Pololu Robotics & Electronics
My account Comments or questions? About Pololu Contact Ordering information Distributors

Pololu Forum

ACS724 Current Sensor noise

Just got the ACS724 and have tried it in series with the 1212, the MCC33926 motor driver board outputs which are powering a 25D metal gear motor. The current feedback from the motor control board is very noisy, I’m not able to get resolution better than .1 amp which is a problem for my application.

I’m using an Texas Instruments MSP430FR2311 MCU to calculate RPM and do the DAC and it’s connected to a Raspberry Pi 3B+ via UART. Everything has a common ground. I tried the ACS724 with the 5VDC from the pi and from the MCU. The problem that I’m having is that the ACS724 is actually a lot noisier than the feedback from the motor control board. I’m not sure why that is? I tried a capacitor but that didn’t make any difference. I have attached a sample waveform from my scope.


Could you post some pictures showing how you have everything connected and how you’re probing the output of the current sensor? Which version of the ACS724 current sensor do you have?