Arduino resetting.


My friends and I are working on a school robotics project and there is an issue we can't seem to fix. We have two robots that "swarm" by randomly assigning a leader and follower, utilizing IR LEDs and receivers.

Our Parts:
Arduino mega
Two h bridges
Four GM6 motors
DC motor
IR Receiver

Max draw:
650milli amps per motor (this is under the 1.2 amp Max draw per motor on the H-Bridge)

The Problem:
The Arduino reboots randomly and we have killed two h-bridges so far. We can individually drop each motor until we find the one that is causing the problem, but when we swap them out, we often get another motor that has the same symptoms, at the start, we had none of these issues, but over time two of the H-Bridges stopped working due to this. Both of the H-Bridges that stopped working were no longer giving a signal to the output pin when checked with a multi-meter. Also, we've been having another problem that has been causing us even greater problems, but we're not sure if the two are related or not. We're using the IR receivers for multiple robots to detect each other and transmit information (each have IR LED's mounted on them) but both of them will get interference at seemingly random times, even when both of their LED's are off, and thus no conceivable light could be hitting the receiver. We don't know if the two problems are linked or not. Please help :slight_smile:

Which h-bridge chips are you using? Some of them require external diodes across the
output terminals.

If you disconnect the motors and run the same sketch, do all the problems go away? If so that would suggest it is a power supply brown-out, or electrical noise from the motor. How is this lot being powered - do the Arduino and h-bridge controllers share the same power supply?