Duemilanove and Motor Controller INTERFERENCES !

Hello,

I have a problem... I just built up 5 robots with DFRobot 4.8-46V, 2A Dual Motor Controller and Arduino Duemilanove Microcontroller.

The thing is that when I load a program it works fine (I monitor it with Serian.Print();), but when I power up the Motors through the motor Controller (the one writen above), Arduino is not working as it should.

For example if I monitor the “millis()” time it gets reseted from time to time as long as the Motor Controller is powerd...

Any suggestins ? Thanx

I think this is very similar to what i'm facing. :-/

Not a lot of details in the above, so here's a few generalizations.

Power surges and switching hash caused by the motors gets into the microprocessor from trying to use a common power source. Power the motors off a separate power supply that is able to provide the current necessary to run all motors at full power.

Not having a common ground between the Micro-controller and the motor controller board.

Not using hash bypass filters on brushed motors. The usual is .01 uf capacitors one each from the motor terminals to the metal motor housing and selected for a working voltage at least twice the source voltage supplied to the motor

Grumpy Mike has a few good pointers on dealing with power problems: http://www.thebox.myzen.co.uk/Tutorial/De-coupling.html

thank you... the really annoying thing is that the delay time for a simple loop like the bellow one, is different almost each time...

void loop() { rotateRight(); // starts motors, rotate right delay(5000); //delay = gives the degrees of rotation stopMotors(); // stop motors }

WHY????