Pages: [1]   Go Down
Author Topic: Dead Arduino Mega 2560? Help and Advice please!!!  (Read 1223 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 2
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I am part of a team working on building a robot to compete in the Oklahoma State University Robot competition. We are using an Arduino Mega 2560 as our robot's microcontroller in conjunction with the Adafruit motor shield for Arduino. One of my team members placed two 11.1-V, 2200mAh batteries in parallel to the Adafruit motor shield's external power input with only two H-bridges installed on the Adafruit. The Arduino board was powered by a single 11.1-V, 2200mAh battery.

All motors connected to the board started running, but then, one of the H-bridges on the Adafruit began to smoke and two of the motors failed while the other two continued to run (there are four motors total). My partner immediately unplugged everything from the Adafruit and Arduino boards. After this, my partner discovered what appeared to be burn marks on the Arduino board.

To make sure that the Arduino Mega 2560 was ok, my partner connected the Arduino board to his computer using a standard USB cable. The power LED came on and glowed constantly. He tried to upload a basic sketch to make the Arduino blink. The uploading of the sketch, however, took forever and never ended. The RX and TX lights on the Arduino blinked at first, but then went out while the uploading process continued. My partner got me involved and I tried uploading a sketch from my computer but with the same result.

This is the first time that this has happened. The Arduino worked right out of the box when we received it in the mail. Also, when two batteries were wired in parallel previously with the Adafruit motor controller, the Adafruit had 4 H-bridges on it and the Arduino and the motors worked perfectly.

Now, we are wondering if the board is dead. Are there some tests that we could run to tell whether or not the Arduino is dead? Or, could someone tell me from my description above of what happened as to whether or not the Arduino might be dead?

If the Arduino board is not dead, are there any suggestions as to how we could fix the Arduino?
Logged

0
Offline Offline
Faraday Member
**
Karma: 16
Posts: 2855
ruggedcircuits.com
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
To make sure that the Arduino Mega 2560 was ok, my partner connected the Arduino board to his computer using a standard USB cable. The power LED came on and glowed constantly. He tried to upload a basic sketch to make the Arduino blink. The uploading of the sketch, however, took forever and never ended.

Well, unfortunately that pretty much says your board is "not ok".

I'm guessing the motor shield you have is quite underpowered for the motors you are trying to run and one of the bridges did indeed overheat and break. A possible failure mode there is short-circuiting the 11.1V from the bridge voltage to the digital Arduino inputs which would indeed fry the Arduino. I'm not sure that's what happened but it's plausible.

--
The Rugged Motor Driver: two H-bridges, more power than an L298, fully protected
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 2
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Thank you for your reply, RuggedCircuits!!!

If my board is dead, what do you think is wrong with it from my description? Is it fixable? Are there tests I could run to determine what's wrong with the board?

I've been scouring other forums, but as far as I can tell, I haven't come across anyone with a similar problem.
Logged

0
Offline Offline
Faraday Member
**
Karma: 16
Posts: 2855
ruggedcircuits.com
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

I think what's wrong with it is that the microcontroller is dead, and possibly the USB interface chip as well.

If you have the facilities I would try replacing those two components.

If the device appears as a programmable device in your Arduino GUI then likely the USB interface chip is OK, at least on the USB side. And you said you tried to program it and kinda-sorta started to work so maybe that chip is OK.

To be honest, it will take less time/effort to just replace two microcontrollers than to diagnose exactly what's wrong. At least that's my opinion....

--
The Quick Shield: breakout all 28 pins to quick-connect terminals
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 36
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

On a Mega2560 board? That's a surface-mount TQFP part, not a socketed one smiley
Logged

Akron, OH
Offline Offline
Newbie
*
Karma: 0
Posts: 17
We need more Jigawatts!!
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Hi eidolon5,

I had the same thing happen to my Mega 2560 randomly after using the 5v power pin to power an IR sensor. I didn't have anything else hooked up to the Mega, just using the 5V pin as an artificial power pack. It's really weird, but I have the exact same thing happen, endless uploading. Just wondering if you had any luck fixing it.

Joseph
Logged

________________
Joseph Anand-Maker
joseph@anandfamily.org

Pages: [1]   Go Up
Jump to: