Hi,

I'm setting up a CNC router with an Arduino Uno connected to pretty standard bipolar stepper drivers powering NEMA 23 motors. Still in the testing phase, none of my motors will move in a positive direction, negative only.

The direction pin is giving me good voltage readings, changing from 5V to 0V as required. However the pulse pin seems a little odd. In a negative direction (for a single step of 1mm) it reads about 350mV, but +ve is only reading about 150mV. Is that normal?

The only other thing I can think of doing is to increase the $0 step pulse.

Any ideas???