I am working on a "drone-boat", using a "FEZ Panda" microcontroller.
The GPS / Data logging part is working well.
The Panda also has to control 2 DC motors (brushed, 12V, 1A, 1000RPM), through a Ardumoto.
When I'm running my app without powering my Ardumoto (and consequently my motors), everything is working great, I can see it in my debugger output & with a LCD display.
But When I'm powering my ardumoto, then my motors start to spin (that's OK!), but my application freezes after few seconds.
Looks like a random problem caused by some noise, but I think I did the things in the right way :
12V motor circuit and 5V Panda "+" circuits are separated. Only ground is shared.
12V Lead batteries power the Ardumoto's VIN pins, and consequently the motors.
The Fez Panda is powered by USB in my testings.
I have put in attachement a simple schematic of what I'm doing (not mentioning GPS, compass, and other stuff)
Do you think all this is OK?
Could you tell me what tests/check I should do to understand where do the problem come from?