Pololu A4988 card issue

Lynxmotion Rovers, Sumo, and Tracked
1

Hello all,
i recently bought a A4988 pololu card and i have an issue with the ENABLE command.
Indeed, even with the Enable pin properly tied to ground, when stepping the function is quite erratic with stepping not clean and motor emitting some strange sound.
When touching the pin with my finger, the function is OK, no bad sound and stepping fine :confused:
Do you think the driver is broken?

Regards
J. collet

2

It seems you are not grounding that pin properly or that there are other floating signals in your system. When you touch it with your finger you a provide a nice and stable ground to your board, which allows it to work properly.

In short, check you connections, make sure no signals are floating, and that your ground is nice and clean.