Evothings

Hi I'm using a Nordic nRF51 DK with a modified version of RedBearLabs "Simple Control" app through EvoThings to drive a small RC car. I have the basic functionality working with buttons in my app to start and stop the motors. However I'm having problems with my BLE connection dropping out. It seems to happen most often after I have the motors running and then tap the button in my app to stop them. Then my BLE connection will drop out essentially every time. If I test pressing the same button sequences with my motors physically detached, I have no disconnection issues. My best guess is some kind of electrical noise interference from these DC motors. Also, if I have the RC car lifted off the ground so there is much less resistance on the wheels that the motors are turning then it also cuts out much less often. Anyone have any ideas?

Certainly seems like an electrical problem. You would want to shield the nrf51 chip from the noise somehow, but how do to that is out of my area of expertise. You might try asking on the Nordic forum.

It sounds like power supply spikes from the motors are resetting the processor. Either run the motors off their own supply or make sure you use a regulator between the motor supply and the cpu. Some capacitors across the motor contacts might fix the problem too.

Mike