highly typed in current practice tends to result in a lot of *DATA_I &lt;= TO_UNSIGNED(32010, DATA_I'LENGTH);* type stuff...  that doesn't bother anyone?  :)   It sure seems like a lot of unnecessary baggage. (Especially when adding *STD_LOGIC_VECTOR()* to that) I've declared my type and size, this should be *DATA_I &lt;= 32010;* That should be implicit. Going between signed/unsigned, etc can and should be be explicit... but a straight unambiguous assignment or operation on integers should be implicit." CreationDate="2011-03-22T14:33:37.480" UserId="1270" />
  <row Id="17657" PostId="11833" Text="Could you provide some citation to your knowledge that microSD cards aren't required to support SPI?" CreationDate="2011-03-22T15:14:27.273" UserId="1407" />
  <row Id="17658" PostId="11834" Text="My electrician will be here later this week for something else and I am going to ask him. I really don't want to PAY him for this job :-).  The point on the circuit breaker is right on, i think.&#xA;&#xA;I might be able to put a 20a breaker in the attic. That's what I'm going to ask him about." CreationDate="2011-03-22T15:23:13.883" UserId="2604" />
  <row Id="17659" PostId="11834" Text="On your question: The automatic drain valve will eventually release all pressure from the tank. I'd rather keep it charged so I don't have to wait for the tank to come up to pressure when I need to use it." CreationDate="2011-03-22T15:24:48.700" UserId="2604" />
  <row Id="17660" PostId="11841" Text="I added the source of the SPI optionality information. So you are probably right. I would like to wait a few days before accepting the answer (if you don't mind) in case someone finds more information." CreationDate="2011-03-22T15:27:57.023" UserId="659" />
  <row Id="17662" PostId="10494" Text="@markrages: If each solenoid had both a series diode to the supply and a reverse-parallel catch diode, multiplexing should be reasonable, though 9:1 seems a bit much.  My inclination, if the application would allow it, would be to use a 4:1 wired multiplex with 12.5% duty cycle for most solenoids; any row which had solenoids that were being newly energized would receive 62.5% duty cycle briefly.  This would require slightly staggering solenoid &quot;grab&quot; operations, but would allow a nice reduction in circuitry." CreationDate="2011-03-22T15:45:28.137" UserId="3123" />
  <row Id="17663" PostId="10494" Text="Depending upon voltage, it may also be possible to have two rows &quot;grab&quot; with 37.5% duty cycle, or to simply feed all rows 25% duty cycle and see if they could &quot;grab&quot; with that." CreationDate="2011-03-22T15:46:02.427" UserId="3123" />
  <row Id="17664" PostId="11818" Text="Can you link to one of these? I need something similar to ignite a small flame effect, but all the piezoelectric igniters I've found have a spring loaded button that taps the piezo material to create the spark. I need a ~5s continuous spark." CreationDate="2011-03-22T15:51:26.320" UserId="1633" />
  <row Id="17665" PostId="11842" Text="Does it run under Linux?" CreationDate="2011-03-22T15:56:31.513" UserId="2134" />
  <row Id="17666" PostId="11842" Text="Nevermind, just found the post about the Linux driver." CreationDate="2011-03-22T15:58:57.780" UserId="2134" />
  <row Id="17667" PostId="11577" Text="@anthony137 that's an interesting idea. I've been thinking in terms of 10-bit converters since that's what microcontrollers usually have built in, but I'll have a look at high-rez converters." CreationDate="2011-03-22T16:09:01.830" UserId="207" />
  <row Id="17668" PostId="11577" Text="@jpc I'll have to test. I'd like to have a system that can adapt to a wide range unknown of conditions, but I can get some ballpark figures." CreationDate="2011-03-22T16:10:59.190" UserId="207" />
  <row Id="17669" PostId="11829" Text="So wait, you replaced the 10k mix pot with a 100k expression pedal?" CreationDate="2011-03-22T16:11:41.493" UserId="142" />
  <row Id="17670" PostId="11827" Text="&quot;Prone to noise&quot;?  Do you mean prone to interference or hum?  When a pot is in the center position, the wiper is at its highest impedance relative to other things, so it's easy for other things to capacitively couple with that node.  The input and output resistors are just bleeders for setting the DC bias to 0 without loading down the guitar.  Leave them as they are." CreationDate="2011-03-22T16:14:27.370" UserId="142" />
  <row Id="17671" PostId="11845" Text="That's what I feared. There's a... communication barrier involved here which makes this extra difficult. It's not &quot;a cable&quot; I want either, it's much more complex. And they've already told me they don't have the tool in stock." CreationDate="2011-03-22T16:14:55.507" UserId="1633" />
  <row Id="17672" PostId="11834" Text="@tig - A drain valve shouldn't release pressure from the tank when the compressor isn't cycling.  I suspect that you've either created a slow leak when installing it, or there's a slow leak in your air lines elsewhere." CreationDate="2011-03-22T16:15:33.377" UserId="857" />
  <row Id="17673" PostId="11845" Text="Try an official FCI distributor. They should be able to advise you." CreationDate="2011-03-22T16:19:51.683" UserId="305" />
  <row Id="17675" PostId="10534" Text="The problem might arise if you are trying to determine which keys were pressed in what order, true, a user pressing a single button may not be able to go that fast, but when you have a hundred keys and 10 fingers with which to actuate them, fast typists will have begun to depress the next key as soon as another has made contact." CreationDate="2011-03-22T16:28:31.720" UserId="1407" />
  <row Id="17676" PostId="11833" Text="I feel like the guy who was editing it wasnt sure himself based off of the wording and changes made." CreationDate="2011-03-22T16:32:34.553" UserId="319" />
  <row Id="17677" PostId="11833" Text="OTOH the guy adding this information did not back it up in any way (it appeared in one big edit to the whole article). Quick google searching also did not reveal anything that would support the optionality of SPI." CreationDate="2011-03-22T16:34:43.540" UserId="659" />
  <row Id="17678" PostId="11844" Text="I think they assume ideal switches (which should be true for MOSFETs and IGBTs at several kHz). Note that this has nothing to do with resonant converters." CreationDate="2011-03-22T16:38:24.797" UserId="659" />
  <row Id="17679" PostId="11845" Text="I've mailed FCI (had to put &quot;Human Being&quot; in the compulsory &quot;Company&quot; field in the contact form), I'll see how we go." CreationDate="2011-03-22T16:54:04.893" UserId="1633" />
  <row Id="17680" PostId="11818" Text="@Robert Atkins, achieving a spark of sustained (5s) duration will be very difficult. Piezo is not the solution nor is an ignition transformer. You could look at a portable TV. The flyback in that puts out from 5 to 30kV and most run from 9V - 12V, that will put out a very large spark, but be **very** careful with this. It's unlikely to kill per se, as the current is very low, however, if you touch it, it will hurt very badly and you could burn or otherwise injure yourself." CreationDate="2011-03-22T16:57:36.520" UserId="1225" />
  <row Id="17681" PostId="3755" Text="It's supported by the Pulsonix software I use, as well as OrCAD, PADS, CADSTAR, etc." CreationDate="2011-03-22T17:13:56.767" UserId="305" />
  <row Id="17682" PostId="11845" Text="It's funny how often my current troubles are reflected on this site. I was searching for about 45 minutes for a crimp tool for pins into a simple 0.1&quot; header before giving up. I ended up actually soldering the wire inside the pin, after only slightly closing it to fit in the header. Obviously that won't work here, but I'm sure it's more reliable than the &quot;correct tool&quot;. I'll probably start doing that instead of the crimp tool from now on." CreationDate="2011-03-22T17:14:21.850" UserId="1270" />
  <row Id="17683" PostId="11845" Text="... now if only I could get the pins to stay locked in place inside the header... it's amazing how poorly made these headers are. The pins are the matching part numbers for these headers, and they're too loose. I guess I'll use silicone...   How can we have X Ghz multicore processors but we can't get a wire to stay attached to a header?" CreationDate="2011-03-22T17:19:23.157" UserId="1270" />
  <row Id="17684" PostId="20" Score="2" Text="@jonox, letting the WDT time out **will** cause a &quot;clean reset&quot; as all registers will be guaranteed to start up in a defined state.  Accomplishing it in software is as simple as disabling interrupts and endlessly looping." CreationDate="2011-03-22T17:22:59.160" UserId="1407" />
  <row Id="17685" PostId="11798" Text="Any voltage source above ELV rating, AC or DC, is hazardous. You cannot 100% say that AC throws and and DC jerks. (I don't intend to test it either.)" CreationDate="2011-03-22T17:24:47.207" UserId="1293" />
  <row Id="17686" PostId="11798" Text="@ThomasO, if he's operating the power supply with no load the whole issue of how to power it is moot, no? : )" CreationDate="2011-03-22T17:25:20.527" UserId="1293" />
  <row Id="17687" PostId="11798" Text="@Madmanguruman, It could be that the computer is switched off (drawing only a few watts standby) during the time it is powered from HVDC. Don't eliminate the possibility." CreationDate="2011-03-22T17:30:29.040" UserId="1225" />
  <row Id="17688" PostId="11845" Score="1" Text="Actually Darron, crimping 0.1&quot; header pins is actually quite tricky to do properly. You do need the tool (any electronics shop should have one for &lt; $20), but it took me a while to get the knack. The crimp tool produces two &quot;folds&quot; of metal, one around the insulation only and one over and into the stripped wires themselves in a kind of heart shape cross-section. I read evidence that a properly done crimp can be better than soldering (google &quot;crimp gas tight cold weld&quot;)" CreationDate="2011-03-22T17:36:36.463" UserId="1633" />
  <row Id="17689" PostId="11835" Text="@JoeMac, yes, I forgot to note you were using 5v logic.  You want the MIC1810 instead of the 1815.  I have modified my answer." CreationDate="2011-03-22T17:40:38.527" UserId="1322" />
  <row Id="17690" PostId="11829" Text="Well, a 100k linear slider pot for the time being. AND the neigbouring 15k resistors with 150k. AND the opamp's feedback resistor with 510k, just as described in the document I linked to. As I said, I was in kind of a hurry, and hoped it would work like this. Now that it doesn't, I'll try with the original values and see what happens." CreationDate="2011-03-22T17:43:20.800" UserId="3075" />
  <row Id="17691" PostId="11845" Text="Also, the crimp pins I've used quite cleverly lock into the headers if you've crimped them correctly and put them in the right way around. You can also buy pre-crimped jumper wires if you need them in quantity." CreationDate="2011-03-22T17:43:31.827" UserId="1633" />
  <row Id="17692" PostId="11759" Text="Yes, it appears that every hole is plated correctly. They tented some vias (completely covered and filled the hole with green soldermask), which is also fine -- the metal *is* shiny under the soldermask. Go ahead and put parts on the board -- the mis-registration appears to be (just barely) small enough not to hurt anything, so it will probably work fine." CreationDate="2011-03-22T17:58:18.660" UserId="813" />
  <row Id="17694" PostId="11812" Text="Reductors meaning gearing the motor down?" CreationDate="2011-03-22T18:11:25.250" UserId="2240" />
  <row Id="17695" PostId="11838" Text="What do flexible drive shafts usually look like, and where can I find them?" CreationDate="2011-03-22T18:21:23.260" UserId="2240" />
  <row Id="17699" PostId="11812" Text="Yes............." CreationDate="2011-03-22T18:51:37.383" UserId="2062" />
  <row Id="17703" PostId="11847" Text="See also http://electronics.stackexchange.com/questions/11816" CreationDate="2011-03-22T19:11:08.773" UserId="142" />
  <row Id="17704" PostId="11666" Text="@jaux - Great question!  Unfortunately, I'm not very experienced with respect to external RAM, but I've dropped a bounty on your question in hopes that someone else will find it." CreationDate="2011-03-22T19:36:28.430" UserId="857" />
  <row Id="17705" PostId="11852" Text="Regarding the PDF: He is writing his own PostScript code to layout the articles and then converts them to PDF so maybe this is triggering a bug in your reader." CreationDate="2011-03-22T19:55:30.730" UserId="659" />
  <row Id="17706" PostId="11852" Text="Regarding the amplifier: the sequences are meant to drive a class D amplifier so it outputs 60Hz (or some other frequency) sine wave. The question remains: does it work as advertised?" CreationDate="2011-03-22T19:56:45.223" UserId="659" />
  <row Id="17707" PostId="11850" Score="1" Text="You are right that RFM12B modules will not work with an analog signal." CreationDate="2011-03-22T19:57:54.487" UserId="659" />
  <row Id="17708" PostId="11852" Score="1" Text="The question was &quot;has anybody actually used these for anything?&quot; which I took to mean digital pulse trains driving switches to produce analog output.  The answer is yes:  Class D amplifiers are used extensively in audio amplifiers." CreationDate="2011-03-22T20:02:14.190" UserId="2664" />
  <row Id="17709" PostId="11730" Text="Please read the question again. I am looking for a implementation for estimating the baud-rate automatically. The figure presented in the question is just an example." CreationDate="2011-03-22T20:08:12.857" UserId="3061" />
  <row Id="17710" PostId="11844" Text="Sounds like a scam to me. I don't ever trust technical papers that are self-published and have numerous advertisements for the authors work. It may very well work, but there is no reason any signal processing guy can't figure it out on their own." CreationDate="2011-03-22T20:09:34.103" UserId="319" />
  <row Id="17711" PostId="11852" Score="1" Text="@jpc, I will support @BenJackson here. Class D amplifiers are the new wave for power savings, many cell phones are starting to use them. A switching regulator is almost just like a class D regulator, except that it has a set target voltage instead of a slowly changing one." CreationDate="2011-03-22T20:12:58.727" UserId="230" />
  <row Id="17712" PostId="11845" Text="The problem with soldering the wire in the terminal is that it makes the wire liable to break if any flexing takes place." CreationDate="2011-03-22T20:14:53.033" UserId="305" />
  <row Id="17714" PostId="11845" Text="@darron, getting a wire to stay attached to a header has always been the hard part." CreationDate="2011-03-22T20:22:11.307" UserId="230" />
  <row Id="17715" PostId="11761" Text="@jpc, my first thought was if it was a steel based house, some people have them, radios love them." CreationDate="2011-03-22T20:27:01.830" UserId="230" />
  <row Id="17716" PostId="11829" Text="Also, I still fail to fully understand impedance, but there's quite a difference between a 15:1000 voltage divider and a 150:1000 one, right? Testing the circuit with an audio probe, the volume starts to drop around the junctions of the 150k resistors... Hmm. That gives me some ideas for things to check." CreationDate="2011-03-22T20:28:31.550" UserId="3075" />
  <row Id="17717" PostId="11842" Text="I was able to get it up and running on a debian server in about 5 minutes." CreationDate="2011-03-22T20:29:41.447" UserId="536" />
  <row Id="17721" PostId="11852" Text="@Kortuk I agree with everything Ben and you wrote but I fail to see how this answers my question. What I wanted to know is whether anyone used these particular &quot;magic&quot; binary sequences and are there any gotchas that will not allow them to work. You are aware the these are not &quot;normal&quot; PWM waveforms?" CreationDate="2011-03-22T20:53:21.370" UserId="659" />
  <row Id="17722" PostId="11813" Text="Will the valve need substantial current?" CreationDate="2011-03-22T20:55:10.387" UserId="659" />
  <row Id="17723" PostId="11852" Text="@JPC, It actually looks sound. Need to build it and pass it through a low pass filter in simulation. I no longer have matlab though." CreationDate="2011-03-22T20:55:37.903" UserId="230" />
  <row Id="17725" PostId="11852" Score="1" Text="@Kortuk I find it really entertaining that you used &quot;build&quot; and &quot;matlab&quot; in the same sentence. :)" CreationDate="2011-03-22T21:01:13.437" UserId="659" />
  <row Id="17726" PostId="11852" Text="@jpc, well played sir." CreationDate="2011-03-22T21:01:56.557" UserId="230" />
  <row Id="17727" PostId="11844" Text="@Kellenjb You are right but OTOH his typography and drawings are quite nice (especially if you consider he is coding them in raw PostScript) and that there are many really interesting ideas in his other articles as well (he published them for the last 20 years or so)." CreationDate="2011-03-22T21:09:48.247" UserId="659" />
  <row Id="17728" PostId="11829" Text="@egasimus :-) think you're going the right way." CreationDate="2011-03-22T21:13:12.143" UserId="3525" />
  <row Id="17729" PostId="11856" Text="I do not see any errors in the theory but I am really curious if it will work in practice. Especially since it is already several years since Don first wrote about this and still no one uses it." CreationDate="2011-03-22T21:16:32.870" UserId="659" />
  <row Id="17730" PostId="11852" Text="@jpc, in that case I think a better question would be an explicit comparison between http://en.wikipedia.org/wiki/Delta-sigma_modulation and whatever Lancaster is doing.  Delta-sigma was chosen for ease of implementation but it seems to me there's no particular reason to discount any method for generating a pulse train with the correct frequency components." CreationDate="2011-03-22T21:17:15.133" UserId="2664" />
  <row Id="17731" PostId="11852" Score="1" Text="@Ben I don't believe that $\Delta\Sigma$ modulators are optimizing for the switch counts (actually I believe it is to the contrary)." CreationDate="2011-03-22T21:21:50.477" UserId="659" />
  <row Id="17732" PostId="11856" Text="@jpc, I really could see issues running the higher frequencies through the LC lowpass. I want to build it now also." CreationDate="2011-03-22T21:22:54.283" UserId="230" />
  <row Id="17735" PostId="11853" Text="I think that (at least where I live) you can build your own for the ISM band as long as it does not violate the terms of use of the band. Or as one of my professors put it: if you ever want to do something stupid then just be 130% sure you stay out of army and flight control bands or they *will* hunt you down *fast*. :)" CreationDate="2011-03-22T21:36:10.600" UserId="659" />
  <row Id="17736" PostId="11814" Text="Nice white-paper. AFAIK the Geckodrive guy is also working on a similar idea." CreationDate="2011-03-22T21:40:24.697" UserId="659" />
  <row Id="17737" PostId="11811" Text="Could you estimate the RPMs you want to get out of it?" CreationDate="2011-03-22T21:41:19.220" UserId="659" />
  <row Id="17740" PostId="11859" Text="@Joby Taffey, I doubt a picture would help but I'll try and get one up soon." CreationDate="2011-03-22T21:57:33.570" UserId="1225" />
  <row Id="17741" PostId="11834" Text="@reemrevnivek - it's an electric powered auto drain valve that opens on a timer. " CreationDate="2011-03-22T22:01:30.757" UserId="2604" />
  <row Id="17743" PostId="11817" Text="@endolith You learn something everyday :)" CreationDate="2011-03-22T22:15:35.403" UserId="3140" />
  <row Id="17744" PostId="11817" Text="@Evan Plaice I will get the file for you....Where do you want to download it from? or could I send it to you via email?" CreationDate="2011-03-22T22:16:46.603" UserId="3140" />
  <row Id="17745" PostId="11859" Text="@Joby Taffey, picture added." CreationDate="2011-03-22T22:25:19.573" UserId="1225" />
  <row Id="17746" PostId="8505" Text="i7 pass-thru adapter for using a jtag here http://www.asset-intertech.com/products_interposers.htm" CreationDate="2011-03-22T22:34:05.020" UserId="1994" />
  <row Id="17747" PostId="8499" Score="3" Text="Intel used to make a test jig called a &quot;slammer&quot; that fit in a CPU socket and operated as a programmable load to verify power supply performance in worst-case scenarios.  Specifically because it's so hard to meet those specs.  1mOhm at 145A is more than 10% voltage offset at 1.1V and would dissipate 20 watts!" CreationDate="2011-03-22T22:46:13.807" UserId="2664" />
  <row Id="17749" PostId="11836" Text="Sounds like overkill though when you can get a USB thermal sensor unit on ebay dirt cheap" CreationDate="2011-03-22T23:02:37.533" UserId="1750" />
  <row Id="17750" PostId="11863" Text="Sounds like overkill though when you can get a USB thermal sensor unit on ebay dirt cheap (is there an echo in here!?)" CreationDate="2011-03-22T23:02:59.140" UserId="1750" />
  <row Id="17751" PostId="11812" Text="I agree, running a stepper too slow can make it very rough.   Running the motor faster and using reduction gears is a good approach." CreationDate="2011-03-22T23:03:37.573" UserId="389" />
  <row Id="17752" PostId="11842" Text="This is exactly what I used (sensor off ebay though) to monitor server room temp on a linux box." CreationDate="2011-03-22T23:04:03.380" UserId="1750" />
  <row Id="17753" PostId="11849" Score="1" Text="Great answer.   As for the voltage, the dielectric strength of dry air is about 33kV/cm, so if the spark jumps 2mm it has to be at least 6600v.&#xA;" CreationDate="2011-03-22T23:08:24.010" UserId="389" />
  <row Id="17754" PostId="11804" Text="Looking very neat too!" CreationDate="2011-03-22T23:10:47.367" UserId="1750" />
  <row Id="17755" PostId="11863" Text="I do program microcontrollers. I just need a solution, that would fit in with `lm_sensors`" CreationDate="2011-03-22T23:12:46.367" UserId="2134" />
  <row Id="17757" PostId="11864" Score="2" Text="Can you post your schematic?  It sounds like you're approaching this wrong.  You want to adjust the contrast by changing the voltage on the $V_o$ pin, which will have a very high impedance (&gt;100k).  If your pot is wired correctly, you'll always have $V/R=5\mbox{ V}/10\mbox{ k}{\Omega}=0.2\mbox{ mA}$ of current, or 1 mW of power.  " CreationDate="2011-03-22T23:22:24.173" UserId="857" />
  <row Id="17758" PostId="11866" Text="@Leon - This is a character LCD, which has several LEDs behind the screen, and, if it's like the other models I've used, the termination resistor is integrated.  The datasheet lists 240mA as typical, not maximum." CreationDate="2011-03-22T23:29:42.713" UserId="857" />
  <row Id="17759" PostId="733" Text="SparkFun also carries the [SparkFun Inventor's Kit for Arduino](http://www.sparkfun.com/products/10173)" CreationDate="2011-03-22T23:31:13.190" UserId="693" />
  <row Id="17760" PostId="11866" Text="Sick! Thanks reemrevnivek. I just thought because it's adjusting the led it would pull 240ma. Oviously I wired it wrong causing it o set on fire lool. It does make sense now. Thanks for the explanination!!!" CreationDate="2011-03-22T23:47:20.163" UserId="2824" />
  <row Id="17761" PostId="11814" Text="@Kortuk - I do try to reference when I can. Some things are better documented then others. @jpc - It doesn't surprise me. If you **have** to use steppers, sinusoidal current drive *is* the way to go. It's just that stepper motors suck, really." CreationDate="2011-03-22T23:50:18.553" UserId="1374" />
  <row Id="17762" PostId="11860" Text="Hmm, there are no metal tabs on mine :(. I can stick them together but they won't stay there long enough for me to screw the case back together. Before, the strip seemed to stick to the LCD, then it came off, now it won't go back on again. :(" CreationDate="2011-03-23T00:28:24.113" UserId="1225" />
  <row Id="17764" PostId="11866" Text="if the the led typically uses 240mA of current, does that mean I can supply it 240mA and it be fine? I need to know since my Power source is a 9V battery. So need to work out the resistence needed to supply 5V – Ageis 15 mins ago. [link]http://img189.imageshack.us/i/lcdl.gif/" CreationDate="2011-03-23T00:57:58.313" UserId="2824" />
  <row Id="17765" PostId="3439" Text="@Rocketmagnet - The PSoC, like an FPGA, is still raw logic.  It's not discrete, sure, but it's just as fast." CreationDate="2011-03-23T00:58:39.413" UserId="857" />
  <row Id="17766" PostId="11779" Text="@kellenJB, as someone whom has done radar &quot;In order to get a greater range you have to turn off your signal and wait long enough for you to receive the reflected signal&quot; is not true. There are many methods around this. In CWFM radar we are sweeping a frequency range and measuring back the different phases. as you increase your sweep you increase the number of points and range you can distinguish. So for really long range you need high power and a decent sweep, honestly with good equipment you just need high power, a couple GHz works on the sweep." CreationDate="2011-03-23T01:00:10.050" UserId="230" />
  <row Id="17767" PostId="11866" Text="The avr has a maximum current on vcc and gnd of 200ma hence the resistor" CreationDate="2011-03-23T01:01:41.633" UserId="2824" />
  <row Id="17768" PostId="11779" Text="@AngZhiPing, the important part from his graph is the linear phase corresponds to a **flat* group delay, the same delay for each frequency. Linear phase filter corresponds to a symmetric filter in the time domain impulse response which is not physically possible with an IIR filter as you would need an anti-causal system." CreationDate="2011-03-23T01:01:48.300" UserId="230" />
  <row Id="17769" PostId="11871" Score="1" Text="A flow meter will be less accurate than a measurement of volume; it will suffer from the same problems you'll get when trying to do dead-reconing with an accelerometer." CreationDate="2011-03-23T01:03:48.813" UserId="857" />
  <row Id="17770" PostId="11869" Text="Ice makers measure the amount of ice in the ice bucket, not the amount of water used.  Is there an analogy for your device?" CreationDate="2011-03-23T01:04:16.317" UserId="857" />
  <row Id="17771" PostId="11851" Score="1" Text="The launchpad is targeted at $4.30, if you buy from sparkfun it is $5 and change.  You can buy several for the cost of an arduino, or one for the fraction of the cost of an arduino.  Dallas, now maxim, used to have a serial to one wire dongle for next to nothing that you could use with their one wire temp sensors, I imagine they have an alternate solution or here again just use an msp430." CreationDate="2011-03-23T01:16:19.103" UserId="985" />
  <row Id="17772" PostId="9251" Text="@bt2 - Did you mean &quot;Differential equation&quot;?" CreationDate="2011-03-23T01:28:10.390" UserId="857" />
  <row Id="17774" PostId="11853" Text="@jpc What would the consequences of running voice communications over the ISM band be?" CreationDate="2011-03-23T03:15:25.203" UserId="3427" />
  <row Id="17775" PostId="11822" Text="But how does that reduce the number of address lines?" CreationDate="2011-03-23T03:16:35.187" UserId="1657" />
  <row Id="17776" PostId="11822" Text="@2000k404notfound It does allows you to expand beyond the address bus width that is available. I think I do not fully understand your question. If you want to address 4k memory you will need 12 bits of address lines *somewhere*. The only question is where do you stuff them." CreationDate="2011-03-23T03:21:19.727" UserId="659" />
  <row Id="17777" PostId="11853" Text="Also, are there any FCC-certified walkie-talkie transceivers (without enclosure)? I read that they will not certify anything until it has an antenna. I would not mind buying something with a hardwired antenna and putting it into an enclosure. The primary purpose of the project is to end up with a small, pocket-sized radio for use with a headset. All commercial walkie-talkies that I could find are relatively bulky and are built for use in the hand, with integrated speaker and microphone. " CreationDate="2011-03-23T03:23:02.000" UserId="3427" />
  <row Id="17778" PostId="11853" Text="I am not qualified to offer you legal advice on this but I believe the ISM band is free to any use and limited only on the power and duty cycle of the signal (the exact numbers and measurement methods vary from country to country)." CreationDate="2011-03-23T03:25:26.683" UserId="659" />
  <row Id="17779" PostId="11853" Text="I believe you could rip the walkie-talkie apart and unless you mess things up a lot it will still transmit the same power on the same frequency so you should be OK." CreationDate="2011-03-23T03:28:06.807" UserId="659" />
  <row Id="17780" PostId="11822" Text="There are two ways to reduce the number of address lines. One is to divide the memory into rows and columns and latch the row address. Truly random access then requires at least 2 clock cycles but columns inside a row can be accessed quickly. This is how DRAM works. The other method is to have a 32-bit data bus, throw away 2 low-order address bits and only access whole words at once." CreationDate="2011-03-23T03:45:28.443" UserId="659" />
  <row Id="17781" PostId="11822" Text="I think it has to do with the last bit of the address. If you have two banks, then you can assign all the even addresses to one line, and all the odd addresses to the other. The last bit tells you if the address is odd or even, but if you use the CS line to select lines, then you don't need it. Does this sound right?" CreationDate="2011-03-23T03:53:59.290" UserId="1657" />
  <row Id="17782" PostId="11810" Text="Don't you mean that the LSB is used for the chip select?" CreationDate="2011-03-23T04:02:40.483" UserId="1657" />
  <row Id="17783" PostId="11847" Text="There are a different type where you press the button, hold it down and get a series of sparks. How do these work and what are they called?" CreationDate="2011-03-23T04:02:58.147" UserId="1633" />
  <row Id="17784" PostId="11839" Text="Will you please why we need high voltage rating switch and what will be if we use low voltage rating switch." CreationDate="2011-03-23T05:20:15.237" UserId="2951" />
  <row Id="17785" PostId="11876" Text="Thank you very much" CreationDate="2011-03-23T05:50:39.173" UserId="3140" />
  <row Id="17786" PostId="11880" Text="So if you put a capacitor in a DC circuit, it will act as an open circuit, and nothing will work?" CreationDate="2011-03-23T06:01:22.647" UserId="1657" />
  <row Id="17787" PostId="11880" Text="Assuming that the circuit is ONLY DC, and there are no transients (switches closing or opening, signal inputs, etc).  DC analysis is best though of as an analogy to statics in mechanical engineering.  Nothing in your circuit is moving or changing, and it is at an equilibrium. AC analysis is when you add some sort of dynamic input to your system.  Once you add a dynamic to the system, then you will have you use LaPlace analysis to determine what the circuit will do over time." CreationDate="2011-03-23T06:07:18.550" UserId="1477" />
  <row Id="17788" PostId="11880" Score="1" Text="What if the voltage source comes from an AC adaptor and it's going into a voltage regulator with capacitors connected to it? Why would a voltage regulator need capacitors if the voltage is DC?" CreationDate="2011-03-23T06:11:10.397" UserId="1657" />
  <row Id="17789" PostId="11880" Text="You typically find capacitors on voltage regulators and next to chips because DC is an ideal (never happens!).  In real life, there is always noise on the supply lines, and the capacitors form a filter (low-pass) with a large RC time constant (and a really low bandwidth).  This means that it essentially forms a filter that blocks everything above a really small frequency (0.1 Hz, 0.001 Hz, etc).  This means that your circuit that you are supplying only &quot;sees&quot; DC, and none of the transient noise from other sources." CreationDate="2011-03-23T06:32:15.643" UserId="1477" />
  <row Id="17790" PostId="11880" Text="What if there was no noise? Would it turn into an open circuit?" CreationDate="2011-03-23T06:35:25.343" UserId="1657" />
  <row Id="17791" PostId="11880" Text="Correct.  The capacitor between the voltage supply and ground is an open circuit when there are no transients." CreationDate="2011-03-23T06:47:35.483" UserId="1477" />
  <row Id="17792" PostId="11880" Text="Then does that mean that the correct functioning of a circuit with a capacitor relies on there being noise?" CreationDate="2011-03-23T07:09:07.950" UserId="1657" />
  <row Id="17793" PostId="11880" Text="It depends on the circuit.  For this example, in order for the capacitor to really do anything, there has to be some transient component to the voltage source.  Basically, capacitors and inductors respond to time-varying signals.  Noise is a type of time-varying signal." CreationDate="2011-03-23T07:12:16.273" UserId="1477" />
  <row Id="17794" PostId="6395" Score="1" Text="@Mark, There was a study that found the tinfoil hat improved matching of certain frequencies into the brain. These frequencies all fell into reserved by Gov't ranges in the USA. I hope that makes you laugh." CreationDate="2011-03-23T07:41:45.213" UserId="230" />
  <row Id="17795" PostId="11869" Text="The ice maker in my freezer appears to use bucket level to decide its ok to empty the tray of frozen cubes, and a timer to control the amount of water to fill the tray knowing that the volume won't vary by much as long as the orifice is relatively constant in size." CreationDate="2011-03-23T07:57:43.850" UserId="1494" />
  <row Id="17796" PostId="11882" Text="Would it point to bytes 8 and 9? If you were to remove the address line corresponding to the MSB, then wouldn't that cut the number of addresses in half?" CreationDate="2011-03-23T08:19:03.370" UserId="1657" />
  <row Id="17797" PostId="11829" Text="Yeah, but that's as far as I get. I'm not sure what to do next." CreationDate="2011-03-23T08:19:27.163" UserId="3075" />
  <row Id="17798" PostId="989" Text="+1 for TeraTerm. Friends don't let friends use Hyperterm. However, for protocols with a lot of binary and checksums or CRC, there's no substitute for having something like Python, Lua or Perl in your toolbag, along with an understanding of your language's best way of using and controlling a serial port." CreationDate="2011-03-23T08:25:20.297" UserId="1494" />
  <row Id="17799" PostId="11837" Text="This is the route I'm actually trying to avoid. Gas grill lighters aren't very reliable. I wan't something that I'm 100% is giving a good spark when I push the button." CreationDate="2011-03-23T08:27:08.433" UserId="1866" />
  <row Id="17800" PostId="11817" Text="@James Do you have a Dropbox account, or equivalent that you could temporarily post a public link. If not, I could provide an email, I just don't want to leave it up for too long (the spam bots haven't seen it yet and I'd like to keep it that way)." CreationDate="2011-03-23T08:35:01.970" UserId="1866" />
  <row Id="17801" PostId="11810" Text="No, you  use the MSB's. That way you're not switching chips every time you increment the address. This makes it much easier to use ROM chips, partially filled address spaces, and devices with a memory bus interface." CreationDate="2011-03-23T09:09:30.387" UserId="638" />
  <row Id="17802" PostId="11875" Score="1" Text="possible duplicate of [Reducing the memory address bus by adding banks](http://electronics.stackexchange.com/questions/11805/reducing-the-memory-address-bus-by-adding-banks)" CreationDate="2011-03-23T09:19:24.200" UserId="638" />
  <row Id="17803" PostId="11879" Text="So what good does it do you if we just tell you the answer?" CreationDate="2011-03-23T09:21:20.033" UserId="638" />
  <row Id="17804" PostId="11810" Text="If you look at page 13 on here the LSB is being used. http://www.ece.cmu.edu/~ece548/handouts/13m_arch.pdf" CreationDate="2011-03-23T09:22:54.760" UserId="1657" />
  <row Id="17805" PostId="11810" Text="If you want to switch chips every read, then you can use the LSB as CS. You can even use a combination of MSB and LSB or any bits in the address, and it will still work. If you are trying to interleave your chips to get a performance advantage, your system must be able to take advantage of that. " CreationDate="2011-03-23T09:36:26.773" UserId="638" />
  <row Id="17808" PostId="11886" Text="Are you asking about using Matlab as a &quot;SPICE replacement&quot; to simulate discrete RLC components, or more along the lines of system simulation?" CreationDate="2011-03-23T10:06:51.167" UserId="638" />
  <row Id="17809" PostId="11817" Text="Here is the file: http://cid-4163e327d6acacd3.office.live.com/self.aspx/.Public/LED.JPG .....Sadly it isn't exactly what I expected myself but there it is. If you would like a proper example I would happily make a schematic with labels and such..Enjoy!" CreationDate="2011-03-23T10:09:02.020" UserId="3140" />
  <row Id="17810" PostId="11886" Text="@W5VO  Both, but with more focus on SPICE. I do know that system simulation can be done with Simulink and that it's not too difficult." CreationDate="2011-03-23T10:16:23.377" UserId="1240" />
  <row Id="17811" PostId="10685" Text="Good Question :)" CreationDate="2011-03-23T10:20:45.323" UserId="3140" />
  <row Id="17812" PostId="10685" Text="Is the BTRate set Correctly?" CreationDate="2011-03-23T10:23:45.883" UserId="3140" />
  <row Id="17813" PostId="11888" Score="1" Text="I'm not completely convinced that power consumption doesn't increase because it's all software. More processing power usually requires either extra hardware or a higher clock frequency, both of which would increase power. If this doesn't apply because there is enough processing power available, then you can probably run at slower clocks for less, say 12, channels." CreationDate="2011-03-23T11:23:04.663" UserId="2064" />
  <row Id="17814" PostId="11886" Score="2" Text="Solving circuits is just solving nonlinear differential equations so it is possible in Matlab. OTOH I since SPICE is really nothing more than a nonlinear differential equation solver then I would use Matlab only if I had a really strange or special problem." CreationDate="2011-03-23T12:02:50.397" UserId="659" />
  <row Id="17815" PostId="11880" Score="1" Text="I would rather say that correct functioning of the real circuit (with noise and transients) relies on there being a capacitor. :) Also, without any capacitors a real voltage regulator may oscillate or do some other strange things." CreationDate="2011-03-23T12:21:03.517" UserId="659" />
  <row Id="17816" PostId="11879" Text="@W5VO Moot question because we won't do it. :P" CreationDate="2011-03-23T12:23:40.490" UserId="659" />
  <row Id="17817" PostId="11887" Text="That is a valid concern. OTOH you only lose 100mA while you are pulling 70A so unless your load is only taking 70A in short impulses, this should not be a problem." CreationDate="2011-03-23T12:35:07.053" UserId="659" />
  <row Id="17818" PostId="11888" Text="Ok, I agree with you :-) But it's non-linear growth :-)" CreationDate="2011-03-23T12:39:31.107" UserId="2062" />
  <row Id="17819" PostId="11876" Text="The limits are set so that the units will not give a solution for a ballistic missile.  In some readings of the specifications for GPS chips they imply that the solution will not be produced if both the altitude and velocity limits are exceeded.  The implication was that if only one of the limits was exceeded the unit would still work." CreationDate="2011-03-23T13:16:57.737" UserId="400" />
  <row Id="17820" PostId="11890" Score="2" Text="SciPy is free, unlike Matlab, and does a lot of the same stuff.  http://www.scipy.org/NumPy_for_Matlab_Users  I think it's pretty great, myself." CreationDate="2011-03-23T13:25:52.977" UserId="142" />
  <row Id="17821" PostId="11868" Text="I answered this somewhere else...lemme see where that was." CreationDate="2011-03-23T13:30:25.267" UserId="857" />
  <row Id="17823" PostId="11888" Text="@stevenvh if there is no extra processing being done then I would assume that no extra power is being drawn. You would only pull more power when yo did have more connected." CreationDate="2011-03-23T13:52:12.493" UserId="319" />
  <row Id="17824" PostId="11880" Text="@200ok404notfound I am confused by your comment about how the correct function relies on their being noise. This makes no sense. In an ideal world when your voltage line is pure DC the capacitors will act as if they just weren't there. It will still function though." CreationDate="2011-03-23T13:57:16.623" UserId="319" />
  <row Id="17825" PostId="11897" Text="Note: The above links to ITAR are an unofficial HTML version.  The official location is [here](http://www.pmddtc.state.gov/regulations_laws/itar_official.html), and the current PDF for section 121.16 is [here](http://www.pmddtc.state.gov/regulations_laws/documents/official_itar/ITAR_Part_126.pdf). " CreationDate="2011-03-23T14:04:06.513" UserId="857" />
  <row Id="17826" PostId="11898" Text="Most meters aren't real good at measuring below 1 ohm anyways..." CreationDate="2011-03-23T14:05:29.493" UserId="857" />
  <row Id="17827" PostId="11898" Text="I've used a bank of Rohm resistors in the same package that were rated at 120W, so we're in the ballpark with 160." CreationDate="2011-03-23T14:06:54.017" UserId="857" />
  <row Id="17828" PostId="11882" Text="You could do two transfers for each address instead of one and not need any additional data lines.  But then of course it's slower" CreationDate="2011-03-23T14:08:46.217" UserId="249" />
  <row Id="17829" PostId="11895" Score="1" Text="How much current do you want to put through the thing?  I'll bet you get nowhere close to the limit with anything you can produce." CreationDate="2011-03-23T14:10:21.050" UserId="249" />
  <row Id="17830" PostId="11882" Text="@200ok It depends on how you choose to count, starting at index 1 you'd get 1-2,3-4,..,7-8; index 0 would give 6-7. And, yes, removing a bit from address line cuts the number of addresses in half." CreationDate="2011-03-23T14:16:24.213" UserId="1507" />
  <row Id="17831" PostId="11898" Text="@Madmanguruman - Thanks! That seems like a fairly good evidenced based ballpark figure to me. Although not shown in the photo, someone did write 4.8 ohms with a marker on the side of it. I'll have to double check the specifications for my meter when I return home tonight." CreationDate="2011-03-23T14:51:59.430" UserId="2612" />
  <row Id="17832" PostId="11895" Score="1" Text="I was considering the possibility of using this as a dummy speaker load so I could silently troubleshoot guitar amplifiers in my apartment if I needed to. Guitar amps typical range from 50 to 120 watts. " CreationDate="2011-03-23T14:57:25.383" UserId="2612" />
  <row Id="17833" PostId="11898" Score="1" Text="@reemrevnivek If he first measures the short circuit resistance of the multimeter leads and internal circuity and subtracts it from the result then I would expect him to get a good estimate after." CreationDate="2011-03-23T15:05:58.857" UserId="659" />
  <row Id="17835" PostId="11898" Score="1" Text="You can also take power supply with current limiting, put 1 Amp through it and measure the voltage. That should be very accurate." CreationDate="2011-03-23T15:07:59.120" UserId="659" />
  <row Id="17836" PostId="7168" Text="which one would you recommend that works with the Launchpad kit?" CreationDate="2011-03-23T15:15:37.540" UserId="2288" />
  <row Id="17837" PostId="11899" Score="4" Text="Short answer is AC to DC conversion is difficult to do efficiently." CreationDate="2011-03-23T15:17:58.787" UserId="319" />
  <row Id="17838" PostId="11899" Score="1" Text="@Kellenjb: Okay, but when there's no phone connected the charger does nothing useful and still consumes power." CreationDate="2011-03-23T15:20:26.167" UserId="3552" />
  <row Id="17839" PostId="11901" Score="1" Text="The existence of Level 2 is frightening.  I wonder if 'special test equipment' overrides the password requirement for level 1?  " CreationDate="2011-03-23T15:24:50.530" UserId="857" />
  <row Id="17840" PostId="11899" Score="1" Text="Why do you care? You'd have to run 1,000 such chargers for 1,000 hours to run up a bill of 1kW, which would cost less than 10 cents in most places. " CreationDate="2011-03-23T15:29:03.870" UserId="857" />
  <row Id="17841" PostId="11899" Score="1" Text="sharptooth: The charger is doing something: waiting. You could say as well say that guards are not doing anything since they are just standing on their posts." CreationDate="2011-03-23T15:31:15.087" UserId="659" />
  <row Id="17842" PostId="11899" Score="1" Text="Also, to nitpick, nothing connected to AC, even if it contains a mechanical switch, truly achieves zero power consumption - Some energy is radiated by the antenna formed by the wiring, and there are other losses to capacitive loading.  What I'm trying to say is, 30mW is close to zero standby power consumption." CreationDate="2011-03-23T15:32:30.373" UserId="857" />
  <row Id="17843" PostId="10507" Text="@Ranieri - That depends entirely on how many micros you need to reflash!" CreationDate="2011-03-23T15:56:26.667" UserId="857" />
  <row Id="17844" PostId="8451" Text="Additional note about the specs: they were recently moved to bluetooth.org, and now you have to sign in to have access to them. The link above doesn't work anymore." CreationDate="2011-03-23T16:01:16.580" UserId="1078" />
  <row Id="17845" PostId="11808" Text="Can you elaborate on this?  &quot;The electrolyte is usually boric acid or sodium borate in aqueous solution&quot;.  The metal conductors touch the electrolyte, and then the electrolyte touches the oxide layer?  Are the ions negative or positive?  When do they flow?" CreationDate="2011-03-23T16:51:25.137" UserId="142" />
  <row Id="17846" PostId="11869" Text="Not the ice bucket . . . the part BEFORE it goes in the ice bucket. From what I can tell it looks like it adds a certain amount of water and doesn't have a &quot;full tray&quot; indicator." CreationDate="2011-03-23T16:56:45.110" UserId="3534" />
  <row Id="17847" PostId="11870" Text="I thought about something like that but I wanted to keep the &quot;logic&quot; simple. If I measure the weight then when I want to &quot;make tea&quot; I have to call for water, wait for the weight, turn off water, start brew process or something like that, whereas if I could measure 1/2 a gallon it could start adding water and start the brew process at the same time." CreationDate="2011-03-23T17:00:01.113" UserId="3534" />
  <row Id="17848" PostId="11910" Score="1" Text="Why do you need external memory?" CreationDate="2011-03-23T18:02:16.590" UserId="305" />
  <row Id="17849" PostId="11910" Text="Havent found something with 512 KB internal memory....." CreationDate="2011-03-23T18:03:19.693" UserId="3186" />
  <row Id="17850" PostId="11798" Text="@ThomasO - back to point 2. If he intends to connect HVDC directly to the bulk caps (bypassing the bridge) then I have less issue with 339VDC, since they would indeed see that voltage (and would be most likely rated for 400VDC). If he intends to connect HVDC to the AC inlet, I would be worried about front-end parts like X-caps and discharge resistors which may only be expecting 240VAC. (And yes, I know that X-caps are tested much higher than at 240VAC.) " CreationDate="2011-03-23T18:16:21.370" UserId="1293" />
  <row Id="17851" PostId="11811" Text="After all the reduction, 1/1440 RPM (1 revolution per day). This is for a sidereal tracking mount." CreationDate="2011-03-23T18:16:47.267" UserId="2240" />
  <row Id="17852" PostId="11814" Text="@Fake Name I don't have to use steppers, but steppers are known for accuracy, which is a goal here. If they would cause more problems than they solve, I'd just use a DC motor." CreationDate="2011-03-23T18:23:05.420" UserId="2240" />
  <row Id="17853" PostId="11811" Text="Actually 1/1436 RPM (1 rev / sidereal day)." CreationDate="2011-03-23T18:24:57.680" UserId="2240" />
  <row Id="17854" PostId="11870" Text="What's to stop you starting the heat as soon as there is enough water to prevent overheating, and continue to poll the load cell?  (I think a timed inflow would serve just as well, but the concept is the same in either case)." CreationDate="2011-03-23T18:31:46.400" UserId="3361" />
  <row Id="17855" PostId="11911" Text="I measured my PC's current consumption before and found it uses twice the current in standby versus when it's off." CreationDate="2011-03-23T18:50:15.530" UserId="1407" />
  <row Id="17856" PostId="3456" Text="FYI, I wrote a pretty good DTMF decoder for a PIC 16C622 a few years ago, using just the comparator as the input." CreationDate="2011-03-23T19:27:35.520" UserId="3123" />
  <row Id="17857" PostId="11839" Text="Ummm, the drawing is missing a capacitor. The guy who wrote the guide says it protects the breaker and may help enhance the spark a little. Read this http://mgaguru.com/mgtech/ignition/ig108.htm, the cap does more than help just a little." CreationDate="2011-03-23T19:35:19.727" UserId="1866" />
  <row Id="17858" PostId="11839" Text="As the switch first starts to open, it will likely pull an arc before the spark plug fires.  A switch which is designed for high voltages will quickly pull the gap wide enough that the magnetic energy stored in the coil will be able to go through the spark plug more easily than through the now-widened gap.  If the switch doesn't pull a wide enough gap fast enough, most or all of the energy will go into making a spark within the switch rather than the spark plug." CreationDate="2011-03-23T19:36:46.293" UserId="3123" />
  <row Id="17859" PostId="11914" Text="http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery http://www.myra-simon.com/bike/charger.html" CreationDate="2011-03-23T19:41:42.267" UserId="142" />
  <row Id="17860" PostId="11817" Text="@James WTF? What's the point of the two transistors that tie to ground? I'm guessing this is supposed to turn off the charging light. I've already got something prototyped on a breadboard to solve this. It's nothing but a 1k resistor with a LED on the + side of the cap with it's own connection to ground. As the cap charges its internal resistance increases to the point where the resistance is higher than the LED resistor (1k) so the LED dims on as the cap charges and shines full when the cap is fully charged." CreationDate="2011-03-23T19:44:48.890" UserId="1866" />
  <row Id="17861" PostId="11900" Score="2" Text="+1 only because I can't vote more than once. I understand GPS so much better now! " CreationDate="2011-03-23T19:48:48.810" UserId="3443" />
  <row Id="17862" PostId="11668" Text="I have no idea.  This was a general hand-waving guess based on my limited analog electronics and Emag experience.  You could probably pick up an Emag book, or check out a site like this: http://www.ece.rutgers.edu/~orfanidi/ewa/  Be warned, the math gets pretty intense quickly with near-field antennas." CreationDate="2011-03-23T19:48:51.657" UserId="1477" />
  <row Id="17863" PostId="11817" Text="@James (cont) It has the added benefit of bleeding the cap when nothing is attached. I accidentally popped a pretty good spark off of one of the caps because I forgot to discharge it before throwing it back into the box. Since I'm not too keen on the idea of buying an igniter coil for this, I'm going to try to get away with using a CCFL inverter for the step up because I have a few spares lying around already (the inverters boost 12v dc up to 800-1200 AC). I'm going to try to get a disposable camera cap before I try to spark it (all I have right now is some 12oo microfarad caps)." CreationDate="2011-03-23T19:49:26.907" UserId="1866" />
  <row Id="17864" PostId="11816" Text="For anybody interested, I'm making progress on a breadboard. I'll try to diagram it and post some pics soon. " CreationDate="2011-03-23T19:50:00.710" UserId="1866" />
  <row Id="17867" PostId="11814" Text="A good DC Servomotor + encoder is *far* more accurate then a stepper motor. Where did you hear that steppers are known for accuracy? They certainly aren't." CreationDate="2011-03-23T20:06:02.243" UserId="1374" />
  <row Id="17868" PostId="11817" Text="That seems quite reasonable......I was quite supirsed myself :S........Would like me to make the correct picture for you? " CreationDate="2011-03-23T20:20:15.000" UserId="3140" />
  <row Id="17869" PostId="11817" Text="I am quite annoyed with myself now :/" CreationDate="2011-03-23T20:21:44.560" UserId="3140" />
  <row Id="17871" PostId="11910" Score="1" Text="@Z-roar: Do you need 512kB of Flash or SRAM? " CreationDate="2011-03-23T20:25:45.867" UserId="857" />
  <row Id="17874" PostId="11911" Score="1" Text="A standby situation will mean it turns of the CPU, but remains power on the RAM modules. Because of that, it will require more power. A 'complete off' (i.e. windows shutdown) situation still draws current, because an ATX system supports wake from LAN, etc. Some even power USB ports when they are off." CreationDate="2011-03-23T20:47:46.723" UserId="1476" />
  <row Id="17875" PostId="11911" Text="@Hans, I know, I was just providing some anecdote to help shake off the misconception that &quot;off&quot; should mean zero." CreationDate="2011-03-23T20:54:15.953" UserId="1407" />
  <row Id="17876" PostId="11925" Text="PS. I would draw a schematic in case I my explanation is not clear enough but I still haven't finished the HTML5 schematic capture tool. ;] Please leave me a comment if you think a schematic would help here." CreationDate="2011-03-23T21:07:52.820" UserId="659" />
  <row Id="17877" PostId="1482" Text="@bpijls I have changed the title." CreationDate="2011-03-23T21:18:45.513" UserId="659" />
  <row Id="17878" PostId="11811" Text="I was asking about the stepper itself but I guess it will also be very low. " CreationDate="2011-03-23T21:23:57.023" UserId="659" />
  <row Id="17880" PostId="11910" Text="I need 256-512 KB SRAM to realize this project" CreationDate="2011-03-23T21:25:44.440" UserId="3186" />
  <row Id="17881" PostId="11814" Text="I guess that even with an encoder it will be difficult to handle 1/1436 RPM without jitter." CreationDate="2011-03-23T21:27:25.573" UserId="659" />
  <row Id="17882" PostId="11915" Text="Maybe, I just vary that it will be a problem further on when I want to design my own PCB, higher freq. means problems on the PCB. " CreationDate="2011-03-23T21:27:46.747" UserId="3186" />
  <row Id="17883" PostId="11803" Text="To oversimplify a bit, when working with low voltage and low current electronics, the biggest remaining risk is shorting (short circuiting) the power supply. So current limiting (such as fuses &amp; resettable fuses, circuit breakers and over-current protection devices/ICs) deals with the majority of the issues. The second is power supply polarity protection which can be handled with a simple diode (or P-channel MOSFET with its gate tied to ground) to ensure that the positive voltage input is correctly connected." CreationDate="2011-03-23T21:34:22.590" UserId="2598" />
  <row Id="17884" PostId="11816" Text="That would be great...Thanks Evan" CreationDate="2011-03-23T22:04:11.000" UserId="3140" />
  <row Id="17885" PostId="10350" Text="Can you provide some information on why you have no knowledge of your symbol rate? I'm having a hard time envisioning a comm. system where the receiver is clueless about symbol rates. Do you not even have an estimate?" CreationDate="2011-03-23T22:17:40.760" UserId="2454" />
  <row Id="17886" PostId="11923" Text="[National's datasheet](http://www.national.com/ds/LM/LM117.pdf) says 5 mA; where are you getting 10 mA from?" CreationDate="2011-03-23T22:25:03.390" UserId="857" />
  <row Id="17888" PostId="9540" Text="He did say he was looking for a Do-It-Yourself solution (see title). So presumably, he would be doing it himself. But at the end he asks for more general advice, so it's a little unclear." CreationDate="2011-03-23T22:57:59.943" UserId="790" />
  <row Id="17889" PostId="11915" Score="2" Text="@Z-roar: You can clock it at 10-20 MHz (or even lower, approaching DC) if you're uncomfortable with a 96 MHz design." CreationDate="2011-03-23T23:00:42.670" UserId="857" />
  <row Id="17890" PostId="11814" Text="..... Uh... no? With a good encoder (2048 lpr) you will get FAR better motion. However, at such insanely low speeds, you really SHOULD use some sort of gearbox." CreationDate="2011-03-23T23:16:36.220" UserId="1374" />
  <row Id="17891" PostId="11910" Text="@Z-roar - Yup, that's basically a mandate for external memory.  " CreationDate="2011-03-23T23:21:15.920" UserId="857" />
  <row Id="17893" PostId="11934" Score="2" Text="&lt;Subjective&gt;I recommend the Arm Cortex-M0, Cortex-M3, and Arm 7 series from that set as the best-documented,  most beginner-friendly, and most available selection. &lt;/Subjective&gt;" CreationDate="2011-03-23T23:37:33.323" UserId="857" />
  <row Id="17894" PostId="11926" Text="This is for mass production, not a one-off.  For the capacitor circuit, I'd be generating 50 V, not 10.  Running a boost converter that outputs 25 V at the SW pin, and then doubling it with two sets of diodes and capacitors." CreationDate="2011-03-23T23:58:29.287" UserId="142" />
  <row Id="17895" PostId="11915" Text="Er, I thought you meant 512 KB of Flash, not RAM. Like reemrevnivek says you'll want a controller with external memory." CreationDate="2011-03-23T23:58:53.993" UserId="2064" />
  <row Id="17896" PostId="1675" Text="Please, do not put your signature again." CreationDate="2011-03-24T00:44:59.800" UserId="938" />
  <row Id="17897" PostId="11926" Text="Sorry, I missed the point about mass-production. I dug further into the switched capacitor circuit and it looks really nice to me." CreationDate="2011-03-24T00:51:32.687" UserId="659" />
  <row Id="17898" PostId="11906" Text="Is the switched capacitor output really +10V and not -10V? It looks to me that you have to reverse the direction of the D3 diodes to get +10V." CreationDate="2011-03-24T00:53:35.353" UserId="659" />
  <row Id="17899" PostId="11871" Score="1" Text="Using a holding tank to pre-measure a volume of water is the way that commercial coffee makers such as those found in offices work. " CreationDate="2011-03-24T00:53:57.730" UserId="3105" />
  <row Id="17900" PostId="11924" Text="@jpc, This is very important knowledge, but really could be used in an addendum to an answer to the actual question." CreationDate="2011-03-24T01:13:18.447" UserId="230" />
  <row Id="17901" PostId="11924" Score="1" Text="But the question is &quot;Is it normal?&quot; and not &quot;How to fix it?&quot; ;]" CreationDate="2011-03-24T01:16:02.207" UserId="659" />
  <row Id="17902" PostId="11779" Text="@Kellenjb: Though I understand group delay, would be good if you can add on the corresponding group delay graphs for added clarity." CreationDate="2011-03-24T01:21:01.727" UserId="2897" />
  <row Id="17903" PostId="11932" Text="A better question would probably be &quot;about the best way to step 12V down to 5V&quot; but then you would have to provide at least your peak current needs." CreationDate="2011-03-24T01:21:29.707" UserId="659" />
  <row Id="17904" PostId="11811" Text="As for the stepper itself, whatever minimizes vibration the most, I suppose." CreationDate="2011-03-24T01:26:29.083" UserId="2240" />
  <row Id="17905" PostId="11814" Text="Fake Name: I guess I should learn more about encoders but for now I will just believe you. :) I agree about the gearbox." CreationDate="2011-03-24T01:34:39.390" UserId="659" />
  <row Id="17908" PostId="11900" Score="1" Text="+1 Wow, that really is comprehensive." CreationDate="2011-03-24T02:04:46.973" UserId="659" />
  <row Id="17909" PostId="11923" Score="1" Text="@reemrevnivek: LM317 parts manufactured by other companies like [ON Semiconductor](http://www.onsemi.com/pub_link/Collateral/LM317-D.PDF) and [Texas Instruments](http://focus.ti.com/lit/ds/symlink/lm317.pdf) have the minimum required load current specified at 3.5 to 10 mA, so that's probably where Hans is getting the 10 mA figure from." CreationDate="2011-03-24T02:22:52.330" UserId="2622" />
  <row Id="17910" PostId="11905" Text="@DavidCary, our protons move quite fast, although they do damage crystalline structures, anything in the way that is electronics does not work so great." CreationDate="2011-03-24T02:38:18.220" UserId="230" />
  <row Id="17911" PostId="11734" Text="@Alex, I intended to write that in my comment but used the word current. Don't write tired." CreationDate="2011-03-24T02:52:42.727" UserId="230" />
  <row Id="17914" PostId="9251" Text="@bt2, I must have misunderstood your comments, based on this feedback I did at least. I will remove my comment!" CreationDate="2011-03-24T03:13:25.597" UserId="230" />
  <row Id="17915" PostId="1584" Text="Just an update about developing with PICs.  The new Microchip IDE, MPLAB X (which is still in beta) is based on NetBeans and allows PIC development on any of the major platforms (Windows/MAC/Linux)." CreationDate="2011-03-24T03:14:31.707" UserId="2377" />
  <row Id="17916" PostId="11814" Text="Hah, yeah. There is a reason that steppers are pretty much never used on big industrial motion systems. All Big CNC systems are servo-motor + encoder based." CreationDate="2011-03-24T03:19:25.823" UserId="1374" />
  <row Id="17917" PostId="11940" Score="2" Text="You don't have to worry about the mechanism of reversing, all the operating systems can do that in software. The chief problem here is sensing the position of the mouse" CreationDate="2011-03-24T04:03:45.493" UserId="1200" />
  <row Id="17918" PostId="11899" Text="@reemrevnivek: I'm very very curious." CreationDate="2011-03-24T05:44:32.627" UserId="3552" />
  <row Id="17919" PostId="11899" Text="@jpc: Well, I can believe the TV is waiting, but the charger circuit that would connect the phone is even disconnected. Where's the waiting? No circuit - no waiting (as far as I see it)." CreationDate="2011-03-24T05:45:45.793" UserId="3552" />
  <row Id="17920" PostId="11944" Score="1" Text="I would just use the USB +5V instead of a battery, since most mice and keyboards are mostly USB " CreationDate="2011-03-24T07:53:09.600" UserId="2060" />
  <row Id="17921" PostId="11945" Text="I have the wiring diagram for the TV set, so identifying parts isn't that complicated. Should I replace all capacitors on the AC/DC converter part?" CreationDate="2011-03-24T08:53:54.653" UserId="2134" />
  <row Id="17922" PostId="11899" Text="@sharptooth: The charger is a circuit by itself - the phone does not complete the circuit, it adds to it. If the charger wasn't &quot;waiting&quot;, then it wouldn't know when you plugged your phone in." CreationDate="2011-03-24T09:43:49.477" UserId="638" />
  <row Id="17923" PostId="11899" Text="@W5VO: I really don't get it. The wall outlet doesn't consume power until I plug something. Why is the charger different?" CreationDate="2011-03-24T09:56:36.577" UserId="3552" />
  <row Id="17924" PostId="11944" Score="1" Text="@jsolarski: On the keyboard side - yes... but the question specifies a wireless mouse." CreationDate="2011-03-24T09:58:08.133" UserId="2426" />
  <row Id="17925" PostId="11947" Text="We have 240V/50Hz in Germany. It has a switch-mode PSU. I don't have a scope." CreationDate="2011-03-24T10:03:38.160" UserId="2134" />
  <row Id="17926" PostId="11947" Text="If it's a SMPS, I guess the 50 Hz noise is interference from the vertical deflection circuit. Will be kind of hard without a scope, but I would test(/replace/try out) (a) the capacitors that stabilize the deflection circuit's supply rails and (b) any capacitors in the signal or power paths between the deflection IC and the deflection yoke (coil). Also, check for bad solder joints around any parts of the deflection circuit. I've successfully repaired quite many TVs just by re-soldering some pins." CreationDate="2011-03-24T10:22:24.370" UserId="930" />
  <row Id="17927" PostId="11944" Text="Sorry missed that part, then hooking into the battery would be the best option." CreationDate="2011-03-24T10:25:41.833" UserId="2060" />
  <row Id="17929" PostId="11947" Text="I checked all solder pins, all are OK. I replaced two capacitors adjacent to the TBA3653B, the rest I need to order. But isn't it like there's unstable power supply since the TV starts to flicker, loses color and sound at bright pictures? I believe all CRT guns at full power (white = all CRT guns at full power) seem to drain too much power, which would suggest an unstable power supply (broken capacitors). Or am I on the wrong path here?" CreationDate="2011-03-24T10:31:29.410" UserId="2134" />
  <row Id="17930" PostId="11899" Text="@sharptooth Because your power outlet does do voltage conversion and is just a mechanical element. A mobile phone charger could also be just a mechanical element but then you would have to carry the power supply circuit inside you phone all the time and it is quite big." CreationDate="2011-03-24T10:43:11.513" UserId="659" />
  <row Id="17931" PostId="11899" Text="@jpc: Well, now it starts making sense. That looks like what I've been looking for. Could you please add it into your answer?" CreationDate="2011-03-24T10:51:35.250" UserId="3552" />
  <row Id="17932" PostId="11949" Text="Thanks for the tip. I think the the cited FCC statement was replaced with a little more permissive one: http://www.tapr.org/ss_fcc.html But your point is still valid." CreationDate="2011-03-24T11:21:31.527" UserId="659" />
  <row Id="17933" PostId="11887" Text="Well, I want to use this in my car, to protect the main starter battery from being discharged below 12.5V by a second - deep cycle AGM battery which is charged off the main battery. That second battery can pull 70A of current, but that will happen only sometimes, when the alternator + main battery are actually able to deliver 70A. But if the low-voltage-disconnect would drain 100mA all the time, that would be unacceptable waste of energy from the main battery, I can afford to lose at most 1Ah per week, that is 6mA average drain. Are you saying that the relay won't drain 100mA all the time?" CreationDate="2011-03-24T11:31:56.017" UserId="1691" />
  <row Id="17934" PostId="11899" Text="@sharptooth I tried. Anything else you would like me to add?" CreationDate="2011-03-24T11:37:10.380" UserId="659" />
  <row Id="17935" PostId="11899" Text="@jpc: Great, thank you." CreationDate="2011-03-24T11:43:58.403" UserId="3552" />
  <row Id="17936" PostId="11947" Text="Yes, also likely. Even without an oscilloscope, measuring the voltages from the power supply with a DMM might give you hints. It is also likely that one voltage is regulated, and the others are just obtained by rectification of other secondary windings in the SMPS main transformer. Also, stuff might be synchronized with the picture (i.e. with the vertical skipping pulses). I'd have to dig into the schematic/service manual to get a better idea." CreationDate="2011-03-24T11:47:14.390" UserId="930" />
  <row Id="17937" PostId="11887" Text="No, you are right that the such high current relay will drain at least 100mA while turned on. You can choose if you want it to conduct or not while turned on (SPDT relays) but this will just make things worse in this particular case. I now found that there are also latching relays which retain their position even without continuous current but they are awfully expensive." CreationDate="2011-03-24T11:48:17.630" UserId="659" />
  <row Id="17938" PostId="11944" Text="@BG100 - Given that the keyboard could still be USB, wouldn't it be better to mount the IR LEDs on the keyboard, and have a low-power receiver on the mouse?" CreationDate="2011-03-24T12:06:22.863" UserId="857" />
  <row Id="17939" PostId="11953" Text="I do not understand the second part of your question. Could you explain it a little bit more?" CreationDate="2011-03-24T12:10:13.453" UserId="659" />
  <row Id="17940" PostId="11944" Text="@reemrevnivek: Yes, I guess that would work... but it might be tricky as you'd have to fit the receiver electronics into the mouse and have that do the button reversing. I've never made anything that small so I don't know how easy that is. You could always make the IR LED pulse so its off most of the time to save on power." CreationDate="2011-03-24T12:11:23.843" UserId="2426" />
  <row Id="17941" PostId="11954" Score="1" Text="I am glad you mentioned the characteristic curve. It frequently surprises people." CreationDate="2011-03-24T12:11:49.990" UserId="659" />
  <row Id="17942" PostId="11952" Text="If you want the fuse to protect the solid state relay then I do not think that reusability of the circuit breaker will help. If there is a big overload (like a short circuit) it will most certainly damage the SSR, badly. The fuse is there to protect from fire but it will not &quot;rescue&quot; the SSR." CreationDate="2011-03-24T12:15:08.803" UserId="659" />
  <row Id="17943" PostId="11956" Text="Good point about the startup time. In general one should always verify all one's fuse bit settings with the datasheet." CreationDate="2011-03-24T12:16:33.623" UserId="659" />
  <row Id="17944" PostId="11892" Text="Thanks James, unfortunately that one only has a single SPDT switch. I was looking for one with a DPDT switch / two SPDT switches." CreationDate="2011-03-24T12:29:48.707" UserId="2914" />
  <row Id="17945" PostId="11955" Text="I always found it kind of interesting that there seems to be a lower bound in this table at 400kHz..." CreationDate="2011-03-24T12:39:09.533" UserId="771" />
  <row Id="17946" PostId="11955" Text="AFAIK the chip will work find down to 1 or 0Hz (it is a fully static design) but the oscillator circuit may not. And then there is an option with CKOPT = 0. It may be difficult to test thou since the only really low frequency crystal I am aware of is the 32kHz watch crystal so you cannot really verify 2Hz operation. ;]" CreationDate="2011-03-24T12:47:16.853" UserId="659" />
  <row Id="17947" PostId="11944" Text="@BG100 @reemrevnivek depending on the the mouse and how much room he has, he could easily fit, a simple 433/315Mgz transmitter in there with a something like an msp430gxxxx and a few IR receivers. ( ! have seen usb hubs implanted into a mouse with a flash drive- (not wireless)) To save power you could have it in a sleep mode and press a simple reset/configure button to set read which side of the key board its on, then go back to sleep/low power mode." CreationDate="2011-03-24T13:00:26.223" UserId="2060" />
  <row Id="17948" PostId="11940" Text="will this be a wireless mouse and keyboard combo? or just a wireless mouse and a wired keyboard?" CreationDate="2011-03-24T13:02:18.670" UserId="2060" />
  <row Id="17950" PostId="11962" Text="@pingswept, literally had 4 coworkers from belgium with me 6 hour ago, if only this had been posted in time!" CreationDate="2011-03-24T13:54:15.553" UserId="230" />
  <row Id="17951" PostId="11959" Text="Thank jsolarski ;) I press the reset butotn on arudino but nothing change, even if I try to upload blinking led sketch nothing happen. Some strange behaviour on Arudino is the mini-led soldierd onboard is blinking continuosly a high frequncy. &lt;br&gt; In led picker sketch at line 25 there's a &quot;const char javascript[] PROGMEM = &quot;, If i leave this as is Arudino IDE dosen't allow me to build. If i broke into 2 parts it run." CreationDate="2011-03-24T13:56:18.260" UserId="3562" />
  <row Id="17952" PostId="11944" Text="I wouldn't count on the IR LED to prove that it's on one side or the other.  Not reliable enough.  It would switch sides every time your hand interrupts the light?   Keyboard is plugged in, so better put the LEDs in there, on both sides. Mouse is wireless so put the detectors in there, on both sides.  Then remember the position, and assume that the position hasn't changed until it sees light to prove otherwise.  " CreationDate="2011-03-24T14:24:57.587" UserId="142" />
  <row Id="17953" PostId="11966" Text="I'm driving it (currently) at 12V, but the voltage isn't really the point. Chopper drivers (like mine) deliver (approximately) constant current, but not (at all) constant voltage. I would like to know what a safe current is." CreationDate="2011-03-24T15:47:29.357" UserId="3240" />
  <row Id="17954" PostId="11934" Score="1" Text="An SPI memory (RAM or flash) chip can fetch an arbitrary byte of memory in about six microseconds or less, and succeeding bytes in less than a microsecond each.  Some applications require memory access at speeds which can't be achieved via SPI flash, but for a hobby-level project wiring up four wires for an SPI memory chip would seem much more appealing than wiring dozens of wires for a parallel memory interface." CreationDate="2011-03-24T15:49:17.047" UserId="3123" />
  <row Id="17955" PostId="7871" Score="1" Text="I would suggest that my_free should set heap_ptr to the passed-in value, effectively freeing the indicated item and everything allocated after it.  Obviously one must allocate things in a sequence that permits such usage, but such patterns aren't uncommon.  Another useful variation is to have two pairs of alloc/free functions, one of which allocates top-down and the other of which allocates bottom-up." CreationDate="2011-03-24T15:53:18.400" UserId="3123" />
  <row Id="17957" PostId="18" Text="I think you should choose the other answer as the Arduino has the watchdog built in." CreationDate="2011-03-24T15:59:22.123" UserId="2006" />
  <row Id="17958" PostId="11948" Text="LED mouse chipsets are actually small cameras.  Consult the datasheet, but it is possible to use them as scanners.  http://blog.savel.org/2010/03/10/mouse-scanner/  Maybe have different patterened mousepads for left and right?" CreationDate="2011-03-24T16:03:28.347" UserId="411" />
  <row Id="17959" PostId="11966" Text="Well, That is was I saying. Increase current while monitoring temperature. Make sure that voltage is not over brakedown limit. That's it :-)" CreationDate="2011-03-24T16:08:22.647" UserId="2062" />
  <row Id="17960" PostId="11934" Text="@supercat - Huh, I didn't know they made serial SRAM.  Neat!  It looks like you'd have to use 2 chips to get 512 kB, but that's still probably preferable to the parallel interface." CreationDate="2011-03-24T16:17:32.143" UserId="857" />
  <row Id="17961" PostId="11970" Score="1" Text="you seem to be assuming a lot. ;0" CreationDate="2011-03-24T16:54:22.547" UserId="2157" />
  <row Id="17962" PostId="11968" Text="Great idea. This would actually be a lot more useful since it solves the problem without relying on the presence of a keyboard." CreationDate="2011-03-24T18:16:17.530" UserId="3362" />
  <row Id="17963" PostId="11923" Text="Because the specifications are measured at Iout = 10mA. The reference voltage is specified between 10mA and Imax. &#xA;Even more important, 5mA is typical, 10mA is worst case. If you do get a bad batch, or a different supplier you want to make it work as well. Some values are also 'ensured by design but not tested'. In other words, don't fixate on exact precise figures in datasheets. Go for a robust solution." CreationDate="2011-03-24T18:28:49.983" UserId="1476" />
  <row Id="17964" PostId="11970" Score="2" Text="I think you might be looking more for a physics book" CreationDate="2011-03-24T18:42:18.053" UserId="536" />
  <row Id="17965" PostId="11948" Text="Erm, I know that. Point being, to register either &quot;lift off&quot; or &quot;landing&quot;. Also, the camera has to have a focal point, so what if you point the camera into the air?" CreationDate="2011-03-24T18:52:31.727" UserId="2134" />
  <row Id="17966" PostId="11906" Text="@jpc: Yeah, not the first time I've seen an error in Maxim's schematics.  :)  I will try to draw what I actually mean instead of using their example." CreationDate="2011-03-24T19:06:32.237" UserId="142" />
  <row Id="17967" PostId="11948" Text="I think focus is just the high-frequency content of the image.  It wouldn't be hard to get this from the bitmap if the sensor DSP doesn't give you this automatically." CreationDate="2011-03-24T19:30:41.477" UserId="411" />
  <row Id="17968" PostId="4265" Text="It's too bad there's no nice way of adding just a little data to a page.  It would have simplified some things.  Still, if you want a robust way of adding data to a rolling log or something, I'd suggest having a system invariant that when the system is idle there will always be two blank pages after the end of the written data, and no others (when the device is new, pre-fill all the other pages).  The page following the two blank pages should be presumed meaningless.  To write a new data page, overwrite the first blank page, then erase the page after the second.  On startup..." CreationDate="2011-03-24T19:52:47.950" UserId="3123" />
  <row Id="17969" PostId="11970" Score="5" Text="Please add some more information about which part of electronics (it is a broad topic) interests you most." CreationDate="2011-03-24T19:54:10.750" UserId="659" />
  <row Id="17970" PostId="4265" Text="...make sure there are two blank pages.  If there's only one, erase the page before it since it might only be partially written.  This will cover the cases where the write of the blank page failed, as well as the case where the erase failed, provided that the memory doesn't get erased just enough that it sometimes reads blank and sometimes not.  There isn't any good way to handle that scenario, except to use checksums and hope for the best." CreationDate="2011-03-24T19:55:57.933" UserId="3123" />
  <row Id="17971" PostId="4265" Text="Note, btw, that if one could add &quot;0&quot;'s to non-blank pages, one could write a protocol that was immune to &quot;almost-erase&quot; operations, but without such a feature it's not possible." CreationDate="2011-03-24T19:56:57.713" UserId="3123" />
  <row Id="17972" PostId="11978" Text="I'm hoping to avoid this kind of story: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1264346368" CreationDate="2011-03-24T20:22:14.180" UserId="207" />
  <row Id="17973" PostId="11892" Text="Ahhh sorry....." CreationDate="2011-03-24T20:22:41.173" UserId="3140" />
  <row Id="17974" PostId="11945" Text="Could it be that it's TDA3653B, and not TBA3653B?" CreationDate="2011-03-24T20:33:07.470" UserId="930" />
  <row Id="17975" PostId="11978" Text="@msutherl - Would it be a big deal if you had to use a mux to connect to this ADC?  You'll have a hard time finding a 16-channel, 16+ bit ADC, but 1-channel or 2-channel parts are fairly easy..." CreationDate="2011-03-24T20:50:48.833" UserId="857" />
  <row Id="17976" PostId="11978" Score="1" Text="Bits alone don't determine dynamic range.   24-bit converters theoretically could have a dynamic range of 144 dB, but real converters are 100-120 dB or so.  Are you sure you need this much resolution for a stretch sensor?  You're trying to handle lots of different stretch sensors of different values?  It would be better to just use a variable-gain amplifier, I would think, and adjust it for each one.  You're going to have to do that calibration somewhere anyway." CreationDate="2011-03-24T21:00:01.607" UserId="142" />
  <row Id="17977" PostId="11970" Text="What kind of &quot;statements&quot; are you looking for?" CreationDate="2011-03-24T21:01:29.827" UserId="142" />
  <row Id="17978" PostId="11980" Text="Actually, the resistors are just 5 W. I've had success with tests previously by building resistor networks, so that load on each resistor is lower than 5 W. I don't need regulation for my idea, so the supply should work. I tested it as mentioned, but it seems that the supply isn't outputting anything at all. Could it be that it needs voltage form the battery to start working? Looks like I'll have to find the manual. " CreationDate="2011-03-24T21:13:49.713" UserId="1240" />
  <row Id="17979" PostId="11988" Score="2" Text="Your 328 is running at 5V, so your IO pins output 5V when high" CreationDate="2011-03-24T21:18:43.220" UserId="566" />
  <row Id="17980" PostId="1443" Text="Disclaimer aside, CodeLite is a great tool.  You don't have to use 'make flash' if you configure CodeLite to work with your build system.   Code::Blocks has similar potential." CreationDate="2011-03-24T21:21:05.763" UserId="857" />
  <row Id="17981" PostId="1439" Text="I was not able to make arduino_make.sh work w/ OSX 10.6 because 'awk -v' doesn't work as expected on OSX and he uses it everywhere." CreationDate="2011-03-24T21:28:13.147" UserId="207" />
  <row Id="17982" PostId="11967" Text="I will try to upload this sketch as soon I restore my Arudino. I'm not able to upload nothing to IT after i upload the ledpitcher sketch. It continuosly blink the mini led and report error top of this page message" CreationDate="2011-03-24T21:48:39.947" UserId="3562" />
  <row Id="17983" PostId="11986" Text="Soft pencils (5B, or #1, can also be found at most office supply and stationery stores (e.g. Staples). " CreationDate="2011-03-24T22:14:51.900" UserId="2598" />
  <row Id="17984" PostId="11826" Text="@RMAAlmeida, this is really determined by country, but yes, they should measure it." CreationDate="2011-03-24T22:20:08.407" UserId="230" />
  <row Id="17985" PostId="11980" Text="I would not think it would need power from the battery. I've never seen that before. That would mean it could not charge a dead battery. The only reason I can think of no voltage is that you would have to give it a load, but you have already done that. Sounds as if there is a problem with the unit. Can you get into the unit? Start with checking the basics; switch, line cord, circuit breaker, etc... " CreationDate="2011-03-24T22:20:41.100" UserId="3453" />
  <row Id="17986" PostId="11903" Text="Or to paraphrase grossly; Ohm's Law doesn't care if the electrons are being _useful_ work or not, they will continue to they leak/ drain/ flow if there is a circuit between a voltage potential. " CreationDate="2011-03-24T22:28:22.813" UserId="2598" />
  <row Id="17987" PostId="11990" Text="Thanks! That's what I was hoping!" CreationDate="2011-03-24T22:31:30.093" UserId="3301" />
  <row Id="17988" PostId="6066" Text="The question is not an exact duplicate due to the difference if being for 12Vdc voltage, but **high current**, and in this case also should be able to withstand over-voltage situations created by an automotive alternator. " CreationDate="2011-03-24T22:51:17.483" UserId="2598" />
  <row Id="17989" PostId="11976" Text="It would only at best inhibit only _charged_ alkaline batteries. " CreationDate="2011-03-24T22:54:00.587" UserId="2598" />
  <row Id="17990" PostId="11980" Text="@Steve  OK. I'll start with the basics." CreationDate="2011-03-24T23:07:31.857" UserId="1240" />
  <row Id="17991" PostId="11995" Text="Do you get a tapered hole?" CreationDate="2011-03-24T23:15:30.077" UserId="2426" />
  <row Id="17992" PostId="11998" Text="but the weird thing is it does it without the avr as well. " CreationDate="2011-03-24T23:26:25.833" UserId="2824" />
  <row Id="17993" PostId="11995" Score="1" Text="A slight taper, but it doesn't matter." CreationDate="2011-03-24T23:26:49.793" UserId="305" />
  <row Id="17994" PostId="11997" Text="Or a pocketknife" CreationDate="2011-03-25T01:26:20.013" UserId="142" />
  <row Id="17995" PostId="11978" Text="**Excellent question! +1**" CreationDate="2011-03-25T04:13:11.473" UserId="2118" />
  <row Id="17996" PostId="11978" Text="@endolith, I suppose in that case I'd have an instrumentation amplifier with a potentiometer to vary the gain? I'd prefer to autocalibrate this in software. The reason to have high dynamic range is to avoid having to deal with amplification. " CreationDate="2011-03-25T04:52:28.990" UserId="207" />
  <row Id="17997" PostId="11945" Text="@zebonaut: Yes of course! *(corrected)*" CreationDate="2011-03-25T05:17:37.400" UserId="2134" />
  <row Id="17998" PostId="11839" Text="@supercat There are ways around that limitation. Basically, on the low side of the low voltage winding you use a n-channel mosfet paired with a capacitor bridging the drain to the source. That should protect the mosfet as well as prevent any sparks that may occur with the circuit is closed. Here's the resource I found to solve this issue. http://www.myelectricengine.com/everythingelse/ignition/ignition.html" CreationDate="2011-03-25T07:03:14.807" UserId="1866" />
  <row Id="17999" PostId="11817" Text="@James Why? You've been a big help so far. My take is, if you aren't learning you're not tying hard enough. My lack of understanding when it comes to charging capacitors is my main advantage for doing this project in the first place." CreationDate="2011-03-25T07:21:53.103" UserId="1866" />
  <row Id="18001" PostId="11982" Text="SEPIC design looks promising, seems to fit the my use case very well. Thanks!" CreationDate="2011-03-25T07:31:31.340" UserId="1562" />
  <row Id="18002" PostId="1439" Text="His question was not about Arduino, but about using avr-gcc and avrdude on Linux" CreationDate="2011-03-25T08:31:04.923" UserId="1675" />
  <row Id="18003" PostId="1445" Text="Get the avr-eclipse plugin, it integrates nicely with avrdude and avr-gcc so you end up with a nice IDE on top of a good, free compiler." CreationDate="2011-03-25T08:32:17.327" UserId="1675" />
  <row Id="18004" PostId="12010" Text="Thanks a lot! I just found out the company part myself. " CreationDate="2011-03-25T08:45:27.613" UserId="1240" />
  <row Id="18006" PostId="11996" Text="By 'light up', do you mean you see black squares? Your LCD probably has 2 controllers, as unixbigot said. And you might have it upside down :-)" CreationDate="2011-03-25T09:02:28.970" UserId="1124" />
  <row Id="18007" PostId="12007" Text="@Mawg, something major changed when we went live. We no longer have robotics in our name. [Robotics](http://area51.stackexchange.com/proposals/29987/robotics-research) is getting its own site." CreationDate="2011-03-25T09:28:37.807" UserId="230" />
  <row Id="18008" PostId="12008" Text="+1 on the voltage reference" CreationDate="2011-03-25T10:09:06.263" UserId="659" />
  <row Id="18009" PostId="11978" Score="1" Text="Do you need 100Hz+ for each sensor or for all of them? With multi-channel ADCs you frequently get 1 ADC and a mux so you will have to divide the SPS by the channel count (or more if the mux/adc pair cannot switch channels very fast)." CreationDate="2011-03-25T10:11:15.857" UserId="659" />
  <row Id="18010" PostId="12012" Score="2" Text="The weight alone doesn't say much, you need the moment of inertia. It's a lot easier to rotate a 1 cm diameter cylinder than one with a 30 cm diameter, even if they're the same weight." CreationDate="2011-03-25T10:22:14.827" UserId="2064" />
  <row Id="18011" PostId="11824" Text="Exactly (and more) what I was looking for. I have experience programming micro controllers. This is the best solution for me. Thanks." CreationDate="2011-03-25T10:24:30.767" UserId="2134" />
  <row Id="18012" PostId="12012" Text="We'll need dimensions of the turntable and mass of its rotating element to get the moment of inertia." CreationDate="2011-03-25T10:26:56.630" UserId="1240" />
  <row Id="18013" PostId="12013" Text="Not unconventional at all. In fact, if he wants to use small 8 bit microcontroller, this way he can avoid dealing with 24 bit values and the complexity may be smaller than interfacing these sophisticated ADCs. The dynamic range can be sum of dynamic ranges of ADC and PWM in ideal case. On the other hand, it seems that for many people analog designs are harder than digital, so just using 24 bit ADC may be simpler. Also, dynamic range of ADC can be increased by oversampling and digital filtering ... well, not simple anymore." CreationDate="2011-03-25T10:57:39.813" UserId="2636" />
  <row Id="18014" PostId="11948" Text="Yeah, you should be able to detect 'no ground' with the camera inside every mouse. Putting the mouse into 'unset' mode once too many, isn't much of a problem, since the arrangement of buttons is set with the next click. Since we need the primary button far more often than the secondary, most people wouldn't even notice an 'unset' state that happens during normal mouse use." CreationDate="2011-03-25T11:04:51.777" UserId="2134" />
  <row Id="18015" PostId="12016" Text="@Mike, he did an edit and we both answered in a 1.5 minute time span." CreationDate="2011-03-25T11:15:23.317" UserId="230" />
  <row Id="18016" PostId="12017" Text="@leonHeller, and you were 30 seconds after Mike. I need to just give others a chance on these questions." CreationDate="2011-03-25T11:26:10.203" UserId="230" />
  <row Id="18017" PostId="11901" Text="@reemrevnivek, for as many people that are scared by that there are probably a large number of failed chips they could not debug without it. If you set level 2 you know what you are doing, really, in a final product you would probably set level 3. Still, great research!" CreationDate="2011-03-25T11:28:15.130" UserId="230" />
  <row Id="18018" PostId="12016" Score="2" Text="@Kortuk - These answers are like London buses. You wait 20 minutes and three turn-up together :o}" CreationDate="2011-03-25T11:59:20.783" UserId="2234" />
  <row Id="18019" PostId="12016" Text="@Mike, haha. Mainly on the common routes though." CreationDate="2011-03-25T12:03:26.893" UserId="230" />
  <row Id="18020" PostId="12017" Score="2" Text="Cheaper and much more efficient at low voltages since you have only 1 diode drop instead of 2." CreationDate="2011-03-25T12:17:41.210" UserId="659" />
  <row Id="18021" PostId="12015" Text="I do not understand your answer despite understanding the question and the circuits... ;]" CreationDate="2011-03-25T12:18:27.950" UserId="659" />
  <row Id="18022" PostId="12013" Text="@Jaroslav Thanks. 1. He already has a Wheatstone bridge so I guess he is not totally afraid of the analog part. :) 2. 1 or 2 bits of additional resolution should be achievable by a simple running sum filter." CreationDate="2011-03-25T12:21:02.550" UserId="659" />
  <row Id="18023" PostId="12013" Score="1" Text="@jpc Indeed! Here is a link for OP: [http://www.dspguide.com/ch15.htm](http://www.dspguide.com/ch15.htm)" CreationDate="2011-03-25T12:42:34.823" UserId="2636" />
  <row Id="18024" PostId="12015" Text="@jpc, I am sorry to hear that. I was trying to focus on the connections and what was happening. I could have done the full wave rectifier approach, this just seemed like what the OP may be missunderstanding." CreationDate="2011-03-25T12:54:18.537" UserId="230" />
  <row Id="18025" PostId="12015" Text="@Kortuk OTOH maybe it is just me since you get only positive votes for this. :)" CreationDate="2011-03-25T13:15:43.413" UserId="659" />
  <row Id="18027" PostId="12020" Score="2" Text="This drawing is so simple and perfect I don't even need to read the answers to understand what's going on." CreationDate="2011-03-25T13:29:54.200" UserId="3582" />
  <row Id="18028" PostId="12019" Text="jpc: You could make that comment into an answer so it can receive upvotes." CreationDate="2011-03-25T13:48:48.980" UserId="568" />
  <row Id="18029" PostId="11978" Score="1" Text="@msutherl Yes, a manual gain pot, or a programmable-gain amplifier.  Something like a [PGA116](http://focus.ti.com/docs/prod/folders/print/pga116.html) could handle sampling all your sensors in round-robin fashion at different gains for each, with everything done in software?" CreationDate="2011-03-25T13:52:43.670" UserId="142" />
  <row Id="18030" PostId="11262" Text="there is a nice iphone app of one of those as well, works quite well..." CreationDate="2011-03-25T13:56:11.880" UserId="985" />
  <row Id="18032" PostId="12026" Text="Mine doesn't even have a ground to be defeated.  :/" CreationDate="2011-03-25T14:39:55.707" UserId="142" />
  <row Id="18033" PostId="12026" Text="What make and model is it?" CreationDate="2011-03-25T14:43:29.020" UserId="305" />
  <row Id="18034" PostId="12026" Text="JingCe JC2062M :D http://www.hzjingce.com/products.asp?id=2" CreationDate="2011-03-25T14:50:34.993" UserId="142" />
  <row Id="18035" PostId="12019" Text="Yes I can. It still would be best represented as an answer." CreationDate="2011-03-25T14:52:23.777" UserId="568" />
  <row Id="18036" PostId="12026" Text="&quot;In your case, I'd use an isolation transformer &quot; on the scope or the DUT?  On the scope wouldn't change anything, right?  Why would I need an Earth-free area if the DUT is floating?  " CreationDate="2011-03-25T14:53:48.143" UserId="142" />
  <row Id="18037" PostId="11978" Text="@jpc thanks for the tip, that didn't occur to me!" CreationDate="2011-03-25T14:55:25.157" UserId="207" />
  <row Id="18038" PostId="12020" Text="@Alain, got my +1. I would agree. I thought the same thing but did not have time or tools to make it." CreationDate="2011-03-25T14:58:27.500" UserId="230" />
  <row Id="18040" PostId="11839" Text="@Evan Plaice: My comment was in response to the question of why one needs a high-voltage switch.  An inadequate switch will end up dissipating an substantial amount of energy in the form of contact arcing.  This will both degrade the switch and waste energy which should be going into the spark plug.  It's possible to use high-voltage electronics instead of a switch, but if the electronics aren't up to the task, the energy will go into destroying the electronics rather than sparking the plug." CreationDate="2011-03-25T15:01:15.340" UserId="3123" />
  <row Id="18042" PostId="11839" Text="@supercat I'll assume that you didn't make the effort to read the article. The point I was making was, &quot;high-voltage electronics&quot; are completely unnecessary. The arcing problem can be easily solved by using a mosfet with a 'snubber'. http://en.wikipedia.org/wiki/Snubber explains what a snubber is." CreationDate="2011-03-25T15:12:41.133" UserId="1866" />
  <row Id="18043" PostId="12026" Score="2" Text="In the case I mentioned we used a large isolation transformer for both the scope and the DUT. If you simply use an isolation transformer on the scope in an earth-free area, you should be OK." CreationDate="2011-03-25T15:13:59.010" UserId="305" />
  <row Id="18044" PostId="11839" Text="@Evan Plaice: A snubber will limit the voltage to sane levels, but with a 100:1 coil, a 30,000 volt spark will require 300 volts on the primary, will it not?  MOSFETs that can handle 300 volts aren't exactly rare, but are still considered &quot;high voltage&quot;.  In any case, I did not see your comment before posting my first one (comments aren't visible until 5 minutes after they're posted, and my comment was probably within 5 minutes of yours), so I hadn't even seen mention of the article until today." CreationDate="2011-03-25T15:26:34.227" UserId="3123" />
  <row Id="18045" PostId="11992" Text="Went to bed pondering the idea of using the two relay legs to switch the 110v drain-valve circuit AND one of the 110v legs from the compressor circuit.&#xA;&#xA;What bugs me about that is that the compressor will be getting 110v on on of the legs and 0v on the other.  If it tries to start it will...try to start...  and that means that the windings in the motor for the &quot;live&quot; leg will energize while the other half wont. It will sit there for maybe months just like that.  Does not seem healthy to me at all. Even though my electrician and his &quot;industrial equipment&quot; expert assure me it's not a problem. " CreationDate="2011-03-25T15:30:39.733" UserId="2604" />
  <row Id="18046" PostId="12029" Score="1" Text="The manual's in Chinese..." CreationDate="2011-03-25T15:33:52.103" UserId="142" />
  <row Id="18047" PostId="12031" Text="Do you have capabilities to wind your own transformer? " CreationDate="2011-03-25T16:02:59.170" UserId="1240" />
  <row Id="18048" PostId="12032" Score="1" Text="And of course YOU personally should be the only one who makes and uses this setup." CreationDate="2011-03-25T16:06:05.283" UserId="659" />
  <row Id="18049" PostId="12023" Score="1" Text="On these voltages you may need x100 probes that can take the voltage, you may be close to the limit with x10 probes. The trick of using the scope to take the difference only works if both inputs are within the scope's common mode and at low frequencies where the probes are matched. The better technique is to use a [differential probe amp](http://www.tek.com/Measurement/App_Notes/Technical_Briefs/tds3000-float/eng/system.html). Although these probably cost more than your scope." CreationDate="2011-03-25T16:06:13.957" UserId="2110" />
  <row Id="18051" PostId="12023" Text="@Martin: Yes, they cost more than the scope.  I'm wondering if there's a trick to doing the differential math method.  Like float the scope, connect the ground of the scope to the reference point of the supply through a large resistor or small capacitor to reduce the common-mode without providing a direct connection, and then connect only the two probes to the circuit and diff them." CreationDate="2011-03-25T17:30:00.613" UserId="142" />
  <row Id="18052" PostId="12038" Score="2" Text="What supply voltages do you have available?" CreationDate="2011-03-25T18:10:45.103" UserId="305" />
  <row Id="18053" PostId="12037" Text="Aluminum oxide has a much higher resistance than aluminum - It's actually a very good insulator.  The coating is thin enough that a screw or bolt will penetrate to the highly conductive aluminum, but I'm not sure how you'll get a large surface area without welding or soldering.  (BTW: [here's](http://www.aws.org/wj/2004/02/046/) a nice article on soldering aluminum)." CreationDate="2011-03-25T18:14:35.453" UserId="857" />
  <row Id="18054" PostId="12038" Text="@leon, anything up to 5V?" CreationDate="2011-03-25T18:35:50.967" UserId="1982" />
  <row Id="18055" PostId="12040" Score="1" Text="@Missionary Man - I'm assuming you've tried the USB/HDMI/HDTV interfaces already present on these cameras?  I've never put any effort into getting data from these ports while taking pictures, but they offer a faster interface than SD card removal; you can probably take a picture while the camera is still connected..." CreationDate="2011-03-25T19:07:36.737" UserId="857" />
  <row Id="18056" PostId="12039" Score="1" Text="Just a note, this question appears to be about _buying advice_ of electronic devices, which is outside the scope of this web site. The moderators (not me) may close this as being off-topic." CreationDate="2011-03-25T19:17:38.713" UserId="2598" />
  <row Id="18057" PostId="12038" Text="http://www.sparkfun.com/products/8745" CreationDate="2011-03-25T19:25:22.993" UserId="319" />
  <row Id="18059" PostId="12043" Text="Thanks for the answer, it's a little too complex for me, but it's something to work towards. Where would I get out the increased signal?" CreationDate="2011-03-25T20:11:49.500" UserId="1982" />
  <row Id="18061" PostId="12038" Text="Ideally I'd like to do it myself." CreationDate="2011-03-25T20:53:15.533" UserId="1982" />
  <row Id="18062" PostId="12040" Text="@reemrevnivek - The HDMI/HDTV interfaces give you a picture you can display on a screen, but I need a picture I can process with a computer; I'll update the question to make that clear.&#xA;&#xA;At least on the face of it, neither the T2i nor the GoPro let you read the stream video or stills while &quot;tethered&quot;." CreationDate="2011-03-25T20:58:36.123" UserId="3591" />
  <row Id="18063" PostId="12045" Text="@trondd - thanks, I will look into the Nikons. Do you have experience with tethered video shoots on the Nikons?" CreationDate="2011-03-25T21:01:41.830" UserId="3591" />
  <row Id="18064" PostId="12043" Score="2" Text="@Jonathan - At the &quot;Out&quot; pin; you'll need a pullup resistor to 5V." CreationDate="2011-03-25T21:14:24.883" UserId="857" />
  <row Id="18065" PostId="12043" Text="Surely I need another voltage in. Also how did you calculate the resistors' resistance?" CreationDate="2011-03-25T21:22:38.530" UserId="1982" />
  <row Id="18066" PostId="12031" Text="From @user3593: &quot;I might be able to wind a transformer, especially if is a matter of rewinding one. I'm not so sure how I might create a proper core.&#xA;&#xA;I realize that aluminum forms an oxide layer and will take pains to make a good electrical contact. I'm also considering copper foil. In any case, I'm trying to only get the foil to heat up to 100C over a couple of seconds. At that point I need to be able to moderate the current. I can get the temperature and have access to PID controllers, but I'm worried about controlling a highly inductive load.&quot;" CreationDate="2011-03-25T21:55:36.267" UserId="230" />
  <row Id="18068" PostId="12053" Text="I fail to see how is this question on topic here." CreationDate="2011-03-25T22:32:49.387" UserId="1240" />
  <row Id="18069" PostId="12052" Score="1" Text="@Moratinos, think about it, if it were water you have a path but the water is at the same height on both sides. water does not flow because it has equal *potential*. " CreationDate="2011-03-25T22:40:32.240" UserId="230" />
  <row Id="18070" PostId="12054" Text="What is IRIG-B?" CreationDate="2011-03-25T22:49:37.920" UserId="305" />
  <row Id="18071" PostId="12053" Text="@Harpreet, This site is for electronics design, not for consumer electronics or shopping advice I am sorry to say. I wish you luck." CreationDate="2011-03-25T22:55:14.453" UserId="230" />
  <row Id="18072" PostId="12053" Text="@Kortuk: My question was from point of view of design, or the concept. Would you relate my comment with the question and then decide if it is still off topic?" CreationDate="2011-03-25T23:05:38.183" UserId="2439" />
  <row Id="18073" PostId="12053" Text="@H_S, I can re-close it as too broad. If you would like to design one with that much description you are asking us to do an entire engineering project for you. Try to bring focused questions where you have reached a technical challenge. If you had started designing it and had an issue with how to pick a relay, for example, that would be perfect." CreationDate="2011-03-25T23:14:56.820" UserId="230" />
  <row Id="18074" PostId="12041" Text="@Jaroslav I'm not sure I understand. In a voltage to current converter, V1 is usually from the sensor – in this case, since R2 is the sensor, what is the effect of U1? What are U3 and U2 for? Are they the instrumentation amplifiers? What are they fore? Finally, you say something about measuring the voltage drop across R1. How do I measure this drop and why do I need it? Finally, what kind of calibration scheme do you have in mind (see the two options I present in the post)? Thanks!" CreationDate="2011-03-25T23:33:38.427" UserId="207" />
  <row Id="18075" PostId="12041" Text="@Jaroslav Ah, I think you've responded to the wrong post. See here: http://electronics.stackexchange.com/questions/11978/high-resolution-adc-for-noisy-sensors-in-variable-conditions" CreationDate="2011-03-25T23:40:48.450" UserId="207" />
  <row Id="18076" PostId="12005" Text="When a receiver sees all of these signals coming from different sources, does it improve positional accuracy?" CreationDate="2011-03-26T00:25:05.433" UserId="550" />
  <row Id="18077" PostId="12041" Text="Thanks for the acknowledgement but to be honest I was imagining something simpler. :) I think you are not really using the ADC much here?" CreationDate="2011-03-26T01:07:06.457" UserId="659" />
  <row Id="18078" PostId="11951" Text="So basically I/Q or at least phase modulation is the best way to go? When demodulating I should demodulate the phase and then perform the correlation on the result? Is simple amplitude or maybe frequency modulation also possible or would I lose all the benefits of DSSS?" CreationDate="2011-03-26T01:33:20.750" UserId="659" />
  <row Id="18079" PostId="12051" Score="1" Text="If you tell us more about the stuff you want to displace we may be able to provide some better suggetions." CreationDate="2011-03-26T01:41:17.690" UserId="659" />
  <row Id="18080" PostId="12041" Text="@jpc indeed, 3 op-amps will take two much space anyway (8-channels, wrist-mounted)" CreationDate="2011-03-26T01:44:32.510" UserId="207" />
  <row Id="18082" PostId="12040" Text="Sounds like part of a cool project. So is this part of some sort of robot computer vision thing?" CreationDate="2011-03-26T01:52:39.990" UserId="813" />
  <row Id="18083" PostId="12043" Text="@Jonathan In such a circuit the resistor values are not very important unless you need fast signals. They should just be higher then several kOhms so that the current stays low. If you set the resistors too low you could overburden your 1.4V outputs." CreationDate="2011-03-26T01:57:40.067" UserId="659" />
  <row Id="18084" PostId="12017" Text="@jpc, but you do &quot;lose&quot; half your number of loops because you center tap. There is a tradeoff there." CreationDate="2011-03-26T02:24:45.767" UserId="230" />
  <row Id="18085" PostId="12043" Score="1" Text="This also inverts the output." CreationDate="2011-03-26T03:30:03.717" UserId="2340" />
  <row Id="18086" PostId="12054" Score="1" Text="What do you want to do with the signal? You say a reader, but what do you plan to connect the reader to? And where is the timecode coming from? " CreationDate="2011-03-26T04:04:24.917" UserId="131" />
  <row Id="18087" PostId="12043" Text="@freespace, Doh! you are correct." CreationDate="2011-03-26T05:25:04.720" UserId="2598" />
  <row Id="18088" PostId="12041" Text="@jpc Your solution does not really increase dynamic range. Simulate or measure to find out why. Also, it has a non-linearity during first 0.6V or so due to base-emitor diode." CreationDate="2011-03-26T05:50:28.180" UserId="2636" />
  <row Id="18089" PostId="12041" Text="@msutherl I admit that it's complicated but that's often what it takes. You asked for adaptive amplifier, I provided :) For 8 channel wrist mounted device use ADS1298, which integrates everything on one chip, including low noise reference, and has low power consumption. I am leaving for the weekend, but if you still really want to explain in more detail how my design works, I can answer that on Sunday." CreationDate="2011-03-26T05:56:45.990" UserId="2636" />
  <row Id="18090" PostId="11577" Text="Which of the answers is the most helpful, @msutherl? I'm leaning towards [@Jaroslav's](http://electronics.stackexchange.com/questions/11577/simple-adaptive-amplifier-options-for-sensor-interfaces/12041#12041)." CreationDate="2011-03-26T06:13:25.693" UserId="2118" />
  <row Id="18091" PostId="11577" Text="@tyblu neither of them really work for me since they're both untested and Jaroslav's is too complicated + has too many components." CreationDate="2011-03-26T07:03:16.480" UserId="207" />
  <row Id="18092" PostId="11978" Text="Right now I'm leaning towards trying the LTC2418 (8 differential channel 24-bit ADC), which has some example Arduino code available already. The signal path would be: textile -&gt; instrumentation amp (AD623) -&gt; LTC2418 -&gt; ATmega328." CreationDate="2011-03-26T07:06:19.147" UserId="207" />
  <row Id="18093" PostId="12043" Text="This circuit is also unidirectional. That will be fine for many circuits, but for those where a line is used by both ends to communicate bidirectionally, no dice." CreationDate="2011-03-26T07:33:56.447" UserId="2523" />
  <row Id="18094" PostId="12014" Text="For this circuit, the orientation of the diodes does not matter, as long as both are the same way round, common cathodes or anodes. - the only difference is the polarity of the output - the bottom circuit - the diodes are positive, and the centre tap is negative." CreationDate="2011-03-26T09:20:01.423" UserId="2192" />
  <row Id="18095" PostId="12066" Text="I thought transformers only work with AC?" CreationDate="2011-03-26T09:57:03.933" UserId="1982" />
  <row Id="18096" PostId="12073" Text="In this case you would need to change the 48000 to 1000 in the conversion. What is the resolution of the `duty` parameter and does it depend on `cycles`? Another possible problem is that you must keep calling this PWM statement on regular intervals or you will get distortion." CreationDate="2011-03-26T10:41:55.193" UserId="659" />
  <row Id="18097" PostId="12073" Text="duty : a value between 0 and 255 which is translated in a voltage between +0 and +5 Volt&#xA;&#xA;mplayer -af resample=1000 is not accepted, according to mplayer rate must be &gt;=8000" CreationDate="2011-03-26T10:55:03.640" UserId="3601" />
  <row Id="18098" PostId="12020" Text="Ms paint is a wonderful tool : )" CreationDate="2011-03-26T11:29:22.797" UserId="1293" />
  <row Id="18099" PostId="12041" Text="@Jaroslav: You are right that the non-linearity will kill the multiplication and limit the dynamic-range gain to 2x or at most 4x (so 2 bits at most). What do you think about adding an op amp to linearize the current source?" CreationDate="2011-03-26T11:33:46.510" UserId="659" />
  <row Id="18100" PostId="12073" Text="1kHz is really very low bandwidth for audio. You may try to use 8kHz — I think you should be able to recognize a slowed down version of your sound. Audacity seems to support 1000 Hz sample rates (and AFAIR it can directly export to a RAW file) so you may try to generate a simple sinusoid to see if the PWM is working well." CreationDate="2011-03-26T11:44:15.053" UserId="659" />
  <row Id="18101" PostId="11577" Text="@tyblu As far as I am concerned Kortuk can refund you the bounty." CreationDate="2011-03-26T12:03:30.537" UserId="659" />
  <row Id="18102" PostId="12076" Text="Is the library source code available online anywhere?" CreationDate="2011-03-26T12:31:29.527" UserId="659" />
  <row Id="18103" PostId="12066" Text="@Jonathan, you are correct." CreationDate="2011-03-26T12:45:23.280" UserId="230" />
  <row Id="18104" PostId="5402" Text="Why so many breadboards? :S I have 2. Are your circuits that big, or do you have many different prototypes at one time?" CreationDate="2011-03-26T12:55:17.280" UserId="1623" />
  <row Id="18105" PostId="12060" Text="What are the boundaries of the 1.8 MHz band?" CreationDate="2011-03-26T12:58:41.027" UserId="1240" />
  <row Id="18106" PostId="11987" Text="They are using &quot;the IEC definition of zero no-load power consumption&quot;, where &quot;zero&quot; is defined as &quot;less than 5 mW&quot;. Pretty impressive." CreationDate="2011-03-26T13:13:13.253" UserId="813" />
  <row Id="18107" PostId="12077" Text="I glanced at the document you're referring to and I noticed an error in the top line of figure 6.1. It says &quot;bipolar RZ&quot;, but should read &quot;bipolar NRZ&quot;. Didn't read it completely, so I don't know if there are other errors." CreationDate="2011-03-26T13:23:16.100" UserId="2064" />
  <row Id="18108" PostId="12067" Text="yeah, you know, if you can line them up and fix them in place (epoxy maybe?), you could probably get a suitable field this way." CreationDate="2011-03-26T13:26:06.880" UserId="740" />
  <row Id="18109" PostId="12038" Text="what drive capability does the 1.4V signal have? if it can source 1 mA or more, that's one thing, but if it has 10M impedance, that's another thing." CreationDate="2011-03-26T13:35:01.213" UserId="740" />
  <row Id="18111" PostId="12075" Text="Good idea. We've got stacks of old hard drives around. I'll take one apart and see how much power the actuator has. My load is going to be around 100grams so I might have to gang up a few of them." CreationDate="2011-03-26T14:02:31.073" UserId="3603" />
  <row Id="18112" PostId="12051" Text="@AndrewQueisser, your accounts have been merged." CreationDate="2011-03-26T14:23:58.607" UserId="230" />
  <row Id="18113" PostId="11974" Text="The amount of current*turns required to match a permanent magnet is fairly high, I would use a permanent magnet unless you want to demonstrate something like an alternator in reverse (where they use field coils to regulate their output voltage)" CreationDate="2011-03-26T14:44:13.003" UserId="1407" />
  <row Id="18114" PostId="11994" Text="What is your question?  Is it valid C?  Looks like it." CreationDate="2011-03-26T15:03:23.907" UserId="1407" />
  <row Id="18115" PostId="12066" Text="The idea of using the 1381 is a clever one, +1" CreationDate="2011-03-26T15:06:54.497" UserId="2340" />
  <row Id="18116" PostId="11901" Text="Still wondering if the key was loaded..." CreationDate="2011-03-26T15:16:11.540" UserId="2062" />
  <row Id="18117" PostId="12077" Text="Yeah, you're perfectly right - the first figure is NRZ. I need to read it carefully :)" CreationDate="2011-03-26T15:20:38.310" UserId="3564" />
  <row Id="18118" PostId="12051" Text="Speakers depend on the cone moving back and forth to keep air flowing and keep the voice coil cool.  DC will, in general, destroy the coil." CreationDate="2011-03-26T15:34:55.113" UserId="142" />
  <row Id="18119" PostId="12079" Text="@Ageis: note that the 0x40 is a hexadecimal value, decimal 64. For an 80 character display you change this value to &quot;80&quot; or &quot;0x50&quot;. For a 40 character display that's &quot;40&quot; or &quot;0x28&quot;, resp." CreationDate="2011-03-26T16:50:53.647" UserId="2064" />
  <row Id="18120" PostId="12041" Text="@msutherl I have updated the answer with what is, I hope, better solution to your problem." CreationDate="2011-03-26T17:01:19.940" UserId="2636" />
  <row Id="18121" PostId="12038" Text="@JustJeff Drive capability?" CreationDate="2011-03-26T17:17:42.277" UserId="1982" />
  <row Id="18123" PostId="12041" Text="@jpc Yes, with linear current source regulated by PWM it would work and it would be simple. However, PWM noise will need good filtering, otherwise it will become dominating noise. The V supply too. More problematic may be that the ranging would be based on slow feedback, which means that the converter will miss values when they get out of range. With 24 bit ADC you can use feed-forward mechanism to adjust your range, so at the end it's a better solution (unless you don't mind this drawback), and also easier for people who don't have black belt in analog-fu." CreationDate="2011-03-26T17:53:00.097" UserId="2636" />
  <row Id="18125" PostId="12041" Text="@Jaroslav I believe that in this application the feedback does not need to be very fast. But I also agree that a 24-bit ADC is a better solution to this problem, especially since the OP is not cost constrained and wants small size and low complexity. Thanks for all your help and suggestions (it shows that I am more digital then analog)." CreationDate="2011-03-26T18:03:35.920" UserId="659" />
  <row Id="18126" PostId="11951" Text="The IQ up/down conversion technique is modulation agnostic, e.g. you use it to shift the signal from one frequency (carrier) to another, e.g. from baseband to transmit freqency or from receive freqency back to baseband. Of course having both I and Q channels makes modulation/demodulation easier if you know the algorithms. I don't have much practical experience with these, which is why I commented only on up/down part, which I know. Look for open source software for software defined radio for study of modulation techniques - GNU radio will probably have plenty of code on these." CreationDate="2011-03-26T18:15:27.520" UserId="2636" />
  <row Id="18127" PostId="12074" Text="Here's something I don't understand then: these are wire-to-wire connectors; I thought &quot;headers&quot; were specifically for wire-to-board connections." CreationDate="2011-03-26T18:19:19.403" UserId="1633" />
  <row Id="18128" PostId="12043" Text="@Warren Young, yes that is correct, but based on the question that does not appear to be a factor in this case." CreationDate="2011-03-26T18:28:34.583" UserId="2598" />
  <row Id="18129" PostId="11818" Text="Hmm. If I said 1-2s would that make a difference? What duration is the spark from a motorbike ignition coil/spark plug? I need a compact, reliable circuit." CreationDate="2011-03-26T18:42:52.957" UserId="1633" />
  <row Id="18130" PostId="12074" Text="The Molex SPOX page is under &quot;wire to board&quot; connectors, so that's not what I want, hence the down vote, sorry." CreationDate="2011-03-26T18:48:12.377" UserId="1633" />
  <row Id="18131" PostId="10795" Score="1" Text="You forgot SiLabs and Microchip. (I haven't seen a USB-&gt;RS232 cable with a Microchip part yet, but given the excellent pricing, it's just a matter of time.) http://www.silabs.com/products/interface/usbtouart http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en546923" CreationDate="2011-03-26T18:51:07.363" UserId="411" />
  <row Id="18132" PostId="12063" Text="NEVER discount simple solutions. I'll probably give it a try and see what happens." CreationDate="2011-03-26T19:10:02.670" UserId="259" />
  <row Id="18133" PostId="12043" Text="@freespace, Thank you. I have replaced the NPN schematic with a non-inverting PNP transistor switch." CreationDate="2011-03-26T19:10:15.467" UserId="2598" />
  <row Id="18134" PostId="11901" Text="I couldn't find any direct reference, stating that the key was loaded but my guess is still yes, just because of the closed nature of the board." CreationDate="2011-03-26T19:46:06.497" UserId="2060" />
  <row Id="18136" PostId="12070" Text="Thanks so much. This is exactly what I needed!" CreationDate="2011-03-26T19:55:15.813" UserId="3597" />
  <row Id="18137" PostId="12066" Text="It's possible to make a dc to dc converter using a 555 timer, thereby changing voltages in direct current. Of course, there are other ways to make them." CreationDate="2011-03-26T19:58:04.440" UserId="3597" />
  <row Id="18138" PostId="12060" Text="1.8 to 2.0 MHz." CreationDate="2011-03-26T20:02:22.393" UserId="3597" />
  <row Id="18139" PostId="12035" Text="Actually, the fumes are a work benefit. Don't miss out." CreationDate="2011-03-26T20:24:44.480" UserId="2118" />
  <row Id="18140" PostId="12087" Text="Did you connect the two grounds together also?" CreationDate="2011-03-26T20:36:32.120" UserId="566" />
  <row Id="18141" PostId="12081" Score="1" Text="Hex files also allow for gaps in the data (the first field is the load address). So, potentially, a small non-contiguous hex file could have a large footprint in RAM/flash" CreationDate="2011-03-26T21:06:53.637" UserId="566" />
  <row Id="18142" PostId="11843" Text="I have now done a mock up, so my inputs all have pullup resistors and all my out pins are set to high, when I want to scan a column I set its out pin to low so when the switch closes (each switch also has a diode) I will get a low on the corresponding in pin." CreationDate="2011-03-26T21:35:41.343" UserId="3108" />
  <row Id="18143" PostId="12092" Text="I mentioned TI and ADI in my question.  As usual, Maxim parts do not exist.  http://octopart.com/partsearch/#search/requestData&amp;q=max4206" CreationDate="2011-03-26T22:21:09.803" UserId="411" />
  <row Id="18144" PostId="12097" Text="sadly, the board that it was attached to was part of some kind of car system. Unknown pinout on it and I've already thrown it away. (namely due to what looked like about 60 pins just to get the small board to run. And it had an epoxy blob microcontroller)" CreationDate="2011-03-26T22:35:11.027" UserId="708" />
  <row Id="18145" PostId="12085" Score="2" Text="This is a good [video](http://www.eevblog.com/2011/01/17/eevblog-139-lets-select-a-dc-dc-boost-converter/) on how to select a part for a project(although the part he is selecting is not the same the steps are very similar)" CreationDate="2011-03-26T23:31:32.863" UserId="1623" />
  <row Id="18146" PostId="12039" Text="As far as I can find, buying advice is not specifically mentioned in the faq's. There is a meta discussion (http://meta.electronics.stackexchange.com/questions/475/questions-about-where-to-buy-something-is-offtopic) about it, but the ruling sentiment there seemed to be that if the question could be answered in an instructive way, rather than just with a link to a product, then it was OKAY to ask." CreationDate="2011-03-27T00:13:39.773" UserId="3174" />
  <row Id="18147" PostId="12085" Text="@Dean thanks! I'm 20 minutes in and this is pretty informative. Not knowing any real electrical engineers, it's very useful to see _how_ one works. Especially the attention he gives to each datasheet – I've been bitten before by purchasing a part without reading the datasheet completely." CreationDate="2011-03-27T01:13:39.453" UserId="207" />
  <row Id="18148" PostId="12096" Score="4" Text="Availability is another big one.  You would be a fool to design a Maxim part into a medium volume design, because they are notorious for availability problems.  Use parts with standard footprints and multiple-sourced parts whenever possible." CreationDate="2011-03-27T01:25:31.893" UserId="411" />
  <row Id="18149" PostId="12038" Text="Did you see the schematic on the Sparkfun page?" CreationDate="2011-03-27T02:49:38.893" UserId="813" />
  <row Id="18150" PostId="12038" Text="How fast is this signal?  If it's fairly slow I'd just use an ADC input and not bother with anything external." CreationDate="2011-03-27T03:31:49.310" UserId="1407" />
  <row Id="18151" PostId="12092" Text="Octopart is **not** comprehensive. For example, does not search Maxim-Direct, i.e. direct from Maxim world-wide. https://shop.maxim-ic.com/storefront/priceavailable.do?Partnumber=MAX4207ETE%2B&amp;event=PartSearch&amp;menuitem=PriceAndAvailability " CreationDate="2011-03-27T03:41:12.017" UserId="2598" />
  <row Id="18152" PostId="12105" Text="Heh. I hadn't thought about the actual size of one frame :/ " CreationDate="2011-03-27T03:45:42.167" UserId="708" />
  <row Id="18153" PostId="12043" Text="@Jonathan - If four parts is too complex, I don't think you're going to have much success in electronics." CreationDate="2011-03-27T05:11:48.037" UserId="1374" />
  <row Id="18154" PostId="12043" Text="@mctylr I think you need to move the output connection so it is pulled up by the 5V line when in is high, which switches the PNP off. As it stands I believe it still inverts. " CreationDate="2011-03-27T06:06:45.120" UserId="2340" />
  <row Id="18155" PostId="12045" Text="I have got a D700 which only stake stills, so no video." CreationDate="2011-03-27T06:11:41.887" UserId="1627" />
  <row Id="18156" PostId="12096" Text="@markrages I agree, especially when buying in tens to hundreds parts and not stocking them. For example last year TLE2426 was unavailable for many months in SMT package. Can be a killer." CreationDate="2011-03-27T06:13:36.893" UserId="2636" />
  <row Id="18157" PostId="12032" Text="Also, never touch the scope itself or its knobs while &quot;live&quot;. They are likely plastic, but not necessarily reinforced-insulation type plastic... And some plastic knobs have small metal screws on the side..." CreationDate="2011-03-27T09:54:34.783" UserId="930" />
  <row Id="18158" PostId="12043" Text="@Fake Name, no i'll just keep trying, and the answer has been edited since then (thanks btw, mctylr). I know a bit of the physics, like what happens inside a diode, but I'm wanting to know the more practical side, and it's why I want to do this myself and not buy a pre made one." CreationDate="2011-03-27T10:24:34.397" UserId="1982" />
  <row Id="18160" PostId="11868" Text="Thanks........." CreationDate="2011-03-27T10:40:52.840" UserId="3140" />
  <row Id="18161" PostId="11897" Text="Thats for the U.S Any for Australia or are they the same?" CreationDate="2011-03-27T10:43:30.170" UserId="3140" />
  <row Id="18162" PostId="12031" Text="@ericShain, Fixed." CreationDate="2011-03-27T10:50:36.683" UserId="230" />
  <row Id="18163" PostId="12020" Text="I just feel lazy now :)" CreationDate="2011-03-27T12:12:09.183" UserId="2234" />
  <row Id="18164" PostId="12096" Text="Yeah - I've found some Maxim video buffers and muxes on a 50 week lead-time. Great products though - if you can get your hands on them :{" CreationDate="2011-03-27T12:20:17.087" UserId="2234" />
  <row Id="18166" PostId="12043" Text="@mctylr, it's still inverted, and if I switch the output and resistor to the other side of the transistor, then the logic is not inverted but the voltage is only increased by 0.4V" CreationDate="2011-03-27T12:54:52.937" UserId="1982" />
  <row Id="18167" PostId="12092" Text="Maxim direct is saying 15 weeks lead time for single parts. So Maxim doesn't have any either." CreationDate="2011-03-27T14:03:40.470" UserId="411" />
  <row Id="18168" PostId="12104" Text="I was told the vcc and gnd is used as detecting the logic level am using. It  doesn't provide power. is that not true" CreationDate="2011-03-27T14:05:27.893" UserId="2824" />
  <row Id="18169" PostId="12091" Text="Thanks, I'll give it a try then." CreationDate="2011-03-27T14:23:40.873" UserId="3603" />
  <row Id="18170" PostId="12109" Text="@tuupola, this site is not intended for shopping advice." CreationDate="2011-03-27T14:27:57.033" UserId="230" />
  <row Id="18171" PostId="12096" Text="Added &quot;availability&quot; item. Thanks for pointing its absence out." CreationDate="2011-03-27T14:29:17.703" UserId="2523" />
  <row Id="18172" PostId="8684" Text="+1 for don't work alone. This is true when messing with any electronics that could possibly hurt. In one video I saw of a plasma generator, the device actually had two buttons required to activate and they were far enough apart that it required two people. I recommend you take the same design even when just prototyping anything with high voltage(including capacitors)" CreationDate="2011-03-27T14:52:04.600" UserId="708" />
  <row Id="18173" PostId="12114" Score="1" Text="Why are you using such an obsolete device?" CreationDate="2011-03-27T14:58:32.280" UserId="305" />
  <row Id="18174" PostId="12117" Text="I already read this, but everything is wrote in assembly and I write this program in C program language. it would make a good, if I have an example in C." CreationDate="2011-03-27T15:08:52.490" UserId="3618" />
  <row Id="18175" PostId="12114" Text="I read that it was a good way to begin learning about microprocessors." CreationDate="2011-03-27T15:11:00.840" UserId="3617" />
  <row Id="18176" PostId="12113" Text="hmm.  that would be useful" CreationDate="2011-03-27T15:11:01.827" UserId="142" />
  <row Id="18177" PostId="12118" Text="How do you escape dollar symbols?" CreationDate="2011-03-27T15:14:52.787" UserId="1217" />
  <row Id="18178" PostId="12114" Score="1" Text="No one uses it any more. There are lots of newer devices that are in common use, and are much easier to use, such as PICs and AVRs." CreationDate="2011-03-27T15:21:29.170" UserId="305" />
  <row Id="18181" PostId="11978" Text="Oops, turns out the LTC2418 is not fast enough for me. Looking at the LTC2449 now. Seems very simple + it's recommended highly in the EEG scene." CreationDate="2011-03-27T16:41:06.710" UserId="207" />
  <row Id="18182" PostId="11978" Text="Starting a bounty – Jaroslav's recommendations were useful and I'm considering those chips, but they seem a bit overcomplicated. Looking for more recommendations." CreationDate="2011-03-27T16:42:42.420" UserId="207" />
  <row Id="18183" PostId="11897" Text="@James - I have no idea about Australian laws, but I would guess that most manufacturers would want to avoid having their products banned from sale in the US.  " CreationDate="2011-03-27T17:07:41.753" UserId="857" />
  <row Id="18184" PostId="12118" Text="@Eric - dollar symbols are the delimiter for $LaTeX$ math markup.  You can create a dollar sign with LaTex with this syntax: `$\$$` $\rightarrow\mbox{ }\$$" CreationDate="2011-03-27T17:10:59.037" UserId="857" />
  <row Id="18185" PostId="12114" Text="Isn't it the basis for most modern processors though?" CreationDate="2011-03-27T17:43:33.953" UserId="3617" />
  <row Id="18186" PostId="11666" Text="Those two sections of the manual are contradictory, unless I'm misunderstanding. I'm inclined to believe the latter. The address bits (other than A10) may be don't-cares for PRECHARGE ALL, so the 0xF may be an attempt to set A10 regardless of the mapping.  &#xA;  &#xA;Is the memory not working with this initialization, and if not, can you describe the problem? Or are you looking to understand how the address mapping works in normal operation?" CreationDate="2011-03-27T18:07:13.553" UserId="3441" />
  <row Id="18187" PostId="12121" Text="thanks that's a really helpful link. however, what are the bits displayed on the state paths? (ie. 1/0, 0/0). What do they represent? Thanks!" CreationDate="2011-03-27T18:10:52.690" UserId="3619" />
  <row Id="18188" PostId="12121" Text="The notation is &lt;input value&gt;/&lt;output value&gt;. Note, that this is a Mealy state machine formally - that is, the output value depends on both current state and input, hence the notation. " CreationDate="2011-03-27T18:16:39.533" UserId="3564" />
  <row Id="18189" PostId="12121" Text="You may find this link useful as well: http://en.wikipedia.org/wiki/Mealy_machine" CreationDate="2011-03-27T18:17:11.000" UserId="3564" />
  <row Id="18190" PostId="12118" Text="Isn't there a way of typing a dollar that doesn't invoke the $\LaTeX$ markup?" CreationDate="2011-03-27T18:26:02.777" UserId="1217" />
  <row Id="18191" PostId="12121" Text="Perfect! Thanks for your help" CreationDate="2011-03-27T18:26:22.417" UserId="3619" />
  <row Id="18192" PostId="12092" Text="You were looking at the part with Pb, look at MAX4207ETE+, the Pb-free/RoHS version which is in stock." CreationDate="2011-03-27T18:33:52.057" UserId="2598" />
  <row Id="18193" PostId="12092" Text="ok, I can buy one for $19.  I'd rather the LOG101 and skip the Maxim hassle.  (BTW, why do they list non-RoHS parts at all?)" CreationDate="2011-03-27T18:41:24.563" UserId="411" />
  <row Id="18194" PostId="12109" Text="@Kortuk, I would argue that the question is specific enough to answer (i.e. which tool manufacturers or brands are associated with quality), yet general enough to be widely useful to others, including over a long period of time making it a very good Q&amp;A." CreationDate="2011-03-27T18:42:31.833" UserId="2598" />
  <row Id="18196" PostId="12122" Text="Do you know about [else if](http://www.cprogramming.com/tutorial/lesson2.html)? Thats a good tutorial on C flow control. " CreationDate="2011-03-27T18:49:12.237" UserId="1623" />
  <row Id="18198" PostId="12109" Text="@mctylr, how do you define quality. This is both overly broad(tools in general) and argumentative(how do you define quality). It could be good to have a CW if we would like to make a good list of different companies and information." CreationDate="2011-03-27T19:01:22.193" UserId="230" />
  <row Id="18200" PostId="12122" Score="1" Text="How is the LDR connected? A schematic would help." CreationDate="2011-03-27T19:13:35.117" UserId="305" />
  <row Id="18201" PostId="12123" Text="OK, the leds are fine now. I need just enable Port RB1 as digital I/O is that correct? and can you give an example how to retrieve the value from the LDR. (My LDR is connected on port RB1 and with the ground)." CreationDate="2011-03-27T19:18:39.043" UserId="3618" />
  <row Id="18202" PostId="12122" Text="My LDR is connected on port RB1 and with the ground." CreationDate="2011-03-27T19:19:08.687" UserId="3618" />
  <row Id="18203" PostId="12125" Text="fyi, I've found some non-standard ways of breaking out QFP components involving soldering thin wires to the leads or setting the chip in a whole drilled into a protoboard and setting it with putty." CreationDate="2011-03-27T19:44:18.357" UserId="207" />
  <row Id="18204" PostId="12126" Text="I've never done homemade PCBs before, but I've read about it. Have you ever done QFP components? It seems like it might be difficult with the tiny pin spacing." CreationDate="2011-03-27T19:46:22.910" UserId="207" />
  <row Id="18205" PostId="12126" Text="I don't have any problems with 0.5 mm lead spacing QFPs on my homemade PCBs." CreationDate="2011-03-27T20:08:31.070" UserId="305" />
  <row Id="18206" PostId="11818" Text="@Robert Atkins, most of those sparks are sub 100 ms. It's very difficult to maintain said spark." CreationDate="2011-03-27T20:55:55.920" UserId="1225" />
  <row Id="18207" PostId="12124" Score="1" Text="@halvorlu, this site does not support general shopping advice." CreationDate="2011-03-27T21:34:23.573" UserId="230" />
  <row Id="18208" PostId="12125" Text="@msu I recommend you start accepting answers!" CreationDate="2011-03-27T21:42:09.900" UserId="708" />
  <row Id="18209" PostId="11860" Text="@Thomas maybe you can help it stick? Tried to just adding a bit of scotch tape? " CreationDate="2011-03-27T21:44:51.350" UserId="708" />
  <row Id="18210" PostId="12132" Score="5" Text="A problem I have with this question (which means maybe you can improve it, or I'm missing something) is that you are being vague on the how you evaluate being _able_ to _&quot;build a CPU&quot;_ out of. Is this a _design_ (logic) question, or a IC family question? Are you asking to determine the logic requirements to design Turing complete computer?" CreationDate="2011-03-27T22:09:38.800" UserId="2598" />
  <row Id="18211" PostId="11860" Text="@Earlz Problem is, it needs to be conductive." CreationDate="2011-03-27T22:59:57.280" UserId="1225" />
  <row Id="18212" PostId="12132" Text="@mctylr: Yes -- What do you call the kind of chips, such as the 4:1 mux, that enable one to design a Turing-complete computer entirely from that chip? I suspect that every IC family has an IC from which (in sufficient numbers) one can build a Turing-complete computer; and has some other IC that, alone, is inadequate to build a Turing-complete computer. What terminology can I use to distinguish the first kind of chip from the second kind of chip?" CreationDate="2011-03-27T23:27:13.413" UserId="813" />
  <row Id="18213" PostId="12132" Score="1" Text="related: [Is there a name for “physical things out of which one can build a Turing machine”?](http://cstheory.stackexchange.com/questions/5695/is-there-a-name-for-physical-things-out-of-which-one-can-build-a-turing-machine)" CreationDate="2011-03-27T23:27:56.330" UserId="813" />
  <row Id="18214" PostId="12086" Text="Great answer – thanks Mark, especially the bit about going with well-known components. I know what it's like to spend an entire weekend trying to get a component to work." CreationDate="2011-03-28T00:00:41.337" UserId="207" />
  <row Id="18215" PostId="12126" Score="1" Text="@Leon I know I can find articles elsewhere, but can you mention briefly how you would go about marking up copper-clad board for a tiny component? Do you print a mask, or just put the component on the board and make marks?" CreationDate="2011-03-28T00:02:22.600" UserId="207" />
  <row Id="18216" PostId="12135" Text="Excellent. So the one kind of chip is &quot;a chip that can act either like a NAND gate, or act like a NOR gate, or both&quot;, and the other kind of chip is &quot;a chip that can't act like a NAND gate, neither can it act like a NOR gate&quot;. Conceptually much simpler. That's probably adequate, but I was hoping for a phrase that rolled off my tongue a little bit easier." CreationDate="2011-03-28T00:03:50.963" UserId="813" />
  <row Id="18217" PostId="12096" Text="The OP's favorite source, Atmel, is another company infamous for low availability (or failure-to-launch) of their products." CreationDate="2011-03-28T01:21:16.607" UserId="857" />
  <row Id="18218" PostId="12137" Text="Most of the special &quot;Flux Removers&quot; are just isopropyl alcohol in an aerosol can with a fancy name." CreationDate="2011-03-28T01:23:27.043" UserId="857" />
  <row Id="18220" PostId="12130" Text="What kit? Who built it? Can you tell us what the SMD1 is exactly, aside from a Stepper driver kit someone somewhere made, at some point?" CreationDate="2011-03-28T04:26:54.403" UserId="1374" />
  <row Id="18221" PostId="12141" Score="1" Text="you do know that acetone is less toxic than isopropanol, right?" CreationDate="2011-03-28T04:27:35.777" UserId="1374" />
  <row Id="18222" PostId="12137" Score="1" Text="@reemrevnivek - The ones I have read the MSDS for are mostly acetone and methanol. I don't think you can generalize in this situation." CreationDate="2011-03-28T04:28:32.077" UserId="1374" />
  <row Id="18223" PostId="12130" Text="@Fake SMD1 is just the model no. for it, I guess it stands for Stepper Motor Driver . Anything that I know is in that [manual](http://www.ramseyelectronics.com/downloads/manuals/SMD1.pdf) from Ramsey Electronics. When I meant made, I meant someone assembled the driver already (The driver works well with the motor), I just want to add an External Control." CreationDate="2011-03-28T04:52:59.653" UserId="3623" />
  <row Id="18224" PostId="12070" Text="Where do you figure the 8.05*10^-8?" CreationDate="2011-03-28T04:55:00.557" UserId="3597" />
  <row Id="18225" PostId="12070" Text="@technowizard12 From the formulas on the site I linked to. $\frac{1}{\ln(2)}=1.442695...\approx1.45$. Next we have $f=\frac{1.45}{(R_1+2R_2)C}$. If we take that f=1.8 MHz, we get $\frac{1.45}{1.8*10^6}=(R_1+2R_2)C$. The left side of the equation is $\approx 8.056*10^{-7}$. I don't know how I got $10^{-8}$ back then. The rest of the calculation is correct." CreationDate="2011-03-28T06:00:06.547" UserId="1240" />
  <row Id="18226" PostId="12145" Score="1" Text="I am not knowledgeable with arduino but I remember once seeing a [video](http://vimeo.com/user528115) with someone checking water flows w/ arduino. Here is his page http://johnny.hcssl.iat.sfu.ca/projects/h2o-ware/ . Any flow sensor/meter will do." CreationDate="2011-03-28T06:05:23.360" UserId="3623" />
  <row Id="18227" PostId="12098" Text="Thanks for that, its working better now that i have aimed the sensor at the edge of the stack instead of at a single sheet, the mass is helping to smooth things a bit. Ithas been running for some weeks now and is very much better than the original fixed input system." CreationDate="2011-03-28T06:17:51.277" UserId="3118" />
  <row Id="18228" PostId="11995" Text="+1. Great, finally I know what a tapered reamer can be used for." CreationDate="2011-03-28T06:21:58.500" UserId="3552" />
  <row Id="18229" PostId="12144" Score="1" Text="We aren't about robotics anymore." CreationDate="2011-03-28T06:58:31.590" UserId="1240" />
  <row Id="18230" PostId="12146" Text="Alright it is becoming a bit clearer what is going on with the switches. I will take a sleep and try it in a few fours. Thanks for the explanation." CreationDate="2011-03-28T07:30:08.513" UserId="3623" />
  <row Id="18231" PostId="12070" Text="I'm not so sure about the rest of the calculation being correct, but the 555 calculator does give frequency of 1798201 Hz for the component values I provided. Strange..." CreationDate="2011-03-28T07:30:16.487" UserId="1240" />
  <row Id="18232" PostId="12109" Text="@kortuk Oh please. Is it prohibited to ask what should I buy? There are many questions like that: http://electronics.stackexchange.com/search?q=what+should+i+buy And what exactly is difficult to understand about this question? When you shop for tools online you really cannot tell whether tool is quality made or not. Then again when you buy a brand which is known to be quality (for example Weller soldering irons) you know it will be quality product when you receive it. So for other tools I would also rather buy something which other members already have good experiences with." CreationDate="2011-03-28T07:51:38.817" UserId="94" />
  <row Id="18233" PostId="12117" Text="@yannick, Leon has shown you how to set the ADCON bits using a valid line of C." CreationDate="2011-03-28T07:56:03.640" UserId="2110" />
  <row Id="18234" PostId="12116" Text="The terminology in your question is not standard, so we have difficulty understanding your meaning. When you say &quot;stream from switches to gates&quot; do you mean &quot;read inputs on ports&quot;?" CreationDate="2011-03-28T08:02:41.653" UserId="2110" />
  <row Id="18235" PostId="12142" Text="[Hand held lead forming tool](http://uk.farnell.com/abeco/tp12/cut-form-tool-lead-small/dp/441065)" CreationDate="2011-03-28T08:16:45.837" UserId="2110" />
  <row Id="18236" PostId="10517" Text="Talking about over engineering. You don't want to implement the whole gain loop  of the SMPS digitally. You just want to influence or offset it slighty with a digital circuit. Using a DAC and a additional resistor is the easiest way. You're setting the SMPS up in a stable situation , and add the extra resistor to apply an offset. You can calculate how the voltage will divide over all 3 resistors, and how much effect that has on the output voltage. Do some math with superposition... Or simulate it." CreationDate="2011-03-28T09:49:14.727" UserId="1476" />
  <row Id="18237" PostId="12085" Text="Just my 2 cents. Some IC's a very specialized or cutting edge. There may only be 1 manufacturer readily supplying that chip. There may be alternatives, but are harder to get or from a less well know supplier. My personal preference is to choose for a more well known supplier , just in case.. Choosing between the big companies is all about getting the best fit, pricing, package, availability and support." CreationDate="2011-03-28T09:56:47.420" UserId="1476" />
  <row Id="18238" PostId="12109" Text="@tuupola, you provided the link, have you actually looked through the list? Easily half of the questions are closed, there are a couple questions that are on the boundary of acceptable, the others are asking clear technical advice, not a broad question that cannot possibly have a single technical answer." CreationDate="2011-03-28T11:23:37.720" UserId="230" />
  <row Id="18239" PostId="12124" Text="MOSFET is better for your here ;-)" CreationDate="2011-03-28T11:50:34.000" UserId="2062" />
  <row Id="18240" PostId="12137" Text="@FakeName, The flux removers I have had to use have always had to be acetone for the resin flux. This is not a case of just alcohol necessarily." CreationDate="2011-03-28T11:52:05.180" UserId="230" />
  <row Id="18241" PostId="12118" Text="@Eric, no. The latex markup expects the dollar sign. There is a request in to change this but do not get your hopes up." CreationDate="2011-03-28T12:00:06.877" UserId="230" />
  <row Id="18242" PostId="12137" Text="IPA works very well for resin and other fluxes. I've used it for years." CreationDate="2011-03-28T12:00:21.680" UserId="305" />
  <row Id="18243" PostId="12078" Text="Normally a hex file is compiled for a specific processor and should be used only in that processor.  At least for the uc I have used." CreationDate="2011-03-26T20:47:33.083" UserId="1498" />
  <row Id="18244" PostId="11227" Text="Starting to think so, yes.." CreationDate="2011-03-28T13:13:50.253" UserId="3318" />
  <row Id="18245" PostId="12139" Text="What's the benefit of this over the autotransformer method?" CreationDate="2011-03-28T13:52:50.853" UserId="142" />
  <row Id="18246" PostId="12137" Text="@Fake Name - Well, the three brands I've seen around the labs at school were mostly isopropyl with some lighter stuff in smaller percentages.  I was generalizing, sorry." CreationDate="2011-03-28T14:12:18.997" UserId="857" />
  <row Id="18247" PostId="12122" Text="@yannick, your connection to your PIC may be improper, with a schematic this can be helped instantly." CreationDate="2011-03-28T14:18:33.910" UserId="230" />
  <row Id="18248" PostId="12155" Text="@Paska, your questions are perfect for this site, but you need to narrow them down. SE sites do very well with specific questions." CreationDate="2011-03-28T14:37:42.230" UserId="230" />
  <row Id="18249" PostId="12156" Text="When you say that continuous transmission **seem** to work, what does it mean exactly? Are you receiving all data, or are there some retransmissions etc?" CreationDate="2011-03-28T14:40:06.753" UserId="2636" />
  <row Id="18250" PostId="12156" Text="Well, we definitely transmit data. We haven't implemented any packet synchronization yet, so I am unsure about how much data we drop during 'continuous' transmissions. However, I am quite sure that it drops data. Having said that, I need to look into other wireless protocols, because as you suggested no matter what I am going to drop data. I guess my problem is how to handle this with burst transmissions." CreationDate="2011-03-28T14:48:10.743" UserId="3630" />
  <row Id="18251" PostId="12155" Text="@kortuk, I don't get it, what kind of more info do you want?" CreationDate="2011-03-28T14:52:00.387" UserId="1200" />
  <row Id="18252" PostId="12155" Text="@Rick_2047, right now it is a request for a project that is wanted. The question is &quot;what do I need for this project?&quot; This is very very broad. This is not, I am stuck and need help, or how do I approach this problem. It is a do my project for me." CreationDate="2011-03-28T14:55:07.230" UserId="230" />
  <row Id="18253" PostId="12159" Text="It's a possibility, but wouldn't it render whole GNU Radio software completely worthless for digital communications? I mean, handshakes are pretty common ..." CreationDate="2011-03-28T15:08:08.150" UserId="2636" />
  <row Id="18254" PostId="12155" Text="@kortuk Thanks for closing question! Greetings" CreationDate="2011-03-28T15:13:15.787" UserId="3359" />
  <row Id="18255" PostId="12160" Text="My guess is it is not a noise issue. My lab mate is doing research on bit error rates and is doing no retx. He found a short message tended to have close to a .5 BER while a long packet was less than .001 for the same power and data rate. Putting a tight filter inline of the antenna makes the idea of a software radio a little less attractive." CreationDate="2011-03-28T15:13:16.350" UserId="319" />
  <row Id="18256" PostId="12156" Text="What frequency and modulation type are you using?" CreationDate="2011-03-28T15:15:59.767" UserId="319" />
  <row Id="18258" PostId="12159" Text="Software radios are no where near prime time ready, doesn't mean they aren't worth the research that is going into getting them implemented." CreationDate="2011-03-28T15:18:59.467" UserId="319" />
  <row Id="18259" PostId="12155" Text="@Paska, Greetings. Thank you for coming to our site. We do very well with very specific questions, we cannot reasonably do an entire project for you and all the way down. If you take facets of the project and ask about them you will get a set of good answers that will all apply directly. For example: if one user gives an excellent answer in application to what you need to make this tool and another a great answer about what sensor would work well, which answer do you pick? They both answered your question well, but you need to pick one answer." CreationDate="2011-03-28T15:21:58.513" UserId="230" />
  <row Id="18260" PostId="12159" Text="I get that, but this is rather basic thing and USRP hardware is not exactly cheap, so if this is really software issue, as your's friend data indicate, then I am still surprised ;) Hams, military, cell phone operators etc. all have SDR software and hardware that is definitely high quality and prime time ready, which is why I have not considered the possibility - that's not to say that you are not right." CreationDate="2011-03-28T15:27:23.907" UserId="2636" />
  <row Id="18261" PostId="11341" Text="WOW thank you so much.  I'm excited to compile this and give it a shot when I get home.  Also, thanks for showing me how to turn the bytes into integers as I didn't know how to do that either. This has shed some serious light on what was otherwise too daunting a task to know where to start!  " CreationDate="2011-03-28T14:56:06.480" UserId="3631" />
  <row Id="18262" PostId="12139" Score="1" Text="The autotransformer method is similar to a non-isolated flyback converter.  When looking at chips you'll probably have better luck looking for the term flyback since it is more common than autotransformer." CreationDate="2011-03-28T15:52:01.207" UserId="3624" />
  <row Id="18263" PostId="12155" Text="@kortuk I don't want the solution for the entire project but only a starting point. Does not matter. Next time i write more specific question. tks" CreationDate="2011-03-28T15:58:04.127" UserId="3359" />
  <row Id="18264" PostId="12144" Text="We should probably change the message that goes on a closed question: it still says that questions are expected to relate to electronics and robotics." CreationDate="2011-03-28T16:00:21.833" UserId="249" />
  <row Id="18265" PostId="12155" Text="@Paska, I understand that, but what hardware you need to start overall and what sensors you need are two different things. I hope this has been constructive advice, you are not in any sort of trouble, please feel free to come into chat if you have any questions." CreationDate="2011-03-28T16:04:53.047" UserId="230" />
  <row Id="18266" PostId="11834" Text="I thought code (in the US) was that 220 circuits could only have one outlet." CreationDate="2011-03-28T16:11:01.717" UserId="3534" />
  <row Id="18267" PostId="11834" Text="@tooshel - You may be correct, but this is a 110 V circuit we're creating here.  If you want to get technical, it's 1.5 outlets, but we're working with integer math here, right?  :)  Those complexities are why I said *You'll need to talk to an inspector or electrician.*" CreationDate="2011-03-28T16:34:53.110" UserId="857" />
  <row Id="18268" PostId="12141" Text="I did not know that.  I guess I'm biased against acetone from growing up in a house full of women/girls who like to paint their nails.  To my nose at least, acetone certainly smells worse." CreationDate="2011-03-28T16:35:33.807" UserId="3624" />
  <row Id="18269" PostId="12157" Text="thanks. this is what i want as response" CreationDate="2011-03-28T16:43:25.930" UserId="3359" />
  <row Id="18270" PostId="12168" Text="@Madmanguruman: Your link doesn't work..." CreationDate="2011-03-28T16:52:29.437" UserId="2426" />
  <row Id="18271" PostId="12168" Text="Works on my PC. I'll relink to the datasheet (no tracking stuff in the URL)" CreationDate="2011-03-28T16:55:17.343" UserId="1293" />
  <row Id="18272" PostId="12168" Text="@Madmanguruman: Is it behind a login page? I get a 403 forbidden error." CreationDate="2011-03-28T16:58:15.457" UserId="2426" />
  <row Id="18273" PostId="12164" Text="Thanks. I actually tried it with the 2 capacitors, but still didn't get anything. How can i get the crystal load capacitance?" CreationDate="2011-03-28T17:08:15.097" UserId="3632" />
  <row Id="18274" PostId="12165" Text="Thanks. I actually used two capacitors in my schematic, and also another inverter at the output, but still that dint work!" CreationDate="2011-03-28T17:09:35.737" UserId="3632" />
  <row Id="18276" PostId="12164" Text="It'll be in the crystal specification. It should work with two 22pF capacitors, although the frequency might be slightly out. Check your soldering." CreationDate="2011-03-28T17:54:52.250" UserId="305" />
  <row Id="18277" PostId="12168" Text="@BG100 Works for me." CreationDate="2011-03-28T17:58:38.080" UserId="1240" />
  <row Id="18278" PostId="12156" Text="I checked with my lab mate, he wanted to know if you were using the built in mod and demod blocks as they are the ones that handle syncing. He also suggested to turn down your bit rate as the USB can provide some latency that causes jitter that is fine when you are able to buffer a longer packet, but with a short message doesn't work so well." CreationDate="2011-03-28T18:54:16.643" UserId="319" />
  <row Id="18279" PostId="12159" Text="@Jaroslav Cmunt These radios are run over USB which provide some latency and jitter that wouldn't be an issue when implementing SDR in a portable device." CreationDate="2011-03-28T18:55:18.140" UserId="319" />
  <row Id="18280" PostId="12159" Text="That really should not be an issue, for example FLEX-1500, Open HPSDR and others also use USB. Open HPSDR even uses the same interface (Cypress EZ-USB FX2) as USRP1 and has the same overall architecture. The data are surely buffered, not just fed directly to FPGA and transmitted immediately, that just would not work. The latency also can't be an issue, otherwise continuous transmissions wouldn't work too. There is a way to debug it: capture the raw data that are being transmitted and analyze them." CreationDate="2011-03-28T19:14:53.133" UserId="2636" />
  <row Id="18281" PostId="12159" Text="And if it turns out it's actually the USB issue, then I would say stay away from GNU Radio until they get it right, because it's clearly not worth the money." CreationDate="2011-03-28T19:17:57.077" UserId="2636" />
  <row Id="18282" PostId="12175" Score="1" Text="Interesting question. I hope that someone will be able to give technical explanation. You may want to consider asking same thing at Super User too. Some people there might have practical experience with network cables and X-Ray equipment." CreationDate="2011-03-28T19:52:12.030" UserId="1240" />
  <row Id="18283" PostId="12146" Text="Yeah this ending up working. I just wasn't putting the ground wire (The lead out of R3) down." CreationDate="2011-03-28T20:50:38.853" UserId="3623" />
  <row Id="18284" PostId="12140" Text="One person on the [Wikipedia functional completeness discussion page](http://en.wikipedia.org/wiki/Talk:Functional_completeness) claims that Fredkin gates are not functionally complete (since if you apply all 0 inputs to one or more Fredkin gates wired in any conceivable arrangement, you can't ever get a 1 at any output), and yet others claim you can build a CPU entirely out of Fredkin gates. So is a Fredkin gate actually &quot;functionally complete&quot;, or am I looking for some broader category that includes &quot;functionally complete&quot; and also Fredkin gates?" CreationDate="2011-03-28T21:17:56.990" UserId="813" />
  <row Id="18285" PostId="12184" Text="@ScottChamberlain, some of the higher end radiation we have stops the storage of computers in the room. It will cause complete failure." CreationDate="2011-03-28T21:22:32.083" UserId="230" />
  <row Id="18286" PostId="12183" Text="So I would be in trouble with 33µH inductors in parallel because those would have half the rms current limit. hmm." CreationDate="2011-03-28T21:25:00.613" UserId="1225" />
  <row Id="18287" PostId="12183" Score="2" Text="What about inductive coupling between them? Would it affect the calculation?" CreationDate="2011-03-28T21:26:22.220" UserId="1240" />
  <row Id="18288" PostId="12140" Text="@David - This is a little off topic, but if you read the article on Fredkin gates, you'll find that the Fredkin gate has the property of swapping the last two bits if the first bit is 1, and it's also reversible.  If you allow 1 and 0 to be hard-coded, it's easy to get any other logic function with a few Fredkin gates.  However, if you allow hard-coding, it's no longer reversible, and thus not a proper Fredkin gate (according to some).  Reversibility is a category independent from functional completeness, and I think functional completeness is sufficient for your problem." CreationDate="2011-03-28T21:33:32.967" UserId="857" />
  <row Id="18289" PostId="12183" Text="mutual inductance will affect the inductance calculation somewhat." CreationDate="2011-03-28T21:33:42.637" UserId="411" />
  <row Id="18290" PostId="12183" Score="1" Text="Two 33uH inductors in parallel will give you a 16.5 uH inductor with double the individual current rating, since each takes half the total current." CreationDate="2011-03-28T21:34:54.963" UserId="411" />
  <row Id="18291" PostId="12147" Text="Thanks for pointing that one out to me. And indeed, it looks like a very good place to start out. It appears I'll be able to easily measure water flow through a garden hose, which is, again a great place to start." CreationDate="2011-03-28T21:37:47.883" UserId="3353" />
  <row Id="18292" PostId="12138" Text="Simulators can also *cause* hours or days of headaches. :)" CreationDate="2011-03-28T21:48:45.253" UserId="2523" />
  <row Id="18293" PostId="12184" Text="@Kortuk - Scott's comment has gone missing; what was the context?" CreationDate="2011-03-28T22:04:06.540" UserId="857" />
  <row Id="18294" PostId="12187" Score="2" Text="Can you please clarify what you are intending?  The diagram is a little misleading.  The diagram is for balanced inputs, unbalanced outputs-- but the output L-/R- connections is not correctly labeled.   So... What do you want?  Knowing what connectors you want would be a good start." CreationDate="2011-03-28T22:13:57.227" UserId="3624" />
  <row Id="18295" PostId="12140" Text="If you apply all 0 inputs to one or more 4:1 muxes wired in any conceivable arrangement, you can't ever get a 1 at any output. So is a mux chip actually &quot;functionally complete&quot;, even though it is never mentioned on that otherwise excellent ProofWiki page, or am I looking for some broader category that includes &quot;functionally complete&quot; and also 4:1 mux chips?" CreationDate="2011-03-28T22:15:56.190" UserId="813" />
  <row Id="18296" PostId="284" Text="This question is about an embedded ethernet switch controller, not a standalone switch device that you describe." CreationDate="2011-03-28T22:16:15.307" UserId="2150" />
  <row Id="18297" PostId="12187" Text="Sorry, messed up there! On the left, we have the inputs. They're coming from the source unit. To the right are the outputs, that are heading to the amplifier. This board is supposed to bring the 10v from the source unit down to something more acceptable. I just can not figure out where the ground input gets hooked up to. " CreationDate="2011-03-28T22:16:30.527" UserId="3634" />
  <row Id="18298" PostId="12187" Score="1" Text="But is the source unit spitting out a balanced signal?  And what's the connector?  And is the amp taking a balanced inputs?  Connector?  These are important things to know if you want to get the best audio quality with the least amount of fuss.  The diagram, as drawn, might work but I wouldn't suggest it as it's not really a balanced circuit." CreationDate="2011-03-28T22:20:13.120" UserId="3624" />
  <row Id="18299" PostId="12187" Text="I just had to look up balanced audio to understand what you're saying. The head unit only had positive and negative for right and left, it is not balanced - nothing in the system is balanced. There is no connector, just bare wires. Did the guy at the store just sell me the wrong thing? " CreationDate="2011-03-28T22:24:22.750" UserId="3634" />
  <row Id="18300" PostId="12132" Text="@reemrevnivek: I thought &quot;diode&quot; had something to do with &quot;diode-resistor logic&quot;." CreationDate="2011-03-28T22:25:09.990" UserId="813" />
  <row Id="18301" PostId="12183" Text="@markrages, Yeah, but each inductor would have (approximately) half the individual rms rating already because it needs twice as much wire." CreationDate="2011-03-28T22:33:23.453" UserId="1225" />
  <row Id="18302" PostId="11759" Text="Interesting that a new board I got is fine. Almost zero registration error. And I used smaller vias @ 14 mil." CreationDate="2011-03-28T22:35:31.923" UserId="1225" />
  <row Id="18303" PostId="12147" Text="There's a range of different sized sensors at futurlec.com too." CreationDate="2011-03-28T22:38:31.717" UserId="389" />
  <row Id="18304" PostId="12187" Score="2" Text="I'm concerned that the diagram that you have might have safety issues.  Without knowing a lot more about the head unit _AND_ the amplifier you want to connect it to I cannot say what the proper connection method could be.  So, without more info I'd tentatively say that the guy at the store did sell you the wrong thing.  I should point out that I'm a Sr. Electrical Engineer at a large professional audio company, so I know a thing or two about blowing up audio equipment." CreationDate="2011-03-28T22:40:58.640" UserId="3624" />
  <row Id="18305" PostId="12187" Text="Wow! Amazing to see such well-qualified people on here. (I spend a lot of time on stackoverflow; it's much more rare to find professionals on there.) Anyways, I didn't want to mention specifics initially because I'm not sure of policies.. but I'm coming from a stock Dodge headunit, which has regular analog output that goes up to 10 volts. Nothing fancy, when I had it going straight to the amp it worked fine. It's going into a regular JL amplifier, with a max input of 4v. I was sold a Raptor LOC15 converter to bring the voltage down. Should I just head off to radioshack, build  my own?" CreationDate="2011-03-28T22:50:08.423" UserId="3634" />
  <row Id="18306" PostId="12184" Text="@reemrevnivek, It is very very hard to figure that out. I am not sure what happened. If it was offensive another mod may have removed it. More likely, he chose to remove it and deleted it himself." CreationDate="2011-03-28T22:53:48.280" UserId="230" />
  <row Id="18307" PostId="11759" Text="I've discovered how to get rid of my tented vias in gEDA/PCB, using ctrl-k, which is good, so I'll see if my latest boards are any better." CreationDate="2011-03-28T23:00:17.870" UserId="1225" />
  <row Id="18308" PostId="12043" Text="@mctylr, pleae your answer is almost there! Then I can accept it. " CreationDate="2011-03-28T23:05:03.873" UserId="1982" />
  <row Id="18309" PostId="12126" Text="@Leon Heller: have you tried any of the Schmartboard products?" CreationDate="2011-03-28T23:16:46.893" UserId="2395" />
  <row Id="18310" PostId="993" Text="+1 for economy of scale." CreationDate="2011-03-28T23:21:34.397" UserId="813" />
  <row Id="18311" PostId="12187" Text="Are you trying to connect a speaker output to a line input?" CreationDate="2011-03-28T23:32:41.680" UserId="142" />
  <row Id="18312" PostId="12187" Text="It's not really a speaker output, it originally went to a factory amplifier... but yeah, basically, that would be the same setup. " CreationDate="2011-03-28T23:37:35.517" UserId="3634" />
  <row Id="18313" PostId="12183" Score="1" Text="No such thing as a free lunch.  An inductor's energy storage capacity is proportional to inductance and current.  So you are finding similar physical sizes have similar energy storage.  Similar to capacitors: Double the voltage rating, half the capacitance for the same physical size.  Approximately." CreationDate="2011-03-28T23:40:26.447" UserId="411" />
  <row Id="18315" PostId="12200" Score="1" Text="Do you have a specific question?" CreationDate="2011-03-29T01:10:31.757" UserId="319" />
  <row Id="18317" PostId="12201" Text="What are you looking for, exactly? I'd like to help you find it, but the question is rather vague." CreationDate="2011-03-29T01:22:03.590" UserId="3597" />
  <row Id="18318" PostId="12203" Text="It is not the size of the capacitor that makes it polarized, instead it is the chemistry of the capacitor. Any electrolytic is polarized." CreationDate="2011-03-29T01:24:16.003" UserId="319" />
  <row Id="18320" PostId="12201" Text="A single detailed example, To understand it" CreationDate="2011-03-29T01:41:13.020" UserId="3628" />
  <row Id="18321" PostId="12201" Text="http://www.ltsnet.net/oscr/Cog_Radio_Work_Presentation.pdf" CreationDate="2011-03-29T01:56:25.383" UserId="2060" />
  <row Id="18322" PostId="12205" Text="@David Kessner: This is a very good answer... I'll keep this info for future reference, thanks!" CreationDate="2011-03-29T03:20:39.820" UserId="2426" />
  <row Id="18323" PostId="12205" Text="Wish I could upvote this 100 times! Before today I didn't even know these differences existed. The resistance between the lighter gnd and the negatives were 6.5k-ish, so I'm going to say this is balanced. (Glad the stereo store guy was right!) I actually just put together this circuit: http://tkk.fi/Misc/Electronics/circuits/speaker_to_line.html and tried it. Thankfully it sorta worked, and I didn't break anything. Anyways from what I can see, the bottom left is what I have and need; all I would have to do is add a 100k resistor in to settle it to zero (That necessary if I have a remote wire?)" CreationDate="2011-03-29T03:28:20.250" UserId="3634" />
  <row Id="18325" PostId="12205" Score="1" Text="The 100K resistor isn't strictly required.  If it's easy, do it.  Otherwise don't worry about it.  And there isn't anything magical about 100K.  Anything from 50k to 400k will work." CreationDate="2011-03-29T03:39:43.013" UserId="3624" />
  <row Id="18326" PostId="12206" Text="Does it really take that long to charge a 1F cap to such a low voltage?" CreationDate="2011-03-29T03:41:05.433" UserId="319" />
  <row Id="18327" PostId="12157" Text="An idea that might be more easily implemented than the magnetic field disturbence is hooking the top cable of the net to a potentiometer and adding a spring to the potentiometer so it returns to zero." CreationDate="2011-03-29T03:41:29.897" UserId="2873" />
  <row Id="18328" PostId="12205" Text="Cool, cool. So I basically will just have to ground the &quot;adapter&quot; out to the chassis. Thanks!&#xA;&#xA;By the way, that bottom right one, the transformer - what's the difference between that and a ground loop isolator? " CreationDate="2011-03-29T03:52:48.137" UserId="3634" />
  <row Id="18329" PostId="12205" Text="The turns ratio of the transformer is not 1:1.  It's whatever is needed to get the right voltage at the output." CreationDate="2011-03-29T04:00:30.033" UserId="3624" />
  <row Id="18330" PostId="12203" Text="@kellen, though you can place two back-to-back and get an effectively non-polarized electrolytic" CreationDate="2011-03-29T04:02:00.327" UserId="1407" />
  <row Id="18331" PostId="12204" Text="The batteries won't be so large and expensive as you expect, because the energy will go to A123 LiFePO4 cells which can accept charge at 4C, so only 16Ah of them are needed to max out a 65A supply, and 1Ah 18650 cells are now 2 USD each at 3.3V, so only 128 of them (at a total cost of 256 USD) are needed to max out the mentioned Vmax=28.8VDC, Imax=65A. So the batteries won't cost more than my inverter budget." CreationDate="2011-03-29T05:57:53.483" UserId="1691" />
  <row Id="18332" PostId="12206" Score="2" Text="The time needed to charge to a certain level (1/e? I'm not exactly sure) is the RC time. The charging time therefore depends on the R of the system. Considering that resistance measuring is often used for continuity (0 ohm), I presume there is a hefty resistor inside the meter. A resistor of 1kOhm would mean 1000 seconds (20 minutes) to charge to 60-ish percent." CreationDate="2011-03-29T07:54:41.500" UserId="1802" />
  <row Id="18333" PostId="7364" Text="Agree, all high frequency ballasted fluorescents put out some modulated RF with components at IR frequencies (36-38kHz), but compact fluorescents are worse than linear tubes." CreationDate="2011-03-29T08:12:26.930" UserId="2110" />
  <row Id="18334" PostId="5303" Text="Do not put the &quot;lighting ballasts in a separate room&quot;, that would make the EMI worse! High frequency ballasts produce a high voltage, high frequency waveform that needs to be wired with very short cables. In a recording studio, do not use any type of fluorescent or switching type low voltage &quot;lighting transformer&quot;, only use mains tungsten/halogen or wirewound transformers (preferrably toriodal, for low radiated field)." CreationDate="2011-03-29T08:20:52.927" UserId="2110" />
  <row Id="18335" PostId="12198" Text="Why the need for the 1F Cap? Doing audio work?" CreationDate="2011-03-29T08:21:19.230" UserId="1623" />
  <row Id="18336" PostId="12198" Score="1" Text="@Dean I'm hoping to use it instead of a battery for a very low power device." CreationDate="2011-03-29T08:44:35.353" UserId="1240" />
  <row Id="18337" PostId="12206" Text="@Kellenjb  For this particular capacitor, the maximum current is just 1 mA and voltage is 5.5 V, so to push it to its limits, 5.5 $k\Omega$ resistor is needed. The time to charge it to 63.2% is then 1.52 hours." CreationDate="2011-03-29T08:45:36.227" UserId="1240" />
  <row Id="18339" PostId="12213" Score="1" Text="have you considered finding a cheap gram scale and taking out the load cell out? usually I see them accurate down to +-.1 grams." CreationDate="2011-03-29T11:08:47.110" UserId="2060" />
  <row Id="18340" PostId="12207" Text="comparator and a 555?" CreationDate="2011-03-29T11:21:06.733" UserId="2157" />
  <row Id="18341" PostId="12215" Score="2" Text="At what power output?" CreationDate="2011-03-29T11:49:33.463" UserId="1827" />
  <row Id="18342" PostId="12210" Text="Does it have to work at 10Mbps, 100Mbps or 1Gbps? Do you require full-duplex?" CreationDate="2011-03-29T11:51:42.710" UserId="1802" />
  <row Id="18343" PostId="12212" Text="Ok, thanks. One thing I dont understand is you say you would dou le the specs of the capacitor but you also say the motor driver is what would handle it." CreationDate="2011-03-29T12:04:17.023" UserId="2873" />
  <row Id="18344" PostId="10873" Text="@taniwha, I think you could continue expanding the number of ports but the number of diodes will grow exponentially." CreationDate="2011-03-29T12:12:06.190" UserId="230" />
  <row Id="18345" PostId="12217" Score="1" Text="Shopping questions are off-topic." CreationDate="2011-03-29T12:22:41.543" UserId="305" />
  <row Id="18346" PostId="12217" Text="Is there such a component in general?" CreationDate="2011-03-29T12:23:29.920" UserId="3130" />
  <row Id="18347" PostId="12219" Text="Can you be more specific? Depending of what you wanna do, maybe it's not necessary to use a vibration sensor." CreationDate="2011-03-29T12:30:18.183" UserId="938" />
  <row Id="18348" PostId="12217" Text="@Powtac -Are you asking where to purchase such a component, or what it is that needs to be purchased to build a Geiger counter?  If the latter, do you need a proportional counter, or will an ordinary Geiger–Müller tube do the job?  (If the former, it is off-topic, as Leon said)." CreationDate="2011-03-29T12:31:58.363" UserId="857" />
  <row Id="18349" PostId="12219" Text="@Daniel See edit." CreationDate="2011-03-29T12:35:34.970" UserId="3359" />
  <row Id="18350" PostId="12203" Score="2" Text="@Nick - Not so, according to [this answer](http://electronics.stackexchange.com/questions/3062/what-are-some-reasons-to-connect-capacitors-in-series/3073#3073)" CreationDate="2011-03-29T12:36:29.687" UserId="857" />
  <row Id="18351" PostId="12221" Text="@fearoffours Can i use piezo to detect if the ball touch or not the pingpong net? Or it detect only vibration sound?" CreationDate="2011-03-29T12:40:21.220" UserId="3359" />
  <row Id="18352" PostId="12140" Text="@David - The 4:1 mux is a specialized device found in electronics.  In the field of electronics, we're rarely, if ever, interested of assembling a computer entirely from one type of IC, and in the field of theoretical computer science (the domain of ProofWiki and the term &quot;functional completeness&quot;), muxes and other specialized ICs are assembled from standard logic gates.  In this no-man's land, I think you get to define your own terms.  " CreationDate="2011-03-29T12:46:01.527" UserId="857" />
  <row Id="18353" PostId="12217" Score="1" Text="I don't want to build a Geiger-Müller tube, I just want to know if it is available as a component. " CreationDate="2011-03-29T12:48:36.373" UserId="3130" />
  <row Id="18354" PostId="12213" Text="@jsolarski Good Idea!! Thanks!!" CreationDate="2011-03-29T12:54:44.287" UserId="2574" />
  <row Id="18355" PostId="12206" Text="@AdrejaKo Wait, what? Are you measuring your cap in side of a circuit? Surely your DMM isn't measuring at 5.5v. They usually have a much smaller voltage." CreationDate="2011-03-29T13:09:49.010" UserId="319" />
  <row Id="18357" PostId="12212" Text="the link you posted shows the capacitor in the upper left corner, I didnt say double the specs, You should use at least double your Source voltage ( as in how much voltage you are putting into the motor driver) for the voltage rating of the cap. Example- Lets say source is 5V powering every thing, then you would want at least a cap rated at 10v or above. the cap is for keeping all the power stable preventing small voltage drops when the motor is running, IE smoothing the power rails." CreationDate="2011-03-29T13:25:21.573" UserId="2060" />
  <row Id="18358" PostId="12225" Text="Do you know if there are any ICs that can be bought even if they are on the spendy side? ...I'm interested for myself." CreationDate="2011-03-29T13:45:38.137" UserId="319" />
  <row Id="18359" PostId="12217" Score="7" Text="I don't see anything wrong with this question.  Most of the questions on the site could be considered &quot;shopping questions&quot; if you twist it enough, like the top voted question, for instance: http://electronics.stackexchange.com/questions/966/ I think this policy of immediately closing anything related to choosing parts should be reconsidered.  It's fundamental to electronics." CreationDate="2011-03-29T14:06:14.247" UserId="142" />
  <row Id="18360" PostId="12226" Score="4" Text="We are going to need many more details. You have marked it as PCB and manufacturing, are you wanting to make your own crystal? Do you want it to be exactly 5.000 GHz?" CreationDate="2011-03-29T14:18:52.120" UserId="319" />
  <row Id="18362" PostId="12208" Text="Use an RC to create the delay on one input.  http://electronics.stackexchange.com/questions/495/how-can-i-convert-the-output-from-a-momentary-switch-to-a-pulse-on-push-and-a-pul/531#531" CreationDate="2011-03-29T14:42:47.100" UserId="142" />
  <row Id="18363" PostId="12207" Text="Is the threshold the same going up as it is going down?" CreationDate="2011-03-29T14:46:31.077" UserId="142" />
  <row Id="18365" PostId="12217" Text="@endolith, the top votes question is a community wiki of useful components. It is our sites list of critical components that are considered useful. This can be easily updated by any user and serves as a standard place to discuss this issue." CreationDate="2011-03-29T14:48:24.233" UserId="230" />
  <row Id="18366" PostId="12198" Text="A 1 F electrolytic capacitor?  o_O  I don't believe supercapacitors are &quot;electrolytic&quot;." CreationDate="2011-03-29T14:49:37.360" UserId="142" />
  <row Id="18367" PostId="12125" Text="I just found this universal QFP adapter: http://www.robotshop.com/ca/schmartboard-2x2-05mm-qfp-surface-mount-prototyping-board.html !" CreationDate="2011-03-29T14:50:06.583" UserId="207" />
  <row Id="18368" PostId="12184" Text="I did not remove it, and I did not think I said anything offensive." CreationDate="2011-03-29T14:52:44.027" UserId="1655" />
  <row Id="18369" PostId="12218" Text="Why the down vote? It's a viable approach." CreationDate="2011-03-29T14:56:50.927" UserId="305" />
  <row Id="18370" PostId="12126" Text="No, but I've heard of people who have used them successfully." CreationDate="2011-03-29T15:01:50.423" UserId="305" />
  <row Id="18371" PostId="12186" Text="I'm not sure what you're doing with this, but maybe it could benefit from parallelization?  Presumably you have multiple batteries.  Maybe it makes more sense to have multiple power converters?" CreationDate="2011-03-29T15:02:39.393" UserId="142" />
  <row Id="18372" PostId="12184" Text="@ScottChamberlain, I am sorry to say only full devs can look into these things. People have told me that someone probably removed it and forgot. I know I did not, I do not remember even reading it. what was the comment?" CreationDate="2011-03-29T15:03:29.873" UserId="230" />
  <row Id="18373" PostId="12217" Text="@Leon Heller: I agree that shopping questions *should* be off-topic -- how can we add this to the FAQ? Can we pull this question on-topic if we re-focus it on &quot;What are the names of electrical components that measure (some physical property), and how do I interface them to a MCU?&quot;?" CreationDate="2011-03-29T15:04:35.850" UserId="813" />
  <row Id="18374" PostId="12217" Text="@davidcary - A diamond mod can edit the FAQ.  FYI, there's been a lot of discussion about these questions on Meta: see the [shopping](http://meta.electronics.stackexchange.com/questions/tagged/shopping) tag." CreationDate="2011-03-29T15:37:57.720" UserId="857" />
  <row Id="18375" PostId="12204" Text="That's an encouraging cost ifthose are A123 cells at that price. &#xA;&#xA;However, battery capacity required depends on how long you want to charge them for.  As I noted&#xA;&#xA;... presumably rated for some hours of operation at this power level.&#xA;&#xA;The A123 array that you mention will charge in about 15 minutes. To provide one hour of storage would cost about $US1000 :-(&gt;&#xA;" CreationDate="2011-03-29T15:39:09.857" UserId="3288" />
  <row Id="18376" PostId="12198" Text="@endolith Datasheet listed them as electrolytic, so that's why I used electrolytic in the question. It also looks like any other electrolytic capacitor and has same markings as electrolytic capacitors do. I'll see if I can dig up the link to datasheet." CreationDate="2011-03-29T15:40:03.913" UserId="1240" />
  <row Id="18377" PostId="12217" Text="@davidcary: That would be two questions." CreationDate="2011-03-29T15:44:25.347" UserId="142" />
  <row Id="18378" PostId="12232" Score="1" Text="Would tin oxide be removable by hand? I can just wipe this stuff with my finger. It doesn't seem to stick at all to the leads." CreationDate="2011-03-29T15:44:31.913" UserId="1240" />
  <row Id="18379" PostId="12232" Text="If there's enough, sure, you could wipe off some of it.  It's going to be on any tin surface in air at some level." CreationDate="2011-03-29T15:49:17.620" UserId="1407" />
  <row Id="18380" PostId="12218" Text="I agree - this is not a &quot;not useful&quot; answer. Compensatory upvote." CreationDate="2011-03-29T15:49:18.010" UserId="3361" />
  <row Id="18381" PostId="12208" Text="@endolith - If he uses a CD4030 for the XOR gate he has three spares which he can use for the delay. Saves a resistor and a capacitor! :-)" CreationDate="2011-03-29T15:49:54.163" UserId="2064" />
  <row Id="18382" PostId="12217" Score="4" Text="@Leon: There is no prohibition against shopping questions, and there shouldn't be.  There are many shopping questions that are great for the site.  The main prohibition is against questions that &quot;would only be relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet&quot;.  Shopping questions that are applicable to a large area of the world or a wide audience are fine." CreationDate="2011-03-29T15:52:21.813" UserId="142" />
  <row Id="18383" PostId="12218" Text="@Leon - It's an idea. I don't think it will be cheaper than a comparator + a CD4030, but it will be smaller like you said. Anyway, I didn't downvote it! :-)" CreationDate="2011-03-29T15:52:52.037" UserId="2064" />
  <row Id="18384" PostId="12198" Text="@Andreja: How big is it?" CreationDate="2011-03-29T15:58:18.160" UserId="142" />
  <row Id="18385" PostId="12218" Text="Given the price of that PIC, it may actually be cheaper (production, not development)." CreationDate="2011-03-29T16:14:10.470" UserId="2636" />
  <row Id="18386" PostId="12218" Text="The 10F200 costs 0.48 (one off). The CD4030 costs 0.55 and the comparator will cost about the same! By the time they are put on a PCB the cost will be much greater. Those small PICs are often used to replace the old 555 timer, these days." CreationDate="2011-03-29T16:15:23.600" UserId="305" />
  <row Id="18387" PostId="12198" Text="@endolith Not very big. It's just 20mmx7mm. " CreationDate="2011-03-29T16:36:12.747" UserId="1240" />
  <row Id="18388" PostId="12204" Score="1" Text="0.5V rectification drop at 28V is a very conservative estimate. Ultrafast rectifiers will be higher than this. Synchronous rectification is the right approach but at voltages &gt;12V you're outside the 'sweet spot' where the silicon has very low Rdson." CreationDate="2011-03-29T16:40:57.393" UserId="1293" />
  <row Id="18389" PostId="12142" Text="Close, but not exactly what I'm looking for. The plastic thingy is interesting though...." CreationDate="2011-03-29T16:41:12.387" UserId="814" />
  <row Id="18390" PostId="12213" Score="1" Text="@jsolarski - I guess display resolution is 0.1 grams; I seriously doubt that you get that kind of precision from a cheap kitchen scale. It's like digital fever thermometers. They usually display to 0.01 degree centigrade. That's not the precision, though. Not for a 10 euro thermometer anyway." CreationDate="2011-03-29T17:24:49.650" UserId="2064" />
  <row Id="18391" PostId="12140" Text="@reemrevnivek: When manufacturing a product, it often saves time, money, and storage space to use a few kinds of generic components that I can buy in bulk from several manufacturers, rather than separately &quot;optimizing&quot; each part and using super-specialized components that are only useful in one place in one product and whose manufacturer will likely declare it &quot;no longer recommended for new designs&quot; in a couple of years. p.s.: ever heard of the Cray-1 or the Apollo Guidance Module? Everything except the memory entirely from one type of IC." CreationDate="2011-03-29T17:33:08.993" UserId="813" />
  <row Id="18392" PostId="12140" Text="@davidcary - I understand that those computers were designed with one IC for synchronizing delay times, not for the reasons you quote.  Also, discrete logic is unlikely to ever be NRND'ed; I think you can count on NOT/OR/AND/NOR/NAND/XOR etc. being available in some form for a long time." CreationDate="2011-03-29T18:00:13.440" UserId="857" />
  <row Id="18393" PostId="12239" Score="1" Text="Is &quot;A microcontroller&quot; with I2C and a timer acceptable, or do you need a custom solution?" CreationDate="2011-03-29T18:03:01.537" UserId="857" />
  <row Id="18394" PostId="12140" Text="@reemrevnivek: I agree that &quot;entirely from one type of IC&quot; is now rare, but I hope you can agree with me that &quot;built from 200 ICs of 11 kinds&quot; is likely to be easier to design, assemble, test, and repair than &quot;built from 198 ICs, each one unique and non-interchangeable with any of the others&quot;." CreationDate="2011-03-29T18:08:18.923" UserId="813" />
  <row Id="18395" PostId="12140" Text="Agreed!!!   Let's put this discussion to rest.  " CreationDate="2011-03-29T18:26:10.680" UserId="857" />
  <row Id="18396" PostId="12244" Text="@eric, if you place the signal through an averaging circuit(low pass) you will lose your response time but you can just read the analog value to know what percentage it is on. To expand on RQDQ's answer." CreationDate="2011-03-29T18:32:34.190" UserId="230" />
  <row Id="18397" PostId="12242" Score="3" Text="@miernik, the reason we purchase fuses is so that a fault event is *quickly* interrupted, you need to make sure copper will flash off fast enough to protect your load/source." CreationDate="2011-03-29T18:33:50.553" UserId="230" />
  <row Id="18400" PostId="12242" Score="4" Text="@miernik, why not a fuse? As Kortuk states, that's the safety function they perform. Wire...dodgy at best and it will not breakdown fast or reliably enough IMO." CreationDate="2011-03-29T18:39:30.763" UserId="2157" />
  <row Id="18401" PostId="12240" Text="I've heard the warning about only using the appropriate chargers for li based batteries but I have never heard the 4.2V limit.  The charger that came with my phone says it delivers 0.7 A at 5V.  Clearly the 5V's isn't a dangerous voltage for the battery.  Can you explain the discrepancy? Clearly I'm missing something." CreationDate="2011-03-29T18:40:21.887" UserId="2809" />
  <row Id="18402" PostId="12208" Text="Resistors and capacitors are cheaper and smaller, no?  They let you easily choose any pulse length you want, not just multiples of nanoseconds, and no need for external multivibrators." CreationDate="2011-03-29T18:56:34.827" UserId="142" />
  <row Id="18403" PostId="12244" Text="**+1** Better yet, those sensors have analog output anyway! I'd still be interested in whether there are PWM input I²Cs out there though." CreationDate="2011-03-29T19:18:00.453" UserId="1217" />
  <row Id="18404" PostId="12240" Text="@mattz, the AC adapter provides 5V but the phone steps down the voltage to charge the battery. The phone probably has a dedicated charging IC." CreationDate="2011-03-29T19:30:41.430" UserId="1225" />
  <row Id="18405" PostId="12242" Text="Because if I am far away from any shop which carries suitable fuses, and I need a solution working now, I need something out of the material I have, which will at least be better then wiring the thing with a thick wire without any fuse, so I am looking for the most suitable wire if copper wire is the only thing I've got. Assume you are on a dessert, far from shops with fuses, you have only wires, and not running the device until you get a proper fuse is not an option. What size wire you would use?" CreationDate="2011-03-29T19:32:48.340" UserId="1691" />
  <row Id="18406" PostId="12245" Text="I think you misunderstood my question. The real question is: assuming you are on a dessert, far from shops with fuses, you have only wires, and not running the device until you get a proper fuse is not an option. What size of wire you would use as a fuse-substitute?" CreationDate="2011-03-29T19:35:23.660" UserId="1691" />
  <row Id="18407" PostId="12241" Text="@JRobert, all filtering will be done on a PC in a realtime signal processing environment. " CreationDate="2011-03-29T19:38:02.020" UserId="207" />
  <row Id="18408" PostId="12240" Text="So if that's the case do I need to worry about the voltage at all?" CreationDate="2011-03-29T19:40:42.037" UserId="2809" />
  <row Id="18409" PostId="12245" Text="You didn't say that in your question! I still don't think you will find a fuse with those characteristics." CreationDate="2011-03-29T19:48:11.847" UserId="305" />
  <row Id="18410" PostId="12173" Text="I hadn't considered a pre-heater, actually. I'll check it out." CreationDate="2011-03-29T19:49:13.607" UserId="70" />
  <row Id="18411" PostId="12240" Text="@mattz, well, you probably need to provide 5V to the phone or it may not work or with higher voltages, it could be damaged." CreationDate="2011-03-29T20:01:49.340" UserId="1225" />
  <row Id="18412" PostId="12245" Text="OK, what if I lower the characteristic to: what is the absolutely smallest copper wire (without isolation) that will allow a 70A DC current continuously without blowing the wire? Will a 2.5mm^2 wire be OK?" CreationDate="2011-03-29T20:05:33.443" UserId="1691" />
  <row Id="18413" PostId="12237" Text="Do you want to make a charging station which will power the phone, charing the battery through the phone, or which will charge the battery outside the phone?" CreationDate="2011-03-29T20:14:31.097" UserId="1691" />
  <row Id="18414" PostId="12236" Text="@Mark Thank you for clearing things up, and I think how the `F` comes into life is just as you mentioned. I have another piece of DDR init code from Freescale in where the address for `PRECHARGE ALL` is `0x80000400`!" CreationDate="2011-03-29T20:21:22.660" UserId="3425" />
  <row Id="18415" PostId="12251" Text="Well, but a fuse is just a piece of wire. OK, its probably something else then copper, but still its just a wire, just of the right size to melt at the right current. Fuses are not God-given and do not fall from the the sky as miraculously self-created objects from a secret source - no, they are made by humans, out of some wire. So I am asking &quot;how to make a 150A fuse&quot;." CreationDate="2011-03-29T20:42:53.580" UserId="1691" />
  <row Id="18416" PostId="12212" Text="Ohhh. I misread, sorry. " CreationDate="2011-03-29T20:55:29.853" UserId="2873" />
  <row Id="18417" PostId="12237" Text="It would charge it through the phone.  I guess I should have mentioned that as the phone may be the limiting factor, not the battery." CreationDate="2011-03-29T21:02:50.983" UserId="2809" />
  <row Id="18418" PostId="12240" Text="Also, how do I know what if it's 1C?  I know this is going to differ from device to device but where would I look?  Is this determined by the phone or the battery or both and if I have to ask the manufacturer, how should I ask?  Sorry for the additional questions.  Let me know if you think these should be broken out into new questions instead of comments." CreationDate="2011-03-29T21:05:52.853" UserId="2809" />
  <row Id="18420" PostId="12255" Score="2" Text="PICs are microcontollers. Here is a good [question](http://electronics.stackexchange.com/questions/1092/whats-the-difference-between-a-microcontroller-and-a-microprocessor) showing the difference between the two. " CreationDate="2011-03-29T21:08:54.993" UserId="1623" />
  <row Id="18422" PostId="12252" Text="I have used a pot as a current limiting resistor and I've measured the current at various voltages between 1.3 to 1.4 V. When I supplied it with 1.35 V the current through the circuit was 100 mA. It won't need any modulation, I just want to switch them on and off in the seconds range." CreationDate="2011-03-29T21:11:38.283" UserId="3049" />
  <row Id="18423" PostId="12240" Text="@mattz, you don't. So best to stick to 0.5C as the manufacturer is using." CreationDate="2011-03-29T21:16:00.773" UserId="1225" />
  <row Id="18425" PostId="12256" Text="And if you have a specific task that you would like to tackle, create a new question stating what it is you want to do and we can help you determine what you need to look for in the best microcontroller." CreationDate="2011-03-29T21:20:55.620" UserId="319" />
  <row Id="18426" PostId="12256" Text="+1 for Atmel AVR. They're used for teaching in many universities." CreationDate="2011-03-29T21:21:37.447" UserId="2134" />
  <row Id="18427" PostId="12240" Text="Thanks for all the info but let me get back to my original question for clarification, how do I determine the values?  I take it that unless its published by the manufacturer I'm out of luck?" CreationDate="2011-03-29T21:22:56.413" UserId="2809" />
  <row Id="18428" PostId="12256" Text="@Polemon and so are PICs and MSP430s." CreationDate="2011-03-29T21:23:01.300" UserId="319" />
  <row Id="18429" PostId="12248" Score="1" Text="Do you want to measure the energy used by something protected by a fuse or the energy lost in the fuse itself?" CreationDate="2011-03-29T21:24:43.170" UserId="659" />
  <row Id="18430" PostId="12245" Text="6 AWG wire (13 mm^2) is OK for 75A. However, the fusing current will be nearly 700A. Forget about it! " CreationDate="2011-03-29T21:25:40.500" UserId="305" />
  <row Id="18431" PostId="12256" Text="@Kellenjb I don't know about PICs and MSP430s in universities. Mine used Atmel AVRs with no prototyping board, just breadboards. I use MSP430 at home to play around with it. I never used PICs though." CreationDate="2011-03-29T21:25:53.917" UserId="2134" />
  <row Id="18432" PostId="12256" Score="1" Text="@Polemon I am saying they are used. I have taught at a university that had PICs at their core and were working on training material for MSP430s" CreationDate="2011-03-29T21:28:06.973" UserId="319" />
  <row Id="18433" PostId="12256" Score="1" Text="@Kellenjb: ¯\\(°_o)/¯" CreationDate="2011-03-29T21:29:53.587" UserId="2134" />
  <row Id="18434" PostId="4320" Text="LEDs work fine as normal diodes at 220V if in series with a 100k or so. They do break down around 100V but the the current is too low to do any serious damage (at least not in several days)." CreationDate="2011-03-29T21:35:01.403" UserId="659" />
  <row Id="18437" PostId="12242" Score="3" Text="If I was on a dessert, and it was so big that there wasn't a place I could get a fuse nearby, I would start eating it, and not worry about electronics for a while!" CreationDate="2011-03-29T21:38:35.333" UserId="857" />
  <row Id="18438" PostId="12266" Score="3" Text="No, strike that, don't kludge anything up!  This is 150A we're talking about here.  " CreationDate="2011-03-29T21:40:44.247" UserId="857" />
  <row Id="18439" PostId="12198" Score="1" Text="The Panasonic 0.1 to 1F Gold Capacitors (also called Electric Double Layer Capacitors) are in fact electrolytic so maybe OP has one of this kind." CreationDate="2011-03-29T21:47:53.020" UserId="659" />
  <row Id="18441" PostId="12217" Text="@endolith - While I think this discussion is getting a little too meta, I'll say that we prohibit questions which are off-topic (we're about electronics design and the subset of shopping that relates to design, not electronics supply/shopping), which are subjective and argumentative (is an Adafruit item a better or worse answer than a Digikey item?).  There are a number of reasons why shopping questions could be closed." CreationDate="2011-03-29T21:51:48.250" UserId="857" />
  <row Id="18442" PostId="12248" Text="the energy used by something (not the fuse)" CreationDate="2011-03-29T21:53:08.687" UserId="3648" />
  <row Id="18443" PostId="12008" Text="+1 for the ADS1298." CreationDate="2011-03-29T21:53:59.787" UserId="2428" />
  <row Id="18444" PostId="12240" Text="@mattz Pretty much. The manufacturer only knows. " CreationDate="2011-03-29T21:55:15.893" UserId="1225" />
  <row Id="18445" PostId="12186" Score="1" Text="When you get to solar power, check out the Free Charge Controller project http://www.freechargecontroller.org/" CreationDate="2011-03-29T21:55:45.187" UserId="813" />
  <row Id="18447" PostId="12242" Score="2" Text="I believe that you won't be able to attain the specs you wrote with just a simple copper wire (you would need a more complicated geometry and materials for it to blow fast and reliably)" CreationDate="2011-03-29T22:05:56.343" UserId="659" />
  <row Id="18449" PostId="12193" Text="+1 for the gain integration idea." CreationDate="2011-03-29T22:06:54.890" UserId="659" />
  <row Id="18450" PostId="12248" Text="Then why did you accept the answer you did?" CreationDate="2011-03-29T22:08:47.887" UserId="659" />
  <row Id="18451" PostId="12206" Text="@Kellenjb No, when I detected the problem, I was checking continuity on unpowered circuit between one pin for IC and power connector. It turns out that I got continuity to both pins of the power connector. The only part which could have made a short was the capacitor, so I removed it from the circuit and investigated it separately." CreationDate="2011-03-29T22:09:50.960" UserId="1240" />
  <row Id="18452" PostId="12261" Text="OTOH if the fuse does not have repeatable resistance then how can it have repeatable resistance-dependent heating effects? I guess that the resistance may vary between models and manufacturers." CreationDate="2011-03-29T22:10:21.427" UserId="659" />
  <row Id="18454" PostId="11988" Text="Awesome! Thanks!" CreationDate="2011-03-29T22:18:19.817" UserId="3301" />
  <row Id="18455" PostId="12251" Score="1" Text="@miernik, how to make a 150A fuse and how to make one from copper are different, you are asking something more specialized. @chris is worried you are going to violate laws or safety. Copper is not ideal as it will not enter thermal runaway as well as devices design for this. Manufacturing fuses is still quite a bit of work." CreationDate="2011-03-29T22:19:43.793" UserId="230" />
  <row Id="18456" PostId="12198" Text="@jpc It looks just like left one showed at the picture on [this](http://industrial.panasonic.com/www-cgi/jvcr13pz.cgi?E+PZ+3+ABC0004+EECF5R5U105+7+WW) page. I'm not sure if its Panasonic. Somehow, I know I used Panasonic's datasheet, but I'm not sure anymore that I've used correct datasheet for it. Some sources say that it's made by ELKO (can't find their website, so I can't confirm). The capacitor itself has [M]GC logo, but I can't find any information on that manufacturer." CreationDate="2011-03-29T22:21:18.707" UserId="1240" />
  <row Id="18458" PostId="12261" Score="2" Text="The resistance of the fuse will definitely change with temperature. At any particular current, its resistance will be repeatable, though." CreationDate="2011-03-29T22:32:09.680" UserId="3588" />
  <row Id="18459" PostId="12198" Text="@AndrejaKo There are several manufacturers of these caps (like [BC Components](http://www.electronicsspecialist.co.uk/double-layer-capacitors-dlc-5-5v-0-22f-.asp) - now Vishay) and I also encountered some for which I failed to determine a manufacturer (so probably Chinese :)." CreationDate="2011-03-29T22:48:43.997" UserId="659" />
  <row Id="18460" PostId="12269" Text="The second song is higher frequency, maybe its aliasing somewhere. The plots don't really look like that though." CreationDate="2011-03-29T22:53:53.620" UserId="319" />
  <row Id="18461" PostId="12269" Text="@Kellenjb  Just to note, the two bottom images are what I get from antenna. They aren't plots of audio files themselves. " CreationDate="2011-03-29T22:56:03.167" UserId="1240" />
  <row Id="18462" PostId="12183" Text="@markrages high mutual inductance would completely change the calculation since if you wind the inductor with a twisted wire pair (which is like two inductors with coupling coefficient = 1) you mostly double the current capacity without lowering the inductance. There is no equivalent effect for capacitors." CreationDate="2011-03-29T22:58:13.103" UserId="659" />
  <row Id="18463" PostId="12183" Score="1" Text="@Thomas You need about 1.41 times more wire since inductance raises to the second power of turn count." CreationDate="2011-03-29T23:00:56.143" UserId="659" />
  <row Id="18464" PostId="9498" Text="@stef It was made to run on a Cortex-M3 (there is a news item in the home page) so I guess the answer is &quot;yes&quot;." CreationDate="2011-03-29T23:19:11.987" UserId="659" />
  <row Id="18465" PostId="12269" Score="2" Text="What is the dc bias path for Q1's emitter?" CreationDate="2011-03-30T00:04:42.260" UserId="411" />
  <row Id="18466" PostId="12242" Text="pretty sure i saw a macgyver episode once where he used a bubble gum wrapper in place of a fuse in a three phase power switch.  Give it a try! (please don't)" CreationDate="2011-03-30T01:02:45.183" UserId="1438" />
  <row Id="18467" PostId="12271" Score="3" Text="@akij, this is not specific enough to explain what you need. What defines stylish?" CreationDate="2011-03-30T01:37:09.380" UserId="230" />
  <row Id="18468" PostId="12269" Text="@Andrejako, what is your audio source?" CreationDate="2011-03-30T02:28:54.620" UserId="230" />
  <row Id="18469" PostId="12269" Text="@markrages I assumed they were the same bias for both songs, but that is a good question" CreationDate="2011-03-30T02:40:29.297" UserId="319" />
  <row Id="18470" PostId="12269" Text="Audio - should be connected to ground.  I can't tell if it is from this schematic  (this is the reason why a point with four connections is poor style)." CreationDate="2011-03-30T02:48:06.613" UserId="411" />
  <row Id="18471" PostId="12256" Text="@polemon - Excellent comment.  Will have to remember that one." CreationDate="2011-03-30T03:42:07.617" UserId="857" />
  <row Id="18472" PostId="12260" Text="Both zener diodes should be on the USB connector side of the 68$\Omega$ resistors." CreationDate="2011-03-30T03:48:05.213" UserId="659" />
  <row Id="18473" PostId="12275" Score="2" Text="I am sorry, but: TL;DR." CreationDate="2011-03-30T03:58:19.467" UserId="659" />
  <row Id="18474" PostId="12147" Text="@unixbigot, Thank you." CreationDate="2011-03-30T04:08:04.367" UserId="3353" />
  <row Id="18475" PostId="12251" Score="1" Text="make sure you put a glass or ceramic envelope around your copper wire.  Copper melts at 1085 °C and I have scars to prove it.  There will almost certainly be a fire if anything flammable is near your melted wire, or underneath where the molten copper splatters." CreationDate="2011-03-30T05:13:27.620" UserId="411" />
  <row Id="18476" PostId="12178" Text="thanx 4 answering my question...." CreationDate="2011-03-30T05:19:31.590" UserId="3633" />
  <row Id="18477" PostId="12178" Text="thanx 4 answering my question....                                i already tried ice, but after 9 degree C, LCD went off.so i didn't go 4 boil water but used soldering iron 2 show dat ckt is working. can u please tell me hw can i check temp of liquids like water with this ic? " CreationDate="2011-03-30T05:30:27.493" UserId="3633" />
  <row Id="18478" PostId="12177" Text="thanx 4 ur suggestions....." CreationDate="2011-03-30T05:31:00.690" UserId="3633" />
  <row Id="18479" PostId="12177" Text=" u hav said that Accuracy is related to voltage, means temperature is changing with respect to volatge, if yes , then can i measure this voltage, do i hv to measrure it from  pin Tout?" CreationDate="2011-03-30T05:41:36.453" UserId="3633" />
  <row Id="18480" PostId="12231" Text="Thank you for your answer. I will just skip the Ethernet hub then, for two reasons: 1. it is not critical for my project (it would just be a cool feature). 2. Getting it to work with all ethernet setups 10/100/1gig ect., will probably be difficult. So I thank you for helping me making the decision.  :-)" CreationDate="2011-03-30T05:47:15.547" UserId="3041" />
  <row Id="18481" PostId="12214" Text="Hi, thanks for your answer. I don't think the passive hub will work probably for all Ethernet setups. Therefore I have decided not to build the Ethernet hub on the board, as it seems more difficult than first assumed." CreationDate="2011-03-30T05:54:47.023" UserId="3041" />
  <row Id="18482" PostId="12255" Score="1" Text="I think Arduino is fine. Later you can move from the Arduino software environment to the bare AVR and a C compiler, which is the way microcontrollers are used in industry." CreationDate="2011-03-30T05:58:10.080" UserId="339" />
  <row Id="18483" PostId="12248" Text="because I think it answered my question, if there is no resistance, the fuse itself can't measure the power. Of course the second answer is right as well, if you have resistance in series, you should be able to measure the power, as long as you know the resistance of the fuse (which should be close to zero). Wrong?" CreationDate="2011-03-30T06:32:31.327" UserId="3648" />
  <row Id="18484" PostId="12178" Text="@yaprism, are you submerging your circuit?" CreationDate="2011-03-30T06:44:05.517" UserId="1225" />
  <row Id="18485" PostId="12213" Text="@stevenh Accuracy depends greatly on the calibration of the circuit and how they measure the load cell. Yes a cheap load cell will have worse characteristics then a High quality one. This is why Scales are calibrated with standard Weights either at the factory or a built in function and I don't see why you couldn't get even Higher accuracy using a better ADC then one in the hacked scale." CreationDate="2011-03-30T07:10:24.513" UserId="2060" />
  <row Id="18486" PostId="12270" Text="That's not necessarily true. Low speed USB mode (which the poster is using judging from his pull-up placement on D-) is fairly lenient, and new versions of VUSB are designed to work with the interal oscillator of the AVR. See http://www.obdev.at/products/vusb/easylogger.html" CreationDate="2011-03-30T08:22:34.567" UserId="1802" />
  <row Id="18487" PostId="12177" Text="@yaprisu Accuracy is related to operating voltage of the sensor. That voltage should be measured on pins 8 (Vdd) and 4 (GND). If the voltage is between 3 V and 5 V, accuracy is $±\frac{1}{2}^\circ C$. Between 2.7 V and 3V, you get $±1^\circ C$. If you're measuring temperatures below $0^\circ C$ and above $70^\circ C$, accuracy is $±2^\circ C$." CreationDate="2011-03-30T08:41:20.103" UserId="1240" />
  <row Id="18488" PostId="12269" Text="@markrages Audio - is connected to ground. There is higher resolution version on instructables so it is obvious there, but here the image gets scaled down. Also what is dc bias path?" CreationDate="2011-03-30T08:44:30.787" UserId="1240" />
  <row Id="18489" PostId="12269" Text="@Kortuk♦ I'm using a computer as audio source. " CreationDate="2011-03-30T08:45:02.160" UserId="1240" />
  <row Id="18490" PostId="12178" Text="@yaprisu What it ckt?" CreationDate="2011-03-30T09:03:29.030" UserId="1240" />
  <row Id="18491" PostId="12214" Text="It would be nice if you still accepted an answer even if you don't use any of the answers." CreationDate="2011-03-30T10:00:58.180" UserId="2395" />
  <row Id="18492" PostId="12215" Text="the current is really small, several miliamps" CreationDate="2011-03-30T11:06:34.957" UserId="3641" />
  <row Id="18493" PostId="11776" Text="@darron Don't worry about the syntax highlighting. The editor and its syntax highlighter are a completely different piece of software from the synthesis tool. Also, unsigned is &quot;just&quot; a datatype. It is part of a standard library, not of the language itself." CreationDate="2011-03-30T11:22:51.460" UserId="3145" />
  <row Id="18494" PostId="12252" Text="It's hard to say if you found the correct drive current by doing that. You could be overdriving (or under-driving) the led. Please use the precautions that reemrevnivek has point out. Your method is fine for determining a standard led that you can see the brightness as you reach the target current, however you would need to measure the IR radiation some how to see if you are driving an IR led efficiently. I assume there is no datasheet available. Perhaps you can find a similar IR led datasheet of the same package and make some assumptions. " CreationDate="2011-03-30T11:46:41.620" UserId="3453" />
  <row Id="18495" PostId="12248" Text="@Beffa I was just thinking that @David reply was a perfect reply to the question you did not ask. :)" CreationDate="2011-03-30T11:58:46.983" UserId="659" />
  <row Id="18496" PostId="12281" Text="Thanks a lot for your excellent explanation! I know that providing a definitive answer is not possible. Was i was wondering if the tollerance is more like +/-1% or +/- 10%." CreationDate="2011-03-30T12:06:48.303" UserId="3662" />
  <row Id="18497" PostId="12281" Text="Tolerance is not going to be a % of actual value.  My static unit can move at 1m/s (sometimes 20m/s vertically :-) !!) which is an infinite % error." CreationDate="2011-03-30T12:14:47.787" UserId="400" />
  <row Id="18498" PostId="12251" Text="@miernik I guess I'm really just concerned about your application. If this if for home, hobby, prototyping some fuse design then cool. However your comment _&quot;I've got. Assume you are on a dessert, far from shops with fuses, you have only wires, and not running the device until you get a proper fuse is not an option. What size wire you would use?&quot;_" CreationDate="2011-03-30T12:28:11.090" UserId="2612" />
  <row Id="18499" PostId="12251" Text="-continued from above- (for some reason my edit did not take)&#xA;&#xA;Coupled with that fact that this is for 150A set off a red flag in my head (probably because I work in a factory setting). If you're building this for home, hobby, or prototyping a fuse design then cool, my bad. If however you're looking for a quick fix for a blown fuse on a piece of equipment in a commercial or industrial setting then I stand by my legal/safety concerns." CreationDate="2011-03-30T12:39:46.230" UserId="2612" />
  <row Id="18500" PostId="12270" Score="1" Text="&quot;V-USB can currently handle clock rates of 12 MHz, 12.8 MHz, 15 MHz, 16 MHz, 16.5 MHz, 18 MHz and 20 MHz. These clock rates are precise! A crystal with 11.9 MHz won't work! Only the 16.5 MHz and 12.8 MHz variants allow a deviation of up to 1%. They are therefore suitable for RC oscillators. 16.5 MHz is suitable for devices which can derive a 16 MHz clock from an RC oscillator (e.g. ATTiny25/45/85 and ATTiny26), 12.8 MHz can usually be reached by calibrating the 8 MHz RC oscillator. Calibration of the RC oscilator is described at examples.&quot;" CreationDate="2011-03-30T12:57:44.740" UserId="659" />
  <row Id="18501" PostId="12225" Text="@Kellenjb Not really. I am now working on using COTS WiFi routers and USB hubs since both are cheaper assembled than the chips inside cost at 50+ quantities." CreationDate="2011-03-30T13:32:30.290" UserId="659" />
  <row Id="18502" PostId="12283" Text="I did some formatting and spelling edits to the post but I am unable to improve on the second paragraph." CreationDate="2011-03-30T13:39:18.820" UserId="659" />
  <row Id="18503" PostId="12289" Score="1" Text="The modern 1uF ceramic capacitors should be a good replacement for both (and allow you to go with far less electrolytics)." CreationDate="2011-03-30T13:41:28.290" UserId="659" />
  <row Id="18504" PostId="12274" Text="Just to clarify, the voltage generators are DC and you need voltage once the circuit stabilizes, right? If that's the case, I might be able to post procedure how to get the calculation using node voltage method in a couple of hours. " CreationDate="2011-03-30T13:58:25.787" UserId="1240" />
  <row Id="18505" PostId="12269" Text="You aren't accidentally cancelling out one channel with the other, are you?  Mono songs would cancel out completely, but stereo songs would have a residual that gets through." CreationDate="2011-03-30T14:02:59.387" UserId="142" />
  <row Id="18506" PostId="12269" Text="@endolith  No. I connected only one channel to the transmitter. The second channel isn't connected to anything. " CreationDate="2011-03-30T14:09:29.197" UserId="1240" />
  <row Id="18507" PostId="12242" Text="It sounds like you want something that behaves like a [fusible link](http://en.wikipedia.org/wiki/Fusible_link).  Any reason you wouldn't just use / build a fusible link?" CreationDate="2011-03-29T18:20:45.227" UserId="1823" />
  <row Id="18508" PostId="12269" Text="I just checked and there is audio on both channels on the second song all the time, so the problem isn't with bad stereo mixing. " CreationDate="2011-03-30T14:17:53.047" UserId="1240" />
  <row Id="18509" PostId="12286" Score="1" Text="Possible Duplicate: http://electronics.stackexchange.com/questions/2272/what-is-a-decoupling-capacitor-and-how-do-i-know-if-i-need-one" CreationDate="2011-03-30T14:22:28.787" UserId="588" />
  <row Id="18510" PostId="12294" Text="Oh and i'm on a x86 Mac with the latest tools installed using Fink." CreationDate="2011-03-30T14:42:29.353" UserId="3309" />
  <row Id="18511" PostId="12294" Score="1" Text="AAAHHH!!! sorted it out... &quot;-lm&quot; should be the last item passed to the linker... !! WTF, been struggling with this for the last 4 days..." CreationDate="2011-03-30T14:49:51.983" UserId="3309" />
  <row Id="18512" PostId="12269" Score="1" Text="It looks as though that circuit is very roughly on-off-keying the transmitter based upon the input signal, and would spew all sorts of harmonic garbage.  The circuit is going to switch on when the signal is above a certain threshold and switch off below that threshold.  I would expect that moving the +5 end of R2, to the wiper of a pot that goes between +5 and ground, would allow you to tweak the threshold to yield much better success, but I find it hard to believe that transmitter would be legal at any power level." CreationDate="2011-03-30T14:50:26.023" UserId="3123" />
  <row Id="18513" PostId="12269" Text="I'm curious why you are trying to use a 555 in that fashion?  Having each audio cycle reset the phase of the oscillator is going to yield a signal which will be hard to receive, but will spill out all manner of junk at other miscellaneous frequencies; it makes no sense to me." CreationDate="2011-03-30T15:00:10.650" UserId="3123" />
  <row Id="18514" PostId="12269" Text="@supercat Because I saw a very simple transmitter which I could build from parts in my drawer. There really isn't any other reason. " CreationDate="2011-03-30T15:06:53.147" UserId="1240" />
  <row Id="18515" PostId="12274" Score="1" Text="If these are ideal voltage sources and capacitors, isn't this a paradoxical circuit?  Like connecting an ideal voltage source to an ideal short." CreationDate="2011-03-30T15:12:00.623" UserId="142" />
  <row Id="18516" PostId="12217" Score="1" Text="@reemrevnivek: Absolutely.  I'm just pointing out that &quot;shopping question&quot; does not imply &quot;off-topic&quot;.  There are plenty of shopping questions that don't fall under any of those prohibitions, and the &quot;shopping question bad&quot; meme is harmful." CreationDate="2011-03-30T15:17:48.200" UserId="142" />
  <row Id="18517" PostId="12184" Text="@Kortuk, I don't remember what the the comment was either :)" CreationDate="2011-03-30T15:20:24.797" UserId="1655" />
  <row Id="18518" PostId="12198" Text="@jpc: EDLC = supercap.  The Wikipedia article distinguishes between electrolytics and EDLCs, and states that EDLCs have &quot;no corrosive electrolyte&quot;, but maybe they can both be considered electrolytic; I don't know." CreationDate="2011-03-30T15:26:36.600" UserId="142" />
  <row Id="18519" PostId="12269" Score="1" Text="@AndrejaKo: I've seen designs for transmitters using one transistor, a transformer, and some resistors and caps.  I think one could also build one with two transistors, some resistors and caps, and no inductors.  Even if one wants to use a 555, I would think that one should let the 555 run undisturbed and have the audio input modulate the output transistor." CreationDate="2011-03-30T15:34:02.197" UserId="3123" />
  <row Id="18521" PostId="12274" Score="2" Text="10 aF is more or less the capacitance between two 1 m2 plates placed 1000 km apart. I don't have them in my component box." CreationDate="2011-03-30T15:43:01.500" UserId="2064" />
  <row Id="18522" PostId="12251" Text="This is for hobby, for charging some batteries. The story about the desert was just to try to keep the answers in the scope of the question - fuse from copper wire." CreationDate="2011-03-30T15:51:32.800" UserId="1691" />
  <row Id="18523" PostId="11838" Text="Sometimes they are a short peice of rubber or platic tube." CreationDate="2011-03-30T16:06:46.147" UserId="1498" />
  <row Id="18524" PostId="11665" Text="The power supply can tell.  Output caps on the PS can supply the current, if it does not have enough already.  A scope on the power supply should not show too much variation when the chopper is on." CreationDate="2011-03-30T16:16:17.353" UserId="1498" />
  <row Id="18525" PostId="12292" Text="But all those things are easily available in all the controllers, why would I use another chip for this?" CreationDate="2011-03-30T16:19:30.253" UserId="1200" />
  <row Id="18526" PostId="12293" Text="I want to get hooked on!! But I can't figure out any project ideas for this." CreationDate="2011-03-30T16:20:10.300" UserId="1200" />
  <row Id="18527" PostId="12294" Score="1" Text="@Jan de Jager Go ahead and do us a favor. Either close your question, or better yet make an answer that explains what was wrong and then select your own answer." CreationDate="2011-03-30T16:33:47.153" UserId="319" />
  <row Id="18528" PostId="12293" Text="Well...  Let's say that you have the Cypress CY8CKIT-014 board (http://www.cypress.com/?rID=43674).  It's only $49, so it's not too expensive but has quite a bit of stuff on it.  One thing that I'd consider doing with it:  Use the capsense slider and 3-axis accelerometer to make some sort of musical instrument.  Use some GPIO pins to drive a speaker directly, or hook up a DAC.   There might also be a DAC in the PSoC 5 itself, too." CreationDate="2011-03-30T16:38:38.067" UserId="3624" />
  <row Id="18529" PostId="12292" Score="3" Text="The PSoC 5 has the following analog blocks: 20-bit sigma-delta ADC, 8-bit IDAC, 8-bit VDAC, 12-bit 1 Msps SAR ADC, PGA, Op-amp, TIA, frequency mixer, comparator, reference, cap-sense block (among others). You will *not* find this mix of hardware in &quot;all the controllers&quot;." CreationDate="2011-03-30T16:48:20.143" UserId="1293" />
  <row Id="18531" PostId="12269" Score="1" Text="@AndrejaKo: A transistor needs a DC bias to amplify.  In other words, there needs to be a path between the emitter of Q1 to ground.  Such as a resistor.  With the emitter floating linke that I suspect that Q1 is doing nothing of value in this circuit." CreationDate="2011-03-30T17:22:29.567" UserId="411" />
  <row Id="18532" PostId="12269" Text="Also, the circuit is really poorly done.  That it works at all is testament to an AM radio's ability to demodulate any kind of noise in its vicinity.  I suggest looking for a better circuit." CreationDate="2011-03-30T17:23:47.943" UserId="411" />
  <row Id="18533" PostId="12291" Score="1" Text="Hopefully they're shipping the PSoC 5 by the time you're a senior...no one has any stock yet." CreationDate="2011-03-30T17:46:26.700" UserId="857" />
  <row Id="18534" PostId="12297" Text="Filtering slows down the response though, so if you are accelerating, your car might show 50 mph and the GPS 45 mph, so that's more than your 2.25 mph error. It'll catch up within a second or two though." CreationDate="2011-03-30T17:55:09.753" UserId="131" />
  <row Id="18535" PostId="12263" Text="Question: Would you also consider CS students if they had applied some knowledge with Embedded Systems (Aka worked with Circuits/Low Level C,Assembly/ and had worked with Microcontrollers and such?" CreationDate="2011-03-30T18:07:32.577" UserId="3073" />
  <row Id="18536" PostId="12262" Text="Im gonna have to look into this!" CreationDate="2011-03-30T18:09:14.277" UserId="3073" />
  <row Id="18537" PostId="12303" Text="Ya I knew that, I dunno why i didn't put that. I meant like not many guides talk about actually connecting a MP and Memory (like flash or eeprom) etc..." CreationDate="2011-03-30T18:12:55.240" UserId="3073" />
  <row Id="18538" PostId="12284" Score="1" Text="Why is the one voltage of the transistors not getting as high as the other? IS that a fault with the simulation as surely they should get to the same with the same resistors and cap sizes. " CreationDate="2011-03-30T18:29:05.523" UserId="1623" />
  <row Id="18539" PostId="12306" Text="So u think theirs still a chance? for CS degrees then? What all does &quot;Embedded Linux&quot; entail? (that sounds pretty cool to me too..)" CreationDate="2011-03-30T18:42:59.410" UserId="3073" />
  <row Id="18540" PostId="12307" Text="Also, read books. It's easy to become over-focused on readying yourself for the job market when it's much more important that you nurture yourself into an interesting _person_." CreationDate="2011-03-30T18:52:15.597" UserId="207" />
  <row Id="18541" PostId="9798" Text="Instead of such a very lossy transformation, if you search now on eBay for something like &quot;DC vehicle power converter&quot; you will find something which transforms vehicle DC -&gt; stable DC directly, and as such more efficiently." CreationDate="2011-03-30T18:56:42.640" UserId="1691" />
  <row Id="18542" PostId="12269" Text="@markrages  OK. I was unfamiliar with the term." CreationDate="2011-03-30T18:59:18.710" UserId="1240" />
  <row Id="18543" PostId="12306" Text="Computer Science is a huge topic, it's important to have a grounding in the essentials. Employers don't expect much more from graduates. If you're keen, do stuff, that will impress. Embedded Linux systems are small non-PC systems running Linux, set-top-boxes, mobile phones, etc." CreationDate="2011-03-30T19:00:02.907" UserId="566" />
  <row Id="18544" PostId="12305" Text="Pretty solid ground. Both batteries should or will be grounded to chasis too. " CreationDate="2011-03-30T19:02:00.300" UserId="2157" />
  <row Id="18545" PostId="12284" Score="1" Text="@Dean: Actually, one of the resistors is 10 ohms less than the other... this is to start the circuit oscillation in the unrealistic world of the simulator." CreationDate="2011-03-30T19:04:36.820" UserId="2426" />
  <row Id="18546" PostId="12303" Score="1" Text="Since most microprocessors now have cache/memory and some I/O, it's a very blurry line. " CreationDate="2011-03-30T19:05:21.030" UserId="2157" />
  <row Id="18547" PostId="12308" Text="But the second battery will be connected to the main circuit using the &quot;FMA PowerLab 8 V2&quot; device, and normally it is not meant to be used with a common ground of input and output. I am wondering will it even operate correctly that way." CreationDate="2011-03-30T19:10:34.710" UserId="1691" />
  <row Id="18548" PostId="12214" Text="Oh, yes... sorry, I'm kinda new to this site. I tried to vote your answer up, but I need more reputation before I'm allowed to do that..." CreationDate="2011-03-30T19:15:03.427" UserId="3041" />
  <row Id="18549" PostId="12302" Score="1" Text="@Sauron - I hate to send you elsewhere, but if you're interested in AVRs you need to know about [AVRfreaks.net](http://www.avrfreaks.net).  " CreationDate="2011-03-30T19:16:13.863" UserId="857" />
  <row Id="18550" PostId="9798" Text="@atmocreations I'm in North America so all of the automotive inverters I see are 120VAC." CreationDate="2011-03-30T19:16:56.487" UserId="1293" />
  <row Id="18551" PostId="9798" Text="@miernik He already has the AC-DC power supply (a point I misunderstood from the original post). It's easier to just supply AC to the existing power supply than to get a DC-DC converter and improvise a connection to the client with it." CreationDate="2011-03-30T19:18:50.243" UserId="1293" />
  <row Id="18552" PostId="12308" Text="As long as the input and output sides are totally isolated from each other it shouldn't be an issue.  But if your second circuit isn't grounded with the first there could be a voltage potential difference between the two ground circuits.  " CreationDate="2011-03-30T19:19:03.797" UserId="2412" />
  <row Id="18553" PostId="12303" Score="1" Text="@Sauron - You sure you knew that?  You used MP again; a microcontroller (which is the correct term for an AVR and 99% of the devices we discuss here) almost always has memory (both non-volatile, like EEPROM and Flash, and volatile SRAM) on-board.  Learn to use the onboard stuff before you start venturing into peripherals." CreationDate="2011-03-30T19:19:37.123" UserId="857" />
  <row Id="18554" PostId="12309" Text="@Mark - ARMs are also RISC processors, the instruction set isn't that bad. It's actually quite nicely designed; there are some instructions for userspace vs. kernelspace differentiation and other complexities, but those can be ignored while you're starting out." CreationDate="2011-03-30T19:21:09.493" UserId="857" />
  <row Id="18555" PostId="12308" Score="1" Text="Hook the device up as the instructions say.  The second battery ground should be connected to the car's ground though the negative on the power source side." CreationDate="2011-03-30T19:23:35.413" UserId="2412" />
  <row Id="18556" PostId="9798" Text="Madmanguruman: maybe easier, but it will increase the power consumption probably by at least 10%-20%, maybe more, 5% in the best case, compared the solution with a direct DC-DC converter. If this is in a car, so running off battery, I assume that every bit of power consumption down matters a lot. Unless it will only be used when the car is running, then it doesn't matter. But if it is meant to be able to use the computer without the car engine running, then even a few % down on power consumption is worth the hassle and a bit extra cost." CreationDate="2011-03-30T19:24:25.327" UserId="1691" />
  <row Id="18557" PostId="12309" Score="1" Text="@reemrevnivek I was more trying to steer him away from the complexities of dealing with multiple processor modes and MMUs as he started into ASM which why I mentioned higher end ARMs.  The initialization and setup of higher end ARM SoCs is also substantially more complex than something like an AVR/PIC/MSP430." CreationDate="2011-03-30T19:33:47.383" UserId="1438" />
  <row Id="18558" PostId="12308" Text="Matthew Whited: your second comment is contradictory in itself and contradictory to the first one. The instructions don't say to connect the negatives together, and if I connect both batteries to car's chassis, they won't be totally isolated from each other. " CreationDate="2011-03-30T19:34:07.553" UserId="1691" />
  <row Id="18559" PostId="12308" Text="Not really.  With your question I was assuming you were creating a secondary circuit to do something like power an extra radio or something that you built totally on your own.  In your comment to me you pointed to a product that you purchased that you are using as some sort of auxiliary power.  The instructions for this device may contradict the grounding reason because it has the potential of connecting batteries in series.  If it does this the negative terminal of one of the batteries could really be a higher potential then ground." CreationDate="2011-03-30T19:44:14.400" UserId="2412" />
  <row Id="18560" PostId="12308" Score="3" Text="&quot;But if your second circuit isn't grounded with the first there could be a voltage potential difference between the two ground circuits&quot;  There are voltage differences between different points in a *single* ground circuit.  Metal is not a perfect conductor and any currents flowing through (cars have large, spikey currents) will create voltage differences from one point to another.  Make sure this isn't going to cause problems if the two circuits share a ground path.  Generally, you want the grounds of different systems connected together at a single point, not two." CreationDate="2011-03-30T19:49:00.307" UserId="142" />
  <row Id="18561" PostId="12308" Text="I didn't mean to imply multiple connections between the grounds.  I meant to imply that the grounds needed to have at least one connection.  While having a second grounding connection should just reduce the overall resistance on the ground." CreationDate="2011-03-30T19:58:02.653" UserId="2412" />
  <row Id="18562" PostId="12263" Text="In this case we are looking for anyone with applicable knowledge or experience (Micro's, C/Asm, VHDL, soldering, etc).  It doesn't matter if they are CS, EE, or working on some liberal arts program.  " CreationDate="2011-03-30T20:07:31.147" UserId="3624" />
  <row Id="18563" PostId="12308" Text="Matthew, what if the secondary installation is not 12V, but for example 24V, 48V or even 96V? Here I got advice to absolutely separate the ground of the higher-voltage installation (although I would like to understand why): http://www.diyelectriccar.com/forums/showthread.php?t=56897 What is your comment on that?" CreationDate="2011-03-30T20:15:19.717" UserId="1691" />
  <row Id="18564" PostId="12308" Text="From the second circuit that negative terminal you want to consider 0 volts would be attached to ground (this is import because you may want the 48v source being +/- 24 volts.)  Typically this would just be the lowest negative terminal if you are chaining batteries in series. " CreationDate="2011-03-30T20:19:57.283" UserId="2412" />
  <row Id="18565" PostId="12308" Text="BTW, do you plan on charging all of these batteries from your car's alternator?  If so you may run into even more problems." CreationDate="2011-03-30T20:22:14.303" UserId="2412" />
  <row Id="18566" PostId="12308" Text="Matthew: yes, all those batteries will be (sometimes, partially) charged from the car's alternator. But not only, sometimes also solar, rectified mains, possibly other sources. Any specific problems with that you have in mind? Anyway it seems I will be making separate isolated ground. Maybe even isolate ground of everything in the car from the chassis." CreationDate="2011-03-30T20:48:50.140" UserId="1691" />
  <row Id="18567" PostId="12317" Text="Hmm hadn't thought of IR.  Have to think about the LOS thing and if that's an issue..." CreationDate="2011-03-30T20:55:56.330" UserId="3666" />
  <row Id="18568" PostId="12309" Text="RISC? im not sure I understand the difference between that and whatever the others are... care to explain? Aren't most Microcontrollers RISC? it just means less instruction sets correct?" CreationDate="2011-03-30T21:12:22.983" UserId="3073" />
  <row Id="18569" PostId="12308" Score="1" Text="@Matthew: &quot;While having a second grounding connection should just reduce the overall resistance on the ground.&quot;  How is this different from &quot;multiple connections between the grounds&quot;?" CreationDate="2011-03-30T21:20:35.500" UserId="142" />
  <row Id="18570" PostId="12308" Text="@miernik: If you're charging both systems from the same alternator, you're going to have to connect them at some point." CreationDate="2011-03-30T21:21:37.557" UserId="142" />
  <row Id="18571" PostId="12317" Text="Calling this good - thanks for that brain nudge I needed BG100!  The first circuit on  http://home.cogeco.ca/~rpaisley4/PhotoDetectors.html (lights when sensing) looks like it would do what I need." CreationDate="2011-03-30T21:25:07.687" UserId="3666" />
  <row Id="18572" PostId="12302" Text="Ya Im leaning towards AVR...mainly because theirs SO much info about them, and they are ALOT cheaper than the TI-MPS430..." CreationDate="2011-03-30T21:37:09.890" UserId="3073" />
  <row Id="18573" PostId="12317" Text="@Tim Holt: No problem..." CreationDate="2011-03-30T21:38:09.320" UserId="2426" />
  <row Id="18574" PostId="12308" Text="endolith: they will be charged from the same alternator, but the second system never directly, but through a switched-mode DC-DC converter, so that would keep it isolated, no?" CreationDate="2011-03-30T21:45:00.113" UserId="1691" />
  <row Id="18575" PostId="12309" Score="1" Text="@sauron I added to my answer re:RISC vs CISC." CreationDate="2011-03-30T21:49:21.890" UserId="1438" />
  <row Id="18576" PostId="5567" Text="Internal resistance and internal impedance of a battery  are different things, I've seen datasheets providing both, with different values (see A123 LiFePO4 datasheets)." CreationDate="2011-03-30T22:02:26.423" UserId="1691" />
  <row Id="18577" PostId="12302" Text="@Sauron - AVR is popular with hobbyists, but I'm not sure where you're getting your cost data.  Both families have some offerings that are less than 1 USD and others pushing 20 USD. " CreationDate="2011-03-30T22:12:06.557" UserId="857" />
  <row Id="18578" PostId="12297" Text="@davr correct, and if someone really needed more accurate data they could add an accelerometer to fill in the gaps and get faster response." CreationDate="2011-03-30T22:18:34.050" UserId="319" />
  <row Id="18579" PostId="12302" Text="Well.....when I was looking at the MPS430 it looked like the software (debuggers etc) were a bit expensive when added onto the development boards." CreationDate="2011-03-30T22:20:46.560" UserId="3073" />
  <row Id="18581" PostId="12279" Text="Strange issue. My circuit does work but only is it's grounded using the ground clip on my scope. why? " CreationDate="2011-03-30T22:47:13.367" UserId="2824" />
  <row Id="18582" PostId="12242" Text="I think you should look at why the fuses are blowing since they are supposed to be OK. Are you sure that your ammeter is reading correctly (e.g. AC vs. DC, high-frequency variation, ...)? Are both fuseholders actually in the circuit (does only one of the fuses ever blow)?" CreationDate="2011-03-30T23:16:55.570" UserId="2838" />
  <row Id="18583" PostId="12242" Text="Kevin: this is DC, the ammeter is a LY5135A-2 with a 200A range which is actually a 75mV voltmeter over a 0.375 mOhm shunt, and the two 50A fuses where two flat pieces of some metal on top of each other, touching each other with full surface, of course they both melt." CreationDate="2011-03-31T00:43:17.033" UserId="1691" />
  <row Id="18584" PostId="12291" Text="Our college has 2 or 3 kits of PSoC 5" CreationDate="2011-03-31T02:00:57.837" UserId="1200" />
  <row Id="18585" PostId="12304" Text="I asked a similar question here: http://electronics.stackexchange.com/questions/1001/do-i-need-to-study-electronics-to-get-a-job-in-signal-processing-or-sensor-networ" CreationDate="2011-03-31T02:22:54.480" UserId="207" />
  <row Id="18587" PostId="12274" Text="@endolith, there will be a tau of 0. It will immediately reach &quot;steady state&quot;. The pre-charged and then leave a floating node makes me laugh." CreationDate="2011-03-31T02:46:14.313" UserId="230" />
  <row Id="18588" PostId="12334" Score="2" Text="Looking at my phone charger right now (one with a permanent cable with micro USB connector on the end), it's just a pair of wires molded together (a la lamp cord or whatever it's called), so concerns about using a charge cable for data may be moot." CreationDate="2011-03-31T02:58:37.253" UserId="1407" />
  <row Id="18589" PostId="12320" Text="The reduced number of registers the S08 has versus the HC11 can make things a little more difficult up front, as you'll need to figure out the stack do to much of anything (which was taught later in my lab with HC11s (or was it 12's)).  By extension, AVRs are really nice because you have a whopping 32 registers to play with before worrying about the stack." CreationDate="2011-03-31T03:01:27.250" UserId="1407" />
  <row Id="18590" PostId="12334" Score="1" Text="@NickT, It seems I may have misunderstood. The &quot;charging cable&quot; is a wallwart with a usb end? ignore point 3 for that." CreationDate="2011-03-31T03:01:37.170" UserId="230" />
  <row Id="18593" PostId="12322" Text="for assembler only you only need binutils, at least for arm/thumb or msp430, and you can build the assembler and linker.  If you want a C compiler from which you can examine the assembler output as a learning tool, then you need mspgcc4 or codesourcery or just use llvm for both." CreationDate="2011-03-31T03:11:33.810" UserId="985" />
  <row Id="18594" PostId="1654" Text="The capacitor + inductor arrangement mentioned in some answers has a name: [bias-T](http://en.wikipedia.org/wiki/Bias-T)." CreationDate="2011-03-31T03:19:14.753" UserId="813" />
  <row Id="18595" PostId="12263" Text="Hey, I *do* know how to calculate an LED's current limiting resistor!  Where do I send my resume?" CreationDate="2011-03-31T03:26:20.260" UserId="1609" />
  <row Id="18596" PostId="12263" Score="1" Text="I tell folks that college gives you a new toolbox with shiny new tools and teaches you the names of the tools.  It is your first real job where you find out what tools you really need and which ones you dont, and find out how to really use them...As well as all the tools you never learned about in school." CreationDate="2011-03-31T04:46:35.363" UserId="985" />
  <row Id="18597" PostId="12307" Text="@msutherl, I would suggest to a greater extent, force yourself to go out and meet new people. Preen your social skills. Good engineering gets you a long way, but not the whole way. Being able to talk to and interact with new people regularly will prepare you for future coworkers, interviews and *customers*!" CreationDate="2011-03-31T04:53:17.433" UserId="230" />
  <row Id="18598" PostId="12320" Text="Actually I like the simplicity of the single accumulator, even though it can be a bottleneck.  Instead of using the stack for temp variables, to start with I find it simpler to use the 144 bytes of direct page variables which are accessible with shorter instructions (the other 112 bytes of direct page are used for I/O registers).  Using the stack (which allows for reentrant and recursive routines) can be learned later." CreationDate="2011-03-31T05:15:24.200" UserId="1322" />
  <row Id="18599" PostId="12320" Text="+1 for praising the 6809!" CreationDate="2011-03-31T06:47:28.283" UserId="2064" />
  <row Id="18600" PostId="7014" Text="I must also mention that I have ordered boards from DorkbotPDX. They turned out quite nice. Laen even spotted a problem with a board and spent the time to explain what I had done wrong in Eagle. Great service and great pricing. Would recommend DorkbotPDX to anyone." CreationDate="2011-03-31T07:16:52.130" UserId="1575" />
  <row Id="18601" PostId="5463" Text="I concur with Yann, it's very personal. I like the Xilinx tools more, but opinions vary wildly and are quite strong. Just download both toolsets (they are free!) and implement a basic VHDL/Verilog design and simulate it. It should give you a good idea of what you're up against." CreationDate="2011-03-31T07:52:16.607" UserId="1802" />
  <row Id="18602" PostId="12279" Text="Sheer Luck? In general while the computer (== USB host) ground and the scope ground could be the same, you have no guarantee that they are." CreationDate="2011-03-31T07:56:54.357" UserId="1802" />
  <row Id="18603" PostId="12302" Score="1" Text="@Sauron My advice is don't pick MSP430 if you're a beginner. The official tools are good, but the free support you'll find online doesn't match up to PIC/AVR" CreationDate="2011-03-31T09:01:41.693" UserId="566" />
  <row Id="18604" PostId="12345" Score="2" Text="How did you get a PWM signal that represents up to 20kHz without a very high frequency PWM in the first place?" CreationDate="2011-03-31T09:06:44.843" UserId="2110" />
  <row Id="18605" PostId="5435" Text="I have bought two kits myself, a spartan II (older) and recently a spartan 6. The most light I can shed on you is ask yourself some key questions. &#xD;&#xA;&#xD;&#xA;1.) What do you want to do with the kit? (Do you want to just turn it on and flash some LEDs? This is what most working engineers do because they have no time IMO.)&#xD;&#xA;&#xD;&#xA;2.) Do you plan to apply it to a specific task? (Do you want to put it on your resume?)&#xD;&#xA;&#xD;&#xA;3.) Do you want the latest and greatest or do you want to learn about something more in practice?&#xD;&#xA;&#xD;&#xA;Not that I have any real world data with regards to the spartan 3/6, but generally the ol" CreationDate="2010-10-22T13:34:32.120" UserId="1670" />
  <row Id="18606" PostId="12252" Text="Oh, there are loads of datasheets available, its from Vishay: http://www.vishay.com/ir-emitting-diodes/list/product-81011/" CreationDate="2011-03-31T09:39:07.887" UserId="3049" />
  <row Id="18607" PostId="12348" Text="Hey Martin, I have to say I'm not particularly hot on this topic. But from your answer I guess you mean I could use Frequency Modulation on the audio signal, merge that onto the DC lines, and then decode the FM signal at the other end in order to get the audio out again?" CreationDate="2011-03-31T10:04:40.953" UserId="3670" />
  <row Id="18608" PostId="12348" Text="Yes, you could use FM or AM (analogue modulation) with a carrier that wasn't necessarily RF although needs to be higher than the audio. Or there are digital [modulation](http://en.wikipedia.org/wiki/Modulation) techniques, or combinations of the two." CreationDate="2011-03-31T10:12:46.813" UserId="2110" />
  <row Id="18609" PostId="12345" Text="@Martin, using Nyquist, the PWM frequency is about 50kHz." CreationDate="2011-03-31T10:30:26.790" UserId="1225" />
  <row Id="18610" PostId="12347" Text="Do you mean `pure-sine` vs `modifed-sine` inverters? " CreationDate="2011-03-31T10:31:01.803" UserId="2234" />
  <row Id="18611" PostId="12345" Score="2" Text="@Thomas, Fine, so you need an active low pass filter with a fairly steep roll off." CreationDate="2011-03-31T10:32:24.160" UserId="2110" />
  <row Id="18613" PostId="12351" Score="1" Text="I got an an answer from the manufacturer: http://www.wattflyer.com/forums/showpost.php?p=797303&amp;postcount=11 of the DC-DC converter that the grounds of both sides can not be connected together, so I'll have to keep them isolated. Maybe I'll isolate the car body from the primary circuit too, put thick negative wire to all car's devices and be completely sure nothing will make the grounds touch." CreationDate="2011-03-31T12:19:49.860" UserId="1691" />
  <row Id="18614" PostId="12291" Text="You might consider splitting this into 2 questions: &quot;Why would I ever use the demo board (development board) for some company's MCU (rather than building things myself out of individual chips)?&quot; and &quot;When would I ever use a PSoC (rather than some other company's MCU)?&quot;." CreationDate="2011-03-31T12:26:32.423" UserId="813" />
  <row Id="18615" PostId="12291" Text="@Rick - The fact that a college has development kits is almost totally decoupled from the potential to integrate one of these chips into a product.  Try this search: http://www.findchips.com/avail?part=CY8C5" CreationDate="2011-03-31T12:42:43.670" UserId="857" />
  <row Id="18616" PostId="12332" Score="1" Text="Why not use an AC power extension lead, and move the physical charger?" CreationDate="2011-03-31T12:42:56.773" UserId="2141" />
  <row Id="18617" PostId="2112" Text="I hear that some experimental musicians like the [Gainer I/O module](http://gainer.cc/), which is now available at SparkFun." CreationDate="2011-03-31T12:45:05.043" UserId="813" />
  <row Id="18619" PostId="5498" Text="@Kortuk - A computer *should* not do it.  Some probably can, though." CreationDate="2011-03-31T12:50:21.653" UserId="857" />
  <row Id="18620" PostId="12242" Text="Do fuses ever blow to the extent that the melting generates a plasma, that then conducts better than the wire itself?" CreationDate="2011-03-31T12:50:31.530" UserId="2141" />
  <row Id="18621" PostId="12358" Score="1" Text="@David - This answer could be improved a lot if you explained how you derive your numbers... (11-bit DAC, 60 db/octave $\rightarrow$ 40 KHz, etc.) " CreationDate="2011-03-31T13:24:02.230" UserId="857" />
  <row Id="18623" PostId="12274" Text="@stevenvh  Well your plates are huge.  It could also be 113 µm² plates 1 mm apart." CreationDate="2011-03-31T13:53:27.967" UserId="142" />
  <row Id="18624" PostId="12358" Text="@reemrevnivek -- You're right.  Maybe that's why I shouldn't be writing answers just after waking up in the morning...   I have to go into a meeting right now, but when I'm done I'll go back over the numbers and make sure they are correct.   " CreationDate="2011-03-31T14:16:46.760" UserId="3624" />
  <row Id="18626" PostId="12339" Text="Awesome, thanks for the info!" CreationDate="2011-03-31T14:18:09.830" UserId="3073" />
  <row Id="18627" PostId="12323" Text="Thanks for the Info.....but then what exactly do the people with CS degrees do? Kernal/Linux Modules and such?" CreationDate="2011-03-31T14:18:45.883" UserId="3073" />
  <row Id="18628" PostId="12360" Score="3" Text="I assume that it is, since corded drills exist...Is there a reason you don't want to use a corded drill?" CreationDate="2011-03-31T14:27:25.367" UserId="857" />
  <row Id="18630" PostId="12341" Score="2" Text="Where is V_OV?  Can you draw a circuit?" CreationDate="2011-03-31T14:38:28.440" UserId="142" />
  <row Id="18631" PostId="12358" Text="This is precisely why I said an RC filter probably wouldn't be an option. I was considering something else, like integrating the PWM ramp up, capturing the voltage and then resetting the ramp. I'll see if I can get an example working..." CreationDate="2011-03-31T14:38:44.583" UserId="1225" />
  <row Id="18632" PostId="12360" Text="Batteries as quite expensive so if you are near an outlet and mobility isnt the issue then you might as well plug it in. Also lets you keep working while your batteries are charging." CreationDate="2011-03-31T14:39:30.667" UserId="3089" />
  <row Id="18633" PostId="12360" Text="Corded drills do exist so in theory you'd imagine it is possible! But how you could make it compatible with the specs on a cordless drill is beyond my knowledge :(" CreationDate="2011-03-31T14:41:25.703" UserId="3089" />
  <row Id="18634" PostId="12360" Text="What is the rating of the battery?  Should say some value of Ah or Ampere hours." CreationDate="2011-03-31T14:50:44.797" UserId="2412" />
  <row Id="18635" PostId="5336" Text="Learn about transistors from a book like The Art of Electronics.  That starts with practical circuits and simple models, and then gets into more detail when you need it.  The textbook way of teaching transistors is terrible, and makes simple things seem amazingly difficult." CreationDate="2011-03-31T14:53:59.463" UserId="142" />
  <row Id="18636" PostId="2112" Text="Gainer is cool, but it doesn't let you mess around with the analog blocks on the PSoC in any meaningful way IIRC. I think you can control a PGA on all input channels however: http://gainer.cc/Tutorial/HowToUseGainerWithMaxMSP?action=dispimg&amp;im=maxmsp_help_patch.p.jpg" CreationDate="2011-03-31T14:54:55.073" UserId="207" />
  <row Id="18637" PostId="5498" Text="@reemrevnivek, this was discussed down below, every computer I have used will **not** deliver 1.8A. I have used a couple that would even shutoff the port if there was too capacitive of a load and you violate the input rush current." CreationDate="2011-03-31T14:58:40.630" UserId="230" />
  <row Id="18638" PostId="12309" Text="Are stuff like AVR's/PICS usually RISC or CISC?" CreationDate="2011-03-31T15:06:12.030" UserId="3073" />
  <row Id="18639" PostId="12364" Text="That was quick!  Do you have a source for this name (and, ideally, others I'll come across), or did it just 'click' for you?" CreationDate="2011-03-31T15:07:01.573" UserId="857" />
  <row Id="18640" PostId="12364" Text="@reemrevnivek: It's just something that I already knew... I'm not sure where I learnt it though! Probably a microchip datasheet or something." CreationDate="2011-03-31T15:09:17.157" UserId="2426" />
  <row Id="18641" PostId="12365" Score="1" Text="The current from the supply needs to be at least as high as the current the drill draws.  You will not &quot;fry the drill&quot; by building a supply that can source more current.  Loads determine current, not supplies." CreationDate="2011-03-31T15:10:53.130" UserId="142" />
  <row Id="18642" PostId="12351" Text="So this means that your converter is not in fact isolated and what's more it has a current sensing resistor in the ground path (so ground potentials will vary a little with the charging output current). As far as isolating your car is concerned I would rather isolate the secondary circuit and leave the primary as is." CreationDate="2011-03-31T15:12:35.313" UserId="659" />
  <row Id="18643" PostId="12364" Score="1" Text="The reason that Microchip don't spell-out the words TRI-STATE is that TRI-STATE® is a registered trademark of National Semiconductor." CreationDate="2011-03-31T15:14:19.853" UserId="2234" />
  <row Id="18644" PostId="12365" Text="You can if the motor stalls and has no protection in the circuit.  A battery has an internal resistance that would reduce the possible load on the device.  A non-certified source couldn't promise the same.  This could be like me attaching a LED with an internal 1k resistor up to a wall outlet and expecting it not to get damaged." CreationDate="2011-03-31T15:16:05.747" UserId="2412" />
  <row Id="18645" PostId="12364" Score="1" Text="@reemrevnivek: I think I learnt this when I first started learning pic assembler from this page: http://www.mstracey.btinternet.co.uk/pictutorial/progtut3.htm The code snippet second from the bottom has this comment: &quot;which is the address of the Tri-State register for PortA&quot;" CreationDate="2011-03-31T15:18:51.287" UserId="2426" />
  <row Id="18648" PostId="12358" Text="@reemrevnivek - I updated my answer with how I got the numbers.&#xA;@ThomasO - While integrating the PWM as you described might make the resulting waveform look all clean, it would still have a huge frequency spike at the PWM frequency.  So you'd still need the same nasty low pass filter." CreationDate="2011-03-31T15:34:43.540" UserId="3624" />
  <row Id="18649" PostId="12345" Text="@Thomas - Have you actually looked at your audio frequencies?  20 kHz is about the theoretical limit of audible signals, which probably isn't the standard you need to meet.  Voice, for instance, can be well represented entirely under 3 kHz." CreationDate="2011-03-31T15:41:22.540" UserId="857" />
  <row Id="18650" PostId="12367" Text="@jpc: My corded drill works with 230v :)" CreationDate="2011-03-31T15:45:16.547" UserId="2426" />
  <row Id="18651" PostId="12365" Text="@Matthew the LED would get killed by a 110V batter as easily. If the battery had any significant internal resistance it would cause serious problems in normal operation. They could put in some kind of overload protection but this not intended for use without human supervision." CreationDate="2011-03-31T15:46:07.250" UserId="659" />
  <row Id="18652" PostId="12367" Text="@BG100 Mine too. In our case my point is even more valid. :P" CreationDate="2011-03-31T15:47:55.050" UserId="659" />
  <row Id="18653" PostId="12365" Text="@jpc, that wasn't the point I was trying to make.  I was making the point that you don't know what the ratings of all of the internal points are.  If you build a supplemental powerfully without knowing what the circuit is you don't know for sure what the internal ratings are.  If something is built on the cheap it may not have the ability to limit current on its own and lower specification parts in the drive may be overwhelmed.  It could even be a burnt brush, overheated pot, blown fuse and many more things.  " CreationDate="2011-03-31T15:57:20.143" UserId="2412" />
  <row Id="18654" PostId="12365" Text="Many of those big battery packs have thermal limiters in them.  This could be part of the protection circuit for the device which helps limit current.  If you build your own power supply it may not have these same protections and could allow the device to get damaged.  Why do you think so many companies frown on people making their own batteries or other power supplies?" CreationDate="2011-03-31T15:57:48.957" UserId="2412" />
  <row Id="18655" PostId="12365" Text="@Matthew The frown at people because they want to make money selling these. Under normal operation the drill should not depend on any kind current limiting, especially not the thermal protection in the batteries. @endolith is right that loads determine currents. The only way in which this could fail would be if the motor stalled for a long period of time and the human operator did not release the switch." CreationDate="2011-03-31T16:04:22.293" UserId="659" />
  <row Id="18656" PostId="12365" Text="@jpc, that is more assumptions.  Too long could be half a second or 30 minutes.  You have no way of knowing especially on cheaper products.  And I agree that under normal running you shouldn't have to worry about the power supply being rated for more current than the device.  (But who uses power tools under normal conditions ;)" CreationDate="2011-03-31T16:09:53.830" UserId="2412" />
  <row Id="18657" PostId="12369" Text="I agree that you can't copyright facts, though you can copyright a presentation of facts. More importantly, they're not copyrighted, they're licensed." CreationDate="2011-03-31T16:10:06.707" UserId="857" />
  <row Id="18659" PostId="12372" Text="That's a cool website simulation thing!  Anyway, when you clean up the &quot;PWM Noise on the peaks&quot; you will find that you have lots of quantization noise (a.k.a. aliasing) on the output waveform.  I think that the noise that you have now, and the 1K/10nF filter on the output is hiding (but not removing) the quantization noise." CreationDate="2011-03-31T16:13:45.783" UserId="3624" />
  <row Id="18660" PostId="12371" Text="IANAL, but the font thing seems like a very similar issue.  They've placed a copyright/license on the source code, but I think that means it can be copied out of the datasheet." CreationDate="2011-03-31T16:14:48.967" UserId="857" />
  <row Id="18661" PostId="12325" Text="The monitor program sounds like it'd be very helpful. What book did u use to learn this? if you mind me asking...." CreationDate="2011-03-31T16:58:13.810" UserId="3073" />
  <row Id="18662" PostId="12369" Score="1" Text="A license implies copyright (or trademark or patent).  If the files are not copyrighted, then no license would be needed." CreationDate="2011-03-31T17:04:29.660" UserId="411" />
  <row Id="18663" PostId="12369" Text="A license implies nothing of the sort - it's simply an agreement between two parties.  While licenses such as GPL deal with restrictions and agreements on copyrighted materials it's not a necessary condition.  " CreationDate="2011-03-31T17:19:49.030" UserId="249" />
  <row Id="18664" PostId="12363" Text="No, $V_{SS}$ is -15V.  If the source were also at 0V, then $V_{GS}$ would be 0V, and you'd need to look at the datasheet for leakage current.  However, $V_{GS}$ is somewhere between 0V and 15V, so the current is not available directly from the datasheet." CreationDate="2011-03-31T17:23:07.467" UserId="857" />
  <row Id="18665" PostId="12369" Text="@AngryEE - TI and Atmel both have decent licensing/copyright (take your pick, or choose something different) policies, as evidenced by MSPGCC, the Stellaris headers, Atmel's avr-gcc and avr-libc, etc.  I guess I'm pointing a finger at Microchip.  " CreationDate="2011-03-31T17:39:27.867" UserId="857" />
  <row Id="18666" PostId="12374" Score="1" Text="Please don't just paste links to Instructables.  Not all of us have subscriptions, and as such, it's a pain to work with (they're always urging you to 'Go pro!' so you can view the community-contributed content).  I navigated the morasse, and that one is about a guy who hooked up a 12V, 1A wall-wart in place of his old battery by soldering two wires, and got crappy torque but a spinning drill as a result." CreationDate="2011-03-31T17:42:05.977" UserId="857" />
  <row Id="18667" PostId="12369" Text="I'm using Stellaris right now - their restrictions against 'viral' GPL licenses rub me the wrong way, but apply only towards the case that you're required to redistribute their headers when coupling their source with GPL source. It's the worst I've seen so far, but I haven't looked at Microchip.  Regardless, the PICs are so simplistic that I wouldn't think it'd be a big deal to recreate the header files (but I'm not going to be the first!)." CreationDate="2011-03-31T18:00:00.320" UserId="249" />
  <row Id="18668" PostId="12323" Text="@Sauron, with your experience with kernel/Linux modules, you could take on an embedded Linux project pretty easily.  For example, one of my projects I am currently working on is to modify a port of Android for a BeagleBoard (beagleboard.org) clone, and my past work with Linux is very valuable.  The ARM code is actually cross-compiled on a Linux laptop running Ubuntu." CreationDate="2011-03-31T18:05:11.440" UserId="1322" />
  <row Id="18669" PostId="12052" Text="@AndrejaKo Using KVL around the loop after redrawing the circuit solved it for me. Thanks!" CreationDate="2011-03-31T18:29:14.980" UserId="3594" />
  <row Id="18670" PostId="12341" Score="2" Text="$V_{ov}$ is usually the symbol for overdrive voltage and is given by $V_{ov}=V_{GS}-V_t$ where $V_{GS}$ is gate-source voltage and $V_t$ is threshold voltage." CreationDate="2011-03-31T18:33:47.787" UserId="3635" />
  <row Id="18671" PostId="12376" Text="This is assuming that the FET is a MOSFET or, if it is a JFET, that the gate-source junction is not forward biased." CreationDate="2011-03-31T18:40:07.343" UserId="3635" />
  <row Id="18672" PostId="12348" Score="1" Text="Martin has a point about the DC supply voltage variation possibly leaking into your audio signal. However, I disagree with the reasoning that lower frequencies will be attenuated more by the shunt capacitance on the DC supply line. Capacitive reactance (i.e. impedance) is inversely proportional to frequency. Therefore as frequency increases, the impedance decreases and the capacitance will effectively short the high frequency signal to ground. That is to say, it will attenuate high frequencies and not attenuate low frequencies." CreationDate="2011-03-31T19:08:52.683" UserId="3635" />
  <row Id="18673" PostId="12341" Text="$V_t$ is the parameter that needs to be retrieved from the datasheet." CreationDate="2011-03-31T19:20:17.223" UserId="857" />
  <row Id="18675" PostId="12348" Text="Adam, you are right you would lose the high frequencies more than the low. I was thinking of the high ESL of large electrolytics but that wouldn't come in at audio frequencies." CreationDate="2011-03-31T19:27:02.693" UserId="2110" />
  <row Id="18676" PostId="12376" Text="I should also note that the drain current equation written above would also need to be adjusted if the device were a JFET." CreationDate="2011-03-31T19:28:14.180" UserId="3635" />
  <row Id="18677" PostId="11918" Text="That's a pretty quirky bank-switching method. Do you know of any particular systems where this exact method was used? (The bank-switching methods I am familiar with are slightly different from and perhaps even more quirky than this method -- usually the external latch grabbed bits from the data bus rather than the address bus)." CreationDate="2011-03-31T20:13:13.433" UserId="813" />
  <row Id="18678" PostId="12309" Text="@sauron they are RISC, i don't know of any CISC cores in microcontrollers." CreationDate="2011-03-31T20:23:00.597" UserId="1438" />
  <row Id="18679" PostId="11822" Score="1" Text="@200ok404notfound: Yes, your description of interleaved memory is valid -- I hesitate to say it is &quot;right&quot; only because bank switching is just as valid.&#xA;&#xA;You are describing [interleaved memory](http://en.wikipedia.org/wiki/interleaved_memory).&#xA;&#xA;W5VO and jpc and supercat are describing [bank switching](http://en.wikipedia.org/wiki/bank_switching).&#xA;&#xA;The Sojourner Mars rover and some TRS-80 Model 100 computers use bank switching between the 16 address pins of the 80C85 and the RAM; they never used interleaved memory.&#xA;&#xA;Both techniques have their place." CreationDate="2011-03-31T20:30:08.427" UserId="813" />
  <row Id="18680" PostId="12270" Text="Solved I just needed to wire my circuit gnd to the gnd pin of my usb port" CreationDate="2011-03-31T20:30:33.060" UserId="2824" />
  <row Id="18681" PostId="9798" Text="I didn't see any mention in the original post concerning doing the conversion in the most efficient manner possible. He has a thin client and an AC power supply, he wants to plug it into his car, and has only very basic electronics experience. Sometimes &quot;good enough&quot; *is* good enough!" CreationDate="2011-03-31T20:35:21.930" UserId="1293" />
  <row Id="18682" PostId="12369" Text="@AngryEE You are incorrect about this.  A copyright/trademark/patent/trade secret creates the prohibition of use.  The license is an agreement to remove the prohibition." CreationDate="2011-03-31T20:38:04.863" UserId="411" />
  <row Id="18683" PostId="12311" Text="@leonHeller, just giving a link does not qualify as an answer. A good answer should explain a solution and give links to source for more detailed information and attribution. This is currently a comment, please expand it and make it great!" CreationDate="2011-03-31T20:43:00.450" UserId="230" />
  <row Id="18684" PostId="12378" Text="@Beffa - Was this the kind of answer you wanted?  The other answers are all very different...." CreationDate="2011-03-31T20:45:00.633" UserId="857" />
  <row Id="18685" PostId="12363" Text="@reemrevnivek The DC current through RG would have to pass through the gate, so you'd need to look at a datasheet to find out the gate resistance, no?" CreationDate="2011-03-31T20:53:01.590" UserId="142" />
  <row Id="18686" PostId="12248" Text="@Beffa - Wrong.  There is significant, controlled resistance.  It's usually less than 1 $\Omega$ for a typical fuse, and *always* greater than zero (otherwise the fuse wouldn't blow).  You can measure the voltage across it to find the current delivered to your circuit, but as [endolith](http://electronics.stackexchange.com/questions/12248/#12261) pointed out, it won't be constant wrt. temperature and thus to current.  You'd need a non-linear function (or lookup table...) to use a fuse as a current-sensing resistor; see my answer for more info." CreationDate="2011-03-31T20:53:06.463" UserId="857" />
  <row Id="18687" PostId="12345" Text="@reemrevnivek Depending on your application, &lt; 3khz could be entirely unacceptable.  You can get the gist of a voice in this range, but to say it can be really encoded in this range is not correct." CreationDate="2011-03-31T20:55:21.290" UserId="3424" />
  <row Id="18688" PostId="12377" Text="Feel free to select this as the answer to your own question.  " CreationDate="2011-03-31T20:56:26.103" UserId="857" />
  <row Id="18690" PostId="12380" Score="1" Text="That article is pretty crazy... " CreationDate="2011-03-31T21:04:33.447" UserId="857" />
  <row Id="18691" PostId="12369" Text="@markrages - I think we fundamentally agree and I'm willing to concede, but to put it more generally a license implies s ownership over property - intellectual or physical.  In this case the argument by TI et. al. would be that the hold a copyright and thus you must agree to their license.  I'm not sure legally whether the header files qualify for copyright but I'm not a lawyer.  Trade secrets, however, are not at all governmentally-protected. If you manage to acquire trade secrets you can do whatever you want with them as long as you don't break an NDA, etc." CreationDate="2011-03-31T21:09:31.573" UserId="249" />
  <row Id="18692" PostId="11918" Text="@davidcary: I don't know the exact details of how arcade games were built, but having 32K of bankable memory was a common pattern.  As for using address instead of data, that was a very common technique for Atari 2600 cartridges (which did not have access to a read-write signal) and for Apple II hardware.  The Atari 2600 cartridge port includes D0-D7, A0-A12, VDD, VSS, and nothing else.  No clocks, read-write controls, or anything.  The internal hardware on the 2600 is enabled when A12 is low (regardless of other address bits), so cartridges have 4K of address space." CreationDate="2011-03-31T21:20:32.673" UserId="3123" />
  <row Id="18693" PostId="11918" Text="@davidcary: Of the cartridges larger than 4K, about 99% of them use addresses 1FF8-1FF9 to switch between two banks (if 8K), or 1FF6-$1FF9 to switch among four (if 16K). Some cartridges have internal RAM, which normally uses different addresses for reading and writing (most such carts 1000-107F for writing and 1080-10FF for reading). I designed a cart for the 2600 which supports reading and writing at the same address; it also allowed hires pixel-plotting to be done in 3 instructions. I built a few prototypes, but someone else came up with a much cheaper way to add RAM to a 2600 cart." CreationDate="2011-03-31T21:24:07.317" UserId="3123" />
  <row Id="18694" PostId="11918" Text="@davidcary: The approach of using addresses to control functions and ignore the data lines was also popular in Apple II hardware.  If one decodes addresses 7Cxx to strobe a latch which grabs 8 bits off the data bus, setting the latches will require two instructions (one to load the data into a register, and one to store it).  If one has the latching circuit grab from A0-A7, one can set the latches with one instruction (simply read the address and ignore the result).  Alternatively, one can use an 8-bit addressable latch chip and have 16 addresses which set or clear one bit each." CreationDate="2011-03-31T21:29:54.707" UserId="3123" />
  <row Id="18695" PostId="12205" Text="So I just finished wiring all of this up, and it seems like it's working (the voltage measurements are.. kinda weird) but, when I turn the volume all the way down, there's a very low frequency humming noise that wasn't there before. I tried putting in a 100k resistor, and the humm was there anyways. Any idea on what could be causing this? Might it be harmful? " CreationDate="2011-03-31T21:34:16.763" UserId="3634" />
  <row Id="18696" PostId="12205" Text="Well, I actually just turned the truck back on and I'm hearing alternator wine. Looks like this is a ground loop... does that sound logical? If so, I already have a 2-channel ground loop isolator that I installed when I hacked into my stereo to allow my ipod to play through it - couldn't charge the iPod at the same time. Could I relocate that to between the headunit and amplifier? Or should I leave it - is it possible to have 2 ground loops? " CreationDate="2011-03-31T21:46:41.307" UserId="3634" />
  <row Id="18697" PostId="12379" Score="1" Text="Is there a question in there?" CreationDate="2011-03-31T21:54:45.303" UserId="319" />
  <row Id="18698" PostId="12205" Text="And my truck just hit 18 volts going down the highway! I turned the radio off, put the truck in neutral and turned it off. Turned it back on and its staying at 14. Possibly still a ground loop? Is that a symptom? " CreationDate="2011-03-31T22:06:43.700" UserId="3634" />
  <row Id="18699" PostId="12332" Text="I could but that would be a lot more bulky and I would still like to be able to take the charger on the go." CreationDate="2011-04-01T00:04:07.267" UserId="2809" />
  <row Id="18700" PostId="12341" Text="What text are you using?" CreationDate="2011-04-01T00:28:59.927" UserId="3635" />
  <row Id="18701" PostId="12345" Text="@JoeMac  A standard phone call is encoded with 8-bit audio at a sample rate of 8 KHz.  But the antialising filter normally is set for a cutoff of 3 KHz (and a high pass filter cuts off everything below about 300 Hz).  So, for many speech applications, 3 KHz is just fine.  Higher does sound better, however, but doesn't add to the intelligibility." CreationDate="2011-04-01T00:49:38.550" UserId="3624" />
  <row Id="18702" PostId="8164" Score="1" Text="This is a great question. I hope someone can answer this. I am leaning towards &quot;no&quot;. At least nothing practical. Kortuk has provided a good response and he surely is correct that a magnetic analog to a transformer/inductor circuit can be constructed, but I am not sure this gets at the fundamental question that endolith is asking. (I have a few bones to pick with some of the points Kortuk makes and hopefully I can rebut them! @Kortuk, I mean no offense. But the magnetic flux does not need to be perpendicular to the wire loop in order for coupling to occur, for one thing.)" CreationDate="2011-04-01T00:55:11.683" UserId="3635" />
  <row Id="18703" PostId="12383" Score="1" Text="Look at the IC's datasheet for clues, and use a scope on the output signals to make sure they look like what you want them to look like. BTW, you are both incrementing and resetting count_aud when it equals 50000; use 'else'." CreationDate="2011-04-01T01:20:03.060" UserId="2531" />
  <row Id="18704" PostId="12384" Text="@Icarus if you do have the LM4550 on your board, definitely check out the general information link, since it's about the same chip" CreationDate="2011-04-01T01:46:33.760" UserId="3441" />
  <row Id="18705" PostId="12369" Text="Take a current example, Google has done similar by taking header files and removing comments and copyright to get past GPL and other licenses, so android can be used with proprietary files/headers. This has brought google some legal trouble. I would have to agree with AngryEE, that writing your own would be the safest bet." CreationDate="2011-04-01T04:14:19.217" UserId="2060" />
  <row Id="18706" PostId="12115" Text="So whats the size of my hex file ? I get the following details while i check my file..&#xA;text - 13858, data - 926, bss - 1043 dec - 15927, hex - 3dd3" CreationDate="2011-04-01T04:56:57.600" UserId="3602" />
  <row Id="18708" PostId="12348" Text="OK that makes sense. Upon further discussion with a friend who is better at this than me, I have more concerns now about reflection due to impedance mismatches between the generator and the inverter, and the noise coming from the brush-based generators. Guess I need to test this out, and then see if these issues can be overcome." CreationDate="2011-04-01T08:58:28.710" UserId="3670" />
  <row Id="18709" PostId="12390" Score="1" Text="Yes, you answered your question correctly for yourself." CreationDate="2011-04-01T10:41:57.917" UserId="2636" />
  <row Id="18710" PostId="12390" Text="Bear in mind that transformers are rated for a.c. rms and fully loaded. Once you regulate and smooth, you get close to the peak voltage (minus diode drops), and will probably be 10% higher than that for small current loads on a small transformer (less for larger transformers, see the regulation figure)." CreationDate="2011-04-01T10:47:16.773" UserId="2110" />
  <row Id="18711" PostId="12390" Text="Rectify it baby... http://en.wikipedia.org/wiki/Rectifier" CreationDate="2011-04-01T10:52:44.483" UserId="2157" />
  <row Id="18713" PostId="12389" Text="	&#xA;Thanks for your reply. I have also looked at the ADF4002, and was thinking about starting by using it as frequency divider, by: Feeding RF to RFin, setting the N-counter and configure the MUX output as &quot;N-Divider output&quot;. Then I should see the divided frequency on MUX output. But if I understand you correct, the best way would be to use the CP output as tune input on the VCO? " CreationDate="2011-04-01T12:06:53.417" UserId="3041" />
  <row Id="18714" PostId="12389" Text="@JakobJ Exactly, but of course you have to filter the output from charge pump by lowpass filter. It can be passive RC filter but it needs some care. Look into some basic PLL design literature or use free simulation tools from the vendors, like [this one](http://forms.analog.com/form_pages/rfcomms/adisimpll.asp)." CreationDate="2011-04-01T12:18:15.790" UserId="2636" />
  <row Id="18715" PostId="12393" Text="Thanks for the schematic BG100. I see you seen Avatar. It was awesome." CreationDate="2011-04-01T12:59:16.020" UserId="2824" />
  <row Id="18716" PostId="12393" Score="1" Text="@BG100, sorry but this is a common error. 12V a.c. into a bridge does not product 12V d.c. More like 17V pk (12 * 1.414)" CreationDate="2011-04-01T13:05:19.383" UserId="2110" />
  <row Id="18717" PostId="12393" Text="Sorry I've been forced onto this project. I'm on a steep learning curve here.  So which one of these rectifiers will do the job for me. http://www.maplin.co.uk/bridge-rectifiers-19088" CreationDate="2011-04-01T13:08:49.833" UserId="2824" />
  <row Id="18718" PostId="12393" Text="Also whats PIV and RMS" CreationDate="2011-04-01T13:09:48.833" UserId="2824" />
  <row Id="18719" PostId="12374" Text="@reemrevnivek We're all in the same boat with instructables.  Is there an alternative?  Can we make one?" CreationDate="2011-04-01T13:27:14.127" UserId="249" />
  <row Id="18720" PostId="12393" Text="@Martin: Absolutely right... I'll edit and correct. Thanks." CreationDate="2011-04-01T13:27:26.500" UserId="2426" />
  <row Id="18721" PostId="12393" Text="@Ageis: They will probably all be suitable. As I don't know the details of what you're going to be powering with your supply, I would go for something in the middle. I suggest Maplins order code: AQ98G (the maplins web site is very poor for specs, so it's difficult to compare!)" CreationDate="2011-04-01T13:35:27.327" UserId="2426" />
  <row Id="18722" PostId="12393" Text="@Ageis: PIV = Peak Inverse Voltage - your rectifier needs to withstand at least 17v (see Martin's comment above). RMS = Root-Mean-Squared. This is the conventional way of measuring AC. A 12V rms voltage will produce the same power in a resistor as a 12V dc voltage. In stevenvh's answer, both waveforms have 12V rms voltage, but the first has an average over time of zero and the second (rectified) has an average of 10.8V. Both reach 17V at the positive peak." CreationDate="2011-04-01T13:36:01.243" UserId="2234" />
  <row Id="18723" PostId="12393" Text="@Ageis: RMS means Root Mean Square. It's a bit tricky to understand this if you don't know a lot about AC waveforms. It's basically the average voltage of AC rather than the peak voltage." CreationDate="2011-04-01T13:36:51.900" UserId="2426" />
  <row Id="18724" PostId="12390" Text="Same exact application, somewhat different question: http://electronics.stackexchange.com/questions/515/how-to-convert-ac-to-dc" CreationDate="2011-04-01T13:44:01.800" UserId="142" />
  <row Id="18725" PostId="12393" Text="LOL I don't think I make it as a sparky then LOOOL. I'm training under city and guilds 2330 lv2. It's only a microcontroller and an lcd so I wouldn't think it will draw that much current. Do I only need one? In the schematic it looks like i need 4" CreationDate="2011-04-01T13:47:27.507" UserId="2824" />
  <row Id="18727" PostId="12393" Text="@Ageis: Don't look too much into that... I just picked a mid range one from the list which will be more than adequate. You only need one. The 4 diodes are surrounded by a dotted box which represents your component. An alternative would be to buy 4 separate rectifier diodes and make your own bridge, but this is easier. " CreationDate="2011-04-01T13:53:01.350" UserId="2426" />
  <row Id="18728" PostId="12400" Text="What do you mean for complex circuits?" CreationDate="2011-04-01T14:06:42.717" UserId="938" />
  <row Id="18729" PostId="12374" Text="Yes, that's basically what we're doing with this Stack Exchange!  If you described the process presented in the Instructable here, linking to it for attribution, we wouldn't have to follow the link. (In this case, it's (1) Determine polarity on the wall wart and on the drill motor (2) Solder the wires together (3) There is no step three)." CreationDate="2011-04-01T14:10:17.630" UserId="857" />
  <row Id="18730" PostId="12400" Text="I mean at least all analog elements (almost) and non-erroneous simulating big ones." CreationDate="2011-04-01T14:10:29.170" UserId="1392" />
  <row Id="18731" PostId="10974" Text="[layer stack-up text](http://techref.massmind.org/techref/app/pwb_design_flow.htm#stack_up_text) (also called a &quot;layer name block&quot;)." CreationDate="2011-04-01T14:14:18.357" UserId="813" />
  <row Id="18732" PostId="12379" Text="@Kellenjb - Nope." CreationDate="2011-04-01T14:16:07.090" UserId="2064" />
  <row Id="18733" PostId="12400" Score="1" Text="This is possibly duplicated with [What are the freeware SPICE simulators available?](http://electronics.stackexchange.com/questions/1206/what-are-the-freeware-spice-simulators-available)" CreationDate="2011-04-01T14:31:10.200" UserId="938" />
  <row Id="18734" PostId="12400" Score="1" Text="@oneat - Do you need complex digital simulation as well as analog (Through Verilog AMS or VHDL-AMS), or would you prefer a schematic based simulator?" CreationDate="2011-04-01T14:31:41.130" UserId="857" />
  <row Id="18735" PostId="12400" Text="@Daniel Grillo - Simulation $\neq$ SPICE!" CreationDate="2011-04-01T14:34:08.287" UserId="857" />
  <row Id="18736" PostId="12400" Score="1" Text="@reemrevnivek, I can't understand. SPICE means Simulation Program with Integrated Circuit Emphasis. Why Simulation ≠ SPICE?" CreationDate="2011-04-01T14:39:46.090" UserId="938" />
  <row Id="18737" PostId="12115" Text="You will need 13858+926=14784 bytes of Flash and 1969 bytes of RAM (+ some space for stack space). I guess that means a part with at least 16kB and 4kB RAM (3 would be enough but that may be hard to find)." CreationDate="2011-04-01T15:04:11.627" UserId="659" />
  <row Id="18738" PostId="12115" Text="You may have trouble fitting into the RAM of the ATmega32. You should either lower the RAM usage, carefully check stack space usage or switch to a part with 4k RAM." CreationDate="2011-04-01T15:07:59.490" UserId="659" />
  <row Id="18739" PostId="6843" Text="folks here is a reference to the source of my comment, &quot;dBm indicates a reference signal producing 1 mW into a 600 ohms load&quot; http://www.dspguide.com/ch14/1.htm" CreationDate="2011-04-01T15:12:03.573" UserId="1397" />
  <row Id="18740" PostId="12382" Text="National used to have a habit of registering just about every term in the English language. Some of the more dubious ones like 'National Anthem' and 'Damn Fast' have disappeared (unsurprisingly) from [their list](http://www.national.com/analog/trademark) but TRI-STATE is still there!" CreationDate="2011-04-01T15:22:20.153" UserId="2234" />
  <row Id="18741" PostId="9456" Text="@Fake Name: My understanding is that 	&#xA;ExpressSCH (schematic) and ExpressPCB (layout) can be linked together, so you don't have to manage your netlists yourself." CreationDate="2011-04-01T15:33:52.953" UserId="813" />
  <row Id="18742" PostId="9456" Text="I [hear that the company used to convert from ExpressPCB to Gerber for a $60 fee](http://opencircuits.com/PCB_Manufacturers#Sunstone_Circuits_aka_PCB123). Is there a page on the ExpressPCB (aka Sunstone) website that has the latest price?" CreationDate="2011-04-01T15:38:06.147" UserId="813" />
  <row Id="18743" PostId="12404" Text="I think its great that your are implementing a build server.  Unfortunately, I have no experience with the Keil development system so I can't really help you out.  I would like to encourage you to post a solution if you when you get it worked out." CreationDate="2011-04-01T15:43:24.497" UserId="529" />
  <row Id="18744" PostId="12400" Score="1" Text="@Daniel - Mathematically, SPICE $\subset$ Simulation.  In prose, there are a wide variety of circuit simulators available, and SPICE is just one of the most popular simulator frameworks.  " CreationDate="2011-04-01T15:47:32.667" UserId="857" />
  <row Id="18745" PostId="12379" Score="1" Text="@kellenjb, @stevenvh, flag for moderator attention!" CreationDate="2011-04-01T16:01:31.680" UserId="230" />
  <row Id="18746" PostId="12409" Score="1" Text="Are you assembling the PCB yourself? Have you tried SMT soldering before?" CreationDate="2011-04-01T16:07:57.480" UserId="2454" />
  <row Id="18747" PostId="8164" Score="1" Text="It occurred to me that my previous comment might not have been totally fair... or clear... The _perpendicular component_ of the B field is what induces emf in a loop of wire. So as long as the field is not exactly parallel to the plane of the loop, there will be coupling. In a transformer, this point is kind of moot since the field is assumed to be perpendicular to each loop in the winding. Also, just a thought: it might be worth asking this question on the physics forum." CreationDate="2011-04-01T16:10:35.417" UserId="3635" />
  <row Id="18748" PostId="12410" Score="1" Text="I agree but if the OP is new to SMD soldering he or she may try to start with 1206." CreationDate="2011-04-01T16:19:26.007" UserId="659" />
  <row Id="18749" PostId="12409" Text="I am actually going to send these to an assembly company " CreationDate="2011-04-01T16:22:38.220" UserId="2968" />
  <row Id="18750" PostId="1207" Text="@davr You are right. I took the liberty to edit the post and remove the SPICE mention so it will not confuse people." CreationDate="2011-04-01T16:23:03.447" UserId="659" />
  <row Id="18752" PostId="1217" Text="ngspice is based on Spice 3f5 while most commercial offerings used the Spice 2 code as a base. This does not mean they are worse since the Spice 3 rewrite is not all roses. Back to the point: the most important difference is the change in specification of nonlinear components (POLYNOMIAL vs. normal equation) which breaks many models and treating node names as strings (in the original Spice 2 they had to be numbers and were compared numerically `0 == 00`)." CreationDate="2011-04-01T16:28:06.067" UserId="659" />
  <row Id="18753" PostId="12400" Text="@reemrevnivek, Ok, now I understood. Thanks." CreationDate="2011-04-01T16:31:56.257" UserId="938" />
  <row Id="18754" PostId="12400" Text="What kind of circuits are you making? Different SPICE engines are better at certain kinds of applications." CreationDate="2011-04-01T16:46:29.550" UserId="2578" />
  <row Id="18755" PostId="12408" Text="Am I the only one who doesn't see the Latex code displayed properly formatted?" CreationDate="2011-04-01T16:59:55.780" UserId="2064" />
  <row Id="18756" PostId="12374" Text="@rem I wouldn't call a stack exchange a good place to put writeups of projects.  I would like a free and open version of instructables - something like Github + documentation." CreationDate="2011-04-01T17:41:54.527" UserId="249" />
  <row Id="18757" PostId="12415" Text="wow, i did not know there were so many different kinds of capacitors. thanks for this useful chart" CreationDate="2011-04-01T18:02:57.127" UserId="2968" />
  <row Id="18758" PostId="1207" Text="It was definitely a good idea to remove the misleading reference from this answer, but the question is about SPICE - Why is an answer that doesn't even mention SPICE so highly voted?" CreationDate="2011-04-01T18:37:26.060" UserId="857" />
  <row Id="18759" PostId="12408" Text="@stevenvh Not work for me too." CreationDate="2011-04-01T18:40:02.393" UserId="207" />
  <row Id="18761" PostId="12205" Text="@kavisiegel Sorry, I somehow missed your replies.  Car power systems are notoriously noisy environments, and that's getting into your sound somehow.  It's probably not a ground loop.  There are two ways it could be getting in:  Noise on the power, and EMI getting into the audio signals themselves-- or both.  Try powering the system off of a separate battery to confirm or eliminate the truck power system as the source.  After that, it's all filtering and shielding." CreationDate="2011-04-01T18:48:10.697" UserId="3624" />
  <row Id="18762" PostId="12415" Text="@umps - 99.9% of the capacitors used in my experience are electrolytic, ceramic, and tantalum.  Yes, they all rate as some form of 'bad' on this chart, but the judgements applied here are definitely subjective." CreationDate="2011-04-01T18:48:41.157" UserId="857" />
  <row Id="18763" PostId="12411" Text="0603 are not just the cheapest, they seem to be generally preferred by reworkers/assembly houses as the ideal size.  I don't think that 0805 is any easier than 0603." CreationDate="2011-04-01T18:49:17.243" UserId="857" />
  <row Id="18764" PostId="12408" Text="Works for me. The latex is only 2 places." CreationDate="2011-04-01T18:49:41.050" UserId="230" />
  <row Id="18765" PostId="12382" Text="@MikeJ-UK: Tri-state is listed as a live trademark according to the USPTO web site, so I would certainly not recommend anyone selling chips describe the outputs as &quot;tri-state&quot;; the trademark may or may not be enforceable given the common generic usage, but that doesn't mean I'd want to spend the legal fees to find out." CreationDate="2011-04-01T18:52:23.047" UserId="3123" />
  <row Id="18766" PostId="12412" Text="@Mark with header tags and some formatting this post could go from good to great. You touched on everything I wanted to note, and very well, but the way the post is formatted fewer people will read it as its length is prohibitive, if you give headers with each section of what you are discussing people will jump to the juicy bit that suites them and your number of +1s will increase a lot. Not from me of course, as you already earned it." CreationDate="2011-04-01T18:53:04.557" UserId="230" />
  <row Id="18767" PostId="12400" Text="@whatsisname - ....And different simulators are better at an even broader variety of applications! " CreationDate="2011-04-01T19:07:31.843" UserId="857" />
  <row Id="18768" PostId="12412" Text="@kurtuk I spit this one out in a rush, I'll clean up the formatting when i have some spare time (or feel free to edit it if you wish)." CreationDate="2011-04-01T19:19:02.553" UserId="1438" />
  <row Id="18769" PostId="12415" Score="2" Text="How current is your copy of the Art of Electronics?  Mine is about two decades old, and it seems to me that components generally have come a long way since then..." CreationDate="2011-04-01T19:21:47.287" UserId="3308" />
  <row Id="18770" PostId="12419" Text="Excellent information, thanks!" CreationDate="2011-04-01T19:27:35.860" UserId="3240" />
  <row Id="18771" PostId="12415" Text="@Toybuilder: Second edition, 1989. I'm glad you pointed this out. I think this chart is intended as a general guideline, not a comprehensive discussion. You can get &quot;NP0&quot; ceramic caps that are very stable with temperature--which goes against the &quot;poor&quot; rating given by H&amp;H, for example. A google search for &quot;dielectric comparison chart&quot; brings up a bunch of results. Definitely would be a good idea to check out other available resources." CreationDate="2011-04-01T19:28:52.577" UserId="3635" />
  <row Id="18772" PostId="12409" Score="1" Text="Talk to your assembler/CM first.  Most that I've worked with can and will happily source the generic passives for you.  They often purchase standard commonly used R's and C's in very large quantity.  You do need to tell them something like '0805 1% 50ohm resistor' or '0.1uF 0603 MLCC X7R capacitor'.  They will usually only stock commonly used values.  Things like tantalum caps, AL caps and precision or high power resistors you will likely have to source yourself." CreationDate="2011-04-01T19:33:53.990" UserId="1438" />
  <row Id="18773" PostId="12422" Score="2" Text="What features do you need?  Sine/Square/PWM/Saw/Triangle, frequency, etc.  " CreationDate="2011-04-01T19:38:31.350" UserId="857" />
  <row Id="18774" PostId="12417" Text="@AngryEE I don't see how using a RRC makes, the &quot;more difficult to produce and detect.&quot; It's all the same filter, no matter what the roll-off is. Besides, that still leaves the question of how the roll-off (other than at 1) affects things - e.g. why choose 0.35 instead of 0.55?" CreationDate="2011-04-01T19:48:02.917" UserId="2454" />
  <row Id="18775" PostId="12422" Text="Updated the question." CreationDate="2011-04-01T20:03:11.910" UserId="1293" />
  <row Id="18776" PostId="12021" Text="What phone firmware do you have that's not encrypted?  I suspect that the firmware binary file you have is actually an encrypted block to be decrypted and written by the bootloader on the phone." CreationDate="2011-04-01T20:19:34.737" UserId="857" />
  <row Id="18777" PostId="12426" Score="1" Text="You had to add 33 ohms to the USB data lines?  *And* caps and diodes?  Wouldn't that do terrible things to the USB eye diagram?" CreationDate="2011-04-01T20:35:07.643" UserId="1278" />
  <row Id="18778" PostId="9066" Text="Thank you for the photo. Looks like you are well on your way towards an awesome project. :-)" CreationDate="2011-04-01T20:47:51.927" UserId="813" />
  <row Id="18779" PostId="12384" Text="Thank you, although I was hoping there might be something simpler, like holding the reset down or some such! Will check out the links!" CreationDate="2011-04-01T20:53:20.480" UserId="3684" />
  <row Id="18780" PostId="12383" Text="Thanks, I'll check out the datasheet." CreationDate="2011-04-01T20:56:15.503" UserId="3684" />
  <row Id="18781" PostId="12381" Score="2" Text="It is not strictly speaking inefficient. It does not lose energy in the capacitors like a resistive divider would. A high current capacitive divider has large $\cos\varphi$ but that means reactive power and so no heating." CreationDate="2011-04-01T21:06:31.390" UserId="659" />
  <row Id="18782" PostId="12426" Score="1" Text="It wasn't bad.  This was USB 1.0, not version 2 or 3.  So the data rate wasn't bad.  If I remember correctly, the caps were only 22 pF and the diodes were &lt;1 pF.  While I was skeptical about 33 ohms, I saw the same resistors used in a TI MSP430 demo board schematic.  In the end, it works beautifully. " CreationDate="2011-04-01T21:08:05.290" UserId="3624" />
  <row Id="18783" PostId="12427" Text="Great answer!  +1 for the resistor labeling and array points, as well as the free nature of the SMT footprints.  I've always used &quot;DNP&quot; for &quot;Do Not Populate&quot;, but DNI works too. &lt;p&gt; However, I'm confused by your QFP/TQFP distinction.  The &quot;T&quot; in TQFP (and TSSOP) stands for *Thin*; I don't think this makes a significant difference when soldering." CreationDate="2011-04-01T21:25:30.293" UserId="857" />
  <row Id="18784" PostId="9070" Text="One resistor for each row driver pin, and one resistor for each column driver pin (in this case, 6 resistors) will work great, whether the software does row scanning or column scanning or both. Most [LED matrix array](http://opencircuits.com/PointLess_LED_Array) only put resistors on the column driver pins, or only put resistors on the row driver pins. (In this case, 3 resistors). That works OK as long as the software and the hardware agree on whether you are doing row scanning, or doing column scanning." CreationDate="2011-04-01T22:09:01.190" UserId="813" />
  <row Id="18785" PostId="12417" Score="1" Text="Smoother roll-off gives worse ISI for 2 reasons: (1) No one ever gets the local bit-clock exactly synchronized with the remote bit-clock. For a given error in the local bit-clock, smoother roll-off produces worse ISI. (2) Nice sharp edges between bits make it much easier (for humans looking at an o'scope) to detect where one bit ends and the next bit begins. Smoother transitions generally cause the local bit-clock to have worse synchronization error (than sharper transitions), leading to even worse ISI." CreationDate="2011-04-01T22:37:29.683" UserId="813" />
  <row Id="18790" PostId="10312" Score="1" Text="You could just give the fan 5 V and select a larger one to compensate for it spinning about half as fast." CreationDate="2011-04-01T23:26:04.423" UserId="1407" />
  <row Id="18791" PostId="12433" Text="Ah :( Is that because the internal structures of FPGAs and thus .bit files are usually trade secret? " CreationDate="2011-04-01T23:33:31.813" UserId="708" />
  <row Id="18792" PostId="12427" Text="You're right about QFP.  For some reason I tend to associate TQFP with smaller pin counts (32, 44) and the associated larger 0.8 and 1.0mm pitches and QPF (or PQFP) with 208, 240 pin packages and 0.5mm spacing.  I have updated my answer to be explicit." CreationDate="2011-04-02T00:11:59.400" UserId="2664" />
  <row Id="18793" PostId="12395" Text="I am not sure that I understand exactly where you are having difficulty, so I would like to ask some questions if I may... If the circuit were reduced to just R3 and D1 from 5V supply to ground, do you understand why it is okay to assume that D1 is on the drop across it is 0.6V? (It sounds like you get that part.) Next, add in R1, D2 and R2 (but leave out the capacitor). Is it clear to you why it still must be assumed that (a) diode D1 is on (with 0.6V across it), (b) that diode D2 is off and that (c) current is only flowing through R3 and D1? I'm running out of chars so I'll stop here for now" CreationDate="2011-04-02T00:28:02.757" UserId="3635" />
  <row Id="18794" PostId="12418" Text="Three phase DC motor? Edit: Nevermind, it's a stepper motor, right? Two phase?" CreationDate="2011-04-02T00:50:07.257" UserId="3635" />
  <row Id="18795" PostId="12437" Score="2" Text="so .. R1, D1 and R3 are basically just a biasing network for D2, so that the input signals don't have to overcome the usual forward diode drop in D2 on their own?" CreationDate="2011-04-02T01:11:36.060" UserId="740" />
  <row Id="18796" PostId="12115" Text="thanks for the help.. " CreationDate="2011-04-02T01:32:35.530" UserId="3602" />
  <row Id="18797" PostId="12435" Text="It's not the same for all microcontrollers; many have weak internal pullup or pulldown resistors that can be used for this purpose." CreationDate="2011-04-02T02:16:34.957" UserId="857" />
  <row Id="18798" PostId="12415" Text="@reem, polyester caps seem to be fairly common in dynamo powered vehicles (motorcycles, snowmobiles, etc).  Regarding everything being &quot;poor&quot;; the chart is notably missing a &quot;cost&quot; column." CreationDate="2011-04-02T02:37:15.020" UserId="1407" />
  <row Id="18799" PostId="12436" Text="Would you require a pullup/down resistor if you took the button out of the equation and just wanted a digital pin to always be high?" CreationDate="2011-04-02T02:49:00.980" UserId="708" />
  <row Id="18800" PostId="12438" Text="What if for some reason during internal initialization of the microcontroller or whatever, that the pin is briefly set to output mode. If it output 0, this would effectively short through the microcontroller and thus break something correct? What protection can I provide against that happening" CreationDate="2011-04-02T02:52:52.427" UserId="708" />
  <row Id="18801" PostId="12426" Text="Just curious. How did you generate this ESD &quot;zap&quot;? I mean, is there some predictable, consistent way to generate a zap?" CreationDate="2011-04-02T02:58:02.220" UserId="708" />
  <row Id="18802" PostId="12438" Text="This may depend on the micro but I believe most default to input on startup. If you want to be careful just add a resistor between the pin and power. Just have to make sure it doesn't have an adverse effect on anything it is connected to." CreationDate="2011-04-02T03:01:54.200" UserId="319" />
  <row Id="18803" PostId="8864" Score="1" Text="@reemrevnivek: The cost of producing 1 wafer's worth of chips is (roughly) constant. Yes, a cutting-edge 32 nm design has a lot of scrap. &quot;The same&quot; chip design printed 100 times larger (on a 3 um process) gives nearly 100% yield, but a given wafer will produce 1/10,000 as many chips, so the result is even more expensive per chip. BarsMonster seems to be pointing out that shrinking the design to some point in the middle -- such that most chips &quot;just barely&quot; work and quite a few don't work at all -- produces the most *good* chips per wafer, and so the lowest cost per chip." CreationDate="2011-04-02T03:41:54.867" UserId="813" />
  <row Id="18804" PostId="11516" Text="All *integrated* digital CMOS designs I've ever seen connect all the nFET substrates together. But is that really necessary? What happens when you build &quot;more complex logic&quot; out of individual discrete transistors, each of which has its own source tied to its own substrate?" CreationDate="2011-04-02T04:58:41.953" UserId="813" />
  <row Id="18805" PostId="12437" Text="I understand the voltage divider part and I see why it is 0.6V but I don't understand what you mean by adding polarizing voltage. I get that the voltage at the node joining C R_1 D_2 should be higher than 0.6V but I don't see why" CreationDate="2011-04-02T06:14:51.460" UserId="3688" />
  <row Id="18806" PostId="12395" Text="I understand until that point but I don't see why that would make the voltage at the node connecting C, D1, R1 higher than 0.6V so that D2 is on. Assuming that we have a square wave signal with a peak voltage of 0.4V, shouldn't that node be at 0.4V?" CreationDate="2011-04-02T06:19:23.573" UserId="3688" />
  <row Id="18807" PostId="12437" Text="@user3688 I tried to expand my answer. Let me know what if something remains unclear." CreationDate="2011-04-02T10:54:27.813" UserId="659" />
  <row Id="18808" PostId="12437" Text="@JustJeff Yup. They also have some effect on input impedance (lowering it from $10$ to $1\,\mathrm{k\Omega}$)." CreationDate="2011-04-02T10:56:14.580" UserId="659" />
  <row Id="18810" PostId="12444" Score="2" Text="@user3699, your question is not completly clear. Most of the issues that come about with up-sampling are how you actually do the upsampling. zero-order hold and an ideal lowpass filter will take care of the job well. Implementing that low pass filter is how you break things." CreationDate="2011-04-02T13:12:22.140" UserId="230" />
  <row Id="18811" PostId="12250" Text="Fuses are actually rated by their I2T value; take a look at datasheets for fuses and you can see how long they'll take to clear a fault of 'X' Amps (among other things). OT for this question, but fusing is actually a fairly complex thing when you get beyond the normal board-level and household type of applications. " CreationDate="2011-04-02T13:47:26.650" UserId="974" />
  <row Id="18812" PostId="12426" Score="1" Text="In the past I've used several methods to generate a zap.  By far the most reliable method was a static gun.  This is an expensive piece of gear made for this task.  I have also used push button piezoelectric BBQ grill lighters.  Not as predictable, but less than US$10.  But the zap's I was making a couple of weeks ago was simply normal ESD created due to the super low humidity here in Colorado.  Again, not as predictable but super abundant." CreationDate="2011-04-02T14:05:33.847" UserId="3624" />
  <row Id="18813" PostId="12429" Score="1" Text="That's what I get for listening to my colleague whine, &quot;We've scoured the globe and can't find anything equivalent!&quot; Well done sir." CreationDate="2011-04-02T15:15:01.110" UserId="1293" />
  <row Id="18814" PostId="12412" Text="@kortuk, name starts with an 'o'. I assumed you had, I was just sharing my view, both for you if you did not already know, but more for the community on the whole." CreationDate="2011-04-02T15:45:32.513" UserId="230" />
  <row Id="18815" PostId="12415" Text="@Nick - I don't see your point.  &lt;&lt;1% of all caps are used in dynamo powered vehicles. " CreationDate="2011-04-02T16:17:38.773" UserId="857" />
  <row Id="18816" PostId="10312" Text="@PICyourBrain - Just find a 5V fan!  That's the cheapest and easiest way to get power to the fan.  Digikey has 75 5V fans in stock right now, starting at a little under $5." CreationDate="2011-04-02T16:29:55.597" UserId="857" />
  <row Id="18817" PostId="12395" Text="I am going to need some extra space to write so I will post a new answer to continue this discussion. It's tough without drawing and redrawing and annotating the circuit but I'll try my best to explain." CreationDate="2011-04-02T17:00:51.547" UserId="3635" />
  <row Id="18818" PostId="12415" Text="Just a general thought, I would not assume that a rating of poor or whatever should be considered a condemnation of a particular type of cap. It's a general statement about a particular characteristic that applies to that given type of dielectric. Take electrolytics, for example. It's true, they are not stable over temperature. It's true, they are not super precision (find me a 1% or better electrolytic... for a &quot;reasonable&quot; price). And that is just fine if you're using it for supply decoupling. But you wouldn't use an electrolytic in a precision filter! That's all..." CreationDate="2011-04-02T17:56:12.170" UserId="3635" />
  <row Id="18820" PostId="12453" Text="Is this homework? If not, what is it for?" CreationDate="2011-04-02T19:24:16.460" UserId="2118" />
  <row Id="18821" PostId="12436" Text="Nope, you can pretty safely tie VCC to a pin if it is configured as an input.  Most uC's have high input resistance." CreationDate="2011-04-02T19:25:57.133" UserId="249" />
  <row Id="18822" PostId="12417" Text="I&quot;m glad someone can explain it better than I.  I majored in comm theory but havent touched it for years." CreationDate="2011-04-02T19:28:30.250" UserId="249" />
  <row Id="18823" PostId="12453" Text="@tyblu: No, not homework, I am just thinking of building a three-phase SMPS some time in the future, and want to know what will be my DC input voltage for the SMPS." CreationDate="2011-04-02T19:39:17.800" UserId="1691" />
  <row Id="18824" PostId="12397" Text="The problem is not why the voltage drop is 0.6V, it's why the input signal *doesn't* drop 0.6V across D2.  The interesting thing here is the coupling, not $V_d$." CreationDate="2011-04-02T20:07:01.653" UserId="857" />
  <row Id="18825" PostId="12454" Text="@Steve: are you sure it will be &quot;slightly less then 650V DC?&quot; Now I found [this graph](http://en.wikipedia.org/wiki/File:3_phase_rectification_2.png) which suggests that three-phase AC rectified with a full-wave rectifier will have voltage slightly lower then peak voltage of each phase, so that would be 325V. Or maybe I don't understand that plot correctly?" CreationDate="2011-04-02T20:07:29.797" UserId="1691" />
  <row Id="18826" PostId="12454" Text="@Steve that depends entirely on what your load current is and how much hold up cap you have on there" CreationDate="2011-04-02T20:29:27.963" UserId="1827" />
  <row Id="18827" PostId="12450" Text="Thanks for your answer this really helped understand things." CreationDate="2011-04-02T20:44:23.210" UserId="3688" />
  <row Id="18828" PostId="12454" Text="@miernik: You are correct. The voltage from neutral to + is +325vdc, and the potential from neutral to - is -325vdc. However they are not additive as I first said, because they interweave into one positive (with respect to negative) wave. Thanks for seeing that! Please see my edit." CreationDate="2011-04-02T21:34:03.417" UserId="3453" />
  <row Id="18829" PostId="11859" Text="Did you get it back together?" CreationDate="2011-04-02T22:20:10.207" UserId="3635" />
  <row Id="18830" PostId="12454" Text="@Steve: it seems we where both wrong, see the other answer which appeared." CreationDate="2011-04-02T23:23:20.000" UserId="1691" />
  <row Id="18831" PostId="12454" Text="[link](http://en.wikipedia.org/wiki/Diode_bridge)" CreationDate="2011-04-03T00:53:26.930" UserId="3453" />
  <row Id="18833" PostId="11844" Text="Would anyone else agree that these &quot;magic sinewaves&quot; look a lot like [pulse density](http://en.wikipedia.org/wiki/Pulse-density_modulation) or [sigma delta modulation](http://en.wikipedia.org/wiki/Delta-sigma_modulation)?" CreationDate="2011-04-03T01:05:07.227" UserId="3635" />
  <row Id="18834" PostId="12465" Text="Well, I'm no expert either but I'd assume as long as there are not &quot;loops&quot; in hardware(ie, serial), then less logic should always be better." CreationDate="2011-04-03T02:54:48.883" UserId="708" />
  <row Id="18836" PostId="12462" Score="1" Text="googling AVR FFT turns up some promising results.  The LEDs will draw far more power than your spectrum analysis." CreationDate="2011-04-03T04:03:54.450" UserId="2664" />
  <row Id="18837" PostId="11844" Score="1" Text="@Kellenjb, Don Lancaster has an extensive history as a well-known and well-respected EE, designer, and technical writer (1969-1996 in dead tree books, plus magazine columns). Employed by or contractor to: Apple, HP, Motorola, Adobe, Western Digital, etc. He _may_ be odd, but he's a smart odd." CreationDate="2011-04-03T04:44:04.940" UserId="2598" />
  <row Id="18838" PostId="12461" Text="headphone cables don't actually work for this, unless you burn/scrape off the insulation over it" CreationDate="2011-04-03T04:50:07.027" UserId="1870" />
  <row Id="18839" PostId="12465" Text="For your edit. Wow, I had forgotten how dense patent pdfs are. " CreationDate="2011-04-03T05:00:24.693" UserId="708" />
  <row Id="18840" PostId="12458" Text="@boomhauer This is the first time I've heard the term &quot;Magic Sinewaves&quot;, although I've been doing something similar for years.  What I've done is implement a &quot;First Order Delta-Sigma DAC&quot; in an FPGA.  That feeds a simple RC filter, and the output is a basic voltage between 0 and 3.3v.  It's a simple matter to generate the sine wave data and feed it into the DAC (which I've also done).  It won't be more efficient than PWM for some things, as the switching frequency is really high and the switching losses will be nasty-- but it works really well for other applications." CreationDate="2011-04-03T05:34:26.303" UserId="3624" />
  <row Id="18841" PostId="12470" Text="After staring at it for a while trying to figure out a more efficient way, I settled with just using the VHDL provided full adder: `S &lt;= (I) + (&quot;00000010&quot;);`" CreationDate="2011-04-03T07:00:41.470" UserId="708" />
  <row Id="18843" PostId="12462" Score="2" Text="Keep in mind that FFT uses a linear frequency axis, while a spectrum analyzer typically has a logarithmic frequency axis." CreationDate="2011-04-03T09:38:04.000" UserId="2064" />
  <row Id="18844" PostId="11859" Text="@Adam P, not yet, unfortunately. However, your answer was the most helpful." CreationDate="2011-04-03T12:00:14.253" UserId="1225" />
  <row Id="18845" PostId="12464" Text="I don't know almost anything about VHDL and maybe you take this for granted when you talk about a full adder, so sorry if that's the case, but for improving performance you have the &quot;carry look-ahead adder&quot;." CreationDate="2011-04-03T12:17:16.303" UserId="3693" />
  <row Id="18846" PostId="12464" Score="2" Text="BTW: link just in case http://en.wikipedia.org/wiki/Carry_look-ahead_adder" CreationDate="2011-04-03T12:17:45.167" UserId="3693" />
  <row Id="18847" PostId="12475" Text="I only understand about half that, unfortunately - and I'm really not keen to use a second wall wart. Is there a sample circuit diagram somewhere you could reference?" CreationDate="2011-04-03T12:46:03.697" UserId="3707" />
  <row Id="18848" PostId="12475" Text="Okay, so an H-Bridge seems more or less the same as the configuration I used for the second relay in my diagram. I'm unclear why I need to &quot;generate high-side drive for the upper bridge FETs&quot;, and why that needs a separate power supply, though. Can you elaborate?" CreationDate="2011-04-03T12:52:15.673" UserId="3707" />
  <row Id="18849" PostId="12475" Score="1" Text="This tutorial covers powering a DC motor from a commonly available low power H-Bridge: http://itp.nyu.edu/physcomp/Labs/DCMotorControl - is there any reason I couldn't simply replace the motor with my ringer coil?" CreationDate="2011-04-03T13:17:11.517" UserId="3707" />
  <row Id="18850" PostId="12471" Text="Hmmm. I wish I could accept both answers. I have one motor that is big enough where I can do the above solution, but I also have one that is too small to do that and will have to follow the below answer. Thanks." CreationDate="2011-04-03T13:33:49.303" UserId="2873" />
  <row Id="18851" PostId="12473" Text="@charles, just linking to another site is a comment, writing something here, like that list, and then linking your source is a great answer. links do die." CreationDate="2011-04-03T14:19:34.133" UserId="230" />
  <row Id="18852" PostId="1793" Text="If Arduino is too &quot;ready-made&quot;, learn about ATmega (AVR) chips from Atmel. From my (small) experience, they are a lot more powerful and easier to work than PIC chips. And they are not expensive." CreationDate="2011-04-03T14:23:42.440" UserId="3411" />
  <row Id="18853" PostId="12478" Score="1" Text="Why do I care? Well... I'm learning, and I'm trying to understand how they work. :)" CreationDate="2011-04-03T14:43:47.190" UserId="3411" />
  <row Id="18854" PostId="12460" Text="This is what we do. It is hard to beat the quality and ruggedness of a molded cable. Even the very cheap ones are far better than anything you can make yourself." CreationDate="2011-04-03T15:05:15.937" UserId="659" />
  <row Id="18855" PostId="12474" Score="1" Text="Depending on your exact application a simpler method might be to flicker the screen in a certain pattern and recognize it with photo diodes. The german chiptan system for online banking uses such an approach with five flickering fields." CreationDate="2011-04-03T15:16:15.183" UserId="339" />
  <row Id="18856" PostId="12486" Text="I must have to use this MCU (PIC24F) because it's to be used in a portable low power application and dsPIC doesn't meet that requirement. The filter is simple, it's a 1st order one. I suppose my problem is on converting double-&gt;fixed point format. However, reading the code I think I'm doing the right thing, but it doesn't work... I wonder why." CreationDate="2011-04-03T16:43:26.510" UserId="1074" />
  <row Id="18857" PostId="12454" Text="An easy way to calculate this would be phase to neutral = 230 volts * 1.73 = ph to ph voltage, 400 volts. 400 * 1.414 (peak)= ~565 volts dc. Been awhile since I've had to use that one!" CreationDate="2011-04-03T16:57:06.727" UserId="3453" />
  <row Id="18858" PostId="12204" Text="@Russell McMahon: I modified my expectations, see edit (I will use a 64S3P A123 battery pack - cells will cost total 400$, charger should not cost more), does that make it easier to build?" CreationDate="2011-04-03T17:03:57.550" UserId="1691" />
  <row Id="18859" PostId="12491" Score="2" Text="I've never gotten those desolder braids to work for me.  " CreationDate="2011-04-03T17:52:01.250" UserId="249" />
  <row Id="18860" PostId="12479" Text="@LeonHeller, why? Sources?" CreationDate="2011-04-03T17:53:38.603" UserId="230" />
  <row Id="18861" PostId="12489" Text="Sometimes one output (wire) is in fact common so the last option is out. All the others are still possible though." CreationDate="2011-04-03T18:23:13.443" UserId="659" />
  <row Id="18862" PostId="12492" Score="1" Text="Actually, ZIF sockets are commonly faked, but &quot;work&quot;. For instance, sparkfun sells one that works fine for me, but it's not the official ZIF socket. ZIF is patented and suppose to only be sold by one manufacturer(that I can't remember the name of)" CreationDate="2011-04-03T18:30:34.737" UserId="708" />
  <row Id="18863" PostId="12493" Score="1" Text="+1 for the desoldering technique. I was not aware of that." CreationDate="2011-04-03T18:32:33.080" UserId="708" />
  <row Id="18864" PostId="12486" Score="2" Text="&quot;used in a portable low power application and dsPIC doesn't meet that requirement&quot; &lt;-- this kind of blanket statement sets off alarm bells in my head.  Power consumption is application-dependent, and hardware support often means lower overall power consumption.  Any low power application will keep the processor asleep most of the time, so reducing &quot;on&quot; time is the path to lower power consumption..." CreationDate="2011-04-03T19:28:04.007" UserId="411" />
  <row Id="18865" PostId="12489" Score="1" Text="@jpc: Not always, I've used many transformers that have two separate unconnected secondary coils." CreationDate="2011-04-03T20:28:56.847" UserId="2426" />
  <row Id="18866" PostId="12470" Text="Also, a good synthesis tool will automatically choose an appropriate implementation based on your constraints, i.e. ripple if speed isn't important, and CLA or other optimized implementation if it is. " CreationDate="2011-04-03T20:32:43.397" UserId="3441" />
  <row Id="18867" PostId="12493" Score="2" Text="Alternatively, a pair of dikes can usually remove each pin individually.  I find that it's hard to get the solder out of the holes when they're attached to planes (like a power transistor should be); I prefer to use braid while the transistor is still on the board and then clip the leads and remove them one by one.  If you're lucky, there won't be any solder left." CreationDate="2011-04-03T20:45:22.203" UserId="857" />
  <row Id="18868" PostId="12460" Score="1" Text="[monoprice.com](http://www.monoprice.com/products/product.asp?c_id=102&amp;cp_id=10218&amp;cs_id=1021802&amp;p_id=644&amp;seq=1&amp;format=2) is my source for cables.  They've got a similar cable for $\$$0.65@1, $\$$0.55@50..." CreationDate="2011-04-03T20:53:26.673" UserId="857" />
  <row Id="18869" PostId="12461" Text="True, but if you get the headphones for free, then a little bit of work to get things solderable isn't too unreasonable. " CreationDate="2011-04-03T21:17:39.253" UserId="638" />
  <row Id="18870" PostId="12489" Score="1" Text="@BG100 I believe that is what is generally meant by the word &quot;sometimes&quot; which I used. ;)" CreationDate="2011-04-03T21:40:54.987" UserId="659" />
  <row Id="18871" PostId="12462" Score="1" Text="@Stevenvh Correct. Still can be done, just needs a longer FFT and some averaging of bins to turn it into sorta log scale." CreationDate="2011-04-03T21:51:20.647" UserId="319" />
  <row Id="18872" PostId="12497" Text="Wow. Now that's just too easy. what if you wanted multiple bit inputs though?" CreationDate="2011-04-03T21:56:17.257" UserId="708" />
  <row Id="18873" PostId="12498" Score="1" Text="The credit card scanning application probably works by receiving credit card data as &quot;sound&quot;(with help from a small dongle like thing) and processing it on the phone's computer." CreationDate="2011-04-03T21:57:29.923" UserId="708" />
  <row Id="18874" PostId="12498" Text="@biba, if it is a fact, give a link and we can weigh in." CreationDate="2011-04-03T22:14:59.743" UserId="230" />
  <row Id="18875" PostId="12489" Score="4" Text="when paralleling secondaries you have to be careful to connect them with the correct polarity. Do it wrong and what you effectively have is the two in series and shorted out." CreationDate="2011-04-03T22:39:18.483" UserId="740" />
  <row Id="18876" PostId="12497" Text="@Earlz  I added multi-bit-wide stuff to my answer, above." CreationDate="2011-04-03T23:09:49.837" UserId="3624" />
  <row Id="18877" PostId="12501" Text="@kurtnelle  What do you mean by &quot;address&quot;?  And more importantly, what are you trying to do and why?  I've been doing Xilinx designs for, well, more years than I care to admit and I have never once needed to know what the &quot;address&quot; of a LUT is.  If you give more info about your issue maybe we can figure it out." CreationDate="2011-04-03T23:14:14.233" UserId="3624" />
  <row Id="18878" PostId="12499" Score="1" Text="Computer audio output headphone jacks are 3.5mm. Larger equipment (guitar amps, etc) use 0.25&quot; jacks." CreationDate="2011-04-03T23:31:19.187" UserId="2255" />
  <row Id="18879" PostId="12502" Text="@Alejandro  In the audio world we call that &quot;Noise Shaping&quot;." CreationDate="2011-04-03T23:40:14.283" UserId="3624" />
  <row Id="18880" PostId="12404" Text="I build Keil projects via batch script without any PATH dependencies (other than to the Keil tools themselves) or __i / _ia files. Can you share any more info on this?" CreationDate="2011-04-03T23:46:12.720" UserId="960" />
  <row Id="18881" PostId="12501" Text="@David Kessner. I've added some more detail as to the intended purpose. As you are an expert and you have no idea what I mean by address it tells me that I may be on the wrong path." CreationDate="2011-04-04T00:01:57.783" UserId="3045" />
  <row Id="18882" PostId="12503" Score="2" Text="When I looked into it, the enclosure / stomp switch was the *hardest* part of making guitar effects.  The circuits inside are usually rather trivial." CreationDate="2011-04-04T00:30:34.480" UserId="411" />
  <row Id="18883" PostId="12505" Text="And if I should want to write a Verilog Compiler? :) What then?" CreationDate="2011-04-04T00:32:51.537" UserId="3045" />
  <row Id="18884" PostId="12505" Score="1" Text="@kurtnelle  If you want to write a Verilog compiler, and you have the talent to do that, then you will have no problems getting a job at Xilinx, Altera, or one of the other FPGA companies and they would be willing to share the transistor-level design files with you.  :)  I say that half-jokingly, because someone with that talent could easily get a job doing it, but also there is a lot of fine details that companies like Xilinx simply won't give out and there is little hope in writing a compiler for Xilinx parts without that info." CreationDate="2011-04-04T00:43:01.477" UserId="3624" />
  <row Id="18885" PostId="12505" Text="@David Kessner So the reason why I can't seem to find this information may be because it's &quot;a secret&quot;? This throws a huge wrench into my plans :(" CreationDate="2011-04-04T00:49:16.587" UserId="3045" />
  <row Id="18886" PostId="12505" Score="2" Text="It's a trade secret.  Besides, if a company like Xilinx released that info then they would have a huge technical support nightmare trying to support customers doing stuff like that-- as it would bee very easy to make the FPGA self destruct." CreationDate="2011-04-04T01:28:54.387" UserId="3624" />
  <row Id="18887" PostId="12464" Text="@JaimePardos, all ALUs use this or a more advanced device to increase speed. Waiting for 32 carry bit delays is not acceptable in a modern processor." CreationDate="2011-04-04T01:45:02.117" UserId="230" />
  <row Id="18888" PostId="12505" Text="Das not good. Das not good at all." CreationDate="2011-04-04T02:00:08.167" UserId="3045" />
  <row Id="18889" PostId="12508" Score="1" Text="@BarsMonster What you're describing isn't faster in an FPGA than using a normal full or half adder, and takes more logic resources.  This isn't intuitive at first, but stick with me here.  If you were implementing the logic out of raw gates and flip-flops then you might be right.  But FPGAs are not raw gates and flip-flops.  FPGAs are fixed but semi-programmable logic structures, and these structures include dedicated carry chains that have been hard-wired to be super fast.  Much faster than the &quot;normal logic&quot;, and using them frees up the normal logic for, well, normal logic.  " CreationDate="2011-04-04T02:38:17.757" UserId="3624" />
  <row Id="18890" PostId="12507" Score="3" Text="You don't need to go through Digikey to get this; talk to the manufacturers.  We've previously done similar mods through [Hammond Mfg](http://www.hammondmfg.com/) (qty ~1000).  However, they couldn't do all of the mods we needed, so we had to send them down to our mechanical/prototype shop.  Once the CAM machinery and jigs were set up, it took a couple days to run through them all." CreationDate="2011-04-04T02:45:44.053" UserId="857" />
  <row Id="18891" PostId="12450" Text="@ergodicsum You're welcome, glad I could help." CreationDate="2011-04-04T02:47:20.730" UserId="3635" />
  <row Id="18892" PostId="12503" Text="Do you have a CNC mill?  It shouldn't take more than a day or two to modify/build 100 boxes, depending on how much customization you want." CreationDate="2011-04-04T02:47:39.700" UserId="857" />
  <row Id="18893" PostId="12504" Text="I have been trying to find an adapter for PC like dual 3.5mm jack (sound/mic) input to a cellphone 3.5mm headset.  I have found some like one at Amazon from Headset buddy, and I've been surprised by their cost -- often about $15 for what would seem to be pretty simple.  Can you speculate on why that is? Simple supply and demand? Or is there something tricky about this sort of adapter?" CreationDate="2011-04-04T02:48:10.197" UserId="3711" />
  <row Id="18894" PostId="12510" Score="1" Text="@BarsMonster, @AdamP, if you add resistance and conductance to capacitance and inductance you have a full picture of your impedance. They also normally have some frequency dependence, but not at &quot;low&quot; frequencies." CreationDate="2011-04-04T02:55:43.683" UserId="230" />
  <row Id="18895" PostId="12510" Text="@Kortuk: That's a great point. Doing that includes losses in the model. Generally it is much easier to assume the ideal (lossless) case, although as Kortuk points out it is not as complete a model." CreationDate="2011-04-04T03:08:05.447" UserId="3635" />
  <row Id="18896" PostId="12497" Score="1" Text="Nice. Would've been a bit better if you had added generics in, but that's pretty easy to change around" CreationDate="2011-04-04T03:22:45.863" UserId="708" />
  <row Id="18897" PostId="12458" Text="@David, I didn't invent them nor did I ask the original question, just trying to add my input. Have a look at Don Lancaster's original work via the link in the original question. " CreationDate="2011-04-04T04:06:18.603" UserId="3705" />
  <row Id="18898" PostId="12508" Text="I think carry-chains are generally better used for applications requiring full adders; the key point, though, should be to specify what one wants the hardware to do and let the FPGA software figure out how best to implement it given the chip resources that exist.  If there are enough other math-ish things to use up whatever dedicated carry chains exist, an incrementer can be done pretty well in ordinary logic.  If carry-chain resources are available, it may be good to use them.  The FPGA software should be able to figure it out." CreationDate="2011-04-04T04:22:53.560" UserId="3123" />
  <row Id="18899" PostId="4978" Text="Another trick for estimating time-average microcontroller current usage in scenarios where current draw will be &quot;bursty&quot; is to charge up a really big capacitor and have it feed a low-quiescent-current regulator to simulate battery voltage.  A 100,000uF capacitor will drop 0.01 volts per milliamp-second.  If it drops by 0.3 volts in five minutes (300 seconds) your average current draw is 100uA." CreationDate="2011-04-04T04:27:43.100" UserId="3123" />
  <row Id="18901" PostId="12516" Score="1" Text="many power supplies today are switching power supplies. They do not have transformers. However the relationship between current and voltage still holds ture" CreationDate="2011-04-04T12:27:35.150" UserId="1810" />
  <row Id="18902" PostId="12497" Text="You have numeric_std - yay!  But then you need &quot;to_integer&quot;, not &quot;conv_integer&quot;.  Then, why not make sel an &quot;unsigned&quot; type?" CreationDate="2011-04-04T12:30:10.433" UserId="763" />
  <row Id="18903" PostId="12516" Score="3" Text="Switchers do have transformers. The same basic math applies, you just use higher frequencies and other waveforms of voltages and currents in the transformers, which is the reason why the transformers in switchers are much, much smaller. But they're there. The question can be answered no matter if it is a 50 or 60 Hertz transformer or a switch-mode power supply." CreationDate="2011-04-04T12:34:51.917" UserId="930" />
  <row Id="18904" PostId="12516" Score="1" Text="Isolating switchers have transformers. Non-isolating switchers could use inductors, especially if a single output is all that is required. Or even capacitors eg IC7660." CreationDate="2011-04-04T12:46:03.160" UserId="2110" />
  <row Id="18905" PostId="12489" Score="2" Text="@jpc - The only case I know of with a common wire is when the two coils are in series and the common wire is a center tap (CT). In those cases you can still create two power supplies from it, one positive and one negative." CreationDate="2011-04-04T13:14:29.823" UserId="2064" />
  <row Id="18906" PostId="12433" Score="1" Text="@earlz Yes, the binary format is a secret. " CreationDate="2011-04-04T13:14:49.337" UserId="3145" />
  <row Id="18907" PostId="12510" Text="@AdamP, was expanding on your statement that characteristic impedance has mostly to do with L and C. This is often a very effective assumption, just sharing that with the two parameters it tells you everything. More of a point for those that read it in the future so that they realize that model is complete." CreationDate="2011-04-04T13:17:17.897" UserId="230" />
  <row Id="18908" PostId="12504" Score="1" Text="@Jerry Cables are usually overpriced in general, best buy is one of the worst at it. The cable you describe is a rather uncommon cable though so it is likely a supply/demand issue. You might want to check to see if http://www.monoprice.com/ has anything like what you want." CreationDate="2011-04-04T13:19:59.460" UserId="319" />
  <row Id="18909" PostId="12516" Text="Why the downvotes?" CreationDate="2011-04-04T13:38:49.140" UserId="305" />
  <row Id="18910" PostId="12489" Text="@stevenh This is what I had in mind. You are right that you get two supplies but I wanted to note that they are not really independent (isolated)." CreationDate="2011-04-04T13:46:16.937" UserId="659" />
  <row Id="18911" PostId="12502" Text="@Alejandro Yes, this looks like the same thing, thanks!" CreationDate="2011-04-04T13:50:40.333" UserId="659" />
  <row Id="18912" PostId="12516" Score="1" Text="If it is a switcher, it must be isolated from the mains with a transformer for safety reasons." CreationDate="2011-04-04T14:10:59.653" UserId="305" />
  <row Id="18913" PostId="12429" Score="1" Text="Sorry, I had to toggle this answer off - my colleague contacted Exar and was told that this part was also discontinued, as per PDN 07-003-01 (which obsoleted the XR2209, coincidentally)." CreationDate="2011-04-04T14:48:28.200" UserId="1293" />
  <row Id="18914" PostId="12505" Text="An HDL compiler does not need to go that deep. It is possible to replace the synthesis portion of the compilation, and hand off a compiled netlist and constraint file to Xilinx tools to map, place, and route.  (the FPGA platform in Altium designer does this, for example)" CreationDate="2011-04-04T14:50:14.457" UserId="1270" />
  <row Id="18915" PostId="12505" Text="You can also implement a new HDL language by translation. Your compiler could generate VHDL, which would be compiled normally.  MyHDL works this way." CreationDate="2011-04-04T14:51:15.783" UserId="1270" />
  <row Id="18916" PostId="12516" Score="1" Text="There isn't an isolation requirement if the power supply is primary-only. You can use a buck converter between rectified AC and a primary-referenced supply that the user isn't directly interacting with, and regulatory agencies won't have a problem with it." CreationDate="2011-04-04T14:55:53.593" UserId="1293" />
  <row Id="18917" PostId="12525" Text="@Leon thanks, I'll take a look at the 20 pin devices.  But for now, I guess it wouldn't hurt to just tackle the LCD and use the built-in COM port via the FET." CreationDate="2011-04-04T15:18:49.100" UserId="2288" />
  <row Id="18918" PostId="12516" Text="The OP seems to have access to the output, so I assumed that it was isolated." CreationDate="2011-04-04T15:32:52.360" UserId="305" />
  <row Id="18919" PostId="12429" Text="Weird. It doesn't mention that anywhere on the website?  It's still listed in parametric searches and is still for sale." CreationDate="2011-04-04T15:34:56.947" UserId="142" />
  <row Id="18920" PostId="12506" Text="Lasering holes in thick metal would take longer than just drilling them, no?" CreationDate="2011-04-04T15:42:51.483" UserId="142" />
  <row Id="18921" PostId="12527" Text="@Ageis, using a higher than 5V coil will mean using a transistor to switch the relay. Also relays are isolated between the contacts and the coil, but triacs are not in themselves isolated so you need a layer of isolation such as an auxillary opto triac or opto isolator. Depending on the load you are driving, relays may be more reliable." CreationDate="2011-04-04T16:08:14.827" UserId="2110" />
  <row Id="18922" PostId="12506" Text="Yes, but you don't need to switch between different drills :-) Anyway, it's robot working, not you :-)" CreationDate="2011-04-04T16:13:16.770" UserId="2062" />
  <row Id="18923" PostId="12527" Text="It it's being driven from microcontroller, he would need extra transistors anyway..." CreationDate="2011-04-04T16:14:56.083" UserId="2062" />
  <row Id="18924" PostId="12429" Text="Agreed. I updated the question with the PCN they sent us." CreationDate="2011-04-04T16:20:57.360" UserId="1293" />
  <row Id="18925" PostId="12508" Text="I don't see where it says it's for an FPGA. I agree with you here." CreationDate="2011-04-04T16:24:11.623" UserId="2062" />
  <row Id="18926" PostId="12502" Score="1" Text="Alejandro, great find, does appear to be the same from what I can determine. I'm still curious how commonly these are implemented though, any ideas? " CreationDate="2011-04-04T16:26:58.090" UserId="3705" />
  <row Id="18927" PostId="12426" Text="I'm curious, did you have a solid inner ground plane in your application?" CreationDate="2011-04-04T16:27:09.963" UserId="1278" />
  <row Id="18928" PostId="12422" Text="What properties do you want from this triangle wave that can't be provided by something simple like a 555/556 IC?  Frequency stability or wave shape is critical?  Consistent amplitude at different frequencies?" CreationDate="2011-04-04T16:37:23.203" UserId="142" />
  <row Id="18930" PostId="12430" Text="the plan that you signed, correct. The code that you write is what I wanted! Many thanks for your help!!! " CreationDate="2011-04-04T16:39:42.140" UserId="3618" />
  <row Id="18931" PostId="12426" Text="@ajs410 It is rare that I have to design a PCB without at least 1 gnd plane.  Most of the time I have 3 non-overlapping planes:  analog, digital, and chassis.  Plus at least 1 power plane, sometimes more." CreationDate="2011-04-04T16:45:00.580" UserId="3624" />
  <row Id="18932" PostId="12182" Text="Very helpfull ! thanks!" CreationDate="2011-04-04T16:48:16.113" UserId="3618" />
  <row Id="18933" PostId="12526" Text="Similar to a relay but typically for higher power/current is a contactor http://en.wikipedia.org/wiki/Contactor" CreationDate="2011-04-04T17:13:11.590" UserId="2157" />
  <row Id="18934" PostId="12527" Text="@jpc Do DC relays give you enough voltage isolation to be safe?" CreationDate="2011-04-04T17:13:52.620" UserId="2157" />
  <row Id="18935" PostId="12521" Text="+1 for freehand circles (and more!)" CreationDate="2011-04-04T17:45:36.607" UserId="2028" />
  <row Id="18937" PostId="12404" Text="@digikata I'm using the option from within the IDE to generate a batch file.  This is described in [Keil's documentation.](http://www.keil.com/support/docs/2594.htm)  There is also a command line driven method described [here](http://www.keil.com/support/man/docs/uv4/uv4_commandline.htm), but I had difficulty getting the proper console output from that command.  The second method starts a new process and gives you the option to copy the output window to an output file - not a good method for a build server." CreationDate="2011-04-04T17:53:21.170" UserId="3346" />
  <row Id="18938" PostId="12531" Text="but i guess i don't need to write to the latch register, since writing to original port register will write to latch, right?" CreationDate="2011-04-04T18:01:57.983" UserId="3720" />
  <row Id="18939" PostId="12531" Text="@Donotalo, You're right. You can write in the port register too. It does not matter." CreationDate="2011-04-04T18:13:41.750" UserId="938" />
  <row Id="18940" PostId="12533" Score="2" Text="Is very difficult to answer your question because capacitors have a vast number of applications. Can you be more specific?" CreationDate="2011-04-04T18:31:01.417" UserId="938" />
  <row Id="18950" PostId="12538" Score="1" Text="`However, any alternating current (AC) signal flows through a capacitor unimpeded.` Any sources for that? From what I've heard, impedance of a capacitor is $R+ \frac {1}{j \omega C}$, where R is resistance of the leads and $\frac {1}{j \omega C}$ is reactance of the capacitor." CreationDate="2011-04-04T19:12:51.600" UserId="1240" />
  <row Id="18954" PostId="5415" Text="Details are at the end of each data sheet. There will be a table with the ordering codes for each package type and another table with descriptions of the package type. There will also be detailed drawings of each package, with dimensions. Reading the data sheet is the only way to be sure you get what you want when ordering parts." CreationDate="2010-10-20T21:47:40.543" UserId="305" />
  <row Id="18955" PostId="12527" Score="1" Text="@kenny, easily. Look for a relay with safety agency approvals. A quick search found [this one](http://uk.farnell.com/finder/32-21-7-005-2000/relay-pcb-5vdc/dp/1329651) with 4 kilovolts of isolation between coil and contacts. " CreationDate="2011-04-04T19:43:16.397" UserId="2110" />
  <row Id="18956" PostId="12528" Text="hey that's a good idea, too!  thanks.  I'm going to see what I can squeeze out of this device first and then will look at the other options." CreationDate="2011-04-04T19:44:47.893" UserId="2288" />
  <row Id="18957" PostId="12538" Score="1" Text="@andrejaKo The comment is a simplification assuming an ideal capacitor which has zero ESR, among other non-realistic attributes.  Your equation is also an idealized simplification which doesn't factor is all real world properties of capacitors.  For instance, you've ignored ESL which is a very important property in many applications." CreationDate="2011-04-04T19:45:45.750" UserId="1438" />
  <row Id="18958" PostId="12542" Text="Thanks, I had a feeling that it was not the way to go.&#xA;Hmmm. This is giving me a headache, probably gonna stick to voltage divider solution of some sort." CreationDate="2011-04-04T19:58:18.360" UserId="3041" />
  <row Id="18959" PostId="12531" Text="@Donotalo: It's possible to write to the port register, but I'd recommend as a matter of habit writing to the LATx registers on those processors that have them, and regarding the PORTx registers as read-only. A &quot;blind&quot; store to a PORTx register (e.g. PORTB = 0x42;) will behave no differently from one to LATBx, and a read-modify-write to a PORTx register (e.g. PORTB |= 0x02;) will have an effect which will either be the same as LATx or else differ in a most-likely-undesirable way. BTW, some of the later pre-Microchip PICs offered LATx; I don't know why Microchip took years (decades?) to do so." CreationDate="2011-04-04T20:21:55.070" UserId="3123" />
  <row Id="18960" PostId="12422" Text="The legacy design has an XR2206. The behaviour of the triangle wave should be 'compatible' with the XR2206 - fixed amplitude and clean egdes. The engineer working on this activity isn't comfortable going with a discrete design." CreationDate="2011-04-04T20:43:16.520" UserId="1293" />
  <row Id="18961" PostId="12234" Text="This sounds like a recipie for disaster! " CreationDate="2011-04-04T20:48:25.347" UserId="1827" />
  <row Id="18962" PostId="12527" Text="@kenny Why DC relays? The OP is explicitly asking for AC. Maybe add a new question about relays for switching DC loads with high isolation voltage." CreationDate="2011-04-04T21:00:17.727" UserId="659" />
  <row Id="18963" PostId="12538" Score="2" Text="Capacitors don't block direct currents.  The voltage just climbs to infinity.  :)" CreationDate="2011-04-04T21:01:08.490" UserId="142" />
  <row Id="18964" PostId="12462" Score="1" Text="http://electronics.stackexchange.com/questions/10371/sound-sensor-that-can-give-feedback-on-the-amplitude-of-different-frequencies" CreationDate="2011-04-04T21:06:22.640" UserId="142" />
  <row Id="18965" PostId="12547" Text="240V * 20A = 4800W, 240V * 30A = 7200W.  Its not that difficult, even in the US you have 240V available in your house(two 120V legs), its just not used for common outlets but rather things like your dryer or electric stove." CreationDate="2011-04-04T21:06:46.507" UserId="1438" />
  <row Id="18966" PostId="8670" Score="1" Text="I second this suggestion. If you do not care about the price then new Beagleboards (or some clones of the original one like IGEPv2) have both WiFi and 100Mbit Ethernet." CreationDate="2011-04-04T21:07:11.453" UserId="659" />
  <row Id="18967" PostId="12547" Text="230V * 16A = 3680W is a standard European socket rating, and I wrote 4kW so to have some overhead and not exploit the DC-DC converter at 100% of its capability, but slightly lower." CreationDate="2011-04-04T21:16:35.020" UserId="1691" />
  <row Id="18968" PostId="12548" Score="3" Text="You missed out 555 timers and some counters(4026 and 4017). Great for a beginners to produce things with flashing lights. " CreationDate="2011-04-04T21:16:46.590" UserId="1623" />
  <row Id="18969" PostId="12547" Text="In the UK the most you can draw from a single socket is 13A" CreationDate="2011-04-04T21:17:56.160" UserId="1827" />
  <row Id="18970" PostId="12527" Text="@jpc When you suggest 12 or 24 volt relays, I assumed you mean DC ones otherwise I thought you would have said 230 volt AC relays." CreationDate="2011-04-04T21:21:07.637" UserId="2157" />
  <row Id="18971" PostId="12553" Text="I hadn't thought of that. Yes I say H-bridge and that relays are a non standard way. He's all for the relays. " CreationDate="2011-04-04T21:39:37.623" UserId="1623" />
  <row Id="18973" PostId="12520" Text="That's neat. I may use that instead, but I'll need to evaluate it a bit more first" CreationDate="2011-04-04T22:09:24.727" UserId="708" />
  <row Id="18974" PostId="12538" Text="@Mark What's ESL? " CreationDate="2011-04-04T22:21:10.183" UserId="1240" />
  <row Id="18976" PostId="12549" Text="@Madmanguruman: I would be more then happy to buy the device instead of designing it myself, provided 1) its at least a bit &quot;open hardware&quot; so I get a schematic of what's inside and not just a black-box that I would need to reverse-engineer to get it repaired (and don't tell me the word &quot;warranty&quot; - I want the thing I spend so much money on to work much longer then any warranty) and 2) it is at least a bit modular, so if my desired output voltage changes a bit, for example I decide to use 172.8V and not 230.4V I can swap a few components instead of buying a whole new device. Any suggestions?" CreationDate="2011-04-04T22:23:07.017" UserId="1691" />
  <row Id="18977" PostId="12557" Text="@Leon: 3 cycles for SRAM byte read from postincremented X is enough for 8MHz PORT output (4MHz on/off) if AVR is clocked at 24MHz (XMEGA can go up to 32MHz), and instructions are ordered one after another without any jump (but for the last read from the table in SRAM). Of course, such frequencies are off the limit for more complex signal shapes, but I was pointing 8MHz as a safe margin." CreationDate="2011-04-04T22:24:00.547" UserId="1129" />
  <row Id="18978" PostId="12550" Text="something like http://waldok.com/ ?" CreationDate="2011-04-04T22:27:57.737" UserId="2157" />
  <row Id="18980" PostId="12554" Text="Here's a circuit that does exactly that: http://www.siliconchip.com.au/cms/A_112070/article.html" CreationDate="2011-04-04T22:42:04.930" UserId="389" />
  <row Id="18981" PostId="12557" Score="1" Text="Have you actually achieved an 8 MHz output? If it's a square wave you will need a much higher performance op amp than a 10 MHz one." CreationDate="2011-04-04T22:44:08.833" UserId="305" />
  <row Id="18982" PostId="12538" Score="1" Text="@andrejaKo ESL = Equivalent Series Inductance, it represents the series inductance of the capacitor and is mostly a result of the package leads.  ESL can result in resonances and is also critical in high frequency operation for  applications like decoupling digital logic.  ESR, Equivalent Series Resistance, the R in your equation above, is not only the result of lead resistance but also loses in the dielectric, additionally it is variable over frequency.  There is also a parasitic capacitance to consider in a real world model when operating at high frequency. " CreationDate="2011-04-04T22:45:41.890" UserId="1438" />
  <row Id="18983" PostId="12547" Text="Thats just for common outlets when using fused plugs.  Duplex outlets for instance are often rated for 20A.  Additionally CEE plugs are used for higher power needs and can easily supply about anything you need." CreationDate="2011-04-04T22:57:17.127" UserId="1438" />
  <row Id="18984" PostId="12559" Text="Is it necessary to differentiate the two power sources if you have a smoothing capacitor like the one in the second link? Also the l293d only has 16 pins, so by 10 and 20, would you be referencing 8 as 10 and 16 as 20?" CreationDate="2011-04-04T23:15:44.747" UserId="2873" />
  <row Id="18985" PostId="12538" Text="@Mark Thanks! I'm aware of the inductance effects, but that was the first time I came into contact with that particular three letter acronym. " CreationDate="2011-04-04T23:18:11.623" UserId="1240" />
  <row Id="18986" PostId="12507" Text="+1 on Hammond - if you call them up, they can turnkey the CNC's end plates for you.  The other possibility is to just call a machine shop and have them fabricate replacement end plates from scratch (often cheaper than using the originally supplied end plates)." CreationDate="2011-04-04T23:58:18.123" UserId="3308" />
  <row Id="18987" PostId="12186" Text="I would be interested to see how you draw 4kw from a single mains socket" CreationDate="2011-04-04T20:47:14.770" UserId="1827" />
  <row Id="18988" PostId="12186" Text="240V * 20A = 4800W, 240V * 30A = 7200W.  Its not that difficult, even in the US you have 240V available in your house(two 120V legs), its just not used for common outlets but rather things like your dryer or electric stove." CreationDate="2011-04-04T21:06:46.507" UserId="1438" />
  <row Id="18989" PostId="12186" Text="230V * 16A = 3680W is a standard European socket rating, and I wrote 4kW so to have some overhead and not exploit the DC-DC converter at 100% of its capability, but slightly lower." CreationDate="2011-04-04T21:16:35.020" UserId="1691" />
  <row Id="18990" PostId="12186" Text="In the UK the most you can draw from a single socket is 13A" CreationDate="2011-04-04T21:17:56.160" UserId="1827" />
  <row Id="18991" PostId="12186" Text="Thats just for common outlets when using fused plugs.  Duplex outlets for instance are often rated for 20A.  Additionally CEE plugs are used for higher power needs and can easily supply about anything you need." CreationDate="2011-04-04T22:57:17.127" UserId="1438" />
  <row Id="18992" PostId="12559" Text="Whoops, the L293 has 16 pins in PDIP.  The SMD version is 20 pin." CreationDate="2011-04-05T00:34:49.793" UserId="389" />
  <row Id="18993" PostId="12559" Text="If you have well regulated power and you're running your motor at the same level as logic, combining the pins is fine." CreationDate="2011-04-05T00:35:29.623" UserId="389" />
  <row Id="18994" PostId="11856" Text="actually you hav eit wrong- he's switching at a lower freq than would normally be used for a plain-ol PWM output, but is using a high-freq clock to time the edges of the state changes very precisely in order to finely tune the lenght of each pulse to kill off harmonics. " CreationDate="2011-04-05T00:35:47.813" UserId="3705" />
  <row Id="18995" PostId="12559" Text="And I am assuming the logic is referring to allowing the l293d to operate. So, could I use a 6V battery pack as the power source for pin 8 and then just wire the 5V from an arduino to the logic? Thank you. " CreationDate="2011-04-05T00:41:30.320" UserId="2873" />
  <row Id="18996" PostId="12559" Text="Also, why does he include the ground rail from the arduino in the circuit?" CreationDate="2011-04-05T00:51:54.757" UserId="2873" />
  <row Id="18997" PostId="12562" Text="Wow, thanks for finding that.  That looks like a perfect part...if only it was easy to find.  I guess that's the next challenge.&#xA;&#xA;And that leads to another question: why haven't more people used this part before?  The MAX611 datasheet is from 1994.  The difficulty seems to be trying to get an isolation transformer that's small enough." CreationDate="2011-04-05T02:19:38.317" UserId="3726" />
  <row Id="18998" PostId="12562" Text="Interesting part, but the datasheet's dated 1994!" CreationDate="2011-04-05T02:21:52.177" UserId="51" />
  <row Id="18999" PostId="12565" Score="2" Text="How big is your soldering iron tip? What about the diameter of the solder?" CreationDate="2011-04-05T02:34:22.557" UserId="319" />
  <row Id="19000" PostId="12546" Score="1" Text="I'd actually recommend the mbed before the Arduino. I think it's easier. Compiler is online, no drivers to install for the programmer, and you get a lot more bang for your buck. Only problem is the community is a bit smaller." CreationDate="2011-04-05T02:49:18.800" UserId="708" />
  <row Id="19001" PostId="12513" Text="I was about to recommend this myself as it seems up the OP's alley" CreationDate="2011-04-05T02:52:24.977" UserId="708" />
  <row Id="19002" PostId="12559" Text="And one last question, how does putting a smoothing capacitor in between the 6V and the ground smooth out the voltage spikes that would damage the l293d?" CreationDate="2011-04-05T03:05:28.490" UserId="2873" />
  <row Id="19003" PostId="12565" Score="1" Text="Are you using any flux?" CreationDate="2011-04-05T03:37:00.030" UserId="638" />
  <row Id="19004" PostId="12565" Score="1" Text="http://electronics.stackexchange.com/questions/tagged/soldering" CreationDate="2011-04-05T04:21:01.857" UserId="319" />
  <row Id="19005" PostId="12557" Text="@Leon: Thank you for this valuable input. So far I have verified simple 3 cycles code in simulator, so I think it is doable (actually even 30% better then that if 32MHz is used instead of 24MHz). I don't know yet how the signal will look on oscilloscope. The only faster opamp I can get is LM318N08 (single 15MHz). Should I bother, or should I just redirect those high frequency squares directly to the output without opamp? Can you guess then if opamp could handle my table based DDS signals properly at least up to about 1MHz?" CreationDate="2011-04-05T06:34:33.383" UserId="1129" />
  <row Id="19006" PostId="12567" Text="+1 - A dished (MiniWave) tip can also help with this technique." CreationDate="2011-04-05T08:05:48.980" UserId="2234" />
  <row Id="19007" PostId="12573" Text="The 555 I'm using should be able to take up to 2.7 MHz and I can get the frequency I expect on the output. " CreationDate="2011-04-05T08:11:39.640" UserId="1240" />
  <row Id="19008" PostId="12469" Text="Your answer was most helpful.  Thanks David!" CreationDate="2011-04-05T08:33:29.050" UserId="3649" />
  <row Id="19009" PostId="12481" Text="Never heard of the Goertzel filter algorithm before but it looks very worthy to check out.  Thanks for the link!" CreationDate="2011-04-05T08:51:04.347" UserId="3649" />
  <row Id="19010" PostId="12278" Text="Instead of Buying a Gram scale, I went to it's service station and enquired about the internal circuits and from where they get these load cells.... Fortunately those guys were enthusiastic and gave me lots of info!! Thanks @jsolarski for this idea!" CreationDate="2011-04-05T08:57:12.550" UserId="2574" />
  <row Id="19011" PostId="12582" Text="Hi, I will have to say, I could find out where the error was. I made a mistake calculating the Phase difference. The code for demodulation should be &quot;theta(i)=angle(DQPSK_Sig(i))-angle(DQPSK_Sig(i-1));&quot; &#xA;&#xA;This fixes the problem." CreationDate="2011-04-05T09:16:29.780" UserId="3733" />
  <row Id="19012" PostId="12585" Text="Thanks! I think you answered my question. The input impedance is 500 ohms, so input voltage is 0.2V(RMS) to 0.7V(RMS). Now, if I terminate the input with a resistor to match my generator output, should I calculate the input power as the power delivered to the 500 ohms resistor? (500 ohms || x ohms) " CreationDate="2011-04-05T10:15:00.377" UserId="3041" />
  <row Id="19013" PostId="12585" Text="Your signal generator presumably has a 50R impedance, so you need a 450R series resistor to match the 500R input impedance of the device. Just use a 500R load resistance representing the DUT, and adjust the generator to give you your required input signal, then remove the 500R resistor and feed the signal directly into the DUT, still using the 450R series resistance." CreationDate="2011-04-05T10:21:27.657" UserId="305" />
  <row Id="19014" PostId="12585" Text="Okay got it! Thanks.  :-)" CreationDate="2011-04-05T10:25:25.177" UserId="3041" />
  <row Id="19015" PostId="12585" Text="Oh, just a follow up question: If the generator has 50R output impedance, the termination impedance at the end of the generator cable should be 50R, to avoid reflection in the cable? (Assuming my cable is longer than quarter wave length) Or am I missing something?" CreationDate="2011-04-05T10:31:42.053" UserId="3041" />
  <row Id="19016" PostId="12588" Text="Why would it not be graphic? I though that the property is defined by it having sliders instead of rotary potentiometers. So having shelving filters isn't a good idea? I though it'd be better if I could cut everything under 60Hz instead of cutting the frequencies around 60Hz but retaining, say, 20Hz (numbers are arbitrary). Care to elaborate?" CreationDate="2011-04-05T10:33:21.993" UserId="3075" />
  <row Id="19017" PostId="12513" Text="Wow it looks amazing ;) Thank you for the link. The best thing is they have a choice to build things in Italy so I could get them faster." CreationDate="2011-04-05T10:46:53.800" UserId="2316" />
  <row Id="19018" PostId="12481" Text="It is not very well known but works really nice and is fast, even on the AVR." CreationDate="2011-04-05T10:53:58.127" UserId="659" />
  <row Id="19019" PostId="12527" Text="@kenny: Oh. I was thinking of the coil voltage. Fixed it, thanks." CreationDate="2011-04-05T10:55:15.880" UserId="659" />
  <row Id="19020" PostId="12588" Text="Well you could do that at the two extreme frequencies but you would be unlikely to want to boost all frequencies under 60Hz or above 15kHz - ie raising the sliders. The point I was making is that the configuration made by the sliders depicts the frequency response of the equaliser, which will only be true if the sliders are independent of each other (ie with separate passbands). Most GR/EQs I have seen have a separate low-cut filter switch which provides a steep roll-off below say 50 or 75Hz." CreationDate="2011-04-05T11:00:54.757" UserId="2234" />
  <row Id="19021" PostId="12562" Score="3" Text="These chips are mostly for non-isolated supplies which are not something you should be using for hobby projects." CreationDate="2011-04-05T11:05:41.887" UserId="659" />
  <row Id="19022" PostId="12588" Text="I understand the part about the bands being independent - but why wouldn't I want to boost the extreme bands if their filters were shelving instead of peaking? I mean, Winamp's EQ does it, right :D" CreationDate="2011-04-05T11:07:14.547" UserId="3075" />
  <row Id="19023" PostId="12532" Text="+1 for linking to a place the clearly describes the (read-modify-write)[http://techref.massmind.org/techref/readmodwrite.htm] problem (and solution)." CreationDate="2011-04-05T11:55:03.220" UserId="813" />
  <row Id="19024" PostId="12531" Text="+1 for mentioning that PIC18F chips (aka &quot;16-bit instruction PICs) have the LAT register, while PIC16F chips (aka &quot;14-bit instruction PICs&quot;) require simulating the LAT register in software (&quot;shadow register&quot;)." CreationDate="2011-04-05T11:59:43.450" UserId="813" />
  <row Id="19025" PostId="12547" Text="Are you talking about 3-phase outlets?" CreationDate="2011-04-05T12:03:18.687" UserId="1827" />
  <row Id="19026" PostId="12548" Text="@Dean - good call.  Also, there is the basic electronics book that got many people started (including myself): http://www.radioshack.com/product/index.jsp?productId=3433933" CreationDate="2011-04-05T12:31:33.887" UserId="1823" />
  <row Id="19027" PostId="12549" Text="You'll not find many off-the-shelf supplies that offer full schematics these days. The return/repair business is too lucrative for the manufacturers. Back in the 80s and 90s, you could get full service manuals and schematics for HP power supplies, loads, etc. ... try getting the same information for any new Agilent product today. At my employer we use Elgar SW series sources up to 10kW - they can deliver AC as well as DC. They're not cheap but they're rugged (we abuse them badly) and are still supported.  [Datasheet](http://www.elgar.com/products/SW/downloads/Elgar_SW_Datasheet.pdf)" CreationDate="2011-04-05T12:52:15.113" UserId="1293" />
  <row Id="19028" PostId="12587" Score="2" Text="Yes, you'll get back one of these (approximately) 13,108 different values, giving log(13,108)/log(2)=13.68 bits. However, since what marketing people call a &quot;16-bit DAC&quot; has a somewhat lower effective number of bits -- the ENOB should be documented in the datasheet of the DAC -- your effective precision (ENOB) will also be somewhat lower than 13.68 bits. Hopefully that will still be more than adequate for your application; otherwise you'll have to improve the ENOB by one technique (18 bit DAC?) or another (voltage divider and op-amp? software dithering and low-pass filter?)." CreationDate="2011-04-05T13:43:01.590" UserId="813" />
  <row Id="19032" PostId="12562" Text="Actually the MAX611 datasheet shows an example use with an isolation transformer." CreationDate="2011-04-05T14:11:19.773" UserId="3726" />
  <row Id="19033" PostId="12521" Text="+1 for clear freehand drawings, rather than &quot;proper&quot; CAD drawings that are often harder to understand." CreationDate="2011-04-05T14:18:39.780" UserId="813" />
  <row Id="19034" PostId="12586" Score="1" Text="Why not use the full range of the DAC between 4 and 5 V?" CreationDate="2011-04-05T14:22:19.593" UserId="142" />
  <row Id="19035" PostId="12589" Score="1" Text="Do you pay per hour that the electricity is turned on, or do you pay per unit of energy that you use?  :)" CreationDate="2011-04-05T14:23:41.093" UserId="142" />
  <row Id="19038" PostId="12592" Text="Oh, you want a 1000V input... Where do you get this 1000V from?" CreationDate="2011-04-05T14:34:51.400" UserId="659" />
  <row Id="19039" PostId="12565" Text="Looks like I need to pick up some flux and keep practicing. I did manage to get power and 3 status pins soldered and got the status wired up to LEDs to confirm I didn't destroy the component. Thanks all." CreationDate="2011-04-05T14:36:35.627" UserId="1227" />
  <row Id="19040" PostId="12592" Text="@jpc: I won't actually apply 1000V, but one or two hundred volts from a solar panel made of cells connected in series might be there. I am just trying to find out if this is a feasible way to do such conversions, and then I'll go on choosing the exact input voltage range. I also need something for rectified mains power input, but that'll probably need an isolation transformer, so things get more complicated. The idea is to combine DC-DC conversion and cell balancing in one go, otherwise I need to design a balancer anyway to each battery cell to go up to 3.6V while charging, no less, no more." CreationDate="2011-04-05T14:45:47.227" UserId="1691" />
  <row Id="19041" PostId="12592" Text="If cabling is not limiting you than maybe two (or three) separate solar panel circuits (with 500V or 340V output each) will be much easier to handle. Most popular cables are not even rated for 1000V operation. Unfortunatelly I am no expert on current balancing." CreationDate="2011-04-05T15:00:01.713" UserId="659" />
  <row Id="19042" PostId="12562" Text="@zydeco100 But this is a normal 50Hz transformer which is heavy and bulky. If you want to go down that route you could just make a simple *transformer + rectifier + linear regulator* supply." CreationDate="2011-04-05T15:04:53.897" UserId="659" />
  <row Id="19043" PostId="12596" Text="@jpc: And what would happen if the battery behind one of the switchers draws less current then others? Will the others down-regulate to the lowest current draw among them all, or something else will happen? As to the input nothing over 600 V will ever possibly appear on the combined input." CreationDate="2011-04-05T15:07:35.033" UserId="1691" />
  <row Id="19045" PostId="12473" Score="1" Text="@Kortuk, I'm new here, wasn't aware of the distinction. Feel free to move / delete my answer if it is inappropriate. I have no desire to cause annoyance. C." CreationDate="2011-04-05T15:16:50.910" UserId="3708" />
  <row Id="19046" PostId="12596" Text="@miernik I expanded the answer. Let me know if you want me to add anything." CreationDate="2011-04-05T15:30:22.683" UserId="659" />
  <row Id="19047" PostId="12550" Score="1" Text="Take one apart and find out what's inside" CreationDate="2011-04-05T15:34:18.297" UserId="142" />
  <row Id="19048" PostId="12562" Text="True.dat  I guess I'm just curious how the newer devices (like waldok, very cool BTW) can do it in a small form factor like this.  Was there some new chip or supercompact transformer that hit the market recently?" CreationDate="2011-04-05T15:43:59.150" UserId="3726" />
  <row Id="19049" PostId="4845" Text="Yes, I've seen some very pretty bits of wire-art sculpture, that also blink an LED or do something else interesting." CreationDate="2011-04-05T16:01:43.553" UserId="813" />
  <row Id="19050" PostId="4845" Text="@mouviciel: Interesting. Could you start a new question something like &quot;What is the most amazing electronic device you've ever seen with no board at all? No PCB, no solderless breadboard, etc.&quot;?" CreationDate="2011-04-05T16:05:10.710" UserId="813" />
  <row Id="19051" PostId="871" Text="Would any of the chips mentioned in http://electronics.stackexchange.com/questions/6676/which-sipo-chip-is-better-74hc4094-or-74hc595-or-something-else work for you?" CreationDate="2011-04-05T16:10:41.140" UserId="813" />
  <row Id="19052" PostId="12473" Text="@charles, I am asking if you would edit and improve your answer. No need to remove it. You will get more upvotes the other way." CreationDate="2011-04-05T16:11:37.707" UserId="230" />
  <row Id="19053" PostId="12591" Text="Thanks for the concern.  I don't need to reinvent the wheel, I just need to locate the components and/or schematic to implement this small power supply in my design.  I plan to build a small run of these devices and I really don't want to tell my CM house to &quot;buy these dongles from monoprice and tear them apart&quot;." CreationDate="2011-04-05T16:14:07.123" UserId="3726" />
  <row Id="19054" PostId="12591" Score="1" Text="Sorry, your intent for manufacturing was not apparent from your question. Maybe check the LinkSwitches I added to the answer." CreationDate="2011-04-05T16:35:36.927" UserId="659" />
  <row Id="19055" PostId="12562" Text="@zydeco100 They use switch-mode supplies with small ferrite transformers for designed high frequency of operation. The problem with these is obtaining the transformers (they are either expensive or custom designed and made in large quantities) and making the SMPS robust to surges and stuff (traditional 50/60Hz transformers give this one for free)." CreationDate="2011-04-05T16:38:23.353" UserId="659" />
  <row Id="19056" PostId="12602" Score="4" Text="Sorry, but I fail to see any correspondence between the title and the actual question in the body. Could you consider rewriting the title to be more precise?" CreationDate="2011-04-05T16:47:50.570" UserId="659" />
  <row Id="19057" PostId="12562" Text="zydec0100: Of course it's not easy to find!  It's a Maxim part!  They make lots of neat parts you will never be able to source in quantity at manufacturing time because they've driven away all of their distributors." CreationDate="2011-04-05T16:59:18.227" UserId="2664" />
  <row Id="19058" PostId="12562" Text="This part appears to be obsolete; so this is pointless." CreationDate="2011-04-05T17:07:48.603" UserId="1407" />
  <row Id="19059" PostId="12292" Text="@Madmanguruman I think I would be better to mention them in your answer instead of the &quot;normal&quot; stuff." CreationDate="2011-04-05T17:08:23.947" UserId="659" />
  <row Id="19060" PostId="12606" Score="2" Text="I do not know the answer but I wonder if there is any correlation to _BCD to 7-Segment Decoder's_?" CreationDate="2011-04-05T17:11:00.543" UserId="2612" />
  <row Id="19061" PostId="12607" Text="How often does an application want to do nothing with a date and time other than display it?  It seems to me that it's far more common to want to do things like compute a time some distance in the future, or determine how much time has elapsed since some particular event, etc.  Which is easier to compute: the date and time 45 seconds after 28-Feb-2000 23:59:52, or 5097582+45 (the latter value assuming midnight 01-Jan-2000 as the epoch)?  How about determining whether 5 minutes have elapsed between 28-Feb-2000 23:59 and 01-Mar-2000 00:03 (vs 5097540.0 and 5184180.0)" CreationDate="2011-04-05T17:44:45.843" UserId="3123" />
  <row Id="19062" PostId="12607" Text="An RTC with a 48-bit counter for 65,536ths of a second and a alarm-compare module which covered the bottom 24 bits or so would be extremely handy for low-power systems since it could be used as the basis for OS scheduling independent of processor waking and sleeping.  If something's supposed to happen 4 seconds from now, the system could note the RTC value when the event should occur.  If 2 seconds from now the processor finds itself with nothing to do, it could set the RTC alarm and go to sleep.  When the event should occur, the system would wake up." CreationDate="2011-04-05T17:53:58.937" UserId="3123" />
  <row Id="19063" PostId="12571" Text="A skinny tip is actually harder to solder with.  About 2mm chisel is as fine as I would recommend." CreationDate="2011-04-05T17:57:21.863" UserId="411" />
  <row Id="19065" PostId="12608" Score="1" Text="the WFI instruction does not require interrupts to be enabled to wake the processor, the F and I bits in CPSR are ignored." CreationDate="2011-04-05T18:05:58.303" UserId="1438" />
  <row Id="19066" PostId="12610" Text="The 48-bit number would be a 32-bit number of seconds and a 16-bit fraction.  Working with 32-bit numbers on an 8-bit micro isn't that bad.  I can imagine that on something like a 6502 which could handle packed BCD nicely, the BCD format might save a few bytes in some cases, though the added complexity of handling carry between seconds-hours-minutes would offset any advantage.  But surely the people who built an RTCC into ST micro's ARM chips weren't expecting someone to use a 6502 to process the data--not with a 32-bit ARM sitting right there!" CreationDate="2011-04-05T18:20:06.767" UserId="3123" />
  <row Id="19067" PostId="12590" Text="@BG100: Thanks for clarifying me." CreationDate="2011-04-05T18:22:29.077" UserId="3734" />
  <row Id="19068" PostId="12608" Text="@Mark I must have missed that bit in the docs, do you have some links/pointers about it? What happens to the interrupt signal that woke up the core? Does it stay pended until interrupt are enabled again?" CreationDate="2011-04-05T18:44:01.293" UserId="1082" />
  <row Id="19069" PostId="12613" Text="This is a 1992 pure-mechanic, no electronics (besides the simple regulator on the alternator) car, no-OBDII, nothing more high-tech then a diode or light bulb is in this car I want to install this measuring device in. As to the accelerometer method, well, that will measure how much power is needed to move the car, but not how much engine power is used - which will be more because of losses in transmission. So I am looking for something to measure how much power the engine generates. Although it might be useful to measure both and calculate the transmission efficiency out of that." CreationDate="2011-04-05T18:55:45.517" UserId="1691" />
  <row Id="19070" PostId="12601" Text="The WFI instruction doesn't put the core to sleep if its wake condition is true when the instruction is executed.  For example if there is an uncleared IRQ when WFI is executed it act as a NOP." CreationDate="2011-04-05T18:56:07.623" UserId="1438" />
  <row Id="19071" PostId="12615" Text="@Adam P: nowhere I am trying to step-up the voltage here, maybe you didn't understand my question. What I am trying to do is to increase the input-voltage range of the DC-DC converter by stacking them in series." CreationDate="2011-04-05T19:00:19.197" UserId="1691" />
  <row Id="19072" PostId="12615" Text="@miernik: You are quite right, answer updated." CreationDate="2011-04-05T19:00:52.460" UserId="3635" />
  <row Id="19073" PostId="12612" Score="3" Text="Let's take a look at the constant. Power in this sense is  moment of force times angular velocity. A problem here are RPM. Let's turn them into angular velocity. So we have number of circles that is made each minute. A single circle is $2 \Pi$ and each minute has 60 seconds, so formula would be $\omega=\frac {2 \Pi RPM} {60}$. When we calculate that, we get it to be approximately 0.1047195512*RPM = C*RPM. Now lets turn multiplication into division. $C^{-1}\approx 9.54929658548$. And since we're using kilowatts, we divide everything by 1000, so in the end we get divisor of around 9549.29658548" CreationDate="2011-04-05T19:08:00.567" UserId="1240" />
  <row Id="19074" PostId="12608" Text="@Igor Skochinsky The ASM reference manual is here: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0489c/CIHEGBBF.html more specific information for the cortex-m3 is here: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0552a/BABHHGEB.html in short when a masked interrupt becomes pending the core wakes up and continues operation after the WFI instruction.  If you tried to issue another WFI without clearing that pending interrupt the WFI would act as a NOP (the core wouldn't sleep since the wake condition for WFI is true)." CreationDate="2011-04-05T19:08:41.940" UserId="1438" />
  <row Id="19075" PostId="12612" Text="So I guess that the number comes form someone approximating it at one point." CreationDate="2011-04-05T19:10:01.033" UserId="1240" />
  <row Id="19076" PostId="12613" Score="1" Text="@miernik  Wow, you got me then.  The accelerometer method will indeed measure the power transferred to the road, not the &quot;gross&quot; power of the engine.  I'm not sure that you could measure the power of the engine separate from everything else (transmission, alternator, fan belt, etc) without removing the engine and putting it on a specific test rig.   As for getting the tach, you could get power from the cigarette lighter and looks for engine noise on that." CreationDate="2011-04-05T19:13:47.037" UserId="3624" />
  <row Id="19078" PostId="12601" Text="@Mark: The issue would be that if an interrupt is taken between the &quot;if (!dont_sleep)&quot; and the &quot;WFI&quot;, the interrupt condition would no longer be pending when the WFI executes, but the interrupt might have set dont_sleep because it did something that would justify the main loop running another iteration.  On a Cypress PSOC application of mine, any interrupts which should cause an extended wakeup would jinx the stack if the main-line code was about to sleep, but that seems pretty icky and I understand ARM discourages such stack manipulations." CreationDate="2011-04-05T19:32:11.293" UserId="3123" />
  <row Id="19079" PostId="12608" Text="@Mark: One thing I was considering would be to have any interrupt handler which sets dont_sleep also execute an SEV (&quot;Set Event&quot;) instruction, and then use WFE (&quot;Wait For Event&quot;) rather than WFI.  The Gekko examples seem to use WFI, but I would think WFE might also work.  Any thoughts?" CreationDate="2011-04-05T19:37:36.980" UserId="3123" />
  <row Id="19080" PostId="12616" Score="1" Text="How long do you plan on running your projector? How much power does your projector take? What's the most weight/volume that you're willing to lug around?" CreationDate="2011-04-05T19:39:17.900" UserId="638" />
  <row Id="19082" PostId="12616" Text="I want it to go for a couple of hours minimum. My laptop charger says on it &quot;ac 19.5 v&quot; .. inout 100v - 240v. I dont actually have a projector but I hopefully want something that is 2500 lumens, something similar to Acer X1261-3D" CreationDate="2011-04-05T19:45:26.663" UserId="2889" />
  <row Id="19083" PostId="12617" Text="Thanks for lots of info. However guess/estimation is not useful for me, because what I want it for is after installing the torque sensor measuring power to also install a fuel flow sensor, and based on that measure the liters/kWh of generated energy for different powers, loads and RPMs to be able to find out at which combination my engine is most efficient in converting fuel into kWh." CreationDate="2011-04-05T19:56:12.697" UserId="1691" />
  <row Id="19084" PostId="12616" Text="also it must be possible to carry/drag on wheels" CreationDate="2011-04-05T20:04:04.220" UserId="2889" />
  <row Id="19085" PostId="12601" Text="@supercat The interrupt may or may not be cleared when WFI executes.  Its up to you and when/where you choose to clear the interrupt. Get rid of the dont_sleep variable and just use a masked interrupt to signify when you want to stay awake or sleep.  You can just get rid of the if statement all together and leave WFI at the end of the main loop.  If you've serviced all requests, clear the IRQ so you can sleep.  If you need to stay awake, trigger the IRQ, its masked so nothing happens, but when WFI tries to execute it will NOP." CreationDate="2011-04-05T20:04:22.800" UserId="1438" />
  <row Id="19086" PostId="12610" Score="1" Text="@supercat - while not hard, doing the 32 bit work on the 8 bit micro is still a pain in the &lt;bleep&gt;. And on something like a PIC (with VERY limited instruction &amp; register &amp; ram spaces) it's even more of a pain. As to the ARM chip - I'm going to bet that has more to do with historical precedent than anything else - everyone's used to doing it that way, so they keep doing it that way. " CreationDate="2011-04-05T20:08:48.237" UserId="259" />
  <row Id="19087" PostId="12601" Text="@supercat At a more fundamental level, it seems that your trying to mix an interrupt-driven design with a 'big main loop' design, which is usually non time critical, often polling based and has minimal interrupts.  Mixing these can get rather ugly rather fast.  If at all possible choose one design paradigm or the other to use.  Remember that with modern interrupt controllers you basically get preemptive multitasking between interrupts and what amounts to task queues (service one interrupt, then the next higher priority, etc).  Use that to your advantage." CreationDate="2011-04-05T20:10:09.923" UserId="1438" />
  <row Id="19088" PostId="12617" Score="2" Text="@miernik Unfortunately there is no reasonable way to do what you want, there is a reason that dynamometers are expensive, calibrated devices.  The only other option is to instrument your vehicle to the level that F1 cars are, but the sensors and modifications alone for such an endeavor would cost many thousands of dollars.  The best your going to get is an estimate of wheel horsepower." CreationDate="2011-04-05T20:27:51.907" UserId="1438" />
  <row Id="19089" PostId="12591" Text="Those look a lot easier to get and come with reference designs.  Thank you. " CreationDate="2011-04-05T20:28:17.087" UserId="3726" />
  <row Id="19091" PostId="8870" Text="Well, this could be interesting - now I want to &quot;network&quot; this thing so I can access it from work to operate stuff, turn my stuff on/off when I am not home to make thieves think I am home." CreationDate="2011-04-05T20:55:51.430" UserId="3381" />
  <row Id="19092" PostId="12292" Text="Agreed and amended." CreationDate="2011-04-05T20:59:19.490" UserId="1293" />
  <row Id="19093" PostId="12592" Text="Don't do it. There are various safety issues." CreationDate="2011-04-05T21:26:37.180" UserId="206" />
  <row Id="19094" PostId="12623" Score="3" Text="But if the PIC is busy updating the display, how's it going to raise the fuel rods in time!" CreationDate="2011-04-05T21:28:08.477" UserId="566" />
  <row Id="19096" PostId="12618" Text="Why are a few dozen calls/sec a problem?  I wouldn't bother unless the project is fully functional and bug-free." CreationDate="2011-04-05T21:53:47.130" UserId="1407" />
  <row Id="19097" PostId="12626" Text="@Leon Heller  3.8% isn't bad.  Assuming 8 data bits, 1 stop, and 1 start bit (10 bits total) then you're 38% of one bit time off at the end of each byte.  RS-232/485 will work with up to 50% of one bit time off at the end of the byte.  Sure, it becomes less tolerant of noise, but there shouldn't be much noise with a 1 meter cable on a balanced signal (if things are done properly).  " CreationDate="2011-04-05T21:55:07.323" UserId="3624" />
  <row Id="19098" PostId="12626" Score="1" Text="It is too high. There could be some error at the other end, as well, which would make things worse. http://pdfserv.maxim-ic.com/en/an/AN2141.pdf" CreationDate="2011-04-05T22:01:07.667" UserId="305" />
  <row Id="19099" PostId="12601" Text="@Mark: I developed a system which used a PIC 18x pretty well in a battery-powered application; because of stack limitations, it couldn't handle too much within an interrupt, so the vast majority of stuff gets handled in the main loop on an as-convenient basis.  It mostly works pretty well, though there are a couple of spots where things get blocked for a second or two because of long-running operations.  If I migrate to an ARM, I may use a simple RTOS to make it easier to split up the long-running operations, but I'm not sure whether to use preemptive or cooperative multitasking." CreationDate="2011-04-05T22:07:35.833" UserId="3123" />
  <row Id="19100" PostId="12626" Text="@Leon Heller  Maybe so.  But it should be possible to calculate the total error for both sides and see what the total error is." CreationDate="2011-04-05T22:12:37.620" UserId="3624" />
  <row Id="19101" PostId="12601" Text="@Mark: On a couple of 8x51 and TMS320xx projects I've used self-written cooperative multitaskers to very good effect.  One great advantage of cooperative multitasking is that locking is only necessary if a thread will need exclusive control over a resource for longer than it should hold the CPU.  In most cases there was no contention at all; on the occasions when it occurred, or I could decide that one particular task was always allowed to use a resource, and all other tasks had to work around it.  For example, a pointer to a buffer that one thread could relocated...." CreationDate="2011-04-05T22:15:04.250" UserId="3123" />
  <row Id="19102" PostId="12626" Text="That isn't necessary with a smaller error." CreationDate="2011-04-05T22:18:01.653" UserId="305" />
  <row Id="19104" PostId="12601" Text="@Mark: ...was owned by the thread that populated the buffer and that thread could move it whenever it wanted; the thread that read from the buffer had assume that on any taskswitch() call the buffer could move.  In a pre-emptive tasking system, it would be necessary for all code that dereferenced the pointer to acquire a lock on it and ensure the it got released.  In the cooperative multitasking system, the implicit lock created in areas without a taskswitch() call was sufficient." CreationDate="2011-04-05T22:19:27.457" UserId="3123" />
  <row Id="19105" PostId="12550" Score="1" Text="endolith: I did and found Chinese HV BJTs almost nobody heard about, a transformer, several resistors and residual flux all over the place. ;]" CreationDate="2011-04-05T22:29:05.047" UserId="659" />
  <row Id="19106" PostId="12624" Score="1" Text="@damian, you never explained how you could tell there were noise problems. Bad data? Oscope measurements, share this. People are grasping at the only thing you told them." CreationDate="2011-04-05T22:31:56.180" UserId="230" />
  <row Id="19107" PostId="12624" Text="As many already noted 3.8% is excessive but what do you have on the receiving side of your 485 link?" CreationDate="2011-04-05T22:32:43.423" UserId="659" />
  <row Id="19108" PostId="12559" Text="All the logic has to have a common ground, otherwise 5v out from the arduino might not look like 5v in at the L293.   This is true in any logic interfacing.    The L293's design requires also that the motor supply shares a common ground with the logic.   It *is* possible to make fully isolated H-bridges, but with *this* chip, use a common ground.  " CreationDate="2011-04-05T22:47:22.147" UserId="389" />
  <row Id="19109" PostId="12629" Text="I've coded for the Atari 2600 (128 bytes RAM), and I know the virtues of BCD.  Things like scores are nearly always computed in BCD; level numbers sometimes are.  Even on a 6502, though, I would expect that if I needed to determine whether two date/times were within five minutes of each other and determine whether daylight saving time was in effect, code to convert a 32-bit seconds counter into YMDHMS would be about as compact as code to do those computations without doing such conversions.  As for newer CPUs, I've seen some with straight 32Khz counters that require the main CPU to be alive..." CreationDate="2011-04-05T22:50:36.607" UserId="3123" />
  <row Id="19110" PostId="12629" Text="...but the chips I've noticed which have a separately-powered RTCC use BCD YMDHMS." CreationDate="2011-04-05T22:51:03.753" UserId="3123" />
  <row Id="19111" PostId="12559" Text="To be absolutely clear, connecting 5v+GND from arduino to logic power, and connecting 6v battery to motor power (and GND) will work.  This is how the chip is intended to be used.   Also, here is some more info on decoupling capacitors: http://electronics.stackexchange.com/questions/2272/what-is-a-decoupling-capacitor-and-how-do-i-know-if-i-need-one" CreationDate="2011-04-05T22:52:48.897" UserId="389" />
  <row Id="19112" PostId="12559" Text="Ok. So he creates this common ground that is shared by both the motor and logic by adding both the ground for the batteries and the arduinos ground. If the decoupling capacitor is stuck directly between the battery pack + and -, how does it protect the voltage spikes from going to the arduino ground?" CreationDate="2011-04-05T22:58:16.003" UserId="2873" />
  <row Id="19113" PostId="12610" Text="I wonder what fraction of the people who use RTCC peripherals don't convert dates/times into Unix-style seconds counters?" CreationDate="2011-04-05T22:58:35.927" UserId="3123" />
  <row Id="19114" PostId="12602" Text="Ok, I took a shoot at the title myself. Feel free to correct me if you wish." CreationDate="2011-04-05T23:09:39.037" UserId="659" />
  <row Id="19115" PostId="12618" Text="I've noticed that if I continuously displaying some number in the main busy loop, the button response becomes slow. I.e., to detect that a button has been pressed, I have to press that button a bit longer. This happens when system clock is running 32768 Hz." CreationDate="2011-04-05T23:10:00.203" UserId="3720" />
  <row Id="19116" PostId="12610" Score="1" Text="supercat: All of them? Of what use are Unix-style timestamps in a clock? OTOH your only use case is RTOS alarms which are better served with a normal timer or with a simple &quot;second increment&quot; interrupt from the RTC." CreationDate="2011-04-05T23:11:41.253" UserId="659" />
  <row Id="19117" PostId="12618" Text="Are you using interrupts?  Why are you using a 32kHz xtal; usually you can get lower power performance if you operate faster and go to sleep when idle." CreationDate="2011-04-05T23:13:43.817" UserId="1407" />
  <row Id="19118" PostId="12621" Text="no, don't have enough memory. I want to do that using addition, subtraction and bit shift." CreationDate="2011-04-05T23:15:48.307" UserId="3720" />
  <row Id="19119" PostId="12618" Text="i'm using interrupts. but just to update display it doesn't worth to switch to high speed oscillation. power-wise. for my project. it has to be run low speed clock nearly 90% of its life time." CreationDate="2011-04-05T23:20:29.283" UserId="3720" />
  <row Id="19120" PostId="12635" Text="While editing the title it occurred to me that we have to leave in a funny age when people need to drag 60 pound lead acid batteries to power their laptop for 2,5 hours. :P" CreationDate="2011-04-05T23:33:16.220" UserId="659" />
  <row Id="19121" PostId="12631" Text="If a chip has the ability to ignore certain bits in its alarm function, I suppose interrupts every ten seconds, sixty seconds, ten minutes, or hour might be nicer than at power-of-two increments, but &quot;alarm = GET_RTC_SECONDS(); alarm -= (alarm % 360)-360; SET_ALARM_SECONDS(alarm); is hardly difficult." CreationDate="2011-04-06T00:27:11.153" UserId="3123" />
  <row Id="19122" PostId="12631" Text="I've just started using the Gekko, which has a 24-bit RTC that's almost what I want except that it can't keep time when the processor's dead.  I was also looking at an ST Micro ARM, which has a silly BCD RTC module which only supports interrupts on a one-second basis.  If the ST chip would never be without power for more than three years, I could jinx the RTC prescalars to run at 32x speed, and then use software tricks to compensate, thus getting 1/32-sec time resolution on the wakeup events, but the times stored in the RTC would have no meaningful relation to calendar time and..." CreationDate="2011-04-06T00:32:09.710" UserId="3123" />
  <row Id="19123" PostId="12631" Text="...so the necessity of converting from the RTC's silly format to 1/32-second increments would be annoying, especially since such a conversion would be required on every sleep/wakeup cycle.  I guess I'm curious how many people use RTCC readouts without converting into unified seconds.  Maybe there are enough to make YMDHMS format worthwhile, but to my mind it's far more useful to reserve YMDHMS for *human* I/O, and use straight seconds (or whatever fraction thereof) for everything else." CreationDate="2011-04-06T00:37:43.587" UserId="3123" />
  <row Id="19124" PostId="12610" Text="@jpc: What if you want to determine whether a given date is in daylight saving time, or determine whether a program that starts on a certain date/time and lasts a certain length will overlap another one?  Such things are easy with straight seconds, but harder with YMDHMS.  As for using a normal timer, what I use at present is a 1/16-sec tick from an RTC chip driving TMR1 and TMR3 on a PIC; that gives me a 1/16-second-accurate wakeup that works even when the main CPU clock is stopped, and I derive all my timing from that." CreationDate="2011-04-06T00:44:58.977" UserId="3123" />
  <row Id="19125" PostId="12612" Text="9548 is 1000 x 60 / (2 * pi). You divide out the 2pi/60 to change RPM to radians/sec, and dividing out the 1000 gives you the answer in kW rather than just plan watts." CreationDate="2011-04-06T01:00:40.717" UserId="740" />
  <row Id="19126" PostId="10379" Score="1" Text="@Andreja - If you include the `http://` part, it gets parsed into a URL automatically (and the whole `http://www.` prefix gets dropped): http://www.analog.com/static/imported-files/data_sheets/AD676.pdf" CreationDate="2011-04-06T01:16:54.933" UserId="857" />
  <row Id="19127" PostId="12618" Text="As general note, the book **Hacker's Delight** by Henry S. Warren, Jr. is *the* source for clever bit-twiddling trickery. I looked for division suggestions, and it doesn't have anything for divide by 10 that is superior to any of the answers below." CreationDate="2011-04-06T01:39:10.127" UserId="1494" />
  <row Id="19128" PostId="12640" Text="The Panda itself is based on an ARM SOC, and is available as a loose chip, preloaded with the framework. But it is a fine pitch package and requires really good soldermask and a stead hand to hand-solder." CreationDate="2011-04-06T01:41:11.857" UserId="1494" />
  <row Id="19129" PostId="12631" Text="@supercat Try that with several alarm lengths (every 10 seconds + every minute). Basically RTCs are *Real Time Clocks* and not monotonic clocks you should base your RTOS timer on. How do you cope with setting the correct time with your RTC based alarms? You may find your system sleeping for a day or a year if the user set the wrong date, you set an alarm and later the user corrects the date." CreationDate="2011-04-06T02:01:25.260" UserId="659" />
  <row Id="19130" PostId="12610" Score="1" Text="@supercat For daylight saving you are doomed since timezone databases are huge and change twice a year. Forget doing this on a really embedded system. The second operation you mention is easy with a second counter but then displaying the date is quite difficult. If it weren't you would not be complaining about the reverse operation. If you need to measure time periods -- use a timer and if you want dates -- use an RTC. What you did on your PIC is the best of both worlds (an RTC and a monotonic counter derived from the same reference)." CreationDate="2011-04-06T02:08:04.820" UserId="659" />
  <row Id="19131" PostId="6113" Text="Just a small correction, stacking two batteries in series would get you to 3.1V if each one is 1.55V but it would not double the capacity so you'd still have 190mAh if that is what each battery is." CreationDate="2010-11-03T12:41:40.907" UserId="1819" />
  <row Id="19132" PostId="12610" Text="Applications I've done didn't use Unix-style timestamps at all until we starting adding support for NTP. Although I'd have to say calculating time differences is easier using the Unix-style timestamps." CreationDate="2011-04-06T02:21:20.993" UserId="588" />
  <row Id="19134" PostId="12640" Text="Interesting. I didnt know you could get that chip preloaded with the framework. To program AVRs, you generally need a seperate hardware programmer, although I've seen Arduinos used for this as well. Is it the same with the ARM SOC?" CreationDate="2011-04-06T02:30:29.067" UserId="3344" />
  <row Id="19135" PostId="12610" Text="@mjh2007 Unix timestamps (by design and implementation)  completely ignore leap seconds which makes them a little problematic as an absolute frame of reference. But they are much better than ISO date strings based on local time without *proper* timezone markings." CreationDate="2011-04-06T02:32:39.410" UserId="659" />
  <row Id="19136" PostId="12635" Text="You know what's funny? I forgot that laptops can operate while not plugged in.... shows you how I use my laptop :)  At any rate, the laptop is only about 15% of the load. Just keep telling yourself it's for the projector." CreationDate="2011-04-06T02:34:04.160" UserId="638" />
  <row Id="19138" PostId="12602" Text="Hmm.. what about this? http://sparkbangbuzz.com/mag-amp/mag-amp.htm" CreationDate="2011-04-06T02:58:52.520" UserId="708" />
  <row Id="19139" PostId="12635" Text="@W5V0 What can I say? Get a Mac(Book Pro)? ;]" CreationDate="2011-04-06T03:01:23.937" UserId="659" />
  <row Id="19141" PostId="12635" Text="@jpc It's almost 4 years old, and I always want the battery charged &quot;just in case&quot; I can't plug in. Although if you leave the screen off (you ARE plugging into a projector) your laptop could probably last for a very long time on its own battery." CreationDate="2011-04-06T04:03:45.873" UserId="638" />
  <row Id="19142" PostId="12644" Score="1" Text="I think he wants to make his kit as accessible to the public as possible, so something as pricey as the Panda doesn't make a lot of sense." CreationDate="2011-04-06T04:17:52.503" UserId="2288" />
  <row Id="19143" PostId="12644" Text="Exactly. This is for a kit and the chip shouldnt be doing much at all, so I don't need all the extra power. I'm looking for a controller thats $5 or less that I can include in the kit so the user can solder it (and other components) onto the PCB and just go. So Dave, you're exactly right. The Panda makes no sense here." CreationDate="2011-04-06T05:24:20.223" UserId="3344" />
  <row Id="19144" PostId="12475" Text="@Madmanguruman I'd love to select this as the answer, if you can just clear up that one last point for me." CreationDate="2011-04-06T05:48:51.683" UserId="3707" />
  <row Id="19146" PostId="12640" Text="Its available from the [GHI](http://www.ghielectronics.com/catalog/category/21/) (makers of the Panda) as the USBizi100 or USBizi144 depending on pin count and functions. It's an LPC2387 or LPC3288 ARM7 chip from NXP with internal 512KB FLASH and 96KB SRAM and lots of peripherals, preloaded with the .NET micro framework. Its often possible to order chips like this pre-programmed. The distributor will use a DataIO or similar device to do the job on the bare package." CreationDate="2011-04-06T06:59:44.287" UserId="1494" />
  <row Id="19147" PostId="12644" Score="1" Text="The bare chip runs just under US$20 for single units. And its a 100 or 144 pin LQFP which is a bit of a bear to solder down by hand without all the right tools." CreationDate="2011-04-06T07:01:15.517" UserId="1494" />
  <row Id="19148" PostId="12640" Score="1" Text="Anything big enough for the .NET micro framework is going to be about as complex as the USBizi100, and tend to have lots of fine pins. You might look at the 32-bit PIC family, some of which is available with lower pin counts. There's also the CORTEX M3 devices such as the STM32F10xxx devices from STMicro. At the really low end they run just a few dollars each, and are nice little ARM cores inside. But still have a lot of pins." CreationDate="2011-04-06T07:03:18.513" UserId="1494" />
  <row Id="19149" PostId="12613" Score="1" Text="A traditional way to get the tach is to sample the low voltage side of the ignition coil and watch the points open and close. You then divide by the number of spark plugs. Seems like torque has to measure force, and that implies load cells somewhere. Perhaps you can make engine mounts with integrated load cells and sum the load on the mount points?" CreationDate="2011-04-06T07:11:23.657" UserId="1494" />
  <row Id="19150" PostId="12650" Text="would a stepper motor work for you instead of a servo?" CreationDate="2011-04-06T07:17:27.443" UserId="2060" />
  <row Id="19152" PostId="12651" Score="1" Text="All the QFP-&gt;dip sockets I have seen so far are either outrageously expensive or intended as interfaces for a specific DIP programmer (they don't bring out all the pins). Am I missing something?" CreationDate="2011-04-06T08:10:09.670" UserId="1802" />
  <row Id="19153" PostId="12657" Text="http://focus.ti.com/docs/prod/folders/print/msp430g2332.html" CreationDate="2011-04-06T08:13:16.623" UserId="2060" />
  <row Id="19154" PostId="12650" Text="I imagine a stepper motor would work (hence the step control statement above) however I don't have a use for a holding torque (which from my understanding is a significant selling-point of the stepper motors) so was leaning towards DC servo motors. As I'm not a motor expert this could obviously be a misdirected effort on my part... have any enlightened suggestions to help me out? :D" CreationDate="2011-04-06T08:48:42.530" UserId="3744" />
  <row Id="19155" PostId="12646" Text="Looks like a [CW multiplier](http://en.wikipedia.org/wiki/Cockcroft-Walton_generator).&#xA;" CreationDate="2011-04-06T10:29:07.903" UserId="3068" />
  <row Id="19156" PostId="12590" Text="The *only* way I could think that you could do this to save money is if the electric company charged different rates depending on current demand, and you charged the UPS during the cheapest time (low demand hours) and switched to it during peak demand hours. " CreationDate="2011-04-06T10:38:39.967" UserId="693" />
  <row Id="19157" PostId="12638" Text="OK but what would be the point in sending 1 to CTRL? it would disable the signal of those 3 other pins right? TDO is actualy supposed to be output pin, it is true though whenever i set PROG to 1 the DONE pin gives 1 and vice versa.." CreationDate="2011-04-06T10:43:54.910" UserId="3736" />
  <row Id="19158" PostId="12628" Text="Good call. I'm using the internal clock of an ATtiny2313, but I can't change that now. The FT232R which is driving the transmitting allows setting non-standard baud rates. I'll see if I can more closely match the 19966 rate I've given myself..." CreationDate="2011-04-06T11:01:12.220" UserId="3741" />
  <row Id="19159" PostId="12624" Text="@damian, IMHO this does not prove that noise is your main problem. It may still be the baudrate error that is causing this. " CreationDate="2011-04-06T11:16:25.927" UserId="659" />
  <row Id="19160" PostId="12602" Text="@Earlz, It is nice but unfortunately neither cheap nor small." CreationDate="2011-04-06T11:21:45.613" UserId="659" />
  <row Id="19161" PostId="12667" Text="thank you so much! all do I need to prepare is just Arduino, Breadboard, some wires, resistors, RC car, RC remote ? " CreationDate="2011-04-06T12:05:02.107" UserId="3746" />
  <row Id="19163" PostId="12651" Text="@Ranieri, he is talking about PCB adapters. You solder your QFN to them and they spread the small pitch pins to a larger pitch connector. They are one time use only." CreationDate="2011-04-06T12:28:56.097" UserId="659" />
  <row Id="19164" PostId="12624" Text="Fix the baud rate error, then see if you still have problems. You should have done that immediately you saw the magnitude of the error!" CreationDate="2011-04-06T12:34:41.727" UserId="305" />
  <row Id="19166" PostId="12638" Text="I would guess it is used when the JTAG header is not used. If the CTRL line is enabled the DB25 connector will drive the signals to the FPGA. If it is not, the JTAG header will drive the signals." CreationDate="2011-04-06T12:40:12.550" UserId="2395" />
  <row Id="19167" PostId="12651" Score="1" Text="@Ranieri - No, you're not missing anything.  PCB adapters are outrageously expensive; it's cheaper to have an intern (Like me...) dead-bug the chip (assuming pin counts are &lt;64 or so) or to just get the custom PCB for your circuit." CreationDate="2011-04-06T12:41:31.440" UserId="857" />
  <row Id="19168" PostId="12475" Text="It will work fine. In software, you will have to alternate the current flow through the ringer coil by alternating between the diagonally-opposite MOSFETs (turn on upper left and lower right, pause, turn off upper left and lower right, pause, turn on upper right and lower left, pause, turn off upper right and lower left, pause etc.) - You need the pauses in there to ensure that the FETs have time to turn off, else you may get shoot-through." CreationDate="2011-04-06T12:53:35.130" UserId="1293" />
  <row Id="19169" PostId="12637" Text="Here's [a resource from UCC](http://www.chemi-con.com/u7002/life_ms.php) on capacitor life, which elaborates on the above." CreationDate="2011-04-06T12:57:47.110" UserId="1293" />
  <row Id="19172" PostId="12668" Text="I wouldn't recommend using a prism, that will direct a beam of invisible, high-power IR light in an unknown direction.  If you don't want a filter, it's much better to have it in line with the green light, so you can avoid pointing it into people's eyes. A filter will block the IR as opposed to diffracting it; a good one won't block much more than a glass prism would." CreationDate="2011-04-06T13:35:26.517" UserId="857" />
  <row Id="19173" PostId="12638" Text="oh.. I thought it's just the other way around, I'll try it out. thank you" CreationDate="2011-04-06T13:52:22.220" UserId="3736" />
  <row Id="19174" PostId="12667" Text="@kim - You'll need some way to connect the (possibly) variant logic levels and ground references between the Arduino and remote.  Optocouplers are a simple solution for this problem, though you may be able to use just wires (and possibly resistors)." CreationDate="2011-04-06T13:53:16.680" UserId="857" />
  <row Id="19175" PostId="12638" Text="That's what I think at least, but it's kinda hard to be entirely sure without looking at a bigger picture." CreationDate="2011-04-06T13:58:30.747" UserId="2395" />
  <row Id="19176" PostId="12674" Text="The number to be displayed on the LCD is a variable, ranging from -1999 to 1999. It indicates a temperature and is calculated in binary format." CreationDate="2011-04-06T14:06:25.097" UserId="3720" />
  <row Id="19177" PostId="12673" Score="2" Text="often when someone rates their device they are rating the **maximum** current their device will draw." CreationDate="2011-04-06T14:19:22.667" UserId="230" />
  <row Id="19178" PostId="12676" Text="@stevenvh- Thanks. Would l7805 do? Hey and also could you please explain how I should charge these batteries(I'll do this most probably using solar). " CreationDate="2011-04-06T14:21:04.667" UserId="2074" />
  <row Id="19179" PostId="12673" Text="but I think according to stevenvh's answer, if I use voltage regulators, I won't have to bother about the current; am I right?" CreationDate="2011-04-06T14:29:43.763" UserId="2074" />
  <row Id="19180" PostId="12676" Text="78L05 would give you 5 V out, not 9 V." CreationDate="2011-04-06T14:34:44.273" UserId="142" />
  <row Id="19181" PostId="12629" Text="The newer CPUs do this since it is cheaper and uses a little less current (especially important since the semiconductor process used is optimized for making CPUs and not RTCs)." CreationDate="2011-04-06T14:47:09.967" UserId="659" />
  <row Id="19182" PostId="12610" Text="@mjh2007: Maybe I'm odd, but the embedded system (electronic locks) I've been working on for a decade has used Unix-style timestamps from the start, even before I started using a separate RTC chip (I went to a separate RTC chip so that reboots wouldn't clobber the time).  Adding daylight saving wasn't hard too bad--the rules are defined in terms of two single-byte parameters: &quot;first_spring&quot; and &quot;last_fall&quot;.  The next generation added a display which could actually show the date, and the one after that added an &quot;I2C&quot; RTC chip which couldn't use hardware I2C because it sent data LSB first." CreationDate="2011-04-06T14:48:22.890" UserId="3123" />
  <row Id="19183" PostId="12610" Text="@mjh2007: The generation after that started using a 16Hz signal from the RTC chip as a time base for most events, which allowed the CPU to go to sleep while events were pending (earlier ones used the primary crystal for all timekeeping except the real-time clock, which meant the CPU had to stay awake whenever the thing wasn't completely idle).  Now I'm looking at choosing an ARM-based core for the next generation, and find it frustrating that haven't yet noticed any with a nice unified timer that's suitable for both event timing and wall time." CreationDate="2011-04-06T14:50:39.047" UserId="3123" />
  <row Id="19184" PostId="12676" Score="1" Text="@gomek - endolith mentions the 78**L**05. Not only will this give you 5V, it the &quot;L&quot; version will also limit the output current to 100mA. So you don't want the 78L09, you want the 7809!" CreationDate="2011-04-06T14:53:49.750" UserId="2064" />
  <row Id="19185" PostId="12676" Text="@gomek - what kind of battery is this? Lead-acid?" CreationDate="2011-04-06T14:55:36.690" UserId="2064" />
  <row Id="19186" PostId="12673" Text="@gomek they voltage regulator will have a current limit as well that you will need to make sure you dont exceed." CreationDate="2011-04-06T14:58:30.490" UserId="319" />
  <row Id="19187" PostId="12610" Text="@jpc: What I'd like would be a long-running battery-backed timer that could provide wakeups with decent resolution (1/16 sec at absolute worst--preferably something like 1/256 or 1/4096 sec), and preferably something whose registers could be written without worrying about clock synchronization and such.  Gekko has pretty much what I'm after, except that I'd like something that could keep long-term time with the CPU powered down, and I'm a little worried that synchronizing the timer-compare register with the 32Khz clock might sometimes cause trouble..." CreationDate="2011-04-06T15:03:45.490" UserId="3123" />
  <row Id="19188" PostId="12679" Score="3" Text="@RobertAtkins, I am sure you know this, but I thought I would say for others. 1C for an 1.8Ah Lithium Ion battery would be 1.8A. 1C is equal to the current you need to discharge in 1 hour nominally." CreationDate="2011-04-06T15:03:53.810" UserId="230" />
  <row Id="19189" PostId="12646" Score="1" Text="Go to http://www.falstad.com/circuit/ and select &quot;Voltage Doubler 2&quot; from the example circuits" CreationDate="2011-04-06T15:05:20.377" UserId="142" />
  <row Id="19190" PostId="12657" Text="thanks for the tips on the newer parts.  I was originally going to say that I'd like to confirm that I'm outside of the capabilities of the smaller chip, but it might also be nice to have a hardware UART.  Decisions, decisions..." CreationDate="2011-04-06T15:05:58.843" UserId="2288" />
  <row Id="19191" PostId="12673" Score="1" Text="@gomek, I am trying to help with understanding. In electronics we control voltage in almost all applications. If they say their device is rated to 9V then it will pull the current it needs. If it says it will pull 1A it will pull 1A. There is no need for you to handle this. If it is electronics of any sort the current draw probably varies a large amount and a series resistor is a poor method for regulation." CreationDate="2011-04-06T15:06:13.810" UserId="230" />
  <row Id="19192" PostId="12610" Text="@jpc: ...in cases where I schedule a timer wakeup but get awakened by something else within 100us that requires me to schedule a different timer wakeup.  I would guess that busy-waiting in such an event before re-updating the Gekko's timer-compare register shouldn't cause a problem, but I'm not sure." CreationDate="2011-04-06T15:06:20.603" UserId="3123" />
  <row Id="19193" PostId="12676" Text="@stevenvh- yes it's lead acid" CreationDate="2011-04-06T15:08:22.350" UserId="2074" />
  <row Id="19194" PostId="12678" Text="Excellent! thanks." CreationDate="2011-04-06T15:12:08.550" UserId="3720" />
  <row Id="19195" PostId="12657" Text="Hmm... looks to me like none of the MSP430G chips have a UART.  See http://focus.ti.com/en/multimedia/flash/selection_tools/mcu/mcu.html.  What's the difference between MSP430C/F/G?  Looks like the F and C types have UARTs available, but I don't think they are compatible with LaunchPad since they don't even come in a DIP package." CreationDate="2011-04-06T15:13:53.607" UserId="2288" />
  <row Id="19196" PostId="12631" Text="@jpc: I do it with several alarm lengths pretty nicely; it would be better if the PIC's timers had compare registers that could operate in async mode, but fortunately there are two 16-bit timers that operate off the same 16Hz clock. Timer 1 free-runs, and I keep track of the last value I observe. For Timer 3, I compute how many 16ths of a second I should sleep, and if the answer is 2-240, I load a value 0xFF10 to 0xFFFE and make sure Timer 1 hasn't moved. If only 1/16 second remains, I busy-wait, since PIC timers will take 65,537 counts to signal overflow if loaded with 0xFFFF." CreationDate="2011-04-06T15:14:51.060" UserId="3123" />
  <row Id="19197" PostId="12631" Text="@jpc: A few timing events like lockout timers, are stored in flash and are based on wall time (to prevent someone from trying a bunch of bogus combinations, power-cycling the machine or ESD-zapping it to induce a reset, trying a bunch more, etc.).  Setting the wall time invalidates all such events (supervisor credentials are required to set wall time)." CreationDate="2011-04-06T15:19:15.610" UserId="3123" />
  <row Id="19198" PostId="12631" Text="@jpc: My inclination would actually have been to never set the RTC-chip time, but instead keep &quot;time since clock battery was installed&quot;, and store the difference between that and wall time.  I used that approach in one generation of the product which used a separate PIC for keeping battery-backed time (the time on that PIC was read-only) and would use it on a chip with a straight counter.  It seemed like a somewhat goofy idea, though, to have the machine's RTC store a meaninglessly-date-formatted value, though if I use the ST Micro chip I might just do that." CreationDate="2011-04-06T15:23:42.393" UserId="3123" />
  <row Id="19200" PostId="12676" Text="@gomek - I haven't used lead-acid in ages, but IIRC charge for 14 hours at 2.3V per cell (13.8V if you place both batteries in series), current limited to 10% of nominal capacity, here 400mA. But I'd like to see these numbers confirmed by an expert!" CreationDate="2011-04-06T15:31:21.247" UserId="2064" />
  <row Id="19201" PostId="12671" Score="1" Text="Thanks for these links. Unless someone can show me otherwise, I've concluded that .Net enabled chips are likely overkill for small, single purpose kits. It seems I'm better off just programming some AVRs for this purpose and saving .Net MF for larger goals." CreationDate="2011-04-06T15:38:00.940" UserId="3344" />
  <row Id="19202" PostId="12629" Text="@jpc: Why is it cheaper and lower-current to use BCD YMDHMS?  I would think a 47-bit read-only counter with a comparator on the bottom 32 bits would be simpler than all the date-parsing stuff in an RTC chip.  Unless there's some master film of a BCD date circuit which, because of some arcane long-forgotten magic, can be plopped into a design to achieve lower currents than are available with modern methods, I'm not clear why BCD would be cheaper or use less current?" CreationDate="2011-04-06T15:43:33.273" UserId="3123" />
  <row Id="19203" PostId="12668" Text="I wasn't meaning to allow this IR beam to just fly somewhere :-) You can see it with webcam, and block it reliably. " CreationDate="2011-04-06T15:44:41.470" UserId="2062" />
  <row Id="19204" PostId="12650" Text="You will need to provide performance specs before anyone will be able to give you a reasonable answer.  How many degrees do you need to rotate your load, and in how much time?" CreationDate="2011-04-06T16:04:13.950" UserId="2288" />
  <row Id="19205" PostId="12680" Text="Which camera are you using?" CreationDate="2011-04-06T16:25:40.023" UserId="305" />
  <row Id="19206" PostId="12668" Text="+1 for unique use of a prism. You could pass the beam through an aperture further on to block out anything that got split off (assuming they were refracted at a significant angle)" CreationDate="2011-04-06T16:32:28.377" UserId="536" />
  <row Id="19207" PostId="12682" Text="Incandescent lamps don't multiplex well: either the current pulses are too low which results in lamps lighting only faintly, or the light is OK but then the higher current pulses will significantly reduce the bulb's life." CreationDate="2011-04-06T16:43:54.397" UserId="2064" />
  <row Id="19208" PostId="12635" Text="Thank you for this great answer it was very useful indeed" CreationDate="2011-04-06T17:01:59.463" UserId="2889" />
  <row Id="19209" PostId="12635" Text="I checked out the lead battery that you recommended its says its rechargable but doesnt say how one goes about it, how do you recharge that beast?" CreationDate="2011-04-06T17:06:55.937" UserId="2889" />
  <row Id="19210" PostId="12546" Text="I've personally never heard of mbed, I will look it up. " CreationDate="2011-04-06T17:09:48.187" UserId="1476" />
  <row Id="19211" PostId="12629" Text="I was thinking about @Toybuilders answer in which he stated that newer CPUs have only counters and not full-blown RPCs." CreationDate="2011-04-06T17:16:00.753" UserId="659" />
  <row Id="19214" PostId="7668" Text="One thing to keep in mind is that it's tempting to copy-and-paste fab notes from an existing design -- but those requirements may sometimes be contrary to your own interests.   Make sure that you agree with the details, especially when they reference a standard.  Otherwise, you may be spec'ing yourself to a more expensive board than you need!" CreationDate="2011-04-06T18:01:55.767" UserId="3308" />
  <row Id="19215" PostId="12629" Text="@jpc: The ones I've seen with counters, from what I've seen require that the main CPU be kept powered (which requires battery-backing the CPU and risking killing the battery if the CPU gets in a bad state while the main supply is off) and generally make it hard to keep continuous time across things like reboots or firmware updates.  The only one's I've seen with separate battery-backup are YMDHMS-parsed BCD." CreationDate="2011-04-06T18:02:08.170" UserId="3123" />
  <row Id="19216" PostId="12689" Text="@Leon Heller How would I determine correct value?" CreationDate="2011-04-06T18:07:49.447" UserId="1240" />
  <row Id="19217" PostId="12681" Text="Ouch. Trying to not have to custom build it (would much rather just use something off-the-shelf). I think I could get by with as small as 3/8&quot; shaft of aluminium tube that's embedded into my wooden shaft (equilateral triangle 3 5/64&quot; wide, 30 inches tall.). The triangular wooden shaft has 3 vertical tube-light fixtures mounted to it, and the shaft needs to rotate 360 degrees then oscillate back so that each light exposes the vertical polycarbonate aquarium tubes surrounding the shaft. Here's a quick google sketchup: http://goo.gl/fZykD" CreationDate="2011-04-06T18:08:18.833" UserId="3744" />
  <row Id="19219" PostId="12630" Text="great link, thanks! it doesn't only optimizes the speed, it also decreases the code size. I've implemented &quot;12 bit binary to 4 ASCII Decimal Digits&quot; from your link because that doesn't involve any multiplication." CreationDate="2011-04-06T18:13:22.037" UserId="3720" />
  <row Id="19220" PostId="12629" Text="@supercat - there are processors with 32 kHz counters that continue running even when the CPU is halted, as long as minimum power was supplied to the appropriate power pin." CreationDate="2011-04-06T18:27:45.657" UserId="3308" />
  <row Id="19221" PostId="12617" Text="@Mark: another thing came to my mind: is the torque a given engine produces at a given RPM always the same? Or does it varies while I drive? If it would be always the same, then if I get a graph/table of power or torque vs. engine RPM for my engine, it is enough to measure the RPM and I can get the actual torque and power from that graph/table? Or would that not give correct results?" CreationDate="2011-04-06T18:28:41.873" UserId="1691" />
  <row Id="19222" PostId="12607" Text="@supercat - for general purpose computers, let the OS keeping track of time and do &quot;useful things&quot; with that time info.  The RTC is only consulted once to initialize the OS's time info, and then time is updated by interrupts.  But for many simple embedded use, it's much more likely that " CreationDate="2011-04-06T18:31:54.123" UserId="3308" />
  <row Id="19223" PostId="12685" Text="So, how do you setup production for these chips? Is there another fuse setup file I have to generate?" CreationDate="2011-04-06T18:32:31.423" UserId="2157" />
  <row Id="19224" PostId="12607" Text="...it's much more likely that the time is not being kept by the program at all -- instead, anytime time is being used, just read/update the values on the RTC chip." CreationDate="2011-04-06T18:32:38.070" UserId="3308" />
  <row Id="19226" PostId="12679" Score="1" Text="@RobertAtkins: worth to say that there are two values of C ratings: for charge rate (how fast you can charge the battery), and discharge rate (how fast you can discharge it). Also the maximum C rate can be given as &quot;continuous rate&quot; so the battery can run charge or discharge at this rate for an unlimited time, and besides that often a (higher) C rating (only for discharge) is given that a battery can sustain for a limited time, for example 10 seconds." CreationDate="2011-04-06T18:36:23.663" UserId="1691" />
  <row Id="19227" PostId="12629" Text="@Toybuilder: A separate power pin from the main CPU power, or the main CPU power pin?  And are the counters big enough to keep time for an extended period (e.g. a year) without the CPU?  I've had units in the field whose clock-backup batteries died killed when the CPU got into a wonky state; having separate power for the timekeeper would seem a significant plus." CreationDate="2011-04-06T18:45:46.227" UserId="3123" />
  <row Id="19228" PostId="12635" Text="http://electronics.stackexchange.com/q/78/638" CreationDate="2011-04-06T18:53:54.247" UserId="638" />
  <row Id="19229" PostId="12686" Text="3 mF or 3 µF​​?" CreationDate="2011-04-06T19:14:48.463" UserId="142" />
  <row Id="19230" PostId="12686" Score="1" Text="@endolith  30 mF or 30000 µF  ." CreationDate="2011-04-06T19:22:32.173" UserId="1240" />
  <row Id="19231" PostId="12676" Text="@gomek (http://www.datasheetcatalog.org/datasheets2/52/529144_1.pdf) shows a circuit for an adjustable 7-30V output regulator using the 7805 (bottom of page 24)" CreationDate="2011-04-06T19:52:53.937" UserId="3122" />
  <row Id="19232" PostId="12607" Text="@Toybuilder: In a battery-powered device, having the CPU service an interrupt hundreds or thousands of time per second when there's nothing useful to be done is a bad idea.  It's much better to set a precise alarm to wake the CPU when needed.  If an ARM chip had an RTC and a useful wakeup timer, both of which could run off the same 32KHz source, that'd be fine.  I'd just fetch the RTC time once on startup, convert to seconds, and be done with it.  None of the chips I've observed which can run the RTC off a separate battery from the CPU have a good wakeup facility, though." CreationDate="2011-04-06T19:53:42.243" UserId="3123" />
  <row Id="19233" PostId="12607" Text="@supercat - correct - the &quot;tick&quot; interrupt while the OS is running is different from the 32 kHz clock that feeds the RTC and the RTC's wakeup match register.  There is a wide variety of BCD RTC chips - many of the ones I used to use had an alarm functionality -- just set the desired time to match to raise an interrupt which would alert the CPU.  For designs that didn't need the alarm, however, you could also just only keep the RTC and the square-wave output for let the CPU keep track of ongoing time." CreationDate="2011-04-06T20:23:20.863" UserId="3308" />
  <row Id="19234" PostId="12629" Text="Correct - these devices have several types of power pins -  I/O voltage, processing core, RTC, etc.  The RTC power pin would be battery-backed, and would require very low power.  At that point, it becomes a question of whether you had a big enough battery.  As @jpc alluded, the semiconductor process for these high-integration MCU devices are favored for CPU performance, so even in their &quot;off&quot; state, they can end up being much more power hungry than dedicated external RTC chips which are optimized for low power consumption.  " CreationDate="2011-04-06T20:33:30.320" UserId="3308" />
  <row Id="19235" PostId="12689" Score="1" Text="I used 1$k \Omega$ resistor and it's not on fire yet, so I guess this works. " CreationDate="2011-04-06T20:40:19.687" UserId="1240" />
  <row Id="19236" PostId="12607" Text="@Toybuilder: The latter is exactly the approach I ended up using in the last few generations of electronic lock.  My biggest annoyances were the lack of any pulse output choices between 32Khz and 16Hz (since I didn't trust a 1M pullup to operate reliably with a 32Khz open-collector output, the only reasonable choice was 16Hz), and the sloppiness of the PIC's timer circuitry." CreationDate="2011-04-06T20:43:47.267" UserId="3123" />
  <row Id="19237" PostId="12629" Text="@Toybuilder: I don't doubt that the process for making a dedicated RTC chip could yield a more power-efficient device than one for making a general-purpose CPU.  On the other hand, I would think that on either type of chip, a straight counter would require no more current than a BCD YMDHMS one; I would also think that a 48 (or whatever) bit straight counter would require less current than the combination of a 24-bit straight counter and a BCD YMDHMS counter." CreationDate="2011-04-06T20:53:22.450" UserId="3123" />
  <row Id="19238" PostId="12627" Text="So, if the solder mask expansion is too large, then it won't prevent neighboring pads from bridging during soldering.&#xA;&#xA;And if the expansion is too small, then the solder mask will cover the pad, potentially causing uneven placement of the component on the board as well as preventing the component lead from soldering to the pad.&#xA;&#xA;Yes?" CreationDate="2011-04-06T21:06:37.523" UserId="1278" />
  <row Id="19239" PostId="12638" Text="It would also be nice if you could accept my answer if you're satisfied with it." CreationDate="2011-04-06T21:18:59.247" UserId="2395" />
  <row Id="19240" PostId="11329" Score="1" Text="Perhaps &quot;dissolve&quot; for &quot;ablösen&quot;?" CreationDate="2011-04-06T21:25:41.037" UserId="813" />
  <row Id="19241" PostId="12559" Text="I just built the circuit shown in the image below and it ran correctly this time. There isn't a smoothing cap, is that ok? If not, where should I add it? http://dl.dropbox.com/u/10949404/P1010132.JPG" CreationDate="2011-04-06T21:29:59.190" UserId="2873" />
  <row Id="19242" PostId="12546" Text="@Hans, basically a super charged Arduino. It's an ARM board designed for prototyping. Has 512k ROM, 64K RAM, ethernet and USB in hardware, and is only $50 USD or so. Also, fits in a breadboard out of the box. " CreationDate="2011-04-06T21:53:57.360" UserId="708" />
  <row Id="19243" PostId="12644" Text="@Kilh I think you're going to have trouble finding anything that can run .Net Micro without requiring surface mount soldering of some sort." CreationDate="2011-04-06T21:55:49.417" UserId="708" />
  <row Id="19244" PostId="12671" Text="@Kilh other than the fun of programming it in .Net, what gain would you actually see for single purpose chips? Unless of course, that single purpose is something very .Net geared. For instance, string parsing in C is a huge pain, but in .Net it's not(sorta). So for something like that it may be worth it. " CreationDate="2011-04-06T21:58:24.253" UserId="708" />
  <row Id="19245" PostId="12697" Score="1" Text="Make 1000v with a relay how? Do you mean control a 1A 1000VDC signal with a DPST relay?" CreationDate="2011-04-06T22:18:21.407" UserId="1623" />
  <row Id="19246" PostId="12503" Text="@markrages Actually I'm making a midi-pedal for keyboards to do some interesting stuff. So, yeah, it's just something like a micro with a serial port and an LCD. :D&#xA;&#xA;&#xA;@reemrevnivek Unfortunately, I don't have a CNC mill :(" CreationDate="2011-04-06T22:24:28.420" UserId="2316" />
  <row Id="19247" PostId="12650" Text="Roger that. Ok, Essentially I am rotating three 6 and a half pound 24 inch long light fixtures attached to a 3 5/64&quot; equilateral triangle vertical mount shaft with an extension aluminium tube shaft from it's base for the motor to couple to. I would prefer the ability to oscillate a full 360 degrees over a variable timeframe (remotely controlled via dial/switch/etc), fastest at 1 full rotation about every 1 second and slowest at 1 full rotation every 10 seconds. The wooden shaft is about 30 inches in height and is poplar wood. As of right now the 3/8&quot; width aluminium shaft is 6&quot; long." CreationDate="2011-04-06T22:32:26.257" UserId="3744" />
  <row Id="19248" PostId="12627" Text="Yup - pretty much!" CreationDate="2011-04-06T22:47:07.207" UserId="3308" />
  <row Id="19250" PostId="12697" Text="yes I just want to transfer it through relay contacts...I mean just imagine relay contacts as a shorting wire." CreationDate="2011-04-06T22:59:19.597" UserId="3757" />
  <row Id="19251" PostId="584" Text="+1 paper: I knew one designer that always, before sending the files to the PCB fab, printed out the files at 1:1 and cemented it to cardboard, cut the cardboard to the size and shape of the PCB, and physically put every component of the final PCB onto this fake cardboard PCB. More often than I care to admit, he found that my PCB layouts tried to put connectors, large caps, and other parts in overlapping locations, much like teleporter experiments gone badly wrong." CreationDate="2011-04-06T23:02:36.250" UserId="813" />
  <row Id="19252" PostId="12629" Text="@supercat: The particulars are beyond me, but I believe the key fundamental difference is leakage current of the process.  Dedicated RTC chips need on the order of 100's of nA while  RTC blocks on a halted MCU need several uA's.  That order-of-magnitude difference outweighs difference in circuit complexity. For a device where time only needs to be kept for a few weeks (a cell phone, for example) a relatively big but &quot;leaky&quot; battery works fine. But for a device that might be unpowered for 10+ years (access control equipment, for example) running on a long-term-stable coin battery? It matters!" CreationDate="2011-04-06T23:05:04.593" UserId="3308" />
  <row Id="19253" PostId="12657" Text="all msp430s with 2 wire SBW (spy by wire) are compatible with the launchpad, I have successfully used f2013, f2011 in projects. I know some of the bigger chips you have to have the FET tool or come they come with a bootloader. I know G line chips are value line chips, F I think is just there standard line, and C I couldn't find any info on. I will dig up some more info in a bit." CreationDate="2011-04-06T23:22:36.367" UserId="2060" />
  <row Id="19255" PostId="12629" Text="@Toybuilder: I can appreciate that there are advantages to standalone RTC chips.  Who knows--maybe there's even one out there that's cheap and has a useful square-wave output that doesn't waste much current in a pullup resistor (e.g. a 256Hz output with a 1/65536sec low time would waste a small fraction of the current of a 16Hz output with a 1/32sec low time, despite offering a 256-fold improvement in resolution)." CreationDate="2011-04-06T23:35:07.390" UserId="3123" />
  <row Id="19256" PostId="12671" Text="I guess I wouldnt gain much. A single purpose chip that simply coordinates the lighting of several LEDs in a sequence doesnt have to be done in .Net and would likely be cheaper and easier for hobbyists to solder than an ARM7 with a surface mount package. This is the route I've decided to take, although I do enjoy programming in .Net and getting full debugger support. I was really hoping for a cheap/easy chip that I could just program in .Net but it sounds like there is a significant trade off." CreationDate="2011-04-06T23:35:42.997" UserId="3344" />
  <row Id="19257" PostId="12644" Text="@Earlz: Agreed." CreationDate="2011-04-06T23:36:18.520" UserId="3344" />
  <row Id="19258" PostId="12657" Text="@jsolarski thanks!  Yeah, google failed me when I was trying to figure out the difference between the letter codes... :)" CreationDate="2011-04-06T23:42:34.657" UserId="2288" />
  <row Id="19259" PostId="12657" Text="@jsolarski so are you proposing that I try one of the other chips with SBW in a non PDIP package, and just fly wires or get an adapter board?  I guess I just have to make sure that the TEST and RST lines are on the right pins..." CreationDate="2011-04-06T23:44:36.103" UserId="2288" />
  <row Id="19260" PostId="6012" Text="+1 aesthetics: Paul Pounds [&quot;LED pocket watch&quot;](http://hackaday.com/2009/10/14/led-pocket-watch/) just wouldn't be the same without arbitrary-angle rotation of each of those little LEDs." CreationDate="2011-04-07T00:01:06.333" UserId="813" />
  <row Id="19261" PostId="12694" Score="1" Text="Plus one million for isolation - 230VAC is scary stuff." CreationDate="2011-04-07T00:04:40.133" UserId="249" />
  <row Id="19262" PostId="12685" Text="Either save the fuse options as command line values or in a file as is described here: http://electrons.psychogenic.com/modules/arms/art/14/AVRFusesHOWTOGuide.php and also fuse calculator here: http://www.engbedded.com/fusecalc/" CreationDate="2011-04-07T00:08:28.477" UserId="249" />
  <row Id="19263" PostId="12693" Text="Thanks. For the loss estimation I could probably use a small temperature sensor taped to the core under (or near) the windings. Since you mention air gaps: What about energy storage in the core? I should be able to calculate its capacity using $I_\rm{max}$ and $L$ or are there any things to watch out for?" CreationDate="2011-04-07T00:10:54.893" UserId="659" />
  <row Id="19264" PostId="12629" Text="@supercat Maybe you should ask a question about building a ultra-low power oscillator + counter from discrete logic chips. Should be doable." CreationDate="2011-04-07T00:14:59.040" UserId="659" />
  <row Id="19265" PostId="12685" Text="@kenny That is a good question (maybe you should ask it). We use a command line programmer and call it with the correct fuse bit settings from scripts (each product gets a new script) but we are a rather small shop. What do the big guys use for AVRs?" CreationDate="2011-04-07T00:18:19.037" UserId="659" />
  <row Id="19266" PostId="12650" Text="Forgot to mention in my last post, that eventually this triangular shaft will be replaced with a square wooden shaft and a fourth light added of the same weight. Also, if anyone could possibly assist with finding a rotary slip ring assembly that would support four 120v~277v 50/60Hz lights through it rotating along with the shaft that'd be helpful as well ;)" CreationDate="2011-04-07T00:20:41.757" UserId="3744" />
  <row Id="19267" PostId="12475" Text="@Madmanguruman Awesome, thank you. The SN754410 HBridge even seems to handle decoding to prevent shoot-through, though I'll still want the delay to get the timing I want anyway." CreationDate="2011-04-07T01:45:55.253" UserId="3707" />
  <row Id="19268" PostId="12667" Score="1" Text="Do you mean optocouplers? Octocouplers sound like something kinky that you do with invertebrates." CreationDate="2011-04-07T01:51:19.757" UserId="3707" />
  <row Id="19269" PostId="12681" Text="Doesn't look so bad. If you can put a shaft on the top of the triangular part and mount a bearing on that top plate and another on the bottom, that should take care of proper support." CreationDate="2011-04-07T02:03:42.343" UserId="2255" />
  <row Id="19270" PostId="12681" Text="Good, already planned on a shaft on top freely spinning. Had planned on maybe using some ball bearing coupling on the top and I guess I could do the same for the bottom, then just have the motor turning the shaft from the bottom where the shaft extends beyond the bottom supporting ball bearing. Now the question is what type of motor, and gearing, and controller, and potentiometer, (etc) do I need to get this puppy rolling..." CreationDate="2011-04-07T02:51:32.173" UserId="3744" />
  <row Id="19271" PostId="12629" Text="@jpc: Doing it with common discrete logic isn't likely to be terribly cost-effective or power-efficient, given the necessity of putting timer output data into physical pins.  From a purely functional standpoint, a minimalist RTC would probably be three chips plus the oscillator.  I'd guess a CD4517 (dual 64-bit shift register), a 74HC373 (latch), and a 74HC153 (2x4 mux).  Such a system could shift out a 64-bit count every 64 cycles (provided a processor helped initialize it).  Power dissipation would be crummy, though." CreationDate="2011-04-07T03:40:55.077" UserId="3123" />
  <row Id="19272" PostId="12629" Text="@jpc: A more interesting question might be why I don't see designs use quadrature-input grayscale counters?  The resource cost is reasonable, and unlike a conventional ripple counter, the quadrature-input grayscale counter wouldn't mind inputs that transition through &quot;funny&quot; states, provided that whenever one input was fuzzy the other was solid." CreationDate="2011-04-07T03:46:09.173" UserId="3123" />
  <row Id="19273" PostId="12629" Text="[correction: graycode counters]" CreationDate="2011-04-07T03:52:27.357" UserId="3123" />
  <row Id="19274" PostId="12657" Text="Its up to you on your package choice, but all i am saying is you have options. From what i have found, G line chips will have uart built in on future chips. As of right now start testing out your code and order msp430g2x52 or comparable chip http://focus.ti.com/mcu/docs/quickdatasheets.tsp?familyId=1937 if you need the extra IO and launchpad compatible." CreationDate="2011-04-07T04:53:09.080" UserId="2060" />
  <row Id="19275" PostId="12657" Text="FYI a another community that can help http://www.43oh.com/" CreationDate="2011-04-07T05:00:12.633" UserId="2060" />
  <row Id="19276" PostId="12694" Text="Thanks! Just what I needed for my design, very good linearity." CreationDate="2011-04-07T06:10:47.170" UserId="3041" />
  <row Id="19277" PostId="5985" Text="One spot I've sometimes thought energy recovery might be interesting would be in LCD display driving.  I'm not sure how one would best keep drive waveforms symmetrical enough to avoid unwanted DC bias, but in theory I would think one could have an LCD driver chip discharge the display capacitance into an inductor and then use the energy in that inductor to charge the display in the other polarity." CreationDate="2011-04-07T06:56:50.370" UserId="3123" />
  <row Id="19278" PostId="12676" Text="You will also need to cool the 7809 to get the full 1A." CreationDate="2011-04-07T07:43:59.953" UserId="339" />
  <row Id="19279" PostId="12699" Text="Very sound advice, despite the harsh tone. Also, have you considered whether FPGA is really the way to go? There seem to be a lot of FPGA-for-FPGA's-sake projects going around these days." CreationDate="2011-04-07T07:55:25.697" UserId="1802" />
  <row Id="19280" PostId="12697" Score="2" Text="What kind of signal is that, at 1A 1000V?" CreationDate="2011-04-07T07:57:48.157" UserId="339" />
  <row Id="19281" PostId="12701" Score="7" Text="It's probably for the better you destroyed it, because those lasers are strong enough to seriously damage your eyes." CreationDate="2011-04-07T08:06:09.630" UserId="339" />
  <row Id="19282" PostId="12699" Text="I don't find the answer to be harsh, just some good questions the poster should ask himself." CreationDate="2011-04-07T08:48:10.837" UserId="2395" />
  <row Id="19283" PostId="12699" Score="1" Text="Don't say that! He's the AngryEE, he's got a reputation to protect! ;)" CreationDate="2011-04-07T08:52:43.453" UserId="1802" />
  <row Id="19284" PostId="12693" Score="1" Text="If you have a big winding, it's better to put the sensor onto the edge of the core. Otherwise, you'll have a combination of winding losses and core losses in your measurement. I'll look into some other detaisl later on..." CreationDate="2011-04-07T09:20:07.107" UserId="930" />
  <row Id="19285" PostId="12708" Text=" There's no regulation and there's nothing to tune inside. The circuit is basically what I showed [here](http://electronics.stackexchange.com/q/12014/1240) plus a circuit beaker and LED on the output and fuse and a power switch on the input. I've had around 8 V of ripple on the output when the supply is unloaded, now I have around 0.1 V. +1 for mentioning high frequency noise. I totally forgot to measure the actual frequencies. Also, where would I add the inductor? " CreationDate="2011-04-07T09:40:03.607" UserId="1240" />
  <row Id="19286" PostId="12679" Text="@miernik Noted, it's the discharge ratings I'm looking for." CreationDate="2011-04-07T09:40:32.873" UserId="1633" />
  <row Id="19287" PostId="12685" Text="@AngryEE and @jpc, thanks. I didn't realize those command line tools existed. And I see that AVRDude is a console application now. " CreationDate="2011-04-07T10:53:10.490" UserId="2157" />
  <row Id="19288" PostId="12685" Text="jpc: I would think that large companies use a gang programmer that can load the fuse configuration from a file, or get their chips supplied pre-programmed." CreationDate="2011-04-07T11:10:19.257" UserId="305" />
  <row Id="19289" PostId="12699" Text="So true, but I try not to be too angry because it puts people off.  Still, I think some people need to realize that the cool-sounding projects they hear about online or in magazines represent weeks or months of work and are not straightforward, simple and fun." CreationDate="2011-04-07T11:57:48.750" UserId="249" />
  <row Id="19290" PostId="12700" Text="I like this description!" CreationDate="2011-04-07T12:00:11.743" UserId="249" />
  <row Id="19291" PostId="12710" Text="What sort of form do you intend for this to take?  An external addon for the phone?  A special base station that turns the landline phone calls into GSM for the phone?" CreationDate="2011-04-07T12:02:34.970" UserId="249" />
  <row Id="19292" PostId="12685" Text="Gang programmer, ha!  He'll set a fuse in yo chip." CreationDate="2011-04-07T12:05:11.770" UserId="249" />
  <row Id="19293" PostId="12708" Text="You just add DCDC converter, which will guarantee 0.01V ripple with 100uF output cap and will be much much better that this. They does not cost much." CreationDate="2011-04-07T12:27:08.787" UserId="2062" />
  <row Id="19294" PostId="12708" Text="@BarsMonster That's my plan. I'll eventually have one at the output and solve the problems. I was concerned that horrible rectifier and transformer side will cause problems to the regulator, so  I added some extra capacitors." CreationDate="2011-04-07T12:31:01.387" UserId="1240" />
  <row Id="19295" PostId="12660" Text="Thanks for your help - there is a reason the Arduino is there. I know its an almost redundant piece of gear, but in this case, it makes one piece of a greater whole. The phone is merely a terminal to a greater network, over PMR.&#xA;I'm not using a Nexus S, and while I'm intrigued by its NFC capabilities, definitely there is no explanation of which frequency and standard it uses.&#xA;I also know about Amarino, and while I agree its quite good, it doesn't serve me in this example. Put quite simply, I was using the wrong serial port on the Arduino. Rewrite of the code fixed that." CreationDate="2011-04-07T12:46:58.607" UserId="3397" />
  <row Id="19296" PostId="12676" Text="Not to thread hijack, but can you put 2 matched 78XX in parallel to double current?" CreationDate="2011-04-07T13:03:55.147" UserId="3122" />
  <row Id="19297" PostId="12657" Text="@jsolarski Thanks!  43oh has come up quite a bit in my searches and it looks like a great resource." CreationDate="2011-04-07T13:26:45.407" UserId="2288" />
  <row Id="19298" PostId="12617" Score="1" Text="@miernik Assuming everything else remains constant, the torque will be the same at a given RPM _and_ throttle position.  But that assumes constant air density (altitude, temperature, humidity) and assumes that engine performance remains constant (the air filter never gets dirty, etc).  You'd need to dyno the car at multiple throttle positions and interpolate between them as power vs throttle isn't strictly linear. " CreationDate="2011-04-07T13:29:52.090" UserId="1438" />
  <row Id="19299" PostId="5413" Text="@mjh2007 Nope, I'm going through the same trouble right now running in 4-bit mode.  It's been about 15 years since I last programmed a simple character LCD, and I remember it being a real pain to debug back when I was in school.  I'm not as far as you, though -- I can't even get the initialization right because I can't display a single character, yet.  :)" CreationDate="2011-04-07T13:30:54.573" UserId="2288" />
  <row Id="19300" PostId="12694" Text="@AngryEE - shocking stuff! :-)" CreationDate="2011-04-07T13:38:42.983" UserId="2064" />
  <row Id="19301" PostId="5414" Text="@ThomasO is there really a maximum allowable delay?  I thought the main thing with these LCDs is that you wait the minimum amount, but if you can't get the timing correct, you can play it safe and just wait longer." CreationDate="2011-04-07T13:39:43.783" UserId="2288" />
  <row Id="19302" PostId="12710" Text="not exactly what you want, but http://www.sparkfun.com/products/286" CreationDate="2011-04-07T13:59:05.350" UserId="2157" />
  <row Id="19303" PostId="12716" Text="It's an N channel Fet. 2N3819. http://www.ee.buffalo.edu/courses/elab/2N3819.pdf" CreationDate="2011-04-07T14:31:17.823" UserId="2824" />
  <row Id="19304" PostId="11329" Text="@davidcary: yes, i've found out that it's called dissolving." CreationDate="2011-04-07T14:55:09.600" UserId="2995" />
  <row Id="19305" PostId="12716" Text="Dammit! you posted your edits just as I posted my answer :)" CreationDate="2011-04-07T14:55:19.627" UserId="2234" />
  <row Id="19306" PostId="12716" Text="Sorry about that! He originally just said that he was using a FET, type unspecified." CreationDate="2011-04-07T15:18:00.450" UserId="305" />
  <row Id="19307" PostId="12718" Text="To clarify the two R1 and R2 problem. Rn, Cn, Ln are often used as variable names in electronics and they usually do not refer to individual resistors. Instead they refer to the value of the resistor, so having multiple R2 resistors just means that you have several resistors of R2 value. " CreationDate="2011-04-07T15:30:06.183" UserId="1240" />
  <row Id="19308" PostId="12719" Text="The community behind the drum module I am using recommends using voltage dividers. These are triggers I'm talking about, not actual audio signals. http://megadrum.info" CreationDate="2011-04-07T15:45:49.093" UserId="3765" />
  <row Id="19309" PostId="12717" Text="Yeah I think that's what my mate was recommending. Trouble is he tried to explain but me no comprehendo. So with the N channel MOSFET it's turn it low to switch on right?" CreationDate="2011-04-07T15:45:52.673" UserId="2824" />
  <row Id="19310" PostId="12719" Text="What about a potentiometer?" CreationDate="2011-04-07T15:48:31.480" UserId="3765" />
  <row Id="19311" PostId="12719" Text="Didn't realize what part of the drum set it was in. Yes, voltage dividers should be ok. Ideally though you want to keep your signal nice and strong until the point they are all mixed together and then adjust relative strengths there, this would be like at a sound board. Potentiometers would work also if you want to go down that path and have adjustable control. You would want to place the pot where R1 is. When the pot is low you will get 100% voltage out." CreationDate="2011-04-07T15:55:15.487" UserId="319" />
  <row Id="19312" PostId="12717" Score="3" Text="No. MOSFETS are enhancement mode so the gate is high to switch on." CreationDate="2011-04-07T16:06:13.323" UserId="2234" />
  <row Id="19313" PostId="12719" Text="I just want to make sure I am reading the schematic correctly:&#xA;&#xA;R1 is soldered to pin-x, the other end continues where the cable was going.&#xA;&#xA;R2 is soldered to the junction of R1 and pin-x, the other end to ground.&#xA;&#xA;R1 is soldered to pin-y, the other end continues where the cable was going.&#xA;&#xA;R2 is soldered to the junction of R1 and pin-y, the other end to ground.&#xA;&#xA;Is this correct?" CreationDate="2011-04-07T17:11:40.643" UserId="3765" />
  <row Id="19314" PostId="12617" Text="@Mark: does it make it simpler if its a diesel? [here](http://en.wikipedia.org/wiki/Throttle#Internal_Combustion_Engines) it says: &quot;The power output of a diesel engine is controlled by regulating the quantity of fuel that is injected into the cylinder. Because the engines do not need to control air volumes, they lack a butterfly valve in the intake tract.&quot; Once in a book I saw a graph of torque vs RPM of an engine similar to mine. It was just a line, there was nothing about throttle position in there. If I take values from such graph, will it be accurate (assuming same air and new filter)?" CreationDate="2011-04-07T17:43:30.130" UserId="1691" />
  <row Id="19315" PostId="12617" Score="1" Text="@miernik Its not really any simpler or harder, its still just reading a throttle position.  A gas engine controls throttle by controlling the air sent into the engine.  The engine computer measures how much air is going in and provides the proper amount of fuel for the target AFR.  The Diesel just controls the amount of fuel sent in and injection timing since 'running lean' isn't an issue.  The graphs you see for torque and horsepower are normally at WOT (wide open throttle).  You'd need to run tests at various partial throttle positions to get all the data you need. " CreationDate="2011-04-07T19:34:16.753" UserId="1438" />
  <row Id="19316" PostId="5414" Text="@Dave, you may have misinterpreted &quot;maximum delay&quot;, it's just a sensible delay I'd recommend. For example, waiting a few hours would be a bit extreme..." CreationDate="2011-04-07T20:04:30.127" UserId="1225" />
  <row Id="19317" PostId="5414" Text="@ThomasO LOL!  Well I figured that's what you meant, but I wanted to ensure that I wasn't missing something, as I have yet to get my LCD initialized.  I wonder if I should go and grab a pot to make sure it's not the contrast that's screwing me up here.  :)" CreationDate="2011-04-07T20:10:02.960" UserId="2288" />
  <row Id="19318" PostId="12701" Score="2" Text="You'll... shoot your eye out?" CreationDate="2011-04-07T20:20:25.990" UserId="3240" />
  <row Id="19319" PostId="12701" Text="@Mark; LOL! Good Ol' &quot;Christmas Story&quot;! :) . Yeah, the LiveLeak link makes that pretty clear at top, for anyone who didn't realize. Great reference though! B)" CreationDate="2011-04-07T20:31:52.450" UserId="3758" />
  <row Id="19320" PostId="12478" Text="For theory sake :) as SAT means both junctions to be forward biased, if you force B,C and E voltages to achieve such a condition, and you force no current, you have a SAT BJT with no current.. but as far as I know it doesn't have any kind of application.." CreationDate="2011-04-07T20:48:44.397" UserId="2285" />
  <row Id="19321" PostId="12485" Text="I'm actually using Bluetooth. The issue here is that the device can be connected to 2 computers but I need to know which one I'm interacting with. So the idea I got is to show on the screen some qrcode and recognise it with my device, equipped with some qrcode detector." CreationDate="2011-04-07T20:53:38.760" UserId="2285" />
  <row Id="19322" PostId="12697" Text="It is a signal coming from a ESD Human Body Model simulator circut I want to make. it discharges a 150pF Capacitor with 1000V" CreationDate="2011-04-07T22:37:03.460" UserId="3757" />
  <row Id="19323" PostId="12727" Text="Here's an experiment on measuring capacity of AA alkalines: http://www.eevblog.com/2011/01/27/eevblog-141-aa-alkaline-battery-capacity-measurement/" CreationDate="2011-04-07T22:39:39.900" UserId="389" />
  <row Id="19324" PostId="12693" Score="1" Text="@zebonaut: You are probably right if he wants to measure them separately. But if he, like me, wants to know &quot;how much current can I push through before the wires overheat and fail&quot;, then that combination of winding losses and core losses is exactly what he wants." CreationDate="2011-04-07T23:10:48.007" UserId="813" />
  <row Id="19325" PostId="12485" Text="Maybe you could use the software you got on the PC to somehow notify the Bluetooth device (virtual com port over Bluetooth is quite easy IIRC)? It seems simpler to me than any machine vision approach." CreationDate="2011-04-07T23:44:32.593" UserId="659" />
  <row Id="19326" PostId="12724" Score="3" Text="I think your best bet is VMWare and Windows XP" CreationDate="2011-04-07T23:27:25.740" UserId="3771" />
  <row Id="19327" PostId="12701" Text="Sorry to have to tell you, the 'LCC' is what prevents the laser diode from burning out, by managing the voltage on the diode so that it draws a constant current." CreationDate="2011-04-08T00:03:00.867" UserId="740" />
  <row Id="19328" PostId="12704" Text="Related: http://electronics.stackexchange.com/questions/11946/power-for-povdisplay" CreationDate="2011-04-08T00:15:52.623" UserId="813" />
  <row Id="19329" PostId="12723" Text="Unfortunately rotating mirrors wouldn't work for the reactor. Yeah I would prefer not to have to part with a tonne of money for this one function... I've considered using Revolving Christmas Tree stands, oscillating tower fans, etc. So far haven't found a way to do this (revolving christmas tree stands don't push enough power their their slip ring)." CreationDate="2011-04-08T01:00:12.787" UserId="3744" />
  <row Id="19331" PostId="12724" Score="3" Text="VirtualBox will be cheaper (free) and just as good. You might try running some software under Wine (using [Wineskin](http://wineskin.doh123.com/); don't worry it is not only for games) but &quot;your mileage may vary&quot;. :)" CreationDate="2011-04-08T01:02:58.077" UserId="659" />
  <row Id="19332" PostId="12722" Text="Oh sorry, knew I'd forgotten something from that first post. :P The shaft dimensions are split into 3 parts due to materials and placement mounts: wooden shaft = 29&quot; (tall) x 3 5/64&quot; (width &amp; depth as equilateral triangle); aluminium tube central shaft (embedded through center of wooden shaft) is currently sized for 3/8&quot; in diameter and extends to 37&quot; tall (2&quot; above the top of the wooden shaft and 6&quot; past the bottom of the wooden shaft); the light mounts are 8&quot; at their widest diameter (including wooden shaft measurement) and 24&quot; tall." CreationDate="2011-04-08T01:08:44.570" UserId="3744" />
  <row Id="19333" PostId="12703" Text="That is probably what the other terminals are connected to... a photodiode to provide feedback to the controller." CreationDate="2011-04-08T01:21:50.277" UserId="1494" />
  <row Id="19334" PostId="12732" Text="Ok, if I am switching the polarity back and forth to make the motor turn differently, should I add two near the motor? One on each wire? Also, are there any cheaper alternatives to an oscilloscope? " CreationDate="2011-04-08T01:30:49.490" UserId="2873" />
  <row Id="19335" PostId="12732" Text="No, you should use only one capacitor, with each lead attached to one pole of the motor." CreationDate="2011-04-08T01:36:06.283" UserId="1325" />
  <row Id="19336" PostId="12732" Score="2" Text="I would also put bypass (0.1 uF) caps next to each power supply pin of the chip connecting from that pin to ground. It wouldn't hurt anything to have larger electrolytic caps at the point where power leads reach your (proto) board either. " CreationDate="2011-04-08T01:41:27.093" UserId="1494" />
  <row Id="19337" PostId="12732" Score="2" Text="@TokenMacGuy, if he was told to put it at the battery terminals or at the IC he is talking about power decoupling for the IC. This should not be placed near motor(although a cap there is good), it should be placed near the IC it is decoupling for." CreationDate="2011-04-08T01:47:28.530" UserId="230" />
  <row Id="19338" PostId="12722" Text="Concerning the flexible cable, I'm sure I can use this in the interim, however future plans include continuous motion in a single direction which would mean that one of the bearings needs to be able to pass the electricity through like a slip ring. I guess I could effectively build a &quot;victorian&quot; slip ring by use of a copper disc and copper brush, but I'd much rather use something off-the-shelf. :) Actually, the original plan was modified to an oscillating movement due to this cabling issue with the idea to allow cable movement until this issue is able to be resolved." CreationDate="2011-04-08T02:13:20.370" UserId="3744" />
  <row Id="19339" PostId="12732" Text="So the new circuit would look like this? Sorry for bad schematic: http://dl.dropbox.com/u/10949404/schem.jpg" CreationDate="2011-04-08T02:21:22.050" UserId="2873" />
  <row Id="19340" PostId="12722" Text="[This, is awesome.](http://electronics.stackexchange.com/questions/11946/power-for-povdisplay/11964#11964)" CreationDate="2011-04-08T02:41:00.130" UserId="3744" />
  <row Id="19341" PostId="12701" Text="Oooh; yeah, after reading people's answers, I was pondering that possibility. All the sites I'd seen where they talked about this project though made the 'lcc' sound like an optional thing, that improved performance but wasn't strictly necessary. Well... here's to learning by jumping right in! Glad the parts aren't expensive!!  ;)" CreationDate="2011-04-08T03:29:27.753" UserId="3758" />
  <row Id="19342" PostId="12723" Text="I like these Mercotac connectors, however because this bioreactor is growing microalgae (spirulina and chlorella) to be within regulations for human consumption I'll need to check if these mercury filled connectors are an option. If not, I'll built my own slip ring using bearings as per the above posted link. :)" CreationDate="2011-04-08T05:58:05.390" UserId="3744" />
  <row Id="19343" PostId="12722" Text="Found some thrust bearings that look like they'll do the job, however now I need to figure out how to build the support to fit the application... it looks like I'll need to use bushings to connect it. Any suggestions for the parts/method to connect these bits?" CreationDate="2011-04-08T06:00:06.167" UserId="3744" />
  <row Id="19344" PostId="10671" Score="2" Text="I 1upped this because it is exactly how I would try it, too. Except, maybe, for the power MOSFETs' gate drivers, they can be built using discretes with not much additional effort (and some great insight into how switching stages can be built). But (fast) OpAmps for generating the sawtooth or triangle and for comparing the audio input will definitely be the best way if you don't want the project to be too complicated." CreationDate="2011-04-08T07:02:03.907" UserId="930" />
  <row Id="19345" PostId="9529" Text="You might want to read up on graycodes (http://en.wikipedia.org/wiki/Graycode) -- this encoder gives you a position error of at most 1 bit.  So with a 2-bit encoder, you have 1 bit of accuracy - so a 150 lpi strip would give you 1/150-in. resolution.  (BTW, this assumes that a black mark and a white space count as two lines for LPI calculation purposes - so in one inch there is 75 black and 75 white.)&#xA;&#xA;" CreationDate="2011-04-08T07:12:41.607" UserId="3308" />
  <row Id="19346" PostId="12731" Score="2" Text="Don't put the same logic level on A &amp; B or the motor will break :o}" CreationDate="2011-04-08T07:46:11.620" UserId="2234" />
  <row Id="19347" PostId="12735" Text="You could help a lot by providing model number of the multimeter." CreationDate="2011-04-08T10:58:00.237" UserId="1240" />
  <row Id="19348" PostId="12735" Text="@AndrejaKo: provided link and description of what is fried." CreationDate="2011-04-08T11:06:29.110" UserId="1691" />
  <row Id="19349" PostId="12701" Score="1" Text="With DVD lasers, it's not just about personal eye safety, either. Of course you wouldn't intentionally point it at anyone else, but you have to worry very seriously about stray reflections finding their way to people, too." CreationDate="2011-04-08T11:15:16.500" UserId="740" />
  <row Id="19351" PostId="12731" Text=" I haven't. I have been switching each from high to low every fifteen seconds to change the direction though." CreationDate="2011-04-08T11:41:55.650" UserId="2873" />
  <row Id="19352" PostId="12731" Score="2" Text="Sorry for my poor wit - I was just joking about the spelling of brake (break) in the truth-table :)" CreationDate="2011-04-08T12:05:31.140" UserId="2234" />
  <row Id="19353" PostId="12717" Score="1" Text="Just for the record: most normal (called &quot;power&quot;) MOSFETs are enhancement mode (you will have a hard time finding a depletion mode power MOSFET). With enhancement mode the N-channel type expects high voltage to switch on and P-channel type needs low voltage (negative with respect to the source pin which you commonly connect to you power supply -- a high-side switch)." CreationDate="2011-04-08T12:25:14.793" UserId="659" />
  <row Id="19355" PostId="12732" Text="That looks right to me." CreationDate="2011-04-08T13:13:46.650" UserId="712" />
  <row Id="19356" PostId="10058" Text="What about other capacitor materials?" CreationDate="2011-04-08T13:18:21.780" UserId="3073" />
  <row Id="19357" PostId="12740" Score="1" Text="I've done this for a fuel oil tank, and it worked well." CreationDate="2011-04-08T14:08:52.920" UserId="51" />
  <row Id="19358" PostId="12544" Text="This is super helpful (sorry for the late comment)" CreationDate="2011-04-08T14:21:14.533" UserId="3073" />
  <row Id="19359" PostId="12731" Text="@MikeJ-UK my first thought when I saw the truth table was &quot;Who would ever design a chip that forces you to always have 2 pins inverted of each other or a motor breaks.&quot; Then I realized what it was trying to mean." CreationDate="2011-04-08T14:26:40.333" UserId="319" />
  <row Id="19360" PostId="12735" Text="I suspect it's irreparably shagged." CreationDate="2011-04-08T14:52:23.460" UserId="2141" />
  <row Id="19361" PostId="12544" Text="@Sauron: No problem. Glad to be of help. When I get some time I may edit my answer and add some more information." CreationDate="2011-04-08T15:15:41.290" UserId="2426" />
  <row Id="19362" PostId="12739" Score="1" Text="How about a force sensor to measure the weight of the tank?" CreationDate="2011-04-08T15:51:35.397" UserId="638" />
  <row Id="19363" PostId="12746" Score="2" Text="Not sure that this will give you any better CMRR because the unbalanced cable will already have common mode noise on it. Converting the signal to balanced doesn't eliminate what has already been induced in the cable." CreationDate="2011-04-08T16:39:00.187" UserId="2110" />
  <row Id="19364" PostId="12746" Text="Is this in the output stage of a product you're designing, or something you're going to add onto an existing product?" CreationDate="2011-04-08T17:01:25.970" UserId="142" />
  <row Id="19365" PostId="12749" Text="The BV4512 is an I2C adapter for KS0108 LCDs. In this case, it's the KS0108 that I'm interested in. It is indeed available, but nowhere near as ubiquitous as the HD44780." CreationDate="2011-04-08T19:08:51.467" UserId="3240" />
  <row Id="19366" PostId="12739" Text="That's not a bad idea. But the tank weighs 100's of pounds." CreationDate="2011-04-08T19:24:55.160" UserId="3045" />
  <row Id="19367" PostId="12740" Text="That's awesome; hadn't thought of that. The surface of the water will reflect the wave." CreationDate="2011-04-08T19:25:29.370" UserId="3045" />
  <row Id="19368" PostId="12741" Text="I think I'll accept this method." CreationDate="2011-04-08T19:25:54.860" UserId="3045" />
  <row Id="19369" PostId="12752" Text="Ya I'd prolly want to stick with Not putting it on my own breadboard right now lol Im not that great with circuits." CreationDate="2011-04-08T19:27:46.140" UserId="3073" />
  <row Id="19370" PostId="12752" Text="@Sauron - hah - either way is good. Whatever gets you hooked! The good thing is the individual chips are pretty cheap (a couple of bucks or so)." CreationDate="2011-04-08T19:29:28.850" UserId="1823" />
  <row Id="19371" PostId="12629" Text="@supercat You are right that power efficiency may be a problem in such circuit. I searched several cheap counter but all use about 80μA at $25^\circ C$. I think I'll ask a question here. :)" CreationDate="2011-04-08T19:40:17.707" UserId="659" />
  <row Id="19372" PostId="12629" Text="@jpc: BTW, how do you like the concept of using a shift-register?  That might be the minimum-circuitry way of doing it (especially if one used four phase shifting, so four transparent latches could hold three bits) though the improved usefulness of a parallel counter and comparator would IMHO be worth the extra circuitry.  A graycode counter would seem the right approach, since it would avoid synchronization issues, though I'm unaware of any low-power counters using graycode.  Not sure why, since graycode ripple counters should be efficient." CreationDate="2011-04-08T19:53:31.550" UserId="3123" />
  <row Id="19373" PostId="12651" Text="@Ranieri: one-time PCB adapters (a tiny PCB that you solder the QFN or whatever to, and has 0.1&quot; pitch pins to plug into a prototyping board) are expensive, but they get away with it because it's sometimes worth it -- they are less expensive than building a couple of custom PCBs. QFP sockets (that let you insert and remove QFP chips easily) are even more expensive, and so far I've managed to avoid them. Occasionally it's worth the convenience to use a [DIP-like demo board](http://opencircuits.com/Demo_board) with many parts on it." CreationDate="2011-04-08T19:58:16.473" UserId="813" />
  <row Id="19374" PostId="3564" Text="Could you accept one, please? It would help others finding this question." CreationDate="2011-04-08T20:11:30.733" UserId="206" />
  <row Id="19375" PostId="12731" Text="Ohhhh. Now I get it. lol. " CreationDate="2011-04-08T20:35:21.200" UserId="2873" />
  <row Id="19376" PostId="12732" Text="@Kortuk, What do you mean by placing it near the IC? As in, between which pins should I place one, and should I lead them to ground? l293d pin labels:  http://luckylarry.co.uk/wp-content/uploads/2009/07/L293D.gif" CreationDate="2011-04-08T20:40:13.727" UserId="2873" />
  <row Id="19377" PostId="12758" Text="The MSP430 you linked to is quite impressive but I cannot verify you 1.5uW power consumption (the lowest thing I could glance from the datasheet is about 15uW) and it does not have a 32kHz crystal oscillator." CreationDate="2011-04-08T20:56:57.017" UserId="659" />
  <row Id="19378" PostId="12629" Text="@supercat I have asked this [as a question](http://electronics.stackexchange.com/questions/12756/how-to-build-an-ultra-low-power-time-counter/12758#12758). The synchronization should be doable by just reading the counter value repeatedly until you get the same value twice." CreationDate="2011-04-08T20:59:22.177" UserId="659" />
  <row Id="19379" PostId="12732" Text="@ASandwhich, between power and ground at the IC." CreationDate="2011-04-08T21:01:57.160" UserId="230" />
  <row Id="19381" PostId="12636" Text="Your wall thermometer may say 25'C, but I guarantee that, in operation, your capacitor is warmer." CreationDate="2011-04-08T21:07:03.167" UserId="813" />
  <row Id="19382" PostId="12637" Text="Do you have a reference for this air flow effect?" CreationDate="2011-04-08T21:08:44.727" UserId="813" />
  <row Id="19383" PostId="12758" Text="You are aware the crystal oscillator is a separate part?" CreationDate="2011-04-08T21:13:25.657" UserId="1363" />
  <row Id="19384" PostId="12758" Text="@jpc  I did a back of the napkin calculation to get 1.5 uW.  The web page, not the PDF, says 0.9v and 45 mA/MHz.  At 0.032768 MHz you get 1.47 uA.  Then * 0.9v you get 1.32 uW.  Then I rounded up to 1.5 uW.  It's not super accurate, but nothing is when you're talking about power consumption on a CPU.  It at least gets you into the proper ballpark." CreationDate="2011-04-08T21:19:09.287" UserId="3624" />
  <row Id="19385" PostId="12628" Text="Perhaps you could do a quick experiment at a much slower rate -- 9600 or perhaps even 300 bps? Then if you're still getting errors, you know it must be something else." CreationDate="2011-04-08T21:20:01.550" UserId="813" />
  <row Id="19386" PostId="12758" Text="@joeforker  I'm not sure about the xtal osc.  It's not obvious from the datasheet, but other TI products are just as non-obvious yet still support xtal's.  If not, you could use that osc that JPC found and still be super low power." CreationDate="2011-04-08T21:21:21.640" UserId="3624" />
  <row Id="19387" PostId="12758" Text="@David You may be right that this is the lowest power way to go but it is strange that a whole uC uses less power than every single logic chip (even simple gates). The interesting thing is that the limiting factor in all of them seems to be the quiescent current and not the dynamic one." CreationDate="2011-04-08T21:26:59.663" UserId="659" />
  <row Id="19388" PostId="12757" Text="What is a &quot;32bit ifx uc&quot;? You've know these errors are common or do you want to determine if they are?" CreationDate="2011-04-08T21:29:09.227" UserId="659" />
  <row Id="19389" PostId="12758" Text="@jpc  It's strange what an entire uC is better and cheaper at.  Recently I was looking for an 8 channel, 12 bit, 200 KHz ADC.  It turns out that the cheapest way to get one is an MSP430.  It's much cheaper than equivalent dedicated ADC parts.  Of course, uC's are so much better than 555's (a friend calls them 666 timers, because they are evil)." CreationDate="2011-04-08T21:32:25.733" UserId="3624" />
  <row Id="19390" PostId="12758" Text="@David True, but 555 timers in particular are still cheaper than uCs." CreationDate="2011-04-08T21:39:48.597" UserId="659" />
  <row Id="19392" PostId="12767" Text="@jpc  Wow, that's a truly scary document!  If done properly according to the spirit of the law, meeting that spec would add a huge amount to the cost of the unit (I'm talking a periodic in the field test, not a simple test at manufacturing time).  It seems to me that some of what Freescale is suggesting in that doc is to meet the letter of the law, not the spirit.   " CreationDate="2011-04-08T21:47:40.667" UserId="3624" />
  <row Id="19393" PostId="12758" Text="IANAEE, but I think the MSP430s will have a built-in 32 kHz oscillator that is low precision, but you can add a watch crystal for accuracy." CreationDate="2011-04-08T21:57:33.433" UserId="1363" />
  <row Id="19394" PostId="12758" Text="@jpc  Ya got me there.  555's are about $0.10, while the cheapest uCs are about $0.30 in 100 piece wholesale pricing.  I still would rather use a uC over a 555." CreationDate="2011-04-08T22:01:30.293" UserId="3624" />
  <row Id="19395" PostId="12629" Text="@jpc: Synchronization can be an issue with wakeup events. If a counter clicks from 7F to 80, the bits may momentarily compare equal to any other value depending upon the order in which they switch. By contrast, if a graycode counter ticks from 40 to C0, or C0 to C1, there's no problem. There are other ways of avoiding false comparisons, but many such approaches have synchronization issues when changing the compare value. If one uses graycode counters, the only synchronization-ish thing one needs to do is guard the compare-match output..." CreationDate="2011-04-08T22:11:51.923" UserId="3123" />
  <row Id="19396" PostId="12629" Text="@jpc: ... by holding it asynchronously in reset during a write, and passing it through a double synchronizer on the main CPU clock which will become transparent when the main clock is stopped (the double synchronizer should avoid metastability problems in the event that the counter advances just after the comparison register is written, thus creating a runt pulse on the compare output)." CreationDate="2011-04-08T22:19:30.477" UserId="3123" />
  <row Id="19397" PostId="12764" Text="It's a little pricey, and it doesn't allow any way to read out increments smaller than a second.  A 4096Hz output would be nice, though it would be far nicer if it were low for 1/65536 of a second and high for 15/65536.  Open-collector outputs should be low as little as possible." CreationDate="2011-04-08T22:24:18.520" UserId="3123" />
  <row Id="19398" PostId="12636" Text="@davidcary, you're right. So, let's assume a 470µF 25V cap which according to the KZE datasheet has an ESR of 0.041 ohms (@25°C) and a ripple current maximum of 1,250mA. We can calculate at, let's say 600mA ripple current, the cap will dissipate 14mW (I^2 * R.) So, where does the cap heat up from, as this is tiny? Am I missing something?" CreationDate="2011-04-08T22:34:22.590" UserId="1225" />
  <row Id="19399" PostId="12767" Text="@David probably all of this document is about how to meet the letter of the law especially since the standard is quite strict on what should be verified. The question remains if these tests have some practical uses. :)" CreationDate="2011-04-08T22:35:44.063" UserId="659" />
  <row Id="19400" PostId="12763" Text="I wish there were some way to design something nice and psychically convince a microcontroller manufacturer that they should build it into their product.  It would seem that a few cascaded quadrature graycode counters (within a single chip) should be able to count using less current than would be required by a synchronous counter, but with a cleaner output than would be offered by a ripple counter.  My ideal device would probably have a 48-bit resettable counter which was readable as either the top or bottom 32 bits, along with a 32-bit compare register." CreationDate="2011-04-08T22:37:19.003" UserId="3123" />
  <row Id="19401" PostId="12763" Text="The counter and about 16 bytes (4x32 bits) of RAM would be separately powered, and should be able to run for decades off a very small battery, or for days if not weeks off a supercap.  From a programming standpoint, it would be nice if the compare register could do a magnitude compare rather than just an equality compare, but provided there aren't weird synchronization issues, software should be able to work just fine using a latching equality comparer." CreationDate="2011-04-08T22:40:38.330" UserId="3123" />
  <row Id="19402" PostId="12772" Text="Thanks for your help Andreja. The only problem is that the reverse side of the adapter is covered in dense foam. Should I cut a little piece off to expose the other side of the board? (I'll post a picture soon)" CreationDate="2011-04-08T23:20:03.070" UserId="3780" />
  <row Id="19403" PostId="12772" Text="Here's the back of the adapter: http://i.imgur.com/cXm3O.jpg" CreationDate="2011-04-08T23:26:39.100" UserId="3780" />
  <row Id="19404" PostId="12772" Text="@Michael The foam could be a problem. It's probably there as an insulator, so it should be safe to cut it and remove a small piece. Just remember to cover the repaired area with something non-conductive after you finish fixing the board. Another function of the foam could be to provide a flat surface, so the bumps of the solder joints aren't exposed. It may be a smart idea to try to keep your patch as thin as possible. " CreationDate="2011-04-08T23:58:27.410" UserId="1240" />
  <row Id="19405" PostId="12772" Text="@AndrejaKo Okay. I think I'll try to fix the connection from the top side before cutting through the back foam. Thanks for the help again." CreationDate="2011-04-09T00:02:50.287" UserId="3780" />
  <row Id="19406" PostId="6812" Text="I would be really great if you could find a nice schematic of this circuit. Unfortunately neither Wikipedia nor the AppNote have good schematics. It &quot;reads&quot; pretty elegant but I am curious how it &quot;looks&quot;. ;]" CreationDate="2011-04-09T01:12:39.540" UserId="659" />
  <row Id="19407" PostId="6812" Text="Ok, it seems that the &quot;fixing manual&quot; has the nicest pictures of them all." CreationDate="2011-04-09T01:19:34.530" UserId="659" />
  <row Id="19409" PostId="12739" Score="1" Text="And they make load cells capable of weighing 80,000 pound trucks." CreationDate="2011-04-09T01:40:57.247" UserId="638" />
  <row Id="19410" PostId="12746" Text="@Martin - Yeah, obviously, I won't be able to lose any noise that was already on the unbalanced line, but, as I understand it, I can prevent some noise received by the lines on the inside of the device from being amplified at the power amp stage" CreationDate="2011-04-09T02:04:46.263" UserId="3424" />
  <row Id="19411" PostId="12746" Text="@endolith - Neither, this would be at the input of a device I'm trying to design, to feed into a power amp IC: [TDA8920B](www.nxp.com/documents/data_sheet/TDA8920B.pdf).  This is why I thought it might be overkill, because the IC is designed to drive an output stage.  Plus David Kessner below believes that I may not even need to balance it at this stage." CreationDate="2011-04-09T02:07:54.060" UserId="3424" />
  <row Id="19412" PostId="12748" Text="The power amp stage will be dominated by [TDA8920B](www.nxp.com/documents/data_sheet/TDA8920B.pdf).  Though not explicitly stated that I can see, the layout seems to suggest that the inputs are meant to be differential, balanced.  If you still believe that they need not be, though, and no one else speaks up to contest you, I can consider this question answered for my purposes." CreationDate="2011-04-09T02:10:53.247" UserId="3424" />
  <row Id="19413" PostId="12748" Text="@Joe Mac  Right, the inputs don't have to be balanced to the NXP part.  Just tie the + input to the audio signal, and the - input to GND.  There is little point in doing a differential signal for the maybe 1 inch of PCB trace, when you have 3 to 20 feet of unbalanced cable feeding it.  Any improvement would be lost in the noise of the NXP part anyway." CreationDate="2011-04-09T03:36:51.550" UserId="3624" />
  <row Id="19414" PostId="12780" Text="If you're building this as an exercise in SRAM design, I'd make it out of discrete transistors. Google will get you many simple sense amplifier designs. Sounds like a neat project if you need custom SRAM circuitry." CreationDate="2011-04-09T04:34:40.087" UserId="2183" />
  <row Id="19415" PostId="12753" Text="Strange, I've had nothing but good experiences with the Atmel IDE and the usbtiny, Also buspirate will double as an isp for many different platforms, great little tool" CreationDate="2011-04-09T05:22:20.170" UserId="1729" />
  <row Id="19416" PostId="12782" Text="+1 Yeah, I've even found &quot;USB port&quot; DC adapters at the dollar store - it's much cleaner to go that way." CreationDate="2011-04-09T07:30:10.530" UserId="3308" />
  <row Id="19417" PostId="12789" Score="1" Text="You should read up on the basics (voltage, current, power, use of resistors to limit current through a LED) before you continue. Otherwise you'll destroy a lot of stuff and maybe set the house on fire." CreationDate="2011-04-09T08:25:29.443" UserId="339" />
  <row Id="19418" PostId="12790" Text="there's nothing special, PC Power supply(red,black)=&gt; two strands of lan cable =&gt; breadboard =&gt; wire =&gt; LED. could you tell me what do you suggest for my experiments? 9V or 5V battery charger would be good choice?" CreationDate="2011-04-09T08:44:22.197" UserId="3746" />
  <row Id="19419" PostId="12789" Score="1" Text="what book or document do you suggest?" CreationDate="2011-04-09T08:49:58.490" UserId="3746" />
  <row Id="19420" PostId="12739" Text="I'm guessing the problem is placing the cells under the tank as much as sourcing them. But still, it's a proven and dependable solution if you can swing it." CreationDate="2011-04-09T09:12:31.137" UserId="1802" />
  <row Id="19421" PostId="12790" Score="2" Text="Battery chargers do not necessarily output a regulated DC voltage. They may be current regulated or even give you a pulsed output. Are you using a resistor in series with the LED?" CreationDate="2011-04-09T09:25:28.347" UserId="930" />
  <row Id="19422" PostId="12795" Text="i just want to buy it from market. actually i am a soft. eng need to used it in my project. Any help(sorry for wrong question in this form)" CreationDate="2011-04-09T11:46:28.613" UserId="3784" />
  <row Id="19423" PostId="12748" Text="Okay, great. Thanks! " CreationDate="2011-04-09T12:00:58.867" UserId="3424" />
  <row Id="19424" PostId="12762" Text="I'm noticing almost everyone is recommending using a thrust bearing at the BOTTOM of the rotating axle, any particular reason? I was hoping to use the thrust bearing assembly at the top to reduce the complexity of the bottom rotating joint so I could work out a solution to passing the electric functionality I need along to the shaft-mount. I guess I could pass the power via the top, but I need to nail down these design elements ASAP. So, Top or bottom mounted thrust bearing to handle load? :)" CreationDate="2011-04-09T13:27:13.643" UserId="3744" />
  <row Id="19425" PostId="12794" Text="google search for wifi temperature sensor 1st hit http://www.aginova.com/sentinelsensors.php" CreationDate="2011-04-09T14:04:22.717" UserId="2157" />
  <row Id="19426" PostId="12758" Text="@jpc - 555's are not exactly low power. Their CMOS counterparts, 7555, are, but I think they're more expensive as well." CreationDate="2011-04-09T15:18:36.650" UserId="2064" />
  <row Id="19427" PostId="12758" Text="@jpc - I once used a MSP430F1101 running off a 32kHz watch crystal, which consumed 5uA @ 3V, or 15uW. It used the on-chip oscillator." CreationDate="2011-04-09T15:21:51.967" UserId="2064" />
  <row Id="19428" PostId="12795" Text="It's off-topic then, and will be closed." CreationDate="2011-04-09T15:30:58.323" UserId="305" />
  <row Id="19429" PostId="7909" Text="The killer feature for SunSpots is not Java, but the built in wireless stuff allowing them to communicate with each other.  If you want awareness of each other or easy wireless communication with the home base, that is very, very nice. " CreationDate="2011-04-09T16:13:32.623" UserId="3785" />
  <row Id="19430" PostId="12798" Text="Square wave open-drain outputs aren't exactly conducive to low-power operation.  If one is supplied by 3 volts and uses a 1Meg pullup current dissipation from the resistor alone will be 1.5 microamps.  Too bad none of the parts I've seen have a low-duty-cycle pulse wave option.  A 1024Hz pulse wave with a 16us low time (half a 32Khz cycle) would only use less than 0.05 microamps--a huge savings.  " CreationDate="2011-04-09T16:43:11.333" UserId="3123" />
  <row Id="19431" PostId="12770" Score="1" Text="Please phrase your question more clearly and provide more information about the problem. You are looking for the thevenin equivalent circuit for that entire thing? Or just for the input source (looks like input source might be Vx &amp; R1 &amp; R4 &amp; R3, is that right?) This looks a lot like a hybrid pi BJT small signal model with some other resistor stuff around it... is that right? " CreationDate="2011-04-09T16:58:42.360" UserId="3635" />
  <row Id="19432" PostId="12732" Text="Oh, and does the capacitor around the motor remain effective even though I am switching the direction/polarity of the motor?" CreationDate="2011-04-09T18:28:51.307" UserId="2873" />
  <row Id="19433" PostId="12801" Text="Can you supply part number, pinout, specs, schematic? I would tend to guess the answer is no... you could maybe parallel them, but there may be a possibility of blowing out one or both. You may be able to put a small resistance between the outputs in order to prevent this. Anybody ever try something like this? " CreationDate="2011-04-09T18:36:49.603" UserId="3635" />
  <row Id="19434" PostId="12732" Text="@a sandwich:  With a DC motor, there are two switching events.  When the driver turns the motor on or off, and when the commutator built into the motor redirects current from one winding to another.  The capacitor on the motor absorbs the ripple current from that second type of switching, over which you have no other control." CreationDate="2011-04-09T18:59:15.023" UserId="1325" />
  <row Id="19436" PostId="12784" Text="But if you short the wires, device might think that it is connected to a charger and try to pull high current which could trip safety on the USB port (or worse, not trip the current limit!)." CreationDate="2011-04-09T19:16:05.207" UserId="1240" />
  <row Id="19437" PostId="12803" Text="thanks. I think I'll stick to splitting the circuit up. I'm by no means experienced!!" CreationDate="2011-04-09T19:24:29.543" UserId="2824" />
  <row Id="19438" PostId="12789" Score="1" Text="http://www.allaboutcircuits.com/vol_3/index.html" CreationDate="2011-04-09T19:27:46.417" UserId="1450" />
  <row Id="19439" PostId="12802" Text="The thing is, I don't want to use any pre-built memory chips. I would like to build the whole system myself if possible. I have most of it designed, I just need the comparator/sense amplifiers for memory output" CreationDate="2011-04-09T19:31:20.657" UserId="3782" />
  <row Id="19440" PostId="11961" Text="@Kamil: are these deep-cycle AGM batteries? Even if they are deep cycle, do not drain then below 50%, because you will decrease their life too much (it would be more economical in the long term to buy two batteries, instead of depleting one below 50%). The 50% mark will be somewhere 12.00 and 12.25 V depending on the battery, load, temperature, battery age. Anyway never run below 12.00V. If it is not deep-cycle, but a starter-battery, then you should not even run them below 80%, and that will be just about 12.4V (+-0.1V), so to be safe do not discharge below 12.5V." CreationDate="2011-04-09T19:58:08.133" UserId="1691" />
  <row Id="19441" PostId="12798" Text="@stevenh But the guaranteed quiescent current over the commercial temperature range is 10 times higher. And an RTC manages to get 400nA over the whole industrial temperature range. Why NXP and Fairchild advertise new ultra-low-power logic gates that are only 2 times better in this regard? It is not that it is impossible to do better (like the RTC and MSP430 chips prove). MSP430 has the ability to go fast if needed, has normal output current capability and still does not sacrifice low quiescent current." CreationDate="2011-04-09T20:55:54.817" UserId="659" />
  <row Id="19442" PostId="12798" Text="@supercat Yup, your low duty OC outputs are a really nice idea." CreationDate="2011-04-09T20:56:42.100" UserId="659" />
  <row Id="19443" PostId="12758" Text="@stevenh Thanks for your datapoint. @David Maybe you could mention it in your answer?" CreationDate="2011-04-09T20:57:48.310" UserId="659" />
  <row Id="19444" PostId="12803" Text="OTOH in this particular situation the 2 diodes method should be okay (@Ageis only asked for a modest 25% boost in maximum current vs. each regulator rating)." CreationDate="2011-04-09T21:01:56.887" UserId="659" />
  <row Id="19445" PostId="12804" Score="1" Text="It's hard to understand the question you are trying to ask.  Can you elaborate?" CreationDate="2011-04-09T21:12:15.330" UserId="1325" />
  <row Id="19446" PostId="12799" Text="You mention NMOS and IIRC there is a connection between the popularity of dynamic logic and complementary MOS (CMOS) not being available yet." CreationDate="2011-04-09T21:13:44.667" UserId="659" />
  <row Id="19447" PostId="12805" Score="1" Text="+1 Long traces can easily ruin the oscillator, especially with a &gt; 8MHz crystal." CreationDate="2011-04-09T21:25:30.200" UserId="659" />
  <row Id="19448" PostId="12806" Text="I would agree but IMHO the goal is not to program whole devices in assembly (I know this is frequently done and I did this as well) but to be able to decode and verify what the C compiler is doing behind your back. It also means you will frequently be able to second guess the compiler and optimize the code you write in C to get small executable size." CreationDate="2011-04-09T21:55:56.767" UserId="659" />
  <row Id="19449" PostId="12804" Text="It's quite obvious to anyone with a Launchpad!" CreationDate="2011-04-09T22:23:49.090" UserId="305" />
  <row Id="19450" PostId="12784" Text="Good thing you mentioned that!" CreationDate="2011-04-09T23:04:17.593" UserId="3783" />
  <row Id="19451" PostId="12787" Text="Would regular black electrical tape work? I'm thinking it's too sticky and it would be better to have a thin and firm type of &quot;tape&quot;." CreationDate="2011-04-09T23:04:47.717" UserId="3783" />
  <row Id="19452" PostId="12782" Text="Do they cost a dollar?" CreationDate="2011-04-09T23:05:20.150" UserId="3783" />
  <row Id="19453" PostId="12781" Text="I tried physically prying out the pins using a knife but was unsuccessful and only managed to gouge the plastic immediately surrounding them." CreationDate="2011-04-09T23:07:03.300" UserId="3783" />
  <row Id="19454" PostId="12781" Text="Also, the other end of the cable has one of those mini USB plugs. Maybe I would have better luck going at it from that end." CreationDate="2011-04-09T23:09:29.463" UserId="3783" />
  <row Id="19455" PostId="6811" Text="Related: http://electronics.stackexchange.com/questions/6016/reading-a-circuit/12760#12760" CreationDate="2011-04-09T23:10:30.710" UserId="813" />
  <row Id="19456" PostId="12799" Text="@jpc: I've examined schematics of various NMOS chips--some in great detail, including the Atari 2600 TIA which is a real work of genius--people are still finding new things to do with it three decades later.  I think one advantage of NMOS versus CMOS from a design-convenience standpoint is that 'shoot-through' (accidental simultaneous activation of high- and low-side drive) is a non-factor, though I'll confess some curiosity as to why CMOS isn't run at a low enough voltage that the cross-over point on an input would leave high and low side drivers off, rather than activating both." CreationDate="2011-04-09T23:31:11.497" UserId="3123" />
  <row Id="19457" PostId="12799" Text="@jpc: In NMOS, it's possible to implement an XOR gate with two transistors and two resistors, if the inputs are sufficiently &quot;strong&quot;.  Even if one has to add inverters to both inputs, a four-transistor four-resistor xor gate would be better than many other approaches.  I've never seen the approach used, though, even though I designed a similar circuit using BJT's around 1978 (the design concept would work better with MOSFETS, but I didn't know anything about them)." CreationDate="2011-04-09T23:34:55.143" UserId="3123" />
  <row Id="19458" PostId="12802" Text="@Nate Koppenhaver: What are you using to hold the data?  As I noted, using sense amplifiers will data to be held using smaller transistors than would otherwise be necessary, but in a 16-row memory array you're almost certainly better off using storage elements that can easily drive logic-level signals, than using &quot;wimply&quot; storage elements along with circuitry to amplify their outputs." CreationDate="2011-04-09T23:36:48.637" UserId="3123" />
  <row Id="19459" PostId="1070" Text="The RCA 1802 ( http://en.wikipedia.org/wiki/RCA_1802 ) was, AFAIK the first micro to allow static operation, way back in 1976." CreationDate="2011-04-09T23:47:23.677" UserId="1322" />
  <row Id="19460" PostId="8109" Text="Optimization comparisons is a subject of high contention. I wouldn't go there." CreationDate="2011-04-10T00:43:01.080" UserId="2118" />
  <row Id="19461" PostId="9793" Text="BarsMonster: It could probably be done using unijunction transistors, but it's necessary to have positive feedback and that isn't going to happen with a single transistor.  On the other hand, I think the transistor clock parts count could be greatly reduced on the 'output' side.  Assuming one has convenient outputs for a 2+4+3+4+3+4-bit BCD value to be displayed (assuming a little circuitry exists to translates hours into hour-tens and hour-units), and assuming one has a six-phase active-low clock available, one should be able to use 20 transistors to get a multiplexed 4-bit digit value..." CreationDate="2011-04-10T00:52:53.213" UserId="3123" />
  <row Id="19462" PostId="9793" Text="...and then use one set of ten transistors and ~90 diodes to convert those to digit shapes, and then use seven segment-drive transistors and six digit-drive transistors to drive a multiplexed display.  Even though one would have to add circuitry to yield a fast six-phase clock and convert the hours count to BCD, the savings in parts should still be significant." CreationDate="2011-04-10T00:57:26.827" UserId="3123" />
  <row Id="19463" PostId="9793" Text="@BarsMonster: BTW, I think it might be possible to reduce the component count for the timekeeping part of the circuit if one multiplexed the counting aspects and used dynamic logic.  The trick would be to essentially build a 5x4 DRAM.  I'd have to work out how to make such a thing actually behave, though." CreationDate="2011-04-10T01:05:59.173" UserId="3123" />
  <row Id="19464" PostId="12762" Text="The primary load is the 30 lbs weight that will be pushing the shaft down into the base, so the thrust bearing is at the bottom to support this load. Another (radial) bearing should be at the top to hold the other end of the shaft and let it rotate." CreationDate="2011-04-10T02:36:40.637" UserId="2255" />
  <row Id="19465" PostId="12803" Text="If you're feeling saucy you could probably even leave the diodes off :)" CreationDate="2011-04-10T03:57:35.993" UserId="771" />
  <row Id="19466" PostId="12770" Score="2" Text="sounds like a homework question?" CreationDate="2011-04-10T03:58:44.887" UserId="771" />
  <row Id="19467" PostId="12787" Score="1" Text="I don't like using electrical tape for anything, because it leaves a goopy mess behind, and it's really thick.  You're probably even better off with a piece of paper just bent over the plug so it covers the leads.  If you're in the US, I can always send you a piece of Kapton to try out." CreationDate="2011-04-10T04:52:45.517" UserId="2288" />
  <row Id="19468" PostId="12740" Text="This is probably the easiest method that requires the least calibration and minimal installation." CreationDate="2011-04-10T04:56:39.893" UserId="2340" />
  <row Id="19469" PostId="12790" Score="2" Text="If it's not out of your budget, you can find pretty cheap laboratory power supplies on eBay and craigslist.  The advantage here is that you can limit the output current and not risk destroying anything.  Once you're comfortable that your circuit is generally correct, then you can slowly increase the output current to the amount you need." CreationDate="2011-04-10T05:10:30.530" UserId="2288" />
  <row Id="19470" PostId="12819" Score="3" Text="Choice of small signal model to use will usually depend on the circuit you are trying to analyze, or perhaps the quantity you are trying to characterize (e.g. input resistance, output resistance). For example, the T model is often used when analyzing the common base amplifier configuration. Can you post a schematic of the circuit in question?" CreationDate="2011-04-10T05:48:41.847" UserId="3635" />
  <row Id="19471" PostId="12485" Text="It's the bluetooth device, that you keep in your hand like a pen, that decides which computer to use, not the other way round. I though vision or color coding were the only possibilities" CreationDate="2011-04-10T09:16:31.820" UserId="2285" />
  <row Id="19473" PostId="12824" Text="From OP's [previous](http://electronics.stackexchange.com/q/12789/1240) question it appears that he was running the diode without a resistor. " CreationDate="2011-04-10T10:06:46.970" UserId="1240" />
  <row Id="19474" PostId="12777" Score="1" Text="This this this! I cannot tell you how confused I was for years on this point—transistors are *used in* amplifiers, they do not &quot;amplify&quot; in and of themselves." CreationDate="2011-04-10T10:30:46.653" UserId="1633" />
  <row Id="19475" PostId="4748" Text="I will work for all Cortex-M3 (and M0) types but you may wish to comment out the building of some STM32 specific libraries." CreationDate="2011-04-10T11:05:45.740" UserId="659" />
  <row Id="19476" PostId="12485" Text="So you basically want a contact less but short range mean of pairing the device with one computer or another? So when the user is in proximity of a computer he will be able to use your pen with it without touching any keys or doing any switching?" CreationDate="2011-04-10T11:07:58.593" UserId="659" />
  <row Id="19477" PostId="12803" Text="@vicatcu I wouldn't leave the diode off unless the datasheet specifically says you can-- or unless you've done lots of testing with many different dummy loads.  " CreationDate="2011-04-10T13:44:37.713" UserId="3624" />
  <row Id="19478" PostId="227" Text="@Jules, this is not the place for shopping advice." CreationDate="2011-04-10T14:10:44.163" UserId="230" />
  <row Id="19479" PostId="12821" Score="1" Text="The solar cells that look like &quot;cracked blue glass&quot; is probably polycrystalline solar panels." CreationDate="2011-04-10T14:10:54.163" UserId="638" />
  <row Id="19480" PostId="12817" Text="thanks Leon, any explanation as to where this voltage increase comes from? " CreationDate="2011-04-10T15:02:12.990" UserId="771" />
  <row Id="19482" PostId="12834" Text="Apparent power has unit of VA, reactive power has units Var and also depends on phi, the power factor. Interesting way of looking at power factor though :)" CreationDate="2011-04-10T15:32:39.713" UserId="2340" />
  <row Id="19483" PostId="12817" Text="I don't know what you mean by &quot;voltage increase&quot;. When fully charged, the cell voltage is 1.4V or so (open circuit). Cell voltage will be about 1.25V when they are on a heavy load and discharging." CreationDate="2011-04-10T15:34:18.680" UserId="305" />
  <row Id="19484" PostId="12834" Text="@freespace - You're right, it's apparent power. It's been a long time... I'll correct it in my answer" CreationDate="2011-04-10T15:34:52.097" UserId="2064" />
  <row Id="19485" PostId="12816" Text="Ah, I think I remember running across someone mentioning that elsewhere," CreationDate="2011-04-10T15:39:08.623" UserId="1227" />
  <row Id="19486" PostId="12834" Text="@stevenvh no worries. I had to check first myself before commenting :)" CreationDate="2011-04-10T15:43:45.413" UserId="2340" />
  <row Id="19488" PostId="12826" Text="It's a surface-mount crystal, headers can't be used." CreationDate="2011-04-10T16:02:24.430" UserId="305" />
  <row Id="19489" PostId="12832" Text="1kW, that's what I call decent lighting! :-) How about your ecological footprint? :-(" CreationDate="2011-04-10T16:06:08.217" UserId="2064" />
  <row Id="19491" PostId="12832" Score="1" Text="Surely it would be regulated, so you can set it anywhere from 100 to 1kW :-) And with 100Lm/W efficiency, I am thinking that indeed 1kW is an overkill. So most likely will limit to 4 or 5 lamps. As for ecology - I don't own a car, so I guess I can afford 1kW lighting instead :-)" CreationDate="2011-04-10T16:10:46.180" UserId="2062" />
  <row Id="19493" PostId="12834" Text="A good answer but it does not really explain the difference in inverter ratings." CreationDate="2011-04-10T16:18:03.813" UserId="659" />
  <row Id="19494" PostId="12834" Text="$\cos(\varphi)$ is a problem for utilities since the back and forth power flow means that the current is higher that it really needs to be (vs. a properly  compensated circuit) and this increases the cable losses." CreationDate="2011-04-10T16:20:34.933" UserId="659" />
  <row Id="19495" PostId="12826" Text="I really do see holes at the crystal symbol on this picture of the MSP430 launchpad: https://jp.rs-online.com/largeimages/R7122649-01.jpg&#xA;  However, I also see that XIN and XOUT are routed outwards to, possibly, a pinheader.. Odd." CreationDate="2011-04-10T16:30:14.830" UserId="1476" />
  <row Id="19496" PostId="12606" Text="@Prof. Meow Meow: Nice name.  The most practical method for storing numbers that are going to be displayed in hardware is BCD.  There are systems that stored numbers to be displayed in other formats, but in many cases they simply used a ROM to map directly from the number to its visual representation (e.g. the arcade machine &quot;Tank&quot; used 6-bit score counters, and a 512 byte ROM to convert each score value to an 8x8 shape) but this was generally only workable if the maximum numerical value was fairly small." CreationDate="2011-04-10T16:58:44.000" UserId="3123" />
  <row Id="19497" PostId="12837" Text="Nice document. 5 channel thing not going to be easy, but at least I don't have to step up from 12V :-)" CreationDate="2011-04-10T17:00:15.247" UserId="2062" />
  <row Id="19498" PostId="12826" Text="You are right, I just checked one of my boards. They are brought out to pins as the same connections can be used for I/O, if the crystal isn't used." CreationDate="2011-04-10T17:14:50.810" UserId="305" />
  <row Id="19500" PostId="6538" Text="Easy to find with a simple Google for the title in the anwser: [Soopa doopa long link](http://www.sciencedirect.com/science?_ob=ArticleURL&amp;_udi=B6THD-4344D6R-3&amp;_user=10&amp;_coverDate=06/30/2001&amp;_rdoc=1&amp;_fmt=high&amp;_orig=gateway&amp;_origin=gateway&amp;_sort=d&amp;_docanchor=&amp;view=c&amp;_searchStrId=1712755825&amp;_rerunOrigin=google&amp;_acct=C000050221&amp;_version=1&amp;_urlVersion=0&amp;_userid=10&amp;md5=3dd4178fe4951dc37294d2f88e655626&amp;searchtype=a). However, you'd have to shell out $31.50 to read it." CreationDate="2011-04-10T18:52:03.577" UserId="3745" />
  <row Id="19501" PostId="12836" Score="3" Text="@Hasan Iq. provide links to relavent material so that bettter information can be provided." CreationDate="2011-04-10T19:23:28.727" UserId="230" />
  <row Id="19502" PostId="12834" Text="Actually some electric companies (like mine) charge for reactive power and then charge extra if the power factor is under 95%! Also a note on the watts and VAs. The 300 VA power supply with $\cos{\phi}=0.9$ will use 270 W and will use $abs{30} VAr$. It will still use whole 300 VA. On the other hand the 300 W power supply will use 300 W and an unknown number of VArs, so its total apparent power is in fact unknown! Some manufacturers also incorrectly use W instead of VA so this adds even more confusion. " CreationDate="2011-04-10T20:12:27.267" UserId="1240" />
  <row Id="19503" PostId="12834" Text="Also Volt*Amperes are very important when designing any type of transmission line because even though some power companies charge only for active power, it's the apparent power that is being transfered through wires and it is important to take the real value of the apparent power into account. The reactive power has same effects on the conductors as active power and imaginary currents is not taken into account can cause all kinds of problems. " CreationDate="2011-04-10T20:18:12.303" UserId="1240" />
  <row Id="19504" PostId="12834" Text="@stevenvh `industries have to pay fines if their cos(phi) becomes too high.` Are you quite sure about that? Shouldn't that be $\sin{\phi}$ or low? High $\cos{\phi}$ (as close to 1 as possible) means low reactive power and more active power and is almost always considered a good thing. " CreationDate="2011-04-10T20:19:57.327" UserId="1240" />
  <row Id="19505" PostId="12842" Text="If I get Spanish correctly (and I'm not 100% sure that I do), OP loses communication with the ATmega 816au after setting the fuse bits. Flash programming seems to be working fine." CreationDate="2011-04-10T20:34:54.307" UserId="1240" />
  <row Id="19506" PostId="12842" Text="@Manuel ¿Nos puede decir que los valores que está utilizando para los fusibles de cristal y que estés usando? (Lo siento por Google Translate)" CreationDate="2011-04-10T20:37:34.150" UserId="1240" />
  <row Id="19507" PostId="12840" Text="Thanks for the help!" CreationDate="2011-04-10T20:59:09.667" UserId="3796" />
  <row Id="19508" PostId="12840" Text="Would you know how to do this with a full adder instead?" CreationDate="2011-04-10T21:02:00.680" UserId="3796" />
  <row Id="19510" PostId="12842" Text="Thanks AndrejaKo,  your translation it is Ok. Crystal is 3,6864MHz. Fuses: WTDOM, SPIEN, CKOPT, BODEN  are &quot;activated&quot;, BODLEVEL = VCC=4V, SUT_CKSEL Ext Cristal/Resonatorhight frecuency start up time 16CK+64mSg" CreationDate="2011-04-10T21:22:24.927" UserId="3798" />
  <row Id="19511" PostId="12846" Score="2" Text="Uhh, for some reason I don't think this counts as a beginner hobbyist level anymore. " CreationDate="2011-04-10T21:52:07.470" UserId="1319" />
  <row Id="19512" PostId="12841" Text="I think that you will have problems with getting even pressure distribution over the whole metal sheets. Some areas may get good contact while other may be loose." CreationDate="2011-04-10T22:00:23.673" UserId="659" />
  <row Id="19513" PostId="12846" Text="@Faken a 10k line encoder isn't exactly hobbyist level to begin with!  Having 6 of those on one micro and expecting the micro to read them when spun at any reasonable angular velocity is asking a lot, I think.  Are you direct-driving your load and require really high resolution?" CreationDate="2011-04-10T22:02:20.257" UserId="2288" />
  <row Id="19514" PostId="12843" Text="Thanks, SPIEN is programmed and clock selected in AVRISP mkII programmer is 125 Khz." CreationDate="2011-04-10T22:07:39.850" UserId="3798" />
  <row Id="19515" PostId="12846" Text="Yea, I understand that 10k encoders are not hobbyist level stuff but to be completely honest, the only difference between a 10k encoder and a 200 line encoder is just that one is more expensive, other than that, they work pretty much the same. The difference between a 16 mhz Arduino and a 500 Mhz XMOS is not quite so simple." CreationDate="2011-04-10T22:10:10.440" UserId="1319" />
  <row Id="19516" PostId="12848" Text="Hmm, separate cheaper micros would defiantly work (and is something I might be able to pull off). Speaking of separate chips, any idea if they make dedicated quadrature decoding ICs? I guess for my application I only need snapshots of encoder positions as opposed to real time tracking. It is only important that all encoders positions are caught at the exact same time." CreationDate="2011-04-10T22:19:07.003" UserId="1319" />
  <row Id="19517" PostId="12847" Score="1" Text="I dont really understand that code" CreationDate="2011-04-10T22:52:01.363" UserId="3796" />
  <row Id="19518" PostId="8848" Text="I'm also searching for a device like this, did you fine one?" CreationDate="2011-04-10T23:04:13.753" UserId="3801" />
  <row Id="19519" PostId="12851" Text="Not sure I know the official answer, so I'm just posting as comment instead. With three phases, 120 degree shift between any two phases is the natural way to do it, since 360/3=120. This makes it easier to work with, control etc. Theoretically, there is no reason you couldn't have any arbitrary relationship between the three phases. But there may be more to it than that... for example, maybe it is easier to construct a three phase AC generator to produce output waveforms 120 degrees apart... but I don't know for sure." CreationDate="2011-04-10T23:54:44.180" UserId="3635" />
  <row Id="19520" PostId="12846" Text="I need to direct drive because of backlash issues of gearing. I'm designing a 6 DOF linkage based coordinate measuring machine, everything is done except the electronics which I'm struggling with." CreationDate="2011-04-11T00:12:37.263" UserId="1319" />
  <row Id="19522" PostId="12848" Score="1" Text="they absolutely do make quadrature decoders.  I haven't used a discrete IC for this in a while, but I think it was the HCTL-2000.  Make sure you pay close attention to the bandwidth of the IC, or the micro that you might use for decoding.  10k lines / rotation is extremely high resolution, so spinning the shaft too quickly could very well result in lost counts.  If you don't mind my asking, what encoder are you using?" CreationDate="2011-04-11T00:41:04.800" UserId="2288" />
  <row Id="19523" PostId="12846" Text="@Faken true, the encoders we use support 6 different resolutions, but the internals are almost identical.  If you're just doing a coordinate measuring device, the good news is that you don't need high speed, you just need to ensure that you don't lose counts." CreationDate="2011-04-11T00:42:58.980" UserId="2288" />
  <row Id="19526" PostId="12848" Text="Ohh hey look! They make 32-bit counter/decoders. That's perfect! Though, I may still need to go through a parallel to serial IC first (outputs in 4 8-bit transfers, not enough pins on micro for 6 of them). 33 Mhz operation is way more than I need. I'm using TRD-S2500-BD encoders." CreationDate="2011-04-11T01:14:31.193" UserId="1319" />
  <row Id="19528" PostId="12853" Text="of course, if you have a system with at least two unique phases, you can derive balanced 3-phase from it (using suitable transformers) and thus put constant power into a load, but the resulting transmission line currents will be asymmetric; with unequal phase angles you'd either have to (1) live with time-varying instantaneous power, (2) under-utilize some of the transmission line conductors, or (3) have differently sized conductors. Equally spaced phase angles give the optimum solution w/regard to conductor sizing-vs-utilization." CreationDate="2011-04-11T01:31:32.840" UserId="740" />
  <row Id="19530" PostId="12834" Text="The power companies do have to pay for thicker copper to handle this power, even though the energy ultimately comes back to them." CreationDate="2011-04-11T02:09:43.320" UserId="142" />
  <row Id="19531" PostId="12848" Text="Would it help at all to do the decoding with logic, and output &quot;up&quot; and &quot;down&quot; pulses to the Arduino?" CreationDate="2011-04-11T02:15:00.107" UserId="142" />
  <row Id="19532" PostId="12802" Text="I'm using arrays of 6-Transistor SRAM cells" CreationDate="2011-04-11T02:37:20.463" UserId="3782" />
  <row Id="19533" PostId="12809" Text="see comment below" CreationDate="2011-04-11T02:37:57.437" UserId="3782" />
  <row Id="19536" PostId="12848" Text="@endolith but I wonder if that would still tax the arduino too much.  You'd then need to make sure the Arduino can capture these rapid up/down pulses from 6 high res encoders while it's dealing with the user app." CreationDate="2011-04-11T03:12:32.433" UserId="2288" />
  <row Id="19538" PostId="12845" Score="1" Text="How fast is it, i.e. how many counts per second do you get?" CreationDate="2011-04-11T05:29:01.520" UserId="339" />
  <row Id="19539" PostId="12834" Text="@AndrejaKo -  You're right, of course. Odd that the error went unnoticed before. I'll correct it at once. " CreationDate="2011-04-11T05:36:08.393" UserId="2064" />
  <row Id="19541" PostId="12834" Text="@stevenvh: How do you calculate the cos(phi) of a load?" CreationDate="2011-04-11T06:38:01.480" UserId="2426" />
  <row Id="19542" PostId="12836" Text="Well I am sharing the link for a paper which I am reading right now where this peaking inductance has been used." CreationDate="2011-04-11T07:57:32.937" UserId="3794" />
  <row Id="19543" PostId="12836" Text="http://amsacta.cib.unibo.it/1039/1/GA042711.PDF" CreationDate="2011-04-11T07:58:54.153" UserId="3794" />
  <row Id="19544" PostId="12849" Text="Hey thx a lot! Clears the air a bit!" CreationDate="2011-04-11T07:59:57.880" UserId="3794" />
  <row Id="19545" PostId="12858" Text="@Jacob - I've added a link to the datasheet, so that people know what you're talking about. Not sure if your figure 15 references this document, though." CreationDate="2011-04-11T08:14:20.377" UserId="2064" />
  <row Id="19546" PostId="12836" Text="The peaking inductance is used in the design of an active balun for the Gilbert cell mixer." CreationDate="2011-04-11T08:22:05.293" UserId="3794" />
  <row Id="19547" PostId="12856" Text="@whoever downvoted this - can you motivate your downvote?" CreationDate="2011-04-11T08:29:06.073" UserId="2064" />
  <row Id="19548" PostId="12834" Text="@BG100 - for appliances like motors, fluorescent lamp ballasts, etc. this should be given by the manufacturer. For your own circuit you'll have to calculate the complex impedance Z = R + j*Zr." CreationDate="2011-04-11T08:36:42.120" UserId="2064" />
  <row Id="19549" PostId="12834" Text="Why UPS devices have their power given in VA instead of Watts and if my computer takes 400W how powerful UPS shouold I have?" CreationDate="2011-04-11T08:37:10.733" UserId="2224" />
  <row Id="19550" PostId="12834" Text="@stevenh Thanks for the edit. +1" CreationDate="2011-04-11T10:09:42.470" UserId="659" />
  <row Id="19551" PostId="12861" Text="Hi. Thanks for your help. Okay thats how you do it!  ....I got some reading to do.  ;-)" CreationDate="2011-04-11T10:10:47.820" UserId="3041" />
  <row Id="19552" PostId="12861" Text="@Jaroslav I was trying to shrink the equations a bit and started to wonder: Do $M$ and $\varphi$ relate somehow to the S-parameters?" CreationDate="2011-04-11T10:17:55.553" UserId="659" />
  <row Id="19553" PostId="12861" Text="@jpc please don't, it become completely nonobvious how to calculate the values." CreationDate="2011-04-11T10:21:24.100" UserId="2636" />
  <row Id="19554" PostId="12861" Text="@jpc MAG and ANG are the values from the datasheet, e.g. MAGS11 and ANGS11." CreationDate="2011-04-11T10:24:38.823" UserId="2636" />
  <row Id="19555" PostId="12834" Score="1" Text="@Kamil The reason is simple. The PSU has its own power factor like any other device. It's same situation as in the examole I mentioned, but a bit more complicated. For example 300 W PSU has power factor of 0.9 and efficiency of 0.8. So if you take 300 W from the supply, it will consume 300/0.8=375 W. Now lets take power factor into account. Active power is in this case 90% of total consumption, so for 375 W we get 375/0.9=417 VA. So for a good 300 W supply you need 420 VA UPS. The power factor and efficiency curves should be printed on PSU or its box, but cheaper units may not show that." CreationDate="2011-04-11T10:32:07.543" UserId="1240" />
  <row Id="19556" PostId="12858" Text="@steven, Ah thanks. :-) You are right, I should have done that." CreationDate="2011-04-11T10:40:43.843" UserId="3041" />
  <row Id="19557" PostId="12853" Text="the short answer - because three evenly spaced phases are simpler to work with (motors/generators don't have to deal with asymmetry) and more economically feasible (all 3 conductors can be spec'd the same) than any other system of three phases." CreationDate="2011-04-11T11:15:31.847" UserId="740" />
  <row Id="19559" PostId="12861" Text="@Jaroslav: Sorry, I checked the linked page and didn't see anything obvious. Do you thing that replacing the $*$ with $\cdot$ would be ok?" CreationDate="2011-04-11T11:38:36.640" UserId="659" />
  <row Id="19560" PostId="12861" Score="1" Text="@jpc actually I think the convention is to leave the multiply sign out altogether, but I am not sure it would help readability ..." CreationDate="2011-04-11T12:20:25.823" UserId="2636" />
  <row Id="19562" PostId="12856" Text="could you post your circuit?" CreationDate="2011-04-11T12:46:53.000" UserId="1266" />
  <row Id="19564" PostId="12485" Text="exactly! and I was thinking about something displayed by the computer that my device can recognize.." CreationDate="2011-04-11T13:41:13.637" UserId="2285" />
  <row Id="19565" PostId="12846" Text="Why the downvote? It's the sort of application that that XMOS devices excel at! They can capture 100 MHz events, are much easier to use than FPGAs, and will usually work out cheaper." CreationDate="2011-04-11T13:51:39.060" UserId="305" />
  <row Id="19566" PostId="12866" Score="3" Text="Also think about what happens if the LED fails and shorts. Limiting resistor is not just a good idea, its the law! (well ok maybe not)" CreationDate="2011-04-11T13:55:32.313" UserId="2340" />
  <row Id="19567" PostId="12802" Text="Using MOSFETs?  How are you implementing the pass-gates?  Within a chip, the substrate of the pass-gate transistor would be tied to VSS, independent of the source and drain, but discrete MOSFETs generally tie the substrate to the source.  Are you using transistors with a discrete substrate connection?  How are you limiting the drive strength of the PFETs so as to allow them to be overdriven?  I would guess that if you precharge all the columns columns to VDD before enabling a row, you would be able to read out a column as a straight logic level." CreationDate="2011-04-11T14:34:33.003" UserId="3123" />
  <row Id="19568" PostId="12777" Text="This always confused me too.  I could never figure out why a load connected between the collector and emitter wouldn't have current pushed through it.  :)  Transistors are *not* amplifiers.  They are current-regulating valves." CreationDate="2011-04-11T14:44:28.593" UserId="142" />
  <row Id="19569" PostId="11517" Text="Is there any nice way to figure the transfer function obtained by cascading resistors and capacitors?  I know the normal style of filter uses one amp for every two orders, but I would expect that cascading N simple RC filters would yield a response somewhere between a first-order filter and an N-order filter.  If R1C1 is the first stage, and R2C2 is the second, and R2 is much greater than R1 (C2 much smaller than C1), I would think the response would be the product of the R1C1 response and the R2C2 response (basically, a second-order filter).  The general difficulty...." CreationDate="2011-04-11T14:56:35.503" UserId="3123" />
  <row Id="19570" PostId="11517" Text="...of such a circuit would be that if R2 is not much greater than R1, the behavior of C2 will affect the signal at C1, and making each stage's resistance much larger than the previous stage's would be difficult if there were very many RC stages between amplifier stages.  I designed a music box some years ago with an ad-hoc filter using four resistors and four caps; I wonder how good or bad the filter actually was (it sounded fine aesthetically)." CreationDate="2011-04-11T14:59:08.560" UserId="3123" />
  <row Id="19571" PostId="12869" Text="@Jason FYI the title is a little misleading -- it looks like you want ethernet converted to RS485, but the Wiz108SR is apparently an RS485 -&gt; ethernet adapter..." CreationDate="2011-04-11T15:03:09.413" UserId="2288" />
  <row Id="19572" PostId="12869" Text="@Dave, it goes both ways. Saleig just listed it that way. I revised the title, hoping it makes more sense." CreationDate="2011-04-11T15:17:13.480" UserId="1960" />
  <row Id="19573" PostId="12868" Text="My soul does not allow me to leave that unfiltered. Also, I &quot;sings&quot; then :-) It will work in my case, is uC will be able to work even in 1-20 range, just need to change PWM value too often..." CreationDate="2011-04-11T15:24:55.967" UserId="2062" />
  <row Id="19574" PostId="12856" Text="Scheme posted.." CreationDate="2011-04-11T15:28:50.707" UserId="2062" />
  <row Id="19575" PostId="12834" Text="@AndrejaKo - I once worked on a robotic system with four linear motors fed by 30A amplifiers. When the breaking at maximum rate (around 2g from 2m/s) it sent enough power back up the three phase for neighbouring units to notice and we got a visit from the power company. We were told we had to sink that power before we could plug the machine in again, so ended up with the whole back side of the control rack as a huge heat sink for a bunch of massive 1&quot;x6&quot; resistors. Even then we blew a few up before getting the duty cycle of the machine optimised. *8')" CreationDate="2011-04-11T15:44:29.007" UserId="3774" />
  <row Id="19576" PostId="12868" Text="@BarsMonster  I'm not sure what you mean by &quot;I 'sings' then&quot;.  If you mean to say, &quot;the fan makes a note&quot; then the simple answer is to change the PWM frequency so it no longer does that.   Also, I edited my answer above to cover the case were you just have to keep the LC filter." CreationDate="2011-04-11T15:59:55.670" UserId="3624" />
  <row Id="19577" PostId="12857" Text="This is a silly example. AVR's have internal pullup resistors, that are very easy to enable. Much easier to connect the button to ground and enable the internal pullup, versus connecting it to 5V with an external pulldown to ground." CreationDate="2011-04-11T16:03:29.280" UserId="131" />
  <row Id="19578" PostId="12846" Text="I think the downvote is because you suggested a quadrature decoder chip which is much more powerful, complicated, and expensive, then the chip that is running the rest of his device. " CreationDate="2011-04-11T16:12:01.833" UserId="131" />
  <row Id="19579" PostId="12846" Text="He can't use his existing device! He needs something with far more performance, or an FPGA as well as the Arduino. The XMOS chip only costs $7.50 and is all he needs." CreationDate="2011-04-11T16:20:15.650" UserId="305" />
  <row Id="19581" PostId="12868" Text="Yes, varying voltage is what I am trying to achieve. I know it should not sing at 30kHz, but for some reason, it does a little without filtering. Increasing clock might be problematic as I would need to add an external clock (this is attiny13, only 8Mhz is available on internal RC, and no way to attach crystal)" CreationDate="2011-04-11T16:33:14.353" UserId="2062" />
  <row Id="19583" PostId="4574" Text="code sourcery publishes their modifications to gcc, so you can take that route, build from their mods to gcc, or just build your own gnu based toolchain directly from the gcc sources, without getting into codesourcery stuff." CreationDate="2011-04-11T17:00:32.013" UserId="985" />
  <row Id="19585" PostId="12872" Text="A current mirror also has a required voltage drop over the transistor. It may be able to follow the current quite well (so you set a 10mA reference and get very close to that on the other side), but it will need a little bit of voltage to work." CreationDate="2011-04-11T17:14:50.200" UserId="1476" />
  <row Id="19587" PostId="12872" Text="@Hans good point, I updated to make that clearer" CreationDate="2011-04-11T17:25:24.207" UserId="3441" />
  <row Id="19588" PostId="12882" Score="1" Text="But it can't generate this heat all by itself; the required power has to be supplied from the outside!" CreationDate="2011-04-11T17:28:31.817" UserId="2064" />
  <row Id="19591" PostId="12886" Text="Tell us how much do you know about electronics? Also while you're waiting for a good answer, take a look at [this](http://www.allaboutcircuits.com/vol_1/index.html) and read the experiments part. Also do you have any equipment? IF the answer is no, then expect to spend at least $200 on basics (**safe** multimeter, breadboards jumper wires, power source etc). The good news is that after you get your basic lab kit,  you can have loads of fun for just another $100. Simple components like resistors, diodes, voltage regulators, buttons, microcontrollers and so on are very very cheap." CreationDate="2011-04-11T17:58:27.647" UserId="1240" />
  <row Id="19593" PostId="12885" Text="The temperatures required to get any noticeable noise produced by the resistors are so high that the resistor would burn first. The thermal noise characteristics are only used to model systems that have equivalent higher noise temperatures." CreationDate="2011-04-11T18:03:08.377" UserId="319" />
  <row Id="19594" PostId="12886" Text="Answered your questions above, thanks.  Also, I will look at the link you sent out." CreationDate="2011-04-11T18:32:00.420" UserId="3810" />
  <row Id="19595" PostId="12889" Score="1" Text="Thanks for the suggestion, I agree with sticking with the basics.  &quot;electronic die...HCMOS ICs, like a 7-segment LED driver&quot; uh...you lost me at electronic die... :o)" CreationDate="2011-04-11T18:33:22.043" UserId="3810" />
  <row Id="19596" PostId="12886" Text="This question might be sort of relevant http://electronics.stackexchange.com/questions/12543/what-good-resources-are-there-for-a-high-school-student-to-start-learning-electro/12548#comment-18968" CreationDate="2011-04-11T18:47:39.927" UserId="1623" />
  <row Id="19600" PostId="12889" Text="In elementary school, I connected a self-contained buzzer to a pushbutton to a 9 V battery to use in class Jeopardy games.  :)  Can't get much more simple than that.  I could follow directions and make working circuits with an electronics kits, but never really understood them until late high-school/college.  Digital logic is a good idea." CreationDate="2011-04-11T18:56:45.877" UserId="142" />
  <row Id="19601" PostId="12886" Text="@Randy Syring OK. Another question: Would you be more interested in building things from round up or are you more interested in just seeing results? This will help us determine direction in which we should take our recommendations. For example if you just want to see things done, you can get an [Arduino](http://www.arduino.cc/) and program a flashing LED quickly and get to use programming. On the other hand making a similar device from scratch would take several projects but you'll understand how each part actually works." CreationDate="2011-04-11T19:03:59.613" UserId="1240" />
  <row Id="19602" PostId="12886" Text="Another interesting question: http://electronics.stackexchange.com/q/966/1240  Mainly focus on capacitors, resistors and fuses, if you don't know what we're talking about there." CreationDate="2011-04-11T19:12:03.510" UserId="1240" />
  <row Id="19604" PostId="12846" Text="@Leon, I think it's a toss-up between the two options (XMOS or programmable logic). Both have unfamiliar development environments, but you could stay &quot;programming only&quot; with the XMOS. " CreationDate="2011-04-11T19:43:51.390" UserId="638" />
  <row Id="19605" PostId="12882" Text="@stevenvh: Yes, but 99% of electronic devices require external power; that doesn't mean they'd be generally considered &quot;useless by themselves&quot;.  A paper photograph is useless for its normal purpose without a light source (possibly the Sun) and a person to view it, but a paper photograph would normally be considered independently useful (in contrast to e.g. an electronically-stored one or even a slide)" CreationDate="2011-04-11T19:44:07.033" UserId="3123" />
  <row Id="19606" PostId="12856" Text="Sorry, finger slip using mobile/touch website. I removed the downvote." CreationDate="2011-04-11T19:44:15.740" UserId="1802" />
  <row Id="19610" PostId="12886" Text="@AndrejaKo: I would rather build from the ground up and get to programming eventually...so far, the experiments section of the website you linked to looks ideal.  I also like the looks of http://www.amazon.com/Make-Electronics-Discovery-Charles-Platt/dp/0596153740/ which was recommended in the link Dean provided." CreationDate="2011-04-11T20:11:00.977" UserId="3810" />
  <row Id="19612" PostId="12846" Text="@leon: I didnt down vote but the XMOS chip is not an entire developer board like the arduino. Just as I can't use my existing divide, neither can I use yours due to its complexity. I've only been playing with electronics for 5 days so far. I stated that I lacked knowledge and experience with electronics in my question, that should have been considered on your answer." CreationDate="2011-04-11T20:22:24.850" UserId="1319" />
  <row Id="19613" PostId="12890" Score="1" Text="Thanks for the suggestion.  I took a look at some of the kits and I think they are a bit too &quot;toyish.&quot;  They look perfect for my six year old, but not my 13 year old.  In addition, I think learning to work with the &quot;real&quot; components will be a better foundation for future learning." CreationDate="2011-04-11T20:22:25.537" UserId="3810" />
  <row Id="19616" PostId="12875" Text="For those who speak german: http://www.elektronik-kompendium.de/" CreationDate="2011-04-11T20:29:30.523" UserId="339" />
  <row Id="19619" PostId="12886" Text="What's wrong with robotics?  When I was that age, I was most impressed with things that move!  It doesn't have to be on the scale of &quot;Danger Will Robinson!&quot;  Little line following robots are a blast." CreationDate="2011-04-11T20:38:43.813" UserId="1823" />
  <row Id="19620" PostId="12846" Text="Thanks I'll take another look at it." CreationDate="2011-04-11T20:45:59.437" UserId="1319" />
  <row Id="19621" PostId="12846" Text="It's a lot easier to use than the other options. A development board only costs 99 dollars, from Digi-Key." CreationDate="2011-04-11T20:47:13.840" UserId="305" />
  <row Id="19622" PostId="12861" Text="@Jaroslav That is why I was suggesting the cdot. To me it looks like multiplication but adds less visual noise." CreationDate="2011-04-11T21:14:23.793" UserId="659" />
  <row Id="19623" PostId="12878" Score="1" Text="It can generate heat." CreationDate="2011-04-11T21:14:48.223" UserId="2157" />
  <row Id="19624" PostId="12474" Text="@starblue You should turn this comment into an answer so people can vote on it. :)" CreationDate="2011-04-11T21:15:28.553" UserId="659" />
  <row Id="19627" PostId="12802" Text="it's still in the design phase, but i'm planning to use 2 NPN transistors (i already have about 250 in my collection :) and 2 inverters for the feedback circuit, probably in a 4049" CreationDate="2011-04-11T21:59:55.670" UserId="3782" />
  <row Id="19630" PostId="12637" Text="@davidcary I actually can't find the original source for that.  I was doing a lot of research on this issue awhile back and it came up in some report I was reading.  The reasoning was that AL caps don't have a perfect seal and the air flow increases evaporation of the electrolyte.  I believe it was in reference to large snap in caps rather than low voltage caps which generally have much better seals." CreationDate="2011-04-11T22:27:13.113" UserId="1438" />
  <row Id="19631" PostId="12841" Text="I tried pretty much this.  To apply even pressure, I used some silicon rubber foam (about 1/4&quot; thick) on either side of the board.  Then it went into the oven.  It worked OK, but not great.  You have to leave it in the oven a while for the heat to diffuse through the foam, which acts like an insulator.  But silicone can handle the heat.  It might work better with a thin silicone sheet instead. " CreationDate="2011-04-11T22:34:08.033" UserId="2773" />
  <row Id="19633" PostId="12847" Text="An HDL like VHDL or Verilog, is the usual way to do things like that, these days." CreationDate="2011-04-11T22:48:43.773" UserId="305" />
  <row Id="19634" PostId="12873" Text="The labels of your first graph disagree with your description of it." CreationDate="2011-04-11T23:31:59.423" UserId="2838" />
  <row Id="19635" PostId="12898" Text="Solid explanation.  I completed the ALU early this morning, but this was a good read.  Thank you.  I would up-vote this if I had the capability." CreationDate="2011-04-11T23:36:04.333" UserId="3796" />
  <row Id="19636" PostId="12873" Text="thank you, fixed." CreationDate="2011-04-11T23:38:32.490" UserId="411" />
  <row Id="19637" PostId="12889" Text="&quot;One possible project is an electronic die.&quot; Die, singular of dice. Building something that would display a random. Can't help you with the rest though." CreationDate="2011-04-12T00:07:10.920" UserId="904" />
  <row Id="19639" PostId="12903" Text="http://www.mosaicengineering.com/docs/OEM-SCM.2010-01-26.pdf" CreationDate="2011-04-12T00:53:31.537" UserId="2157" />
  <row Id="19640" PostId="12903" Text="You also might want to search for OEM camera makers. Many have 'smart cameras'." CreationDate="2011-04-12T00:55:06.183" UserId="2157" />
  <row Id="19641" PostId="12903" Text="Thanks Kenny, I'll look it up! I failed to mention earlier, I was hoping to find something that is programmable in C / Matlab, as a preference." CreationDate="2011-04-12T00:55:28.650" UserId="3458" />
  <row Id="19642" PostId="12903" Text="Kenny, the link you posted seems to be a prelim offering, I don't think its available to consumers. Also, they make no mention of how to program it ..." CreationDate="2011-04-12T00:57:14.780" UserId="3458" />
  <row Id="19643" PostId="12906" Text="If in doubt, remember that assume makes an ass of u and me :) " CreationDate="2011-04-12T03:24:24.200" UserId="2340" />
  <row Id="19644" PostId="12905" Text="Once generated, feed your signal into a flip-flop and divide it down to something you can measure." CreationDate="2011-04-12T03:32:34.633" UserId="411" />
  <row Id="19645" PostId="12905" Text="If you make a square wave, don't forget to filter off the harmonics before making response measurements." CreationDate="2011-04-12T03:33:18.110" UserId="411" />
  <row Id="19646" PostId="12909" Score="1" Text="@Keith Nicholas  Define &quot;Very Stable&quot;.  And define &quot;won't drift with temp/time&quot;.  Everything will drift, so it's mainly a matter of how much drift is acceptable.  Also, over what time period does this clock need to be running?  1 hour, 1 day, 1 century?  What about power requirements?  Battery or AC powered?   " CreationDate="2011-04-12T03:47:22.137" UserId="3624" />
  <row Id="19647" PostId="12909" Text="@David,  fair enough! to less than 0.01 of Hz.   It will be running in the order of a week.   It will be powered with a DC power supply or battery." CreationDate="2011-04-12T03:53:19.147" UserId="1260" />
  <row Id="19648" PostId="12846" Text="Not sure why your answer got downvoted.  I am equally confused why my answer was considered bad as well..." CreationDate="2011-04-12T04:09:27.407" UserId="2288" />
  <row Id="19649" PostId="12869" Text="@Jason ah cool, ok!" CreationDate="2011-04-12T04:10:11.507" UserId="2288" />
  <row Id="19650" PostId="12910" Text="ok, so no super simple method for doing it.  But I'm pretty happy at throwing a PIC at the problem to solve it." CreationDate="2011-04-12T04:26:04.130" UserId="1260" />
  <row Id="19652" PostId="12861" Text="@jpc sure, do it, when it comes to math, I am just a consumer, and thanks" CreationDate="2011-04-12T05:22:47.680" UserId="2636" />
  <row Id="19653" PostId="12825" Text="Maybe it's a extended limo-van." CreationDate="2011-04-12T05:43:50.283" UserId="2118" />
  <row Id="19654" PostId="12911" Text="What's the variable capacitor in this circuit for?" CreationDate="2011-04-12T05:49:31.420" UserId="2426" />
  <row Id="19655" PostId="12910" Score="1" Text="I disagree with the microcontroller. There's nothing simpler than an oscillator followed by a prescaler, see Jaroslav's answer." CreationDate="2011-04-12T06:12:29.623" UserId="2064" />
  <row Id="19656" PostId="12911" Text="@BG100 It's a Pierce oscillator, so you need to match (here unknown) load capacitance of crystal with the capacitors. You don't have to use variable, though, find the correct value on breadboard or from crystal's datasheet." CreationDate="2011-04-12T06:23:15.717" UserId="2636" />
  <row Id="19657" PostId="8943" Text="I picked up some similar chips for a great price!  I think this will totally work.  Thanks for the suggestion!" CreationDate="2011-04-12T06:24:23.890" UserId="2288" />
  <row Id="19658" PostId="12914" Text="A red LED will drop 0 volts at 0 current.  And a sleeping MSP430 is pretty close to zero current." CreationDate="2011-04-12T06:41:32.887" UserId="411" />
  <row Id="19659" PostId="12914" Text="And the MAX232?" CreationDate="2011-04-12T06:52:20.043" UserId="3743" />
  <row Id="19660" PostId="12911" Score="1" Text="+1 for the cheapest and simplest solution." CreationDate="2011-04-12T06:55:27.060" UserId="2064" />
  <row Id="19661" PostId="12875" Score="1" Text="I also come from a programming background and have exactly this problem: http://electronics.stackexchange.com/questions/5336/i-dont-care-how-a-transistor-works-how-do-i-get-one-to-work" CreationDate="2011-04-12T07:35:17.973" UserId="1633" />
  <row Id="19662" PostId="12905" Text="I thought it would be exponential, like in this image: http://en.wikipedia.org/wiki/File:Butterworth_response.png  and then that would be a simple equation to work out -3dB from -1dB... but perhaps it is not?" CreationDate="2011-04-12T07:44:27.813" UserId="1225" />
  <row Id="19663" PostId="12842" Text="Can we please stick to English? This site will become a terrible mess if everybody starts using a local language!" CreationDate="2011-04-12T09:39:50.743" UserId="2064" />
  <row Id="19664" PostId="12915" Text="67 ohms, wtf?? Why not 68, that's an E12 value? BTW, I prefer diodes over resistors to create this voltage drop. In case of resistors, the voltage drop will vary with the load." CreationDate="2011-04-12T09:57:38.450" UserId="2064" />
  <row Id="19665" PostId="12913" Score="2" Text="You only state a car battery, but car power has a number of very tricky power situations and surges that you need to design for. Read a number of articles on the web, since you'll need to include a lot of safety in the circuit and protection diodes." CreationDate="2011-04-12T10:17:24.907" UserId="2157" />
  <row Id="19666" PostId="12842" Text="steven, I agree with the main thrust of the argument, but dismissively calling Spanish a &quot;local language&quot; is ridiculous. It is spoken by over 400 million people and is an official language of 20 countries." CreationDate="2011-04-12T10:40:37.097" UserId="1802" />
  <row Id="19667" PostId="8848" Text="I have just bought a PST-T100 &quot;GO Everywhere&quot; GPS Tracker. I'm able to set the IP and port on the device with SMS commands. All i need now is the server software, but i'm &quot;working&quot; on that issue overe here http://stackoverflow.com/questions/5633467/gps-tracker-sends-data-to-ip-whats-next" CreationDate="2011-04-12T10:43:35.820" UserId="3801" />
  <row Id="19668" PostId="12919" Text="Note that even deeper pipelines don't need to cost much in the Spartan 3A family. Up to 16 bits deep fits in one LUT configured as a shift register.&#xA;It may also be useful to consider whether the counter needs to match an addressing scheme (in a FIFO, for instance, you only need a sequence, not an up counter) and you could do the delay by changing the values you compare to generate the sync pulses." CreationDate="2011-04-12T10:47:13.517" UserId="1181" />
  <row Id="19669" PostId="12842" Text="sorry stevenvh,  " CreationDate="2011-04-12T11:08:17.033" UserId="3798" />
  <row Id="19670" PostId="10534" Text="@NickT - what you're talking about is what's known as 'roll-over', when key presses start overlapping. The wait-two-scans thing will still work for individual keys, because any *individual* key press is relatively slow. Of course roll-over, and pressing multiple keys in general invites the issue of ghosting, where if three keys happen to lie on the corners of a rectangle within the matrix, it becomes impossible to tell if the key at the 4th corner of the rectangle is pressed, but that's another issue." CreationDate="2011-04-12T11:30:00.123" UserId="740" />
  <row Id="19672" PostId="12915" Text="@stevenvh Totally agree with 68 Ohms. But preferring diodes? A resistor will indeed cause the voltage drop to vary with the load - that's the point when trying to stabilise the current." CreationDate="2011-04-12T12:03:51.570" UserId="2234" />
  <row Id="19673" PostId="12354" Text="Curiously this does not explain the error messages above, as they show a multiple definition, not an undefined symbol. Also, for mutual dependencies, sometimes adding the same library more than once can help." CreationDate="2011-04-12T12:06:22.780" UserId="1181" />
  <row Id="19674" PostId="10282" Text="Note that the advantage - Xilinx designed - is also the disadvantage. The Microblaze is only officially available for Xilinx chips. There are clones of both platforms, however, as well as independent designs." CreationDate="2011-04-12T12:14:26.483" UserId="1181" />
  <row Id="19675" PostId="12842" Text="@Ranieri - I didn't call Spanish a local language. But it starts with Spanish, and the next day you get questions in Mandarin, Hindi, Arabic and French (to name a few other world languages), and why would it stop there? Why wouldn't I post in Dutch? That's where the local languages come in." CreationDate="2011-04-12T12:18:37.627" UserId="2064" />
  <row Id="19676" PostId="12915" Text="@Mike - You're assuming nice, smooth load characteristics, like positive dynamic impedance everywhere. If you don't have these your &quot;regulator&quot; may show some strange behavior. You don't know what the load characteristics are, so why not choose for a solution which has a *fixed* voltage drop, instead of something variable?" CreationDate="2011-04-12T12:34:00.810" UserId="2064" />
  <row Id="19677" PostId="12915" Text="@stevenvh - We're talking about an LED backlight here. It will have a low dynamic resistance above the knee so driving it with constant voltage will give unpredictable current." CreationDate="2011-04-12T12:40:40.867" UserId="2234" />
  <row Id="19678" PostId="12908" Text="I've seen some brand new VGA cables which didn't even have some pins on the connector, so +1." CreationDate="2011-04-12T12:43:38.153" UserId="1240" />
  <row Id="19679" PostId="12924" Text="Hi, thank you very much for your answer. A second question, if the line is longer than 1/10, and I use a transmission line. Do I always have to match the source output impedance (with the line impedance)? even if the connection from the source to the beginning of the transmission line is short?" CreationDate="2011-04-12T12:45:49.120" UserId="3041" />
  <row Id="19681" PostId="12910" Text="@stevenvh  Yes, Jaroslav's circuit is simple, but the thing is, nobody needs just a 4 Hz clock.  And we don't know everything that Kieth has in plan for his project.  So, while you might disagree with an MCU it might end up being the better solution given the big picture that only Keith knows.  That's why in my answer I threw out three solutions:  a counter chip, a CPLD/FPGA, and a MCU." CreationDate="2011-04-12T13:05:01.300" UserId="3624" />
  <row Id="19682" PostId="12924" Text="Okay, so I will not get a reflection from the beginning of the transmission line, if the source output impedance is not matched?" CreationDate="2011-04-12T13:11:34.227" UserId="3041" />
  <row Id="19683" PostId="12924" Text="No, the impedance should be matched." CreationDate="2011-04-12T13:13:22.040" UserId="305" />
  <row Id="19684" PostId="12913" Text="@kenny is that true even for accessory power?  I thought that circuit was relatively safe.  I'll revise my post because I should have stated this, but I will also look into it more on the web.  Thanks for the tip!" CreationDate="2011-04-12T13:22:59.703" UserId="2288" />
  <row Id="19685" PostId="12916" Text="Thanks!  I'll definitely keep that in mind." CreationDate="2011-04-12T13:24:25.833" UserId="2288" />
  <row Id="19686" PostId="12846" Text="I don't think that the Arduino could keep up with the data from six slave MCUs. I2C would definitely be too slow, and I can't see SPI on the Arduino being fast enough." CreationDate="2011-04-12T13:27:55.887" UserId="305" />
  <row Id="19687" PostId="12915" Text="@Mike - Alright, I guess I was misled by OP's &quot;I was thinking about trying 3.3V on the backlight -- the specs state 3V typical, but don't specify a min or max value.&quot;. I presumed he wanted a 3V regulated voltage." CreationDate="2011-04-12T13:43:06.587" UserId="2064" />
  <row Id="19688" PostId="12924" Text="@LeonHeller, A very big rule people forget is to treated the line as a lumped LC circuit if it is below 1/10 the wavelength. The inductance and capacitance of the line can still cause substantial ringing." CreationDate="2011-04-12T13:53:41.350" UserId="230" />
  <row Id="19689" PostId="12924" Text="@JakobJ, if your source impedance does not match your line impedance your wave will not be full magnitude as it travels the line." CreationDate="2011-04-12T14:11:15.087" UserId="230" />
  <row Id="19690" PostId="12915" Text="@markrages Ah, thank you for catching that!  I subconsciously purposely set the LCD voltage on my breadboard to 3.3V so I wouldn't have to worry about the logic levels going to the MSP430.  Do you think it's reasonable to just do that, or should I actually use 5V for the LCD logic and add the necessary protection?  I wonder if the 3.3V supply power is the reason for my inability to initialize the LCD...  :)" CreationDate="2011-04-12T14:18:42.363" UserId="2288" />
  <row Id="19691" PostId="12915" Text="@Dave the specsheet says 3.3V minimum, so it should work.  You'll probably have to fiddle with the contrast to see anything though." CreationDate="2011-04-12T14:25:57.830" UserId="411" />
  <row Id="19693" PostId="12930" Score="1" Text="possible duplicate of [Understanding when to use basic Components](http://electronics.stackexchange.com/questions/10696/understanding-when-to-use-basic-components)" CreationDate="2011-04-12T16:26:15.780" UserId="142" />
  <row Id="19695" PostId="12929" Score="2" Text="If you have a specific question, feel free to ask. But, you aren't going to get any good answers for such a broad question." CreationDate="2011-04-12T16:30:49.283" UserId="319" />
  <row Id="19696" PostId="12930" Text="@Sauron what was the similar question you are talking about? if it is the question endolith linked to then it is probably worth another pass from the community to see if we can explain more/better." CreationDate="2011-04-12T16:35:13.507" UserId="319" />
  <row Id="19697" PostId="12930" Text="^^ That was my question before, but it was more for a general electronics knowledge, This one is specifically for Inductors/Caps" CreationDate="2011-04-12T16:35:22.680" UserId="3073" />
  <row Id="19698" PostId="12929" Text="The places I always look for information is google, google scholar, and the ieee xplore." CreationDate="2011-04-12T16:37:07.467" UserId="319" />
  <row Id="19699" PostId="12930" Score="1" Text="http://electronics.stackexchange.com/questions/9553/inductor-vs-a-capacitor was the similar one" CreationDate="2011-04-12T16:39:21.473" UserId="3073" />
  <row Id="19700" PostId="12930" Score="2" Text="Caps are used for voltage smoothing, inductors are used for current smoothing. A switching regulator makes use of current smoothing to produce a relative stable output voltage, however it does have switching noise. Switching regulators are much more efficient than their linear (Like LM317)  counterparts." CreationDate="2011-04-12T16:53:21.970" UserId="1476" />
  <row Id="19702" PostId="12905" Text="It depends on the scheme specifics. If might fall faster or slower, it might have input filter..." CreationDate="2011-04-12T17:05:59.553" UserId="2062" />
  <row Id="19703" PostId="12732" Text="What's the function of the capacitor at the motor? You better place a chunky one at the +12V where the motor is driven from. You don't need to put a big cap at the motor outputs. Always put 100nF as closely as possible to IC supply pins, bigger capacitors are putten after (so can be further). Furthermore, switching direction changes the voltage upon the cap, blowing it up if it's an polarized one." CreationDate="2011-04-12T17:29:22.970" UserId="1476" />
  <row Id="19704" PostId="12910" Text="@David - &quot;nobody needs just a 4 Hz clock&quot;. I've got the idea he does. It sounds to me OP wants a test circuit which supplies this 4Hz signal to an existing DUT. Something like that. In that case microcontroller and especially FPGA are way overkill. You can build Jaroslav's solution in the time it takes to start your FPGA's IDE, so to speak. :-)" CreationDate="2011-04-12T17:39:20.970" UserId="2064" />
  <row Id="19705" PostId="12937" Score="1" Text="Why the concern about the mains power supply adapter? I assumed they had a regulator or switcher in them." CreationDate="2011-04-12T17:48:32.900" UserId="206" />
  <row Id="19706" PostId="12847" Text="@Leon - Give the guy a break, not everybody knows VHDL or is working with programmable logic yet. It's still possible to build an ALU using classic logic ICs." CreationDate="2011-04-12T17:49:47.513" UserId="2064" />
  <row Id="19707" PostId="12912" Text="Thanks for the info.  The parallel cable should work and I can probably accommodate the larger size.  What about a gameport-style DB15 cable?  Do you think it will suffer from the same connection-shortcuts that a VGA cable may exhibit?" CreationDate="2011-04-12T18:20:45.600" UserId="3814" />
  <row Id="19708" PostId="12920" Text="I'm not trying to measure a signal using a lower sample rate, I'm trying to measure the bandwidth of a discrete analog transmitter (which AFAIK has no sample rate per se as it is a 2.4GHz tx.)" CreationDate="2011-04-12T18:21:17.337" UserId="1225" />
  <row Id="19709" PostId="12935" Text="I would worry a bit about stability. On charge, my laptop has a 4.97V USB output. On the battery near the end of the discharge cycle, it drops to 4.75V." CreationDate="2011-04-12T18:22:36.727" UserId="1225" />
  <row Id="19710" PostId="12944" Score="1" Text="Those are file-transfer protocols, not command protocols." CreationDate="2011-04-12T18:45:29.007" UserId="3835" />
  <row Id="19711" PostId="12949" Text="thanks for your help! much appreciated! RS is out of stock :( you dont happen to have a link do you? just i will prob order some crap :( lol thanks again!" CreationDate="2011-04-12T19:31:55.540" UserId="3834" />
  <row Id="19712" PostId="12929" Text="Are you sure this isn't about opto-isolators perhaps?" CreationDate="2011-04-12T19:40:17.627" UserId="2028" />
  <row Id="19713" PostId="10282" Text="Are there any designs for the ARM cortex 9 for Xilinx chips?" CreationDate="2011-04-12T19:41:44.833" UserId="3045" />
  <row Id="19714" PostId="12948" Text="ah OK! Why didn't they write it on same page grr· I ripped a heat sink out of an old AT power supply awhile back. Smart thinking!" CreationDate="2011-04-12T19:46:43.627" UserId="2824" />
  <row Id="19717" PostId="12949" Text="Farnell is out of stock of similar units." CreationDate="2011-04-12T20:08:16.693" UserId="305" />
  <row Id="19718" PostId="12949" Text="would this one work?  http://www.maplin.co.uk/metallised-polypropylene-capacitors-382?ordercode=RG23A actually nope - but im getting desperate! lol" CreationDate="2011-04-12T20:10:19.453" UserId="3834" />
  <row Id="19719" PostId="12929" Text="A Google search for &quot;Optical Chip&quot; returns 77,600 results.  Most of it about optical networking or quantum computing.  Seems like that's where you should start." CreationDate="2011-04-12T16:15:18.640" UserId="3624" />
  <row Id="19720" PostId="12929" Text="I've googled &quot;optical chip&quot; and I see nothing but news on the latest ones or how they are being used in blah-blah-blah. I'm just trying to find some basic information on what the hell an &quot;optical chip&quot; actually is and how it works. " CreationDate="2011-04-12T16:29:10.517" UserId="3831" />
  <row Id="19721" PostId="12929" Text="@Bob  The info is there, you just have to dig.  For example, one link on the first page of Google results, http://www.physorg.com/news203866876.html, says that the research will be published in the next issue of Science.   And this article, http://www.networkworld.com/news/2009/020309-optical-chip.html, says that their stuff will be published in the journal Optical Express.   As usual, use Google to find the semi-interesting bits and then use normal research to get the details." CreationDate="2011-04-12T16:58:16.527" UserId="3624" />
  <row Id="19722" PostId="12787" Text="Good ideas! Thanks!!" CreationDate="2011-04-12T20:18:34.687" UserId="3783" />
  <row Id="19724" PostId="12942" Score="1" Text="This is not a useful answer - it entirely dodges the question.  Inductors have many uses and are very much desired in many circuits.  What you say about the transfer functions is true but needs more explanation." CreationDate="2011-04-12T20:38:02.373" UserId="249" />
  <row Id="19725" PostId="12955" Score="2" Text="Yes, but you pay for it in resolution." CreationDate="2011-04-12T20:47:09.047" UserId="1802" />
  <row Id="19727" PostId="12918" Text="Thanks for the reply, it's all starting to make sense. Sorry that I can only accept one answer (" CreationDate="2011-04-12T20:50:03.490" UserId="710" />
  <row Id="19728" PostId="12942" Text="I agree with @AngryEE, and I feel obligated to vote this answer down... sorry. This answer is very misleading." CreationDate="2011-04-12T21:01:04.463" UserId="3635" />
  <row Id="19729" PostId="12953" Text="I'm not sure, but I think that the answer to second question is yes. In the worst case, you could build your own board, because the default behavior of AVRs is to power on and start executing as soon as it receives voltage. Also Arudino doesn't use microprocessors, it uses microcontrollers. The difference is significant, if you ever want to make your own board, because microcontroller has everything a computer has except power supply and clock crystal (but there is internal clock source that can be used)." CreationDate="2011-04-12T21:25:51.960" UserId="1240" />
  <row Id="19730" PostId="12910" Text="Steven is right, I basically just need a test signal (that we can make a fair few of and is reasonably cheap) to feed into a data logging device." CreationDate="2011-04-12T21:29:28.367" UserId="1260" />
  <row Id="19731" PostId="12956" Text="Thanks @Dave. Couldn't the bowing and distortion be corrected in software?" CreationDate="2011-04-12T21:35:42.647" UserId="3839" />
  <row Id="19732" PostId="12948" Text="The 3.6 A are available only when the voltage difference between input and output is 14 V, so that too needs to be taken into account." CreationDate="2011-04-12T21:41:11.860" UserId="1240" />
  <row Id="19733" PostId="12850" Text="@DavidKessner, I would suggest some headings and formatting changes to make this answer perfect." CreationDate="2011-04-12T21:51:19.903" UserId="230" />
  <row Id="19734" PostId="12956" Text="I haven't tried that, but it seems plausible that you could do some correction in software.  Here's something that the google told me about: http://fisheyelensreview.com/defishing-software/top-3-defishing-software-programs-to-easily-defish-your-images/" CreationDate="2011-04-12T21:58:15.817" UserId="2288" />
  <row Id="19735" PostId="12957" Text="I don't believe it's possible to use heat energy for anything by itself; only heat differentials.  In the case of your water heater, it's the differential between the inside of the tank and the room that the tank is in." CreationDate="2011-04-12T21:59:50.027" UserId="142" />
  <row Id="19736" PostId="12770" Text="maybe exam question" CreationDate="2011-04-12T22:03:15.047" UserId="3628" />
  <row Id="19737" PostId="12488" Text="It didn't solve but it helped on better understanding the code and the compiler &quot;tricks&quot;. The problem was with the coefficients. It should be a1*xn and b0*y. A really lame mistake indeed eheh Thanks for your help!" CreationDate="2011-04-12T22:08:31.423" UserId="1074" />
  <row Id="19738" PostId="12950" Score="1" Text="Use a CPLD, like one of the Altera MAX II devices. You will find it much easier than connecting 500 flip-flops together." CreationDate="2011-04-12T19:37:50.403" UserId="305" />
  <row Id="19739" PostId="12950" Text="@Leon Thank you for the reply, I have to use discrete flip-flops for this job, it's for a proprietary design." CreationDate="2011-04-12T20:27:23.487" UserId="3836" />
  <row Id="19740" PostId="12950" Score="1" Text="It's a silly way to do it!" CreationDate="2011-04-12T20:48:07.017" UserId="305" />
  <row Id="19741" PostId="12957" Text="@endolith for sure, I'm sorry if I implied that I was looking to use heat alone.  For something like running &quot;Peltiers backward&quot;, I would have one end on the heat source, and the other at ambient, just like with my water heater." CreationDate="2011-04-12T22:16:48.773" UserId="2288" />
  <row Id="19742" PostId="12942" Text="I explicitly prefixed my answer by stating that I was referring to **electronics**, as opposed to power circuits like most of the other answers have addressed." CreationDate="2011-04-12T22:22:36.893" UserId="3823" />
  <row Id="19743" PostId="12922" Text="+1 for mentioning command line tools" CreationDate="2011-04-12T22:35:41.103" UserId="708" />
  <row Id="19744" PostId="12905" Text="@BarsMonster, so could it be done from measuring many points on a curve? How do you build a reliable sine wave oscillator for a 10 - 50 MHz sweep?" CreationDate="2011-04-12T23:00:17.220" UserId="1225" />
  <row Id="19745" PostId="12961" Text="@supercat: Thank you but I can't use a CPLD, I have to use discrete flip-flops." CreationDate="2011-04-12T23:05:18.107" UserId="3836" />
  <row Id="19746" PostId="12950" Text="@Leon: If you knew what I was doing you would see why I can't use a CPLD. Can you help me with my original question? Thanks!" CreationDate="2011-04-12T23:07:57.590" UserId="3836" />
  <row Id="19747" PostId="12961" Text="@Tim Smith: Any particular reason?  I would suggest that if you're using a lot of flip flops and want to minimize current consumption, you might do well to use a counter and one or more demultiplexers and multiplexers (or maybe a one-hot counter and discrete gates).  For example, by adding a 74HC4019 (one-hot decade counter), ten 'nand' gates, and a ten-input &quot;nor&quot; gate, one could probably cut the current consumption by a factor of eight or more.  Wire up ten strings of fifty flip flops, and use the outputs from the 74HC4019 to clock them." CreationDate="2011-04-12T23:19:10.210" UserId="3123" />
  <row Id="19748" PostId="12961" Text="@Tim Smith: Use the ten &quot;nand&quot; gates to combine the outputs of the shift registers with the appropriate 4019 outputs, and use the &quot;nor&quot; gate to combine them.  The result would be that on each clock cycle, the counter would advance once, 50 latches would see a rising clock edge, 50 would see a falling clock edge, two NANDs would see input changes, and some inputs on the NOR might change.  Power dissipation from that should be much less than that of clocking all 500 flip flops." CreationDate="2011-04-12T23:22:45.680" UserId="3123" />
  <row Id="19750" PostId="12961" Text="@supercat: I don't want to add any other logic gates to the circuit; and I don't care about minimizing the current, I just need to know what my power requirements will be for driving all 500 flip-flops and their respective clocks. I looked at the data sheet for this TI flip flop but i didn't understand the ratings. For instance,the sheet gives a figure of .5uA for Iclock. Does this mean I just multiply this figure by 500 to figure my clock buffer output current? Also they dont tell you the imput impedence of the D imput, how can you calculate current draw from the previous stage?" CreationDate="2011-04-13T00:10:56.123" UserId="3836" />
  <row Id="19751" PostId="12966" Text="I remember stories of [soviet radios](http://thisbluemarble.com/showthread.php?t=35990) which were heat powered and were supposed to be cheap for the time. Maybe some more research is needed? I know that you can get some power using thermocouples, but from what I can see, it's too little." CreationDate="2011-04-13T00:15:10.053" UserId="1240" />
  <row Id="19752" PostId="12912" Text="You'll have to look at the pin outs online. So far it doesn't seem that that game port styled cable is very standardized (though I'm not sure, I never used them) so it may vary from cable to cable. The parallel port on the other hand is very standardized and the minimum specifications guarantee at least those 17 pins be connected. " CreationDate="2011-04-13T00:19:58.243" UserId="1319" />
  <row Id="19753" PostId="12942" Text="I fail to see any distinction between electronics and power circuits.  Also, your answer is plainly an opinion, not a fact.  " CreationDate="2011-04-13T01:00:42.650" UserId="249" />
  <row Id="19754" PostId="12975" Text="I understand that. I need to make a diagram for a 2's complementer." CreationDate="2011-04-13T01:20:52.897" UserId="3619" />
  <row Id="19755" PostId="12972" Score="3" Text="Is it a design constraint that you have exactly 1 PNP and 1 NPN? Or can you have more than one of each?" CreationDate="2011-04-13T01:23:21.710" UserId="740" />
  <row Id="19756" PostId="12973" Text="you might want to tag this something like 'sequential logic'" CreationDate="2011-04-13T01:24:53.877" UserId="740" />
  <row Id="19757" PostId="12973" Text="not enough rep to make new tags :(" CreationDate="2011-04-13T01:33:24.497" UserId="3619" />
  <row Id="19758" PostId="12977" Text="I get your implementation, but my question uses a shift register and a flip flop along with external gates. We aren't allowed to use half-adders. This is basically what I have to come up with http://k5rec.blogspot.com/2006/12/digital-electronics-serial-twos.html . But I can't figure out HOW to get that state diagram." CreationDate="2011-04-13T02:00:54.453" UserId="3619" />
  <row Id="19759" PostId="12978" Text="http://www.arduino.cc/en/Hacking/LibraryTutorial" CreationDate="2011-04-13T02:06:27.750" UserId="1227" />
  <row Id="19761" PostId="12950" Score="1" Text="You must use that flip-flop? You couldn't even use something like a 8-bit shift register?" CreationDate="2011-04-13T02:26:18.130" UserId="638" />
  <row Id="19762" PostId="12832" Text="Making your own light fittings like that could cause problems if one caused a fire. Your insurance would be invalid." CreationDate="2011-04-10T15:59:26.990" UserId="305" />
  <row Id="19763" PostId="12979" Text="what the heck is a 4-bit cpu!?" CreationDate="2011-04-13T02:51:24.057" UserId="771" />
  <row Id="19764" PostId="7297" Text="Good ideas. In particular, an array of sound sensors could use ideas from [LOUD: Large acOUstic Data Array Project](http://groups.csail.mit.edu/cag/mic-array/)" CreationDate="2011-04-13T03:16:05.540" UserId="813" />
  <row Id="19765" PostId="12974" Text="This question would only be relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. &lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;WHy not ? &#xA;&#xA;&#xA;&#xA;what the hell is this suppose to me ask it somewhere else? its the www i can ask anything i want in this case a ram question what gives u the right to close my post its still a vaid question relate the the field. " CreationDate="2011-04-13T03:37:35.483" UserId="3842" />
  <row Id="19766" PostId="12983" Text="Golden! Thanks mate!" CreationDate="2011-04-13T04:08:27.263" UserId="3619" />
  <row Id="19767" PostId="12979" Text="Dose a 4-bit CPU truly have only 16 possible commands?" CreationDate="2011-04-13T04:39:05.017" UserId="1319" />
  <row Id="19768" PostId="12972" Text="The less the better, so it if it's necessary, it can be more." CreationDate="2011-04-13T04:49:33.240" UserId="2062" />
  <row Id="19769" PostId="12985" Text="Unfortunately, this is not for RS232. This is to build fast (&gt;10Mhz) driver of tiny N-mosfets (not these bulky power mosfets, tiny ones, like 2N7002). That's denies the idea of using MOSFET's by itself - it's just going to be too slow." CreationDate="2011-04-13T04:51:54.297" UserId="2062" />
  <row Id="19770" PostId="1843" Score="3" Text="Sorry, mechanical engineer needs to jump in for a sec. You MUST consider corrosion issues. Since it is for a food application, I'm assuming that there will be a lot of stainless steel around the work area. Stainless steel and aluminum will form a galvanic corrosion cell, the aluminum if electrically connected to SS will corrode preferentially (especially around food, plenty of electrolytes around). Please consider using a 316 stainless steel instead." CreationDate="2011-04-13T04:52:48.427" UserId="1319" />
  <row Id="19771" PostId="12979" Score="1" Text="@vicatcu: The [Intel 4004](http://en.wikipedia.org/wiki/Intel_4004) was a well known 4-bitter." CreationDate="2011-04-13T05:19:27.260" UserId="3769" />
  <row Id="19772" PostId="12984" Score="1" Text="You may also want to take note of the reason they don't go across like that. If you look at your Arduino, the socketed microcontroller (an Atmel AVR) has two rows of pins, in what's called a Dual In-line Package (DIP). A major task of the Arduino is to give you those pins accessible as slots, known as a break-out board (it also holds some power circuitry, a USB interface and an oscillator resonator of some sort). The breadboards are meant to do the same thing, so you can put a DIP across the gap. " CreationDate="2011-04-13T05:40:03.550" UserId="1181" />
  <row Id="19773" PostId="12987" Score="3" Text="+1 for the digital clocks. " CreationDate="2011-04-13T06:33:01.503" UserId="689" />
  <row Id="19774" PostId="12928" Text="Hi, Thank you very much for your fine answer." CreationDate="2011-04-13T06:59:49.693" UserId="3041" />
  <row Id="19775" PostId="12928" Text="I will try some simulations in spice, to see how this works. Ok, so basically the source impedance matching is only important for maximum power transfer? (If source is 10 ohms, and the cable and load is 50 ohms, I will not get maximum power transfered to the load)." CreationDate="2011-04-13T07:15:01.387" UserId="3041" />
  <row Id="19776" PostId="12974" Score="1" Text="It is an extremely narrow situation -- people that got your exact same homework assignment. If you had bothered to phrase the question in more general terms, instead of just pasting the homework question verbatim, it would have been a different matter. As to what gives him the right, the little diamond next to his name means that the users of this site have entrusted him with the power and duty to keep this site free from questions like yours. Frankly I find your sense of entitlement a bit jarring." CreationDate="2011-04-13T08:19:28.547" UserId="1802" />
  <row Id="19777" PostId="11856" Text="This sounds a lot like the Tripath class-D design (which they called class-T) where they vary both the frequency and the on/off state. They claim it generates a cleaner signal." CreationDate="2011-04-13T09:03:01.800" UserId="3846" />
  <row Id="19778" PostId="12925" Text="Hi, thank you very much for your answer.  :-)" CreationDate="2011-04-13T09:28:07.533" UserId="3041" />
  <row Id="19779" PostId="12950" Text="@Tim - I guess you have a good reason to use that particular IC, but unless you can explain it to us, we'll all find it an idiotic idea. Like W5VO says, can't you at least use an 8-bit shift register? This would reduce IC count from 500 to 63, which still is much. If you need the outputs of every FF individually you can't use Leon's CPLD; they don't have 500 I/Os. " CreationDate="2011-04-13T09:40:40.807" UserId="2064" />
  <row Id="19780" PostId="12928" Text="That depends on what you can vary. If the source impedance is fixed at 10 Ohms, you would get maximum power transfer with a 10 Ohm cable and load. If both the cable and load are fixed at 50 Ohms, you would get maximum power transfer with a source impedance of zero. If the source is fixed at 10 Ohms and the cable is fixed at 50 Ohms, you *could* get maximum power transfer with a 10 Ohm load but only if the cable length is an odd multiple of half-wavelengths ($\frac{\lambda}{2}$, $\frac{3\lambda}{2}$ etc) but this would only be appropriate with sine waves or a narrow-band signal." CreationDate="2011-04-13T09:41:24.423" UserId="2234" />
  <row Id="19781" PostId="12928" Text="It is possible to match any impedance at a specific frequency by adding capacitance/inductance at the source *see [antenna tuning](http://en.wikipedia.org/wiki/Antenna_tuning_unit)* or lengths of transmission line *see [stub matching](http://en.wikipedia.org/wiki/Stub_(electronics))*." CreationDate="2011-04-13T09:43:34.487" UserId="2234" />
  <row Id="19782" PostId="12982" Score="1" Text="May i suggest you use [fritzing](http://fritzing.org/) for circuit diagrams. It does them straight on to breadboards and includes Arduinos :). So saves on taking photos. It also runs on windows linux and OS X :). Forgot to mention its also free :) " CreationDate="2011-04-13T10:43:10.480" UserId="1623" />
  <row Id="19783" PostId="12985" Text="A TTL-to-EIA232 level shifter would have the output voltages reversed." CreationDate="2011-04-13T10:46:20.210" UserId="2064" />
  <row Id="19784" PostId="7006" Text="Weird, back when I was still making my own boards, pressing the iron really hard was the key to screwing it up: the toner would melt and flow sideways! Perhaps my printer deposited the toner too generously or something :)" CreationDate="2011-04-13T10:49:33.000" UserId="1951" />
  <row Id="19785" PostId="12976" Score="1" Text="@ricedragon - changed &quot;u&quot; to &quot;you&quot;. Please don't use SMS-language." CreationDate="2011-04-13T10:59:47.687" UserId="2064" />
  <row Id="19786" PostId="12998" Text="Very very close, but is that possible to replace output resistor with another transistor somehow to get faster transitions/higher drive capability?" CreationDate="2011-04-13T11:18:42.700" UserId="2062" />
  <row Id="19787" PostId="12998" Text="@BarsMonster - I was just thinking the same myself. I'm still thinking ..." CreationDate="2011-04-13T11:47:33.993" UserId="2234" />
  <row Id="19788" PostId="12950" Text="An FPGA would solve that problem. The Xilinx XC6SLX150 has 576 I/Os." CreationDate="2011-04-13T11:55:18.240" UserId="305" />
  <row Id="19789" PostId="12993" Score="2" Text="I still have a love for building &lt; $1 PICs into projects. 8 bits will never die and likely still beats 32 bit installations by far I suspect/guess. " CreationDate="2011-04-13T11:58:04.437" UserId="2157" />
  <row Id="19790" PostId="12951" Score="1" Text="+1 interesting device. Wikipedia has a pretty [photo of chipTAN comfort (flickering)](http://de.wikipedia.org/wiki/Transaktionsnummer#chipTAN_comfort.2Fsm.40rtTAN_optic_.28Flickering.29)." CreationDate="2011-04-13T12:11:38.747" UserId="813" />
  <row Id="19791" PostId="13000" Text="Looks like an error in the datasheet to me." CreationDate="2011-04-13T12:26:37.923" UserId="2064" />
  <row Id="19792" PostId="13001" Text="A suggestion. I thing [ZOC Terminal](http://www.emtec.com/download.html#zocfiles) is the best to works with modems." CreationDate="2011-04-13T12:33:05.960" UserId="938" />
  <row Id="19793" PostId="13000" Text="It looks like there are 3 different speed grades for this chip. 0 to $70^oC$ is typically dubbed &quot;commercial grade&quot; and $-40^oC$ to $+85^oC$ as &quot;industrial grade&quot;." CreationDate="2011-04-13T12:38:46.570" UserId="2234" />
  <row Id="19794" PostId="12979" Text="@Faken The bit size is related more strongly with data and register size than the instruction length. The PIC mcus are an example of this. Further, many processors employ variable instruction length. In the case of a 4 bit processor, you could have 12 of the instructions be the very common instructions, and use 4 instructions to indicate that the next instruction is a special instruction. In this way you would have 12 four bit instructions, then 4 pages of 16 more instructions, giving you a total of 60 instructions. There'd be 12 one nibble instructions, and 48 two nibble instructions." CreationDate="2011-04-13T12:42:40.190" UserId="161" />
  <row Id="19795" PostId="12951" Score="1" Text="The Timex Datalink also read data off a flickering computer screen.[1](http://www.bobdbob.com/~protius/timex/) [2](http://www.ferretronix.com/~protius/timex/) Perhaps that would be an easier protocol to implement." CreationDate="2011-04-13T12:44:01.953" UserId="813" />
  <row Id="19796" PostId="12979" Text="Though in typical usage, 4 bit processors really do have very, very few instructions because they are meant to require very little silicon real estate, and so you might find a four bit processor that only has 16 instructions.  Technically you only need a handful of instructions to implement a Turing machine." CreationDate="2011-04-13T12:44:19.363" UserId="161" />
  <row Id="19797" PostId="13002" Score="1" Text="I would opt for the former!" CreationDate="2011-04-13T12:49:39.747" UserId="2288" />
  <row Id="19798" PostId="12982" Text="+1 for following up your question and sharing your experience with others new to electronics!" CreationDate="2011-04-13T12:57:10.250" UserId="2288" />
  <row Id="19799" PostId="12958" Text="thanks to both of you." CreationDate="2011-04-13T13:09:46.210" UserId="2824" />
  <row Id="19800" PostId="13002" Text="@Dave I'd turn it off on the modem if I were writing an AT command parser in software. That way it can send &quot;AT\n&quot; and expect &quot;OK&quot;, not expect &quot;AT\nOK&quot;" CreationDate="2011-04-13T13:24:06.783" UserId="566" />
  <row Id="19801" PostId="13002" Text="Ah, excellent point, I wasn't thinking it through all of the way and putting myself in the position of the modem.  Thanks!" CreationDate="2011-04-13T13:38:55.130" UserId="2288" />
  <row Id="19802" PostId="12993" Score="1" Text="@kenny - IIRC NXP has an ARM controller for &lt; $1 too. That's just the point: 32-bit is affordable (more so than 16-bit like 68HC12 ever has been, for instance). But I agree that 8-bitters will be around for quite a while still, especially in smaller packages. I'm not sure if you can fit an ARM in a SOT-23 package." CreationDate="2011-04-13T13:55:22.730" UserId="2064" />
  <row Id="19804" PostId="13002" Text="Yea...i turned of the echo using ATE0, and the repetition stops. But how can we explain for the strange characters been displayed. Also, I am using a baud rate of 9600, but when I changed the baud rate to 115200, i did not experience this strange situation. Unfortunately, my intended application (in communicating with a micro controller) is designed to work for 9600. Finally, how can i turn off the echo of my terminal emulator?" CreationDate="2011-04-13T14:23:38.260" UserId="3632" />
  <row Id="19805" PostId="12934" Text="Doesn't the 'L' for Inductors stand for 'Loop'?" CreationDate="2011-04-13T14:26:35.063" UserId="3122" />
  <row Id="19806" PostId="13000" Text="@stevenvh Why? The speeds are mentioned throughout the datasheet, and surely you wouldn't accidentally qualify a part for a different temperature range accidentally?" CreationDate="2011-04-13T14:29:19.633" UserId="638" />
  <row Id="19807" PostId="13000" Text="@W5VO - It makes sense that, when you can allow higher temperatures, you can go to higher frequencies as well. In that sense you would expect frequency to go monotonous with temperature." CreationDate="2011-04-13T14:39:41.023" UserId="2064" />
  <row Id="19808" PostId="13007" Score="1" Text="@V5VO is correct, but I'd like to add a little.  When talking about the minimum temp, like -40C in this case, it is assumed to be &quot;Non-Condensing&quot;.  Meaning, the temp hasn't dropped below the dew point and water starts condensing on the PCB's.  Water condensing is bad." CreationDate="2011-04-13T14:41:41.707" UserId="3624" />
  <row Id="19809" PostId="12992" Text="By my reading of the data sheet, the ΔIC figure is suggesting that if the input is 0.6 volts short of VDD the device current may rise by 40-50uA; if that figure applies for all voltages between 0.6 and 2.6 volts, this could be significant.  If one tries to drive 750pF with a source that can source/sink 20mA (pretty beefy), and VDD is 3.2 volts, then for about 75ns the input will be between 0.6 volts and 2.6 volts.  If you're driving at 1.5MHz, the input will be in the 0.6-2.6 zone about half the time, adding another 40*500uA half the time, or about 10mA net." CreationDate="2011-04-13T14:50:40.047" UserId="3123" />
  <row Id="19810" PostId="13009" Text="What is the value of $V_{IN}$ you are trying to measure?" CreationDate="2011-04-13T15:27:24.350" UserId="2234" />
  <row Id="19812" PostId="13009" Text="what is FF22x4?" CreationDate="2011-04-13T15:32:26.017" UserId="411" />
  <row Id="19813" PostId="13009" Text="do you mean 430f22x4?  you should not refer to pin numbers on a part with multiple pinouts." CreationDate="2011-04-13T15:32:57.373" UserId="411" />
  <row Id="19814" PostId="13009" Text="are you sure there are no other interrupts enabled?" CreationDate="2011-04-13T15:39:38.427" UserId="411" />
  <row Id="19815" PostId="13008" Text="But is a open source project a &quot;development tool&quot;? Let's say I'm writing a open source blinky program, and push that code onto github. Can that really be defined as be &quot;distributed within development tools&quot;? " CreationDate="2011-04-13T15:40:42.170" UserId="689" />
  <row Id="19816" PostId="13009" Text="These are the ADC10MEM values I am getting, considering last 10 bits. Following calculations use Vr+ = 1.5, Vr- = 0.&#xA;&#xA;For input voltage 0.38V, N=1100000010 i.e. 770, and Vin=1.12.&#xA;&#xA;For input voltage 0.5V, N=1101010110 i.e. 854, and Vin=1.25.&#xA;&#xA;For input voltage 1V, N=1110101001 i.e. 937, and Vin = 1.37.&#xA;&#xA;For input voltage 1.45V, N=1111011000 i.e. 984, and Vin = 1.44.&#xA;&#xA;As I said, the value is increasing/decreasing with increase/decrease in input, but it isn't correct." CreationDate="2011-04-13T15:40:54.917" UserId="3852" />
  <row Id="19817" PostId="13009" Text="I mean EZ430-RF2500. FF22x4 is the microprocessor. This is the [User's Guide](http://rfic.eecs.berkeley.edu/ee42/labs/slau144e.pdf) I am following." CreationDate="2011-04-13T15:43:12.527" UserId="3852" />
  <row Id="19818" PostId="12940" Text="related: [Implementing a Simple Protocol for XBee Comms](http://electronics.stackexchange.com/questions/5881/doubts-on-implementing-a-simple-protocol-for-xbee-comms) and [Serial (UART) communication](http://electronics.stackexchange.com/questions/10249/serial-uart-communication)" CreationDate="2011-04-13T15:44:57.577" UserId="813" />
  <row Id="19819" PostId="13009" Text="@MikeJ-UK, @markrages: Thanks for your help. I have edited the question. Please look for EDIT1 and EDIT2." CreationDate="2011-04-13T15:51:30.367" UserId="3852" />
  <row Id="19820" PostId="13009" Text="The processor is &quot;msp430f22x4&quot;.  Only one &quot;F&quot;." CreationDate="2011-04-13T15:52:06.327" UserId="411" />
  <row Id="19821" PostId="13009" Text="You don't show where you enabled analog input in your code.  Did you do this?  Direction should be set to input by default." CreationDate="2011-04-13T15:53:08.603" UserId="411" />
  <row Id="19822" PostId="13009" Text="Thanks for the reply. Do you mean ADC10AE0 |= 0x02;   and P4DIR |= 0x00;  ?" CreationDate="2011-04-13T15:57:04.933" UserId="3852" />
  <row Id="19823" PostId="13011" Text="@johnjimmy please do not put any signatures or advertisement in your answers." CreationDate="2011-04-13T16:30:05.273" UserId="319" />
  <row Id="19824" PostId="13008" Text="And down at &quot;(iii) use, copy, modify and sublicense the Example Code&quot;. I think the magic word is sublicense, since that must mean that I can modify and redistribute with a open source license?" CreationDate="2011-04-13T16:36:56.420" UserId="689" />
  <row Id="19826" PostId="12885" Text="Without the resistor, you have the atmosphere acting as a resistor *and* a matrix for charged particles, which generates thermal noise." CreationDate="2011-04-13T17:00:57.530" UserId="3835" />
  <row Id="19827" PostId="12992" Text="@supercat: Good call. Without more information, it would be difficult to speculate on a short-circuit power. Multiple buffers could break up the load too. The flip-side of that is that there shouldn't be any short circuit power for VDD &lt; 1.2V" CreationDate="2011-04-13T17:03:30.730" UserId="638" />
  <row Id="19828" PostId="13000" Text="@stevenvh I disagree. Increasing temperature decreases maximum speed, no matter what chip you're talking about. " CreationDate="2011-04-13T17:07:53.550" UserId="638" />
  <row Id="19829" PostId="13009" Text="OK, I don't have time to research all the ez430 code samples to see what they might be doing.  I suggest you read the about the ADC and the interrupt system. " CreationDate="2011-04-13T17:15:33.743" UserId="411" />
  <row Id="19830" PostId="13009" Text="&quot;P4DIR |= 0x00;&quot; is a no-op, do you understand why?" CreationDate="2011-04-13T17:18:20.510" UserId="411" />
  <row Id="19831" PostId="12993" Text="@stevenvh Thanks, I've been looking at the NXP Arms though I guess mostly the high end ones, since I have seen any that cheap. My fav language is C# and tinyclr.com looks interesting.... Hopefully someone will port that to a lower end NXP.  " CreationDate="2011-04-13T17:23:55.890" UserId="2157" />
  <row Id="19832" PostId="13009" Text="I understand that. I will try P4DIR &amp;= 0x00" CreationDate="2011-04-13T17:48:56.320" UserId="3852" />
  <row Id="19833" PostId="1479" Text="+1 for adding the point regarding the self-discharge of the batteries." CreationDate="2011-04-13T17:49:49.520" UserId="529" />
  <row Id="19834" PostId="13009" Text="P4DIR defaults to zero." CreationDate="2011-04-13T17:56:41.010" UserId="411" />
  <row Id="19835" PostId="13012" Text="nice links to microbuilder.eu and those project." CreationDate="2011-04-13T19:38:38.647" UserId="689" />
  <row Id="19836" PostId="12992" Text="@W5VO: There is, however, another issue I should also have mentioned: if one uses such a slow rise time, one runs a risk that one latch might see the clock before the &quot;preceding&quot; latch in the chain has done so.  Buffers may be needed not only to minimize shoot-through currents, but also to ensure correct operation." CreationDate="2011-04-13T19:53:27.400" UserId="3123" />
  <row Id="19837" PostId="1455" Text="What I personally love about DS1052E is that it has a proper amount of memory. Cheapest Agilent at three times the price has only 20K samples, but this one has 1M, allowing you to properly zoom in when necessary. Can be a real lifesaver for certain glitches!" CreationDate="2011-04-13T20:03:31.727" UserId="1951" />
  <row Id="19838" PostId="3663" Text="Rather than Ethernet data over AC mains power, many people prefer [DC power and Ethernet data over CAT5 cable (PoE)](http://electronics.stackexchange.com/questions/tagged/poe)" CreationDate="2011-04-13T23:10:34.300" UserId="813" />
  <row Id="19839" PostId="12567" Text="thanks a ton. these tips are easy to start using and made life so much easier." CreationDate="2011-04-13T23:52:16.527" UserId="1227" />
  <row Id="19841" PostId="12992" Text="@supercat - right, I thought I mentioned that. (maybe not explicitly enough). At VDD=3.3V, I figure that the inputs need to be synchronized better than 5ns" CreationDate="2011-04-14T00:07:43.713" UserId="638" />
  <row Id="19842" PostId="13013" Text="You need to explain the terms you're using.  I'm totally lost." CreationDate="2011-04-14T00:11:38.443" UserId="249" />
  <row Id="19843" PostId="12984" Text="I'm fascinated by this stuff, haven't taken the plunge yet, and this is just the kind of thing I'd do if I hadn't read about it here first. Thanks for posting and following up." CreationDate="2011-04-14T00:18:54.980" UserId="3857" />
  <row Id="19844" PostId="13008" Score="1" Text="The important part is 'for use with Cortex-M *'.  Chip makers want you to use their chips!  The license permits this - as you noticed in subpoint iii.  The important part is that anything you sell with it or any sublicensing you do must incorporate ARM Cortex * chips.  So just don't modify the files to work with an MSP430 and redistribute them and you're fine." CreationDate="2011-04-14T00:23:55.687" UserId="249" />
  <row Id="19845" PostId="13013" Text="@booyakasha, I am sorry, this is too localized in both time and location." CreationDate="2011-04-14T01:06:53.937" UserId="230" />
  <row Id="19846" PostId="13023" Score="2" Text="Just to be clear: Are you looking to make a light or to buy a prefabricated device? If it's the second, than take a look at our [FAQ](http://electronics.stackexchange.com/faq)." CreationDate="2011-04-14T01:10:51.877" UserId="1240" />
  <row Id="19847" PostId="13024" Score="1" Text="How would such a thing even work?  It needs an external reference of some sort, like GPS or other positioning system." CreationDate="2011-04-14T01:43:44.590" UserId="142" />
  <row Id="19848" PostId="13015" Text="A/Cs switch on and off, so the energy usage is intermittent.  What period of time are you averaging over?" CreationDate="2011-04-14T01:49:03.557" UserId="142" />
  <row Id="19849" PostId="12982" Text="@Dean true, but then we wouldn't have immediately seen the problem with the circuit - @JasCav forgot to bridge the gap!" CreationDate="2011-04-14T02:29:19.340" UserId="693" />
  <row Id="19850" PostId="12915" Text="@stevenvh a diode's forward voltage also varies with load, especially right around the knee; Dropping 2V will require 2 or 3 diodes and not really give you any current limit either. I think a resistor's the better option in this case." CreationDate="2011-04-14T02:36:47.757" UserId="974" />
  <row Id="19851" PostId="13024" Text="@endolith Simple, its almost like measuring voltage with a single probe (no ground reference). Wait, not so simple :-)" CreationDate="2011-04-14T02:41:31.327" UserId="319" />
  <row Id="19852" PostId="13019" Text="have you tried &quot;NewSoftSerial bluetooth(3, 2);&quot; ?&#xA;" CreationDate="2011-04-14T03:54:13.853" UserId="771" />
  <row Id="19853" PostId="13013" Text="@Kortuk I am located in Israel and I want to buy cheap components that are not made in China. The product we develop goes to the US.If this is too localized for you... well. Also don't you think that the information regarding cheap components can be useful for others as well? Also I fail to recognize the correlation between the 'specific moment in time, or an extraordinarily narrow situation' you mentioned in the closing reason and the question asked. Good luck and keep being a jerk." CreationDate="2011-04-14T03:59:01.913" UserId="3854" />
  <row Id="19854" PostId="12995" Text="Thanks, Ranieri! " CreationDate="2011-04-14T04:01:39.510" UserId="3654" />
  <row Id="19855" PostId="13013" Text="@AngryEE use Google for the terms you don't understand or be more specific (specify what exactly do you not understand)" CreationDate="2011-04-14T04:02:37.263" UserId="3854" />
  <row Id="19856" PostId="13022" Text="not sure he could move it.  2600W @ 28V ~ 92A on the secondary, I would imagine this is a pretty large and heavy unit." CreationDate="2011-04-14T04:11:55.270" UserId="1438" />
  <row Id="19857" PostId="12974" Text="oh believe me it  is a lot more general compare what the book actually wrote out. the question was like a freaking essay i just summarized the main points.&#xA;&#xA;" CreationDate="2011-04-14T04:41:31.067" UserId="3842" />
  <row Id="19858" PostId="12987" Score="2" Text="They are also very popular in the super cheap IR remotes you get with almost every piece of electronics." CreationDate="2011-04-14T05:21:10.590" UserId="1438" />
  <row Id="19859" PostId="13030" Score="1" Text="You're thinking of the Nabaztag (http://en.wikipedia.org/wiki/Nabaztag); they don't work terribly well in my experience (just won't connect to modern wifi networks)." CreationDate="2011-04-14T05:33:09.147" UserId="1633" />
  <row Id="19860" PostId="13018" Text="wow, it looks promising." CreationDate="2011-04-14T07:03:12.773" UserId="2313" />
  <row Id="19861" PostId="13016" Text="Okay, Thanks! :-) But if add a larger load impedance on the antenna, say 1K ohms, would I get a larger voltage? (I'm adding a amplifier, so a larger voltage would be nice)." CreationDate="2011-04-14T07:05:46.030" UserId="3041" />
  <row Id="19862" PostId="12378" Text="Sorry for the late reply, was on holiday. I just wonder if it would be possible to replace the fuse with a power measure device (which of course would still work as a fuse). I found something (digitalstorm.org) which works somehow the way I expect and does even more. So, all answer helped me to understand, how I should do it, even if they're completely different. Thanks." CreationDate="2011-04-14T07:26:43.307" UserId="3648" />
  <row Id="19863" PostId="12248" Text="O.K. I understand" CreationDate="2011-04-14T07:29:12.620" UserId="3648" />
  <row Id="19864" PostId="12982" Text="@Jared Harley yes very true. " CreationDate="2011-04-14T08:57:58.377" UserId="1623" />
  <row Id="19865" PostId="13024" Score="1" Text="I presume you mean without mechanical contact with a surface such as a trundle wheel and rotary encoder? Or a surface with stripes on it? That gives me a thought, do you mean like a laser mouse?" CreationDate="2011-04-14T09:13:42.680" UserId="2110" />
  <row Id="19866" PostId="13003" Score="1" Text="Not battery operated?" CreationDate="2011-04-14T09:42:01.777" UserId="659" />
  <row Id="19867" PostId="12354" Text="@Yann Right. I was trying to explain why passing the `-lm` last fixed the problem and I failed to notice what the error messages really were. The OP could add some minimal code that triggers the error but I do not think he cares anymore – he already fixed his problem after all." CreationDate="2011-04-14T09:46:02.070" UserId="659" />
  <row Id="19868" PostId="13012" Score="1" Text="@Johan, they have 13xx codebase also: http://code.google.com/p/lpc1343codebase/" CreationDate="2011-04-14T10:30:11.720" UserId="2679" />
  <row Id="19869" PostId="12985" Text="@Bars BJTs are going to be even slower unless you go to great lengths to keep them out of saturation. Small signal MOSFETs are nice, quite cheap and fast." CreationDate="2011-04-14T10:39:29.300" UserId="659" />
  <row Id="19870" PostId="13037" Text="I think OP is more interested in optical computing; his class was assigned papers on random topics of *computer hardware*." CreationDate="2011-04-14T10:46:05.107" UserId="2064" />
  <row Id="19871" PostId="12929" Text="@JYelton - Nope. OP says &quot;topics of computer hardware&quot;. I presume that means optical computing." CreationDate="2011-04-14T10:48:27.367" UserId="2064" />
  <row Id="19872" PostId="13013" Text="@Kortuk IMHO it is not very localized (in neither space nor time) since he wants a manufacturer and not a merchant." CreationDate="2011-04-14T10:58:42.113" UserId="659" />
  <row Id="19873" PostId="9980" Text="I got confused by the third person in your answer... Weren't you the one that asked the question on the first place? ;]" CreationDate="2011-04-14T11:03:40.830" UserId="659" />
  <row Id="19874" PostId="13013" Text="@booyakasha You're the one asking the question.  If you don't want to explain and possibly get more answers then it's no skin off of my noise.  In terms of what I don't understand it's every acronym in your question." CreationDate="2011-04-14T11:11:42.590" UserId="249" />
  <row Id="19875" PostId="13016" Text="yes you'd get a larger voltage, but you'd achieve less actual power transfer. Not that it's all about power transfer with receiving, but it does help." CreationDate="2011-04-14T11:14:35.943" UserId="740" />
  <row Id="19880" PostId="13024" Score="1" Text="Perhaps if you describe your application, there might be some usable solution.  As others clearly pointed out, you can't simply measure velocity in a self-contained manner." CreationDate="2011-04-14T12:16:32.920" UserId="3308" />
  <row Id="19881" PostId="13023" Text="I would prefer #2 .. BUT .. it's assumed I would have to do some hacking/coding with it (which i'm totally kewl with). Otherwise, i'm kewl to get some parts and make something up - if there is enough guidance :)" CreationDate="2011-04-14T12:18:54.727" UserId="3858" />
  <row Id="19882" PostId="13030" Text="@Dave - *free network LED* ??? What's that? If it is *literally* hooking up a monitor to a PC or a USB Light .. then nope. I was hoping to have an individual solution not dependent upon another computer (which also has to be ON)." CreationDate="2011-04-14T12:21:41.027" UserId="3858" />
  <row Id="19883" PostId="13003" Text="@jpc added as optional requirement" CreationDate="2011-04-14T12:24:32.573" UserId="2313" />
  <row Id="19884" PostId="13007" Text="This kind of answers the second part of my question. &quot;Risking it&quot; is not an option here, we're talking about thousands of devices already running in an industrial environment... I was just wondering why the manufacturer chose to clock them @ 162MHz, and if we could give them a performance boost by clocking them higher." CreationDate="2011-04-14T12:46:36.500" UserId="1124" />
  <row Id="19885" PostId="13000" Text="After asking around a bit, someone mentioned 'bandgap voltage reference', as seen in this picture: http://www.national.com/rap/images/bgfig7.gif&#xA;&#xA;Could that be the reason?" CreationDate="2011-04-14T12:53:15.607" UserId="1124" />
  <row Id="19886" PostId="13030" Text="@Pure.Krome I was just speaking metaphorically, so yes I was being literal.  Sounds like you need Chumby, or better, a simple embedded ethernet solution.  You're at the right place for the latter option -- you can pick numerous embedded microcontrollers for this task.  I'll update my answer." CreationDate="2011-04-14T13:06:53.887" UserId="2288" />
  <row Id="19887" PostId="13030" Score="1" Text="@Robert Atkins: thanks!!!  For the life of me, I just couldn't remember the name of that product.  If it didn't work so well, I guess I understand why I couldn't find it last night.  :)  I was searching for stuff &quot;network rabbit bunny&quot;.  haha" CreationDate="2011-04-14T13:14:49.413" UserId="2288" />
  <row Id="19888" PostId="13046" Text="+1 It makes sense. I just wait for other additional answers." CreationDate="2011-04-14T13:44:21.833" UserId="3866" />
  <row Id="19889" PostId="13013" Text="@booyakasha, As a mod I have very set rules that I follow on questions. Your question is asking for fabs in **Russia** (*relevant to a small geographic area*). You are asking what fabs **currently** make something(*a specific moment in time*). In 2 years the could be a completely different set of fabs. Fabs do not change as often as merchants @jpc, but they do change, fabs go out of business and open new facilities. @booyakasha, this is a site rule, as the site just graduated most users do not have rep to vote close, i received flags asking me to close this as too localized, and I agreed." CreationDate="2011-04-14T14:06:34.100" UserId="230" />
  <row Id="19890" PostId="13050" Text="I'm no expert on this so I'm just going to make a short comment.  While you might need to follow the ISO 9000 family of standards, you also have to think about the market that your device is targeting.  For example, if it's a medical device, you could be required to get FDA certification." CreationDate="2011-04-14T14:25:00.440" UserId="2288" />
  <row Id="19891" PostId="12992" Text="@W5VO: You said delivering it simultaneously would be difficult, but didn't specify why.  There are two issues that come up: (1) electrical propagation, and (2) threshold uncertainty.  It's possible to construct latches in such a way as to eliminate the second problem by making them sample the input when the clock voltage is below one threshold, and copy the previously-sampled input to the output when the clock is above a higher threshold.  If the worst-case values of the thresholds don't overlap, a slow rise will be good, ensuring that no latch sees the clock enter high region..." CreationDate="2011-04-14T14:38:13.450" UserId="3123" />
  <row Id="19892" PostId="13041" Score="1" Text="Post the links with spaces in them and we'll fix it for you" CreationDate="2011-04-14T14:39:24.900" UserId="142" />
  <row Id="19893" PostId="12992" Text="@W5VO: ...before the latch it's feeding has seen the clock leave the &quot;low&quot; region.  With such a latch, if the clock originated at the downstream end of the cable, one might have to worry about an RC cable delay skewing fast clocks edges, but slow clock edges would be safe.  I don't think the OP's chosen latch works like that, though; the issue isn't just ensuring that all latches see the same voltage simultaneously, but ensuring that they'll all act upon it either simultaneously or in the correct order." CreationDate="2011-04-14T14:42:14.413" UserId="3123" />
  <row Id="19894" PostId="12992" Text="@W5VO: BTW, I wonder why master-slave flip flops aren't more common (sample on one clock polarity; copy to output on the other).  A master-slave flip flop is electrically simpler than an edge-triggered one, and in many cases could be a drop-in replacement that would improve timing margins." CreationDate="2011-04-14T14:47:00.023" UserId="3123" />
  <row Id="19895" PostId="13048" Score="1" Text="These consequences would be fatal to at least the generator. All electrical grid components are always precisely synchronized (using phase detectors) before being connected together." CreationDate="2011-04-14T14:53:01.593" UserId="659" />
  <row Id="19896" PostId="13013" Text="@booyakasha On chat @Kortuk suggested you may try asking a new question (a community wiki) without the Russia restriction." CreationDate="2011-04-14T15:02:05.113" UserId="659" />
  <row Id="19897" PostId="13006" Text="I disagree with the last paragraph. Most simple serial protocols are in fact simple and you can go a long way with just some packet timing requirements and CRC. Text based serial protocols without CRC are a different matter altogether." CreationDate="2011-04-14T15:13:16.090" UserId="659" />
  <row Id="19898" PostId="12877" Text="Why the downvote?" CreationDate="2011-04-14T15:22:04.357" UserId="305" />
  <row Id="19899" PostId="12943" Text="This one is really nice and simple. Just stick to Modbus RTU and do not worry about the standard &quot;function codes&quot;." CreationDate="2011-04-14T15:23:04.573" UserId="659" />
  <row Id="19900" PostId="13054" Text="First item abbreviation is EMC, not CE. The CE mark implies that the item meets all the relevant directives." CreationDate="2011-04-14T15:23:35.920" UserId="2110" />
  <row Id="19901" PostId="13054" Text="@Martin - Well spotted &amp; duly corrected!" CreationDate="2011-04-14T15:27:18.703" UserId="2234" />
  <row Id="19902" PostId="13052" Text="Just a note: The voltage should be applied in series with the resistor. So you will have GND-$V_\rm{source}$-1$\,\rm{G\Omega}$-DMM-GND." CreationDate="2011-04-14T15:49:38.010" UserId="659" />
  <row Id="19903" PostId="13000" Text="It's not likely that a bandgap voltage reference (by itself) is the cause. Even a crude version would give relatively good stability and operates over a wide temperature range." CreationDate="2011-04-14T15:50:02.843" UserId="638" />
  <row Id="19904" PostId="13007" Text="Honestly, this is something that the manufacturer decides. There's a good chance that they will work at a higher frequency at room temperature, but the manufacturer will not guarantee it over the full temperature range." CreationDate="2011-04-14T15:52:59.037" UserId="638" />
  <row Id="19905" PostId="13055" Text="Very well said! I suspected as much, although to be fair I wouldn't mind a good guide that's limited to only basic uses." CreationDate="2011-04-14T16:07:09.317" UserId="1951" />
  <row Id="19906" PostId="13023" Text="I don't have a lot of guidance to offer, but a starting point would be to get soemthing like [this](http://www.mikroe.com/eng/products/view/596/serial-ethernet-2-board/) or [this](http://www.mikroe.com/eng/products/view/572/easywifi-board/) and connect it to a microcontroller board like [Arduino](http://www.arduino.cc/en/). Then just connect LEDs you like to the microcontroller board and the only remaining part would be programming.(Note that I posted links only to illustrate what you should be looking for, I have no experience with those products, so I can't say if they're good, bad or ugly)" CreationDate="2011-04-14T16:07:41.167" UserId="1240" />
  <row Id="19907" PostId="13041" Score="1" Text="Two questions: How will you know you've succeeded?  And also, from the datasheet it looks like the BOOT pin is connected to the baseband processor.  My understanding is that this chip handles the cellular radio - not the higher functions - and that playing with it is a serious no-no as far as the FCC is concerned.  What is your understanding of the connection of the BOOT pin?" CreationDate="2011-04-14T16:08:23.287" UserId="249" />
  <row Id="19908" PostId="13059" Text="+1. I was going to put more in my own answer but the more I thought about it, the more I lost the will to live. It's a horrible minefield of a subject that could well do with simplification and international standardization." CreationDate="2011-04-14T16:08:27.137" UserId="2234" />
  <row Id="19909" PostId="12987" Score="1" Text="Also: 4-bit CPUs running in BCD mode are often used in calculators -- such as the [HP Saturn (microprocessor)](http://en.wikipedia.org/wiki/HP_Saturn_%28microprocessor%29) used in some HP graphing calculators." CreationDate="2011-04-14T16:41:51.033" UserId="813" />
  <row Id="19910" PostId="13048" Text="The generator and turbine assembly would rather break apart mechanically than run asychronously to the net." CreationDate="2011-04-14T17:06:42.843" UserId="339" />
  <row Id="19911" PostId="13058" Text="-1: question asks how to _measure_ it" CreationDate="2011-04-14T17:18:01.567" UserId="1609" />
  <row Id="19912" PostId="13038" Text="The schematic is inline, saving us all a wait for that server.   Also got rid of the gray background." CreationDate="2011-04-14T17:27:47.233" UserId="1609" />
  <row Id="19913" PostId="13019" Text="@vicatcu I did try swapping them, same results, though for different reasons most likely." CreationDate="2011-04-14T18:10:10.563" UserId="1227" />
  <row Id="19916" PostId="13063" Text="possible duplicate of [How do BJT transistors work in a saturated state?](http://electronics.stackexchange.com/questions/12477/how-do-bjt-transistors-work-in-a-saturated-state)" CreationDate="2011-04-14T18:21:31.960" UserId="305" />
  <row Id="19918" PostId="13013" Text="@AngryEE GaN - means Gallium Nitride. GaN transistors are pretty broadband and very efficient. MMIC=Monolithic microwave integrated circuit - usually bare die components with integrated circuit on them (amps, mixers, switches etc.)" CreationDate="2011-04-14T18:57:25.353" UserId="3854" />
  <row Id="19919" PostId="12950" Text="@stevenvh: My conjecture would be that the goal is to have the 500 flip flops mounted in physically different places; one may be able to use a four-wire or five-wire daisy-chained cable in such a case, whereas using larger chips would require running individual wires from each chip to the things it controlled." CreationDate="2011-04-14T19:15:51.047" UserId="3123" />
  <row Id="19920" PostId="13013" Text="@Kortuk, do you actually understand what you wrote? Russia + Eastern Europe = 'small geographic area' (Go to Google Maps,  they possibly have some news for you.) " CreationDate="2011-04-14T19:29:16.357" UserId="3854" />
  <row Id="19921" PostId="13063" Text="That question is, &quot;how does it work when it's saturated?&quot;, my question is, &quot;how do I get it to be saturated?&quot;" CreationDate="2011-04-14T19:58:14.923" UserId="3240" />
  <row Id="19922" PostId="13067" Text="Because I have BJTs, and I don't have any MOSFETs. I also understand BJTs better than I understand MOSFETs." CreationDate="2011-04-14T20:13:19.943" UserId="3240" />
  <row Id="19923" PostId="13073" Text="That's a great idea. Besides building one from scratch, it would be great to find someone selling these.." CreationDate="2011-04-14T20:25:58.570" UserId="2920" />
  <row Id="19924" PostId="13063" Text="It's answered there." CreationDate="2011-04-14T20:26:44.460" UserId="305" />
  <row Id="19925" PostId="13073" Text="@David Kessner you broad knowledge scope and ability to explain well is much appreciated. Keep it up!" CreationDate="2011-04-14T20:27:24.047" UserId="319" />
  <row Id="19926" PostId="13051" Text="I don't think that the ULN2003A is suitable for the MSP430 outputs, the voltage is too low." CreationDate="2011-04-14T20:28:59.683" UserId="305" />
  <row Id="19927" PostId="13070" Score="2" Text="It usually helps to look at what is happening graphically. I don't have the time right now to fully go into it, maybe someone else does, but if I were you I would start by drawing an arbitrary function and performing the operations you mentioned." CreationDate="2011-04-14T20:32:35.413" UserId="319" />
  <row Id="19928" PostId="13063" Text="I guess I'm looking for something a little more clear than your answer there. FWIW, it was your answer to that question that prompted me to ask this one. You say what saturation MEANS, but not WHY. Why does additional base current result in no more collector current? Is it because some transistor-specific limit has been reached? Is it because the circuit being switched by the transistor has a sufficiently high impedance to require no more current?" CreationDate="2011-04-14T20:35:37.950" UserId="3240" />
  <row Id="19929" PostId="13070" Text="@vKellenjb Good idea, I'll check out Wolfram Alpha." CreationDate="2011-04-14T20:37:02.223" UserId="1240" />
  <row Id="19930" PostId="13073" Text="@Mattias  I doubt that you'll find anyone selling these things pre-made.  But they are super easy to make, so...   @Kellenjb  Thanks!   @All  I added a picture!" CreationDate="2011-04-14T20:39:08.667" UserId="3624" />
  <row Id="19931" PostId="13041" Score="1" Text="Good updates, but in the future mark them so we know there was an update.  Question the third: are you willing to crack open one of these phones and check traces to see if the signal goes to the right place? Also, question the fourth: what is the application processor?  I'd like to find a datasheet." CreationDate="2011-04-14T20:41:30.740" UserId="249" />
  <row Id="19932" PostId="13041" Text="Thanks for fixing the link endolith. AngryEE, thanks for your interest, I added more details to the question (last 2 paragraphs). There's a schematic fragment in the phone's service manual that shows the baseband processor and it doesn't have the BOOT_MODE signal going to it, so I'm hoping that it goes to the application processor." CreationDate="2011-04-14T20:41:54.030" UserId="3862" />
  <row Id="19933" PostId="13074" Text="There's a serious mistake in this post, fixing it now." CreationDate="2011-04-14T20:45:42.547" UserId="1240" />
  <row Id="19934" PostId="13041" Text="AngryEE, yes I was on the verge of doing that last night, but looking at the board layout in the service manual it looks like you would have to unsolder the application processor to get at the processor pin, which is beyond my skills and tools." CreationDate="2011-04-14T20:46:58.677" UserId="3862" />
  <row Id="19935" PostId="13041" Text="@AngryEE http://www.google.com/search?q=S5PC110_EVT1_UM10" CreationDate="2011-04-14T20:49:05.137" UserId="3862" />
  <row Id="19936" PostId="13063" Score="1" Text="It's explained by the Ebers-Moll model of the transistor: http://ecee.colorado.edu/~bart/book/book/chapter5/ch5_3.htm" CreationDate="2011-04-14T20:53:00.657" UserId="305" />
  <row Id="19937" PostId="13077" Text="the 2N7000 has a maximum current of 200mA, where the 2N2222 has a maximum current of ~600mA. is there something in that neighborhood that is easy to drive with a 3.3v MCU?" CreationDate="2011-04-14T20:53:52.733" UserId="3240" />
  <row Id="19938" PostId="13063" Text="That's not really helpful. I could become an expert in transistor theory, but then I wouldn't need to ask here..." CreationDate="2011-04-14T20:55:40.437" UserId="3240" />
  <row Id="19939" PostId="13074" Text="Should be fixed now." CreationDate="2011-04-14T20:58:07.190" UserId="1240" />
  <row Id="19940" PostId="13070" Score="2" Text="x(−t) is a reversal of time, not an inversion of the signal.  Inversion would be -x(t)." CreationDate="2011-04-14T20:58:48.827" UserId="142" />
  <row Id="19941" PostId="13070" Text="@endolith  You're right. We use term &quot;time inversion&quot; for &quot;reversal of time&quot; and in my case, I dropped the &quot;time&quot; part where I mustn't have. " CreationDate="2011-04-14T21:01:00.230" UserId="1240" />
  <row Id="19942" PostId="13070" Score="1" Text="It would be cool if an inverting amplifier could predict the future though." CreationDate="2011-04-14T21:02:26.530" UserId="142" />
  <row Id="19943" PostId="12842" Text="hello all,  the problem was with the external oscillator. in these conditions it is possible to program the flash but fuses need the external oscillator is well.&#xA;" CreationDate="2011-04-14T21:11:51.520" UserId="3798" />
  <row Id="19944" PostId="13077" Text="What number am I looking for to determine whether 3.3V is enough to turn the MOSFET on? Phillips' 2N7000 has a VGS(th) (gate-source threshold voltage) of 2V typ, does that mean that 2V would turn the MOSFET completely &quot;on&quot;, or just barely &quot;on&quot;?" CreationDate="2011-04-14T21:19:15.510" UserId="3240" />
  <row Id="19945" PostId="13074" Text="Dang, Nice explanation. But then why do people always call it &quot;multiplexers&quot; instead of demultiplexers when controlling LEDS, im assuming you can do both but de-multi's are easier?" CreationDate="2011-04-14T21:25:41.000" UserId="3073" />
  <row Id="19946" PostId="13074" Text="@Sauron I'm not sure. Maybe multiplexers can be used in both roles so in reality only multiplexers are manufactured? " CreationDate="2011-04-14T21:28:23.290" UserId="1240" />
  <row Id="19947" PostId="13063" Text="drive enough current into the base so that the base-collector junction becomes forward biased. how much current will depend on the type of transistor. 'saturation' has to do with how many of the charge carriers in the base region can make it into the collector region. some will come from the base terminal, but many more will come into the base from the emitter. beyond a certain amount of base current, there just won't be an increase in the available charge carriers." CreationDate="2011-04-14T21:35:18.653" UserId="740" />
  <row Id="19948" PostId="13063" Text="@JustJeff perfect, put it as an answer so I can give you credit!" CreationDate="2011-04-14T21:36:48.327" UserId="3240" />
  <row Id="19949" PostId="13081" Text="Would you say, then, that the suggestions I've gotten to use MOSFETs are just plain wrong? Specifically, the answer to my question about LEDs?" CreationDate="2011-04-14T21:58:10.080" UserId="3240" />
  <row Id="19950" PostId="13081" Text="Yes. You don't see many LED drivers using MOSFETs." CreationDate="2011-04-14T22:04:04.583" UserId="305" />
  <row Id="19951" PostId="13081" Text="they switch ON faster than they switch OFF, don't they?" CreationDate="2011-04-14T22:11:26.080" UserId="740" />
  <row Id="19952" PostId="13051" Text="@Leon Yikes, I should have looked at the datasheet.  I drove ULN2003As from an HC11, but of course that is a 5V chip.  Thank you for bringing that up." CreationDate="2011-04-14T22:27:09.477" UserId="2288" />
  <row Id="19953" PostId="13077" Text="You will probably only get 1 mA through it with 2V on the gate, according to the data sheet." CreationDate="2011-04-14T22:32:22.980" UserId="305" />
  <row Id="19954" PostId="13046" Text="What would be the effect of mechanically connecting two squirrel-cage motors which had appropriately-different different numbers of windings (e.g. a 119:99 ratio)?  My impression would be that the 60Hz motor would want to turn at 0.504 revs/sec while the 50Hz motor would want to turn 50.505 revs/sec.  The net effect would be that the 50Hz motor would convert electrical power to mechanical energy, and the 60Hz motor would do the opposite.  There would be some &quot;slippage&quot; of the fields in the cage, but I don't know how much energy that would represent." CreationDate="2011-04-14T22:45:22.267" UserId="3123" />
  <row Id="19955" PostId="12895" Text="The [experiments section of the All About Circuits website](http://www.allaboutcircuits.com/vol_6/index.html) and the _Make: Electronics_ book are the direction I am going to head.  I learned about these originally from AndrejaKo and through a link provided by Dean, but they were both comments.  Since Arturo also suggested _Make: Electronics_ he gets the solution." CreationDate="2011-04-14T22:47:42.593" UserId="3810" />
  <row Id="19956" PostId="13073" Text="@David Kessner: super cool implementation!" CreationDate="2011-04-14T22:49:55.913" UserId="2288" />
  <row Id="19957" PostId="13041" Score="1" Text="Have you tried booting the phone, watching dmesg and changing the resistor values?  I would try to setup a continually variable resister over the ranged needed and slowly change its value.  I would expect the driver to dump mode information into dmesg." CreationDate="2011-04-14T23:31:48.580" UserId="1438" />
  <row Id="19958" PostId="13078" Text="*one* book? that's a *lot* of material to cover. :)" CreationDate="2011-04-14T23:44:55.847" UserId="1938" />
  <row Id="19959" PostId="13081" Score="1" Text="what exactly makes a BJT 'much more suitable' for LED driving?  There are tons of LED drivers that use MOSFET switches." CreationDate="2011-04-14T23:52:44.870" UserId="1438" />
  <row Id="19960" PostId="12991" Text="It's instructive to look at the cost of pixels on camera versus the cost of lenses &amp; motors. For some applications like robot situational awareness it's a good tradeoff." CreationDate="2011-04-15T00:19:48.977" UserId="1481" />
  <row Id="19961" PostId="13090" Text="The servo will still have DC power, just the signal line will be low. Would it hold it?" CreationDate="2011-04-15T00:58:36.473" UserId="1225" />
  <row Id="19962" PostId="11420" Text="@supercat: hope you don't mind the little tweak I made to your post." CreationDate="2011-04-15T01:14:11.960" UserId="813" />
  <row Id="19963" PostId="13088" Text="depending on the value of the cap the thickness can be a large issue.  Your average 0805 resistor is 15-20mil thick, a 10uF MLCC is ~60mil tall which can be really tall for a stock 0805 land pattern." CreationDate="2011-04-15T01:39:54.210" UserId="1438" />
  <row Id="19964" PostId="13072" Score="2" Text="what assembly process? (wave, reflow, hand, etc)" CreationDate="2011-04-15T01:40:35.770" UserId="1438" />
  <row Id="19965" PostId="13058" Text="@DarrenW But there were several sub-questions about the resistance of cheap voltmeters and the method to determine one. IMHO looking at the specs is the simples way to determine the resistance, especially since it is commonly included (even in the specs of the cheap models). Tomorrow I will add info about my Escort. I may even try the measuring method." CreationDate="2011-04-15T02:08:30.563" UserId="659" />
  <row Id="19967" PostId="12998" Score="1" Text="First off, @BarsMonster: good question, +1, I have really been enjoying thinking about it. And @Mike, good answer, too. +1. I have been thinking about this a lot, I think pretty much the right solution to this problem is a +/-12V comparator, discrete or otherwise, right? I have been playing around with a few ideas but I haven't figured it out quite right... never designed a comparator and the only bipolar op amp I have studied is the 741..." CreationDate="2011-04-15T02:14:03.057" UserId="3635" />
  <row Id="19968" PostId="13080" Text="Since saturation is a speed limiting factor with BJTs: Is forward biasing enough to negatively impact the turn-off time or should we approach $V_\rm{CEsat}$ for this to matter?" CreationDate="2011-04-15T02:20:10.933" UserId="659" />
  <row Id="19969" PostId="12998" Text="@AdamP The slew rate and bandwidth of the comparator will a limiting factor, especially with cheap comparator ICs. I am curious how far can you go with an IC+discrete." CreationDate="2011-04-15T02:30:44.903" UserId="659" />
  <row Id="19970" PostId="13077" Text="@Mark Barely. It's like just passing above the threshold voltage on a BJT. Unfortunately with the MOSFET you do not have the exponential characteristic." CreationDate="2011-04-15T02:33:42.767" UserId="659" />
  <row Id="19971" PostId="13013" Text="@booyakasha, Asia Would have been closed for the same reason. So would North America. on that note, at some point I thought it said GaAs, sorry about that, I think we all know the difference." CreationDate="2011-04-15T02:51:57.847" UserId="230" />
  <row Id="19972" PostId="13078" Text="I can't say I have seen a single book that covers all of that. I have a book in my lab that covers frequency hopping and time slicing with a bit of low power and a separate book that covers routing. Can't say I have anything that covers cryptography, unless you are talking about using low level methods of disguising your transmission like DSSS." CreationDate="2011-04-15T03:51:15.843" UserId="319" />
  <row Id="19973" PostId="13082" Text="Absolutely brilliantly written, thank you very much." CreationDate="2011-04-15T04:23:45.140" UserId="3240" />
  <row Id="19974" PostId="13089" Text="So basically it's a standard brushless motor? Why do they say it uses an iron core? I thought you needed a magnetic core for high power applications." CreationDate="2011-04-15T04:37:20.930" UserId="1319" />
  <row Id="19975" PostId="13075" Text="&quot;more appropriate&quot; sounds silly to me. Usually BJTs are cheaper, so I'd use a FET only if a BJT won't do." CreationDate="2011-04-15T06:07:20.783" UserId="339" />
  <row Id="19976" PostId="13081" Text="I meant ordinary low-current LEDs and displays. You don't see MOSFETs used for driving them, very often." CreationDate="2011-04-15T06:19:15.217" UserId="305" />
  <row Id="19977" PostId="2064" Text="@Leon man you are getting me interested in XMOS products.  I'm going to have to try really hard to resist picking up that development kit.  Do you know if there is an RTOS available for it?" CreationDate="2011-04-15T06:47:18.067" UserId="2288" />
  <row Id="19978" PostId="13082" Text="Another look at it: There is minimum Vce voltage (which is usually given in datasheet) below which increasing base current/voltage will not result in decreasing Vce further. At which base current/voltage it will be achieved depends on load conditions." CreationDate="2011-04-15T07:26:28.353" UserId="1471" />
  <row Id="19979" PostId="2064" Text="It doesn't really need an RTOS, because of the hardware threads. That said, one or two people are working on one." CreationDate="2011-04-15T07:47:42.473" UserId="305" />
  <row Id="19980" PostId="13078" Text="Several books would do..." CreationDate="2011-04-15T08:34:33.453" UserId="566" />
  <row Id="19981" PostId="13087" Score="1" Text="It could be a motor that is on or off :L " CreationDate="2011-04-15T08:51:53.963" UserId="1623" />
  <row Id="19982" PostId="13078" Text="@Kellenjb By cryptography, I mean using symmetric and asymmetric ciphers to secure radio transmissions. Privacy and authentication." CreationDate="2011-04-15T08:53:40.487" UserId="566" />
  <row Id="19984" PostId="13087" Text="Could it be a stepper motor in disguise? :p" CreationDate="2011-04-15T01:11:32.277" UserId="1938" />
  <row Id="19985" PostId="13099" Text="As funny as this is, i'd rather keep away from Sarcastic answers. What's obvious to you may not be obvious to another person. " CreationDate="2011-04-15T11:03:32.997" UserId="3073" />
  <row Id="19987" PostId="12998" Text="@BarsMonster, MikeJ-UK - To make it a push-pull: the collector of Tr1 is either at +12V (input low) or 0V (input high). You replace the output resistor (pull-down to -12V) with an NPN transistor in common-emitter. Use a resistor divider from collector Tr1 to -12V to drive the base. Choose resistor values such that base voltage is either just below or well above Vbe, depending on collector of Tr1 being 0V or +12V resp." CreationDate="2011-04-15T11:18:42.220" UserId="2064" />
  <row Id="19988" PostId="12998" Text="@stevenvh - Yes, that might work. That last sentence is especially important, but if the input has slow transitions, both output transistors could turn-on together. A hysteresis resistor from output to Tr1b might help a bit." CreationDate="2011-04-15T11:26:32.773" UserId="2234" />
  <row Id="19989" PostId="13061" Text="Thank you all for helping me out, you are building up good karma! :)" CreationDate="2011-04-15T11:41:19.837" UserId="3836" />
  <row Id="19991" PostId="13041" Text="But the bootloader download prompt most likely only shows up for a brief period while the phone is booting - then it goes away and tries normal operation.  I think that they'll have to change the resistor values, then start up the phone, check, try again, etc." CreationDate="2011-04-15T12:20:23.890" UserId="249" />
  <row Id="19992" PostId="13093" Text="	&#xA;a cautionary tale: when I was in college, I put together a simple power supply, using a 12.6V transformer, a 1N4001 diode, and an electrolytic cap, probably 100uF. Very shortly after plugging it in, there was this loud hissing/whistling noise, and I was alarmed to see a large jet of smoke blowing out the top of a very swollen, half split open capacitor. The problem: I had put 12.6*sqrt(2) volts (about 18) onto a 16V rated capacitor. " CreationDate="2011-04-15T12:26:12.967" UserId="740" />
  <row Id="19993" PostId="13041" Text="@Mark thanks, unfortunately it only seems to register resistance changes if you unplug then reconnect the plug. I have tried the slow and painful way of setting a resistor to each value in the list." CreationDate="2011-04-15T12:30:35.587" UserId="3862" />
  <row Id="19994" PostId="13067" Score="1" Text="No, not if there isnt more current in the base than in the collector divided by the current gain. And MOSFETs are not always better" CreationDate="2011-04-15T12:47:08.630" UserId="2110" />
  <row Id="19995" PostId="8688" Text="check out this 'ROM' from the days of discrete transistors: http://en.wikipedia.org/wiki/Core_rope_memory" CreationDate="2011-04-15T12:47:50.103" UserId="740" />
  <row Id="19996" PostId="8694" Text="It was probably something like what mctylr said. In machines of this type, there was usually a small 'monitor' program in ROM. When you entered bytes with the keypad, it was actually the 6502 (or 8085 or whatever) reading the keys, modifying memory, updating the LEDs, etc." CreationDate="2011-04-15T12:53:12.813" UserId="740" />
  <row Id="19997" PostId="5216" Text="I assume that was the intention though :)" CreationDate="2011-04-15T12:57:06.293" UserId="249" />
  <row Id="19998" PostId="8692" Score="1" Text="In 'front panel' machines, like the earlier S-100 systems, the switches let you take control of the system bus. One switch would let you suspend the processor. While the processor was suspended, you could then manually put an address on the address bus (via switches), put data on the data bus (more switches), and then manually cause a write-cycle on the bus (another switch), or a read-cycle to pull data back to 8 individual LEDs and read the binary, etc. Doing this, you could store enough machine code in RAM, un-suspend the processor, and go from there." CreationDate="2011-04-15T12:57:33.157" UserId="740" />
  <row Id="20000" PostId="13116" Text="Good thinking, but the problem is space. The 5v is not especially tight. I have space for 1 N size, or 1 AAAA." CreationDate="2011-04-15T13:07:40.957" UserId="1402" />
  <row Id="20001" PostId="13115" Text="I might have to go the regulator route. I'd rather not use the space it takes up, but there may be no other choice. Space is really tight." CreationDate="2011-04-15T13:09:23.433" UserId="1402" />
  <row Id="20003" PostId="13115" Text="@Dirk - if you're going for small space, and running from N or coin cells, then if you have to use an active circuit to change voltage, use the switching regulator as stevenvh suggests. With tiny cells like you're talking about, a linear regulator (e.g., 7805) will waste too much energy." CreationDate="2011-04-15T13:12:17.987" UserId="740" />
  <row Id="20004" PostId="13116" Text="BTW, the application is a remote control. " CreationDate="2011-04-15T13:19:11.460" UserId="1402" />
  <row Id="20005" PostId="13096" Text="I would speculate that Microchip is using the SD card in MMC mode, to avoid having to pay the SD consortium licensing fees." CreationDate="2011-04-15T13:30:51.907" UserId="1293" />
  <row Id="20007" PostId="13081" Text="Faster switching doesn't necessarily have anything to do with high-power applications. Darlington pairs (BJTs), etc. can be used to switch high power. You're answer doesn't get to the heart of the problem.&#xA;" CreationDate="2011-04-15T14:13:46.177" UserId="2454" />
  <row Id="20008" PostId="13079" Text="Battery limitations aren't the only reason to conserve power. What about heat dissipation? What about cost to operate? What about product lifetime (that can be limited by heat)?" CreationDate="2011-04-15T14:16:50.670" UserId="2454" />
  <row Id="20009" PostId="13117" Text="Difficult to drive a VN2222 from a 3.3v MCU, though, and they're not exactly readily available." CreationDate="2011-04-15T14:18:47.627" UserId="3240" />
  <row Id="20010" PostId="13081" Score="1" Text="Power Darlingtons are slow compared to MOSFETs! Fast switching is desirable to minimise inductor size and increase efficiency." CreationDate="2011-04-15T14:27:41.553" UserId="305" />
  <row Id="20011" PostId="13072" Text="Lead free reflow" CreationDate="2011-04-15T14:33:50.257" UserId="1278" />
  <row Id="20012" PostId="13077" Text="@Leon Heller I found the BS108, but it tops out at significantly less current than the 2N2222. It's more like a 2N3904 in current characteristics. It's more expensive than the equivalent BJT, and it's not in-stock at either Mouser or Digi-key." CreationDate="2011-04-15T14:41:09.050" UserId="3240" />
  <row Id="20013" PostId="13096" Text="Yes, they are using the SPI interface.  But they are also only full-speed USB, where the Alcor chip is hi-speed." CreationDate="2011-04-15T14:51:11.347" UserId="411" />
  <row Id="20014" PostId="13088" Text="I think I read something about how the solder should reflow to the top of the component.  Considering that a cap is taller than a resistor, this would imply that the land pattern should be larger, to allow for more solder paste that can reflow properly.  I think this was called the...toe fillet?" CreationDate="2011-04-15T14:51:44.317" UserId="1278" />
  <row Id="20015" PostId="13077" Text="@Leon Heller It seems to me that when they say &quot;Logic Level MOSFET&quot;, what they really mean is, &quot;5V Logic Level MOSFET&quot;. MOSFETS that can pass reasonable current at 3.3V seem to be few and far-between. I guess I'll stick with my trusty BJTs." CreationDate="2011-04-15T14:52:05.247" UserId="3240" />
  <row Id="20016" PostId="13099" Score="1" Text="It was not intended as sarcasm.  Sometimes an analogy helps understand a new concept." CreationDate="2011-04-15T14:52:10.953" UserId="411" />
  <row Id="20018" PostId="13116" Score="1" Text="@Dirk, most remote controls use 3V micros, which solves the problem the other way." CreationDate="2011-04-15T15:18:03.903" UserId="2110" />
  <row Id="20019" PostId="13094" Text="Please, could you put any link?" CreationDate="2011-04-15T15:18:17.893" UserId="2597" />
  <row Id="20020" PostId="9980" Text="Well, I am the same person in both cases, It´s more natural to me to wrote the answer in that way. Besides I could have sense for a person who just only is reading without take care who write the question and who answer it." CreationDate="2011-04-15T15:21:00.030" UserId="2597" />
  <row Id="20021" PostId="13121" Text="The xflow.results you have linked doesn't seem to match the question." CreationDate="2011-04-15T15:44:57.580" UserId="3441" />
  <row Id="20022" PostId="13081" Text="&quot;Faster switching doesn't necessarily have anything to do with high-power applications&quot;  It does if you're switching thousands of times per second.  Not if you're switching once per day." CreationDate="2011-04-15T16:02:23.690" UserId="142" />
  <row Id="20023" PostId="13100" Text="What do you mean by a queue accessed by multiple tasks? Do you mean posting to the queue or reading from the queue? Multiple tasks should be able to post to a queue with minimal overhead. The RTOS should handle the mutexing so that a post is an atomic operation. For 99% of tasks, you should have a loop that pends on a queue and processes the message. A queue should (usually) only be read by one task. You probably need to look at your design and how you are using queues instead of replacing them." CreationDate="2011-04-15T16:06:00.457" UserId="2150" />
  <row Id="20024" PostId="13089" Score="2" Text="&quot;And as the carbon brushes wear down, they emit carbon particles, which is bad for the environment.&quot;  What a bunch of nonsense." CreationDate="2011-04-15T16:06:56.103" UserId="142" />
  <row Id="20025" PostId="13081" Text="That sort of application is quite rare, compared to power conversion and motor control." CreationDate="2011-04-15T16:16:37.007" UserId="305" />
  <row Id="20026" PostId="13105" Score="2" Text="Explain? Im not sure I understand what you mean or why." CreationDate="2011-04-15T16:25:34.217" UserId="3073" />
  <row Id="20027" PostId="13041" Score="1" Text="@thebeano - From looking at the datasheet it seems that the chip can only have so many ways of determining that whether the cable has been unplugged.  five lines isn't a whole lot to solder up relays for, and if we can identify a set of resistors that can produce any valid value then it might be possible to rig up an automated tester." CreationDate="2011-04-15T16:25:51.730" UserId="249" />
  <row Id="20028" PostId="13096" Text="MMC mode is significantly slower than true SD-mode." CreationDate="2011-04-15T16:26:46.253" UserId="1293" />
  <row Id="20029" PostId="13089" Text="My gaming computer has 8 fans in it, that's 8 digital motors right there, and strangely none of them say Dyson on them." CreationDate="2011-04-15T17:33:27.730" UserId="1225" />
  <row Id="20030" PostId="13125" Text="Are the supplies completely separate, with two mains connections?" CreationDate="2011-04-15T17:35:02.300" UserId="305" />
  <row Id="20031" PostId="13087" Score="4" Text="You push it around with a finger!" CreationDate="2011-04-15T17:30:35.707" UserId="1158" />
  <row Id="20032" PostId="3718" Text="There is a workaround for this problem: You can reprogram the fuses using debugWire/avarice. So, after your debug session, just reset the DWEN fuse with avarice and you've got ISP back." CreationDate="2011-04-15T17:49:00.570" UserId="3827" />
  <row Id="20033" PostId="13089" Score="2" Text="That EEV blog is hilarious!" CreationDate="2011-04-15T17:51:04.397" UserId="2426" />
  <row Id="20037" PostId="13116" Score="1" Text="@Dirk, that is a good thing to include in a question." CreationDate="2011-04-15T19:52:14.713" UserId="230" />
  <row Id="20038" PostId="13109" Text="@AngryEE, I was going to say the same thing. If you just pass pointers to the data in queues you can increase speed, but make sure you do not end up with two threads trying to use and change the data." CreationDate="2011-04-15T19:59:23.587" UserId="230" />
  <row Id="20040" PostId="13094" Text="http://www.ise.pw.edu.pl/dydaktyka/psap/320C3x.pdf starting with section 4.3" CreationDate="2011-04-15T20:08:31.400" UserId="985" />
  <row Id="20042" PostId="13087" Text="@ThomasO, you need to provide links to information like this." CreationDate="2011-04-15T20:40:32.210" UserId="230" />
  <row Id="20049" PostId="13087" Text="@Kortuk Do dyson not advertise in the states?" CreationDate="2011-04-15T22:42:22.187" UserId="1623" />
  <row Id="20050" PostId="13105" Score="1" Text="@Sauron - the capacitance of an ideal capacitor is a constant, no matter what voltage you have across it, but for real capacitors, this is not always the case." CreationDate="2011-04-15T22:56:26.903" UserId="740" />
  <row Id="20055" PostId="12987" Text="&quot;very optimal&quot; haha" CreationDate="2011-04-15T23:55:59.023" UserId="771" />
  <row Id="20058" PostId="13123" Text="Be careful here, remember that Morse code is digital. Not all digital codes contain error correction or check bits, so just because it is digital does not guarantee perfect reception." CreationDate="2011-04-16T02:09:03.203" UserId="3869" />
  <row Id="20059" PostId="13123" Text="I didn't mean that it guarantees perfect reception.  I mean that, if there are no errors, the signal is transmitted with zero degradation.  If you transmit it through the same channel many times it will not degrade, while analog will, even if the noise floor is very low." CreationDate="2011-04-16T04:04:25.600" UserId="142" />
  <row Id="20062" PostId="13121" Text="I´ve just changed it." CreationDate="2011-04-16T05:34:53.357" UserId="2597" />
  <row Id="20063" PostId="13087" Text="It makes all sorts of `oooonnnnneeeezzzzeeeerroozzzzzzz` noises." CreationDate="2011-04-16T06:43:02.020" UserId="1940" />
  <row Id="20064" PostId="13041" Text="@AngryEE that's a good idea, I'm not sure I want it that badly though. But it may come to that. :-)" CreationDate="2011-04-16T09:02:39.063" UserId="3862" />
  <row Id="20065" PostId="13137" Text="@Leon - you don't explain why the software solution would be better. Also, the Atmel appnote only describes a generator, while the MT8889 is a generator/decoder." CreationDate="2011-04-16T09:34:15.240" UserId="2064" />
  <row Id="20066" PostId="13137" Text="He only wants a dialler!" CreationDate="2011-04-16T09:41:22.710" UserId="305" />
  <row Id="20067" PostId="13137" Score="1" Text="Okay, but why is the software solution better?" CreationDate="2011-04-16T10:07:01.000" UserId="2064" />
  <row Id="20068" PostId="13137" Text="I added it to my answer, although it's quite obvious!" CreationDate="2011-04-16T10:26:30.893" UserId="305" />
  <row Id="20069" PostId="13140" Score="1" Text="He's using an AVR so he only needs a single output to drive the CS pin." CreationDate="2011-04-16T10:35:42.607" UserId="305" />
  <row Id="20071" PostId="13132" Text="Thanks for your answer.  I have been suspecting a grounding problem as well, but I wasn't too sure.  Your idea about the (-) breadboard rail riding up makes sense.  All grounds in my circuit are on the same breadboard bus line.  Even though the motor PS is a battery pack, the (-) lead from that is attatched to the ground rail on the breadboard, along with the ground pin of the Arduino and the ground pin of the pot.&#xA;Perhaps cutting the power lead in the USB cable would help?  If this is a grounding problem, how else can I ground if I need both externally powered motors and USB communication?" CreationDate="2011-04-16T12:28:51.547" UserId="3881" />
  <row Id="20072" PostId="13087" Score="1" Text="@Dean, People easily found the information, so I assume it was easy to come by, but when you want to discuss someone's claims it helps if you link directly to their claims. This will improve the quality of the site directly. Directly quoting the claims with links will provide best results. This way in 20 years people can still understand the context." CreationDate="2011-04-16T13:27:28.117" UserId="230" />
  <row Id="20073" PostId="12385" Text="http://www.opencircuits.com/Arduino_Command_Interpreter for example" CreationDate="2011-04-01T03:38:15.263" UserId="1498" />
  <row Id="20074" PostId="13110" Text="And how do you do the voltage translation for the totem?" CreationDate="2011-04-16T14:19:26.767" UserId="659" />
  <row Id="20075" PostId="13023" Score="1" Text="Personally, I would just have the automated build process send an email when it's done.  When this email is sent to specific addresses, like _cell_phone_number_@attwireless.net then the email would be sent as a text message to your phone.  Nothing to build, and doesn't need line-of-sight to work." CreationDate="2011-04-16T14:44:54.953" UserId="3624" />
  <row Id="20076" PostId="13132" Text="if your motor p.s. was already a battery, my theory is probably toast. Unless you had another wire from the battery (-) to the arduino. if the only connection to the battery (-) is via the breadboard, then it wouldn't matter if the battery (-) was slightly more negative than the breadboard ground." CreationDate="2011-04-16T17:12:43.940" UserId="740" />
  <row Id="20077" PostId="13147" Score="1" Text="Could you please post a proper schematic?" CreationDate="2011-04-16T18:59:27.290" UserId="305" />
  <row Id="20078" PostId="13142" Score="1" Text="So you're going to protect eyes by using short, high-power pulses... like LASIK?  :)  Depending on whether tissue cares more about average power or peak power, it will either be equally damaging or worse, not better." CreationDate="2011-04-16T20:53:13.717" UserId="142" />
  <row Id="20080" PostId="12628" Text="I finally got to try this today, and actually, according the ATtiny2313 datasheet, the baudrate I'm using is very accurate (to within 0.2% or so), so this isn't the problem." CreationDate="2011-04-16T22:54:42.020" UserId="3741" />
  <row Id="20081" PostId="12624" Score="1" Text="Well this is embarrassing, but in the end it turned out to be a software error on the PC (transmitting) end.. Moral of the story, double check serial transmission buffer sizes + get a logic analyser to confirm." CreationDate="2011-04-16T22:57:55.153" UserId="3741" />
  <row Id="20082" PostId="12625" Text="I'm accepting this answer as it seems most likely from an electronics point of view..." CreationDate="2011-04-16T22:58:27.320" UserId="3741" />
  <row Id="20083" PostId="13151" Text="so does that means as long as I can find ones that have a common anode all will be fine?" CreationDate="2011-04-16T23:16:44.070" UserId="2824" />
  <row Id="20084" PostId="12625" Text="+1 for pointing out that those 1A slugs of return current are sharing a wire with the 0V reference. If you have 0.5 ohm in that wire, returning the 1A LED current means the ground at your device is going to float up to (0.5ohm)(1A)=0.5V . And since you're PWM-ing this current, inductance of the return wire will only make this effect worse. It's like 'ground bounce'." CreationDate="2011-04-16T23:29:29.680" UserId="740" />
  <row Id="20085" PostId="12985" Text="@BarsMonster: Even though [cube-shaped CM canisters were not designed for your cylinder-socket LM application](http://en.wikipedia.org/wiki/Apollo_13), perhaps they will still work with a bit of duct tape. :-)" CreationDate="2011-04-16T23:35:29.867" UserId="813" />
  <row Id="20086" PostId="13151" Text="@Ageis: No.  There are four possible arrangements for a three-terminal red-green LED: red cathode to green cathode (common cathode), red anode to green anode (common anode), red anode to green cathode, or red cathode to green anode.  Only the latter two will allow series operation; those types are particularly nice if one is trying to drive the LED from a port pin in a 3.3 volt system.  Wire the non-common anode to VDD and the non-common cathode to VSS.  Connect the LED to the port pin via resistor.  Drive the pin high for one color or low for the other.  Float the pin for LED off." CreationDate="2011-04-16T23:53:49.517" UserId="3123" />
  <row Id="20088" PostId="12636" Text="@Thomas O: For some strange reason, people try to hide most capacitors in opaque boxes full of *other* heat-generating stuff -- fast CPUs, or quickly-discharging batteries, or transistors switching heavy currents, or etc. The temperature of the cap (and everything else in that box) is at least the product of the total heat energy generated by *everything* inside that box, multiplied by the thermal resistance of that box. I don't know anyone who can look at a schematic and accurately guess the actual interior temperature. In my experience, it's always at least 10'C hotter than anyone expected." CreationDate="2011-04-17T00:29:11.297" UserId="813" />
  <row Id="20089" PostId="13151" Text="oh so like these? http://www.rapidonline.com/netalogue/specs/55-0251.pdf. I need to pray rs will let me return 144 leds lol" CreationDate="2011-04-17T00:29:52.810" UserId="2824" />
  <row Id="20090" PostId="11918" Text="@supercat: Thank you for that trip down memory lane." CreationDate="2011-04-17T00:41:30.830" UserId="813" />
  <row Id="20092" PostId="13151" Text="are you sure about 'float the pin for LED off' ? With the pin floating, wouldn't both red and green be forward biased, and therefore go on?" CreationDate="2011-04-17T01:02:47.310" UserId="740" />
  <row Id="20093" PostId="13151" Text="@JustJeff: Most LEDs have a forward voltage of 1.7 volts or more.  Two such diodes in series would have a combined forward voltage of 3.4 volts; a 3.3 volt supply would thus be a little short of what would be required to light them.  Note that with some LEDs there isn't a whole lot of margin; the trick may be better on 3.0 volts that 3.3 volts." CreationDate="2011-04-17T01:31:15.087" UserId="3123" />
  <row Id="20095" PostId="11534" Text="You can check the answers to my question as well: http://electronics.stackexchange.com/questions/10596/is-there-another-arduino-ethernet-module-besides-the-arduino-ethernet-shield" CreationDate="2011-03-16T14:40:37.510" UserId="3130" />
  <row Id="20096" PostId="11561" Text="Async Labs out of business - see http://www.asynclabs.com/home" CreationDate="2011-04-17T01:36:42.740" UserId="3894" />
  <row Id="20097" PostId="11534" Score="2" Text="Here is a great blog entry on how to connect a low cost WiFi router to an Arduino:&#xA;http://todbot.com/blog/2010/12/16/wifi-for-arduino-with-asus-wl-520gu/" CreationDate="2011-03-17T20:28:41.790" UserId="2489" />
  <row Id="20100" PostId="13136" Score="1" Text="I found [this][1] in a few seconds with Google. I searched on &quot;removing conformal coating&quot;. [1]: http://www.dymax.com/pdf/literature/lit078_rework_removal_of_uv_conformal_coating_tb.pdf" CreationDate="2011-04-16T08:58:05.837" UserId="305" />
  <row Id="20101" PostId="12762" Text="I suppose it is possible to use a thrust bearing at the TOP of the rotating axle that holds up everything hanging from it. If you then put your motor near the top, then perhaps you wouldn't need *anything* touching the bottom." CreationDate="2011-04-17T05:24:17.693" UserId="813" />
  <row Id="20102" PostId="13153" Text="@supercat The photo is in UP way as you see and i trying to display &quot;:) arduino&quot;. For the wires, i followed exactly documentation as showed in link, i hope there are corrected... but i don't understand why it don't work!" CreationDate="2011-04-17T11:27:07.613" UserId="3359" />
  <row Id="20103" PostId="13147" Text="@Leon The schema is in the posted link. I followed the instructon as shown. Schema is here: http://www.emartee.com/Attachment.php?name=41903.pdf" CreationDate="2011-04-17T11:28:56.537" UserId="3359" />
  <row Id="20104" PostId="13164" Text="Hmm, nice stuff but I looked up a price for 6.5&quot; of the stuff, and it's £7, given that that probably wouldn't remove many components (dsPIC is £4, sync sep £2) it's too expensive for me. :(" CreationDate="2011-04-17T12:34:11.037" UserId="1225" />
  <row Id="20105" PostId="13168" Text="It depends on the LEDs and how you are switching them." CreationDate="2011-04-17T12:51:00.903" UserId="305" />
  <row Id="20107" PostId="13164" Text="Given the price of the board that will usually be repaired with it, it's very good value." CreationDate="2011-04-17T14:12:59.693" UserId="305" />
  <row Id="20108" PostId="13153" Text="It does not appear that the LSB of the row select is working.  Without a schematic of the LCD board I can't tell for sure whether it's the OIA or OID wire that's not working, nor whether it's stuck high or low, but one of the OIx wires doesn't seem to be behaving as it should.  Try disconnecting them individually and see what happens.  My guess is that disconnecting OIA will have no effect." CreationDate="2011-04-17T14:17:23.137" UserId="3123" />
  <row Id="20109" PostId="13171" Text="That's the Chip Quik I mentioned in my answer." CreationDate="2011-04-17T14:34:00.133" UserId="305" />
  <row Id="20110" PostId="13163" Score="1" Text="Devices that use zero crossing circuitry certainly may not work as well or at all, as well as devices with active  power factor correction, especially processor based PFC.  Digital products may have functional issues with all the additional harmonics introduced onto the line.  Not working as well may be subjective.  A radio may work but sound like crap with a modified sine wave supply due to the harmonics coupling into the speaker amplifier.  The &quot;damage&quot; referred to may be caused by excess heat dissipated in inductive loads and the greater stress on the power supply components and filter." CreationDate="2011-04-17T15:37:52.817" UserId="2377" />
  <row Id="20111" PostId="13164" Text="@Leon Heller I get my boards for £2 each from China." CreationDate="2011-04-17T17:13:58.217" UserId="1225" />
  <row Id="20112" PostId="13172" Text="Which version are you using?" CreationDate="2011-04-17T18:23:43.950" UserId="206" />
  <row Id="20113" PostId="13172" Text="12.4, 64bit Linux" CreationDate="2011-04-17T18:41:02.960" UserId="2395" />
  <row Id="20114" PostId="13173" Score="1" Text="partially to accommodate 600 mil wide devices I would think." CreationDate="2011-04-17T19:43:24.013" UserId="2157" />
  <row Id="20115" PostId="13175" Text="You are right! It was staring me right in the face. Thanks bunches, the eagle library system can be annoying at times." CreationDate="2011-04-17T20:13:20.830" UserId="1802" />
  <row Id="20117" PostId="13029" Text="tutorial: http://www.sparkfun.com/tutorials/65. 10k resistor: http://www.sparkfun.com/products/8374 " CreationDate="2011-04-17T20:27:53.047" UserId="1227" />
  <row Id="20118" PostId="13134" Text="@gorgen, can you give probes of signals? Can you please post your code to this site instead of pastebin? We really cannot help easily without for more information. I am closing this and when you are ready to make updates let me know and I will reopen(just flag for moderator attention)." CreationDate="2011-04-17T20:41:43.093" UserId="230" />
  <row Id="20119" PostId="13173" Score="1" Text="In the wire wrapping days the pins were long enough for 3 connections and usually that was enough. 5 slots, 1 for the chip, 3 according to wire wrapping and +1 for good measure? I wouldn't really know, just a wild guess." CreationDate="2011-04-17T21:02:55.610" UserId="1319" />
  <row Id="20120" PostId="13177" Text="Are there other numbers you can't see?" CreationDate="2011-04-17T22:10:16.267" UserId="142" />
  <row Id="20121" PostId="13177" Score="6" Text="Any additional information would be useful.  Type of package, number of pins, any logos, suspected component type (CPU, diode, etc.).  A close-up photo would be great.  Also, where did you get this part?  What kind of device was/is it in?" CreationDate="2011-04-17T22:56:25.000" UserId="3624" />
  <row Id="20122" PostId="13177" Text="Have you tried asking Digikey for help?" CreationDate="2011-04-17T23:00:00.397" UserId="1944" />
  <row Id="20123" PostId="13183" Text="Problem is the temp controlled ones are kinda expensive &lt;_&lt;" CreationDate="2011-04-17T23:10:36.797" UserId="3073" />
  <row Id="20124" PostId="13176" Score="1" Text="Please post the meter ranges question separately. Let this question be about soldering irons." CreationDate="2011-04-17T23:12:35.633" UserId="2523" />
  <row Id="20125" PostId="13182" Text="I'm evidently just going crazy trying to adequately decouple a very small BGA (0.8mm pitch, 4/4 trace space, 8/18 vias... the via annular ring is killing me) I have a couple caps with long-ish traces to the nearest via, and I'm trying to find a good way to compensate (by making the other caps as good as possible).  I'm very likely entirely overthinking it..." CreationDate="2011-04-17T23:13:18.430" UserId="1270" />
  <row Id="20126" PostId="13174" Text="link doesn't work for me" CreationDate="2011-04-17T23:16:58.560" UserId="1688" />
  <row Id="20127" PostId="13174" Text="Fixed, somehow a space sneaked into the URL" CreationDate="2011-04-17T23:20:44.313" UserId="1802" />
  <row Id="20128" PostId="13182" Text="I'm trying very hard to avoid via-in-pad or microvias. I've just about got it but I'm very nervous about SI as I've never done DDR2 before. There are a lot of 'firsts' for this board for me.  It's right at the edge of my ability." CreationDate="2011-04-17T23:20:50.143" UserId="1270" />
  <row Id="20129" PostId="13183" Text="@Sauron  I added some stuff to my answer regarding the iron I use." CreationDate="2011-04-17T23:23:37.950" UserId="3624" />
  <row Id="20130" PostId="13182" Text="@darron  I have never had to use via-in-pad or microvias for a BGA before.  The vias I use have 10 mil holes and 22 mil pads.  This has worked fine for me with BGA's down to a 0.8 mm ball pitch.  Below that you need to either have a very creative fanout (works for smaller chips) or special vias.  Give me a part number and I'll see what I can come up with for how to route that part." CreationDate="2011-04-17T23:26:35.407" UserId="3624" />
  <row Id="20131" PostId="13183" Text="Ah thanks, I guess i'll be breadboarding stuff for awhile before I decide to officially invest in one anyways." CreationDate="2011-04-17T23:53:40.577" UserId="3073" />
  <row Id="20132" PostId="10268" Text="If the motor in question has a split ring commutator, the field on the rotor will actually be AC, at least from the rotor's frame of reference. So, not equivalent to permanent magnets on the rotor. Back emf is going to occur where the time-varying fields pass through coils. If you do have a permanent magnet rotor, you have to commutate the field windings, and you do get back emf in the field windings." CreationDate="2011-04-18T00:02:51.430" UserId="740" />
  <row Id="20133" PostId="13184" Text="+1 for the general idea. Now about the cheap pencil iron part: It is as good as it is bad. In case of problems, a beginner won't be able to tell if he's just bad at soldering or if it's the iron which is the problem. So my advice would be: Get a soldering iron which is a bit better than the cheapest you can find. Instead use the cheapest one which has a composite tip (that is the tip which isn't just made out of copper). That may solve some problems with wetting the tip and may make the soldering introduction a bit more gentle. " CreationDate="2011-04-18T00:16:57.103" UserId="1240" />
  <row Id="20134" PostId="13184" Text="About the power: I myself solved the problem by getting a relatively cheap 25 W soldering iron and then getting a very cheap (~ $10) 20 W to 80 W soldering gun. Just as Warren said, such iron won't overheat components quickly, but it won't work with thick cables either (but you probably won't need to work with them at first anyway), so you could consider a gun if you ever have a need to work with anything bulky before you get a real soldering iron." CreationDate="2011-04-18T00:24:07.647" UserId="1240" />
  <row Id="20135" PostId="13188" Text="It is unfortunate that hardware debuggers for AVR are very expensive (for example the JTAGICE mkII is over $300 on digikey). Do you know of any cheap alternatives?" CreationDate="2011-04-18T00:27:55.553" UserId="1240" />
  <row Id="20137" PostId="13182" Text="Freescale iMX283. It's a solid 17x17 grid. I guess vias are my main problem... (0.8mm - 18mil via) / 3 = ~4.5mil trace/space. I don't see how 22mil vias are possible.  Wouldn't that be (0.8mm - 22mil) / 3 = ~2mil trace/space?  Ho do you fit traces between vias?" CreationDate="2011-04-18T01:40:00.237" UserId="1270" />
  <row Id="20138" PostId="13182" Text="@darron  Give me a day or two to work on the fanout of this part.  Besides, we're getting off topic for this question.  I'll figure out how to post the fanout when I'm done with it." CreationDate="2011-04-18T01:46:02.403" UserId="3624" />
  <row Id="20139" PostId="13182" Text="I'm using almost every pin. I'm not using the LCD interface, but that's all on an outside corner and so it doesn't help relieve the pressure much at all.  I managed to fit 18 0402 caps under the chip.  (out of 72 total)" CreationDate="2011-04-18T01:48:14.830" UserId="1270" />
  <row Id="20140" PostId="13182" Text="I'd hate to see you waste much time on this...  but any general suggestion as to how to size vias and routing would be great. The best I can come up with is 4.5/4.5 routing with 8/18 vias like I said.  The recommended ball pad size for this part is 17mil." CreationDate="2011-04-18T01:51:03.860" UserId="1270" />
  <row Id="20141" PostId="13182" Text="Okay, I'm just worrying too much. I took a closer look at the reference design. It's been slightly useful before, but not nearly useful as it should be due to it's use of 8/16 vias. The decoupling on that looks insane to my eye and the board works. (They've got 5 decoupling caps tied lengthwise to a single via. Crazy)  I've probably been reading too much Howard Johnson and letting my idea of how close I have to get to the ideal he describes get out of hand.  Compared to this, my board should be fine." CreationDate="2011-04-18T02:47:24.157" UserId="1270" />
  <row Id="20142" PostId="13109" Text="@AngryEE: As @Kortuk said, I need &quot; make sure you do not end up with two threads trying to use and change the data&quot;... Which means increase in overhead... I don't want much processing! :(" CreationDate="2011-04-18T03:58:15.313" UserId="2574" />
  <row Id="20143" PostId="13100" Text="@Erik : Sorry! I am using the mechanism you mentioned.... I wanted to say something else and I wrote different.... I'll edit that!! Thanks for Pointing out the mistake! I am waiting for the queue access in my code!" CreationDate="2011-04-18T04:00:01.723" UserId="2574" />
  <row Id="20144" PostId="13152" Text="Excellent, thank you.  I definitely need the coherence of a laser.  I'm using the laser light as a tool to help measure distance.  Something like this: http://www.makerscanner.com/" CreationDate="2011-04-18T04:03:12.780" UserId="3889" />
  <row Id="20145" PostId="13152" Text="In any case, it's good to know that I can pulse the laser rapidly.  Any ideas on a circuit with which to do it?" CreationDate="2011-04-18T04:03:39.130" UserId="3889" />
  <row Id="20146" PostId="13142" Text="Ummm.  Not quite.  What I'm trying to do is increase the power output to like 10mW, so that it can be visible in a bright environment.  I'm spreading the light out over a 2x120 degree arc, so the brightness isn't bad enough to cause an issue.  Nonetheless, it looks like I can't increase the output, due to optical concerns.  Safety is my number one concern, I wouldn't do anything that could damage anybody.  " CreationDate="2011-04-18T04:05:46.490" UserId="3889" />
  <row Id="20147" PostId="13144" Text="@Andy: thanks, it wasn't more difficult than that." CreationDate="2011-04-18T07:23:38.207" UserId="3882" />
  <row Id="20148" PostId="12628" Text="According to the datasheet, internal clock of ATtiny2313 has only 10% accuracy, this is waaaay off for UART communication." CreationDate="2011-04-18T09:10:08.043" UserId="1472" />
  <row Id="20149" PostId="13196" Text="first of all , thanks for your answer.Lastly,I want to a question.What websites&amp;books can you  recommended related semiconductor devices?" CreationDate="2011-04-18T09:44:38.600" UserId="3916" />
  <row Id="20150" PostId="13196" Text="@Cell-o - The question about electronics books has been asked a few times in the past, read e.g. http://electronics.stackexchange.com/questions/4795/books-for-basic-electronics" CreationDate="2011-04-18T09:51:32.250" UserId="2064" />
  <row Id="20151" PostId="13196" Text="@stevenvh - Thanks again." CreationDate="2011-04-18T10:03:02.413" UserId="3916" />
  <row Id="20152" PostId="13157" Score="1" Text="I'm not so sure about the legality of buying a Kindle and rooting it, even if it is just to make prototype. If you are making a professional product, there is a chance you could get your company in trouble." CreationDate="2011-04-18T12:34:35.273" UserId="2857" />
  <row Id="20153" PostId="10804" Text="Is there a reason the Arduino you have doesn't allow the new functionality you want?" CreationDate="2011-04-18T12:53:14.157" UserId="3847" />
  <row Id="20154" PostId="76" Text="May we see the schematic? It might help." CreationDate="2009-11-02T14:06:35.980" UserId="11" />
  <row Id="20155" PostId="13185" Text="I thought most MC's have on-board oscillators." CreationDate="2011-04-18T14:41:50.617" UserId="3073" />
  <row Id="20156" PostId="13061" Text="It's worth mentioning that one 20mA LED at 3.3V will have more power consumption than the logic. I didn't see that LEDs were driven anywhere - but it's likely that the load will dominate power consumption. " CreationDate="2011-04-18T14:47:45.600" UserId="638" />
  <row Id="20157" PostId="13176" Text="@Sauron: I got that iron from SparkFun about 2 months ago, and it's been wonderful for me thus far. The temperature control makes soldering much more reliable than my old non-adjustable finger-burn iron. Plus, for 40 dollars, even if you don't like it after using it for a but, it was only 40 dollars!" CreationDate="2011-04-18T14:59:27.170" UserId="3122" />
  <row Id="20158" PostId="13203" Score="2" Text="Yes, and in principle, any reverse-biased PN junction is sensitive to light. The more fossilised of us will remember the OC71 germanium transistor which was encapsulated in a small glass envelope painted black. The manufacturers (Mullard) then produced the OCP71 phototransistor in a clear glass envelope which was much more expensive. Enterprising hackers soon realised that you could just scrape the paint off an OC71 and get a phototransistor with identical performance." CreationDate="2011-04-18T15:25:58.077" UserId="2234" />
  <row Id="20160" PostId="13206" Score="1" Text="Yes, but E192 is not very common, and more expensive as well, because being precision, (0.1%?)" CreationDate="2011-04-18T15:40:22.230" UserId="3920" />
  <row Id="20161" PostId="13182" Text="@darron  I looked at a design we did here with 0.8mm pitch.  I was mistaken before.  We used an 8/16 via and a 16 mil BGA pad.  We use a larger via on our 1.0mm BGA's.  Putting caps under the BGAs is a good thing to do, and 18 of them sounds reasonable.  On some BGA's I can use cap arrays.  Howard Johnson is a good source, and sometimes paranoia can be a good thing." CreationDate="2011-04-18T15:43:28.780" UserId="3624" />
  <row Id="20162" PostId="13205" Text="Good question. I've never used them, and I see that teardrops are sometimes optional in EDA suites." CreationDate="2011-04-18T15:44:09.873" UserId="2064" />
  <row Id="20163" PostId="13206" Text="@Federico - True, but the only times I have ever needed a very accurate ratio, I needed the precision anyway." CreationDate="2011-04-18T15:48:41.647" UserId="2234" />
  <row Id="20164" PostId="13205" Score="1" Text="Possible to show a picture on what you mean?" CreationDate="2011-04-18T15:53:19.343" UserId="1623" />
  <row Id="20165" PostId="13205" Score="1" Text="@Dean - added a picture (I think you need a minimum rep to do so)" CreationDate="2011-04-18T16:00:14.070" UserId="2064" />
  <row Id="20166" PostId="13205" Text="Going to guess to improve connectivity between track and pad. " CreationDate="2011-04-18T16:00:35.823" UserId="1623" />
  <row Id="20167" PostId="13207" Score="2" Text="@Leon - Is that because it's single-sided, or (with all respect) because it's non-professional (DIY)? In other words, are they also useful if you have your PCBs produced in a shop?" CreationDate="2011-04-18T16:11:14.730" UserId="2064" />
  <row Id="20168" PostId="13157" Text="I am not designing this for a company. I want to build this for myself and show it to potential investors, and if there's a market, I'll go ahead and buy the dev board." CreationDate="2011-04-18T16:30:23.053" UserId="3895" />
  <row Id="20169" PostId="13207" Score="1" Text="It's mainly because single-sided boards don't have PTH." CreationDate="2011-04-18T16:37:57.043" UserId="305" />
  <row Id="20170" PostId="13203" Score="1" Text="Mullard got wise to that, and painted the inside of the glass!" CreationDate="2011-04-18T16:39:16.997" UserId="305" />
  <row Id="20171" PostId="13205" Text="Thanks, stevenvh" CreationDate="2011-04-18T16:42:04.003" UserId="3920" />
  <row Id="20172" PostId="13157" Score="1" Text="@Ryan - I think it's perfectly alright to root it: if you buy it it becomes your property, you can do with it whatever you like, despite what Amazon may say (see also Apple). You may have trouble buying the screen from Amazon's supplier, though. If it was designed for (and the design paid for by) Amazon, it's unlikely that Amazon let others parasite on their investment." CreationDate="2011-04-18T16:58:32.333" UserId="2064" />
  <row Id="20173" PostId="13207" Score="1" Text="@Leon Heller, that was going to be my answer... The bit about it not having plated through holes which results in the pad being able to be pulled up a lot easier or move around with shock resulting in breaks over time." CreationDate="2011-04-18T17:13:48.953" UserId="319" />
  <row Id="20174" PostId="13203" Score="1" Text="Why did they use glass? Cheapest to seal?" CreationDate="2011-04-18T17:14:31.947" UserId="2064" />
  <row Id="20175" PostId="13157" Text="@stevenvh From what I can tell, it's just the [E-Ink Pearl](http://www.eink.com/sell_sheets/pearl%20sell%20sheet.pdf) from E-ink. They may have modded the connectors, but I have a soldering iron for than =)" CreationDate="2011-04-18T17:14:54.813" UserId="3895" />
  <row Id="20176" PostId="13179" Text="Yeah, it looks like the KS0108 is the common one." CreationDate="2011-04-18T17:22:12.867" UserId="3240" />
  <row Id="20177" PostId="13213" Text="It might help the drilling process, but I've seen plenty of them on SMT pads." CreationDate="2011-04-18T17:25:54.267" UserId="3624" />
  <row Id="20178" PostId="13213" Text="We have never had any issues that I know of with pads getting pulled up when drilling after etching." CreationDate="2011-04-18T17:30:38.407" UserId="319" />
  <row Id="20179" PostId="13207" Score="1" Text="@Leon - In my dictionary PTH = Pin Through Hole, but I guess you mean Plated Through Hole. :-)" CreationDate="2011-04-18T17:30:41.933" UserId="2064" />
  <row Id="20180" PostId="13203" Score="2" Text="Does this mean that a LED technically consumes slightly less current when turned on in a very bright environment compared to a dark one? :-)" CreationDate="2011-04-18T17:58:56.930" UserId="319" />
  <row Id="20181" PostId="13182" Text="8/16 is a no-go for 4PCB, sierra proto express, and a few others I've checked and forgotten. 5 mil annular ring minimum (some say 6) It sure would have been nice though (the DDR2 routing could have been done in a single inner layer). I also ended up dropping some ports, and removing their corresponding vias meant I could get 6 more caps under the chip. I'm feeling a lot better about it in general now. I don't mind if something's wrong the first time... but my nightmare is spending $1800 on this board, it not working, and there being no obvious reason why not. :)" CreationDate="2011-04-18T18:11:06.333" UserId="1270" />
  <row Id="20182" PostId="13182" Text="The docs say the footprint was optimized for &quot;low cost 4 or 6 layer PCBs&quot;...  only you have to use multiple expensive options to produce it (8 mil vias, 4/4 trace/space). 1mm pitch would have been SO much better. It'd be a 300 dollar prototype instead of 1800 dollars." CreationDate="2011-04-18T18:12:28.547" UserId="1270" />
  <row Id="20183" PostId="13157" Score="2" Text="For personal use, I don't think there is a problem with rooting a Kindle. However, if you take an existing design, and hack it to make a new product, you are going to run into copyright issues. I'm not sure if you can get in trouble for hacking the equipment for a professional prototype, but I would be careful." CreationDate="2011-04-18T18:13:41.403" UserId="2857" />
  <row Id="20184" PostId="13157" Text="@Ryan - Yeah, I understand the risks. I just want to know if it's possible, and if so, what resources I could look at to get started." CreationDate="2011-04-18T18:17:47.360" UserId="3895" />
  <row Id="20185" PostId="13198" Score="2" Text="To be specific, it's only bad to short--circuit *charged* electrolytic capacitors." CreationDate="2011-04-18T19:05:33.210" UserId="1374" />
  <row Id="20186" PostId="13183" Text="@Sauron: I tend to breadboard a lot anyway, as I like to take stuff apart and put it together differently. Maybe it's just the LEGO builder in me! FWIW, I've always gotten along with my RS firestarter (30W, I believe, but maybe it's 25W)." CreationDate="2011-04-18T19:17:52.803" UserId="3240" />
  <row Id="20188" PostId="13086" Text="I have been wondering somewhat the same thing, but I plan to remove all power. Still I suspect transients on shut down and start up may make it twitch." CreationDate="2011-04-15T21:59:04.037" UserId="1498" />
  <row Id="20189" PostId="13212" Score="2" Text="I see how they could be little use; but how are they trouble? (as in &quot;more trouble than they are worth.&quot;)" CreationDate="2011-04-18T20:06:02.643" UserId="3053" />
  <row Id="20191" PostId="13212" Score="1" Text="@Javier  It really depends on how your CAD software handles them.  What you don't want is to have to draw the teardrops manually for every pad/via.  Years ago I used Protel that would make good looking teardrops, but had some bugs that caused problems in the gerber output when teardrops were used.  Now I use Cadence Allegro, which has lots of issues.  At the very least, the teardrops simply take longer to draw and makes editing the PCB more cumbersome (assuming that you have a super complex PCB to begin with)." CreationDate="2011-04-18T20:20:17.010" UserId="3624" />
  <row Id="20192" PostId="13207" Text="Why the downvote?" CreationDate="2011-04-18T20:28:38.233" UserId="305" />
  <row Id="20193" PostId="1083" Text="That stuff is awesome flexible :)" CreationDate="2011-04-18T20:39:20.847" UserId="3240" />
  <row Id="20194" PostId="8525" Text="Clever answer. :)" CreationDate="2011-04-18T21:42:59.993" UserId="3745" />
  <row Id="20195" PostId="13215" Score="2" Text="What is the application? Low power? Low Cost? Long Range? etc." CreationDate="2011-04-18T21:48:39.637" UserId="319" />
  <row Id="20196" PostId="13199" Text="even discharge rates that are less than short-circuit can be hard on a capacitor, if they happen frequently enough. learned this lesson by replacing the capacitor in a strobe light with an ordinary electrolytic - it got REALLY hot." CreationDate="2011-04-18T22:20:10.130" UserId="740" />
  <row Id="20197" PostId="13175" Text="BTW, do you have any idea what the proper PCB thickness would be? It looks like it's at least 1mm, maybe more." CreationDate="2011-04-18T22:41:30.260" UserId="1802" />
  <row Id="20198" PostId="13219" Text="I would be there is probably a part for 2x25 as well." CreationDate="2011-04-18T23:45:31.330" UserId="319" />
  <row Id="20199" PostId="13219" Text="2x8, 2x10, 2x12, and 2x26 -- but no 2x25  :)  It would easy to modify any of these using cut and paste to create a larger array, e.g. 10x50" CreationDate="2011-04-18T23:53:22.053" UserId="1322" />
  <row Id="20201" PostId="13217" Score="2" Text="you can't just place pads freehand in Eagle? Every piece of PCB software I have used has let you place primitives in the PCB design stage without having to have analogous schematic entities, they just don't have nets (which isn't important here, anyways)." CreationDate="2011-04-19T05:16:05.200" UserId="1374" />
  <row Id="20202" PostId="13222" Score="2" Text="What is a &quot;RCD&quot;?" CreationDate="2011-04-19T05:45:00.470" UserId="638" />
  <row Id="20204" PostId="13224" Text="I understand that the hole isn't always dead in the center, but if it's so far off that it goes off the pad I think I would go and find another manufacturer." CreationDate="2011-04-19T06:13:20.223" UserId="2064" />
  <row Id="20206" PostId="13217" Text="I've searched around a bit and I have not found a way to place pads free-hand (yet), but that does not mean it's not there. If I try to drop, say, a 1x1 connector it tells me I should be making changes in the schematic instead. It's my first non-toy PCB projects, so I'm learning as I go along. " CreationDate="2011-04-19T06:56:35.903" UserId="1802" />
  <row Id="20207" PostId="13219" Text="Just to be clear, when you say &quot;modify to taste&quot;, do you mean to modify it in the library or in the PCB editor?" CreationDate="2011-04-19T06:57:17.383" UserId="1802" />
  <row Id="20208" PostId="13220" Text="Yes, I was indeed talking about the solder mask. Thanks for the useful link. If I understand it correctly by placing polygons over the top/bottom of the vias in the t_stop/b_stop layers I can force the vias' copper to be exposed." CreationDate="2011-04-19T06:59:58.113" UserId="1802" />
  <row Id="20209" PostId="13232" Score="3" Text="Can you give us an idea of the range of input frequencies you wish to measure, as well as the voltage levels and waveform? Are we talking a 100Hz 0-5V square wave or a 350Mhz 120mV peak-to-peak signal? They both necessitate very different handling." CreationDate="2011-04-19T07:20:43.627" UserId="1802" />
  <row Id="20210" PostId="13175" Text="I'm not sure, I'd suggest contacting the author of the GoodFET project I posted" CreationDate="2011-04-19T07:54:34.597" UserId="566" />
  <row Id="20211" PostId="13215" Text="@Kellenjb i've added a few more details now. " CreationDate="2011-04-19T08:15:20.157" UserId="1623" />
  <row Id="20212" PostId="13219" Score="1" Text="I meant creating a custom version in the library for your own needs, using this as a starting point.  There are several tutorials around on this topic; just Google: modifying eagle cad library" CreationDate="2011-04-19T08:18:13.460" UserId="1322" />
  <row Id="20213" PostId="13177" Text="@endolith - don't you find that a rather weird question? :-)" CreationDate="2011-04-19T09:34:38.147" UserId="2064" />
  <row Id="20214" PostId="13225" Score="1" Text="+1 for mentioning Darwin Awards!" CreationDate="2011-04-19T09:57:14.507" UserId="2064" />
  <row Id="20215" PostId="13222" Text="@W5VO, residual current device, similar to a GFCI in the US. It trips on an imbalance between live and neutral currents which indicates an earth fault." CreationDate="2011-04-19T11:23:52.310" UserId="1225" />
  <row Id="20216" PostId="13229" Text="Actually, I have no buffer. The signal from the camera is being manipulated directly. Although I can presume the camera and TV card both have built in 75 ohm amplifiers." CreationDate="2011-04-19T11:32:01.177" UserId="1225" />
  <row Id="20217" PostId="13220" Text="@Ranieri, I don't use Eagle so I wouldn't know, unfortunately. I would think there is an easier way." CreationDate="2011-04-19T11:36:19.253" UserId="1225" />
  <row Id="20219" PostId="13240" Text="Yes, I understand that the hole is needed, but I was wondering if I had to provide it in the pad's copper, or let the drill do the work." CreationDate="2011-04-19T11:56:55.627" UserId="2064" />
  <row Id="20220" PostId="13241" Text="I was considering that idea too, but there's a but. The datasheet recommends a way to wind the inductor, but I can't find any information on the recommended ferrite cores. To make things even better, catalogs of the stores in my area don't have any information on relative permeability of the cores. There are markings such as &quot;FM 452 50&quot; or &quot;45010&quot;, but Internet searches bring up tons of unrelated information. " CreationDate="2011-04-19T12:04:33.127" UserId="1240" />
  <row Id="20221" PostId="13238" Text="I only need the nodes to run for about a day. Probably not even that about 4 hours maximum. " CreationDate="2011-04-19T12:05:38.803" UserId="1623" />
  <row Id="20222" PostId="13238" Text="Even Nordic's &quot;Ultra low power&quot; consumes &gt; 13 mA in receive mode. The only way to get a long battery life is to go to extremely low duty cycles. This should be specified." CreationDate="2011-04-19T12:18:27.513" UserId="2064" />
  <row Id="20223" PostId="13241" Text="Try Amidon: https://www.amidoncorp.com/" CreationDate="2011-04-19T13:07:25.050" UserId="305" />
  <row Id="20224" PostId="13244" Text="I'm aware of general use of the coil and of its significant characteristics. Here I'm more looking for a way to understand how the number itself was derived." CreationDate="2011-04-19T13:21:30.270" UserId="1240" />
  <row Id="20225" PostId="13124" Text="A small side note -- If I had known I was going to use the MSP430 for this project, I would have picked out a more suitable LCD, like the NHD-C0220AU-FSW-FTS, which is a 3.3V part.  I'm not sure if part of my issue stems from using 3.3V logic signals to bitbang the data bus.  I might order one of these LCDs now because I'm wasting too much time on this." CreationDate="2011-04-19T13:35:00.093" UserId="2288" />
  <row Id="20226" PostId="13246" Text="My question is the first one. So if I understand your answer correctly, the correct number has been determined experimentally?" CreationDate="2011-04-19T13:39:43.303" UserId="1240" />
  <row Id="20227" PostId="13247" Text="I'm very stoo-pid. :-/" CreationDate="2011-04-19T13:41:36.833" UserId="2064" />
  <row Id="20228" PostId="13240" Score="1" Text="You shouldn't have the holes in your Gerbers, some PCB suppliers don't like it and will send you an email saying something like &quot;No donuts!&quot;. Others will just ignore it. The drill file is where it belongs." CreationDate="2011-04-19T13:43:11.413" UserId="305" />
  <row Id="20229" PostId="13177" Score="1" Text="@stevenvh No?  I mean half the chip could be covered by a shield, glue, scraped off, etc, and that part could have the identifiers." CreationDate="2011-04-19T13:53:04.020" UserId="142" />
  <row Id="20230" PostId="12713" Text="Well, I just developed the code for modulation and demodulation in Matlab using the CCK Encoding table. Just in case, if someone is interested, here is the code for the CCK encoding table: matlab.my/hj870O " CreationDate="2011-04-19T14:26:42.673" UserId="3733" />
  <row Id="20231" PostId="13248" Text="The coin cell was just an initial idea. I get the general feeling that it is not possible. So will probably end up using 2 AAs. " CreationDate="2011-04-19T14:32:56.777" UserId="1623" />
  <row Id="20232" PostId="10668" Text="endolith, I would have thought so as well. Except until today, when I found something: http://electronics.stackexchange.com/questions/10668/good-design-for-a-basic-non-ic-class-d-audio-amp/13243#13243" CreationDate="2011-04-19T14:37:04.600" UserId="930" />
  <row Id="20233" PostId="13203" Text="I have an LED in a very low power application, and I am afraid that this LED might drain a few microamperes from the battery. Would that be possible or realistic?" CreationDate="2011-04-19T14:55:02.897" UserId="3922" />
  <row Id="20234" PostId="13230" Text="So where's the datasheet?" CreationDate="2011-04-19T14:57:37.883" UserId="1657" />
  <row Id="20235" PostId="13230" Score="1" Text="Did you downvote me because I can't produce a datasheet for something which isn't even a part number, let alone that we know who's the manufacturer??" CreationDate="2011-04-19T15:03:19.180" UserId="2064" />
  <row Id="20236" PostId="13226" Text="What is a 276-640? Make and Model will help. " CreationDate="2011-04-19T15:13:53.577" UserId="1623" />
  <row Id="20237" PostId="13226" Text="@Dean - it's a IR-receiver module offered by Radio Shack. 276-640 is the catalog number. The Radio Shack website doesn't give details about make or type. And apparently 200ok404notfound doesn't understand that you can't produce a datasheet if you don't know the type..." CreationDate="2011-04-19T15:39:22.020" UserId="2064" />
  <row Id="20238" PostId="13230" Text="@stevenvh  I upvoted you cuz I thought your use of &quot;Radio Shack&quot; and &quot;Advant Garde&quot; in the same sentence was inspired.  " CreationDate="2011-04-19T15:40:10.600" UserId="3624" />
  <row Id="20239" PostId="13232" Text="possible duplicate question: http://electronics.stackexchange.com/questions/2811/measuring-0-1mhz-0-25hz-resolution-squarewave-using-an-mcu" CreationDate="2011-04-19T15:49:55.800" UserId="771" />
  <row Id="20240" PostId="13248" Text="@Dean I have worked for a company that makes a device that is run off of 2 coin cells and can last for 3+ years on the same set of coin cells. We use an MSP430 and CC1100 and have had plans on switching to the CC430. So it is possible, you just have to watch your coding." CreationDate="2011-04-19T16:04:02.577" UserId="319" />
  <row Id="20241" PostId="13248" Text="@Dean Also, the standard modules that you buy are usually much more power hungry then they need to be. You really only need to use much power while transmitting." CreationDate="2011-04-19T16:05:35.523" UserId="319" />
  <row Id="20242" PostId="13252" Text="Oh, you have hot air, so you could put the board in a vise and blow air at it until the part slides off.  This is an easy application of air because you aren't concerned about disturbing neighboring parts, so crank up the air volume and blow the chip off the board... " CreationDate="2011-04-19T16:06:37.970" UserId="411" />
  <row Id="20243" PostId="13238" Text="@stevenvh Or a wake on radio type environment" CreationDate="2011-04-19T16:08:50.963" UserId="319" />
  <row Id="20244" PostId="13226" Text="@Stevenvh I do agree with you comment you make on your answer that components without datasheets are useless. " CreationDate="2011-04-19T16:11:45.670" UserId="1623" />
  <row Id="20245" PostId="13249" Text="&quot;note, that I'm more concerned with signal integrity than EMI&quot; ... Aren't those two pretty closely coupled?" CreationDate="2011-04-19T16:17:32.717" UserId="319" />
  <row Id="20246" PostId="13242" Text="No ripple... well, a few millivolts, but it has always had that since I got it 3 months ago." CreationDate="2011-04-19T16:39:07.227" UserId="1225" />
  <row Id="20247" PostId="13255" Text="The other lines can also be used to help with coding. You can do stuff like your microcontroller will tell your PC when it is ready to receive data. This can be really helpful when you are having to do some stuff that requires your attention and you can't be interrupted to clear your buffer." CreationDate="2011-04-19T16:46:34.647" UserId="319" />
  <row Id="20248" PostId="11765" Text="That's sort of right, but the text needs to be converted to ascii code before writing. Then when reading back they need to be converted back to text." CreationDate="2011-04-19T17:25:28.527" UserId="1657" />
  <row Id="20249" PostId="13224" Text="It might be a cost-quality tradeoff.  &#xA;&#xA;Perhaps the main goal is to slap a product together cheaply - they might be willing to go with a lower-precision fab, and design the board to accomodate that choice.&#xA;&#xA;It might also be that there is only a small handful of parts that need extra densely placed PTH's that doesn't justify paying for higher precision fab for the other 99% of the board.   The teardrop might be the &quot;compromise&quot; solution for those cases." CreationDate="2011-04-19T17:31:39.963" UserId="3308" />
  <row Id="20250" PostId="13230" Text="The tsop 1236 is an old part. It can't operate with anything below 4.5V. The Radio Shack equivalent has been discontinued and has been replaced with the 276-640 which can operate with as little as 2.7V." CreationDate="2011-04-19T17:35:39.500" UserId="1657" />
  <row Id="20251" PostId="13255" Score="3" Text="You also need GND." CreationDate="2011-04-19T17:56:53.337" UserId="204" />
  <row Id="20252" PostId="13257" Text="B) No.  You need GND shared." CreationDate="2011-04-19T17:57:46.393" UserId="204" />
  <row Id="20254" PostId="13257" Text="Thanks @Robert. I've edited my answer." CreationDate="2011-04-19T18:03:24.660" UserId="938" />
  <row Id="20256" PostId="13260" Text="The very first LCD module I ever got, circa 1989, was DOA; the enable line acted like a 100-ohm or so resistor to ground.  Digi-Key replaced it at no charge other than shipping (nice of them) and the replacement worked first try." CreationDate="2011-04-19T18:08:36.587" UserId="3123" />
  <row Id="20259" PostId="13256" Text="What exactly are you looking to know? Like do you want to know how the modulation techniques and MIMO (in 802.11n) are setup or packet retransmission type stuff." CreationDate="2011-04-19T19:13:35.413" UserId="319" />
  <row Id="20260" PostId="13261" Text="I created a part with the pads in the proper places, and I'm happy to report it was easier than I thought it would be. Having troubles connecting the pads though (I'd like to make a few islands, as well as 5V and GND rails). The saga continues." CreationDate="2011-04-19T19:48:20.803" UserId="1802" />
  <row Id="20261" PostId="13236" Text="When trying to connect the pads with wires in the package editor, I rack up tons of &quot;Overlap&quot; DRC errors. I read in the Eagle forums that it's a known problem (can't change the name of wires in teh package editor, so Eagle does not know they are supposed to be the same connection). The PCB house requires a clean DRC. Any suggestions?" CreationDate="2011-04-19T19:48:56.497" UserId="1802" />
  <row Id="20262" PostId="13234" Text="... and the connected components fail DRC because of overlaps. Sounds familiar? ;)" CreationDate="2011-04-19T19:50:07.213" UserId="1802" />
  <row Id="20263" PostId="13261" Text="In your schematic component, wire the appropriate &quot;pins&quot; to the Vcc and ground nets.  Or, better yet, wire them to &quot;proto_vcc&quot; and &quot;proto_gnd&quot; nets, separate from the main vcc and gnd nets." CreationDate="2011-04-19T20:12:51.447" UserId="3308" />
  <row Id="20264" PostId="13266" Text="Yeah the RS listing is very light on details, but if I had to guess I'd say that I've found a roughly equivalent unit here: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=425-2611-ND" CreationDate="2011-04-19T20:36:47.817" UserId="249" />
  <row Id="20265" PostId="13262" Text="@ToyBuilder thanks for the point about delays after setting the data bits.  My code shows the delay that I'm using, which is none.  :)  I only have a delay of 1000 ticks between E high and E low, which equals about 10ms according to my oscilloscope.  I'll give the delay before strobing E a try now." CreationDate="2011-04-19T20:43:33.633" UserId="2288" />
  <row Id="20266" PostId="11765" Text="What do you mean when you say &quot;text&quot;? I do not understand what you want to do: most textual data today is actually encoded as a sequence of ASCII bytes." CreationDate="2011-04-19T20:44:59.967" UserId="659" />
  <row Id="20267" PostId="13256" Score="1" Text="I would be interested in having the block diagram of the Transmitter and Receiver for different standards. I did not get a clear picture from the Standard.&#xA;&#xA;Like the blocks like Scrambling, Modulation and Spreading(The order of these blocks) in the Transmitter and the Receiver." CreationDate="2011-04-19T20:52:00.067" UserId="3733" />
  <row Id="20268" PostId="13229" Text="@Thomas O: I tried making an OSD circuit with no buffer once, using a Cypress PSOC.  It kinda-sorta worked, but the output was pretty mungy--much like yours.  Adding a couple of video buffers improved things immensely." CreationDate="2011-04-19T20:54:35.503" UserId="3123" />
  <row Id="20269" PostId="13257" Text="thx for answer -  one more thing  should I leave not used  inputs floating?" CreationDate="2011-04-19T20:54:44.560" UserId="1471" />
  <row Id="20270" PostId="13262" Text="MSP430 output level is Vcc-0.3V, so that's 3V.  The LCD has a min input high of 2.4V, so I should be good to go.  I set the delays to 100ms for *everything*, and the LCD still just flickers during init and doesn't show me anything." CreationDate="2011-04-19T21:09:36.713" UserId="2288" />
  <row Id="20271" PostId="13214" Score="1" Text="aim for the center of the band, and don't expect to get good performance outside of half an octave either side." CreationDate="2011-04-19T21:49:19.817" UserId="740" />
  <row Id="20272" PostId="13268" Score="1" Text="Depends on the circuit" CreationDate="2011-04-19T21:50:41.890" UserId="142" />
  <row Id="20273" PostId="13236" Text="Don't use the package editor for this. Draw directly on the PCB itself. Use the VIA command for the pads/holes, and the WIRE command to connect them. You can use WIRE to draw the silkscreen outlines as well. I just tried it, and it passes the default DRC settings, at least." CreationDate="2011-04-19T22:19:56.440" UserId="2523" />
  <row Id="20274" PostId="13269" Text="Here's a schematic of the old version: http://super-osd.googlecode.com/hg/hardware/V2%20%28FPV%20version%29/FPV_version_video_core.png&#xA;I don't have a schematic of the current version unfortunately. " CreationDate="2011-04-19T23:11:55.383" UserId="1225" />
  <row Id="20275" PostId="11765" Text="I just mean normal characters." CreationDate="2011-04-19T23:19:29.487" UserId="1657" />
  <row Id="20279" PostId="1029" Text="This looks interesting." CreationDate="2011-04-20T01:58:25.887" UserId="1227" />
  <row Id="20280" PostId="13246" Text="The capacitor ripple voltage is fundamentally due to the superimposed inductor current, which is calculated as a function of the inductance, duty cycle, input voltage and load. If you look up buck converters you can easily find the formulae." CreationDate="2011-04-20T03:15:57.133" UserId="1293" />
  <row Id="20281" PostId="13185" Text="They do, however, from what I've read the accuracy of them isn't nearly as good as a crystal. This can be important for things like serial communication or achieving accurate micro-second timing." CreationDate="2011-04-20T03:36:58.137" UserId="3301" />
  <row Id="20282" PostId="13256" Text="Questions formated like &quot;I need x&quot; or &quot;I am looking for y&quot; are not very good questions on this site. If there is some specific question that you have, feel free to edit your question. Is there an application that you need this block diagram for? Or some particular misunderstanding of the technologies?" CreationDate="2011-04-20T03:58:16.243" UserId="319" />
  <row Id="20283" PostId="13109" Text="So There is No as such replacement for Queues... Instead of Data Queue, I need to use Pointer Queue! " CreationDate="2011-04-20T04:05:24.757" UserId="2574" />
  <row Id="20284" PostId="13229" Score="1" Text="Well, No-Buffer = your problem. If you're generating white lettering by simply forcing the video signal high, you are going to get *all sorts* of refections from **both ends** of the video cable." CreationDate="2011-04-20T04:26:48.200" UserId="1374" />
  <row Id="20285" PostId="13229" Text="Ok, looking at your schematic, you're switching a 2:1 multiplexer between a 3.3v signal (It's an IO line, don't think PICs have internal DACs, do they?) and the input video signal to generate white text, correct? I am pretty sure you are massively overdriving the input to the video display. Composite signals &quot;reference-white&quot; according to wikipedia is **1.000 Volt**. You need to divide the &quot;level bit&quot; signal down by *at least three*, and then it needs to be buffered to allow it to drive the video line with a high speed buffer before it's fed into the multiplexer." CreationDate="2011-04-20T04:33:24.103" UserId="1374" />
  <row Id="20286" PostId="13229" Text="Frankly, if I am understand the circuit correctly, you may actually damage some video displays by overdriving the input with the setup you have. Be careful." CreationDate="2011-04-20T04:34:45.600" UserId="1374" />
  <row Id="20287" PostId="13229" Text="It would probably also be wise to buffer the video signal locally as well." CreationDate="2011-04-20T04:36:00.293" UserId="1374" />
  <row Id="20289" PostId="13230" Text="@200ok404notfound - Not true. [this datasheet](http://www.vishay.ru/docs/82013/tsop12xx.pdf) for the TSOP1236 says minimum 2.5V. BTW, how do you know about the 276-640 being 2.7V? Did you find a datasheet?" CreationDate="2011-04-20T05:30:20.190" UserId="2064" />
  <row Id="20290" PostId="13230" Text="It says 2.6V on the package." CreationDate="2011-04-20T05:42:21.350" UserId="1657" />
  <row Id="20291" PostId="13266" Text="@AngryEE - if OP doesn't care too much about the stand-off there's dozens of IR-receivers to be found at http://www.vishay.com/ir-receiver-modules/" CreationDate="2011-04-20T06:28:38.243" UserId="2064" />
  <row Id="20292" PostId="13281" Score="1" Text="The standard approach would be to put another microcontroller next to the sensor and make it communicate the data." CreationDate="2011-04-20T06:44:37.640" UserId="339" />
  <row Id="20293" PostId="13276" Score="3" Text="Please show what you have done, and where you get stuck." CreationDate="2011-04-20T06:52:27.630" UserId="2118" />
  <row Id="20294" PostId="13253" Text="A side note, since you need a level shifter for RS232 anyway you could think about uart to usb chip instead (http://www.ftdichip.com/Products/ICs/FT232R.htm) since it is way easier to find a pc with usb..." CreationDate="2011-04-20T07:43:10.033" UserId="689" />
  <row Id="20297" PostId="11765" Text="Then I do not understand the need of conversion you are talking about. Could you provide some examples of what you have in mind?" CreationDate="2011-04-20T08:13:47.123" UserId="659" />
  <row Id="20298" PostId="13256" Text="Ya.. I did not get a clear understanding from the IEEE Tec.Specification. &#xA;I would like to understand the way the Packet are formed in the PHY Layer till it is transmitted and how the reverse process works in the Receiver as well. " CreationDate="2011-04-20T08:45:58.747" UserId="3733" />
  <row Id="20299" PostId="13277" Text="http://electronics.stackexchange.com/questions/1024/good-tools-for-drawing-schematics (Maybe this question should be close for duplication...?)" CreationDate="2011-04-19T23:49:45.703" UserId="3078" />
  <row Id="20300" PostId="13290" Text="I don't see a specific question here. Microchip has many app notes on CAN that would help you learn. Most new designs would use a PIC with built in CAN module such as 18F4585." CreationDate="2011-04-20T09:35:09.843" UserId="2110" />
  <row Id="20301" PostId="13289" Text="+1 Very thorough, good work!" CreationDate="2011-04-20T09:35:34.963" UserId="659" />
  <row Id="20302" PostId="13272" Text="Indeed, that's FX2LP uC. I'm fully aware of the official requirement to use 4-layer board, and if that was a commercial project I'd not even think about 2-layers PCB :)" CreationDate="2011-04-20T09:50:50.667" UserId="3564" />
  <row Id="20303" PostId="13290" Text="@Vicky - Unless you can be more specific I'd vote for closing as &quot;not a real question&quot;" CreationDate="2011-04-20T09:56:59.327" UserId="2064" />
  <row Id="20304" PostId="13272" Text="I should be able to get 90 ohm differential impedance on 2-layers board with wide traces (my estimates show that ~2mm spaced ~3mm on 1mm thick FR4 are OK - unless I made some mistake). Sure, it's far from perfect, and traces of this size will need some stubs at both ends, but still I hope it'd be good enough." CreationDate="2011-04-20T10:01:01.140" UserId="3564" />
  <row Id="20305" PostId="13286" Text="What do you mean by &quot;calipers&quot;? The only calipers I know are http://en.wikipedia.org/wiki/File:Messschieber.jpg" CreationDate="2011-04-20T10:42:51.847" UserId="2064" />
  <row Id="20306" PostId="13275" Text="Is this for bootloader?" CreationDate="2011-04-20T11:00:40.520" UserId="938" />
  <row Id="20307" PostId="13275" Text="No, it's for a network application" CreationDate="2011-04-20T11:04:53.060" UserId="566" />
  <row Id="20308" PostId="13286" Score="1" Text="@stevenvh There are electronic calipers which have a capacitive strip inside and a display. Maybe OP is trying to hack one of those?" CreationDate="2011-04-20T11:20:06.097" UserId="1240" />
  <row Id="20309" PostId="13170" Text="Thanks David, there's some good advice in there.  I'm all too familiar with skunking &amp; just tried to keep the question on-topic for this site." CreationDate="2011-04-20T12:07:03.523" UserId="3898" />
  <row Id="20310" PostId="12457" Text="@Krapht, this is a case of a shopping case that does not fit well on this site." CreationDate="2011-04-20T12:08:56.667" UserId="230" />
  <row Id="20311" PostId="13109" Text="@Swanand if plan your application such that queues are only unidirectional (ie, you never read the same queue in two tasks) and you process the data stored at the pointer immediately then free it you shouldn't have a problem with sharing the data.  There will be increased overhead as you may have to create multiple queues to pass data reliably back and forth but this is the cost of doing business in a multi-tasking environment." CreationDate="2011-04-20T12:56:15.367" UserId="249" />
  <row Id="20312" PostId="13266" Text="@stevenh Yeah, all these options can get confusing.  It's like we need an expert system to find parts on Digikey." CreationDate="2011-04-20T13:00:36.690" UserId="249" />
  <row Id="20313" PostId="13293" Text="ThreadX's a commercial product, I'd expect the vendor's support to be the best place to ask :)&#xA;Why is the tick period important for you? Is it timer resolution you're concerned about, or preemption?" CreationDate="2011-04-20T14:07:32.143" UserId="3564" />
  <row Id="20314" PostId="13297" Text="Most likely getting impedance and length matching perfect on those lines wont make that big of a difference, especially if the lengths aren't too different. I would like to see what a &quot;professional&quot; has to say though." CreationDate="2011-04-20T14:13:29.717" UserId="319" />
  <row Id="20315" PostId="13297" Text="Which encapsulation (package) are you using?" CreationDate="2011-04-20T14:24:51.620" UserId="938" />
  <row Id="20317" PostId="13297" Text="For the connector? It's something like this: &#xA;http://www.farnell.com/cad/452550.pdf&#xA;&#xA;The chip itself is TQFP-100 version." CreationDate="2011-04-20T14:33:39.130" UserId="3564" />
  <row Id="20318" PostId="13300" Text="Pins appear swapped at the PCB level, not at the plug level, due to different receptacle geometry - unless I've messed it up :) " CreationDate="2011-04-20T14:58:16.387" UserId="3564" />
  <row Id="20319" PostId="13297" Text="Be careful when you're laying out this part.  Do not run traces underneath, between the mounting lugs, because the metal is sharp and can scratch through the solder mask." CreationDate="2011-04-20T15:23:53.657" UserId="411" />
  <row Id="20320" PostId="13300" Text="@Czajnik, could it be that it's intended to be mounted on the bottom of the board and someone is just tricking it?" CreationDate="2011-04-20T15:45:23.963" UserId="2157" />
  <row Id="20321" PostId="13290" Text="They also have a lot of code that probably already does what you need as a base API." CreationDate="2011-04-20T15:46:41.653" UserId="2157" />
  <row Id="20322" PostId="13286" Text="@stevenvh: Sorry, I meant digital calipers, specifically the cheap Chinese ones. http://www.shumatech.com/support/chinese_scales.htm. With these interfaced I can make my own DRO's or in the future implement full linear feedback servo motors." CreationDate="2011-04-20T16:05:40.443" UserId="1319" />
  <row Id="20323" PostId="13292" Text="The large-ish capacitance of a Zener is one of the reasons they need alternative architectures for ESD protection on very high-speed data lines." CreationDate="2011-04-20T16:48:15.307" UserId="1278" />
  <row Id="20326" PostId="13096" Text="Interesting - I had no idea that such a common IC could be so difficult to procure! Thank you for your feedback!" CreationDate="2011-04-20T18:32:25.427" UserId="1021" />
  <row Id="20329" PostId="13300" Text="I guess not, as PCBs with components on one side are obviously cheaper to manufacture. The receptacle I want to use is a standard, commonly used component. Perhaps the perfect impedance and length match is not as critical as I think?" CreationDate="2011-04-20T19:15:38.143" UserId="3564" />
  <row Id="20330" PostId="13256" Text="I think your question is still way to broad. A,b,g, and n all have different methods of doing things and some change based off of speeds that you are running at as well as encryption methods. Not to mention once get to go 'n' your block diagram will change depending on if you are using MIMO or not." CreationDate="2011-04-20T19:48:17.227" UserId="319" />
  <row Id="20331" PostId="13308" Text="Why do I have to be careful in this instance? I'm not quite understanding. I'm very new to electronics. Been forced into doing this. Are u saying I need some sort of protection diode? but I thought that was for induductive loads? Its leds am switching" CreationDate="2011-04-20T20:07:40.697" UserId="2824" />
  <row Id="20332" PostId="13261" Text="When trying to connect the pads with wires in the package editor, I rack up tons of &quot;Overlap&quot; DRC errors. I read in the Eagle forums that it's a known problem: can't change the name of wires in teh package editor, so Eagle does not know they are supposed to be the same connection. Oh joy." CreationDate="2011-04-20T20:18:31.947" UserId="1802" />
  <row Id="20333" PostId="13308" Text="No just when handling them such as placing in breadboards and things. " CreationDate="2011-04-20T20:20:39.997" UserId="1623" />
  <row Id="20334" PostId="13261" Text="What I'm suggesting (and I haven't used Eagle in like a decade so I'm only talking about general principals here) is to leave  the pad area component unwired.  Instead, make the bare component with only the pins/pads, and then wire them as appropriate in the schematic and pcb editors." CreationDate="2011-04-20T20:31:24.730" UserId="3308" />
  <row Id="20335" PostId="13308" Text="ah thanks. I assumed it was something more complictaed lol" CreationDate="2011-04-20T20:44:05.240" UserId="2824" />
  <row Id="20336" PostId="13229" Text="@Fake Name, thanks for the advise. I have found that most video cards use two series diodes to limit the signal to 1.4V maximum. And the 75 ohm termination basically means the PIC's output drops anyway. I found that resistors made the OSD far dimmer than I could cope with." CreationDate="2011-04-20T20:46:18.633" UserId="1225" />
  <row Id="20337" PostId="13281" Text="@starblue: you mean a buffer amplifier?" CreationDate="2011-04-20T20:48:16.607" UserId="142" />
  <row Id="20338" PostId="13175" Score="1" Text="Btw I emailed Travis of GoodFET fame. He said that the GF31 is produced on a board with a thickness of 0.078&quot;. He also suggested to round up when performing metric conversion to 2mm." CreationDate="2011-04-20T20:56:40.633" UserId="1802" />
  <row Id="20339" PostId="13302" Score="1" Text="Can you tell us a bit more about your setup?  Processor board, number of boardss, anything?" CreationDate="2011-04-20T21:21:54.787" UserId="249" />
  <row Id="20340" PostId="13229" Text="The trick isn't to use resistor dividers, it's to use a **buffered** resistor divider. you need a source with a low impedance, which the PIC obviously isn't. Take a nice, fast op-amp (Like http://www.national.com/profile/snip.cgi/openDS=LMH6658? ), and use it in unity gain to buffer the 1V signal." CreationDate="2011-04-20T22:12:29.793" UserId="1374" />
  <row Id="20341" PostId="13307" Text="Yeah, I definitely have the backlight working!  It's bright.  The one thing that concerns me is that when I twist the contrast knob, I don't see any visual indication that it's working, and tech support has told me that I should see blocks appear on the first line." CreationDate="2011-04-21T00:05:41.400" UserId="2288" />
  <row Id="20342" PostId="13307" Text="And it looks like you've tested that your contrast pot not broken...weird." CreationDate="2011-04-21T00:14:58.173" UserId="2157" />
  <row Id="20343" PostId="13199" Text="OT, but I just wanted to mention that discharging lead-acid batteries with a short circuit is even worse...  Don't test car batteries with a crow bar!" CreationDate="2011-04-21T00:18:07.690" UserId="3308" />
  <row Id="20344" PostId="13203" Score="1" Text="Forest Mims used colored LED's specifically to get wavelength-matched photodetection of the sun. http://www.opticsinfobase.org/abstract.cfm?URI=ao-31-33-6965" CreationDate="2011-04-21T00:24:00.727" UserId="3308" />
  <row Id="20345" PostId="13305" Score="1" Text="This question is more appropriate for a physics forum than it is for here. Although it's still a fun problem." CreationDate="2011-04-21T00:32:55.830" UserId="3635" />
  <row Id="20346" PostId="13281" Score="1" Text="@endolith - i think starblue means, do the ADC conversion on-site and link digital data back over the 100m of wire." CreationDate="2011-04-21T01:48:08.953" UserId="740" />
  <row Id="20347" PostId="13307" Text="Yes, I've watched the voltage swing when I turn it." CreationDate="2011-04-21T02:04:56.853" UserId="2288" />
  <row Id="20348" PostId="13275" Text="Microchip has an implementation for dsPIC and PIC 24 that has a code size of 3,018 bytes, but it only had encryption, no decryption. Guessing this doesn't cut it for you though." CreationDate="2011-04-21T02:28:42.353" UserId="319" />
  <row Id="20349" PostId="13293" Text="@Czajnik I want to change it because Thread_Sleep(1) will yeild sleep of 10ms.... I want a thread_sleep of 1ms to speed up the process." CreationDate="2011-04-21T04:34:59.717" UserId="2574" />
  <row Id="20351" PostId="13305" Text="My guess is that it would be more something like `k * cos(a-b) * D^-2`" CreationDate="2011-04-21T07:46:16.633" UserId="2064" />
  <row Id="20353" PostId="13320" Score="1" Text="+1 on measurement with the hands off" CreationDate="2011-04-21T08:44:32.623" UserId="3308" />
  <row Id="20354" PostId="13323" Text="He's pushing about 100 mA from two AA batteries... Which works out to about 30 ohms.  A 2.5 ohm shunt would contribute close to a 10% error right there!" CreationDate="2011-04-21T08:48:41.903" UserId="3308" />
  <row Id="20355" PostId="3843" Text="Try helping a bunch of fashion students with an electronics project some day. Then you'll see." CreationDate="2011-04-21T08:56:23.703" UserId="1024" />
  <row Id="20356" PostId="13275" Text="@Kellenjb Interesting, but I'm looking for something small for 8 bit micros" CreationDate="2011-04-21T09:31:04.807" UserId="566" />
  <row Id="20357" PostId="13321" Score="2" Text="I plan to integrate the charging pad into the glove box or on central console,  I did not decided yet.But the most important case for me is the efficiency &amp; quality of the components, because there are lots of regulations on automotive industry.There should not be any interferences by other signals (key system,radio system etc...)" CreationDate="2011-04-21T09:33:19.427" UserId="3935" />
  <row Id="20358" PostId="13326" Text="Silver surprises me. We once had a batch of boards which were accidentally *completely* gold finished, and I found them impossible to solder, at least by hand, but I think reflow wouldn't have worked either. Gold has a melting temperature over 1000°C (silver is not much less), and soldering occurs at temperatures around 300°C." CreationDate="2011-04-21T09:54:07.627" UserId="2064" />
  <row Id="20359" PostId="13326" Text="@myself :-) - Apparently there's a binary eutectic Ag alloy with a low melting point, but it's Ag-Pb, so wouldn't be RoHS compliant." CreationDate="2011-04-21T10:21:53.030" UserId="2064" />
  <row Id="20361" PostId="13326" Text="I've tried to solder (lead-tin) on a gold plated connector, but the solder refused to flow over the gold. Maybe because gold on a connector is thicker than the immersion gold." CreationDate="2011-04-21T11:11:08.933" UserId="3920" />
  <row Id="20362" PostId="13326" Text="@federico - thickness has nothing to do with it. Below the melting point the material is not permeable for the solder, even when only a few tens of atoms thick. Soldering is a metallurgical process. I don't understand how it can work for Leon." CreationDate="2011-04-21T11:39:54.900" UserId="2064" />
  <row Id="20363" PostId="13328" Text="@Steve Thanks, would you mind telling what type of diode should I use in this case?" CreationDate="2011-04-21T12:00:10.403" UserId="3757" />
  <row Id="20364" PostId="13327" Text="I asked a similar [question](http://electronics.stackexchange.com/questions/7620/when-driving-stepper-motors-do-i-need-to-worry-about-back-emf). " CreationDate="2011-04-21T12:16:47.443" UserId="1623" />
  <row Id="20365" PostId="13328" Text="@Sean87 - You don't need a diode, they're integrated in the IC." CreationDate="2011-04-21T12:51:53.743" UserId="2064" />
  <row Id="20366" PostId="13326" Text="@stevenvh - You can solder to copper - which melts at 1085°C" CreationDate="2011-04-21T12:55:04.380" UserId="2234" />
  <row Id="20367" PostId="13333" Text="What could be a problem with antenna? Shavers have a very narrow base - much smaller than the back of a phone. In fact whole back of the phone can be covered with wires on the inside and be used as an antenna." CreationDate="2011-04-21T13:07:38.880" UserId="3552" />
  <row Id="20368" PostId="13326" Text="@MikeJ-UK - Yeah, that crossed my mind just now too. I don't know why there's this difference between gold and copper. They have almost the same melting point, and also their crystal structure is the same (cubic close-packed)." CreationDate="2011-04-21T13:09:26.570" UserId="2064" />
  <row Id="20369" PostId="13323" Text="Are you sure it is 0.1 ohms? It is usually 0.01 ohms in almost every cheap meter I've ever seen." CreationDate="2011-04-21T13:20:42.940" UserId="1225" />
  <row Id="20370" PostId="13326" Text="As I said, I've had absolutely no problems with silver or gold coatings. I use Metcal equipment, perhaps that helps. :)" CreationDate="2011-04-21T13:28:17.417" UserId="305" />
  <row Id="20372" PostId="13256" Text="Actually, I would need the order in which the following things happen at the transmitter for 802.11b&#xA;Scrambling&#xA;Spreading&#xA;Modulation&#xA;I know the modulation techniques, just the Transmit procedure and the Receive Procedure&#xA;" CreationDate="2011-04-21T13:46:51.933" UserId="3733" />
  <row Id="20373" PostId="13330" Score="1" Text="The pin numbers in the schematic don't agree with the schematic pinout at the bottom of your post." CreationDate="2011-04-21T13:59:00.677" UserId="3920" />
  <row Id="20374" PostId="13334" Text="Some inductive chargers, especially in electric toothbrushes, have a ferrite core as part of the charger. " CreationDate="2011-04-21T14:12:05.397" UserId="1802" />
  <row Id="20375" PostId="13334" Text="@Ranieri: Okay, but th core won't pass through the other coil located in the brush will it?" CreationDate="2011-04-21T14:15:24.093" UserId="3552" />
  <row Id="20376" PostId="13334" Text="Yes, actually it does. Let me see if i can dig up a picture: http://braunelectrictoothbrush.org/images/page3/4.jpg That little plastic nub houses the ferrite core. It sticks into the toothbrush acting both as a transformer core and as an anchor." CreationDate="2011-04-21T14:17:37.353" UserId="1802" />
  <row Id="20377" PostId="13323" Text="I think this is indeed what's happening in my case! Thank you for the answer! I have never measured this multimeter, because I have never thougth that is has so much resistance in the 200 mA range. I have updated my question with findings." CreationDate="2011-04-21T14:31:30.880" UserId="3049" />
  <row Id="20378" PostId="13332" Score="1" Text="Because people are willing to buy things without it.  :)" CreationDate="2011-04-21T14:51:42.987" UserId="142" />
  <row Id="20379" PostId="13340" Score="1" Text="I was going to go edit your code block to make it easier to read, but boy is it messed up. Might be easier for you to just do it yourself. Edit your question, copy your code in fresh, and then highlight it, and select the code button." CreationDate="2011-04-21T15:03:07.983" UserId="319" />
  <row Id="20380" PostId="13332" Score="1" Text="The argument of &quot;It's year wxyz and we have microchips with millions of transistors on them - why don't we have abcd&quot;, doesn't usually ever work well. I could use the same argument for so much. Example, with obesity being such a large issue, why not have a sensor built into your phone that tells you your BMI by just holding on to two contacts, one for each hand. It's so simple that even many cheap scales have that technology. Might be simple, and a good idea, but phone companies really don't get much benefit from adding something like this." CreationDate="2011-04-21T15:51:03.447" UserId="319" />
  <row Id="20381" PostId="13332" Score="1" Text="Or, it is the year 2011 and we have all of this great technology, why don't all of our cars have the technology to drive themselves? The technology exists to do this now, but you just need to give it time for cultural and business aspects to change." CreationDate="2011-04-21T15:53:32.227" UserId="319" />
  <row Id="20382" PostId="13333" Score="2" Text="So I assume you design cell phones or have extensive experience taking them apart and analyzing the mechanical packaging?  So you'd be qualified to say there's plenty of room in there and none of the materials will block the RF energy to the antenna, and there's room for sufficient shielding of sensitive components from charger EMI and that the charger won't interfere with cellular communication?  That the antenna won't heat up and damage any components? You know all that for a fact?  " CreationDate="2011-04-21T16:09:53.030" UserId="249" />
  <row Id="20383" PostId="13323" Text="@Thomas, depends on the cheapness of the meter I suppose." CreationDate="2011-04-21T16:23:53.827" UserId="411" />
  <row Id="20384" PostId="13323" Score="1" Text="@zsero You can eliminate this kind of surprise by using your own shunt resistor as part of the circuit, then measure it's voltage and use Ohm's law to get current." CreationDate="2011-04-21T16:24:38.507" UserId="411" />
  <row Id="20385" PostId="13331" Text="I got it from a local electronics store called „Kelco”. They actually make the kits, so I'll contact them about the problem. I wanted a second opinion because they've been making various kits for some 20-30 years and I didn't expect such a basic error from them." CreationDate="2011-04-21T16:36:23.767" UserId="1240" />
  <row Id="20386" PostId="13336" Text="I'm aware of that, but when I connect a capacitor, I get horrible distortions on the output." CreationDate="2011-04-21T16:38:03.937" UserId="1240" />
  <row Id="20387" PostId="13330" Text="@Frederico I'm aware of that." CreationDate="2011-04-21T16:38:51.753" UserId="1240" />
  <row Id="20388" PostId="13313" Text="You are probably seeing effects of the AA cell's internal resistance.  Compare open-circuit voltage with loaded voltage.  The one-ohm resistor is not a great circuit as it will be very sensitive to battery aging." CreationDate="2011-04-21T16:48:29.820" UserId="411" />
  <row Id="20389" PostId="13336" Score="1" Text="Probably caused by all the other problems with the circuit." CreationDate="2011-04-21T17:13:12.627" UserId="305" />
  <row Id="20392" PostId="13326" Text="@Leon - yes, that's what you told me. For me it doesn't work: the solder forms a drop which seems to be repelled by the gold; it never starts flowing. The only explanation I can think of is that the immersion gold is actually an alloy. I don't think the equipment is relevant. " CreationDate="2011-04-21T18:00:47.473" UserId="2064" />
  <row Id="20393" PostId="13275" Text="Might try asking this on StackOverflow.com with the &quot;embedded&quot; tag on the quesiton" CreationDate="2011-04-21T18:02:58.407" UserId="3803" />
  <row Id="20394" PostId="13347" Text="This looks great, I'm running off a single Double A battery and a very small motor, so the amperage is quite low." CreationDate="2011-04-21T18:03:42.850" UserId="3942" />
  <row Id="20395" PostId="13340" Score="2" Text="Generally, an interrupt should be handled 'as quickly as possible'. Doing things like an A to D conversion in an interrupt is not considered good design. Have your interrupt change a state variable so that your processing can be done in your main loop." CreationDate="2011-04-21T20:29:37.377" UserId="2150" />
  <row Id="20396" PostId="13352" Score="2" Text="Could you please post a schematic of what you currently have? It would help us a lot." CreationDate="2011-04-21T20:32:59.110" UserId="1240" />
  <row Id="20397" PostId="13291" Text="Any Suggestions?" CreationDate="2011-04-21T20:52:29.793" UserId="3916" />
  <row Id="20398" PostId="13292" Text="@Martin- Is there a relationship mobility of holes in PN junction?" CreationDate="2011-04-21T20:55:17.137" UserId="3916" />
  <row Id="20399" PostId="13349" Text="Wow, that DYI boost converter is pretty cool. " CreationDate="2011-04-21T21:03:44.553" UserId="1802" />
  <row Id="20400" PostId="12235" Text="Why are the sensor suppliers backed up, and how do you know this?" CreationDate="2011-04-21T21:22:31.423" UserId="1227" />
  <row Id="20401" PostId="13350" Text="This is close to off topic, but the general question of how long a USB cable can be is very useful for any EE that is running into issues. I am not closing this as a very good question for USB. I would like the answer accepted to have references." CreationDate="2011-04-21T21:29:03.277" UserId="230" />
  <row Id="20402" PostId="13359" Text="F-F, M-F, and M-M jumpers do exist: http://www.pololu.com/catalog/category/65" CreationDate="2011-04-21T22:48:20.353" UserId="2654" />
  <row Id="20403" PostId="13229" Text="Everyone! I fixed it! The solution was not a buffer. It was to insert a series 75 ohm resistor with my video signal. I used 68 ohm as it was the closest I had on hand but it does still work. It has also greatly improved video contrast. I have to thank a friend of mine for suggesting this. Transmission line theory to the rescue again!" CreationDate="2011-04-21T22:57:16.113" UserId="1225" />
  <row Id="20404" PostId="13358" Text="Is there the same amount of weight on each wheel, ie the batteries are on the left circuit on the right so it is off balance?" CreationDate="2011-04-21T22:59:45.793" UserId="1623" />
  <row Id="20405" PostId="13355" Text="So once I hit 5m, I can use a powered hub and get another 5m (per output on the hub) up to 30m (per chain) with identical performance to a single 5m cable?" CreationDate="2011-04-22T00:04:56.757" UserId="2090" />
  <row Id="20406" PostId="13364" Text="Wow I really thought it was going to be much more complicated than that. This might be why I found it difficult to get a direct definition for electronics." CreationDate="2011-04-22T00:14:39.787" UserId="1623" />
  <row Id="20407" PostId="13358" Text="I made sure it was as balanced as possible, but I thought with the use of encoders I could avoid any distortion caused by external factors... Maybe it was not the way to go." CreationDate="2011-04-22T00:18:42.970" UserId="3949" />
  <row Id="20408" PostId="13358" Score="2" Text="A friend with robotics experience once told me that just because your wheel &quot;turned&quot; the same distance, does not mean that the wheels moved the same distance - especially when you're dealing with potentially uneven, slippery, or resistant surfaces.&#xA;" CreationDate="2011-04-22T00:47:11.023" UserId="3308" />
  <row Id="20409" PostId="13229" Text="Great, but I also suggested this in my answer - `Another thing you could try is putting a 75 ohm resistor as close to the output pin as possible on the OSD pcb.`" CreationDate="2011-04-22T01:11:17.377" UserId="1374" />
  <row Id="20410" PostId="13163" Text="Yes, as I mentioned, some people claim that certain loads &quot;may&quot; not work as well. Can you give *any* particular examples, as I did, or are you merely repeating an urban legend?" CreationDate="2011-04-22T01:52:56.980" UserId="813" />
  <row Id="20411" PostId="13364" Text="@Dean - Almost any waveform can be generated by summing sines and cosines at various frequencies and amplitudes. The bandwidth is the highest frequency in the signal minus the lowest frequency (e.g. f1 = 10 Hz, f2 = 100 Hz, B = f2 - f1 = 90 Hz). The bandwidth of an amplifier or filter is typically defined by the [3-dB frequency (half-power point)](http://en.wikipedia.org/wiki/Half_power_point)." CreationDate="2011-04-22T01:58:06.880" UserId="721" />
  <row Id="20412" PostId="13358" Score="1" Text="To illustrate @Toybuilder's point, imagine a robot on a frictionless plane. The wheel encoders keep ticking over, but robot goes no where. Encoders can't help with slipping or different wheel radius, etc." CreationDate="2011-04-22T04:34:58.843" UserId="2340" />
  <row Id="20414" PostId="13372" Score="3" Text="I'm a mechanical engineer specializing in manufacturing. I can tell you right off the bat, unless you have an entire company backing you, this will be pretty much impossible. From a manufacturing standpoint, a single plastic injection mold for a single component can cost up to $40,000. If you don't intend to produce this product en mass (10,000+ units) you can forget about the profit part. However, if you do have a company backing you, China is always happy to build your designs, if you have money for them." CreationDate="2011-04-22T05:46:49.377" UserId="1319" />
  <row Id="20415" PostId="13374" Score="1" Text="For mechanical design, I suggest SolidWorks or Inventor. Fairly quick learning curves and very powerful. Rapid prototyping is definably a possibility for prototyping. For an entire laptop's mechanical components, do expect to spend around 1k - 5k depending on the process you chose." CreationDate="2011-04-22T06:40:50.223" UserId="1319" />
  <row Id="20416" PostId="13355" Text="Only every other hub needs to be powered. There are even 10m cables with a hub in the middle. The performance shouldn't depend on cable length." CreationDate="2011-04-22T06:41:26.377" UserId="339" />
  <row Id="20417" PostId="13374" Score="1" Text="@Faken - don't forget the &quot;unusually shaped&quot; keyboard. If every key has its own shape this already adds a few kilodollar." CreationDate="2011-04-22T06:57:40.220" UserId="2064" />
  <row Id="20418" PostId="13374" Score="1" Text="Well, for rapid prototyping, the cost associated with complexity can be completely ignored as they generally charge on a per weight basis, a beautiful property of rapid prototyping. Using cheap material (nylon) with low quality processes (fused material deposition) you can do the entire laptop for around 1k. Using expensive materials (steel/titanium!) in high quality processes (selective laser sintering) you'll run into the 10's of k." CreationDate="2011-04-22T07:02:38.560" UserId="1319" />
  <row Id="20419" PostId="13343" Text="OK. I will try it. Thanks for your reply!" CreationDate="2011-04-22T07:26:06.223" UserId="3940" />
  <row Id="20420" PostId="13275" Text="A major question is does it need to be AES? There are other crypto schemes more optimised to low-end micros. Similarly does it have to be PIC18? There may be more suitable targets. Which compiler are you using? The paid-for versions of hitech C have significantly better code efficiency than the free ones.  " CreationDate="2011-04-22T08:38:06.310" UserId="1681" />
  <row Id="20421" PostId="13353" Score="1" Text="You can probably get that from one op-amp. They make *really* fast op-amps (In the GHz!). If you are going to use discretes, just use only discretes. Mixing them isn't worth the effort." CreationDate="2011-04-22T09:47:15.757" UserId="1374" />
  <row Id="20422" PostId="13377" Text="That's ingenious. " CreationDate="2011-04-22T10:35:04.603" UserId="1802" />
  <row Id="20423" PostId="13377" Score="1" Text="OP wants a 5 GHz GBW product (50 * 100 MHz), which is way to much for most opamps." CreationDate="2011-04-22T11:41:43.563" UserId="2064" />
  <row Id="20424" PostId="13381" Text="So far I've found that NXP is the best by far, or at theirs doesn't look like it was scanned and PDFed like TI's" CreationDate="2011-04-22T12:24:00.997" UserId="1319" />
  <row Id="20425" PostId="13381" Text="@Faken - I don't see anything wrong with TI's documents, in fact I still own a 1980 copy of &quot;The TTL Data Book for Design Engineers&quot;, which at the time was a standard." CreationDate="2011-04-22T12:53:55.490" UserId="2064" />
  <row Id="20426" PostId="13382" Text="You don't explain what frequency actually is!" CreationDate="2011-04-22T13:31:00.967" UserId="3920" />
  <row Id="20427" PostId="13379" Score="1" Text="Are you sure the datasheet doesn't explain what &quot;OE&quot; means?  There's almost always a list of the pins and their functions." CreationDate="2011-04-22T13:36:16.997" UserId="142" />
  <row Id="20428" PostId="13364" Text="@eryksun - I'd say &quot;Any repeating waveform&quot; instead of &quot;Almost any waveform&quot;." CreationDate="2011-04-22T13:38:00.710" UserId="2064" />
  <row Id="20429" PostId="13317" Text="Duplicate? http://electronics.stackexchange.com/questions/2178/inductive-charging" CreationDate="2011-04-22T13:49:50.340" UserId="142" />
  <row Id="20430" PostId="13257" Text="@mazurnification - technically you should not leave the inputs floating.  The PC will have pull-ups/pull-downs to protect itself.  If your board has the extra signals on the connector not connected, then you don't need to do anything.  Make sure your RS232 driver chip has all the inputs set to a level." CreationDate="2011-04-22T13:51:06.047" UserId="204" />
  <row Id="20431" PostId="13247" Text="This is just wrong, the hole drilled is independent of any hole in the copper layer. Though maybe your software doesn't make this clear to you." CreationDate="2011-04-22T14:03:50.710" UserId="339" />
  <row Id="20432" PostId="13366" Text="nice answer, thanks." CreationDate="2011-04-22T14:09:37.863" UserId="1227" />
  <row Id="20433" PostId="13319" Text="What page number?" CreationDate="2011-04-22T14:34:55.730" UserId="3635" />
  <row Id="20434" PostId="13364" Text="@stevenvh and @eryksun:  This is a little beyond the scope of this question, but Google &quot;additive synthesis&quot;.  It's a method for creating arbitrary waveforms by adding a bunch of sine waves together.  This link is good: http://www.soundonsound.com/sos/jun00/articles/synthsec.htm  Make sure to read the &quot;Now Let's Get Noisy&quot; section at the end of that page." CreationDate="2011-04-22T14:49:24.143" UserId="3624" />
  <row Id="20435" PostId="13260" Text="I don't think the LCDs are damaged.  Tech support corrected themselves and let me know that the blocks will not appear when the contrast pot is adjusted w/o initializing first.  Still working on this!" CreationDate="2011-04-22T14:56:41.733" UserId="2288" />
  <row Id="20436" PostId="13292" Text="@Cell-o, you'll have to look that up. As a practising engineer, I haven't had the need to use zeners with anything approaching RF so the theoretical reason for the capacitance isn't something that springs to mind." CreationDate="2011-04-22T15:08:01.020" UserId="2110" />
  <row Id="20437" PostId="13275" Text="@mikeselectricstuff Yes, it needs to be AES. I am trying to interoperate with an existing system using AES-128. I'm interested in any small AES implementation, but I am currently targetting PIC18. I'm using the HiTech Pro picc18 compiler." CreationDate="2011-04-22T15:10:03.467" UserId="566" />
  <row Id="20438" PostId="13378" Text="I misread by a factor of 10 on the axTLS version. You're right. But, I'm still interested in more efficient versions of AES..." CreationDate="2011-04-22T15:10:43.433" UserId="566" />
  <row Id="20441" PostId="13317" Text="nope, I opened it after getting down votes refer to my question there...!" CreationDate="2011-04-22T16:18:01.260" UserId="3935" />
  <row Id="20447" PostId="13292" Text="ok.martin thanks again." CreationDate="2011-04-22T19:31:59.563" UserId="3916" />
  <row Id="20452" PostId="13395" Score="2" Text="Can you add a circuit diagram please" CreationDate="2011-04-22T21:22:48.290" UserId="1623" />
  <row Id="20456" PostId="13396" Text="I can't. I wanted to try that too. The problem is that the walltransformer I am using is a 2 prong and I can't find one I need with 3. The wall transformer selection these days seems to have gotten pretty thin. Digikey nor mouser have one. It's just a 12V 1A supply so it's nothing fancy. And dean I can't upload a schematic, sorry. I know it would help but I can't upload from my phone, I don't have the file on here. Everything seems to work just fine other than the noise in the ground that's causing me problems. Would a solid ground be better or isolated ground planes with a star ground? " CreationDate="2011-04-22T21:51:38.363" UserId="3960" />
  <row Id="20457" PostId="13377" Text="Furthermore, the crossover distortion from that crude push-pull gets worse at higher frequencies.  It's bad enough at audio frequencies..." CreationDate="2011-04-22T21:52:23.233" UserId="411" />
  <row Id="20458" PostId="13396" Text="I hope I understood you correctly when you said line cord ground. I'm by no means an electronics expert just a tinkerer! It gets me into messes like this more often than not. It wouldn't be any fun though if I didn't have to beat my head against the bench at least twice a day though :)" CreationDate="2011-04-22T22:17:48.227" UserId="3960" />
  <row Id="20459" PostId="13397" Text="So what is the advantage of using this part compared to driving the triac directly - is it the reduced current because the main triac trigger current is only consumed when this optocoupler detects zero crossing?" CreationDate="2011-04-22T22:21:48.327" UserId="1951" />
  <row Id="20460" PostId="13397" Text="If it switched at a point other than zero crossing, the initial current surge often creates spiking that leads to RFI." CreationDate="2011-04-22T22:32:27.300" UserId="3453" />
  <row Id="20461" PostId="13398" Text="That all depends on how the FIFO was coded." CreationDate="2011-04-22T22:36:11.040" UserId="1438" />
  <row Id="20462" PostId="13396" Text="Yes, I meant house service ground. Can you replace the motor supply with perhaps a &quot;brick&quot; type supply that has a three prong plug?" CreationDate="2011-04-22T22:43:16.600" UserId="3453" />
  <row Id="20463" PostId="13399" Text="All the active converters I've seen go the other way:  Plug a PS/2 keyboard into a USB port." CreationDate="2011-04-22T23:04:59.710" UserId="411" />
  <row Id="20464" PostId="13401" Text="right on. there's no way a PS2 mouse or keyboard port is going to operate a USB device. the ones of these that i've seen came with M$ mice, that could tell which kind of port they were connected to." CreationDate="2011-04-23T00:05:55.537" UserId="740" />
  <row Id="20465" PostId="13400" Text="hi David ... thnx for your response ...." CreationDate="2011-04-23T00:06:12.783" UserId="3957" />
  <row Id="20467" PostId="13400" Text="@David actually i was confused a bit and started thinking FIFO as a linked list rather than a queue(a simple FIFO..first in first out).Such a FIFO would take an element as an input then search for it in the queue and then delete accordingly..also the data stored in the FIFO buffer could be sorted .. i started to think in those terms .but right now i am implementing a very simple FIFO which is very much similar to a queue storing data and performing two very simple functions i.e.insert and delete.after doing these two things i would be adding a few additional features which i had been thinking." CreationDate="2011-04-23T00:10:49.843" UserId="3957" />
  <row Id="20468" PostId="13319" Text="@Adam: it is 28 in my book, but i'm using the english edition published in China, so it maybe a little difference there." CreationDate="2011-04-23T00:38:46.567" UserId="493" />
  <row Id="20469" PostId="13396" Text="Yea I just found one today and ordered it. We will see how that goes. Hopefully it works out. I will let you know!" CreationDate="2011-04-23T01:03:57.413" UserId="3960" />
  <row Id="20470" PostId="13402" Text="The pcb I have right now has 3 separate grounds. One for the microcontroller, one for the a/d and another for the stepper motor driver. The stepper ground has a trace that runs back and is grounded beside the ground from the power supply. The a/d and microcontroller grounds are connected with a zero ohm resistor. I did this to try and keep everything isolated. What your saying is I need to get rid of the resistor and run a trace from a/d ground and tie it into the same point at the stepper ground. I hope I understood you correctly. " CreationDate="2011-04-23T01:13:37.813" UserId="3960" />
  <row Id="20471" PostId="13402" Text="@Noremac - not sure i'm picturing what you have correctly, but it doesn't sound as though you're passing the motor return currents through the same path as the a/d and logic returns - in which case what i said doesn't help much. sounds like what you have may be more of an emi situation in the ground loop your a/d and logic form through the 0-ohm." CreationDate="2011-04-23T01:39:58.237" UserId="740" />
  <row Id="20472" PostId="13404" Text="It seems like you're missing a word somewhere in there..." CreationDate="2011-04-23T01:51:33.037" UserId="638" />
  <row Id="20473" PostId="13402" Text="No they aren't being passed through the same return. The only two that are connected are microcontroller and a/d grounds and that's done with the zero ohm res. How could I test to see if it was emi?  I really think it's coming from the motor driver because there is a slight pattern to it. If I could just isolate it from the a/d it would be fine. The rest of the circuit is fine, it's around 20mV of noise that is shoing up so it really messes with my a/d values. That's a lot of noise so the only thing I can think is it's coming from the driver. It's an allegro a3977" CreationDate="2011-04-23T02:55:36.207" UserId="3960" />
  <row Id="20474" PostId="13372" Text="Would a 3d Printer work? (You know the plastic kind?), that would reduce the cost considerably from $40,000 to probably the cost of a 3d printer, and some plastic (maybe $500 max?)" CreationDate="2011-04-23T03:47:26.330" UserId="982" />
  <row Id="20475" PostId="13372" Text="3D printers do work, but the cost for your case would still be in the low thousands, and there are caveats to the output of the 3D printers - surface finish and strength varies, and is never as good as an injection molded part, also if I was bothering to custom make a laptop, I would want to do it out of metal anyways, so CNC machining is a more likely venue." CreationDate="2011-04-23T05:36:55.210" UserId="1374" />
  <row Id="20476" PostId="13374" Text="I want to point out that, by **far**, the most complex part here is the custom motherboard. If you do want to go with a custom mobo, the design time involved will **massively** outweigh the mechanical design time. Also, you will **have** to get a partnership of some sort with Intel/AMD, since their chipsets do not have full design documents available." CreationDate="2011-04-23T05:39:21.430" UserId="1374" />
  <row Id="20477" PostId="13353" Text="That doesn't sound like a good idea to me. Why don't you just cascade two op-amps?" CreationDate="2011-04-22T05:56:01.160" UserId="3953" />
  <row Id="20478" PostId="13353" Score="1" Text="Actually, it is very common (and good) idea to place transistors on the output of operation amplifiers, still enclosed in the feedback path for the reason that the non-linearity of transistors can be (in part) compensated by the feedback, given that there is enough open-loop gain in the op amp." CreationDate="2011-04-22T16:49:18.443" UserId="2656" />
  <row Id="20479" PostId="13377" Text="Well, it just illustrates the basic idea. Please feel free to add base biasing or a cascode confuguration as desired. My scopes have a push-pull stage for the vertical amp, and they work beyond 100 MHz, too. I was just trying to give a starting point for further searches... If a transistor/opamp combination makes sense, it's likely something like this." CreationDate="2011-04-23T06:39:55.017" UserId="930" />
  <row Id="20482" PostId="13409" Text="&quot;not a real question&quot;?" CreationDate="2011-04-23T07:57:23.607" UserId="2064" />
  <row Id="20483" PostId="13409" Text="what do you mean?" CreationDate="2011-04-23T08:22:27.807" UserId="3963" />
  <row Id="20484" PostId="13397" Text="@Steve R - you can't proportionally control with this opto-coupler." CreationDate="2011-04-23T08:55:51.733" UserId="2064" />
  <row Id="20485" PostId="13409" Text="Posts here can be closed if they're considered not a real question. The idea of this forum is that you ask a question and users answer it, where it's a plus if this brings useful information for the community. It's not clear what you're asking here." CreationDate="2011-04-23T09:03:32.443" UserId="2064" />
  <row Id="20486" PostId="13409" Text="I am asking how to check that system is working.So its pretty real I think" CreationDate="2011-04-23T09:06:13.793" UserId="3963" />
  <row Id="20487" PostId="13409" Score="1" Text="it's a *good* question, but it's a mathy, computer-sciency kind of question, which is likely to get it migrated .." CreationDate="2011-04-23T10:41:52.717" UserId="740" />
  <row Id="20489" PostId="13409" Text="i have asked it on stackoverflow and didn't received answer there.Does anyone know some other forum?" CreationDate="2011-04-23T11:14:23.247" UserId="3963" />
  <row Id="20491" PostId="13413" Text="I was afraid of that. Kewlio." CreationDate="2011-04-23T12:23:32.160" UserId="3045" />
  <row Id="20492" PostId="13364" Text="@stevenh - True, my use of the term 'generated' implies a countably finite number of sinusoids with non-infinitesimal magnitudes. In contrast, an aperiodic waveform has a continuous spectrum. I was actually hedging against the possibility of a pathological function that lacks a Fourier transform, not that I can think of an example or even how to go about constructing one." CreationDate="2011-04-23T13:44:35.103" UserId="721" />
  <row Id="20493" PostId="12235" Score="1" Text="I know this from reading Sparkfun's website at the time of my posting, and the reason was general interest in radiation monitoring after the Fukushima Daiichi nuclear power plant incident. As of today (2011-04-23) they are still back ordered on the tubes and assemblies." CreationDate="2011-04-23T15:26:06.683" UserId="259" />
  <row Id="20495" PostId="13041" Text="Let me ask the dumb question: the block diagram has a &quot;float detect&quot;. Not sure how they'd do this without an internal pullup (ie assuming that open == 'floating'). Are you sure that you need a resistor between this pin and VBUS_IN, as opposed to a resistor between this pin and GND? I.e, a pull down instead of a pullup? What is the voltage on ID_CON? If non-zero, is it stable with a weak (100K+) pulldown? If so, then you might want to try various resistor values between it and GND." CreationDate="2011-04-23T17:11:21.693" UserId="906" />
  <row Id="20496" PostId="13403" Text="That must be passive on both ends. There's almost no logical reason for a PS/2 -&gt; USB converter to detect USB on the input and pass it through. There's not a chance in hell that you can plug one half of a differential asynchronous massively complex serial bus into a synchronous bus' clock IO pin and the other half into it's data IO pin and expect anything remotely correct to happen." CreationDate="2011-04-23T17:15:55.933" UserId="1270" />
  <row Id="20498" PostId="13409" Text="I think it's on-topic as a VLSI/FPGA question, unless interview questions are off-topic." CreationDate="2011-04-23T18:41:44.697" UserId="3441" />
  <row Id="20499" PostId="13378" Score="1" Text="Efficient in terms of size or speed? What are the constraints, actually? Keep in mind that smaller libraries will likely be slower - if you look into the source code of the bigger (in terms of code section) libraries, most of the bloat is due to pre-calculated constant arrays." CreationDate="2011-04-23T19:35:02.603" UserId="3564" />
  <row Id="20501" PostId="13416" Text="Thank you for this! It looks like I was looking for &quot;encoder/decoder&quot; chips; I had no idea what the generic name was for this kind of IC, or if it even existed. Follow-up: do you have any examples or walkthroughs for projects that use these? (you can imagine that &quot;encoder/decoder&quot; brings a *lot* of google results.)" CreationDate="2011-04-23T20:06:55.540" UserId="1021" />
  <row Id="20502" PostId="13422" Text="I was hoping to avoid a switching supply because my telescope starts acting up if I connect a switching supply. I'm not sure why this is so, but a linear supply, in my case, has never caused a problem whereas with a switching supply (which had sufficient power) the telescope wouldn't even startup startup sometimes and once it corrupted SRAM inside (I fixed that by removed the internal battery for 30 mins or so). Would you still recommend a switching regulator or should I stick with a linear one just in case?" CreationDate="2011-04-23T20:46:23.447" UserId="3966" />
  <row Id="20503" PostId="13422" Text="Also, with 6 outputs 4A each, DC-DC converter seems to be much better choice. With 7812, assuming 2V voltage drop, each output would generate 4A*2V = 8W of dissipated power. That's quite a lot!" CreationDate="2011-04-23T20:46:46.523" UserId="3564" />
  <row Id="20504" PostId="13423" Text="Thanks for the response. The problem is, the scope is very sensitive to power supply fluctuations. If you read the comment above, I've already had the SRAM chip being erased due to a switching supply. Now, weather this was due to a bad supply or not, I don't know. I simply switched to a 12V linear supply and the problems completely went away. Also, do you recommend one regulator with multiple outputs or separate regulators for each output?" CreationDate="2011-04-23T21:07:31.643" UserId="3966" />
  <row Id="20505" PostId="13378" Text="In terms of RAM and ROM footprint. Speed isn't an issue, but I'm looking to cram a lot of functionality into a small device." CreationDate="2011-04-23T21:13:00.113" UserId="566" />
  <row Id="20506" PostId="13423" Score="3" Text="@saad  I seriously doubt that the problems you've experienced are due to a switching supply.  Well, let me put that differently...  _IF_ your problems are due to a switching supply then it's not the supply that is the problem, it's the scope.  Probably the only thing in the scope that actually runs off of +12v would be the motors and maybe the cooling system on the CCD (if you have that).  Everything else will run off of 1.0 to 5.0v, so there are regulators inside that will take the 12 and drop it down.  If the input power is causing issues, then these regulators are the true problem." CreationDate="2011-04-23T21:15:19.733" UserId="3624" />
  <row Id="20507" PostId="13423" Text="Also, for what its worth, the manual for the telescope suggests that a regulated supply is a must (this is written in bold text, in fact!). It can handle a range of 12-18V. I understand that the chips inside the electronics panel will be running at 5.0V, but since switch to a 12V linear supply I've had no problems whatsoever. Its been 7-8 months, so I feel thats a good enough test. Perhaps it was the supply." CreationDate="2011-04-23T21:17:29.487" UserId="3966" />
  <row Id="20508" PostId="13423" Score="4" Text="@saad  I think you're confusing a &quot;well regulated supply&quot; with &quot;low-noise supply&quot;.  If you take the &quot;12v lead-acid&quot; battery output, it will be within the 12-18v range of your scope.  It will also be about the most noise free that you can practically get.  Try that and I'll bet you it would work.  And honestly, if it doesn't then there's a problem with the scope." CreationDate="2011-04-23T21:45:38.307" UserId="3624" />
  <row Id="20509" PostId="13423" Text="Thanks for the response. What about the camera and accessories such as the focuser? Should those be run off straight off the battery as well or would regulation be recommended in this case?" CreationDate="2011-04-23T21:50:40.733" UserId="3966" />
  <row Id="20510" PostId="13422" Text="@saad - when you're running from a battery, inefficiency means shorter times between charging. instead of following a DC-DC converter with a linear regulator, you could try some passive filtering." CreationDate="2011-04-23T22:46:52.220" UserId="740" />
  <row Id="20511" PostId="13423" Score="1" Text="@saad  Look at the specs in the manual, or call their technical support.  My _guess_ is that it'll work, but it's worth double checking just to be on the safe side." CreationDate="2011-04-23T22:48:07.370" UserId="3624" />
  <row Id="20512" PostId="1876" Text="That shouldn't have been an answer, just a comment on jluciani's answer. You can include links in comments too." CreationDate="2011-04-23T23:38:34.747" UserId="2395" />
  <row Id="20514" PostId="13427" Text="breadboards :( me don't like the sound of that.. well then.. is it possible to let the Computer A communicate with Computer B which then communicates with Arduino Nano which handles the electrical engine control? " CreationDate="2011-04-21T00:12:43.410" />
  <row Id="20515" PostId="13427" Text="Buy a regular Arduino for now and save the Nano for when you get a bit more experienced." CreationDate="2011-04-24T02:53:24.367" UserId="3785" />
  <row Id="20517" PostId="13280" Text="Well, I went straight off of their datasheet, rather than pulling from past experience, so I am all wired up properly.  But what it sounds like, tech support thinks I simply shouldn't use this LCD with the MSP430 due to incompatible voltage levels.  I have a 3.3V part on order and that might solve all of my problems.  But honestly, I still don't understand why a 3.3V MCU wouldn't work with this LCD." CreationDate="2011-04-24T03:28:13.020" UserId="2288" />
  <row Id="20518" PostId="13280" Text="In reference to your first edit, I don't believe this is the case.  I've got the LCD powered up long before I go through my initialization routine." CreationDate="2011-04-24T03:29:25.047" UserId="2288" />
  <row Id="20519" PostId="13262" Text="I need to understand this part better.  From what I can tell, the MSP430 outputs are within spec for the LCD input logic high levels, but tech support thinks that the contrast is the issue." CreationDate="2011-04-24T03:30:37.777" UserId="2288" />
  <row Id="20521" PostId="13436" Text="What is the resolution? USB speed?" CreationDate="2011-04-24T11:25:07.360" UserId="305" />
  <row Id="20522" PostId="13436" Text="Most likely something like 1280x720 and USB 2.0 but depends on the hardware..." CreationDate="2011-04-24T12:00:55.553" UserId="140" />
  <row Id="20523" PostId="13275" Text="you need both encrypt and decrypt?" CreationDate="2011-04-24T14:56:44.897" UserId="985" />
  <row Id="20524" PostId="10782" Text="Thanks for the hint, I just posted a question about this possibility! http://electronics.stackexchange.com/questions/13439/linux-on-a-mcu-boards-and-examples" CreationDate="2011-04-24T15:07:24.870" UserId="2285" />
  <row Id="20525" PostId="13439" Text="Um, are you asking us to choose between these two for you, suggest more, critique them? What?" CreationDate="2011-04-24T15:08:08.560" UserId="249" />
  <row Id="20526" PostId="13439" Text="Suggest some demo-board you have experience with and you think may be suitable for such an application, or in case you think linux is too much for what I need, insult it :)" CreationDate="2011-04-24T15:10:34.927" UserId="2285" />
  <row Id="20527" PostId="13435" Text="What about wire-to-pad soldering? Would that work?" CreationDate="2011-04-24T15:50:08.153" UserId="1633" />
  <row Id="20528" PostId="13439" Text="@stef I can't really tell what would be suitable because while you've discussed peripherals I have no idea what it is you want to DO with them.  It sounds like you want to do some image processing and information storage but that's just a guess.  How quickly does the image processing have to work?  How much storage will you need?  What will you be communicating over bluetooth?  What kind of camera?  There's any number of combinations of hardware that might fulfill your requirements but I don't have enough information to narrow it down." CreationDate="2011-04-24T17:30:33.587" UserId="249" />
  <row Id="20529" PostId="13402" Text="@noremac You said that the stepper ground is running through a trace.  That better be a big trace or you'll get large ground bouncing issues due to high switching currents." CreationDate="2011-04-24T17:49:00.337" UserId="1438" />
  <row Id="20530" PostId="13402" Text="@noremac Also remember that high frequency ground return currents will travel through the path of least inductance rather than the path of least resistance.  Functionally this means that the ground current for a particular signal will try to travel as close to the signal trace as it can.  This can result in large loops which will radiate EMI.  It can also mean that return currents are actually traveling back through the other sections of your circuit rather than through the ground trace.  If you can post the schematic and PCB layout for more detailed recommendations." CreationDate="2011-04-24T17:52:15.920" UserId="1438" />
  <row Id="20531" PostId="13395" Text="@noremac check my answer to this question it may be helpful: http://electronics.stackexchange.com/questions/3760/moderately-priced-6-layer-pcb-fab/3985#3985 (i'm the same Mark as the one there I just lost the login for that account way back)" CreationDate="2011-04-24T17:56:13.047" UserId="1438" />
  <row Id="20532" PostId="13275" Text="@dwelch Yes, CBC mode for encrypt/decrypt and CBC MAC" CreationDate="2011-04-24T18:18:28.293" UserId="566" />
  <row Id="20533" PostId="13443" Text="The image processing doesn't need to be going at all times, just when I need to recognize a new qrcode tag.&#xA;The bluetooth communication needs to be as fast as possible (file transfer) but for short time (the time needed to transfer documents, pictures.. not movies).&#xA;I'm not developing a prototype I need to redesign from the scratch when I'm done (I did that already with PIC, with no qrcode) so I'd rather choose a platform I can use then in my commercial device directly. Because of this I think the beagle is too much.." CreationDate="2011-04-24T18:19:15.550" UserId="2285" />
  <row Id="20534" PostId="13443" Text="@stef I think you'll find that the qr code scanning is the most challenging aspect of what your doing and will likely drive the design.  You've mentioned no user feedback mechanism so your scanning needs to be fast to give feedback to the user (with a beep or led) or the product will be really hard to use.  Additionally I don't know of any free for commercial use qr code image decoding libraries that are written in C, ZXing's objective-C port is probably the closest.  I'd start by building your qr code decoding library to determine its size and processing requirements, they choose a platform." CreationDate="2011-04-24T19:00:05.793" UserId="1438" />
  <row Id="20535" PostId="13443" Score="1" Text="@stef you could also look at using a 2D bar code scanning module in place of the camera+image processing." CreationDate="2011-04-24T19:00:38.820" UserId="1438" />
  <row Id="20536" PostId="13439" Text="Why closed? I didn't think enumerating some low-cost Linux-based MCU systems is too vague for this site." CreationDate="2011-04-24T20:56:31.497" UserId="2285" />
  <row Id="20537" PostId="13436" Text="The linux requirement makes it very difficult to be small and cheap. The HD requirement also makes things more difficult. Not sure if there is a right answer for you." CreationDate="2011-04-24T21:03:52.377" UserId="319" />
  <row Id="20538" PostId="13409" Text="We don't have anything against interview questions, they fall in the same category as homework questions. It is more about the content of the question then where the question came from." CreationDate="2011-04-24T21:06:03.640" UserId="319" />
  <row Id="20539" PostId="13446" Text="Dont forget the dsPIC, in particular the [dsPIC33FJ128GP804](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en532299) has 2x16-bit D/A @ 100ksps with 256x oversampling and it comes in a DIP package. [This synth](http://www.frequencyresponse.ch/?p=dspicsynth)  is based on one " CreationDate="2011-04-24T21:58:28.690" UserId="819" />
  <row Id="20540" PostId="12039" Text="The question is, why *not* DVD players? It's undoubtedly the cheapest solution. I can pick up a good player from a well known supermarket here for £25. 12 of them would conceivably cost only £300, probably a little less because of bulk discounts and shipping costs..." CreationDate="2011-04-24T22:14:12.117" UserId="1225" />
  <row Id="20541" PostId="12039" Text="@Brdma, Sorry, this site is for discussion about the design of electronics, not consumer electronics. I hope you find a good solution. I believe many companies offer solutions for this exact problem. @Sean, please take a look at the FAQ." CreationDate="2011-04-24T23:05:04.270" UserId="230" />
  <row Id="20542" PostId="13446" Text="Have you heard of the Chipophone? It is an AVR-based synthesizer built into an organ. http://www.linusakesson.net/chipophone/index.php" CreationDate="2011-04-25T00:51:58.280" UserId="1363" />
  <row Id="20543" PostId="13439" Text="@Stef - It's not vague, it's overly broad.  There's TONS of Linux-capable systems out there that might suffice for your application.  You need to set more ground rules before the field can be narrowed down." CreationDate="2011-04-25T01:26:02.183" UserId="249" />
  <row Id="20547" PostId="13134" Text="@Gorgen, it seems someone already helped you. I have reopened, but it seems the question is pretty much solved. The things I want to note is that someone really could use a schematic and probed signals for a more complicated problem. As the solution seems to be relatively easy and very specific to your situation I closed it. With code someone now has a full guide for interfacing with this flash. Good luck and have fun. " CreationDate="2011-04-25T02:35:38.427" UserId="230" />
  <row Id="20548" PostId="8558" Text="Awesome - someone actually made one of these. Great idea - she used a thermistor to detect when the dishwasher was run. http://makeprojects.com/Project/Dish-O-Tron-6000/728/1" CreationDate="2011-04-25T02:51:55.027" UserId="2258" />
  <row Id="20549" PostId="13395" Text="Thanks mark. I have seen grounds laid out like the one in the image on that post and always wondered why they did that. That is definitely possible for my application. Should I ground the motor driver to the same plane as the microcontroller? I would love to upload an image of the schematic or board layout but my Internet is down right now and I am having to do everything from my phone. But on my next board revision I will try that layout. Also my return from the motor is a 70mil trace so I'm not sure if that is enough copper for a return. I will try adding a wire to the return tomorrow." CreationDate="2011-04-25T03:34:02.690" UserId="3960" />
  <row Id="20550" PostId="13435" Text="It certainly works, but it's messy. I don't think the type of joint would really change anything." CreationDate="2011-04-25T03:52:27.467" UserId="1374" />
  <row Id="20551" PostId="13449" Score="1" Text="For the ceramic?  Where?  All I see is &lt; 0.05 DF. " CreationDate="2011-04-25T04:11:44.290" UserId="411" />
  <row Id="20552" PostId="13134" Score="1" Text="@Kortuk: I will.. :)" CreationDate="2011-04-25T05:18:56.487" UserId="3882" />
  <row Id="20553" PostId="13443" Text="@Mark thank you for the hint, I didn't think they existed, I'll give a look right now.. Any brand you suggest?" CreationDate="2011-04-25T06:26:12.327" UserId="2285" />
  <row Id="20554" PostId="13280" Text="Looking at the datasheet on your specific part, I agree that it looks like it would be able to operate (although at the margins) at 3.3V.  " CreationDate="2011-04-25T06:37:13.540" UserId="3308" />
  <row Id="20555" PostId="13435" Score="1" Text="In my experience, wire to pad soldering is unreliable (long term) if the wire is going to move around. " CreationDate="2011-04-25T06:55:47.510" UserId="3308" />
  <row Id="20556" PostId="13454" Text="Hi Mark,  So the ceramics I've now linked too (needed more rep) will have lower ESR than the 300mOhm tantalums ones?&#xA;Thats great - I just didnt understand what 'Low ESR' means... yep I've included the 10nF bypass cap - how high should I go with the ceramic in this case?&#xA;Thank you!" CreationDate="2011-04-25T08:21:52.783" UserId="3975" />
  <row Id="20557" PostId="13449" Text="[link]http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=445-4585-1-ND&#xA;These are the ceramics, it wouldnt let me link with low rep." CreationDate="2011-04-25T08:22:41.393" UserId="3975" />
  <row Id="20558" PostId="13449" Text="@Token, @James: The only mention of &quot;300&quot; on that page is in the price. Seriously, where? :)" CreationDate="2011-04-25T10:34:16.967" UserId="1951" />
  <row Id="20559" PostId="13440" Score="1" Text="Are you looking for a book on designing CPUs or on using CPUs?" CreationDate="2011-04-25T12:18:13.280" UserId="2157" />
  <row Id="20560" PostId="13455" Text="Great catch!  Thank you for finding that -- I totally thought things were working with my bit twiddling but I overlooked the lower byte during testing.  I'm pretty sure this is the cause of the problem, and will test soon." CreationDate="2011-04-25T13:09:22.327" UserId="2288" />
  <row Id="20561" PostId="13455" Text="When I find extra time, I'll have to use the scope on the lower nibble.  I thought for sure this fix would have made everything work, but the LCD still isn't initializing.  Thanks again for catching my mistake!  I completely missed that every time I looked at the code...  really embarrassing.  :)" CreationDate="2011-04-25T13:20:56.603" UserId="2288" />
  <row Id="20562" PostId="13455" Text="ok, should actually be `P1OUT = ((command &amp; 0x0F) &lt;&lt; 4) | (P1OUT &amp; 0x0F);`  I wish I could make an excuse, like &quot;I'm dyslexic&quot;, but I can't.  I've verified the data bus bits on the scope, but need to re-verify the bits that get strobed because it's still not working.  I'm now probing on the LCD itself, rather than poking the breadboard." CreationDate="2011-04-25T13:38:43.403" UserId="2288" />
  <row Id="20563" PostId="13452" Text="No way those are smaller then a beagleboard." CreationDate="2011-04-25T14:02:47.633" UserId="319" />
  <row Id="20564" PostId="13384" Text="That would be a great solution in many cases, but I'm not sure if a relay would work for the application I have in mind, in which the jack acts as both a power switch and a digital trigger. In other words, the device consumes no power at all while the jack is disconnected.  &#xA;&#xA;I should point out that at this stage I've given up on finding a low-quantity supplier for DPDT minijacks for this project and am going with the 1/4&quot; DPDT jacks instead. Thanks for all the suggestions though!" CreationDate="2011-04-25T14:03:36.003" UserId="2914" />
  <row Id="20565" PostId="10479" Text="Using a with a somewhat off-balance color wheel might work, but getting it to function reliably may be difficult.  The idea would be to have the wheel (attached to the second hand) enough off-balance that when it is in a certain position, short pulses will be unable to drive it, but longer pulses will still work.  The indicator couldn't update very fast (perhaps a minute if you want to run to the 'sticking' point and then run 270 degrees past it) but you might be able to get workable open-loop operation." CreationDate="2011-04-25T14:46:32.683" UserId="3123" />
  <row Id="20566" PostId="7915" Text="It's a packing space problem, not just a legacy problem. Imagine a box and a bunch of little sticks you're trying to pack in the box. If a human being does the packing, they're going to either go with everything at 90 degrees or they're going to just naively toss them all in. Which one do you think is going to work better? I doubt that autorouters are generally smart enough to not have the same problem, really." CreationDate="2011-04-25T14:48:25.440" UserId="1270" />
  <row Id="20567" PostId="13459" Text="You could put 1/2 w on it and see if it gets hot. If it does, unhook it and go to the store." CreationDate="2011-04-25T14:57:47.113" UserId="319" />
  <row Id="20568" PostId="13395" Text="@noremac well, if you can upload the images I can help but fundamentally what you want to do is draw the current/ground paths for signals over an image of the PCB (remember high frequency returns along the path of least impedance not resistance).  Focus on signals that are sensitive, high current or connect sections with different grounds. Look for large loops (EMI issue) and/or places that ground currents are traveling under sensitive sections of the circuit.  You also want to look for places where the resistance to ground may be high, such as long traces / lack of ground plane(s)." CreationDate="2011-04-25T14:59:52.857" UserId="1438" />
  <row Id="20570" PostId="13461" Text="&quot;Is there anyway I can test to see the power rating?&quot; You didn't answer his only question." CreationDate="2011-04-25T15:05:41.800" UserId="319" />
  <row Id="20571" PostId="12832" Text="You aren't setting up a cannabis farm, are you?" CreationDate="2011-04-25T15:06:23.237" UserId="305" />
  <row Id="20572" PostId="13446" Text="My parents had a Conn Minuet organ (circa 1967) which I'd been considering doing something like that with.  I didn't really have the space for such a project, and I wasn't keen on junking the guts, though the organ might have been destined for the scrap heap anyway if my parents hadn't found someone who wanted it.  I've never used an ARM for making music myself, though I did a PIC-based music box (8 voice @10MHz) around 1996 and a PSOC-based one (16 voice @24Mhz) around 2004." CreationDate="2011-04-25T15:09:41.903" UserId="3123" />
  <row Id="20573" PostId="13459" Text="Thats not the real problem I will if I need to I wanted to see if there was a quick test to see if you could calculate the power of a given resistor. " CreationDate="2011-04-25T15:12:39.827" UserId="1623" />
  <row Id="20574" PostId="13463" Text="Thats the problem they were just in a box loose. So I don't know the manufacturer so can't find a datasheet. I guess I will have to go buy 1 or maybe 100. " CreationDate="2011-04-25T15:33:15.043" UserId="1623" />
  <row Id="20576" PostId="13461" Text="@JRobert  Because you don't know what the max temp the resistor is designed for.  Some resistors can handle temps that are much higher than others, so what's &quot;hot&quot; for one resistor might not be &quot;hot&quot; for another.  Also, most resistors are too small to accurately measure their temperature without expensive gear so &quot;see if it is getting hot&quot; usually means touching it and saying &quot;ouch&quot;.  This is very inaccurate." CreationDate="2011-04-25T15:58:35.600" UserId="3624" />
  <row Id="20577" PostId="13461" Text="How is &quot;see if it is getting hot&quot; not a way to test it? It is a pretty good guide to whether the resistor sufficiently dissipates the applied power.  And yes, too hot is subjective, at least until the the resistor destroys itself or something else.  A &quot;rating&quot; is just that - someone's &quot;estimate of goodness&quot; for a particular purpose, not an inherent and measurable physical property." CreationDate="2011-04-25T16:01:35.133" UserId="3361" />
  <row Id="20578" PostId="13464" Text="Those look nice, although Digikey's MSDS link for that chemistry takes you to a document that refers to a requirement for a big label saying &quot;PRIMARY LITHIUM BATTERIES - FORBIDDEN FOR TRANSPORT ABOARD PASSENGER AIRCRAFT&quot;. There's a note that it CAN be shipped by air according to various listed standards as of Jan 2011, but it doesn't specify that that includes passenger aircraft. I'd guess not, since the labeling requirement is still apparently valid. It also strangely says not to heat over 100 degC (which is really odd for a -40 to 125 degC rated battery)" CreationDate="2011-04-25T16:18:48.183" UserId="1270" />
  <row Id="20579" PostId="13464" Text="I've searched a bit at this point... I'm not finding much temperature data for Silver Oxide, etc either. I was hoping someone on here had already solved this problem. :)" CreationDate="2011-04-25T16:20:05.577" UserId="1270" />
  <row Id="20580" PostId="7943" Text="Aligning things on a grid helps to avoid situations where when using e.g. 5 mil tracks with 5 mil spacing, there ends up being a 14 mil space on one side of a component where it would be useful to have a track, while on the other side there's a 7-mil space that could just as well be a 5-mil space.  If one has tools that can efficiently move things around while keeping a layout tidy, one could simply shove the component and some tracks to expand the 14-mil gap to 15 mils, but if one can't move things so nicely, it's easier to start with a grid and avoid such problems in the first place." CreationDate="2011-04-25T16:20:35.467" UserId="3123" />
  <row Id="20581" PostId="13464" Text="I borrowed a very large book on batteries &quot;Handbook of Batteries 3rd edition&quot; which is nearly 10 years old but seems to do a good job of showing me what I'm up against. It doesn't look good... one chart lists quite a few different battery chemistries including operating temperature, and nothing is really coming close. I may need to just make the battery a build option. I'd hate to have the units lose the clock just in transport, though. Perhaps I'll make some extra pins on an external connector for a special external battery module for transport. Ugh." CreationDate="2011-04-25T16:49:58.393" UserId="1270" />
  <row Id="20582" PostId="13458" Text="thanks for the response. yeah actually it just won't charge but audio does work. I get an error alert on the ipod saying that it is not compatible. " CreationDate="2011-04-25T17:02:05.607" UserId="2619" />
  <row Id="20583" PostId="13458" Text="@phirschybar since that is the case I will go look a bit harder to see if I can find some links for you. It is pretty common to do so there are lots of people that show how they have done it on the web." CreationDate="2011-04-25T17:07:07.233" UserId="319" />
  <row Id="20584" PostId="13435" Text="My plan now is to pot the joints in heatshrink filled with e2000. I just find wire to pad soldering difficult because I dont have enough hands for the wires, solder and iron at once." CreationDate="2011-04-25T17:27:30.390" UserId="1633" />
  <row Id="20585" PostId="13459" Text="Standard run-of-the-mill carbon resistors seem to be 1/4W." CreationDate="2011-04-25T17:41:41.393" UserId="339" />
  <row Id="20586" PostId="13448" Text="You need to clarify what part doesn't work.  The connectors are the same, aren't they?" CreationDate="2011-04-25T17:50:37.390" UserId="142" />
  <row Id="20587" PostId="13410" Score="5" Text="Please consider removing all the *commented code*. I know you probably commented this out while debugging, but it does not help people on this site understand your problem." CreationDate="2011-04-25T17:51:34.870" UserId="3145" />
  <row Id="20588" PostId="13395" Text="Dumb question, how do I upload the schematic and pcb layout?" CreationDate="2011-04-25T17:52:40.853" UserId="3960" />
  <row Id="20589" PostId="13459" Text="they appear bigger than my other 1/4 watt ones. I've bought some now and done the job. " CreationDate="2011-04-25T18:00:34.720" UserId="1623" />
  <row Id="20590" PostId="13458" Text="You can get analog audio out of any model without any authentication chip, but digital audio requires it and a microcontroller, etc.  Ladyada reverse-engineered a charger to get the resistor values for a 1 A charger that will work with any modern iPod/iPhone model: http://www.ladyada.net/make/mintyboost/icharge.html http://www.ladyada.net/images/mintyboost/usb4res.png" CreationDate="2011-04-25T18:02:41.203" UserId="142" />
  <row Id="20592" PostId="13432" Text="For circuit-bending purposes, can you just supply the clock input from a variable frequency source in order to generate whatever tone you want?" CreationDate="2011-04-25T18:47:39.247" UserId="142" />
  <row Id="20593" PostId="13422" Text="@saad: &quot;my telescope starts acting up if I connect a switching supply&quot;  You need a better-regulated switching supply?" CreationDate="2011-04-25T18:49:04.377" UserId="142" />
  <row Id="20594" PostId="13472" Text="What integrated circuit? For example the 555 timer the plans are online usually in the datasheet. " CreationDate="2011-04-25T18:50:35.827" UserId="1623" />
  <row Id="20595" PostId="13470" Text="QPSK is what I would prefer, but currently using a form of FM. It sounds like you are explaining a simplified form of Raptor/fountain codes. I am more concerned about noise causing the demodulator to flip the bit even though it still has a lock." CreationDate="2011-04-25T18:54:54.963" UserId="319" />
  <row Id="20596" PostId="13461" Text="I would consider &quot;ouch&quot; to be hotter than I want a component to run (assuming it's not meant to be a heater).  Not to be argumentative; just to point out that this can be judgement call.  That's where I'd make mine in most cases." CreationDate="2011-04-25T20:03:02.163" UserId="3361" />
  <row Id="20597" PostId="13473" Text="Aha, thanks. Particularly for the info about frequencies that get cut out. I hadn't realized that the power would actually affect the quality of the sound and not just the volume. " CreationDate="2011-04-25T20:10:45.550" UserId="3981" />
  <row Id="20599" PostId="13475" Score="1" Text="What's illegal about reverse-engineering a competitor's chip?" CreationDate="2011-04-25T20:32:59.263" UserId="142" />
  <row Id="20600" PostId="13475" Text="@endolith  I didn't say that reverse-engineering is illegal.  But someone would probably make the case that it is (DCMA and all).  That being said, reverse engineering is required to make counterfeit chips-- which is illegal in most countries.  And, I should add, counterfeit chips is a big problem for most medium to large manufacturers.  I know that our purchasing department has been trained to spot counterfeit chips, and has actually caught some before it made it into our system." CreationDate="2011-04-25T20:40:52.080" UserId="3624" />
  <row Id="20601" PostId="13475" Score="1" Text="I think reverse engineering to make an exact copy instead of using it to learn how it worked would fall under copyright infringement." CreationDate="2011-04-25T20:41:40.993" UserId="536" />
  <row Id="20602" PostId="13289" Text="As a contribution to mazurnification's 3rd point, here is a &quot;90 minute&quot; guide about modern microprocessors, and why there's more to speed than just Megahertz: http://www.lighterra.com/papers/modernmicroprocessors/ it explains things like pipelining and superscalar structure in a basic manner." CreationDate="2011-04-25T21:12:07.423" UserId="3078" />
  <row Id="20603" PostId="13435" Text="@Robert Atkins - Really? Then you are doing it wrong. Tin the pad, so you have a dome of solder. Then tin the wire end. finally, place wire end on pad solder dome, heat with soldering iron. Result - Nice solder joint." CreationDate="2011-04-25T21:36:06.150" UserId="1374" />
  <row Id="20604" PostId="13470" Text="How does the likelihood of having a single bit flip without affecting any other bits compare with the likelihood of having a noise glitch cause a synchronization problem or otherwise distort many bits?  There are some data-transmission systems which can do a good job of maintaining sync in the presence of noise, but even with those a glitch which affects one bit is far more likely to affect neighboring bits as well than arbitrary other bits.  Design of any good scheme will require an understanding of the relative probabilities of different types of errors." CreationDate="2011-04-25T21:37:34.883" UserId="3123" />
  <row Id="20605" PostId="12832" Text="Nope, just like light )" CreationDate="2011-04-25T21:39:53.277" UserId="2062" />
  <row Id="20606" PostId="13470" Text="From real life test data that I have seen a single bit flip is pretty common." CreationDate="2011-04-25T21:59:17.900" UserId="319" />
  <row Id="20607" PostId="13470" Text="If single-bit flips are common, it might be useful to do error correction in hardware, but it's apt to be resource-intensive.  Unless you need to be able to identify &quot;interesting-looking&quot; packets in the presence of errors, and can't afford to bother the CPU with packets that shouldn't be considered &quot;interesting&quot;, it may be better to do error-correction in software.  BTW, would it be possible to have the receiver produce a &quot;quality&quot; indicator for each bit (e.g. characterize each bit as &quot;definite zero&quot;, &quot;definite one&quot;, &quot;probable zero&quot;, or &quot;probable one&quot;)?  Such info may be tricky..." CreationDate="2011-04-25T22:10:34.423" UserId="3123" />
  <row Id="20608" PostId="13470" Text="...for a hardware ECC to use most effectively, but could be very useful for a software ECC (e.g. the latter could decide that a triple-bit error on three bits that were marked as &quot;probable zero&quot; was more likely than a single-bit error on a bit marked as &quot;definite one&quot;, but such logic would be difficult to implement in hardware." CreationDate="2011-04-25T22:12:06.620" UserId="3123" />
  <row Id="20609" PostId="13470" Score="1" Text="That is what my question is about, is if there is hardware out there that handles all of that for me. Even if it is really software on the device, I just would like it to be off of my processor." CreationDate="2011-04-25T23:07:26.313" UserId="319" />
  <row Id="20610" PostId="13470" Score="1" Text="I am not aware of any hardware to do such things as a general solution.  It may exist in certain specialized communications IC's, and hardware ECC certainly exists within things like memory chips and memory controllers, but in general the type of ECC that's suitable for a particular application will be highly application-specific, and except for things like high-bandwidth memories I think that letting the processor handle the ECC is often the best approach." CreationDate="2011-04-25T23:10:03.110" UserId="3123" />
  <row Id="20612" PostId="13473" Text="I would expect the thing to make an RL-filter, as the speaker is mostly inductive (coil)." CreationDate="2011-04-25T23:19:58.840" UserId="1802" />
  <row Id="20613" PostId="13473" Score="1" Text="@ranieri. It certainly does, but the results are more unpredictable since it's dependent on the speaker impedance over the entire frequency spectrum. This effect is actually the biggest reason for using large gauge speaker cable, btw. " CreationDate="2011-04-26T00:38:58.023" UserId="3624" />
  <row Id="20614" PostId="12582" Text="@student, as you solved it and it is getting low views and is very narrowly applicable to your situation I have closed it." CreationDate="2011-04-26T01:00:09.323" UserId="230" />
  <row Id="20615" PostId="13482" Text="hmm.. is this a hardware question or a software question? do you want to know which tools to use? which processes to use? which companies to contract to? what techniques to learn?" CreationDate="2011-04-26T01:10:23.823" UserId="1938" />
  <row Id="20616" PostId="13482" Text="I'm just looking for an overview, hardware, software, tools and processes. I read this post: http://electronics.stackexchange.com/questions/7003/best-one-off-diy-pcb-creation-technique, but we do not need to etch our own boards - we're happy to send them out. If there's any one area where I need to most guidance, it's probably software tools. I downloaded the free version of OrCAD, but that seems definitely like overkill. " CreationDate="2011-04-26T01:26:15.510" UserId="3985" />
  <row Id="20617" PostId="13482" Text="I also tried Sunstone PCB123, but that seemed clunky and proprietary." CreationDate="2011-04-26T01:34:21.480" UserId="3985" />
  <row Id="20618" PostId="13435" Text="@Fake Name I knew that :-). Thanks for the tips, I'm going to have a get-it-right-or-die-trying session over the weekend." CreationDate="2011-04-26T01:45:10.767" UserId="1633" />
  <row Id="20619" PostId="13482" Score="1" Text="Then consider gEDA pcb, which is clunky and open, or Altium, which is clunky and expensive, or Eagle, which is clunky and limited in various ways." CreationDate="2011-04-26T02:44:30.757" UserId="411" />
  <row Id="20620" PostId="13482" Text="@mark, 5kUSD for Altium is out of price range. This is really a _occasional_ need." CreationDate="2011-04-26T05:08:20.140" UserId="3985" />
  <row Id="20621" PostId="13482" Text="It also needs to run on the Windows platform." CreationDate="2011-04-26T05:09:40.797" UserId="3985" />
  <row Id="20622" PostId="13482" Score="1" Text="@ThomasMcLeod I would be interested to know what type of environment this lab is in, like if it is for a company or university or what not. In most cases if you work for a decently large organization there probably already is some licenses of some software tools that you can use, you might want to check around if you think this may be the case for you. It is especially helpful to use what others in your organization have used before as it means there is probably someone around who can help." CreationDate="2011-04-26T05:12:36.503" UserId="319" />
  <row Id="20623" PostId="13435" Text="@Robert Atkins - Then why are you holding solder while trying to attach the wire to the pad? `the wires, solder and iron`" CreationDate="2011-04-26T06:03:37.043" UserId="1374" />
  <row Id="20624" PostId="13482" Text="I don't find Altium clunky at all.... Buggy, yes, but not clunky." CreationDate="2011-04-26T06:04:46.340" UserId="1374" />
  <row Id="20625" PostId="11759" Text="Registration will vary on a per-panel basis, since it is determined by the unmounting of the board from one machine, and remounting in another. Basically, there is some variability in the precision, and the fab house should specify their worst-case error. Some production runs will indeed be fine." CreationDate="2011-04-26T06:15:56.310" UserId="1374" />
  <row Id="20626" PostId="13476" Text="You can only implement it in an FPGA after you reversed engineered it. The question is about this reverse engineering. OP doesn't seem to have a datasheet." CreationDate="2011-04-26T07:37:57.633" UserId="2064" />
  <row Id="20627" PostId="13435" Text="I mean, I've obviously been doing it wrong up until now because it's been unusually difficult and/or unsuccessful, but I'll give it another go and take your advice." CreationDate="2011-04-26T07:41:35.863" UserId="1633" />
  <row Id="20628" PostId="13482" Text="@Kellenjb, it's basically a startup. Everyone else is a scientist, I'm the main engineer that's designing equipment to support the research (in infrared spectroscopy). There's no prior institutional experience in this area - I get to choose what I want to use. Keeping in mind that this is for occasional use, learning curve, cost, design flexibility and quality are considerations. So we're not looking for a hobbyist-level setup (though we could probably improvise a solder oven); more entry-level professional." CreationDate="2011-04-26T07:50:02.407" UserId="3985" />
  <row Id="20629" PostId="13483" Text="He wants to know the difference between a PUT and a BJT!" CreationDate="2011-04-26T08:04:13.903" UserId="3920" />
  <row Id="20630" PostId="13483" Text="@Federico: He is following directions in a recipe book. He is 10 years old. There are no &quot;non-tech terms&quot; for the difference between a BJT (assuming that is a &quot;normal transistor,&quot; which is not true nowadays anyway) and a PUT, which barely qualifies as a transistor at all." CreationDate="2011-04-26T08:12:41.510" UserId="3835" />
  <row Id="20631" PostId="13483" Text="I think, if he really wanted a comparison of discrete semiconductor devices, he would have specified BJT or FET." CreationDate="2011-04-26T08:14:05.393" UserId="3835" />
  <row Id="20632" PostId="13486" Text="I would recommend placing the headers into the board and plugging a mating socket over the pins before soldering. This will keep the pins parallel and keep them in place if the plastic carrier softens during soldering. An alternative is a 40 way IDC socket (as used on PATA disk drives) along with a ribbon cable salvaged from an old PC (assuming a 0.1&quot; pitch of course)." CreationDate="2011-04-26T10:13:51.093" UserId="2234" />
  <row Id="20633" PostId="13477" Text="Thank you for you answer. I will see the links." CreationDate="2011-04-26T10:25:17.120" UserId="3982" />
  <row Id="20634" PostId="13476" Text="He hasn't said that. It's a viable approach if a data sheet is available, and far cheaper than the other suggestions." CreationDate="2011-04-26T10:35:33.140" UserId="305" />
  <row Id="20635" PostId="13478" Text="Thanks, that covers most of my thoughts. I still have 1 question, probably going for phisics." CreationDate="2011-04-26T11:14:15.323" UserId="2062" />
  <row Id="20638" PostId="13489" Score="1" Text="This isn't exactly what you are asking, but it is pretty close and might just answer your actual question: http://electronics.stackexchange.com/questions/2272/what-is-a-decoupling-capacitor-and-how-do-i-know-if-i-need-one" CreationDate="2011-04-26T12:47:08.093" UserId="319" />
  <row Id="20639" PostId="13488" Text="That looks awesome! Wish they were still around." CreationDate="2011-04-26T12:48:36.750" UserId="319" />
  <row Id="20640" PostId="13488" Text="http://electronics.stackexchange.com/questions/11692/seeking-small-cheap-embedded-pc and http://electronics.stackexchange.com/questions/2191/options-for-a-small-linux-hw-platform" CreationDate="2011-04-26T12:51:34.640" UserId="319" />
  <row Id="20641" PostId="13458" Text="I read the article. While fascinating, I am not sure how to proceed with hacking the dock connector so that it circumvents the charging issue. " CreationDate="2011-04-26T14:03:41.127" UserId="2619" />
  <row Id="20642" PostId="13438" Text="But which ground?" CreationDate="2011-04-26T14:08:29.300" UserId="142" />
  <row Id="20643" PostId="13482" Text="@thomasmcleod I'd say your best off finding an independent consultant to design the boards for you when needed.  Picking up PCB design doesn't sound like a time or cost effective course of action for your company for only occasional use." CreationDate="2011-04-26T14:36:57.383" UserId="1438" />
  <row Id="20644" PostId="13212" Text="I've seen a number of PCBs with broken pads that cracked at the point where the teardrop touches the trace." CreationDate="2011-04-26T14:41:16.213" UserId="142" />
  <row Id="20645" PostId="13493" Text="As far as (AC) signal is concerned, as well-decoupled Vcc plane acts the same as a ground plane. So stick in a big cap and pour your Vcc plane if it suits your design better." CreationDate="2011-04-26T14:51:35.303" UserId="1802" />
  <row Id="20646" PostId="13214" Text="I think it's possible to do better than just &quot;aiming for the center&quot;, but I don't remember the details.  You use filters to match at different frequencies.  http://www.edaboard.com/thread145663.html  http://www.freescale.com/files/rf_if/doc/app_note/AN721.pdf" CreationDate="2011-04-26T15:04:21.520" UserId="142" />
  <row Id="20647" PostId="13473" Text="A coil which is rigidly mounted so it can't move will act as an inductor.  A coil which is mounted so it can move (whether in a speaker or a motor) will accelerate in response to current fed through it, and will generate back EMF proportional to its velocity.  In the absence of inductance, resistance, mechanical friction or boundaries, commutator effects, etc. the increase in back EMF in response to coulombs flowing through would mimic the response of an ideal capacitor.   Of course, in practice the those effects make speakers and motors behave like highly non-ideal caps." CreationDate="2011-04-26T15:08:51.833" UserId="3123" />
  <row Id="20648" PostId="13472" Text="It would be possible to design a chip reader that could &quot;reverse-engineer&quot; certain types of chips (e.g. any design one could put in a 16V8, or most designs one could put in a 22V10), but in general there are far too many things a chip could do for one to be confident in any reverse-enginnering effort done through probing alone. Even something like a 22V10 could behave one way until seven precise ten-bit addresses are clocked in, and then start behaving entirely differently. There'd be no way to probe all possible 70-bit address sequences, so one couldn't be sure no features were left out." CreationDate="2011-04-26T15:19:35.080" UserId="3123" />
  <row Id="20649" PostId="13482" Text="@Mark, your point is a good one. However, we're contractually prohibited from hiring contractors. Moreover, almost everything we do is one-off or experimental, so resourcefulness is part of our culture." CreationDate="2011-04-26T15:47:24.650" UserId="3985" />
  <row Id="20650" PostId="8497" Text="In some cases, a pin may not be connected to the die of the parts presently leaving the factory, there's no guarantee that will always be true of future parts." CreationDate="2011-04-26T16:20:15.287" UserId="3123" />
  <row Id="20651" PostId="5644" Text="Many video devices are AC coupled on the inputs and outputs; it might be nice if that weren't the case, but in practice unless one knows one will only be accepting signals from devices with DC-coupled inputs, one has to accept AC-coupled signals. Further, in many cases, if one will have to deal with AC-coupled signals, it's often helpful to AC-couple one's own input stage.  See http://electronics.stackexchange.com/questions/11334/dc-restoration-of-a-video-signal for more info." CreationDate="2011-04-26T16:21:31.663" UserId="3123" />
  <row Id="20653" PostId="13503" Text="So, what's the question?" CreationDate="2011-04-26T18:58:11.080" UserId="3624" />
  <row Id="20654" PostId="13214" Text="@endolith - 200 to 600 just seems kind of wide. you could probably get a fair match over 200 to 400, and a similarly fair match over 300 to 600." CreationDate="2011-04-26T19:01:04.683" UserId="740" />
  <row Id="20655" PostId="13504" Text="Adding better insulation to a simple design can often provide more cost savings than a more complex design. Also, a more complex design can be harder to insulate well." CreationDate="2011-04-26T19:03:18.317" UserId="3624" />
  <row Id="20656" PostId="13506" Text="All the heat loss is at the border. So, as you say the insulation is the key. You could maintain cooling on a hollow mountain full of soda cans as easily as a soda machine (after the initial cool down, of course) if they had the same heat loss through the insulation." CreationDate="2011-04-26T19:16:17.057" UserId="1270" />
  <row Id="20657" PostId="13502" Text="Hmm...  how often is the ringing you mention a real problem?  Will it add noise or cause the whole thing to go unstable? (LDO)  If a datasheet has a example circuit with tantalum, should I take that as a requirement? Many times I think they're just arbitrarily showing you what someone's done before with the chip." CreationDate="2011-04-26T19:30:59.470" UserId="1270" />
  <row Id="20658" PostId="13506" Text="Thank you! Fascinating insights. :)" CreationDate="2011-04-26T19:34:51.780" UserId="3995" />
  <row Id="20660" PostId="13460" Text="This is a good idea as well. The challenge is the size as well. The device is about 8mm in height. Any other types of micro-actuators you can think of?" CreationDate="2011-04-26T19:40:58.673" UserId="3089" />
  <row Id="20661" PostId="12370" Text="Assuming cost is not an issue though. How might one go about doing this from scratch?" CreationDate="2011-04-26T19:43:02.697" UserId="3089" />
  <row Id="20662" PostId="13513" Text="Could someone please edit my tags. Thank you" CreationDate="2011-04-26T19:56:08.947" UserId="3089" />
  <row Id="20663" PostId="13513" Score="1" Text="I think you might be confused as to what phantom power is. http://en.wikipedia.org/wiki/Phantom_power" CreationDate="2011-04-26T19:58:33.010" UserId="319" />
  <row Id="20665" PostId="13513" Text="I am referring to the current drawn by devices when switched off. Phantom power, stand-by power whichever term you prefer. But in the context of electrical conservation, not microphones." CreationDate="2011-04-26T20:01:48.053" UserId="3089" />
  <row Id="20666" PostId="13513" Text="sounds like a 'trickle stop' power strip i just saw today, so clearly it's doable. (google 'trick stop power strip', you'll probably see what i saw)" CreationDate="2011-04-26T20:13:54.680" UserId="740" />
  <row Id="20667" PostId="13513" Text="@JustJeff, Thanks. Yes, this is what I was referring to. How do those devices detect if a TV is on or off? " CreationDate="2011-04-26T20:14:23.557" UserId="3089" />
  <row Id="20668" PostId="13513" Text="Tricklestar brand claims that the switch off threshold is at 18W or 35W and that their standby power is less then 1W. That doesn't seem all that great to me" CreationDate="2011-04-26T20:25:00.420" UserId="319" />
  <row Id="20669" PostId="13508" Score="3" Text="A replacement flapper valve is about $2." CreationDate="2011-04-26T20:25:18.873" UserId="411" />
  <row Id="20670" PostId="13513" Text="the puzzle seems to be, if you disconnect the load b/c it is drawing less than (say for example) 18W, how do you know when, if reconnected, the load would be greater than 18W. What do they do, turn the load side on for a half cycle every 500 msec or something?" CreationDate="2011-04-26T20:28:06.107" UserId="740" />
  <row Id="20671" PostId="13511" Text="{thanks}   is there any current gain in transister?   " CreationDate="2011-04-26T20:37:05.587" UserId="3998" />
  <row Id="20673" PostId="13513" Text="@JustJeff turning the load on occasionally is the only thing that I can think of that would work. At a rating of less than 1 watt at standby, I am sure something like this could be done, even for longer then half a cycle." CreationDate="2011-04-26T20:42:07.777" UserId="319" />
  <row Id="20674" PostId="13515" Score="1" Text="Essentially, Rule of thumb is, if you keep your wireless signals mostly on your private property then there is not much to worry about. As soon as you get strong enough that it could interfere with others then you can start worrying about getting caught." CreationDate="2011-04-26T20:51:05.923" UserId="319" />
  <row Id="20675" PostId="13513" Score="4" Text="Slightly off topic to the actual question, but based off of the numbers provided by Tricklestar, it would take about 1,800 years for the power strip to pay for itself (not accounting for inflation and what not)" CreationDate="2011-04-26T21:00:57.177" UserId="319" />
  <row Id="20676" PostId="13513" Score="1" Text="Boy the more I read about those power strips the more I think its just a few companies that are trying to make money and not real science. The wikipedia page is full of sales jargon but not a single bit of science. It even says &quot; Video games often use power when they are turned off, but the standby power can be further reduced if the correct options are set.&quot; I am sure they mean video game consoles, but its very clearly not what they said." CreationDate="2011-04-26T21:06:06.233" UserId="319" />
  <row Id="20677" PostId="13513" Text="I've retagged as per OP request." CreationDate="2011-04-26T21:06:45.653" UserId="1293" />
  <row Id="20678" PostId="13517" Text="Yes, I edited to fix that.  &quot;since the resonant tank includes three reactive elements ... there are two resonant frequencies associated to this circuit. One (f0 = fR1) is related to the condition of the secondary winding(s) conducting, where the inductance Lp disappears because dynamically shorted out by the low-pass filter and the load ... the other resonant frequency (fp = fR2) is relevant to the condition of the secondary winding(s) open, where the tank circuit turns from LLC to LC because Ls and Lp can be unified in a single inductor&quot;" CreationDate="2011-04-26T21:18:40.233" UserId="142" />
  <row Id="20679" PostId="13492" Text="Does it run Linux?" CreationDate="2011-04-26T21:51:41.120" UserId="2134" />
  <row Id="20680" PostId="13517" Text="Yes, the output rectifier uses paralleled Schottky diodes.  They're operating it *below* the f0 resonant frequency, not above." CreationDate="2011-04-26T21:53:02.683" UserId="142" />
  <row Id="20681" PostId="13492" Text="The Wikipedia page in the link says yes" CreationDate="2011-04-26T21:58:22.633" UserId="566" />
  <row Id="20682" PostId="13513" Score="1" Text="I think the term you were looking for was vampire power - please edit, very confusing for people for whom phantom power has a distinct meaning." CreationDate="2011-04-26T22:13:13.747" UserId="1269" />
  <row Id="20683" PostId="13516" Score="2" Text="well now that's just too easy" CreationDate="2011-04-26T22:24:35.070" UserId="740" />
  <row Id="20684" PostId="13523" Score="1" Text="it's probably not the true RMS thing; cheaper meters that aren't true RMS are usually built to give the correct reading for sinusoidal power at mains frequency on their AC settings." CreationDate="2011-04-26T23:15:52.953" UserId="740" />
  <row Id="20685" PostId="13511" Text="bipolar junction transistors (BJTs) are inherently current-gain devices. the collector resistor in the CE configuration translates the increased current to a voltage." CreationDate="2011-04-26T23:19:01.843" UserId="740" />
  <row Id="20686" PostId="13523" Text="Ok yeah we only have cheap meters at school where we are testing the transformer because people break them, and steal them. :@" CreationDate="2011-04-26T23:20:50.963" UserId="1623" />
  <row Id="20687" PostId="13508" Score="1" Text="good thing there isn't a plumbing SE .. or is there?" CreationDate="2011-04-26T23:21:37.147" UserId="740" />
  <row Id="20688" PostId="12370" Text="@aaronfarr The easy way would be to start with an AC/DC power supply that has the correct voltage and current.  Then, take a battery pack, remove the batteries, and either fit the power supply in it or use the battery pack as a sort of bulky adapter.  In that way the drill would remain unmodified and hopefully wouldn't kill the drill.  I don't know if that meets your &quot;from scratch&quot; requirement, but that's how I'd do it." CreationDate="2011-04-26T23:26:41.417" UserId="3624" />
  <row Id="20689" PostId="13214" Score="1" Text="use a transformer?" CreationDate="2011-04-27T00:04:08.430" UserId="411" />
  <row Id="20690" PostId="13522" Text="Oh wow, thanks for mentioning the stack-up plane distances. The power plane is closer to the inner signal layer than the ground plane. I'm not sure I would have noticed that. I'll change it." CreationDate="2011-04-27T00:22:07.907" UserId="1270" />
  <row Id="20691" PostId="13529" Score="2" Text="Professors being overly vague is usually a good thing when it comes to homework. However, questions being overly vague is not a good thing. For us to help out you need to ask a question, you have not done that. " CreationDate="2011-04-27T04:04:05.680" UserId="319" />
  <row Id="20692" PostId="13527" Text="Your 6 layer stackup is what I'd normally use. The layout guide for this processor recommends this odd S-G-P-S-G-S stackup, claiming it increases plane capacitance (which while I'm sure it does, I'm not sure this is system fast enough to matter) I was going to space them 5-5-21-5-5.  (4PCB uses foil on the outer layers, so the central gap is prepreg not core)" CreationDate="2011-04-27T04:55:57.100" UserId="1270" />
  <row Id="20693" PostId="13530" Text="I find the issue very strange.. i am running out of time.. help me at the earliest.. thanks in advance.." CreationDate="2011-04-27T05:23:37.563" UserId="1484" />
  <row Id="20694" PostId="13530" Score="1" Text="Sounds like an MCLR issue." CreationDate="2011-04-27T05:42:31.180" UserId="319" />
  <row Id="20695" PostId="13502" Text="Ringing is fairly common for ceramic output caps. It can help to change to a higher spec part (higher voltage or better dielectric) or a different package size. Tantalum is an easy fix as they are not prone to microphonics. " CreationDate="2011-04-27T06:53:33.330" UserId="3876" />
  <row Id="20696" PostId="13502" Text="The ringing produces a small voltage noise, but it won't cause instability in a DC converter. I would not take tantalum output caps as a strict requirement." CreationDate="2011-04-27T07:02:47.287" UserId="3876" />
  <row Id="20697" PostId="13529" Text="Usually this forum expects you to have done some work on the problem, show us what you have and where you are stuck." CreationDate="2011-04-27T07:08:20.490" UserId="2110" />
  <row Id="20698" PostId="4884" Text="&quot;Online potentiometer handbook&quot; sounds like a handbook for online potentiometers… on the other hand it looks wonderfully retro." CreationDate="2011-04-27T07:17:41.213" UserId="3835" />
  <row Id="20699" PostId="13521" Text="The statements inside a process are executed *sequentially*. They are, by definition, sequential statements. However, they are executed within the same delta cycle, which means that no simulated time passes. Compare that to statements inside an architecture, which are *concurrent* statements. " CreationDate="2011-04-27T08:19:00.450" UserId="3145" />
  <row Id="20700" PostId="13531" Text="Just so we're all on the same page, can you tell us where the 10 comes from? I suppose it's some characteristic dimension of your structure in some unit (or, actually, 1/dimension). " CreationDate="2011-04-27T08:22:15.017" UserId="1802" />
  <row Id="20701" PostId="13531" Text="Something like that. Also I didn't mention that when regulating the angle it has to be accurate enough to adjust the angle of the object by +/- 0.25 degrees. Is this achievable." CreationDate="2011-04-27T08:42:17.520" UserId="4004" />
  <row Id="20702" PostId="13531" Text="I'm still having a bit of trouble distilling the actual question. " CreationDate="2011-04-27T09:34:40.123" UserId="1802" />
  <row Id="20703" PostId="13531" Text="How do I get started? I want to learn robotics, how can I do this?" CreationDate="2011-04-27T09:37:59.053" UserId="4004" />
  <row Id="20705" PostId="13429" Text="You could use a Power-MOSFET to control the solenoid and a switching diode to short the EMF. Same circuit as you would use the control a normal relay (one with a coil). Sorry for not answering the question directly, but you can generally use a switching diode to short the EMF, when controlling a solenoid (with a DC current)." CreationDate="2011-04-27T11:13:25.450" UserId="3041" />
  <row Id="20706" PostId="13276" Text="Are you still working on the circuit? As I might be able to help you." CreationDate="2011-04-27T11:21:47.680" UserId="3041" />
  <row Id="20707" PostId="13535" Text="Yes its a lighting display casing. Which has stopped working when the lights and motor are on. So I assumed it was the transformer. " CreationDate="2011-04-27T11:29:43.853" UserId="1623" />
  <row Id="20708" PostId="13525" Text="Thanks, I found some stuff on google, which explained it pretty good. When using a RF-transistor, they design for constant gain, but for a couple of frequencies inside the band. So matching is basically done for a couple of different frequencies." CreationDate="2011-04-27T11:34:10.387" UserId="3041" />
  <row Id="20709" PostId="13536" Text="How do (did) you kill just the BIOS chip?" CreationDate="2011-04-27T11:41:24.427" UserId="2110" />
  <row Id="20710" PostId="13535" Text="Motor? It could be that it only accepts resistive loads (read: halogen or incandescent lamps) and no motors. When motors start up, they need much current, acutually they look like a short when they are just beginning to move. This might trigger the supply's protection or, if it is not protected, blow it altogether." CreationDate="2011-04-27T11:46:45.253" UserId="930" />
  <row Id="20711" PostId="13535" Score="2" Text="@zebonaut, you are correct, these are known as &quot;transformers&quot; in the lighting industry but are basic switched mode power supplies, without the DC filtering stage or regulation. The name is historical, they used to use wound transformers, and still do in some cases, but often an &quot;electronic transformer&quot; is used for efficiency, weight, cost etc. The output waveform is messy, no meter reads it well, best tested with a lamp. Regulation is omitted so that they are dimmable, and ac is better for the lamp. Don't drive a motor with it, the output will be surge protected." CreationDate="2011-04-27T12:00:50.143" UserId="2110" />
  <row Id="20712" PostId="13536" Text="@Martin: **ASUS update utility**. that darn app started looping over and after waiting 10 mins i pretty much knew that the BIOS was corrupted. After reboot black screen, no post, no nothing." CreationDate="2011-04-27T12:45:47.763" UserId="2296" />
  <row Id="20713" PostId="13530" Text="The hex comparison suggests that you didn't change the build type, but anyway, be aware that if you burn a debug build (in contrast to a release build), it will not start running by itself, even when you disconnect the PICkit." CreationDate="2011-04-27T13:23:25.610" UserId="1950" />
  <row Id="20714" PostId="13514" Text="A cool addition would be to replace the toilet flusher with a servo-actuated flusher which has a flush button mounted on top of the toilet which is used for normal flushing, and the microcontroller monitoring water flow to pulse the actuator to jiggle the chain if needed." CreationDate="2011-04-27T13:40:20.063" UserId="3122" />
  <row Id="20715" PostId="13452" Text="You'd be surprised what you can fit into a small package nowadays and there's literally hundreds of devices on those pages, so I wouldn't count it out outright.  But per his requirements this is probably the best he can hope for other than building his own board." CreationDate="2011-04-27T14:19:57.563" UserId="249" />
  <row Id="20716" PostId="13455" Text="@ToyBuilder: FYI, after switching LCDs, my code is working, but your answer was certainly a key ingredient in getting there.  I don't know why this didn't work with the 5V LCD, because my logic levels were within the specs.  Anyhow, I decided to restart the bounty, and tomorrow I will award it to you for this answer.  Thanks again!" CreationDate="2011-04-27T14:28:35.340" UserId="2288" />
  <row Id="20717" PostId="13517" Score="1" Text="So they're opting for soft commutation at the expense of having the switching frequency moving around somewhat. That's a perfectly valid design decision." CreationDate="2011-04-27T14:59:14.393" UserId="1293" />
  <row Id="20718" PostId="13548" Text="If anyone answers this, I'd be curious to know the answer to a strongly-related question: if one wants to store a battery in such a way as to not burn the house down if it self-ignites, what sort of fire-proof container would one need?  Would a typical steel lockbox (non-airtight) on a non-flammable surface likely be sufficient?" CreationDate="2011-04-27T15:12:00.733" UserId="3123" />
  <row Id="20719" PostId="13551" Text="yes it does but it is inaccessible, since it is on the same chip. there is no output to my screen, nothing shows up, even when i insert usb or floppy." CreationDate="2011-04-27T15:16:03.230" UserId="2296" />
  <row Id="20720" PostId="3958" Text="I can second allaboutcircuits.com. It's very easy to understand!" CreationDate="2011-04-27T15:30:48.117" UserId="4009" />
  <row Id="20721" PostId="13551" Score="1" Text="As long as the flash chip isn't dead, reflashing with CrashFree 3 should work properly. Here are some more links with details on how others got it to work: [link 1](http://hardforum.com/showthread.php?t=1111827%22) [link 2](http://www.hardwareanalysis.com/content/topic/70427/)" CreationDate="2011-04-27T15:32:21.053" UserId="1293" />
  <row Id="20722" PostId="13527" Text="Wouldn't the higher inductance of the return path along the split plane discourage high-frequency return paths from forming on that plane?  Particularly if the unbroken plane was 4x closer, which probably results in a significantly smaller loop?" CreationDate="2011-04-27T15:32:24.953" UserId="1278" />
  <row Id="20723" PostId="13521" Score="1" Text="Precisely, that's why I said everything inside the Process is executed concurrently (i.e. same delta cycle), yet the last of multiple assignments will win (i.e. executed sequentially)" CreationDate="2011-04-27T15:39:33.233" UserId="1278" />
  <row Id="20724" PostId="13469" Text="Most synthers ignore the process sensitivity list anyway, so I imagine in practice that the code will synthesize valid RTL.  His problem isn't really using combinatorial flags (which is perfectly valid), or forgetting to register the flags with clk'event (which is the smart thing to do).  His problem is that the flags themselves are not generated correctly.  See my comment below." CreationDate="2011-04-27T15:47:45.150" UserId="1278" />
  <row Id="20725" PostId="13546" Score="1" Text="an important thing to note about the layout is that the tuning capacitors should have as close to the same ground as possible.  That is they should not be tied to the ground plane through separate vias but tied together and then taken to ground ASAP." CreationDate="2011-04-27T15:52:20.407" UserId="1438" />
  <row Id="20727" PostId="13555" Text="Aka. Commutating or snub diodes" CreationDate="2011-04-27T16:05:12.813" UserId="4010" />
  <row Id="20728" PostId="13550" Text="This would be my guess, noise coming from the phone and not the battery." CreationDate="2011-04-27T16:06:51.423" UserId="4010" />
  <row Id="20729" PostId="13548" Text="Google RC lipo charging bags" CreationDate="2011-04-27T16:08:41.097" UserId="4010" />
  <row Id="20730" PostId="13540" Score="4" Text="&quot;optimum&quot;?  Probably zero." CreationDate="2011-04-27T16:12:44.790" UserId="1407" />
  <row Id="20731" PostId="13157" Text="I don't see the interface between the screen and host documented anywhere. How do you intend to reverse whatever protocol they're using?" CreationDate="2011-04-27T16:20:32.997" UserId="1293" />
  <row Id="20732" PostId="13559" Text="I would be very interested to know their range over enemy territory, then. It should be quite limited." CreationDate="2011-04-27T16:26:51.563" UserId="1625" />
  <row Id="20733" PostId="13550" Text="Vibration motor perhaps, at a very low voltage, or just speaker noise." CreationDate="2011-04-27T16:29:55.630" UserId="249" />
  <row Id="20734" PostId="13558" Text="Sure there's lag in satellite control, but it's not like there needs to be sub-second responses when flying through a tremendous volume of essentially empty space.  A Boeing 767 doesn't need to maneuver on a dime just because it's fast." CreationDate="2011-04-27T16:33:26.403" UserId="1407" />
  <row Id="20735" PostId="13515" Text="Thanks for your answer" CreationDate="2011-04-27T16:37:36.297" UserId="3982" />
  <row Id="20736" PostId="13558" Text="@Nick T I would not feel confident to push &quot;fire&quot; on a laster controlled rocket, if there was one second of delay, unless the underlaying systems had a really nice way of handling the latency. " CreationDate="2011-04-27T16:38:24.860" UserId="1625" />
  <row Id="20737" PostId="13558" Text="Also, these are military satellites they're using, not consumer grade. They may have significantly less latency due due to lower load, priority for certain devices, or better/newer hardware." CreationDate="2011-04-27T17:03:49.890" UserId="536" />
  <row Id="20740" PostId="13568" Text="What board do you have? Pro?" CreationDate="2011-04-27T08:00:44.693" UserId="4009" />
  <row Id="20741" PostId="13568" Text="Arduino is an ATmega1280.  LCD is an Elatec EL1602" CreationDate="2011-04-27T08:19:13.637" />
  <row Id="20744" PostId="13566" Text="Do things like View-Master also use such lens focus techniques?" CreationDate="2011-04-27T18:16:22.520" UserId="1200" />
  <row Id="20745" PostId="13566" Text="http://en.wikipedia.org/wiki/View-Master" CreationDate="2011-04-27T18:16:30.430" UserId="1200" />
  <row Id="20746" PostId="13558" Score="1" Text="The &quot;latency&quot; in a rocket or bomb reaching it's destination after firing is going to swamp any latency in the communication systems." CreationDate="2011-04-27T18:17:26.133" UserId="1407" />
  <row Id="20747" PostId="13558" Text="Ok. You both have good points. So I am convinced that it is feasible that they are using satelite communication." CreationDate="2011-04-27T18:19:53.883" UserId="1625" />
  <row Id="20748" PostId="9221" Text="&quot;The effects of electrical current passing through the human body are covered at length in the International Electro Technical Commission document IEC 479-2:1987. In this document it indicates that a transient or capacitive discharge, as is the case with static electricity, requires energy in excess of 5 Joules (5000mJ) to produce a direct serious risk to health.&quot;  http://www.wolfsonelectrostatics.com/04_news/index.html" CreationDate="2011-04-27T18:32:17.243" UserId="142" />
  <row Id="20749" PostId="13429" Text="Put it in am answer, add a circuit our two and you've  answered the question based on what I needed as opposed what I thought I wanted. I'd accept that ad am answer." CreationDate="2011-04-27T18:44:55.897" UserId="1319" />
  <row Id="20750" PostId="13568" Text="What Arduino kit exactly? Link?" CreationDate="2011-04-27T18:50:55.420" UserId="3130" />
  <row Id="20751" PostId="13455" Text="It may have to do with the ability of the LCD controller to generate the appropriate drive voltage for the liquid crystal in the device -- it might be that at 3.3V, the LC is not getting sufficiently biased to make a visible difference..." CreationDate="2011-04-27T18:54:06.913" UserId="3308" />
  <row Id="20752" PostId="13571" Text="The question as written is vague. Is there a specific aspect that you're having trouble with? I'd suggest confining the question to one subject out of load estimation, frequency change, or voltage change. It may make sense to work on load estimation and frequency changing before attempting voltage changing. Here's a relevant paper: [Energy management for commodity short-bit-width microcontrollers](http://scholar.google.com/scholar?cluster=16316802717899282769)." CreationDate="2011-04-27T18:55:32.777" UserId="3441" />
  <row Id="20753" PostId="9221" Text="EN 60065 limits the maximum energy of a discharge to 350 mJ for safety certification." CreationDate="2011-04-27T19:32:53.040" UserId="142" />
  <row Id="20754" PostId="13566" Text="@Rick_2047  Yes, they do.  Also, the film is farther away from the eye, which helps a little." CreationDate="2011-04-27T19:37:43.007" UserId="3624" />
  <row Id="20755" PostId="13583" Text="It's not the accuracy of the oscillator that I'm concerned with, because I am attempting to compensate for the error.  My problem is that after analyzing the accuracy and compensating for it, it is still measurably inaccurate.  The error remains the same run after run, so my measurements are precise." CreationDate="2011-04-27T19:51:23.957" UserId="1278" />
  <row Id="20756" PostId="13583" Text="If the error is repetitive, than it implies that your 27 tick-per-second adjustment is the issue. What happens if you try and adjust by 30 ticks per second? Also, is there a possiblilty that your reference clock is changing by 3 PPM?" CreationDate="2011-04-27T20:06:05.533" UserId="1293" />
  <row Id="20757" PostId="13583" Text="Yes, my regression is not calculating the correct error.  If I adjust by 30 PPM, I get the expected negligible 0.1 PPM error.  If the reference clock was changing by 3 PPM, I would be getting results all over the map, instead of consistently getting 27 PPM error &quot;uncompensated&quot; and 3 PPM error &quot;compensated&quot; and 0.1 PPM &quot;double-compensated&quot;." CreationDate="2011-04-27T20:15:21.500" UserId="1278" />
  <row Id="20758" PostId="13584" Text="To an extent, I can control the frequency of the oscillator-under-test (OUT).  After tuning OUT for 27 extra tick/s, I re-run the accuracy analysis (same reference), and I am still 3 tick/s short.  Tuning OUT for an additional 3 tick/s (on top of the original 27), re-run accuracy analysis, and now I am 0.1 tick/s short, which is as good an accuracy as I can get." CreationDate="2011-04-27T20:31:05.820" UserId="1278" />
  <row Id="20759" PostId="13568" Text="Ummm...why does it matter what kit?  An EL1602 is an EL1602 is an EL1602" CreationDate="2011-04-27T20:47:54.060" UserId="4017" />
  <row Id="20761" PostId="13558" Score="2" Text="The latency is mainly determined by the distance. If the satellites are in a low orbit the latency will be low low enough, while with satellites in geostationary orbit it could be a problem." CreationDate="2011-04-27T21:06:17.773" UserId="339" />
  <row Id="20762" PostId="13559" Score="2" Text="The surveillance video is unencrypted, mostly for the convenience of the ground troops using it, while the command and control channel is encrypted. http://www.schneier.com/blog/archives/2009/12/intercepting_pr.html" CreationDate="2011-04-27T21:11:03.433" UserId="339" />
  <row Id="20763" PostId="13578" Score="1" Text="thanks , but why there waveform are almost same??   " CreationDate="2011-04-27T21:12:22.607" UserId="3998" />
  <row Id="20764" PostId="7101" Text="If connectors are required, make sure to 'glue' everything. Neither forget screws, anything that could get loose, like loose electrolytic caps. There is special glue that is easily removal and non-conductive. We also use a lot of tie wraps to tie cables together or fixate them wherever necessary.&#xA;Assembly time goes up a lot, but that's a part of the cost." CreationDate="2011-04-27T21:16:23.800" UserId="1476" />
  <row Id="20765" PostId="13569" Text="I could only find a PDF data sheet which isn't very clear.  But yes, I think this might be the way to do it - see what else people come up with.  Since I am just getting into this, the obvious solution wasn't so obvious to me." CreationDate="2011-04-27T21:35:48.467" UserId="4017" />
  <row Id="20766" PostId="13569" Text="Ahhh here we go. http://www.fisnet.ru/techdocs/lcd/elatec.pdf     &#xA;&#xA;The image on the title page is indicative of what I have." CreationDate="2011-04-27T21:59:26.887" UserId="4017" />
  <row Id="20767" PostId="13443" Text="@stef I don't have experience with any of them but a quick google search did turn up a bunch.  Its the type of component that usually requires a bit of digging to find.  If your working with a supplier for components for your build, someone like Arrow for instance, reach out to them, they often have better feelers out there for such components." CreationDate="2011-04-27T22:30:09.883" UserId="1438" />
  <row Id="20768" PostId="13595" Score="2" Text="not quite any analog signal, the signal has to be periodic in nature (or you have to confine your analysis to a section of the signal which is periodic).  Your also not limited to analog signals and I would imagine that most fourier transforms today are performed on sampled (discrete) data, that is a DFT is performed rather than a 'normal' Fourier Transform." CreationDate="2011-04-27T22:59:19.790" UserId="1438" />
  <row Id="20769" PostId="13595" Score="2" Text="You can take the Fourier transform of a non-periodic signal - but where the Fourier transform of a periodic signal consists only of discrete multiples of the base frequency the Fourier transform of a transient signal is continuous in the frequency domain - all frequencies have some content." CreationDate="2011-04-27T23:28:03.270" UserId="249" />
  <row Id="20770" PostId="13527" Text="@ajs410, more current will flow in a closer plane.  But if we make pretend planes are equally spaced, but one has a split, the current will still flow equally in each plane (at high frequency) because the signal can't look ahead to see the split.  The return current is flowing in the planes before the signal reaches it's end destination.  Check out this video of charge in motion from Howard Johnson's site,http://www.signalintegrity.com/Pubs/news/14_02.htm, also may want to look up &quot;partial inductance&quot;" CreationDate="2011-04-27T23:28:58.073" UserId="2377" />
  <row Id="20771" PostId="13527" Text="@darron, yeah that's weird.  I would think the inferior routability (if that's a word) of that stackup would outweigh the gained inter-plane capacitance." CreationDate="2011-04-27T23:33:09.567" UserId="2377" />
  <row Id="20772" PostId="13579" Text="those happen to be digital modulations - there are also analog FM and PM, which have rather more complex spectra." CreationDate="2011-04-27T23:47:48.677" UserId="740" />
  <row Id="20773" PostId="13579" Text="@JustJeff Yes, thank you for pointing that out. I think looking at the digital case of modulation makes it the easiest to understand, analog then just &quot;fills in the gaps&quot;." CreationDate="2011-04-27T23:55:59.780" UserId="319" />
  <row Id="20774" PostId="13588" Text="I am very confused by your title." CreationDate="2011-04-28T00:17:54.847" UserId="319" />
  <row Id="20775" PostId="13595" Score="1" Text="@AngryEE, I think he was just trying to make the point to specifically analyze a periodic signal you compute its fourier series, but a general fourier transform handles any signal. The OP was asking about fourier series. Just a note to clear it up." CreationDate="2011-04-28T00:51:06.527" UserId="230" />
  <row Id="20776" PostId="13594" Text="That is the gain I get for the T model.  For the hybrid-Pi model I get: Vo/Vi = (gm*Rl*Rpi) / (gm * Rs * Rpi + Rs + Rpi).  The difference is that gm term on the bottom when the equation is simplified down.&#xA;&#xA;That extra term comes from when I solve for the currents coming into and out of the emitter.  As the base is grounded Ve determines Vbe so I get:&#xA;Ve/Rpi = gm(-Ve) + (Vs-Ve)/Rs&#xA;&#xA;The gm(-Ve) term propagates through and causes the gm * Rs * Rpi difference in the final answer.&#xA;&#xA;Thanks." CreationDate="2011-04-28T00:55:05.430" UserId="4018" />
  <row Id="20777" PostId="13538" Text="@steveR, I can vouch that loading a 16f877a into a 16f876a works. There is a difference in the 877 and the 877a, so that can cause issues(and I have seen it). I believe they only match up if your Ram and Rom use are low, but I have forgotten." CreationDate="2011-04-28T00:55:11.980" UserId="230" />
  <row Id="20778" PostId="13518" Score="4" Text="Madmanguruman, you have been adding many tag wikis in the background and made many edits. These are things that most people do not know unless they are a mod and the one approving the changes. I think you would make an excellent mod and would like the community to recognize your behind the scene contribution. Good Luck, you have my full backing (not to imply I am not running myself)." CreationDate="2011-04-28T00:58:56.627" UserId="230" />
  <row Id="20779" PostId="13525" Text="Yeah, doing all that on a paper smith chart is pretty tough. Take a look at Microwaves101.com, they have some s-parameter calculations in Excel that might be helpful.  Link here &lt;http://www.microwaves101.com/content/downloads.cfm&gt;" CreationDate="2011-04-28T01:22:34.060" UserId="2148" />
  <row Id="20780" PostId="13595" Text="True true, there is a distinction that can be made there.  I always thought of series referred to the fact that it was an infinite series of additions." CreationDate="2011-04-28T01:41:00.377" UserId="249" />
  <row Id="20781" PostId="13599" Score="2" Text="I think that this is off topic.  I see no relevance to bicycles.  " CreationDate="2011-04-28T01:34:38.137" />
  <row Id="20782" PostId="13599" Score="1" Text="Maybe this should be directed to an electronics forum." CreationDate="2011-04-28T01:38:11.643" />
  <row Id="20783" PostId="13455" Text="3.3V is within spec, though, and I confirmed that with their tech support.  Maybe I'll switch back over to the 5V display tomorrow just for fun, now that I've confirmed that the code is working properly." CreationDate="2011-04-28T04:46:30.717" UserId="2288" />
  <row Id="20784" PostId="13538" Text="I stand with Kortuk. Hex of Devices of a family, with same flash memory size can be interchanged." CreationDate="2011-04-28T04:51:45.960" UserId="1484" />
  <row Id="20785" PostId="13532" Text="@martin: And it worked!! Spent some time on configuration Bits - Settings.&quot;Crystal-XT&quot; and &quot;Power-Up on Timer Enable Bit&quot; were the culprit.. Thanks a lot.. But it leads to my next question - Why does the settings in the Mplab Change randomly??" CreationDate="2011-04-28T04:57:35.527" UserId="1484" />
  <row Id="20786" PostId="6034" Text="What are KVL and KCL? Definitions please." CreationDate="2011-04-28T06:09:41.220" UserId="1374" />
  <row Id="20787" PostId="13603" Score="1" Text="I think this is a bicycle, not a motorcycle. But a generator hub would work in that case. " CreationDate="2011-04-28T07:03:57.463" UserId="2348" />
  <row Id="20788" PostId="13554" Text="BTW, if you need a bias you can also use a LED (check the data sheet, the forward drop is significantly larger and varies with wavelenght!) and you get a little indicator light out of it too!" CreationDate="2011-04-28T07:51:11.610" UserId="1802" />
  <row Id="20789" PostId="13598" Score="1" Text="@AngryEE - Right-click the formula and select &quot;show source&quot; from the MathJax context menu :- $C_{DE}=\tau_F.g_m$" CreationDate="2011-04-28T08:01:00.753" UserId="2234" />
  <row Id="20790" PostId="13569" Text="Yah, looks like the right kind of holes, if you know what I mean :D Not sure how &quot;obvious&quot; this is, someone else might want to use female pins (they're good for use with wires). But that's what works best for me :)" CreationDate="2011-04-28T08:28:53.947" UserId="4028" />
  <row Id="20791" PostId="13609" Text="Does this mean that the circuit is currently sending a waveform to the speaker? Would a capacitor be used to smooth this out and keep my reed switch closed? how would I work out the required capacitance?" CreationDate="2011-04-28T08:50:53.360" UserId="4029" />
  <row Id="20792" PostId="13609" Text="No. The circuit applies 9V dc to the sounder. The sounder has it's own built-in oscillator. The 9V output could equally be applied to a relay coil. The diode is required to suppress the voltage spike produced by the relay when it switches off - but some relays have this built-in." CreationDate="2011-04-28T09:08:34.250" UserId="2234" />
  <row Id="20793" PostId="13553" Text="This is a clear case of overly broad." CreationDate="2011-04-28T10:12:51.230" UserId="230" />
  <row Id="20795" PostId="13544" Text="DFN-6 is a bit tiny for manual soldering. But I'll take a look at the other package options." CreationDate="2011-04-28T10:50:01.363" UserId="2134" />
  <row Id="20796" PostId="13538" Text="@Vicky Rao Yes, its true that many times within the same family they can be exchanged. However my point was whenever posible to use the code written for the device you are using. There are definite differences between part numbers. Unless you know what the differences are it could create problems" CreationDate="2011-04-28T10:52:44.457" UserId="3453" />
  <row Id="20797" PostId="13531" Text="Robotics is no longer on-topic here. See [meta](http://meta.electronics.stackexchange.com/questions/474/electronics-and-robotics-has-been-renamed-to-electronics)" CreationDate="2011-04-28T11:39:38.297" UserId="938" />
  <row Id="20798" PostId="13609" Text="Thanks for your help, found everything I need - just need to solder it with a minimum of burnt fingers" CreationDate="2011-04-28T12:02:37.800" UserId="4029" />
  <row Id="20799" PostId="13610" Score="1" Text="In an op amp circuit, they determine the gain and/or the differentiation/integration time. See also http://en.wikipedia.org/wiki/Operational_amplifier_applications" CreationDate="2011-04-28T12:12:43.780" UserId="1802" />
  <row Id="20800" PostId="13591" Score="1" Text="Why the down vote? This is a very common question among new engineers." CreationDate="2011-04-28T13:46:14.230" UserId="319" />
  <row Id="20802" PostId="13517" Text="How would one determine the resonant frequency at full load to ensure we don't go below it?" CreationDate="2011-04-28T14:54:39.730" UserId="142" />
  <row Id="20803" PostId="13535" Text="Just thought i might give you an update. I found out that it was wired [incorrectly](http://tinypic.com/r/29ghb9s/7). After I was told that the plug had been checked :L. This is [how](http://www.ultimatehandyman.co.uk/plug8.jpg) a UK plug should be wired. " CreationDate="2011-04-28T15:05:56.143" UserId="1623" />
  <row Id="20804" PostId="13596" Text="The &quot;oscillator's current tick&quot; is read from a register.  I &quot;tune&quot; the oscillator by using a floating-point multiply; the oscillator never actually changes speed.  After &quot;tuning&quot;, the tick register is cleared, to prevent the old tick count from interfering with regression analysis.  Data has been taken over the course of minutes to hours.  After two analyses, the error is always below 1 PPM (the resolution of the tick), and the error remains stable for over an hour.  I want to sync to the reference clock, regardless of its accuracy." CreationDate="2011-04-28T15:34:12.423" UserId="1278" />
  <row Id="20806" PostId="13622" Score="1" Text="They do exist, I have seen them with a big (4&quot; diameter) knob to adjust the resistance. I have no clue what they are called though." CreationDate="2011-04-28T15:48:42.067" UserId="319" />
  <row Id="20807" PostId="13527" Text="@bt2, thanks for the video.  I still don't understand why the high frequency current has to &quot;look ahead&quot;.  Does low frequency current look ahead with parallel resistors to see which path has least resistance?  The higher inductance of the split plane return path exists whether or not any current flows.  Given a lower inductance path, proportionally more AC current will choose that path.  So it really should depend on how badly a split plane ruins the inductance of a path, even with equally spaced planes." CreationDate="2011-04-28T15:52:31.587" UserId="1278" />
  <row Id="20808" PostId="13624" Text="Huh, I didn't know they made them that big.  http://www.tycoelectronics.com/catalog/feat/en/s/26913  Looks like they're about $500 each.  Doesn't the power rating change with the setting though?" CreationDate="2011-04-28T16:05:33.543" UserId="142" />
  <row Id="20809" PostId="13532" Text="@Vicky, Hmm, I've had MLAB settings change on me too. Might be due to opening a different workspace. Hopefully these settings will be stored per project and not per workspace when they release MPLAB X. Either way, open a new question if you want others to see it." CreationDate="2011-04-28T16:34:12.850" UserId="2110" />
  <row Id="20810" PostId="13599" Text="Other possibilities than solar would be a hub generator (expensive), &quot;bottle generator&quot; (dynamo that presses against the tire), or using magnets and coils similar to [systems for lights only](http://www.instructables.com/id/Contactless-dynamo-powering-bike-safety-lights/) ([commercial version](http://www.reelight.com/)) to turn your bicycle wheel into a dynamo (generator)." CreationDate="2011-04-28T16:48:27.410" UserId="4033" />
  <row Id="20811" PostId="13517" Score="1" Text="If you're below the load-dependent resonant frequency, the converter will be unable to control the output any longer, and the primary-side losses will be huge. If you're between the two resonant frequencies, you should see discontinuous secondary current (dead time between peaks). If you're above the load-independent frequency, the secondary current will be continuous (see figure 11 in AN-4151)." CreationDate="2011-04-28T17:11:33.217" UserId="1293" />
  <row Id="20812" PostId="11851" Text="I actually have two of those launchpads. I didn't do much with it, but for that thermometer thing, I'd rather use a tiny adapter directly connected to USB." CreationDate="2011-04-28T17:38:21.457" UserId="2134" />
  <row Id="20813" PostId="13492" Text="for 400 USD this is quite expensive, compared to picotux..." CreationDate="2011-04-28T17:39:52.627" UserId="2134" />
  <row Id="20814" PostId="13544" Text="SHT25 looks really interesting, but it's like not available whatsoever. I guess I'd have to wait till engineering samples become available. Accuracy wise, this thing should be excellent. " CreationDate="2011-04-28T17:43:20.643" UserId="2134" />
  <row Id="20815" PostId="13606" Text="No, that appears to be for driving the bus. I'm looking to monitor it." CreationDate="2011-04-28T18:42:56.140" UserId="206" />
  <row Id="20816" PostId="13623" Text="@Joby I've read that when you buy a shield, it is typically shipped with a C library which is used to interface it with the arduino program. Can these libraries be imported also in those proposed esoteric languages?" CreationDate="2011-04-28T18:49:36.743" UserId="2313" />
  <row Id="20818" PostId="13623" Score="1" Text="With some porting work, yes. For interpreted languages, you could port the shield's driver into the interpreter and add calls. For a compiled language, you could add the shield's driver to the runtime." CreationDate="2011-04-28T19:00:13.477" UserId="566" />
  <row Id="20819" PostId="13628" Text="Can you elaborate a bit on the active loads?" CreationDate="2011-04-28T19:29:51.523" UserId="142" />
  <row Id="20820" PostId="13632" Text="Oh, the rheostat would be acting as a load, so it would be down near 10 Ω." CreationDate="2011-04-28T19:30:17.513" UserId="142" />
  <row Id="20821" PostId="13626" Text="are you asking how to write the PIC code or ?" CreationDate="2011-04-28T19:30:49.793" UserId="2157" />
  <row Id="20822" PostId="13633" Score="4" Text="and to minimize signal reflections" CreationDate="2011-04-28T19:31:06.797" UserId="819" />
  <row Id="20823" PostId="13632" Text="In that case, I would suggest that you might want to use series and parallel resistors together with the rheostat.  If you want a load between 5 and 30 ohms, put a 20-ohm resistor in series with a 10-ohm rheostat, and add 15 100-ohm resistors that can be switched in parallel with them (assembled as parallel groups of 1, 2, 4, and 8 resistors).  That will allow 16 overlapping ranges; at the lower ranges, relatively little power will go through the rheostat." CreationDate="2011-04-28T20:18:35.800" UserId="3123" />
  <row Id="20824" PostId="13636" Text="OMG Thank you very much" CreationDate="2011-04-28T20:21:19.340" UserId="3045" />
  <row Id="20825" PostId="13632" Text="For example, with a 1-watt rheostat, 2-watt 20-ohm resistor, and half-watt 100-ohm resistors, one could handle about 6.3 volts at any scale.  At 5.45 ohms (all resistors enabled--rheostat at full scale), one would be dissipating 7.2 watts, but only one watt of that would be in the rheostat." CreationDate="2011-04-28T20:24:07.510" UserId="3123" />
  <row Id="20826" PostId="13632" Text="One could increase the series resistance of the rheostat (thus reducing the amount of power it would have to handle) by adding more parallel resistors.  The difference in parallel-resistance current between adjacent selections has to be less than the difference between full-scale and zero-scale rheostat current." CreationDate="2011-04-28T20:26:10.720" UserId="3123" />
  <row Id="20827" PostId="13584" Text="What I'm wondering is how you can know how much you've moved the frequency of OUT, other than by using the accuracy analysis?  In which case, the analysis should re-confirm the adjustment you just made.  If you're using a different means - reference - to monitor your adjustment, how does its reference compare to that used for the accuracy analysis?  Maybe I'm missing something, but if you're using A to tweak the OUT, and B to see how well you did, don't you need to also compare A to B before you can critique the results?" CreationDate="2011-04-28T20:28:32.293" UserId="3361" />
  <row Id="20828" PostId="12966" Text="TEC's are not that expensive, especially in bulk. You can buy TEC's off ebay for very cheap just to expirament with them, http://computers.shop.ebay.com/i.html?_nkw=peltier&amp;_sacat=80149&amp;_odkw=&amp;_osacat=80149&amp;_trksid=p3286.c0.m270.l1313 like that. They are also known as peltiers." CreationDate="2011-04-28T20:30:27.163" UserId="2050" />
  <row Id="20829" PostId="13635" Score="2" Text="http://electronics.stackexchange.com/questions/7042/how-much-does-it-cost-to-have-a-custom-asic-made" CreationDate="2011-04-28T20:41:56.923" UserId="566" />
  <row Id="20830" PostId="13636" Text="@kurtnelle, @toybuilder: Which process will yield a price around $2k? I got $8k+ for the ones I tried" CreationDate="2011-04-28T20:42:48.080" UserId="2395" />
  <row Id="20831" PostId="13633" Score="1" Text="@volting - different side of the same coin" CreationDate="2011-04-28T21:08:42.123" UserId="740" />
  <row Id="20832" PostId="13631" Score="2" Text="I'm surprised this hasn't been asked before.  Related: http://electronics.stackexchange.com/questions/6846/how-important-is-impedance-matching-in-audio-applications  Also Wikipedia already answers the question: http://en.wikipedia.org/wiki/Impedance_matching" CreationDate="2011-04-28T21:10:07.250" UserId="142" />
  <row Id="20833" PostId="13633" Text="@JustJeff thats true, I still think it was worth mentioning." CreationDate="2011-04-28T21:15:29.460" UserId="819" />
  <row Id="20834" PostId="13544" Text="Just tried to sample the SHT21: Nope, they're not gonna send me one to my private address. They might send them to my university, though. But it seems you may order just one at a time..." CreationDate="2011-04-28T21:58:20.383" UserId="2134" />
  <row Id="20836" PostId="13603" Text="Well it was definitely migrated from bicycles SE so if it isn't then the OP was in the wrong place initially too." CreationDate="2011-04-28T22:19:10.483" UserId="103" />
  <row Id="20837" PostId="13633" Text="@volting - indeed. so +1" CreationDate="2011-04-28T22:42:53.623" UserId="740" />
  <row Id="20839" PostId="13634" Score="2" Text="Strangely the Wikipedia article makes no mention of the large amounts of Hydrogen (explosive) and Chlorine (toxic) that will be produced!" CreationDate="2011-04-28T23:33:53.863" UserId="2234" />
  <row Id="20840" PostId="13527" Text="@ajs410, maybe I was unclear, the signal can't look ahead, which is why return current flows in both planes as the signal propagates down the trace, even if one plane has a split.  Another example of this is stubs.  Some people, for example, run a clk trace to the edge of the board to a test point for debugging.  This causes noise which can lead to FCC failure.  Why does current flow through an unterminated trace?  Because the signal doesn't know it isn't terminated until it reaches the end of the trace; it can't see the future.  The trace becomes an antenna." CreationDate="2011-04-29T00:25:07.347" UserId="2377" />
  <row Id="20842" PostId="13636" Text="This might be only &gt;1um and with 50% student price... " CreationDate="2011-04-29T01:03:17.977" UserId="2062" />
  <row Id="20843" PostId="13637" Text="Maybe they can't afford anything else?" CreationDate="2011-04-29T01:04:48.863" UserId="142" />
  <row Id="20844" PostId="13634" Text="Do it outside :)" CreationDate="2011-04-29T01:08:40.373" UserId="142" />
  <row Id="20845" PostId="12966" Text="Yeah, I did end up buying one on eBay and it was very cheap!  We'll have to see what sort of power it's good for..." CreationDate="2011-04-29T01:27:04.797" UserId="2288" />
  <row Id="20846" PostId="13643" Score="1" Text="has to be a schmitt-trigger; without the hysteresis it will just settle at a voltage somewhere near the middle of the rails." CreationDate="2011-04-29T01:33:32.483" UserId="740" />
  <row Id="20848" PostId="13646" Text="Jeff, i concur with your assessment" CreationDate="2011-04-29T02:07:43.513" UserId="771" />
  <row Id="20849" PostId="13642" Text="the comment 20000000UL  // 1MHz seems inaccurate :)" CreationDate="2011-04-29T02:08:16.553" UserId="771" />
  <row Id="20850" PostId="13647" Score="1" Text="Subjective. Mark as community wiki." CreationDate="2011-04-29T03:15:25.397" UserId="206" />
  <row Id="20851" PostId="13646" Text="If you have a pull-down on the mosfet gate, both options would work. However, if you just let it float, setting the pin to an input would cause it to behave in an unspecified manner." CreationDate="2011-04-29T03:18:40.927" UserId="1374" />
  <row Id="20852" PostId="11286" Score="1" Text="Leon's solution is overkill for what you need, but I presume he posted it before he knew exactly what your application was." CreationDate="2011-04-29T06:41:41.077" UserId="2064" />
  <row Id="20853" PostId="13643" Text="Is there any drawback to using an op-amp based schmitt trigger over one of the 74HC14s?" CreationDate="2011-04-29T07:53:57.947" UserId="1802" />
  <row Id="20854" PostId="13643" Score="1" Text="@Ranieri - not really. I posted this because it's the absolutely minimum component count solution. It has fixed trigger levels, however, in the opamp version you can set the trigger levels yourself." CreationDate="2011-04-29T08:01:58.810" UserId="2064" />
  <row Id="20855" PostId="13041" Text="Thanks, sorry I didn't phrase that very clearly, it's the combination of voltage or no voltage on VBUS_IN, and resistors between ID_CON and ground that I'm looking at. Although looking at the block diagram again perhaps I should also be looking at charger detection since that's another input to switch control. Anyway I'm building an automated tester now with a motorized potentiometer (homemade, from Lego!) to try different combinations." CreationDate="2011-04-29T08:15:21.603" UserId="3862" />
  <row Id="20856" PostId="13626" Text="@kenny - as you said,I am asking how can I write PIC code." CreationDate="2011-04-29T09:25:32.293" UserId="3916" />
  <row Id="20857" PostId="13637" Text="@hak8or - thanks for your answer." CreationDate="2011-04-29T09:25:55.647" UserId="3916" />
  <row Id="20858" PostId="13647" Text="@hak8or, this site is for technical questions that will not be subjective or argumentative. This question is very open ended and opinionated. I hope you continue to contribute, but bring great technical questions and problems." CreationDate="2011-04-29T09:30:04.220" UserId="230" />
  <row Id="20859" PostId="13650" Text="@danielGrillo, as I was clicking close you beat me to it. @alex, this site is for designing electronics, not consumer usage." CreationDate="2011-04-29T09:30:56.013" UserId="230" />
  <row Id="20860" PostId="13643" Score="1" Text="Getting an op amp circuit to oscillate at 1 MHz to 10 MHz will be very difficult!" CreationDate="2011-04-29T10:07:03.333" UserId="305" />
  <row Id="20861" PostId="13654" Score="3" Text="Are we talkign about a graphical display or a segmented character display? On a segmented display, you can't obviously display anythign that does not fit the segment pattern. For &quot;western&quot; non-ascii uses, you can probably fall back to the base (non-accented etc.) character. For other scripts you are most likely out of luck." CreationDate="2011-04-29T10:26:58.990" UserId="1802" />
  <row Id="20862" PostId="13643" Text="This circuit is nice, but I've used them at my college and even on a little PCB designed exactly for this most chips can only manage ~3.5 MHz. I had an old 74LS00 NAND gate lying around, and I got that to go up to 75 MHz(!)" CreationDate="2011-04-29T10:30:06.490" UserId="1225" />
  <row Id="20863" PostId="13650" Text="@kortuk, it happened with me too in another question " CreationDate="2011-04-29T10:34:46.250" UserId="938" />
  <row Id="20865" PostId="13656" Text="You are on point, thats exactly what i need, a motor that is slow and strong enough to slide that flatebed foreward and reverse. Thank you, Two thumbs up !" CreationDate="2011-04-29T11:39:26.233" UserId="4039" />
  <row Id="20867" PostId="13646" Score="1" Text="actually switching it to input with the port set to one enables the internal pullup, so the output would in effect always be high." CreationDate="2011-04-29T12:26:52.490" UserId="771" />
  <row Id="20868" PostId="13628" Score="1" Text="Well, I deal in power supplies between 12V and 54V, generally, and the company has a large number of (now discontinued) Hewlett-Packard HP6050 active load mainframes. I use between 10 and 12 channels of 60V/60A load to test the power supplies, using LabVIEW-based automation software. Agilent (HP succesor for test equipment) has a replacement (Agilent N33xx series) and Chroma has similar-styled loads." CreationDate="2011-04-29T12:50:18.883" UserId="1293" />
  <row Id="20869" PostId="13655" Text="@Cza thank you; do you think this kind of [Tft graphical display](http://www.watterott.com/en/Arduino-S65-Shield) could offer a better unicode support?" CreationDate="2011-04-29T13:05:31.123" UserId="2313" />
  <row Id="20870" PostId="13643" Score="1" Text="@Leon - you're right (I forgot the frequency requirements for a moment.)" CreationDate="2011-04-29T13:14:51.910" UserId="2064" />
  <row Id="20871" PostId="13517" Score="1" Text="Otherwise, you have to remove the transformer and measure the magnetizing inductance and leakage inductances, and follow the derivations in the datasheets to calculate the resonant frequencies." CreationDate="2011-04-29T13:14:52.600" UserId="1293" />
  <row Id="20872" PostId="13655" Score="1" Text="This is a graphics display, as far as I can see, so it can display pretty much anything you want. The library provided provides functions to paint text as well, but again it supports 8-bit characters only. &#xA;&#xA;So, with this display you either need to the same sort of conversion as described above and use the library as is, or you have to modify the library to support UTF8.&#xA;&#xA;Keep in mind, that using a graphics display will make your code bigger - you need extra library, font, etc. But at least you have full control of the available character set - the font is part of the software.&#xA; " CreationDate="2011-04-29T13:22:18.770" UserId="3564" />
  <row Id="20873" PostId="13618" Score="1" Text="I've just noticed this tutorial on [freetronics](http://www.freetronics.com/pages/stacking-arduino-shields) about stacking shields." CreationDate="2011-04-29T13:46:17.570" UserId="1623" />
  <row Id="20875" PostId="13527" Text="I'm agreeing with you that the signal can't look ahead, but the concept of &quot;looking ahead&quot; is at odds with the circuits being loops.  In your unterminated trace, for example, I thought it was the parasitic inductance and capacitance of the trace/testpoint that &quot;completed the circuit&quot;, allowing the high frequency currents to form a loop.  The magnitude of the noise from the test point is probably a function of its parasitics.  To take your clock stub as an example, gradually add trace length (i.e. parasitics) to the stub.  For some lengths, it will pass FCC testing." CreationDate="2011-04-29T15:41:53.670" UserId="1278" />
  <row Id="20876" PostId="13642" Text="lol yeah I didn't change the comment. Originally the example was for the internal oscillator.  I'm a lazy bugger lool." CreationDate="2011-04-29T15:47:29.837" UserId="2824" />
  <row Id="20877" PostId="13584" Text="I only have two clocks, OUT and REF.  My goal is not to sync to &quot;real time&quot;, but sync to REF, regardless of its accuracy.  I analyze OUT against REF with regression, determine how many tick/sec OUT is ahead or behind REF (R^2 = 0.999), and tune OUT to compensate for the missing ticks.  I then run the analysis a second time, expecting to get fractional tick/sec.  Instead I get another R^2=0.999 line.  Adding the second adjustment to the first generates the desired fractional tick/sec.  REF remains stable throughout the analysis, done over minutes to hours." CreationDate="2011-04-29T15:52:34.897" UserId="1278" />
  <row Id="20878" PostId="13527" Text="Yes the parasitics will complete the loop.  The idea, when designing a PCB, is to provide as low impedance as possible for the return current to prevent electromagnetic radiation from flying off the board.  In the case of a split in an adjacent plane, the return current will have a nice low inductance path as the signal propagates down the board until the split is hit, at which point parasitics will come into play as the signal jumps over the split (through the air).  " CreationDate="2011-04-29T18:13:11.043" UserId="2377" />
  <row Id="20879" PostId="13527" Text="But since the signal doesn't know about the split ahead of time, it can't avoid the split by sending all the return current to the opposing plane.  Once the signal reaches its destination and a DC loop is formed, the current will travel through the plane without a split.  There isn't anything invalidating current loops here though.  As the signal initially travels down its trace, the return current flows in the adjacent planes because of the low inductance.  During this extremely small amount of time we are concerned with &quot;partial inductance&quot; instead of the total inductance." CreationDate="2011-04-29T18:26:49.393" UserId="2377" />
  <row Id="20880" PostId="13527" Text="In the case of the clk testpoint.  If the parasitcs are such that the energy is absorbed and returned through the ground plane, you're really good or lucky.  This isn't much different than putting a cap across a plane split in close proximity to where a trace crosses the split.  You are providing a low impedance loop closure on the board, which is far superior to off the board (unless you are purposely designing an antenna).  A propagating signal is a wild beast (or heard of beasts) we try to provide the lowest possible impedance for to keep things contained to the board." CreationDate="2011-04-29T18:38:18.103" UserId="2377" />
  <row Id="20881" PostId="13618" Text="@Systempuntoout I have no added it as an answer." CreationDate="2011-04-29T18:47:22.700" UserId="1623" />
  <row Id="20882" PostId="13636" Text="That $2K estimate is 7+ years old; times prob changed." CreationDate="2011-04-29T18:56:28.320" UserId="3045" />
  <row Id="20883" PostId="13413" Text="So it turns out that the Dremel 4000 is more robust and stalling doesn't damage it. Time to upgrade." CreationDate="2011-04-29T18:59:41.733" UserId="3045" />
  <row Id="20884" PostId="13404" Text="I've read it over and over and can't figure out the word that's missing." CreationDate="2011-04-29T19:02:24.957" UserId="3045" />
  <row Id="20885" PostId="13524" Text="Thanks for your response" CreationDate="2011-04-29T20:09:10.063" UserId="3089" />
  <row Id="20886" PostId="13519" Text="Thanks for your response. In power bars which have a &quot;control&quot; outlet, how does it know when the power it turned on for that outlet? Specially what kinds of components?" CreationDate="2011-04-29T20:10:21.747" UserId="3089" />
  <row Id="20887" PostId="13653" Text="Should be mentioned that the symbol in the inverter means it has a Schmitt trigger input.  It won't work otherwise." CreationDate="2011-04-29T20:41:54.430" UserId="142" />
  <row Id="20888" PostId="11254" Text="What are you using to emit sound?  Piezo or regular speaker?" CreationDate="2011-04-29T20:43:03.023" UserId="142" />
  <row Id="20889" PostId="13663" Text="Higher never hurts unless the ESR is less." CreationDate="2011-04-29T20:51:32.153" UserId="206" />
  <row Id="20890" PostId="13664" Text="@LeonHeller - I can't find anything like that on the data sheet(s) I'm checking - can you tell me what to look under and possibly a link to the sheet you're looking at?  Thanks" CreationDate="2011-04-29T20:53:22.897" UserId="3778" />
  <row Id="20891" PostId="13664" Text="Try http://www.fairchildsemi.com/ds/LM/LM7812.pdf, page 23." CreationDate="2011-04-29T20:54:19.453" UserId="305" />
  <row Id="20892" PostId="13664" Text="Ah, got it, thanks!" CreationDate="2011-04-29T20:55:10.370" UserId="3778" />
  <row Id="20893" PostId="13663" Text="ESR is irrelevant in this situation." CreationDate="2011-04-29T21:01:55.390" UserId="305" />
  <row Id="20894" PostId="13662" Score="1" Text="Can you provide a minimal example that shows the problem?" CreationDate="2011-04-29T21:10:52.490" UserId="206" />
  <row Id="20895" PostId="13663" Text="well .. when you energize the circuit, the cap will look like a short circuit for a short time. larger capacitors present more stress to the devices that charge them up, potentially shortening their lifespan. you could probably use 470uF as well as 100uF; just don't stick a 50,000uF on there." CreationDate="2011-04-29T21:40:56.493" UserId="740" />
  <row Id="20896" PostId="13598" Text="@Mike, I didn't know you could do that! Nice..." CreationDate="2011-04-29T21:44:58.147" UserId="3635" />
  <row Id="20897" PostId="13659" Score="1" Text="When I see people inventing such crazy transistors schemes - I just feel stupid :-) Unfortunately, this is too complex :-/" CreationDate="2011-04-29T22:32:40.030" UserId="2062" />
  <row Id="20898" PostId="12864" Text="No power dissipation on mosfet, it opens fully. I can't use low-side N-MOSFET as I need to sense rotation speed. I have some ringing but it's not my main problem at the moment." CreationDate="2011-04-29T22:36:27.530" UserId="2062" />
  <row Id="20899" PostId="13628" Score="1" Text="I used the carbon disk rheostats for discharging Ni Cad aircraft batteries in the Airforce. they can handle high wattage. " CreationDate="2011-04-29T22:37:31.600" UserId="1810" />
  <row Id="20902" PostId="13651" Text="@Elias, we cannot do your entire project for you. There is a lack of enough detail to really give a full solution and you are mostly asking for directions to where you can buy a solution." CreationDate="2011-04-30T00:41:34.537" UserId="230" />
  <row Id="20903" PostId="13665" Score="3" Text="look at my usb [single chip scope here](http://yveslebrac.blogspot.com/2008_10_01_archive.html), it is difficult to do with fewer parts&#xA;1 ATTiny45 and a couple of zener, 2 chanels HID" CreationDate="2011-04-29T23:23:04.977" UserId="4047" />
  <row Id="20904" PostId="13665" Text="Very cool project!" CreationDate="2011-04-29T23:24:28.127" UserId="3564" />
  <row Id="20906" PostId="13678" Text="@codeMonk can you supply more detail on using pyserial to interface with Arduino? Code sample or links appreciated." CreationDate="2011-04-30T05:22:35.697" UserId="3926" />
  <row Id="20907" PostId="13679" Text="@LeanerRocky, I am sorry but shopping advice does not fit well into Stack Exchange sites." CreationDate="2011-04-30T06:38:58.403" UserId="230" />
  <row Id="20908" PostId="13676" Text="`Otherwise they are really the same thing` - This hasn't been true in anything but some (musical) instrument microphones for decades. Everything on the market at this point pretty much uses little electret mics, which are a whole different ball-o-wax." CreationDate="2011-04-30T08:11:56.793" UserId="1374" />
  <row Id="20909" PostId="13626" Text="@kenny - is there a sample PIC code in your hands?" CreationDate="2011-04-30T08:32:21.570" UserId="3916" />
  <row Id="20910" PostId="1480" Text="@Jluciani, we discussed this in the past, and it seems it must be discussed again. Signatures are **not** allowed on SE sites. I have removed your signature a second time after you rolled back to add it. Your site is interesting, put it in your bio so that all can see it easily." CreationDate="2011-04-30T10:21:57.500" UserId="230" />
  <row Id="20911" PostId="13626" Text="@Cell-o, try something and people here will help." CreationDate="2011-04-30T12:50:06.460" UserId="2157" />
  <row Id="20912" PostId="11767" Text="i'm definitely getting the impression that i misapprehended how simulators work. if a trusted tool like SPICE doesn't need to derive equations, doesn't seem likely anyone else would bother. so i'll accept this for now." CreationDate="2011-04-30T13:39:35.017" UserId="740" />
  <row Id="20913" PostId="13690" Text="fwiw, the sealed lead-acid battery (SLB), which is what is probably in your UPS, and the automotive battery are constructed a little differently. SLB's have a gel electrolyte and car batteries have a liquid system. This might make a difference. (If I knew, I'd post an answer)" CreationDate="2011-04-30T13:57:26.647" UserId="740" />
  <row Id="20915" PostId="5509" Text="@Thomas Dave of the EEVblog loves sticking cheap multimeters on ohm setting into mains - like in [this $100 multimeter shootout](http://www.eevblog.com/2010/07/11/eevblog-99-100-multimeter-shootout-extech-amprobe-bk-precision-ideal-uei-uni-t-part-1of2/) - sadly, none of them blew up :)" CreationDate="2011-04-30T14:27:24.823" UserId="1951" />
  <row Id="20916" PostId="13684" Text="Someone I asked in person suggested that since `220.0 k` and `0.2200M` are exactly the same thing, this might just be because nobody cares. If you don't care, that would be a helpful answer too :)" CreationDate="2011-04-30T14:33:39.170" UserId="1951" />
  <row Id="20917" PostId="11344" Text="Next step in this project: http://electronics.stackexchange.com/questions/11502/playing-with-a-shift-register-and-some-leds" CreationDate="2011-04-30T14:46:34.177" UserId="813" />
  <row Id="20918" PostId="13690" Text="@JustJeff it is possible to get sealed car batteries. " CreationDate="2011-04-30T14:52:16.930" UserId="1623" />
  <row Id="20927" PostId="13690" Text="@Dean, yeah, most of them actually seem to be sealed, but I believe they're still liquid electrolyte, aren't they? " CreationDate="2011-04-30T15:23:14.657" UserId="740" />
  <row Id="20934" PostId="13692" Text="With energy harvesting, plenty of power will be available for an MCU and LED." CreationDate="2011-04-30T16:33:39.310" UserId="305" />
  <row Id="20935" PostId="13678" Score="1" Text="Sure thing. Check out the example." CreationDate="2011-04-30T16:42:56.803" UserId="2762" />
  <row Id="20936" PostId="13697" Score="1" Text="Related: http://electronics.stackexchange.com/questions/6615/title-my-resume-electronics-engineer-w-o-an-ee-degree" CreationDate="2011-04-30T16:52:44.910" UserId="536" />
  <row Id="20937" PostId="13697" Score="1" Text="And to add my comment, depending on where you work, you may or may not be legally allowed to call yourself an engineer without being a P.Eng." CreationDate="2011-04-30T16:54:07.717" UserId="536" />
  <row Id="20938" PostId="13698" Text="What about flashing the LED to indicate the wind speed?" CreationDate="2011-04-30T16:59:34.047" UserId="305" />
  <row Id="20939" PostId="13698" Text="Theoretically the capacitor will charge until the voltage for the Joule Thief to lit the LED is enough. Then when the LED lights up, the capacitor will discharge so things will start again from the start." CreationDate="2011-04-30T17:04:01.333" UserId="2639" />
  <row Id="20940" PostId="13698" Score="1" Text="Once it gets to a certain speed, which could be quite low, won't the LED be on continuously?" CreationDate="2011-04-30T17:14:31.053" UserId="305" />
  <row Id="20941" PostId="13697" Text="Thanks, and I find your second point extremely annoying.  My limited exposure to Architectural electrical engineering is that it is barely engineering.  It is basically following rules.  Apparently, the government thinks this is engineering while designing a computer isn't.  But, it seems like everyone knows this so it may not be a big deal.  I know there are plenty of contract engineers out there who may not be PEs, so I'm basically wondering what they call themselves, or if my perspective of what a PE is (or its value) is completely wrong." CreationDate="2011-04-30T17:18:40.877" UserId="2377" />
  <row Id="20942" PostId="13698" Text="In this case, he could use a divider to charge the capacitor slower. Or use a smaller capacitor. Or both. It's trial and error." CreationDate="2011-04-30T17:22:59.497" UserId="2639" />
  <row Id="20944" PostId="13698" Text="He said he wanted the LED to blink according to the wind speed. That looks like flashing to me!" CreationDate="2011-04-30T17:51:59.337" UserId="305" />
  <row Id="20945" PostId="13690" Text="I've got a bunch of smaller 12v gel cell batteries already, and I could hook them up in parallel, but no idea what that would be like.  One of them could be weaker, etc.  The liquid car batteries have an open cell potential of 13.8v, is it different for gel cells?" CreationDate="2011-04-30T17:53:19.007" UserId="4054" />
  <row Id="20946" PostId="13697" Score="3" Text="In what country?" CreationDate="2011-04-30T18:08:54.113" UserId="206" />
  <row Id="20947" PostId="13685" Text="The point is to blink the LED using only the generated electricity. By &quot;making the LED blink according to the wind speed.&quot; i meant that with higher wind speed electricity would be stored faster making it discharge more frequently." CreationDate="2011-04-30T18:11:54.467" UserId="4052" />
  <row Id="20948" PostId="1133" Text="Please split out the relay question into a separate question " CreationDate="2011-04-30T18:12:36.633" UserId="206" />
  <row Id="20951" PostId="13700" Text="That sounds like a pretty good system.  Do you provide the quote with a bunch of legal mumbo jumbo or just in a short plain English document?" CreationDate="2011-04-30T19:06:27.197" UserId="2377" />
  <row Id="20952" PostId="13699" Score="1" Text="Probably a better fit for http://answers.onstartups.com/ or project management maybe, not sure , but I went ahead and put down what I do." CreationDate="2011-04-30T19:27:48.473" UserId="319" />
  <row Id="20953" PostId="13679" Score="1" Text="This is a legit question!  Have you ever tried to find a USB-&gt;I2C bridge?  USB-&gt;Async serial is easy, but I2C isn't." CreationDate="2011-04-30T19:45:47.637" UserId="411" />
  <row Id="20954" PostId="13700" Score="1" Text="@bt2 I just give my terms up front in simple english. If people are going to rip me off I am usually at least left with 66%." CreationDate="2011-04-30T19:47:16.337" UserId="1225" />
  <row Id="20955" PostId="13578" Text="Both techniques vary the &quot;angle&quot; of the carrier wave. Hence carrier amplitude will be constant in both cases. Although the change in &quot;angle&quot; is governed by different rules. It's still same in terms of how a wave &quot;looks&quot; when plotted." CreationDate="2011-04-30T20:12:18.000" UserId="3199" />
  <row Id="20956" PostId="13695" Text="@Leon Heller That's not strictly correct.  Check out this datasheet, http://www.national.com/ds/LP/LP2985.pdf, page 15, reverse output-input voltage.  Most regulators have some sort of diode, but it can be easy to exceed the power rating on that diode.  In those cases, an external diode is required.   Reducing the caps on the output can help this diode situation, but sometimes that can't be avoided." CreationDate="2011-04-30T21:34:23.803" UserId="3624" />
  <row Id="20957" PostId="4287" Text="Do you have a particular goal or project in mind?" CreationDate="2010-09-07T14:57:20.537" UserId="1307" />
  <row Id="20958" PostId="4287" Text="I agree. To me this is all about getting specific things done. Arduino is just a tool like anything else." CreationDate="2010-09-07T15:57:49.267" UserId="1402" />
  <row Id="20959" PostId="4287" Text="What I'm working on right now is a multiplexed LED array. Not that difficult in Arduino, but I want to get rid of the training wheels. I mean, ultimately, there's an ATmega168 chip on the Arduino board. If I could figure out how to work with it directly, I think that would satisfy what I'm trying to achieve." CreationDate="2010-09-07T21:17:21.310" UserId="989" />
  <row Id="20960" PostId="4287" Text="You're actually pretty direct to the chip with the Arduino.  It doesn't have that many drivers or anything attached to the pins.  The headers go directly there.  Perhaps a breadboarduino?" CreationDate="2010-09-08T15:13:45.767" UserId="249" />
  <row Id="20961" PostId="4287" Text="@angryee - I think Chris means, program the ATmega chip directly, without the Arduino IDE + libraries, which could be seen as training wheels.  " CreationDate="2010-09-11T22:06:41.233" UserId="374" />
  <row Id="20962" PostId="13642" Text="can you look up the source to the _delay_ms() function/macro?  I suspect you are overflowing something inside there." CreationDate="2011-04-30T22:12:24.547" UserId="411" />
  <row Id="20963" PostId="13642" Score="1" Text="It's bad style to let execution flow to the end of main() in an embedded processor.  There's nothing to return to.  So add a &quot;while (1);&quot; at the end to loop forever." CreationDate="2011-04-30T22:13:51.910" UserId="411" />
  <row Id="20964" PostId="13695" Text="It does apply to most of the popular regulators, though, such as the LM78xx." CreationDate="2011-04-30T22:18:39.430" UserId="305" />
  <row Id="20965" PostId="13679" Score="1" Text="Hmm, *where* might've been the wrong way to ask. What he means is, *which* USB &lt;-&gt; I²C Bridge he should invest in. The focus here, is on an actual product, not a webshop or something. I've stumbled upon this question since I'm looking for one myself." CreationDate="2011-04-30T22:26:31.087" UserId="2134" />
  <row Id="20966" PostId="13693" Text="Toss a diode in series with the output - Hey-Presto, any regulator will now work!" CreationDate="2011-04-30T22:30:31.673" UserId="1374" />
  <row Id="20967" PostId="13690" Text="woops, i put SLB when i meant SLA." CreationDate="2011-04-30T22:46:38.977" UserId="740" />
  <row Id="20968" PostId="13695" Text="@Leon Heller  I've encountered it enough where I always check the datasheets.  Better safe than sorry.  It does appear to be more common on the newer regulators, regulators with lower current specs, and LDO's.  You're right that the 78XX series does not appear to mention it in the datasheets.  I just have to mention, however, that I haven't used a 78XX in over 15 years-- although given the types of people who are normally on this web site I'm the odd man out." CreationDate="2011-04-30T22:48:17.673" UserId="3624" />
  <row Id="20969" PostId="13693" Text="@Fake Name, you gonna tell your 3.3V micro to work at 2.6V?" CreationDate="2011-04-30T22:51:19.103" UserId="1225" />
  <row Id="20970" PostId="13705" Text="I have never before seen `do` without a `{}` code block `do (i--)`. Interesting. GCC seems to allow dropping the `()` too" CreationDate="2011-04-30T23:15:23.410" UserId="566" />
  <row Id="20971" PostId="13705" Text="how we are going to set delay time" CreationDate="2011-04-30T23:17:13.677" UserId="3426" />
  <row Id="20972" PostId="13705" Text="Just change the value of i." CreationDate="2011-04-30T23:20:43.620" UserId="305" />
  <row Id="20973" PostId="13705" Text="Joby: A single statement doesn't need braces round it." CreationDate="2011-04-30T23:27:25.687" UserId="305" />
  <row Id="20974" PostId="13707" Text="Um, what do you consider high-bandwidth and insanely expensive?" CreationDate="2011-04-30T23:43:21.473" UserId="206" />
  <row Id="20975" PostId="13705" Text="i increased but's it's nearly same" CreationDate="2011-05-01T00:07:58.713" UserId="3426" />
  <row Id="20976" PostId="13695" Text="I'd also be fairly wary about saying it's a &quot;requirement of voltage regulators&quot;.  Generally true, but if you assume incorrectly very bad things can happen." CreationDate="2011-05-01T00:45:54.563" UserId="1407" />
  <row Id="20977" PostId="13705" Score="2" Text="You can't increase i to more than 65535, because it's 16-bit integer.  (It's a good habit to use types like &quot;uint16_t&quot; instead of &quot;unsigned int&quot;, so that overflows don't sneak up on you.  Also, this causes the code to behave the same when compiled on your desktop PC, where it's easier to debug tricky algorithms.)" CreationDate="2011-05-01T03:51:14.597" UserId="411" />
  <row Id="20978" PostId="13705" Score="2" Text="&quot;do (i--); while (i != 0);&quot; is the same as &quot;while (--i);&quot;, no?" CreationDate="2011-05-01T03:52:43.677" UserId="411" />
  <row Id="20979" PostId="13679" Text="@markrages, I2C is definitely harder, that does not make a question that asks, &quot;Where can I buy X?&quot; an acceptable question. Asking about solutions for USB to I2C and their technical advantage with long and technical answers would work. This is clearly shopping." CreationDate="2011-05-01T04:07:23.927" UserId="230" />
  <row Id="20980" PostId="13699" Score="2" Text="Put a lot of thought into how you define completion, and what happens when (not if, WHEN) the requirements change." CreationDate="2011-05-01T04:34:18.680" UserId="2246" />
  <row Id="20981" PostId="1133" Text="As important to splitting out the relay question would be specifying what sort of power - AC, DC, high voltage or high current, what kind of load (resistive or inductive), etc.  " CreationDate="2011-05-01T04:38:41.043" UserId="2246" />
  <row Id="20982" PostId="13713" Text="I  want to control Dc Motor with L293D.I connected the pins with each other.So I want to motor turns for more than 3 second.But first,for experimental I'm trying to blink led for5 second but it took 1 or 2 seconds.What should I do" CreationDate="2011-05-01T07:40:43.060" UserId="3426" />
  <row Id="20983" PostId="13693" Text="@Thomas O - Then use a Schottky, or an adjustable reg." CreationDate="2011-05-01T08:30:26.553" UserId="1374" />
  <row Id="20984" PostId="13705" Text="what shoud i do for led blink for more than 1 second" CreationDate="2011-05-01T08:44:23.837" UserId="3426" />
  <row Id="20985" PostId="13693" Text="@Fake Name, a diode has further issues; namely, increased drop out voltage, and making the output less stable with load current. Also, there's the extra cost, and surface area. With an adjustable regulator, you have to have feedback resistors, further increasing cost and size. And not all adjustable regulators - especially LDOs - will be happy with a diode in the feedback loop." CreationDate="2011-05-01T09:35:55.270" UserId="1225" />
  <row Id="20986" PostId="13678" Text="@codeMonk I really appreciate the example. You are legend!!" CreationDate="2011-05-01T09:39:25.143" UserId="3926" />
  <row Id="20987" PostId="13679" Text="I want to learn about I2C. I just want to get started quickly. :/ I will repost a new question." CreationDate="2011-05-01T09:44:09.383" UserId="3926" />
  <row Id="20988" PostId="13712" Text="@Ang, this is not my specialty, but it often helps if you give us a link to the source of your information. Even I may be able to help with the context of the claim. On that note, in a digital system the clock rate is constant. If you had a slower rise or fall time then the clock rate would have to be designed for the slower signals. By having matching rising and falling times your clock matches the speed of both." CreationDate="2011-05-01T10:00:54.130" UserId="230" />
  <row Id="20990" PostId="13703" Text="@angryEE, and those that live in states where your business card cannot say engineer without it. Yes, there are always other names you can use, but some of us like the term engineer. Otherwise, I agree with the rest. Almost every state requires you are licensed or certified engineering company to place engineer in your name." CreationDate="2011-05-01T10:25:43.073" UserId="230" />
  <row Id="20991" PostId="13705" Score="1" Text="Make i an unsigned long and increase the value. Invest in a good book on C, such as The C Programming Language by Kernighan and Ritchie, read it, and you will be able to work this stuff out for yourself!" CreationDate="2011-05-01T10:43:48.440" UserId="305" />
  <row Id="20994" PostId="13707" Text="To be more specific, define a price range. That way answers can be more targeted and less vague." CreationDate="2011-05-01T12:37:44.850" UserId="3926" />
  <row Id="20995" PostId="13717" Text="Why can't you use the Microchip code?" CreationDate="2011-05-01T12:46:22.923" UserId="305" />
  <row Id="20996" PostId="8688" Text="40 years on, as I read about the Intel 4004.. it's amazing, what a feat!" CreationDate="2011-05-01T12:48:00.067" UserId="3926" />
  <row Id="20997" PostId="13715" Text="answering your own question is an accepted practice, for those that wonder. This does seem like a very narrow question though. Is this going to really be of long term value to the site and community on the whole?" CreationDate="2011-05-01T12:51:12.517" UserId="230" />
  <row Id="20998" PostId="13717" Score="1" Text="I can use it. But it's inevitable that a free and easily distributable source code will exist, if not already." CreationDate="2011-05-01T12:53:15.473" UserId="3926" />
  <row Id="20999" PostId="13703" Score="1" Text="@Kortuk - I hadn't heard the business card thing.  Maybe it's not a thing in Florida because my last job (big, major corporation who probably had actual PEs working for it) put 'Controls Engineer' on the card and no one seemed to care.  Not that I got much use out of those cards..." CreationDate="2011-05-01T12:53:42.930" UserId="249" />
  <row Id="21000" PostId="13717" Text="Why do you need open-source code? You can distribute and sell software built with the Microchip code." CreationDate="2011-05-01T13:05:43.343" UserId="305" />
  <row Id="21001" PostId="13715" Text="I think, it will help because lack of webcite push us to look other source. The topic asmd chart is important part of the digital design and It should be learned very well, but I have not seen any book except below one and webpage which express it with verilog code. When I found a one, I want share this link, not for  getting  a vote." CreationDate="2011-05-01T13:19:23.697" UserId="3192" />
  <row Id="21002" PostId="13718" Text="Oh, I didn't say what the problem is. The problem is that I get nothing at all on the serial port output. I would expect a stream of letters 'd's (ascii code 100)" CreationDate="2011-05-01T13:38:17.743" UserId="710" />
  <row Id="21003" PostId="13718" Text="I just found similar code on http://www.fpga4fun.com/SerialInterface.html which works when I try it. I would still like to know what's wrong with mine though" CreationDate="2011-05-01T13:55:34.593" UserId="710" />
  <row Id="21004" PostId="13718" Score="2" Text="I don't speak Verilog, but I noticed that your stopbit is zero, which should be 1. Are you reading the port on a scope, or are you reading on a UART? In the latter case you may not have a character received if it doesn't see the stopbit." CreationDate="2011-05-01T14:05:02.370" UserId="2064" />
  <row Id="21005" PostId="13720" Text="Yes absolutly this is to learn verilog. Seemed like a nice manageable little project to learn some basics." CreationDate="2011-05-01T15:04:51.317" UserId="710" />
  <row Id="21006" PostId="13720" Text="I'll add a reset. I figured that the clock would wrap around soon enough anyway though so this would just cause the first bit to be delayed a few ms. Not what I'd do for real projects but a reasonable shortcut while learning. Am I wrong?" CreationDate="2011-05-01T15:05:54.257" UserId="710" />
  <row Id="21008" PostId="13718" Text="Oh no a typo. That's all it was. I looked at that code 100 times and didn't notice. Thank you, it works perfectly now. Can you put this as an answer then I can accept it?" CreationDate="2011-05-01T15:17:02.000" UserId="710" />
  <row Id="21010" PostId="13721" Text="Have you tried the Launchpad support forum?" CreationDate="2011-05-01T15:51:14.887" UserId="305" />
  <row Id="21011" PostId="13720" Score="1" Text="You cannot assume that the registers start at 0. Therefore, it is imperative that all registers be reset to a known state at startup. In your case, *state* and *clockdiv* are both undefined at startup. So, incrementing an undefined value is still undefined, etc..." CreationDate="2011-05-01T16:38:18.440" UserId="1938" />
  <row Id="21012" PostId="13720" Text="I figured that it would have *some* value between 0..8191 so would eventually end up at zero and start working. Point taken though, I will be sure to handle reset properly in future. " CreationDate="2011-05-01T17:03:47.583" UserId="710" />
  <row Id="21014" PostId="13733" Text="Ok. I chose this programmer because of the price, and (this probably isn't good, but) I dislike in-circuit programming. Is there another similar to this that uses a usb interface? Also, you wouldn't happen to have a basic schematic on how to set up a pic with an external oscillator?" CreationDate="2011-05-01T18:19:46.910" UserId="2873" />
  <row Id="21015" PostId="13733" Text="Just [googled](http://urriellu.net/sections/projects/electronics/picdub18-pic-development-board/img/nrm/schematic.png) and found that its connected to the PIC in the lower left hand side of the image. It uses two capacitors connected to osc1 and osc2." CreationDate="2011-05-01T18:23:19.980" UserId="1623" />
  <row Id="21016" PostId="13720" Score="2" Text="On an FPGA, a reset may not be strictly necessary. I don't know for sure about Spartan-3, but for other Xilinx architectures, the initial state of the registers is defined in the configuration. For maximum portability (to different architectures, or an ASIC), HDL descriptions should typically still have a reset, but a reset is not required." CreationDate="2011-05-01T18:52:38.710" UserId="3441" />
  <row Id="21017" PostId="13733" Score="2" Text="That datasheet for any pic will specify how to connect the oscillator" CreationDate="2011-05-01T18:53:47.647" UserId="319" />
  <row Id="21018" PostId="13733" Score="2" Text="http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&amp;nodeId=1406&amp;dDocName=en010020 &lt;-Microchips out of circuit programmer. It will be very beneficial to do in circuit programing though, having to pop pics in and out of a programmer and bread board really takes a toll on the pins and will more then likely cause you problems that are hard to debug." CreationDate="2011-05-01T18:55:34.790" UserId="319" />
  <row Id="21019" PostId="13736" Text="Why the downvotes?" CreationDate="2011-05-01T19:04:25.327" UserId="305" />
  <row Id="21020" PostId="8428" Text="Something like the USBee SX (http://usbee.com) or Saleae Logic (http://saleae.com/logic) USB logic analyzers would do this easily and for under $150. I personally own the USBee SX but should have got the Saleae (I don't run Windows). Both are otherwise pretty much identical." CreationDate="2011-05-01T19:50:55.070" UserId="974" />
  <row Id="21021" PostId="13703" Text="Another context in which a P.E. license may come up for EE's is if you ever do any consulting in a legal setting or serve as an expert witness. Without a P.E., the opposing party is likely to target you as &quot;unqualified&quot;, however ridiculous that may sound." CreationDate="2011-05-01T19:54:14.437" UserId="4066" />
  <row Id="21022" PostId="13724" Score="2" Text="You need to specify the package that you are using. There are two variants with different pin assignments." CreationDate="2011-05-01T21:45:59.637" UserId="638" />
  <row Id="21023" PostId="13741" Text="I'm not convinced this is on-topic; thoughts?" CreationDate="2011-05-01T21:49:16.947" UserId="1227" />
  <row Id="21024" PostId="13741" Text="@Antony.Trupe, I think people working with the bluetooth module asking for help probably fits. They will not get help on another SE site and it normally has to do with the detailed workings of the technology, for this example, bluetooth. I think that this is getting to the boundary of our site, but is still on the boundary and worth answering. " CreationDate="2011-05-01T21:54:10.467" UserId="230" />
  <row Id="21025" PostId="13711" Text="are you using mspgcc or IAR or CCS?" CreationDate="2011-05-02T00:03:04.143" UserId="2060" />
  <row Id="21026" PostId="13595" Text="@AngryEE, a Fourier transform is an amplitude density function in units of amplitude per Hz (or per rad/s). `F(w0) = A` doesn't mean the signal has a term `A*exp(j*w0*t)`. Instead you have to integrate over a spectral band to compute the corresponding time-domain function. As the bandwidth shrinks to 0, the time-domain value becomes infinitesimal -- unless the spectral band contains a delta function. In general you have an uncountably infinite (it can't be indexed) sum of infinitesimal amplitude sinusoids." CreationDate="2011-05-02T01:41:36.413" UserId="721" />
  <row Id="21027" PostId="12771" Text="This is one of the more useful techniques of [immunity aware programming](http://en.wikipedia.org/wiki/immunity_aware_programming)." CreationDate="2011-05-02T01:56:20.573" UserId="813" />
  <row Id="21028" PostId="13671" Text="I had a feeling that with big enough cap I should get any voltage between 0 and 12, and with 10'000uF I kinda get that. The only problem is that PWM-&gt;Voltage graph is very very nonlinear, so it's hard to control below 10V. That's the question - how to make 'rampup' slower let's say on 50% duty cycle." CreationDate="2011-05-02T02:10:39.340" UserId="2062" />
  <row Id="21029" PostId="5091" Text="@DarenW, I like your power-of-2 approach, but I've been thinking about going the opposite direction -- limiting the unique resistor values in my &quot;carry with me everywhere&quot; box to only power-of-10: 10, 100, 1K, 10K, 100K, 1M -- with at least a dozen of each. As Joby Taffey mentioned, we both can still form any possible resistor value to almost any desired precision with parallel and series combination. I don't know if the advantages of having 1/3 as many resistor bins in my box will outweigh the disadvantage of occasionally using 3 or 4 resistors in a location where you would only need 1 or 2." CreationDate="2011-05-02T02:13:25.233" UserId="813" />
  <row Id="21030" PostId="13751" Text="What IC is that? What is P1.2?" CreationDate="2011-05-02T03:18:28.057" UserId="319" />
  <row Id="21031" PostId="13751" Text="I'm using Msp430 Launchpad,i think it's the only one which can create pin" CreationDate="2011-05-02T03:19:34.433" UserId="4063" />
  <row Id="21032" PostId="13751" Text="Instead of using pwm, you might be able to use a simple circuit with a transistor, diode, and capacitor. Unless you really want to use pwm. http://itp.nyu.edu/physcomp/Tutorials/HighCurrentLoads" CreationDate="2011-05-02T03:26:56.460" UserId="2873" />
  <row Id="21033" PostId="13713" Text="If you're okay using a tight loop for now to do delays (I wouldn't recommend it for the final implementation), then I'd hook a scope up to an output pin and have it set a bit high, delay X ticks, set the bit low, delay X ticks again in a loop.  Then modify the number of loop iterations until you get the desired time delay.  You can't just use a ginormous number like you are currently doing, like what John Lopez already said.  If you need a bigger delay than what a 32 bit number gives you, then you need to use a nested for loop." CreationDate="2011-05-02T04:02:40.750" UserId="2288" />
  <row Id="21034" PostId="13752" Text="I would have to agree with Kellenjb, and suggest using a transistor to turn the motor on. If the motor is small like a pager motor you could use some thing like a 2n2222. " CreationDate="2011-05-02T04:23:59.740" UserId="2060" />
  <row Id="21035" PostId="13603" Text="Yep, I'm one of the ones who migrated it. " CreationDate="2011-05-02T04:26:18.437" UserId="2348" />
  <row Id="21036" PostId="12468" Text="Have you seen the [High Voltage Ringer tutorial](http://www.sparkfun.com/tutorials/50)? Check out the schematics for the [Portable Rotary Phone](http://www.sparkfun.com/products/286) and the [Bluetooth Portable Rotary Phone](http://www.sparkfun.com/products/8929)." CreationDate="2011-05-02T04:49:26.117" UserId="813" />
  <row Id="21037" PostId="13747" Text="this is a much better way to implement the delays!  great example." CreationDate="2011-05-02T05:33:55.897" UserId="2288" />
  <row Id="21039" PostId="13745" Score="3" Text="Many audio ADCs filter out DC.  Read the datasheet carefully." CreationDate="2011-05-02T06:44:04.070" UserId="411" />
  <row Id="21041" PostId="13745" Score="2" Text="Remember, getting anything close to 20+ bits, let alone *31* requires **extreme attention** to noise issues. To manage something like 22+ bits, the *whole system* pretty much will have to be isolated, and powered by a custom-designed low-noise DC-DC power supply. Grounding will be extremely critical, and a 4 layer PCB is almost absolutely necessary. Remember, 1 bit from a 24 bit converter w/4.096v reference is 244 **nanovolts**. Even with excellent PSRR in the ADC, your rails have to be dead-quiet." CreationDate="2011-05-02T07:38:01.960" UserId="1374" />
  <row Id="21042" PostId="9328" Text="If you connect two negative resistors in parallel, at 88 mph, don't you rip a hole in universe, and go back in time?" CreationDate="2011-05-02T07:48:26.017" UserId="1374" />
  <row Id="21043" PostId="13694" Text="Even though I disagree on what's more readable and in which reading the precision is more obvious, your answer points out that it is indeed more subjective than I thought. Thanks!" CreationDate="2011-05-02T08:28:20.290" UserId="1951" />
  <row Id="21044" PostId="13756" Score="1" Text="I've just found this cool [demonstration](http://demonstrations.wolfram.com/PiFilter/) to do with a Pi Filter from wolfram. Download their CDF Player then download the demonstration and it allows you to play with different values in the circuit. " CreationDate="2011-05-02T09:51:09.437" UserId="1623" />
  <row Id="21045" PostId="13746" Score="3" Text="While electrons flow from negative to positive, it's usually better to just play along with the convention that current flows from positive to negative so you don't confuse anyone when you talk about it." CreationDate="2011-05-02T12:08:14.320" UserId="1407" />
  <row Id="21046" PostId="13743" Text="Three wires for just the sensor, or for the sensor and motor?" CreationDate="2011-05-02T12:09:54.037" UserId="1407" />
  <row Id="21047" PostId="13741" Text="What do you mean &quot;PuTTY doesn't allow data entry&quot;?  You don't see anything?  Unless what you're connecting to actually sends some sort of reply, the window won't show anything, even if you're transmitting." CreationDate="2011-05-02T12:13:35.983" UserId="1407" />
  <row Id="21048" PostId="13743" Text="He stated that the feedback mechanism has three wires!" CreationDate="2011-05-02T12:23:24.643" UserId="305" />
  <row Id="21049" PostId="13743" Score="1" Text="Total of five wires. 2 got the motor and 3 for the sensor." CreationDate="2011-05-02T12:24:13.240" UserId="1319" />
  <row Id="21051" PostId="13762" Text="I may just be confused by his question, or the Mac side of things, but he wants to know if he can use Xcode, which the other answer's links to an option that does use Xcode." CreationDate="2011-05-02T12:44:42.940" UserId="319" />
  <row Id="21053" PostId="9328" Text="@tyblu  MPEG is an asymmetric encoding standard, which means that it takes much more cpu cycles or logic gates to encode than it does to decode.  I forget what the ratio is, but it is somewhere between 10:1 and 500:1." CreationDate="2011-05-02T12:55:47.283" UserId="3624" />
  <row Id="21054" PostId="13753" Score="1" Text="I love the &quot;chain&quot; or &quot;link&quot; analogy. I have been told other analogies, but none as good as those." CreationDate="2011-05-02T13:04:08.527" UserId="319" />
  <row Id="21055" PostId="13760" Score="1" Text="Are you wanting to use Xcode or just have heard you can use Xcode? Try editing your title and question to be a little bit more clear." CreationDate="2011-05-02T13:07:49.553" UserId="319" />
  <row Id="21056" PostId="13762" Text="It looks like a useful way to do AVR development with OS X without needing Xcode. He hasn't said that he must use Xcode." CreationDate="2011-05-02T13:10:58.207" UserId="305" />
  <row Id="21057" PostId="13762" Text="I meant if there is the way to run avr code in Xcode and &quot;upload&quot; it to microcontroller directly from Xcode(something like &quot;Press Run = upload&quot;)." CreationDate="2011-05-02T13:16:26.793" UserId="4076" />
  <row Id="21058" PostId="13724" Text="But we can give 5-36 volt from pin 8 in this picture&#xA;http://320volt.com/wp-content/uploads/2009/01/l293d-motor-surucu-entegresi.png" CreationDate="2011-05-01T16:54:52.960" UserId="4063" />
  <row Id="21059" PostId="13724" Text="You don't seem to have read the data sheet either! Pin 8 is Vss." CreationDate="2011-05-01T17:03:52.840" UserId="305" />
  <row Id="21060" PostId="13762" Text="You should have mentioned that in your question!" CreationDate="2011-05-02T13:27:15.790" UserId="305" />
  <row Id="21061" PostId="13762" Score="2" Text="@Mark Fedurin I would recommend editing your question, it is pretty unclear as it stands now." CreationDate="2011-05-02T13:29:09.207" UserId="319" />
  <row Id="21062" PostId="13763" Score="1" Text="The charge current is usually given in &quot;C&quot;, meaning a factor of the capacity in Ah. So a charge time of 1h corresponds to a charge current of 1C. Excellent link, thanks!" CreationDate="2011-05-02T13:55:55.040" UserId="897" />
  <row Id="21066" PostId="12771" Text="@davidcary: Nice article, though the 'token passing' scheme could be made safer by using +=, ^=, or other such techniques to manipulate the 'token' rather than direct assignment.  Otherwise a program-counter glitch that lands on the token assignment could cause things to appear normal even when they are not." CreationDate="2011-05-02T14:16:28.840" UserId="3123" />
  <row Id="21068" PostId="13741" Text="@Nick T I was expecting to be able to type a string, hit enter, and be moved to the next line, rinse, repeat." CreationDate="2011-05-02T14:35:19.703" UserId="1227" />
  <row Id="21069" PostId="13764" Score="1" Text="Why the downvote? It seems like a great question to me, sometimes just finding the right name or search terms is all thats needed to answer questions, doesn't make it a bad question though." CreationDate="2011-05-02T14:37:18.413" UserId="319" />
  <row Id="21070" PostId="13769" Text="What type of door?" CreationDate="2011-05-02T14:59:43.463" UserId="305" />
  <row Id="21071" PostId="13752" Text="OK I learned it but i need to work just one dc motor.So how i'm gonna connect P1.2 to two side dc motor" CreationDate="2011-05-02T15:17:20.137" UserId="4063" />
  <row Id="21072" PostId="13752" Text="Just how it is drawn in the image, with one connected to ground." CreationDate="2011-05-02T15:20:40.943" UserId="319" />
  <row Id="21073" PostId="13772" Text="I'll try to explain it deeper, then you could advice me better. I live at the second floor of a house and last weekend the garage door left opened the whole night by mistake. I want a method to detect the door is opened. My first thought (I'm newbie in electronics) has been to place the arduino I own in the garage, and putting some sensor detect the door is opened and then send via wireless to another arduino place at the second floor that the door is opened and reproduce some sound to warn the garage door is opened." CreationDate="2011-05-02T15:22:12.040" UserId="4079" />
  <row Id="21074" PostId="13769" Text="A simple garage door that can be opened and closed via remote control. See below in one of my comments I'll explain deeper my 'problem'" CreationDate="2011-05-02T15:27:42.130" UserId="4079" />
  <row Id="21076" PostId="13768" Text="Accepted this answer because it was my actual problem. But thanks for all the input too from others, +1 for them :)" CreationDate="2011-05-02T15:32:23.800" UserId="710" />
  <row Id="21077" PostId="13771" Text="See my comments below. There I'll explain my needs and maybe you can give me some help" CreationDate="2011-05-02T15:33:57.180" UserId="4079" />
  <row Id="21078" PostId="13770" Text="yes, it can be placed on the door. But when I detect door opened I want to send this to the second floor. See my comment above. Thanks" CreationDate="2011-05-02T15:35:39.860" UserId="4079" />
  <row Id="21079" PostId="13753" Score="1" Text="A hand-crank on one end of a chain and a load on the other end.  When you turn it, the entire chain moves, but it's not used up. Energy is transferred by the chain links pulling on each other, and this pulling movement travels very quickly from source to load, even if the chain links themselves move slowly.  The only downside of the analogy is that the links only pull, they don't push on the other half of the circuit.  Pipes filled with water works a little better." CreationDate="2011-05-02T15:39:19.903" UserId="142" />
  <row Id="21080" PostId="13767" Text="Do these exist in 0.1&quot; through-hole packages?" CreationDate="2011-05-02T15:46:31.073" UserId="1217" />
  <row Id="21081" PostId="13753" Text="I've used pipes filled with water some, but in that analogy I find that people tend to think of the water &quot;going away&quot; as soon as it comes out of the end. Guess it depends on who you are talking to and what you are trying to explain for what works the best." CreationDate="2011-05-02T15:52:56.177" UserId="319" />
  <row Id="21082" PostId="13713" Text="You are correct you can source from all those clocks,   but in the case of the launchpad, he will have the choice of the aclk or smclk or mclk sourced from either the DCO or crystal. no VLO on the value line series chips. From the code he posted he will be using the defualt mclk @1MHz. as for WDT_MDLY_64 64ms is based on SMCLK @1MHz. I can elaborate more later if needed." CreationDate="2011-05-02T15:55:50.163" UserId="2060" />
  <row Id="21083" PostId="13720" Text="While it's okay to allow specific signals to be undefined if they cannot take illegal values, it's generally good form to provide some mechanism to reset all flops to a known state.  You'll be glad you did once it comes time to debug things.  That said, the state variable of a finite state machine is most definitely not one of those signals that can be left undefined - ever.  You must start from a known state." CreationDate="2011-05-02T16:04:50.253" UserId="1278" />
  <row Id="21085" PostId="9324" Text="There are billions of transistors in just a single modern GPU or FPGA, so my guess is that it would rival the US debt..." CreationDate="2011-05-02T16:09:47.520" UserId="1278" />
  <row Id="21086" PostId="13776" Score="1" Text="With diodes though you are effectively reducing the voltage out of your battery by 0.4v ish" CreationDate="2011-05-02T16:37:28.160" UserId="1827" />
  <row Id="21087" PostId="13745" Text="@markrages The device that I am investigating has the option to leave the DC component in :) I checked that at least. @FakeName won't a regular regulated supply work? I understand about the nanovolt precision, and I know that I may not need 24 bits, but I know that 16 is not enough." CreationDate="2011-05-02T16:38:18.070" UserId="3045" />
  <row Id="21088" PostId="13754" Text="Hey temp control, didn't think about that. Thanks for the advice!" CreationDate="2011-05-02T16:40:33.903" UserId="3045" />
  <row Id="21089" PostId="13774" Text=":( Didn't know that either, and it makes sense. Wish I could mark all as correct." CreationDate="2011-05-02T16:44:43.710" UserId="3045" />
  <row Id="21094" PostId="13750" Text="The complications that would arise are spoken about in the post by ajs410 below." CreationDate="2011-05-02T17:04:50.533" UserId="3045" />
  <row Id="21095" PostId="13779" Score="2" Text="ED is open to technical questions, not to shopping advice." CreationDate="2011-05-02T17:10:09.360" UserId="2064" />
  <row Id="21097" PostId="13767" Text="@Eric; see http://www.vishay.com/docs/94554/8sth06.pdf for a TO220 (0.1&quot;) package, as mentioned in my answer. Although such a device may be overkill with its 600V rating..." CreationDate="2011-05-02T17:17:48.953" UserId="1225" />
  <row Id="21099" PostId="13780" Score="1" Text="nice. I'm sure the other questions similar to mine were ganked too? no? okay guess it's just me" CreationDate="2011-05-02T17:29:02.017" UserId="4084" />
  <row Id="21100" PostId="13753" Text="A *loop* of pipe, completely filled with water, with no outlets.  An outlet would be like electric charge spraying out of the end of a wire, which it doesn't do.  If the pipe is cut, it immediately forms caps to prevent the water from escaping.  :)  If you pump water at one point in the loop, it pushes and pulls and causes the water in the entire pipe to loop at the same speed.  If you use a piston to move it back and forth, the energy travels in waves at the speed of sound in water, while the water itself moves slowly." CreationDate="2011-05-02T17:57:31.970" UserId="142" />
  <row Id="21101" PostId="9324" Text="A trillion is a thousand billion, so it's still &quot;billions&quot;.  :)" CreationDate="2011-05-02T18:28:52.213" UserId="142" />
  <row Id="21102" PostId="13742" Text="Ah, that sounds like the interface used by some TI CODECs I've used.  The CODECs used the same clock for data acquisition as for shifting data, so it was necessary to have the clock running whether or not data was actually being clocked out." CreationDate="2011-05-02T18:30:59.600" UserId="3123" />
  <row Id="21104" PostId="13713" Text="@jsolarski thanks for the info -- but I cannot find data confirming the lack of VLO in the Valueline series.  I'm looking at the datasheet for the MSP430G2231 right now, and it discusses the DCO and VLO, but makes no mention about the VLO not being available in certain series." CreationDate="2011-05-02T18:41:51.657" UserId="2288" />
  <row Id="21105" PostId="13672" Score="2" Text="You've been a diligent moderator ever since the diamond was awarded to you, and I hope you are given an opportunity to continue moderating." CreationDate="2011-05-02T18:56:29.303" UserId="1293" />
  <row Id="21107" PostId="13764" Text="Why do you need Schottky diodes? " CreationDate="2011-05-02T18:58:09.333" UserId="339" />
  <row Id="21108" PostId="13783" Text="I understand the pair of COM ports now, thanks." CreationDate="2011-05-02T19:25:38.307" UserId="1227" />
  <row Id="21109" PostId="13674" Text="Are you sure they're not both speakers?  One for external and one for the ear?" CreationDate="2011-05-02T19:25:50.917" UserId="142" />
  <row Id="21110" PostId="13721" Score="1" Text="@Cff, your questions are generally of low quality and hard to understand, and mostly in the [&quot;please do not ask questions of this type&quot; category of our FAQ](http://electronics.stackexchange.com/faq#dontask). Please, take a look in the [how to ask page](http://electronics.stackexchange.com/questions/how-to-ask)" CreationDate="2011-05-02T19:26:03.457" UserId="938" />
  <row Id="21111" PostId="13783" Text="I probably am confusing the physical/virtual ports. I have an ardiuno uno wired up to the physical module's rx and tx pins. If I send a character to the module from my pc, I should be able to read it off the physical uart_rx pin, right?" CreationDate="2011-05-02T19:39:19.220" UserId="1227" />
  <row Id="21112" PostId="13606" Text="Actually it has a slave too, it's not just for driving the bus. But I still think it isn't what I'm looking for." CreationDate="2011-05-02T20:28:48.653" UserId="206" />
  <row Id="21113" PostId="13792" Text="Too vague and should be closed!" CreationDate="2011-05-02T20:58:14.720" UserId="305" />
  <row Id="21114" PostId="13792" Text="I can edit it..." CreationDate="2011-05-02T20:59:00.883" UserId="4086" />
  <row Id="21115" PostId="13792" Text="What type of CAD? 3d cad, schematic capture, etc" CreationDate="2011-05-02T21:04:18.607" UserId="319" />
  <row Id="21116" PostId="13792" Text="I am interested in learning CAD for drawing mechanicals and also PADs for drafting schematic." CreationDate="2011-05-02T21:06:13.437" UserId="4086" />
  <row Id="21117" PostId="13792" Text="Just buy PADS and start using it! Mechanical CAD isn't anything to do with electronic design." CreationDate="2011-05-02T21:08:05.787" UserId="305" />
  <row Id="21118" PostId="13792" Text="@user4086 - CAD (as I understand it) is an acronym for Computer Aided Design.  There are a multitude of applications for CAD, so you need to specify what subject matter or program you want to focus on.  I'd also suggest that you first learn the principles behind the topic in general, and then move to the implementations of various software vendors.  Once you know the principles, learning a new CAD system just involves printing out the keyboard shortcuts and working through a few tutorials. In my experience, though, CAD often refers to mechanical design, which would be off-topic for this site." CreationDate="2011-05-02T21:08:57.463" UserId="857" />
  <row Id="21120" PostId="13784" Text="Also, this question is too localized - You're likely the only person ever to ask this question, and probably the only one who ever will!  We'd rather answer questions that are of more use to the general audience of the Internet, like how to identify components in general." CreationDate="2011-05-02T21:17:39.813" UserId="857" />
  <row Id="21123" PostId="13796" Text="@Thomas - you should have posted these as answers to your [duplicate question](http://electronics.stackexchange.com/questions/6108/small-sot-23-transistor-markings)!  Good links, though." CreationDate="2011-05-02T21:31:30.510" UserId="857" />
  <row Id="21125" PostId="13758" Text="Any idea what kind of interface it would be? Analog voltage? Sine waves? " CreationDate="2011-05-02T21:35:12.143" UserId="1319" />
  <row Id="21127" PostId="13788" Score="1" Text="He doesn't seem to know how much current he wants to pass, and seems to want to use individual NMOS and PNOS transistors." CreationDate="2011-05-02T21:42:09.877" UserId="305" />
  <row Id="21128" PostId="13797" Text="+1 for Analog Devices.  They have the widest selection of odd-voltage analog switch parts." CreationDate="2011-05-02T21:42:44.230" UserId="411" />
  <row Id="21129" PostId="13743" Text="any evidence of permanent magnets in that rotor?" CreationDate="2011-05-02T21:50:21.543" UserId="740" />
  <row Id="21132" PostId="13797" Text="I want to do this on-chip, not using outside switches." CreationDate="2011-05-02T21:55:22.737" UserId="2985" />
  <row Id="21133" PostId="13110" Text="Lately I've had good results using logic level MOSFETs and running the totem on the 3V3 rail. You can also use a BJT for voltage translation if you are ok with the signal being inverted." CreationDate="2011-05-02T22:08:01.240" UserId="3876" />
  <row Id="21134" PostId="13797" Text="@Cenoc If so you probably want some kind of CMOS transmission gate." CreationDate="2011-05-02T22:09:11.270" UserId="1225" />
  <row Id="21135" PostId="13780" Text="In general shopping questions are not welcome and yours is overly vague: you have no idea what this system might require - point 4 can't even be evaluated without more information (what picture format is the camera using is a basic question).  Also, it sounds like you haven't done any research yourself and you assume this is an 'off the shelf' sort of solution when it's not.  I can't speak for others, but it annoys me when people do that. If you can do the work yourself, check out OpenWRT, beagleboard, pandaboard, hawkboard, linux stamp or any other the other embedded linux boards. " CreationDate="2011-05-02T22:15:13.593" UserId="249" />
  <row Id="21136" PostId="13743" Text="Actually no, there wasn't any (tested it with a small piece of steel but I didn't test it against a magnet for fear of damaging it with strong neodymium magnets). I also only tested the outside face, not the one facing the PCB." CreationDate="2011-05-02T22:28:58.280" UserId="1319" />
  <row Id="21137" PostId="13801" Text="There is nothing in the datasheet or on digikey's parametric search that indicates this part has a low-voltage version.  The only alternate part numbers control for the frequency stability." CreationDate="2011-05-02T22:34:08.980" UserId="1278" />
  <row Id="21139" PostId="13783" Text="That's how I understand the docs - in the data (default) mode, the module should be transparent. Yet I have spent only a few minutes browsing the manual." CreationDate="2011-05-02T22:39:29.113" UserId="3564" />
  <row Id="21140" PostId="13801" Score="1" Text="You have to order the low-voltage version from the supplier, as a non-standard item. It will probably be more expensive. Plenty of 3.3V oscillators are available as standard items." CreationDate="2011-05-02T23:01:33.477" UserId="305" />
  <row Id="21141" PostId="13803" Text="Hmm, great suggestion! For some reason I haven't actually thought about &quot;design for test&quot; in this context before. " CreationDate="2011-05-02T23:02:22.213" UserId="3876" />
  <row Id="21142" PostId="13713" Text="I will have to correct my self a bit, If you look at the basic clock module chapter in the user guide, BCSCTL3 LFXT1Sx bits 5-7, VLO can be sourced instead of the crystal. the info is a bit cryptic and buried lol, the VLOCLK is a valid source for value line chips, instead of the crystal." CreationDate="2011-05-02T23:06:38.793" UserId="2060" />
  <row Id="21143" PostId="13803" Score="2" Text="you can take it to the next level by designing in self-test capability. it adds to the complexity of your board, but it can make your design verification easier, and even gives you the option to include power-on self tests in your fielded product." CreationDate="2011-05-02T23:06:43.363" UserId="740" />
  <row Id="21144" PostId="13802" Score="2" Text="may be a good idea to populate your power supply and distribution, including bulk and bypass caps, and then apply input power to the board. if you have a tantalum cap in backwards, you'll know in a hurry. then check that the MCU (and etc.) has the right supply voltages at the right pins, before moving on to populate those devices." CreationDate="2011-05-02T23:09:56.530" UserId="740" />
  <row Id="21145" PostId="13758" Score="1" Text="@Faken - probably one line is a ground, another is excitation (might be DC, might be AC), and the 3rd line is some kind of sense signal, that will just give you speed." CreationDate="2011-05-02T23:43:49.837" UserId="740" />
  <row Id="21146" PostId="13802" Score="1" Text="As a side comment, I think it's good practice to keep your code 'modular' like you did (removing functionality for missing peripherals).  I always write my code such that it will function in a 'demo' mode that ignores missing peripherals but still runs through the program logic until I'm sure the peripherals are debugged correctly. Then your program at least runs so you can tell if it got programmed." CreationDate="2011-05-02T23:45:55.700" UserId="249" />
  <row Id="21147" PostId="13798" Text="I've never found solidworks clunky. " CreationDate="2011-05-03T00:05:23.170" UserId="1374" />
  <row Id="21148" PostId="13783" Text="gotchu. I really appreciate you taking a look at this with me." CreationDate="2011-05-03T00:15:01.443" UserId="1227" />
  <row Id="21150" PostId="13743" Text="tried to read the markings off that end plate. could you post that info?" CreationDate="2011-05-03T00:29:02.607" UserId="740" />
  <row Id="21151" PostId="13525" Text="If you're feeling ambitious &quot;Closed Form Solutions for the Design of optimum Matching networks&quot; Dale Dawson IEEE TMTTS V57N1. The only downside is this seems to assume you are matching impedances, not a trace on a smith chart. Extracting impedances from smith chart traces is another one of those important skills that's been absorbed into design software. " CreationDate="2011-05-03T00:31:30.263" UserId="2148" />
  <row Id="21153" PostId="13787" Text="@reemrevnivek, in a perfect world there would be a moderator with enough time to give a large amount of attention to meta. I have tried to explain points there, but often the mod whom took the action is not the person people want an explanation from. You have stepped up and explained why actions were taken. Up until this point I have almost moderated alone, glad you are thinking of joining the ranks. The only surprising point to me is how long it took you to nominate." CreationDate="2011-05-03T01:06:21.707" UserId="230" />
  <row Id="21154" PostId="13673" Text="@NickT, I think you would take a bit to learn all of the ropes of moderation, but I think you would be excellent at handling the many different tag issues and just dealing with the number of flags we get in a day. I look forward to seeing if you make the cut." CreationDate="2011-05-03T01:07:15.637" UserId="230" />
  <row Id="21155" PostId="12455" Text="Those sites don't seem to offer components (question seeks to save space), let alone small, low-power, board-level modules.  Also, given some fairly specific requirements it's a very vague answer." CreationDate="2011-05-03T01:57:04.857" UserId="1407" />
  <row Id="21156" PostId="13797" Text="There would be a problem with the biasing of the substrate diode if I do that, wouldnt there be?" CreationDate="2011-05-03T02:04:41.133" UserId="2985" />
  <row Id="21157" PostId="13736" Text="I recently bought a 555cn timer ic for another purpose, would this work as an external oscillator?" CreationDate="2011-05-03T02:14:37.443" UserId="2873" />
  <row Id="21158" PostId="13808" Score="10" Text="Ummm...  Can you be a bit more vague?  That's a bit like saying, &quot;I want to build a car.  It should be yellow.  Any pointers?&quot;   Give us more info, like how bright should it be?  How long should a charge last?  What skills do you have that might be relevant?  " CreationDate="2011-05-03T03:09:54.810" UserId="3624" />
  <row Id="21159" PostId="13795" Text="@Dean, in general, Good questions are harder to come by then good answers. There are definitely always a need for both. I can vouch that you regularly flag for attention and allow my job to be much easier. If you are not sure of the action, as when I am not, we have a mod channel to discuss. I think you could make a great mod. I heard you have complained that you feel you have a lack of technical knowledge, but this is not required for this job. I do however wish we could continue with 4 moderators instead of 3. I wish you luck." CreationDate="2011-05-03T04:02:07.640" UserId="230" />
  <row Id="21160" PostId="13804" Score="3" Text="@Leon, it only takes one major bug found this way to make it much much faster" CreationDate="2011-05-03T05:45:47.963" UserId="230" />
  <row Id="21161" PostId="13802" Score="2" Text="When you apply input power, start with a low current limit." CreationDate="2011-05-03T06:07:55.500" UserId="339" />
  <row Id="21162" PostId="13797" Text="@Cenoc only if current flows from anode to cathode. You are talking to a CMOS idiot!" CreationDate="2011-05-03T06:49:49.130" UserId="1225" />
  <row Id="21163" PostId="13797" Text="The substrate is tied to Vss, which is always the most negative voltage to prevent forward-biasing the substrate/nfet junction." CreationDate="2011-05-03T06:53:21.110" UserId="638" />
  <row Id="21164" PostId="13808" Score="12" Text="He says it's cordless, and then asks for leads. :)" CreationDate="2011-05-03T07:25:49.840" UserId="305" />
  <row Id="21167" PostId="13808" Score="2" Text="@Leon, that is one of the worst jokes I have ever laughed at." CreationDate="2011-05-03T09:35:35.913" UserId="230" />
  <row Id="21168" PostId="13788" Score="1" Text="@Leon, you are very knowledgeable, but as our highest rep user, can you please try to be a bit more civil and inviting? I understand frustration with basic questions, but it would be better to phrase it so the user does not feel like they are being attacked or mocked." CreationDate="2011-05-03T10:27:13.633" UserId="230" />
  <row Id="21169" PostId="13813" Text="The easiest way is a simple RC circuit, but if your board does not have one, you will have to add it. It is very very easy to add though, just a resistor and a capacitor." CreationDate="2011-05-03T11:18:17.440" UserId="230" />
  <row Id="21170" PostId="12455" Text="The question actually asks for a single IC that will do it, not components - should I downvote the other answer?  The links will give you a solution, if you take the time to look through properly  " CreationDate="2011-05-03T11:52:07.613" UserId="1827" />
  <row Id="21171" PostId="13812" Text="I think he wants to connect something to either -5V or +10V, using 5V or 0V." CreationDate="2011-05-03T12:16:15.113" UserId="305" />
  <row Id="21172" PostId="13788" Text="The question should be closed. He doesn't seem to know what he wants!" CreationDate="2011-05-03T12:17:17.313" UserId="305" />
  <row Id="21173" PostId="13787" Text="@Kortuk - As I said in chat yesterday, I just came off of a month-long hiatus from Electronics Design to finish up my school semester.  It's purely coincidental that I came back the day before nominations closed! If nominated to be Moderator, though, I would be sure to check in more regularly." CreationDate="2011-05-03T12:22:58.113" UserId="857" />
  <row Id="21174" PostId="13816" Text="Sorry the picture hasn't uploaded. Will do it when I get back. " CreationDate="2011-05-03T12:52:54.917" UserId="1623" />
  <row Id="21176" PostId="13805" Text="Sounds like how I do it which I feel is a very nice way to evolve a design. It also makes it possible to reuse parts later." CreationDate="2011-05-03T13:10:46.297" UserId="2395" />
  <row Id="21177" PostId="13787" Text="@reemrevnivek, I was really wondering why we had not seen you. I was quite confused by it. I assumed like many you were busy with school." CreationDate="2011-05-03T13:12:41.643" UserId="230" />
  <row Id="21178" PostId="13785" Text="@KellenJb, you have had consistent flags. I have yet to get a flag from you that I did not consider valid and you are one of the more prolific flaggers. I can think of 3 or 4 top people for flags and you are on the list. I wish you luck, maybe you will be a toss up vote, but we will have to wait and see." CreationDate="2011-05-03T13:16:24.963" UserId="230" />
  <row Id="21179" PostId="13802" Text="What capacitors are you using that can't be hand-soldered?  0201s?" CreationDate="2011-05-03T13:21:18.853" UserId="857" />
  <row Id="21180" PostId="12455" Text="@Eddie - Thomas' solution was compact, even if it wasn't a single IC per se.  Since it answers the spirit of the question, if not the letter, it probably doesn't need a downvote.  In any case, this discussion should be a comment to that answer." CreationDate="2011-05-03T13:29:16.917" UserId="857" />
  <row Id="21181" PostId="13816" Text="What type of battery is it?" CreationDate="2011-05-03T13:29:20.287" UserId="305" />
  <row Id="21182" PostId="13817" Score="2" Text="Many manufacturers of cheap chargers don't seem to bother with any of this - resulting in the premature death of expensive rechargeable cells. Of course they also make the cells. Pure coincidence I'm sure :o{" CreationDate="2011-05-03T13:31:20.673" UserId="2234" />
  <row Id="21183" PostId="12455" Text="@Nick T - Those sites certainly do offer components and low-power board-level modules. I found compatible modules from [Mornsun](http://www.mornsun-power.com/UploadFiles/pdf/PWA_CS-2W%20&amp;%20PWB_CS-2W_EN.pdf), [XPPower](http://www.xppower.com/pdfs/SF_IA.pdf), and [Murata](http://www.murata-ps.com/data/power/ncl/kdc_mea.pdf).  I agree that the answer could do more to flesh out the search process, but there's no need to downvote it." CreationDate="2011-05-03T13:36:23.933" UserId="857" />
  <row Id="21187" PostId="13787" Text="@Kortuk - Sorry to leave you wondering! I left a message in chat and a note on my profile.  Good to know I was missed!" CreationDate="2011-05-03T13:55:31.177" UserId="857" />
  <row Id="21188" PostId="13515" Text="Seems like they could do a better job than this.  Even consumer phones can detect their location based on making maps of Wi-Fi signal levels." CreationDate="2011-05-03T13:55:46.217" UserId="142" />
  <row Id="21189" PostId="13515" Text="@endolith True, but the phone wouldn't be able to do that if there wasn't someone who came along before with a GPS and recorded wifi data vs gps location. They could drive around the radiator once and then use the signal strength at different locations to get a pretty good guess at where it is coming from, but even then reflections of RF can do weird things resulting in you possible thinking its next door or something. So they still have to go back to the hot and cold game in the end." CreationDate="2011-05-03T14:19:05.687" UserId="319" />
  <row Id="21190" PostId="13818" Score="1" Text="@Sandos - I think your 2nd to last paragraph needs revision. If (since) 1.5V is not enough to drive high-power white LED, you'll require a **boost** circuit.  A buck converter lowers the voltage, a boost converter increases it.  If you were using &quot;buck circuit&quot; to mean a generic DC-DC LED driver, you may want to clarify this." CreationDate="2011-05-03T14:25:27.340" UserId="857" />
  <row Id="21191" PostId="13819" Score="1" Text="Resistors do a lot for your efficiency - They degrade it by the ratio of the voltage across the resistor to the voltage across the resistor - LED combination!" CreationDate="2011-05-03T14:27:17.810" UserId="857" />
  <row Id="21195" PostId="7475" Score="1" Text="Thanks for the link!  The Google translation seems to indicate that it's a perfect fit for this question.  However, we'd prefer that (1) the text is in English (we're an [English-speaking community](http://blog.stackoverflow.com/2009/07/non-english-question-policy/), even though many of us are at least bilingual) - Auto-translate only if you have to (2) the answer includes a summary of the article in case the link goes dead.  I've edited your post to adhere to these guidelines, and given you an upvote for it!" CreationDate="2011-05-03T14:47:52.900" UserId="857" />
  <row Id="21196" PostId="13513" Text="Worrying about standby power is filtering out gnats while swallowing camels." CreationDate="2011-05-03T14:50:31.043" UserId="142" />
  <row Id="21197" PostId="13515" Text="&quot;They could drive around the radiator once and then use the signal strength at different locations to get a pretty good guess at where it is coming from&quot;  Yes, that's what I mean.  It seems like it would be much more accurate to computerize it than play hot and cold." CreationDate="2011-05-03T14:52:02.883" UserId="142" />
  <row Id="21198" PostId="13508" Text="Just fix the damn chain." CreationDate="2011-05-03T14:54:04.207" UserId="142" />
  <row Id="21199" PostId="5875" Text="Assuming you have space, you should still break out the inner layers to test points somewhere on the outer layers.  They rarely need track hacking, but it's a pain to try to get power or ground by attaching to an existing part's pins if you do need to do some hacking. Also, in debugging, verification of power and ground is one of the first things I'd do!" CreationDate="2011-05-03T14:57:50.947" UserId="857" />
  <row Id="21200" PostId="101" Text="@Zefiro - We didn't allow links to be inserted by new users to prevent spam.  The links you posted were very good, though!  Here's an upvote to help you gain more privileges and continue contributing." CreationDate="2011-05-03T15:02:17.450" UserId="857" />
  <row Id="21201" PostId="13517" Text="If it dips below the resonant point, the switching frequency will become erratic and then suddenly drop significantly as it loses control?  The output VDC will drop, there is an audible noise, and the half-bridge FETs occasionally blow up?  :)" CreationDate="2011-05-03T15:03:52.330" UserId="142" />
  <row Id="21202" PostId="13517" Score="1" Text="The gain characteristic is reversed below the resonant point, so the control law no longer works - lower frequency further reduces the gain. You also lose soft commutation of the primary FETs (no more ZVS) and get body-diode reverse recovery, so yes, acoustic noise and explosions may happen if the parts cannot handle the stress." CreationDate="2011-05-03T15:11:19.097" UserId="1293" />
  <row Id="21204" PostId="13801" Text="I tried giving it 3.3V and it oscillated quite happy at the correct frequency.  And with a littie bit of ringing, too." CreationDate="2011-05-03T15:36:20.553" UserId="1278" />
  <row Id="21206" PostId="13807" Text="headers are great, especially if you need to rework or add features later, or you need impromptu debugging outputs.  I also like the idea of doing a BareBones for small protos...might just do that myself" CreationDate="2011-05-03T15:42:18.507" UserId="1278" />
  <row Id="21207" PostId="13818" Text="@reemrevnivek: Out of curiosity, are there any good flyback-mode LED drivers that can operate independent of whether the supply is above or below the LED voltage?  I have a project where the LED voltage is about 5 volts and the supply is about 4-15 (depending upon battery configuration and condition).  At present, the LED driver shares the main supply switcher (which converts to 3.3 volts) so it always gets 3.3 volts, but it would be nicer if it could run directly off the raw supply." CreationDate="2011-05-03T15:49:03.807" UserId="3123" />
  <row Id="21208" PostId="13584" Text="I appreciate the anecdote on the odometer - it makes me feel like I'm not actually losing faith in mathematics.  I think I see what you're talking about now.  It's not that REF is 27 ppm above OUT, but that OUT is 27 ppm below REF." CreationDate="2011-05-03T15:59:07.750" UserId="1278" />
  <row Id="21209" PostId="13818" Text="@supercat - I've not used any personally, but I'm sure there are.  Flyback is almost always a buck-boost configuration. See [this National article](http://www.national.com/nationaledge/jul03/article.html), specifically the **Flyback/Buck-Boost/Boost ICs** heading, where they explain that a flyback buck-boost converter is essentially the same as a generic boost converter.  [Here's](http://cds.linear.com/docs/Datasheet/3783fb.pdf) an example of a Linear Tech part for this purpose. But we're getting off topic." CreationDate="2011-05-03T16:13:05.073" UserId="857" />
  <row Id="21211" PostId="8774" Text="CVS a beautiful system when compared with the horror that is Microsoft Visual Source Safe, which I'm locked into for a project I'm working on at the moment. Blech." CreationDate="2011-05-03T16:19:04.667" UserId="857" />
  <row Id="21213" PostId="8772" Score="2" Text="+1 for the use of text-based formats for files.  Disk space is cheap, and compression of text is easy.  I wish that binary blobs were less common." CreationDate="2011-05-03T16:20:43.777" UserId="857" />
  <row Id="21214" PostId="13815" Score="1" Text="Also this white paper from Xilinx can be useful: http://www.xilinx.com/support/documentation/white_papers/wp272.pdf" CreationDate="2011-05-03T16:20:55.077" UserId="3564" />
  <row Id="21215" PostId="13825" Score="1" Text="This buying question is off-topic and will be closed!" CreationDate="2011-05-03T16:35:18.520" UserId="305" />
  <row Id="21216" PostId="13825" Text="OK, umm. Where could I post it instead please?" CreationDate="2011-05-03T16:38:07.533" UserId="4096" />
  <row Id="21218" PostId="13825" Text="Call up the chip distributor and ask for volume pricing" CreationDate="2011-05-03T16:46:05.217" UserId="566" />
  <row Id="21219" PostId="13825" Text="@Simon, no other [Stack Exchange sites](stackexchange.com/sites) will accept shopping questions. I don't know where is the best place you can get your answer. Maybe others members could help you. But I hope that you continue here contributing with questions and answers." CreationDate="2011-05-03T16:47:23.560" UserId="938" />
  <row Id="21220" PostId="13816" Text="NiMH battery. But the question is on how the operation of the PIC should be. " CreationDate="2011-05-03T16:56:33.050" UserId="1623" />
  <row Id="21221" PostId="13825" Score="4" Text="I don't think this is really a buying question though it was phrased that way. I would suggest you reword it w/o words like, buy, cost, price, etc...  and the the word/question police will stop nagging. " CreationDate="2011-05-03T16:59:22.820" UserId="2157" />
  <row Id="21222" PostId="13795" Score="2" Text="@Dean - I'm with Kortuk on this one.  We need lots of good questions just as much as we need answers!  Your 52 questions/28 answers isn't out of line.  Also, as I said (or, rather, tried to say) in chat, *You don't need to be an electronics genius to be a moderator! ... Character and attitude are far more important. Better a beginner who is fair, patient, and helpful* [such as yourself] *than a genius who is partial, dismissive, and unfriendly.*" CreationDate="2011-05-03T17:05:59.073" UserId="857" />
  <row Id="21223" PostId="13785" Score="1" Text="@KellenJb - Then I'll toot it for you!  You've been a valuable contributor since the Chiphacker days, you're knowledgeable (7 months away from a Master's in electrical engineering), and you've been a valuable contributor in Meta.  I wish you the best of luck." CreationDate="2011-05-03T17:08:45.437" UserId="857" />
  <row Id="21224" PostId="13673" Text="@Nick T - We haven't always agreed on things, but we've had a lot of good debates.  You're definitely an investor in the site!  You also bring experience from other Stack Exchange sites to the table.  You'd have to stop investing so much in Gaming, though, if you want to be a mod here (seriously?  almost 3k rep in the past three weeks? Nice work!) Plus, you're a fellow Michigander." CreationDate="2011-05-03T17:15:29.273" UserId="857" />
  <row Id="21225" PostId="13672" Text="@Kortuk, thanks so much for all you've done for the site, both during your pro temp moderator period and before.  Your contributions to the site here in its infancy have incalculable value.  I doubt that we would have even reached graduation without you.  I'm not sure how the voting works, but I'll vote myself down and you up if that's what it takes to have you continue as a community moderator." CreationDate="2011-05-03T17:19:35.463" UserId="857" />
  <row Id="21226" PostId="13518" Score="1" Text="@Madmanguruman - Your experience has been helpful not only in relations but also in your answers to questions ([1](http://electronics.stackexchange.com/questions/6212/6214#6214), [2](http://electronics.stackexchange.com/questions/6172/6215#6215), [2](http://electronics.stackexchange.com/questions/9272/9275#9275), [3](http://electronics.stackexchange.com/questions/13802/13826#13826) [4](http://electronics.stackexchange.com/questions/12409/12416#12416)).  Dean, Kellen, Nick and I are just student young'uns, but your experience is extremely important and brings a real-world element to this site." CreationDate="2011-05-03T17:30:19.517" UserId="857" />
  <row Id="21227" PostId="2829" Text="This should be a community wiki." CreationDate="2011-05-03T17:39:49.487" UserId="206" />
  <row Id="21228" PostId="12521" Text="Downvoted because the explanation is a little bit too simplified. It does nothing to explain the crucial point about the voltage being different and total power etc... If I knew &quot;nothing&quot; about electronics, I'd probably be puzzled by that diode in the switch mode supply. Do diodes magically create current? etc. I simply think your explanation does more to confuse than it does to enlighten." CreationDate="2011-05-03T17:46:35.373" UserId="3745" />
  <row Id="21229" PostId="10094" Text="Why the downvote?" CreationDate="2011-05-03T17:49:50.390" UserId="305" />
  <row Id="21232" PostId="13818" Score="1" Text="@reemrevnivek: In some applications, a flyback and boost converter would be similar, but LED drivers I've seen use a low-side current sensing input which they would expect to measure current below the positive rail.  The LT part looks interesting, though it requires more external components than some other drivers.  As for topicality, the OP's goal seems to be to drive an LED using some type of switcher; having a switching topology which is agnostic to whether the input voltage is above or below the LED forward voltage would seem a useful option.  " CreationDate="2011-05-03T18:03:19.240" UserId="3123" />
  <row Id="21233" PostId="4971" Text="I believe the XP2 has simulation support with the free version of Aldec distributed by Lattice.  I could be mistaken." CreationDate="2011-05-03T18:04:40.330" UserId="2059" />
  <row Id="21234" PostId="4971" Text="I overlooked it because it isn't available on my platform. It is Windows Only: http://www.latticesemi.com/products/designsoftware/diamond/index.cfm" CreationDate="2011-05-03T18:09:45.393" UserId="1181" />
  <row Id="21235" PostId="13802" Score="1" Text="Should be community wiki." CreationDate="2011-05-03T18:22:33.787" UserId="206" />
  <row Id="21236" PostId="13826" Text="+1 for the eye/ear protection!  I once heard an exploding DAC from across the lab -- the guy working on it had a temporary blind spot in his vision for about 5 minutes!" CreationDate="2011-05-03T18:58:31.837" UserId="3308" />
  <row Id="21238" PostId="3472" Text=".. the second is to get a cheap FPGA dev board. While some are designed to emulate a graphics card, CPU, or microcontroller, and are super-fast and super-big, and therefore super-expensive, other dev kits are available in the range of $\$$50 (About a day′s labor at minimum wage over here.) That level will get you 100,000 or more gates, often enough to make a simple 8−bit micro. The cost of enough 74xx to begin work ona COMPUTER will be much greater than the cost of an FPGA. Also, the bare FPGA chip runs as low as $\$$10-$\$$20, a few hours of work, although the circuit will be hard. " CreationDate="2011-05-03T19:21:24.377" UserId="857" />
  <row Id="21239" PostId="3472" Text="(above comment deleted and reposted due to TeX dollar-sign munging)." CreationDate="2011-05-03T19:21:44.983" UserId="857" />
  <row Id="21240" PostId="13828" Text="@Daniel - Glad to have you in the running.  You're a bit overly self-depreciating in this post, or else my memory is poor.  You've been a good contributor as far as I remember.  Care to point out what it is you're specifically regretting?  (Oh, and neat link, BTW)." CreationDate="2011-05-03T19:53:38.807" UserId="857" />
  <row Id="21241" PostId="13830" Text="@Mark - Wow, bringing some controversy to the election! I disagree with you on the first two points: I expressed my frustration at bad shopping questions [here](http://meta.electronics.stackexchange.com/questions/475/489#489), and the related questions issue is new, but I articulated my opinion on it [here](http://meta.electronics.stackexchange.com/questions/553/555#555). I'm not sure what your action plan is for the last two. I think we do a good job of closing bad questions.  I loved Electropus, but I'm not sure what can be done to bring the Chiphacker brand back and that's not a mod's job. " CreationDate="2011-05-03T19:59:24.827" UserId="857" />
  <row Id="21242" PostId="12455" Text="FWIW I`m not into spoon feeding people answers, a pointer in the right direction will certainly help in the long run :-)" CreationDate="2011-05-03T20:14:30.373" UserId="1827" />
  <row Id="21243" PostId="13825" Score="1" Text="Thanks for the feedback chaps, I have read a couple of the meta questions related to shopping type questions and hopefully I have reworded it well enough to focus on the technical aspects of the problem, cheers" CreationDate="2011-05-03T21:16:45.657" UserId="4096" />
  <row Id="21244" PostId="13833" Score="1" Text="Regarding pure water - your water may be pure now, but after soaking your PCB, it won't be pure any more. The inert chemical you may have been thinking of is Fluorinert." CreationDate="2011-05-03T21:29:16.610" UserId="638" />
  <row Id="21245" PostId="4113" Text="Is it safe to use/store oxalic acid just for that? Its safety sheet looks a bit scary. " CreationDate="2011-05-03T21:31:44.597" UserId="1078" />
  <row Id="21246" PostId="13817" Text="Yeah I was unsure about that as well will half the voltage to 3 to make it safe then. " CreationDate="2011-05-03T21:33:03.483" UserId="1623" />
  <row Id="21247" PostId="13833" Text="Flourinert (http://en.wikipedia.org/wiki/Fluorinert)" CreationDate="2011-05-03T21:55:57.510" UserId="3308" />
  <row Id="21248" PostId="13832" Text="Some cables are specified to withstand oil (for example Lapp Ölflex)." CreationDate="2011-05-03T22:02:54.157" UserId="339" />
  <row Id="21249" PostId="13833" Text="conformal coating guards against humidity, but for serious immersion you're looking at potting." CreationDate="2011-05-03T22:21:14.643" UserId="740" />
  <row Id="21250" PostId="13832" Text="What is the actual problem you're trying to address?" CreationDate="2011-05-03T22:27:49.003" UserId="1407" />
  <row Id="21251" PostId="13832" Score="1" Text="@Nick T  There's no particular problem at the moment. I was hoping to get some information on failure modes and as you said it `all sorts of problems with high-speed and/or high-impedance circuits`. I did have some simple projects which should be able to survive rain in mind, but I was planning to use urethan based coating on them." CreationDate="2011-05-03T22:37:56.490" UserId="1240" />
  <row Id="21252" PostId="13642" Text="I prefer for(;;){}" CreationDate="2011-05-03T22:37:57.227" UserId="771" />
  <row Id="21253" PostId="13702" Text="avr-gcc has a macro _BV(x) for doing this sort of thing too, fyi... _BV(1) == 0b00000001, _BV(2) == 0b00000010, etc..." CreationDate="2011-05-03T22:41:19.907" UserId="771" />
  <row Id="21254" PostId="13839" Text="That will reduce the intensity, though, as you only have a 25% duty cycle for each individual display." CreationDate="2011-05-03T23:49:55.007" UserId="3745" />
  <row Id="21255" PostId="13839" Text="That is fixed by putting more current through the displays, by using lower value segment resistors. Because of the low duty cycle, high currents are possible, increasing the brightness as much as necessary, without wasting power." CreationDate="2011-05-04T00:00:18.097" UserId="305" />
  <row Id="21257" PostId="13839" Text="I think this is what I'm doing now, multiplexing. I have segments A – G on pins 11 – 19 (skipping 13). And digit 1 - 4 on pins 7 - 10. This works fine except for the brightness issue. The 8888 should be brighter or the 1 should be dimmer, preferably the former so it's nice and bright. Thanks for the feedback though." CreationDate="2011-05-04T00:29:38.543" UserId="4101" />
  <row Id="21258" PostId="13839" Text="Do you have resistors for the segments?" CreationDate="2011-05-04T00:31:05.603" UserId="305" />
  <row Id="21259" PostId="13839" Text="@Leon Heller. I had 60 ohm resistors, but replaced them with 3ohm to try to increase brightness It made everything a little brighter, but the 1 is still too hot. Do I need an LED driver, or could I get away with a cheaper part like a 74HC595 shift-register or I2C I/O expander? " CreationDate="2011-05-04T00:33:58.213" UserId="4101" />
  <row Id="21260" PostId="13829" Score="1" Text="knjn.com point-blank refuses to release the schematics for their *development boards*. I urge you to stay away from them, if you can." CreationDate="2011-05-04T00:43:25.747" UserId="1374" />
  <row Id="21261" PostId="13839" Text="3R is far too low, and is causing the brightness variation." CreationDate="2011-05-04T00:48:10.877" UserId="305" />
  <row Id="21262" PostId="2425" Text="@Mark - Very apropos for me right now that you cited separate analog and digital ground planes as almost always resulting in EMI disasters - that's exactly what I'm going through right now. Traditional &quot;star&quot; topology rules were more or less followed, theoretically bringing analog and digital grounds separately back to a central ground point. And I have an EMI disaster on my hands, sigh. OTOH, common grounds might introduce digital noise into the analog stuff which is what the separate grounds are supposed to avoid... what to do?" CreationDate="2011-05-04T00:50:57.427" UserId="4102" />
  <row Id="21263" PostId="2425" Text="@Mark, I would not agree on the separate ground planes causing issues if done properly. You should be able to segregate a large amount of noise so that your analog has higher SNR. You can however do this very very wrong, very easily." CreationDate="2011-05-04T00:54:41.543" UserId="230" />
  <row Id="21264" PostId="2425" Text="@user4102, if you have a specific questions you should ask it to the site, if you are just stuck on a problem, you have to do what we all do at some point, research and learn how. If you have time and drive, i would suggest [my favorite handbook of black magic](http://www.amazon.com/High-Speed-Digital-Design-Handbook/dp/0133957241/ref=sr_1_1?ie=UTF8&amp;qid=1304470547&amp;sr=8-1)." CreationDate="2011-05-04T00:56:16.487" UserId="230" />
  <row Id="21265" PostId="13833" Text="@JustJeff, based on my research conformal coatings often gaurd against water better then humidity. At my last job we were having a problem where the humidity, which can move through the conformal coating easily, would condense on the board under the coating and cook components." CreationDate="2011-05-04T00:59:33.490" UserId="230" />
  <row Id="21266" PostId="13832" Text="@Andrejako, we run quite a bit of DI water at my work for this very reason, we need to liquid cool and we do not want to cause shorts. DI water does the job. " CreationDate="2011-05-04T01:01:34.940" UserId="230" />
  <row Id="21267" PostId="13834" Text="@Jason, are you worried that you will not get an answer that matches the requirements and are waiting to add a bounty? On that note, glad to see you on the site again. I do not think I have seen you in a while. " CreationDate="2011-05-04T01:05:26.623" UserId="230" />
  <row Id="21268" PostId="13839" Text="Thanks Leon. My board is running at 3V3 and the LEDs are specced at 2V1, does this mean I should have 120 ohm resistors for each of the segments(7) and digits(4)? Or just the segments OR digits? " CreationDate="2011-05-04T01:10:36.590" UserId="4101" />
  <row Id="21269" PostId="13842" Score="1" Text="Also a 9V alkaline battery's voltage starts decaying faster after about 7V. It seems a natural fit to a 7805 regulator." CreationDate="2011-05-04T01:20:56.850" UserId="721" />
  <row Id="21270" PostId="13833" Text="@Kortuk - well, the liquids thing is a whole spectrum of problems. there's humidity, there's rain, there's immersion, pH, salinity, pressure, all that. my point was just that most things I've seen that are intended for submersion are potted in epoxy (or something like it)" CreationDate="2011-05-04T01:32:04.020" UserId="740" />
  <row Id="21271" PostId="13833" Text="@JustJeff, I was not disagreeing with the epoxy, just sharing what I have learned." CreationDate="2011-05-04T01:33:00.930" UserId="230" />
  <row Id="21272" PostId="13834" Score="1" Text="@Kortuk: I don't like SE's bounty system. I'd happily give away 100 points right now to some kind of escrow agent, but I don't want to have the points awarded by default. re: my absence -- life's short, things come up, I started here at a time of year when I had more free time...." CreationDate="2011-05-04T01:50:48.530" UserId="330" />
  <row Id="21273" PostId="13846" Score="1" Text="you could probably rig something to do it, but the interface circuitry would probably be the most complex part of the resulting system, and there'd be little practical value in the result." CreationDate="2011-05-04T01:57:46.240" UserId="740" />
  <row Id="21274" PostId="13834" Text="@JasonS, I am still glad to see you return, and I can understand that. People probably used it as a method to flag a question and would just never award." CreationDate="2011-05-04T02:04:16.470" UserId="230" />
  <row Id="21275" PostId="13848" Text="have to confess i've thought about interfacing some old DIP DRAM to my arduino, just fer larfs. (but, that'd be doable, on a breadboard even, w/4164 era junk). otherise, i totally agree." CreationDate="2011-05-04T02:04:42.397" UserId="740" />
  <row Id="21276" PostId="13829" Text="good to know, thanks." CreationDate="2011-05-04T02:17:16.143" UserId="985" />
  <row Id="21277" PostId="13743" Score="1" Text="@JustJeff: Sure thing:(1st line) DC-5216-053 (2nd line) DC24V 1.65A 1200r.p.m. (3rd line) 12Gq 80011 (4th line) 54031 (5th line) SHINANO KENSHI CO.,LTD. MADE IN JAPAN. I tried googling the model number and looking it up on the manufacturer website but I found nothing." CreationDate="2011-05-04T02:33:50.747" UserId="1319" />
  <row Id="21278" PostId="13849" Score="1" Text="Can an AVR execute code from RAM in any circumstances?" CreationDate="2011-05-04T03:33:20.963" UserId="1407" />
  <row Id="21279" PostId="13842" Text="That's a really clear answer. Thanks!" CreationDate="2011-05-04T03:45:49.637" UserId="3926" />
  <row Id="21280" PostId="13848" Text="That's a quality answer, using step by step assumptions and arriving at the end condition. Nice job!" CreationDate="2011-05-04T04:17:28.083" UserId="3926" />
  <row Id="21281" PostId="13753" Score="1" Text="That Circuit Simulator applet is awesome ... played with it for 30 minutes now. :)" CreationDate="2011-05-04T05:58:24.480" UserId="4070" />
  <row Id="21282" PostId="13839" Text="Assuming that you are switching on the digits one after another for multiplexing, you need the 120 Ohm resistors on the segments. The value would be right, as you are only allowed 100mA for all the pins on one port, see the notes on 28.2. DC Characteristics in the data sheet. You are exceeding the limits by far." CreationDate="2011-05-04T06:04:53.113" UserId="339" />
  <row Id="21283" PostId="13839" Score="1" Text="With 3 Ohm = 400mA at 1.2V you are exceeding the absolute limit of 40mA per port pin by far, the ATmega168 could take damage." CreationDate="2011-05-04T06:12:09.297" UserId="339" />
  <row Id="21284" PostId="13802" Text="@starblue, in most complex boards your needed current to power on is more than enough to damage a components that is hooked in incorrectly. For example, when my board needs 500mA at 5V to run I could cook any component. " CreationDate="2011-05-04T06:18:58.127" UserId="230" />
  <row Id="21285" PostId="13802" Text="@BrianCarlton, it takes moderator intervention for community wiki, someone needs to flag a moderator." CreationDate="2011-05-04T06:19:44.960" UserId="230" />
  <row Id="21286" PostId="11427" Text="@Shawarma, we need more detail to handle this, part numbers, schematics. You would be amazed where the most common issues come from. Please flag for moderator attention if you think the question is updated to a level that will be answerable." CreationDate="2011-05-04T06:22:48.063" UserId="230" />
  <row Id="21287" PostId="13832" Text="@Kortuk♦ What's DI water? Deionized maybe?" CreationDate="2011-05-04T07:00:35.703" UserId="1240" />
  <row Id="21288" PostId="13854" Score="1" Text="Oh yeah, and don't think about sending an Arduino into space - unless you like ionizing radiation." CreationDate="2011-05-04T07:21:24.003" UserId="3926" />
  <row Id="21289" PostId="13861" Text="TSOP package isn't easy to solder by hand! The MAX7221 exists in DIL package." CreationDate="2011-05-04T07:28:03.733" UserId="3920" />
  <row Id="21290" PostId="13757" Text="In my case i'm using it to power supply filtering, do you have any idea how to choose the right value ?" CreationDate="2011-05-04T07:34:00.637" UserId="199" />
  <row Id="21291" PostId="13861" Text="@Federico - well, if you want to save space, you have to suffer! :-). The MAX6950 package is only 5x5mm! BTW, if you want the 7221 because of better solderability you can still choose the SOIC package." CreationDate="2011-05-04T07:40:26.313" UserId="2064" />
  <row Id="21292" PostId="13802" Text="@Kortuk It could still prevent your traces going up in smoke. In any case, it's not a one size fits all, you have to adapt to the situation at hand." CreationDate="2011-05-04T08:13:28.493" UserId="339" />
  <row Id="21293" PostId="13762" Score="1" Text="I don't think it's that bad a question; I asked something similar on Stackoverflow and got crickets in response: http://stackoverflow.com/questions/4540219/arduino-programming-on-mac-os-x-with-xcode" CreationDate="2011-05-04T08:32:07.250" UserId="1633" />
  <row Id="21294" PostId="13802" Text="@Starblue, yes, I do always set a limit for just a little higher then what my board needs for first power up, in an ideal situation populating as I test. Most of electrical engineering is knowing how complicated the design needs to be for the situation. Adaptation is our life. I, as always, was adding just as a note for those that do not yet know enough to know the rule that no rules(minus Maxwell's) hold true all the time. " CreationDate="2011-05-04T09:27:51.940" UserId="230" />
  <row Id="21295" PostId="13832" Text="@Andrejako, Sorry, I forget that at one point I had to learn the slang also. We reference it regularly, and yes, it is deionized to 10 Mohm. And yes, when you expose the water to air it might as well be normal water in under an hour(in my experience in under 5 minutes). If you do not know what a megger is already, look into it. It will be key to checking insulation." CreationDate="2011-05-04T09:32:09.287" UserId="230" />
  <row Id="21296" PostId="13870" Score="2" Text="Anyone care to comment on the downvotes for myself &amp; Leon Heller? Both answers seem perfectly reasonable to me." CreationDate="2011-05-04T09:37:08.303" UserId="2234" />
  <row Id="21300" PostId="13849" Text="@Nick T - I was not indirectly suggesting that there are any such scenarios where it could; I was *directly* saying that in case someone was thinking of interfacing to this kind of RAM, it would be mistaken to think they could use it thus. " CreationDate="2011-05-04T11:24:46.907" UserId="740" />
  <row Id="21301" PostId="13877" Text="Do you mean the ground from the USB i.e. computer? Couldn't this be different from the return (or -ve) of the 12V battery?" CreationDate="2011-05-04T11:27:03.260" UserId="3966" />
  <row Id="21302" PostId="13877" Score="4" Text="@saad, negative of a battery is not ground. Unless you connect it to ground yourself." CreationDate="2011-05-04T12:21:34.287" UserId="2110" />
  <row Id="21303" PostId="13802" Text="@reemrevnivek Sorry, poor wording on my part. I meant to say that I started off with minimum parts, *plus* parts that I can't hand solder later (like QFN packages)." CreationDate="2011-05-04T12:48:15.510" UserId="3876" />
  <row Id="21304" PostId="13880" Text="That's very good to know, but right now I can't obtain any cheap shiny magazine paper and I have a stock of expensive press and peel which I'd like to use. Also, any specifics on the paper type? I'd guess over 200 $\frac{g}{m^2}$ and shiny, but specific type would be good." CreationDate="2011-05-04T12:52:02.933" UserId="1240" />
  <row Id="21305" PostId="13870" Text="I upvoted your answer, perhaps you can return the favour." CreationDate="2011-05-04T12:52:03.810" UserId="305" />
  <row Id="21306" PostId="13802" Score="1" Text="@Morten - Ah, makes sense.  You're right, caps are unlikely to cause problems." CreationDate="2011-05-04T12:53:33.260" UserId="857" />
  <row Id="21307" PostId="13880" Text="Everything you need to know about making PCBs is available from the Homebrew PCB group." CreationDate="2011-05-04T12:55:01.310" UserId="305" />
  <row Id="21308" PostId="13680" Text="Bit steep, but thanks!~" CreationDate="2011-05-04T12:55:15.667" UserId="3926" />
  <row Id="21309" PostId="13880" Text="@Leon Heller OK. Just for those who can't search for it, the link appears to be http://tech.groups.yahoo.com/group/Homebrew_PCBs/" CreationDate="2011-05-04T12:56:21.293" UserId="1240" />
  <row Id="21310" PostId="13809" Text="I've used the same approach. It usually works, but a couple of times it has come back to bite me rather badly. This last time it was a seemingly innocent slot under a connector that had been plated through during manufacturing and shorted the ground and power planes. My own fault entirely, but it was a frustrating and hard-to-find error." CreationDate="2011-05-04T12:57:48.690" UserId="3876" />
  <row Id="21311" PostId="13809" Text="To use the &quot;Just build the thing&quot; approach, I think I need to order more than a single PCB." CreationDate="2011-05-04T13:00:42.027" UserId="3876" />
  <row Id="21313" PostId="13838" Score="1" Text="@user4101 - I removed your header and the signature (per [this guideline](http://meta.stackoverflow.com/q/5029/146495)) and fixed the formatting at '&quot;888&quot;.\nSomeone...' If you want people to know your name, add it to your profile [here](http://electronics.stackexchange.com/users/edit/4101) and it will appear, with your [gr]avatar, at the bottom-right of your posts. Good question, though!" CreationDate="2011-05-04T13:14:56.933" UserId="857" />
  <row Id="21314" PostId="13870" Text="All answers were down-voted for some reason... very weird" CreationDate="2011-05-04T13:20:55.743" UserId="638" />
  <row Id="21315" PostId="13867" Text="I was just thinking the same myself (about &quot;mutually recalibrating&quot; the votes, that is!)." CreationDate="2011-05-04T13:27:38.370" UserId="2234" />
  <row Id="21316" PostId="13036" Text="Totally protected? The [datasheet](http://www.vishay.com/docs/72705/2n70000k.pdf) says (very prominently) 2000V, which is quite a lot for a FET, but that's only class 1C under the human body model." CreationDate="2011-05-04T13:30:16.240" UserId="857" />
  <row Id="21317" PostId="13860" Score="1" Text="@Thomas - Are you being charged per-character by your ISP?  I kid, but you could probably develop this answer a bit further..." CreationDate="2011-05-04T13:57:28.050" UserId="857" />
  <row Id="21318" PostId="13871" Score="1" Text="What you described is valid for 16-bit operation. As far as I remember only timer 2 can operate as 16-bit counter with auto-reload. Timers 0 and 1 can only be used as 8-bit counters, if auto-reload feature is used (mode 2). " CreationDate="2011-05-04T14:06:57.087" UserId="3564" />
  <row Id="21319" PostId="13869" Text="Note: the calculator I linked above can be used for both 8-bit timer 0/1 and 16-bit timer 2." CreationDate="2011-05-04T14:07:56.727" UserId="3564" />
  <row Id="21320" PostId="13760" Text="Looks like a real question to me." CreationDate="2011-05-04T14:08:21.687" UserId="1892" />
  <row Id="21321" PostId="13882" Text="The basic theft tags just depend on magnetism, not RFID. http://en.wikipedia.org/wiki/Security_tags#Magnetic_systems" CreationDate="2011-05-04T14:15:38.157" UserId="142" />
  <row Id="21322" PostId="13871" Text="@Czajnik - Quite right! I should have double-checked before posting. I've edited my answer." CreationDate="2011-05-04T14:21:44.687" UserId="2234" />
  <row Id="21323" PostId="13865" Text="You know that a 5 V, 700 mA source can be replaced by a 5 V, 2 A source, right?" CreationDate="2011-05-04T14:22:17.370" UserId="142" />
  <row Id="21324" PostId="13870" Text="I downvoted Leon Hellers entry because I think it's a bad idea to use a bench power supply to supply power to a bunch of gadgets to save space+energy, which is what I think the OP was asking for. If he wanted a laboratory power supply, then Leons answer would be the correct one." CreationDate="2011-05-04T14:35:54.910" UserId="1675" />
  <row Id="21325" PostId="13856" Text="The ADC operates while in sleep mode?  Do you mean analog comparator?" CreationDate="2011-05-04T14:40:46.700" UserId="142" />
  <row Id="21326" PostId="13834" Text="@Jason: Agreed that the bounty system is flawed.  I never thought of working around it like that, though.  Good idea." CreationDate="2011-05-04T15:05:50.750" UserId="142" />
  <row Id="21327" PostId="13880" Text="You don't have to run the whole sheet of PnP through the printer if you're doing a small board.  I had good luck printing the artwork on plain paper, then cutting out a rectangle of the right size, and taping it onto the paper over the artwork along the top edge.  Then I ran the sheet again to print onto the PnP." CreationDate="2011-05-04T15:22:37.990" UserId="2773" />
  <row Id="21328" PostId="13872" Text="A 6V 1,000mA adapter might not be a perfect substitute for a device which expects a 6V 100mA adapter.  Some adapters put out a higher-than-spec voltage when they are used significantly below their rated current.  A device which uses a linear regulator to supply up to 100mA at 5 volts might expect to have the regulator dissipate 100mW (1V @ 100mA) when drawing 100mA, and wouldn't mind if it had to drop 2V when the device was only drawing 50mA or even 4V (9 volt supply) when the device was drawing 25mA; it might not be quite so happy, though, with an adapter..." CreationDate="2011-05-04T15:33:55.170" UserId="3123" />
  <row Id="21329" PostId="13872" Text="...that puts out 8 volts@100mA, which is something a nominal 6V 1000mA adapter might do." CreationDate="2011-05-04T15:35:07.007" UserId="3123" />
  <row Id="21330" PostId="13157" Text="@tjameson - Re: Designing for a company - It sounds like you *are* designing this for a company.  Even if the company doesn't exist yet, Amazon's lawyers can still find out about your initial prototype and come for your company once it's made some money.  That would suck." CreationDate="2011-05-04T15:40:25.693" UserId="857" />
  <row Id="21331" PostId="13809" Text="I've seen &quot;squeaker&quot; probes used for a similar purpose - to zero in on the short.  Sadly, I can't find a link to the product." CreationDate="2011-05-04T15:58:12.757" UserId="3308" />
  <row Id="21332" PostId="13769" Score="1" Text="@User4079 - This isn't a forum.  There's no reason not to edit your original post to improve its clarity or add information!  I've pulled your comment (which is way at the bottom right now) into the question, but feel free to do this yourself in the future." CreationDate="2011-05-04T15:59:22.250" UserId="857" />
  <row Id="21333" PostId="13884" Score="1" Text="This is a very important effect, I was about to ask Kortuk to add it to his answer. One of the factors behind the max Tj spec for a processor is that above that Tj the processor may not work at the rated speed. This is also why better cooling helps in overclocking." CreationDate="2011-05-04T16:00:35.493" UserId="3441" />
  <row Id="21334" PostId="13721" Text="@Cff - Another aspect of the FAQ is that you can answer your own question.  People won't look in the question for the answer, they'll look for the answer with the green check mark.  You should pull your last sentence out of the question, paste it as an answer (possibly with some additional information on how you discovered the problem, or why you suspect that the initial USB port didn't work), and mark it as the solution to your problem.  Thanks!" CreationDate="2011-05-04T16:02:54.840" UserId="857" />
  <row Id="21335" PostId="13810" Score="1" Text="Good answer to a bad question!" CreationDate="2011-05-04T16:04:15.810" UserId="857" />
  <row Id="21336" PostId="3949" Score="1" Text="Old thread, but FYI: XR-2206 is obsolete: see (http://electronics.stackexchange.com/questions/12422/analog-function-generator-ics) for details" CreationDate="2011-05-04T16:53:50.710" UserId="1293" />
  <row Id="21337" PostId="13860" Text="@Reemrevnivek, I had to rush to go to college, and had 2 mins to type out that answer... 1.5 mins of that were finding the link to what I wanted." CreationDate="2011-05-04T16:55:23.127" UserId="1225" />
  <row Id="21339" PostId="13888" Text="Yeah, the HC595 is perfect for SPI outputs, there just doesn't seem to be the same kind of match for inputs... 597s are being made by fewer manufacturers and don't support very high clock rates unless you use 5V logic supplies." CreationDate="2011-05-04T17:31:37.997" UserId="330" />
  <row Id="21340" PostId="13771" Text="+1 for the link to the SkyLink Garage Door Monitor" CreationDate="2011-05-04T18:58:19.153" UserId="1322" />
  <row Id="21341" PostId="13890" Text="Do you have time to describe the circuit? I'm new to fluorescent lamps." CreationDate="2011-05-04T19:08:54.513" UserId="2172" />
  <row Id="21342" PostId="13890" Text="It's quite obvious if you buy standard 12&quot; fluorescent light fittings. The ballasts should have the connections on them." CreationDate="2011-05-04T19:24:31.163" UserId="305" />
  <row Id="21343" PostId="13857" Text="My thought as well.  And have the FPGA be a transparent refresh controller.  But really... wouldn't it be simpler and cheaper to _emulate an arduino in software_ on a small ARM system?" CreationDate="2011-05-04T19:54:57.490" UserId="2246" />
  <row Id="21344" PostId="13848" Score="2" Text="Don't overlook the refresh issues.  Another reason &quot;command based&quot; flash is probably a better match when a mouse of a controller is trying to drive a mack truck of a memory." CreationDate="2011-05-04T19:57:32.963" UserId="2246" />
  <row Id="21345" PostId="13883" Text="There's plenty of source code out there, too." CreationDate="2011-05-04T20:13:49.170" UserId="3308" />
  <row Id="21346" PostId="13856" Text="I didn't think the avrs that arduino uses had internal comparators. After going back and looking again it turns out I was wrong! I'm not sure what sleep states they are turned off in though." CreationDate="2011-05-04T20:27:03.957" UserId="4034" />
  <row Id="21347" PostId="13884" Text="The first paragraph is why your computer stops working when it gets hot - it slows down too much to keep pace with the clock frequency." CreationDate="2011-05-04T20:39:04.817" UserId="638" />
  <row Id="21348" PostId="13884" Text="Actually, there's another factor which may possibly have played a role in NMOS devices, though I wouldn't expect it in most typical designs: many NMOS devices had *minimum* clock speeds, imposed by a requirement to use or refresh the data in dynamic storage nodes before it got drained out by leakage.  If leakage currents increase with temperature, the minimum clock speed would also increase.  I suspect most devices were operated sufficiently above minimum clock speed that an increase in the minimum speed wouldn't be a problem, but I'm not sure." CreationDate="2011-05-04T20:53:50.773" UserId="3123" />
  <row Id="21349" PostId="13662" Text="Sorry for the earlier clutter. I have cut down the code pasted in question, and have also updated the question itself. Could you please have a look now?" CreationDate="2011-05-04T21:09:18.263" UserId="3852" />
  <row Id="21350" PostId="13569" Text="I got some pins, soldered them in and the thing half worked.  I could light it up, I could send to it but it was gibberish.  After a couple of days of frustration I had a close look at the soldering and thought...hmmm...that one looks a bit dodgy.  Eureka!!!  It works.  Thanks for all input." CreationDate="2011-05-04T21:20:01.983" UserId="4017" />
  <row Id="21351" PostId="13857" Text="However fun or educational it might be DDR is not simple, and not beginner stuff.  Find another laptop or motherboard to put this memory in and learn about DDR using say an fpga eval board that has a little bit on the side or maybe a beagleboard or something like that.  The first problem is pin count, second is the signals, timing, etc.  It is hard to get it to work when you make your own pcboard.  It is not like an lcd interface or something like that that you can breadboard to a microcontroller." CreationDate="2011-05-04T21:46:39.243" UserId="985" />
  <row Id="21352" PostId="13877" Text="+1 what Martin said - the battery, and any load connected to it, are 'floating' with respect to ground, unless you establish a connection between some part of the battery/load system and an actual ground. In this case, you can take the ground in your 232 connection as the definition of 'ground' for your battery/load combo, once you connect it." CreationDate="2011-05-04T22:17:17.530" UserId="740" />
  <row Id="21353" PostId="13743" Text="@Faken - yeah, I see what you mean. It's probably one of their 'custom assemblies'." CreationDate="2011-05-04T22:47:05.923" UserId="740" />
  <row Id="21354" PostId="13662" Text="You're enabling interrupts in ADC10CTL0, yet you mention interrupts are not used.  Is that intentional?" CreationDate="2011-05-04T23:31:39.023" UserId="2308" />
  <row Id="21355" PostId="13884" Text="@Supercat, @Andy, @W5VO, I was writing my answer last night and forgot that mid way. Night shift does damage to your brain." CreationDate="2011-05-05T00:00:27.107" UserId="230" />
  <row Id="21356" PostId="13854" Score="2" Text="@LeanerRocky, I love ionizing radiation. Lets send an arduino into space." CreationDate="2011-05-05T00:01:58.273" UserId="230" />
  <row Id="21357" PostId="13662" Text="@AustinPhillips, I think he is enabling setting of the flag, he is however not enabling the global flag for interrupts. This can be a dangerous practice as if global flag is set by another module it will result in the interrupt being serviced. If this happened and the code is not there it will cause your code to fail." CreationDate="2011-05-05T00:08:56.400" UserId="230" />
  <row Id="21358" PostId="13894" Text="Won't the switch stay high if you use a capacitor?  And won't it interpret that as a command to force off?  Or does it need to see a falling edge before it will register the switch held down?" CreationDate="2011-05-05T01:14:59.193" UserId="249" />
  <row Id="21359" PostId="13662" Text="Even if I don't set ADC10IE, it makes no difference." CreationDate="2011-05-05T01:16:05.027" UserId="3852" />
  <row Id="21360" PostId="13466" Text="Wow. thanks - I appreciate all the info. Definitely coming from a programmer background, but I was interested in the electrical engineering perspective. I had heard that x86 wasn't the best and that it &quot;should&quot; have been replaced a while ago. " CreationDate="2011-05-05T01:17:43.257" UserId="3972" />
  <row Id="21361" PostId="13662" Text="Try polling for ADC10BUSY rather than ADC10IFG.  ADC10IFG will be set after the first conversion and your loop will then drop through even though second conversion is still in progress." CreationDate="2011-05-05T01:43:05.740" UserId="2308" />
  <row Id="21362" PostId="13662" Text="Thanks. I will try that and let you know how it went here." CreationDate="2011-05-05T01:51:02.797" UserId="3852" />
  <row Id="21363" PostId="10152" Text="Why microvolt signals?  If you can interface to more standard logic levels, it might be better to use TMDS/LVDS transceivers and serialize the data.  No matter what you do, I doubt 40 conductors would turn out to be all that flexible..." CreationDate="2011-05-05T01:53:25.160" UserId="3308" />
  <row Id="21364" PostId="259" Text="I'm just curious, but why do you specifically want a capacitive one?" CreationDate="2009-11-07T14:12:50.193" UserId="213" />
  <row Id="21365" PostId="13898" Score="1" Text="@Delinquentme, We are an electronics design site, not a mechanical one." CreationDate="2011-05-05T04:19:45.230" UserId="230" />
  <row Id="21366" PostId="13898" Text="is this a legitimate question: YES" CreationDate="2011-05-05T04:57:27.087" UserId="4067" />
  <row Id="21367" PostId="13898" Text="is there a stack overflow mechanical : NO" CreationDate="2011-05-05T04:58:52.933" UserId="4067" />
  <row Id="21368" PostId="13898" Text="Y you troll mister kortuk?!" CreationDate="2011-05-05T04:58:59.907" UserId="4067" />
  <row Id="21369" PostId="13898" Score="1" Text="@Delinquentme, Just because your question does not have a good home does not mean we can give it one. We used to have robotics in our name and handle robotics. This has since changed and will instead go with the [robotics research](http://area51.stackexchange.com/proposals/29987/robotics-research) site. I am not sure why you ask me if I troll, but I am sorry if this is frustrating to you. I also find it frustrating that Robotics did not want to work here and has since failed to form a site." CreationDate="2011-05-05T05:19:00.333" UserId="230" />
  <row Id="21370" PostId="13903" Text="@SimonBarker, When I say that the dopants become more mobile, I mean the physical atoms, not the carriers. The PN junction can drift and stop being a diode with time and heat. Second, When you get a higher enough temp your thermal energy, which creates both high energy phonons that interact with the electrons and much higher IR levels inside the structure, can give electrons high enough energy to jump the band-gap between conduction and valence layers. The Si tops out because its bandgap is such that 150degC will give electrons the ability to jump." CreationDate="2011-05-05T06:38:25.303" UserId="230" />
  <row Id="21371" PostId="13569" Text="Very welcome. Good luck with those crystals ;)" CreationDate="2011-05-05T06:50:53.370" UserId="4028" />
  <row Id="21372" PostId="13900" Score="1" Text="I'm very surprised they didn't have the '3904, it's practically a jelly bean part. What about the 2N2222?" CreationDate="2011-05-05T07:02:56.633" UserId="1225" />
  <row Id="21373" PostId="13901" Text="You need to be more specific." CreationDate="2011-05-05T07:03:16.960" UserId="1225" />
  <row Id="21374" PostId="13901" Text="@RichaGupta, please give us a bit more detail, just edit it in, and then flag for moderator attention and I can reopen it if it fits our site. Thank you for visiting!." CreationDate="2011-05-05T07:30:33.453" UserId="230" />
  <row Id="21375" PostId="13898" Text="http://www.archive.org/details/fivehundredseven00browiala" CreationDate="2011-05-05T07:40:22.683" UserId="411" />
  <row Id="21376" PostId="13894" Text="The high state of the signaling pin just means &quot;switch open&quot; and does nothing. " CreationDate="2011-05-05T07:46:36.313" UserId="1472" />
  <row Id="21377" PostId="13872" Text="You are right that unregulated PSUs will put out a higher voltage, if it's not loaded down enough. I should clarify that I was talking about regulated switchmode PSUs, which will put out the specified voltage no matter what current is being pulled." CreationDate="2011-05-05T07:49:47.220" UserId="1675" />
  <row Id="21378" PostId="13898" Text="@Markrages, Nice reference. @reopen voter, Why? I would be very interested how someone thinks this fist our site." CreationDate="2011-05-05T07:53:18.903" UserId="230" />
  <row Id="21379" PostId="13903" Text="Yeah, I think we are saying the same thing just from different starting point." CreationDate="2011-05-05T08:41:24.037" UserId="4096" />
  <row Id="21380" PostId="13903" Text="@SimonBarker, The way you are explaining it sounds exactly how I would of after taking device physics, after taking some applied Quantum and solid state devices I say it a little differently, but we both know how oversimplified these explanations are. I added a bit about this affect to my answer as I think it is very important, I gave you your first +1, which you deserved. This is an important affect as it leads to thermal runaway very quickly." CreationDate="2011-05-05T08:46:49.953" UserId="230" />
  <row Id="21381" PostId="13906" Score="1" Text="@Stevenvh, I think this answer is more of a comment. Yes, this formula is important, but more detail and explanation may be warranted. Clearly, we do not want to do someones homework for them, but an example or showing some example changes might be worth it. Just my opinion." CreationDate="2011-05-05T08:59:34.457" UserId="230" />
  <row Id="21384" PostId="13196" Text="@stevenvh, this is specifically for Si diodes, or does this apply to all diodes." CreationDate="2011-05-05T09:19:44.790" UserId="230" />
  <row Id="21385" PostId="13908" Text="@JustJeff, for a homework question I think that some examples of different steps or some guide on what it means to be in polar form compared to rectangular form might be helpful. I have met multiple people whom never had the triangle explanation given to them." CreationDate="2011-05-05T09:21:26.257" UserId="230" />
  <row Id="21387" PostId="13908" Text="@Kortuk - I was intentionally being sketchy specifically b/c I didn't want to just hand over the answer, due to the word 'exam' in the question." CreationDate="2011-05-05T09:26:15.287" UserId="740" />
  <row Id="21388" PostId="13908" Text="@JustJeff, Yes, I assumed. I was suggesting maybe putting in a picture that connects the polar and rectangular form. " CreationDate="2011-05-05T09:27:33.927" UserId="230" />
  <row Id="21390" PostId="13909" Score="1" Text="@MikeJ-UK, I think we need to avoid solving the full problem for [someone when it is homework](http://meta.electronics.stackexchange.com/questions/80/homework-problems). How about you edit it out, or, even better, delete your answer and post a new one that does not give the solution?" CreationDate="2011-05-05T09:29:24.193" UserId="230" />
  <row Id="21391" PostId="13909" Score="1" Text="@Kortuk - You just suggested to JustJeff that he should have put some examples in his answer!. I have only addressed his last example using standard formulae found in any reference and I haven't answered his original question. I'll change some numbers anyway if it's not too late!" CreationDate="2011-05-05T09:34:58.763" UserId="2234" />
  <row Id="21393" PostId="13909" Text="@MikeJ-UK, I misread your example and thought you did the exact problem he was assigned. My bad. This is why I should not review content when I have been awake for 13 hours during a night shift. Please accept my apology and up-vote." CreationDate="2011-05-05T09:40:57.667" UserId="230" />
  <row Id="21394" PostId="13909" Text="i was getting the sense Kortuk was hoping he could mash our answers together =P" CreationDate="2011-05-05T09:45:55.387" UserId="740" />
  <row Id="21395" PostId="13906" Text="@Kortuk - Euler is the answer to OP's question. I'm sure he learned it previously, but probably didn't think about it right away. I just wanted to put him back on the tracks without making the complete exercise for him." CreationDate="2011-05-05T09:49:33.400" UserId="2064" />
  <row Id="21396" PostId="13909" Text="@Kortuk - No need to apologize. It's a fine line between helping &amp; doing the work!" CreationDate="2011-05-05T09:54:37.383" UserId="2234" />
  <row Id="21397" PostId="13909" Text="@JustJeff, my intentions are hidden, maybe. @MikeJ-UK, I would clear out the comments, but I prefer people occasionally see me be an idiot. People never think me a fool, I always open my mouth and prove it." CreationDate="2011-05-05T10:02:30.590" UserId="230" />
  <row Id="21398" PostId="13909" Text="@Justjeff, on that note, I really want to edit in a picture of the connection between mag-phase format and rectangular format. It seems the OPs core issue is this difference between these formats and what they mean." CreationDate="2011-05-05T10:07:49.140" UserId="230" />
  <row Id="21399" PostId="13906" Text="@Stevenvh, the thought of someone knowing euler's formula and not knowing to use it without a misunderstanding of the formula did not cross my mind. I was only saying it was more of a comment because a single equation with no explanation seems like more of a comment to me. Please do not take offense, I am just trying to help improve the site where I can while I have a moment to look at things. I rarely get time to wait around but I had a large amount of vacuum system work tonight and it never ever goes quickly." CreationDate="2011-05-05T10:10:34.427" UserId="230" />
  <row Id="21400" PostId="13906" Text="@stevenvh Thank you, i learned it previously but forgot it." CreationDate="2011-05-05T10:37:20.930" UserId="3817" />
  <row Id="21401" PostId="13196" Text="@Kortuk - this is for Si, I'll add this to the answer. Ge diodes have a higher tempco. Don't know the exact value though." CreationDate="2011-05-05T11:17:13.750" UserId="2064" />
  <row Id="21402" PostId="13894" Text="Ah, opposite of what I thought.  That's pretty cool then." CreationDate="2011-05-05T11:27:06.283" UserId="249" />
  <row Id="21403" PostId="13196" Text="@Stevenvh, I was 99% sure of that, but thought I should ask, figured a short and sweet answer needed that added." CreationDate="2011-05-05T11:27:43.983" UserId="230" />
  <row Id="21404" PostId="13911" Text="@JustJeff, I would suggest adding some information about a buck-boost regulator. I do not have time right now, but if you cannot get to it I can try to look up information later." CreationDate="2011-05-05T11:32:19.897" UserId="230" />
  <row Id="21405" PostId="13910" Text="@Ahnurmi, there are major differences here if the input already has some regulation on it. I would be that it does not." CreationDate="2011-05-05T11:32:44.590" UserId="230" />
  <row Id="21406" PostId="13898" Text="@kortuk .. what guides these mechanical motions?  There are HARDLY &quot;too many posts&quot; in here to manage .. instead you're stifling the ability for a community to start and spawn into something else" CreationDate="2011-05-05T11:32:54.310" UserId="4067" />
  <row Id="21407" PostId="13898" Score="1" Text="@Delinquentme, We are attempting to continuing growing into an electronics design site. Please take a look at http://meta.electronics.stackexchange.com/questions/474/electronics-and-robotics-has-been-renamed-to-electronics" CreationDate="2011-05-05T11:48:09.763" UserId="230" />
  <row Id="21408" PostId="13196" Text="@Stevenvh - what is the reverse recovery time in diode?&#xA;" CreationDate="2011-05-05T12:10:17.597" UserId="3916" />
  <row Id="21409" PostId="13899" Text="The MCP2551 isn't another complete CAN node that can acknowledge packets, it is just a transceiver. Do you have another complete CAN node connected, that is known to work, eg a CAN USB sniffer? Also ensure to have the CAN line termination resistors fitted (even on a very short line)." CreationDate="2011-05-05T12:11:27.487" UserId="2110" />
  <row Id="21410" PostId="13898" Text="is this posting of detriment to that? NO. " CreationDate="2011-05-05T12:16:29.657" UserId="4067" />
  <row Id="21411" PostId="13909" Text="Thank you. Helped. But now i have the next problem...edited my question" CreationDate="2011-05-05T12:39:19.920" UserId="3817" />
  <row Id="21412" PostId="13898" Text="@delinquentme - See also [here](http://meta.electronics.stackexchange.com/questions/429/another-robotics-proposal-on-area51), [here](http://discuss.area51.stackexchange.com/questions/1064/we-already-have-electronics-and-robotics), and [here](http://discuss.area51.stackexchange.com/questions/1078/please-support-this-proposal-as-a-means-to-split-robotics-from-the-electronics-si) for more discussion about how 'Robotics' was dropped from the site's topics." CreationDate="2011-05-05T13:07:38.023" UserId="857" />
  <row Id="21413" PostId="13898" Text="Also, the link Kortuk (who is not a troll, he's actually one of the best loved moderators on the site, and has a good deal of authority when it comes to closing questions) posted has -3 votes not because we didn't want to drop robotics (we did) but because we didn't want to be renamed Electronics, instead preferring &quot;Chiphacker&quot;, &quot;Short Circuit&quot; or &quot;Electronics Design&quot;." CreationDate="2011-05-05T13:11:00.067" UserId="857" />
  <row Id="21414" PostId="13196" Text="@Cell-o - That question is (mostly) unrelated to the effect of temperature on a diode.  Please post it as a new question, if it's not a duplicate of [this question](http://electronics.stackexchange.com/questions/3821/what-is-a-fast-2a-type-diode)." CreationDate="2011-05-05T13:14:02.390" UserId="857" />
  <row Id="21415" PostId="13825" Score="1" Text="@Simon - Nicely done!  The initiative you showed to read up on Meta and fix the question as well as you did is much appreciated.  I just had to touch up the title a little, but I think it's ready to be reopened now." CreationDate="2011-05-05T13:32:29.370" UserId="857" />
  <row Id="21417" PostId="4859" Text="Obligatory http://xkcd.com/730/" CreationDate="2011-05-04T20:47:10.860" UserId="4112" />
  <row Id="21418" PostId="13825" Score="1" Text="However, I'm curious what transceivers you've found that are so expensive.  Are you comparing, say, the Lantronics WiPort and Digi Connect to stuff like the Microchip MRF24J40?  That's not apples-to-apples at all!" CreationDate="2011-05-05T13:36:15.093" UserId="857" />
  <row Id="21419" PostId="13538" Text="@SteveR, I was not disagreeing, just telling you in this situation I think it will not be a source of error." CreationDate="2011-05-05T13:44:31.220" UserId="230" />
  <row Id="21420" PostId="13912" Score="1" Text="@Cell-o, what have you read so far, what do you already know about diodes?" CreationDate="2011-05-05T13:50:07.223" UserId="230" />
  <row Id="21421" PostId="13912" Text="@Kortuk - of course ,I have read.But,I do not exactly  understand.So,  What factors affect  reverse recovery time in diode? " CreationDate="2011-05-05T13:55:13.067" UserId="3916" />
  <row Id="21422" PostId="13913" Score="1" Text="Lead is a heavy metal, it is not good for you to handle or ingest heavy metals. RoHS is an EU directive that bans those materials in products. When I did work with devices entering cattle we were required by the FDA to use lead free products. When will it affect at home use, not at all, unless you are dealing with lead free solder." CreationDate="2011-05-05T14:03:50.173" UserId="230" />
  <row Id="21423" PostId="13825" Text="@reemrevnivek thank you for reopening the question! - the meta was really useful in clearing things up. I had been looking at the WiPort along with the WiFly and FlyPort that coolcomponents stock. I had been comparing them to microchip one you mention along with a FreeScale MC13202FC on RS. I had started to realise that I wasn't comparing like for like and that's where my confusion occurs - I feel like I am missing the bit of knowledge on how a simple 2.4GHz transceiver becomes a WiFi device that can join a home network - which is ultimately what I want to do - I'll add this to the question" CreationDate="2011-05-05T14:06:56.193" UserId="4096" />
  <row Id="21424" PostId="13913" Score="5" Text="@Kortuk - Isn't that an answer? :-)" CreationDate="2011-05-05T14:08:41.090" UserId="2064" />
  <row Id="21425" PostId="13913" Score="2" Text="@Stevenvh, I felt it was a poor attempt at one without sources. I am too tired to write a good answer right now. Just sharing what I already know with the OP, if there are not answers later I will write one, but there will be." CreationDate="2011-05-05T14:09:57.033" UserId="230" />
  <row Id="21426" PostId="13662" Text="Doesn't work even if I get rid of IFG and start using BUSY. Moreover, with BUSY, I am not getting any results even for a single channel." CreationDate="2011-05-05T14:11:05.793" UserId="3852" />
  <row Id="21427" PostId="13662" Score="1" Text="Could you help me in making this interrupt based? If there's an interrupt on DTC transfer complete, and if I read data in ISR, this could work. But I am a bit shaky when it comes to interrupts." CreationDate="2011-05-05T14:12:31.020" UserId="3852" />
  <row Id="21428" PostId="13914" Text="@morten, I thought many different components like LEDs often had a waiver not requiring RoHS compliance, do you know if this is true?" CreationDate="2011-05-05T14:16:38.650" UserId="230" />
  <row Id="21429" PostId="13915" Text="@SimonBarker, maybe that the device the military is using is more dangerous then the risk of touching lead? I still thought they tried not to restrict technology by allowing devices that could not exist otherwise, like some LEDs, to use heavy metals." CreationDate="2011-05-05T14:22:43.607" UserId="230" />
  <row Id="21430" PostId="13915" Text="I'm not sure, but that sounds reasonable - especially given that the heavy metal inside LEDs is likely encased in plastic so it would be difficult to touch." CreationDate="2011-05-05T14:28:45.927" UserId="4096" />
  <row Id="21431" PostId="13913" Score="2" Text="@Kortuk - Putting a poor attempt at an answer in a commment (for fear of downvotes?  for fear of looking bad?) is silly.  Make it an actual answer, and then update/revise it later (or, hope that someone else does) if it's really that bad." CreationDate="2011-05-05T14:41:02.677" UserId="857" />
  <row Id="21432" PostId="13872" Text="@dren: True, provided that there's at least a minimum load.  Some switch-mode power supplies won't be happy without a certain minimum load; supplies with higher maximum loads will often have higher minimum loads (many supplies may be able to dissipate power internally in the absence of an external minimum load, but this will of course waste energy)." CreationDate="2011-05-05T14:44:37.173" UserId="3123" />
  <row Id="21433" PostId="13916" Score="1" Text="FT232 chips are full-speed devices, running at a maximum of 12 Mbit/s.  The Cypress chip referenced is a USB 2.0 High-speed device, which can do up to 480 Mbit/s.  The routing requirements are similar (at least they're both using differential signals), but they won't be identical." CreationDate="2011-05-05T14:47:25.073" UserId="857" />
  <row Id="21434" PostId="13913" Score="1" Text="@reemrevnivek, it is not a fear of anything, if I do not consider a statement an answer and more a passing comment, I make it a comment. In this case it would have saved me time with answering had I know the number of responses I would have received." CreationDate="2011-05-05T14:52:55.400" UserId="230" />
  <row Id="21435" PostId="13915" Text="@SimonBarker, so would the lead inside an IC, I think they are trying to avoid letting heavy metals into landfills and the environment. Finding the reason behind legislation though, good luck." CreationDate="2011-05-05T14:53:37.100" UserId="230" />
  <row Id="21436" PostId="13912" Score="1" Text="It's caused by the carrier recombination time, and the explanation requires a lot of difficult maths." CreationDate="2011-05-05T14:56:28.733" UserId="305" />
  <row Id="21437" PostId="13912" Text="@Leon Heller - Can you give me more detail related with that?" CreationDate="2011-05-05T15:06:57.283" UserId="3916" />
  <row Id="21438" PostId="13918" Text="@david, thanks very much. I have added my intended use in the question. I didn't initially as I thought it may be to detailled. Your answer has helped start to clear up my confusion - hopefully my edit gets my intention across better" CreationDate="2011-05-05T15:27:57.670" UserId="4096" />
  <row Id="21439" PostId="13917" Text="Wow thank you for your answer reemrevnivek - it's what I am after. So there is a lot more to this issue than I first thought then!?!? At least I can now see why the Lantronix etc stuff is so pricey. I feel like yours and Davids answer has helped me lift the lid on a very large can of worms. I will have a good read through those documents you have pointed me to and then see about getting stuck into the maxim hardware." CreationDate="2011-05-05T15:31:32.720" UserId="4096" />
  <row Id="21440" PostId="13914" Text="@Kortuk Yes, there is a list of exemptions including color LEDs that use phosphors containing cadmium. Products that does not have a feasible substitute can get a time limited exemption for 5-10 years it seems." CreationDate="2011-05-05T15:38:49.387" UserId="3876" />
  <row Id="21441" PostId="13910" Score="1" Text="Here is a recent 12V supply question that may provide some useful background: http://electronics.stackexchange.com/questions/13421/some-power-supply-questions-multiple-rails-or-single-rail-w-multiple-outputs" CreationDate="2011-05-05T15:46:29.903" UserId="3441" />
  <row Id="21442" PostId="13909" Text="@madmax - There's something wrong there. Your voltage and current are *in* phase so there can be no imaginary power. You have taken your resultant argument as 31.78 + 31.78 instead of 31.78 - 31.78 = 0, ie 68.13 + j0 - which still doesn't agree with your given answer." CreationDate="2011-05-05T15:51:48.803" UserId="2234" />
  <row Id="21444" PostId="13922" Text="For purposes of this question, I *do* want to get really fancy.  Can you elaborate on SSHI?  Any relation to http://en.wikipedia.org/wiki/Active_rectification?" CreationDate="2011-05-05T16:04:07.103" UserId="142" />
  <row Id="21445" PostId="13915" Text="I believe Military and aerospace applications are exempt because the reduced reliability of lead-free solder connections would be unacceptable there.  If someone's television set fails because the lead-free connections developed faults, that's a good thing--means the guy has to get a new television set.  But if a plane falls from the sky, that's not so good." CreationDate="2011-05-05T16:05:45.823" UserId="3123" />
  <row Id="21446" PostId="13920" Text="`to be legally sold` in the EU.  [Other regions](http://en.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directive#RoHS_in_other_regions) (notably including most of the USA) have less stringent requirements for electronics." CreationDate="2011-05-05T16:07:01.993" UserId="857" />
  <row Id="21447" PostId="13924" Text="For those that want a summary of the links... &quot;Every audio cable, no matter the manufacturer, has a point along the audio bandwidth where the relationship of capacitance and inductance is most efficient at storing energy.&quot; They then claim they use different wires to produce these poles at different frequencies." CreationDate="2011-05-05T16:14:40.577" UserId="319" />
  <row Id="21448" PostId="13909" Text="I think i know where my problem is... It is an RLC network and i only use the voltage of the resistor for the power of the source" CreationDate="2011-05-05T16:17:15.193" UserId="3817" />
  <row Id="21449" PostId="13924" Score="8" Text="It looks like complete rubbish to me. I'd like to see whether listeners can tell the difference between those cables and ordinary mains cable with double-blind testing. I very much doubt it." CreationDate="2011-05-05T16:18:57.617" UserId="305" />
  <row Id="21450" PostId="13924" Score="4" Text="I like the word rubbish." CreationDate="2011-05-05T16:27:05.667" UserId="319" />
  <row Id="21451" PostId="13899" Text="I do have the Microchip CAN analyzer - but it doesn't work correctly with x64. You are right the transceiver won't ACK the message, but I should still be able to see the message repeatedly sent on my logic analyzer, but the RX line is always HIGH (idle)." CreationDate="2011-05-05T16:28:29.177" UserId="2150" />
  <row Id="21452" PostId="13927" Score="3" Text="The article is very good, and I wholeheartedly agree that these insane cables are sort of like the lottery (which tax the math-challenged); they tax the physics-challenged." CreationDate="2011-05-05T16:29:21.613" UserId="2028" />
  <row Id="21453" PostId="13925" Score="1" Text="+1 for the electronics equipment already having filters and EQ" CreationDate="2011-05-05T16:31:45.027" UserId="2028" />
  <row Id="21454" PostId="13924" Score="2" Text="just read this, an 'articulation pole' is just a made up term referencing the LC resonance point of the cable, which is itself mostly a myth as its being presented as a result of improper understanding of transmission line effects: http://www.audioholics.com/education/cables/debunking-the-myth-of-speaker-cable-resonance" CreationDate="2011-05-05T16:32:33.573" UserId="1438" />
  <row Id="21455" PostId="13926" Score="1" Text="I like the word hogwash also." CreationDate="2011-05-05T16:32:50.123" UserId="319" />
  <row Id="21456" PostId="13924" Score="3" Text="Note: the &quot;MIT&quot; in &quot;MIT Cables&quot; is not the venerable Massachusetts Institute of Technology, it stands for &quot;Music Interface Technologies.&quot; Feels spammy to me." CreationDate="2011-05-05T16:34:02.573" UserId="857" />
  <row Id="21457" PostId="13924" Text="MIT Cables also has some white papers which I am willing to bet will cause many electrical engineers to go WTF? See: http://www.mitcables.com/pdf/wp101.pdf" CreationDate="2011-05-05T16:35:13.273" UserId="2028" />
  <row Id="21458" PostId="13928" Text="@Roberto - As this question stands, it's a bad shopping question.  A source for this stuff is going to be localized geographically (where are you from?  Not everyone ships there...) and temporally (prices change...).  Also, you're unlikely to learn much if someone gives you a link, so it's not a real question.  Please revise it (read up on the [\[shopping tag\]](http://meta.electronics.stackexchange.com/questions/tagged/shopping) on Meta) and you'll get a much better reception." CreationDate="2011-05-05T16:37:04.600" UserId="857" />
  <row Id="21459" PostId="13924" Text="@Mark thanks for the link." CreationDate="2011-05-05T16:37:51.523" UserId="2028" />
  <row Id="21460" PostId="13922" Text="Not really related, although Ferrari did present a paper at the 2008 IEEE Sensors conference where they attempted something similar - replacing passive diodes with switched FETs. Have a read of http://jim.sagepub.com/content/17/8-9/831.abstract or &quot;Toward Heat Energy Harvesting using Pyroelectric Material&quot;&#xA;DANIEL GUYOMAR or http://iopscience.iop.org/0964-1726/16/6/028/ what is your end application? It's worth bearing in mind that any clever processing/control added in needs to use less power than it creates" CreationDate="2011-05-05T16:44:01.130" UserId="4096" />
  <row Id="21461" PostId="13926" Score="2" Text="It's b*ll*cks, to use a good old English epithet." CreationDate="2011-05-05T17:00:40.077" UserId="305" />
  <row Id="21462" PostId="13927" Text="I wish I could 'favourite' or 'like' users here." CreationDate="2011-05-05T17:08:13.123" UserId="536" />
  <row Id="21463" PostId="13927" Text="@pfyon  Thanks Pfyon!" CreationDate="2011-05-05T17:10:51.963" UserId="3624" />
  <row Id="21464" PostId="13920" Text="For now.  But the EU is a large market already; and California already has the RoHS law as well - and as California goes, so goes the rest of the U.S., eventually.  " CreationDate="2011-05-05T17:13:00.107" UserId="3308" />
  <row Id="21465" PostId="13928" Text="@reemrevnivek — I rewrote the article as requested. Would you now kindly undo the negative vote? .. my god, I guess everyone votes down questions here. after rewriting it, its down-voted again. I'm beginning to wonder if there is a more neutral forum to ask this sort of question" CreationDate="2011-05-05T17:15:08.170" UserId="4125" />
  <row Id="21466" PostId="13928" Score="1" Text="It isn't any better!" CreationDate="2011-05-05T17:19:04.453" UserId="305" />
  <row Id="21468" PostId="13928" Score="1" Text="@Leon — please see http://meta.electronics.stackexchange.com/questions/516/how-do-we-formulate-good-and-bad-shopping-questions-for-faq .. my rewrite is explicitly modelled after the top &quot;good question&quot; in that meta" CreationDate="2011-05-05T17:20:20.257" UserId="4125" />
  <row Id="21469" PostId="13912" Text="Any suggestions?" CreationDate="2011-05-05T17:21:46.993" UserId="3916" />
  <row Id="21470" PostId="13927" Text="I have a slight disagreement with the testing methodology: a good test should allow the subjects to supply a CD of audio for the test, and should inform them what types of &quot;cabling&quot; they'll be comparing.  Give the test subjects twelve buttons: &quot;A&quot;, &quot;B&quot;, and &quot;0&quot;-&quot;9&quot;.  Button &quot;A&quot; will select fancy cables.  Button &quot;B&quot; select cheap cables.  Buttons 0-9 will select fancy or cheap, and the test subject must determine which.  Let the test subject go back and forth between known and unknown samples as often as desired.  If there's any difference..." CreationDate="2011-05-05T17:24:53.180" UserId="3123" />
  <row Id="21471" PostId="13927" Text="...such a test should let the subject find it.  If the subject can't identify the difference, the subject would have no basis for claiming one exists. " CreationDate="2011-05-05T17:26:16.253" UserId="3123" />
  <row Id="21473" PostId="13927" Score="3" Text="@supercat  Such a test would determine if there is a difference between two cables, true.  But it wouldn't determine which cable &quot;sounds better&quot;.  If the subject is aware of which is the expensive cable then the placebo effect would tend to have that person select the expensive cable as the better sounding.  Knowing that there is a difference is only half the battle.  Confidently knowing which sounds better (if any) would win the battle." CreationDate="2011-05-05T17:36:57.667" UserId="3624" />
  <row Id="21474" PostId="13930" Score="1" Text="+1 Would give more votes if I could. Thanks for the lengthy, but brilliant explanation." CreationDate="2011-05-05T17:41:21.273" UserId="2028" />
  <row Id="21475" PostId="13913" Text="lead is very bad.  I heard somewhere that now we (usa) doesnt have the mental instability problems and other issues in the younger generation that has grown up without lead in the air.  From an engineering perspective where you would choose to use it or not has to do with selling the product.  If you want to make a product and sell it choose lead-free now and just get used to doing that.  If this is a hobby project, it is your choice, take the leaded stuff its probably cheaper (and more reliable).  but expect not to be able to thrown that item in the trash can in the future" CreationDate="2011-05-05T17:41:24.510" UserId="985" />
  <row Id="21476" PostId="13928" Score="1" Text="No it's not.  The top question made plain that the person had attempted to do some research and that isn't apparent from either the original or your rewrite.  Can you put at least one link to show you've looked at something but found it in appropriate in some way?" CreationDate="2011-05-05T17:42:00.140" UserId="249" />
  <row Id="21477" PostId="13912" Score="1" Text="If you don't have a good electronics book handy I recommend Sedra and Smith 4th edition, found here: http://www.amazon.com/Microelectronic-Circuits-Electrical-Computer-Engineering/dp/0195323033/ref=sr_1_1?s=books&amp;ie=UTF8&amp;qid=1304617544&amp;sr=1-1" CreationDate="2011-05-05T17:46:04.227" UserId="249" />
  <row Id="21478" PostId="13928" Text="@AngryEE — you want me to show you an example of something that is not what I want? Why is that necessary? Anyway, fine I'll do that." CreationDate="2011-05-05T17:46:51.760" UserId="4125" />
  <row Id="21479" PostId="13912" Text="@AngryEE-thanks for your suggestion.BTW-is there any ideas related my question?" CreationDate="2011-05-05T17:56:41.863" UserId="3916" />
  <row Id="21480" PostId="13927" Text="@David Kessner: For the issue of which &quot;sounds better&quot; to be relevant, there has to be some difference between the cables.  Under my proposed test, when the subject pushes button 0-9, the subject wouldn't be told whether the signal was going through the first or second cable (the subject's job would be to determine that).  No matter how much the subject may believe the expensive cable sounds better, if there's in reality no difference the subject's belief in the superiority of the expensive cable wouldn't help him identify which buttons were connected to it." CreationDate="2011-05-05T18:03:12.477" UserId="3123" />
  <row Id="21481" PostId="13936" Text="Thanks for the clear explanation, David. I probably should have also mentioned cable length because obviously longer runs merit a heavier gauge (but only to a point)." CreationDate="2011-05-05T18:09:01.910" UserId="2028" />
  <row Id="21482" PostId="13928" Score="1" Text="whoa closed now? This had 30 views in under 2 hours! There's no way it should have been closed :( at least direct me to a more appropriate forum befor shutting the door in my face" CreationDate="2011-05-05T18:12:56.217" UserId="4125" />
  <row Id="21483" PostId="13936" Text="@JYelton  The cable resistance is specified in Ohms Per Foot.  So the length is factored in there when you calculate the total resistance of the cable.  Be sure to use the total resistance of both legs of the cable." CreationDate="2011-05-05T18:14:34.920" UserId="3624" />
  <row Id="21484" PostId="13920" Text="@Toybuilder - California only implements a small subset of the RoHS directive.  Also, California does a lot of weird stuff - I hope the rest of the US doesn't follow them in *every* area..." CreationDate="2011-05-05T18:18:38.453" UserId="857" />
  <row Id="21485" PostId="13922" Text="My end application is curiosity.  :)  Thought I guess I'm imagining things powered by human movement.  But other methods (like in self-winding watches) may be better than piezos, this was just a tangent." CreationDate="2011-05-05T18:46:28.430" UserId="142" />
  <row Id="21486" PostId="13920" Score="1" Text="@reemrevnivek - well, it's certainly been said of music and cars... and products from a certain company in Cupertino, California! :)   Thanks for pointing out that California's restriction only applies to a small subset (for now).  I do believe that in the long term, the RoHS rules will harmonize globally like safety rules, and so RoHS will be universal." CreationDate="2011-05-05T18:46:57.337" UserId="3308" />
  <row Id="21487" PostId="13937" Score="5" Text="Weird - when I just tried to go to avesodisplays.com, Chrome put up a malware alert." CreationDate="2011-05-05T18:49:59.020" UserId="3308" />
  <row Id="21488" PostId="11392" Text="Ah, the NEC V-series!  I had a lot of fun with those!" CreationDate="2011-05-05T18:51:49.907" UserId="3308" />
  <row Id="21489" PostId="13937" Score="6" Text="Same here, with Firefox." CreationDate="2011-05-05T18:52:47.737" UserId="305" />
  <row Id="21490" PostId="13915" Score="1" Text="One major reliability worry from RoHS is Tin Whiskers. Since the lead in solder is usually replaced with more tin, this can be a major issue related with shorting things out. http://nepp.nasa.gov/whisker/background/" CreationDate="2011-05-05T18:55:53.693" UserId="638" />
  <row Id="21491" PostId="13910" Score="1" Text="Are you willing to open up the synth and see if it has an internal regulator on the power supply connector?" CreationDate="2011-05-05T19:00:11.517" UserId="142" />
  <row Id="21492" PostId="10848" Text="It's not inexplicable - they want their salespeople to probe you, prod you and try to get you to buy things you weren't planning on.  It's not helpful, but it's not inexplicable." CreationDate="2011-05-05T19:06:33.250" UserId="249" />
  <row Id="21493" PostId="13863" Text="AFAIK DDR uses SSTL not LVDS" CreationDate="2011-05-05T19:06:53.223" UserId="1471" />
  <row Id="21494" PostId="13939" Score="2" Text="Why are you trying to build one? Maybe it has this level of security because they want to keep people out?" CreationDate="2011-05-05T19:17:14.320" UserId="1623" />
  <row Id="21495" PostId="13928" Text="@roberto, the official statement is here: http://blog.stackoverflow.com/2010/11/qa-is-hard-lets-go-shopping/ " CreationDate="2011-05-05T19:19:33.807" UserId="938" />
  <row Id="21496" PostId="13935" Text="Not an answer since your requirements include not being tied to a specific ARM vendor, but the LPC LH754xx family of microcontrollers includes an integrated LCD driver. " CreationDate="2011-05-05T19:26:42.683" UserId="857" />
  <row Id="21497" PostId="13940" Score="1" Text="apple! they are getting nastier and nastier.... and future ipods may do it differently." CreationDate="2011-05-05T19:29:28.060" UserId="2157" />
  <row Id="21498" PostId="13935" Text="Also, your 0% accept rate is discouraging. " CreationDate="2011-05-05T19:33:05.660" UserId="857" />
  <row Id="21499" PostId="11145" Text="That's cute, though the speed would be somewhat limited." CreationDate="2011-05-05T19:40:23.110" UserId="3123" />
  <row Id="21500" PostId="13935" Text="@reemrevnivek: I've gone back and added accepts to the best answers to previous questions.  There are a number of ARM chips with small LCD drivers; I can't imagine any chip having a driver suitable for any useful size graphics display appearing in a package that would be usable in anything other than a chip-on-glass scenario.  A chip might have a controller, but an LCD with a chip-on-glass controller would seem more power-efficient and easier to work with.  I'll check out the chip you mentioned, though--might be interesting." CreationDate="2011-05-05T19:49:31.927" UserId="3123" />
  <row Id="21501" PostId="13711" Score="1" Text="@Cenk any update on this?  How are you coming along with your project?" CreationDate="2011-05-05T19:49:57.887" UserId="2288" />
  <row Id="21502" PostId="13943" Score="1" Text="Thanks a lot! I hope it's not too much to ask, but could you explain the operation of the (negative charge pump part of the) circuit?" CreationDate="2011-05-05T19:51:11.440" UserId="2985" />
  <row Id="21503" PostId="13863" Text="@mazurnification, Yeah, you're correct (my error.) Still, a nightmare to control from an Arduino." CreationDate="2011-05-05T19:59:03.617" UserId="1225" />
  <row Id="21504" PostId="13939" Score="1" Text="&quot;Educational purposes&quot;, presumably..." CreationDate="2011-05-05T20:03:46.667" UserId="142" />
  <row Id="21505" PostId="13935" Text="@supercat - I'm thinking of LCDs that have an RGB interface: pixel clock, frame sync, and line sync control lines, with a parallel pixel data bus.  Are you expecting to use a COG controlled display?" CreationDate="2011-05-05T20:11:12.867" UserId="857" />
  <row Id="21506" PostId="13940" Text="See http://www.apple.com/ipod/car-integration/ for more information...I doubt that you'll get any technical data from that page or its links, but it's worth a try." CreationDate="2011-05-05T20:13:58.763" UserId="857" />
  <row Id="21507" PostId="13927" Text="@supercat: so, it would bias the experiment in cases when you could tell some kind of difference, but if there was no discernible difference at all then it's  possibly a stronger debunk?" CreationDate="2011-05-05T20:17:41.557" UserId="1270" />
  <row Id="21508" PostId="13945" Text="I'd guess that it will behave differently.  @Oliver - Can you probe pin 21 of your car's dock connector to determine the resistance between pin 21 and its complement (guessing that resistance is resistance to ground), as suggested by the pinouts.ru link?" CreationDate="2011-05-05T20:18:18.620" UserId="857" />
  <row Id="21509" PostId="13946" Text="Note to editors: Feel free to prune non-color controllers from this list.  I don't have time at the moment." CreationDate="2011-05-05T20:19:17.247" UserId="857" />
  <row Id="21510" PostId="13938" Text="Wikipedia's article on charge pumps is a good starting place.  http://en.wikipedia.org/wiki/Charge_pump" CreationDate="2011-05-05T20:23:07.423" UserId="3308" />
  <row Id="21511" PostId="13930" Text="I totally agree with the condemnation of this garbage cable, but there's nothing unreasonable about wanting 'warm', 'bright', etc filtering. I generally prefer one of the DSP settings on my (fairly cheap) AV receiver over the original source. You seem to equate these with the snake oil of cables like the one we're talking about here. However, I'd very much prefer to leave any filtering to a DSP and not have anything hard-wired into my speakers, wire, etc... as occasionally the original sound is better." CreationDate="2011-05-05T20:32:20.890" UserId="1270" />
  <row Id="21512" PostId="13809" Text="Ah, here it is: http://www.oteinstruments.com/cart/catalog/wavetek/wavetek-meterman-sf10-short-finder-brush-966.html http://www.bellnw.com/products/9970/  " CreationDate="2011-05-05T20:36:04.240" UserId="3308" />
  <row Id="21513" PostId="13945" Text="Bummer. Though I can force the radio into &quot;iPod mode&quot; so it still might accept audio over the standard audio pins... Maybe I'll get a cable and do a $15 experiment." CreationDate="2011-05-05T20:39:34.380" UserId="4128" />
  <row Id="21514" PostId="13908" Score="1" Text="@Kortuk - if i figure out how to post pictures, i might do that." CreationDate="2011-05-05T20:43:11.917" UserId="740" />
  <row Id="21515" PostId="13827" Text="Some manufacturers (like 4pcb) even offer free DFM tests on your gerbers.  Those free tests are a nice addition to your PCB tools' DRC." CreationDate="2011-05-05T20:44:15.317" UserId="1278" />
  <row Id="21516" PostId="13930" Text="@darron I agree with you except to the extent that it's snake oil for me to tell you that this cable will make your sound 'warmer'.  'Warm' is entirely subjective adjective that means different things to different people.  It's entirely valid to talk about the saturation of tube amps vs. D-class transistor amplifiers - they have different characteristics and produce different sounds.  But that can be measured and therefore discussed in a helpful manner as opposed to the snake oil methods most sellers try to pull. " CreationDate="2011-05-05T20:49:13.927" UserId="249" />
  <row Id="21517" PostId="13914" Text="@morten Strange that LEDs using cadmium would be allowed, but CdS (cadmium sulphide) cells - arguably the simplest light sensor - are not." CreationDate="2011-05-05T20:56:15.237" UserId="1225" />
  <row Id="21518" PostId="13927" Score="1" Text="@darron: Precisely.  If there's some identifiable circumstance where fancier cables produce results that are discernible from cheap cables, then it's essentially impossible to prove that there would be no circumstance in which the fancier cables sound better.  But if the promoter of the cable can't provide a test subject who can discern the difference, then there's no basis for the promoter to claim superiority of sound (claims of things like mechanical flexibility and resilience, corrosion resistance, etc. would not be invalidated by an audio test)." CreationDate="2011-05-05T20:57:09.097" UserId="3123" />
  <row Id="21519" PostId="13935" Score="1" Text="@reemrevnivek: That's what I'd been thinking.  They seem to be pretty common, since they're used in a lot of portable battery-powered devices like cell phones.  A COG display with built-in controller is going to be much more power-efficient than one which requires continuously-clocked RGB data." CreationDate="2011-05-05T21:01:26.987" UserId="3123" />
  <row Id="21520" PostId="13946" Text="@reemrevnivek: I'd been thinking of color LCDs with built-in controllers.  They seem pretty common, but the ones I've seen generally seem to expect the CPU to clock in many bits per pixel even though a common display scenario is the display of solid-color text.  I implemented a DMA-based 4-level grayscale LCD controller once using a CPLD, and it worked very nicely, but that was a line-powered device." CreationDate="2011-05-05T21:04:24.127" UserId="3123" />
  <row Id="21521" PostId="13940" Text="Note that that pinout is backwards http://replay.web.archive.org/20080514075959/http://ipodlinux.org/Dock_Connector" CreationDate="2011-05-05T21:06:32.330" UserId="142" />
  <row Id="21522" PostId="13927" Text="@supercat  But if the results of your test show that there is a difference, then you must follow up with another test.  But if the subject doesn't know what cable he/she is listening to then you effectively do &quot;both tests&quot; at the same time." CreationDate="2011-05-05T21:10:31.200" UserId="3624" />
  <row Id="21523" PostId="13855" Score="1" Text="The default libraries have most of these devices already available.  Check ref-packages.lbr for footprints. " CreationDate="2011-05-05T21:19:01.900" UserId="857" />
  <row Id="21524" PostId="13440" Score="1" Text="@Kalaracey - Microchip [(link)](http://www.microchip.com/) is a company which sells integrated circuits.  A microcontroller [(link)](http://en.wikipedia.org/wiki/Microcontroller) is a type of microprocessor which adds peripherals like volatile and/or non-volatile memory, general-purpose IO, and other hardware peripherals.  I've edited your question because I believe that you intended to use &quot;microcontroller&quot;, but please feel free to revert the change if you want to know about the company (though I imagine you'll need a job there to learn details about their processors...)" CreationDate="2011-05-05T21:24:59.633" UserId="857" />
  <row Id="21525" PostId="13852" Text="So there's some freedom in trading between charging time, charger complexity and cycle lift. Good info, thanks!" CreationDate="2011-05-05T22:12:37.723" UserId="897" />
  <row Id="21526" PostId="13908" Text="@Justjeff, there is a button for pictures near where the button for links is, just give it a link to your picture and it will handle it." CreationDate="2011-05-05T22:18:54.860" UserId="230" />
  <row Id="21527" PostId="13912" Text="in this strange item where everyone's commenting and no one's answering, no one seems to have mentioned it's the short time immediately following the voltage going into reverse polarity, during which the diode conducts in reverse." CreationDate="2011-05-05T22:19:33.383" UserId="740" />
  <row Id="21528" PostId="13783" Text="I got the bt module connected to an Uno to send messages to PuTTY, and PuTTy to send messages to the bt module and echo'd to the serial monitor of the Uno!" CreationDate="2011-05-05T22:55:50.993" UserId="1227" />
  <row Id="21529" PostId="13846" Text="Thanks for the great answers! Very interesting. I'm gradually learning about how the pieces fit together. Thanks." CreationDate="2011-05-05T23:09:57.590" UserId="4103" />
  <row Id="21530" PostId="13848" Text="I put a comment above, with the question, but I guess I should really put it here. Thank you so much for the answer. Stack exchange is a super resource, and it's all because of people taking time to provide quality answers." CreationDate="2011-05-05T23:12:21.143" UserId="4103" />
  <row Id="21531" PostId="13596" Text="@ajs410 Whats the nature of this 'floating-point multiply' step?  If your using IEEE floats, they are not precise by nature.  Depending on how your doing this it could be your issue." CreationDate="2011-05-05T23:39:47.043" UserId="1438" />
  <row Id="21532" PostId="13937" Text="Opera doesn't for some reason." CreationDate="2011-05-05T23:40:05.657" UserId="2873" />
  <row Id="21533" PostId="13908" Text="@kortuk - yeah, the issue is i don't have any place to host pictures, but now we're way off topic. (btw I'm gonna zorch my last two comments when BBT is over)" CreationDate="2011-05-06T00:14:38.320" UserId="740" />
  <row Id="21534" PostId="13908" Text="@JustJeff, discussions like these should be left, it allows other to learn. SO has a paid account with a host, I think imgur. It automatically uploads to their account and hosts from there." CreationDate="2011-05-06T00:17:37.740" UserId="230" />
  <row Id="21535" PostId="13908" Text="@Kortuk - voila. May I draw the reader's attention to the little picture icon in the row of controls at the top of the edit pane. No worries about where the picture gets served from, SO has it covered. (Now if I just had a better picture)" CreationDate="2011-05-06T01:04:07.737" UserId="740" />
  <row Id="21536" PostId="13908" Text="@JustJeff, I take time to do things like this so that good users like yourself can learn all of the hidden features. Chiphacker and this site for a little did not have hosting, but they added it, and it is awesome." CreationDate="2011-05-06T01:07:03.543" UserId="230" />
  <row Id="21537" PostId="8611" Text="Do you have a brand or model number?" CreationDate="2011-05-06T01:12:04.863" UserId="206" />
  <row Id="21538" PostId="1480" Text="When this message was originally posted signatures were allowed on SE sites so the &quot;Grandfather&quot; principle should be applied." CreationDate="2011-05-06T01:18:56.607" UserId="424" />
  <row Id="21539" PostId="1480" Text="@jluciani, We discussed this months ago in email. Signatures are not allowed. We are not active going through and removing your signatures, but as a question becomes active again or someone flags it we will remove the signature. We are not trying to actively go through and remove your signatures, but we also do not grandfather anything into rules. We removed your signature, you cannot roll it back, we discussed this and you agreed." CreationDate="2011-05-06T02:07:39.787" UserId="230" />
  <row Id="21540" PostId="13943" Score="3" Text="Pin 3 is the output of the 555, which will be a square wave between ground and the supply voltage. When the output is high, the 22uF charges up through D1. When the 555 output goes low, the 22uF cap will discharge through the 555, through ground, the 100uF cap and D2, putting a negative voltage on the 100uF cap with respect to ground." CreationDate="2011-05-06T02:20:31.550" UserId="1293" />
  <row Id="21541" PostId="13916" Text="Sorry, I didn't make it clear that those recommendations are from the datasheet for the CY7C68013A that the OP is using. I don't think the FT232 datasheet has such strict requirements, as you suggested. " CreationDate="2011-05-06T02:38:10.107" UserId="2827" />
  <row Id="21542" PostId="13954" Text="i used a fan and a heat sink to cool the hot side. Is there any other way to cool it?&#xA;or should I forget about the peltier and get another cooler? if that's the case, do you know any other device which is more effective than peltier?" CreationDate="2011-05-06T04:43:50.720" UserId="4134" />
  <row Id="21543" PostId="13958" Text="what will be the best source for my peltier? I want to use a dc source." CreationDate="2011-05-06T04:48:20.233" UserId="4134" />
  <row Id="21544" PostId="13922" Text="Cool, well MIT  (and maybe Berkley if my memory is correct) have done work into the idea of bionic soldiers powering their own kit. Piezoelectric backpack straps and knee braces have been produced so far. MIT also made a piezoelectric shoe heel insert a couple of years back now. Have fun!" CreationDate="2011-05-06T05:24:51.913" UserId="4096" />
  <row Id="21545" PostId="13931" Text="https://secure.wikimedia.org/wikipedia/en/wiki/American_wire_gauge" CreationDate="2011-05-06T05:31:04.113" UserId="339" />
  <row Id="21546" PostId="13958" Score="2" Text="please describe your setup in detail. What chip are you trying to cool with what peltier?" CreationDate="2011-05-06T05:34:11.500" UserId="3438" />
  <row Id="21547" PostId="13954" Text="When it is about cooling limited power up to a few hundred watts, there is nothing more efficient than fan cooling, possibly aided by heatpipes in the cooler. I am not aware of a situation where you profit from a peltier element between the heated chip and the cooler, unless you have very special requirements on the temperature of the chip, like, say, a thermal imaging camera." CreationDate="2011-05-06T07:10:32.070" UserId="1381" />
  <row Id="21548" PostId="13939" Score="3" Text="http://scanlime.org/2008/09/using-an-avr-as-an-rfid-tag/" CreationDate="2011-05-06T07:14:27.277" UserId="339" />
  <row Id="21550" PostId="13871" Text="Thanks everyone!" CreationDate="2011-05-06T07:22:03.713" UserId="3632" />
  <row Id="21551" PostId="13942" Score="3" Text="'more atoms than the universe has' - not even close. Observable universe has at least 10^78 atoms = 2^259." CreationDate="2011-05-06T08:09:13.550" UserId="2064" />
  <row Id="21552" PostId="13964" Text="@Philippe, this is good advice, but does not approach if arduino is suitable for robotics." CreationDate="2011-05-06T09:18:06.627" UserId="230" />
  <row Id="21553" PostId="13966" Text="Ah yes the link was to an example of the sort of device, not the exact one I'd use. 5v clearly isn't correct.... Yes fpga's can have this amount of memory but I was hoping to use a small one for this.&#xA;&#xA;And yes it's just occured to me that at this speed it's likely that an &quot;amateur&quot; designed PCB probably will have issues.... Hmmm" CreationDate="2011-05-06T10:08:33.790" UserId="710" />
  <row Id="21554" PostId="13942" Text="@Stevenvh, I thought about making the same comment, but it does make the point it would not be easy to pick." CreationDate="2011-05-06T10:09:34.957" UserId="230" />
  <row Id="21555" PostId="13961" Score="2" Text="Arduino is not exactly suitable for anything other than starting. If you want to do something at intermediate level arduino will pose more hindrances. It takes away some memory for bootloader and if you do something very time constrained you would not be able to do it as arduino does not give control over the timing." CreationDate="2011-05-06T10:21:20.220" UserId="1200" />
  <row Id="21556" PostId="13961" Score="3" Text="@Rick_2047 - otoh, it is a mega328 on a nice carrier board. one only has to develop the wherewithal to directly program the 328 to get full control over it, a worthwhile exercise for someone graduating from beginner to intermediate." CreationDate="2011-05-06T10:32:01.550" UserId="740" />
  <row Id="21558" PostId="13912" Text="@Cell-o, when you say &quot;what factors affect reverse recovery time&quot; do you mean the chemical and physical factors decided when the diode is made or the circuit conditions eg forward bias current prior to the reversing of the bias voltage?" CreationDate="2011-05-06T11:04:18.287" UserId="2110" />
  <row Id="21559" PostId="13914" Text="Well, I guess it makes sense... There are alternatives to CdS based sensors readily available. Non-Cd phosphors are becoming available for LEDs as well, so it is possible that LEDs won't be exempt after 2014." CreationDate="2011-05-06T11:05:04.623" UserId="3876" />
  <row Id="21560" PostId="13968" Score="1" Text="(Yes, NXT is more powerful than RCX, but that's beside the point)" CreationDate="2011-05-06T11:24:17.843" UserId="740" />
  <row Id="21561" PostId="13953" Score="1" Text="@peeps, target temperature for the device you are cooling? is ambient temperature just 70 F? How much power are you dissipating?" CreationDate="2011-05-06T11:59:27.237" UserId="230" />
  <row Id="21562" PostId="13924" Text="@JYelton, that article was painful, I stopped at page 1. It was clearly written to take advantage of those not technically sound." CreationDate="2011-05-06T12:10:18.800" UserId="230" />
  <row Id="21563" PostId="13898" Text="@reemrevnivek, yes, I was worried the -3 might be confusing but hoped users would scroll down and see the suggested names and the number of upvotes for support." CreationDate="2011-05-06T12:53:15.537" UserId="230" />
  <row Id="21564" PostId="13937" Text="@aSandwich, seems you can have a virus to go with it." CreationDate="2011-05-06T12:56:58.293" UserId="230" />
  <row Id="21565" PostId="13952" Text="@ToyBuilder, what size display was the quote for?" CreationDate="2011-05-06T12:57:45.673" UserId="230" />
  <row Id="21566" PostId="13928" Text="@RobertoTomas, please do not missunderstand. Moderation is something that takes a large amount of time. When a question needs to be closed we generally close it and if you update and think it will fit the quality considerations of the site you can flag it for us to look at it again. **This is in no way shutting the door in your face**. We are happy to have you here, very. We just have to try to maintain the site, which is a time consuming task. Unless you have been with stackexchange for a while it is hard to recognize what we look for in a good and timeless question." CreationDate="2011-05-06T13:01:34.547" UserId="230" />
  <row Id="21567" PostId="13802" Text="@reemrevnivek, clearly you have never put one on backwards because the notch is almost no noticeable. Good for you." CreationDate="2011-05-06T13:04:16.493" UserId="230" />
  <row Id="21568" PostId="13954" Text="If you plan on convection cooling in air, it is fairly simple. Unless you want to get fancy, what matters is the surface area of the heat sink and the velocity of air over the surface. " CreationDate="2011-05-06T13:17:47.383" UserId="3876" />
  <row Id="21570" PostId="13942" Text="Ah, I must have been thinking of cryptography instead.  My bad.  " CreationDate="2011-05-06T13:27:03.283" UserId="249" />
  <row Id="21571" PostId="13687" Score="3" Text="you really need to be careful with an ohmmeter, especially with a processor that has its maximum voltage down near the bandgap. you can seriously damage devices with an ohmmeter." CreationDate="2011-05-06T13:38:54.380" UserId="974" />
  <row Id="21572" PostId="13151" Text="@supercat It sounds like you're talking about wiring the two LEDs _inside that package_ in series. I feel like the asking is asking about wiring many of these LEDs in series." CreationDate="2011-05-06T14:01:10.307" UserId="2827" />
  <row Id="21573" PostId="13940" Text="Is this really an electronics design question? Looks like consumer electronics to me." CreationDate="2011-05-06T14:19:58.237" UserId="1225" />
  <row Id="21574" PostId="13912" Score="1" Text="I think no one has answered because the question is very vaguely worded and could mean anything and the poster has failed to change his wording or offer any hints as to what exactly he wants.  That and general laziness.  Plus I get the impression that even with a good answer the poster will ask something like 'what is this mean?  how do i use it?!'" CreationDate="2011-05-06T14:21:57.783" UserId="249" />
  <row Id="21575" PostId="13963" Text="Those EM tokens are 40 bits with 8 bits, as you say, reserved as a &quot;customer ID&quot;. But EM's customers are generally resellers so anyone who buys from those resellers ends up with the same prefix! I guess EM have more than 256 customers anyway :)" CreationDate="2011-05-06T14:45:10.440" UserId="2234" />
  <row Id="21576" PostId="13965" Text="Due to the actual signals required (H-Sync, V-Sync), you'll find that your system will need to run at just over 25 MHz. This means that your period for memory fetch is going to be about 39ns." CreationDate="2011-05-06T14:52:06.600" UserId="638" />
  <row Id="21577" PostId="13151" Text="@fizzisist: Rereading the question, you're right. Not sure how I missed that. Depending upon how one arranges and drives one's matrix, one could put two of each color in series by using a mixture of common-anode and common-cathode LEDs. Each pair of rows and columns would operate two pairs of bi-color LEDs with positive rows and negative columns (or vice versa), or four pairs of LEDs if rows and columns could be driven both high and low (or floated). One LED of each pair would be common-anode, and the other common-cathode; the common terminals of the LEDs in each pair would be wired together." CreationDate="2011-05-06T14:52:06.517" UserId="3123" />
  <row Id="21578" PostId="13967" Text="That's a very interesting processor, thanks for sharing.  I am going to check out what it can do!  Do you have any examples of things you've done with the Propeller?" CreationDate="2011-05-06T15:01:01.963" UserId="2288" />
  <row Id="21579" PostId="13965" Text="Why do you want to store 60 frames in memory? Approaches that I have successfully used only have two frames - a current frame and then the next frame. That big of a memory requirement will be expensive ($20+)" CreationDate="2011-05-06T15:06:15.563" UserId="638" />
  <row Id="21580" PostId="13966" Text="@Thomas O  640x480x24bits = about 7.4 mbits.  That works out to about 450 block rams (16kbit BRAM's).  That's not going to fit inside any FPGA that we have a budget to buy." CreationDate="2011-05-06T15:26:28.470" UserId="3624" />
  <row Id="21581" PostId="13965" Text="I don't . I want to store one frame in memory. I have to retrieve it 60 time a second though.... looks like this project isn't practical in this form for me right now anyways" CreationDate="2011-05-06T15:35:08.193" UserId="710" />
  <row Id="21582" PostId="13966" Text="@Thomas O  I might have misread the question.  He said &quot;One byte color per pixel&quot;, which I interpreted as one byte for red, one byte for green, and one byte for blue.  If it is 1 byte per pixel, total, then he'll need about 2.5 mbits of RAM, or 150 block RAMs.  That's still a huge amount of BRAM's, but doable in a medium sized FPGA." CreationDate="2011-05-06T15:36:31.143" UserId="3624" />
  <row Id="21583" PostId="13966" Text="@David Kessner, I interpreted it as one byte per pixel, in other words some kind of byte stuffing like RRRGGGBB." CreationDate="2011-05-06T15:46:37.580" UserId="1225" />
  <row Id="21584" PostId="13935" Text="@reemrevnivek: I just updated my question with more detail." CreationDate="2011-05-06T15:53:33.710" UserId="3123" />
  <row Id="21585" PostId="13973" Score="4" Text="What about the MC34063? http://electronics.stackexchange.com/questions/11736/need-3-3v-regulator/11738#11738" CreationDate="2011-05-06T16:16:22.330" UserId="2654" />
  <row Id="21586" PostId="13966" Text="Worth mentioning is that according to DigiKey, 2.5+ mbit  FPGA's only come in BGA packages - this may be a non-starter" CreationDate="2011-05-06T16:18:41.223" UserId="638" />
  <row Id="21587" PostId="13965" Text="Ahhh.... that makes more sense" CreationDate="2011-05-06T16:19:16.620" UserId="638" />
  <row Id="21588" PostId="13966" Text="Yes I meant one byte per pixel with 2 bits per color and one spare. this isn't going to work for me I'm the current form until I learn a lot more " CreationDate="2011-05-06T16:22:25.747" UserId="710" />
  <row Id="21589" PostId="13967" Text="I was developing software for a refrigerated container data logging system using it, but the client pulled out of the project for some reason. I got paid, though. 8-) I've also interfaced one to a 1600 MIPS XMOS board." CreationDate="2011-05-06T16:26:54.430" UserId="305" />
  <row Id="21590" PostId="13973" Score="1" Text="@Craig  I've never heard of the MC34063.  The thing that made chips like the 78xx, 555, LM712, and LM317 so popular wasn't that they were great (in their day, maybe, but not now) but that everyone and their cousin made them.  They were easy and cheap to buy.  But this is not the case with most modern chips (except the really simple ones), including the newer/better switching regulators.  Because of this, there is no clear &quot;must have&quot; switcher chip.  @Brian Carlton does have a good point, however, in that the POLA people do make reasonable converter modules that do cross w/other manufacturers." CreationDate="2011-05-06T16:27:38.917" UserId="3624" />
  <row Id="21591" PostId="13839" Text="@starblue, I don't think the mega will be damaged, the current will just limit at 40mA." CreationDate="2011-05-06T16:34:13.150" UserId="771" />
  <row Id="21592" PostId="13977" Text="What version of tools?" CreationDate="2011-05-06T16:52:49.580" UserId="206" />
  <row Id="21593" PostId="13973" Score="2" Text="I second the MC34063.  A quick look at DigiKey has 5 manufacturers for the 8-DIP.  It's also flexible enough to do Buck, Boost, and Invert topologies." CreationDate="2011-05-06T17:06:14.477" UserId="204" />
  <row Id="21594" PostId="13952" Text="That was for a 6&quot;, back around December 2007.  I'm sure prices have fallen significantly from there, but not &quot;dirt cheap&quot; levels.  I updated the main text of my answer to reflect this. Thanks." CreationDate="2011-05-06T17:36:25.023" UserId="3308" />
  <row Id="21595" PostId="13839" Text="@vicatcu: Wrong. AVR IO ports are *not* current limited, like almost every microcontroller. Increasing the current too far will cause internal heating of the chip, which will eventually lead to failure." CreationDate="2011-05-06T18:08:24.913" UserId="1225" />
  <row Id="21596" PostId="13937" Text="@roberto, I removed the link because of malware." CreationDate="2011-05-06T18:13:08.900" UserId="938" />
  <row Id="21597" PostId="13961" Text="@justjeff, you don't even have to develop the programming circuitry. Just some jumper wires from the awesome ftdi chip would do. Here is a guide http://arduino.cc/en/Tutorial/ArduinoISP&#xA;&#xA;http://www.geocities.co.jp/arduino_diecimila/bootloader/index_en.html&#xA;&#xA;The second link uses this to install the bootloader. But this is basically using the bitbang mode of ftdi to do programming which is a general thing and can be used with avrdude.&#xA;&#xA;Happy hacking" CreationDate="2011-05-06T19:33:20.660" UserId="1200" />
  <row Id="21599" PostId="10730" Text="If the link dies, this answer loses its value. Care to provide a brief synopsis?" CreationDate="2011-05-06T20:03:53.257" UserId="2028" />
  <row Id="21600" PostId="13984" Score="2" Text="Do you mean wet bulb temperature? https://secure.wikimedia.org/wikipedia/en/wiki/Wet-bulb_temperature" CreationDate="2011-05-06T20:26:39.467" UserId="339" />
  <row Id="21601" PostId="13950" Text="come to think of it, it might be that the fundamental isn't even in the std AM broadcast band, your receiver could be grabbing on of the harmonics." CreationDate="2011-05-06T20:39:46.887" UserId="740" />
  <row Id="21602" PostId="13955" Score="1" Text="Your title is an &quot;it depends&quot; question." CreationDate="2011-05-06T23:07:13.050" UserId="206" />
  <row Id="21603" PostId="13996" Text="Agreed, there are so many flash chips with all sorts of different interfaces (serial, parallel) there can't really be a &quot;standard&quot;" CreationDate="2011-05-07T00:32:14.147" UserId="1407" />
  <row Id="21604" PostId="13955" Score="2" Text="I'll be sure to ask only yes/no questions in the future." CreationDate="2011-05-07T00:39:08.357" UserId="638" />
  <row Id="21605" PostId="10513" Text="See also [this question][1] [1]: http://electronics.stackexchange.com/questions/3578/whats-the-best-way-to-store-and-categorise-resistors-capacitors-ics-etc/3579#3579 &quot;whats-the-best-way-to-store-and-categorise-resistors-capacitors-ics-etc&quot;" CreationDate="2011-02-22T11:11:22.790" UserId="244" />
  <row Id="21607" PostId="13967" Text="ah yes, XMOS...  I still need to read up more on that.  You have experience with a large variety of processors.  How lucky!!!  :)" CreationDate="2011-05-07T03:31:21.847" UserId="2288" />
  <row Id="21608" PostId="13992" Score="1" Text="Three towers with lights on them and some photoresistors on the device to recognize amount of light and corelate it to distance?" CreationDate="2011-05-07T03:55:15.123" UserId="2873" />
  <row Id="21609" PostId="14002" Text="and just disregard the other one? sounds easy enough. " CreationDate="2011-05-07T04:40:54.293" UserId="3796" />
  <row Id="21610" PostId="14002" Text="@TrevorMA: yes, you can just ignore the other one.  Just don't hook up something else to it, as flipping the switch will connect the other circuit as well." CreationDate="2011-05-07T04:43:11.157" UserId="2288" />
  <row Id="21611" PostId="14002" Text="So it's basically just a switch that controls two things?" CreationDate="2011-05-07T04:44:48.487" UserId="3796" />
  <row Id="21612" PostId="14000" Score="2" Text="Would the Num-Lock LED satisfy &quot;a&quot; LED? :)" CreationDate="2011-05-07T04:47:09.003" UserId="638" />
  <row Id="21613" PostId="14002" Text="@TrevorMA that's how I've always seen it, though I haven't used those types of switches very much." CreationDate="2011-05-07T05:10:41.270" UserId="2288" />
  <row Id="21614" PostId="14004" Text="I don't think that I/O on the Launchpad or the Arduino can be controlled via the USB port." CreationDate="2011-05-07T05:29:31.187" UserId="305" />
  <row Id="21615" PostId="13946" Text="@supercat - Very few LCD controllers expect a *CPU* to clock many bits per pixel in for each frame. They generally are expecting *dedicated graphics hardware* to be doing this. Basically, once you get to fairly large (i.e. &gt; 128*128) RGB displays, the processing power required to generate the image for the screen is large enough that a dedicated GPU of some sort (even if it is integrated into the MCU) is pretty much always present." CreationDate="2011-05-07T05:35:36.060" UserId="1374" />
  <row Id="21617" PostId="14004" Score="1" Text="the USB port is actually a USB-to-serial adapter, and you can implement your own serial command interpreter on the MSP430.  At least, that's what I've read.  If for some reason that's really not true, then he would have to use some of the software serial implementations available on the net.  But if you plug a Launchpad into the PC, it will come up as both a USB-to-serial adapter, as well as a USB FET for debugging." CreationDate="2011-05-07T05:53:23.213" UserId="2288" />
  <row Id="21618" PostId="13297" Text="The USB Spec is *Extremely* conservative. I've done some horrible things to USB cables, and still managed to run full USB 2.0 over them. " CreationDate="2011-05-07T05:58:57.593" UserId="1374" />
  <row Id="21619" PostId="14004" Text="I'll check for more information, as I don't want to give the OP any bad information here.  I hope I didn't recall something incorrectly." CreationDate="2011-05-07T06:00:09.373" UserId="2288" />
  <row Id="21620" PostId="13987" Score="4" Text="What is the concrete thing you want to do?" CreationDate="2011-05-07T06:05:53.613" UserId="339" />
  <row Id="21621" PostId="13946" Text="@Fake Name: If the goal was to display full motion video, some specialized hardware would be necessary.  But my goal is to display plain text and simple graphics, quickly.  The controllers I've been looking at have a maximum SPI data rate of 10mbps; that limit would apply whether the data was being supplied by a CPU or a dedicated controller.  Using a parallel-input mode would speed things up, but if character shapes are stored with 1 bit per pixel (as would be typical) using code to unpack them would be slower than having the ARM output SPI and having a CPLD convert that to parallel data." CreationDate="2011-05-07T07:17:36.387" UserId="3123" />
  <row Id="21622" PostId="13946" Text="@supercat - But what you describe, a specialized CPLD that does ASCII to raster conversions, *basically is (custom) specialized graphics hardware*. I'm basically saying don't re-invent the wheel, and it's probably easier and more cost-efficient to just buy a MCU with a video-interface built-in then design one yourself." CreationDate="2011-05-07T07:27:41.467" UserId="1374" />
  <row Id="21623" PostId="13946" Text="Anyways, If you really want to roll-your-own, I would say use a couple of dual-port SRAM ICs, and use one port for outputting to the LCD, and the other for the MCU. This lets the MCU change the memory contents at whatever speed it wants, and the LCD can run at it's refresh rate." CreationDate="2011-05-07T07:29:02.193" UserId="1374" />
  <row Id="21624" PostId="13988" Score="4" Text="It's funny that it's hailing the letters #REFDES from the left cloud. Seems like the layout software wouldn't accept the picture without wanting to impose a name for it, but the engineer left the default value and didn't change it to &quot;STORM1&quot;. Maybe the reason was that once it would have been changed to &quot;STORM1&quot;, the thing would have shown up in the parts list and the purchase department would have wondered from which distributor they could have gotten a quote and the respective lead time info for it..." CreationDate="2011-05-07T07:30:03.080" UserId="930" />
  <row Id="21625" PostId="13946" Text="All the high-resolution LCDs I have seen don't really bother with addressing, they just typically have a frame start (vsync), a line start (hsync), and a clock input (and the pixel data lines, but that's a given). Basically, you use a couple of counters and some AND gates so that each pixel clock increments the address for the SRAM data, and the AND gates output the h and v sync signals at the appropriate time. The whole thing then runs at whatever clock speed is needed to give you the refresh rate you want." CreationDate="2011-05-07T07:31:23.013" UserId="1374" />
  <row Id="21626" PostId="14008" Text="@supercat, in superb SE style, you answer the question by teaching more then was needed, but enough that they can do the &quot;best&quot; job" CreationDate="2011-05-07T07:39:54.367" UserId="230" />
  <row Id="21627" PostId="9328" Text="Good to know, @David! I bet many other compression algorithms have that as a goal as well." CreationDate="2011-05-07T08:51:01.670" UserId="2118" />
  <row Id="21628" PostId="14010" Text="@JohnBurton, I would say that you are going to need to educate yourself before you reach the full speed potential of a homemade PCB. Pro PCBs can do very nice things, but without good design principles you will get the same result you would get with homemade. Also, please note that it is the rise time of your digital signal that plays the largest part in determining the highest frequencies of your spectral content." CreationDate="2011-05-07T08:57:01.740" UserId="230" />
  <row Id="21629" PostId="14010" Text="Indeed. I'm just interested to find out what frequencies are likely to work with only basic care.. " CreationDate="2011-05-07T09:17:33.723" UserId="710" />
  <row Id="21630" PostId="14011" Text="I shall experiment, that's exactly my plan :) I just want to be sure that what I start with has *some* chance to work " CreationDate="2011-05-07T09:56:07.530" UserId="710" />
  <row Id="21631" PostId="13992" Text="Motion capture! Didn't think about that. Perhaps ultrasound measuring time-to-distance + doppler shift (if that can be done precise enough)? Great tips. I'll have to read up on the various motion capture hacks." CreationDate="2011-05-07T10:26:56.150" UserId="941" />
  <row Id="21632" PostId="13988" Text="@zebonaut - yeah, that could be a long-lead item." CreationDate="2011-05-07T11:11:10.480" UserId="740" />
  <row Id="21633" PostId="14010" Text="@John, that is why I made it a comment, it is definitely not an answer." CreationDate="2011-05-07T12:17:26.017" UserId="230" />
  <row Id="21634" PostId="13988" Score="1" Text="@justjeff I used to work for Cirrus Logic. They always had a hard time making those non-Cirrus storm clouds. " CreationDate="2011-05-07T12:19:46.000" UserId="3624" />
  <row Id="21635" PostId="14012" Score="2" Text="@fatai, this question is not up to par. We need more information and more detail about your task. I am not a verilog expert, but I have no idea what you are trying to do here." CreationDate="2011-05-07T12:30:24.127" UserId="230" />
  <row Id="21637" PostId="14004" Text="Arduino does work on Linux, and I was considering buying one. But this thing you have here is a lot cheaper, does it have lots of the same features?  Could I make a Strobe light? A POV clock? or POV display, etc?  that would be really awesome" CreationDate="2011-05-07T12:59:51.600" UserId="4148" />
  <row Id="21638" PostId="14008" Text="If I don't use the capacitor-hold approach then it's likely that the LED will always shut off when I change inputs, right?" CreationDate="2011-05-07T13:06:24.780" UserId="3796" />
  <row Id="21639" PostId="14004" Text="Agreed - right now, the TI Launchpad is the ridiculously cheap way to go." CreationDate="2011-05-07T13:41:58.147" UserId="3308" />
  <row Id="21640" PostId="14005" Text="Can you give me an example code? that's kind of what I want! If I can find my serial adapter.. then I could try it" CreationDate="2011-05-07T13:55:42.260" UserId="4148" />
  <row Id="21641" PostId="14014" Text="+1 for &quot;A good breadboard can probably run faster than a bad 2-layer PCB.&quot;" CreationDate="2011-05-07T13:56:26.813" UserId="3308" />
  <row Id="21642" PostId="14000" Text="@W5V0 no, I meant an &quot;external LED&quot; that I've wired, connected to some port on my laptop" CreationDate="2011-05-07T13:57:54.927" UserId="4148" />
  <row Id="21643" PostId="13674" Score="1" Text="I thought about that but the component with the three holes in the center was located underneath the hole at the mouth piece end of the phone.&#xA;I'm starting a Circuits and Devices class here soon so I'm going to hook the 'microphone' up to a function generator and then an oscillator to see what happens. The speaker I've already hooked up to a function generator." CreationDate="2011-05-07T14:47:33.610" UserId="3392" />
  <row Id="21644" PostId="14004" Text="I just bought one. **I CAN'T BELIEVE** I missed the half off coupon code &quot;HALFMSPTOOL&quot;.. it seemed to have expired. Agggggg! To think I could have gotten it for a little over $2....... oh well. I might end up having to boot into windows to program it, but, I suppose I can live with that. Hopefully I can use Wine windows emulator to run the software." CreationDate="2011-05-07T15:03:33.880" UserId="4148" />
  <row Id="21645" PostId="14014" Text="@DavidKessner, A bad pcb is just like having a bad breadboard, normally more constrained because you are limited on the number of layers of wire you can have. Otherwise you earned my +1. I think you could make your list of issues a numbered or bulleted list and break up your post to look much nicer." CreationDate="2011-05-07T15:44:37.037" UserId="230" />
  <row Id="21646" PostId="13802" Text="@Kortuk - I assumed we were talking about the unpolarized 0.1uF ceramics that litter most boards.  I readily admit that I've put polarized caps on backwards before!" CreationDate="2011-05-07T15:47:06.320" UserId="857" />
  <row Id="21647" PostId="14020" Text="The double insulation does not have to concern to the whole device? For example if the adapter goes wrong and outputs 230V, the metal parts of the PC became lethal isn't it?" CreationDate="2011-05-07T16:38:38.970" UserId="1514" />
  <row Id="21648" PostId="14012" Score="1" Text="I'm not a verilog expert either, but I understand perfectly what he wants. IMO the downvote is undeserved." CreationDate="2011-05-07T16:40:38.333" UserId="2064" />
  <row Id="21650" PostId="14002" Text="@Dave It's too bad the packaging says &quot;Let your imagination be your guide.&quot; where the contact configuration should be" CreationDate="2011-05-07T17:02:31.143" UserId="3796" />
  <row Id="21652" PostId="14020" Text="If it outputs 230V something in the PC will probably explode! Those regulations prevent anything like that happening." CreationDate="2011-05-07T17:29:35.873" UserId="305" />
  <row Id="21653" PostId="14012" Text="This was cross-posted to stackoverflow, although that version has more detail. http://stackoverflow.com/questions/5920197/initializing-all-bits-with-zero" CreationDate="2011-05-07T17:42:23.517" UserId="3441" />
  <row Id="21654" PostId="13992" Text="In addition to the motion capture, if this project allows room for it, a beagleboard with opencv and camera." CreationDate="2011-05-07T17:44:41.313" UserId="2873" />
  <row Id="21655" PostId="13927" Text="\$8500 = \$30 wire + $8470 of state-of-the-art ultra-glossy marketing." CreationDate="2011-05-07T17:46:23.823" UserId="740" />
  <row Id="21656" PostId="13946" Text="@Fake Name - Yes, that's the type of LCD I'm familliar with as well.  The COG displays that supercat is referring to are unfamiliar territory for me." CreationDate="2011-05-07T18:24:59.437" UserId="857" />
  <row Id="21657" PostId="14025" Text="Awesome, thank you" CreationDate="2011-05-07T18:36:36.777" UserId="3796" />
  <row Id="21658" PostId="14025" Text="Unless it's driven by something that outputs very close to Vcc for a high level, it might want a pull-up on the base." CreationDate="2011-05-07T18:38:28.587" UserId="740" />
  <row Id="21659" PostId="14025" Text="@stevenvh but wait, where do i connect the led for an output? from the collector?" CreationDate="2011-05-07T18:54:53.023" UserId="3796" />
  <row Id="21660" PostId="14025" Text="@TrevorMA - yeah, output would be from the collector." CreationDate="2011-05-07T19:04:25.343" UserId="740" />
  <row Id="21661" PostId="13997" Text="I'm looking to do this on-demand without gui-interaction.  I.e. programmatically.&#xA;&#xA;I do have access to DC." CreationDate="2011-05-07T19:21:53.283" UserId="1708" />
  <row Id="21662" PostId="13991" Score="1" Text="If you need 6-DOF positioning you need a 3-axis accelerometer and a 3-axis gyro.  All accelerometers are noisy, various types of Kalman filters are normally used to clean up the data.  Sparkfun has several sensor boards you could use as an example: http://www.sparkfun.com/categories/160" CreationDate="2011-05-07T19:27:12.103" UserId="1438" />
  <row Id="21663" PostId="14025" Text="@JustJeff Why do you go from ground to collector then?" CreationDate="2011-05-07T19:32:20.900" UserId="3796" />
  <row Id="21664" PostId="14025" Score="1" Text="it works but i think something it burning!!!" CreationDate="2011-05-07T19:33:19.513" UserId="3796" />
  <row Id="21665" PostId="14025" Text="I took the load resister to ground off the collector and it sort of works.  but instead of going off the led just dims" CreationDate="2011-05-07T19:44:16.637" UserId="3796" />
  <row Id="21667" PostId="14018" Text="Regardless of whether this is a safety issue I am sceptical that the PicoPSU can put out 150W without melting." CreationDate="2011-05-07T20:15:56.517" UserId="1225" />
  <row Id="21668" PostId="13912" Text="@Martin- I mean the chemical and physical factors." CreationDate="2011-05-07T20:21:52.780" UserId="3916" />
  <row Id="21669" PostId="14014" Text="Great answer! and although most modern parts need a PCB they can usually be obtained an a simple breakout board, or put on a tiny one for connecting to a breadboard" CreationDate="2011-05-07T20:21:53.690" UserId="710" />
  <row Id="21670" PostId="14018" Text="That's not an issue for me, because the whole box consumes about 40 watts :)" CreationDate="2011-05-07T20:26:16.307" UserId="1514" />
  <row Id="21672" PostId="13946" Text="@Fake Name: It wouldn't be ASCII to raster conversion.  It would basically be bit-per-pixel to multibit-per-pixel conversion.  I think you're misunderstanding what I'm looking at.  I'm not looking for displays which have *drivers only*, but ones which include drivers *and controllers*, so they only need to be fed data when stuff on screen changes." CreationDate="2011-05-07T20:39:23.140" UserId="3123" />
  <row Id="21674" PostId="14031" Score="5" Text="I don't think thermistors are one time use. Fuses are, but thermistor are just variable resistences upon temperature changes. I guess these PTC fuses act like circuit breakers, but are esentially a special type of thermistor with a huge resistance upon reaching a certain intensity (and therefore, temperature.) These thermistors are not linear, so I guess they have a steep resistance near the limit intensity. I will ask for them as non-linear thermistors and see if I'm lucky :)" CreationDate="2011-05-07T20:46:18.323" UserId="4156" />
  <row Id="21675" PostId="13946" Text="@Fake Name: I'd be looking at a display like http://www.crystalfontz.com/products/document/2361/CFAF320240F-T_Data_Sheet_v1.2.pdf whose controller data sheet can be found at http://www.crystalfontz.com/controllers/SSD2119.pdf (note that many displays omit some controller pins, and that many controllers are similar to this one, but slightly different)." CreationDate="2011-05-07T20:49:54.220" UserId="3123" />
  <row Id="21676" PostId="13946" Text="@reemrevnivek: See above comment for links to the type of display I'm looking at." CreationDate="2011-05-07T20:50:29.087" UserId="3123" />
  <row Id="21678" PostId="14031" Text="@JGord What do you mean by triggered? Normally thermistors don't have any trigger. They always change their resistance according to temperature and are among other things used to control fan speeds in computer power supplies and so on. Are you sure you used appropriate thermistors for your job? " CreationDate="2011-05-07T21:14:48.573" UserId="1240" />
  <row Id="21680" PostId="14023" Text="Your first step is to contact the incubator manufacturer and obtain it's power consumption (or even better current consumption) and operating voltages. After that, you can start looking for a kit that will power it, because you will actually know what to look for. Also, since you're considering alternative sources, please describe locations which you'll be wisting and your budget. There may be other alternative solutions available which could work better than a solar cell (for example is there's a stream, you could use car alternator to construct a power plant and use it with inverter)." CreationDate="2011-05-07T21:24:43.233" UserId="1240" />
  <row Id="21681" PostId="14031" Text="Once there is sufficient current to increase the temperature the resistance starts to increase, which leads to more power loss in the thermistor, so more heating, even higher resistance, etc, until there is a high resistance and only a small current left. When power is removed and it is cooled down it should conduct again, as before. " CreationDate="2011-05-07T21:44:48.933" UserId="339" />
  <row Id="21682" PostId="14032" Text="Already readed Wikipedia's article before asking, of course, but thanks anyways." CreationDate="2011-05-07T22:10:56.830" UserId="4156" />
  <row Id="21683" PostId="14025" Text="@TrevorMA - your input high voltage isn't high enough. Wait, I'll edit my answer." CreationDate="2011-05-07T22:22:18.327" UserId="2064" />
  <row Id="21685" PostId="13157" Score="1" Text="@reemrevnivek - If I can find out a way to do this, I'll talk to a lawyer about the specifics (my cousin does litigation, and I'm sure he has friends who've dealt with stuff like this)." CreationDate="2011-05-07T22:48:23.473" UserId="3895" />
  <row Id="21686" PostId="13157" Text="@Madmanguruman - AFAIK, the Kindle runs Android or something like it (definitely Linux), so if they made kernel changes, they'd have to be open source. If not, I can just steal the binaries. Or I could write my own. I just need to get the screen on the gumstix, software is the next battle." CreationDate="2011-05-07T22:51:55.627" UserId="3895" />
  <row Id="21687" PostId="13674" Text="If you pulled a component out of the mouthpiece, doesn't that mean it's a microphone?" CreationDate="2011-05-07T23:16:36.067" UserId="142" />
  <row Id="21688" PostId="14031" Text="@AndrejaKo: Some companies make devices whose resistance is quite low until they reach a certain temperature, whereupon the resistance increases very rapidly with temperature.  What will end up happening is that the device's resistance will increase until the electrical power dissipated in the device falls to the match the level of heat the device can dissipate.  Generally the devices don't work as effectively as a good fuse (they may allow 50% overcurrent to flow for a long time before they get hot enough to reduce power) but they can cycle hundreds of times without replacement." CreationDate="2011-05-08T00:54:24.103" UserId="3123" />
  <row Id="21689" PostId="14012" Text="@Stevenvh, what fpga, what system, what board? There is no detail here. I do not downvote for things like this, I warn, and if no action is taken, i close." CreationDate="2011-05-08T00:57:05.847" UserId="230" />
  <row Id="21690" PostId="14023" Text="What kind of eggs? The cheapest incubator for e.g., chicken's eggs is a broody hen. She knows what to do, including how often to turn the eggs, and you can pay her chickenfeed!" CreationDate="2011-05-07T20:17:55.137" UserId="2255" />
  <row Id="21691" PostId="14035" Text="@supercat, if you include digital filtering, it is pretty amazing how brick wall a response you can get without overshoot." CreationDate="2011-05-08T01:29:44.433" UserId="230" />
  <row Id="21692" PostId="14005" Text="@Matt, example code is not normally given on here. We are about designing the electronics, if you just want to know how to make the RTS go high on an RS232 cable then you will get great responses on SO. @markrages may have code available, but he may not even have ubuntu." CreationDate="2011-05-08T01:31:34.850" UserId="230" />
  <row Id="21693" PostId="14035" Score="1" Text="@Kortuk: Really?  I would think it would be hard to avoid overshoot, since a brick-wall-filtered square wave has little spikes whose width approaches zero as the cutoff frequency rises but whose amplitude does not.  What would be a good reference?" CreationDate="2011-05-08T01:34:21.570" UserId="3123" />
  <row Id="21694" PostId="14023" Text="Or obtain the incubator and measure the power usage yourself with a kill-a-watt.  " CreationDate="2011-05-08T01:34:48.670" UserId="249" />
  <row Id="21695" PostId="14026" Score="1" Text="Maybe I am on the wrong track but Couldn't also use a digital Compass to have your &quot;Fixed point&quot;. You may already done this but here is something that might help: http://www.sparkfun.com/products/9371 and http://www.sparkfun.com/search/results?term=3-axis&amp;what=products for a &quot;general look&quot;. Note that if this is what you want I can give you a full answer." CreationDate="2011-05-08T01:45:36.937" UserId="3140" />
  <row Id="21696" PostId="14036" Text="Would this be the link you looked at? :D http://www.rc-cam.com/forum/index.php?/topic/1400-how-to-use-a-common-led-as-a-photodetector/" CreationDate="2011-05-08T02:07:23.650" UserId="3140" />
  <row Id="21697" PostId="14035" Text="@supercat, I am sorry to say I do not have good references to teach about digital filtering, I have taken classes and designed filters. The advantage to a digital filter is the order you can implement easily and ideally." CreationDate="2011-05-08T02:13:53.367" UserId="230" />
  <row Id="21698" PostId="14036" Text="In fact, yes. But I looked at te link that it gave and it made absolutely no sense to me whatsoever... :/ Sorry, I'm a noob." CreationDate="2011-05-08T02:38:50.577" UserId="4161" />
  <row Id="21699" PostId="14016" Text="just finished my project,works outstanding,thanks for the response Leon!" CreationDate="2011-05-08T02:47:36.753" UserId="4151" />
  <row Id="21700" PostId="14036" Text="Hey....So am I :D" CreationDate="2011-05-08T03:16:53.437" UserId="3140" />
  <row Id="21701" PostId="14036" Score="1" Text="I will Have a proper look for you but it looks like there is not much on it at all....I would probably recommend using a actual photo-detector in your case. Is there a project you wish to do with this or are you just looking? If you do have a project I could help you with it concerning the light sensor to the best of my abilities." CreationDate="2011-05-08T03:21:53.633" UserId="3140" />
  <row Id="21702" PostId="13157" Text="@tjameson - Get the lawyer *before* you invest time and money, not after." CreationDate="2011-05-08T03:37:22.750" UserId="857" />
  <row Id="21703" PostId="14036" Text="I need a wavelength-sensitive photodetector. " CreationDate="2011-05-08T04:30:29.653" UserId="4161" />
  <row Id="21704" PostId="14036" Text="Right :D&#xA;Looking...." CreationDate="2011-05-08T04:31:21.833" UserId="3140" />
  <row Id="21705" PostId="14036" Text="...No 1: http://www.sparkfun.com/products/8940   No 2: http://www.sparkfun.com/products/9088 No 3: http://www.sparkfun.com/products/8348 I am guessing you want No 2 But there are 2 other options" CreationDate="2011-05-08T04:34:59.973" UserId="3140" />
  <row Id="21706" PostId="14036" Text="Would you like me to put that into a answer for you?" CreationDate="2011-05-08T04:35:52.763" UserId="3140" />
  <row Id="21707" PostId="14036" Text="Thanks! Put it in an answer so that I can accept it." CreationDate="2011-05-08T04:39:33.717" UserId="4161" />
  <row Id="21708" PostId="14038" Score="2" Text="This might be worth discussing on meta, but in my opinion, this question is about debugging a burnt PCB and valuable to the general audience of the internet doing Electronic design. it may be someone whom has consumer electronics that it burnt on, but how to repair a burnt pcb seems valid. If people have some doubt of this, please open a meta post and link from here to it." CreationDate="2011-05-08T04:41:03.633" UserId="230" />
  <row Id="21709" PostId="14036" Text="Wait, one second. Number 3 seems to be only a light intensity transistor. And number 2 is a variale resistor based on intensity  But I found the answer. It is a photodiode, and it is available in different wavelengths. " CreationDate="2011-05-08T04:41:23.973" UserId="4161" />
  <row Id="21710" PostId="14036" Text="Where? Which one?" CreationDate="2011-05-08T04:42:51.573" UserId="3140" />
  <row Id="21711" PostId="14036" Text="Sorry, there was an error in my comment. I meant number 3, and I added a sentence about number 2. But the photodiode (I found after a quick search of google shopping) seems to be wavelength sensitive, (only reacts to a certain color, or reacts differently to different colors). The link is here. &quot;http://www.newark.com/jsp/search/productdetail.jsp?SKU=95B4214&amp;CMP=AFC-GB100000001&quot;. It is an IR photodiode. " CreationDate="2011-05-08T04:45:49.480" UserId="4161" />
  <row Id="21712" PostId="14036" Text="oh...:D Ok Aren't I a noob:D" CreationDate="2011-05-08T04:47:11.253" UserId="3140" />
  <row Id="21713" PostId="14036" Text="Sorry, I was on a smartphone, and the save comment button was pressed before the comment was finished. The link for the product is in my previous comment." CreationDate="2011-05-08T04:48:54.737" UserId="4161" />
  <row Id="21714" PostId="14036" Text="Sorry I wasn't much help..." CreationDate="2011-05-08T04:50:34.260" UserId="3140" />
  <row Id="21715" PostId="14036" Text="That is okay, thank you for your efforts anyway." CreationDate="2011-05-08T04:54:16.283" UserId="4161" />
  <row Id="21716" PostId="14041" Score="5" Text="I would be loath to attempt any repair on an AC power supply other than reheating solder joints; clearly that's not going to be sufficient here.  Most UL-approved wall-powered devices are designed to open-circuit before they cause a fire, but improperly-performed repairs may cause different, more dangerous, failure modes." CreationDate="2011-05-08T05:19:20.970" UserId="3123" />
  <row Id="21717" PostId="14004" Text="what?  there was a coupon code???  Could have been an even more amazing deal, but at $5 you still can't complain.  :)" CreationDate="2011-05-08T05:37:23.990" UserId="2288" />
  <row Id="21718" PostId="14004" Text="@Leon: ok, I found the information on the new Launchpad website: *In addition to programming and debugging, the on-board flash emulation tool also allows for bi-directional serial communication with a PC. This allows data to be sent to the PC to be displayed on a hyperterminal or graphical user interface. Or, the PC can be used to send the LaunchPad board signals and commands.*" CreationDate="2011-05-08T06:16:18.450" UserId="2288" />
  <row Id="21719" PostId="14031" Text="@supercat What you described is standard way of thermistor operation. I fail to see how is that different from overloading any other type of resistor. Such reasoning led me to make the last part of my comment:`Are you sure you used appropriate thermistors for your job? `. If the thermistors keep blowing up, then thermistors which can dissipate larger amounts of heat should be used, so that they don't overload when they start dissipating large amounts of heat." CreationDate="2011-05-08T08:02:27.690" UserId="1240" />
  <row Id="21720" PostId="13987" Text="Just thinking of how to get different pieces of a system to pass data to each other in a small box, so distance can be assumed to be very short.  The reason for having different pieces in a box is to simplify functions so that each piece has its own function (hopefully that makes sense..)" CreationDate="2011-05-08T08:29:01.387" UserId="3649" />
  <row Id="21721" PostId="14038" Text="Interesting that the area around the resistor is fairly clear of traces. Makes me suspect that some part was energised with high voltage, and it arced over (possibly due to dust or contamination or even a tin whisker.) If that is the case, it could have damaged something else." CreationDate="2011-05-08T10:32:06.927" UserId="1225" />
  <row Id="21722" PostId="14023" Text="@AngryEE  The advantage of not measuring the consumption is that you don't have to spend money on the device itself. Another manufacturer may have device with similar characteristics and lower power consumption. " CreationDate="2011-05-08T10:32:12.313" UserId="1240" />
  <row Id="21723" PostId="14038" Text="Actually, look at the fine wire emanating from the zero-ohm resistor. Looks like a tin whisker to an area that isn't supposed to have a connection. That would explain the rather sudden failure. A close inspection seems to show many whisker like objects - this board was just waiting for a failure to happen." CreationDate="2011-05-08T10:36:08.363" UserId="1225" />
  <row Id="21724" PostId="14038" Text="what was the orientation of the board, in its normal operating position? specifically, was that massive heat sink *below* the smoked resistor? if so, that would be kind of a design issue. if they didn't derate that resistor for a hostile thermal environment, you'd almost expect it to fail." CreationDate="2011-05-08T12:40:25.587" UserId="740" />
  <row Id="21726" PostId="14005" Text="oh.. I see. well I posted the Q here because it was electronic-related. lol" CreationDate="2011-05-08T13:42:58.093" UserId="4148" />
  <row Id="21727" PostId="14050" Score="1" Text="Not much use without the Eagle file!" CreationDate="2011-05-08T13:56:47.823" UserId="305" />
  <row Id="21728" PostId="14030" Text="Do you mean R3 = 680omh?" CreationDate="2011-05-08T13:58:46.627" UserId="3796" />
  <row Id="21729" PostId="14030" Text="Nothin seemed to change.  I'll upload a picture" CreationDate="2011-05-08T14:09:32.690" UserId="3796" />
  <row Id="21730" PostId="14050" Text="http://hotfile.com/dl/117141178/db825d8/RelayBoard-Large-v11.brd.html. Sorry I've not explained it very well. The gnd wire from the avr gets masked over as well. So when I generate the toolpath it aint there!" CreationDate="2011-05-08T14:10:33.997" UserId="2824" />
  <row Id="21732" PostId="14048" Text="This question is probably better suited for superuser." CreationDate="2011-05-08T14:36:40.257" UserId="638" />
  <row Id="21733" PostId="14050" Text="It seems to only happen when I rename the polygon to gnd. Otherwise it's fine. Why is that?" CreationDate="2011-05-08T14:45:21.270" UserId="2824" />
  <row Id="21736" PostId="14030" Text="@JustJeff oh, no I mean that you said R2 twice.  I was the one who spelt ohm wrong" CreationDate="2011-05-08T15:14:24.757" UserId="3796" />
  <row Id="21737" PostId="14050" Text="I downloaded the eagle file, and I don't see a regulator anywhere - it's a relay + driver. It doesn't have any polygons in the design. When I add a GND polygon to the top or bottom, I don't see anything unusual. The default Eagle install doesn't have anything for the MDX20, as far as I can tell. Please include before/after pics." CreationDate="2011-05-08T15:14:28.500" UserId="638" />
  <row Id="21738" PostId="14030" Text="@TrevorMA - woops you are correct. fixing .." CreationDate="2011-05-08T15:21:13.927" UserId="740" />
  <row Id="21739" PostId="14050" Text="Thanks for having a bash at it. I found the problem now. I used the gnd symbol from the supply library. That symbol was for gnd plane. When I replaced it with 0v symbol it worked. It was right at the bottom to the right of the dc jack." CreationDate="2011-05-08T15:26:32.593" UserId="2824" />
  <row Id="21741" PostId="14045" Score="2" Text="My meaning by wavelength-sensitive is that it only responds to a certain wavelength. But yesterday I read that an LED can be used as a photodiode that responds to wavelengths equal to or smaller than the LED's dominant wavelength, so I will accept your answer. " CreationDate="2011-05-08T16:09:48.567" UserId="4161" />
  <row Id="21742" PostId="14031" Text="@AndrejaKo: A typical 1-ohm resistor, when overloaded, might have its resistance increase to 1.1 ohms or so before it blows up; a polyfuse which is overloaded could have its resistance increase from 0.1 ohms to 10 megs.  To overheat a polyfuse to the point of destruction would require putting a very large voltage across it; otherwise a polyfuse simply won't allow through enough current to self-destruct, almost no matter how much or how little heat it can dissipate.  What will be affected by heat dissipation ability is..." CreationDate="2011-05-08T16:27:27.557" UserId="3123" />
  <row Id="21743" PostId="14031" Text="@AndrejaKo: ...the device's circuit-protection behavior.  Throw a cryo-cooler on a polyfuse and it will let through many times the rated current while keeping a low resistance.  Seal it in a Dewar flask and it would be unable to pass through its rated current without eventually getting hot enough to substantially increase its resistance." CreationDate="2011-05-08T16:29:30.530" UserId="3123" />
  <row Id="21744" PostId="14055" Text="Many high capacity microSD cards are created from several stacked flash memories." CreationDate="2011-05-08T18:22:00.160" UserId="1225" />
  <row Id="21745" PostId="14053" Score="1" Text="Are you sure there isn't a chip embedded in the USB plug?" CreationDate="2011-05-08T17:06:20.313" UserId="733" />
  <row Id="21746" PostId="14054" Text="Actually sometimes it can be very useful. One of my friends got a watch with a hidden camera and a microphone. Putting a micro or mini USB port on it would have been too obvious, but the (2.5 mm in his case) TRRS receptacle was cleverly hidden as one of the knobs, so it doesn't look out of place on a watch at all. " CreationDate="2011-05-08T18:35:16.583" UserId="1240" />
  <row Id="21747" PostId="14055" Text="So it's in layers? interesting, I wonder If there is any limit to the amount of data to be stored on a microSd card." CreationDate="2011-05-08T18:36:04.500" UserId="4170" />
  <row Id="21748" PostId="1158" Text="This works especially well for perf boards. Score down the center of a row of holes, line the score line up with the edge of the table, and press down quickly on the overhanging piece." CreationDate="2011-05-08T18:39:28.773" UserId="2827" />
  <row Id="21749" PostId="14026" Text="@james thanks! that would definitely yield heading info for the base.  But I need rotational info and height from the floor for the arm since it rotates about AND goes up/down the vertical axis" CreationDate="2011-05-08T18:43:49.923" UserId="4155" />
  <row Id="21751" PostId="14055" Text="@Randalfien - more layers, more cost. Also, microSDHC is limited to 2 terabytes I believe, in terms of physical addressing." CreationDate="2011-05-08T19:16:20.467" UserId="1225" />
  <row Id="21752" PostId="13988" Text="#David Kessner: Thank you `:)`" CreationDate="2011-05-08T19:18:17.203" UserId="4144" />
  <row Id="21753" PostId="14050" Text="@Ageis If that comment solved you problem, post it as an answer and select if when you can." CreationDate="2011-05-08T19:18:49.230" UserId="1240" />
  <row Id="21754" PostId="13157" Text="@tjameson - I doubt that they'd have to customize the kernel, most likely just make a device driver (loaded separately) which would have no legal obligation to be shared." CreationDate="2011-05-08T19:24:27.333" UserId="1293" />
  <row Id="21755" PostId="14057" Score="1" Text="There are also multilevel cells which store more than one bit." CreationDate="2011-05-08T19:39:29.687" UserId="339" />
  <row Id="21756" PostId="8982" Score="1" Text="If one wants twelve frequency bands and they're not equally spaced, would it be better to do an FFT, or to simply compute twelve pairs of integrals of reference-wave-times-original?  The PIC 18 series isn't set up terribly well for that, but a DSP or an ARM should be able to handle it well enough." CreationDate="2011-05-08T19:40:05.243" UserId="3123" />
  <row Id="21757" PostId="14054" Score="2" Text="The cable is labeled &quot;AUDIO&quot;.  My guess is that there's an ADC and controller inside the USB plug.  I'm not sure why there's a four-conductor connector, but perhaps some portable audio players would use the extra connector for something (video, maybe?) and having the extra conductor would avoid interference from that." CreationDate="2011-05-08T20:20:20.370" UserId="3123" />
  <row Id="21758" PostId="14055" Text="SD is up to 2GB. SDHC is used for 2GB-64GB. SDXC is used from 64GB to , potentially, 2TB. But I wouldn't be surprised if there would be a faster communication protocol implemented before 2TB would comes around." CreationDate="2011-05-08T20:58:37.217" UserId="1476" />
  <row Id="21759" PostId="14054" Text="There are special compact audio devices that use the audio jack terminal as both USB plug and audio output. They already come on the cheapest MP3s around, as I got such a device when I opened my student back account. But yeah, i dunno what will happen when you would plug this in your normal mobile phone.." CreationDate="2011-05-08T21:02:07.160" UserId="1476" />
  <row Id="21764" PostId="14062" Text="@Ranieri - oops, I can't delete the question, what can I do?" CreationDate="2011-05-08T22:04:55.580" UserId="4173" />
  <row Id="21766" PostId="14067" Score="1" Text="When measuring the voltage was the device under a load? If not would explain why." CreationDate="2011-05-08T22:28:31.980" UserId="1623" />
  <row Id="21767" PostId="14062" Text="I thought it looked familiar. I answered the earlier one (19 points), but gave more detail for this answer." CreationDate="2011-05-08T22:29:53.040" UserId="305" />
  <row Id="21768" PostId="14062" Text="@ranieri why not vote to close?" CreationDate="2011-05-08T22:43:11.627" UserId="319" />
  <row Id="21769" PostId="14055" Text="Questions support [math latex](http://meta.electronics.stackexchange.com/questions/434/test-the-new-latex-markdown-in-this-sandbox-question) for equations in questions. " CreationDate="2011-05-08T22:44:16.270" UserId="1623" />
  <row Id="21770" PostId="14062" Score="1" Text="@Kellenjb we(me and @ranieri) don't have enough rep to close questions. " CreationDate="2011-05-08T22:59:53.740" UserId="1623" />
  <row Id="21771" PostId="14062" Text="i don't usually like to close, but that really is a dupe." CreationDate="2011-05-08T23:08:56.347" UserId="740" />
  <row Id="21772" PostId="14070" Text="@Niko, this site is for designing electronics, not for supporting consumer electronics. I am sorry for any confusion." CreationDate="2011-05-09T00:04:40.897" UserId="230" />
  <row Id="21773" PostId="14062" Text="@LeonHeller, update your old answer with more detail!" CreationDate="2011-05-09T00:08:07.413" UserId="230" />
  <row Id="21774" PostId="14067" Text="@user4175, this seems like a consumer electronics question, not an electronics design question. Does anyone else agree?" CreationDate="2011-05-09T00:14:25.317" UserId="230" />
  <row Id="21775" PostId="13487" Text="Thanks for the suggestion. There are so many software choices, it's a bit overwhelming. " CreationDate="2011-05-09T02:00:28.670" UserId="3985" />
  <row Id="21776" PostId="14052" Text="@JustJeff, what do you think of my edits? I put mathjax in, if you do not like it roll it back, but I thought you might enjoy the improved reading quality." CreationDate="2011-05-09T02:43:49.087" UserId="230" />
  <row Id="21777" PostId="13989" Text="@JustJeff, CANbus is very involved, and ethernet is not? CAN is very simple to get working for simple back and forth messaging. They are dedicated chips and most families support internal to their micro controllers." CreationDate="2011-05-09T03:18:21.117" UserId="230" />
  <row Id="21778" PostId="13987" Score="2" Text="@O_O, that is not what people normally call a system. Those are more what I would define as sub-systems. They form part of what you could consider a single system accomplishing a single set of tasks. It is semantics, but I think many of your answers are very broad because they do not have a perfect idea of what you are looking for from the question." CreationDate="2011-05-09T03:30:18.933" UserId="230" />
  <row Id="21779" PostId="14029" Text="I got the USB bub board (http://shop.moderndevice.com/products/usb-bub) for USB -&gt; RS-232. It's pretty cheap and works well! I would recommend it for this purpose." CreationDate="2011-05-09T03:42:31.797" UserId="4034" />
  <row Id="21780" PostId="14054" Score="3" Text="The later generation iPod Shuffles use that type of cable for their USB connection: http://market.bit2u.biz/cache/product_images/big/20110426/iPod_Shuffle_USB_Cable_Attels_jpg_1.jpg" CreationDate="2011-05-09T04:27:45.083" UserId="4129" />
  <row Id="21781" PostId="13674" Text="True but it was awhile ago and I couldn't remember which came from which end." CreationDate="2011-05-09T04:49:42.007" UserId="3392" />
  <row Id="21782" PostId="14067" Text="@Kortuk - Agreed.  The user has not provided any information about the circuit being powered (and probably could not if asked), so any answers will be just guesses, and no electronics design will ever be performed here." CreationDate="2011-05-09T04:59:36.303" UserId="857" />
  <row Id="21783" PostId="14067" Text="@user4175, The question has been closed as per the previous discussion. This site is for designing electronics. If you are curious about this, to not leave you empty handed, if this device is sold as a car charger I would assume you did not measure it under load. It probably sags considerably. If it is marketed as a car charger it is 90% safe just by knowing that. On top of that, your phone charger probably has a form of buck/boost regulator to charge and power the phone. There are a number of reasons this should work fine for you.&#xA;" CreationDate="2011-05-09T05:02:37.270" UserId="230" />
  <row Id="21784" PostId="14054" Text="@supercat - I doubt that you could have this cable with logic inside (ADC, controller) for $5" CreationDate="2011-05-09T06:38:51.437" UserId="2064" />
  <row Id="21785" PostId="8505" Text="@osgx, if this is an answer that actually helps you, why would you accept an answer that did not answer your question?" CreationDate="2011-05-09T06:48:31.717" UserId="230" />
  <row Id="21786" PostId="13846" Text="ARM9 and ARM11 platforms host DDR2 controllers, but then you're not talking about microcontrollers but about microproccesors. FPGA can interface with it as well. The whole task is quite complex. An arduino is only 8-bit, so it just can't do the massive addressing job in hand." CreationDate="2011-05-09T06:59:15.820" UserId="1476" />
  <row Id="21788" PostId="14067" Text="I thank everyone who commited his or hers time to address my question. I realize the mistake is all mine to post anything without knowing particular domain of this site. And regardless of that, I **did** get very useful answers, which is great. Stackexchange is a great knowledge sharing place, I'm really glad it exists! " CreationDate="2011-05-09T07:21:47.530" UserId="4175" />
  <row Id="21789" PostId="14079" Text="@Leon, i disagree with a bit of this. I have a few friends whom do this regularly. The cost for doing this project is not primarily influenced by what frequency he is at, but what frequency bandwidth he wants for his signals. I can build a VCO and mixer that goes to 2.4GHz for only 10 or 20 dollars more then one that stops at 10MHz. The ADC to handle 20MHz of sample space, now that is a problem." CreationDate="2011-05-09T08:07:01.727" UserId="230" />
  <row Id="21790" PostId="14026" Text="I have been looking for similar info for awhile. one place i started looking was http://en.wikipedia.org/wiki/Path_planning It gave me a basic concept and terminology used." CreationDate="2011-05-09T08:08:55.907" UserId="2060" />
  <row Id="21791" PostId="14079" Text="That's why the professionals use a very fast ADC at the front end and don't bother with a mixer!" CreationDate="2011-05-09T08:22:21.473" UserId="305" />
  <row Id="21792" PostId="14079" Score="3" Text="@LeonHeller, The ADC is what costs so much, and a 10GHz adc is not really reasonable except at very very high cost. I have not heard of SDRs not using a mixer. The more expensive ones my friends have also still use a mixer." CreationDate="2011-05-09T08:36:28.260" UserId="230" />
  <row Id="21793" PostId="13760" Text="@Janm, there are issues with what is actually needed here. Do they need help specifically with xcode or are other solutions available. We can think up a few more quesitons, but there have already been comments asking for more information. Also, do we want to be a site about helping users install IDEs on a new platform and getting the IDE working, or do we want to focus on teaching what you do with the IDE? " CreationDate="2011-05-09T09:03:11.253" UserId="230" />
  <row Id="21795" PostId="14079" Text="Many of the commercial ones, up to 500 MHz or so, just use an ADC. A mixer will be needed at higher frequencies, of course. It just isn't needed below 500 MHz." CreationDate="2011-05-09T09:25:46.490" UserId="305" />
  <row Id="21796" PostId="13297" Text="Also, do you really need a USB-B-mini? The layout for a USB-B full-size is very clean." CreationDate="2011-05-09T09:27:37.020" UserId="1374" />
  <row Id="21797" PostId="13297" Text="Indeed, and that's exactly what I did - I'm using full size USB, it's an experiment after all. I had no time to finish this PCB yet, unfortunately, so I'm not able to share the results." CreationDate="2011-05-09T10:15:16.097" UserId="3564" />
  <row Id="21798" PostId="14079" Text="@LeonHeller, I would agree with that. i was just pointing out that the ADC would be the cost, but your answer is updated now. I like it, enjoy your first +1, surprised it is your first also." CreationDate="2011-05-09T10:26:46.907" UserId="230" />
  <row Id="21802" PostId="14079" Text="Thanks. I'll be up to 16K soon!" CreationDate="2011-05-09T10:31:49.417" UserId="305" />
  <row Id="21803" PostId="14052" Text="@Kortuk - yeah, I tried to invoke the LaTex thing to no avail. Not to go all meta, but does the text in the main answer use different formatting rules than the text in comments?" CreationDate="2011-05-09T10:33:41.210" UserId="740" />
  <row Id="21805" PostId="14079" Text="If you had a USB oscilloscope of sufficient bandwidth, could you not down-covert the broadcast band, and then capture it to a file using the O-scope? One could then go back and 'tune' through at leisure, using s/w on the PC." CreationDate="2011-05-09T10:54:26.323" UserId="740" />
  <row Id="21806" PostId="13910" Text="Thanks for all the answers. I understand that unless I can get proof that the device is happy with 10-14V, there is a risk involved when plugging it directly to a car battery. However, regulation via some sort of boost-buck converter is a more complex solution that also wastes some power. I guess opening up the synth and trying to find the possible internal regulator is the way the proceed, although I'm not sure if I can find it." CreationDate="2011-05-09T11:22:52.993" UserId="4122" />
  <row Id="21807" PostId="14080" Text="@Leon, while this is true I dont think it answers this question. Kevin would need a &quot;DMX dimmer&quot; which takes in the DMX and puts out a phase cut mains waveform." CreationDate="2011-05-09T11:45:13.153" UserId="2110" />
  <row Id="21808" PostId="14079" Text="oscilloscope is not for long continous recording, they usually can grab only several milliseconds (if grabbing at high rate)" CreationDate="2011-05-09T11:50:13.540" UserId="1994" />
  <row Id="21810" PostId="14062" Text="@Dean, Sorry, Didn't realize how high the close rep is now." CreationDate="2011-05-09T12:28:50.223" UserId="319" />
  <row Id="21811" PostId="14068" Text="I don't understand - why the downvote?" CreationDate="2011-05-09T12:31:26.180" UserId="1225" />
  <row Id="21812" PostId="14080" Text="I tend to write my answers a bit at a time, adding to them as I think of more stuff." CreationDate="2011-05-09T12:42:20.887" UserId="305" />
  <row Id="21813" PostId="7815" Text="Did you ever get this squared away?" CreationDate="2011-05-09T13:15:05.040" UserId="982" />
  <row Id="21814" PostId="14079" Text="@Leon Heller @Kortuk The SDR that I have seen used has a 500 MHz ADC and then daughter boards are used to down convert the desired frequency low enough for the ADC" CreationDate="2011-05-09T13:45:04.023" UserId="319" />
  <row Id="21815" PostId="14081" Text="A diagram would help." CreationDate="2011-05-09T13:46:50.607" UserId="305" />
  <row Id="21816" PostId="14079" Text="@Kellenjb, can you tell more about that SDR in new answer? What is the price? Is it ready to use product or only schemes of PCB? " CreationDate="2011-05-09T14:17:37.227" UserId="1994" />
  <row Id="21817" PostId="6196" Text="Werewolf ICs have issues too." CreationDate="2010-11-04T15:23:48.127" UserId="1414" />
  <row Id="21818" PostId="6196" Text="&quot;Your killing me smalls.&quot;" CreationDate="2010-11-04T15:26:24.550" UserId="1413" />
  <row Id="21819" PostId="6196" Text="I am serious!!!!!!   Only silver solder can stop em." CreationDate="2010-11-04T15:41:44.453" UserId="1414" />
  <row Id="21820" PostId="6196" Text="You get +1 for making me snigger..." CreationDate="2010-11-04T15:48:56.373" UserId="1225" />
  <row Id="21821" PostId="6196" Text="The answer was a little silly but you brought it back on the rebound! +1 points!" CreationDate="2010-11-04T15:49:23.380" UserId="249" />
  <row Id="21822" PostId="6196" Text="http://www.wolfsonmicro.com/about_us/" CreationDate="2010-11-04T20:53:15.647" UserId="1158" />
  <row Id="21823" PostId="6196" Text="+1 because that answer is epic." CreationDate="2011-02-18T03:17:20.637" UserId="3045" />
  <row Id="21824" PostId="14054" Text="@stevenvh: A PIC with USB and ADC inputs can be had from Digi-Key for $1.58@1000pcs.  I'm sure a high-end vendor doing chip-on-board stuff could come up with something cheaper.  I wouldn't be surprised if USB and ADC could be found together for under $0.50 in 100,000pc quantities." CreationDate="2011-05-09T14:54:53.830" UserId="3123" />
  <row Id="21825" PostId="14086" Text="Upload the image to http://imgur.com/ and give us a link and we can add the image to your post" CreationDate="2011-05-09T16:27:11.527" UserId="319" />
  <row Id="21826" PostId="14086" Text="Post a link to image and I'll put it in your post." CreationDate="2011-05-09T16:27:37.997" UserId="1240" />
  <row Id="21827" PostId="13863" Text="@Thomas - Then correct your answer!" CreationDate="2011-05-09T17:15:28.750" UserId="857" />
  <row Id="21828" PostId="13849" Score="1" Text="Serial Flash or SRAM are usually a good deal quicker than EEPROM.  If you need lots of nonvolatile data (the remote code use case), Flash is probably the better choice.  For large buffers, use SRAM; it's much faster than EEPROM.  If you have a few configuration bits that need to be toggled independently, that's really the only niche left for EEPROMs." CreationDate="2011-05-09T17:19:01.053" UserId="857" />
  <row Id="21829" PostId="13863" Text="@reemrevnivek, okay. Corrected. However, I was merely pointing out that it was impractical. No matter which signalling format is used." CreationDate="2011-05-09T17:24:04.923" UserId="1225" />
  <row Id="21830" PostId="14091" Text="@Steven - You may have missed that Paul A. posted the question you linked..." CreationDate="2011-05-09T17:56:18.697" UserId="857" />
  <row Id="21831" PostId="14091" Text="Yes! I am using a baudrate 9600. And I am sure of the settings. And also I am recieving some characters but it appears that some characters get missing. Appearing like the transfer rate of the character is faster for the micro controller to recieve while it is still processing an earlier received character." CreationDate="2011-05-09T17:58:11.813" UserId="3632" />
  <row Id="21832" PostId="14090" Score="1" Text="Have you read the [appnote](http://www.st.com/stonline/products/literature/an/17353.pdf)?  It talks a lot about proximity to constant and transient (&quot;hard&quot; and &quot;soft&quot;) EM sources and calibration.  " CreationDate="2011-05-09T18:04:01.280" UserId="857" />
  <row Id="21833" PostId="14092" Text="Hmm, this is worrying. Now, could I apply the inverse square law in this situation? If 10mA is okay at, say, 5mm, then 640mA should be okay at 4cm... but that's still way less than 2A. Ugh. " CreationDate="2011-05-09T18:06:23.920" UserId="1225" />
  <row Id="21834" PostId="14092" Text="If you put a magnetic shield cage around the SMPS, you might be able to further reduce the interfering magnetic effects." CreationDate="2011-05-09T18:09:24.377" UserId="3308" />
  <row Id="21835" PostId="14092" Score="2" Text="Inverse square law should work in this case, however keep in mind that the 10 mA figure is for DC current through a single wire/trace. The inductor will both produce a stronger magnetic field and be a nastier source of interference, because of the AC ripple from the coil when it's being charged and discharged at a high frequency." CreationDate="2011-05-09T18:23:19.537" UserId="3745" />
  <row Id="21836" PostId="5506" Text="The answer is too brief to be helpful, in my opinion." CreationDate="2011-05-09T18:27:02.170" UserId="3745" />
  <row Id="21837" PostId="14093" Text="This site is a good place to learn about CPLD types, manufacturers, and programming systems, but it doesn't cater well to comparing current offerings dollar-for-dollar from current distributors." CreationDate="2011-05-09T18:32:41.790" UserId="857" />
  <row Id="21838" PostId="14093" Text="Could you revise your question to be less focused on the current prices and offerings, and more focused on cross-platform drivers, staying power of the part, and flexibility?  Then we could educate you and future readers, rather than just giving you a link. (See the [\[shopping\]](http://meta.electronics.stackexchange.com/questions/tagged/shopping) tag and [FAQ](http://electronics.stackexchange.com/faq) for more info on this policy)." CreationDate="2011-05-09T18:36:14.547" UserId="857" />
  <row Id="21839" PostId="14092" Text="@nitro2k01 Looks like shielding is the way to go. What are my options for shielding a power supply or the magnetometer?" CreationDate="2011-05-09T18:53:44.820" UserId="1225" />
  <row Id="21840" PostId="14079" Text="For 20 MHz bandwidth, you can sample at 40 MHz.  Explicitly downmixing isn't necessary, you can just sample one of the aliases.  Use a bandpass antialiasing filter on the RF." CreationDate="2011-05-09T18:59:16.677" UserId="411" />
  <row Id="21841" PostId="14085" Text="As supercat said, if your repair causes it to work, but then light on fire a few months later and burn down the house, I would consider that &quot;making it worse&quot;." CreationDate="2011-05-09T19:15:19.557" UserId="142" />
  <row Id="21842" PostId="14035" Text="You say &quot;non-causal&quot; in the question, but all your examples are causal.  Which do you mean?  Non-causal requires you to record the entire waveform and then apply the filter to the recording. (Or, perhaps, the use of flux capacitors and large power sources.)" CreationDate="2011-05-09T19:22:29.923" UserId="142" />
  <row Id="21843" PostId="14036" Text="LEDs as detectors: http://electronics.stackexchange.com/questions/13201/led-current-while-off" CreationDate="2011-05-09T19:26:35.007" UserId="142" />
  <row Id="21844" PostId="14086" Text="@user4185 - Here's an upvote to get you closer to the required privileges.  Kellenjb and AndrejaKo, if you'd just upvoted him, he'd have it by now..." CreationDate="2011-05-09T19:33:07.343" UserId="857" />
  <row Id="21845" PostId="14092" Text="Shielding will help with the e-field but not with the magnetic field.  If your are having magnetic coupling problems increasing the distance or changing orientation is your best bet.  The magnetic field size will be bigger with larger physical inductors and higher currents.  The inductor is a antenna so it will be directional and you are worried about the near field where the magnetic field dominates." CreationDate="2011-05-09T19:40:49.747" UserId="540" />
  <row Id="21846" PostId="14089" Score="1" Text="Can you post your source code/assembly?" CreationDate="2011-05-09T19:54:40.703" UserId="566" />
  <row Id="21847" PostId="14035" Text="@endolith: What would be the optimum filter, assuming it's not required to be causal." CreationDate="2011-05-09T19:59:16.890" UserId="3123" />
  <row Id="21848" PostId="12473" Text="@Charles - I edited a few books in for you." CreationDate="2011-05-09T20:27:53.893" UserId="857" />
  <row Id="21849" PostId="12473" Text="@Kortuk - I fixed it.  However, this situation may be different because the link appears to be subject to change.  Therefore, the current answer is just a snapshot.  I agree, though, we need at least a summary of the content of a link." CreationDate="2011-05-09T20:29:22.860" UserId="857" />
  <row Id="21850" PostId="13717" Score="1" Text="@Leon - There are a large number of reasons why open-source code would be desired, including (but not limited to) ability to integrate into an open-source product, cost, community support, not being tied to any one manufacturer, ease of debugging, ability to port to other architectures, other customization possibilities...the list goes on." CreationDate="2011-05-09T20:39:31.647" UserId="857" />
  <row Id="21852" PostId="8448" Text="@Kellenjb - I think it's a duplicate of that question, and a poor one at that. Voting to close." CreationDate="2011-05-09T20:43:25.260" UserId="857" />
  <row Id="21853" PostId="13989" Text="@Kortuk - insofar as something like 232 has a sort of peer-to-peer symmetry, while 1553 or CAN impose a master/slave relationship, yes. I don't believe I said that ethernet is simple, just that it doesn't impose a bus controller/bus device distinction on the end points." CreationDate="2011-05-09T20:46:01.077" UserId="740" />
  <row Id="21855" PostId="14084" Text="Thanks for the Insteon link. It appears there is some kind of Insteon protocol that would let me interface with their dimmers. Is it some variation of X10?" CreationDate="2011-05-09T21:05:50.897" UserId="3353" />
  <row Id="21856" PostId="14080" Text="DMX is fairly cool to play with, but will probably prove to be overkill for what I'm doing. Especially as this is an in-wall system." CreationDate="2011-05-09T21:06:52.970" UserId="3353" />
  <row Id="21857" PostId="8448" Text="@reemrevnivek I voted to close back when the question was asked, but seem to remember that I was the only vote." CreationDate="2011-05-09T21:13:02.407" UserId="319" />
  <row Id="21858" PostId="14098" Score="2" Text="You want to count states as 2^9 not 9^2.  That's 512." CreationDate="2011-05-09T21:16:25.633" UserId="1609" />
  <row Id="21859" PostId="8448" Text="@Kellenjb - Oh, makes sense. Close votes disappear after a while." CreationDate="2011-05-09T21:19:20.567" UserId="857" />
  <row Id="21860" PostId="14079" Text="@osgx - i'm just say, 50 million samples/sec or better ADC, USB interface, the hardware's all there. USB 2.0 should have enough bandwidth to stream the data. Of course, re-purposing it might be the hard part." CreationDate="2011-05-09T21:19:21.720" UserId="740" />
  <row Id="21861" PostId="14098" Text="@DarenW you're right, not sure what I was thinking..." CreationDate="2011-05-09T21:20:12.607" UserId="4191" />
  <row Id="21862" PostId="13989" Text="also, full disclosure - my opinion of CAN is entirely from tangential exposure; it has been an unused optional peripheral on several systems I've worked on, but after hundreds of passes through the documentation, you absorb a little about the unused options just by osmosis. So I'm labouring under the assumption that CAN is a controller/controlled-device type of architecture." CreationDate="2011-05-09T21:22:54.417" UserId="740" />
  <row Id="21863" PostId="14098" Text="interesting. i would suspect your custom 4-bit slice would end up resembling 4 one-bit full adders with a carry look-ahead circuit, but it might not. Here's the thing- it would certainly not need to be any more complex than that. However, the question of whether you could optimize over 4x full add + 4bit CLA is an interesting one." CreationDate="2011-05-09T21:26:25.613" UserId="740" />
  <row Id="21864" PostId="14084" Text="After some more research, Insteon dimmers are really looking like the way to go. It looks as if I can at least _send_ them X10 signals. Been Googling around to find some documentation or example projects. Haven't found anything yet." CreationDate="2011-05-09T21:54:40.430" UserId="3353" />
  <row Id="21865" PostId="14097" Text="One would be hard pressed to find a circular LCD... other than that +1." CreationDate="2011-05-09T22:06:49.127" UserId="2157" />
  <row Id="21866" PostId="14033" Text="I contacted the manufacturer and he gave me:&#xA;Little Giant 10200 or 9200 with Fan Kit = 48 watts&#xA;&#xA;He also mentioned another:&#xA;HovaBator 1602N with Fan Kit = 34 watts (at full power)&#xA;Egg Turner = 3-5 watts&#xA;&#xA;http://incubatorwarehouse.com/index.php/hova-bator-incubator-circulated-air.html?___store=default&amp;___store=default&#xA;&#xA;@AndrejaKo Ill be visiting Alduba, Ethiopia and my budget isn't an issue. " CreationDate="2011-05-09T22:15:56.940" UserId="4153" />
  <row Id="21867" PostId="14097" Text="@Kenny - (1) Cut a circle, slightly smaller than the minor axis of the LCD, out of some opaque material. (2) Place this object in front of LCD.  (3) Look at the LCD.  Circular LCD found!" CreationDate="2011-05-09T22:27:20.887" UserId="857" />
  <row Id="21868" PostId="14098" Text="@JustJeff The main driving reason for this implementation is that in a four-bit full adder, the signals would only need to pass through two levels of gates instead of the 8 or so gates necessary for 4 one-bit full adders. It would be a 4x speed up. And I'm sure a 4-bit full adder would outperform a 4-bit CLA adder. Again, it is only two levels." CreationDate="2011-05-09T22:36:43.050" UserId="4191" />
  <row Id="21869" PostId="14103" Text="@David How do I know this for sure. Ultimately this comes done to the number of LUTs used, do you know for a fact that the Xilinx or Altera synthesizers do a better job than a true structural description. I'm sure they do an excellent job, but this is more of a curiosity for me." CreationDate="2011-05-09T22:37:55.063" UserId="4191" />
  <row Id="21870" PostId="14093" Text="@reemrevnivek I've added to the question. Hopefully, it clarifies the questions rattling around in my head." CreationDate="2011-05-09T22:41:10.663" UserId="550" />
  <row Id="21871" PostId="14094" Text="@Leon I've found some ebay Altera programmers as you've suggested. Thank you. I'm not able to find a Xilinx compatible one. What should I search for?" CreationDate="2011-05-09T22:42:45.250" UserId="550" />
  <row Id="21872" PostId="14103" Text="@seljuq70  There are many ways to analyze this, but ultimately it comes down to either &quot;blindly&quot; trusting what the compiler is doing, doing some trial and error yourself, or analyzing the compiler output to see what it's doing (a.la. Xilinx FPGA Editor).  I've done enough trial and error to know that the compiler does properly use the dedicated carry chain logic.   Also, it's not just a LUT usage issue but a speed issue as well.  Because of the dedicated logic and routing for the carry chain, this solution can be much faster than a LUT only solution." CreationDate="2011-05-09T22:50:25.800" UserId="3624" />
  <row Id="21873" PostId="14097" Text="@reemrevnivek. Assuming the outside form-factor is square and if so, why a circle?" CreationDate="2011-05-09T23:33:31.777" UserId="2157" />
  <row Id="21874" PostId="14050" Text="@Ageis, yes, if you solve the problem, please post the solution so that others that google the same problem in the future can solve it the same way with much ease." CreationDate="2011-05-09T23:48:48.103" UserId="230" />
  <row Id="21875" PostId="13760" Text="@Kortuk The answer would cover three things: editing the code, compiling and linking to produce a binary and programming the device. The answer would explain that Xcode can edit code, you need a toolchain to cross compile, and you need something to take the binary and program the device. It would then describe how to integrate a build process into Xcode and use its C editing features.  The point of the answer is to explain the parts of the process rather than to give an answer like &quot;use product X&quot;. The Xcode part is really a sideline. Once I got here, it was already closed, so I didn't answer." CreationDate="2011-05-09T23:56:30.843" UserId="1892" />
  <row Id="21876" PostId="14074" Text="Not to mention that you need to refresh the memory rather frequently as well!  The Arduino would be busy spending all its time driving the memory control lines!" CreationDate="2011-05-09T23:57:19.923" UserId="3308" />
  <row Id="21877" PostId="14094" Text="I think it was this one: http://cgi.ebay.co.uk/Xilinx-FPGA-CPLD-USB-download-Cable-JTAG-/150576429795?pt=LH_DefaultDomain_0&amp;hash=item230f0dfae3 There are others." CreationDate="2011-05-10T00:00:29.780" UserId="305" />
  <row Id="21878" PostId="13760" Text="@janm, it sounds like you have some excellent knowledge. How about opening a question about how to setup a compiler for embedded systems. Make it a question name that matches what you would google if you needed this process. Then write this as an answer. I am sorry you feel like I shut an outlet for a great answer, but I am not sure that is what this poster wanted. I could turn any closed question to a good on topic question. The issue is that often the person will need exactly what they wrote, which is not a good fit for the site." CreationDate="2011-05-10T00:02:09.840" UserId="230" />
  <row Id="21879" PostId="13760" Text="@janm, it seems they are specifically asking about using a specific IDE on mac. Just setting up a program is not a perfect fit for us. We could handle 8 million questions that really are better questions for Super User. One really great explanation about what goes into setting up an IDE and development chain would be useful to have. We could link to it when someone has these questions. I would upvote both your question and answer if you were to post what I suggested in my previous comment." CreationDate="2011-05-10T00:03:42.877" UserId="230" />
  <row Id="21880" PostId="14083" Text="I think my best bet is to find an X10 compatible light switch/dimmer." CreationDate="2011-05-10T00:05:46.213" UserId="3353" />
  <row Id="21881" PostId="14094" Text="Search for &quot;Xilinx cable&quot;" CreationDate="2011-05-10T00:08:16.397" UserId="305" />
  <row Id="21882" PostId="14099" Text="Ugh.... Stepper motors are horrible for any serious motion control. If you're serious, stick encoders on your brushed motors, and use closed-loop servo controllers to move the arm." CreationDate="2011-05-10T00:09:36.287" UserId="1374" />
  <row Id="21883" PostId="11143" Text="@imelza, I am sorry to say that the robotics part of our site has left. Please help support [this proposal](http://area51.stackexchange.com/proposals/29987/robotics-research) so that there is a robotics site again!" CreationDate="2011-05-10T00:11:21.850" UserId="230" />
  <row Id="21884" PostId="14052" Text="@JustJeff, I think it does, but does \$2^2\$ show up as tex here in a comment? If you type something you need to click out of the edit box and watch the preview for just a little before it will show the result(can be 10 or 20 seconds). This does not work in all situations, but it works for me in FF." CreationDate="2011-05-10T00:14:51.647" UserId="230" />
  <row Id="21885" PostId="14052" Text="@JustJeff, I spent forever trying to figure out how to make a nice Square root, and then @Andrejako pulls it off right below. Thanks for the help @andrejako." CreationDate="2011-05-10T00:19:31.777" UserId="230" />
  <row Id="21886" PostId="14052" Text="@Kortuk - well, thanks for the free radical =P seriously though, the formatting behaves oddly. I figured out how to escape \$ signs, so as to put two of them in a comment. On the 1st refresh, I saw the dollar signs as anticipated. Then less than 1 minute later, and I don't know if there was a 2nd refresh, the comment apparently got evaluated a *second* time, and the dollars disappeared but everything between them went italic. " CreationDate="2011-05-10T00:23:48.797" UserId="740" />
  <row Id="21888" PostId="14052" Text="@justjeff, a dollar sign is a $ all alone, you must escape the dollar sign for it to go to mathjax now." CreationDate="2011-05-10T00:26:56.173" UserId="230" />
  <row Id="21889" PostId="14103" Score="1" Text="It's like the situation with software compilers; twenty years ago, optimizing compilers were dubious, but today they are quite good. It stands to reason if there are optimal solutions for logic, the hardware compilers are probably using them already." CreationDate="2011-05-10T00:28:19.527" UserId="740" />
  <row Id="21890" PostId="14035" Text="For a brickwall digital filter, I would just do an FFT, throw away the frequencies I don't want, and IFFT, but I don't know if that's really optimal, and it overshoots." CreationDate="2011-05-10T00:33:21.930" UserId="142" />
  <row Id="21891" PostId="14099" Text="@jsolarski @Kellenjb @Fake  thanks everyone for the inputs/answers.  I am very interested in the forces generated at an impact point by the combined motion of the base and arm, so I am thinking a gyro/accelerometer at the end of the arm in combo with the base vector would give me a good starting point." CreationDate="2011-05-10T00:35:33.787" UserId="4155" />
  <row Id="21892" PostId="14002" Text="@Trevor: Measure the contacts with a multimeter continuity tester to determine which is which." CreationDate="2011-05-10T00:36:27.607" UserId="142" />
  <row Id="21893" PostId="13987" Text="along the lines of what Kortuk said, it helps to define the problem. One important question to ask yourself is whether you might intend to replace individual subsystems with different implementations of the same function, or if this is a one-time as-is design. If you use a real bus, and expose implementation details of the subsystems to your cpu, then a subsystem change requires a s/w change for your controller, whereas if you use a communication interface, it doesn't matter *how* you implement a (replacement) subsystem, as long as it meets the same message protocol." CreationDate="2011-05-10T00:36:46.320" UserId="740" />
  <row Id="21894" PostId="14103" Text="@JustJeff Exactly!  Designing good FPGA logic requires knowing what can safely be left for the compiler to do, and what we need to do manually. Unfortunately that is a moving target and requires experience to figure out. " CreationDate="2011-05-10T00:47:48.257" UserId="3624" />
  <row Id="21895" PostId="14052" Text="testing .. x = \${\sqrt{2}}/{y_0^{2}}\$    how about \$\frac{1}{3}\$" CreationDate="2011-05-10T00:54:02.040" UserId="740" />
  <row Id="21896" PostId="14052" Text="@JustJeff, pretty awesome in my opinion." CreationDate="2011-05-10T01:00:45.430" UserId="230" />
  <row Id="21906" PostId="13849" Text="@reemrevnivek - good point, I +1 your comment. If you're keeping a few dozen configuration settings around, EEPROM. If you want to keep frames of video, SRAM." CreationDate="2011-05-10T01:51:57.597" UserId="740" />
  <row Id="21908" PostId="14104" Text="@Andy Thank you so much. That was an excellent article you pulled. I guess I might as well forget about the 4-bit full adder. I kind of knew it was too far of a stretch. Still would be nice to have a verilog file for such a thing. Anyway, thanks for the help..." CreationDate="2011-05-10T02:13:31.283" UserId="4191" />
  <row Id="21909" PostId="14097" Text="@Kenny - Well, in that case, you just make the cover larger, and cut the outside into a circle! (o)  Sorry, just pointing out a potential workaround..." CreationDate="2011-05-10T02:14:06.947" UserId="857" />
  <row Id="21910" PostId="14093" Text="@mmccoo - Excellent revisions!" CreationDate="2011-05-10T02:16:22.420" UserId="857" />
  <row Id="21911" PostId="14002" Text="Yes, that goes back to my suggestion in the answer, which is to check the resistance between contacts.  For your purposes, you can also use the continuity check that endolith has referred to, provided that your multimeter has this feature (believe it or not, one of mine does not)." CreationDate="2011-05-10T02:26:42.093" UserId="2288" />
  <row Id="21912" PostId="14106" Text="(64 * 64 * 3 ) / 1024 != 12288.  Also, we have [gorgeous LaTeX support through MathJax,](http://meta.electronics.stackexchange.com/q/434/857), so that could be $\left( 64 \cdot 64 \cdot 3 \right) \div 1024 = 12\mbox{ kB}$ (right click to view source)" CreationDate="2011-05-10T02:31:15.370" UserId="857" />
  <row Id="21914" PostId="13717" Text="@reemrevnivek, I think the embedded world is not nearly as open source as every microcontroller is like changing your operating system. I understand people prefer open-source, but open-source depends on a large number of users for the product dedicating free time, take the number of embedded experts with free time they want to do embedded in and divide it over every microcontroller. it gets messy. However,It is still valid to ask for access to open source projects for a task. It just may not receive answers." CreationDate="2011-05-10T02:42:24.617" UserId="230" />
  <row Id="21915" PostId="14106" Score="1" Text="By my calculations, your data requirements are only about 40 kB/second, which should be pretty easy with on-the-fly loading, SD cards, or (some) wireless networking options, as well as serial Flash memory (I think you want Flash, not RAM, for this).  Could you explain how you ascertained that they can't keep up?" CreationDate="2011-05-10T03:03:22.143" UserId="857" />
  <row Id="21917" PostId="14035" Text="@endolith: In some contexts, overshoot is simply not possible.  For example, some types of signals have absolute limits one way or another.  Also, there are some physical ways of implementing filtering which only work with positive impulse functions (e.g. the spot function on a film recorder can only lay down light; it can't erase it)." CreationDate="2011-05-10T03:12:16.830" UserId="3123" />
  <row Id="21918" PostId="10014" Text="Do you want to actually multiply it by 1000, then truncate it to an integer? I'm confused by the &quot;as if I multiply it by 1000&quot; statement." CreationDate="2011-05-10T03:17:47.017" UserId="2827" />
  <row Id="21919" PostId="14108" Text="Do you know how to convert the difference equation into a transfer function in the z domain? That would probably be the best first step to take into finding out why the phase response is what it is." CreationDate="2011-05-10T03:19:38.793" UserId="4129" />
  <row Id="21920" PostId="14108" Text="sorry no.. i did not study z doamin.. yet" CreationDate="2011-05-10T03:28:53.613" UserId="4180" />
  <row Id="21921" PostId="14108" Score="1" Text="To get up to speed, you may want to have a look at the first couple of parts of the following ebook section: https://ccrma.stanford.edu/~jos/filters/Transfer_Function_Analysis.html.  Once you know how to convert a difference equation into its z domain representation, the following section: https://ccrma.stanford.edu/~jos/filters/Frequency_Response_Analysis.html will tell you how to find the frequency and phase response." CreationDate="2011-05-10T03:39:40.973" UserId="4129" />
  <row Id="21922" PostId="7525" Text="Need to know how big the solenoids are - voltage/current." CreationDate="2010-12-05T00:35:20.090" UserId="1681" />
  <row Id="21924" PostId="7525" Text="I'm looking at these that draw 6 to 8W.  If you know of a better/cheaper one that will control the release of water &quot;droplets&quot; do share. $50/per unit is expensive http://www.ascovalve.com/Applications/ProductSearch/ProductInfo.aspx?productid=8262H001AC120/60,110/50D&amp;userAction=view " CreationDate="2010-12-05T01:45:36.013" UserId="2180" />
  <row Id="21927" PostId="14108" Text="&quot;I failed to understand&quot; is not a question." CreationDate="2011-05-10T05:25:23.627" UserId="411" />
  <row Id="21928" PostId="14108" Score="3" Text="You don't need the z-transform to understand phase." CreationDate="2011-05-10T05:26:05.263" UserId="411" />
  <row Id="21929" PostId="14084" Text="I read back up on the Insteon kit. It's X10 compatible, in that it will coexist with X10. It has a higher data rate, all devices are repeaters and all messages are acknowledged." CreationDate="2011-05-10T05:28:49.403" UserId="746" />
  <row Id="21930" PostId="14084" Text="There's a good whitepaper here: http://www.insteon.net/about-whitepapers.html" CreationDate="2011-05-10T05:29:08.187" UserId="746" />
  <row Id="21931" PostId="14108" Text="@Bitrex, you may be a member of those here whom understand and love the z domain, but for most that do not know it, it is quite a hurdle. Significantly more complicated then frequency space when related to something &quot;real&quot; for a new learned. Do not misunderstand me, I am with you, Z domain is my only true love." CreationDate="2011-05-10T05:29:25.097" UserId="230" />
  <row Id="21932" PostId="14111" Text="@markrages, I am not sure I would have made as concise an example. Too many years with only using the z transform. I knew that was the reason, but turning the brain on is never easy." CreationDate="2011-05-10T05:58:01.490" UserId="230" />
  <row Id="21933" PostId="9140" Text="Well, that would do it! +1 for admitting your mistake." CreationDate="2011-05-10T06:22:00.940" UserId="2150" />
  <row Id="21934" PostId="14109" Score="3" Text="&quot;I did not understand&quot; is not a question." CreationDate="2011-05-10T06:41:05.403" UserId="411" />
  <row Id="21935" PostId="14067" Text="@user4175, we enjoy you taking part in our site, and we hope you continue. We have been having a brash of consumer electronics questions and are currently tight on the rules. If you decide to start doing any hobby electronics(or already do) I hope you come and join us. You have already learned to ask the questions that need to be asked." CreationDate="2011-05-10T07:06:17.677" UserId="230" />
  <row Id="21936" PostId="13899" Text="@Erik, you are on the right path then, nothing is sending. The lack of an ack node always makes my tx repeat till time ends, which I believe is per spec." CreationDate="2011-05-10T07:08:09.607" UserId="230" />
  <row Id="21937" PostId="14035" Text="@supercat, it is a digital filter, why not just have a simple check, if (signal&lt;0) signal=0;?" CreationDate="2011-05-10T07:26:34.983" UserId="230" />
  <row Id="21938" PostId="13760" Text="@Kortuk: Do you really think that a question about how to program an AVR on a Mac from someone who knows how to do it on Windows is appropriate for SuperUser? The primary question was &quot;how do I develop for an AVR on a Mac?&quot; The Xcode was just a supplementary question. You could argue that it really belongs on stackoverflow ..." CreationDate="2011-05-10T07:34:15.317" UserId="1892" />
  <row Id="21939" PostId="14108" Text="@Miss, why did you write Too Long; Didnt Read at the top of the question? If you didn't read the material on the topic, how can you expect to understand it?" CreationDate="2011-05-10T07:47:57.550" UserId="2110" />
  <row Id="21940" PostId="13760" Text="@Janm, that may seem to be clear now. Take a look at the question before @nickt changed it. She specifically asked, &quot;I know how to do this on windows but I want to know how can I do this on my Mac.&quot; He wants to know how to use the IDE on his mac instead of PC. She is not asking how to do AVR in general, he is specifically asking how to get xcode to work on a mac. A user trying to be helpful and make an edit can sometimes obscure what the OP actually wanted to know." CreationDate="2011-05-10T07:55:24.213" UserId="230" />
  <row Id="21941" PostId="14109" Score="1" Text="maybe you should try telling what exactly did you not understand" CreationDate="2011-05-10T08:15:57.417" UserId="1200" />
  <row Id="21943" PostId="14089" Text="Please view the source file below" CreationDate="2011-05-10T08:26:31.403" UserId="3632" />
  <row Id="21944" PostId="14089" Text="I can't see any source? You could edit it into your question" CreationDate="2011-05-10T08:27:24.310" UserId="566" />
  <row Id="21945" PostId="14095" Text="void initUART()&#xA;{       SCON = 0x50;TMOD = 0x20;&#xA;        TH1 = TL1 =-3;TR1 = 1;       }&#xA;void sendCHAR()&#xA;{        SBUF = uartBUFF[s];&#xA;        while(!TI);&#xA;        TI=0;     }&#xA;&#xA;void serial_isr(void) interrupt 4  &#xA;{  &#xA;        if (RI)&#xA;        {RI = 0;&#xA;        tmpBUFF = SBUF; &#xA;        charFLAG=1;}&#xA;}&#xA;&#xA;main()&#xA;{&#xA;        IE= 0x91;&#xA;        initUART();&#xA;        while (1)&#xA;        {&#xA;                if(charFLAG)&#xA;                {       SBUF = (tmpBUFF+1);&#xA;                        while(!TI);&#xA;                        TI=0;&#xA;                        charFLAG = 0;&#xA;                }&#xA;        }&#xA;}" CreationDate="2011-05-10T08:34:44.093" UserId="3632" />
  <row Id="21946" PostId="14089" Text="void initUART()&#xA;{       SCON = 0x50;TMOD = 0x20;&#xA;        TH1 = TL1 =-3;TR1 = 1;       }&#xA;void sendCHAR()&#xA;{        SBUF = uartBUFF[s];&#xA;        while(!TI);&#xA;        TI=0;     }&#xA;&#xA;void serial_isr(void) interrupt 4  &#xA;{  &#xA;        if (RI)&#xA;        {RI = 0;&#xA;        tmpBUFF = SBUF; &#xA;        charFLAG=1;}&#xA;}&#xA;&#xA;main()&#xA;{&#xA;        IE= 0x91;&#xA;        initUART();&#xA;        while (1)&#xA;        {&#xA;                if(charFLAG)&#xA;                {       SBUF = (tmpBUFF+1);&#xA;                        while(!TI);&#xA;                        TI=0;&#xA;                        charFLAG = 0;&#xA;                }&#xA;        }&#xA;}" CreationDate="2011-05-10T08:36:13.657" UserId="3632" />
  <row Id="21947" PostId="13717" Text="reemrevnivek, none of those answers make sense for something complex like a USB stack for a particular family of MCUs. There simply isn't any incentive for anyone to develop an open-source version. I've never heard of one for PICs, so the OP is wasting his time looking for it! He can distribute code using the Microchip library." CreationDate="2011-05-10T09:10:40.053" UserId="305" />
  <row Id="21948" PostId="14091" Text="@reemrevnivek - Yes, I missed that :-)" CreationDate="2011-05-10T09:30:33.867" UserId="2064" />
  <row Id="21949" PostId="14095" Text="Looking at the original poster's code, you're right, he needs a ring buffer. Here's one google threw up http://www.8052.com/codelib/files/efdUartDriver.zip" CreationDate="2011-05-10T09:37:31.050" UserId="566" />
  <row Id="21950" PostId="14097" Text="Doh! You're right a circle with a border of 6+ inches, Nice! And you can use an LCD as the opaque cutout too!! " CreationDate="2011-05-10T10:46:20.150" UserId="2157" />
  <row Id="21951" PostId="6061" Text="@BradHein, Do you realize that bluetooth and zigbee are very different protocols? If you need zigbee bluetooth does not do the job. One device to another for bluetooth, perfect. For a set of slaves and a master, yes. For a mesh network with many nodes, bluetoth will not work. " CreationDate="2011-05-10T10:52:05.610" UserId="230" />
  <row Id="21954" PostId="14109" Text="@rick_2047: how did the system removed  the DC component according to figure? " CreationDate="2011-05-10T11:39:44.423" UserId="4180" />
  <row Id="21955" PostId="14116" Text="&quot;Ergometer&quot; would seem to mean something for measuring work in Nm or Joules, but you seem to require a speedometer." CreationDate="2011-05-10T11:40:09.400" UserId="305" />
  <row Id="21956" PostId="14097" Text="@Kortuk thanks for the edit - I have javascript disabled on my browser and didn't see how that looked." CreationDate="2011-05-10T11:43:55.420" UserId="249" />
  <row Id="21957" PostId="14111" Text="@markages: i understand he applied formula for straight line.. taninver(b/a) .. so that mean phase changes depend on frequency.." CreationDate="2011-05-10T12:14:03.017" UserId="4180" />
  <row Id="21958" PostId="14099" Text="@Fake Name - if you pulse a stepper motor at the right frequency it runs as smooth as a brushed motor." CreationDate="2011-05-10T12:14:13.663" UserId="2064" />
  <row Id="21959" PostId="14109" Text="@Miss, what do you understand? At what point are you losing the scent of the method?" CreationDate="2011-05-10T13:08:06.923" UserId="230" />
  <row Id="21960" PostId="14117" Score="1" Text="@Leon: &quot;suitable&quot; is really dependent upon the hobbyist's comfort level with certain technologies.  I think it's reasonable to say that RS232 is a good lowest-common-denominator PC interface, and FTDI chips make it very easy to implement serial interfaces when your PC only has a USB port.  Bike stands are common as well, so the OP could use a stand + mjh2007's suggestion and the execution would probably be simpler than coming up with rollers and an additional support for the bike." CreationDate="2011-05-10T13:15:44.353" UserId="2288" />
  <row Id="21961" PostId="14116" Text="I edited my question to make sure it is clear what kind of &quot;ergometer&quot; I mean." CreationDate="2011-05-10T13:27:43.667" UserId="4197" />
  <row Id="21962" PostId="14120" Text="I thought about this design as well, but where would I mount such a sensor on the kind of &quot;bicycle&quot; used in fitness centers?" CreationDate="2011-05-10T13:39:10.233" UserId="4197" />
  <row Id="21963" PostId="14123" Text="@dave: thanks for clearing the question.." CreationDate="2011-05-10T13:45:19.343" UserId="4180" />
  <row Id="21964" PostId="14123" Text="and the system emphasized the higher frequecny (nearly omega =pi) to the lower frequency.. how the system is high pass filter;?" CreationDate="2011-05-10T13:49:48.140" UserId="4180" />
  <row Id="21965" PostId="14035" Text="@Kortuk: Clipping the signal at zero is going to totally annihilate any benefits of filtering.  And while I'm posting in DSP, I'm also curious about things like audio film recorders (from an intellectual rather than practical aspect admittedly) where one can make whatever non-negative impulse function one wants, subject to a width constraint." CreationDate="2011-05-10T13:51:35.520" UserId="3123" />
  <row Id="21966" PostId="14035" Text="@supercat, if you have a signal that is bouncing negative that should not be negative, it is not going to be harmed by that clipping. An ideal low pass will not bounce negative at all as long as you give a small loss the the lowest AC frequency and have a  large bias like a square wave would. If you are talking about analog system you are going to have to bias your signal to not go negative." CreationDate="2011-05-10T13:54:00.660" UserId="230" />
  <row Id="21967" PostId="14124" Text="i think it will be 0 for any value of n... because its costant at n =1..." CreationDate="2011-05-10T13:54:09.387" UserId="4180" />
  <row Id="21968" PostId="14095" Text="Updated my answer as question now contains code." CreationDate="2011-05-10T13:54:57.703" UserId="1472" />
  <row Id="21969" PostId="14124" Text="@kortuk: as i know DC component at frequency omega =0 .. " CreationDate="2011-05-10T13:56:00.667" UserId="4180" />
  <row Id="21970" PostId="14124" Text="@miss, a signal that is a constant for all n is a DC signal. If your output is perfectly 0 after the filter you have rejected the signal, right?" CreationDate="2011-05-10T14:00:20.247" UserId="230" />
  <row Id="21971" PostId="13760" Text="@Kortuk: Yes, I did, before I wrote that it looked like a real question to me on May 4.  &quot;Mac OS X and avr microcontroller programming?&quot; was the primary sentence. Followed by &quot;Really? How?&quot; Followed by &quot;Can I use Xcode for this?&quot; This IS asking how to do AVR in general, not how to get Xcode to work on a MAC (other than as a secondary or even tertiary question.)" CreationDate="2011-05-10T14:01:51.290" UserId="1892" />
  <row Id="21972" PostId="14124" Text="@kortuk : yes right ..." CreationDate="2011-05-10T14:04:52.023" UserId="4180" />
  <row Id="21973" PostId="14124" Text="@kortuk: that mean in the above figure .. DC component is not there.. but how this system is high pass filter at nearly omega =pi ?" CreationDate="2011-05-10T14:07:41.650" UserId="4180" />
  <row Id="21974" PostId="13760" Text="@janm, if you would like to continue discussing we could probably do this more effectively in chat. As a final note, the title was originally, &quot;Mac OS X and avr microcontroller programming? Really? How? Can I use Xcode for this?&quot;. It could be either way, but the body and the fact he has not returned to explain what he is asking being very confusing has led to this question being closed as not a real question." CreationDate="2011-05-10T14:08:23.877" UserId="230" />
  <row Id="21975" PostId="14124" Text="@kortuk: ahh i see.. since there exit a DC compoent at omega =0.. so after filtering ..the constant signal removed.. thats why its a high pass filter at omega = pi ... yes now its make sence to me" CreationDate="2011-05-10T14:14:35.720" UserId="4180" />
  <row Id="21976" PostId="14124" Text="@kortuk : thanks " CreationDate="2011-05-10T14:14:46.127" UserId="4180" />
  <row Id="21977" PostId="14124" Text="@kortuk: the point here is that still there are discountinous at omega =0,2pi...it should removed.. is't" CreationDate="2011-05-10T14:18:53.473" UserId="4180" />
  <row Id="21978" PostId="14111" Text="@Miss You don't need a transcendental function to explain it... higher frequency means things are happening faster, so more change happens in a fixed amount of time." CreationDate="2011-05-10T14:23:52.303" UserId="411" />
  <row Id="21979" PostId="13987" Text="It is not simpler to split functionality across multiple devices for no other reason than separating tasks.  Communications and synchronization are more complex than having two processes in the same micro. Now, if these processes have particularly incompatible latency profiles (one must update quickly while the other can take some time to complete a chunk), then there MAY be a valid reason to split them. Even then, the more common solution is to use interrupts or find a way to break the longer task down further. With what you've described I'm leaning towards thinking you should rethink this." CreationDate="2011-05-10T14:25:26.437" UserId="1270" />
  <row Id="21980" PostId="14124" Text="if high pass filter can remove the DC component then can it remove also discountinous in signal.. as it have discontinous at omega = 0 and 2pi.." CreationDate="2011-05-10T14:26:26.873" UserId="4180" />
  <row Id="21981" PostId="14120" Text="there is usually a flywheel of some kind.  Or you can mount the magnet on the chainwheel.  Cadence is proportional to wheel RPM on a fixed-gear bike like a fitness bike." CreationDate="2011-05-10T14:27:03.063" UserId="411" />
  <row Id="21982" PostId="14124" Text="@miss, there are not any discontinuities. " CreationDate="2011-05-10T14:27:42.017" UserId="230" />
  <row Id="21983" PostId="14120" Score="1" Text="You say the bicycle already has a computer.  Look for its speed sensor.  If it is a magnet / reed switch, you can mount another reed switch nearby to be tripped by the same magnet." CreationDate="2011-05-10T14:27:53.437" UserId="411" />
  <row Id="21984" PostId="14123" Text="can a high pass filter remove the discontinous and DC from signal.. if yes then why there is discontiouse in the siganl given in figure..." CreationDate="2011-05-10T14:27:56.763" UserId="4180" />
  <row Id="21985" PostId="14124" Text="@kotuk: no, phase have discontinuties at omega = 0 ,2pi.." CreationDate="2011-05-10T14:31:36.483" UserId="4180" />
  <row Id="21986" PostId="14116" Text="Have you thought about converting a regular bicycle into an exercise bicycle? I've seen devices that lift the back tire off the ground and add resistance using a fan. They look relatively in expensive. This would solve the problem of attaching to a wheel-less exercise bike." CreationDate="2011-05-10T14:32:49.780" UserId="588" />
  <row Id="21987" PostId="14124" Text="@miss, phase graphs are from -180 degrees to +180 degrees, it is not a discontinuity, 181 degrees and -179 degrees are equal. This means that it has just gone from 180 to -180. This is not a discontinuity. " CreationDate="2011-05-10T14:33:49.267" UserId="230" />
  <row Id="21988" PostId="13989" Text="I think bus has different meanings in different contexts. From a schematic level, any interface with multiple signals can be considered a bus. As you move to higher levels with more abstraction, bus changes meanings. Slightly higher, bus usually means there are or can be multiple devices involved. RS485 multipoint is a definitely a bus, for instance. Much higher up, from a Linux device point of view, RS485 becomes a comm interface again and is demoted from being a bus... until you add your own protocol layer on top of it turning it back into a bus.  At each level is has different meanings." CreationDate="2011-05-10T14:37:35.967" UserId="1270" />
  <row Id="21989" PostId="14124" Text="@kortuk: hmm but book mentioned that phase have discontinus at omega =0,+ve2pi and -ve2pi" CreationDate="2011-05-10T14:38:06.920" UserId="4180" />
  <row Id="21990" PostId="14061" Text="Funny you should mention this... I'm having to turn a SPI interface into a non-bidirectional I2C-like interface (the first byte is an address) to enable many more devices to participate on the bus than I have chip selects for. It works if your slave devices are all FPGAs.  :)  I too have wished there was something in between those two major synchronous standards." CreationDate="2011-05-10T14:45:23.330" UserId="1270" />
  <row Id="21991" PostId="14124" Text="book mentioned also that &quot;the size of discontinous is pi. &quot;" CreationDate="2011-05-10T14:48:18.073" UserId="4180" />
  <row Id="21992" PostId="14061" Text="Oh, I guess I should clarify that the output enables on the slaves don't get asserted until it's address byte is received and they stay on until the single chip select is deasserted... so it's obviously slightly different than normal SPI + high level protocol.  However, it's totally compatible with standard SPI from a master device point of view.  (like a microprocessor)" CreationDate="2011-05-10T14:51:06.327" UserId="1270" />
  <row Id="21993" PostId="14035" Text="@Kortuk: Suppose one is trying to design a video projector to show continuous-tone pictures.  Although one could design it to show hard-edged pixels, those will add high-frequency visual components which are useful when displaying text, but which may cause aliasing when showing graphics whose frequency components approach Nyquist.  If one properly blurred the pixels so they overlapped properly, one could minimize the aliasing effects.  It's impossible, though, to spread the light from one pixel so it darkens other pixels, though." CreationDate="2011-05-10T14:51:11.957" UserId="3123" />
  <row Id="21994" PostId="14035" Text="@Kortuk: The pattern of light produced by a single pixel would correspond to the impulse function of a low-pass filter.  If the pattern is too broad, it will attenuate frequencies well below Nyquist; if it's too narrow, it won't do a good job of attenuating frequencies above Nyquist.  It would seem like there should be some way of characterizing the optimal frequency response that could be obtained under such constraints." CreationDate="2011-05-10T14:57:36.077" UserId="3123" />
  <row Id="21995" PostId="14120" Text="Most of these bicycles (haven't decided which one to use) come with several resistance levels that make it harder/less hard to move the pedals (like driving in different gears). How would I get the speed if I did't know in which &quot;gear&quot; the bicycle is? In addition, it seems rather wasteful to me to duplicate what is already there. Thus I would really like to know if there is any solution that uses the speed computed by the bicycle's computer." CreationDate="2011-05-10T14:59:21.587" UserId="4197" />
  <row Id="21996" PostId="14116" Text="This sounds interesing. But I'd rather not build something from scratch. The project seems difficult enough to me as it is and I am not an engineer but a programmer with some knowledge of electronics." CreationDate="2011-05-10T15:01:53.313" UserId="4197" />
  <row Id="21997" PostId="14061" Text="@darron: Cool.  I wonder what would have to happen for the industry to start using an open-standard three-wire communications bus where wires are actively driven high and low?  I guess there's a slight conflict between avoiding passive pull-ups and allowing any device to signal an interrupt, though that might be remedied by adding an interrupt pin which could be wired to the master or not at the slaves' convenience (my present implementation of the protocol only has one slave, so it can use the data return wire to asynchronously signal when it wants to be serviced)." CreationDate="2011-05-10T15:03:37.697" UserId="3123" />
  <row Id="21998" PostId="14126" Text="For reasons explained in other comments, I'd rather not use my own sensors. And wireless data transmission really isn't needed, at least not for now." CreationDate="2011-05-10T15:07:16.243" UserId="4197" />
  <row Id="21999" PostId="14061" Text="@darron: To avoid having to use a chip-select pin, the master signals start-of-command by sending two rising edges on the data wire while the clock is low; slaves can indicate whether their last data byte was valid by outputting a status value when clock and data are both low (idle); otherwise they indicate that they want attention when clock is low and data is high. If I were designing master hardware for this protocol, I would add the ability to send 8 clocks pulses where the data wire mirrored clock, and in slave hardware include an asynchronous count of the number of rising edges during..." CreationDate="2011-05-10T15:08:33.530" UserId="3123" />
  <row Id="22000" PostId="14061" Text="@darron: ...a data byte.  If five or greater, the byte would be ignored (the slave would assume the master was interested in receiving a byte of data, but had nothing it actually wanted to say).  That wouldn't be nearly as significant, though, as having the slave report the last-byte status when clock was low (which would, if the slave device was a processor, allow the master to know that the slave hadn't been ready and had missed the last 'transaction opportunity'." CreationDate="2011-05-10T15:10:22.737" UserId="3123" />
  <row Id="22001" PostId="14035" Text="@supercat, I wish I could sit down with a whiteboard and see how I miss-communicating with you. There is something you are saying that I am not interpreting correctly. I hope as answer show up I learn what I am not interpreting. " CreationDate="2011-05-10T15:36:19.050" UserId="230" />
  <row Id="22002" PostId="14035" Text="@Kortuk: Filters have many applications, some dealing with time frequency and others with spacial frequency in one, two, or more dimensions.  In some applications, one may be constrained to either have a uniformly-positive impulse function, or not have an output which overshoots the behavior of the input.  I don't think it's mathematically possible for a brick-wall filter to achieve such behavior (some attenuation of signals below the cutoff is necessary to avoid ringing) but I don't know what the actual limit is." CreationDate="2011-05-10T15:56:21.170" UserId="3123" />
  <row Id="22003" PostId="1404" Text="For a project hack, maybe using a BT headset (practically free sometimes) and using audio to transport data?  Pretty lousy bandwidth, but it'll speak bluetooth! :)" CreationDate="2011-05-10T16:00:19.703" UserId="3308" />
  <row Id="22004" PostId="13957" Text="Dave - Thanks for the voice of experience! However, &quot;they probably take more care&quot; isn't very authoritative or specific. Can you point to some evidence of this?" CreationDate="2011-05-10T16:01:03.887" UserId="857" />
  <row Id="22005" PostId="13957" Text="Also, the tagline is unnecessary - Your signature is already at the bottom right, with an avatar, information on your badges/rep, and a link to your profile." CreationDate="2011-05-10T16:01:54.993" UserId="857" />
  <row Id="22006" PostId="12447" Text="If one upsamples an 8KS/s signal to 64KS/s, in such a way as to minimally affect signals below 4KHz but maximally attenuate signals in the range 4KHz-32KHz, one can then pass the resulting signal through a low-pass filter whose pass band extends to 4KHz and whose stop band starts at 32KHz.  That may be a lot easier than trying to design a purely-analog filter whose pass band extends to 3.5KHz and whose stop band starts at 4.5KHz, while offering better performance in the 3.5-4.5KHz region than would the analog design." CreationDate="2011-05-10T16:02:59.610" UserId="3123" />
  <row Id="22007" PostId="13962" Text="The weave of the board can affect the impedance of a trace?  That makes me cringe." CreationDate="2011-05-10T16:06:12.603" UserId="857" />
  <row Id="22008" PostId="13919" Text="Why the downvote?" CreationDate="2011-05-10T16:41:13.950" UserId="305" />
  <row Id="22010" PostId="14086" Text="Thanks for the supports guys. I just uploaded my schematic. " CreationDate="2011-05-10T16:58:09.470" UserId="4185" />
  <row Id="22011" PostId="14088" Text="Yes, you could be right. But on Arduino board, it seems ok when using 9v battery to run bluetooth, mcu and motor. " CreationDate="2011-05-10T16:59:40.547" UserId="4185" />
  <row Id="22012" PostId="14129" Text="Good point. Also high resistance loads are especially troubling and on some PICs I've even seen bleed over between analog inputs probably via the analog mux.  " CreationDate="2011-05-10T17:03:27.470" UserId="2157" />
  <row Id="22013" PostId="14135" Text="Hemowork should be tagged with `homework`. You should probably try to improve your English a bit. What do you mean by &quot;1 sample&quot;? There are no samples in the analog world. Did you even try to understand the problem on your own before asking?" CreationDate="2011-05-10T20:13:08.200" UserId="3745" />
  <row Id="22014" PostId="14132" Text="That's actually a pretty great idea. Unfortunately the wiring is already done, hence no longer making selective LED lighting a viable option. I'll be keeping this in mind for future projects!" CreationDate="2011-05-10T20:18:34.103" UserId="3353" />
  <row Id="22015" PostId="14108" Text="@Martin - That was me, I edited it and the images took up a lot of space, obscuring the question way at the bottom.  So, I stuck a TLDR notice at the top.  It could be &quot;Executive Summary&quot; if you prefer." CreationDate="2011-05-10T20:34:32.470" UserId="857" />
  <row Id="22016" PostId="14132" Text="All of the power for a circuit goes through a switch (in order to make the lights controllable). Could you not just put the arduino by the switch and use the thick cabling for the LEDs (overkill, but it would still work). Unless you already have purchases lighting fixtures/bulbs?" CreationDate="2011-05-10T20:39:43.603" UserId="4201" />
  <row Id="22017" PostId="14136" Text="it's probably too much to hope that those leads are color coded to any kind of standard." CreationDate="2011-05-10T20:46:57.843" UserId="740" />
  <row Id="22018" PostId="14120" Text="@Kim Stebel - are you sure they use gearing? I was under the impression they simply changed the friction factor." CreationDate="2011-05-10T20:55:54.683" UserId="740" />
  <row Id="22019" PostId="14120" Text="@JustJeff i said &quot;like driving in different gears&quot;. Of course they do not use gearing." CreationDate="2011-05-10T21:27:29.493" UserId="4197" />
  <row Id="22020" PostId="14140" Score="1" Text="Related Question: http://electronics.stackexchange.com/q/9510/638" CreationDate="2011-05-10T21:36:07.160" UserId="638" />
  <row Id="22021" PostId="14099" Text="@stevenvh - Sure, but you can't ever avoid the possibility of dropped steps unless you put an encoder on it, and at that point, you're better off with a brushed motor, because they have far more torque for their size, and you already have everything needed to implement a closed loop servo anyways." CreationDate="2011-05-10T21:36:40.850" UserId="1374" />
  <row Id="22022" PostId="14136" Text="@JustJeff - They're usually color coded, but the color-code is different for almost every motor, and you don't know how it maps to the coils." CreationDate="2011-05-10T21:43:43.627" UserId="1374" />
  <row Id="22023" PostId="14140" Score="1" Text="Thanks - I didn't know about the &quot;emission coefficient.&quot; edit: I think perhaps what I'll do is find a generic LED spice model of a particular color and use the values I find there as a first approximation for my calculations." CreationDate="2011-05-10T21:45:09.773" UserId="4129" />
  <row Id="22024" PostId="14136" Text="@Fake Name - that's what i'm saying. if you pulled the same motor from the same model of three printers, i imagine the phases would have the same colors. but two different motors? wouldn't count on it." CreationDate="2011-05-10T21:45:30.690" UserId="740" />
  <row Id="22025" PostId="14088" Text="The arduino uses a different microcontroller, with a different fab-house. Noise sensitivity between the two may be wildly different. Also, are you running the motors straight off the battery on the arduino? If so you are getting some noise rejection from the onboard voltage regulator." CreationDate="2011-05-10T21:56:37.120" UserId="1374" />
  <row Id="22026" PostId="14141" Text="Great, thank you!" CreationDate="2011-05-10T21:58:15.970" UserId="4129" />
  <row Id="22027" PostId="14135" Text="@nitro2k01..ofcourse " CreationDate="2011-05-10T22:20:55.027" UserId="4180" />
  <row Id="22028" PostId="14136" Text="@JustJeff - Whoops, I somehow completely glossed over the &quot;Any kind of standard&quot; part of your comment. Too early in the morning for me, I guess." CreationDate="2011-05-10T22:34:57.223" UserId="1374" />
  <row Id="22029" PostId="14132" Text="I suppose that could work. Since I need to have both &quot;traditional&quot; dimmer switches and microcontroller control, would I need to make my own wall dimmers that hook into the Arduino?" CreationDate="2011-05-10T23:02:28.067" UserId="3353" />
  <row Id="22030" PostId="8516" Text="@Kell the third prong is tied to the ground. The main two are tied to a live and a neutral wire. If you had all three then you could detect which is live and which is neutral by measuring voltage w.r.t. the ground. But the OP is that you don't have that ground reference." CreationDate="2011-05-11T00:17:38.807" UserId="1951" />
  <row Id="22031" PostId="10692" Text="AVR assembly is a very nice introduction to assembly language!  Just because it's not necessary for the ATmega doesn't mean it's a dead art.  There's a lot of microcontrollers that must be programmed in assembly." CreationDate="2011-05-11T00:29:12.653" UserId="857" />
  <row Id="22032" PostId="14139" Text="I'm talking about things like &quot;designing a queue with virtual resources&quot;, or &quot;crediting schemes and common pitfalls&quot;, or &quot;when to break layering abstractions&quot;.  The best-practices and methods of designing components.  Stuff that the veterans of chip design already know.  I don't see a lot of practical design guidance in IEEE.  Is there an RTLer's &quot;Code Complete&quot; out there?" CreationDate="2011-05-11T01:05:51.297" UserId="1708" />
  <row Id="22033" PostId="14132" Text="You want to run both traditional incandescent lights and LEDs from the arduino? Easily done. Most of those $6 dimmers you can buy at the hardware store use a 10k pot for the dimmer dial. Open the unit up and replace the wires for the 10k pot with wires to a digital pot. The digital pot can be controlled from the arduino via I2C. If it's a simple on/off you can drive a 5v mosfet with the arduino to drive a 24V control for a solenoid. " CreationDate="2011-05-11T01:11:06.600" UserId="4201" />
  <row Id="22034" PostId="12768" Text="I think the advice to use something other than a L293 is more sound than I thought a month ago." CreationDate="2011-05-11T01:35:16.267" UserId="3778" />
  <row Id="22035" PostId="14151" Text="I guess that gets a bit more to the underlying question.  I am trying to learn some electronics, how do I determine the 'minimum' chip I would use or even _what_ chip would do the job.  How do you learn that sort of stuff?  It seems like such an 'how long is a piece of string' type question that I don't even know where to start." CreationDate="2011-05-11T02:58:00.177" UserId="4017" />
  <row Id="22036" PostId="14153" Text="It's possible that there are high current draw *spikes*, but the average current draw is ~42mA. Therefore, if you measure the device with a current meter that averages over a few seconds, you get one value, and a fast current meter gets the other." CreationDate="2011-05-11T04:09:08.357" UserId="1374" />
  <row Id="22037" PostId="14035" Text="@supercat, you have peaked my interest, I will get my matlab working again and see what I can do. I do not agree that you must have attenuation in the lower frequencies to stop overshoot. An ideal low pass filter would generate a perfect sinusoid from a square wave(if the cutoff is designed for that)." CreationDate="2011-05-11T04:11:09.713" UserId="230" />
  <row Id="22038" PostId="14152" Text="Thank you very much, that make my day, everything is clear as potable water jeje thanks!" CreationDate="2011-05-11T04:19:27.543" UserId="3365" />
  <row Id="22039" PostId="14149" Score="3" Text="Is this a hobby-style servo motor? Is the precision of the &quot;one hour&quot; critical or important at all? You're comfortable designing a PCB but not a small circuit? (don't expect an answer to have a schematic that you can drop directly into PCB software)..." CreationDate="2011-05-11T04:27:35.063" UserId="638" />
  <row Id="22040" PostId="14152" Text="I didn't believe that the word choice (misspelling) was that bad, but sure enough it's good for 1W drinkable amplifiers." CreationDate="2011-05-11T04:36:10.917" UserId="638" />
  <row Id="22041" PostId="14106" Text="12kB a frame and 10 frames a sec for a total of 120 kB a sec. \left( 12 \cdot 10 \right) = 120\mbox{ kB} But you are right that does not make sense. The SD card should be able to keep up at that rate. I will edit the question with my experience with the SD card. " CreationDate="2011-05-11T04:41:41.260" UserId="3407" />
  <row Id="22042" PostId="14112" Text="Thats fantastic thank you, I think this is exactly what I am looking for. " CreationDate="2011-05-11T04:46:25.187" UserId="3407" />
  <row Id="22043" PostId="14124" Text="@miss, that is not a discontinuity I would fret over, but do you also notice that the signal is 0? If the signal is 0 the phase shift affects nothing." CreationDate="2011-05-11T05:28:48.177" UserId="230" />
  <row Id="22044" PostId="14159" Text="You make excellent points, especially the twitch from the outputs not being correct for the motor - that would cause me greater grief than the lack of holding torque (which I'd already considered).  My biggest concern with the doing the A498X on my own board is that I've not done surface mount soldering before.  Pololu makes a board for the A4983, but its uneconomical to purchase one for every motor I need.  Maybe its just time to bite the bullet on SMD..." CreationDate="2011-05-11T05:32:54.263" UserId="3778" />
  <row Id="22045" PostId="10014" Text="@fizzisist: Yes, I want to perform this operation: x1000. But I don´t want to use the mult block. I suspect May be there is a truncate way." CreationDate="2011-05-11T06:01:01.903" UserId="2597" />
  <row Id="22046" PostId="14155" Text="@henry, why not give some information about how you would test it?" CreationDate="2011-05-11T06:40:54.347" UserId="230" />
  <row Id="22047" PostId="14088" Text="Does motor driver IC help the noise issue?" CreationDate="2011-05-11T06:48:03.117" UserId="4185" />
  <row Id="22048" PostId="14159" Text="@rfusca - while SMD isn't always difficult to do, leadless packages like QFN may prove frustrating as a first experience. When the occasion arises you could start with something like SOIC." CreationDate="2011-05-11T07:14:24.293" UserId="2064" />
  <row Id="22049" PostId="14149" Score="1" Text="would a solenoid work? My thinking is that a servo has many more mechanical and electrical parts that may fail in an aquatic environment. Also the ease of use of a solenoid compared to trying to drive a servo motor, may make things less complex." CreationDate="2011-05-11T07:44:16.610" UserId="2060" />
  <row Id="22050" PostId="14162" Text="Please add the position of the decimal point to the numbers in your question. I assume it is something like .15 or 0.15 in the 2000 mA range and 150 in the 200 mA range. Note that 0.15 A = 150 mA." CreationDate="2011-05-11T08:10:36.057" UserId="930" />
  <row Id="22051" PostId="14162" Text="@user4185, the 400m is intended as 400mA and is written that way for space. Same with all of the A measurements." CreationDate="2011-05-11T08:10:52.390" UserId="230" />
  <row Id="22052" PostId="14166" Text="Is there a good way to tell how long my resistor will last if I briefly pulse enough current to exceed its power rating 10x? My resistors don't have an instantaneous max current rating (that I can find)." CreationDate="2011-05-11T08:47:18.127" UserId="1951" />
  <row Id="22053" PostId="14164" Score="1" Text="Always use the lowest - yes.  However always 'start' with the highest." CreationDate="2011-05-11T08:58:48.447" UserId="4211" />
  <row Id="22054" PostId="13991" Text="@Mark: Thanks for the tip. This could've been posted as an answer." CreationDate="2011-05-11T09:46:23.010" UserId="941" />
  <row Id="22055" PostId="14165" Text="Thanks guys. on 2000mA it reads = 120. on 200mA it reads = 12. on 20mA it reads = 1.2. on 2000u it reads = 0. So what's the correct current?" CreationDate="2011-05-11T09:54:23.347" UserId="4185" />
  <row Id="22056" PostId="14162" Text="Thanks guys. on 2000mA it reads = 120. on 200mA it reads = 12. on 20mA it reads = 1.2. on 2000u it reads = 0. So what's the correct current?" CreationDate="2011-05-11T09:56:52.907" UserId="4185" />
  <row Id="22057" PostId="14164" Text="Thanks guys. on 2000mA it reads = 120. on 200mA it reads = 12. on 20mA it reads = 1.2. on 2000u it reads = 0. So what's the correct current?" CreationDate="2011-05-11T09:57:06.137" UserId="4185" />
  <row Id="22058" PostId="14162" Text=" @zebonaut: No decimal point. Only when I see to 20mA, it shows 1.2" CreationDate="2011-05-11T09:59:57.007" UserId="4185" />
  <row Id="22059" PostId="14165" Score="1" Text="This is weird. If it reads 120 on 2000mA, I would expect 120.0 on 200 mA and Overload (or something like 1.___) on 20 mA. Are there different plugs for the 2000 mA range and, respectively, the lower ranges?" CreationDate="2011-05-11T10:11:36.170" UserId="930" />
  <row Id="22060" PostId="14138" Text="Why the downvote?" CreationDate="2011-05-11T10:18:56.227" UserId="305" />
  <row Id="22061" PostId="13736" Text="It would, but there isn't any point. The internal oscillator will be a lot faster and more stable." CreationDate="2011-05-11T10:21:10.107" UserId="305" />
  <row Id="22062" PostId="14166" Score="1" Text="@romkyns You can sometimes use I^2*t. That is, 10 times *current* will only be okay for 1/100th the time. Work out allowed current from P = I^2*R." CreationDate="2011-05-11T11:00:30.057" UserId="1225" />
  <row Id="22063" PostId="14166" Text="@Thomas sounds useful, but unfortunately I only have these numbers: 5mA is OK forever, which doesn't let me use your relation..." CreationDate="2011-05-11T11:23:50.787" UserId="1951" />
  <row Id="22064" PostId="14165" Text="@zebonaut: you are right! Thanks! It has anohter plug. the other plug is for 200mA Max (Fused). So when I measured it using 200m, it gave me consistent reading. When I turned it to 20m, it gave me 1. Which is correct." CreationDate="2011-05-11T11:54:48.173" UserId="4185" />
  <row Id="22065" PostId="14162" Text="Related to precision, not exactly what is being asked though: http://electronics.stackexchange.com/questions/13313/different-current-readings-with-a-multimeter-between-the-200-ma-and-the-10-a-slot" CreationDate="2011-05-11T11:55:53.413" UserId="319" />
  <row Id="22066" PostId="14162" Text="Based off of all of the answers given so far, this question is a duplicate of the question I linked to. I don't think that is the issue he is having though. He is trying to figure out why there is a 0 missing when he switches ranges." CreationDate="2011-05-11T11:58:26.693" UserId="319" />
  <row Id="22067" PostId="14161" Text="If his informant is anything like some people I know, they know a current draw from a different GPS and try to act like know-it-alls and tell you that they know the current draw for that specific one, when they are in fact wrong." CreationDate="2011-05-11T12:02:14.147" UserId="319" />
  <row Id="22068" PostId="14163" Text="Thanks. I appreciate your comment" CreationDate="2011-05-11T12:02:29.890" UserId="4185" />
  <row Id="22069" PostId="14165" Text="I want to add, the reading 2000ma is the correct reading. So I motor is 150mA." CreationDate="2011-05-11T12:04:30.840" UserId="4185" />
  <row Id="22070" PostId="14106" Text="@Steven - Surround math with `$` signs to invoke LaTeX formatting.  However, I'm missing the point where you need to multiply by three - Do you have 8 bits for each color of the RGB LEDs?" CreationDate="2011-05-11T12:36:13.433" UserId="857" />
  <row Id="22071" PostId="14151" Score="1" Text="@Steve Since you mentioned that you don't know how to pick the minimum chip, here are some tips: First familiarize yourself with [Atmel](http://www2.atmel.com/)'s site. Two pages which are worth putting in favorites are the [megaAVR](http://www.atmel.com/dyn/products/devices.asp?category_id=163&amp;family_id=607&amp;subfamily_id=760&amp;source=left_nav) and [tinyAVR](http://www.atmel.com/dyn/products/devices.asp?category_id=163&amp;family_id=607&amp;subfamily_id=791&amp;source=left_nav) pages. They have descriptions of AVR microcontrollers you'll be mostly using. " CreationDate="2011-05-11T12:47:19.303" UserId="1240" />
  <row Id="22072" PostId="14151" Score="1" Text="@Steve Next analyze part names. They will tell you some basic information about the part itself. For example the mega or tiny tells you what type of features to expect from the unit. First couple of digits tell you the available flash memory. It's usually 4, 8, 16, 32, 64 or 128 KiB. The rest or the digits I couldn't decode. Next, for each device, there's a short summary. If you click on the name and then click on the documents, you'll find its summary. Download the file and read it. It contains the basic information about the device and should be good enough for start." CreationDate="2011-05-11T12:59:30.013" UserId="1240" />
  <row Id="22073" PostId="14166" Text="According to the datasheet the resistor is conducting only when the triac is off; once the triac is on, the resistor and phototransistor are essentially shorted by the triac." CreationDate="2011-05-11T13:23:06.723" UserId="1293" />
  <row Id="22074" PostId="14166" Text="Is there a chance that the triac isn't turning on properly, and the resistor is carrying load current some of the time?" CreationDate="2011-05-11T13:29:29.787" UserId="1293" />
  <row Id="22076" PostId="14116" Text="If you want to avoid changing the electronics and want to do everything in software then you are going to need to find an exercise bike that has a PC interface RS-232, USB, or Ethernet and publishes the protocol details. Good luck." CreationDate="2011-05-11T13:42:24.187" UserId="588" />
  <row Id="22077" PostId="14035" Text="@Kortuk: An brick-wall low-pass filter which was between the first and third overtones of a square wave would pass through a nice simple sine wave, but what about one between the third and fifth?" CreationDate="2011-05-11T13:45:58.457" UserId="3123" />
  <row Id="22078" PostId="14151" Score="1" Text="I would just get an the exact chip that your arduino has. Then you won't need to worry about getting any other chips (like a programmer) you can just put it into the chip socket on the arduino, program it and then put it into your circuit. Even though you won't be using a lot of the features the chip does not cost that much so it's worth the ease of use. " CreationDate="2011-05-11T13:52:27.793" UserId="4201" />
  <row Id="22080" PostId="14035" Text="@supercat, I think I understand what is being asked about. I think it is the non-ideal components that are used in analog filtering that cause affects like this, with an ideal low pass you would not have the overshoot. It is officially on my to do list to spend some time on this and try to make you a real answer. Give me a month." CreationDate="2011-05-11T13:57:55.983" UserId="230" />
  <row Id="22081" PostId="10014" Text="@fizzisist: But, it is not exactly the same, this is about SYSTEM GENERATOR, even system generator have many things in common with VHDL, both are different things, aren´t they?" CreationDate="2011-05-11T14:02:03.850" UserId="2597" />
  <row Id="22083" PostId="10041" Text="Is your input stream of FP in IEEE-754 single precision format? In a VHDL program, in a C program?&#xA;Is your output stream of Int in a signed twos-complement 32 bit format? In a VHDL program, in a C program? Answers to these questions will determine the scope of an answer. Thanks!&#xA;alan" CreationDate="2011-02-22T18:08:40.673" UserId="3120" />
  <row Id="22084" PostId="14178" Text="If you're going to disagree with Wikipedia, you need to provide references to back it up.  And yes, noise is important, at least in my field.  :)" CreationDate="2011-05-11T15:13:00.380" UserId="142" />
  <row Id="22085" PostId="14178" Text="More specifically, I'm trying to save parts by using a somewhat noisy supply (250 µV RMS) for a low-noise amplifier.  One op-amp model passes more of the power supply noise to the output than another, though the PSRR graphs in their datasheets would imply the opposite.  Empirically, I can solve the problem just by RC filtering the supply, but I'd still like to get a better understanding of PSRR." CreationDate="2011-05-11T15:56:02.777" UserId="142" />
  <row Id="22086" PostId="14178" Text="@endolith - do you mean that you always accept Wikipedia as Absolute Truth? I find that a great many articles have inaccuracies and errors. Like here the example which indicates an erroneous 120 dB. My argument is in the first sentence of my answer." CreationDate="2011-05-11T15:56:26.460" UserId="2064" />
  <row Id="22087" PostId="14155" Text="@Kortuk, I am quite new to the site, I thought that was outside the scope of the question (I assume there is a question somewhere here such as 'how do I measure the draw of a low voltage DC device' or something. Next time I will try to answer more completely." CreationDate="2011-05-11T15:57:36.420" UserId="4209" />
  <row Id="22088" PostId="14180" Text="Er, isn't 1 mV/100 not 10 uV?" CreationDate="2011-05-11T15:59:16.300" UserId="2064" />
  <row Id="22089" PostId="14180" Text="@stevenvh 1mV output noise referred to the input of a X100 amplifier is 10uV and 20*log(1V/10uV) = 100dB" CreationDate="2011-05-11T16:02:19.497" UserId="2234" />
  <row Id="22090" PostId="14178" Text="@stevenh: No, but Wikipedia's statement has 3 references, and yours has zero.  (I can't check those references to verify that they say what Wikipedia says, though.)  If the power supply noise is coupled to &quot;various stages&quot;, then it can be coupled to the input stage and go through the gain of the op-amp, no?" CreationDate="2011-05-11T16:02:25.783" UserId="142" />
  <row Id="22091" PostId="14151" Text="This is just a minor step up from breadboarding, and you're still not able to reuse the Arduino which makes the final device much more expensive than necessary." CreationDate="2011-05-11T16:04:39.813" UserId="4220" />
  <row Id="22092" PostId="14166" Text="@romkyns I = sqrt(P / R). If you say 5mA is okay continuously this dissipates 0.25W. That would make 50mA okay for 1/100th the time. 50mA dissipates 25W briefly, but 0.25W on average." CreationDate="2011-05-11T16:44:22.337" UserId="1225" />
  <row Id="22093" PostId="14148" Text="I understand how to determine which wires belong to the same coil (easiest way is to measure resistance), I would like to know what happens if one of the coil is wired backwards." CreationDate="2011-05-11T17:31:52.143" UserId="3240" />
  <row Id="22094" PostId="14143" Text="Perfect, thank you. Indeed, it looks like swapping the polarity on one of the coils will send you in reverse and off by one or two steps, depending on which coil was reversed. I wonder what happens when you're half/eighth/sixteenth stepping..." CreationDate="2011-05-11T17:35:43.843" UserId="3240" />
  <row Id="22096" PostId="14155" Text="@Hemry. As a mod(for atleast 1 more hour) I am just here to help give people steering in answers. Yes, this person did not ask, but if you were to explain it also, it is probably a logical next step. It would also make a much more substantial answer, you already earned my +1 as you are correct, but I think you could have a great answer with more detail. The great part about stack exchange is you can edit in more detail now! You will get even more upvotes, I promise. A great answer is often worth 10." CreationDate="2011-05-11T17:55:41.173" UserId="230" />
  <row Id="22097" PostId="14178" Text="@endolith See my answer but if your concern is AC noise on the supply, then &quot;Power Supply Rejection Ratio&quot; is not the measurement to be concerned about as it refers to changes in DC level.  Rather you need to look at &quot;Power Supply Ripple Rejection&quot; which pertains to AC components and is frequency dependent.  Some manufacturers inter-twine these terms in their datasheets or just infer which is being discussed by the context of the measurement." CreationDate="2011-05-11T18:20:11.890" UserId="1438" />
  <row Id="22099" PostId="14184" Text="My question is about op-amps.  I'm highly skeptical that there are distinct definitions for &quot;Power Supply Rejection Ratio&quot; (PSRR) and &quot;Power Supply Ripple Rejection&quot; (PSRR).  I suspect they are the same thing, measured the same way, and the DC measurement is just the component at 0 Hz.  The datasheets I'm looking at are by different manufacturers, and their charts are labeled &quot;POWER-SUPPLY REJECTION RATIO vs. FREQUENCY&quot; and &quot;POWER SUPPLY REJECTION RATIO vs FREQUENCY&quot;." CreationDate="2011-05-11T18:48:19.710" UserId="142" />
  <row Id="22100" PostId="14167" Text="excellent recommendation.  I wasn't aware of this book." CreationDate="2011-05-11T18:54:57.197" UserId="1708" />
  <row Id="22101" PostId="14184" Text="@endolith I added several examples...there is no standardization in the industry when it comes to these terms, you just have to figure out what they are referring to by context or by looking at a particular manufacturers definitions. " CreationDate="2011-05-11T19:22:24.730" UserId="1438" />
  <row Id="22102" PostId="13736" Text="Ah, makes sense." CreationDate="2011-05-11T19:30:11.973" UserId="2873" />
  <row Id="22103" PostId="14186" Text="This is a shopping question and should be closed." CreationDate="2011-05-11T19:42:38.950" UserId="305" />
  <row Id="22104" PostId="14184" Text="Still looks like there's no difference between AC and DC measurements in op-amps, and the terms are used interchangeably." CreationDate="2011-05-11T19:49:02.810" UserId="142" />
  <row Id="22105" PostId="14186" Score="5" Text="Well, finding tools/devices is an important part of engineering, how can you design a system without knowing which parts/tools are available and where to get them? It's not like I'm asking where to buy the cheapest iPhone 4..." CreationDate="2011-05-11T19:53:08.357" UserId="1346" />
  <row Id="22106" PostId="14156" Text="I think the question is not about damaging the LD1117, but damaging the controller." CreationDate="2011-05-11T19:54:45.033" UserId="339" />
  <row Id="22107" PostId="14189" Text="I can normally remove the solder, but I find that on these chips, solder gets caught under the pins and once it's under there, it doesn't want to come out." CreationDate="2011-05-11T19:57:35.403" UserId="1225" />
  <row Id="22108" PostId="14188" Text="what flux are you using?" CreationDate="2011-05-11T19:58:57.073" UserId="411" />
  <row Id="22109" PostId="14189" Text="Chip Quik should deal with that, all the solder is melted at low temperature." CreationDate="2011-05-11T20:00:16.947" UserId="305" />
  <row Id="22110" PostId="13596" Text="It's a double precision float.  I don't think the accuracy of the multiply is the issue, because after the second regression analysis it is dead on.  If it was a precision issue, the second regression analysis would not create a better result." CreationDate="2011-05-11T20:03:30.967" UserId="1278" />
  <row Id="22111" PostId="14188" Text="Could it be that the pads extend too far under the chip?" CreationDate="2011-05-11T20:07:04.690" UserId="339" />
  <row Id="22112" PostId="14139" Text="RTL synthers are &quot;less rigorous&quot; than C compilers.  There is some latitude left to the synthesis implementation.  That's why it's a good idea to read the doc for the synther you plan on using.  For instance, Xilinx's synther is XST, and they have an XST User Guide that describes what design patterns create proper FSMs, how to avoid inadvertently creating latches, stuff like that." CreationDate="2011-05-11T20:12:32.250" UserId="1278" />
  <row Id="22113" PostId="14189" Text="@Leon, nice idea... if only it weren't so expensive. Student budgets... :(" CreationDate="2011-05-11T20:15:10.797" UserId="1225" />
  <row Id="22114" PostId="14184" Text="@endolith the fact that there is no standard naming convention was indeed the point of my answer..." CreationDate="2011-05-11T20:25:25.120" UserId="1438" />
  <row Id="22115" PostId="14189" Text="I think they'll send you a sample kit, enough for two or three QFPs." CreationDate="2011-05-11T20:35:00.723" UserId="305" />
  <row Id="22116" PostId="14185" Text="What do you understand it to mean?" CreationDate="2011-05-11T20:41:05.943" UserId="305" />
  <row Id="22117" PostId="14186" Score="2" Text="I think there is enough here to be acceptable on the site. Where to get them and quantity is localized shopping, but trying to find a component that meets specs is good questions" CreationDate="2011-05-11T20:44:05.150" UserId="319" />
  <row Id="22118" PostId="14151" Text="I don't think you are understanding what I am saying - just buy an ATMEL 328P. Download your code to it through the arduino, and then take it out and place it on a breadboard. You will now have 2 328Ps, one of which will remain in the arduino while the other will sit on his project breadboard." CreationDate="2011-05-11T20:44:55.557" UserId="4201" />
  <row Id="22119" PostId="14189" Text="@Leon, yeah, but you need to pay for it..." CreationDate="2011-05-11T20:50:59.003" UserId="1225" />
  <row Id="22120" PostId="14186" Score="1" Text="I agree, you're not asking about the lowest price for a specific item but this is a bad question period.  You're asking us to find a device ready for purchase that meets an odd mixture of vague requirements (cellular radio for an unknown network and has at least one DIO pin for a button?  Seriously?) at an entirely arbitrary price point.  No, sorry, there is no single black-box solution you can buy to make this happen. Ask a more specific question like 'Where can a hobbyist like me find cellular radios for either GSM or CDMA networks?'  THAT's a good question." CreationDate="2011-05-11T20:51:52.293" UserId="249" />
  <row Id="22121" PostId="14189" Text="They sent mine free. I subsequently bought the full kit." CreationDate="2011-05-11T21:01:42.220" UserId="305" />
  <row Id="22122" PostId="14166" Text="@Madman I suppose there is; I picked the value by starting large and going down until it started to turn on at roughly the right times, but perhaps it's staying off for too long." CreationDate="2011-05-11T21:33:56.003" UserId="1951" />
  <row Id="22123" PostId="14192" Score="1" Text="Okay - a side question. I have a 350mA power LED, and it requires a good heatsink for it to stay cool, yet a 1A diode doesn't. The die of my LED is about the same size of the diode, maybe a bit less. Why does it require such cooling?" CreationDate="2011-05-11T22:03:42.890" UserId="1225" />
  <row Id="22124" PostId="13440" Text="Thank you reemrevnivek - microcontroller architecture is definitely on the same topic" CreationDate="2011-05-11T22:18:25.963" UserId="3972" />
  <row Id="22125" PostId="14186" Text="Edited.      _____________" CreationDate="2011-05-11T22:42:59.923" UserId="1346" />
  <row Id="22126" PostId="14100" Text="A [Gaussian](http://en.wikipedia.org/wiki/Gaussian_filter) fits the requirement for a nonnegative impulse response, but it's not much of a brick wall. On the other hand, Butterworth, Bessel, and Chebyshev have sinc-like oscillations in their impulse response, leading to overshoot. Of those the [Bessel filter](http://en.wikipedia.org/wiki/Bessel_filter) has the least overshoot since it has a nearly flat group delay (linear phase) in the passband." CreationDate="2011-05-11T23:11:47.190" UserId="721" />
  <row Id="22127" PostId="14192" Score="2" Text="light emitters always have a higher voltage drop at a given current, therefore, dissipate more power at the same current." CreationDate="2011-05-11T23:46:59.610" UserId="740" />
  <row Id="22128" PostId="14196" Score="1" Text="There are actually purpose-built circuit board washers used to clean excess flux.  An example can be seen at this [link](http://www.stoelting.com/cleaning-equipment/electronic-assembly-cleaning-systems/batch-stencil-cleaner.php)" CreationDate="2011-05-11T23:59:33.587" UserId="529" />
  <row Id="22129" PostId="14199" Text="+1 for LaTeX-y skills. :p" CreationDate="2011-05-12T00:19:44.413" UserId="1938" />
  <row Id="22130" PostId="13957" Text="Here's an interesting link I came across http://www.freelists.org/post/si-list/Fr-4-Er-variation that should help with this. " CreationDate="2011-05-12T00:36:45.440" UserId="2148" />
  <row Id="22131" PostId="14156" Text="The LD1117 is the only thing involved when too much current is drawn. The MCU may act strangely, but it shouldn't be affected much." CreationDate="2011-05-12T01:17:31.130" UserId="1374" />
  <row Id="22132" PostId="14100" Text="Other than the Gaussian, these filters are causal. For offline processing, a linear phase NNFIR (nonnegative FIR) would work well, or you can cancel the phase distortion of a causal recursive filter by using the *filtfilt* technique.... Of course you still need a way to design an NNIR LPF to avoid overshoot/undershoot. Suggestions anyone? References?" CreationDate="2011-05-12T01:55:11.930" UserId="721" />
  <row Id="22133" PostId="14203" Text="More Flux always gets +1." CreationDate="2011-05-12T02:15:20.533" UserId="3624" />
  <row Id="22134" PostId="14207" Text="There is one of those sites that will serve bogus results with a pdf mime type, just to spam the results you are getting.  But Google works well enough that the spam results won't be on the first page of results." CreationDate="2011-05-12T03:01:53.227" UserId="411" />
  <row Id="22135" PostId="14084" Text="Thanks. This should prove useful in the unfortunate event that I need to manually interface with the INSTEON protocol. ;)" CreationDate="2011-05-12T04:05:47.133" UserId="3353" />
  <row Id="22136" PostId="14132" Text="Good to know. If I implement LED lights, I'll probably be using this or a similar method." CreationDate="2011-05-12T04:06:37.150" UserId="3353" />
  <row Id="22137" PostId="14188" Text="Oh come on. I've got a Aoyou 968 too. I wouldn't call it 'nothing fancy'. 'Nothing Fancy' would be a trash shack firestarter." CreationDate="2011-05-12T04:38:36.423" UserId="746" />
  <row Id="22138" PostId="14204" Score="1" Text="+1 because for old parts, they are a good source (and way better than other data sheet archives and whatnot). They also give hints about second source manufacturers. For current products, the manufacturer is the place to get reliable information at." CreationDate="2011-05-12T05:13:19.710" UserId="930" />
  <row Id="22139" PostId="14207" Score="1" Text="+1 for googlehacks. Also very (!) helpful in google: add the phrase site:manufacturer.com, for example: 74LS04 datasheet filetype:pdf site:nxp.com&#xA;" CreationDate="2011-05-12T05:14:14.733" UserId="930" />
  <row Id="22140" PostId="14207" Text="@zebonaut: that's another useful one for sure, though I tend to not use it for datasheets." CreationDate="2011-05-12T05:16:28.217" UserId="2288" />
  <row Id="22141" PostId="14202" Score="1" Text="For one thing, use the Optimize Google extension to filter out the sites you don't want in your search results." CreationDate="2011-05-12T05:22:07.533" UserId="142" />
  <row Id="22142" PostId="14156" Text="Ah, sorry, I misread the question." CreationDate="2011-05-12T05:29:26.860" UserId="339" />
  <row Id="22143" PostId="14192" Score="1" Text="Also, FYI, high power diodes *do* require heatsinking too, it's just most smaller diodes get sufficient heatsinking through the leads. Ever wonder why the legs on something like a 1N4001 are so thick? now you know." CreationDate="2011-05-12T05:29:59.260" UserId="1374" />
  <row Id="22144" PostId="14205" Score="1" Text="Compressed air is also a great way to dry wet, populated PCBs. Of course, it does require a compressor, but if you already have one, it's a great way to get everything really dry." CreationDate="2011-05-12T05:34:31.490" UserId="1374" />
  <row Id="22145" PostId="14197" Score="1" Text="Note: Do **not** so this in a dishwasher that you also use for food." CreationDate="2011-05-12T05:35:14.670" UserId="1374" />
  <row Id="22146" PostId="14205" Score="1" Text="Also, interesting fact: *Pure* water is actually a *very good* insulator (&gt;18MΩ/cm, better than mineral oil, IIRC). However, pure water will actually fairly aggressively scavenge ions from whatever container it is in, so it is very hard to *keep* it pure." CreationDate="2011-05-12T05:38:36.293" UserId="1374" />
  <row Id="22147" PostId="14190" Text="Another option for dealing with solder-bridges under the IC is to heat the chip and solder till ALL the pads melt, and then nudge the chip gently. It should move, and spring back into position, due to solder surface tensions, and with any luck, this should break or disrupt any connections under the device. (Note: this requires additional flux to work properly, solder doesn't have much surface tension when it is oxided over.)" CreationDate="2011-05-12T05:44:55.107" UserId="1374" />
  <row Id="22148" PostId="14188" Text="@Ducksauz It's certainly no Weller but does the job." CreationDate="2011-05-12T06:35:40.360" UserId="1225" />
  <row Id="22149" PostId="14203" Text="What flux should I use? My supplier has about 10 million different types." CreationDate="2011-05-12T06:36:09.020" UserId="1225" />
  <row Id="22150" PostId="14212" Text="That's interesting. They use a hatched ground plane; is the board hand soldered?" CreationDate="2011-05-12T06:44:18.580" UserId="1225" />
  <row Id="22151" PostId="14202" Score="2" Text="Also, don't forget AdBlock Plus, don't see any ads on those sites ;)." CreationDate="2011-05-12T06:45:17.583" UserId="1225" />
  <row Id="22152" PostId="14212" Text="I don't know, but I'd hope not since we're generally purchasing these 30-40 at a time.  They're keyboards without a lot of components (couple dozen resistors, a couple of ICs and other misc parts), so I suppose it's possible.  They seem to have other oddities as well such as the blackened traces and black splotches on some of them (both visible in the second photo above).  The problems with the plated holes is driving us nuts." CreationDate="2011-05-12T06:53:00.970" UserId="4227" />
  <row Id="22153" PostId="3779" Text="@FakeName, how do you not give a schematic for a dev board? Isn't that the point? Reference design?" CreationDate="2011-05-12T09:21:37.460" UserId="230" />
  <row Id="22154" PostId="3779" Score="1" Text="@Kortuk - See why I was irritated about it? What's going on is the guy running KNJN came up with some clever way to program a FPGA (normally takes JTAG) using only the TX and RX lines of a serial port. Apparently he considers it a trade secret or something. I still have the e-mails where I asked for the schematic, and he told me no, I replied saying I would reverse it by taking one of the boards apart, and he went on about not releasing it. I wound up not bothering (easier to roll my own, with a normal JTAG), but that's the attitude KNJN takes for supporting their products... " CreationDate="2011-05-12T09:39:48.173" UserId="1374" />
  <row Id="22155" PostId="14203" Text="I use Warton Metals rework jelly: http://www.warton-metals.co.uk/re-work.html It's superb stuff!" CreationDate="2011-05-12T09:44:12.307" UserId="305" />
  <row Id="22156" PostId="3779" Score="1" Text="Basically, he doesn't provide a complete schematic for **any** of his boards (even the ones that are just ADCs!), and provides almost NO documentation aside from pinout for most of them. Furthermore, most of the demo code is available **only** once you buy the products. " CreationDate="2011-05-12T09:49:33.213" UserId="1374" />
  <row Id="22157" PostId="14212" Text="Which vias are failing? The soldermask covered ones, or the little square 4-via arrangements?" CreationDate="2011-05-12T09:52:12.980" UserId="1374" />
  <row Id="22158" PostId="3779" Text="@FakeName, how people stay in business sometimes astounds me." CreationDate="2011-05-12T12:17:31.113" UserId="230" />
  <row Id="22159" PostId="14186" Text="@AngryEE it is a perfectly acceptable answer to tell him that a device doesn't exist and tell him an approach to take." CreationDate="2011-05-12T12:32:04.657" UserId="319" />
  <row Id="22161" PostId="14189" Text="@Leon ChipQuik looks like great stuff!  I just watched a video where they used it and was very intrigued." CreationDate="2011-05-12T13:03:48.737" UserId="2288" />
  <row Id="22162" PostId="14208" Text="Digikey and Mouser rule!" CreationDate="2011-05-12T13:09:15.567" UserId="330" />
  <row Id="22165" PostId="14205" Text="@Fake Name  You have to be a bit careful with compressed air, as it can create static zaps.  Still, it can be quite useful." CreationDate="2011-05-12T13:20:56.720" UserId="3624" />
  <row Id="22166" PostId="14197" Text="@Fake Name  Doing this once in a while isn't too bad.  But I do run the dishwasher empty after, to clean it out." CreationDate="2011-05-12T13:21:57.313" UserId="3624" />
  <row Id="22167" PostId="14203" Text="Those flux-dispensing pens are the most convenient for clearing bridged pins." CreationDate="2011-05-12T13:42:58.090" UserId="411" />
  <row Id="22169" PostId="14212" Text="@Thomas: Is anything in China *not* hand-soldered?" CreationDate="2011-05-12T13:58:06.547" UserId="142" />
  <row Id="22170" PostId="14223" Score="2" Text="@petergassner, you seem to be a user of consumer electronics, not someone designing electronics. I do not think this question will mesh well on this site." CreationDate="2011-05-12T13:58:33.073" UserId="230" />
  <row Id="22171" PostId="14212" Text="@endolith, For small production runs this is probably hand soldered, but I'm working with a manufacturer for a run of 100 boards, and that will be done by pick and place with only the final through hole stuff being hand soldered." CreationDate="2011-05-12T14:07:50.857" UserId="1225" />
  <row Id="22172" PostId="14224" Text="@jsolarski : I have been edited my post and include something like what you mentioned before. " CreationDate="2011-05-12T14:10:31.013" UserId="4234" />
  <row Id="22173" PostId="14221" Text="I am not a well versed C  so i don't usually use pointers, but I do know that ADC10SA has to be an address " CreationDate="2011-05-12T14:27:16.277" UserId="2060" />
  <row Id="22174" PostId="14201" Text="I like the wireless router idea! Do you have any suggestions on how to hack the router into accepting a 1 bit digital input?" CreationDate="2011-05-12T15:07:34.590" UserId="1346" />
  <row Id="22175" PostId="14225" Score="7" Text="@NathanVagle, can you take the time to fix up the formatting a bit. Also, can we have links to the exact products you are using. Third, can you give us some scope traces and such from what the signals are doing?" CreationDate="2011-05-12T15:08:49.480" UserId="230" />
  <row Id="22176" PostId="14197" Text="I wouldn't use the dishwasher for cleaning flux or anything similar - just the grease and dirt in your keyboard. I don't see a problem with this, especially since it isn't a regular event. " CreationDate="2011-05-12T15:35:19.723" UserId="4201" />
  <row Id="22177" PostId="14006" Text="Thanks for your answer. I have since worked out that the XBee works OK in that mode with an earlier version of the Freetronics Board the Twenty-Ten. It's connected using a Sparkfun XBee shield.  Now the issue is .. why would it work with the Twenty-Ten and not the Eleven!! They are supposed to be basically the same thing... maybe something to do with the power draw as you suggest." CreationDate="2011-05-12T15:40:00.430" UserId="4133" />
  <row Id="22178" PostId="13960" Text="Thanks for your answer. I did run out and get some resistors to try this solution but it still didn't work.I have since worked out that the XBee works OK in that mode with an earlier version of the Freetronics Board the Twenty-Ten. It's connected using a Sparkfun XBee shield.  Now the issue is .. why would it work with the Twenty-Ten and not the Eleven!! They are supposed to be basically the same thing..." CreationDate="2011-05-12T15:40:27.137" UserId="4133" />
  <row Id="22179" PostId="14220" Text="I had missed that it was a clock output. Glitches are almost certainly the &quot;major issue&quot;. I was thinking that one of the answers had a more optimal logic solution (fewer gates)." CreationDate="2011-05-12T15:58:53.150" UserId="638" />
  <row Id="22180" PostId="14185" Text="My question is; why do you care what _my_ concept is? Surely you want the standard definition. @Cell-o, questions like this and [the reverse recovery time in a diode](http://electronics.stackexchange.com/questions/13912/what-is-the-reverse-recovery-time-in-diode) are best answered in text books on semiconductors. Have a browse in a bookshop with a technical section, possibly near a university, if you can't see what you want on semiconductor physics on amazon or similar. [Other suggestions on this site](http://electronics.stackexchange.com/questions/616/basic-electronics-book)" CreationDate="2011-05-12T16:07:41.550" UserId="2110" />
  <row Id="22181" PostId="1759" Text="Prices have now fallen - $25 for the 10cmx10cm and $10 for the 5cmx5cm. I've used Seeed before and can recommend them, but shipping takes quite a long time, the only disappointment." CreationDate="2011-05-12T17:49:51.760" UserId="1225" />
  <row Id="22182" PostId="14226" Text="Given how relatively cheap it is, I'd stock a whole bunch!" CreationDate="2011-05-12T17:55:04.673" UserId="3308" />
  <row Id="22183" PostId="14232" Text="+1. I'm not a native English speaker, but this is exactly what I would say, too. Using data sheet terms, pinch off translates to gate-source threshold voltage, V_GS,th" CreationDate="2011-05-12T18:48:02.630" UserId="930" />
  <row Id="22184" PostId="13551" Text="@Madmanguruman: i finally got my hands on a PCI graphics card. i tried the steps given on the links, but nothing :( i guess the chip is fubar." CreationDate="2011-05-12T19:58:59.630" UserId="2296" />
  <row Id="22185" PostId="10974" Text="@markrages - in our case, I wouldn't rule out suspicion of the board house, or the outside layout guy, or simple paranoia on the engineer's part. He used to verify the Gerber files against the schematics by hand before sending to layout." CreationDate="2011-05-12T20:06:00.147" UserId="259" />
  <row Id="22186" PostId="3779" Text="Exactly. Horrible, do not buy a KNJN. I ended up switching boards." CreationDate="2011-05-12T20:18:23.660" UserId="876" />
  <row Id="22187" PostId="10974" Text="I was burnt by layer numbering today, make sure that your &quot;1&quot; can't be mistaken as a marker for pin 1 on some nearby connector" CreationDate="2011-05-12T20:19:28.500" UserId="566" />
  <row Id="22188" PostId="14201" Text="A lot of them already have it present in some fashion (for instance, the reset button on some is a DIO input) but I don't really know how to access it in Linux is the thing.  I can try to look into it a bit more." CreationDate="2011-05-12T20:28:09.533" UserId="249" />
  <row Id="22189" PostId="1151" Text="Don't use tinsnips - crap goes everywhere and you ruin the edge of the board." CreationDate="2010-06-17T06:50:43.410" UserId="1307" />
  <row Id="22190" PostId="1151" Text="Have you considered a Dremel tool? Or is it not a fine enough cut?" CreationDate="2009-12-21T10:51:17.703" UserId="368" />
  <row Id="22191" PostId="1151" Text="I've used a Dremel tool before with very nice results. Be aware though that you'll generate a lot of heat, the cutting discs are fairly brittle and the Dremel is a hand tool, so very long cuts are likely to increase your chances of busting the disc. Also, as mentioned up top by @jluciani, this cutting process will produce a lot of glass fibre dust which you absolutely should not breathe in. A conventional dust mask probably won't cut it for protection either as the dust is extremely fine." CreationDate="2010-01-05T23:30:30.010" UserId="295" />
  <row Id="22192" PostId="14236" Score="2" Text="Some may feel otherwise, but currently we accept homework questions. If you think it is a poor one please feel free to ask the user to improve it." CreationDate="2011-05-12T20:40:13.497" UserId="230" />
  <row Id="22193" PostId="14239" Text="85A, ouch... So how likely is it was fried by a stalled motor? I'm thinking another failure now." CreationDate="2011-05-12T20:53:48.480" UserId="1225" />
  <row Id="22194" PostId="14239" Score="1" Text="Maybe the catch diode failed first and overvolted the FET?  Don't read too much into ID numbers, they are fantasy.  Design with RDS(on) instead." CreationDate="2011-05-12T21:01:02.380" UserId="411" />
  <row Id="22195" PostId="14239" Text="@markrages Yeah I noticed that diode went pop at first, powered it up and the fet started blowing smoke, but the motor still runs (it's just uncontrollable, the fet is shorted.) " CreationDate="2011-05-12T21:14:24.517" UserId="1225" />
  <row Id="22196" PostId="14238" Text="Ok, so i just have to swap the phase angle for $U_L$ with the one from $U_C$. Thought that $\phi_(Uc) = \phi_(ic) - 90°$" CreationDate="2011-05-12T21:14:31.880" UserId="3817" />
  <row Id="22197" PostId="14242" Text="This type of question is not welcome here. It will probably be closed as subjective and argumentative. See [here](http://meta.electronics.stackexchange.com/questions/428/brainstorming-in-the-form-of-a-question) for more information." CreationDate="2011-05-12T21:43:48.423" UserId="938" />
  <row Id="22198" PostId="14241" Text="Hi Dave. THanks for that. You've pretty much summarised exactly where I'm at with the problem. The nub of the issue for me seems to be that you dump your byte into SPDR and then wait for SPSR and SPIF to indicate that transmission is complete, as I understand it that's all the resolution you get." CreationDate="2011-05-12T21:54:34.107" UserId="4232" />
  <row Id="22199" PostId="14242" Score="4" Text="I very carefully examined the FAQ section before asking this question so if it falls under an unwelcome category, then I would suggest that be made explicitly clear in a highly visible place. That said, I don't agree that my question is 'poorly defined' or that I have 'little to no experience' in  problem domain. I asked a &quot;specific electronics design problem&quot;, namely a request for expert input on a project in the planning stage of development. If this is not suitable, then can you suggest a more appropriate form of the question?" CreationDate="2011-05-12T21:58:09.923" UserId="3174" />
  <row Id="22200" PostId="14160" Text="The newer Arduino boards (Uno and Duemilanove) use the ATMega328P rather than the 168 that the diecimila has. " CreationDate="2011-05-12T21:58:11.907" UserId="4201" />
  <row Id="22201" PostId="3779" Text="I'm still tempted to reverse engineer the programming interface out of spite, but I'm lazy, and it's a lot of work." CreationDate="2011-05-12T22:25:01.827" UserId="1374" />
  <row Id="22202" PostId="14238" Score="2" Text="@madmax, $\angle U_C = \angle I_C - 90^\circ$ and $\angle U_L = \angle I_L + 90^\circ$. However, $I_C \not= I_L$ since the capacitor is in parallel with a resistor. The phase of $U_C$ is determined by the parallel impedance $Z_C \parallel R$. If you need $I_C$ you can use the current divider rule or just calculate $\frac{U_C}{Z_C}$." CreationDate="2011-05-12T22:32:26.303" UserId="721" />
  <row Id="22203" PostId="14243" Text="Interesting idea, to just add an alternate set of connections to my existing ESC. That wouldn't have even occurred to me. It's easy enough to set up, so I'll try it and see what happens. Good point about the number of poles, I will experimentally investigate that at the same time." CreationDate="2011-05-12T22:45:21.787" UserId="4217" />
  <row Id="22204" PostId="14242" Score="1" Text="Its a decent question, but it is subjective. It is similar to asking a question asking what the best approach to writing a program to stream a web cam. Some might say you should go with a web programming environment like flash while others can offer a solution using c ++. And then another person might not talk about programming language and just talk about communication protocols. Give us more detail off what you want and then we can help." CreationDate="2011-05-12T23:10:34.047" UserId="319" />
  <row Id="22205" PostId="14242" Text="Your question is more suited to the diydrones.com forum. Try there." CreationDate="2011-05-12T22:14:25.547" UserId="4232" />
  <row Id="22206" PostId="14106" Text="@reemrevnivek - Yes, 8 bits of brightness per color on the RGB LEDs. Sorry I should have been more clear. In other words it takes 3 BYTES or 24 bits for every single RGB LED. " CreationDate="2011-05-12T23:43:25.777" UserId="3407" />
  <row Id="22207" PostId="13534" Text="Vicky - Your question is somewhat unclear.  I have tried to help out by converting the screenshot to more readable text (use the command-line 'dir' utility in the future, please!), but you still have a lot of extraneous information without critical context that would identify the bootloader contents and the settings that need to be changed for different PICs." CreationDate="2011-05-12T23:55:27.047" UserId="857" />
  <row Id="22208" PostId="13534" Text="If [Steve's answer](http://electronics.stackexchange.com/questions/13534/burning-a-bootloader-into-pic-mcu-which-file-should-i-choose/13538#13538) solved your problem, you should mark it as the solution.  If you found the answer independently, please feel free to post it and accept your own answer.  If you still have not found the solution, please add any new information you've learned to the question to increase your chances of getting an answer.  Thanks!" CreationDate="2011-05-12T23:58:01.927" UserId="857" />
  <row Id="22209" PostId="14249" Score="1" Text="Is there any reason why would a fuse with higher voltage rating be a bad replacement for a fuse with lower voltage rating? From what I've read (do correct me if my sources are wrong), the voltage rating of the fuse shows the highest voltage on which the fuse is guaranteed to be able to open the circuit." CreationDate="2011-05-13T00:05:35.860" UserId="1240" />
  <row Id="22211" PostId="14248" Score="4" Text="Is that mF or $\mu F$? The ones with higher voltage will probably be larger, so space could be an issue, especially if the capacitor is in fact 470 mF." CreationDate="2011-05-13T00:05:46.610" UserId="1240" />
  <row Id="22212" PostId="14007" Text="+1 I've ran into the distance factor a few times." CreationDate="2011-05-13T00:09:51.503" UserId="4223" />
  <row Id="22213" PostId="14249" Text="@AndrejaKo, Fuse voltage rating is fine also. I assumed the advice about matching rating had been received because increasing the current rating of a fuse is poor practice. I will edit that in." CreationDate="2011-05-13T00:11:34.857" UserId="230" />
  <row Id="22214" PostId="14212" Text="@Fake Name, the ones failing are the smaller ones attached to the traces which appear &quot;discolored&quot; in the photos (sort of a white/blue instead of the usual copper/green color that most of them have." CreationDate="2011-05-13T00:42:06.283" UserId="4227" />
  <row Id="22215" PostId="14215" Text="The board are mounted on brushed aluminum plates with sort sort of laminate over it.  The full assembly gets bolted into a steel kiosk enclosure bolted to a wall, so there shouldn't be much movement for the board once it's in place.  It's a possibility though.  We'd considered that possibly the frame was distorted or bent during installation, but even the hand-installed units have been failing from time to time." CreationDate="2011-05-13T00:46:05.140" UserId="4227" />
  <row Id="22216" PostId="14214" Text="Yes, it's a two-layer board, fairly basic in design from what I can tell as an amateur.  Unfortunately we purchase the assembled keyboards, so I'm not sure whether the manufacturer we get the keyboards from actually manufactures the boards themselves or if they outsource to someone else." CreationDate="2011-05-13T00:50:46.547" UserId="4227" />
  <row Id="22217" PostId="14241" Text="@jamesotron: I see.  My only other suggestion would have been to tie data out to an input pin, and then have an ISR toggle LI any time a `counter % 31 == 0`.  But if you're going through that hassle, that defeats the point of using SPI -- you might as well just bitbang an output pin.  I actually don't see why SPI is any more convenient.  You're forced to jump through hoops that, in the end, result in less manageable code... and you haven't gained any I/O by using SPI." CreationDate="2011-05-13T00:57:18.917" UserId="2288" />
  <row Id="22218" PostId="14241" Text="@dave mainly I'm trying to get a speed gain by using SPI because the MCU will handle clock generation and things faster than I can do it in software." CreationDate="2011-05-13T01:06:37.043" UserId="4232" />
  <row Id="22219" PostId="13960" Text="From the schematics [Eleven](https://github.com/freetronics/Eleven/raw/6b156d8878ddad8dd678f38a1216415c642d213c/Eleven.pdf) and [Ten](https://github.com/freetronics/TwentyTen/raw/eea66705fd64c000046d528d24947bf786b82698/docs/TwentyTen_sch.pdf) - the reset circuit is different because the FT232 has been replaced by the AtMega8U2. Also, it seems on the Eleven the CTS triggers the reset, while on the Ten its DTR. The two are notable different. Have a look at the schematics. Is bridge SJ1 (used to enable/disable the serial/programming reset) open or closed on both?" CreationDate="2011-05-13T01:07:06.013" UserId="1612" />
  <row Id="22220" PostId="13960" Text="One more thing you can try is to use softserial on different AtMega pins - this would eliminate any issues with the boards serial implementation." CreationDate="2011-05-13T01:13:51.083" UserId="1612" />
  <row Id="22221" PostId="13960" Text="Last one - have a look here: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1217201592/0" CreationDate="2011-05-13T01:20:22.033" UserId="1612" />
  <row Id="22222" PostId="14243" Text="@Doug McClean - just make sure you don't try to drive the motor with both the ESC and whatever else you devise, at the same time. There will almost certainly be smoke." CreationDate="2011-05-13T02:15:24.103" UserId="740" />
  <row Id="22223" PostId="14158" Text="Keep in mind etching chemicals are 1) nasty and 2) have to be disposed of properly." CreationDate="2011-05-13T02:35:57.310" UserId="206" />
  <row Id="22224" PostId="9276" Score="1" Text="It is not illegal to sell such a power supply.  Your local electrical inspector may not approve the installation which can lead to issues from your insurance company but those are separate issues from the legality of selling the product.  It should also be noted that the NEC is not written in stone but rather is often enforced in various degrees and forms based on the locale.  Ultimately the way the NEC code is written it is entirely up to the local authority to determine its application.  That however, does not impact legality of sale of any product.  " CreationDate="2011-05-13T03:00:59.023" UserId="1438" />
  <row Id="22225" PostId="8051" Score="1" Text="A UL certification (or similar), in general, is not required by law.  It may be required by the nature of your market, such as a public school.  It may result in the loss of an insurance pay out in the event of a fire, even in your home. etc. A UL certification &quot;gets you in the door&quot; in some markets and &quot;covers your liability&quot; in almost all instances, but it is not legally required in the general case.  An FCC part 15 certification, if required by your device, is legally mandatory if the product is sold as an end user device." CreationDate="2011-05-13T03:07:26.350" UserId="1438" />
  <row Id="22226" PostId="8051" Text="An FCC part 15 certification may not be required if your product is being sold under certain situations that do not constitute end user use.  For instance many/most vendor produced development boards are not and don't need to be FCC certified." CreationDate="2011-05-13T03:08:59.950" UserId="1438" />
  <row Id="22227" PostId="8042" Text="In some regards EU certification is actually tougher than the US requirements, such as mandated RoHS compliance." CreationDate="2011-05-13T03:11:50.290" UserId="1438" />
  <row Id="22228" PostId="14214" Text="The manufacturer has a problem and they need to take care of it.  It seems like a combination of poor pcb manufacturing and poor design to me.  They can get a more expensive, better quality manufacturer, or they redesign to use larger vias and annular rings.  Really, there is plenty of room on that board, so why the tiny vias?" CreationDate="2011-05-13T03:26:34.173" UserId="411" />
  <row Id="22229" PostId="14250" Score="11" Text="Beautiful CAD output!" CreationDate="2011-05-13T03:28:50.430" UserId="411" />
  <row Id="22230" PostId="13276" Text="@Vilive, please follow through with what @tyblu is asking for, flag for moderator attention when you have updated it and we can look at reopening it." CreationDate="2011-05-13T03:29:57.350" UserId="230" />
  <row Id="22231" PostId="2461" Text="Another reason to consider something other than the OP's idea is safety. Maybe you're not comfortable running 115VAC, 10A, into your homemade clock. I wasn't, so I used a 6VAC wall wart run into a step-up transformer." CreationDate="2011-05-13T03:30:21.890" UserId="906" />
  <row Id="22233" PostId="14241" Text="@jamesotron but it's not like you need things clocked precisely.  The beauty of something like SPI is that the data is clocked by edge transitions, but it's not like RS232, where the timing needs to be precise.  You should be able to clock out the 31 bits as fast as you can go.  Reset LI, loop over each bit and strobe CI each time, set LI.  Maybe I'm missing something, but it seems that such an approach will work fine." CreationDate="2011-05-13T05:04:53.177" UserId="2288" />
  <row Id="22234" PostId="14225" Text="@Nathan, you can edit your post to improve it, When you have done this just flag for moderator attention and ask for us to review your changes. If they are satisfactory we will reopen the question. Please do not take a closed question as a sign that you are not welcome, this is a good question, we just do not have enough to help you yet." CreationDate="2011-05-13T05:45:41.067" UserId="230" />
  <row Id="22235" PostId="3779" Text="@samoz, if you changed products does that make this question a bit mute? You can update it with why you chose to move to a new product and accept that so others might learn from your pain. We can also just close the question and remove it as there is no real way to resolve it. I would prefer the former so that others might learn from your strife." CreationDate="2011-05-13T05:48:46.350" UserId="230" />
  <row Id="22236" PostId="14159" Text="@rfusca sounds like the perfect opportunity to learn SMD soldering!  Watch this helpful video to get a head start: http://store.curiousinventor.com/guides/Surface_Mount_Soldering/101/" CreationDate="2011-05-13T06:01:31.623" UserId="2288" />
  <row Id="22237" PostId="14252" Score="4" Text="+1 for this excellent answer. Here's another source about how to determine the values of an RC snubber combination across a diode: http://www.ridleyengineering.com/snubber.htm" CreationDate="2011-05-13T06:32:36.320" UserId="930" />
  <row Id="22239" PostId="14248" Text="I agree, and to elaborate: 1 mF is 1000 μF, so a 470 mF capacitor is HUGE. mF is pronounced milifarad and μF is pronounced microfarad." CreationDate="2011-05-13T07:55:14.430" UserId="1675" />
  <row Id="22240" PostId="14238" Text="When i calculate  $\frac{U_C}{Z_C}$, i get the same value and phase as $I_L$. Although i use $U_C$ and Z without $\omega L$. $I_C$ should be 18.5 A." CreationDate="2011-05-13T08:38:39.910" UserId="3817" />
  <row Id="22241" PostId="14160" Text="I'm going this route right now. I got myself a bunch of attiny45s (8 pin DIP is enough for my current project) and a USD13 avrdude-compatible programmer off eBay. I breadboarded the whole thing without using a dev board (not Arduino for me, but close), then i laid out the schematic in eagle and sent it off to seeedstudio's FusionPCB service. Fingers crossed! The whole thing has been an amazing learning experience." CreationDate="2011-05-13T08:48:55.870" UserId="1802" />
  <row Id="22242" PostId="14256" Text="I'd guess that the charger has a switched mode power supply and that the sound you're hearing is made by vibrations of the coils. It's a common problem and there's no easy solution for a consumer." CreationDate="2011-05-13T09:06:27.010" UserId="1240" />
  <row Id="22243" PostId="14248" Score="2" Text="very, very similar question to http://electronics.stackexchange.com/questions/13091/high-voltage-capacitor-in-a-low-voltage-system/13093#13093&quot;&gt;13091" CreationDate="2011-05-13T09:43:31.767" UserId="740" />
  <row Id="22244" PostId="14257" Text="High dielectic constant capacitors can squeak too, due to the piezoelectric effect." CreationDate="2011-05-13T09:54:46.800" UserId="2110" />
  <row Id="22246" PostId="14260" Text="Indeed, looking at the datasheet again, it requires negative supply." CreationDate="2011-05-13T10:29:36.343" UserId="3564" />
  <row Id="22247" PostId="14260" Text="@Czajnik Sorry to leave your comment hanging! I added another answer." CreationDate="2011-05-13T10:34:52.857" UserId="4129" />
  <row Id="22248" PostId="14260" Text="@Bitrex No worries :) BTW, see the appnote from National above - it describes how to use DAC-08 with a single power supply." CreationDate="2011-05-13T10:39:41.600" UserId="3564" />
  <row Id="22249" PostId="14260" Text="Hmmm... That's [single supply] starting to get as bulky as an R/2R ladder.   Maybe I'll just scrap the DAC and stick to a ladder - it's so much simpler..." CreationDate="2011-05-13T10:52:05.107" UserId="4245" />
  <row Id="22250" PostId="14250" Score="1" Text="If I hadn't known that was a circuit diagram when I started looking at that it would have taken me a minute to figure out what it was." CreationDate="2011-05-13T11:00:09.237" UserId="3847" />
  <row Id="22251" PostId="14260" Text="@Matt Jenkins perhaps you should look for a single-supply DAC, and DAC-08 is way old btw. What are you trying to build?" CreationDate="2011-05-13T11:07:39.863" UserId="3564" />
  <row Id="22252" PostId="14260" Text="A DAC-08 is what I have to hand - I ripped it from an old UPS.  I'm not trying to build anything - just experimenting with it." CreationDate="2011-05-13T11:08:42.017" UserId="4245" />
  <row Id="22253" PostId="14159" Text="@Dave - Thanks, I've watched that and about a million other tutorials on it lol.   I've decided to do it, I've got some SMD parts on the way and so then I'll etch some simpler circuits to practice on." CreationDate="2011-05-13T12:52:16.910" UserId="3778" />
  <row Id="22254" PostId="14262" Score="1" Text="While the answer by David Kessner is fantastic, for more detailed guidance you might want to consult the following [Articles by Keith Armstrong, free registration required](http://www.compliance-club.com/KeithArmstrong.aspx) and his book, [EMC for Printed Circuit Boards by Keith Armstrong](http://www.emcacademy.org/books.asp)" CreationDate="2011-05-13T15:40:15.550" UserId="2110" />
  <row Id="22255" PostId="14258" Text="Triangle waveform or sawtooth?" CreationDate="2011-05-13T15:43:33.450" UserId="142" />
  <row Id="22256" PostId="3299" Text="http://electronics.stackexchange.com/questions/616/basic-electronics-book   http://amasci.com/miscon/elect.html" CreationDate="2011-05-13T15:51:31.883" UserId="142" />
  <row Id="22257" PostId="14267" Text="http://en.wikipedia.org/wiki/Embedded_C%2B%2B" CreationDate="2011-05-13T15:54:30.447" UserId="566" />
  <row Id="22258" PostId="14267" Text="@Joby Taffey: I guess I edited my post to omit mention that the creator of C++ wasn't keen on an embedded subset; I'm aware that there were efforts, but by my understanding they hadn't really gotten all that far.  I do think there's would be definite use for a standardized language which would be amenable to 8-bit processors, and features such as I described above would seem useful on any platform.  Have you heard of any languages offering things like #3 above?  It would seem very useful, but I've never seen any language offer it." CreationDate="2011-05-13T16:05:25.267" UserId="3123" />
  <row Id="22259" PostId="9276" Text="In Canada, the CEC is universally enforced, and special inspection only applies to &quot;limited quantities&quot; of equipment. It's important to note that the end user is responsible for getting the special inspection if the product isn't marked, which isn't cheap. I've revised my answer accordingly." CreationDate="2011-05-13T16:34:13.437" UserId="1293" />
  <row Id="22261" PostId="14268" Score="2" Text="It's most likely OK, but you provided almost no information about the battery and the charger, so we can't give you a good answer." CreationDate="2011-05-13T11:24:28.970" UserId="1240" />
  <row Id="22262" PostId="14268" Text="Thanks AndrejaKo " CreationDate="2011-05-13T12:14:15.210" />
  <row Id="22263" PostId="14268" Score="1" Text="Please move the question to electronics.SE. Also describe your components in more detail. A solar charging system consists of at least three components: solar panel - DC/DC charger - battery. Now I guess your battery is lead 5 Ah (not amp), 12V. I also guess your charger is 12 Ampere, making it about 100W max. That would require about 1 sq. meter of area to harvest. Do you have that? Also: every charger is able to damage any battery if configured wrong. A 1 ampere charger can damage a 120 Ah battery if applied wrongly. A 100 ampere charger might be fine with a 5 Ah battery if done right. " CreationDate="2011-05-13T12:38:58.680" />
  <row Id="22264" PostId="14268" Score="1" Text="As Posipet says, you probably mean Ah not A. 5A is unbelievably high for a consumer-grade solar lead-acid battery charger. If worried about current and the battery can't be charged at more than 5A, fit a 5A fuse in the charging circuit. " CreationDate="2011-05-13T13:33:42.033" UserId="2191" />
  <row Id="22265" PostId="14239" Score="1" Text="I agree with @markrages. These sorts of FETs are hard to kill by current, and much easier to kill by avalanche voltage. You may want to look into a more robust clamp diode for the motor to prevent this sort of damage from happening again. Is that 1k gate resistor in the picture still good? If not, the MOSFET driver may also be damaged." CreationDate="2011-05-13T16:51:13.667" UserId="1293" />
  <row Id="22266" PostId="14252" Score="2" Text="It's fairly common to see capacitors across high-frequency rectifier diodes in power supplies, especially at higher voltages (48V or higher) where you can't get good Schottky rectifiers . The main purpose for the capacitors is to soften the commutation, reducing the amount of EMI generated." CreationDate="2011-05-13T16:57:18.510" UserId="1293" />
  <row Id="22267" PostId="14269" Text="That is an excellent point to bring up, but his cap is rated in mF (!!), so I doubt this is a high-performance ceramic chip capacitor." CreationDate="2011-05-13T17:16:30.047" UserId="1278" />
  <row Id="22268" PostId="14266" Text="It are indeed the clock signals for ADC's. The crystal oscillator inputs resides at the analog part of the chip. I have chosen not to use an external crystal but providing an external clock signal. This signal is centrally generated in the digital section and distributed all over the board via a buffer. " CreationDate="2011-05-13T17:25:03.577" UserId="4176" />
  <row Id="22269" PostId="14263" Text="If you absolutely must use a cap to &quot;stitch&quot; split planes together, make sure you attach the cap to either side of the plane.  Engineers have a bad habit of assuming one leg of a cap is always attached to GND and the other to some VCC, when in reality you'd be connecting both sides to GND or both sides to VCC, depending on the plane you're stitching." CreationDate="2011-05-13T17:26:56.087" UserId="1278" />
  <row Id="22270" PostId="14263" Text="I was assuming that the return current would go through the nearest/shorted ground path and not nessecary the power plane which seems to be wrong" CreationDate="2011-05-13T17:31:15.940" UserId="4176" />
  <row Id="22271" PostId="14270" Text="@ajs410  It really depends on the board.  For a 4 layer PCB, you're absolutely correct.  For boards with more than 4 layers, it might be better to put your clocks on an inner layer (between the power/ground planes).  If there is a signal layer between the top and the first plane then the impedance of traces on the top will be terrible so putting the clock on a different layer could be a plus.  And finally, for BGA's you often can't fan the signal out without going to an inner layer-- in which case you don't have a choice.  It helps to put a cap near the clock via, to reduce the loop currents." CreationDate="2011-05-13T17:48:39.113" UserId="3624" />
  <row Id="22272" PostId="12969" Text="Double check the data sheet, but most of the time when you enable a PIC's UART it will automatically configure RX as input and TX as output regardless of TRIS bits" CreationDate="2011-05-13T17:59:40.833" UserId="1278" />
  <row Id="22273" PostId="14254" Text="One way that I usually test this is to fire up your terminal of choice, let TX and RX float, scope both of them, and just hold down a key.  Whichever line toggles is the line the PC sends the data out." CreationDate="2011-05-13T18:01:16.073" UserId="1278" />
  <row Id="22274" PostId="14175" Text="Thank You very much for ur help,I had already the above article when i Googled POWER MOSFET,I need behaviourial and characteristic difference between the two.&#xA;I have referred fairchild ,ST,Omega data sheets.And I found only info in the following link:&#xA;http://ecee.colorado.edu/~bart/book/book/chapter7/ch7_8.htm" CreationDate="2011-05-13T06:47:49.443" UserId="4215" />
  <row Id="22275" PostId="14258" Text="sorry, yes, saw-tooth.  My bad." CreationDate="2011-05-13T18:36:51.147" UserId="4245" />
  <row Id="22276" PostId="14236" Text="Agree. Bad homework questions (showing no effort except cutting and pasting the original question) will get no or poor answers, clever homework questions that specify one or two things that are not clear should have the chance to get good answers." CreationDate="2011-05-13T19:10:31.153" UserId="930" />
  <row Id="22277" PostId="13103" Score="1" Text="Voltage is analogous to pressure, so the voltage rating is the same thing as the pressure rating on a pressurized tank.  If you apply too much pressure, both a capacitor and a tank will explode.  For an unpressurized tank, the voltage rating would be the height of the tank before it overflows?  So you can have two tanks of different heights but the same capacity.  This analogy is more direct, I think: http://www.wisc-online.com/objects/ViewObject.aspx?ID=ACE4803  http://amasci.com/emotor/cap1.html If the pressure is too high, the membrane fails." CreationDate="2011-05-13T19:21:14.737" UserId="142" />
  <row Id="22278" PostId="2451" Text="I've got a flashlight that flashes at 96 Hz, and it's totally obvious to me.  Move the light or sweep your eye from side to side and you can see flickering easily.  It's like a biological oscilloscope." CreationDate="2011-05-13T19:32:46.827" UserId="142" />
  <row Id="22279" PostId="14269" Score="1" Text="I don't think he meant millifarads. I think he meant microfarads. Also, my discussion above is specific to aluminum electrolytic caps (I have different advice for ceramic caps.)" CreationDate="2011-05-13T19:35:53.753" UserId="1293" />
  <row Id="22280" PostId="14273" Score="7" Text="Does simple include a relay and a DC supply? If so, it's easy as long as the relay has a normally-closed contact..." CreationDate="2011-05-13T19:40:15.370" UserId="1293" />
  <row Id="22281" PostId="14254" Text="@ajs410, yes, I was just pointing out that the tests that had been completed would not have caught this error." CreationDate="2011-05-13T19:52:29.320" UserId="230" />
  <row Id="22282" PostId="13103" Text="@endolith I hadn't thought to use pressure for voltage and volume for charge, but that's a much better idea. Thank you!" CreationDate="2011-05-13T19:55:23.207" UserId="2028" />
  <row Id="22283" PostId="14268" Text="@riz, if you get a chance to give us more information, like links to the product and the issue you have please flag for moderator attention and we can discus reopening the question." CreationDate="2011-05-13T19:56:57.543" UserId="230" />
  <row Id="22284" PostId="618" Text="The analog sections are great, espectially the coverage of BJTs and op-amps." CreationDate="2011-05-13T20:12:25.263" UserId="2059" />
  <row Id="22285" PostId="14236" Text="Well, i think i showed some effort. The question is just not really wide-ranging." CreationDate="2011-05-13T20:47:11.490" UserId="3817" />
  <row Id="22286" PostId="14238" Text="Thank you for the calculated values. The problem is my $Z_C$. My $Z_C = 24.38 e^{-j77.2°}$  $Z_C$ is just Z without $\omega L$, isn't it ?" CreationDate="2011-05-13T21:00:14.803" UserId="3817" />
  <row Id="22287" PostId="14238" Score="1" Text="@madmax, that's the value of $R \parallel Z_C$. The phase shift of an ideal capacitor is $-90^\circ$." CreationDate="2011-05-13T21:16:51.273" UserId="721" />
  <row Id="22288" PostId="14238" Text="@madmax, the voltage drop across parallel circuit elements is the same, but the current through each branch will vary. Their sum is equal to the input at the fanout node. Thus $I = \frac{U_C}{R} + \frac{U_C}{Z_C}$." CreationDate="2011-05-13T21:29:21.567" UserId="721" />
  <row Id="22289" PostId="12970" Text="The FT232 is TTL only - you need a level converter to get to RS232 signaling levels." CreationDate="2011-05-13T21:56:18.063" UserId="1374" />
  <row Id="22290" PostId="2304" Text="You should have a 10uF cap between the regulator input and ground, and another between the output and ground." CreationDate="2011-05-13T22:00:53.303" UserId="1374" />
  <row Id="22291" PostId="1517" Text="@jluciani - if it's just a wall-wart, good luck. I don't think I've ever seen specs for those. " CreationDate="2011-05-13T22:02:06.143" UserId="1374" />
  <row Id="22292" PostId="14276" Text="I'm checking out the links now . . . but this looks promising. Note that, in order to get it to fetch beer I'm going to try and get the Roomba to work with the Google's arduino compatible ADB device just announced at Google I/O. I think that has bluetooth built in so I can send commands using my phone. If not, I may need to connect a phone to the arduino and use another phone to send commands.  I still have a ton of research to do as you can tell!" CreationDate="2011-05-14T00:13:06.870" UserId="3534" />
  <row Id="22293" PostId="14276" Score="1" Text="That PDF mentions that ALL Roombas have a serial port! Crazy!" CreationDate="2011-05-14T00:14:07.493" UserId="3534" />
  <row Id="22294" PostId="14263" Text="@Bianco, it will follow whatever path minimizes inductance. What we call power is still a plate of meta held at a constant voltage and will form the return path. That is because at your chip there should be decoupling caps, the signal can use these to &quot;complete&quot; the circuit if needed. Often you are switching a power signal also, in which case the caps will not be needed." CreationDate="2011-05-14T01:18:36.057" UserId="230" />
  <row Id="22296" PostId="14283" Text="-1  That link is not accurate, and doesn't show any places in Michigan, where @BCarpe is located." CreationDate="2011-05-14T05:39:20.710" UserId="3624" />
  <row Id="22297" PostId="714" Text="I like the Philips circuit.  Clever.  It might in some ways be better if the I2C outputs didn't have to sink all the current from all the pull-ups, but designing an active I2C repeater is hard; I don't think it can be done with normal logic, since the repeater must be able to detect a rising edge and react to it before any I2C devices can." CreationDate="2011-05-14T05:48:34.360" UserId="3123" />
  <row Id="22298" PostId="14283" Text="@markrages  I'm an idiot.  I'd undo the -1 if I could, but it won't let me.  I midread the question as &quot;my geographic location&quot;, not &quot;by geographic location&quot;.  Sorry.  I'll make it up to you sometime." CreationDate="2011-05-14T05:53:24.000" UserId="3624" />
  <row Id="22299" PostId="14283" Text="@David No problem.  I've made this a community wiki, so if you find a better list please share it." CreationDate="2011-05-14T05:57:28.057" UserId="411" />
  <row Id="22300" PostId="14242" Text="@Sean, I removed the part asking for links to guides and such. I think I misinterpreted your intention. I thought the guides were your primary intention and the large number of flags led me astray also. I made a minor edit to your question. Please forgive me if this entire process has caused any grief, we are not paid and try to give the most time possible to moderation activities and it is not perfect. Feel free to come talk to me in chat if you ever have an issue." CreationDate="2011-05-14T06:13:15.017" UserId="230" />
  <row Id="22301" PostId="14277" Text="I've never heard of one. Try Yellow Pages." CreationDate="2011-05-14T03:23:09.770" UserId="305" />
  <row Id="22302" PostId="1000" Text="-&quot;If the only tool you have is a hammer, every problem looks like a nail...&quot;. Maybe some other components as well?" CreationDate="2011-05-14T06:35:03.963" UserId="689" />
  <row Id="22303" PostId="14277" Score="1" Text="Get over it and buy online." CreationDate="2011-05-14T06:58:24.040" UserId="339" />
  <row Id="22304" PostId="14279" Text="The 100nF has to be ceramic for a reason (low ESR). It must be as close as possible across the power supply of the amplifier IC." CreationDate="2011-05-14T07:02:33.113" UserId="339" />
  <row Id="22305" PostId="14266" Text="@Bianco, that sounds like the source of a large amount of noise issues. High frequency clocks are the devil in the details." CreationDate="2011-05-14T07:12:55.160" UserId="230" />
  <row Id="22306" PostId="14280" Text="@Dave, I read advice like this regularly and I am of the opinion that those whom do not get better results with a split plan are not doing it right. Designing a high speed RF board is serious business, designing a high speed RF board with separate analog and digital grounds is more serious business. This is an opinion, but with great design practice and a tedious design a separated board can receive benefits for your analog system. Those digital lines just generate so many frequencies. If you have very low speed digital then you digital does not need to segregate." CreationDate="2011-05-14T07:16:46.093" UserId="230" />
  <row Id="22307" PostId="14280" Text="@Dave, I think it, like most of engineering is not an easy task that has the same solution space every time. That is why they pay engineers well." CreationDate="2011-05-14T07:17:00.007" UserId="230" />
  <row Id="22308" PostId="14284" Score="3" Text="@StarBlue, why not add a circuit to show an example?" CreationDate="2011-05-14T07:22:35.087" UserId="230" />
  <row Id="22309" PostId="14278" Score="2" Text="@davidKessner, Why not add a bit of explanation of why it requires an amplifying element?" CreationDate="2011-05-14T07:23:00.780" UserId="230" />
  <row Id="22310" PostId="14217" Text="Nice comprehensive answer.  Thanks for that, will definitely take much of it on board" CreationDate="2011-05-14T07:50:20.327" UserId="4017" />
  <row Id="22311" PostId="14158" Text="Thanks for that.  Eagle is a bit pricey though :P" CreationDate="2011-05-14T07:51:34.210" UserId="4017" />
  <row Id="22312" PostId="14223" Text="@Kortuk, @DanielGrillo: I did try hard to find the right SE forum and this seemed the best fit. I'm trying to use a Kinect (could also be a X-tion Pro) as a sensor and am not looking at it as consumer electronics in this case. If you have suggestions for a more fitting SE forum, that would be appreciated!" CreationDate="2011-05-14T08:55:13.920" UserId="4236" />
  <row Id="22313" PostId="14226" Text="Thanks for also pointing out the fans, I would've forgot about those. And yes, I think I'll stock a couple of extras, they're not that expensive." CreationDate="2011-05-14T08:59:00.843" UserId="4236" />
  <row Id="22314" PostId="14238" Text="Ok, my problem was i assumed $Z_C$ as $R||Z_C$. Now i got it! Thank you." CreationDate="2011-05-14T09:01:08.253" UserId="3817" />
  <row Id="22315" PostId="14223" Text="@petergassner, you are buying a consumer product and using it and would like to estimate how often you have to buy a new one. Estimating the true cost of a project to maintain it is very very important, but it is not designing electronics. I am sorry to say a consumer electronics SE does not exist. An SE that gives you information about designing and estimating cost would also be valuable. Possibly a project management SE would help. I am not qualified to be sure of that. " CreationDate="2011-05-14T09:04:41.917" UserId="230" />
  <row Id="22316" PostId="14244" Text="@mikeselectricstuff: thanks for pointing out the sound chip, I looked that one up and discovered that the fan really only kicks in when the device gets hot enough – this might be an area where I could also provide good external cooling to spare the internal fan." CreationDate="2011-05-14T09:10:17.183" UserId="4236" />
  <row Id="22317" PostId="14231" Text="@Madmanguruman: this is exactly my fear. What I take away from the other answers is that the individual parts I'm actually using should last a while, but I will have to take extra care to provide a clean and cool environment." CreationDate="2011-05-14T09:15:06.743" UserId="4236" />
  <row Id="22318" PostId="14283" Score="1" Text="@David Kessner Can't you just edit the post, undo the vote and roll back?" CreationDate="2011-05-14T09:21:38.323" UserId="1240" />
  <row Id="22319" PostId="14281" Text="Thanks a lot! The potentiometer fixed the problems with power supply voltage. When I set input voltage to say 100 mV, the output volume is really low, but there's no interference. I also tried with 8 $\Omega$ speaker and there was no difference in the output. I'll try with a PCB and a 100 nF capacitor next." CreationDate="2011-05-14T10:12:52.410" UserId="1240" />
  <row Id="22320" PostId="14285" Text="@Sam, Asking a [question on two SEs](http://stackoverflow.com/questions/6001025/implementing-a-fsm-in-vhdl) at the same time is considered abuse of the system. Please choose which site fits your question the best. Next, normally you use a module to allow a subsystem to be recreated over and over." CreationDate="2011-05-14T10:16:50.250" UserId="230" />
  <row Id="22321" PostId="14285" Text="Sorry!! I didn't realise replicating it was bad. Where is the best place to ask?&#xA;&#xA;And could you please expand about using a module? :)" CreationDate="2011-05-14T10:18:21.607" UserId="4257" />
  <row Id="22322" PostId="14285" Score="1" Text="@Sam, been two years since I coded in an HDL, previously I have seen questions posted about HDL both on SO and here, SO had better answers when it is a pure software question." CreationDate="2011-05-14T10:22:20.307" UserId="230" />
  <row Id="22323" PostId="14283" Text="@DavidKessner, do as AndrejaKo says and you can undo the vote." CreationDate="2011-05-14T11:29:04.937" UserId="230" />
  <row Id="22324" PostId="14285" Text="@Kortuk, I know I'm being a bit impatient but I still haven't gotten an answer over there.. would you mind explaining what you mean by using a module and subsystem? I googled but couldn't find anything relevant. Even a link to something would be great.. I'm really pulling my hair out here." CreationDate="2011-05-14T12:47:38.177" UserId="4257" />
  <row Id="22325" PostId="14280" Text="@Kortuk-The double negative is a bit confusing. I take it you are saying that if you do it right, a split plane will give you better results? That's not my experience, but you are correct that there isn't the same solution space every time, which is maybe the bigger point!  You have to start with a good floorplan, separating analog, digital and power supplies as much as possible to start with, or you're swimming upstream..." CreationDate="2011-05-14T12:54:22.620" UserId="2148" />
  <row Id="22326" PostId="2451" Score="1" Text="@endolith - i know what you mean, i can see the flickering in the LED tail lights on certain cars. but in the case of nixie equipment, it's usually the viewers head moving, not the display. stroboscopic effects seem worse when its the display that moves." CreationDate="2011-05-14T13:35:02.477" UserId="740" />
  <row Id="22327" PostId="4169" Text="@ajs410: My guess would be that the device producing the data and clock for the device switches both simultaneously, and the squiggle helps ensure that the proper signal is registered first.  Though that would seem an awfully short squiggle to have much effect." CreationDate="2011-05-14T15:08:58.060" UserId="3123" />
  <row Id="22328" PostId="5140" Text="@Kortuk: I would guess cross-hatched ground planes probably came about when automated tools didn't do thermal reliefs." CreationDate="2011-05-14T15:11:02.693" UserId="3123" />
  <row Id="22329" PostId="14289" Text="Can we see a circuit diagram please of how its wired up." CreationDate="2011-05-14T15:19:07.767" UserId="1623" />
  <row Id="22330" PostId="14285" Score="3" Text="VHDL isn't quite software....  Do we really consider VHDL out of bounds here?" CreationDate="2011-05-14T15:23:09.887" UserId="249" />
  <row Id="22331" PostId="14289" Score="2" Text="22pF may be even too high. Try 12-18pf range. Also, are you using a breadbord?" CreationDate="2011-05-14T15:34:52.507" UserId="1476" />
  <row Id="22332" PostId="14289" Text="Yes, I am using a breadboard.  And I think 22pf may be my smallest cap available at the moment." CreationDate="2011-05-14T15:38:13.057" UserId="4245" />
  <row Id="22333" PostId="14106" Text="In case you still read this: newly announced chipKIT Max32 has 512kB Flash" CreationDate="2011-05-14T15:52:20.517" UserId="3438" />
  <row Id="22334" PostId="14289" Score="1" Text="Ohkay - if I run it in HS oscillator mode, and ditch the capacitors (just have a crystal linked between pins 15 and 16) I get it working.  If I then add the capacitors it stalls.  Well, I say stalls - it appears to possibly be working at about 0.1Hz." CreationDate="2011-05-14T16:27:43.343" UserId="4245" />
  <row Id="22335" PostId="14291" Text="I had just installed updates for existing products. I clicked the other option to search for updates to all products and checked everything. It gave me an error when I checked GRACE, so I left it unchecked. I will let you know if this works." CreationDate="2011-05-14T16:30:12.827" UserId="3906" />
  <row Id="22336" PostId="14283" Text="@AndrejaKo  Hey, that worked!  Thanks all." CreationDate="2011-05-14T16:31:27.680" UserId="3624" />
  <row Id="22337" PostId="14290" Text="If it's just online then they are competing with DigiKey and Mouser and Sparkfun.  Good luck with that! Radio Shack's selection of in-store components is unchanged from when I was a kid, and they were selling obsolete components then. (lm741, really? *every* *single* 1n400x diode, what is the point?)  I can buy etchant at my Radio Shack, but they quit carrying copper-clad boards..." CreationDate="2011-05-14T16:44:19.347" UserId="411" />
  <row Id="22338" PostId="14289" Score="1" Text="Solderless breadboards can be troublesome, especially for circuits involving crystal oscillators; I never use them. Try putting it on a PCB." CreationDate="2011-05-14T16:48:47.710" UserId="305" />
  <row Id="22339" PostId="14289" Score="3" Text="Do not stay too long with the 16F84.  It is obsolete, expensive, limited in capability. Try 16F88 instead: http://www.finitesite.com/d3jsys/16F88.html" CreationDate="2011-05-14T16:55:32.390" UserId="411" />
  <row Id="22340" PostId="1111" Text="You listed very good reasons that microcontroller hobbyists like Arduino, but the question was about ARM vs AVR. Arduino was mentioned due to its decision to select the AVR series of MCUs for its implementation. I think some more relevant answers lie below your post; for example, the fact that Atmel supports its AVR series with a C compiler. Good info nonetheless for someone unfamiliar with Arduino, however." CreationDate="2011-05-14T17:17:01.600" UserId="4258" />
  <row Id="22341" PostId="14294" Text="NPN MOSFETs? `NPN` is a bipolar junction transistor designation." CreationDate="2011-05-14T17:21:18.180" UserId="2064" />
  <row Id="22342" PostId="14294" Text="@stevenvh sorry my mistake, an N-channel MOSFET" CreationDate="2011-05-14T17:28:15.797" UserId="4209" />
  <row Id="22343" PostId="14285" Score="2" Text="Until there is an actual FPGA/programmable logic site, I think it is related to the electronics SE. Otherwise, the MCU programming discussions would also be off topic. The FAQ, btw, specifically talks of bare metal and RTOS programming as on topic; I don't see how those are more 'electronic' than VHDL..." CreationDate="2011-05-14T17:30:51.487" UserId="3308" />
  <row Id="22344" PostId="14294" Text="Henry, you can edit your question." CreationDate="2011-05-14T17:33:45.557" UserId="411" />
  <row Id="22345" PostId="14294" Text="@markrages thank you I have done so" CreationDate="2011-05-14T17:34:58.207" UserId="4209" />
  <row Id="22346" PostId="2121" Score="1" Text="forget the 741 op-amp!  You can buy better opamps for less money." CreationDate="2011-05-14T18:04:48.170" UserId="411" />
  <row Id="22347" PostId="974" Text="1V &quot;zeners&quot; have a soft knee and generally lousy specs.  So don't string them together, get the higher-voltage part." CreationDate="2011-05-14T18:06:49.527" UserId="411" />
  <row Id="22348" PostId="14266" Text="I'm reworking my design now to use multiple clock sources instead of a central one. I want to avoid unnessecary taunting with the devil." CreationDate="2011-05-14T18:47:19.427" UserId="4176" />
  <row Id="22349" PostId="14290" Text="Sadly, none of the RS around me have a useful selection of components. They have some switches and a few transistors and that's it. Definitely checkout your local RS, but don't be disappointed if they don't have much. " CreationDate="2011-05-14T19:29:18.413" UserId="259" />
  <row Id="22350" PostId="14277" Text="Definitely paw through the yellow pages, but don't be shocked if there simply aren't any." CreationDate="2011-05-14T19:33:11.420" UserId="259" />
  <row Id="22351" PostId="14290" Text="@mark - Odd - RS is the only place I could find the copper clad boards locally." CreationDate="2011-05-14T20:02:22.550" UserId="249" />
  <row Id="22352" PostId="14283" Text="This is why we should be able to change votes." CreationDate="2011-05-14T20:17:43.557" UserId="142" />
  <row Id="22353" PostId="14289" Text="@markrages yeah, I know, but it's the best I could get locally.  I am going to get some of the newer flash PICs with built-in USB2 soon, when I can find somewhere to get one from." CreationDate="2011-05-14T20:26:39.097" UserId="4245" />
  <row Id="22356" PostId="14291" Text="Ok, everything has been installed now, still no TMS320C5505. The TMS320C*'s only range from TMS320C2801 to TMS320C28346. All TMS320C* device numbers I see in CCS start with a 28. How do I fix this? Is there a work-around? " CreationDate="2011-05-14T20:54:57.647" UserId="3906" />
  <row Id="22357" PostId="14290" Text="Be careful with names: there is a distributor named RS electronics, not related to Radio Shack." CreationDate="2011-05-14T20:57:39.313" UserId="411" />
  <row Id="22358" PostId="14289" Text="microchipdirect.com is the best place to buy PICs. Every distributor has some as well.  And Microchip is pretty generous with the free samples." CreationDate="2011-05-14T20:59:49.090" UserId="411" />
  <row Id="22360" PostId="14289" Text="@markrages does that include the UK?" CreationDate="2011-05-14T21:05:04.883" UserId="4245" />
  <row Id="22361" PostId="14289" Text="microchipdirect (and their samples) ship from Thailand. I'm not familiar with all the UK distributors, but Farnell appears to list a couple thousand types of PIC." CreationDate="2011-05-14T21:18:20.113" UserId="411" />
  <row Id="22364" PostId="14289" Text="Well, this is my first PIC, and I'm mighty proud of what I have done given I've never programmed on before.  I have interfaced an 8 channel ADC0838 serial ADC to the PIC on port A, and port B links to a pair of 7 segment displays via two MC14495 hex drivers, and the LEDs display a hex representation of the ADC's channel 1 input.  Now if I could somehow combine the /CE and CLK signals from the PIC to the ADC I'd be only using 2 lines of port A instead of 3." CreationDate="2011-05-14T22:00:13.010" UserId="4245" />
  <row Id="22365" PostId="14289" Text="Oh, and thanks for the tip about the free samples - I now have 2 'F88s and an 'F777 on their way for me to play with." CreationDate="2011-05-14T22:25:47.857" UserId="4245" />
  <row Id="22366" PostId="14303" Text="did you remove the pots from the circuit before measuring?" CreationDate="2011-05-14T23:04:46.957" UserId="411" />
  <row Id="22367" PostId="14303" Text="Yes, I did. I took them off the circuit board and soldered on some wires so I could measure more easily, but that's all I've done to them." CreationDate="2011-05-14T23:18:45.877" UserId="4261" />
  <row Id="22368" PostId="14299" Text="@David I really appreciate your thorough response, I will get diodes in the range you suggested and measure, maybe I'll even remember to come update this question with some more information!" CreationDate="2011-05-14T23:24:06.510" UserId="4209" />
  <row Id="22369" PostId="14303" Score="1" Text="What is the tolerance on your measurement?" CreationDate="2011-05-14T23:25:56.057" UserId="249" />
  <row Id="22370" PostId="14303" Text="This is bizarre.  Either Kirchoff's Current Law or Ohm's law is being violated.   What ohmmeter are you using? Are your fingers touching the terminals while measuring?" CreationDate="2011-05-14T23:30:46.107" UserId="411" />
  <row Id="22371" PostId="14303" Text="Before you swap in digital pots, measure the voltages on the pots to make sure they are within the digital pot's supply rails." CreationDate="2011-05-14T23:31:39.117" UserId="411" />
  <row Id="22372" PostId="14303" Text="The multimeter manual says plus or minus (1.0%+2). Not sure what the +2 means." CreationDate="2011-05-14T23:36:30.727" UserId="4261" />
  <row Id="22373" PostId="14303" Text="markrages - No, I'm using alligator clips." CreationDate="2011-05-14T23:37:10.837" UserId="4261" />
  <row Id="22374" PostId="14303" Text="that means 1% + 2 counts" CreationDate="2011-05-14T23:46:27.713" UserId="411" />
  <row Id="22375" PostId="14303" Score="1" Text="next experiment, put a known 1k resistor in series, then put a battery across 1k, A, B in series.  Then measure the three voltages, across the 1k, across A-&gt;wiper, across wiper-&gt;B." CreationDate="2011-05-14T23:47:59.037" UserId="411" />
  <row Id="22376" PostId="14303" Text="Good idea. Don't have any 1k's, so I used a 4.7k. Battery voltage: 9.62V; Resistor (actual measurement): 4.63k; Voltage across resistor: 4.68V; A-&gt;W: 1.489V; W-&gt;B: 3.412V. All that adds up to 9.581 which is fairly close to the expected 9.62." CreationDate="2011-05-15T00:09:11.620" UserId="4261" />
  <row Id="22377" PostId="14303" Text="What if there was for some reason a fixed resistor connected to the wiper terminal of the potentiometer? Wouldn't that explain all of the measurements?" CreationDate="2011-05-15T00:11:22.740" UserId="4261" />
  <row Id="22378" PostId="14291" Score="2" Text="It sounds like this is more of a question for TI support." CreationDate="2011-05-15T00:28:57.127" UserId="319" />
  <row Id="22379" PostId="5140" Text="@supercat, and for very thin PCB where you need a high impedance." CreationDate="2011-05-15T00:31:28.423" UserId="230" />
  <row Id="22380" PostId="14285" Text="@AngryEE, @ToyBuilder. You may misunderstand why this was closed. This was posted to both SO and here at the same time. One of them needed to be closed. The last time we had an HDL question and it was crossposted they got great answers on SO and no answers on here. I chose to close the one here and inform the user not to crosspost. If they want to remove their question there they can and choose to only post here. Crossposting is considered abuse of the system and I chose ours to close instead of flagging the SO one. My target here is for the OP to get the best answer possible." CreationDate="2011-05-15T00:33:47.923" UserId="230" />
  <row Id="22381" PostId="14285" Text="@Sam, Sorry, it has really been too long for me to give good advice here. I found [this googling VHDL Module](http://en.wikibooks.org/wiki/Programmable_Logic/VHDL_Module_Structure) that if you scroll down starts to explain it. You will have to try to learn how to make these sub units you can use and that can save copy and pasting 10 different times. It is similar to using a function in C, it just defines a specific set of logic for a certain construct and then you can initiate the construct as often as you want." CreationDate="2011-05-15T00:40:49.753" UserId="230" />
  <row Id="22382" PostId="14305" Score="2" Text="@AngryEE, and it will be coated if the board specifically is very sensitive to changes in electrical properties. For example, the grease from your hand over time will oxidize to form a mildly conductive coating, if your board is sensitive to leakage current or is doing coulomb counting this can cause an increases error from someone touching it." CreationDate="2011-05-15T00:43:19.377" UserId="230" />
  <row Id="22383" PostId="14303" Score="1" Text="@Computerish, I was going to say, if there is a resistive connection from the wiper you would get very odd skew, if you take, multiple controlled measurements with controlled number of turns between and the turns are mostly linear, you can approximate the offset from the wiper connection." CreationDate="2011-05-15T00:46:28.890" UserId="230" />
  <row Id="22384" PostId="14302" Text="@DavidKessner, If you just some &lt;h3&gt;&lt;/h3&gt; tags to dictate some section headings and put your post in logic sections it would make biting off a chunk much much easier for a reader. It would also allow an informed reader to read the sections they need." CreationDate="2011-05-15T00:48:17.373" UserId="230" />
  <row Id="22385" PostId="14302" Text="@DavidKessner, on that note, the advantage of being in medical industry Is that I have Xray generators everywhere. Got to love the advantage of checking BGAs without needing extra equipment." CreationDate="2011-05-15T00:49:21.740" UserId="230" />
  <row Id="22386" PostId="14305" Score="2" Text="@AngryEE - Any medical devices that touch the patient will also usually be coated, for much the same reasons Kortuk mentioned - you really don't want your leakage current to change over time on an EEG monitor!" CreationDate="2011-05-15T01:18:27.613" UserId="259" />
  <row Id="22387" PostId="14302" Text="I certainly plan to get an assembly company to do my real boards.  I just want to be able to test a board to see if I'm even close. My first board with 2 BGAs (289 pin ARM processor, 90 pin DDR2) comes up fine, all functions working so far.  :)" CreationDate="2011-05-15T03:15:45.693" UserId="1270" />
  <row Id="22388" PostId="14302" Text="If I start getting odd glitches, I will get a board made with the BGAs put on by someone else. Actually, I plan on stopping by an assembly house I know and ask for these to be X-rayed." CreationDate="2011-05-15T03:18:42.367" UserId="1270" />
  <row Id="22389" PostId="14265" Text="@darron, if you figured out the problem and none of the answer document the solution, please write a nice answer explaining the procedure. Take some pictures, make a nice answer. You will others with your solution and a good solution with pictures is worth a million rep(10 or more upvotes)." CreationDate="2011-05-15T03:56:09.870" UserId="230" />
  <row Id="22390" PostId="12770" Text="@vicatcu, we have agreed in the past to handle homework problems. Now, it is important that no one gives the solution, but just explanation on how to approach the problem and how circuits are approached." CreationDate="2011-05-15T04:04:24.507" UserId="230" />
  <row Id="22391" PostId="8489" Text="@BrianCarlton, Community Wiki is a moderator option only. This is because users often use CW to keep poor questions. We will watch this and hope that we get quality answers. If many poor opinionated answers with nothing else pop up we will have to close out the question and have another go at opening a better one." CreationDate="2011-05-15T04:20:05.113" UserId="230" />
  <row Id="22392" PostId="14302" Score="1" Text="I needed to be able to do this... if anything, to justify my new hot air rework station to my wife...  :)" CreationDate="2011-05-15T04:29:10.470" UserId="1270" />
  <row Id="22393" PostId="14303" Text="So the series resistor measurement removes wiper resistance from the equation, because the current through the wiper is almost zero.  It looks like Raw + Rbw = 5150 ohms and Rab = 4840 ohms.  So there is an excess of 5150-4840, or 310 ohms.  But that's counting wiper resistance twice, so the actual wiper resistance is about 150 ohms.  What is the minimum resistance you can measure between a terminal and the wiper, with the wiper turned all the way to that end?" CreationDate="2011-05-15T04:39:57.490" UserId="411" />
  <row Id="22394" PostId="14302" Score="1" Text="@darron  that's the best reason yet!" CreationDate="2011-05-15T04:53:34.153" UserId="3624" />
  <row Id="22395" PostId="14265" Text="@Kortuk: as David says, this is a fairly risky procedure. I think I've figured out that in order to do this right you really need a calibrated system that you can run a proper reflow profile through. I'll leave this open for now... once I see the xrays for these BGAs it might be obvious it's not something to encourage anyone else to do... :)" CreationDate="2011-05-15T05:03:06.830" UserId="1270" />
  <row Id="22396" PostId="14265" Text="@Darron, the advantage to working somewhere with an X-ray machine." CreationDate="2011-05-15T06:36:32.890" UserId="230" />
  <row Id="22397" PostId="14289" Text="How do you know you have no clock? Many scopes will kill the ossc when connected. Make sure you are on the 10x setting and have 10 meg input or more." CreationDate="2011-05-14T17:25:19.047" UserId="1498" />
  <row Id="22398" PostId="14289" Text="@russ_hensel,I'm looking at CLKOUT, the clock/4 output from the PIC" CreationDate="2011-05-14T20:29:18.627" UserId="4245" />
  <row Id="22399" PostId="14289" Text="@Matt, isn't CLKOUT the same pin as one of the oscillator pins? I thought it was multiplexed. You only use it for an external RC oscillator, or the internal FRC. But that might only apply for the 24F/H and dsPIC series which have a PLL." CreationDate="2011-05-14T20:38:21.020" UserId="1225" />
  <row Id="22400" PostId="14289" Text="@russ_hensel, That is true (it is shared) but I can measure the clock on it with a crystal attached.  And regardless of that, with the xtal+2caps the program doesn't run.  Without the caps it runs beautifully." CreationDate="2011-05-14T21:04:30.640" UserId="4245" />
  <row Id="22401" PostId="14289" Score="2" Text="@MattJenkins, it is actually the input capacitance and inductance of the scope probe that often kills the xtal when you touch it. Second, as pointed out, too much capacitance can often be a larger issue then too little. " CreationDate="2011-05-15T06:41:38.707" UserId="230" />
  <row Id="22402" PostId="14303" Text="A-B resistance is like this: o========o; to the wiper it is like this: o==&gt;&lt;=====o. It is the taper of the current distribution that leads to the increase in resistance." CreationDate="2011-05-15T07:17:41.107" UserId="3438" />
  <row Id="22403" PostId="14305" Text="Depends on the case as well. If you're certain your case is completely IP67 rated and tested, it may seem unnecessary to protect your boards." CreationDate="2011-05-15T08:11:57.933" UserId="1476" />
  <row Id="22404" PostId="14289" Text="@Matt, I live in the UK and Microchip Direct are great. They handle paying VAT and shipping direct from Thailand. I've bought from them before and their service is great, and prices are very competitive with distributors." CreationDate="2011-05-15T08:49:14.913" UserId="1225" />
  <row Id="22405" PostId="14307" Score="3" Text="Why the downvote... I thought it was a reasonable question?" CreationDate="2011-05-15T11:11:57.617" UserId="1225" />
  <row Id="22406" PostId="14307" Text="Because the answer is obvious?" CreationDate="2011-05-15T11:22:21.603" UserId="305" />
  <row Id="22407" PostId="14307" Text="@Leon Why would I ask an obvious question? For all I know it could be called something else, like &quot;output impedance&quot;, not &quot;on resistance.&quot; " CreationDate="2011-05-15T11:24:06.623" UserId="1225" />
  <row Id="22408" PostId="14308" Text="Unfortunately, an 0603 resistor is about my limit in terms of components. I already use an analog mux in my design, but that's for generating on screen display graphics. It has a resistance of 2.5 ohms. The technology is similar (CMOS), which makes me wonder why an MCU doesn't have a stated resistance; could it be down to reasons of cost or yield?" CreationDate="2011-05-15T11:26:13.270" UserId="1225" />
  <row Id="22409" PostId="14307" Text="What about my answer? Is it helpful?" CreationDate="2011-05-15T11:27:21.227" UserId="305" />
  <row Id="22410" PostId="14307" Text="@Leon, it's helpful in explaining why it is not specified, but see my comment." CreationDate="2011-05-15T11:28:13.063" UserId="1225" />
  <row Id="22411" PostId="14308" Text="I'd find a way to add it, I don't think that you have any other option! It's what most people would do." CreationDate="2011-05-15T11:32:46.357" UserId="305" />
  <row Id="22412" PostId="14310" Text="+1 A detailed answer which answers my question. Thanks!" CreationDate="2011-05-15T14:23:11.140" UserId="1225" />
  <row Id="22413" PostId="14310" Text="@Thomas O - even in CMOS linear/triode region resistance is pretty much not linear so with calculation method above one is still on &quot;pessimistic side&quot; for very small current loads" CreationDate="2011-05-15T15:27:53.553" UserId="1471" />
  <row Id="22414" PostId="14310" Text="@mazurnification When you say pessimistic, do you mean that the resistance is estimated to be higher than the actual value?" CreationDate="2011-05-15T15:32:07.280" UserId="1225" />
  <row Id="22415" PostId="14310" Text="@Thomas O - yes - on very small currents this could be significant difference" CreationDate="2011-05-15T15:37:25.513" UserId="1471" />
  <row Id="22416" PostId="14301" Score="1" Text="He's asking about *manuals*, not *chips*, however..." CreationDate="2011-05-15T16:11:07.440" UserId="2288" />
  <row Id="22417" PostId="14302" Text="@darron you had to be able to do BGA to impress your wife?  That in itself is pretty cool." CreationDate="2011-05-15T16:25:12.683" UserId="2288" />
  <row Id="22418" PostId="14307" Text="Look in Datasheet: Iol and Ioh (current out low and current out high). Ohms Law: R=U/I. And yes, the R to high will be a different value from R to low." CreationDate="2011-05-15T17:07:30.207" UserId="1472" />
  <row Id="22419" PostId="14158" Text="Guess you missed the Freeware edition of Eagle. That's why so many people use it. It has limitations on board size and number of layers, but is otherwise fully functional. For small DIY projects, it's generally good enough. http://cadsoft.de/freeware.htm" CreationDate="2011-05-15T17:36:27.457" UserId="746" />
  <row Id="22421" PostId="14315" Text="As I remember, some logic required the -5V back in the day. " CreationDate="2011-05-15T19:00:46.473" UserId="259" />
  <row Id="22422" PostId="14315" Text="@Michael Kohne: It did, but I think such logic was rare by the time the PC came on the scene." CreationDate="2011-05-15T19:31:44.897" UserId="3123" />
  <row Id="22423" PostId="14316" Text=" I do not think your description of the MOSFET transistor operation is correct. Any combination of linear elements (current sources and resistors) will not give non linear behavior, which is necessary to describe transistor." CreationDate="2011-05-15T20:44:29.243" UserId="1471" />
  <row Id="22424" PostId="14316" Text="Note however that one often do the &quot;trick&quot; of transistor linearization to make calculations easier. Giving that assumption original rds on question make perfect sense and gives meaningful parameter.   " CreationDate="2011-05-15T20:57:43.570" UserId="1471" />
  <row Id="22425" PostId="14315" Text="Wasn't it that the old days DRAMs required negative power supply? It's just a blind guess, but as far as I remember, good old ZX Spectrum suffered from frequent DRAM damages caused by -5V supply failures. " CreationDate="2011-05-15T21:42:02.093" UserId="3564" />
  <row Id="22426" PostId="14315" Text="@supercat - I'm looking at the schematics for Missile Command (1980, predating the PC by 1 year or so), and it uses -5 on it's masked ROMs of all things, but apparently not on general logic. So Czajnik probably has the right of it - it was memories, not logic that the -5 was for." CreationDate="2011-05-15T22:55:10.550" UserId="259" />
  <row Id="22427" PostId="14302" Text="@Dave: No, it's simply the answer to &quot;What does that let you do that you couldn't do before?&quot;" CreationDate="2011-05-16T01:00:35.223" UserId="1270" />
  <row Id="22428" PostId="14315" Score="2" Text="I spent a few days diagnosing a problem with a company that was trying to get an old ISA card working on modern PCs. (They had found some specialty motherboards that had ISA slots) They started me off with a good bit of misdirection in that they were sure the problem was in their custom device driver's timing routines. Turns out, the power supplies they bought with the new PCs simply lacked -5V." CreationDate="2011-05-16T01:07:25.063" UserId="1270" />
  <row Id="22430" PostId="14266" Text="Besides the clock signal, your ADC data lines will also have to be connected -- many ADC's are designed to have separate DGND and AGND, and to separate the digital pins from the analog -- you can then split the ground planes right under the IC's (see http://www.analog.com/static/imported-files/tutorials/MT-031.pdf figure 8)  Does that separation not exist in your ADC's?  " CreationDate="2011-05-16T04:38:39.097" UserId="3308" />
  <row Id="22433" PostId="2251" Score="1" Text="@endolith, when I was first learning amplifiers people kept telling me for a small input current there was a large one, I was very lost until I finally figured out that there still had to be a source of power." CreationDate="2011-05-16T05:11:13.503" UserId="230" />
  <row Id="22434" PostId="14315" Text="@darron ATX version 1.2 can leave out -5 V and 1.3 and up must not have it." CreationDate="2011-05-16T08:09:25.647" UserId="1240" />
  <row Id="22435" PostId="14310" Text="@Mazurnification, you are answering the questions they way they should be answered. I put a quick answer in to help the user but did not have time to put alot of time into it, or your expertise. Thank you." CreationDate="2011-05-16T08:20:16.887" UserId="230" />
  <row Id="22436" PostId="7981" Text="Great response by Leon above, the only thing I would add to that is if you would like to learn more, do come and chat with our huge community over at http://xcore.com/ - if you have any project ideas I am sure we can help you out to decide if XMOS is right for you. Also as Miguel mentioned above, do check out our videos and our YouTube channel (MyXMOS) to see XMOS in action and what our community has made already - some great inspiration." CreationDate="2010-12-17T17:14:26.987" UserId="2317" />
  <row Id="22437" PostId="14324" Text="Thanks Johan! How can I check this though?" CreationDate="2011-05-16T10:55:17.710" UserId="4257" />
  <row Id="22438" PostId="1098" Score="1" Text="The only persons that get any money from patents is the lawyers..." CreationDate="2011-05-16T10:59:44.647" UserId="689" />
  <row Id="22439" PostId="14324" Text="I have not worked with the AVR:s for a while, but first check that datasheet if there is any pull up/down:s to begin with. Then I think you play with the fuses to enable/disable them. (but I'm not sure)" CreationDate="2011-05-16T11:01:49.373" UserId="689" />
  <row Id="22440" PostId="14322" Text="I'd start with the $99 XC1-A. It's got everything you need, including lots of LEDs and buttons, and interface connectors." CreationDate="2011-05-16T11:19:38.133" UserId="305" />
  <row Id="22442" PostId="14323" Text="Post your schematic, and software." CreationDate="2011-05-16T11:23:28.833" UserId="305" />
  <row Id="22443" PostId="14323" Text="@Leon done, please let me know if you have any ideas. :)" CreationDate="2011-05-16T11:49:03.980" UserId="4257" />
  <row Id="22444" PostId="14323" Text="I asked for the code in case you have the ADC input configured as an output that is driven low. Post the initialisation code. Have you checked the ADC with input from a pot?" CreationDate="2011-05-16T11:59:23.213" UserId="305" />
  <row Id="22445" PostId="14323" Text="The code is a bit long to post in full.. what should I be looking for though? Writes to DDRA? I am setting all the data direction bits of A to 1, could that be it? " CreationDate="2011-05-16T12:04:32.110" UserId="4257" />
  <row Id="22446" PostId="14323" Text="And I am unfamiliar with the term pot.. any links would be great. :)" CreationDate="2011-05-16T12:04:54.153" UserId="4257" />
  <row Id="22447" PostId="14323" Text="I'm guessing pot = potentionmeter on second thought. I haven't tested with one but I have tested with a variable DC supply unit and that has worked very well so I know that that is working. It is only when I try to hook up my circuitry it doesn't work as expected." CreationDate="2011-05-16T12:07:25.773" UserId="4257" />
  <row Id="22448" PostId="14323" Text="A pot is a potentiometer." CreationDate="2011-05-16T12:12:03.550" UserId="305" />
  <row Id="22449" PostId="14325" Text="Actually, I just checked my code and I do have `DDRA = 0xFF` in there but I don't ever set `PORTA` to anything. Could that be the problem? &#xA;&#xA;The weird thing is that the ADC does still work with the pins set to be an output.. I get a value from 0 to 100 out depending on how much voltage the mic is putting out. Is that expected behaviour? I can't test anything again till tomorrow." CreationDate="2011-05-16T12:13:41.680" UserId="4257" />
  <row Id="22450" PostId="14325" Text="Additionally, do I have to set `DDRA` to anything to use one of its pins for ADC? Or will the ADC code I posted do everything I need?" CreationDate="2011-05-16T12:14:27.407" UserId="4257" />
  <row Id="22452" PostId="5272" Text="Umm, BIG warning here, please look at jluciani 's post, you cannot charge a mobile battery directly, not only is there a little bit of math, but you HAVE to have a temperature sensor, every phone has one AFAIK, it's probably a legal requirement... anyway, there a chips that will do the whole trick for you, or you can use a microcontroller ,or 2 timers and a comparator or three ... + a temp sensor. DO NOT credit my answer click on jluciani!" CreationDate="2010-10-16T19:10:50.893" UserId="1357" />
  <row Id="22453" PostId="14323" Text="Setting DDRA to 0xFF makes all the pins outputs!" CreationDate="2011-05-16T12:33:11.857" UserId="305" />
  <row Id="22454" PostId="12441" Text="@Eric - This is a very subjective question, and may end up closed.  See the [FAQ](http://electronics.stackexchange.com/faq#dontask) for more information about subjective questions.  " CreationDate="2011-05-16T12:58:33.433" UserId="857" />
  <row Id="22455" PostId="14322" Text="@Leon thanks, I'll place an order for one today!" CreationDate="2011-05-16T12:58:38.603" UserId="2288" />
  <row Id="22456" PostId="14277" Score="1" Text="This question is not a good fit for our site. It generates a lot of potentially rude answers, and is unlikely to be maintained as URLs go stale and stores open and close.  Finally, in spite of the fact that you ask for a list, you're unlikely to get geographically neutral answers.  Please take questions like this to sources of knowledge which are concentrated in your own area, like a hackerspace or school." CreationDate="2011-05-16T13:11:21.630" UserId="857" />
  <row Id="22457" PostId="10668" Text="Build a class A amp. You just need a voltage source, 1 inductor, a few capacitors, a bunch of resistors, and some bjt's (make sure to get a high current rated bjt for the final stage). It's not efficient but it sounds good." CreationDate="2011-04-07T22:22:52.647" UserId="3770" />
  <row Id="22458" PostId="1450" Text="STMicroelectronics released a new STM32 discovery board http://www.st.com/internet/evalboard/product/250863.jsp, its $10. Pretty decent board to learn the basics at a very cheap price." CreationDate="2011-04-06T13:20:17.897" UserId="3748" />
  <row Id="22459" PostId="1450" Score="1" Text="That's got an ARM Cortex-M3, not an ARM 9! It won't run Linux." CreationDate="2011-04-06T13:24:51.040" UserId="305" />
  <row Id="22460" PostId="9915" Text="Ordinary BJTs are sensitive to ESD, also, especially high-frequency devices." CreationDate="2011-02-09T19:32:13.333" UserId="305" />
  <row Id="22461" PostId="9915" Text="The question was about MOSFETs.  It's good to know that BJTs are sensitive, but this doesn't answer the question." CreationDate="2011-02-09T20:53:03.660" UserId="857" />
  <row Id="22462" PostId="9915" Text="I mentioned it in case people thought that MOSFETs were the only discrete devices that could be damaged by ESD." CreationDate="2011-02-09T21:26:02.190" UserId="305" />
  <row Id="22463" PostId="14316" Text="@mazurnification: A current source with a finite compliance voltage is a non-linear device.  I think it's pretty self-explanatory that the compliance voltage of each constant-current source will be limited to VDD." CreationDate="2011-05-16T13:16:56.307" UserId="3123" />
  <row Id="22464" PostId="14286" Text="TVSs should help, such as AVX TransGuards. I've seen them recommended for that purpose." CreationDate="2011-05-14T12:03:05.973" UserId="305" />
  <row Id="22467" PostId="13977" Text="If it were me, I would ask Xilinx support." CreationDate="2011-05-06T16:53:19.610" UserId="206" />
  <row Id="22468" PostId="14324" Text="@Johan - This answer is a little brief.  Can you expand a little?  Readers might be unfamiliar with the states in which you'd have a pull-down resistor enabled.  Also, it would be good to explain why this would cause the behavior that the OP is observing." CreationDate="2011-05-16T13:23:13.693" UserId="857" />
  <row Id="22469" PostId="14325" Text="@Mad - Your answer is overly brief, and could probably be a comment.  Could you explain how the pin might be configured as an output and set low, and why this would cause the OP to observe the problematic behavior?" CreationDate="2011-05-16T13:25:21.103" UserId="857" />
  <row Id="22470" PostId="13391" Text="uC's are standard parts. I would just use one. Need not be an arduino." CreationDate="2011-04-23T15:45:48.793" UserId="1498" />
  <row Id="22471" PostId="13788" Text="Use a 5V relay with changeover contacts (SPCO) if you need to pass a lot of current." CreationDate="2011-05-02T21:20:11.737" UserId="305" />
  <row Id="22472" PostId="13405" Text="@Steven - Your question was a little hard to parse, which could lead to answers that don't solve your problem.  I've looked at it, and tried to reorganize it to more clearly explain what your problem is: You suspect that you can damage your Arduino by interfacing with servo control lines, and want to protect against that.  Is that correct?  If not, please edit it so that your question is easily recognizable." CreationDate="2011-05-16T13:45:10.150" UserId="857" />
  <row Id="22473" PostId="13405" Text="Also, if any of these answers solve your problem, please mark them as the solution.  Your 50% accept rate is low: We hope that people can give a correct answer closer to 90% of the questions on the site, and we'd also hope that askers accept that correct answer on closer to 90% of the questions they ask!" CreationDate="2011-05-16T13:48:00.007" UserId="857" />
  <row Id="22475" PostId="5671" Text="How about getting the function generator, the oscilloscope and the logic analyzer for $35 ?&#xA;[Xprotolab](http://www.gabotronics.com/development-boards/xmega-xprotolab.htm &quot;Xprotolab&quot;)" CreationDate="2010-12-03T19:13:46.180" />
  <row Id="22477" PostId="5148" Text="The [Electra](http://www.konekt.com/) autorouter is available for Eagle and many other packages. I use the version supplied with Pulsonix, it's excellent." CreationDate="2010-10-12T22:03:36.827" UserId="305" />
  <row Id="22478" PostId="7721" Text="Q factor plays a major role. concentrate on it" CreationDate="2011-01-11T10:08:54.347" UserId="2572" />
  <row Id="22480" PostId="7359" Score="1" Text="Matthias - This *does* provide a way to use TopoR with EagleCad, but it's not obvious from your answer.  Please keep your answers as complete as possible on this site, without a dependency on external links (especially links which require scrolling).  Note that the Eagle rep was similarly worried about the link expiration." CreationDate="2011-05-16T15:24:34.137" UserId="857" />
  <row Id="22481" PostId="7359" Score="1" Text="Also, please don't add a tagline to your answers.  You've already got a profile link in the lower right corner, and a whole profile on which to express yourself.  Signature lines are highly discouraged: I won't edit it this time (since I'm hoping you'll edit it yourself as described by my previous comment), but please refrain from the practice in the future.  " CreationDate="2011-05-16T15:26:30.313" UserId="857" />
  <row Id="22482" PostId="4211" Text="You never said *why* you want to do this. What's the problem with the current setup?" CreationDate="2011-05-16T14:32:09.503" UserId="2255" />
  <row Id="22483" PostId="14325" Text="agreed. and fixed up." CreationDate="2011-05-16T16:33:29.573" UserId="1293" />
  <row Id="22484" PostId="14323" Text="You return (adc); but its never created nor assigned in your code segment. This could be creating an issue. " CreationDate="2011-05-16T17:25:05.100" UserId="1623" />
  <row Id="22485" PostId="14325" Text="@Mad - Thanks, and upvoted!" CreationDate="2011-05-16T17:46:22.080" UserId="857" />
  <row Id="22486" PostId="10615" Text="@Powtac - please add your &quot;solution&quot; as an answer. Also, quoting some of that content in your answer or summarizing it would not only make the your answer more valuable in the event that Arduino changed their URL structure or removed that page, it would make it quicker and easier for readers to decide if they wanted to click that link." CreationDate="2011-05-16T17:56:18.860" UserId="857" />
  <row Id="22488" PostId="2672" Text="It can also be used for an AC constant current source. The SPICE simulator I use has both DC and AC current sources using that symbol." CreationDate="2010-05-17T14:47:25.650" UserId="305" />
  <row Id="22489" PostId="14289" Text="Ok, putting it on a bit of stripboard has done the trick.  I guess the tracks on the breadboard have quite a high capacitance of their own.  Thanks all.  Btw, 22pf is good.  The datasheet says anywhere between 15pF and 33pf for 4mhz." CreationDate="2011-05-16T18:36:37.813" UserId="4245" />
  <row Id="22490" PostId="13195" Text="@Cell-o: Many books could be written and armies of PhD students employed to investigate this problem as stated, and there would still be more to learn.  What do you want to know about the effects of temperature on a diode?  This question is overly broad, and could be closed." CreationDate="2011-05-16T18:39:27.497" UserId="857" />
  <row Id="22491" PostId="13195" Text="@Cell-o: Also, I've removed your &quot;Hi&quot; and &quot;Thanks&quot; lines per the site guidelines.  They are considered good manners in some contexts, but the Stack Exchange network is not one of these places: Here, they're noise and distract from the asking and answering of questions. Please don't do this in the future! &lt;irony&gt;Thanks!&lt;/irony&gt;" CreationDate="2011-05-16T18:41:21.177" UserId="857" />
  <row Id="22492" PostId="14333" Text="As an example, the Slave Select line of SPI devices is often used to explicitly address devices that are sharing a common SPI bus." CreationDate="2011-05-16T18:51:47.177" UserId="1278" />
  <row Id="22493" PostId="14333" Text="@ajs410: SPI with a shared data return would be an example of multiple devices sharing a common wire, but only talking on it when addressed.  I think most SPI devices use 3-state outputs, precluding wire-or behavior, but since they're in the category of bus that would generally not be called wired-AND/wired-OR, that doesn't really matter." CreationDate="2011-05-16T18:59:47.810" UserId="3123" />
  <row Id="22494" PostId="14336" Text="I don't understand. Are you saying that Quartus *does* support different libraries? Do you have a pointer to their documentation? -- thanks" CreationDate="2011-05-16T19:32:47.327" UserId="3145" />
  <row Id="22495" PostId="13195" Text="Reverse leakage current will also increase - many of the answers to [this question](http://electronics.stackexchange.com/questions/13873/why-exactly-do-chips-start-malfunctioning-once-they-overheat/13903#13903) will also apply to what you have asked here" CreationDate="2011-05-05T09:07:30.020" UserId="4096" />
  <row Id="22496" PostId="10626" Text="What ever happened to using the good ol' Dremel with a cutoff wheel?" CreationDate="2011-02-24T03:54:40.197" UserId="2288" />
  <row Id="22497" PostId="9435" Text="An LC filter will be more effective." CreationDate="2011-01-26T04:15:09.987" UserId="305" />
  <row Id="22498" PostId="110" Text="You could perhaps get a driver chip from an old dvd/cd-rom player." CreationDate="2010-06-12T13:32:29.460" UserId="323" />
  <row Id="22499" PostId="7913" Text="Modern tools support arbitrary angles, so that's no longer the reason." CreationDate="2010-12-16T00:46:03.890" UserId="206" />
  <row Id="22500" PostId="9833" Text="I think it's better to use a Varistor instead of diodes." CreationDate="2011-02-07T19:18:43.257" UserId="938" />
  <row Id="22501" PostId="6731" Text="You should really have a licensed electrician do this for you, inexperience working with mains voltage wiring can possibly kill." CreationDate="2010-11-14T10:08:59.253" UserId="1307" />
  <row Id="22502" PostId="6731" Text="Thanks for your concern. I am not working with it plugged in though (only to check). And the setup is fairly safe (the light dimmer sits in a box). I have fixed plenty of wires before this is just new to me." CreationDate="2010-11-14T10:13:37.007" UserId="1949" />
  <row Id="22504" PostId="14336" Text="I said that they can be used if required! It isn't the default behaviour, though." CreationDate="2011-05-16T20:22:18.333" UserId="305" />
  <row Id="22505" PostId="14336" Text="+1 Thanks for the link, @Leon. Since entities cannot have the same name, I'd qualify this as &quot;almost&quot; supports libraries. " CreationDate="2011-05-16T21:10:02.547" UserId="3145" />
  <row Id="22506" PostId="14341" Text="Thanks! However, according to the datasheet, at VCC=5V, the buffer needs at least 3.5V on input to indicate high-level (see Vih parameter). How should I solve that?" CreationDate="2011-05-16T21:50:45.887" UserId="1850" />
  <row Id="22507" PostId="14341" Text="@avakar  Hmm, that will be a little tricky.  The easiest way I can think of, while keeping things simple and fast, would be to use two of these parts in series.  The first one bumps up the signal to maybe 4.2 volts while the second one is powered off of whatever the devices VCC rail is.  Alternatively, TI has basically the same part in different logic families.  One of those families might be closer to what you need." CreationDate="2011-05-16T22:04:11.457" UserId="3624" />
  <row Id="22508" PostId="14342" Text="@Ian, this is not the target of our site I am sorry to say. We do not handle shopping style questions." CreationDate="2011-05-16T22:13:06.647" UserId="230" />
  <row Id="22509" PostId="14341" Text="@David, I could potentially use [SN74AHCT1G04](http://focus.ti.com/docs/prod/folders/print/sn74ahct1g04.html), which has TTL input levels to boost to 5V and then down-convert to VDD. But I'd need two boosts per pin, one for input and one for output-enable." CreationDate="2011-05-16T22:20:31.353" UserId="1850" />
  <row Id="22510" PostId="14343" Text="@Joby, thanks! The problem is the same as with David's answer though. CMOS input levels are out of range for a 3.3V chip when VDD=5V." CreationDate="2011-05-16T22:21:31.230" UserId="1850" />
  <row Id="22511" PostId="14344" Score="2" Text="More of an explanation than it implements the device side of a USB CDC device? http://en.wikipedia.org/wiki/USB_communications_device_class" CreationDate="2011-05-16T22:29:26.207" UserId="2157" />
  <row Id="22512" PostId="14341" Text="@avakar  You can use the Hex version of that part: SN74AHCT04, http://focus.ti.com/lit/ds/symlink/sn74ahct04.pdf. It doesn't help you much in complexity, but cuts down on the number of chips.  The bottom line is this:  You want high-ish speed and a wide voltage range.  These are not common things, so you whatever solution you end up with will be a compromise.  It will have one or more of the following features:  slow, costly, lots of parts, or expensive.  It's up to you to pick the mis-features that you can live with." CreationDate="2011-05-16T22:36:25.033" UserId="3624" />
  <row Id="22513" PostId="14343" Text="@Joby, this is clearly enough, but it would be nice if you brought over some of why they work." CreationDate="2011-05-16T23:12:11.000" UserId="230" />
  <row Id="22517" PostId="14280" Text="@Kortuk: Howard Johnson in &quot;High Speed Digital Design&quot; advocates for a single ground plane pretty strongly." CreationDate="2011-05-16T23:27:28.427" UserId="1270" />
  <row Id="22518" PostId="14343" Text="@Kortuk Converted to community wiki, feel free to edit" CreationDate="2011-05-16T23:57:49.680" UserId="566" />
  <row Id="22519" PostId="14342" Text="If you wish to measure 3d orientation of a stationary or relatively slow moving object, consider using a 3-axis accelerometer. With it, you can detect the ever-present acceleration due to gravity (a constant ~9.81 m/s^2) and from that you can figure out which way is &quot;down.&quot;" CreationDate="2011-05-17T01:30:12.333" UserId="3174" />
  <row Id="22520" PostId="14348" Text="I found this little thing on eBay which does have a pot, no schematic provided, but as you say probably not very efficient: http://cgi.ebay.com/Step-Up-MC34063-Based-Switching-Regulator-Adapter-USA-/360132101130" CreationDate="2011-05-17T04:03:22.620" UserId="2654" />
  <row Id="22521" PostId="14344" Score="1" Text="@kenny, actually, it doesn't. It uses a proprietary profile, which is why you need to install drivers to use it (at least on Windows)." CreationDate="2011-05-17T05:57:57.997" UserId="1850" />
  <row Id="22522" PostId="14325" Text="Thanks so much, this was indeed the issue. :)" CreationDate="2011-05-17T07:29:54.877" UserId="4257" />
  <row Id="22523" PostId="14323" Text="@Dean adc is defined in avr/io.h I think. The code does work but thanks anyway. :)" CreationDate="2011-05-17T07:30:31.833" UserId="4257" />
  <row Id="22524" PostId="14344" Score="1" Text="@avakar, it uses drivers on all OSs, some just come preloaded." CreationDate="2011-05-17T08:04:40.480" UserId="230" />
  <row Id="22525" PostId="3261" Text="@Joby, can you bring over the info so if the link dies we still have it." CreationDate="2011-05-17T08:05:42.260" UserId="230" />
  <row Id="22526" PostId="3262" Text="@kellen, can you bring over the info so if the link dies we still have it." CreationDate="2011-05-17T08:05:57.563" UserId="230" />
  <row Id="22527" PostId="14314" Text="The coating process is expensive. But most of the cost comes from the labour of masking the connectors rather than the coating material itself." CreationDate="2011-05-17T08:09:40.683" UserId="2110" />
  <row Id="22528" PostId="14347" Text="Pretty much all sound compression filters I've seen were digital. I suppose you could ADC-&gt;DSP-&gt;DAC it (x2 for stereo) but there must be a simpler analog way. I'll be keeping an eye on this question with keen interest." CreationDate="2011-05-17T08:21:38.353" UserId="1802" />
  <row Id="22529" PostId="3262" Text="That's exceedingly clever." CreationDate="2011-05-17T08:27:22.577" UserId="1802" />
  <row Id="22530" PostId="14352" Text="We actually can't tell, other than 24 V motor uses 24 V and 36 V motor uses 36 V. The procedure to obtain that information is to look for exact manufacturer part numbers for motors and find their datasheets (usually good search engines will easily locate them, once you know the part number) and then look at characteristics in the datasheet. We can speculate that higher voltage motor may have higher torque, but we can't tell you for sure. Also, for the unique bicycle angle there's [this](http://bicycles.stackexchange.com/) site. " CreationDate="2011-05-17T08:41:03.690" UserId="1240" />
  <row Id="22531" PostId="14355" Score="1" Text="Create your own! It only takes a couple of minutes with the PCB software I use." CreationDate="2011-05-17T10:52:19.730" UserId="305" />
  <row Id="22532" PostId="14355" Text="@Leon HellerWhich software do you use sir?? How to create it?? Help me with study materials pl.." CreationDate="2011-05-17T11:00:21.927" UserId="1484" />
  <row Id="22533" PostId="14355" Text="The microbuilder library is a Cadsoft Eagle library. The library editor comes with Eagle. There are many online step+by+step tutorials on how to make Eagle parts. E.g. http://duckduckgo.com/?q=how+to+make+a+custom+part+in+eagle" CreationDate="2011-05-17T11:26:57.557" UserId="3876" />
  <row Id="22534" PostId="13290" Text="@Vicky, be definition just asking for the best ways to learn something is subjective." CreationDate="2011-05-17T11:32:55.797" UserId="230" />
  <row Id="22535" PostId="14352" Score="1" Text="This question got cross posted [here](http://bicycles.stackexchange.com/questions/3788/24v-vs-36v-brushless-dc-hub-motor-for-electric-bike). See my answer [here](http://bicycles.stackexchange.com/questions/3788/24v-vs-36v-brushless-dc-hub-motor-for-electric-bike/3791#3791)" CreationDate="2011-05-17T12:11:12.027" UserId="1486" />
  <row Id="22536" PostId="14355" Text="I use Pulsonix: http://www.pulsonix.com/index.asp" CreationDate="2011-05-17T12:16:00.003" UserId="305" />
  <row Id="22537" PostId="14357" Text="+1 Thanks Martin. Symplify passes the test!" CreationDate="2011-05-17T12:21:39.803" UserId="3145" />
  <row Id="22538" PostId="14352" Text="See [here](http://meta.stackoverflow.com/questions/64068/is-it-possible-to-post-questions-across-a-couple-of-the-sites-because-its-debata) about cross posted" CreationDate="2011-05-17T13:06:29.353" UserId="938" />
  <row Id="22539" PostId="2764" Text="I have no idea what to tag this. Ideas?" CreationDate="2011-05-17T13:10:06.360" UserId="1227" />
  <row Id="22540" PostId="1733" Text="We've extensively tested the Energize Lithiums in a cryochamber down to -40.  You can still pull 2 amps out of them at -20.  This drops to about 250 mA at -40, though." CreationDate="2011-05-17T13:17:50.380" UserId="3395" />
  <row Id="22541" PostId="1020" Text="With test as with design, there are those problems you struggle with and cannot conquer and you take those home (in your mind) and fight with them around the clock until you win." CreationDate="2011-05-17T13:53:49.990" UserId="985" />
  <row Id="22542" PostId="2510" Text="@manico - Thanks for the pics!  However, you should use the picture upload button in the future, instead of hosting them on your dropbox.  That automatically posts them to our site's permanent imgur account, so we don't loose them if you need to reorganize your dropbox.  Thanks!" CreationDate="2011-05-17T14:41:28.967" UserId="857" />
  <row Id="22543" PostId="14355" Score="1" Text="It only takes a few minutes with Eagle as well. I know people who will spend hours looking footprints of a simple part, when it would take less than 10 minutes to learn how." CreationDate="2011-05-17T14:44:37.453" UserId="638" />
  <row Id="22544" PostId="14355" Score="1" Text="@Morten - Please link to a result that you found useful, instead of posting a search.  For instance, I started with [these videos](http://claymore.engineer.gvsu.edu/~steriana/Videos/) and usually reference [this tutorial](http://myhome.spu.edu/bolding/EE4211/EagleTutorial4.htm) or the manual that comes with Eagle when I can't remember how to do something.  " CreationDate="2011-05-17T14:48:06.980" UserId="857" />
  <row Id="22545" PostId="14355" Score="1" Text="Note: Even better than posting a link would be a post here describing how to do it..." CreationDate="2011-05-17T14:48:54.670" UserId="857" />
  <row Id="22546" PostId="14355" Text="@Vicky - It appears from these comments that you're unlikely to get such a library (though you're welcome to wait a while).  Would you be interested in an answer describing how to do it yourself? " CreationDate="2011-05-17T14:49:45.793" UserId="857" />
  <row Id="22548" PostId="14361" Text="@Thomas O  What is the end goal of this?  Meaning, what are you going to do with the 4.43 or 3.57 MHz clock?  I'm just thinking that what you're asking is rather difficult and knowing a bit more can give us insight into what's important and what isn't." CreationDate="2011-05-17T15:06:00.787" UserId="3624" />
  <row Id="22549" PostId="1208" Text="I applaud this poster for their politeness - it is seriously undeserved in this case...." CreationDate="2011-05-17T15:49:53.820" UserId="249" />
  <row Id="22550" PostId="14365" Score="1" Text="I don't think a 4046 will work for color synchronization, since one only gets a about 2.5us of chroma reference every ~64us, and will thus have to 'coast' for about 60us while having a wave which is accurate to within a fraction of a microsecond at the end of that time.  One would either need to use a crystal-controlled PLL, or else have a crystal-controlled reference signal which one can phase-shift by very small amounts.  I'll extend my answer to cover the latter approach." CreationDate="2011-05-17T15:56:43.203" UserId="3123" />
  <row Id="22551" PostId="14361" Text="@David The end goal is a colour video overlay. I need to separate the colour burst from the video signal to generate the chroma signals." CreationDate="2011-05-17T16:43:19.547" UserId="1225" />
  <row Id="22552" PostId="14364" Text="I know that there is at least one OSD chip out there which does colour and certainly doesn't have enough memory for storing an entire frame (only about 1 Mbit.) So I think it's possible, but out of the realms of ASICs... it might be tricky. Thanks for the tips." CreationDate="2011-05-17T16:44:14.350" UserId="1225" />
  <row Id="22553" PostId="14364" Text="I was considering some kind of FPGA to do this if needs be." CreationDate="2011-05-17T17:01:04.047" UserId="1225" />
  <row Id="22554" PostId="14364" Text="@Thomas O: I think using a pseudo-delay-line approach (a series of gates feeding each other) might be good if you're using a chip where the delays work out to something reasonable.  Not so fast that you need to waste oodles of gates to get your delay, but not so slow that you have no real resolution.  See PPS above." CreationDate="2011-05-17T17:12:32.963" UserId="3123" />
  <row Id="22555" PostId="3854" Text="@Andrew Kohlsmith: If the timer is in synchronous mode, your approach is fine.  If the timer is running in asynchronous mode and isn't too fast (e.g. it's running off a 32KHz watch crystal) it's better to reloop if the LSB of the timer has changed.  Otherwise there's a risk that the timer might change precisely as it's being read, yielding an invalid reading." CreationDate="2011-05-17T17:24:34.160" UserId="3123" />
  <row Id="22556" PostId="14370" Text="@orbit, i hope to have time to talk about this later, but any data a processor is interpreting is binary in form. an ADC turns an analog point back into a digital value(which is a string of 1s and 0s. There are just more complex ways to do this then a magnitude." CreationDate="2011-05-17T19:07:14.330" UserId="230" />
  <row Id="22557" PostId="14376" Text="@Stephanie  So what's your question?  I could make some guesses, but it's best if you just ask it." CreationDate="2011-05-17T19:45:06.997" UserId="3624" />
  <row Id="22558" PostId="14374" Text="@P. Brian - Thanks for bringing this information here, but the question as stated is a *shopping* question, not an electronics design question.  We usually discourage those pretty heavily.  Can you try to adapt your question to better fit the scope of the site?  I understand that this tool could be useful when designing electronics.  I don't want to have to close your first question! " CreationDate="2011-05-17T20:37:59.307" UserId="857" />
  <row Id="22559" PostId="14373" Text="David - There's no need to dismiss the topic even though it is very theoretical and math-intensive.  &quot;People use this kind of stuff for their Ph.D. thesis&quot; reads like &quot;It's hard, you shouldn't try it&quot;, which is unmerited." CreationDate="2011-05-17T20:44:31.313" UserId="857" />
  <row Id="22560" PostId="14373" Text="@reemrevnivek  I wasn't dismissing it, you just interpreted it wrong.  If I thought that someone shouldn't even try it then I would have said so up front and not bothered linking to Wikipedia or wherever.  On the contrary, I feel that subjects like this are good to at least be familiar with even if we never actually implement one of these modulation schemes.  But it is worth knowing that there are few electrical subjects with as steep of a learning curve.  It's not something you can master after reading a book or a couple of web pages." CreationDate="2011-05-17T21:23:22.700" UserId="3624" />
  <row Id="22561" PostId="14373" Text="@David - OK, my bad.  Thanks for clarifying." CreationDate="2011-05-17T21:32:24.713" UserId="857" />
  <row Id="22562" PostId="14380" Text="Yes, someone has hacked it and made diagrams of the pinouts.  Do you have a more specific question?  Which data do you want to access?" CreationDate="2011-05-17T21:48:01.937" UserId="142" />
  <row Id="22564" PostId="14370" Text="@Kortuk - thanks for the reply here. My idea is to use the processor for this instead of sending the binary over the wire, so that more data can be transmitted in a single 'bit'. I see that at some point, this has to happen, but just not sure why we need to modulate with binary." CreationDate="2011-05-17T22:00:05.993" UserId="3621" />
  <row Id="22565" PostId="14375" Text="Thank you for the thorough response. The part about the practical limitation (the difficulty in being able to distinguish the precise signal, considering errors, etc) was particularly helpful. It doesn't completely deter me though, I just have to determine a level at which the error rate is low but the base is high (at whatever level feasible). Thanks again for the answer.  " CreationDate="2011-05-17T22:08:25.133" UserId="3621" />
  <row Id="22566" PostId="14373" Text="@David - Thanks for the links to the reading. I'll have to review these different methods so I can more intelligently compare and contrast them with the scheme I'm thinking of." CreationDate="2011-05-17T22:09:56.457" UserId="3621" />
  <row Id="22567" PostId="14371" Text="@supercat - Thanks for the helpful reply. I'm curious about the interference you speak of - the amplitude modulation will affect more than the frequency i'm transmitting on?  " CreationDate="2011-05-17T22:11:01.573" UserId="3621" />
  <row Id="22568" PostId="14372" Text="@stevenvh - thanks for the reply. I think what you are saying about the levels is like what AngryEE is saying about the number of valid voltage levels. I'm curious about different ways to help maintain the integrity of the system - any reasonable ways to help filter out the noise and ensure that the transmitter current is precise and without undue fluctuation?" CreationDate="2011-05-17T22:13:20.747" UserId="3621" />
  <row Id="22570" PostId="14367" Text="Siemens is another vendor...if not owning on of those mentioned. " CreationDate="2011-05-17T22:19:31.637" UserId="2157" />
  <row Id="22571" PostId="14368" Text="Yeah, my power EE college selected those for our hybrid boat project and contactors for AC signals." CreationDate="2011-05-17T22:21:11.730" UserId="2157" />
  <row Id="22572" PostId="14363" Text="@Jon: And how certain are you that there isn't a firmware program being executed?  Microcontrollers usually require fewer logic gates than the equivalent ASIC dedicated-hardware implementation.  It's really hard to tell a microcontroller from an ASIC, if the microcontroller firmware isn't user-accessible." CreationDate="2011-05-17T23:02:08.757" UserId="1743" />
  <row Id="22573" PostId="14375" Text="Keep in mind there's plenty that you haven't even touched on: coding techniques for one.  Reed-Solomon codes are an example - they're use in CDs.  The basic idea is that a group of n bits is encoded into n+m bits.  Codes are mainly used for error correction but can have other beneficial properties.  They're sort of the other half of communication theory - so both halves would be waveforms and codes." CreationDate="2011-05-17T23:23:32.550" UserId="249" />
  <row Id="22574" PostId="14370" Text="@orbit, I am just making the point if you are modulating to 256 different levels, you are still modulating with binary. It is all about bit error rate for the same output power when you talk about which communication scheme is going to work the best." CreationDate="2011-05-17T23:27:23.367" UserId="230" />
  <row Id="22575" PostId="14382" Score="1" Text="@GeorgeH, can you please bring over the information from your post and explain here. Links die, but Stack exchange never will." CreationDate="2011-05-17T23:28:58.373" UserId="230" />
  <row Id="22576" PostId="14377" Score="1" Text="@P.Brian.Mackey, just a link has very little value. We need to know what it does and why it does the job with a link to give supporting and more detailed information. Right now a dead link makes your answer invalid." CreationDate="2011-05-17T23:39:33.557" UserId="230" />
  <row Id="22577" PostId="14382" Text="Sorry - I tried, but the pinouts.ru page has a pretty in depth table that I couldn't figure out how to bring over." CreationDate="2011-05-17T23:52:05.880" UserId="3556" />
  <row Id="22578" PostId="14382" Text="@GeorgeH, Just sharing that a good source often dies but SE keeps it data available for download regularly. If the link dies your answer does not have any substance." CreationDate="2011-05-18T00:02:21.730" UserId="230" />
  <row Id="22579" PostId="14370" Text="@Orbit, There is one important step I am glad you are connecting. You are thinking about why we do something beyond being told it is how it is done. It is important to think about why a certain method is chosen to understand how things work." CreationDate="2011-05-18T00:13:38.100" UserId="230" />
  <row Id="22580" PostId="14383" Text="@hosiers, sorry, we do design of electronics. Finding components for consumer grade electronics and/or finding someone to purchase a component do not fit well in the Stack Exchange system." CreationDate="2011-05-18T00:43:24.313" UserId="230" />
  <row Id="22581" PostId="10189" Text="Mmmmm, doesn't sound like homework to me." CreationDate="2011-05-18T00:47:53.867" UserId="330" />
  <row Id="22583" PostId="5707" Text="Very nice! I use this sort of stuff all the time. " CreationDate="2011-05-18T01:22:20.327" UserId="330" />
  <row Id="22584" PostId="14363" Text="@Ben:  You know what? I probably shouldn't have said that.  Answer has been edited due to my ignorance.  I went with my gut assumption after looking at the block diagram, but I suppose it would be better to abstract any potential uC details anyways.  I suppose only those at FTDI would know, and I suppose it comes down to core licensing costs vs in house development time." CreationDate="2011-05-18T01:24:37.867" UserId="4172" />
  <row Id="22585" PostId="14383" Score="1" Text="Am I the only one that hoped this was for an old school Apple II?" CreationDate="2011-05-18T01:52:48.630" UserId="249" />
  <row Id="22586" PostId="14382" Text="is there a diagram (picture) of which wires send which signal?&#xA;thats what im asking" CreationDate="2011-05-18T02:03:16.827" UserId="3947" />
  <row Id="22587" PostId="14380" Text="^ that website does not work" CreationDate="2011-05-18T02:04:47.217" UserId="3947" />
  <row Id="22588" PostId="14380" Text="and where can i find the diagrams because i have not seen any and i have been looking" CreationDate="2011-05-18T02:05:09.273" UserId="3947" />
  <row Id="22589" PostId="14380" Text="http://ipl.derpapst.eu/wiki/Dock_Connector" CreationDate="2011-05-18T03:18:39.153" UserId="142" />
  <row Id="22590" PostId="14387" Text="Wow. Are there really oscilloscopes out there that can visualize a 10 GHz signal? That's pretty impressing." CreationDate="2011-05-17T20:38:13.660" />
  <row Id="22591" PostId="14387" Text="oops, wrote 1.25 gigabytes when I meant 1.25 gigabits." CreationDate="2011-05-17T21:33:57.557" UserId="4290" />
  <row Id="22592" PostId="14387" Text="But yeah, there are scopes that can do a really good job on 10Gig signaling. Anyone doing the latest PCI or 10Gig ethernet stuff needs them." CreationDate="2011-05-17T21:35:00.147" UserId="4290" />
  <row Id="22593" PostId="14386" Text="Why the downvote?" CreationDate="2011-05-18T04:49:08.073" UserId="305" />
  <row Id="22594" PostId="14387" Text="possible duplicate of [Alternating patterns in 8b/10b encoding](http://electronics.stackexchange.com/questions/14379/alternating-patterns-in-8b-10b-encoding)" CreationDate="2011-05-18T05:57:13.073" UserId="2064" />
  <row Id="22595" PostId="14386" Text="@Leon - Perhaps because of the 263(!) character URI. Ever heard of TinyURL?" CreationDate="2011-05-18T06:01:41.663" UserId="2064" />
  <row Id="22596" PostId="14387" Text="I doubt it because the running disparity calcs will keep selecting between different codes. Is there any testmode you can put the device into that you could use? " CreationDate="2011-05-18T06:42:57.947" UserId="814" />
  <row Id="22597" PostId="14390" Score="1" Text="Is the the supply a.c. or d.c? a.c. is better for the lamp and would allow you to use a phase control dimmer instead. If it is d.c. then you should consider a PWM control method for efficiency." CreationDate="2011-05-18T07:57:28.263" UserId="2110" />
  <row Id="22598" PostId="14395" Text="Thanks guys, I have edited my post with details on my project." CreationDate="2011-05-18T08:05:18.073" UserId="4297" />
  <row Id="22599" PostId="14383" Text="Finding specific electronic components should be able to fit in this site, but apparently I disagree with the moderators on this.  However, if you post a picture, and measure the distance between the pins, someone should be able to help you." CreationDate="2011-05-18T09:32:25.910" UserId="161" />
  <row Id="22600" PostId="14397" Text="Thanks toybuilder, I realised it is not cheap. Could you guys tell me the recommended hardware for this set-up. I need to estimate the cost involve." CreationDate="2011-05-18T09:33:23.023" UserId="4297" />
  <row Id="22601" PostId="14396" Text="@Stevenvh, or a lot of 555 timers pulsing to get better light out of a cheaper LED." CreationDate="2011-05-18T09:42:50.130" UserId="230" />
  <row Id="22602" PostId="14398" Score="2" Text="Solar panel data sheet?" CreationDate="2011-05-18T09:55:52.090" UserId="305" />
  <row Id="22603" PostId="14404" Text="Why do you need to bias the signal?" CreationDate="2011-05-18T12:00:04.680" UserId="305" />
  <row Id="22604" PostId="14404" Score="1" Text="Small note, you say you have a  220 uF decoupling cap. I think you might be referring to a coupling cap." CreationDate="2011-05-18T12:16:14.507" UserId="319" />
  <row Id="22605" PostId="14404" Score="1" Text="The signal is going to be read by an ADC, for a BPM counter(beats per min) And Kellenjb you are correct coupling cap and not decoupling - fixed" CreationDate="2011-05-18T12:31:23.990" UserId="2060" />
  <row Id="22606" PostId="14396" Score="2" Text="I'd use 72x70 for easier arithmetic. Or even 64x80, it uses the same number of 8 output ICs." CreationDate="2011-05-18T13:02:40.260" UserId="339" />
  <row Id="22607" PostId="14396" Text="@starblue - you're right, 64x80 makes more sense." CreationDate="2011-05-18T13:29:56.330" UserId="2064" />
  <row Id="22608" PostId="14392" Text="My setup is a GMII interface to a PCS/PMA wrapper that directly drives a transceiver. Output is 1000Base-TX (for driving an optical SFP)." CreationDate="2011-05-18T14:01:55.807" UserId="4290" />
  <row Id="22609" PostId="14387" Text="I think removing my PCS/PMA wrapper from my transceiver might be what I want to do." CreationDate="2011-05-18T14:04:14.293" UserId="4290" />
  <row Id="22610" PostId="14413" Text="Another (naive) thought I had was what about multiplying the number of I/O pins by the max current allowed per pin? Kind of a 'worst-case' scenario." CreationDate="2011-05-18T14:23:25.673" UserId="2654" />
  <row Id="22612" PostId="14415" Text="I doubt there will be a production board for this since I just want to mess around and learn stuff. Problem is that I only have one bench power supply output." CreationDate="2011-05-18T14:42:24.770" UserId="4303" />
  <row Id="22614" PostId="14413" Text="The problem is that the 1.2V VCCINT (core voltage I believe?) uses a lot of current as well if I'm not mistaken. 3.3V is only for I/Os and that maximum can be approximated rather easily, I assume." CreationDate="2011-05-18T14:44:48.543" UserId="4303" />
  <row Id="22615" PostId="14414" Text="I did try to use that but got an error (&quot;Compile error&quot;) when I loaded it into Excel. This is probably because I'm using it on a Mac with Office:mac 2011." CreationDate="2011-05-18T14:45:23.003" UserId="4303" />
  <row Id="22616" PostId="14405" Text="http://electronics.stackexchange.com/questions/515/how-to-convert-ac-to-dc  http://electronics.stackexchange.com/questions/12390/using-a-transformer-to-step-down-230v-to-12v" CreationDate="2011-05-18T14:45:34.737" UserId="142" />
  <row Id="22617" PostId="14414" Text="That's a very likely reason, unfortunately I only have Pages on my Mac at work, so I'm not able to confirm it right now." CreationDate="2011-05-18T14:50:13.880" UserId="3564" />
  <row Id="22618" PostId="14389" Text="Okay, thanks. I'm just really new to electronics." CreationDate="2011-05-18T14:55:06.590" UserId="4161" />
  <row Id="22619" PostId="14413" Text="Well for comparison sake, that big &quot;DE2&quot; board uses two AME1117 (1-amp) LDOs in parallel for the 1.2V VCCINT." CreationDate="2011-05-18T14:57:03.317" UserId="2654" />
  <row Id="22620" PostId="14413" Text="That's good to know! At least I'm starting to get the idea of which ballpark we're talking about." CreationDate="2011-05-18T15:58:57.730" UserId="4303" />
  <row Id="22621" PostId="14404" Score="1" Text="As a note: I use the first solution with no problems but my circuit is definitely not a high fidelity one as it is on a model aircraft with lots of other noise (motors, servo, wind etc.)" CreationDate="2011-05-18T16:11:20.387" UserId="1225" />
  <row Id="22622" PostId="14407" Score="1" Text="If the voltage from which the ADC derives its reference feeds the resistor divider, I don't see that having that voltage coupled into the audio feeding the ADC will be much of a problem.  Indeed, if there's any wavering in the ADC reference, I would think having it coupled to the ADC input with 50% amplitude would be better than having the reference move and the input not, although the audio signal would be degraded in any case.  If the ADC reference is an absolute voltage which is not available on an output pin, your bias should likewise be an absolute voltage (from a regulator or whatever)." CreationDate="2011-05-18T16:42:17.213" UserId="3123" />
  <row Id="22623" PostId="14412" Text="It is possible to achieve that kind of signal - it is right there in the table D10.2 D10=01010 and D.X.2=010 (EDCBA=01010 and HGF=010) and this is the same for both run disparities. " CreationDate="2011-05-18T17:18:50.657" UserId="1471" />
  <row Id="22624" PostId="14419" Text="Huh...  I just tried that and didn't get any hits. I must have messed up the topology and didn't notice." CreationDate="2011-05-18T17:23:12.120" UserId="1270" />
  <row Id="22625" PostId="14392" Text="you should be ok then by driving d10.2 (010 01010)" CreationDate="2011-05-18T17:24:46.847" UserId="1471" />
  <row Id="22626" PostId="14419" Text="Ah... I came in from a single small category, got distracted, then forgot that little detail when I came back to it. LTC3862 looks good to me. Thanks!" CreationDate="2011-05-18T17:43:49.607" UserId="1270" />
  <row Id="22627" PostId="2400" Text="I have used PacTec and Polycase enclosures before. They are really nice. For my application, I needed the Polycase enclosures modified with one rectangular and one circular cutout. Both the setup and per-piece (I ordered only 25x at a time) were very reasonable and cheap enough that it wasn't worth doing it myself." CreationDate="2011-05-18T18:07:55.520" UserId="2255" />
  <row Id="22628" PostId="11051" Score="2" Text="Sometimes the slider is called a wiper." CreationDate="2011-05-18T18:43:25.063" UserId="1225" />
  <row Id="22629" PostId="14352" Text="@JavaMan, I cannot close as duplicate from another site due to how the mechanics work, but cross posting is considered abusive behavior." CreationDate="2011-05-18T19:03:54.800" UserId="230" />
  <row Id="22630" PostId="2226" Text="What is your target cost?&#xA;What is your target size?&#xA;What type of environment do you need the system to work in?&#xA;What does the system actually need to do? It sounds like you have an embedded PC you are trying to replace.&#xA;Are embedded PCs too expensive for your application? USB can be converted to RS232 without much difficulty. I am not sure about the Modem. Haven't looked for one in&#xA;a while." CreationDate="2011-05-18T11:29:04.640" UserId="424" />
  <row Id="22631" PostId="5082" Text="Since I have been asked a number of times for parts/tools recommendations I placed two lists on my site. For parts see http://wiblocks.luciani.org/FAQ/faq-parts-list.html For tools see http://wiblocks.luciani.org/FAQ/faq-tools.html" CreationDate="2011-05-18T11:35:42.523" UserId="424" />
  <row Id="22632" PostId="14421" Text="@Dean, can you define what you mean by accurate?" CreationDate="2011-05-18T19:09:19.727" UserId="230" />
  <row Id="22633" PostId="14422" Text="This seems to be more of a consumer electronics question then a design question, what do others think?" CreationDate="2011-05-18T19:14:48.207" UserId="230" />
  <row Id="22634" PostId="14421" Text="@Kortuk edited question. " CreationDate="2011-05-18T19:18:30.513" UserId="1623" />
  <row Id="22635" PostId="3541" Text="I believe a typical cap actually behaves as a bunch of caps in parallel, each with a different ESR.  At any given frequency, the &quot;partial caps&quot; with higher ESR won't charge and discharge as much as those with smaller ESR, and they'll thus play less of a role in circuit behavior; this effect will be more pronounced at higher frequencies.  In axial electrolytics, the ESR of the &quot;partial caps&quot; would be pretty similar; in radial caps, the ESR of the portions nearer the leads will be much lower than that those further away." CreationDate="2011-05-18T19:39:06.130" UserId="3123" />
  <row Id="22636" PostId="3541" Text="For many power-supply applications, a cap with a non-uniform ESR may be preferable to one with a uniform ESR.  For things like audio coupling and filtering applications, the reverse may be true." CreationDate="2011-05-18T19:40:05.253" UserId="3123" />
  <row Id="22637" PostId="13515" Text="@kullin choksi If you are interested, here is a thesis that talks about this a bit, you probably have to be at a university to see it though. http://gradworks.umi.com/14/53/1453083.html" CreationDate="2011-05-18T19:46:31.850" UserId="319" />
  <row Id="22638" PostId="14422" Text="@kortuk The amount of design work is more centered around the mechanical aspects instead of the electrical ones." CreationDate="2011-05-18T19:47:54.610" UserId="319" />
  <row Id="22639" PostId="14422" Text="I think it's okay and someone answered with exactly what he was looking for. The question isn't obnoxious and is more than slightly electronics-centered.  I'd leave it." CreationDate="2011-05-18T20:43:39.223" UserId="249" />
  <row Id="22640" PostId="14412" Text="oh man, you're right. I don't know how many times I scanned the table (literally dozens) and missed that. Should've used a regular expression." CreationDate="2011-05-18T21:19:09.917" UserId="4290" />
  <row Id="22641" PostId="14392" Text="You're right. I got distracted by your mention of PAM-5 and missed that you gave me the data word I needed. Thanks for your help." CreationDate="2011-05-18T21:22:01.770" UserId="4290" />
  <row Id="22642" PostId="14427" Score="1" Text="As an aside - you may want to pop over to photo.stackexchange.com and ask if that battery usage rate is normal or if using a different battery may be better.  We have several prominent Pentax members." CreationDate="2011-05-18T22:58:05.037" UserId="3778" />
  <row Id="22643" PostId="14428" Text="What do you mean by a &quot;front end&quot;? More details are required, such as the sensitivity, output frequency, etc. The nRF24L01 is a complete transceiver." CreationDate="2011-05-18T23:10:14.857" UserId="305" />
  <row Id="22644" PostId="14428" Text="Sorry, I meant to say transceiver. The sensitivity has to be more than -80dBm.The modulation used is ASK with 256Kb/sec. " CreationDate="2011-05-18T23:46:46.563" UserId="4260" />
  <row Id="22645" PostId="14428" Text="As with most questions like this can you provide an example that is close but doesn't meet your requirements so we can get a better idea of what you're looking for?  Ultimately, with such broad requirements there's no guarantee that anyone will suggest something you're looking for." CreationDate="2011-05-19T00:10:01.200" UserId="249" />
  <row Id="22646" PostId="14428" Text="@Alexbb, by closing the question you are protected from downvotes, when you gain a larger amount of detail for what you are needing update your question and flag for moderator attention. We can come and reopen it then." CreationDate="2011-05-19T00:13:54.107" UserId="230" />
  <row Id="22647" PostId="14374" Text="@P.Brian.Mackey, if you can rectify the question as @reemrevnivek is asking we will reopen it. Just flag for mod attention when you think it is ready." CreationDate="2011-05-19T00:15:32.093" UserId="230" />
  <row Id="22648" PostId="14422" Text="@AngryEE, I think it is right at the boundary and just was looking for input. I currently hold no intention of removing it." CreationDate="2011-05-19T00:20:11.997" UserId="230" />
  <row Id="22649" PostId="14429" Text="@ToyBuilder, often the easiest way to make ultra high resolution time clocks is counting frequency from the mains voltage. Very easy, source is given, you just have to count." CreationDate="2011-05-19T00:21:55.100" UserId="230" />
  <row Id="22650" PostId="14430" Text="@Dr.Watson, Mathjax is there to make equations look nice. Please check that I have not changed any equations of yours to mean something else." CreationDate="2011-05-19T01:43:52.890" UserId="230" />
  <row Id="22651" PostId="14430" Text="@Kortuk: I had no idea we had such a markup!  Thanks for editing my post and demonstrating this for me.  In the future I will be sure to use it!" CreationDate="2011-05-19T01:54:28.753" UserId="2059" />
  <row Id="22652" PostId="14430" Text="@Dr.Watson, glad I did not mess up your equations, those edits too me a bit." CreationDate="2011-05-19T02:45:22.760" UserId="230" />
  <row Id="22653" PostId="14428" Text="OK, sounds fair. Will clear my thoughts before posting questions :o)." CreationDate="2011-05-19T03:16:05.843" UserId="4260" />
  <row Id="22654" PostId="14423" Text="If you don't have a microcontroller that can do 64 bit numbers, then you can always use multiple 16 or 32 bit counters to get the same result." CreationDate="2011-05-19T03:59:41.417" UserId="2288" />
  <row Id="22655" PostId="14393" Text="How about using a laser pointer intstead, scanning the wall with the pigeon holes, remotely reading the barcode on the front of the boxes, and illuminating the required area, maybe even with some cool patterns?" CreationDate="2011-05-19T05:17:17.220" UserId="3438" />
  <row Id="22656" PostId="14393" Text="How big do you plan to make each box? And, what for? " CreationDate="2011-05-19T05:35:14.307" UserId="3438" />
  <row Id="22657" PostId="14423" Score="3" Text="&quot;millisecond accuracy over days&quot; would mean about 10 ppb = 0.01 ppm." CreationDate="2011-05-19T05:44:30.390" UserId="339" />
  <row Id="22658" PostId="14370" Text="@Kortuk 256 levels is not a binary modulation.  Don't mistake the nature of the data feeding the modulator for the modulation.  " CreationDate="2011-05-19T06:29:52.230" UserId="2246" />
  <row Id="22659" PostId="14371" Text="@Orbit Any modulation will spread your signal out.  Only a pure un-modulated sine wave is a single frequency (and good luck building an oscillator without any phase noise).  Even just tapping out morse code spreads the carrier, especially if you want the starts and stops of the dots to be clear - there's actually an art to getting the turn on/turn off envelope of a keyed transmitter right, so that the symbols are distinct but not so punchy that they interfere with other communications only a few hundred hertz away" CreationDate="2011-05-19T06:42:32.350" UserId="2246" />
  <row Id="22660" PostId="14363" Score="1" Text="Usually, when you have a &quot;protocol&quot; you end up with a &quot;program&quot; to handle it... even if it's running on an engine buried deep in an ASIC or FPGA.  The exception would be things where blindingly fast speed trumps complexity, where you are likely to see a state machine or massive parallelism.  In between are engines where the compute path is built out of proportion to the control logic - sort of the original idea behind DSP processors" CreationDate="2011-05-19T06:48:01.303" UserId="2246" />
  <row Id="22661" PostId="14342" Text="I really don't see a generic question about a type of technology as being &quot;shopping&quot;.  To answer, anywhere from $\$$10-$\$$30.  Cheap enough to be found in PS3 controllers.  R/C helicopters in the $100 all-up price range can have impressive yaw control via these - from blurred rotation to instant stop when the control stick is released.  Or they can require constant trim changes if they have a bad and temperature sensitive implementation.  But ultimately they still are rate gyros - they should not be expected to hold a heading without slow drift for minutes at a time." CreationDate="2011-05-19T06:55:21.640" UserId="2246" />
  <row Id="22663" PostId="14249" Text="The real issue with a higher voltage rating is not cost, but the design trade-offs, such as a higher ESR and larger package." CreationDate="2011-05-19T07:08:43.680" UserId="2246" />
  <row Id="22664" PostId="14243" Text="I think the proper way to do this would be to reprogram the ESC to activate the necessary FETs for this mode. However, current draw is going to be involved; this may result in deeper discharge of your drawn down battey than is &quot;healthy&quot; for the typical Lipo cells, and if you are planning to operate the radio off the same battery, could result in drawing it down to the point where you loose the radio.  Plus without at least one sensor, it's as likely to cog in and undesired position as a desired one. " CreationDate="2011-05-19T07:14:43.287" UserId="2246" />
  <row Id="22665" PostId="14355" Text="@reemrevivek I remember that tutorial, very useful when I tried to figure out Eagle. I would also suggest looking at the Sparkfun tutorials: http://www.sparkfun.com/tutorials/110" CreationDate="2011-05-19T07:18:41.287" UserId="3876" />
  <row Id="22666" PostId="14223" Text="Just because the intended market of something was consumer use doesn't not preclude it being evaluated by engineers for another use.  As such, this is extremely _ON TOPIC_.  The valuable points raised in the answers are ample proof of that." CreationDate="2011-05-19T07:22:15.683" UserId="2246" />
  <row Id="22667" PostId="14370" Text="@Chris, I am not, I am trying to make a point that it is still just a method of sending 1s and 0s. " CreationDate="2011-05-19T07:29:23.010" UserId="230" />
  <row Id="22668" PostId="14416" Text=" As for the pre-amp would that circuit bias signal if I were using a un-amplified(phono) signal or microphne? or should it just go through a pre-amp that doesnt bias and bias the signal near the filter?" CreationDate="2011-05-19T07:47:15.723" UserId="2060" />
  <row Id="22669" PostId="4619" Text="Have you done some math? Simple non-usb RS232 usually has max speed of 115200bps, which is approximately 10KB. Let's say that each channel needs just 1 byte (which I doubt). You want to send 64 x 1000 bytes each second which is around 64KB. Much more then your serial throughput. There are some high speed USB serial cables with 921600bps, and although theoretically possible I doubt this is useful since this is on the edge and as I said 1 byte will hardy be enough, and micro controller will hardly have time for anything else. You will either have to lower your demands or prepare your wallet." CreationDate="2011-05-19T08:44:06.300" UserId="1129" />
  <row Id="22670" PostId="14429" Text="@Kortuk - from what I interpreted from Wikipedia, however, it appears that they target for 60 Hz, but may be off by a few seconds on any given day.  That doesn't sound like a truly great &quot;ultra high resolution&quot;..." CreationDate="2011-05-19T08:58:28.353" UserId="3308" />
  <row Id="22671" PostId="14416" Score="1" Text="Excellent explanation! Thanks!" CreationDate="2011-05-19T09:13:46.740" UserId="1802" />
  <row Id="22672" PostId="14429" Text="@ToyBuilder, actually, you have half the story. They keep track of how many cycles are going and if they get off they will then increase the number of cycles(60.1 instead of 60 Hz) to correct. This means over months you have a spot on reference, but can bounce by a few seconds in a day." CreationDate="2011-05-19T09:39:00.510" UserId="230" />
  <row Id="22673" PostId="14352" Text="@JavaMan: For reference, you can ask something on both sites, but tune the question to each site. Ask about the theoretical difference between different voltage motors here, and ask for suggestions between exact models on the bicycle site. What you can't do is ask the same general question on both sites even though it has aspects related to each. Either pick a site and go with it or split the question up to get fine tuned answers." CreationDate="2011-05-19T10:00:32.253" UserId="1486" />
  <row Id="22674" PostId="14434" Score="1" Text="I am sorry @Hitesh, This site is about designing electronics and I think that your question has more to do about using electronics as a consumer or software developer, chances are this question will be closed." CreationDate="2011-05-19T11:04:42.653" UserId="305" />
  <row Id="22675" PostId="14436" Text="Agreed!  When the hole is in a huge ground plane, it becomes almost impossible to solder properly with a regular iron!" CreationDate="2011-05-19T11:12:41.690" UserId="3308" />
  <row Id="22676" PostId="14436" Text="@Toybuilder - true, but my point is about vias, which aren't soldered at all!" CreationDate="2011-05-19T11:35:27.687" UserId="2064" />
  <row Id="22677" PostId="14436" Text="As I said, they sometimes are soldered." CreationDate="2011-05-19T11:37:32.187" UserId="305" />
  <row Id="22678" PostId="14436" Text="@Leon - I've hardly ever seen vias filled with solder. How would you fill a 0.1mm via, like between the pads of a 0.5mm pitch BGA? And even bigger vias (the one in the image is 0.5mm) are almost always covered with solder resist." CreationDate="2011-05-19T11:39:58.340" UserId="2064" />
  <row Id="22679" PostId="14432" Text="Good point, if we are looking at a change, the 0.6V constant should probably drop out somewhere.  I probably should just move onto Sedra&amp;Smith with the models like you mentioned, such as hybrid-pi. " CreationDate="2011-05-19T11:44:28.833" UserId="2059" />
  <row Id="22680" PostId="14434" Text="Hello Leon, My question is if we can design such electronic hardware? If yes, whats the strategy to follow?" CreationDate="2011-05-19T11:55:42.647" UserId="4314" />
  <row Id="22681" PostId="14436" Text="@Leon, I think the word &quot;flooding&quot; fits better than &quot;Tent&quot;." CreationDate="2011-05-19T12:05:17.560" UserId="938" />
  <row Id="22682" PostId="14440" Score="1" Text="[See this answer to a similar question.](http://electronics.stackexchange.com/questions/14385/potentiometer-vs-transistor/14386#14386)" CreationDate="2011-05-19T12:18:41.050" UserId="2110" />
  <row Id="22683" PostId="14440" Score="3" Text="possible duplicate of [I don't care how a transistor works, how do I get one to work?](http://electronics.stackexchange.com/questions/5336/i-dont-care-how-a-transistor-works-how-do-i-get-one-to-work)" CreationDate="2011-05-19T12:34:13.457" UserId="319" />
  <row Id="22684" PostId="14440" Score="3" Text="Eh, not sure if it is an exact duplicate. Slight difference between &quot;How do I get one to work&quot; and &quot;How does it work&quot;." CreationDate="2011-05-19T12:36:02.847" UserId="319" />
  <row Id="22685" PostId="14444" Text="I think I may not have worded the question well.  In the parallel RLC circuit I am describing, the Q of the circuit will depend only upon the inductor (assuming the capacitor is lossless), because it was created by forming an _equivalent_ circuit out of the series inductor and its losses modeled by a series resistor.   You obtain the equivalent parallel RLC circuit by applying the equations in my post.  What I'm not understanding is why when the value for the inductor calculated in this equivalent circuit is different, the resonant frequency of the tank stays the same." CreationDate="2011-05-19T12:53:48.930" UserId="4129" />
  <row Id="22686" PostId="14445" Text="If one-way communication is the only requirement perhaps it could be simpler to use some FSK modulator (based on NE555 perhaps?) and demodulate in software?" CreationDate="2011-05-19T12:54:24.933" UserId="3564" />
  <row Id="22687" PostId="14444" Text="Let's say I have a 50 nH coil in series with 10 ohms, representing its internal losses.  In parallel with that I have a capacitor, value doesn't matter.  Applying the transformations above,  its equivalent parallel representation is a 108 ohm resistor in parallel with a 55 nH inductor.  The Q of the series combination or parallel combination at a frequency is the same, since they represent the same inductor.  But is the resonant frequency of the tank calculated using the original inductance, or the new inductance? The above analysis indicates the &quot;old&quot; inductance.  So what's the 55nH about?" CreationDate="2011-05-19T13:00:27.490" UserId="4129" />
  <row Id="22688" PostId="14432" Text="+1 This is the best way. (@Dr. Watson - I've just gone through the Hybrid-pi analysis over a cup of coffee. I can post my result if you like)." CreationDate="2011-05-19T13:02:10.420" UserId="2234" />
  <row Id="22689" PostId="14436" Score="1" Text="@Daniel Grillo  &quot;Tent&quot; is the &quot;proper&quot; word.  I agree that it's a dumb term, but people know what it means.  Where if you say &quot;flooding&quot; then they might not understand.  Normally &quot;flooding&quot; refers to copper planes on a PCB that are not on the normal power or ground layers.  " CreationDate="2011-05-19T13:03:02.293" UserId="3624" />
  <row Id="22690" PostId="14445" Text="@Czajnik I have found that purely analog based methods tend to be harder to design and get working then digital. It is all where your comfort zone is though." CreationDate="2011-05-19T13:05:17.547" UserId="319" />
  <row Id="22691" PostId="14436" Text="@David, Ok. Thanks for your explanation. I suggest &quot;flooding&quot; because I thought it was more commonly used." CreationDate="2011-05-19T13:10:20.293" UserId="938" />
  <row Id="22692" PostId="14446" Text="@David, You also do not use thermal relief for through hole pads?" CreationDate="2011-05-19T13:24:39.863" UserId="938" />
  <row Id="22693" PostId="14440" Text="The &quot;Transistor man&quot; cartoon is intended to show how a transistor works. A seven year old should be able to understand it." CreationDate="2011-05-19T13:29:16.397" UserId="305" />
  <row Id="22694" PostId="14439" Text="Bottom of the thread you linked says they're servos and the guy who said they're steppers said he was just guessing." CreationDate="2011-05-19T13:35:33.247" UserId="3778" />
  <row Id="22695" PostId="14444" Score="1" Text="Those two R/L combinations will have the same impedance at about 100MHz, but then so would 50nH in parallel with a 98Ω resistor and that combination would have the same Q with a resonant capacitor of about 51pF. That is, it's only consistent if you have $R_p=Q^2R_s$ which you get by multiplying $Q=\frac{X_L}{R_s} by Q=\frac{R_p}{X_L}$" CreationDate="2011-05-19T13:43:58.483" UserId="2234" />
  <row Id="22696" PostId="14432" Text="@MikeJ-UK:  If it would not be too much trouble, I'd appreciate it.  My copy of Sedra&amp;Smith just arrived this morning, and I can try to follow." CreationDate="2011-05-19T13:48:32.403" UserId="2059" />
  <row Id="22697" PostId="14445" Text="@Kellenjb Same here, I'm primarily a software developer, feeling much more comfortable in the digital world, yet for this particular thing analog way looks tempting :)" CreationDate="2011-05-19T13:50:43.537" UserId="3564" />
  <row Id="22698" PostId="14448" Score="8" Text="What about the delay in the detector?" CreationDate="2011-05-19T13:53:46.803" UserId="2234" />
  <row Id="22699" PostId="14446" Text="@Daniel Grillo. Right. I don't use thermal reliefs anywhere. " CreationDate="2011-05-19T13:59:54.010" UserId="3624" />
  <row Id="22700" PostId="14442" Score="1" Text="@Hitesh, nice job re-posting. I think this fits pretty well." CreationDate="2011-05-19T14:00:35.287" UserId="230" />
  <row Id="22701" PostId="14443" Score="1" Text="The controllable valve part is correct, but I don't like it when people say a transistor &quot;acts as an amplifier&quot;, especially not to newbies.  It's used *to build* amplifiers.  An amplifier is the whole assembly, including the power source and a controllable valve.  Transistors do not have a power source inside.  The first amplifiers used carbon microphones as their controllable valve, but people don't call capsules of carbon &quot;amplifiers&quot;." CreationDate="2011-05-19T14:02:37.890" UserId="142" />
  <row Id="22702" PostId="14444" Text="Right, it's only consistent if the series reactance is equal to the parallel reactance after the transformation.  But that's just an approximation: for low values of inductor Q the parallel reactance is not equal to the series reactance.  So what happens to the resonant frequency of the tank? The resonant frequency is always going to be fixed by the lossless inductor and capacitor values.  But at low Q values it seems the equivalent parallel value of inductance increases.I know that with low damping the peak gain frequency of a tuned circuit will shift, perhaps that's how it's showing up here?" CreationDate="2011-05-19T14:02:39.277" UserId="4129" />
  <row Id="22703" PostId="14444" Text="I think I understand what's going on now.  The &quot;undamped&quot; resonant frequency is in the equations, but at low values of Q the peak of the response is going to shift, which is why the equivalent value of parallel reactance will change at low Q - the frequency where the impedance of the circuit is at maximum has changed." CreationDate="2011-05-19T14:14:14.243" UserId="4129" />
  <row Id="22704" PostId="14404" Text="You're intentionally trying to isolate low frequencies with those RC filters, right?" CreationDate="2011-05-19T14:17:10.560" UserId="142" />
  <row Id="22705" PostId="14448" Score="1" Text="@MikeJ-UK oops.. I should consider that.." CreationDate="2011-05-19T14:17:49.977" UserId="4317" />
  <row Id="22706" PostId="14416" Text="@jsolarski: I don't understand your question about the preamp.  That circuit is a high-gain mic element preamplifier.  Are you just looking to buffer the signal before it goes into the ADC?" CreationDate="2011-05-19T14:19:07.173" UserId="142" />
  <row Id="22707" PostId="14371" Text="@Chris Stratton: Indeed.  My point was that modulating a signal on every wave, even if one had the technical means to do so, would generate a signal which would splatter a huge amount of the surrounding bandwidth.  You are correct that on-off keying can be nasty if the switch-on/switch-off transitions are too sharp; in the early days of radio telegraphy, I don't think people worried about the spill of keying onto adjacent channels since the resulting noise bursts would be small and infrequent enough as to not preclude hearing the main signal of interest." CreationDate="2011-05-19T14:21:29.070" UserId="3123" />
  <row Id="22708" PostId="3687" Text="@Fake Name:  Depends on how hefty a joule thief we're talking.  With a supply that could provide a lot of current it would probably be possible to construct a blocking oscillator type circuit that could do significantly more than a few mA.  A more refined joule thief that could put out several watts would probably be what's called a &quot;self resonant flyback converter.&quot;" CreationDate="2011-05-19T14:26:17.213" UserId="4129" />
  <row Id="22709" PostId="14371" Text="@Chris Stratton: Of course, one one tries to get radio to go from being something one can listen to and decode to being something that's pleasant to listen to, all the little noise bursts caused by adjacent channels would become unacceptable, especially as the number of radiotelegraph operators increased.  BTW, I wonder if there are any RF data receivers that are designed for use with OOK transmitters, but provide analog outputs?  It would seem like capturing an analog signal would allow a processor to improve reception using retroactive threshold adjustment." CreationDate="2011-05-19T14:27:28.647" UserId="3123" />
  <row Id="22710" PostId="14446" Text="Where I work we still use thermal relief for through hole pads. We don't use it for vias. We sell thousands of products a month and we don't have any trouble." CreationDate="2011-05-19T14:27:53.873" UserId="938" />
  <row Id="22711" PostId="14418" Text="@Leon: I ended up going with National's LM5118...  the web designer is a very nice tool." CreationDate="2011-05-19T14:34:50.093" UserId="1270" />
  <row Id="22712" PostId="14444" Text="@Bitrex - I see what you're getting at. The frequency of peak gain in a series LCR circuit will change with frequency - but at high damping/low Q. For instance with damping approaching zero (Q infinite) peak gain is observed at resonance. With damping of 0.5 (Q=1) peak gain is at 71% of the natural frequency." CreationDate="2011-05-19T14:35:54.943" UserId="2234" />
  <row Id="22713" PostId="3802" Text="The GameBoy Color used a reflective full-color LCD, and TI graphing calculators used a reflective pseudo-color LCD (I think varying the activation level of a pixel would change the hue).  I don't know why I haven't seen reflective color displays for sale anywhere, nor have I seen them used for the outside display on cell-phones, since they'd seem very useful." CreationDate="2011-05-19T15:05:34.963" UserId="3123" />
  <row Id="22714" PostId="14451" Text="It sure looks like it. Good thing I don't have any iDevices then." CreationDate="2011-05-19T15:07:55.203" UserId="1240" />
  <row Id="22715" PostId="14436" Text="@stevenh: It's very common with prototypes to solder wires to vias, for test points if nothing else.  If a board (proto or early production) needs to be altered, having a via available to solder to can make rework much easier." CreationDate="2011-05-19T15:13:04.443" UserId="3123" />
  <row Id="22716" PostId="14429" Score="1" Text="That chip-scale atomic clock looks really cool.  There are definitely uses for such precision.  If one could get such precision in a cheap low-power device (dreaming, I know) one could greatly improve the network efficiency and reduce the network acquisition time of things like cell phones.  Though actually what I'd like to see would be a standard time signal that would be broadcast nationwide using repeaters (perhaps piggy-backing on cell-phone equipment).  WWV is slow, and reception is spotty at most times of day.  If a communications device could power on and..." CreationDate="2011-05-19T15:21:27.857" UserId="3123" />
  <row Id="22717" PostId="14429" Score="1" Text="...within a second (and without using too much energy) be able to know within 10ms or so what time the device it wanted to communicate with would think it was, that would make it much easier for low-power devices to maintain occasional communication." CreationDate="2011-05-19T15:22:58.090" UserId="3123" />
  <row Id="22718" PostId="3797" Text="I've found the LCD on my Nokia phone to be relatively daylight readable but my cheap Sagem is almost completely unreadable. Maybe something to check out: PDA or phone LCDs from Nokia and other slightly higher-end phones." CreationDate="2011-05-19T15:47:47.643" UserId="1225" />
  <row Id="22719" PostId="14452" Text="+1 - Very difficult to answer this kind of question and make it accessible, interesting and correct. Nicely worded." CreationDate="2011-05-19T15:56:47.510" UserId="2234" />
  <row Id="22720" PostId="14418" Text="Try not to use electrolytic capacitors (they tend to dramatically lose capacitance at -40C) and make sure that you have ample cooling for the device - the MOSFET drivers inside the IC will dissipate power and it won't take much for the IC to reach OTP at 85C ambient. You could consider having high input-Z drivers outside the IC, moving the power from inside the package to outside of it. Make sure you have an external over-voltage protection circuit too, for safety." CreationDate="2011-05-19T15:59:24.757" UserId="1293" />
  <row Id="22721" PostId="14371" Text="If you want to do further processing on an OOK signal, you can mix it down so that the center frequency is an audio tone (how code was traditionally ear-demodulated) and then do DSP at audio frequencies.  In actuality this gets you both the desired signal and it's image, which can be annoying, so a common technique today is to mix with two local oscillator phases, producing audio frequency I and Q signals - by examining the phase there you can tell the positive and negative frequencies apart.   By fortunate coincidence a lot of cheap widely installed ADC's already have two channels... " CreationDate="2011-05-19T16:00:56.543" UserId="2246" />
  <row Id="22722" PostId="14370" Text="@Kortuk - only if you choose to confine yourself to that.  It could as easily be a method of sending 0s, 1s, and 2s, or {1-10}s or whatever.  We're best at building binary computers, so we habitually translate to that, but there's no such preference in the modulation math." CreationDate="2011-05-19T16:04:56.417" UserId="2246" />
  <row Id="22723" PostId="14443" Score="1" Text="The output or current flowing through is related through multiplication of the input, so saying that it amplifies, is not incorrect.  Fits with the dictionary definition of the word." CreationDate="2011-05-19T16:41:12.837" UserId="985" />
  <row Id="22724" PostId="14370" Text="@ChrisStratton, i understand that. I am saying that any value you send and then decode is going to be binary, that is the nature of current processors. It is not about what the signaling is on the line, it is about what the datarate is for a specific SNR. I think you are taking me far too literally. I could represent it in hex also, that has not affect on the limits of it. We use phase encoding because of the very low BER for the same power." CreationDate="2011-05-19T16:42:56.303" UserId="230" />
  <row Id="22725" PostId="14443" Text="back to the faucet or valve or tap, turn it on a little you get a little water, but at some point you turn it on all the way and you dont get any more water, there is a limit, that is when the transistor becomes a switch, close the faucet, off, or open the faucet at least to the point that the flow is at a maxium and the switch is on." CreationDate="2011-05-19T16:43:26.813" UserId="985" />
  <row Id="22728" PostId="14448" Score="1" Text="How long is your fiber?" CreationDate="2011-05-19T17:06:39.183" UserId="339" />
  <row Id="22729" PostId="14371" Text="@Chris Stratton: I was thinking of something that would simply give a DC level in relation to signal strength at a given frequency, with the intention that the level would be used similar to the on/off output of a typical OOK receiver, but with better control over detection thresholds.  Among other things, if were trying to receive data encoded using a 3-of-13 method (three pulses every thirteen time slots to encode 8 bits of data) one could examine the signal levels in thirteen time slots and select the top three.  This would improve rejection of some types of noise." CreationDate="2011-05-19T17:18:03.697" UserId="3123" />
  <row Id="22730" PostId="14371" Text="@supercat A regular AM demodulator will give you an analog level which you can digitize, but you need a filter to limit the bandwidth.  The narrowness of your filter constrains how fast you can have the signal appear to turn on and turn off.  At intermediate frequencies suitable for narrowband data rates, it's much, much cheaper to make a precise narrow filter (to get the point on this tradeoff you desire) computationally than with crystals or mechanical resonators.  Also if you are too narrow, you will run into problems if the transmitter frequency is slightly off from the receiver." CreationDate="2011-05-19T17:22:15.910" UserId="2246" />
  <row Id="22731" PostId="14436" Text="Sometimes, the other end of the via goes right to a SMD pad, and heat will get sunk to the planes through the via." CreationDate="2011-05-19T18:12:47.503" UserId="3308" />
  <row Id="22732" PostId="14453" Text="Nice explanation, so +1. I used term complicated mainly because of the way PCB was made (and that can't be seen on the schematic). They had tons of extremely thin tracks running under tiny SMD resistors." CreationDate="2011-05-19T18:13:00.420" UserId="1240" />
  <row Id="22733" PostId="14451" Text="Removing the resistors will not likely make it charge, since only the VCC and GND are required for that. +1 about the iDevices." CreationDate="2011-05-19T18:14:01.060" UserId="2157" />
  <row Id="22734" PostId="3082" Text="Vector used to sell &quot;eyelets&quot; for their protoboards that could also be used for a similar purpose - although the hole sizes are significantly larger than for wires. (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&amp;name=V1066-ND - Thanks Digikey!)" CreationDate="2011-05-19T18:15:26.143" UserId="3308" />
  <row Id="22735" PostId="14371" Text="@Chris Stratton: I think I see what you're getting at.  Most receivers are hetrodynes rather than homodynes, so after the receiver has done its first bit of processing, the signal will be in the form of a modulated IF wave.  I recall reading some years ago about some companies using a homodyne receiver design, but I don't know what became of that.  As for the efficiency of computationally filtering the IF, that could certainly be done, but I don't know how energy-efficient that would be?  One of my potential future projects..." CreationDate="2011-05-19T18:34:08.623" UserId="3123" />
  <row Id="22736" PostId="14371" Text="@Chris Stratton: ...may be a store-and-forward network of battery-powered data acquisition units.  It would be possible to demodulate a 100KHz IF wave using an ARM, but I would expect that the current required to run a processor that could do that would exceed the current required for a decent analog receiver." CreationDate="2011-05-19T18:37:47.387" UserId="3123" />
  <row Id="22737" PostId="14459" Text="Any suggestions on what is causing the loss of volume then (because attenuation is definitely the issue), and everything from the coax converter works fine on other machines. So it is either the laptop or that cable." CreationDate="2011-05-19T18:56:31.303" UserId="4324" />
  <row Id="22738" PostId="2258" Text="With a single supply, I would suggest looking at the INA210 instead, and put in on the low side. It has a CMRR that extends below 0. I've used it before, it is an excellent little amp. You could probably do without any external components besides your shunt resistor. And a bypass cap..." CreationDate="2011-05-19T18:58:03.063" UserId="3876" />
  <row Id="22739" PostId="14371" Text="@supercat I think you'll find most low power consumption receivers today are DSP rather than analog, though likely dedicated hard wired DSP rather than a general purpose processor.  One of the reasons is you can play games like only wake up the receiver intermittently if you are willing to put a preamble on the initial message.  An analog receiver is likely to have bias current flowing all the time.  Precision analog stuff is also a lot more expensive to manufacture." CreationDate="2011-05-19T19:01:23.010" UserId="2246" />
  <row Id="22740" PostId="14459" Score="2" Text="@Ali Lown,  I would rule out the cable if you're hearing your audio properly (at any volume).  This would indicate that the digital bit-stream is intact.  As Taniwha mentioned, this is a digital signal, and we're simply sending a stream of numbers from the 3.5mm jack on your laptop all the way to the decoder.  I would look in to the laptop's settings some more - I know you said you checked things out on that end but I'd be tempted to say that a stone was left unturned.  Good luck!" CreationDate="2011-05-19T19:14:36.793" UserId="4172" />
  <row Id="22741" PostId="14371" Text="@Chris Stratton: I would have expected there to be various games with things like switched-capacitor circuits.  For example, if one has filtered an input to take care of everything above 1.5x the target frequency, I would expect that one could use four pass-gate integrators (a,b,c,d), each driven at the target frequency, but 90 degrees out of phase, to feed four filters.  The strength of the detected signal, squared, would be (a-c)^2+(b-d)^2.  I would think running a pass-gate integrator at a high frequency would be cheaper than running an ADC at that rate." CreationDate="2011-05-19T19:46:18.917" UserId="3123" />
  <row Id="22742" PostId="14445" Text="I would be a bit concerned about the availability of power.  I suspect that the square needs far less current than an image sensor running fast enough to read fingerprint features." CreationDate="2011-05-19T20:16:21.087" UserId="3308" />
  <row Id="22743" PostId="686" Text="Why the downvote?" CreationDate="2011-05-19T20:45:39.650" UserId="305" />
  <row Id="22745" PostId="14464" Text="Just be careful not to reverse the polarity of the neutron flow." CreationDate="2011-05-19T20:54:48.470" UserId="3876" />
  <row Id="22746" PostId="14371" Text="@supercat - you've just re-invented the commutating mixer, often implemented with bus switches rather than &quot;rf&quot; parts.  It's a well known technique - a clean oscillator, a digital divider to get phases, a bus switch, I and Q op amp low pass filters each taking differential input from opposing integrators, and then into a dual channel audio rate ADC, possibly a soundcard." CreationDate="2011-05-19T20:58:08.850" UserId="2246" />
  <row Id="22747" PostId="14465" Score="1" Text="Afterthought: would it be okay to ask for the word on english.SE?" CreationDate="2011-05-19T21:02:12.083" UserId="3438" />
  <row Id="22750" PostId="14455" Text="@Madmanguruman, So no scaring my family with terrible tales of killer telephones then ;D. Very definitive answer, Thank You!" CreationDate="2011-05-19T21:05:58.970" UserId="4184" />
  <row Id="22751" PostId="14461" Text="Hmm, are you sure it is RMW? Because OP mentions that it does not effect PORTB. " CreationDate="2011-05-19T21:08:30.237" UserId="1225" />
  <row Id="22752" PostId="14464" Text="Current is a flow of charge, so it's not really an &quot;opposite&quot;.  Putting energy into a capacitor might more accurately be called &quot;voltaging&quot;  :)" CreationDate="2011-05-19T21:11:50.360" UserId="142" />
  <row Id="22754" PostId="14397" Text="Probably less than 20 EUR per box. Certainly more than 1 EUR per box. Development might be around one engineer-month, putting it at about 10k plus hardware. If I had to place a bet, I would go for 25k - 50k Euros for the prototype. " CreationDate="2011-05-19T21:18:31.197" UserId="3438" />
  <row Id="22755" PostId="14461" Text="The ports are different, because of the comparator inputs. That might have an effect." CreationDate="2011-05-19T21:31:09.157" UserId="305" />
  <row Id="22756" PostId="14462" Text="What the flux? Had to say it. And I do not think saying you are charging it is a misnomer. You are causing a separation of charge and moving charge. I can see where the confusion comes from." CreationDate="2011-05-19T21:33:20.783" UserId="230" />
  <row Id="22757" PostId="14461" Text="Well, whatever the reason, abstracting the port via my own register seems to have solved it - seems a bit strange as the data sheet says it does a read-modify-write for all the ports.  My guess is a bug in the system means the read of an output bit is not working right." CreationDate="2011-05-19T21:36:09.730" UserId="4245" />
  <row Id="22758" PostId="13937" Text="@daniel ok thats fine - thats an american manufacturing company, surprising they have malware on their site" CreationDate="2011-05-19T21:36:22.897" UserId="4125" />
  <row Id="22759" PostId="14371" Text="@Chris Stratton: My point was that I'd think that semi-analog approach would be more efficient than trying to process signals numerically at a frequency substantially above the highest demodulated frequency of interest.  Actually, I'm curious what disadvantages exist to that general approach as compared with a super-hetrodyne?  Note that if the frequency references are stable, one could probably generate an accurate enough quadrature gate without needing a higher frequency to derive it." CreationDate="2011-05-19T21:42:18.157" UserId="3123" />
  <row Id="22760" PostId="14457" Text="I don't know exactly (because I'm using some kind of experiment kit) but it seems that your guess is right.&#xA;Thanks for the answer!" CreationDate="2011-05-19T22:20:50.953" UserId="4317" />
  <row Id="22761" PostId="10666" Text="you can get several miles of range in the 900Mhz ISM band with appropriate antennas without exceeding FCC limits." CreationDate="2011-05-19T22:31:30.913" UserId="1438" />
  <row Id="22762" PostId="14469" Score="1" Text="can you comment on this requirement a bit more? &quot;a socket connection is made on a specific local port&quot;  What is the host machine in this case?" CreationDate="2011-05-19T22:54:20.287" UserId="4172" />
  <row Id="22763" PostId="13937" Text="@Roberto, it have happend with my blog too, sometime ago. Shits happen :)" CreationDate="2011-05-20T00:30:23.060" UserId="938" />
  <row Id="22764" PostId="7735" Text="+1 6809 for the win!  I loved my Coco" CreationDate="2011-05-20T01:44:58.313" UserId="3983" />
  <row Id="22765" PostId="14453" Text="Thanks for the up vote. I didn't mean to give offense with the voltage divider explanation. It was a reflection of the process I went through when I was building my own USB chargers." CreationDate="2011-05-20T01:47:44.223" UserId="4319" />
  <row Id="22766" PostId="10666" Text="Or just get a ham radio license." CreationDate="2011-05-20T01:59:51.270" UserId="1374" />
  <row Id="22767" PostId="3760" Text="Sounds like you have some layout issues - your AGND and DGND layers shouldn't be overlapping (they'll couple together), so you shouldn't need separate planes for the two." CreationDate="2011-05-20T02:01:11.160" UserId="1374" />
  <row Id="22768" PostId="14478" Text="Is there any particular reason why you're using a circuit for a motor with a kickback diode?  I would just pull the 1N4001 and try again." CreationDate="2011-05-20T05:19:27.053" UserId="2288" />
  <row Id="22769" PostId="14445" Text="@kellenjb Thanks so much. It was insightful." CreationDate="2011-05-20T06:08:37.463" UserId="4314" />
  <row Id="22770" PostId="14445" Text="@Toybuilder the scanner I am planning to use consumes just 20mA of power (at 4.5V). Do you think this can be managed from the headphone jack or do I have to provide an external power source?" CreationDate="2011-05-20T06:10:36.103" UserId="4314" />
  <row Id="22771" PostId="1040" Text="**HIGHLY** recommended.  You end up learning about not only the FPGA and VHDL side of things, but also how processors work, what's needed in the way of development tools to support a processor, etc." CreationDate="2011-05-20T06:28:07.677" UserId="2246" />
  <row Id="22772" PostId="14439" Text="Probably brushless servo motors.  Actually steppers _are also_ brushless motors, only ones with an inordinately high number of poles and low efficiency compared to the ones used in closed-loop servo systems." CreationDate="2011-05-20T06:30:55.773" UserId="2246" />
  <row Id="22773" PostId="1856" Text="This is not really an answer to the specific question.&#xA;Drop the multimeter and buy one of these: [http://www.ztsinc.com/minimbt.html](http://www.ztsinc.com/minimbt.html)&#xA;I use many alcaline batteries (an application where rechargeables are not an option) and it really works, flawless." CreationDate="2010-03-14T11:17:06.700" UserId="244" />
  <row Id="22774" PostId="14491" Text="Vision system??" CreationDate="2011-05-20T13:04:09.570" UserId="2157" />
  <row Id="22777" PostId="14497" Score="2" Text="are you talking about a serial-in, serial-out shift register, or a serial-in, parallel-out one?" CreationDate="2011-05-20T13:31:22.947" UserId="2288" />
  <row Id="22778" PostId="14497" Text="What's the difference, and does it make a difference?" CreationDate="2011-05-20T13:46:36.293" UserId="1657" />
  <row Id="22779" PostId="14497" Score="1" Text="Give a device reference, so that we can check a data sheet." CreationDate="2011-05-20T14:11:34.340" UserId="305" />
  <row Id="22780" PostId="14497" Text="serial-in serial-out will time delay all of the data you are clocking in.  serial-in parallel-out will output all of the data you clocked in at once on a parallel data bus.  I have used the latter to drive things like LED segments, or any time I don't have enough I/O available." CreationDate="2011-05-20T14:24:21.797" UserId="2288" />
  <row Id="22783" PostId="14497" Text="So basically, the serial-in parallel-out register is asynchronous." CreationDate="2011-05-20T14:39:11.663" UserId="1657" />
  <row Id="22785" PostId="14501" Text="If I simulate sending commands to a shift register right at the rising edge, the shift register doesn't respond. I have to start the command before the rising edge and leave it on during the rising edge for it to be recognized. Why is that?" CreationDate="2011-05-20T14:51:05.413" UserId="1657" />
  <row Id="22786" PostId="14501" Text="@2000k404notfound  Sounds like you need to understand what setup and hold time is.  Here's a link:  http://en.wikipedia.org/wiki/Flip-flop_(electronics)#Setup_and_hold_times" CreationDate="2011-05-20T15:00:43.930" UserId="3624" />
  <row Id="22787" PostId="14474" Text="Yeah, you can't go wrong with a MAXn232, and there are a million projects out there that do nothing but level shifting for that sort of situation." CreationDate="2011-05-20T15:01:36.053" UserId="3983" />
  <row Id="22788" PostId="14477" Text="Yeah, I'm covered for LCD's.  I have that Parallax IR motion detector and I will buy a few photosensitive devices.  Also, a few temp sensors would be handy.  But that is off the point of my question, though." CreationDate="2011-05-20T15:03:24.273" UserId="3983" />
  <row Id="22789" PostId="14474" Text="Can't go wrong with Maxim, period!" CreationDate="2011-05-20T15:04:06.313" UserId="3983" />
  <row Id="22790" PostId="14457" Score="1" Text="6ms ~ 1200km. Speed of light in a fiber is only about 200 000 km/s" CreationDate="2011-05-20T15:18:47.363" UserId="2064" />
  <row Id="22791" PostId="14484" Text="@AndreHeath, this is a better fit for super user. This has some to do with consumer electronics, but is not about designing electronics." CreationDate="2011-05-20T15:24:31.033" UserId="230" />
  <row Id="22792" PostId="14498" Text="How about making one of the countless serial AVR programmers and using it to write the Arduino firmware? [This](http://electronics-diy.com/avr_programmer.php) one worked for me, but I have USB to serial converter, so it works at amazing 3 B/s. If the programer lines on your other project are available, you can dump firmware using AVRdude. You could also probably get it form the Internet, but I don't know where to look. " CreationDate="2011-05-20T15:28:49.030" UserId="1240" />
  <row Id="22793" PostId="14474" Text="Build the converter into the cable, then you need only one." CreationDate="2011-05-20T15:41:50.823" UserId="1498" />
  <row Id="22794" PostId="10587" Score="1" Text="You need a Duemilanove, until they port the code to the Uno. Find someone with the former who can help." CreationDate="2011-02-23T10:49:19.500" UserId="305" />
  <row Id="22795" PostId="14491" Score="2" Text="The answer depends on some factors: is the object metallic? How much it weights? How much you're able to modify the table to achieve this? Do you want to track multiple objects that are placed and removed from the table, or you want just to know if there's any object or not?&#xA;" CreationDate="2011-05-20T16:05:59.013" UserId="1078" />
  <row Id="22796" PostId="14491" Score="1" Text="Please, be more specific as @fceconel said." CreationDate="2011-05-20T16:35:55.337" UserId="938" />
  <row Id="22799" PostId="14503" Text="@rfusca, sorry. I commit a mistake. Thank you. But it deserves +1 anyway." CreationDate="2011-05-20T16:45:42.147" UserId="938" />
  <row Id="22800" PostId="14464" Text="&quot;spinning up an inductor&quot;?" CreationDate="2011-05-20T16:51:13.203" UserId="142" />
  <row Id="22801" PostId="14467" Text="That works for capacitors, too, without the inaccuracy of &quot;charging&quot;." CreationDate="2011-05-20T16:52:34.667" UserId="142" />
  <row Id="22802" PostId="14462" Text="@Kortuk: Well, &quot;charging&quot; a metal sphere in the context of electrostatics means adding net charge to it.  &quot;Charging&quot; a capacitor or battery just means moving the charge from one place to another within the object. The net charge stays the same." CreationDate="2011-05-20T16:54:03.527" UserId="142" />
  <row Id="22803" PostId="14503" Text="@Daniel Grillo - No worries :) Thanks" CreationDate="2011-05-20T16:56:12.803" UserId="3778" />
  <row Id="22804" PostId="14462" Text="@endolith, and you get a capacitance when you charge a sphere between it and the ground. It is a poor capacitance so you are able to move a very large amount of charge and get a very high voltage." CreationDate="2011-05-20T17:23:06.727" UserId="230" />
  <row Id="22806" PostId="14500" Score="1" Text="Does the mux go straight into the op amp?  Is there anything else loading the line, like a big capacitor?  Is this on a breadboard or soldered to protoboard?" CreationDate="2011-05-20T17:57:54.987" UserId="1278" />
  <row Id="22808" PostId="14509" Score="1" Text="You are going to have a trade off between size, brightness, and battery life." CreationDate="2011-05-20T18:15:14.383" UserId="319" />
  <row Id="22809" PostId="4010" Text="+1 my guess would be capacitive loading, too.  That rise time is orders of magnitude slower than it should be, I don't see it being a termination problem." CreationDate="2011-05-20T18:18:01.147" UserId="1278" />
  <row Id="22810" PostId="14461" Text="Is it possible that the PORTB has better current capability than PORTA?  RA0 might not rise in time to look like a 1 by the time BSF PORTA,1 is executed." CreationDate="2011-05-20T18:24:18.863" UserId="1278" />
  <row Id="22811" PostId="14460" Text="How long is &quot;delay&quot;?  1 us?  1 ms?  1 s?" CreationDate="2011-05-20T18:24:32.793" UserId="1278" />
  <row Id="22812" PostId="14491" Text="http://electronics.stackexchange.com/questions/1253/sensing-touch-through-a-thick-surface" CreationDate="2011-05-20T18:27:15.383" UserId="142" />
  <row Id="22813" PostId="14509" Score="1" Text="@Michael - I think you missed Kellenjb's point.  &quot;Ultra-bright 5mm LED&quot;, tiny battery, and a life measured in months just don't go together - you're going to have to relax *at least one* of your criteria." CreationDate="2011-05-20T18:28:37.263" UserId="3778" />
  <row Id="22814" PostId="14457" Text="+1 photodetector latency.  Most photodetectors need a transimpedance amplifier to turn the small photocurrent into a low-impedance output voltage.  The design tradeoff is speed for sensitivity.  Though 6 ms seems a bit steep even for that." CreationDate="2011-05-20T18:30:56.237" UserId="1278" />
  <row Id="22815" PostId="14509" Text="Fair enough. I'm a noob, so the more explicit someone can spell it out, the better :) So, let's relax the &quot;tiny&quot; criteria. Can anyone recommend a self-contained, long-life solution, regardless of size? Note: I'll edit the question as such, and accept any answer that can explain this to me." CreationDate="2011-05-20T18:36:42.450" UserId="4343" />
  <row Id="22816" PostId="14443" Text="I understand endolith's concern.  Just because a transistor amplifies base current, doesn't make it an *amplifier*.  An amplifier is a complete device.  Logic gates can compute, but gates does not a computer make." CreationDate="2011-05-20T18:37:31.893" UserId="1278" />
  <row Id="22817" PostId="14509" Text="On the flip side, if you use a not-so-bright blinking LED (available from RadioShack and other electronics stores), you can run one for almost 6 months on a pair of AA's." CreationDate="2011-05-20T18:46:35.413" UserId="3308" />
  <row Id="22818" PostId="1162" Text="QRSS lets you transmit 2000 km with 10 mW.  The data rate's a bit low, though, around 0.0001 kbit/s.  :D" CreationDate="2011-05-20T18:58:42.683" UserId="142" />
  <row Id="22819" PostId="1194" Text="Do you mean Python?" CreationDate="2011-05-20T19:06:29.093" UserId="142" />
  <row Id="22821" PostId="14495" Text="@stevenvh, it would be nice to have some references, but a nicety, not required." CreationDate="2011-05-20T19:19:08.530" UserId="230" />
  <row Id="22822" PostId="14495" Text="@stevenvh: Would it be possible, on some chip packages, to have concave areas molded into the underside of the package where capacitors could be placed on board?  That wouldn't work on chips where the package and die are nearly the same size, but on many packaged ICs the die cavity is a small portion of the package." CreationDate="2011-05-20T19:26:09.803" UserId="3123" />
  <row Id="22823" PostId="14467" Score="1" Text="Personally, I don't have too much reservations about _charging_, as literally &quot;applying charge to some object&quot; is far less often used than &quot;moving some of the charges from one of the condenser's plates over to the other one&quot;, and it's just a matter of efficiency to use the shortest word for the most often used phrase. But it would certainly be more consequent to use _energizing_ for both capacitors an inductors." CreationDate="2011-05-20T19:32:19.583" UserId="4327" />
  <row Id="22825" PostId="14509" Score="3" Text="Maybe chemistry can be better than electronics to solve your problem. How about use [tritium illumination](http://en.wikipedia.org/wiki/Tritium_illumination)?" CreationDate="2011-05-20T19:35:23.213" UserId="938" />
  <row Id="22826" PostId="14462" Score="1" Text="The term &quot;charge&quot; has been used to describe the addition of energetic stuff to many sorts of things (such as cannons) for a long time, even before the discovery of electricity.  Indeed, I believe that the term &quot;electrical charge&quot; is derived from the more general usage.  I see no reason to regard &quot;charging an inductor&quot; to be any more dubious usage than &quot;charging a SCUBA tank&quot;." CreationDate="2011-05-20T19:41:39.580" UserId="3123" />
  <row Id="22827" PostId="14509" Text="Ha! Great idea. I was actually wondering about something like that originally. I'll have to investigate this :)" CreationDate="2011-05-20T19:43:23.383" UserId="4343" />
  <row Id="22828" PostId="2769" Text="That perfboard looks more like phenolic than fiberglass.  I don't think I've ever seen any fiberglass perfboard, with the exception of proto boards that featured drilled plated through holes and were made by a full-fledged double-sided circuit-board making process.  Phenolic is soft enough to allow holes to be punched rather than drilled.  Such holes are too uneven to be plated, so phenolic boards are only used in applications where a single-sided board will suffice." CreationDate="2011-05-20T19:44:46.677" UserId="3123" />
  <row Id="22829" PostId="14509" Score="1" Text="Tritium illumination actually has much less to do with chemistry than an electric circuit with a battery... but you're right, this would be an option worth a thought, the least unviable kind of nuclear-powered light." CreationDate="2011-05-20T19:47:29.100" UserId="4327" />
  <row Id="22830" PostId="14512" Text="Thanks for the feedback, hah!  I love Phish.  I understand that hollow-body electrics are more resonant, but still not getting the part where these vibrations are being transferred electronically" CreationDate="2011-05-20T19:50:21.173" UserId="4345" />
  <row Id="22831" PostId="14512" Text="@Big Map Ideas, @Jon's answer addresses this directly (the transfer is the physical movement of the pickup in relation to the string, as well as the string itself moving in response to being struck/resonating)." CreationDate="2011-05-20T19:56:34.350" UserId="1269" />
  <row Id="22832" PostId="14517" Text="And +1 to you - it's critical to examine/consider the instrument as a whole." CreationDate="2011-05-20T19:57:56.177" UserId="1269" />
  <row Id="22835" PostId="14511" Score="3" Text="&quot;doesn't have any influence on the sound&quot; is plainly wrong." CreationDate="2011-05-20T20:05:56.200" UserId="4327" />
  <row Id="22836" PostId="14513" Text="@Lyndon - See the comments on Leon's answer for more on why brief answers like this should be comments instead." CreationDate="2011-05-20T20:06:27.320" UserId="857" />
  <row Id="22837" PostId="14491" Text="If you can connect something to it a capacitive sensor could work." CreationDate="2011-05-20T13:17:01.047" UserId="305" />
  <row Id="22838" PostId="14517" Text="Thank you for the help!" CreationDate="2011-05-20T20:16:37.360" UserId="4345" />
  <row Id="22839" PostId="14520" Text="Thank you for the help!" CreationDate="2011-05-20T20:16:52.070" UserId="4345" />
  <row Id="22840" PostId="14462" Text="@supercat: You're right.  *charge (v.) &#xA;    early 13c., from O.Fr. chargier &quot;to load, burden,&quot; from L.L. carricare &quot;to load a wagon, cart,&quot; from L. carrus &quot;wagon&quot; (see car). Sense of &quot;rush in to attack&quot; is 1560s, perhaps through earlier meaning of &quot;load a weapon&quot; (1540s). Related: Charged; charging. Chargé d'affaires was borrowed from French, 1767, lit. &quot;charged with affairs.&quot;*" CreationDate="2011-05-20T20:20:51.193" UserId="142" />
  <row Id="22841" PostId="14519" Text="Thanks for your response. The bottle concept was actually just meant to illustrate the &quot;self contained&quot; concept. I'm not literally putting LEDs in a bottle, sorry for the confusion. Explaining the real setup would be pretty convoluted/confusing, so I was just trying to think of a simple example that illustrated the basic idea. In hindsight, seeing that my question has been down-voted, I'm thinking that I should have just asked a more specific question." CreationDate="2011-05-20T21:38:22.330" UserId="4343" />
  <row Id="22842" PostId="14509" Text="@left, I know just a little about chemistry. They use phosphor too, so I thought it was about chemistry." CreationDate="2011-05-20T22:03:48.513" UserId="938" />
  <row Id="22843" PostId="14519" Text="@Michael please revise your question, and then maybe someone will be able to give you some better guidance.  Just get as close as possible without giving away proprietary details, if any.  Eventually, I think the idea will be clearer." CreationDate="2011-05-20T22:54:40.530" UserId="2288" />
  <row Id="22844" PostId="14443" Score="1" Text="A transistor definitely amplifies - it exactly fits the definition...within that small region. Outside that it approximates a switch well enough to be used as part of a logic gate - but that is due to the amplifier aspect of it being either cranked up against the limit of VCC or down at 0." CreationDate="2011-05-20T23:27:13.700" UserId="3525" />
  <row Id="22845" PostId="14511" Text="Certainly has less effect than a resonating body, but yeah - I have to say @leftaround is right on this" CreationDate="2011-05-20T23:30:50.903" UserId="3525" />
  <row Id="22846" PostId="14498" Text="@AndrejaKo, that first link is what I was looking for. If you would put that as an answer, I'd be willing to mark it correct. I'm pretty new to the embedded world and a simple yet effective tutorial like that link is exactly what I was looking for. " CreationDate="2011-05-21T00:55:05.467" UserId="2833" />
  <row Id="22847" PostId="14523" Text="One nasty gotcha with something like a 74xx595 is that there's no specification that guarantees that the output from one 74HC595 won't change fast enough in response to the clock to violate the setup time for a succeeding 74HC595.  In practice, chips which have longer setup times are also apt to have longer propagation delays, so if the source and destination chip are of the same family things will generally work.  Still, I think it's a bit icky to have the output change on the same edge as the input." CreationDate="2011-05-21T02:40:50.837" UserId="3123" />
  <row Id="22848" PostId="3262" Text="The op-amp circuit simulates one capacitance using a different capacitance values, but changing the cap values on the fly would require changing some resistors.  I think in practice the best way to simulate variable capacitance is to switch various capacitors into and out of a circuit using FET switches." CreationDate="2011-05-21T02:45:41.097" UserId="3123" />
  <row Id="22850" PostId="14520" Text="&quot;but the pickups don't have any sound to themselves anyway&quot; Disagreed. Resonances in the coil, the type of magnet you use and how worn out the magnet is can have an effect on the sound." CreationDate="2011-05-21T06:28:06.977" UserId="3745" />
  <row Id="22851" PostId="14513" Text="can you provide examples or links to examples of these old IC sockets?" CreationDate="2011-05-21T06:29:42.967" UserId="1197" />
  <row Id="22852" PostId="14511" Score="3" Text="@leftaroundabout, Rory - fair enough. You explain me the electromagnetic effects of a wooden box." CreationDate="2011-05-21T06:37:59.130" UserId="2064" />
  <row Id="22853" PostId="14457" Text="@stevenh Oops, yes, refraction. Used to think about that in terms of angles, but you are right. The speed of light varies in different materials. Thanks." CreationDate="2011-05-21T07:13:41.010" UserId="3876" />
  <row Id="22854" PostId="14493" Text="As people have mentioned you can get the caps built in to the socket. I found these on [RS](http://uk.rs-online.com/web/1982183.html) other suppliers may sell them as well. Although they are more expensive then just standard sockets. I feel that the cost might not be worth it in industry compared with buying the sockets and caps separately. " CreationDate="2011-05-21T08:22:46.830" UserId="1623" />
  <row Id="22855" PostId="14513" Score="2" Text="The question was about caps within ICs (die) or IC packages. This is an IC socket, not a package. These sockets may have been invented to save space on PCBs while SMT was not yet the norm, and they are limited to common logic packages where GND is on pin (#total_pins/2) and VCC is on pin (#total_pins)" CreationDate="2011-05-21T08:29:30.023" UserId="930" />
  <row Id="22856" PostId="14513" Score="1" Text="@Jeff - I added an image to lyndon's answer. The reason why you don't see those anymore is that they apply only to a specific pinning, like Vcc on pin 20, gnd on pin 10. Typically LSTTL and HCMOS building blocks. Placing power pins like that was a pretty daft idea to start with, and it's not done anymore. Modern ICs can have their power pins pretty much anywhere, but they're often placed more closely together. Also, this is DIL!, who uses that anymore? :-)" CreationDate="2011-05-21T08:29:48.880" UserId="2064" />
  <row Id="22858" PostId="14495" Text="@Kortuk - typically Kortuk, always wanting more! :-) The thing is that manufacturers don't make statements why they don't integrate decoupling capacitors; for them it's obvious." CreationDate="2011-05-21T10:16:00.627" UserId="2064" />
  <row Id="22859" PostId="14532" Text="For start, read section 5 of [this](http://www.atmel.com/atmel/acrobat/doc2521.pdf) document. Each crystal needs certain capacitance to work. To get the exact number, you should read the crystal's datasheet. Then you should take into account capacitances you're already getting from the chip and the PCB. When you get the existing capacitance, you should calculate the capacitance of capacitors which should increase the total capacitance so that it reaches the amount prescribed by the crystal datasheet." CreationDate="2011-05-21T10:37:44.080" UserId="1240" />
  <row Id="22864" PostId="14532" Score="1" Text="Not quite right! The correct load capacitance is required to ensure that the crystal operates at the stated frequency. It will probably still oscillate with incorrect capacitor values, or even no capacitors, with feedback provided by stray capacitance, but at the wrong frequency." CreationDate="2011-05-21T11:05:17.877" UserId="305" />
  <row Id="22866" PostId="14536" Text="He wants something very cheap!" CreationDate="2011-05-21T11:10:15.643" UserId="305" />
  <row Id="22867" PostId="14530" Text="You could use an external macro-processor, such as m4. It's very powerful." CreationDate="2011-05-21T11:24:21.403" UserId="305" />
  <row Id="22868" PostId="14537" Text="are all the spacings ok for 220v with that kind of solution?" CreationDate="2011-05-21T11:30:34.230" UserId="2157" />
  <row Id="22870" PostId="14528" Text="Thanks for that info, very helpful. I was actually more thinking it of package integrated as in your last paragraph. Seems to be that the lead frame venders, sorry if that's dated, could it into the design. Maybe something about that process or the expense to do it is why?" CreationDate="2011-05-21T11:39:28.200" UserId="2157" />
  <row Id="22871" PostId="14513" Score="1" Text="@stevenvh, I know it's in jest, but... we still use DIL, a lot! :( When designing with high power, it's lowest cost my EE power supply partner tells me because many components require thru-hole and thus it's more expensive to have both in the board fab. " CreationDate="2011-05-21T11:42:36.793" UserId="2157" />
  <row Id="22872" PostId="14537" Text="The relay should be OK, if it is designed to switch mains voltages. It's up to the PCB designer to ensure that the board clearances are correct." CreationDate="2011-05-21T11:47:01.290" UserId="305" />
  <row Id="22873" PostId="14495" Text="@stevenvh, I'm sorry, but I don't buy &quot;it's obvious...&quot; because I think that's a narrow view that doesn't look at the big picture. I agree about the cell phone and packaging concerns, that's probably true. It's seems to me that a material that has the desired capacitance could be designed into the packaging and just bonded to by the wire bonder. Maybe that's not obvious or perhaps more likely ignorant. Not to mention, I would think they require more space on the board than integrated in any way." CreationDate="2011-05-21T11:47:52.843" UserId="2157" />
  <row Id="22874" PostId="14493" Text="They sometimes are! I've seen PC CPUs with them. It's too expensive for ordinary devices, and will make them too large." CreationDate="2011-05-20T13:14:54.543" UserId="305" />
  <row Id="22875" PostId="14520" Text="I didn't say the pickups don't _affect_ the sound - of course they do, very much so. The point is that they don't _produce_ it, in particular they have, unlike the neck and body, neglectable influence back on the original string vibration. So speaking of a pickup's sound in relation to a guitar's is little more then relating a microphone's sound to a singer's, though microphones usually vary much less in their characteristics than guitar pickups do." CreationDate="2011-05-21T12:41:01.547" UserId="4327" />
  <row Id="22876" PostId="14511" Score="1" Text="Ok, it seems like you interpreted the question a little differently than we did. You're right that the body does not directly affect the _pickups_, but the point I hopefully made with my answer is that the sound that's coming from the ampifier (and though it's not written in the headline, this seems to be what the question is about) does _not_ come from the pickups, it only passes _through_ them. So in order to affect the sound, the body does not have to have any direct influence on the pickups themselves whatsoever." CreationDate="2011-05-21T12:52:34.907" UserId="4327" />
  <row Id="22877" PostId="14447" Text="@kellenjb, give us some links to more information about these things so the OP can dig in immediately if they would like to. I also think since the segway knows the orientation of the segway from the gyros it just constantly tries to stand it up straight. I think this is easier to do then many of the control systems I have seen." CreationDate="2011-05-21T12:54:34.240" UserId="230" />
  <row Id="22879" PostId="14469" Text="localhost. that is, i want to be able to trigger the alarm remotely from another machine on the network if needed." CreationDate="2011-05-21T13:02:04.290" UserId="4329" />
  <row Id="22881" PostId="14473" Text="Thanks for this answer -- i am picking it as best because the speaker is the part of the project i am less familiar with. All other answer are very welcomed, though. I will now spend sometime researching all the options; i am a bit intrigued by the bifferboard because it's x86." CreationDate="2011-05-21T13:07:10.167" UserId="4329" />
  <row Id="22882" PostId="14483" Text="Indeed I am now looking at a solution based on a bifferboard; total cost for this project should be lower and it can probably host some other services too. Thanks!" CreationDate="2011-05-21T13:08:15.797" UserId="4329" />
  <row Id="22883" PostId="14532" Text="possible duplicate of [Crystals and Load Capacitance](http://electronics.stackexchange.com/questions/4225/crystals-and-load-capacitance)" CreationDate="2011-05-21T13:15:22.000" UserId="142" />
  <row Id="22884" PostId="14533" Score="1" Text="http://electronics.stackexchange.com/questions/8929/switching-a-kettle-on-off-using-a-arduino http://electronics.stackexchange.com/questions/14077/arduino-home-light-dimming" CreationDate="2011-05-21T13:20:44.427" UserId="142" />
  <row Id="22886" PostId="14495" Text="@kenny - I said it's obvious for the manufacturer, not that it should be for us mere mortals. And about an external cap requiring more space: that's only true if they don't have to enlarge the package to fit the capacitor in. And like I explained in the BGA example, there's simply no room to place an 0402, probably not even an 0201.  Besides, the latter don't go to 100 nF. (I'm also wondering if the bonding machine doesn't require a flat surface.)" CreationDate="2011-05-21T14:16:43.803" UserId="2064" />
  <row Id="22887" PostId="14491" Text="@fceconel My surface is a wood table. It's weight like a 4 person table. tks" CreationDate="2011-05-21T14:19:34.653" UserId="3359" />
  <row Id="22889" PostId="14537" Score="1" Text="Relays have ratings too, check them." CreationDate="2011-05-21T15:42:29.043" UserId="2246" />
  <row Id="22890" PostId="14528" Text="AFAIK, capacitors are soldered in hybrid packages, and hybrid packages always contain some sort of board material, be it ceramic or similar to FR4 (but with a thermal extension characteristic that better matches silicon). With only a die, a leadframe and a package around that, there is bonding only, and no soldering. I don't know if caps can actually be bonded. " CreationDate="2011-05-21T16:31:24.440" UserId="930" />
  <row Id="22893" PostId="14469" Text="I see.  That shouldn't require anything special then, as long as the localhost in this case can open a connection with the monitoring device." CreationDate="2011-05-21T17:01:34.243" UserId="4172" />
  <row Id="22894" PostId="14544" Text="Interesting, I will definitely have to try that. " CreationDate="2011-05-21T17:13:49.180" UserId="4354" />
  <row Id="22895" PostId="1268" Text="@Edward - &quot;Faraday cage only stops electrostatic fields, not AC&quot;. Not true. Try to receive a radio signal in a Faraday cage." CreationDate="2011-05-21T17:21:44.160" UserId="2064" />
  <row Id="22896" PostId="14544" Text="+1 because it's a nice hobbyist's approach using a simple inductor and really just standard parts. I think even the operational amplifier could be replaced with a 324 or something similar, because I guess the thing need not be super precise. Using a step-up configuration with an auto-transformer might be built smaller and with better efficiency, though." CreationDate="2011-05-21T17:28:42.630" UserId="930" />
  <row Id="22897" PostId="14544" Text="A suitable auto-transformer is going to be tricky to design, and expensive." CreationDate="2011-05-21T17:34:27.367" UserId="305" />
  <row Id="22898" PostId="14434" Text="I don't think this question is off topic. It just need a little more clarity. From the FAQ, it should not be about &quot;consumer electronics such as media players, cell phones or smart phones, _except when designing these products or hacking their electronics for other uses_&quot;." CreationDate="2011-05-21T17:50:50.063" UserId="4277" />
  <row Id="22899" PostId="14478" Text="@Dave Maybe it is used to denote a large load." CreationDate="2011-05-21T18:02:03.610" UserId="4277" />
  <row Id="22900" PostId="14536" Text="Please explain how SSR enhances a bulb's lifespan?" CreationDate="2011-05-21T18:07:31.983" UserId="4277" />
  <row Id="22901" PostId="14536" Score="1" Text="@oxakhil - It's not just the SSR, it's the zero-crossing switching. You may have noticed that incandescent bulbs always fail when they're switched on. That's because the mains phase can be near its maximum when switching on. Combined with the low resistance of a cold bulb this results in a high current peak, which may burn the filament. When you switch on a zero crossing you avoid these peaks." CreationDate="2011-05-21T18:20:12.830" UserId="2064" />
  <row Id="22903" PostId="14547" Score="2" Text="What voltage are you getting from the Li cells?" CreationDate="2011-05-21T20:40:55.413" UserId="305" />
  <row Id="22904" PostId="14530" Text="I've found myself wishing for the ability to overload inline functions based upon whether the compiler can evaluate a parameter as a constant.  In a function like &quot;raise x to the power y&quot;, it would be worthwhile for an inline version to special-case constant powers of 0 to 3, and call a library function for other powers.  It would not be worthwhile to generate inline code to test for those constants, though.  Unfortunately, I don't know nay compilers, for any language, that can distinguish overloads based upon constant values." CreationDate="2011-05-21T21:19:06.610" UserId="3123" />
  <row Id="22905" PostId="14543" Text="@JustJeff Thanks! my bad. I did read it as .02 A." CreationDate="2011-05-22T01:21:16.907" UserId="319" />
  <row Id="22906" PostId="14553" Text="@John Lopez: The reason I am asking is because for one of the monitors I recently purchased, the manufacturer gave a plug that works with the 110V supply in the US but he mentions that the device also works with 220V in countries elsewhere. So I don't think that just by looking at the plug one would be able to determine this. Any more suggestions?" CreationDate="2011-05-22T03:17:56.820" UserId="1863" />
  <row Id="22908" PostId="14533" Text="@stevenvh @leon- I am a bit confused between the solutions provided by both of you. I am going for relay solution because I think it is simpler and cheaper and it will serve my purpose. " CreationDate="2011-05-22T08:36:35.490" UserId="4277" />
  <row Id="22909" PostId="14537" Text="@LeonHeller- What rating of relay should I go for? Here in my country we get 220-230V, 50Hz AC supply? What is VAC parameter in a relay's rating?" CreationDate="2011-05-22T08:50:05.270" UserId="4277" />
  <row Id="22910" PostId="14552" Text="If its a standard kettle lead then is there a switch to change it between 110 and 220? Most PSUs on Computers usually have one. " CreationDate="2011-05-22T09:16:44.807" UserId="1623" />
  <row Id="22911" PostId="14555" Text="I read something last year (or the one before) in IET's E&amp;T magazine about it being related to I^2 R losses but I can't remember any more than that - hopefully someone can chime in with an answer" CreationDate="2011-05-22T10:09:19.223" UserId="4096" />
  <row Id="22912" PostId="14556" Score="1" Text="What transistor are you interested in? MOSFET, BJT, JFET, IGBT? Are you looking for a signal level analysis or a fundamental model focusing on how the carriers inside the device behave?" CreationDate="2011-05-22T10:10:20.813" UserId="4096" />
  <row Id="22913" PostId="14556" Score="1" Text="@Simon- about simple BJT. I have seen portions like h-parameters, small signal models etc in my syllabus and have used them extensively in the last 2 semesters for analysis. But still I dont have an idea about them. Textbook are not making any sense to me. They all start with those complicated math stuff. So please give me good start so that later on I can refer those book again." CreationDate="2011-05-22T10:27:22.367" UserId="4277" />
  <row Id="22914" PostId="14460" Text="It's around 0.5 seconds - enough time to see the sequence unfold before me." CreationDate="2011-05-22T10:35:16.707" UserId="4245" />
  <row Id="22916" PostId="14559" Text="Battery Type? As different batteries need different charging methods. Such as Ni-Cad and NiMH can be charged with a constant current source. " CreationDate="2011-05-22T11:25:20.287" UserId="1623" />
  <row Id="22917" PostId="14559" Score="1" Text="thanks for the response - have amended the question and am now researching constant current source!" CreationDate="2011-05-22T11:44:32.613" UserId="4360" />
  <row Id="22918" PostId="14562" Text="Okey, maybe I should edit my question. I know these things. Tell me what is h-parameters? What is its significance?" CreationDate="2011-05-22T12:03:49.870" UserId="4277" />
  <row Id="22919" PostId="2011" Text="What is the difference between triac and TRIAC?!!!" CreationDate="2011-05-22T12:10:34.947" UserId="4277" />
  <row Id="22920" PostId="14562" Text="As I said previously, ask your teachers. Why don't you do that?" CreationDate="2011-05-22T12:12:44.247" UserId="305" />
  <row Id="22921" PostId="14562" Text="Ahh ok yes reword the question to get an answer to suit the question you want as I understood it to be what is a transistor - the basics. " CreationDate="2011-05-22T12:14:29.380" UserId="1623" />
  <row Id="22922" PostId="14562" Text="@Leon I don't mind writing that as thats my revision for BJTs for my exam next month :D." CreationDate="2011-05-22T12:15:37.037" UserId="1623" />
  <row Id="22923" PostId="14560" Score="1" Text="What's the link to the image? we'll add it" CreationDate="2011-05-22T12:16:24.090" UserId="142" />
  <row Id="22924" PostId="14560" Text="Here you are http://img269.imageshack.us/i/dzielenie.png/" CreationDate="2011-05-22T12:24:35.243" UserId="4359" />
  <row Id="22925" PostId="14553" Score="1" Text="@Legend It's quite possible (especially if the  monitor is new) that it can work with everything from 85 V to 265 V at 47 Hz to 63 Hz. New switch mode power supplies are capable of that." CreationDate="2011-05-22T12:28:00.557" UserId="1240" />
  <row Id="22926" PostId="14556" Score="1" Text="You should ask specific questions. This one should be closed." CreationDate="2011-05-22T12:28:16.050" UserId="305" />
  <row Id="22927" PostId="14557" Text="I remember once blowing an adapter of my NES by accidentally choosing 110V when it should have been 220V. :(" CreationDate="2011-05-22T12:29:34.567" UserId="4277" />
  <row Id="22928" PostId="14556" Text="okey I will edit it." CreationDate="2011-05-22T12:34:34.357" UserId="4277" />
  <row Id="22929" PostId="14555" Score="2" Text="Losses would be decreased by *increasing* the voltage, which is why power lines run at thousands of volts.  Assume the power delivered to the load is constant.  If you use a higher voltage to send it, the current decreases, and the I²R losses in the wire are lower." CreationDate="2011-05-22T12:34:58.480" UserId="142" />
  <row Id="22930" PostId="14556" Score="2" Text="The Hybrid-Pi model? This is like pulling teeth!" CreationDate="2011-05-22T12:44:57.400" UserId="305" />
  <row Id="22931" PostId="14429" Text="I think the Power supply line frequency can vary. Even though the error can be minute, that will magnify over long period of time." CreationDate="2011-05-22T14:01:42.373" UserId="4277" />
  <row Id="22932" PostId="11622" Text="I think this the best solution." CreationDate="2011-05-22T14:06:42.423" UserId="4277" />
  <row Id="22933" PostId="14423" Text="with any microcontroller you can daisy chain the adders and make the counter width as wide as you like, say a 256 bit or 512 bit millisecond counter for example. (know the accuracy of your clock source though and how that affects the accuracy of your time measurement over long periods)" CreationDate="2011-05-22T14:40:46.430" UserId="985" />
  <row Id="22934" PostId="14560" Text="If no is zero, wouldn't that give a polynomial of degree two?  If your circuit were expanded to 33 bits, that would allow for all polynomials up to degree 33 (albeit with some delay before data started flowing into the polynomial).  Another approach is to have input data feed through a single XOR before feeding through a straight shift register, and have the taps of the shift register get multiplied by a polynomial and fed into the input xor.  That approach requires the polynomial to be written differently, but it can solve the same problems as the one you've drawn." CreationDate="2011-05-22T14:47:08.040" UserId="3123" />
  <row Id="22935" PostId="14552" Text="curious .. i see a down vote and a vote-to-close, yet no one has offered any constructive criticisms here .." CreationDate="2011-05-22T14:50:29.880" UserId="740" />
  <row Id="22937" PostId="14565" Score="3" Text="There are a few other questions you should check out: http://electronics.stackexchange.com/questions/tagged/fcc" CreationDate="2011-05-22T16:15:15.040" UserId="319" />
  <row Id="22938" PostId="14560" Text="n0 is lowest coefficient. If w(x) would be changed to polynomial of degree 2, then n3 should be zero, but then division will not work, because on the top line will be always signal zero." CreationDate="2011-05-22T16:44:58.480" UserId="4359" />
  <row Id="22939" PostId="14567" Score="1" Text="I don't think he is intending to produce a device that blinks a couple of LEDs. That was just an example." CreationDate="2011-05-22T17:54:06.213" UserId="305" />
  <row Id="22940" PostId="14558" Text="Note that the tolerance are not always that well strived. I have heart some stories about factories or farms in desolate places only getting 180V AC. I assume they are on the end of the phase line with some heavy users in their area." CreationDate="2011-05-22T17:57:59.160" UserId="1476" />
  <row Id="22941" PostId="14149" Text="Provided you mean a PWM-type hobby servo, just about any micro-controller can do it.  I'd be more worried about a shaft seal that's not going to be a slow leak over a period of months." CreationDate="2011-05-22T18:15:37.730" UserId="2246" />
  <row Id="22942" PostId="11405" Text="The guide posted on this answer is worth checking. It does explain how to search for discoverable bluetooth devices." CreationDate="2011-05-22T18:16:10.490" UserId="4277" />
  <row Id="22943" PostId="14560" Text="If n0 is zero, and all the other n's are shifted over one place so that n3 becomes the old n2, n2 becomes the old n1, and n1 becomes the old n0, the circuit would seem to be an order-two polynomial the input delayed by one input stage." CreationDate="2011-05-22T18:16:42.377" UserId="3123" />
  <row Id="22944" PostId="14567" Text="Would there be any way to get a stable 8,192Hz signal without requiring FCC certification?" CreationDate="2011-05-22T18:19:06.277" UserId="3123" />
  <row Id="22945" PostId="14560" Text="Yes, you are right. There should be some control unit to place coefficients of w(x) in proper multiplicators according to w(x)'s degree. There is however one bad case and it is when w(x) will be of degree 0 - constant, then this should not work. Thanks." CreationDate="2011-05-22T18:31:06.633" UserId="4359" />
  <row Id="22947" PostId="11083" Text="@BarsMonster Is it possible to supply a quick circuit diagram?" CreationDate="2011-05-22T19:14:32.120" UserId="1623" />
  <row Id="22948" PostId="14552" Text="@JustJeff It is a consumer electronics question." CreationDate="2011-05-22T19:19:27.837" UserId="319" />
  <row Id="22949" PostId="14553" Score="1" Text="@John Lopez This is not an answer, rather it is purely a comment." CreationDate="2011-05-22T19:21:42.470" UserId="319" />
  <row Id="22950" PostId="14567" Text="@Leon Heller, if the question really was that broad then it is an exact duplicate and/or a not very good question, I was trying to give the benefit of the doubt. @Supercat, I am not sure I understand what you are getting at." CreationDate="2011-05-22T19:30:20.553" UserId="319" />
  <row Id="22951" PostId="14552" Text="For the one who down voted, there is an 'edit' button if you would like to rewrite my question into a form that is meaningful." CreationDate="2011-05-22T20:09:57.007" UserId="1863" />
  <row Id="22952" PostId="14544" Text="With a few modifications the Maxim op amp and reference in that design could be replaced with a TL431, making the circuit even cheaper." CreationDate="2011-05-22T20:48:18.977" UserId="4129" />
  <row Id="22953" PostId="14570" Score="4" Text="What is the &quot;something&quot;?" CreationDate="2011-05-22T21:06:58.157" UserId="305" />
  <row Id="22955" PostId="14567" Text="The LED was just an example or a low power device that isn't very likely to emit RF. Or if it does it would be very low power and wouldn't get very far. I'm more trying to get an idea if there is any conditions that would make you exempt, such as low power or something like that. I mean, imagine a passive microphone for a computer. Since the audio picked up from the microphone would be higher than 9 kHz, that would already break the 9 kHz rule and would need testing. But to me, it seems silly to test something like that." CreationDate="2011-05-22T21:35:43.177" UserId="4362" />
  <row Id="22956" PostId="4619" Text="Maybe you should reread your comments for obvious errors before you bash someone...GPOI pins output bits not bytes. That means 64 kiloBITS/s, well under the max 115.2kbs" CreationDate="2011-05-22T21:48:06.640" UserId="1319" />
  <row Id="22957" PostId="14552" Text="@Kellenjb - you know that, i know that, i just think it ought to be spelled out, so new people can 'get educated' about these things." CreationDate="2011-05-22T22:11:10.633" UserId="740" />
  <row Id="22958" PostId="14552" Text="@justjeff it is spelled out in the faq." CreationDate="2011-05-22T22:25:56.680" UserId="319" />
  <row Id="22959" PostId="14538" Score="1" Text="While not providing all the details I was looking for, your answer ultimately led me to my answer. Taking a PIC as an example, there are multiple steps in between the process of writing code on your computer and having that code running on the PIC. You have to compile it and upload it, and there are different ways to do even these. In order to, say, write with D for a PIC, someone would have to write an equivalent of [SDCC](http://sdcc.sourceforge.net/) for D." CreationDate="2011-05-22T22:36:54.293" UserId="4349" />
  <row Id="22960" PostId="14567" Text="@w1res I believe if it is purely passive then there is no need for fcc since you aren't generating the signal. In the case of the LED, it doesn't matter what the power is, if you have a oscillator greater then 9khz, a poor board design can cause you to radiate. " CreationDate="2011-05-22T22:37:21.970" UserId="319" />
  <row Id="22961" PostId="14571" Text="Connect 1 k $\Omega$ resistor to the leads and see if you get voltage drop across it. It should be enough to start the supply." CreationDate="2011-05-22T23:36:54.673" UserId="1240" />
  <row Id="22962" PostId="14572" Score="2" Text="288 $\Omega$ isn't a standard resistor value, so it's going to be hard to obtain." CreationDate="2011-05-22T23:40:30.273" UserId="1240" />
  <row Id="22963" PostId="11083" Text="I am also working on driving a fan with PWM signals and have the same problem.&#xA;The fan is running if I am using the BS170 N-FET without caps and without the inductor, but with noise. Can BarsMonster or anybody else support me with a circuit diagram?" CreationDate="2011-05-22T18:04:59.963" UserId="4363" />
  <row Id="22964" PostId="11083" Text="@Biko, this should be a comment on BarsMonsters answer not an answer. " CreationDate="2011-05-22T19:09:51.000" UserId="1623" />
  <row Id="22965" PostId="14565" Text="The other questions in the FCC tag linked by Kellenjb are possible duplicates.  However, this is an area where there's a lot of variation.  @w1res - What differentiates your question from the linked ones? (specifically [this one](http://electronics.stackexchange.com/q/5196/857) and [this one](http://electronics.stackexchange.com/q/5556/857)) " CreationDate="2011-05-22T23:47:13.893" UserId="857" />
  <row Id="22966" PostId="14571" Text="Is there any documentation as to why that is? I'd like to learn more." CreationDate="2011-05-22T23:54:55.443" UserId="3045" />
  <row Id="22967" PostId="14571" Score="4" Text="@kurtnelle Description says: `VCT VM 80W12 Universal 12V AC / DC Converter Adapter ~ Input 110V or 220V / 240V AC - Output 12V DC 5.3 Amp Comes With Multiple Tips` The part you're looking at is 12 V, 5.3 A. So you need a resistor that will give some current at 12 V, but it needs to be less than 5.3 A. You also need to take a look at resistor's power rating, so that resistor doesn't burn itself. I put 1 k$\Omega$ for no particular reason. It's a common value and the dissipated power should be 0.144 W, so you can use cheap 1/4 W resistors. " CreationDate="2011-05-23T00:13:46.153" UserId="1240" />
  <row Id="22968" PostId="14571" Text="@kurtnelle For further reading, take a look [here](http://en.wikipedia.org/wiki/Ohm%27s_law) for the resistance value and [here](http://en.wikipedia.org/wiki/Electric_power) for power calculation." CreationDate="2011-05-23T00:15:06.607" UserId="1240" />
  <row Id="22969" PostId="14552" Text="@Legend - I didn't down-vote you, but a rewrite of your question in a meaningful form would not get you the answer you want: We'd prefer questions about, say, plug *design* and power supply *design* that will allow consumers of the products *we build* to differentiate between (or not worry about) supply voltages.  The question you wrote was from a consumer standpoint, which we explicitly disallow [in the FAQ](http://electronics.stackexchange.com/faq). " CreationDate="2011-05-23T00:16:40.493" UserId="857" />
  <row Id="22970" PostId="14552" Text="Due to the commenting above, and the answers below, I'm going to close this: It's a consumer electronics question.  If you'd like to know the answer to a question on this topic that's within our scope, please ask a new question." CreationDate="2011-05-23T00:18:14.973" UserId="857" />
  <row Id="22971" PostId="14553" Text="@John - Kellenjb is correct.  A good answer would contain more information than your four words and one link: a start might be to include images of the plugs used for various voltages and describe where various voltages and plug styles are used.  However, I've closed the question, so it's sort of a moot point." CreationDate="2011-05-23T00:20:43.680" UserId="857" />
  <row Id="22972" PostId="14572" Text="I've always wondered what the standard resistor values were - Is there a formula or a list somewhere?" CreationDate="2011-05-23T00:31:44.047" UserId="4201" />
  <row Id="22973" PostId="14572" Text="@charliehorse55 There's a way to get the numbers. First, the scale for the resistors is logarithmic. Scales are published by Electronic Industries Association and International Electrotechnical Commission. The name of the scale starts with E and is followed by a number. The number tells us how many steps there are in the scale. The scale goes from one to 100 to 1000 and if you need smaller or larger values, you multiply and divide the scale.  " CreationDate="2011-05-23T00:49:26.887" UserId="1240" />
  <row Id="22974" PostId="14572" Score="1" Text="You can find some more information, tips and the scales themselves [here](http://www.smpspowersupply.com/resistor/decadetable.html) and [here](http://www.logwell.com/tech/components/resistor_values.html). There are many other sites explaining this, so searching for `standard resistor values table` for example will probably give you interesting information.  Do keep in mind that the tables aren't limiting and that manufacturers can make any type of resistor they want. It's just that these are &quot;standard&quot; and others are proprietary" CreationDate="2011-05-23T00:51:17.650" UserId="1240" />
  <row Id="22975" PostId="14567" Text="@Kellenjb: My understanding is that if nothing on the board runs above a given frequency, one can skip FCC certification; it sounds based on other posts as though the limit is 9KHz.  I was wondering whether one could practically design something like a battery-operated clock without needing any frequencies over 9KHz." CreationDate="2011-05-23T01:18:51.127" UserId="3123" />
  <row Id="22976" PostId="14570" Score="7" Text="My guess would be that the device is a six-cell battery; six NiCd or NiMH cells will provide about 7.2 volts, while six ZnC or alkaline cells will produce about 9 volts.  The device probably expects six batteries to be installed, and is prepared to operate correctly with anything between 7.2 and 9 volts." CreationDate="2011-05-23T01:20:46.967" UserId="3123" />
  <row Id="22977" PostId="13717" Text="There are open source USB stacks for many micros, assuming they make the necessary hardware documentation available there is no reason there cannot be one for the PIC.  But that's not the same as saying there is one." CreationDate="2011-05-23T01:48:00.107" UserId="2246" />
  <row Id="22978" PostId="14567" Text="@Supercat - That's correct (for the USA, at least) - FCC part 15 subpart A defines a digital device, in part, as *An unintentional radiator (device or system) that generates and uses timing signals or pulses at a rate in excess of 9,000 pulses (cycles) per second and uses digital techniques.* There are other inclusions, and intentional radiators (RF transmitters) are elsewhere.  But yes, 9kHz is the number." CreationDate="2011-05-23T03:01:22.907" UserId="857" />
  <row Id="22979" PostId="14527" Score="1" Text="Do you like Forth?  That's a popular language for embedded devices.  There was a recent article [here](http://www.forth.org/lost-at-c.html) and discussion on Hacker News [here](http://news.ycombinator.com/item?id=2574204), with very informative comments.  Don't have time to bring any of that over here at the moment, though.  If someone wants to craft that information into an answer, I'd be much obliged!" CreationDate="2011-05-23T03:12:43.377" UserId="857" />
  <row Id="22980" PostId="14552" Text="@reemrevnivek: Apologies. I should've read that. Will take care next time but thank you for pointing it out." CreationDate="2011-05-23T03:16:43.290" UserId="1863" />
  <row Id="22981" PostId="14541" Score="1" Text="Microcontrollers are merely low-power microprocessors with integrated peripherals.  You can't run any old programming language on an FPGA (with soft core, I think we're assuming) or microcontroller because they're too slow, too small, and too low-level for other languages to work well (and, consequently, they don't have compilers written for those languages.  Microprocessor vs. Microcontroller isn't the distinction we're interested in here." CreationDate="2011-05-23T03:17:44.197" UserId="857" />
  <row Id="22982" PostId="14525" Text="3 B/s?  That *is* amazing!" CreationDate="2011-05-23T03:21:34.257" UserId="857" />
  <row Id="22983" PostId="14486" Text="Answerers: Please be aware that this could be a [bad shopping question](http://meta.electronics.stackexchange.com/questions/tagged/shopping).  Please remember to include how you found the proximity sensor, so that Federico and other readers can find sensors applicable to their situation in the future. " CreationDate="2011-05-23T03:24:55.593" UserId="857" />
  <row Id="22984" PostId="14486" Text="@Federico - If you could edit your question to better conform to the FAQ, you'd learn more, get better answers, and get more votes.  Please read the first section of the  [FAQ](http://electronics.stackexchange.com/faq) and peruse the [[shopping](http://meta.electronics.stackexchange.com/questions/tagged/shopping)] tag on Meta to learn about our policy on shopping questions.  " CreationDate="2011-05-23T03:27:09.193" UserId="857" />
  <row Id="22985" PostId="14478" Text="@0xakhil - In any case, it isn't the proper schematic!  Dave's point was valid. " CreationDate="2011-05-23T03:28:54.090" UserId="857" />
  <row Id="22986" PostId="14478" Text="@Andrew - Can you revise your schematic?  The [current image](http://i.stack.imgur.com/wsWkU.png) isn't correct. For one thing, you'll want current limiting somewhere. " CreationDate="2011-05-23T03:29:46.773" UserId="857" />
  <row Id="22987" PostId="14434" Text="Revised, upvoted, and answered [here](http://electronics.stackexchange.com/questions/14442/how-to-make-a-fingerprint-scanner-uart-serial-for-a-headphone-jack-on-android)." CreationDate="2011-05-23T03:34:48.403" UserId="857" />
  <row Id="22988" PostId="14429" Score="2" Text="@0xakhil - It can vary by a few milliseconds per day, but they synchronize it every 24 hours to an atomic clock (imagine if two power generation stations were out of sync...).  For long-term timing (on the order of years), I don't think there are any other mechanisms that approach power line clocking for prevention of long-term drift." CreationDate="2011-05-23T03:39:28.290" UserId="857" />
  <row Id="22989" PostId="14527" Text="@reemrevnivek I actually saw that article earlier today, and I don't think Forth fits my personal taste, but definitely thanks for sharing that!" CreationDate="2011-05-23T04:06:10.783" UserId="4349" />
  <row Id="22990" PostId="14567" Text="@reemrevnivek: Thus the question of whether there's any practical way to design a digital device with a reasonably-precise timebase without requiring FCC certification.  An AC-powered clock could probably use line frequency as a 'precise' timebase, and an RC oscillator as a rough timebase, but what about e.g. a battery-powered one?" CreationDate="2011-05-23T04:23:07.997" UserId="3123" />
  <row Id="22991" PostId="14404" Text="@endolith Yes I am intentionally trying to isolate low frequencies, under 3KHz " CreationDate="2011-05-23T06:08:53.810" UserId="2060" />
  <row Id="22992" PostId="14416" Text="@endolith as to my earlier comment, I will have to post another question when I get to that point, my concern is I have multiple signals, some are line level and some will be very low level mic inpputs or phono inputs. I just need a way to keep the levels in the same range, when plugging in different sources." CreationDate="2011-05-23T06:25:17.000" UserId="2060" />
  <row Id="22994" PostId="14486" Text="@reemrevnivek - I agree with Federico that this isn't a shopping question. There are lots of questions which have answers like &quot;You could use a ...&quot;. Wouldn't that also be shopping advice then?" CreationDate="2011-05-23T07:15:51.647" UserId="2064" />
  <row Id="22995" PostId="14525" Text="@reemrevnivek♦ Yes, especially when I want to upload a 10K program into it. In retrospective, this made me debug much more before burning programs into EEPROM." CreationDate="2011-05-23T07:54:21.730" UserId="1240" />
  <row Id="22996" PostId="14486" Text="@reemrevnivek: I read the first section of the FAQ, and it says questions about &quot;a specific electronics design problem&quot; are OK. Doesn't this apply to my question?" CreationDate="2011-05-23T08:09:11.270" UserId="3920" />
  <row Id="22997" PostId="14576" Score="3" Text="The P89V51RD2 is just a controller, not a board like Arduino. Can you tell us more about the board you bought, probably a link to a specification?" CreationDate="2011-05-23T08:45:11.927" UserId="2064" />
  <row Id="22998" PostId="14576" Text="Or at least a picture of the board would be helpful (if you can't post pictures yet, post a link to the picture and someone will put it in your question)." CreationDate="2011-05-23T09:15:58.777" UserId="1240" />
  <row Id="23000" PostId="14570" Score="3" Text="Post a picture! It would help tremendously." CreationDate="2011-05-23T09:36:11.713" UserId="1374" />
  <row Id="23001" PostId="14573" Text="Writing to all the address it could be could do really strange things - You might change the behavior of lots of pieces of hardware that are on the same bus. I wouldn't advise it." CreationDate="2011-05-23T09:39:15.117" UserId="1374" />
  <row Id="23002" PostId="11083" Text="@Dean @Biko http://electronics.stackexchange.com/questions/12856/pwm-output-voltage" CreationDate="2011-05-23T09:42:03.417" UserId="2062" />
  <row Id="23004" PostId="14578" Score="2" Text="I don't know this title, but audio books almost always focus on preserving the original signal as much as possible. I think OP is looking for distortion." CreationDate="2011-05-23T09:49:22.067" UserId="2064" />
  <row Id="23005" PostId="14567" Text="That would presumably be using a 32.768 kHz clock, and would need to be tested." CreationDate="2011-05-23T10:59:40.063" UserId="305" />
  <row Id="23006" PostId="14567" Text="@supercat the part I am confused by is if you are asking this for your own interest or trying to point out something." CreationDate="2011-05-23T11:05:52.257" UserId="319" />
  <row Id="23007" PostId="14486" Text="@Federico - Your previous question was borderline, but the revised version is just fine." CreationDate="2011-05-23T11:33:45.357" UserId="857" />
  <row Id="23008" PostId="14576" Text="@stevenvh @AndrejaKo The board I bought - http://bit.ly/iRcFKE" CreationDate="2011-05-23T13:05:01.523" UserId="4369" />
  <row Id="23009" PostId="4351" Text="Huh...as a Mac user, it's been my experience that it's Windows first, Linux second, and Mac third (if ever)." CreationDate="2011-05-23T13:25:52.347" UserId="857" />
  <row Id="23011" PostId="14581" Score="2" Text="@AndrejaKo can you explain the process over here?" CreationDate="2011-05-23T13:42:34.067" UserId="319" />
  <row Id="23012" PostId="14576" Text="Dude you got totally ripped off. I am not saying that the board is of no use, but 8051 only exists because colleges use it. Although the controller you have is slightly powerful, it is no match to atmel chips.&#xA;&#xA;1. The same 8051 power chip from atmel costs 50Rs (40 pin AT89c52).&#xA;&#xA;2. You could have totally got an arduino for 1250Rs from banglore, or a compatible board from here, http://www.roboticsindia.com/store/index.php?route=product/product&amp;path=46&amp;product_id=72 or here http://robokits.co.in/shop/index.php?main_page=index&amp;cPath=6. &#xA;&#xA;3. search ebay.in for arduino you can get one for &gt;1000." CreationDate="2011-05-23T13:55:39.720" UserId="1200" />
  <row Id="23013" PostId="14576" Text="Feel free to contact me for more pointers, I am in Ahmedabad, Gujarat." CreationDate="2011-05-23T13:56:01.410" UserId="1200" />
  <row Id="23014" PostId="14493" Score="2" Text="@Leon: That could be an answer instead of a comment :)" CreationDate="2011-05-23T14:02:49.160" UserId="142" />
  <row Id="23015" PostId="14416" Score="1" Text="@jsolarski: It'll be like any audio mixer input, then.  You'll need some variable gain control for the unpredictable low-level inputs, and maybe separate jacks for the line-level, depending on the connectors you want to use.  For a BPM counter, low-noise probably isn't that important, so you could just use a single op-amp gain stage with a wide gain range.  Alternately, a narrower gain range and a 20 dB pad switch." CreationDate="2011-05-23T14:06:10.300" UserId="142" />
  <row Id="23016" PostId="14576" Text="@Rick_2047 I feel the same thing. I wasted the thousand rupees. Take a look at this one - http://bit.ly/kWERq0 and let me know what you think.. As I said, I'm just a beginner and would like to explore all this :)" CreationDate="2011-05-23T14:14:14.583" UserId="4369" />
  <row Id="23017" PostId="14574" Score="2" Text="This is too general of a question.  The sound is not affected by individual components, but by blocks of components used together.  A capacitor can have very different effects depending on the circuit it is used in.  Do you have a specific sound you want to implement?" CreationDate="2011-05-23T14:25:15.187" UserId="142" />
  <row Id="23018" PostId="14571" Text="@AndrejaKo: That should have been an answer, not a comment" CreationDate="2011-05-23T14:31:25.970" UserId="142" />
  <row Id="23019" PostId="14573" Text="It might be a good idea to disconnect any real world hardware first, and power cycle after as there's a small chance of introducing instability, but systems of that age are pretty resilient hardware wise.  If faced between the choice of not accomplishing my project vs. the .01% chance of damaging the equipment that wasn't currently useful to my project, I'd take it." CreationDate="2011-05-23T14:54:14.477" UserId="2246" />
  <row Id="23020" PostId="14567" Text="@Kellenjb: The former.  Just curious.  I know that 32KHz crystals are the slowest common crystal oscillator I've seen, but perhaps there's other nice way of getting a stable timebase; if one got a timebase from some FCC-approved device that output a signal below 9KHz, would one need FCC approval for one's own circuitry?" CreationDate="2011-05-23T14:56:54.340" UserId="3123" />
  <row Id="23021" PostId="14565" Text="One other side of things is that anything being sold to EU will need ROHS and be lead-free soldered." CreationDate="2011-05-23T14:58:30.593" UserId="4342" />
  <row Id="23022" PostId="14567" Text="@supercat Sounds like you have a specific enough question to ask a new question." CreationDate="2011-05-23T14:58:32.653" UserId="319" />
  <row Id="23023" PostId="14567" Text="@Kellenjb: I don't have an immediate need for an answer myself; I thought the question was reasonably topical for the initial question that was asked (how to design an electronic device that can do something useful without needing FCC approval)." CreationDate="2011-05-23T15:24:07.263" UserId="3123" />
  <row Id="23024" PostId="14585" Text="Thanks, I have [Osram halogen Decostar 51s](http://www.osram.com/osram_com/Professionals/General_Lighting/Halogen_lamps/Product_overview/Low_voltage/DECOSTAR/DECOSTAR_51_ALU/index.html) 12v 35w, I'll try this. " CreationDate="2011-05-23T15:32:33.437" UserId="4372" />
  <row Id="23025" PostId="14582" Text="Added a rough sketch, in case my description wasn't clear." CreationDate="2011-05-23T15:57:51.407" UserId="4342" />
  <row Id="23026" PostId="14581" Text="@Kellenjb  Indeed. I seem to be getting it wrong these days. " CreationDate="2011-05-23T16:03:36.620" UserId="1240" />
  <row Id="23027" PostId="14570" Text="@supercat - why not post this as an answer so that people can vote for it." CreationDate="2011-05-23T16:22:59.490" UserId="2064" />
  <row Id="23028" PostId="14425" Score="1" Text="+1 you simply NEED an external reference to an atomic clock in order to have accuracy long-term.  Oscillators drift by one or two PPM throughout the day; even if it was *just* calibrated you won't be able to keep 10 PPB accuracy for more than half an hour." CreationDate="2011-05-23T16:38:23.733" UserId="1278" />
  <row Id="23029" PostId="14535" Text="Microchip has another awesome oscillator app note [here](http://ww1.microchip.com/downloads/en/AppNotes/00588b.pdf)" CreationDate="2011-05-23T16:44:43.857" UserId="1278" />
  <row Id="23030" PostId="14582" Text="You could also use the other 4 ADC inputs on the Uno to monitor each cell for up to a 5 cell pack (using the overall voltage for the fifth).  Most advanced LiPo batteries have taps for each cell.  You would need to calibrate your voltage dividers and use some simple math, because each reading would be cumulative from all previous cells to ground." CreationDate="2011-05-23T17:02:37.583" UserId="4342" />
  <row Id="23031" PostId="14571" Text="Can someone explain how this would work, because wouldn't connecting a multimeter provide the resistive load or is it too small for the supply to output something. " CreationDate="2011-05-23T17:03:40.757" UserId="1623" />
  <row Id="23032" PostId="8818" Text="The most common failure for old power supplies is dried up electrolytic filter capacitors." CreationDate="2011-05-23T17:14:39.987" UserId="4342" />
  <row Id="23033" PostId="14581" Text="@Andreja - Excellent edit!  I TeXified the rest of your numbers to try to make it look more consistent." CreationDate="2011-05-23T17:18:10.237" UserId="857" />
  <row Id="23038" PostId="14570" Text="@Joe: Did someone post a rude comment under your answer?  I never saw either.  I posted a comment rather than an answer because, at the time I replied, the question was rather vague and I didn't want to put up an &quot;answer&quot; without more information about what was really being asked." CreationDate="2011-05-23T17:43:14.593" UserId="3123" />
  <row Id="23039" PostId="14570" Text="@supercat - I accused Joe of stealing your answer." CreationDate="2011-05-23T17:49:59.630" UserId="2064" />
  <row Id="23040" PostId="10610" Text="I go with the netlist reason.  A lot of people write textual documents on paper and then key them into a computer, but I've never heard a word processing app called a &quot;document capture&quot; program.  The part of a &quot;schematic capture&quot; program that produces the netlist will typically represent a tiny portion of the program's complexity, but will be absolutely vital to the program's usefulness." CreationDate="2011-05-23T17:50:52.743" UserId="3123" />
  <row Id="23041" PostId="14570" Text="@stevenvh - That was rude. If supercat wanted to answer he would have. I don't think Joe 'stole' anything.  And certainly, nothing of value was lost except an answer that could be accepted by the poser." CreationDate="2011-05-23T18:00:11.620" UserId="249" />
  <row Id="23042" PostId="14589" Text="Sounds like you have a config of some sort wrong. " CreationDate="2011-05-23T18:04:01.607" UserId="319" />
  <row Id="23043" PostId="14570" Text="@AngryEE - Maybe it wasn't nice. But that was what it looked like to me; Joe posted his answer after I suggested to supercat to post *his* comment as an answer." CreationDate="2011-05-23T18:07:25.320" UserId="2064" />
  <row Id="23045" PostId="14591" Text="Euclid's algorithm for polynomials. I think that supercat's answer is all right, which is to shift polynomial coefficients to max right part of LFSR and assigning zero to unused multiplicators." CreationDate="2011-05-23T18:10:44.690" UserId="4359" />
  <row Id="23049" PostId="14592" Score="2" Text="I thought I saw &quot;pages&quot; as well." CreationDate="2011-05-23T18:44:44.577" UserId="2064" />
  <row Id="23050" PostId="14588" Text="@Joe - I can't undo my vote until you edit your answer." CreationDate="2011-05-23T18:48:25.967" UserId="2064" />
  <row Id="23051" PostId="14582" Text="This is great, thanks!  You should think about starting your build and blogging it... I would be thrilled to follow along!" CreationDate="2011-05-23T18:58:49.207" UserId="1756" />
  <row Id="23052" PostId="14582" Text="I'm building a new lab power supply and will be doing just that on joesacher.com.  The last bit I'm researching is easy input protection.  With the voltage divider for the input, you have a choice of resolution vs. input protection.  I'm not sure if a clamping zener is enough or if I need to get more complex.  I had my heat sinks come in, so I'll start breadboarding this in the next few weeks." CreationDate="2011-05-23T19:02:54.177" UserId="4342" />
  <row Id="23054" PostId="14592" Score="2" Text="These all seem like multiple names for the same thing.  I don't know if I've seen pages in the context of erasing, more for reading and writing blocks.  Generally a number of blocks make up a page and an number of pages makes up the full memory.  I think &quot;block&quot; would be the most general term." CreationDate="2011-05-23T19:19:17.930" UserId="4342" />
  <row Id="23055" PostId="14594" Text="OK, cool.  I bought the Netduino from AdaFruit which I figured would be a good place to get parts.  However, the hive usually knows better than one person." CreationDate="2011-05-23T19:19:56.513" UserId="4375" />
  <row Id="23056" PostId="14593" Text="This question is overly broad.  It's also about consumption of electronics as a good, rather than their design, so I'm closing it as off-topic.  " CreationDate="2011-05-23T19:23:16.183" UserId="857" />
  <row Id="23057" PostId="14576" Text="Looks good, but keep in mind that this will work in only computers which have serial ports. Check if you have a 9 pin port at the back of CPU, modern laptops do not have these.&#xA;&#xA;You have two options to use this for modern laptops, either use a USB to serial converter (150Rs) or buy a USB board like this, http://cgi.ebay.in/USB-Atmega328-Arduino-AVRdude-ArduinoISP-programmer-/140504704113?pt=LH_DefaultDomain_203&amp;hash=item20b6bba471&#xA;&#xA;But I personally would just buy the riduino I linked above, its much cheaper." CreationDate="2011-05-23T19:25:00.090" UserId="1200" />
  <row Id="23058" PostId="14594" Text="You will usually be much cheaper to get them from Mouser or Jameco for basic parts.  All Electronics can often have great deals if you aren't too picky.  They buy in lots.  I would also suggest that you buy a 1/4W resistor assortment.  You can google &quot;E12&quot; and &quot;E24&quot; for common values.  You will probably need many around the 500-3k ranges for current limiting LEDs and such.  It all depends on what you want to do." CreationDate="2011-05-23T19:26:40.637" UserId="4342" />
  <row Id="23059" PostId="14593" Text="We'd welcome questions about how to do a specific project (&quot;I bought LCD screen X, connected it this way (schematic Y), and got this error/scope trace when trying to use driver Z.  How do I fix this?&quot;), but this question is about all possible projects.  If you're a software guy, I'd make the analogy &quot;I decided to learn C++.  GCC just finished downloading.  Where do I get additional libraries?  What libraries does everyone else use?&quot;" CreationDate="2011-05-23T19:28:02.513" UserId="857" />
  <row Id="23060" PostId="14593" Text="I would argue that someone would then say.  Well if you're looking for libraries a lot of people go to SourceForge.  But I get your point to an extent." CreationDate="2011-05-23T19:32:44.350" UserId="4375" />
  <row Id="23061" PostId="14593" Text="@PSU - Thanks for understanding.  As [the FAQ](http://electronics.stackexchange.com/faq) says, &quot;...ask practical, answerable questions based on actual problems that you face.&quot;  When you have one of those, bring it over and we'll hopefully be able to give you a warmer welcome." CreationDate="2011-05-23T19:41:04.627" UserId="857" />
  <row Id="23062" PostId="14547" Text="In addition, is there a DC to DC converter already inside the PC?  If running on battery, it might make sense to jump past that with the DC to DC solution.  This will be more efficient than boosting up to 19 and letting it convert back down a second time." CreationDate="2011-05-23T20:09:17.743" UserId="4342" />
  <row Id="23063" PostId="14570" Text="@stevenvh: It is rude to accuse someone of stealing absent evidence of deliberate intent.  If the answer seems to duplicate another &quot;answer&quot;, it's fine to post a comment indicating that the answer seems similar to another; perhaps the person writing the answer meant to provide more detail than the original answer (and may or may not have gotten around to doing so).  If it's similar to a comment, that's probably only worth pointing out if the comment contains some interesting information that the answer lacks." CreationDate="2011-05-23T20:23:04.063" UserId="3123" />
  <row Id="23067" PostId="14598" Score="1" Text="I think your thinking is partially correct.  If a current is flowing, this automatically implies a potential difference and hence power - even in cases where the current is not generated by the potential difference itself but by other means, such as thermally.  Current on its own can't indicate power, though, since if there are moving charges there will always be a potential difference involved." CreationDate="2011-05-23T20:47:41.597" UserId="4129" />
  <row Id="23068" PostId="14598" Score="2" Text="Can you provide a quote from wherever you read this from?  Just so we can rule out any mis-interpretation. My guess is that whoever made that statement was trying to say that knowing only the voltage or the current alone is not enough to calculate the precise Power.  You are correct in that current does imply power but it says *nothing* about **how much** power." CreationDate="2011-05-23T21:00:39.290" UserId="4172" />
  <row Id="23069" PostId="14601" Score="1" Text="Obviously I am too used to the AVRs which only have a datasheet and do not also have a user manual. Always check the user manual. Thanks!" CreationDate="2011-05-23T21:20:23.427" UserId="1363" />
  <row Id="23070" PostId="14598" Text="&quot;doesn't current alone already imply voltage?&quot;  Yes.  But how much?  Depends on the resistance.  The power does also." CreationDate="2011-05-23T21:23:21.710" UserId="142" />
  <row Id="23071" PostId="14601" Score="1" Text="For the NXP ARM chips all the important stuff is in the user manuals, apart from the pinouts and electrical stuff." CreationDate="2011-05-23T21:24:02.587" UserId="305" />
  <row Id="23072" PostId="14241" Text="Okay. I had an idea. Because it's a shift register I can essentially just keep shifting in zeros to drive the clock as long as I only latch when actually sending data. If I create a buffer long enough to contain however many registers I have in the chain and make sure that the data is aligned with the _right_ byte boundary of the last byte I can shift out those bytes and latch at the end and then just go on shifting zeros - at least that's my guess. I guess I'll test it tonight." CreationDate="2011-05-23T21:55:47.127" UserId="4232" />
  <row Id="23073" PostId="14602" Score="2" Text="It looks like a capacitor." CreationDate="2011-05-23T22:04:17.620" UserId="3308" />
  <row Id="23075" PostId="14589" Text="I have loaded the correct device-specific configuration file, and these errors are being reported as syntax errors. I was hoping someone with more experience with assembly could point out some bonehead error (missing semicolon or something) which was causing this." CreationDate="2011-05-23T22:30:03.053" UserId="3906" />
  <row Id="23076" PostId="14605" Text="Note that all the designators in this section of the board are prefixed with &quot;P&quot;.  e.g. PQ23, PJ2, PC44.  My guess is the board is so large that they didn't want to get into designators like C1044, so they broke the board into sections and prefix P so they could reset the designator count." CreationDate="2011-05-23T22:32:07.483" UserId="1278" />
  <row Id="23077" PostId="14597" Text="So with forward bias, the depletion region shrinks to nothing.  If &quot;instantly&quot; reverse biased, the depletion region will require some finite amount of time to grow large enough to prevent conductance.  Yeah?" CreationDate="2011-05-23T22:37:03.127" UserId="1278" />
  <row Id="23078" PostId="14608" Score="1" Text="ESC = Electronic Speed Controller, and BEC = Battery Eliminator Circuit, correct?  Not everyone uses the same acronyms." CreationDate="2011-05-23T22:49:13.747" UserId="857" />
  <row Id="23079" PostId="14598" Text="@Jon- I got most of this from Kuphaldt's 'Lessons in Electric Circuits, Volume I - DC, Ohm's Law', which you may have seen at &lt;http://www.allaboutcircuits.com/vol_1/chpt_1/index.html&gt;. " CreationDate="2011-05-23T22:59:37.360" UserId="4376" />
  <row Id="23080" PostId="14605" Text="Oh, I didn't know they did that. Makes perfect sense." CreationDate="2011-05-23T22:59:46.470" UserId="4378" />
  <row Id="23081" PostId="14612" Text="Is your aim to make a faithful copy of Spacewar! or to learn about driving a VGA display?" CreationDate="2011-05-24T00:22:53.270" UserId="566" />
  <row Id="23082" PostId="14612" Text="faithful copy of Spacewar!, but I'm trying to learn as much as possible so VGA would be nice. Alternatively I could use other methods to send the data to my laptop and from there simulate a display, but that wouldn't be as cool :)" CreationDate="2011-05-24T00:32:17.350" UserId="2717" />
  <row Id="23083" PostId="14612" Score="2" Text="I defer to Leon Heller on this one, but on a few occasions he has mentioned the Parallax Propeller.  Well, I got a screaming deal on their development board, and it has a VGA port built-in.  From the videos I've seen, I would not be surprised if they make sending video signals very easy.  Check it out!" CreationDate="2011-05-24T00:42:09.677" UserId="2288" />
  <row Id="23084" PostId="14597" Text="That is the way I understand it.  With it forward biased, the silicon is &quot;on&quot;.  So it has the ability to flow backwards until the flow causes it to turn off." CreationDate="2011-05-24T01:48:24.200" UserId="4342" />
  <row Id="23085" PostId="14614" Text="if you have an nds laying around and get a gba, I highly recommend the ez flash 3 in 1, make sure it is the GBA sized.  To get started you can program it initially on the nds (well you need a slot 1 cartridge for that too, any will do there are lots of $20 ones), then once you have a bootloader you can re-program it from the gba, the company has an open source library for performing these tasks." CreationDate="2011-05-24T02:09:02.837" UserId="985" />
  <row Id="23086" PostId="10573" Text="These would be appropriate if you can configure an analog line on the PBX, but not if you only have access to a digital line." CreationDate="2011-05-24T02:17:09.143" UserId="1295" />
  <row Id="23087" PostId="14576" Text="@Rick_2047 Yep, I have that converter. What do you think I should do of this 8051 dev board? Sell it off ebay? Will anyone even buy it? Also, can I use the product I mentioned in my previous comment just as Arduino Uno (I mean the programming stuff and all) ?" CreationDate="2011-05-24T02:17:17.083" UserId="4369" />
  <row Id="23088" PostId="10569" Text="You might be able to start with something like this adaptor found on Amazon: [link](http://www.amazon.com/Headset-Buddy-Adapter-CISCO-Phone/dp/B003EALLHE/ref=zg_bs_172607_33)" CreationDate="2011-05-24T02:32:08.090" UserId="1295" />
  <row Id="23089" PostId="14576" Text="yes that seems to be fine, but I don't exactly know the difference between Duemilanove and Uno (I am not a big arduino fan, I started on bare AVR and always recommend doing that)." CreationDate="2011-05-24T04:16:34.133" UserId="1200" />
  <row Id="23090" PostId="14617" Text="I'm not a fan of .NET, but that is pretty much the type of thing I was looking for. =)" CreationDate="2011-05-24T05:39:45.417" UserId="4349" />
  <row Id="23091" PostId="14583" Text="Thank you, it helped me a lot" CreationDate="2011-05-24T05:52:44.627" UserId="4372" />
  <row Id="23092" PostId="14581" Text="Thank you for references, it helped me a lot" CreationDate="2011-05-24T05:53:33.723" UserId="4372" />
  <row Id="23093" PostId="14429" Text="@reemrevnivek Does the total load in an area has any effect on the frequency of the power supply?" CreationDate="2011-05-24T06:57:44.303" UserId="4277" />
  <row Id="23094" PostId="14589" Text="New info: as it turns out, there are two types of assembler language, algebraic and mnemonic. The above code is algebraic, so you have to go into the compiler options by right clicking on the assembly file, clicking properties, c/c++ build, c5500 compiler, Runtime Model Options and check &quot;codegen outputs algebraic assembly&quot;.&#xA;&#xA;This however generates a new error.&#xA;                                                                       &#xA;undefined first referenced&#xA;symbol       in file&#xA; --------- ------ &#xA; _main C:\TI\ccsv4\tools\compiler\C5500 Code Generation Tools 4.3.8\lib\rts55x.lib&lt;args_main.obj&gt;" CreationDate="2011-05-24T07:05:41.960" UserId="3906" />
  <row Id="23095" PostId="14589" Text="and no, adding the path to the file mentioned did not work." CreationDate="2011-05-24T07:08:34.703" UserId="3906" />
  <row Id="23096" PostId="14612" Score="2" Text="@nvm If you go for propeller, do note that it's much easier to interface PS/2 keyboards and mice to it than USB." CreationDate="2011-05-24T07:52:34.650" UserId="1240" />
  <row Id="23097" PostId="14622" Text="Thank you!, this helps *alot*" CreationDate="2011-05-24T08:17:13.220" UserId="2717" />
  <row Id="23098" PostId="14541" Text="I did not say microcontroller, I said microprocessor, which includes microcontrollers, but also your regular Intel Core i7 processor. As for FPGA's with soft cores or hard cores; they come in many different sizes and yes, the can run any language. They run an entire Linux operating system." CreationDate="2011-05-24T08:23:35.540" UserId="3145" />
  <row Id="23100" PostId="14608" Text="I was under the impression everyone knew in this context, but yes you are correct." CreationDate="2011-05-24T08:34:50.060" UserId="4381" />
  <row Id="23101" PostId="14624" Text="is there an eas way to spot which is 'and' and which is 'or' when looking at a circuit diagram? Going by what you say I cannot spot any mistakes in my answer..." CreationDate="2011-05-24T09:58:29.077" UserId="4386" />
  <row Id="23102" PostId="14624" Text="AND is when inputs are in series, OR is when they are in parallel. Think of light switches: the light is on if series switches A AND B are on, or when parallel switches C OR D are on." CreationDate="2011-05-24T10:01:01.537" UserId="2064" />
  <row Id="23103" PostId="14624" Text="So in the top circuit, w can be 1 if either t is shut or p,q and s are shut? Also going by your above comment, isn't the top circuit then NOT((P AND S AND Q) OR T)" CreationDate="2011-05-24T10:04:59.310" UserId="4386" />
  <row Id="23104" PostId="14624" Text="the bottom half will not output zero if p q and s are 0 and t = 1 though will it?" CreationDate="2011-05-24T10:29:59.953" UserId="4386" />
  <row Id="23105" PostId="2676" Text="@Kortuk: &quot;_They will end up using a small amount of power charging each-other small amounts_&quot;. What, they charge each other?" CreationDate="2011-05-24T11:36:30.173" UserId="4277" />
  <row Id="23106" PostId="14627" Text="what is vdd and vss?" CreationDate="2011-05-24T11:51:03.423" UserId="4386" />
  <row Id="23107" PostId="14627" Text="Vdd is the voltage applied to Drain and Vss is the voltage at the Source." CreationDate="2011-05-24T11:53:55.093" UserId="4277" />
  <row Id="23109" PostId="14429" Text=" 0xakhil - It can have an effect on the phase angle, which might cause a constant offset in your detector circuit, but the frequency is always the same, regardless of load." CreationDate="2011-05-24T12:51:29.890" UserId="857" />
  <row Id="23110" PostId="12278" Text="Care to share that information?" CreationDate="2011-05-24T04:46:01.273" UserId="4385" />
  <row Id="23111" PostId="14621" Text="I came to post the same exact answer. Fix the issue, don't make a detector for when the issue happens.  I've replaced all mine with Deans Ultra.  Like a 20A US plug, there is no way to get it in backwards." CreationDate="2011-05-24T13:28:37.160" UserId="4342" />
  <row Id="23112" PostId="14619" Text="Is this based on a real problem that you face?  Our [FAQ](http://electronics.stackexchange.com/faq) reads, *&quot;You should only ask practical, answerable questions based on actual problems that you face. Chatty, open-ended questions diminish the usefulness of our site and push other questions off the front page.&quot;*" CreationDate="2011-05-24T13:29:46.490" UserId="857" />
  <row Id="23113" PostId="14605" Score="1" Text="Maybe the bad power supply had the polarity switched-- tantalum caps explode if you get the polarity wrong." CreationDate="2011-05-24T13:32:23.547" UserId="712" />
  <row Id="23114" PostId="14619" Score="1" Text="@reemrevnivek: I'm interested in this just the same way as I'm interested in http://electronics.stackexchange.com/questions/14433/how-is-precise-control-over-motor-as-in-segway-achieved Do I have problems building my Segway clone? No, I don't." CreationDate="2011-05-24T13:38:49.380" UserId="3552" />
  <row Id="23115" PostId="14632" Score="1" Text="Agreed, avr, arm, pic, doesnt matter you always have to do your system engineering and read data sheets and connect things properly." CreationDate="2011-05-24T13:52:14.957" UserId="985" />
  <row Id="23116" PostId="14632" Text="@dwelch that was helpful." CreationDate="2011-05-24T14:31:51.770" UserId="4277" />
  <row Id="23117" PostId="14636" Text="I will have to check at home if this works, but so far thanks for your answer (will accept it as soon as I know more)." CreationDate="2011-05-24T14:47:00.433" UserId="4381" />
  <row Id="23118" PostId="14616" Text="the more posts I read from you about this micro, the more I'm dying to use my dev kit.  Parallax recently had them on sale for $119!  Are you using ViewPort?" CreationDate="2011-05-24T14:49:26.940" UserId="2288" />
  <row Id="23119" PostId="2676" Text="@oxakhil, yes, if you just connect two batteries you can have differences in batteries and in connections cause small charge movements between the batteries." CreationDate="2011-05-24T14:56:16.923" UserId="230" />
  <row Id="23120" PostId="14633" Text="I found something like LVC on the NXP's site. I have never heard of it. Maybe it is related to LVCMOS." CreationDate="2011-05-24T14:57:45.583" UserId="4277" />
  <row Id="23121" PostId="14639" Text="I completely agree with the idea of reusing what has been done in the original control circuitry, but it really seems complicated to me :p. I've tried to follow the lines and connections, but that is all mixed with the control of the motor for the vacuum cleaner so I'm afraid to mixed them." CreationDate="2011-05-24T15:00:42.507" UserId="4389" />
  <row Id="23122" PostId="14639" Text="I didn't think of going backwards though, thank you for bringing that up. With the H-bridge, will I still need the N-channel MOSFET ?" CreationDate="2011-05-24T15:02:02.817" UserId="4389" />
  <row Id="23123" PostId="14644" Text="@Vicky Rao Could you put the code in the code tabs as its really confusing how it looks. I would change it but I don't want to end the content. " CreationDate="2011-05-24T15:18:13.620" UserId="1623" />
  <row Id="23124" PostId="14627" Text="@user559142  http://encyclobeamia.solarbotics.net/articles/vxx.html   http://en.wikipedia.org/wiki/IC_power_supply_pin" CreationDate="2011-05-24T15:18:17.990" UserId="142" />
  <row Id="23125" PostId="10573" Text="That's not true. Polycom makes speakerphones that connect to digital PBX systems." CreationDate="2011-05-24T15:26:59.570" UserId="3105" />
  <row Id="23126" PostId="14643" Score="1" Text="Well, you have a set of two simultaneous linear equations with two unknowns (I1, I2). That's not even college stuff." CreationDate="2011-05-24T15:28:51.003" UserId="2064" />
  <row Id="23127" PostId="3129" Text="@Mark is it okey to breadboard an external eeprom working in SPI/IIC mode? I am looking forward to extend my MCU's flash memory using 24c64 IC." CreationDate="2011-05-24T15:30:16.063" UserId="4277" />
  <row Id="23128" PostId="14611" Text="Yep.  Ideally, change the connector.  If you can't change the connector, then the MOSFET protection is the way to go.  It won't waste as much energy as the diode.  Note that the body diode needs to be connected in the direction of current flow so it doesn't defeat the whole thing.  See [Reverse Current/Battery Protection Circuits](http://focus.ti.com/lit/an/slva139/slva139.pdf)" CreationDate="2011-05-24T15:30:18.077" UserId="142" />
  <row Id="23129" PostId="14639" Text="Do a google search on the term &quot;H-bridge&quot; Wikipedia has a simple explanation of 4 switches.  These will usually be 4 MOSFETS, either 2 N channel and 2 P channel or with some extra complexity 4 N channel.  (N channel is better than P channel in most regards.)  There are chips out there for driving an H-bridge and might even be a shield you could use on the Arduino." CreationDate="2011-05-24T15:33:31.357" UserId="4342" />
  <row Id="23130" PostId="14620" Text="Why can't they detect the location?  An impedance mismatch on a transmission line reflects waves back to the source, and the waves travel at a measurable velocity, so you can detect the location of discrepancies along a line.  http://en.wikipedia.org/wiki/Time-domain_reflectometer" CreationDate="2011-05-24T15:41:15.857" UserId="142" />
  <row Id="23131" PostId="14631" Score="2" Text="What shields?  They're bare aluminum wires." CreationDate="2011-05-24T15:43:43.437" UserId="142" />
  <row Id="23132" PostId="14619" Score="1" Text="@reemrevnivek: If the FAQ prohibits questions like this, then I think the FAQ should be changed." CreationDate="2011-05-24T15:45:14.187" UserId="142" />
  <row Id="23133" PostId="14619" Text="@endolith - I discussed it with the other mods, and the general policy is something like this algorithm: if off-topic and “real question” then&#xA;    close&#xA;else if interesting then&#xA;    keep&#xA;else if actual problem then&#xA;    keep&#xA;else&#xA;    maybe close&#xA;end -- It's not a hard and fast rule.  " CreationDate="2011-05-24T15:51:46.873" UserId="857" />
  <row Id="23134" PostId="14619" Text="I've only been a mod for a week - I need a little time to learn this stuff.  While you should keep this policy in mind, you can know that I'll be a little soft on it for many questions.  If it fails the test, though, we may have to drop the close hammer on it." CreationDate="2011-05-24T15:54:14.750" UserId="857" />
  <row Id="23135" PostId="14643" Score="1" Text="@Cell-o: We prefer homework conditions (and other questions too) which show evidence of effort and prior research.   This might as well have a &quot;Plz send me teh codez&quot; tag (but please don't add it!). We won't do your homework for you." CreationDate="2011-05-24T15:58:03.510" UserId="857" />
  <row Id="23136" PostId="13626" Text="@Cell-o, This question (like [this one](http://electronics.stackexchange.com/q/14643/857) and [this one](http://electronics.stackexchange.com/questions/14185/pinchoff-voltage-in-an-fet)) shows little evidence of effort. This one has come and gone, but I'm closing it as a reminder and so that your future behavior will hopefully change." CreationDate="2011-05-24T16:04:59.010" UserId="857" />
  <row Id="23137" PostId="14636" Text="Sweet, it works like a charm! My unconsciousness probably didn't believe you because I connected everything without lifting up the wheels of the car; it resulted in the car shooting forward :-D" CreationDate="2011-05-24T16:05:29.697" UserId="4381" />
  <row Id="23138" PostId="14605" Score="1" Text="Agree with @Leon, that's a tantalum capacitor. I disagree that the polarity was switched; more likely, overvoltage killed it. The cap is probably across the output of a DC-DC buck converter in which the series MOSFET has failed. (Those large surface-mount inductors are screaming 'buck' to me.) Excessive input voltage could definitely be the cause." CreationDate="2011-05-24T16:40:43.753" UserId="1293" />
  <row Id="23139" PostId="14644" Text="@Dean - Wrapping code in code tags, as you can see, puts vertical scroll bars on long code sections.  You don't have to worry about pushing content down." CreationDate="2011-05-24T16:43:55.123" UserId="857" />
  <row Id="23140" PostId="14644" Text="@Daniel - Nice edit!" CreationDate="2011-05-24T16:44:09.523" UserId="857" />
  <row Id="23141" PostId="14636" Text="That'll teach you!  :)" CreationDate="2011-05-24T16:47:14.557" UserId="4342" />
  <row Id="23142" PostId="14642" Text="@nootropic, can you give us more technical details of what you have done. It sounds interesting but my goal is to always avoid answers that need the other site to know the details, albeit that without your site your product would not be available, bringing a different bag of worms." CreationDate="2011-05-24T16:48:05.030" UserId="230" />
  <row Id="23143" PostId="14622" Text="@avra, can you give me a bit more detail about why the tv out library is great?" CreationDate="2011-05-24T16:48:31.800" UserId="230" />
  <row Id="23144" PostId="14613" Text="Agreed. The powertrain in the adapter would make a good input stage for a buck converter to generate the 8V 6A, but reconfiguring the charger to give 8V at higher current goes beyond tinkering." CreationDate="2011-05-24T16:50:40.630" UserId="1293" />
  <row Id="23145" PostId="14644" Text="@reem, Thanks. But merits to @lacop who made the first edit." CreationDate="2011-05-24T16:51:41.770" UserId="938" />
  <row Id="23146" PostId="14642" Score="1" Text="Sure.  TVout is an Arduino library that makes it easy to generate low-res monochrome composite video for a TV.  I designed a device (Hackvision) that is essentially an Arduino board and game controller combined, and it has audio/video outputs that you connect to your TV.  TVout, my controllers library, and game examples make it easy to start writing your own games.  And the since the games are written with the normal Arduino IDE, it's fine for beginners.  Hackvision would be useful to the original poster because all the hardware is taken care of, and Arduino coding is widely understood." CreationDate="2011-05-24T17:03:49.920" UserId="4390" />
  <row Id="23147" PostId="14646" Text="That looks like it handles bi-directional as well, which should make it easy." CreationDate="2011-05-24T17:27:06.153" UserId="4342" />
  <row Id="23148" PostId="14648" Text="Steppers taking 50 mA?" CreationDate="2011-05-24T17:27:49.643" UserId="305" />
  <row Id="23149" PostId="14632" Text="I was just expanding on what stevenvh had said" CreationDate="2011-05-24T17:28:42.110" UserId="985" />
  <row Id="23150" PostId="14648" Text="from 50mA at idle, to 1A loaded - but then the author mention the wheel is turning free - so I guess he either already figured out how to wire a stepper, or it is some form of a DC comutated motor." CreationDate="2011-05-24T17:30:40.690" UserId="2292" />
  <row Id="23151" PostId="14429" Text="@oxakhil - I believe that's why the utilities regularly adjust their generator frequency - so that the error is brought back close to zero over time." CreationDate="2011-05-24T18:02:02.057" UserId="3308" />
  <row Id="23152" PostId="14603" Text="You nailed it.." CreationDate="2011-05-24T18:14:00.460" UserId="4277" />
  <row Id="23153" PostId="14598" Text="@Bitrex isn't thermally generated current is random so that net current flow is zero?" CreationDate="2011-05-24T18:18:30.800" UserId="4277" />
  <row Id="23154" PostId="14603" Text="@Scott We increase voltage at the cost of current during power transmission to reduce I^2xR loss. Why doesn't V^2/R equation to calculate power applicable there?" CreationDate="2011-05-24T18:29:44.153" UserId="4277" />
  <row Id="23155" PostId="14628" Text="+1 thanks for adding these 4 synthesis tools" CreationDate="2011-05-24T18:41:12.443" UserId="3145" />
  <row Id="23156" PostId="14646" Text="Yes, it's got an H-bridge." CreationDate="2011-05-24T18:44:04.643" UserId="305" />
  <row Id="23157" PostId="4282" Text="Bootloader for ATtiny13 (uses near 25% of FLASH):&#xA;http://jps.hut2.ru/free_avr_loader_en.html" CreationDate="2011-05-23T06:03:56.647" UserId="4367" />
  <row Id="23158" PostId="14642" Text="@nootropic, edit it in, make your answer more thorough and complete!" CreationDate="2011-05-24T19:59:54.000" UserId="230" />
  <row Id="23159" PostId="14603" Text="It does.  But the V in that equation is the V between the two ends of the line (or the difference in V-to-ground at the two ends of the line), not the transmission voltage itself. If you doubled the transmission voltage (halving the current and dividing the power loss by 4), you'd also expect to see the voltage drop along the line get halved, and the v^2/R would produce the same result as I^2*R." CreationDate="2011-05-24T20:27:04.033" UserId="3361" />
  <row Id="23160" PostId="5010" Text="An unexciting practical answer: http://tinyurl.com/3t2htbr - a mechanical timer wall switch.  About $12.  Mount it straight into the control panel plate of the washing machine..." CreationDate="2011-05-24T20:32:45.470" UserId="3308" />
  <row Id="23161" PostId="14651" Text="This question cannot be reasonably answered in its current form.  There's a whole industry of EMC consultants employed to handle these questions on a case-by-case basis, it's unreasonable to think that a complete list can be managed here.  There are also significant books, such as the venerated [Handbook of black magic](http://www.amazon.com/High-Speed-Digital-Design-Handbook/dp/0133957241) and [Intro to EMC](http://www.amazon.com/Introduction-Electromagnetic-Compatibility-Microwave-Engineering/dp/0471755001) that deal with this question in great detail." CreationDate="2011-05-24T21:25:07.437" UserId="857" />
  <row Id="23162" PostId="14651" Text="Additionally, your second paragraph indicates a lot of subjectivity.  There's no reason to suspect that datasheet authors create example schematics without important parts for marketing reasons. " CreationDate="2011-05-24T21:26:49.357" UserId="857" />
  <row Id="23163" PostId="14651" Text="Finally, the question doesn't have a single correct answer, as discussed in [the FAQ](http://electronics.stackexchange.com/faq#dontask).  List questions are rarely a good thing. I'm closing this question for this reason and the others I've mentioned above." CreationDate="2011-05-24T21:27:51.603" UserId="857" />
  <row Id="23164" PostId="14656" Score="6" Text="Um - They popped - blown, gone, killed...." CreationDate="2011-05-24T21:50:26.400" UserId="1750" />
  <row Id="23165" PostId="10640" Text="@pingswept, any links?" CreationDate="2011-05-24T21:52:06.987" UserId="230" />
  <row Id="23166" PostId="14656" Score="1" Text="I also noticed that my white LEDs went from white to blue and then to purple before they popped. @Linker3000 Define &quot;popped&quot;, &quot;blown&quot;, &quot;gone&quot;, &quot;killed&quot;. They are all different words with different meanings and each of the words has large number of meanings which are not related to process that occurred here. To me it looks like the question is about the physical process of LED destruction, which is very important to understand so that its early stages could be detected in a circuit that appears to be running fine. " CreationDate="2011-05-24T21:55:55.223" UserId="1240" />
  <row Id="23168" PostId="14527" Text="@arussell - Yeah, I wasn't sure it fit the mold of D, Rust, or Go." CreationDate="2011-05-24T22:14:18.057" UserId="857" />
  <row Id="23169" PostId="13190" Text="You might like to study the [µWatch](http://www.calcwatch.com/) project." CreationDate="2011-05-24T23:28:35.913" UserId="2838" />
  <row Id="23170" PostId="14622" Text="I think that generating video signal in pure software with exact timing without external video chip is fascinating and I like it. It has it's use. If you google around, you will see that color is also achieved this way, and with external ram it's not just a color bar but real TV or VGA character and graphics generator. Another fascinating AVR usage is USB device in pure software." CreationDate="2011-05-24T23:51:51.953" UserId="1129" />
  <row Id="23172" PostId="10573" Text="@longneck -- you're right.   I was fooled by them being listed under the &quot;analog conference stations&quot; heading.  If one of them matches the system JYelton has, it would be the easiest solution, but may be more expensive that what he is looking to do.   If quality is important, it would definitely be the way to go." CreationDate="2011-05-25T01:21:03.660" UserId="1295" />
  <row Id="23173" PostId="14660" Score="3" Text="I have heard about this but I don't know if it was lead-acid (difficult to blow up) or NiMH/NiCD (less difficult to blow up).  I wouldn't try it with Li-on or Li-Poly (too easy to blow up)" CreationDate="2011-05-25T01:28:07.707" UserId="249" />
  <row Id="23174" PostId="14631" Text="Agreed - I worked for a company that developed a prototype power line monitoring robot that derived its power from the field around the line.  It's possible." CreationDate="2011-05-25T01:30:13.710" UserId="249" />
  <row Id="23175" PostId="12278" Text="what information are you looking for?" CreationDate="2011-05-25T01:37:47.097" UserId="2060" />
  <row Id="23176" PostId="14609" Score="1" Text="The best reverse-polarity protection option here (weight-constraints, size-constraints, etc...) is to just get a connector with good polarization protection. Dean's ultra connectors are nice, and good for 100's of amps, and there are other similar connectors out there. Any other option is going to be pretty bulky, and waste some energy." CreationDate="2011-05-25T02:01:06.213" UserId="1374" />
  <row Id="23177" PostId="14623" Score="1" Text="Smells like homework......" CreationDate="2011-05-25T02:02:20.520" UserId="1374" />
  <row Id="23178" PostId="14603" Text="Replace 'electron' with 'electric charge'. It's $VI = \frac{J}{C} \frac{C}{s} = \frac{J}{s} = W$, where J is joules of energy and C is coulombs of charge. If you short circuit a high AC voltage with your body, a large current flows through you, but it's a flow of ions, not electrons." CreationDate="2011-05-25T02:13:55.210" UserId="721" />
  <row Id="23179" PostId="14619" Text="@KevinVermeer is right here. @endolith, this is a bit of an open ended chatty question, but with great answers there is no reason to worry about it. If the answers are very very poor then we should probably start to worry and will probably remove it as answers are a clear litmus test of question value." CreationDate="2011-05-25T02:31:26.840" UserId="230" />
  <row Id="23180" PostId="14643" Text="@Kevin Vermeer - Dammit, now I REALLY want to add a `&quot;Plz send me teh codez&quot;` tag...." CreationDate="2011-05-25T02:41:01.437" UserId="1374" />
  <row Id="23181" PostId="14616" Score="1" Text="Hell, don't bother with the dev-kit, just buy a protoboard and a prop-clip (or a USB proto-board) - That's like $50" CreationDate="2011-05-25T02:42:24.773" UserId="1374" />
  <row Id="23182" PostId="14648" Text="I have **NEVER** seen steppers to drive wheels (well, maybe in some hobby projects). Stepper motors are horrible for just about everything. The robot's is almost guaranteed to use brushed DC motors. Steppers have HORRIBLE torque (brushed DC motors have ~10x the torque in the same volume), and brushed motors are also far easier to control. They just don't offer precision positioning without a encoder. The **only** situation where you would **ever** want a stepper is when you need some precision **and are too cheap to put together a servo-motor system**." CreationDate="2011-05-25T02:46:34.183" UserId="1374" />
  <row Id="23183" PostId="14656" Score="5" Text="You turned it into a DED, a Dark Emitting Diode.  Although you might have gotten lucky and turned it into a SED, or Smoke Emitting Diode." CreationDate="2011-05-25T02:49:34.177" UserId="3624" />
  <row Id="23184" PostId="14655" Score="1" Text="Note: even with a output pullup, it is still metastable on powerup. Board debris or strange output loading could still cause it to come up in the alternate state. A power-on reset system is the only real way to be confident it will always power up in the same state. " CreationDate="2011-05-25T02:50:33.920" UserId="1374" />
  <row Id="23186" PostId="14527" Text="D? Rust? What?....." CreationDate="2011-05-25T02:56:27.697" UserId="1374" />
  <row Id="23187" PostId="14642" Text="As far as my needs go, this is the answer I was hoping for. Great work, this should be so much fuun :D. The price range is great, it's arduino so it's *nix friendly, the examples look soooo cool, I'm sorry I can only upvote your answer once." CreationDate="2011-05-25T03:51:42.643" UserId="2717" />
  <row Id="23188" PostId="14642" Score="1" Text="whoa.  this is bad.  not bad meaning bad, but bad meaning good." CreationDate="2011-05-25T04:06:59.590" UserId="2288" />
  <row Id="23189" PostId="14656" Text="I hooked a white LED across a 9V battery once (after the series resistor slipped out of place) and it went from bright white, to green, to orange, to pop/smoke/dead." CreationDate="2011-05-25T06:39:52.197" UserId="638" />
  <row Id="23190" PostId="14529" Text="Perhaps Go and Rust ultimately won't be suitable for embedded programming. They are a bit new, I guess, but they claim to be systems programming languages, which is why I listed them as examples. There's also been some news regarding these languages recently in programming circles, so I tried to pick languages that weren't too obscure." CreationDate="2011-05-25T07:38:59.903" UserId="4349" />
  <row Id="23192" PostId="14660" Score="3" Text="Voltages aren't passed through: currents are passed through, voltages are applied across. This is more a matter of having the concepts right in your mind than just being pedantic about the terms used." CreationDate="2011-05-25T07:49:44.273" UserId="2110" />
  <row Id="23193" PostId="14620" Text="@endolith - The amount of tapped power versus the transmitted power is probably too low to be detectable. Also I guess the resolution for the exact location is a function of the wavelength, which is 6000 km for a 50 Hz wave." CreationDate="2011-05-25T08:59:15.280" UserId="2064" />
  <row Id="23194" PostId="12071" Text="The FXLP34L6X is a leadless package. If you want actual pins, you need the FXLP34P5X which comes in an SC70 package" CreationDate="2011-05-25T10:21:08.437" UserId="3920" />
  <row Id="23195" PostId="14620" Text="@stevenvh TDR uses pulses with lots of high frequency energy, not 60 Hz waveforms.  Not sure if this would allow them to detect a load that's tuned to 60 Hz, though." CreationDate="2011-05-25T10:35:42.427" UserId="142" />
  <row Id="23196" PostId="14664" Text="On your point about trespass/vandalisation, power lines normally go across farmland with the power companies paying rent to the landowner for the privilege of putting a pylon on their land. If that landowner wanted to lay a cable alongside the transmission lines on his own land then what would stop him? The only thing a power company could do to stop this is to move their transmission lines!" CreationDate="2011-05-25T11:14:06.137" UserId="2426" />
  <row Id="23197" PostId="14655" Text="@Fake Name - feel free to describe a power-on-reset circuit. i've expunged the pull up." CreationDate="2011-05-25T12:03:52.710" UserId="740" />
  <row Id="23198" PostId="14669" Text="this resembles the outcome in the garage of the guy i knew that was rolling his own lithium packs." CreationDate="2011-05-25T12:07:44.253" UserId="740" />
  <row Id="23199" PostId="14648" Text="I have only 2 wires per motor, I think a stepper needs more right ?" CreationDate="2011-05-25T12:43:25.927" UserId="4389" />
  <row Id="23200" PostId="14646" Text="You are a genius :p you made my day. This is so simple I feel guilty ! Thanks" CreationDate="2011-05-25T12:43:58.983" UserId="4389" />
  <row Id="23201" PostId="14646" Text="I've got one. It's a nice kit, and easy to build." CreationDate="2011-05-25T13:00:35.417" UserId="305" />
  <row Id="23202" PostId="12071" Text="@Federico - You're right, thanks for pointing this out. I'll edit my answer." CreationDate="2011-05-25T13:52:54.483" UserId="2064" />
  <row Id="23203" PostId="14620" Text="@endolith - Apart from the problem of having to couple this signal onto a 380 kV line, how far do you think it will travel? I don't know what frequency you would use. (My only experience with TDR is OTDR for detecting faults in optical fiber and there you use the same signal as the carrier, like 1.5 um)" CreationDate="2011-05-25T14:26:49.247" UserId="2064" />
  <row Id="23204" PostId="14620" Text="@stevenh: I don't know, but it seems plausible to me.  One document even says &quot;Time-domain reflectometry (TDR) is a cable-testing technique that was originally developed to detect faults along power transmission lines&quot;" CreationDate="2011-05-25T14:50:19.597" UserId="142" />
  <row Id="23205" PostId="14671" Text="This issue has been dealt with before [here](http://electronics.stackexchange.com/questions/14296/why-snub-an-optoisolator). Pages 6 &amp; 7 of the [fairchild datasheet](http://www.fairchildsemi.com/ds/MO/MOC3010M.pdf) refer to inductive loads." CreationDate="2011-05-25T14:55:09.197" UserId="2234" />
  <row Id="23206" PostId="14527" Score="1" Text="What would the modern languages bring to (really) embedded programming? PS. In this context by embedded programming I mean programming in which a Cortex-M3 is a screaming performance beast and you only ever use on-chip SRAM and Flash." CreationDate="2011-05-24T21:54:47.820" UserId="659" />
  <row Id="23207" PostId="14669" Text="Does this really answer the question?" CreationDate="2011-05-25T15:03:50.980" UserId="319" />
  <row Id="23208" PostId="14644" Score="1" Text="I think I figured out the problem.. The DO line of the SD card never becomes high(which is usually high and turns low when card is giving response).. Please tell me why it is not getting high.." CreationDate="2011-05-25T15:06:24.487" UserId="1484" />
  <row Id="23209" PostId="14665" Text="@Fakename, I have read many times that when a lithium ion discharges too much it will trip the charge control circuit and it will not accept a new charge as the charge controller is no allowing current. When pulsed with a high voltage in this state a small amount of trickle allows the charge controller to reset and allow charge. I read an article saying that this makes up more then 90% of cell phone battery returns. I will try to find you links." CreationDate="2011-05-25T15:08:07.697" UserId="230" />
  <row Id="23210" PostId="14665" Text="@FakeName, [this seems to talk about it some](http://batteryuniversity.com/learn/article/how_to_service_cell_phone_batteries)." CreationDate="2011-05-25T15:09:45.307" UserId="230" />
  <row Id="23211" PostId="14666" Text="@Joe, this is used in Lithium also." CreationDate="2011-05-25T15:10:16.307" UserId="230" />
  <row Id="23212" PostId="14673" Text="@vicky, we need more information. We need links to parts and a schematic." CreationDate="2011-05-25T15:10:44.823" UserId="230" />
  <row Id="23213" PostId="14669" Score="2" Text="@Kellenjb I'm just warning the OP that messing with lithium batteries is very dangerous." CreationDate="2011-05-25T15:11:15.453" UserId="1225" />
  <row Id="23214" PostId="14631" Text="I was talking about underground electric wires." CreationDate="2011-05-25T15:12:20.350" UserId="4277" />
  <row Id="23215" PostId="14673" Text="I added link to what I think is part one of the question. If it's incorrect, please fix it. In future when you post multi-part questions, please include links to previous parts. Right now, the part one is easy to find, but it may not be so in say one month when Google points someone with similar problem here. " CreationDate="2011-05-25T15:12:50.413" UserId="1240" />
  <row Id="23216" PostId="14673" Text="@kortuk I am using Sandisk 1Gb card.. If you can please refer to the source code that I have posted in part1 of this question, you will find that I have been doing bit banking for spi.. RD0-&gt; CLK, RD1-&gt; DI,RD2-&gt; DO,RD3-&gt; CS.. 80K pull up resistor for CS alone.." CreationDate="2011-05-25T15:15:33.890" UserId="1484" />
  <row Id="23217" PostId="14673" Text="@Vicky, you have not resolved part 1, why is there a part 2?" CreationDate="2011-05-25T15:22:15.060" UserId="230" />
  <row Id="23218" PostId="14673" Text="@kortuk this is a sub question of the previous one.. thought it would look neat if I put this in new post.. Sorry sir..  " CreationDate="2011-05-25T15:25:27.317" UserId="1484" />
  <row Id="23219" PostId="14673" Text="@Vicky, I would prefer you added the detail and information needed to get the first question resolved instead of opening new questions and giving no detail expecting users to look up a previous question." CreationDate="2011-05-25T15:27:51.103" UserId="230" />
  <row Id="23220" PostId="14655" Text="@JustJeff, With TTL I thought there often was a default state. [on wiki](http://en.wikipedia.org/wiki/Transistor%E2%80%93transistor_logic) the first example nand gate will clearly default to an output of high. Now, if you wanted to design an SR latch I think the POR state could be controlled." CreationDate="2011-05-25T15:33:39.723" UserId="230" />
  <row Id="23221" PostId="14666" Text="@Kortuk, you are correct.  I have slightly changed my answer to reflect this.  I believe most of the respondents wanted to error on the side of safety, because this could be a very dangerous thing to do without full knowledge." CreationDate="2011-05-25T15:57:12.333" UserId="4342" />
  <row Id="23223" PostId="14655" Text="@Kortuk - let's say a lone NAND defaults to high; if you cross-connect two of them, it's still going to be a race condition. And just b/c those two NAND implementation default high, is it necessarily so that *all* NAND implementations would do so? Does it imply anything about NOR gates? I don't think there's a whole lot can be said beyond &quot;it's indeterminate, don't count on it coming up the same way every time&quot;. Still hoping @Fake Name will be forthcoming with a POR." CreationDate="2011-05-25T17:48:30.387" UserId="740" />
  <row Id="23224" PostId="14655" Text="@JustJeff, yes, but if you wanted to design a system that had a controlled POR state you would design, lets say the R side, to default to off by using pull downs and the transistors as pull ups. It really comes down to the design and datasheet, as most things." CreationDate="2011-05-25T18:05:54.230" UserId="230" />
  <row Id="23225" PostId="14675" Text="@KPL If that comment solved you problem, post it as an answer and accept it when you can." CreationDate="2011-05-25T18:06:42.263" UserId="1240" />
  <row Id="23228" PostId="14679" Text="I don't want to use any external crystal. Can I use the pins XIN, XOUT for my I/O purposes?" CreationDate="2011-05-25T19:08:56.930" UserId="4412" />
  <row Id="23229" PostId="14680" Text="if you google &quot;apollo flight computer&quot; you can get detailed plans, schematics even." CreationDate="2011-05-25T19:10:35.150" UserId="740" />
  <row Id="23230" PostId="14679" Text="If you want any sort of accuracy a crystal is essential! Even if you dispense with it, you won't have enough outputs (you need 11)." CreationDate="2011-05-25T19:15:52.280" UserId="305" />
  <row Id="23231" PostId="14664" Text="@Fake Name, can you explain this a little more? `On some long distance transmission power lines, they use high-voltage DC to reduce losses`? I'm an EE grad but I barely passed my power classes (3 phase power is confusding ;_;) But I don't understand in what situation using DC power over long distances reduces losses." CreationDate="2011-05-25T19:17:19.537" UserId="1360" />
  <row Id="23233" PostId="14659" Score="1" Text="Maybe the phosphor already died at that point. The orange/red glow is probably from heat alone. Once upon a time I had an EPROM glow red when I accidentally reversed the polarity of the power supply." CreationDate="2011-05-25T19:28:16.967" UserId="339" />
  <row Id="23234" PostId="1214" Text="Open-source support for Atmel AVR is very nice (avr-gcc and avrdude)." CreationDate="2011-05-25T19:42:26.617" UserId="339" />
  <row Id="23235" PostId="14655" Text="please see edit" CreationDate="2011-05-25T19:48:53.817" UserId="4396" />
  <row Id="23236" PostId="14653" Text="ah - well for homework type purposes, you just assume that Q and !Q are both high, and go from there - but be sure to state that this is an assumption you've made. for completeness, you can then assume that they both start out low, and do another analysis. professors like it when you clearly state what assumptions you make, and also why you are forced to make them, and then follow through on the analysis." CreationDate="2011-05-25T20:00:56.843" UserId="740" />
  <row Id="23237" PostId="14665" Text="I can confirm that &quot;jump starting&quot; from a bench power supply works for NiMH batteries. Here's what I have tried with AA and AAA NiMH cells: set a bench power supply to a max. current of 1 A and 0 V. Connect the battery. Increase the voltage until the current maxes out at 1 A. After a short time, the current will decrease to some mA. This is about when a normal charger will be able to charge the battery without indicating &quot;BAD&quot;. Do this with NiMH cells for just some seconds, maybe repeat, and don't try it for batteries containing Lithium." CreationDate="2011-05-25T20:42:53.687" UserId="930" />
  <row Id="23238" PostId="14684" Text="Thank you very much, I try to find the correct one!" CreationDate="2011-05-25T21:12:41.323" UserId="3130" />
  <row Id="23239" PostId="14653" Score="1" Text="A non-reset SR latch should go into a logic chain that goes through a reset sequence that clears the latch to a known state." CreationDate="2011-05-25T21:13:51.230" UserId="3308" />
  <row Id="23240" PostId="14683" Score="1" Text="The MAX6950 costs $13.84 from Digi-Key!" CreationDate="2011-05-25T21:23:57.427" UserId="305" />
  <row Id="23241" PostId="9522" Text="Why the downvote?" CreationDate="2011-05-25T22:04:55.880" UserId="305" />
  <row Id="23242" PostId="14644" Score="2" Text="CMD0 is `0x40` and not `0x44`, see [Simplified Specs](http://www.sdcard.org/developers/tech/sdcard/pls/simplified_specs/) on sdcard.org" CreationDate="2011-05-25T22:08:30.107" UserId="1472" />
  <row Id="23243" PostId="14665" Text="@Kortuk - If you are applying a high voltage to the battery IO pins, you may be doing bad things to the controller circuit, like overvoltaging the the protection switching MOSFETs. It may work, but it may damage the battery circuitry subtly." CreationDate="2011-05-25T22:50:01.070" UserId="1374" />
  <row Id="23244" PostId="14681" Text="`Apollo guidance computer was one of the first to use ICs` Interesting. I didn't know that. I'll have to look that up." CreationDate="2011-05-25T22:50:27.547" UserId="1360" />
  <row Id="23245" PostId="14576" Text="@KPL - You've written too many questions in one.  I understand that the context ties them all together, but they're very capable of standing independently.  (With the exception that 2 is too broad, and 3 is barely on-topic).  Please either consolidate your questions into one answerable question, or separate them into 4 individual questions." CreationDate="2011-05-25T22:51:27.797" UserId="857" />
  <row Id="23246" PostId="14578" Text="@Martin - What about it?  We need some context for the link.  Why is this resource helpful?" CreationDate="2011-05-25T22:52:57.107" UserId="857" />
  <row Id="23247" PostId="14664" Text="@Falmarri - http://en.wikipedia.org/wiki/High-voltage_direct_current , Basically, if you think about it, a long high-voltage line is a giant capacitor, with the wire forming one terminal, and th earth the other. Therefore, every AC Cycle, this large capacitor has to be charged and discharged. While it is a capacitive load, and therefore purely reactive (which means the capacitor itself dissipates no power), it does mean that a lot of current has to flow to charge the capacitor, which results in ohmic loss, and the need for the supply generator to be able to charge it every cycle [continued]" CreationDate="2011-05-25T22:58:34.850" UserId="1374" />
  <row Id="23248" PostId="14664" Text="[continued]... in addition to the load current. However, with High-voltage DC power lines, since the voltage does not change, there is no reactive loading of the power lines, so the only current the generator needs to drive is the load current." CreationDate="2011-05-25T22:59:51.387" UserId="1374" />
  <row Id="23249" PostId="14683" Text="So? It's not like he asked for cheap - he asked for possible." CreationDate="2011-05-25T23:03:44.657" UserId="249" />
  <row Id="23250" PostId="14623" Text="notice that the top and bottom are complements of one another. the bottom section can pull W *down* if T is high, AND (P is high OR Q is high OR S is high); the top section pulls W *up* if T is low, OR (P is low AND Q is low AND S is low). This means W is always driven one way or the other, and you only need to look at half the circuit. Your truth table looks correct." CreationDate="2011-05-25T23:04:37.263" UserId="740" />
  <row Id="23251" PostId="8768" Text="@tyblu - I've been managing huge (5 GB +) folders of Binary PCB Projects in SVN for years now, with no issues. What was your problem?" CreationDate="2011-05-25T23:31:09.477" UserId="1374" />
  <row Id="23252" PostId="3854" Text="@supercat I am not sure I understand; if the timer is asynchronous to the CPU clock then you will be at most 1 timer tick off; that doesn't mean the reading is invalid. If, however, you mean that the bit pattern in the register will be invalid then it's a very poor CPU/peripheral design; peripheral registers should be properly synchronized by the vendor." CreationDate="2011-05-25T23:55:38.707" UserId="974" />
  <row Id="23253" PostId="14687" Score="3" Text="your instinct is correct - assign labels to the FF outputs, e.g., Q1 and Q2. to form a table, on the left side, list the the four possible states of Q1, Q2; on the right side, write the values that Q1 and Q2 will assume after the next clock pulse. The table will then contain a complete description of the state machine." CreationDate="2011-05-26T00:53:58.927" UserId="740" />
  <row Id="23254" PostId="14679" Text="yes you can use xin and xout they are labeled P2.6 and P2.7" CreationDate="2011-05-26T04:47:40.593" UserId="2060" />
  <row Id="23255" PostId="14678" Text="msp430 14 pin DIPS have 10 ports P1.0 to P1.7 and P2.6 and p2.7" CreationDate="2011-05-26T04:49:11.233" UserId="2060" />
  <row Id="23256" PostId="14687" Text="thanks. when there's a diagram like this, would you assume the output is the Q' on the right-hand JK flipflop?  On the other one's i've seen it usually specifically shows the output.  I need to make a state diagram, so would I just omit the intput/output value that's usually included on the paths between the nodes?" CreationDate="2011-05-26T05:44:51.073" UserId="4396" />
  <row Id="23257" PostId="14683" Text="@Leon - Yes, that's not cheap. I wonder why. It's a rather simple die, 17000 transistors. IIRC I bought the 7219 for 2.50 euros." CreationDate="2011-05-26T06:18:06.250" UserId="2064" />
  <row Id="23258" PostId="14683" Text="@Leon - I went looking around for other display drivers from Maxim, and I found that the MAX6955 (which you recommended [here](http://electronics.stackexchange.com/questions/2185/i2c-7seg-driver)) costs even twice as much! ($28)" CreationDate="2011-05-26T06:27:20.153" UserId="2064" />
  <row Id="23259" PostId="2186" Score="1" Text="For some reason Maxim display drivers are terribly expensive. Leon rightfully [remarked](http://electronics.stackexchange.com/questions/14678/is-it-possible-to-drive-4-seven-segment-display-with-msp430g2231) that the MAX6950 costs $\$$13.84, but this one is even $28(!)" CreationDate="2011-05-26T06:29:53.410" UserId="2064" />
  <row Id="23260" PostId="14683" Text="It looks like Maxim got remarks from customers who found the max7219 too big, so they went from a 24 pin skinny DIP to a 16 pin QSOP (5 mm long vs. 30!). That's too little pins for the usual multiplexing like the max7219 uses, so the max6950 uses charlieplexing." CreationDate="2011-05-26T06:41:22.053" UserId="3920" />
  <row Id="23261" PostId="14598" Score="1" Text="@endolith - &quot;doesn't current alone already imply voltage?&quot; No! In a superconductor you can have current without a voltage drop" CreationDate="2011-05-26T07:09:16.043" UserId="2064" />
  <row Id="23262" PostId="14687" Text="@JustJeff - This should be an answer." CreationDate="2011-05-26T07:32:06.047" UserId="2064" />
  <row Id="23263" PostId="14679" Text="@Leon - The PCF8575 is not very well suited as a LED driver. Maximum allowed device current is 100 mA, so if you want to drive 16 LEDs simultaneously (2 digits in @frbry's clock) you can only have 6 mA per LED" CreationDate="2011-05-26T07:44:54.020" UserId="2064" />
  <row Id="23264" PostId="14695" Text="Sorry for not helping, but let me reassure you that it can be done. I've seen a system using DIY transducers at one of the tech fairs in my country. Unfortunately, I don' have any specifics." CreationDate="2011-05-26T07:59:38.000" UserId="1240" />
  <row Id="23265" PostId="14695" Text="@andre, I was quite sure this could be done as I have seen the openEEG project which is doing it. But their website is a mess and its an ongoing process to make something very big. But any pointers to things that might make me get closer would be nice" CreationDate="2011-05-26T08:26:33.797" UserId="1200" />
  <row Id="23266" PostId="14684" Text="Digikey tould me that there is no connector from FFC 1mm pitch to patch panel with 2.54mm spacing. What actually makes sense." CreationDate="2011-05-26T08:38:21.627" UserId="3130" />
  <row Id="23267" PostId="8774" Text="@Kevin Vermeer You know you are on the negative side on the scale when you are comparing two &quot;not that nice&quot; things with each other ;)" CreationDate="2011-05-26T08:47:08.340" UserId="689" />
  <row Id="23268" PostId="8769" Text="If you are on windows this is a good solution." CreationDate="2011-05-26T08:48:08.357" UserId="689" />
  <row Id="23269" PostId="14677" Text="Well... You should have many small repos, one repo per project." CreationDate="2011-05-26T08:49:56.730" UserId="689" />
  <row Id="23270" PostId="10615" Text="@Kevin Vermeer: I added an answer [below](http://electronics.stackexchange.com/questions/10615/arduino-board-power-polarity/14701#14701)" CreationDate="2011-05-26T09:06:25.603" UserId="3130" />
  <row Id="23271" PostId="14687" Text="@stevenvh - all righty then" CreationDate="2011-05-26T10:33:03.233" UserId="740" />
  <row Id="23272" PostId="14698" Text="glad you found that, i knew it was out there, just couldn't dredge it up." CreationDate="2011-05-26T10:35:56.820" UserId="740" />
  <row Id="23273" PostId="14698" Text="btw, you might want to indent the abstract, make it be a different font, or at least throw quotation marks around it." CreationDate="2011-05-26T10:36:22.670" UserId="740" />
  <row Id="23274" PostId="14699" Text="Calculations for the resistor dissipation?" CreationDate="2011-05-26T10:52:05.300" UserId="305" />
  <row Id="23275" PostId="14679" Text="It would need some driver transistors." CreationDate="2011-05-26T10:54:35.567" UserId="305" />
  <row Id="23276" PostId="14699" Score="2" Text="try sizing the 680 ohm as though you were planning on putting it and the 0.1uF cap in series across the full line voltage; by my calculation the 680 ohm would dissipate a tad more than 1.3W .. so a 2W or better part should take it." CreationDate="2011-05-26T11:03:12.203" UserId="740" />
  <row Id="23277" PostId="14678" Text="@jsolarski - He would at least need 11: 7 for the segments and 4 for the digits. (And maybe a few buttons)" CreationDate="2011-05-26T11:10:32.997" UserId="2064" />
  <row Id="23278" PostId="14678" Text="@stevenh good time to use the new 20 pin msp430g2x52 or msp430g2x12? 16 pins for GPIO +8K programming space and 256b ram" CreationDate="2011-05-26T11:16:08.517" UserId="2060" />
  <row Id="23280" PostId="12066" Text="The trigger level of the 1381 seems to be 2V minimum, which means it will never trigger on an input signal between 0 and 1.4V." CreationDate="2011-05-26T12:46:53.627" UserId="2064" />
  <row Id="23281" PostId="14698" Text="JustJeff, I knew exactly where to find that page: in my &quot;TO DO&quot; bookmarks :-)  (You're right... I've put blockquotes around abstract) " CreationDate="2011-05-26T12:50:35.213" UserId="244" />
  <row Id="23282" PostId="14711" Score="1" Text="@stevenvh  While most microcontrollers do include a watchdog, I would omit the phrase &quot;on the same die as the rest of the microcontroller&quot;, since that's not an important feature/misfeature of the microcontroller.  Any hardware failure that would take out a uC would likely be unrecoverable.  But, +1 for saying that it is meant to catch SW errors.  It will also catch the odd event, like a cosmic ray, but those are secondary.  " CreationDate="2011-05-26T13:02:53.740" UserId="3624" />
  <row Id="23283" PostId="14710" Text="In addition to what stevenh said below in his answer, if (for some reason) you don't trust the *system* upon recovering from a watchdog reset, you can also completely disable the watchdog.  But the idea here is that your code never gets into a condition where it gets lost in la-la land and doesn't ping the watchdog timer to reset it." CreationDate="2011-05-26T13:03:43.920" UserId="2288" />
  <row Id="23286" PostId="14711" Score="1" Text="@David - I included that phrase because OP suggested that the watchdog maybe was &quot;implemented in a different silicon and later attached to the main chip circuit&quot;, which definitely isn't so. It would be too expensive that way, and of little use, because the hardware is much more reliable that the software." CreationDate="2011-05-26T13:11:22.317" UserId="2064" />
  <row Id="23287" PostId="14713" Score="1" Text="Will you be using this to check different places or leave it connected once it is installed?" CreationDate="2011-05-26T13:20:04.990" UserId="4342" />
  <row Id="23288" PostId="14679" Text="	&#xA;@Leon - &quot;some driver transistors&quot;. Yes, 16 of them. Plus 16 extra resistors. Hm. Wouldn't something like TPIC6C595 be more appropriate? Doesn't do I2C, but is easy enough to bit-bang. And you would two of them for 16 I/Os (they're cascadable), but at least you don't need all that chicken feed." CreationDate="2011-05-26T13:27:07.960" UserId="2064" />
  <row Id="23289" PostId="14711" Text="@David - about cosmic rays, I don't know how big a problem this is on earth. I can imagine, however, that rad-hard devices for use in space do have more comprehensive security measures than a simple watchdog timer." CreationDate="2011-05-26T13:40:57.913" UserId="2064" />
  <row Id="23290" PostId="14715" Text="@MikeJ-UK Yeah, I have ct's that I could use, but the problem is it must be a clamp on. I can not physically make or break the line. Thanks." CreationDate="2011-05-26T13:49:11.940" UserId="3453" />
  <row Id="23291" PostId="14713" Text="It will be left connected at one location. " CreationDate="2011-05-26T13:51:22.450" UserId="3453" />
  <row Id="23293" PostId="14713" Text="@Steve R Damn, I was thinking you were trying to make a devices that could help someone find where the valve was instead of having to dig up a yard (as I have once done before)" CreationDate="2011-05-26T13:53:32.263" UserId="319" />
  <row Id="23294" PostId="14711" Score="1" Text="@stevenvh Cosmic rays are in fact a problem - if my old-school professor is to be believed (he has a beard and wears suspenders, so I assume he knew what he was talking about) then the first computers were plagued by single-bit errors that couldn't be reliably traced.  Turned out it was cosmic rays.  The more you know!" CreationDate="2011-05-26T14:00:19.110" UserId="249" />
  <row Id="23295" PostId="14716" Text="The (miserably failed) Intel iAPX432 also has some level of fault tolerance by having two iAPX432s in tandem." CreationDate="2011-05-26T14:01:01.180" UserId="2064" />
  <row Id="23296" PostId="14711" Text="@AngryEE - I would have expected that modern controllers would be more vulnerable, given the small feature size of the die and the smaller signal levels (voltage and current) involved. But of course I believe your professor. Suspenders never lie. :-)" CreationDate="2011-05-26T14:14:35.313" UserId="2064" />
  <row Id="23297" PostId="3854" Text="@Andrew Kohlsmith: A counter which may be reliably read by a CPU whose clock is asynchronous to it requires a fair bit of silicon.  Essentially, one must either count in graycode or convert the count to graycode, then synchronize that, and then convert the graycode value back to &quot;normal&quot; binary.  For cases where the CPU clock will--*when running*--be at least 3x faster than the signal to be counted, it might be easier to arrange for the counter to be clocked synchronously when the CPU is awake and asynchronously when it's asleep..." CreationDate="2011-05-26T14:18:07.563" UserId="3123" />
  <row Id="23298" PostId="14715" Text="@Steve R - I was afraid you would say that! Looking around, I see the [Magnelab SCT-0750](http://www.magnelab.com/products/Current-Voltage-Sensors/split-core-ac-current-sensor-sct-0750) (for around £28 UK). Very convenient, but the highest sensitivity (1A) model only gives 33mV/100mA. You might be able to loop a few turns if you have enough slack." CreationDate="2011-05-26T14:18:17.320" UserId="2234" />
  <row Id="23299" PostId="3854" Text="@Andrew Kohlsmith: ...but switching between synchronous and asynchronous clocking without gaining or losing a count--even in edge cases--is difficult.  If software can get by with reading the timer repeatedly until it gets the same answer multiple times, that will be allow the use of simpler hardware than would otherwise be necessary.  Note that the only time that approach really won't work is when the count rate is pretty high compared with the to the CPU clock rate, which would suggest that the graycode approach is the right one." CreationDate="2011-05-26T14:20:32.167" UserId="3123" />
  <row Id="23300" PostId="14711" Text="A professor with a beard wearing suspenders? You cannot imagine the terrible image we British users now have in our heads." CreationDate="2011-05-26T14:24:09.527" UserId="2234" />
  <row Id="23301" PostId="14711" Text="Apparantly [Intel has a patent for cosmic ray detectors](http://www.newscientist.com/blog/technology/2008/03/do-we-need-cosmic-ray-alerts-for.html) inside chips&#xA;and the effect is further [discussed on StackOverflow](http://stackoverflow.com/questions/2580933/cosmic-rays-what-is-the-probability-they-will-affect-a-program)." CreationDate="2011-05-26T14:33:19.457" UserId="2110" />
  <row Id="23302" PostId="14576" Text="Don't be discouraged thinking that you made a bad purchase, I've used this exact micro-controller for many of my university projects, primarily used for learning but it is more than capable for beginner projects.  Please take a look at this: http://www.8052.com/forum/read/146829 .  It is an excellent post made by one of my professors on how to get started with 8051 programming.  If anything, you have the potential to learn more with real C on this platform than learning the arduino C-like language." CreationDate="2011-05-26T14:46:28.760" UserId="4172" />
  <row Id="23303" PostId="14706" Text="I did not see any mention of bitwise operation in the original post and I see that Dave has added the bitwise-operations tag, but just to be clear here, the topic you are asking about is bitwise-operations and you should supplement any answer here with a google search of what these operators are (AND, OR, inverse, shift, etc).  Ignore this comment if you already know your C bitwise operators." CreationDate="2011-05-26T14:53:59.253" UserId="4172" />
  <row Id="23304" PostId="14715" Text="@MikeJ-UK - Yeah that one is a little pricey @ 45 usd each.The thing is that the project needs to be disposable, therefore cheap. I face the real possibility of it not being returned.  " CreationDate="2011-05-26T15:37:53.173" UserId="3453" />
  <row Id="23305" PostId="14718" Text="I half suspected I was wrong with neurofeedback. But the site is somewhat messy and I didn't do my research. But right now I am looking for a concise tutorial or booklet which would walk me through the theory and practice of making these electrodes. I did find some designs with open eeg but everything is scattered everywhere. Maybe when my exams are completed then I would get some time to plow through the website. Maybe my mistake was to first go to the warnings page. " CreationDate="2011-05-26T16:19:40.437" UserId="1200" />
  <row Id="23306" PostId="14719" Score="1" Text="A &quot;Complementary Filter&quot; is when a Diva/Princess only hears the good comments about her, and ignores or doesn't hear the criticisms.  " CreationDate="2011-05-26T16:38:01.043" UserId="3624" />
  <row Id="23307" PostId="14713" Text="As an alternate I would consider a contact-less voltage detection circuit, like those pens used by electricians. Problem is I haven't seen any that work as low as 24 vac. If I could find a circuit, I might be able to redesign for my needs. I assume they detect RF! The AC interference gives and output? In any case it would need to be reliable with no false triggers. " CreationDate="2011-05-26T16:58:07.360" UserId="3453" />
  <row Id="23308" PostId="14704" Text="I just tried again with the 100-ohm resistor and 100nF capacitor removed. The same thing happened -- the 680-ohm resistor fried as soon as I put the optocoupler in the ON state. The load doesn't seem to get any power. It smells as though my triac is fried -- lots of power going into the gate without triggering the triac." CreationDate="2011-05-26T17:32:39.857" UserId="2172" />
  <row Id="23309" PostId="14704" Text="And yes, my calculations were indeed wrong -- I wasn't even thinking about the current that would flow into the 100nF capacitor through the 680-ohm resistor. But the resulting power dissipation in the OFF state wasn't sufficient to make the resistor smoke (at least not initially). It's the ON state current that is worrisome." CreationDate="2011-05-26T17:35:05.317" UserId="2172" />
  <row Id="23310" PostId="14704" Text="Read what I wrote, again. I said remove the resistor in question and the 0.1 uF capacitor, not the 100R and 100nF!" CreationDate="2011-05-26T17:49:44.863" UserId="305" />
  <row Id="23311" PostId="3854" Text="@Andrew Kohlsmith: Note that unless a facility is provided for synchronous 16-bit reading, or the count rate is so fast that the CPU won't be able to read low-high-low before low changes, there's no real disadvantage to having the counter return corrupt values if it's read while it's changing (it's certainly less of a disadvantage than would be an occasional gained or lost count caused by switching between synchronous and asynchronous modes)." CreationDate="2011-05-26T17:54:11.217" UserId="3123" />
  <row Id="23312" PostId="14598" Text="@stevenvh True.  Also the voltage drops in a loop of wire in a changing magnetic field are weird.  Depends on how you orient the probe wires?  Should be a question about that." CreationDate="2011-05-26T18:03:41.357" UserId="142" />
  <row Id="23313" PostId="8767" Text="+1 For recognizing that the HW projects could benefit from source control.  The guys I work with seem to have a tough time realizing this." CreationDate="2011-05-26T18:06:16.503" UserId="923" />
  <row Id="23314" PostId="8774" Text="@KevinVermeer, I had to use sourcesafe, the bane of the version control world. My last boss allowed complete neglect of version control because of it." CreationDate="2011-05-26T18:11:24.877" UserId="230" />
  <row Id="23315" PostId="14684" Text="I've seen some break out boards for 1mm to 2.54mm.  This is often used for LCD displays.  Are you putting this into a 0.1&quot; protoboard or something?" CreationDate="2011-05-26T18:14:13.873" UserId="4342" />
  <row Id="23316" PostId="14704" Text="I removed the 100-ohm instead of the 680-ohm resistor (I removed the 0.1uF capacitor). Sorry for not doing exactly as you said ... Even so, I was expecting (in this modified circuit) the OFF state power dissipation of the 680-ohm resistor to be 0W and the ON state power dissipation to be approx. (0.035)*(VT)/2*asin(VT/120)/Pi (in watts) where VT is the voltage across the 680-ohm resistor required to trigger the power triac (VT = 0.035*680). That works out to 0.026 watts. ... Do you agree I probably have a fried triac?" CreationDate="2011-05-26T18:23:53.827" UserId="2172" />
  <row Id="23317" PostId="14722" Score="2" Text="We're not that kind of electronics site - try superuser.com" CreationDate="2011-05-26T19:02:52.277" UserId="249" />
  <row Id="23318" PostId="14722" Text="But if its not working and new i would take it back to the shop and complain. " CreationDate="2011-05-26T19:05:19.483" UserId="1623" />
  <row Id="23319" PostId="14688" Score="2" Text="Actually the bigger ones nowadays contain billions of transistors." CreationDate="2011-05-26T19:59:13.467" UserId="339" />
  <row Id="23320" PostId="14726" Text="I've never seen a diode rated in power. Voltage drop is very much proportional to current, so they are just rated in amps." CreationDate="2011-05-26T20:40:55.150" UserId="1225" />
  <row Id="23321" PostId="14726" Text="Am I right in assuming that derating can be some combination of lower max current, shorter max current duration, and/or longer off period?" CreationDate="2011-05-26T20:41:02.420" UserId="1278" />
  <row Id="23323" PostId="14729" Text="Definitely don't need high bandwidth. Would be happy with transmitting a text file (say up 100kb). &#xA;&#xA;What network are devices like this Sparkfun one using? Are you paying for the data?" CreationDate="2011-05-26T21:21:37.343" UserId="2484" />
  <row Id="23324" PostId="14729" Score="1" Text="Your best bet is to search for free plans.  They seem to exist, but in general you'll need a registered SIM card so you can log into the network." CreationDate="2011-05-26T21:57:42.690" UserId="2288" />
  <row Id="23325" PostId="14726" Text="@ajs410  Derating is basically intentionally not stressing the part to the amount that's technically allowed in the datasheet.  The specifics on that is completely up to you.  Max current and average power dissipation are two good areas to consider.  @ThomasO You're mostly right.  Power is the other side of the Current coin.  Sometimes amps makes more sense, sometimes it's watts-- but as you said they are directly related.   I just went to the diodes.com advanced parametric search and one of the columns you can sort on is power rating, so I'm not completely alone in this thinking." CreationDate="2011-05-26T22:35:04.900" UserId="3624" />
  <row Id="23326" PostId="14725" Score="1" Text="For some types of chips such as NAND flash memories, manufacturers routinely push the envelope beyond the point where zero-defect chips would be the norm, but most of the failures will have somewhat predictable characteristics, and the devices using the chips will be expected to work around them." CreationDate="2011-05-26T22:42:17.587" UserId="3123" />
  <row Id="23327" PostId="14656" Score="1" Text="You released the Magic Smoke!" CreationDate="2011-05-26T23:32:11.920" UserId="1374" />
  <row Id="23328" PostId="14731" Text="Upvote for ingenuity, details, &amp; safety pointers. This is one I need to try." CreationDate="2011-05-26T23:43:17.980" UserId="3361" />
  <row Id="23329" PostId="14684" Text="Joe, yes a 2.54 mm spacing bread board." CreationDate="2011-05-26T23:44:40.527" UserId="3130" />
  <row Id="23330" PostId="14382" Text="I edited my answer to add an image of the connector" CreationDate="2011-05-27T01:05:14.633" UserId="3556" />
  <row Id="23331" PostId="14732" Score="2" Text="not to split hairs, but you could get in an argument over whether intentionally operating a device that is well known to cause interference, constitutes intentionally causing interference." CreationDate="2011-05-27T01:19:25.227" UserId="740" />
  <row Id="23333" PostId="14732" Text="@justjeff Two words:  plausible deniability.  But seriously, my answer was intentionally short so as to raise the legal questions while also leaving them unanswered." CreationDate="2011-05-27T02:28:59.403" UserId="3624" />
  <row Id="23334" PostId="14677" Score="1" Text="@Johan - ......Yeah.... Good luck with that maintenance nightmare. Anyways, I have 1 repo per client (about 4, repositories, now), with many sub-projects, and it works pretty well. SVN, at least, seems to be able to handle 5+ GB of binary data without too much trouble." CreationDate="2011-05-27T02:55:26.380" UserId="1374" />
  <row Id="23335" PostId="14732" Text="even for testing?" CreationDate="2011-05-27T03:15:39.353" UserId="142" />
  <row Id="23336" PostId="14732" Text="I understand that it is illegal in most countries. I live in the US and I'm pretty sure it is illegal however I am I just running some tests at home. " CreationDate="2011-05-27T03:34:05.253" UserId="4429" />
  <row Id="23337" PostId="14735" Text="I want to test and see if my device at home can resist an EMI. " CreationDate="2011-05-27T03:35:10.107" UserId="4429" />
  <row Id="23338" PostId="14738" Text="http://lxr.linux.no/linux+v2.6.39/drivers/mmc/core/" CreationDate="2011-05-27T05:27:49.297" UserId="411" />
  <row Id="23339" PostId="14738" Text="http://fxr.watson.org/fxr/source/dev/mmc" CreationDate="2011-05-27T05:30:29.530" UserId="411" />
  <row Id="23340" PostId="14730" Score="3" Text="interface or interference? title and body of question disagree" CreationDate="2011-05-27T07:53:19.150" UserId="2110" />
  <row Id="23341" PostId="14732" Text="I am not a lawyer, but EM radiates reasonably well, gets picked up and retransmitted by every piece of metallic junk around, your main lines etc. However, you might want to check out WaveBubble by LadyAda." CreationDate="2011-05-27T08:18:16.027" UserId="2292" />
  <row Id="23342" PostId="14737" Text="Why the downvote, it's a very sensible suggestion. Microchip has excellent material on PID, and their dsPIC motor control chips are ideal for it." CreationDate="2011-05-27T09:46:09.737" UserId="305" />
  <row Id="23343" PostId="14732" Text="i'm just saying, if one makes a nuisance of one's self, and the law becomes involved, don't count on an &quot;i didn't know&quot; defense. anyway, +1 for raising it." CreationDate="2011-05-27T09:47:49.897" UserId="740" />
  <row Id="23344" PostId="14738" Text="What is the SDIO bus?" CreationDate="2011-05-27T09:53:00.940" UserId="305" />
  <row Id="23346" PostId="14736" Text="you might be able to do the job with an arduino, it all depends on how fast you want the PID to run. if you're just recomputing the motor current command at 50Hz, that's probably reasonable." CreationDate="2011-05-27T09:56:20.377" UserId="740" />
  <row Id="23347" PostId="14737" Text="dsPICs are very nice to use for motor control. I would highly recommend this route." CreationDate="2011-05-27T10:45:38.007" UserId="319" />
  <row Id="23348" PostId="14731" Text="although this is not what I have been looking for, I can try this in the mean time. Would look for other ways to make my gel as I don't know what exactly you are talking about." CreationDate="2011-05-27T10:52:29.240" UserId="1200" />
  <row Id="23349" PostId="14738" Score="1" Text="@Leon - http://www.sdcard.org/developers/tech/sdio/" CreationDate="2011-05-27T11:25:20.657" UserId="2064" />
  <row Id="23350" PostId="14730" Text="The TRS-80 Model I generated a lot of interference; my next door neighbours were always complaining about mine messing up their TV reception. They then got an external antenna, which solved the problem. 8-)" CreationDate="2011-05-27T12:02:20.383" UserId="305" />
  <row Id="23351" PostId="14736" Score="2" Text="Don't expect the &quot;thinking&quot; part of your system to be able to power your motors directly." CreationDate="2011-05-27T12:13:44.293" UserId="319" />
  <row Id="23352" PostId="14727" Text="A friend of a friend was working in a busbar cabinet, bolting down something with a spanner when he was startled by a spider - so he threw the spanner at it! As you said, the tool vaporized, but the resulting induction field twisted half the box off the wall. The engineer survived. No word on the spider." CreationDate="2011-05-27T13:48:57.120" UserId="1750" />
  <row Id="23353" PostId="14742" Text="On current law:  If sum is not 0 then charge is added to node, this charge repells itself and this force stops more charge from accumulating.  Does that help?" CreationDate="2011-05-27T13:57:52.197" UserId="1498" />
  <row Id="23354" PostId="14743" Text="Do you mind explaining what a fiducial is?" CreationDate="2011-05-27T14:19:27.740" UserId="319" />
  <row Id="23355" PostId="14742" Score="3" Text="They are often abbreviated to KCL and KVL." CreationDate="2011-05-27T14:21:09.550" UserId="305" />
  <row Id="23356" PostId="14743" Score="2" Text="@Kellenjb - fiducials are reference points (as copper circles) for the pick and place machine. They should be clearly isolated from anything else on the board (including silkscreen). You typically add 3 or 4 of them near the corners of the PCB." CreationDate="2011-05-27T14:25:44.737" UserId="2064" />
  <row Id="23357" PostId="14743" Text="@stevenvh thank you!" CreationDate="2011-05-27T14:26:41.633" UserId="319" />
  <row Id="23358" PostId="14579" Text="This is the best way to go, some of the analog components that were used in guitar petals are relatively difficult to source and/or are expensive as they are no longer manufactured.  For instance bucket-brigade devices used for analog delays (echo type effects)." CreationDate="2011-05-27T14:46:43.303" UserId="1438" />
  <row Id="23359" PostId="14746" Text="Ok, I already have a Ultrasonic sensor. I'll try..." CreationDate="2011-05-27T15:19:25.293" UserId="3359" />
  <row Id="23360" PostId="14744" Text="A pick and place machine positions a part using absolute coordinates from fiducials (either global or local), not by trying to line up pins and pads." CreationDate="2011-05-27T15:57:06.090" UserId="857" />
  <row Id="23361" PostId="14729" Text="You could even just transfer it via many text messages - braindead but effective." CreationDate="2011-05-27T16:05:57.367" UserId="249" />
  <row Id="23362" PostId="14744" Text="Why the downvote?" CreationDate="2011-05-27T16:09:45.073" UserId="305" />
  <row Id="23363" PostId="14744" Text="None of the boards I have with TQFP parts on them have fiducials, they were presumably assembled with pick and place machines." CreationDate="2011-05-27T16:10:59.083" UserId="305" />
  <row Id="23366" PostId="14744" Score="1" Text="@Leon - The downvote is because &quot;the answer is not useful&quot;: The pin/pad alignment idea is incorrect by my understanding, and I've seen fiducials on TQFPs (0.5mm pitch, rectangular profile used on some of the video ICs we work with) but not on BGAs.  Also, as David pointed out, the lower pitch on TQFPs makes it more important.  It's nothing personal!" CreationDate="2011-05-27T16:30:17.983" UserId="857" />
  <row Id="23367" PostId="14744" Text="They are required for manual placement of BGAs, according to assemblers I've used." CreationDate="2011-05-27T16:33:52.977" UserId="305" />
  <row Id="23368" PostId="14750" Score="2" Text="Post the schematic!" CreationDate="2011-05-27T16:59:46.587" UserId="305" />
  <row Id="23369" PostId="14749" Text="While true, is that a situation he will likely encounter? Won't the MIDI endpoints be reasonably similar in their resistive load especially given the small value of R?" CreationDate="2011-05-27T17:01:51.377" UserId="4319" />
  <row Id="23370" PostId="14749" Text="I'm not sure I quite understand. Why would the 10k and 1k  be parallel in Circuit B but not in A? I'm sure this is a complete noob question, but there's some bit of theory here that hasn't clicked yet." CreationDate="2011-05-27T17:05:03.027" UserId="4438" />
  <row Id="23371" PostId="14748" Text="Not directly related to your question but a design consideration: failure of R in circuit B means failure for all ports. If too many devices cause the resistor to fail, all ports will become useless." CreationDate="2011-05-27T17:08:36.740" UserId="4319" />
  <row Id="23372" PostId="14750" Text="If it works when your programmer is plugged in, what makes you think your ground is connected to the wrong place?" CreationDate="2011-05-27T17:24:44.827" UserId="319" />
  <row Id="23373" PostId="14750" Text="Should the 1.5k resistor pull up on the D- line should be connected to the vcc of the usb connection? I have connected it to my 5v regulator. Can someone recommend me a book / website where i can learn about communications. I want to understand why my board has to be at the same potiential as the pc." CreationDate="2011-05-27T17:24:51.617" UserId="2824" />
  <row Id="23374" PostId="14750" Text="@Ageis please edit your question" CreationDate="2011-05-27T17:26:03.797" UserId="319" />
  <row Id="23375" PostId="14745" Text="I agree about the self-aligning of the BGAs, but doesn't that also go for the QFPs? All QFPs I've seen are perfectly centered on their pads. Would pitch be the criterion for using fiducials? Like required for pitch 0.5mm or less?" CreationDate="2011-05-27T17:38:41.330" UserId="2064" />
  <row Id="23376" PostId="14750" Text="http://en.wikipedia.org/wiki/Universal_Serial_Bus" CreationDate="2011-05-27T17:40:21.623" UserId="2157" />
  <row Id="23377" PostId="14744" Text="I agree with David about the self-aligning of BGAs. I once used an SRAM in BGA48, pitch 0.75mm. There was no room for fiducials, but I got no complaints from the assembly shop." CreationDate="2011-05-27T17:40:49.847" UserId="2064" />
  <row Id="23378" PostId="14749" Text="Pete, in circuit A you'd end up (effectively) with a 1220 Ohm resistor in parallel with 10220 Ohm resistor for an final resistance of 1090 Ohms. In circuit B you'd end up with 1000 and 10000 Ohm resistors in parallel, both in series with a 220 Ohm resistor for a final resistance of 1130 Ohms." CreationDate="2011-05-27T17:41:15.903" UserId="4441" />
  <row Id="23379" PostId="14749" Text="@Scott Thanks. That helps a lot." CreationDate="2011-05-27T17:47:36.717" UserId="4438" />
  <row Id="23380" PostId="14745" Text="@stevenvh  All parts will self-align to some extent.  In the case of QFPs and TSSOPs it doesn't take much for a single pin to bridge the gap between two pads.  If that happens then the part won't self-align.  The worst case is when the part is slightly rotated.  It's all because of the thin and long pads/pins on a fine pitch.  BGAs are a bit more forgiving because of the geometry of the pads." CreationDate="2011-05-27T17:54:31.993" UserId="3624" />
  <row Id="23381" PostId="14749" Text="In MIDI, isn't the load just an LED, not resistive?  Like http://dernulleffekt.wolfgang-spahn.de/midi.html" CreationDate="2011-05-27T17:57:14.257" UserId="142" />
  <row Id="23382" PostId="14749" Text="@Erik: Even if all the loads were exactly the same 10K resistors, when they're combined in parallel it will be 1.4K, which will drop the voltage more than if each 220R only saw 10K." CreationDate="2011-05-27T17:57:54.460" UserId="142" />
  <row Id="23383" PostId="14752" Text="Awesome, thanks" CreationDate="2011-05-27T17:59:03.597" UserId="4438" />
  <row Id="23384" PostId="14752" Text="`neither is working correctly any more.` Not only that, but there could be a high chance that the chips there will let their magic blue smoke go. " CreationDate="2011-05-27T18:00:59.077" UserId="1240" />
  <row Id="23385" PostId="14752" Text="A through G are inputs or outputs?" CreationDate="2011-05-27T18:07:20.860" UserId="142" />
  <row Id="23386" PostId="14753" Text="Yes. Obviously the real circuit is more complex, but the +5V (not signal, just power) is shown in my diagram. The points A-G are pin 4 on a MIDI Thru (out) jack. When implemented properly, an optocoupler is used, as you show. There are no guarantees of that, but for the most part, that's a reasonable assumption. Also as shown in your diagram, the receiving end also has a 220ohm resistor, when implemented correctly." CreationDate="2011-05-27T18:20:06.040" UserId="4438" />
  <row Id="23387" PostId="14754" Text="Paul, excellent explanation, thanks!" CreationDate="2011-05-27T18:24:35.747" UserId="4438" />
  <row Id="23388" PostId="14752" Score="1" Text="A through G are outputs. Pin 4 in a MIDI jack." CreationDate="2011-05-27T18:25:24.343" UserId="4438" />
  <row Id="23389" PostId="14755" Text="possible duplicate of [Choosing a PID controller](http://electronics.stackexchange.com/questions/14736/choosing-a-pid-controller)" CreationDate="2011-05-27T18:25:41.830" UserId="305" />
  <row Id="23390" PostId="14753" Text="@Pete: The resistor at the receiving end would eliminate the current-hogging problem, but not the low-current problem.  And you can't guarantee the resistors are there either?  And you can't guarantee they didn't implement the inputs without optocouplers?  Definitely should stick with a resistor on each output, as designed." CreationDate="2011-05-27T18:36:03.613" UserId="142" />
  <row Id="23391" PostId="14748" Text="Why are you trying to avoid the resistors?  Ease of construction?  Space?  Cost?  There are packages that contain lots of resistors tied to one common pin to save space.  http://www.interfacebus.com/resistor-network-schematic-bused-resistors-sip.html" CreationDate="2011-05-27T18:37:31.180" UserId="142" />
  <row Id="23392" PostId="14754" Score="1" Text="For more fun, it hadn't even occurred to me (as some of the other posts are pointing out) to consider &quot;what if&quot; someone else decided to remove pieces of their circuit to help control costs/parts count/board space. " CreationDate="2011-05-27T18:41:59.903" UserId="4440" />
  <row Id="23393" PostId="14730" Text="A mains powered electric drill.  They cause lots." CreationDate="2011-05-27T18:45:36.853" UserId="4245" />
  <row Id="23394" PostId="14755" Text="not a duplicate but I had more specific questions to ask about the voltage and current." CreationDate="2011-05-27T18:50:16.363" UserId="3267" />
  <row Id="23395" PostId="14752" Score="1" Text="@Pete: Then this answer doesn't apply, since it's talking about shorting a bunch of outputs together, like if A and B were inputs and connected to different sources and one tried to send high while the other sent low." CreationDate="2011-05-27T18:50:31.120" UserId="142" />
  <row Id="23396" PostId="14750" Text="sorry I forgotten to connect the vcc that why it worked when I plugged in my programmer. It has to be connected to my regulator to determine the logic level am using." CreationDate="2011-05-27T18:53:47.520" UserId="2824" />
  <row Id="23398" PostId="14752" Text="@Pete: Often, inputs are shown on the left and outputs on the right, so that signal flow is from left to right.  Of course the circuit works the same no matter how it's drawn, but it helps readability and preventing misinterpretations like this. http://opencircuitdesign.com/xcircuit/goodschem/goodschem.html" CreationDate="2011-05-27T19:01:29.173" UserId="142" />
  <row Id="23399" PostId="14755" Text="This is like a better phrasing of your earlier question. (as identified by @Leon Heller). It would be good if you edited this detail into that question." CreationDate="2011-05-27T19:55:14.333" UserId="740" />
  <row Id="23400" PostId="14731" Score="1" Text="@Rick_2047 - here in the US, in just the last couple of years, you can hardly turn around without seeing these alcohol-based hand sanitizer dispensers everywhere. you can usually get your own personal supply in a pharmacy for very little money. They even gave some out free where I work, which is how I came by it. The stuff evaporates very quickly so I mixed baking soda (NaHCO3) into it. Probably baking soda and water would work just as well." CreationDate="2011-05-27T20:01:01.150" UserId="740" />
  <row Id="23402" PostId="14692" Text="Thanks for the enlightenment. I'll try to whip up a circuit using your advice. If only I had an oscilloscope to check the actual range of voltages it would have been a lot easier." CreationDate="2011-05-27T20:11:29.163" UserId="4414" />
  <row Id="23403" PostId="14686" Text="I assume that stevenvh edited the title of my question. I'd like to say thanks. I noticed I made a mistake with the title just recently but my net connection broke so I wasn't able to change it. Thanks again stevenvh. :)" CreationDate="2011-05-27T20:13:28.973" UserId="4414" />
  <row Id="23404" PostId="8769" Text="@Johan, if you are on linux/mac don't they come with SVN servers and clients built in? perhaps something like &quot;sudo apt-get install subversion&quot; should do the trick I reckon. Here's some ubuntu instructions I found with the Google: http://www.subversionary.org/howto/setting-up-a-subversion-server-on-ubuntu-gutsy-gibbon-server" CreationDate="2011-05-27T20:24:54.270" UserId="771" />
  <row Id="23405" PostId="14763" Text="Tried that already - no joy.  Neither of the pic18s I have want to do anything.  I didn't know there was a Linux version of mplab now - downloading it now." CreationDate="2011-05-27T20:45:52.140" UserId="4245" />
  <row Id="23406" PostId="14762" Text="measure the voltage while the load (the stereo) is attached." CreationDate="2011-05-27T20:55:19.967" UserId="740" />
  <row Id="23407" PostId="14762" Score="2" Text="and turned on and belting out some hardcore tunez" CreationDate="2011-05-27T20:56:01.683" UserId="4245" />
  <row Id="23408" PostId="14692" Text="I picked up a $400 Rigol 1052E DSO (which you can modify to 100 MHz with a software hack.)  This is the first scope I've been able to afford for home.   It is really great to have access to for this sort of thing.  I would err on the side of too much attenuation and work from there.  You could easily damage a sensitive input with too much power." CreationDate="2011-05-27T20:59:30.350" UserId="4342" />
  <row Id="23409" PostId="14760" Score="1" Text="Devices do not &quot;use&quot; voltage.  You supply a voltage to a device and it uses *energy* by drawing current.  The total energy it's using will vary depending on the loudness of the music, and can be averaged out over time to produce an average number of watts." CreationDate="2011-05-27T21:06:41.223" UserId="142" />
  <row Id="23410" PostId="14762" Score="1" Text="The measurement will fluctuate a lot with music.  You need to play something constant like a sine wave if you want an easily-readable current measurement." CreationDate="2011-05-27T21:06:49.570" UserId="142" />
  <row Id="23411" PostId="14763" Text="From within MPLAB, you can specify the configuration registers (Configure -&gt; Configuration bits) and see what the actual hex values should be. You can then write those directly with sdcc instead of concatenating flags." CreationDate="2011-05-27T21:19:42.173" UserId="1293" />
  <row Id="23412" PostId="14762" Text="if it's a radio that will *let* you tune to a blank spot on the dial, that would give you some nice even powered white noise." CreationDate="2011-05-27T21:24:24.633" UserId="740" />
  <row Id="23413" PostId="14762" Text="when you switch your meter to current, just be sure that you put the meter in series with the circuit (i.e. you need to break the circuit and insert the ammeter), not in parallel..." CreationDate="2011-05-27T21:33:08.610" UserId="771" />
  <row Id="23414" PostId="14763" Text="Can't get mplab-x working - the installer just segv's.  Could be because I'm in 64 bit linux?" CreationDate="2011-05-27T21:49:07.883" UserId="4245" />
  <row Id="23415" PostId="14752" Score="2" Text="endolith is right, if A-G are all outputs, then my comments don't make sense. But there must be more circuitry not shown here then because otherwise it's going to be really boring output (a steady +5 volts)." CreationDate="2011-05-27T22:21:55.933" UserId="4441" />
  <row Id="23416" PostId="14763" Text="@Madmanguruman, if your compiler can't binary-AND constants together, you have bigger problems than config bits" CreationDate="2011-05-27T22:36:47.520" UserId="411" />
  <row Id="23417" PostId="14763" Text="@Leon, you are incorrect that SDCC is more complex than MPLAB+C18" CreationDate="2011-05-27T22:42:56.743" UserId="411" />
  <row Id="23418" PostId="14763" Text="I meant that he is more likely to get his program working if he uses MPLAB and C18. Setting configuration bits is much easier." CreationDate="2011-05-27T23:17:15.677" UserId="305" />
  <row Id="23419" PostId="14752" Text="@endolith: If outputs are on the right and inputs are on the left, wouldn't signal-flow before from right-to-left?" CreationDate="2011-05-27T23:42:47.400" UserId="1305" />
  <row Id="23420" PostId="14752" Text="@BlueRaja: If the inputs are on the left, and the outputs are on the right, then the signal is flowing from left to right.  It comes in from external circuits on the left, is processed by the device in the middle, and is output to external devices on the right.  Not sure what you're imagining." CreationDate="2011-05-28T00:17:12.543" UserId="142" />
  <row Id="23421" PostId="14752" Text="@endolith: Oh I see, I was confusing the device's outputs with components which output a signal.  Thanks for clearing that up." CreationDate="2011-05-28T00:34:36.760" UserId="1305" />
  <row Id="23422" PostId="14757" Text="saw these guys at the maker faire, pretty nifty stuff... maybe ask Garrett what they used to power their chinese lantern display, i'm guessing a lot more than 10 octobright's" CreationDate="2011-05-28T00:41:00.617" UserId="771" />
  <row Id="23423" PostId="14767" Score="1" Text="Many actually do 'support' USB OTG, its just not been enabled (lack of software support).  However it often can be enabled via third party software.  Nexus One, Motorola Droid, Samsung galaxy S, etc all support USB OTG at a hardware level." CreationDate="2011-05-28T01:03:33.733" UserId="1438" />
  <row Id="23424" PostId="13305" Text="... assuming a spherical cow on a frictionless surface ..." CreationDate="2011-05-28T02:43:45.640" UserId="771" />
  <row Id="23425" PostId="14527" Text="related: [What are good options for beginning hardware programming using high-level languages?](http://stackoverflow.com/questions/366991/what-are-good-options-for-beginning-hardware-programming-using-high-level-languag)" CreationDate="2011-05-28T03:48:21.820" UserId="813" />
  <row Id="23426" PostId="14527" Text="related: [What are the available interactive languages that run in tiny memory?](http://stackoverflow.com/questions/1082751/what-are-the-available-interactive-languages-that-run-in-tiny-memory)" CreationDate="2011-05-28T03:50:12.287" UserId="813" />
  <row Id="23429" PostId="14748" Text="I was trying to simplify the circuit. In the end, it's not a big deal, but the additional resistors do complicate the trace routing." CreationDate="2011-05-28T05:40:52.613" UserId="4438" />
  <row Id="23430" PostId="14752" Score="1" Text="@endolith etc. Sorry, yes, the points on the left are all outputs. " CreationDate="2011-05-28T05:42:38.367" UserId="4438" />
  <row Id="23431" PostId="14770" Text="Ugh, that seems like way over my head. The device takes up to 30volts. Do the spikes likely get that high? The spec sheet seems pretty much in/out voltages. 1amp is the max that MacBookPro USB puts out. But this seems to indicate that this isn't going to be as simple as it would seam. Thanks sir!" CreationDate="2011-05-28T06:52:31.703" UserId="4450" />
  <row Id="23432" PostId="14771" Text="Thanks. It seems more and more attractive to just solder directly to a third party completed unit and tap into the wires on the 12 volt socket to power it. :-( Now I wish I hadn't just ordered the damn thing." CreationDate="2011-05-28T06:56:24.137" UserId="4450" />
  <row Id="23433" PostId="14771" Text="@Scott Anguish Well, it it will make you feel better, most of the cheaper car chargers I've seen don't have much (or even any) protections Rick M. recommended. Still, if you can, do add them. Most of the iDevices are very expensive and you don't want to risk them on a cheap car charger. Capacitors should be cheap and easy to obtain, but make sure you use ones rated at 35 V or higher, just to be safe. The datasheet for regulator recommends 470 $\mu F$ on sensitive output. " CreationDate="2011-05-28T07:03:41.230" UserId="1240" />
  <row Id="23434" PostId="14770" Text="Well, it's not that the spikes would damage the regulator, it's that it wouldn't react fast enough to clamp them on the output. They might &quot;get through&quot; to the connected device. Moreover, the power is noisy, which might introduce noise on the analog outputs or erratic behavior in the device.&#xA;&#xA;Erm...see my updated answer." CreationDate="2011-05-28T07:10:20.103" UserId="4452" />
  <row Id="23435" PostId="14763" Text="I have tried: copy config bits from mplab in windows to sdcc in linux, compile &amp; install on linux - fail.  Compile in mplab in windows, install in linux - fail.  Compile and install in mplab in windows - fail.  I can't have killed both my pic18's can I?  They are only a few days old." CreationDate="2011-05-28T08:19:57.107" UserId="4245" />
  <row Id="23436" PostId="14341" Text="@David, thank you for help! I went with your solution, 74ahct04 for boost to 5V plus three SN74LVC1G126 to get three 3-state pins." CreationDate="2011-05-28T10:15:02.713" UserId="1850" />
  <row Id="23437" PostId="14770" Score="2" Text="@Scott Automotive regulators for 12V vehicles have to be rated to handle up to 60V for t &lt; 100ms and 28V continuously (i.e. double battery jump start.) Often, negative spikes are tolerated too. And yes, 60V spikes are not uncommon in even small vehicles. They are called load dumps and they can occur when you switch lights on or off, but also any number of other power hungry systems can cause spikes due to the high inductance of the alternator." CreationDate="2011-05-28T10:20:54.120" UserId="1225" />
  <row Id="23438" PostId="14763" Text="You should have started with one of the simpler PIC18 parts, such as the 18F1220. The ones you have chosen are very complex." CreationDate="2011-05-28T10:22:02.417" UserId="305" />
  <row Id="23439" PostId="14773" Score="1" Text="You could try making a USB based memory device. For example, get a USB to serial converter chip, a microcontroller and some $I^2C$ memory for it. You could then write a program that will communicate with the micro and write to the memory and read from it. Just don't expect the capacity and speed to be anything close to the one of a commercial USB flash drive. Still, it will give you a starting point." CreationDate="2011-05-28T11:05:48.200" UserId="1240" />
  <row Id="23441" PostId="14763" Text="@leon I'll order one of those with my next sample order, but that won't be till the middle of next month now." CreationDate="2011-05-28T11:46:36.650" UserId="4245" />
  <row Id="23442" PostId="14763" Text="If you can't get MPLAB-X working, try the forum: http://www.microchip.com/forums/f238.aspx" CreationDate="2011-05-28T11:46:51.997" UserId="305" />
  <row Id="23443" PostId="14774" Text="I once arrived at a friend's while he was doing open heart surgery on a HDD, sitting at the kitchen table with an ashtray next to the open drive :-)" CreationDate="2011-05-28T12:15:31.107" UserId="3920" />
  <row Id="23444" PostId="8994" Text="très artistique! :-)" CreationDate="2011-05-28T12:21:38.370" UserId="2064" />
  <row Id="23446" PostId="14773" Text="What are you actually planning to do? Build the physical storage medium from scratch, or use preexisting physical storage and just do the interfacing? And what kind of stuff do you want to interface it with? PC or microcontroller or what?" CreationDate="2011-05-28T12:41:09.487" UserId="1381" />
  <row Id="23447" PostId="14774" Text="@Federico - Yeah, so much for clean room conditions... :-( " CreationDate="2011-05-28T13:31:55.557" UserId="2064" />
  <row Id="23449" PostId="14777" Text="@David - about the PDP-8 HDD. That was then, data densities nowadays are much higher, so that the head has to fly much closer to the platter's surface, typically 1 um. A hard dust particle of 1 um may crash the head." CreationDate="2011-05-28T14:38:59.927" UserId="2064" />
  <row Id="23450" PostId="14763" Text="I have just got mplab-x installed using the text-mode installer - someone else on the forums was having the same problem, so I posted the answer there too." CreationDate="2011-05-28T15:06:28.433" UserId="4245" />
  <row Id="23451" PostId="14779" Text="Are you sure it's the monitor?  Try it connected to a friend's computer / laptop to check it's not the computer.  Alternatively try a different monitor on the computer.  It's quite likely it's the graphics card on the computer that's failed." CreationDate="2011-05-28T15:27:13.680" UserId="4245" />
  <row Id="23452" PostId="14779" Text="@Matt Jenkins I'm sure its the monitor. I have another, identical monitor, and if I connect it it displays fine. I'll edit the question to make it clear." CreationDate="2011-05-28T15:28:34.023" UserId="4458" />
  <row Id="23453" PostId="3854" Text="@supercat interesting. I've dealt with a lot of microcontrollers over the years and am learning VHDL and I've never run across this before. I also conferred with my VHDL &quot;tutor&quot; and he's also never seen this kind of problem in a microcontroller. Where have you seen this before? I bet that was a real bear to debug!" CreationDate="2011-05-28T15:36:09.977" UserId="974" />
  <row Id="23454" PostId="14778" Text="It's an idea, but I would hate to think of weaving something bigger than an 8 byte memory :-)" CreationDate="2011-05-28T16:01:27.990" UserId="3920" />
  <row Id="23455" PostId="14763" Text="Ok, if I'd posted my program someone may have noticed something I didn't...  Here's a little snipped from the 18f14k50 manual... *&quot;PORTA is 5 bits wide. PORTA&lt;5:4&gt; bits are bidirectional ports and PORTA&lt;3,1:0&gt; bits are input-only ports.&quot;* - and there's me trying to flash RA0!!!  D'oh!  I have it working on that chip using PORTC and the internal RC osc (using mplab-x)...  Not sure why I can't get the 4455 working though...  well, plough on I suppose..." CreationDate="2011-05-28T16:15:14.530" UserId="4245" />
  <row Id="23456" PostId="14777" Text="Isn't the index of refraction for fiber (both glass and plastic) about 1.5? That would give a speed of light of 8 inches (20 cm) per nanosecond." CreationDate="2011-05-28T16:18:40.670" UserId="2064" />
  <row Id="23457" PostId="14767" Text="@Mark, I wish they all did!" CreationDate="2011-05-28T16:52:48.023" UserId="230" />
  <row Id="23458" PostId="14778" Text="@Federico What about 32 bit on an Arduino shield? :-)) http://www.corememoryshield.com/report.html" CreationDate="2011-05-28T18:48:10.983" UserId="244" />
  <row Id="23459" PostId="14777" Text="@stevenvh  Wow, tough crowd!  While data densities of modern drives are high and the head height is super low, we are not talking about a modern drive.  We're taking about something that someone built in their home.  Using the PDP-8 as a point of reference, I doubt that anyone can build a HDD as good in their home.  At least not on their first or second try.  So, my point stands.  You don't need a clean room when making a HDD from scratch.  As for the propagation speed in a fiber:  you'r just being pedantic.  :)" CreationDate="2011-05-28T19:31:32.970" UserId="3624" />
  <row Id="23460" PostId="14763" Text="Well, the '4455 is working now...  I was trying to install a USB bootloader and it was not working - couldn't work out why.  It would appear that I have managed to blow the internal Vusb regulator.  Link myself up a little LM317T to generate 3.3v and pipe that in (with the right config #pragma to turn the internal usb VREG off) and voila, it works!" CreationDate="2011-05-28T20:12:13.357" UserId="4245" />
  <row Id="23461" PostId="14779" Text="Have you tried a different VGA cable?" CreationDate="2011-05-28T21:18:24.073" UserId="638" />
  <row Id="23462" PostId="14779" Text="@W5VO, yes, with another cable too. The problem is in the electronics of the monitor. Also, if I just unplug the vga cable from the faulty monitor and connect it to the second identical good one, everything works fine." CreationDate="2011-05-28T21:36:16.170" UserId="4458" />
  <row Id="23463" PostId="14527" Text="@davidcary I was looking more for answers about system programming languages rather than higher-level or interpreted languages, but there's still some good info in those links. Thanks." CreationDate="2011-05-28T22:04:25.673" UserId="4349" />
  <row Id="23464" PostId="3854" Text="@Andrew Kohlsmith: Debugging async stuff isn't too hard if one assumes signals will go out of their way to change at the worst possible times.  Actually, in many cases I prefer totally unsynchronized timers to those which attempt to avoid the problems associated with being asynchronous, since I have on a number of occasions had to deal with hardware bugs related to such matters.  For example, one undocumented annoyance on many PIC timers is that if the timer holds a value other than FFFF, and it's written with FFFF, the overflow interrupt..." CreationDate="2011-05-28T22:05:27.547" UserId="3123" />
  <row Id="23465" PostId="3854" Text="...won't happen on the next count, but instead after 65,537 counts.  I suspect that design stems from a desire to avoid having a spurious interrupt get triggered if e.g. the counter had held 128 and it was being written with 127 just as a count came in, but I would have rather simply had the documentation specify that any write to the timer in async mode may erroneously set the interrupt flag, so safe operation would require disabling the interrupt, writing the timer, clearing the flag, and re-enabling the interrupt." CreationDate="2011-05-28T22:08:34.737" UserId="3123" />
  <row Id="23466" PostId="3854" Text="@Andrew Kohlsmith: What I'd most like to have would be a system with an asynchronous 48-bit counter, running from its own supply, and a compare register on the bottom 32 bits which could operate even when the processor's main clock was stopped.  There would be no need to write to the 48-bit counter, and I wouldn't mind having to disable compare interrupts when writing to the compare register.  A timer system like that would allow an RTOS to schedule tasks with 17us or 33us precision, and power down the main oscillator any time it wasn't needed." CreationDate="2011-05-28T22:13:17.963" UserId="3123" />
  <row Id="23467" PostId="14527" Text="@jpc It seems to me that rather than being genuinely curious, you're simply implying that you aren't interested in the answers to my question. If you aren't interested in anything but C, you can just ignore my question. Otherwise, I'd be happy to answer more specific questions." CreationDate="2011-05-28T22:14:37.713" UserId="4349" />
  <row Id="23468" PostId="3854" Text="@Andrew Kohlsmith: The EFM Gekko is almost perfect; my only complaint is that the timer is only 24 bits and can't keep time while the CPU is powered down.  The ST Micro 32F series seems somewhat better, with a real-time clock in the form of a 32-bit linear counter and programmable prescalar.  My only complaint with that 32 bits is a little too short (using a 256Hz count rate, the thing would effectively forget the date if powered down for a year; at a faster count rate it would overflow sooner)." CreationDate="2011-05-28T22:17:10.567" UserId="3123" />
  <row Id="23469" PostId="14769" Text="That looks a costly device - surely something like an LM317T and a couple of resistors and capacitors would do the same job at a fraction of the price?" CreationDate="2011-05-28T22:18:38.630" UserId="4245" />
  <row Id="23470" PostId="3854" Text="@Andrew Kohlsmith: Unfortunately, ST somewhat ruined things with the 32L series.  The RTC chip has a settable prescalar, but unfortunately has to be read out in a YMDHMS format which assumes a 1-second increment rate, and its alarm registers assume HMS format; if the count rate is 256Hz, the alarm registers would represent units of 1/256 second, 15/64 second, and 14 1/16 second (with the latter wrapping every 337.5 seconds).  Far less convenient for use with RTOS scheduling." CreationDate="2011-05-28T22:34:32.833" UserId="3123" />
  <row Id="23471" PostId="14789" Score="1" Text="There are many devices and internet gateways which can do this. It's not really an engineering question. But, you might want to try http://diy.stackexchange.com/questions/tagged/home-automation http://diy.stackexchange.com/questions/2984/scalable-affordable-home-automation" CreationDate="2011-05-28T23:41:31.750" UserId="566" />
  <row Id="23472" PostId="14692" Text="Thanks for the heads up. I'll try looking for that model in the local market. Oscilloscopes tend to be prohibitively expensive on this part of the world so I hope I can find a good deal. I'm also concerned about possible damage on my device's inputs so I'll play safe and acquire an oscilloscope first. Thanks again." CreationDate="2011-05-29T00:09:20.477" UserId="4414" />
  <row Id="23473" PostId="14790" Text="So from the details of just it's clock speed, the number of transistors, voltage, and watts and size could you give me an example equastion for 1GHz, 47 Million, 45 nm, 1 Volt, and 5 Watts could you use these numbers to calculate it's power usage in say, watt hours?" CreationDate="2011-05-29T03:40:25.863" UserId="4460" />
  <row Id="23474" PostId="14783" Text="I think this is off topic and/or subjective and argumentative." CreationDate="2011-05-29T03:40:58.047" UserId="319" />
  <row Id="23475" PostId="14786" Score="1" Text="I also think that part of what causes this is that you don't exactly get the &quot;cream of the crop&quot; engineers working on budget TV development.  That vast majority of high quality engineers are working in more interesting and challenging markets.  Mobile phones, sensors, ultra-low power, robotics, etc..." CreationDate="2011-05-29T04:41:57.207" UserId="1438" />
  <row Id="23476" PostId="14786" Text="Devices with DRM built in has per definition a &quot;kill switch&quot;, and therefore is designed to deliberately fail on demand regardless of what the consumer want. But in other cases, they are not designed to fail..." CreationDate="2011-05-29T10:09:30.640" UserId="689" />
  <row Id="23477" PostId="14790" Text="@Mark: It doesn't work that way in general (not all the transistors are in use at the same frequency). Also the question in your comment makes no sense. If you want energy use in watt-hours you need to know time. If you want power use in watts, you've already stated 5 watts so what's the question?" CreationDate="2011-05-29T11:18:37.590" UserId="330" />
  <row Id="23479" PostId="14795" Text="For first one: R23= 1/2 + 1/2 = 1, I23 = 11 / 1 = 11A, I1 = 11/3 = 3.7A, I23 + I1 = 14,7A? Is that right?" CreationDate="2011-05-29T12:05:23.983" UserId="4464" />
  <row Id="23481" PostId="14795" Text="No. 1/R23 = 1/R2 + 1/R3, so R23 = 0.67 Ohm. Current from source = 11V / (R1 + R23). You forgot that it also passes through R1." CreationDate="2011-05-29T12:11:47.383" UserId="2064" />
  <row Id="23484" PostId="14795" Text="So... R23 = 1/3 + 1/2 = 1.5Ohm, then current = 11 / (3+1.5) = 2.4. | Second one: R13 = 1/0.5 + 1/2 = 2.5Ohm, current = 10 / (2.5+0.6) = 3.23. And, it's finished?" CreationDate="2011-05-29T12:24:27.577" UserId="4464" />
  <row Id="23487" PostId="14795" Text="Maybe my comment wasn't clear, but my LaTeX code seems to have errors. The 1.5 = 1/R23 --&gt; R23 = 1/1.5 = 0.67." CreationDate="2011-05-29T12:43:26.080" UserId="2064" />
  <row Id="23489" PostId="14797" Score="1" Text="http://www.google.com/search?source=ig&amp;hl=en&amp;rlz=&amp;=&amp;q=Tognola+Wavelet&amp;aq=f&amp;aqi=&amp;aql=&amp;oq=" CreationDate="2011-05-29T13:12:51.727" UserId="305" />
  <row Id="23490" PostId="14795" Text="I think it doesn't work because of the ( just before the R2 instead of {" CreationDate="2011-05-29T13:21:21.837" UserId="4464" />
  <row Id="23491" PostId="14795" Text="Anyway. The answer for 1 is: 11 / (0.67 + 3) = 2.9972752. Is it answer for question in the assignment?" CreationDate="2011-05-29T13:24:25.410" UserId="4464" />
  <row Id="23494" PostId="14795" Text="Well, it's actually exactly 3 A (the 0.67 is 2/3). I(R3) is given as 2 A, and R2 is twice as big, so will have half the current, so I(R2) is 1 A. Together 3 A. So that's right." CreationDate="2011-05-29T13:30:34.760" UserId="2064" />
  <row Id="23495" PostId="14795" Text="Surely. So for the second one it is 1/R13 = 1/0.5 + 1/2 = 1. Current = 10 / (1+0.6) = 6.25. Correct?" CreationDate="2011-05-29T13:30:39.297" UserId="4464" />
  <row Id="23496" PostId="14795" Text="is $\frac{1}{0.5} + \frac{1}{2}$ equal to 1?? " CreationDate="2011-05-29T13:34:44.783" UserId="2064" />
  <row Id="23498" PostId="14795" Text="It's 2.5. I forgotten about  1/. And it's final?" CreationDate="2011-05-29T13:55:14.687" UserId="4464" />
  <row Id="23499" PostId="14795" Text="Yes. \$R13 = \frac{1}{2.5} = 0.4\$ Ohm. Total resistance = R2 + R13 = 0.6 + 0.4 = 1 Ohm. I(R2) = 10 V / 1 Ohm = 10 A. I(R1) = 8A, I(R3) = 2 A." CreationDate="2011-05-29T14:01:40.773" UserId="2064" />
  <row Id="23505" PostId="14795" Text="You're good. Many thanks." CreationDate="2011-05-29T14:30:56.850" UserId="4464" />
  <row Id="23506" PostId="14783" Score="1" Text="@Kellenjb: He asked if there was any _evidence_. That is vastly different from asking people's opinions." CreationDate="2011-05-29T14:39:50.580" UserId="4097" />
  <row Id="23507" PostId="14783" Score="2" Text="@voithos problem is that what one person thinks is evidence of intentionally failing can be considered as cost savings by another. Also we are about designing electronics not trying to determine companies intentions." CreationDate="2011-05-29T14:55:48.593" UserId="319" />
  <row Id="23508" PostId="14786" Text="Actually I would argue that a higher level of skill is required to make something cheaply. Anyone can achieve the requirements using expensive components. But it takes skill and experience to get the same behavior using the cheapest components and assembly methods available. " CreationDate="2011-05-29T16:05:44.487" UserId="2255" />
  <row Id="23509" PostId="14798" Score="1" Text="Can't you just add a switch to the V+ line somewhere between it reaches the voltage regulator to be able to switch between external power supply. " CreationDate="2011-05-29T16:50:00.347" UserId="1623" />
  <row Id="23510" PostId="2543" Text="Encoding won't remove the spikes, and penjuin will still have problems telling his signal apart from the noise. A good decoder algorithm will help, but this is true for every kind of encoding." CreationDate="2011-05-29T17:32:08.460" UserId="3920" />
  <row Id="23511" PostId="14801" Text="do you mean the change of voice?" CreationDate="2011-05-29T18:14:32.647" UserId="493" />
  <row Id="23512" PostId="14800" Text="the &quot;3 dB point&quot; is actually 10⋅log10(1/2) = -3.0102999566398... dB.  It's chosen because 1/2 power is exactly where the asymptotes meet if you plot it on a log-log plot (I believe)." CreationDate="2011-05-29T18:16:44.037" UserId="142" />
  <row Id="23513" PostId="14801" Text="It applies to hearing" CreationDate="2011-05-29T18:18:01.443" UserId="305" />
  <row Id="23514" PostId="14801" Text="I think general consensus is that 1 dB is the smallest change in sound level detectable by humans." CreationDate="2011-05-29T18:29:16.137" UserId="3876" />
  <row Id="23515" PostId="14799" Text="I had the same concept which stevenvh explained here. Resistor and capacitor together acts like a voltage divider with the output taken across capacitor. Higher the frequency lower will be the capacitor's impedance and less will be the output voltage which is the drop across the capacitor. But doesn't the whole design breaks when we connect the output to another load?" CreationDate="2011-05-29T18:35:22.777" UserId="4277" />
  <row Id="23516" PostId="14801" Text="http://hyperphysics.phy-astr.gsu.edu/hbase/sound/db.html#c4" CreationDate="2011-05-29T18:37:35.773" UserId="142" />
  <row Id="23517" PostId="14805" Score="4" Text="What type of signals? Anything can be transmitted or received by TRS and TRRS connectors. Heck you could convert USB to run using TRRS connectors. " CreationDate="2011-05-29T19:37:55.760" UserId="1623" />
  <row Id="23519" PostId="14805" Text="Signal is signal, isn't it? It has some physical attributes etc. What do I want trasmit? Audio signal (mobile phone - headphones)" CreationDate="2011-05-29T20:35:07.543" UserId="4468" />
  <row Id="23520" PostId="14805" Score="2" Text="So how are you producing the audio signal? Is this what you want help with, as I think you have failed to understand what the connectors are. They are just a physical connection between something and any peripherals you want to connect it with. " CreationDate="2011-05-29T20:50:16.113" UserId="1623" />
  <row Id="23521" PostId="14804" Text="Sorry Mark I'm not understanding what you're saying. By supply line do you you mean the 5v line of the 7805cv and the +19v of the dc jack. By the way it's a 7805cv am using . The version of eagle am using doesn't seem to have 7805cv regulator in it's components library. Sorry i didn't mention that." CreationDate="2011-05-29T22:14:40.797" UserId="2824" />
  <row Id="23522" PostId="14809" Text="The key specification isn't setup time, but hold time; see my answer below." CreationDate="2011-05-29T22:37:40.603" UserId="3123" />
  <row Id="23523" PostId="4321" Text="Doesn't a railgun want them all in parallel for high current?" CreationDate="2011-05-30T00:11:40.263" UserId="142" />
  <row Id="23525" PostId="14527" Text="@arussell84: I am genuinely interested in the answer to both your question and mine. Also: believe me that I really am fed up with plain C in embedded programming. I believe there is much to improve in the field of embedded programming languages but I do not believe that &quot;normal&quot; programming languages for big computers will offer much of this improvement. This is why I asked how do you expect them to help." CreationDate="2011-05-30T01:10:30.317" UserId="659" />
  <row Id="23526" PostId="1902" Text="@jpc You could also measure pressure by measuring the amount of force you have to apply to the membrane/piston to *prevent it* from moving." CreationDate="2011-05-30T01:24:28.887" UserId="142" />
  <row Id="23527" PostId="11734" Text="@jpc: &quot;It shall be noted that in the classical view, there are only electrons moving in the same average direction both in the case of electron or hole conductivity. This cannot explain the opposite sign of the Hall effect observed. ... A common source of confusion with the Hall Effect is that holes moving to the left are really electrons moving to the right, so one expects the same sign of the Hall coefficient for both electrons and holes. This confusion, however, can only be resolved by modern quantum mechanical theory of transport in solids.&quot; http://en.wikipedia.org/wiki/Hall_effect" CreationDate="2011-05-30T01:31:57.477" UserId="142" />
  <row Id="23528" PostId="14817" Text="I still work with 6502-based systems as a hobby.  It'd be nice to know some particulars of metastability problems on bus data.  I can certainly envision that if the accumulator holds $FF and one reads a value that's either $00 or $01, the accumulator could end up with any possible value.  Before any branch could be taken, though, I would expect two more cycles would have to elapse, during which the flags would get relatched twice.  I can't imagine a metastable state remaining for that long." CreationDate="2011-05-30T01:36:55.103" UserId="3123" />
  <row Id="23529" PostId="9023" Text="A bigger issue that switch bounce is processor behavior during power-down.  In particular, it may be good to make sure that the processor can only turn the supply on when its VDD is above the point where correct operation is guaranteed.  I've had to tweak some auto-power-down circuits that would occasionally fail as a consequence of the processor running random code when VDD fell below the valid operating voltage.  The random code could set the &quot;power on&quot; output high, which would in turn power the device back up, running code at a random address." CreationDate="2011-05-30T01:45:05.280" UserId="3123" />
  <row Id="23530" PostId="14808" Text="I had an idea of reusing the calculator for another purpose. I dont find any chip in its board. All it got is a chip on board covered with a black wax or something like that. " CreationDate="2011-05-30T03:29:56.520" UserId="4277" />
  <row Id="23531" PostId="14799" Text="I follow. Thanks for the follow up." CreationDate="2011-05-30T04:35:46.907" UserId="2524" />
  <row Id="23532" PostId="11517" Text="@Leon Heller: this should be a comment. You are not explaining anything." CreationDate="2011-05-30T05:35:54.787" UserId="3920" />
  <row Id="23533" PostId="14799" Text="@oxakhil - If you connect a load to the divider you're indeed changing the divider's ratio. Usually you'll have some impedance parallel to the capacitor. If that's unwanted you'll have to place a high impedance buffer after the filter." CreationDate="2011-05-30T05:59:00.483" UserId="2064" />
  <row Id="23534" PostId="14804" Text="@Ageis Check my edit" CreationDate="2011-05-30T06:29:02.513" UserId="1438" />
  <row Id="23535" PostId="14788" Text="Thanks for the reply, everything seems a lot fuzzy but your answer helped me a lot." CreationDate="2011-05-30T06:33:56.770" UserId="4461" />
  <row Id="23536" PostId="14787" Text="Thanks for your answer, it seems a lot more difficult for a beginner like me that I thought at first, but mixing all the answer will probably help me :)" CreationDate="2011-05-30T06:34:35.553" UserId="4461" />
  <row Id="23537" PostId="14788" Text="@cx42net Just don't forget that if you get stuck on a step of the solution that isn't programming of the Java program on the main computer, you could ask for clarification here." CreationDate="2011-05-30T06:49:36.640" UserId="1240" />
  <row Id="23538" PostId="14774" Text="There are hard drive failures where opening it, fixing the problem, and then _immediately_ imaging it to a good drive is a pragmatically reasonable alternative.  Back in the day, I remember running a scrap &lt;20mb drive open, it &quot;seemed&quot; to work for a few hours, but I think not when I tried it again days later." CreationDate="2011-05-30T07:35:59.290" UserId="2246" />
  <row Id="23539" PostId="14778" Text="Building a large, low density hard drive could be a fun project." CreationDate="2011-05-30T07:36:57.137" UserId="2246" />
  <row Id="23540" PostId="14777" Text="I'm not sure much is to be gained by replacing the electronics in a tape deck; you are still going to have to modulate and demodulate the data stream, and are still going to be bandwidth limited to probably not much more than audio by the head.  You might get a little better with fancier amplifiers and speeding up that tape.  Want to store a lot?  Use a VCR instead of an audio deck." CreationDate="2011-05-30T07:39:06.060" UserId="2246" />
  <row Id="23541" PostId="14814" Text="For a really long delay line, use a geosynchronous comsat... or a repeater on the moon." CreationDate="2011-05-30T07:41:50.040" UserId="2246" />
  <row Id="23542" PostId="14801" Text="&quot;0dB is the absolute threshold, below which the stimulus isn't detected.&quot;  What do you mean by this?  0 dB is by definition a ratio of 1 - ie, no change.  Do you perhaps mean 0 dB relative to some reference power?" CreationDate="2011-05-30T07:44:26.093" UserId="2246" />
  <row Id="23543" PostId="14824" Text="Oops, I missed that. Thank you." CreationDate="2011-05-30T07:49:17.490" UserId="3920" />
  <row Id="23545" PostId="14738" Text="If you really want to &quot;learn&quot; a protocol, block out some time, and implement one half of it.  Either get a device and write some low level software, or get an FPGA and write a device." CreationDate="2011-05-30T08:15:18.553" UserId="2246" />
  <row Id="23546" PostId="14817" Text="This was something I heard second or third hand maybe 20 years ago, but it did originate from people that absolutely knew what they were doing - it was to do with the Tube interface on the 6502 second processor for the BBC Micro, and reading of status flags, and was a once-n-a-blue-moon occurrance but frequent enough that it delayed the product launch.  It wouldn't have necessarily needed to last 2 cycles as signals are probably being latched internally at various stages of the pipeline. I think it was also the fastest 6502 variant available at the time - 3MHz 65C02 ISTR." CreationDate="2011-05-30T08:49:05.660" UserId="1681" />
  <row Id="23547" PostId="14686" Text="@DeVilFisCh - You're welcome. If you want to know who made which changes to a question or answer click on the date next to &quot;edited&quot;." CreationDate="2011-05-30T09:14:29.117" UserId="2064" />
  <row Id="23548" PostId="14804" Text="+1 for the LTC4413" CreationDate="2011-05-30T09:40:41.813" UserId="2064" />
  <row Id="23549" PostId="14801" Text="@Chris - it's not 0 dB relative to some reference, but 0 dB *as* a reference. We talk about sound levels of 90 dB, but that's always compared to some other level. Which is the 0 dB level. There are several dB scales each with its own reference. On the dBm scale for instance 0 dB is 775mV in 600 Ohm, or 1 mW." CreationDate="2011-05-30T09:50:33.467" UserId="2064" />
  <row Id="23550" PostId="14818" Text="@AngryEE As I mentioned in a comment above, I've already changed the VGA cable once, no changes with that. One idea I had yesterday was that maybe there is a fault with the LVDS cable. Could it be? Nice idea about the D-sub connector, I have to try that!" CreationDate="2011-05-30T10:12:32.013" UserId="4458" />
  <row Id="23551" PostId="14825" Text="Your answer is promising, do you have a link for examples/prices please?" CreationDate="2011-05-30T10:23:34.493" UserId="4461" />
  <row Id="23552" PostId="101" Text="Thanks very much. Unfortunately though AVR Freaks discontinued the device list (or at least searching for it), leading to Atmel.com which search and comparison featuers are really lacking. Personally, I doubt the smartness of this decision from Atmel Corp." CreationDate="2011-05-30T10:40:00.750" UserId="45" />
  <row Id="23553" PostId="14801" Text="When we are talking about sound, dB is used for sound pressure and the reference (0 dB) is 20µPa, which is considered the smallest pressure detectable by a normal human ear." CreationDate="2011-05-30T11:14:20.540" UserId="1950" />
  <row Id="23554" PostId="14794" Text="Note that writing the unit in square brackets is rather strange, it should rather be written 10V, 3Ω, etc. " CreationDate="2011-05-30T12:19:25.253" UserId="339" />
  <row Id="23555" PostId="14805" Text="Come on... Guys, give him a break. What are These connectors usually used for? Audio! Okay so he is probably sending an audio signal. Is it a microphone signal or headphone signal? Well Headphone is about the most common for &quot;normal&quot; consumers. So we can assume he want's to drive a pair of headphones. And look, this was exactly what he wanted! So I assume he wants to know what signal levels and impedance he needs. No need to be rude and close his legitimated question. My answer would be, it depends on the amplifier's and the headphones impedance and Watt. Usually in range mV to a few volt." CreationDate="2011-05-30T12:47:18.180" UserId="4474" />
  <row Id="23556" PostId="14829" Text="What is the LED spec? (I and V) and the value of R10 and Volt in to DCJ0202?" CreationDate="2011-05-30T12:55:21.037" UserId="4474" />
  <row Id="23557" PostId="14829" Text="2.5 v 30ma  sorry i meant 10 ohms. 19volts dc" CreationDate="2011-05-30T12:56:46.233" UserId="2824" />
  <row Id="23558" PostId="14717" Text="I'm fairly sure my triac was fried. I wired up a simple circuit with only a 100-ohm resistor between hot and the gate (always on) and the resistor roasted, then tried it again with a fresh triac and it worked." CreationDate="2011-05-30T13:04:29.840" UserId="2172" />
  <row Id="23559" PostId="14777" Text="@Chris Statton  By replacing the electronics you can do:  Automagic seeking (use one of the channels as an index, store the data in the other channel, then automatically FF and RWD to find where the data is stored).  Replace the normal tape bias with your own modulation to increase the storage density.  Run the motors at a higher speed for higher data rates.  Finer control of the erase head allows more selective writes.  Etc." CreationDate="2011-05-30T13:19:45.703" UserId="3624" />
  <row Id="23560" PostId="14829" Score="6" Text="Placing LEDs in parallel is a Bad Idea. You risk that LEDs in one branch light more brightly than the others. Replace R10 with a resistor for each branch." CreationDate="2011-05-30T13:33:08.177" UserId="2064" />
  <row Id="23561" PostId="1902" Text="endolith: Good idea. Now, are there methods for measuring force without everything moving at least a tiny bit... ;)" CreationDate="2011-05-30T13:35:40.830" UserId="659" />
  <row Id="23562" PostId="14829" Text="so you're saying each row of three resistors shud have it's own resistor?" CreationDate="2011-05-30T13:36:03.110" UserId="2824" />
  <row Id="23563" PostId="11734" Text="@endolith: This is a very interesting point, thanks for the link. :)" CreationDate="2011-05-30T13:39:00.343" UserId="659" />
  <row Id="23565" PostId="14830" Score="1" Text="fwiw, the bad old days of CRT video (at least, in the U.S.) can be understood by googling RS-170A, the signal spec that gave the timings for the non-display parts of the signal. however, that system was only good for about 320 x 200 @ 60, so expect things to have moved on a bit." CreationDate="2011-05-30T13:48:41.277" UserId="740" />
  <row Id="23567" PostId="14829" Score="1" Text="also, you know that with the limiting resistors suitably adjusted, an unregulated 7.5V (etc) works just as well for lighting LED's as a regulated 5V, right? with currents like these, that can cut down the load to your regulator, and thereby the heating, considerably." CreationDate="2011-05-30T13:58:08.103" UserId="740" />
  <row Id="23568" PostId="14830" Text="I have updated the info. Still the _formula_ should be the same regardless of the number of lines and pixels." CreationDate="2011-05-30T14:06:00.183" UserId="4474" />
  <row Id="23569" PostId="14830" Text="Ahh, okay, when I added the extra lines and pixels the math adds up correctly :) 1688 x 1066 x 85 = 152,94968 MHz" CreationDate="2011-05-30T14:08:45.927" UserId="4474" />
  <row Id="23572" PostId="14812" Text="The data changing on the negative clock edge is actually how my teacher said it behaved but it seems that this is not very common and that was what made me confused. But now it certainly makes sense :)" CreationDate="2011-05-30T14:20:30.473" UserId="4303" />
  <row Id="23573" PostId="14829" Text="Three LEDs in series can't be lit by 5 V, unless their individual drop is less than 1.6 V.  http://www.oksolar.com/led/led_color_chart.htm  If the LED drop is 2.5 V, and you have a 19 V supply, then use that.  You can get 7 in series lit with 19 V." CreationDate="2011-05-30T14:21:37.740" UserId="142" />
  <row Id="23574" PostId="14829" Score="2" Text="@Ageis - Yes, each row should have its own resistor (Accidentally deleted my previous comment)" CreationDate="2011-05-30T14:42:15.300" UserId="2064" />
  <row Id="23575" PostId="14825" Text="Answering that would turn it into a &quot;shopping&quot; question and cause some folks to vote to close - but a web search should find you examples." CreationDate="2011-05-30T15:25:11.690" UserId="2246" />
  <row Id="23576" PostId="14817" Text="Interesting. [BTW, is there any way to use punctuation without StackExchange munging it?] In the normal behavior of e.g. &quot;ADC 0xD000&quot; the address would be output on phase 1 of the fourth cycle, and the data would be latched at the end of phase 2 of that cycle. The data would feed into the ALU in phase 1 of th next cycle (which would be the opcode fetch for the following instruction). The cycle after that would be the operand fetch. If things were still metastable at that point, the system could melt down, but that would seem unlikely since the dynamic registers would have been relatched twice." CreationDate="2011-05-30T15:27:11.447" UserId="3123" />
  <row Id="23577" PostId="14801" Text="@stevenh If you talk aboout 0dB as a reference, you are mis-speaking.  dB is always a ratio, relative to some reference.   &quot;x dBm&quot; is a power stated by its ratio to a milliwat, but &quot;x dB&quot; is only a ratio, since no reference is given.  You must give a reference to state a power logarithmically." CreationDate="2011-05-30T15:29:28.663" UserId="2246" />
  <row Id="23578" PostId="14817" Text="I don't want to say it's impossible for data-bus metastability to affect the 6502, because I know there are some other weird behaviors I can't explain. For example, the data bus is latched during phase 2 of the clock, and acted upon during the following phase 1. It thus shouldn't matter if it changes during phase 2 provided it's stable at the end. There are a few undocumented instructions, however, whose behavior is affected by the contents of the data bus during the earlier part of the cycle (demonstrable on machines like the C64 and Apple that fetch video during phase 1). I don't know how..." CreationDate="2011-05-30T15:29:53.177" UserId="3123" />
  <row Id="23579" PostId="14817" Text="...the behavior of those instructions is actually getting affected by the early data bus behavior, but I suspect it's some sort of weird race condition.  IIRC, one of the opcodes matches the decode patterns for LDA #imm, LDX #imm, and TAX, so the ALU's output is being mapped back to its input.  Weird." CreationDate="2011-05-30T15:31:57.030" UserId="3123" />
  <row Id="23580" PostId="14812" Text="@Emil Eriksson: I'm surprised that there aren't more &quot;jellybean&quot; chips (74xx and 40xx, etc.) which sample on one edge and output on the other.  For designs within a chip, there's generally no problem ensuring that clocks get distributed so as to satisfy setup/hold requirements, and latches which feed each other can be assumed to be part of the same process lot (since they are of course on the same die).  When going between chips, it's harder to ensure that setup/hold times are met.  I'm really curious why the split clock behavior isn't more common..." CreationDate="2011-05-30T15:40:38.260" UserId="3123" />
  <row Id="23581" PostId="14812" Text="@Emil Eriksson: ...especially since it's actually easier to implement in silicon than a chip where the output changes on the same edge as the input." CreationDate="2011-05-30T15:41:10.147" UserId="3123" />
  <row Id="23582" PostId="14783" Text="For those wondering why I would answer a question I voted to close: I changed my mind. Votes for closing can't be undone, so I voted to reopen :-)" CreationDate="2011-05-30T16:10:43.193" UserId="2064" />
  <row Id="23583" PostId="5631" Text="@THomasO - was the watch dog timer overflowing and causing the chip to reset?" CreationDate="2011-05-30T16:14:47.413" UserId="4096" />
  <row Id="23584" PostId="14801" Text="@Chris - wow, tough crowd :-). Talking about dBm, 1mW is the reference to which everything else is compared. Everybody working with dBm knows what this reference is. So, if you have a 1 mW signal, that's 0 dBm higher than the reference, only by convention the &quot;higher than the reference&quot; is dropped, and we say it's a 0 dBm signal. Likewise, a 10 mW signal is 10 dBm (compared to the reference)." CreationDate="2011-05-30T16:58:26.363" UserId="2064" />
  <row Id="23585" PostId="14801" Text="This isn't correct, at least not as I'm reading it.  In acoustics a +3dB SPL is a doubling of acoustical power input (how much air the speakers are moving), it doesn't have anything to do with human perception.  An actual doubling of sound pressure is +6dB SPL and a doubling of loudness as perceived by a human is +10dB SPL. " CreationDate="2011-05-30T17:38:33.070" UserId="1438" />
  <row Id="23586" PostId="14835" Text="Thanks, I have notice both connectors but I didn't know if it was necessary ( I was thinking it had a internal antenna )" CreationDate="2011-05-30T17:52:41.990" UserId="170" />
  <row Id="23587" PostId="14801" Text="The rules I've mentioned above are just 'estimates' they are rounded off and when considering the human perception numbers like +10dB = double loudness, a proper weighing curve needs to be applied based on level (A,B or C) to compensate for the perceived frequency response of the ear." CreationDate="2011-05-30T18:04:40.700" UserId="1438" />
  <row Id="23588" PostId="14801" Text="@stevenh &quot;Everybody working with dBm knows what this reference is&quot; yes, they know what the reference is because the 'm' in 'dBm' refers to the milliwatt reference.  But if someone just says 'dB' there is no reference.  You can perhaps argue that 'dB SPL' encodes a reference power in the definition of 'SPL' - but 'dB' by itself is a ratio, and it's improper to use it as a power." CreationDate="2011-05-30T18:11:44.080" UserId="2246" />
  <row Id="23589" PostId="14813" Text="Right idea, but mixing two concepts.  First, dB is a _ratio_ relative to some reference, not an absolute value.  Second, as you point out, it's a logarithmic representation of that ratio rather than a linear one." CreationDate="2011-05-30T18:18:35.197" UserId="2246" />
  <row Id="23590" PostId="14834" Score="1" Text="yes, that is what AGC is for." CreationDate="2011-05-30T18:22:55.670" UserId="740" />
  <row Id="23591" PostId="14837" Score="1" Text="There are some comments on the bootloader on the Sparkfun page. Also, have you tried the Sparkfun forum?" CreationDate="2011-05-30T18:23:19.207" UserId="305" />
  <row Id="23592" PostId="14834" Text="in the audio world, it's also known as 'compression'" CreationDate="2011-05-30T18:26:21.127" UserId="740" />
  <row Id="23593" PostId="14834" Text="Ok. Thanks for your answer. " CreationDate="2011-05-30T18:45:14.333" UserId="4476" />
  <row Id="23594" PostId="14835" Score="1" Text="You can check the signal strength on most cell modules using the AT+CSQ command.  The first number returned is a signal strength from 0-31 or 99 (the latter means it doesn't have a signal yet).  A value around 6 or 7 is like a single bar on a cell phone; a value around 20 or more is very good, like four bars." CreationDate="2011-05-30T19:13:30.763" UserId="1322" />
  <row Id="23595" PostId="14805" Text="@Max Kielland, it was closed because of the lack of detail in the question so that other people in the community cannot benefit from answers if the question could be answered. It lacks detail because he doesn't explain how he's creating the audio signal nor if he wants help with how to create the signal. " CreationDate="2011-05-30T19:34:28.070" UserId="1623" />
  <row Id="23596" PostId="14840" Score="2" Text="Can someone explain why they downvoted? " CreationDate="2011-05-30T19:40:00.317" UserId="1225" />
  <row Id="23597" PostId="14839" Text="If you want high quality, go with class AB.  Class D *can* be made just as high quality as anything else, but it's not easy.  It depends on component quality, PCB layout, etc.  Playing music continuously into headphones for 10 hours seems like decent battery life to me." CreationDate="2011-05-30T20:14:22.560" UserId="142" />
  <row Id="23598" PostId="14547" Text="You could probably get away with a 5S LiPo pack, but you would be running at 21V at maximum, and at 3.7V/cell, about 18.5V (which may be too low.)" CreationDate="2011-05-30T20:39:15.967" UserId="1225" />
  <row Id="23599" PostId="14843" Score="1" Text="I didn't down-vote, but what you're asking is basically a design of a whole product which is in itself very complicated. " CreationDate="2011-05-30T21:08:58.917" UserId="1240" />
  <row Id="23600" PostId="14843" Score="1" Text="Apart from where to buy the module, which is off-topic, there is not a solid question here. This question will be closed as such. If you run into specific technical hurdles please feel free to ask a question about that. Please do not let this be a negative experience for you, but the stack exchange system works best under very specific conditions." CreationDate="2011-05-30T21:46:20.403" UserId="305" />
  <row Id="23601" PostId="14527" Text="@jpc In that case, bear with me, as comments are only allowed to have so many characters. D is supposed to be an improvement on C++. I don't mean higher-level such as C# or Java. Can still manually manage memory and use pointers. Read the [D overview](http://www.digitalmars.com/d/2.0/overview.html). Two features I'm particularly interested in are closures and anonymous functions. Go and Rust I believe might become popular, but might not actually be suitable for embedded devices. Too soon to tell. Objective-C might work, though; I haven't looked." CreationDate="2011-05-30T22:00:18.957" UserId="4349" />
  <row Id="23602" PostId="14844" Score="1" Text="Question is off-topic, and will be closed." CreationDate="2011-05-30T22:02:23.293" UserId="305" />
  <row Id="23603" PostId="14840" Text="That's not me :-) But If you click on any of these you will see that they have separate output for headphones, based on usual AB amplifiers. And it's like that for all manufacturers, for some reason they just does not expect users to plug headphones into speaker output for some reason, and that leaves me puzzled. Maybe efficiency/quality sucks at low power." CreationDate="2011-05-31T00:43:12.687" UserId="2062" />
  <row Id="23604" PostId="14844" Text="If you want to record the audio, just get a cable to connect the headphone jack to the line in (or less ideally microphone input) of your sound card; it's possible you might need an inline attenuator if the level is too high.  There are also USB audio ADCs but they tend to be expensive since the market is situations where the built in ones are not good enough.  If you want to capture what note is being played from a keyboard which has MIDI out (no idea if this one does), what you want it is a USB MIDI interface." CreationDate="2011-05-31T02:33:07.227" UserId="2246" />
  <row Id="23605" PostId="14757" Text="It worked, using the 5v rail to power the Arduino and the logic boards and the 3.3v to power the LED on the boards. http://www.youtube.com/watch?v=Gr5vzWoasUw  " CreationDate="2011-05-31T06:35:21.797" UserId="3407" />
  <row Id="23606" PostId="14846" Score="4" Text="What voltage, what current?" CreationDate="2011-05-31T07:22:16.437" UserId="2064" />
  <row Id="23607" PostId="14846" Score="2" Text="We need current to know what type of supply you'll need to build. In general, multi rail supplies are difficult to build. The problem is that different voltage regulators (even if they are same model and from same batch) will provide different voltages. You should be able to find the tolerances in your datasheet. So when you put them in parallel, you could get large currents between them. You'll need a way to stop that. Also so called computer multi rails PSUs don't actually have multiple power rails. Instead they have 1 big source and several current limiting circuits which they call rails." CreationDate="2011-05-31T08:20:32.007" UserId="1240" />
  <row Id="23608" PostId="14613" Score="1" Text="A buck DC/DC controller will give you automagically a higher output current than the input current if you step down from 19V to 8V." CreationDate="2011-05-31T09:51:16.763" UserId="2064" />
  <row Id="23609" PostId="14848" Text="What are the question marks in hex or binary? They may not be a specific character code, but just mean something the terminal cannot display. If they are not all the same character, it may give you more information about what is going on." CreationDate="2011-05-31T10:24:35.143" UserId="1374" />
  <row Id="23610" PostId="14848" Text="Also, do you have an oscilloscope or logic analyzer? That would be the best way to debug what is going on. You could actually see the bit-timings and data content the chip is outputting." CreationDate="2011-05-31T10:25:24.770" UserId="1374" />
  <row Id="23611" PostId="14848" Text="From what I can see with my scope the actual data format and content looks ok, but I'm not sure about the timing." CreationDate="2011-05-31T10:34:48.587" UserId="4245" />
  <row Id="23612" PostId="14852" Text="What's the voltage drop on the diode? Also, [here](http://ledcalc.com/)'s a nice calculator that worked for me in the past." CreationDate="2011-05-31T10:34:59.477" UserId="1240" />
  <row Id="23613" PostId="14850" Text="With a little bit of tweaking for the '14k50 (PLL is in config, not register controlled), I get a screen full of 'B' with that program." CreationDate="2011-05-31T10:35:32.033" UserId="4245" />
  <row Id="23615" PostId="14852" Text="I am new to electronics, could you say what voltage drop is?" CreationDate="2011-05-31T10:36:55.397" UserId="1982" />
  <row Id="23616" PostId="14852" Text="Maybe the software is assuming that the voltage drop of diode is 1.9V which is used for high-brightness red LEDs. But usually most of the LEDs have 1.7V drop and that would make the total voltage of the circuit 1.3V and minimum resistance at 43ohms. It is always best to use a 47ohm resistor. " CreationDate="2011-05-31T10:42:20.257" UserId="1200" />
  <row Id="23617" PostId="14848" Score="1" Text="If you can see the data you're sending on the bus, you're 90% of the way there. As for timing, Measure it! An oscilloscope or logic analyzer makes an excellent precision timer. If it all looks good, time to start looking at the PC end of the affair." CreationDate="2011-05-31T10:44:34.667" UserId="1374" />
  <row Id="23618" PostId="14848" Text="Note: Are you certain that you don't have a signal inversion somewhere? Is it possible the PIC output is active low, and the computer active-high (or vice versa)? Serial interfaces come in both flavors, and you need to make sure that both ends match." CreationDate="2011-05-31T10:45:23.887" UserId="1374" />
  <row Id="23619" PostId="14853" Score="1" Text="by using a voltmeter in the software the voltage across the LED is 1.9V, I'm guessing that is the voltage drop." CreationDate="2011-05-31T10:47:22.047" UserId="1982" />
  <row Id="23620" PostId="14853" Text="Could you explain this sentence a bit more: &quot;To get 30 mA through the resistor (and thus also the LED) your resistor has the be 1V / 30 mA = 33 Ohm.&quot; Why do we use the difference? Is it that all the voltage needs to be 'used up' before the circuit 'reaches' the battery again." CreationDate="2011-05-31T10:48:30.440" UserId="1982" />
  <row Id="23621" PostId="14848" Text="The PIC has data inversion configuration bits TXCKP and RXDTP, which invert the Tx and Rx line respectively. I think they map to BAUD_IDLE_CLK_HIGH (assuming baudUSART() controls the BAUDCON register). If you are going into something like a FTDI chip, you need to set your idle clock low, since the FTDI chips are normally low." CreationDate="2011-05-31T10:49:50.097" UserId="1374" />
  <row Id="23622" PostId="14853" Text="@Jonathan - You could use that wording. There's a Kirchhoff's voltage law (KVL) which says that the total voltage of your loop always is zero. That means that the sum of the voltages of your power sources matches the sum of the voltages over your loads. " CreationDate="2011-05-31T10:55:26.933" UserId="2064" />
  <row Id="23623" PostId="14853" Text="@Jonathan - More about this. Say you have 2 resistors in series in your circuit, 10 ohm and 20 ohm. That's a total of 30 ohm, so the current will be 3v / 30 ohm = 100 mA. If you calculate the voltages over your resistors you get 100 mA * 10 ohm = 1 V, and 100 mA * 20 ohm = 2V. 1V + 2V = the 3V of your source. It always work!" CreationDate="2011-05-31T11:00:24.480" UserId="2064" />
  <row Id="23624" PostId="14853" Text="@stevenh, that explains it well, thank you very much!" CreationDate="2011-05-31T11:04:28.087" UserId="1982" />
  <row Id="23625" PostId="14848" Text="I am going from the PIC to a MAX232 as I always have done." CreationDate="2011-05-31T11:13:01.750" UserId="4245" />
  <row Id="23626" PostId="14853" Text="@stevenh, I didn't see that you have answered first. I flagged to mod to delete my answer if necessary. I upvoted it." CreationDate="2011-05-31T11:34:09.283" UserId="938" />
  <row Id="23627" PostId="14837" Text="Done that, my friend. And no answers whatsoever. " CreationDate="2011-05-31T12:15:57.647" UserId="170" />
  <row Id="23628" PostId="14794" Text="@Mark - As with any question on this site, we require that you show effort when asking the question.  It must stand on its own.  In fact, the homework tag has been deprecated and I've removed it.  " CreationDate="2011-05-31T12:19:43.537" UserId="857" />
  <row Id="23629" PostId="14848" Text="Tried it with BAUD_IDLE_CLK_HIGH and BAUD_IDLE_CLK_LOW in the baudUSART() but to no avail." CreationDate="2011-05-31T12:21:09.223" UserId="4245" />
  <row Id="23630" PostId="14850" Text="Transmit 'U' continuously and check the bit time with a scope." CreationDate="2011-05-31T12:24:04.733" UserId="305" />
  <row Id="23631" PostId="101" Text="@Zefiro - Thanks for the update on the broken link.  I've fixed your answer for now, you can edit it with new information in the future with the &quot;Edit&quot; link.  " CreationDate="2011-05-31T12:27:01.517" UserId="857" />
  <row Id="23632" PostId="101" Text="(Note that the `strike` tags are just because I agree that AVR Freaks' removal of the device list is ill advised, and the links to the individual micros are still working so I think they might bring it back - you are free to remove obsolete information entirely if you like.)" CreationDate="2011-05-31T12:27:40.813" UserId="857" />
  <row Id="23633" PostId="14855" Text="Not a real question. It will be closed." CreationDate="2011-05-31T12:39:21.127" UserId="305" />
  <row Id="23634" PostId="14848" Text="I appear to currently have a symbol time of about 0.42ms, which I believe is 2380 baud? (it's not an exact measurement, but close) - I'm currently supposedly running at 9600 baud (that's what the formula tells me - 16,000,000 / (16*(103+1)) = 9615.39).  If I switch the PC to 2400 baud I get something looking much nicer." CreationDate="2011-05-31T12:56:42.950" UserId="4245" />
  <row Id="23635" PostId="14857" Score="1" Text="http://electronics.stackexchange.com/questions/9147/tips-for-wire-to-pad-and-wire-to-wire-soldering" CreationDate="2011-05-31T13:08:47.883" UserId="566" />
  <row Id="23636" PostId="2732" Text="@Lawrence Johnston I second the request for a blog post!  :)" CreationDate="2011-05-31T13:20:02.610" UserId="2288" />
  <row Id="23637" PostId="14848" Text="Well, looks like I cracked it - thanks for all your input guys, you've been a big help in tracking this one down." CreationDate="2011-05-31T13:28:20.220" UserId="4245" />
  <row Id="23639" PostId="14840" Text="@BarsMonster: Yeah, getting really good efficiency is usually only important at high powers.  If you're doing 1 kW at low efficiency, you need huge expensive heavy heatsinks, so it makes sense to use a more efficient, but more complex Class D or Class G, and spend a lot of time getting the best sound out of it.  For low powers, it's better to just use a Class AB that works well out of the box." CreationDate="2011-05-31T14:44:11.260" UserId="142" />
  <row Id="23640" PostId="14857" Score="3" Text="This is called tinning the wire. " CreationDate="2011-05-31T14:46:19.300" UserId="1623" />
  <row Id="23641" PostId="14852" Text="[LED voltages for different colors](http://www.oksolar.com/led/led_color_chart.htm)" CreationDate="2011-05-31T14:49:26.590" UserId="142" />
  <row Id="23642" PostId="14853" Text="@Jonathan: Voltage is not &quot;used up&quot;.  It drops.  It's the same as the drop in pressure when water passes through a narrow opening, if that helps." CreationDate="2011-05-31T14:51:18.193" UserId="142" />
  <row Id="23643" PostId="14861" Text="This is the best answer, but you'll need to find some of these pins first." CreationDate="2011-05-31T14:53:21.577" UserId="142" />
  <row Id="23644" PostId="14848" Text="Not that PLL and 4-cycle-instructions would make reading the datasheet complicated enough, they added another prescaler... wow." CreationDate="2011-05-31T15:00:52.373" UserId="1950" />
  <row Id="23645" PostId="14848" Text="Lots of PICs have a default divide by 4 for the clock." CreationDate="2011-05-31T15:04:03.747" UserId="305" />
  <row Id="23646" PostId="14853" Text="@Daniel - no problem. Sometimes it helps if you see another way to calculate it. (Not necessary here, but in case you want your own answer deleted, that's something you do yourself)" CreationDate="2011-05-31T15:13:40.880" UserId="2064" />
  <row Id="23647" PostId="14853" Text="@Daniel, please leave your answer, hopefully I will be able to come back to it and fully understand this." CreationDate="2011-05-31T15:15:42.567" UserId="1982" />
  <row Id="23648" PostId="14853" Text="@endlith, thanks I wasn't sure of the terminology." CreationDate="2011-05-31T15:16:02.363" UserId="1982" />
  <row Id="23649" PostId="14857" Text="Related question: http://electronics.stackexchange.com/q/4828/1240" CreationDate="2011-05-31T15:53:04.183" UserId="1240" />
  <row Id="23650" PostId="14813" Text="@Chris Stratton: By &quot;absolute number&quot; I didn't mean an absolute quantity, but rather a &quot;bare&quot; number without a dB suffix, as distinct from one with such a suffix.  I should also have mentioned that it's easier to compare things that attenuate by 40, 50, 60, and 120dB than things which scale a signal by 0.01, 0.0033, and 0.001, and 0.000001." CreationDate="2011-05-31T16:21:50.557" UserId="3123" />
  <row Id="23651" PostId="14836" Text="Mostly nice answer, but another thing to mention is that because of propagation delays, there's no single metastable state but rather a whole family of them, and there's no certain way to identify metastable states.  One may design a circuit with a three-state output (high/low/metastable), and arrange things so that &quot;high&quot; will never be reported if the output may end up going low, or vice versa, but there's no guarantee the output won't bounce between 'high' and 'metastable' (ending up 'high'), or between 'low' and 'metastable' (ending up 'low')." CreationDate="2011-05-31T16:31:16.627" UserId="3123" />
  <row Id="23652" PostId="14813" Text="@supercat - the word you want is 'linear' not 'absolute'" CreationDate="2011-05-31T16:31:53.507" UserId="2246" />
  <row Id="23653" PostId="14852" Text="You can also think about the voltage across the LED from the LEDs perspective: When you apply 0V to the LED, there will also be no current through it. When you increase the voltage, almost no current will develop until you reach approximately (!) 1.6V (exact values will vary from LED to LED). A further increase of the voltage will then cause a drastic increase in current. This is exactly the point where you need the resistor: The resistor will define the current above the voltage where the LED starts to conduct heavily. You choose a resistor for the difference between supply and &quot;LED voltage&quot;." CreationDate="2011-05-31T16:45:15.727" UserId="930" />
  <row Id="23655" PostId="12314" Score="2" Text="@umps using hysteresis in the way stevenvh is describing is known as a Schmitt trigger. Just thought I would add. http://en.wikipedia.org/wiki/Schmitt_trigger" CreationDate="2011-05-31T18:52:26.560" UserId="1337" />
  <row Id="23656" PostId="14848" Text="@LeonHeller, everyone one I have ever used. @Matt, if you are going to write a solution please make an answer from it." CreationDate="2011-05-31T19:07:52.890" UserId="230" />
  <row Id="23657" PostId="14859" Text="Why the downvote? It's the easiest and cheapest solution." CreationDate="2011-05-31T19:22:11.617" UserId="305" />
  <row Id="23658" PostId="10753" Text="Making 100 units doesn't seem so hard. How long does it take you to make five? I just don't see that number of components being a problem:  I started my career in a small electronics company. 100-200 units was our average lot size and it was all hand soldered. A board with about 100 through-hole components would take me IIRC, about 30 minutes. SMT would be much faster since I could solder with hot-plate or reflow." CreationDate="2011-05-31T19:33:58.617" UserId="2255" />
  <row Id="23659" PostId="14816" Score="1" Text="Leslie Lamport (he of $\LaTeX$ fame) wrote a good description of metastability in this paper: http://research.microsoft.com/users/lamport/pubs/buridan.pdf" CreationDate="2011-05-31T19:48:49.353" UserId="411" />
  <row Id="23660" PostId="14840" Text="In my case it does matter :-) If I can output sound at 80% efficiency, that just means double battery time :-) That's the question if I can use Class D output on these parts to drive weak headphones with high impedance..." CreationDate="2011-05-31T19:49:30.103" UserId="2062" />
  <row Id="23661" PostId="14848" Text="@Kortuk Answer made." CreationDate="2011-05-31T20:06:45.433" UserId="4245" />
  <row Id="23662" PostId="14816" Text="@markrages Brilliant. This can also happen with [falling cats and buttered toast](http://skeptics.stackexchange.com/questions/3060/do-cats-always-land-on-their-feet/3063#3063)." CreationDate="2011-05-31T21:22:26.443" UserId="1419" />
  <row Id="23663" PostId="14871" Text="Keil give an example of this in their documentation http://www.keil.com/support/man/docs/gsac/gsac_gpio.htm. I think the hardware SysTick timer is common to all Cortex-M0 and Cortex-M3, so the approach is portable." CreationDate="2011-05-31T23:13:51.293" UserId="566" />
  <row Id="23664" PostId="14861" Text="They are quite easy to find; in the US probably in any Radio Shack or local electronic shop; even repair shops would have. And they can be salvaged from old PC boards, floppy drives, etc. since it's the same header used for IDE and many other connections." CreationDate="2011-05-31T23:16:27.597" UserId="1078" />
  <row Id="23665" PostId="7129" Text="Delay loops are not something which port easily, they are specific to CPU core and clock speed. So, you either maintain a big collection of #ifdefs with calibrated and calculated delay loops. Or, you do what @supercat suggests and build on a hardware timer." CreationDate="2011-05-31T23:17:04.870" UserId="566" />
</comments>