Problem between A4988 and drv8825

egards. I just signed up, because I was searching the internet for a problem I have, and I found this forum. I have an arduino one to which I have connected a cnc shield with A4988 drivers, to control three nema 17 motors of 12 V. and 0.4 amp., (Axes X, Y, Z, of a CNC), the axis driver was damaged Z, and replace it with a drv8825, but this one did not work, when measuring the voltage between the potentiometer and GND, it gave 0V, rotate the potentiometer both ways and the voltage was still 0V, and the motor didn’t move either, I removed it and put in an A4988, and to my surprise the Z axis doesn’t work for me now. I have read that both are compatible and can be swapped considering the connections which I did correctly. The program that the arduino has is the GRBL controler. What may be happening. Thanks for your attention.

You need to set the current control properly on any of those drivers. If you have the genuine Pololu driver boards, then follow the instructions on the appropriate product page and/or watch the video.

If your driver boards are not genuine Pololu, the instructions may not apply.