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11956  Community / Website and Forum / Re: Smilies on: January 28, 2011, 09:59:29 pm
  smiley-eek-blue   That one looks like Homer Simpson.
11957  Community / Bar Sport / Re: Your latest purchase on: January 28, 2011, 09:54:52 pm
Looks like there will be a lot of mercury inside it.

http://en.wikipedia.org/wiki/Ignitron
11958  Community / Website and Forum / Re: Smilies on: January 28, 2011, 09:30:02 pm
But where is the I have to go to the bathroom soon smiley?
11959  Development / Other Hardware Development / Re: Mega 2560 Solder Bridge on: January 28, 2011, 09:26:18 pm
Wow, and on a genuine Arduino board too. Will the Asian cloners copy that.  smiley
11960  Development / Suggestions for the Arduino Project / Re: if(a=b) is not if(a==b) could IDE check this b4 upload? on: January 28, 2011, 09:22:44 pm
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That's the oldest gotcha in the C book. Welcome to the club


Indeed. In my case it's the gift that keeps on giving.  smiley
11961  Community / Bar Sport / Re: New post notification question. on: January 28, 2011, 09:06:45 pm
Little light inside aside, don't most men suffer from refrigerator blindness, can't find anything unless it's in front?

That's from a Rita Rudner routine, funny as hell.

Lefty
11962  Community / Bar Sport / Re: Your latest purchase on: January 28, 2011, 08:56:00 pm
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220648404910&ssPageName=STRK:MEWNX:IT
11963  Community / Bar Sport / Re: Arduino- when is one never enough? on: January 28, 2011, 08:54:20 pm
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having just fried an RFDuino I need to get a replacement


Get a smokeless version.  smiley
11964  Using Arduino / Project Guidance / Re: Maximum current draw on 5v and vin pins? on: January 28, 2011, 08:11:39 pm
That switching regulator is a nice device due to it's much better efficiency over linear voltage regulators.

However you might want to take a gander at a switching regulator I have ordered (but not received) as it's cheaper, has a higher current range and is adjustable in output voltage. It is however perhaps a little larger in size:

http://arduino.cc/forum/index.php/topic,50185.0.html

Lefty
11965  Using Arduino / General Electronics / Re: Should I consider transistor saturation voltage when calculating LED's resistor on: January 28, 2011, 07:36:43 pm
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so should I calculate resistor for 5V or for 5V-1V=4V (LED current is 320mA)?

Yes you should include it, however you also must include the Vf drop of the specific led you are using.
For your example lets assume a 3vdc Vf drop for the led assembly as I don't know the spec for your led.

R = (5v - (1v + 3v)) / .320 = 3.1 ohms

By the way, those high current led assemblies almost always recommend not to try and use a simple series current limiting resistor to maintain proper current control. They demand a constant current driver to operate safely.

Lefty
11966  Using Arduino / General Electronics / Re: Odd fluctuations in analog readings when using external power on: January 28, 2011, 07:22:06 pm
Whichever voltage reference is being used (AVcc, external voltage applied to Aref pin, or internal bandgap voltage(s) ) it will be seen on and can be measured at the Aref pin when selected. That makes for a good common spot to add a .1ufd bypass cap. Not all boards include this cap. I have both a Seeeduino mega board and a clone RS-232 mega328 board which do not. If I run a continuous analogRead() with a good regulated clean voltage applied to the analog input pin and print the results to the serial monitor I see a +/- single count flicker at all times on the 328 board, but just a stable reading on the mega board. I soldered a .1ufd cap from the aref pin to ground on the serial board and then it to became flicker free.

 As Grumpy said other things that can effect the A/D conversion noise. Such as filtering method on the Avcc pin, layout of the grounds between the analog and digital runs, source Vcc noise, etc. It all relates, however being only a 10 bit A/D conversion it's not too hard to tame it to be useful to the resolution possible with only a 10 bit conversion.

Lefty
11967  Using Arduino / General Electronics / Re: Cheap/Good PCB houses outside China (Chinese New Year) on: January 28, 2011, 07:08:39 pm
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Is this going to become the most political thread on the board?

 That was my fault, my attempt at a humorious remark got a stone rolling, or is that a rolling stone?

My personal thoughts on China:

 I respect their country as a whole just for surviving to be the oldest continuous civilization on earth.
 I respect their burden to have to govern the single largest population on earth.
 Do I respect their present government? It's certainly better then Mao's rein, and they have made good progress in
 improving the life of some of their population. But they certainly have a long was to go before their people can
enjoy the same freedoms we often take for granted.

Lefty
11968  Using Arduino / Programming Questions / Re: use my mate's PIC ICSP for an ATMega? on: January 28, 2011, 06:55:27 pm
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or are they completely different programmers

They are completely different programmers. However the more basic problem is that any AVR software, including the Aruino platform will not know how to talk to a PIC ICSP hardware programmer.


11969  Using Arduino / Project Guidance / Re: Maximum current draw on 5v and vin pins? on: January 28, 2011, 06:44:01 pm
Well here are the rules for +5vdc usage for output pin current ratings, total processor chip rating, and total board current ratings.

Output pins:     Recommended continuous current, 20ma. Absolute maximum above which will damage pin/chip 40ma (use 20ma recommendation)

Total chip Vcc current (all output pins total and chip overhead): 200ma., i.e. 10 output pin driving 10 leds @ 20 ma is max for whole chip.

Total +5vdc current available for on-board and external use:

If USB powered: 500ma max limited by on-board thermofuse and USB standards.

If powered via on-board +5vdc voltage regulator driven by external power socket (Input Voltage (recommended) 7-12V ) :
not specified, but don't plan on using more then 500ma max.
11970  Community / Bar Sport / Re: Snow Removal Ideas on: January 28, 2011, 02:05:31 pm
Snow is something I have to drive 200 miles to the Sierra Nevada mountains to see. And I like it that way, very much.  smiley-grin
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