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1  Using Arduino / Microcontrollers / Re: 328 TQFP on: August 07, 2014, 12:27:07 pm
If you're worried about $0.01 in cost, you aren't buying from catalog distributors like Mouser anyway.
2  Using Arduino / Project Guidance / Re: High and Low = 5V and ground? on: August 06, 2014, 07:23:00 pm
Quote
proper Diode
??
1n4001 or similar.
3  Using Arduino / Project Guidance / Re: Internal pullups not working? on: August 01, 2014, 07:19:18 pm
Hmm, the 5V rail measured against ground reads 4.6 V.
That's outside of the USB spec.  There's probably some ripple on that rail as well, which may be causing the erratic behavior.   A good test might be putting a powered hub in between.


In the same ball park
That's part of the problem.  It shouldn't be "in the ball park."  It should be within a few millivolts, maybe 10s of millivolts.


TX shouldn't be on continuously, but it is. Between reboots of the Arduino (power cycling, not resetting), that behavior can change and sometimes it's LED13 that stays on permanently (although not prompted to do so by any code)
Well clearly something is broken.  If you aren't sending stuff over the serial port, your TX light shouldn't be on.

Again, I think your supply voltage is doing something funky, giving you bad behavior.
I was pondering for a long time to get a second Arduino board (a Nano) to tinker with. I might as well do that and see how it works out...
4  Using Arduino / Installation & Troubleshooting / Re: Mounting hardware for Arduino boards on: August 01, 2014, 10:11:33 am
I cannot understand the thought processes of the people who laid out the Arduino boards-
They were thinking these would be prototype boards that never got mounted anywhere.  Perhaps the the holes were added at the last minute.  Interestingly, they are in the same place as the very original Arduino.  So no future thought has been given to them.

[Edit:  Correction.  The Uno did get a slight modification.  A hole was added or moved.]

Using stand-offs, I have successfully mounted Uno boards in enclosures (while waiting for my custom board to be finished.)
5  Using Arduino / Installation & Troubleshooting / Re: 3.3V POWER PIN is supplying 5 volts on: August 01, 2014, 10:08:45 am
Both the 5v and 3.3v pins show 4.99 volts on my multimeter.
If they're showing the same voltage down to the 2nd decimal, there is a short somewhere.  Could be the regulator is gone or it could be elsewhere on the board.  Since there isn't anything on the board that uses 3.3v, its pretty likely the regulator. 
6  Using Arduino / Installation & Troubleshooting / Re: 3.3V POWER PIN is supplying 5 volts on: July 31, 2014, 06:26:25 pm
Was it exactly 5volts or close to it?  How far was it from the actual 5volt rail?

Also, look at the pins on the bottom.  Is there a short or some dried flux between the 5V and 3V3 pins?
7  Using Arduino / Installation & Troubleshooting / Re: ebay knockoff arduino vs genuine 2560 r2 on: July 31, 2014, 06:24:29 pm
Looks like there are differences from the "original" mega.

http://arduino.cc/en/Main/ArduinoBoardMega
http://arduino.cc/en/Main/ArduinoBoardMega2560
8  Using Arduino / Installation & Troubleshooting / Re: programmer is not responding arduino uno Mac OS X on: July 31, 2014, 06:16:38 pm
I would just exchange it for another one. 
9  Using Arduino / Project Guidance / Re: Internal pullups not working? on: July 31, 2014, 06:15:21 pm
The reading was 4.3 V. Maybe a bit on the low side,
A pin with the pull-up enabled (and nothing else connected) will measure the same as the 5V pin.  So compare to that.

the TX LED would sometime flicker or stay on
What do you mean stay on?  For how long?  TX should only be on while you are actually transmitting.  The really simple code example I gave you, does nothing with the serial port, so after the code has been uploaded, it shouldn't be on anymore.

Are you sure the IDE isn't giving you an error message after it is done uploading?  Copy the text in the black area and paste it here, after you upload the simple example I gave you.
10  Using Arduino / General Electronics / Re: Arduino Micro voltage requirements on: July 30, 2014, 08:32:10 pm
To reiterate, the question is, “why is the voltage regulator needed?”  
What value decoupling caps are you using when you do (and don't) have the regulator?

My guess is that your LEDs are causing enough ripple that it giving the on-board regulator a hard time.  When you use your off board regulator, it becomes the "decoupling" device. 
11  Using Arduino / Installation & Troubleshooting / Re: Is this a problem? on: July 30, 2014, 08:19:16 am
Yes, huge problem.  Based on the picture, you only received 1/4th of the entire board!

Since you didn't describe a problem, I assume that was your question.

[Edit: If this seems out of the place.  The original post was a link to the picture, repeated twice with no other context.]
12  Using Arduino / Installation & Troubleshooting / Re: programmer is not responding arduino uno Mac OS X on: July 30, 2014, 08:13:44 am
You are down to:

1) The serial device you selected is the right one.
2) The USB to Serial chip on your Arduino is broken.

#1 tends to be unlikely, there aren't any other devices these days that enumerate as a "usbmodem". 

#2 seems unlikely because if the chip enumerates, then it is generally fine.  However, your loopback test suggests something is wrong.

You should try reflashing the 8u2/16u2 firmware (the usb to serial chip) or get a new board.

Just to make sure the ATmega328 wasn't the problem, before replacing the board, I would remove the ATmega328 then do loopback again.
13  Using Arduino / General Electronics / Re: Arduino Micro voltage requirements on: July 29, 2014, 09:51:20 pm
The Jameco ReliaPro UL Listed DC converter (rated at 6VDC, 800 mA) delivered 8.0 V. 
The DC converter rated at 12V delivered 8.5 V under load and the one rated at 9V also delivered 8.5 V under load.
Assuming your 750mA load, nothing here matches up with what is expected.  Except that I would expect a 800mA rated supply to be in regulation, not wildly out of it.

3)  The 7805 voltage regulator is described here:  addicore.com/Addicore-L7805CV-5V-Voltage-Regulators-5-pieces-p/114.htm
A TO-220 package can handle SIGNIFICANTLY more current than the tiny sot-23 package used on the Arduino board....

Oh, dear, In the process of measuring the current and voltage, I bypassed the voltage regulator in order to reproduce the erratic behavior that I described previously.  I, um,  fried my Arduino Micro.
Changing connections (including measurements) should not be done while the board is powered.  If you're moving probes around while powered, your attenshion (your eyes) should 110% be focused on where the leads are going.

Yes, I know, the Arduino Micro max current is 50 mA.
I'm not sure where you got that from.  The max current that the 3.3V rail is rated for is (erroneously) 50mA.  (It's actually 150mA).

The 5V rail is rated for whatever you can draw until it shuts down, and that depends on Vin.

 However, let's keep in mind that this current is not going through the Arduino (see schematic). 
I'm confused.  Has this been your setup the entire time, or just after adding your own regulator?
14  Using Arduino / Project Guidance / Re: Arduino Programs on: July 29, 2014, 10:12:51 am
It is a cool effort, nice job.  Reminds me of playing breakout on my Ti-85.

I would suggest a different name... might cause some confusion.  (Don't you even say in your video it isn't based on the Gameduino)
http://excamera.com/sphinx/gameduino/
http://playground.arduino.cc/Main/Gameduino
https://www.adafruit.com/products/1654

Clevel concept of the "Guess the Numbers" game.  Like that.
15  Using Arduino / Project Guidance / Re: Internal pullups not working? on: July 28, 2014, 10:03:56 pm
finally the internal pull-up sketch and that didn't work
A clear picture of your wiring would be helpful.  Maybe also a schematic (hand drawn okay).

Also, sometimes nice to see the code to make sure you aren't inadvertently turning the resistor off somewhere (see below for test.)

(wiring for that one is pretty simple, so I'm fairly sure that's not the culprit).
You'd be surprised.  New users always want to blame the hardware... smiley-wink

Now, I'm wondering: are there any more troubleshooting options?
Use a simple sketch to turn on the pull-up and measure the pin with a mulitmeter.

Code:
void setup() {
   pinMode(2, INPUT_PULLUP);
}

void loop() {}

Use your multimeter to test the voltage of the pin with the pull-up on.  Disconnect your button or any other hardware.  Although, you might need to add a piece of wire or trace back to the pin on the ATmega328.  I wouldn't trust just "sticking your probe" into the pin header of the Arduino.

If you measure 5V (or whatever you 5V pin is at), the pull-up is working fine.
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