Noise when using the Pololu Dual G2 High-Power Motor Driver 24v14 Shield for Arduino

I’m using the Pololu Dual G2 High-Power Motor Driver 24v14 Shield for Arduino with the A-Star 32U4 Prime SV. I am using the 5V from the A-Star to power a hall effect sensor on the actuators controlled by the 24V14 shield. I am seeing significant noise on the 5V when the PWM duty cycle is anything less than 100%. The PWM is operating at 20KHz. The sensor square wave is 280Hz at full speed. The noise is around 10Mhz which appears to be coming from the on-off switching of the PWM. How can I eliminate this noise? It’s also showing up on the encoder signal making it useless. I use a separate 12VDC power supply for the A-Star with a common ground with the 24VDC used to power the motors.

I took the encoder out of the circuit and I powered the A-Star with the Vreg from the motor driver. I am measuring 1.5V spikes on A-Star 5V pin at around 70KHz. The motor controller is letting noise form the motor back into the A-Star. How can this be prevented?


What are you using for your 24V supply and motor? Links to product pages or datasheets would be useful. Have you added any extra capacitors across VM and GND on the shield? Could you post pictures of your setup?


You took so long to reply, i had to take down the setup and use a different motor controller that has the power side optically isolated from the logic side. I was quite surprised when I discovered your controller does not do that. Datasheets are not available for the motor and power supply. Yes I tried a .1uF cap across VM and GND.