I searched for a while but I couldn’t find a similar issue about mine. This is the first time I am using a4988 and I have already blow one I try to drive a bi-polar step motor and wired as shown b.pololu-files.com/picture/0J336 … f0619afadf except the micro controller part. Before connecting it, I wanted to simulate it manually. However, when it is powered, step motor starts to rotate regardless of the step input even the step pin is not high or low, it is just floating. (When I connect it to high or low, it stops) I expect to control the rotation by connecting step pin to high and low repetitively. Is it normal? In this situation, I believe given pulses to Step pin by micro controller won’t work. BTW, while it is rotating I can control the direction by connecting Dir pin to high or low.
Thanks in advance